git/cache.h

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#ifndef CACHE_H
#define CACHE_H
#include "git-compat-util.h"
#include "strbuf.h"
#include "hashmap.h"
#include "advice.h"
#include "gettext.h"
#include "convert.h"
#include "trace.h"
#include "string-list.h"
pack-revindex: drop hash table The main entry point to the pack-revindex code is find_pack_revindex(). This calls revindex_for_pack(), which lazily computes and caches the revindex for the pack. We store the cache in a very simple hash table. It's created by init_pack_revindex(), which inserts an entry for every packfile we know about, and we never grow or shrink the hash. If we ever need the revindex for a pack that isn't in the hash, we die() with an internal error. This can lead to a race, because we may load more packs after having called init_pack_revindex(). For example, imagine we have one process which needs to look at the revindex for a variety of objects (e.g., cat-file's "%(objectsize:disk)" format). Simultaneously, git-gc is running, which is doing a `git repack -ad`. We might hit a sequence like: 1. We need the revidx for some packed object. We call find_pack_revindex() and end up in init_pack_revindex() to create the hash table for all packs we know about. 2. We look up another object and can't find it, because the repack has removed the pack it's in. We re-scan the pack directory and find a new pack containing the object. It gets added to our packed_git list. 3. We call find_pack_revindex() for the new object, which hits revindex_for_pack() for our new pack. It can't find the packed_git in the revindex hash, and dies. You could also replace the `repack` above with a push or fetch to create a new pack, though these are less likely (you would have to somehow learn about the new objects to look them up). Prior to 1a6d8b9 (do not discard revindex when re-preparing packfiles, 2014-01-15), this was safe, as we threw away the revindex whenever we re-scanned the pack directory (and thus re-created the revindex hash on the fly). However, we don't want to simply revert that commit, as it was solving a different race. So we have a few options: - We can fix the race in 1a6d8b9 differently, by having the bitmap code look in the revindex hash instead of caching the pointer. But this would introduce a lot of extra hash lookups for common bitmap operations. - We could teach the revindex to dynamically add new packs to the hash table. This would perform the same, but would mean adding extra code to the revindex hash (which currently cannot be resized at all). - We can get rid of the hash table entirely. There is exactly one revindex per pack, so we can just store it in the packed_git struct. Since it's initialized lazily, it does not add to the startup cost. This is the best of both worlds: less code and fewer hash table lookups. The original code likely avoided this in the name of encapsulation. But the packed_git and reverse_index code are fairly intimate already, so it's not much of a loss. This patch implements the final option. It's a minimal conversion that retains the pack_revindex struct. No callers need to change, and we can do further cleanup in a follow-on patch. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-12-21 14:19:49 +08:00
#include "pack-revindex.h"
#include "hash.h"
#include "path.h"
#include "sha1-array.h"
#ifndef platform_SHA_CTX
/*
* platform's underlying implementation of SHA-1; could be OpenSSL,
* blk_SHA, Apple CommonCrypto, etc... Note that including
* SHA1_HEADER may have already defined platform_SHA_CTX for our
* own implementations like block-sha1 and ppc-sha1, so we list
* the default for OpenSSL compatible SHA-1 implementations here.
*/
#define platform_SHA_CTX SHA_CTX
#define platform_SHA1_Init SHA1_Init
#define platform_SHA1_Update SHA1_Update
#define platform_SHA1_Final SHA1_Final
fix openssl headers conflicting with custom SHA1 implementations On ARM I have the following compilation errors: CC fast-import.o In file included from cache.h:8, from builtin.h:6, from fast-import.c:142: arm/sha1.h:14: error: conflicting types for 'SHA_CTX' /usr/include/openssl/sha.h:105: error: previous declaration of 'SHA_CTX' was here arm/sha1.h:16: error: conflicting types for 'SHA1_Init' /usr/include/openssl/sha.h:115: error: previous declaration of 'SHA1_Init' was here arm/sha1.h:17: error: conflicting types for 'SHA1_Update' /usr/include/openssl/sha.h:116: error: previous declaration of 'SHA1_Update' was here arm/sha1.h:18: error: conflicting types for 'SHA1_Final' /usr/include/openssl/sha.h:117: error: previous declaration of 'SHA1_Final' was here make: *** [fast-import.o] Error 1 This is because openssl header files are always included in git-compat-util.h since commit 684ec6c63c whenever NO_OPENSSL is not set, which somehow brings in <openssl/sha1.h> clashing with the custom ARM version. Compilation of git is probably broken on PPC too for the same reason. Turns out that the only file requiring openssl/ssl.h and openssl/err.h is imap-send.c. But only moving those problematic includes there doesn't solve the issue as it also includes cache.h which brings in the conflicting local SHA1 header file. As suggested by Jeff King, the best solution is to rename our references to SHA1 functions and structure to something git specific, and define those according to the implementation used. Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2008-10-02 02:05:20 +08:00
#endif
#define git_SHA_CTX platform_SHA_CTX
#define git_SHA1_Init platform_SHA1_Init
#define git_SHA1_Update platform_SHA1_Update
#define git_SHA1_Final platform_SHA1_Final
#ifdef SHA1_MAX_BLOCK_SIZE
#include "compat/sha1-chunked.h"
#undef git_SHA1_Update
#define git_SHA1_Update git_SHA1_Update_Chunked
fix openssl headers conflicting with custom SHA1 implementations On ARM I have the following compilation errors: CC fast-import.o In file included from cache.h:8, from builtin.h:6, from fast-import.c:142: arm/sha1.h:14: error: conflicting types for 'SHA_CTX' /usr/include/openssl/sha.h:105: error: previous declaration of 'SHA_CTX' was here arm/sha1.h:16: error: conflicting types for 'SHA1_Init' /usr/include/openssl/sha.h:115: error: previous declaration of 'SHA1_Init' was here arm/sha1.h:17: error: conflicting types for 'SHA1_Update' /usr/include/openssl/sha.h:116: error: previous declaration of 'SHA1_Update' was here arm/sha1.h:18: error: conflicting types for 'SHA1_Final' /usr/include/openssl/sha.h:117: error: previous declaration of 'SHA1_Final' was here make: *** [fast-import.o] Error 1 This is because openssl header files are always included in git-compat-util.h since commit 684ec6c63c whenever NO_OPENSSL is not set, which somehow brings in <openssl/sha1.h> clashing with the custom ARM version. Compilation of git is probably broken on PPC too for the same reason. Turns out that the only file requiring openssl/ssl.h and openssl/err.h is imap-send.c. But only moving those problematic includes there doesn't solve the issue as it also includes cache.h which brings in the conflicting local SHA1 header file. As suggested by Jeff King, the best solution is to rename our references to SHA1 functions and structure to something git specific, and define those according to the implementation used. Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2008-10-02 02:05:20 +08:00
#endif
fix openssl headers conflicting with custom SHA1 implementations On ARM I have the following compilation errors: CC fast-import.o In file included from cache.h:8, from builtin.h:6, from fast-import.c:142: arm/sha1.h:14: error: conflicting types for 'SHA_CTX' /usr/include/openssl/sha.h:105: error: previous declaration of 'SHA_CTX' was here arm/sha1.h:16: error: conflicting types for 'SHA1_Init' /usr/include/openssl/sha.h:115: error: previous declaration of 'SHA1_Init' was here arm/sha1.h:17: error: conflicting types for 'SHA1_Update' /usr/include/openssl/sha.h:116: error: previous declaration of 'SHA1_Update' was here arm/sha1.h:18: error: conflicting types for 'SHA1_Final' /usr/include/openssl/sha.h:117: error: previous declaration of 'SHA1_Final' was here make: *** [fast-import.o] Error 1 This is because openssl header files are always included in git-compat-util.h since commit 684ec6c63c whenever NO_OPENSSL is not set, which somehow brings in <openssl/sha1.h> clashing with the custom ARM version. Compilation of git is probably broken on PPC too for the same reason. Turns out that the only file requiring openssl/ssl.h and openssl/err.h is imap-send.c. But only moving those problematic includes there doesn't solve the issue as it also includes cache.h which brings in the conflicting local SHA1 header file. As suggested by Jeff King, the best solution is to rename our references to SHA1 functions and structure to something git specific, and define those according to the implementation used. Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2008-10-02 02:05:20 +08:00
#include <zlib.h>
2011-06-11 02:52:15 +08:00
typedef struct git_zstream {
z_stream z;
unsigned long avail_in;
unsigned long avail_out;
unsigned long total_in;
unsigned long total_out;
unsigned char *next_in;
unsigned char *next_out;
} git_zstream;
void git_inflate_init(git_zstream *);
void git_inflate_init_gzip_only(git_zstream *);
void git_inflate_end(git_zstream *);
int git_inflate(git_zstream *, int flush);
void git_deflate_init(git_zstream *, int level);
void git_deflate_init_gzip(git_zstream *, int level);
void git_deflate_init_raw(git_zstream *, int level);
2011-06-11 02:52:15 +08:00
void git_deflate_end(git_zstream *);
int git_deflate_abort(git_zstream *);
2011-06-11 02:52:15 +08:00
int git_deflate_end_gently(git_zstream *);
int git_deflate(git_zstream *, int flush);
unsigned long git_deflate_bound(git_zstream *, unsigned long);
/* The length in bytes and in hex digits of an object name (SHA-1 value). */
#define GIT_SHA1_RAWSZ 20
#define GIT_SHA1_HEXSZ (2 * GIT_SHA1_RAWSZ)
/* The length in byte and in hex digits of the largest possible hash value. */
#define GIT_MAX_RAWSZ GIT_SHA1_RAWSZ
#define GIT_MAX_HEXSZ GIT_SHA1_HEXSZ
struct object_id {
unsigned char hash[GIT_MAX_RAWSZ];
};
#if defined(DT_UNKNOWN) && !defined(NO_D_TYPE_IN_DIRENT)
#define DTYPE(de) ((de)->d_type)
#else
#undef DT_UNKNOWN
#undef DT_DIR
#undef DT_REG
#undef DT_LNK
#define DT_UNKNOWN 0
#define DT_DIR 1
#define DT_REG 2
#define DT_LNK 3
#define DTYPE(de) DT_UNKNOWN
#endif
/* unknown mode (impossible combination S_IFIFO|S_IFCHR) */
#define S_IFINVALID 0030000
/*
* A "directory link" is a link to another git directory.
*
* The value 0160000 is not normally a valid mode, and
* also just happens to be S_IFDIR + S_IFLNK
*/
#define S_IFGITLINK 0160000
#define S_ISGITLINK(m) (((m) & S_IFMT) == S_IFGITLINK)
tree-diff: rework diff_tree() to generate diffs for multiparent cases as well Previously diff_tree(), which is now named ll_diff_tree_sha1(), was generating diff_filepair(s) for two trees t1 and t2, and that was usually used for a commit as t1=HEAD~, and t2=HEAD - i.e. to see changes a commit introduces. In Git, however, we have fundamentally built flexibility in that a commit can have many parents - 1 for a plain commit, 2 for a simple merge, but also more than 2 for merging several heads at once. For merges there is a so called combine-diff, which shows diff, a merge introduces by itself, omitting changes done by any parent. That works through first finding paths, that are different to all parents, and then showing generalized diff, with separate columns for +/- for each parent. The code lives in combine-diff.c . There is an impedance mismatch, however, in that a commit could generally have any number of parents, and that while diffing trees, we divide cases for 2-tree diffs and more-than-2-tree diffs. I mean there is no special casing for multiple parents commits in e.g. revision-walker . That impedance mismatch *hurts* *performance* *badly* for generating combined diffs - in "combine-diff: optimize combine_diff_path sets intersection" I've already removed some slowness from it, but from the timings provided there, it could be seen, that combined diffs still cost more than an order of magnitude more cpu time, compared to diff for usual commits, and that would only be an optimistic estimate, if we take into account that for e.g. linux.git there is only one merge for several dozens of plain commits. That slowness comes from the fact that currently, while generating combined diff, a lot of time is spent computing diff(commit,commit^2) just to only then intersect that huge diff to almost small set of files from diff(commit,commit^1). That's because at present, to compute combine-diff, for first finding paths, that "every parent touches", we use the following combine-diff property/definition: D(A,P1...Pn) = D(A,P1) ^ ... ^ D(A,Pn) (w.r.t. paths) where D(A,P1...Pn) is combined diff between commit A, and parents Pi and D(A,Pi) is usual two-tree diff Pi..A So if any of that D(A,Pi) is huge, tracting 1 n-parent combine-diff as n 1-parent diffs and intersecting results will be slow. And usually, for linux.git and other topic-based workflows, that D(A,P2) is huge, because, if merge-base of A and P2, is several dozens of merges (from A, via first parent) below, that D(A,P2) will be diffing sum of merges from several subsystems to 1 subsystem. The solution is to avoid computing n 1-parent diffs, and to find changed-to-all-parents paths via scanning A's and all Pi's trees simultaneously, at each step comparing their entries, and based on that comparison, populate paths result, and deduce we could *skip* *recursing* into subdirectories, if at least for 1 parent, sha1 of that dir tree is the same as in A. That would save us from doing significant amount of needless work. Such approach is very similar to what diff_tree() does, only there we deal with scanning only 2 trees simultaneously, and for n+1 tree, the logic is a bit more complex: D(T,P1...Pn) calculation scheme ------------------------------- D(T,P1...Pn) = D(T,P1) ^ ... ^ D(T,Pn) (regarding resulting paths set) D(T,Pj) - diff between T..Pj D(T,P1...Pn) - combined diff from T to parents P1,...,Pn We start from all trees, which are sorted, and compare their entries in lock-step: T P1 Pn - - - |t| |p1| |pn| |-| |--| ... |--| imin = argmin(p1...pn) | | | | | | |-| |--| |--| |.| |. | |. | . . . . . . at any time there could be 3 cases: 1) t < p[imin]; 2) t > p[imin]; 3) t = p[imin]. Schematic deduction of what every case means, and what to do, follows: 1) t < p[imin] -> ∀j t ∉ Pj -> "+t" ∈ D(T,Pj) -> D += "+t"; t↓ 2) t > p[imin] 2.1) ∃j: pj > p[imin] -> "-p[imin]" ∉ D(T,Pj) -> D += ø; ∀ pi=p[imin] pi↓ 2.2) ∀i pi = p[imin] -> pi ∉ T -> "-pi" ∈ D(T,Pi) -> D += "-p[imin]"; ∀i pi↓ 3) t = p[imin] 3.1) ∃j: pj > p[imin] -> "+t" ∈ D(T,Pj) -> only pi=p[imin] remains to investigate 3.2) pi = p[imin] -> investigate δ(t,pi) | | v 3.1+3.2) looking at δ(t,pi) ∀i: pi=p[imin] - if all != ø -> ⎧δ(t,pi) - if pi=p[imin] -> D += ⎨ ⎩"+t" - if pi>p[imin] in any case t↓ ∀ pi=p[imin] pi↓ ~ For comparison, here is how diff_tree() works: D(A,B) calculation scheme ------------------------- A B - - |a| |b| a < b -> a ∉ B -> D(A,B) += +a a↓ |-| |-| a > b -> b ∉ A -> D(A,B) += -b b↓ | | | | a = b -> investigate δ(a,b) a↓ b↓ |-| |-| |.| |.| . . . . ~~~~~~~~ This patch generalizes diff tree-walker to work with arbitrary number of parents as described above - i.e. now there is a resulting tree t, and some parents trees tp[i] i=[0..nparent). The generalization builds on the fact that usual diff D(A,B) is by definition the same as combined diff D(A,[B]), so if we could rework the code for common case and make it be not slower for nparent=1 case, usual diff(t1,t2) generation will not be slower, and multiparent diff tree-walker would greatly benefit generating combine-diff. What we do is as follows: 1) diff tree-walker ll_diff_tree_sha1() is internally reworked to be a paths generator (new name diff_tree_paths()), with each generated path being `struct combine_diff_path` with info for path, new sha1,mode and for every parent which sha1,mode it was in it. 2) From that info, we can still generate usual diff queue with struct diff_filepairs, via "exporting" generated combine_diff_path, if we know we run for nparent=1 case. (see emit_diff() which is now named emit_diff_first_parent_only()) 3) In order for diff_can_quit_early(), which checks DIFF_OPT_TST(opt, HAS_CHANGES)) to work, that exporting have to be happening not in bulk, but incrementally, one diff path at a time. For such consumers, there is a new callback in diff_options introduced: ->pathchange(opt, struct combine_diff_path *) which, if set to !NULL, is called for every generated path. (see new compat ll_diff_tree_sha1() wrapper around new paths generator for setup) 4) The paths generation itself, is reworked from previous ll_diff_tree_sha1() code according to "D(A,P1...Pn) calculation scheme" provided above: On the start we allocate [nparent] arrays in place what was earlier just for one parent tree. then we just generalize loops, and comparison according to the algorithm. Some notes(*): 1) alloca(), for small arrays, is used for "runs not slower for nparent=1 case than before" goal - if we change it to xmalloc()/free() the timings get ~1% worse. For alloca() we use just-introduced xalloca/xalloca_free compatibility wrappers, so it should not be a portability problem. 2) For every parent tree, we need to keep a tag, whether entry from that parent equals to entry from minimal parent. For performance reasons I'm keeping that tag in entry's mode field in unused bit - see S_IFXMIN_NEQ. Not doing so, we'd need to alloca another [nparent] array, which hurts performance. 3) For emitted paths, memory could be reused, if we know the path was processed via callback and will not be needed later. We use efficient hand-made realloc-style path_appendnew(), that saves us from ~1-1.5% of potential additional slowdown. 4) goto(s) are used in several places, as the code executes a little bit faster with lowered register pressure. Also - we should now check for FIND_COPIES_HARDER not only when two entries names are the same, and their hashes are equal, but also for a case, when a path was removed from some of all parents having it. The reason is, if we don't, that path won't be emitted at all (see "a > xi" case), and we'll just skip it, and FIND_COPIES_HARDER wants all paths - with diff or without - to be emitted, to be later analyzed for being copies sources. The new check is only necessary for nparent >1, as for nparent=1 case xmin_eqtotal always =1 =nparent, and a path is always added to diff as removal. ~~~~~~~~ Timings for # without -c, i.e. testing only nparent=1 case `git log --raw --no-abbrev --no-renames` before and after the patch are as follows: navy.git linux.git v3.10..v3.11 before 0.611s 1.889s after 0.619s 1.907s slowdown 1.3% 0.9% This timings show we did no harm to usual diff(tree1,tree2) generation. From the table we can see that we actually did ~1% slowdown, but I think I've "earned" that 1% in the previous patch ("tree-diff: reuse base str(buf) memory on sub-tree recursion", HEAD~~) so for nparent=1 case, net timings stays approximately the same. The output also stayed the same. (*) If we revert 1)-4) to more usual techniques, for nparent=1 case, we'll get ~2-2.5% of additional slowdown, which I've tried to avoid, as "do no harm for nparent=1 case" rule. For linux.git, combined diff will run an order of magnitude faster and appropriate timings will be provided in the next commit, as we'll be taking advantage of the new diff tree-walker for combined-diff generation there. P.S. and combined diff is not some exotic/for-play-only stuff - for example for a program I write to represent Git archives as readonly filesystem, there is initial scan with `git log --reverse --raw --no-abbrev --no-renames -c` to extract log of what was created/changed when, as a result building a map {} sha1 -> in which commit (and date) a content was added that `-c` means also show combined diff for merges, and without them, if a merge is non-trivial (merges changes from two parents with both having separate changes to a file), or an evil one, the map will not be full, i.e. some valid sha1 would be absent from it. That case was my initial motivation for combined diffs speedup. Signed-off-by: Kirill Smelkov <kirr@mns.spb.ru> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-04-07 05:46:26 +08:00
/*
* Some mode bits are also used internally for computations.
*
* They *must* not overlap with any valid modes, and they *must* not be emitted
* to outside world - i.e. appear on disk or network. In other words, it's just
* temporary fields, which we internally use, but they have to stay in-house.
*
* ( such approach is valid, as standard S_IF* fits into 16 bits, and in Git
* codebase mode is `unsigned int` which is assumed to be at least 32 bits )
*/
/* used internally in tree-diff */
#define S_DIFFTREE_IFXMIN_NEQ 0x80000000
/*
* Intensive research over the course of many years has shown that
* port 9418 is totally unused by anything else. Or
*
* Your search - "port 9418" - did not match any documents.
*
* as www.google.com puts it.
*
* This port has been properly assigned for git use by IANA:
* git (Assigned-9418) [I06-050728-0001].
*
* git 9418/tcp git pack transfer service
* git 9418/udp git pack transfer service
*
* with Linus Torvalds <torvalds@osdl.org> as the point of
* contact. September 2005.
*
* See http://www.iana.org/assignments/port-numbers
*/
#define DEFAULT_GIT_PORT 9418
/*
* Basic data structures for the directory cache
*/
#define CACHE_SIGNATURE 0x44495243 /* "DIRC" */
struct cache_header {
uint32_t hdr_signature;
uint32_t hdr_version;
uint32_t hdr_entries;
};
#define INDEX_FORMAT_LB 2
#define INDEX_FORMAT_UB 4
/*
* The "cache_time" is just the low 32 bits of the
* time. It doesn't matter if it overflows - we only
* check it for equality in the 32 bits we save.
*/
struct cache_time {
uint32_t sec;
uint32_t nsec;
};
struct stat_data {
struct cache_time sd_ctime;
struct cache_time sd_mtime;
unsigned int sd_dev;
unsigned int sd_ino;
unsigned int sd_uid;
unsigned int sd_gid;
unsigned int sd_size;
};
struct cache_entry {
struct hashmap_entry ent;
struct stat_data ce_stat_data;
unsigned int ce_mode;
unsigned int ce_flags;
unsigned int ce_namelen;
unsigned int index; /* for link extension */
struct object_id oid;
char name[FLEX_ARRAY]; /* more */
};
#define CE_STAGEMASK (0x3000)
#define CE_EXTENDED (0x4000)
"Assume unchanged" git This adds "assume unchanged" logic, started by this message in the list discussion recently: <Pine.LNX.4.64.0601311807470.7301@g5.osdl.org> This is a workaround for filesystems that do not have lstat() that is quick enough for the index mechanism to take advantage of. On the paths marked as "assumed to be unchanged", the user needs to explicitly use update-index to register the object name to be in the next commit. You can use two new options to update-index to set and reset the CE_VALID bit: git-update-index --assume-unchanged path... git-update-index --no-assume-unchanged path... These forms manipulate only the CE_VALID bit; it does not change the object name recorded in the index file. Nor they add a new entry to the index. When the configuration variable "core.ignorestat = true" is set, the index entries are marked with CE_VALID bit automatically after: - update-index to explicitly register the current object name to the index file. - when update-index --refresh finds the path to be up-to-date. - when tools like read-tree -u and apply --index update the working tree file and register the current object name to the index file. The flag is dropped upon read-tree that does not check out the index entry. This happens regardless of the core.ignorestat settings. Index entries marked with CE_VALID bit are assumed to be unchanged most of the time. However, there are cases that CE_VALID bit is ignored for the sake of safety and usability: - while "git-read-tree -m" or git-apply need to make sure that the paths involved in the merge do not have local modifications. This sacrifices performance for safety. - when git-checkout-index -f -q -u -a tries to see if it needs to checkout the paths. Otherwise you can never check anything out ;-). - when git-update-index --really-refresh (a new flag) tries to see if the index entry is up to date. You can start with everything marked as CE_VALID and run this once to drop CE_VALID bit for paths that are modified. Most notably, "update-index --refresh" honours CE_VALID and does not actively stat, so after you modified a file in the working tree, update-index --refresh would not notice until you tell the index about it with "git-update-index path" or "git-update-index --no-assume-unchanged path". This version is not expected to be perfect. I think diff between index and/or tree and working files may need some adjustment, and there probably needs other cases we should automatically unmark paths that are marked to be CE_VALID. But the basics seem to work, and ready to be tested by people who asked for this feature. Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-02-09 13:15:24 +08:00
#define CE_VALID (0x8000)
#define CE_STAGESHIFT 12
/*
* Range 0xFFFF0FFF in ce_flags is divided into
* two parts: in-memory flags and on-disk ones.
* Flags in CE_EXTENDED_FLAGS will get saved on-disk
* if you want to save a new flag, add it in
* CE_EXTENDED_FLAGS
*
* In-memory only flags
*/
#define CE_UPDATE (1 << 16)
#define CE_REMOVE (1 << 17)
#define CE_UPTODATE (1 << 18)
#define CE_ADDED (1 << 19)
Fix name re-hashing semantics We handled the case of removing and re-inserting cache entries badly, which is something that merging commonly needs to do (removing the different stages, and then re-inserting one of them as the merged state). We even had a rather ugly special case for this failure case, where replace_index_entry() basically turned itself into a no-op if the new and the old entries were the same, exactly because the hash routines didn't handle it on their own. So what this patch does is to not just have the UNHASHED bit, but a HASHED bit too, and when you insert an entry into the name hash, that involves: - clear the UNHASHED bit, because now it's valid again for lookup (which is really all that UNHASHED meant) - if we're being lazy, we're done here (but we still want to clear the UNHASHED bit regardless of lazy mode, since we can become unlazy later, and so we need the UNHASHED bit to always be set correctly, even if we never actually insert the entry into the hash list) - if it was already hashed, we just leave it on the list - otherwise mark it HASHED and insert it into the list this all means that unhashing and rehashing a name all just works automatically. Obviously, you cannot change the name of an entry (that would be a serious bug), but nothing can validly do that anyway (you'd have to allocate a new struct cache_entry anyway since the name length could change), so that's not a new limitation. The code actually gets simpler in many ways, although the lazy hashing does mean that there are a few odd cases (ie something can be marked unhashed even though it was never on the hash in the first place, and isn't actually marked hashed!). Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-02-23 12:37:40 +08:00
#define CE_HASHED (1 << 20)
#define CE_WT_REMOVE (1 << 22) /* remove in work directory */
#define CE_CONFLICTED (1 << 23)
#define CE_UNPACKED (1 << 24)
#define CE_NEW_SKIP_WORKTREE (1 << 25)
unpack-trees.c: prepare for looking ahead in the index This prepares but does not yet implement a look-ahead in the index entries when traverse-trees.c decides to give us tree entries in an order that does not match what is in the index. A case where a look-ahead in the index is necessary happens when merging branch B into branch A while the index matches the current branch A, using a tree O as their common ancestor, and these three trees looks like this: O A B t t t-i t-i t-i t-j t-j t/1 t/2 The traverse_trees() function gets "t", "t-i" and "t" from trees O, A and B first, and notices that A may have a matching "t" behind "t-i" and "t-j" (indeed it does), and tells A to give that entry instead. After unpacking blob "t" from tree B (as it hasn't changed since O in B and A removed it, it will result in its removal), it descends into directory "t/". The side that walked index in parallel to the tree traversal used to be implemented with one pointer, o->pos, that points at the next index entry to be processed. When this happens, the pointer o->pos still points at "t-i" that is the first entry. We should be able to skip "t-i" and "t-j" and locate "t/1" from the index while the recursive invocation of traverse_trees() walks and match entries found there, and later come back to process "t-i". While that look-ahead is not implemented yet, this adds a flag bit, CE_UNPACKED, to mark the entries in the index that has already been processed. o->pos pointer has been renamed to o->cache_bottom and it points at the first entry that may still need to be processed. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-01-08 06:59:54 +08:00
checkout: avoid unnecessary match_pathspec calls In checkout_paths() we do this - for all updated items, call match_pathspec - for all items, call match_pathspec (inside unmerge_cache) - for all items, call match_pathspec (for showing "path .. is unmerged) - for updated items, call match_pathspec and update paths That's a lot of duplicate match_pathspec(s) and the function is not exactly cheap to be called so many times, especially on large indexes. This patch makes it call match_pathspec once per updated index entry, save the result in ce_flags and reuse the results in the following loops. The changes in 0a1283b (checkout $tree $path: do not clobber local changes in $path not in $tree - 2011-09-30) limit the affected paths to ones we read from $tree. We do not do anything to other modified entries in this case, so the "for all items" above could be modified to "for all updated items". But.. The command's behavior now is modified slightly: unmerged entries that match $path, but not updated by $tree, are now NOT touched. Although this should be considered a bug fix, not a regression. A new test is added for this change. And while at there, free ps_matched after use. The following command is tested on webkit, 215k entries. The pattern is chosen mainly to make match_pathspec sweat: git checkout -- "*[a-zA-Z]*[a-zA-Z]*[a-zA-Z]*" before after real 0m3.493s 0m2.737s user 0m2.239s 0m1.586s sys 0m1.252s 0m1.151s Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-03-27 13:58:21 +08:00
/* used to temporarily mark paths matched by pathspecs */
#define CE_MATCHED (1 << 26)
#define CE_UPDATE_IN_BASE (1 << 27)
#define CE_STRIP_NAME (1 << 28)
/*
* Extended on-disk flags
*/
#define CE_INTENT_TO_ADD (1 << 29)
#define CE_SKIP_WORKTREE (1 << 30)
/* CE_EXTENDED2 is for future extension */
#define CE_EXTENDED2 (1U << 31)
#define CE_EXTENDED_FLAGS (CE_INTENT_TO_ADD | CE_SKIP_WORKTREE)
/*
* Safeguard to avoid saving wrong flags:
* - CE_EXTENDED2 won't get saved until its semantic is known
* - Bits in 0x0000FFFF have been saved in ce_flags already
* - Bits in 0x003F0000 are currently in-memory flags
*/
#if CE_EXTENDED_FLAGS & 0x803FFFFF
#error "CE_EXTENDED_FLAGS out of range"
#endif
/* Forward structure decls */
struct pathspec;
struct child_process;
/*
* Copy the sha1 and stat state of a cache entry from one to
* another. But we never change the name, or the hash state!
*/
static inline void copy_cache_entry(struct cache_entry *dst,
const struct cache_entry *src)
{
unsigned int state = dst->ce_flags & CE_HASHED;
/* Don't copy hash chain and name */
memcpy(&dst->ce_stat_data, &src->ce_stat_data,
offsetof(struct cache_entry, name) -
offsetof(struct cache_entry, ce_stat_data));
/* Restore the hash state */
dst->ce_flags = (dst->ce_flags & ~CE_HASHED) | state;
}
static inline unsigned create_ce_flags(unsigned stage)
{
return (stage << CE_STAGESHIFT);
}
#define ce_namelen(ce) ((ce)->ce_namelen)
#define ce_size(ce) cache_entry_size(ce_namelen(ce))
#define ce_stage(ce) ((CE_STAGEMASK & (ce)->ce_flags) >> CE_STAGESHIFT)
#define ce_uptodate(ce) ((ce)->ce_flags & CE_UPTODATE)
#define ce_skip_worktree(ce) ((ce)->ce_flags & CE_SKIP_WORKTREE)
#define ce_mark_uptodate(ce) ((ce)->ce_flags |= CE_UPTODATE)
#define ce_intent_to_add(ce) ((ce)->ce_flags & CE_INTENT_TO_ADD)
#define ce_permissions(mode) (((mode) & 0100) ? 0755 : 0644)
static inline unsigned int create_ce_mode(unsigned int mode)
{
if (S_ISLNK(mode))
return S_IFLNK;
if (S_ISDIR(mode) || S_ISGITLINK(mode))
return S_IFGITLINK;
return S_IFREG | ce_permissions(mode);
}
static inline unsigned int ce_mode_from_stat(const struct cache_entry *ce,
unsigned int mode)
{
extern int trust_executable_bit, has_symlinks;
if (!has_symlinks && S_ISREG(mode) &&
ce && S_ISLNK(ce->ce_mode))
return ce->ce_mode;
if (!trust_executable_bit && S_ISREG(mode)) {
if (ce && S_ISREG(ce->ce_mode))
return ce->ce_mode;
return create_ce_mode(0666);
}
return create_ce_mode(mode);
}
static inline int ce_to_dtype(const struct cache_entry *ce)
{
unsigned ce_mode = ntohl(ce->ce_mode);
if (S_ISREG(ce_mode))
return DT_REG;
else if (S_ISDIR(ce_mode) || S_ISGITLINK(ce_mode))
return DT_DIR;
else if (S_ISLNK(ce_mode))
return DT_LNK;
else
return DT_UNKNOWN;
}
static inline unsigned int canon_mode(unsigned int mode)
{
if (S_ISREG(mode))
return S_IFREG | ce_permissions(mode);
if (S_ISLNK(mode))
return S_IFLNK;
if (S_ISDIR(mode))
return S_IFDIR;
return S_IFGITLINK;
}
#define cache_entry_size(len) (offsetof(struct cache_entry,name) + (len) + 1)
#define SOMETHING_CHANGED (1 << 0) /* unclassified changes go here */
#define CE_ENTRY_CHANGED (1 << 1)
#define CE_ENTRY_REMOVED (1 << 2)
#define CE_ENTRY_ADDED (1 << 3)
#define RESOLVE_UNDO_CHANGED (1 << 4)
#define CACHE_TREE_CHANGED (1 << 5)
#define SPLIT_INDEX_ORDERED (1 << 6)
#define UNTRACKED_CHANGED (1 << 7)
struct split_index;
struct untracked_cache;
struct index_state {
struct cache_entry **cache;
unsigned int version;
unsigned int cache_nr, cache_alloc, cache_changed;
struct string_list *resolve_undo;
struct cache_tree *cache_tree;
struct split_index *split_index;
struct cache_time timestamp;
unpack_trees(): protect the handcrafted in-core index from read_cache() unpack_trees() rebuilds the in-core index from scratch by allocating a new structure and finishing it off by copying the built one to the final index. The resulting in-core index is Ok for most use, but read_cache() does not recognize it as such. The function is meant to be no-op if you already have loaded the index, until you call discard_cache(). This change the way read_cache() detects an already initialized in-core index, by introducing an extra bit, and marks the handcrafted in-core index as initialized, to avoid this problem. A better fix in the longer term would be to change the read_cache() API so that it will always discard and re-read from the on-disk index to avoid confusion. But there are higher level API that have relied on the current semantics, and they and their users all need to get converted, which is outside the scope of 'maint' track. An example of such a higher level API is write_cache_as_tree(), which is used by git-write-tree as well as later Porcelains like git-merge, revert and cherry-pick. In the longer term, we should remove read_cache() from there and add one to cmd_write_tree(); other callers expect that the in-core index they prepared is what gets written as a tree so no other change is necessary for this particular codepath. The original version of this patch marked the index by pointing an otherwise wasted malloc'ed memory with o->result.alloc, but this version uses Linus's idea to use a new "initialized" bit, which is conceptually much cleaner. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-08-24 03:57:30 +08:00
unsigned name_hash_initialized : 1,
initialized : 1;
struct hashmap name_hash;
struct hashmap dir_hash;
unsigned char sha1[20];
struct untracked_cache *untracked;
};
extern struct index_state the_index;
/* Name hashing */
extern int test_lazy_init_name_hash(struct index_state *istate, int try_threaded);
extern void add_name_hash(struct index_state *istate, struct cache_entry *ce);
name-hash.c: fix endless loop with core.ignorecase=true With core.ignorecase=true, name-hash.c builds a case insensitive index of all tracked directories. Currently, the existing cache entry structures are added multiple times to the same hashtable (with different name lengths and hash codes). However, there's only one dir_next pointer, which gets completely messed up in case of hash collisions. In the worst case, this causes an endless loop if ce == ce->dir_next (see t7062). Use a separate hashtable and separate structures for the directory index so that each directory entry has its own next pointer. Use reference counting to track which directory entry contains files. There are only slight changes to the name-hash.c API: - new free_name_hash() used by read_cache.c::discard_index() - remove_name_hash() takes an additional index_state parameter - index_name_exists() for a directory (trailing '/') may return a cache entry that has been removed (CE_UNHASHED). This is not a problem as the return value is only used to check if the directory exists (dir.c) or to normalize casing of directory names (read-cache.c). Getting rid of cache_entry.dir_next reduces memory consumption, especially with core.ignorecase=false (which doesn't use that member at all). With core.ignorecase=true, building the directory index is slightly faster as we add / check the parent directory first (instead of going through all directory levels for each file in the index). E.g. with WebKit (~200k files, ~7k dirs), time spent in lazy_init_name_hash is reduced from 176ms to 130ms. Signed-off-by: Karsten Blees <blees@dcon.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-02-28 07:57:48 +08:00
extern void remove_name_hash(struct index_state *istate, struct cache_entry *ce);
extern void free_name_hash(struct index_state *istate);
#ifndef NO_THE_INDEX_COMPATIBILITY_MACROS
#define active_cache (the_index.cache)
#define active_nr (the_index.cache_nr)
#define active_alloc (the_index.cache_alloc)
#define active_cache_changed (the_index.cache_changed)
#define active_cache_tree (the_index.cache_tree)
#define read_cache() read_index(&the_index)
#define read_cache_from(path) read_index_from(&the_index, (path))
#define read_cache_preload(pathspec) read_index_preload(&the_index, (pathspec))
#define is_cache_unborn() is_index_unborn(&the_index)
#define read_cache_unmerged() read_index_unmerged(&the_index)
#define discard_cache() discard_index(&the_index)
#define unmerged_cache() unmerged_index(&the_index)
#define cache_name_pos(name, namelen) index_name_pos(&the_index,(name),(namelen))
#define add_cache_entry(ce, option) add_index_entry(&the_index, (ce), (option))
#define rename_cache_entry_at(pos, new_name) rename_index_entry_at(&the_index, (pos), (new_name))
#define remove_cache_entry_at(pos) remove_index_entry_at(&the_index, (pos))
#define remove_file_from_cache(path) remove_file_from_index(&the_index, (path))
#define add_to_cache(path, st, flags) add_to_index(&the_index, (path), (st), (flags))
#define add_file_to_cache(path, flags) add_file_to_index(&the_index, (path), (flags))
#define chmod_cache_entry(ce, flip) chmod_index_entry(&the_index, (ce), (flip))
#define refresh_cache(flags) refresh_index(&the_index, (flags), NULL, NULL, NULL)
#define ce_match_stat(ce, st, options) ie_match_stat(&the_index, (ce), (st), (options))
#define ce_modified(ce, st, options) ie_modified(&the_index, (ce), (st), (options))
#define cache_dir_exists(name, namelen) index_dir_exists(&the_index, (name), (namelen))
#define cache_file_exists(name, namelen, igncase) index_file_exists(&the_index, (name), (namelen), (igncase))
#define cache_name_is_other(name, namelen) index_name_is_other(&the_index, (name), (namelen))
#define resolve_undo_clear() resolve_undo_clear_index(&the_index)
#define unmerge_cache_entry_at(at) unmerge_index_entry_at(&the_index, at)
#define unmerge_cache(pathspec) unmerge_index(&the_index, pathspec)
#define read_blob_data_from_cache(path, sz) read_blob_data_from_index(&the_index, (path), (sz))
#endif
enum object_type {
OBJ_BAD = -1,
OBJ_NONE = 0,
OBJ_COMMIT = 1,
OBJ_TREE = 2,
OBJ_BLOB = 3,
OBJ_TAG = 4,
/* 5 for future expansion */
OBJ_OFS_DELTA = 6,
OBJ_REF_DELTA = 7,
OBJ_ANY,
OBJ_MAX
};
static inline enum object_type object_type(unsigned int mode)
{
return S_ISDIR(mode) ? OBJ_TREE :
S_ISGITLINK(mode) ? OBJ_COMMIT :
OBJ_BLOB;
}
/* Double-check local_repo_env below if you add to this list. */
#define GIT_DIR_ENVIRONMENT "GIT_DIR"
$GIT_COMMON_DIR: a new environment variable This variable is intended to support multiple working directories attached to a repository. Such a repository may have a main working directory, created by either "git init" or "git clone" and one or more linked working directories. These working directories and the main repository share the same repository directory. In linked working directories, $GIT_COMMON_DIR must be defined to point to the real repository directory and $GIT_DIR points to an unused subdirectory inside $GIT_COMMON_DIR. File locations inside the repository are reorganized from the linked worktree view point: - worktree-specific such as HEAD, logs/HEAD, index, other top-level refs and unrecognized files are from $GIT_DIR. - the rest like objects, refs, info, hooks, packed-refs, shallow... are from $GIT_COMMON_DIR (except info/sparse-checkout, but that's a separate patch) Scripts are supposed to retrieve paths in $GIT_DIR with "git rev-parse --git-path", which will take care of "$GIT_DIR vs $GIT_COMMON_DIR" business. The redirection is done by git_path(), git_pathdup() and strbuf_git_path(). The selected list of paths goes to $GIT_COMMON_DIR, not the other way around in case a developer adds a new worktree-specific file and it's accidentally promoted to be shared across repositories (this includes unknown files added by third party commands) The list of known files that belong to $GIT_DIR are: ADD_EDIT.patch BISECT_ANCESTORS_OK BISECT_EXPECTED_REV BISECT_LOG BISECT_NAMES CHERRY_PICK_HEAD COMMIT_MSG FETCH_HEAD HEAD MERGE_HEAD MERGE_MODE MERGE_RR NOTES_EDITMSG NOTES_MERGE_WORKTREE ORIG_HEAD REVERT_HEAD SQUASH_MSG TAG_EDITMSG fast_import_crash_* logs/HEAD next-index-* rebase-apply rebase-merge rsync-refs-* sequencer/* shallow_* Path mapping is NOT done for git_path_submodule(). Multi-checkouts are not supported as submodules. Helped-by: Jens Lehmann <Jens.Lehmann@web.de> Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-11-30 16:24:36 +08:00
#define GIT_COMMON_DIR_ENVIRONMENT "GIT_COMMON_DIR"
ref namespaces: infrastructure Add support for dividing the refs of a single repository into multiple namespaces, each of which can have its own branches, tags, and HEAD. Git can expose each namespace as an independent repository to pull from and push to, while sharing the object store, and exposing all the refs to operations such as git-gc. Storing multiple repositories as namespaces of a single repository avoids storing duplicate copies of the same objects, such as when storing multiple branches of the same source. The alternates mechanism provides similar support for avoiding duplicates, but alternates do not prevent duplication between new objects added to the repositories without ongoing maintenance, while namespaces do. To specify a namespace, set the GIT_NAMESPACE environment variable to the namespace. For each ref namespace, git stores the corresponding refs in a directory under refs/namespaces/. For example, GIT_NAMESPACE=foo will store refs under refs/namespaces/foo/. You can also specify namespaces via the --namespace option to git. Note that namespaces which include a / will expand to a hierarchy of namespaces; for example, GIT_NAMESPACE=foo/bar will store refs under refs/namespaces/foo/refs/namespaces/bar/. This makes paths in GIT_NAMESPACE behave hierarchically, so that cloning with GIT_NAMESPACE=foo/bar produces the same result as cloning with GIT_NAMESPACE=foo and cloning from that repo with GIT_NAMESPACE=bar. It also avoids ambiguity with strange namespace paths such as foo/refs/heads/, which could otherwise generate directory/file conflicts within the refs directory. Add the infrastructure for ref namespaces: handle the GIT_NAMESPACE environment variable and --namespace option, and support iterating over refs in a namespace. Signed-off-by: Josh Triplett <josh@joshtriplett.org> Signed-off-by: Jamey Sharp <jamey@minilop.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2011-07-06 01:54:44 +08:00
#define GIT_NAMESPACE_ENVIRONMENT "GIT_NAMESPACE"
introduce GIT_WORK_TREE to specify the work tree setup_gdg is used as abbreviation for setup_git_directory_gently. The work tree can be specified using the environment variable GIT_WORK_TREE and the config option core.worktree (the environment variable has precendence over the config option). Additionally there is a command line option --work-tree which sets the environment variable. setup_gdg does the following now: GIT_DIR unspecified repository in .git directory parent directory of the .git directory is used as work tree, GIT_WORK_TREE is ignored GIT_DIR unspecified repository in cwd GIT_DIR is set to cwd see the cases with GIT_DIR specified what happens next and also see the note below GIT_DIR specified GIT_WORK_TREE/core.worktree unspecified cwd is used as work tree GIT_DIR specified GIT_WORK_TREE/core.worktree specified the specified work tree is used Note on the case where GIT_DIR is unspecified and repository is in cwd: GIT_WORK_TREE is used but is_inside_git_dir is always true. I did it this way because setup_gdg might be called multiple times (e.g. when doing alias expansion) and in successive calls setup_gdg should do the same thing every time. Meaning of is_bare/is_inside_work_tree/is_inside_git_dir: (1) is_bare_repository A repository is bare if core.bare is true or core.bare is unspecified and the name suggests it is bare (directory not named .git). The bare option disables a few protective checks which are useful with a working tree. Currently this changes if a repository is bare: updates of HEAD are allowed git gc packs the refs the reflog is disabled by default (2) is_inside_work_tree True if the cwd is inside the associated working tree (if there is one), false otherwise. (3) is_inside_git_dir True if the cwd is inside the git directory, false otherwise. Before this patch is_inside_git_dir was always true for bare repositories. When setup_gdg finds a repository git_config(git_default_config) is always called. This ensure that is_bare_repository makes use of core.bare and does not guess even though core.bare is specified. inside_work_tree and inside_git_dir are set if setup_gdg finds a repository. The is_inside_work_tree and is_inside_git_dir functions will die if they are called before a successful call to setup_gdg. Signed-off-by: Matthias Lederhofer <matled@gmx.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-06-06 15:10:42 +08:00
#define GIT_WORK_TREE_ENVIRONMENT "GIT_WORK_TREE"
#define GIT_PREFIX_ENVIRONMENT "GIT_PREFIX"
#define GIT_SUPER_PREFIX_ENVIRONMENT "GIT_INTERNAL_SUPER_PREFIX"
#define GIT_TOPLEVEL_PREFIX_ENVIRONMENT "GIT_INTERNAL_TOPLEVEL_PREFIX"
#define DEFAULT_GIT_DIR_ENVIRONMENT ".git"
Rename environment variables. H. Peter Anvin mentioned that using SHA1_whatever as an environment variable name is not nice and we should instead use names starting with "GIT_" prefix to avoid conflicts. Here is what this patch does: * Renames the following environment variables: New name Old Name GIT_AUTHOR_DATE AUTHOR_DATE GIT_AUTHOR_EMAIL AUTHOR_EMAIL GIT_AUTHOR_NAME AUTHOR_NAME GIT_COMMITTER_EMAIL COMMIT_AUTHOR_EMAIL GIT_COMMITTER_NAME COMMIT_AUTHOR_NAME GIT_ALTERNATE_OBJECT_DIRECTORIES SHA1_FILE_DIRECTORIES GIT_OBJECT_DIRECTORY SHA1_FILE_DIRECTORY * Introduces a compatibility macro, gitenv(), which does an getenv() and if it fails calls gitenv_bc(), which in turn picks up the value from old name while giving a warning about using an old name. * Changes all users of the environment variable to fetch environment variable with the new name using gitenv(). * Updates the documentation and scripts shipped with Linus GIT distribution. The transition plan is as follows: * We will keep the backward compatibility list used by gitenv() for now, so the current scripts and user environments continue to work as before. The users will get warnings when they have old name but not new name in their environment to the stderr. * The Porcelain layers should start using new names. However, just in case it ends up calling old Plumbing layer implementation, they should also export old names, taking values from the corresponding new names, during the transition period. * After a transition period, we would drop the compatibility support and drop gitenv(). Revert the callers to directly call getenv() but keep using the new names. The last part is probably optional and the transition duration needs to be set to a reasonable value. Signed-off-by: Junio C Hamano <junkio@cox.net>
2005-05-10 08:57:56 +08:00
#define DB_ENVIRONMENT "GIT_OBJECT_DIRECTORY"
#define INDEX_ENVIRONMENT "GIT_INDEX_FILE"
#define GRAFT_ENVIRONMENT "GIT_GRAFT_FILE"
#define GIT_SHALLOW_FILE_ENVIRONMENT "GIT_SHALLOW_FILE"
#define TEMPLATE_DIR_ENVIRONMENT "GIT_TEMPLATE_DIR"
#define CONFIG_ENVIRONMENT "GIT_CONFIG"
#define CONFIG_DATA_ENVIRONMENT "GIT_CONFIG_PARAMETERS"
#define EXEC_PATH_ENVIRONMENT "GIT_EXEC_PATH"
#define CEILING_DIRECTORIES_ENVIRONMENT "GIT_CEILING_DIRECTORIES"
#define NO_REPLACE_OBJECTS_ENVIRONMENT "GIT_NO_REPLACE_OBJECTS"
#define GIT_REPLACE_REF_BASE_ENVIRONMENT "GIT_REPLACE_REF_BASE"
Add basic infrastructure to assign attributes to paths This adds the basic infrastructure to assign attributes to paths, in a way similar to what the exclusion mechanism does based on $GIT_DIR/info/exclude and .gitignore files. An attribute is just a simple string that does not contain any whitespace. They can be specified in $GIT_DIR/info/attributes file, and .gitattributes file in each directory. Each line in these files defines a pattern matching rule. Similar to the exclusion mechanism, a later match overrides an earlier match in the same file, and entries from .gitattributes file in the same directory takes precedence over the ones from parent directories. Lines in $GIT_DIR/info/attributes file are used as the lowest precedence default rules. A line is either a comment (an empty line, or a line that begins with a '#'), or a rule, which is a whitespace separated list of tokens. The first token on the line is a shell glob pattern. The rest are names of attributes, each of which can optionally be prefixed with '!'. Such a line means "if a path matches this glob, this attribute is set (or unset -- if the attribute name is prefixed with '!'). For glob matching, the same "if the pattern does not have a slash in it, the basename of the path is matched with fnmatch(3) against the pattern, otherwise, the path is matched with the pattern with FNM_PATHNAME" rule as the exclusion mechanism is used. This does not define what an attribute means. Tying an attribute to various effects it has on git operation for paths that have it will be specified separately. Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-04-12 16:07:32 +08:00
#define GITATTRIBUTES_FILE ".gitattributes"
#define INFOATTRIBUTES_FILE "info/attributes"
attribute macro support This adds "attribute macros" (for lack of better name). So far, we have low-level attributes such as crlf and diff, which are defined in operational terms --- setting or unsetting them on a particular path directly affects what is done to the path. For example, in order to decline diffs or crlf conversions on a binary blob, no diffs on PostScript files, and treat all other files normally, you would have something like these: * diff crlf *.ps !diff proprietary.o !diff !crlf That is fine as the operation goes, but gets unwieldy rather rapidly, when we start adding more low-level attributes that are defined in operational terms. A near-term example of such an attribute would be 'merge-3way' which would control if git should attempt the usual 3-way file-level merge internally, or leave merging to a specialized external program of user's choice. When it is added, we do _not_ want to force the users to update the above to: * diff crlf merge-3way *.ps !diff proprietary.o !diff !crlf !merge-3way The way this patch solves this issue is to realize that the attributes the user is assigning to paths are not defined in terms of operations but in terms of what they are. All of the three low-level attributes usually make sense for most of the files that sane SCM users have git operate on (these files are typically called "text'). Only a few cases, such as binary blob, need exception to decline the "usual treatment given to text files" -- and people mark them as "binary". So this allows the $GIT_DIR/info/alternates and .gitattributes at the toplevel of the project to also specify attributes that assigns other attributes. The syntax is '[attr]' followed by an attribute name followed by a list of attribute names: [attr] binary !diff !crlf !merge-3way When "binary" attribute is set to a path, if the path has not got diff/crlf/merge-3way attribute set or unset by other rules, this rule unsets the three low-level attributes. It is expected that the user level .gitattributes will be expressed mostly in terms of attributes based on what the files are, and the above sample would become like this: (built-in attribute configuration) [attr] binary !diff !crlf !merge-3way * diff crlf merge-3way (project specific .gitattributes) proprietary.o binary (user preference $GIT_DIR/info/attributes) *.ps !diff There are a few caveats. * As described above, you can define these macros only in $GIT_DIR/info/attributes and toplevel .gitattributes. * There is no attempt to detect circular definition of macro attributes, and definitions are evaluated from bottom to top as usual to fill in other attributes that have not yet got values. The following would work as expected: [attr] text diff crlf [attr] ps text !diff *.ps ps while this would most likely not (I haven't tried): [attr] ps text !diff [attr] text diff crlf *.ps ps * When a macro says "[attr] A B !C", saying that a path does not have attribute A does not let you tell anything about attributes B or C. That is, given this: [attr] text diff crlf [attr] ps text !diff *.txt !ps path hello.txt, which would match "*.txt" pattern, would have "ps" attribute set to zero, but that does not make text attribute of hello.txt set to false (nor diff attribute set to true). Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-04-14 23:54:37 +08:00
#define ATTRIBUTE_MACRO_PREFIX "[attr]"
#define GIT_NOTES_REF_ENVIRONMENT "GIT_NOTES_REF"
#define GIT_NOTES_DEFAULT_REF "refs/notes/commits"
#define GIT_NOTES_DISPLAY_REF_ENVIRONMENT "GIT_NOTES_DISPLAY_REF"
#define GIT_NOTES_REWRITE_REF_ENVIRONMENT "GIT_NOTES_REWRITE_REF"
#define GIT_NOTES_REWRITE_MODE_ENVIRONMENT "GIT_NOTES_REWRITE_MODE"
add global --literal-pathspecs option Git takes pathspec arguments in many places to limit the scope of an operation. These pathspecs are treated not as literal paths, but as glob patterns that can be fed to fnmatch. When a user is giving a specific pattern, this is a nice feature. However, when programatically providing pathspecs, it can be a nuisance. For example, to find the latest revision which modified "$foo", one can use "git rev-list -- $foo". But if "$foo" contains glob characters (e.g., "f*"), it will erroneously match more entries than desired. The caller needs to quote the characters in $foo, and even then, the results may not be exactly the same as with a literal pathspec. For instance, the depth checks in match_pathspec_depth do not kick in if we match via fnmatch. This patch introduces a global command-line option (i.e., one for "git" itself, not for specific commands) to turn this behavior off. It also has a matching environment variable, which can make it easier if you are a script or porcelain interface that is going to issue many such commands. This option cannot turn off globbing for particular pathspecs. That could eventually be done with a ":(noglob)" magic pathspec prefix. However, that level of granularity is more cumbersome to use for many cases, and doing ":(noglob)" right would mean converting the whole codebase to use "struct pathspec", as the usual "const char **pathspec" cannot represent extra per-item flags. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-12-20 06:37:30 +08:00
#define GIT_LITERAL_PATHSPECS_ENVIRONMENT "GIT_LITERAL_PATHSPECS"
#define GIT_GLOB_PATHSPECS_ENVIRONMENT "GIT_GLOB_PATHSPECS"
#define GIT_NOGLOB_PATHSPECS_ENVIRONMENT "GIT_NOGLOB_PATHSPECS"
#define GIT_ICASE_PATHSPECS_ENVIRONMENT "GIT_ICASE_PATHSPECS"
#define GIT_QUARANTINE_ENVIRONMENT "GIT_QUARANTINE_PATH"
/*
setup: suppress implicit "." work-tree for bare repos If an explicit GIT_DIR is given without a working tree, we implicitly assume that the current working directory should be used as the working tree. E.g.,: GIT_DIR=/some/repo.git git status would compare against the cwd. Unfortunately, we fool this rule for sub-invocations of git by setting GIT_DIR internally ourselves. For example: git init foo cd foo/.git git status ;# fails, as we expect git config alias.st status git status ;# does not fail, but should What happens is that we run setup_git_directory when doing alias lookup (since we need to see the config), set GIT_DIR as a result, and then leave GIT_WORK_TREE blank (because we do not have one). Then when we actually run the status command, we do setup_git_directory again, which sees our explicit GIT_DIR and uses the cwd as an implicit worktree. It's tempting to argue that we should be suppressing that second invocation of setup_git_directory, as it could use the values we already found in memory. However, the problem still exists for sub-processes (e.g., if "git status" were an external command). You can see another example with the "--bare" option, which sets GIT_DIR explicitly. For example: git init foo cd foo/.git git status ;# fails git --bare status ;# does NOT fail We need some way of telling sub-processes "even though GIT_DIR is set, do not use cwd as an implicit working tree". We could do it by putting a special token into GIT_WORK_TREE, but the obvious choice (an empty string) has some portability problems. Instead, we add a new boolean variable, GIT_IMPLICIT_WORK_TREE, which suppresses the use of cwd as a working tree when GIT_DIR is set. We trigger the new variable when we know we are in a bare setting. The variable is left intentionally undocumented, as this is an internal detail (for now, anyway). If somebody comes up with a good alternate use for it, and once we are confident we have shaken any bugs out of it, we can consider promoting it further. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-03-08 17:32:22 +08:00
* This environment variable is expected to contain a boolean indicating
* whether we should or should not treat:
*
* GIT_DIR=foo.git git ...
*
* as if GIT_WORK_TREE=. was given. It's not expected that users will make use
* of this, but we use it internally to communicate to sub-processes that we
* are in a bare repo. If not set, defaults to true.
*/
#define GIT_IMPLICIT_WORK_TREE_ENVIRONMENT "GIT_IMPLICIT_WORK_TREE"
/*
* Repository-local GIT_* environment variables; these will be cleared
* when git spawns a sub-process that runs inside another repository.
* The array is NULL-terminated, which makes it easy to pass in the "env"
* parameter of a run-command invocation, or to do a simple walk.
*/
extern const char * const local_repo_env[];
extern void setup_git_env(void);
config: only read .git/config from configured repos When git_config() runs, it looks in the system, user-wide, and repo-level config files. It gets the latter by calling git_pathdup(), which in turn calls get_git_dir(). If we haven't set up the git repository yet, this may simply return ".git", and we will look at ".git/config". This seems like it would be helpful (presumably we haven't set up the repository yet, so it tries to find it), but it turns out to be a bad idea for a few reasons: - it's not sufficient, and therefore hides bugs in a confusing way. Config will be respected if commands are run from the top-level of the working tree, but not from a subdirectory. - it's not always true that we haven't set up the repository _yet_; we may not want to do it at all. For instance, if you run "git init /some/path" from inside another repository, it should not load config from the existing repository. - there might be a path ".git/config", but it is not the actual repository we would find via setup_git_directory(). This may happen, e.g., if you are storing a git repository inside another git repository, but have munged one of the files in such a way that the inner repository is not valid (e.g., by removing HEAD). We have at least two bugs of the second type in git-init, introduced by ae5f677 (lazily load core.sharedrepository, 2016-03-11). It causes init to use git_configset(), which loads all of the config, including values from the current repo (if any). This shows up in two ways: 1. If we happen to be in an existing repository directory, we'll read and respect core.sharedrepository from it, even though it should have no bearing on the new repository. A new test in t1301 covers this. 2. Similarly, if we're in an existing repo that sets core.logallrefupdates, that will cause init to fail to set it in a newly created repository (because it thinks that the user's templates already did so). A new test in t0001 covers this. We also need to adjust an existing test in t1302, which gives another example of why this patch is an improvement. That test creates an embedded repository with a bogus core.repositoryformatversion of "99". It wants to make sure that we actually stop at the bogus repo rather than continuing upward to find the outer repo. So it checks that "git config core.repositoryformatversion" returns 99. But that only works because we blindly read ".git/config", even though we _know_ we're in a repository whose vintage we do not understand. After this patch, we avoid reading config from the unknown vintage repository at all, which is a safer choice. But we need to tweak the test, since core.repositoryformatversion will not return 99; it will claim that it could not find the variable at all. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-13 11:24:15 +08:00
/*
* Returns true iff we have a configured git repository (either via
* setup_git_directory, or in the environment via $GIT_DIR).
*/
int have_git_dir(void);
extern int is_bare_repository_cfg;
extern int is_bare_repository(void);
extern int is_inside_git_dir(void);
Clean up work-tree handling The old version of work-tree support was an unholy mess, barely readable, and not to the point. For example, why do you have to provide a worktree, when it is not used? As in "git status". Now it works. Another riddle was: if you can have work trees inside the git dir, why are some programs complaining that they need a work tree? IOW it is allowed to call $ git --git-dir=../ --work-tree=. bla when you really want to. In this case, you are both in the git directory and in the working tree. So, programs have to actually test for the right thing, namely if they are inside a working tree, and not if they are inside a git directory. Also, GIT_DIR=../.git should behave the same as if no GIT_DIR was specified, unless there is a repository in the current working directory. It does now. The logic to determine if a repository is bare, or has a work tree (tertium non datur), is this: --work-tree=bla overrides GIT_WORK_TREE, which overrides core.bare = true, which overrides core.worktree, which overrides GIT_DIR/.. when GIT_DIR ends in /.git, which overrides the directory in which .git/ was found. In related news, a long standing bug was fixed: when in .git/bla/x.git/, which is a bare repository, git formerly assumed ../.. to be the appropriate git dir. This problem was reported by Shawn Pearce to have caused much pain, where a colleague mistakenly ran "git init" in "/" a long time ago, and bare repositories just would not work. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-08-01 08:30:14 +08:00
extern char *git_work_tree_cfg;
introduce GIT_WORK_TREE to specify the work tree setup_gdg is used as abbreviation for setup_git_directory_gently. The work tree can be specified using the environment variable GIT_WORK_TREE and the config option core.worktree (the environment variable has precendence over the config option). Additionally there is a command line option --work-tree which sets the environment variable. setup_gdg does the following now: GIT_DIR unspecified repository in .git directory parent directory of the .git directory is used as work tree, GIT_WORK_TREE is ignored GIT_DIR unspecified repository in cwd GIT_DIR is set to cwd see the cases with GIT_DIR specified what happens next and also see the note below GIT_DIR specified GIT_WORK_TREE/core.worktree unspecified cwd is used as work tree GIT_DIR specified GIT_WORK_TREE/core.worktree specified the specified work tree is used Note on the case where GIT_DIR is unspecified and repository is in cwd: GIT_WORK_TREE is used but is_inside_git_dir is always true. I did it this way because setup_gdg might be called multiple times (e.g. when doing alias expansion) and in successive calls setup_gdg should do the same thing every time. Meaning of is_bare/is_inside_work_tree/is_inside_git_dir: (1) is_bare_repository A repository is bare if core.bare is true or core.bare is unspecified and the name suggests it is bare (directory not named .git). The bare option disables a few protective checks which are useful with a working tree. Currently this changes if a repository is bare: updates of HEAD are allowed git gc packs the refs the reflog is disabled by default (2) is_inside_work_tree True if the cwd is inside the associated working tree (if there is one), false otherwise. (3) is_inside_git_dir True if the cwd is inside the git directory, false otherwise. Before this patch is_inside_git_dir was always true for bare repositories. When setup_gdg finds a repository git_config(git_default_config) is always called. This ensure that is_bare_repository makes use of core.bare and does not guess even though core.bare is specified. inside_work_tree and inside_git_dir are set if setup_gdg finds a repository. The is_inside_work_tree and is_inside_git_dir functions will die if they are called before a successful call to setup_gdg. Signed-off-by: Matthias Lederhofer <matled@gmx.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-06-06 15:10:42 +08:00
extern int is_inside_work_tree(void);
extern const char *get_git_dir(void);
$GIT_COMMON_DIR: a new environment variable This variable is intended to support multiple working directories attached to a repository. Such a repository may have a main working directory, created by either "git init" or "git clone" and one or more linked working directories. These working directories and the main repository share the same repository directory. In linked working directories, $GIT_COMMON_DIR must be defined to point to the real repository directory and $GIT_DIR points to an unused subdirectory inside $GIT_COMMON_DIR. File locations inside the repository are reorganized from the linked worktree view point: - worktree-specific such as HEAD, logs/HEAD, index, other top-level refs and unrecognized files are from $GIT_DIR. - the rest like objects, refs, info, hooks, packed-refs, shallow... are from $GIT_COMMON_DIR (except info/sparse-checkout, but that's a separate patch) Scripts are supposed to retrieve paths in $GIT_DIR with "git rev-parse --git-path", which will take care of "$GIT_DIR vs $GIT_COMMON_DIR" business. The redirection is done by git_path(), git_pathdup() and strbuf_git_path(). The selected list of paths goes to $GIT_COMMON_DIR, not the other way around in case a developer adds a new worktree-specific file and it's accidentally promoted to be shared across repositories (this includes unknown files added by third party commands) The list of known files that belong to $GIT_DIR are: ADD_EDIT.patch BISECT_ANCESTORS_OK BISECT_EXPECTED_REV BISECT_LOG BISECT_NAMES CHERRY_PICK_HEAD COMMIT_MSG FETCH_HEAD HEAD MERGE_HEAD MERGE_MODE MERGE_RR NOTES_EDITMSG NOTES_MERGE_WORKTREE ORIG_HEAD REVERT_HEAD SQUASH_MSG TAG_EDITMSG fast_import_crash_* logs/HEAD next-index-* rebase-apply rebase-merge rsync-refs-* sequencer/* shallow_* Path mapping is NOT done for git_path_submodule(). Multi-checkouts are not supported as submodules. Helped-by: Jens Lehmann <Jens.Lehmann@web.de> Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-11-30 16:24:36 +08:00
extern const char *get_git_common_dir(void);
extern char *get_object_directory(void);
extern char *get_index_file(void);
extern char *get_graft_file(void);
extern int set_git_dir(const char *path);
extern int get_common_dir_noenv(struct strbuf *sb, const char *gitdir);
extern int get_common_dir(struct strbuf *sb, const char *gitdir);
ref namespaces: infrastructure Add support for dividing the refs of a single repository into multiple namespaces, each of which can have its own branches, tags, and HEAD. Git can expose each namespace as an independent repository to pull from and push to, while sharing the object store, and exposing all the refs to operations such as git-gc. Storing multiple repositories as namespaces of a single repository avoids storing duplicate copies of the same objects, such as when storing multiple branches of the same source. The alternates mechanism provides similar support for avoiding duplicates, but alternates do not prevent duplication between new objects added to the repositories without ongoing maintenance, while namespaces do. To specify a namespace, set the GIT_NAMESPACE environment variable to the namespace. For each ref namespace, git stores the corresponding refs in a directory under refs/namespaces/. For example, GIT_NAMESPACE=foo will store refs under refs/namespaces/foo/. You can also specify namespaces via the --namespace option to git. Note that namespaces which include a / will expand to a hierarchy of namespaces; for example, GIT_NAMESPACE=foo/bar will store refs under refs/namespaces/foo/refs/namespaces/bar/. This makes paths in GIT_NAMESPACE behave hierarchically, so that cloning with GIT_NAMESPACE=foo/bar produces the same result as cloning with GIT_NAMESPACE=foo and cloning from that repo with GIT_NAMESPACE=bar. It also avoids ambiguity with strange namespace paths such as foo/refs/heads/, which could otherwise generate directory/file conflicts within the refs directory. Add the infrastructure for ref namespaces: handle the GIT_NAMESPACE environment variable and --namespace option, and support iterating over refs in a namespace. Signed-off-by: Josh Triplett <josh@joshtriplett.org> Signed-off-by: Jamey Sharp <jamey@minilop.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2011-07-06 01:54:44 +08:00
extern const char *get_git_namespace(void);
extern const char *strip_namespace(const char *namespaced_ref);
extern const char *get_super_prefix(void);
Clean up work-tree handling The old version of work-tree support was an unholy mess, barely readable, and not to the point. For example, why do you have to provide a worktree, when it is not used? As in "git status". Now it works. Another riddle was: if you can have work trees inside the git dir, why are some programs complaining that they need a work tree? IOW it is allowed to call $ git --git-dir=../ --work-tree=. bla when you really want to. In this case, you are both in the git directory and in the working tree. So, programs have to actually test for the right thing, namely if they are inside a working tree, and not if they are inside a git directory. Also, GIT_DIR=../.git should behave the same as if no GIT_DIR was specified, unless there is a repository in the current working directory. It does now. The logic to determine if a repository is bare, or has a work tree (tertium non datur), is this: --work-tree=bla overrides GIT_WORK_TREE, which overrides core.bare = true, which overrides core.worktree, which overrides GIT_DIR/.. when GIT_DIR ends in /.git, which overrides the directory in which .git/ was found. In related news, a long standing bug was fixed: when in .git/bla/x.git/, which is a bare repository, git formerly assumed ../.. to be the appropriate git dir. This problem was reported by Shawn Pearce to have caused much pain, where a colleague mistakenly ran "git init" in "/" a long time ago, and bare repositories just would not work. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-08-01 08:30:14 +08:00
extern const char *get_git_work_tree(void);
/*
* Return true if the given path is a git directory; note that this _just_
* looks at the directory itself. If you want to know whether "foo/.git"
* is a repository, you must feed that path, not just "foo".
*/
extern int is_git_directory(const char *path);
/*
* Return 1 if the given path is the root of a git repository or
* submodule, else 0. Will not return 1 for bare repositories with the
* exception of creating a bare repository in "foo/.git" and calling
* is_git_repository("foo").
*
* If we run into read errors, we err on the side of saying "yes, it is",
* as we usually consider sub-repos precious, and would prefer to err on the
* side of not disrupting or deleting them.
*/
extern int is_nonbare_repository_dir(struct strbuf *path);
#define READ_GITFILE_ERR_STAT_FAILED 1
#define READ_GITFILE_ERR_NOT_A_FILE 2
#define READ_GITFILE_ERR_OPEN_FAILED 3
#define READ_GITFILE_ERR_READ_FAILED 4
#define READ_GITFILE_ERR_INVALID_FORMAT 5
#define READ_GITFILE_ERR_NO_PATH 6
#define READ_GITFILE_ERR_NOT_A_REPO 7
#define READ_GITFILE_ERR_TOO_LARGE 8
extern void read_gitfile_error_die(int error_code, const char *path, const char *dir);
extern const char *read_gitfile_gently(const char *path, int *return_error_code);
#define read_gitfile(path) read_gitfile_gently((path), NULL)
extern const char *resolve_gitdir_gently(const char *suspect, int *return_error_code);
#define resolve_gitdir(path) resolve_gitdir_gently((path), NULL)
extern void set_git_work_tree(const char *tree);
#define ALTERNATE_DB_ENVIRONMENT "GIT_ALTERNATE_OBJECT_DIRECTORIES"
extern void setup_work_tree(void);
/*
* Find the commondir and gitdir of the repository that contains the current
* working directory, without changing the working directory or other global
* state. The result is appended to commondir and gitdir. If the discovered
* gitdir does not correspond to a worktree, then 'commondir' and 'gitdir' will
* both have the same result appended to the buffer. The return value is
* either 0 upon success and non-zero if no repository was found.
*/
extern int discover_git_directory(struct strbuf *commondir,
struct strbuf *gitdir);
extern const char *setup_git_directory_gently(int *);
extern const char *setup_git_directory(void);
extern char *prefix_path(const char *prefix, int len, const char *path);
extern char *prefix_path_gently(const char *prefix, int len, int *remaining, const char *path);
/*
* Concatenate "prefix" (if len is non-zero) and "path", with no
* connecting characters (so "prefix" should end with a "/").
* Unlike prefix_path, this should be used if the named file does
* not have to interact with index entry; i.e. name of a random file
* on the filesystem.
*
* The return value is always a newly allocated string (even if the
* prefix was empty).
*/
extern char *prefix_filename(const char *prefix, const char *path);
extern int check_filename(const char *prefix, const char *name);
extern void verify_filename(const char *prefix,
const char *name,
int diagnose_misspelt_rev);
extern void verify_non_filename(const char *prefix, const char *name);
extern int path_inside_repo(const char *prefix, const char *path);
#define INIT_DB_QUIET 0x0001
#define INIT_DB_EXIST_OK 0x0002
extern int init_db(const char *git_dir, const char *real_git_dir,
const char *template_dir, unsigned int flags);
extern void sanitize_stdfds(void);
extern int daemonize(void);
#define alloc_nr(x) (((x)+16)*3/2)
/*
* Realloc the buffer pointed at by variable 'x' so that it can hold
* at least 'nr' entries; the number of entries currently allocated
* is 'alloc', using the standard growing factor alloc_nr() macro.
*
* DO NOT USE any expression with side-effect for 'x', 'nr', or 'alloc'.
*/
#define ALLOC_GROW(x, nr, alloc) \
do { \
if ((nr) > alloc) { \
if (alloc_nr(alloc) < (nr)) \
alloc = (nr); \
else \
alloc = alloc_nr(alloc); \
REALLOC_ARRAY(x, alloc); \
} \
} while (0)
/* Initialize and use the cache information */
struct lock_file;
extern int read_index(struct index_state *);
extern int read_index_preload(struct index_state *, const struct pathspec *pathspec);
extern int do_read_index(struct index_state *istate, const char *path,
int must_exist); /* for testting only! */
extern int read_index_from(struct index_state *, const char *path);
extern int is_index_unborn(struct index_state *);
extern int read_index_unmerged(struct index_state *);
#define COMMIT_LOCK (1 << 0)
#define CLOSE_LOCK (1 << 1)
extern int write_locked_index(struct index_state *, struct lock_file *lock, unsigned flags);
extern int discard_index(struct index_state *);
extern void move_index_extensions(struct index_state *dst, struct index_state *src);
extern int unmerged_index(const struct index_state *);
extern int verify_path(const char *path);
extern int strcmp_offset(const char *s1, const char *s2, size_t *first_change);
extern int index_dir_exists(struct index_state *istate, const char *name, int namelen);
extern void adjust_dirname_case(struct index_state *istate, char *name);
extern struct cache_entry *index_file_exists(struct index_state *istate, const char *name, int namelen, int igncase);
/*
* Searches for an entry defined by name and namelen in the given index.
* If the return value is positive (including 0) it is the position of an
* exact match. If the return value is negative, the negated value minus 1
* is the position where the entry would be inserted.
* Example: The current index consists of these files and its stages:
*
* b#0, d#0, f#1, f#3
*
* index_name_pos(&index, "a", 1) -> -1
* index_name_pos(&index, "b", 1) -> 0
* index_name_pos(&index, "c", 1) -> -2
* index_name_pos(&index, "d", 1) -> 1
* index_name_pos(&index, "e", 1) -> -3
* index_name_pos(&index, "f", 1) -> -3
* index_name_pos(&index, "g", 1) -> -5
*/
extern int index_name_pos(const struct index_state *, const char *name, int namelen);
#define ADD_CACHE_OK_TO_ADD 1 /* Ok to add */
#define ADD_CACHE_OK_TO_REPLACE 2 /* Ok to replace file/directory */
#define ADD_CACHE_SKIP_DFCHECK 4 /* Ok to skip DF conflict checks */
#define ADD_CACHE_JUST_APPEND 8 /* Append only; tree.c::read_tree() */
#define ADD_CACHE_NEW_ONLY 16 /* Do not replace existing ones */
#define ADD_CACHE_KEEP_CACHE_TREE 32 /* Do not invalidate cache-tree */
extern int add_index_entry(struct index_state *, struct cache_entry *ce, int option);
extern void rename_index_entry_at(struct index_state *, int pos, const char *new_name);
/* Remove entry, return true if there are more entries to go. */
extern int remove_index_entry_at(struct index_state *, int pos);
check_updates(): effective removal of cache entries marked CE_REMOVE Below is oprofile output from GIT command 'git chekcout -q my-v2.6.25' (move from tag v2.6.27 to tag v2.6.25 of the Linux kernel): CPU: Core 2, speed 1999.95 MHz (estimated) Counted CPU_CLK_UNHALTED events (Clock cycles when not halted) with a unit mask of 0x00 (Unhalted core cycles) count 20000 Counted INST_RETIRED_ANY_P events (number of instructions retired) with a unit mask of 0x00 (No unit mask) count 20000 CPU_CLK_UNHALT...|INST_RETIRED:2...| samples| %| samples| %| ------------------------------------ 409247 100.000 342878 100.000 git CPU_CLK_UNHALT...|INST_RETIRED:2...| samples| %| samples| %| ------------------------------------ 260476 63.6476 257843 75.1996 libz.so.1.2.3 100876 24.6492 64378 18.7758 kernel-2.6.28.4_2.vmlinux 30850 7.5382 7874 2.2964 libc-2.9.so 14775 3.6103 8390 2.4469 git 2020 0.4936 4325 1.2614 libcrypto.so.0.9.8 191 0.0467 32 0.0093 libpthread-2.9.so 58 0.0142 36 0.0105 ld-2.9.so 1 2.4e-04 0 0 libldap-2.3.so.0.2.31 Detail list of the top 20 function entries (libz counted in one blob): CPU_CLK_UNHALTED INST_RETIRED_ANY_P samples % samples % image name symbol name 260476 63.6862 257843 75.2725 libz.so.1.2.3 /lib/libz.so.1.2.3 16587 4.0555 3636 1.0615 libc-2.9.so memcpy 7710 1.8851 277 0.0809 libc-2.9.so memmove 3679 0.8995 1108 0.3235 kernel-2.6.28.4_2.vmlinux d_validate 3546 0.8670 2607 0.7611 kernel-2.6.28.4_2.vmlinux __getblk 3174 0.7760 1813 0.5293 libc-2.9.so _int_malloc 2396 0.5858 3681 1.0746 kernel-2.6.28.4_2.vmlinux copy_to_user 2270 0.5550 2528 0.7380 kernel-2.6.28.4_2.vmlinux __link_path_walk 2205 0.5391 1797 0.5246 kernel-2.6.28.4_2.vmlinux ext4_mark_iloc_dirty 2103 0.5142 1203 0.3512 kernel-2.6.28.4_2.vmlinux find_first_zero_bit 2077 0.5078 997 0.2911 kernel-2.6.28.4_2.vmlinux do_get_write_access 2070 0.5061 514 0.1501 git cache_name_compare 2043 0.4995 1501 0.4382 kernel-2.6.28.4_2.vmlinux rcu_irq_exit 2022 0.4944 1732 0.5056 kernel-2.6.28.4_2.vmlinux __ext4_get_inode_loc 2020 0.4939 4325 1.2626 libcrypto.so.0.9.8 /usr/lib/libcrypto.so.0.9.8 1965 0.4804 1384 0.4040 git patch_delta 1708 0.4176 984 0.2873 kernel-2.6.28.4_2.vmlinux rcu_sched_grace_period 1682 0.4112 727 0.2122 kernel-2.6.28.4_2.vmlinux sysfs_slab_alias 1659 0.4056 290 0.0847 git find_pack_entry_one 1480 0.3619 1307 0.3816 kernel-2.6.28.4_2.vmlinux ext4_writepage_trans_blocks Notice the memmove line, where the CPU did 7710 / 277 = 27.8 cycles per instruction, and compared to the total cycles spent inside the source code of GIT for this command, all the memmove() calls translates to (7710 * 100) / 14775 = 52.2% of this. Retesting with a GIT program compiled for gcov usage, I found out that the memmove() calls came from remove_index_entry_at() in read-cache.c, where we have: memmove(istate->cache + pos, istate->cache + pos + 1, (istate->cache_nr - pos) * sizeof(struct cache_entry *)); remove_index_entry_at() is called 4902 times from check_updates() in unpack-trees.c, and each time called we move each cache_entry pointers (from the removed one) one step to the left. Since we have 28828 entries in the cache this time, and if we on average move half of them each time, we in total move approximately 4902 * 0.5 * 28828 * 4 = 282 629 712 bytes, or twice this amount if each pointer is 8 bytes (64 bit). OK, is seems that the function check_updates() is called 28 times, so the estimated guess above had been more correct if check_updates() had been called only once, but the point is: we get lots of bytes moved. To fix this, and use an O(N) algorithm instead, where N is the number of cache_entries, we delete/remove all entries in one loop through all entries. From a retest, the new remove_marked_cache_entries() from the patch below, ended up with the following output line from oprofile: 46 0.0105 15 0.0041 git remove_marked_cache_entries If we can trust the numbers from oprofile in this case, we saved approximately ((7710 - 46) * 20000) / (2 * 1000 * 1000 * 1000) = 0.077 seconds CPU time with this fix for this particular test. And notice that now the CPU did only 46 / 15 = 3.1 cycles/instruction. Signed-off-by: Kjetil Barvik <barvik@broadpark.no> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-02-19 06:18:03 +08:00
extern void remove_marked_cache_entries(struct index_state *istate);
extern int remove_file_from_index(struct index_state *, const char *path);
#define ADD_CACHE_VERBOSE 1
#define ADD_CACHE_PRETEND 2
#define ADD_CACHE_IGNORE_ERRORS 4
#define ADD_CACHE_IGNORE_REMOVAL 8
#define ADD_CACHE_INTENT 16
/*
* These two are used to add the contents of the file at path
* to the index, marking the working tree up-to-date by storing
* the cached stat info in the resulting cache entry. A caller
* that has already run lstat(2) on the path can call
* add_to_index(), and all others can call add_file_to_index();
* the latter will do necessary lstat(2) internally before
* calling the former.
*/
extern int add_to_index(struct index_state *, const char *path, struct stat *, int flags);
extern int add_file_to_index(struct index_state *, const char *path, int flags);
extern struct cache_entry *make_cache_entry(unsigned int mode, const unsigned char *sha1, const char *path, int stage, unsigned int refresh_options);
extern int chmod_index_entry(struct index_state *, struct cache_entry *ce, char flip);
Convert "struct cache_entry *" to "const ..." wherever possible I attempted to make index_state->cache[] a "const struct cache_entry **" to find out how existing entries in index are modified and where. The question I have is what do we do if we really need to keep track of on-disk changes in the index. The result is - diff-lib.c: setting CE_UPTODATE - name-hash.c: setting CE_HASHED - preload-index.c, read-cache.c, unpack-trees.c and builtin/update-index: obvious - entry.c: write_entry() may refresh the checked out entry via fill_stat_cache_info(). This causes "non-const struct cache_entry *" in builtin/apply.c, builtin/checkout-index.c and builtin/checkout.c - builtin/ls-files.c: --with-tree changes stagemask and may set CE_UPDATE Of these, write_entry() and its call sites are probably most interesting because it modifies on-disk info. But this is stat info and can be retrieved via refresh, at least for porcelain commands. Other just uses ce_flags for local purposes. So, keeping track of "dirty" entries is just a matter of setting a flag in index modification functions exposed by read-cache.c. Except unpack-trees, the rest of the code base does not do anything funny behind read-cache's back. The actual patch is less valueable than the summary above. But if anyone wants to re-identify the above sites. Applying this patch, then this: diff --git a/cache.h b/cache.h index 430d021..1692891 100644 --- a/cache.h +++ b/cache.h @@ -267,7 +267,7 @@ static inline unsigned int canon_mode(unsigned int mode) #define cache_entry_size(len) (offsetof(struct cache_entry,name) + (len) + 1) struct index_state { - struct cache_entry **cache; + const struct cache_entry **cache; unsigned int version; unsigned int cache_nr, cache_alloc, cache_changed; struct string_list *resolve_undo; will help quickly identify them without bogus warnings. Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-07-09 23:29:00 +08:00
extern int ce_same_name(const struct cache_entry *a, const struct cache_entry *b);
extern void set_object_name_for_intent_to_add_entry(struct cache_entry *ce);
extern int index_name_is_other(const struct index_state *, const char *, int);
extern void *read_blob_data_from_index(const struct index_state *, const char *, unsigned long *);
/* do stat comparison even if CE_VALID is true */
#define CE_MATCH_IGNORE_VALID 01
/* do not check the contents but report dirty on racily-clean entries */
#define CE_MATCH_RACY_IS_DIRTY 02
/* do stat comparison even if CE_SKIP_WORKTREE is true */
#define CE_MATCH_IGNORE_SKIP_WORKTREE 04
/* ignore non-existent files during stat update */
#define CE_MATCH_IGNORE_MISSING 0x08
/* enable stat refresh */
#define CE_MATCH_REFRESH 0x10
extern int ie_match_stat(const struct index_state *, const struct cache_entry *, struct stat *, unsigned int);
extern int ie_modified(const struct index_state *, const struct cache_entry *, struct stat *, unsigned int);
#define HASH_WRITE_OBJECT 1
#define HASH_FORMAT_CHECK 2
extern int index_fd(unsigned char *sha1, int fd, struct stat *st, enum object_type type, const char *path, unsigned flags);
extern int index_path(unsigned char *sha1, const char *path, struct stat *st, unsigned flags);
/*
* Record to sd the data from st that we use to check whether a file
* might have changed.
*/
extern void fill_stat_data(struct stat_data *sd, struct stat *st);
/*
* Return 0 if st is consistent with a file not having been changed
* since sd was filled. If there are differences, return a
* combination of MTIME_CHANGED, CTIME_CHANGED, OWNER_CHANGED,
* INODE_CHANGED, and DATA_CHANGED.
*/
extern int match_stat_data(const struct stat_data *sd, struct stat *st);
extern int match_stat_data_racy(const struct index_state *istate,
const struct stat_data *sd, struct stat *st);
extern void fill_stat_cache_info(struct cache_entry *ce, struct stat *st);
#define REFRESH_REALLY 0x0001 /* ignore_valid */
#define REFRESH_UNMERGED 0x0002 /* allow unmerged */
#define REFRESH_QUIET 0x0004 /* be quiet about it */
#define REFRESH_IGNORE_MISSING 0x0008 /* ignore non-existent */
#define REFRESH_IGNORE_SUBMODULES 0x0010 /* ignore submodules */
#define REFRESH_IN_PORCELAIN 0x0020 /* user friendly output, not "needs update" */
extern int refresh_index(struct index_state *, unsigned int flags, const struct pathspec *pathspec, char *seen, const char *header_msg);
merge: avoid "safer crlf" during recording of merge results When merge_recursive() decides what the correct blob object merge result for a path should be, it uses update_file_flags() helper function to write it out to a working tree file and then calls add_cacheinfo(). The add_cacheinfo() function in turn calls make_cache_entry() to create a new cache entry to replace the higher-stage entries for the path that represents the conflict. The make_cache_entry() function calls refresh_cache_entry() to fill in the cached stat information. To mark a cache entry as up-to-date, the data is re-read from the file in the working tree, and goes through convert_to_git() conversion to be compared with the blob object name the new cache entry records. It is important to note that this happens while the higher-stage entries, which are going to be replaced with the new entry, are still in the index. Unfortunately, the convert_to_git() conversion has a misguided "safer crlf" mechanism baked in, and looks at the existing cache entry for the path to decide how to convert the contents in the working tree file. If our side (i.e. stage#2) records a text blob with CRLF in it, even when the system is configured to record LF in blobs and convert them to CRLF upon checkout (and back to LF upon checkin), the "safer crlf" mechanism stops us doing so. This especially poses a problem during a renormalizing merge, where the merge result for the path is computed by first "normalizing" the blobs involved in the merge by using convert_to_working_tree() followed by convert_to_git() with "safer crlf" disabled. The merge result that is computed correctly and fed to add_cacheinfo() via update_file_flags() does _not_ match what refresh_cache_entry() sees by converting the working tree file via convert_to_git(). We can work this around by not refreshing the new cache entry in make_cache_entry() called by add_cacheinfo(). After add_cacheinfo() adds the new entry, we can call refresh_cache_entry() on that, knowing that addition of this new cache entry would have removed the stale cache entries that had CRLF in stage #2 that were carried over before the renormalizing merge started and will not interfere with the correct recording of the result. The test update was taken from a series by Torsten Bögershausen that attempted to fix this with a different approach. Signed-off-by: Torsten Bögershausen <tboegi@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com> Reviewed-by: Torsten Bögershausen <tboegi@web.de>
2016-07-09 01:59:15 +08:00
extern struct cache_entry *refresh_cache_entry(struct cache_entry *, unsigned int);
extern void update_index_if_able(struct index_state *, struct lock_file *);
extern int hold_locked_index(struct lock_file *, int);
extern void set_alternate_index_output(const char *);
extern int verify_index_checksum;
/* Environment bits from configuration mechanism */
extern int trust_executable_bit;
extern int trust_ctime;
extern int check_stat;
extern int quote_path_fully;
extern int has_symlinks;
extern int minimum_abbrev, default_abbrev;
extern int ignore_case;
"Assume unchanged" git This adds "assume unchanged" logic, started by this message in the list discussion recently: <Pine.LNX.4.64.0601311807470.7301@g5.osdl.org> This is a workaround for filesystems that do not have lstat() that is quick enough for the index mechanism to take advantage of. On the paths marked as "assumed to be unchanged", the user needs to explicitly use update-index to register the object name to be in the next commit. You can use two new options to update-index to set and reset the CE_VALID bit: git-update-index --assume-unchanged path... git-update-index --no-assume-unchanged path... These forms manipulate only the CE_VALID bit; it does not change the object name recorded in the index file. Nor they add a new entry to the index. When the configuration variable "core.ignorestat = true" is set, the index entries are marked with CE_VALID bit automatically after: - update-index to explicitly register the current object name to the index file. - when update-index --refresh finds the path to be up-to-date. - when tools like read-tree -u and apply --index update the working tree file and register the current object name to the index file. The flag is dropped upon read-tree that does not check out the index entry. This happens regardless of the core.ignorestat settings. Index entries marked with CE_VALID bit are assumed to be unchanged most of the time. However, there are cases that CE_VALID bit is ignored for the sake of safety and usability: - while "git-read-tree -m" or git-apply need to make sure that the paths involved in the merge do not have local modifications. This sacrifices performance for safety. - when git-checkout-index -f -q -u -a tries to see if it needs to checkout the paths. Otherwise you can never check anything out ;-). - when git-update-index --really-refresh (a new flag) tries to see if the index entry is up to date. You can start with everything marked as CE_VALID and run this once to drop CE_VALID bit for paths that are modified. Most notably, "update-index --refresh" honours CE_VALID and does not actively stat, so after you modified a file in the working tree, update-index --refresh would not notice until you tell the index about it with "git-update-index path" or "git-update-index --no-assume-unchanged path". This version is not expected to be perfect. I think diff between index and/or tree and working files may need some adjustment, and there probably needs other cases we should automatically unmark paths that are marked to be CE_VALID. But the basics seem to work, and ready to be tested by people who asked for this feature. Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-02-09 13:15:24 +08:00
extern int assume_unchanged;
extern int prefer_symlink_refs;
extern int warn_ambiguous_refs;
cat-file: disable object/refname ambiguity check for batch mode A common use of "cat-file --batch-check" is to feed a list of objects from "rev-list --objects" or a similar command. In this instance, all of our input objects are 40-byte sha1 ids. However, cat-file has always allowed arbitrary revision specifiers, and feeds the result to get_sha1(). Fortunately, get_sha1() recognizes a 40-byte sha1 before doing any hard work trying to look up refs, meaning this scenario should end up spending very little time converting the input into an object sha1. However, since 798c35f (get_sha1: warn about full or short object names that look like refs, 2013-05-29), when we encounter this case, we spend the extra effort to do a refname lookup anyway, just to print a warning. This is further exacerbated by ca91993 (get_packed_ref_cache: reload packed-refs file when it changes, 2013-06-20), which makes individual ref lookup more expensive by requiring a stat() of the packed-refs file for each missing ref. With no patches, this is the time it takes to run: $ git rev-list --objects --all >objects $ time git cat-file --batch-check='%(objectname)' <objects on the linux.git repository: real 1m13.494s user 0m25.924s sys 0m47.532s If we revert ca91993, the packed-refs up-to-date check, it gets a little better: real 0m54.697s user 0m21.692s sys 0m32.916s but we are still spending quite a bit of time on ref lookup (and we would not want to revert that patch, anyway, which has correctness issues). If we revert 798c35f, disabling the warning entirely, we get a much more reasonable time: real 0m7.452s user 0m6.836s sys 0m0.608s This patch does the moral equivalent of this final case (and gets similar speedups). We introduce a global flag that callers of get_sha1() can use to avoid paying the price for the warning. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-07-12 14:20:05 +08:00
extern int warn_on_object_refname_ambiguity;
extern const char *apply_default_whitespace;
extern const char *apply_default_ignorewhitespace;
extern const char *git_attributes_file;
extern const char *git_hooks_path;
extern int zlib_compression_level;
Custom compression levels for objects and packs Add config variables pack.compression and core.loosecompression , and switch --compression=level to pack-objects. Loose objects will be compressed using core.loosecompression if set, else core.compression if set, else Z_BEST_SPEED. Packed objects will be compressed using --compression=level if seen, else pack.compression if set, else core.compression if set, else Z_DEFAULT_COMPRESSION. This is the "pack compression level". Loose objects added to a pack undeltified will be recompressed to the pack compression level if it is unequal to the current loose compression level by the preceding rules, or if the loose object was written while core.legacyheaders = true. Newly deltified loose objects are always compressed to the current pack compression level. Previously packed objects added to a pack are recompressed to the current pack compression level exactly when their deltification status changes, since the previous pack data cannot be reused. In either case, the --no-reuse-object switch from the first patch below will always force recompression to the current pack compression level, instead of assuming the pack compression level hasn't changed and pack data can be reused when possible. This applies on top of the following patches from Nicolas Pitre: [PATCH] allow for undeltified objects not to be reused [PATCH] make "repack -f" imply "pack-objects --no-reuse-object" Signed-off-by: Dana L. How <danahow@gmail.com> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-05-10 04:56:50 +08:00
extern int core_compression_level;
extern int pack_compression_level;
Fully activate the sliding window pack access. This finally turns on the sliding window behavior for packfile data access by mapping limited size windows and chaining them under the packed_git->windows list. We consider a given byte offset to be within the window only if there would be at least 20 bytes (one hash worth of data) accessible after the requested offset. This range selection relates to the contract that use_pack() makes with its callers, allowing them to access one hash or one object header without needing to call use_pack() for every byte of data obtained. In the worst case scenario we will map the same page of data twice into memory: once at the end of one window and once again at the start of the next window. This duplicate page mapping will happen only when an object header or a delta base reference is spanned over the end of a window and is always limited to just one page of duplication, as no sane operating system will ever have a page size smaller than a hash. I am assuming that the possible wasted page of virtual address space is going to perform faster than the alternatives, which would be to copy the object header or ref delta into a temporary buffer prior to parsing, or to check the window range on every byte during header parsing. We may decide to revisit this decision in the future since this is just a gut instinct decision and has not actually been proven out by experimental testing. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-12-23 15:34:28 +08:00
extern size_t packed_git_window_size;
extern size_t packed_git_limit;
extern size_t delta_base_cache_limit;
extern unsigned long big_file_threshold;
extern unsigned long pack_size_limit_cfg;
/*
* Accessors for the core.sharedrepository config which lazy-load the value
* from the config (if not already set). The "reset" function can be
* used to unset "set" or cached value, meaning that the value will be loaded
* fresh from the config file on the next call to get_shared_repository().
*/
void set_shared_repository(int value);
int get_shared_repository(void);
void reset_shared_repository(void);
/*
* Do replace refs need to be checked this run? This variable is
* initialized to true unless --no-replace-object is used or
* $GIT_NO_REPLACE_OBJECTS is set, but is set to false by some
* commands that do not want replace references to be active. As an
* optimization it is also set to false if replace references have
* been sought but there were none.
*/
extern int check_replace_refs;
extern char *git_replace_ref_base;
extern int fsync_object_files;
extern int core_preload_index;
extern int core_apply_sparse_checkout;
git on Mac OS and precomposed unicode Mac OS X mangles file names containing unicode on file systems HFS+, VFAT or SAMBA. When a file using unicode code points outside ASCII is created on a HFS+ drive, the file name is converted into decomposed unicode and written to disk. No conversion is done if the file name is already decomposed unicode. Calling open("\xc3\x84", ...) with a precomposed "Ä" yields the same result as open("\x41\xcc\x88",...) with a decomposed "Ä". As a consequence, readdir() returns the file names in decomposed unicode, even if the user expects precomposed unicode. Unlike on HFS+, Mac OS X stores files on a VFAT drive (e.g. an USB drive) in precomposed unicode, but readdir() still returns file names in decomposed unicode. When a git repository is stored on a network share using SAMBA, file names are send over the wire and written to disk on the remote system in precomposed unicode, but Mac OS X readdir() returns decomposed unicode to be compatible with its behaviour on HFS+ and VFAT. The unicode decomposition causes many problems: - The names "git add" and other commands get from the end user may often be precomposed form (the decomposed form is not easily input from the keyboard), but when the commands read from the filesystem to see what it is going to update the index with already is on the filesystem, readdir() will give decomposed form, which is different. - Similarly "git log", "git mv" and all other commands that need to compare pathnames found on the command line (often but not always precomposed form; a command line input resulting from globbing may be in decomposed) with pathnames found in the tree objects (should be precomposed form to be compatible with other systems and for consistency in general). - The same for names stored in the index, which should be precomposed, that may need to be compared with the names read from readdir(). NFS mounted from Linux is fully transparent and does not suffer from the above. As Mac OS X treats precomposed and decomposed file names as equal, we can - wrap readdir() on Mac OS X to return the precomposed form, and - normalize decomposed form given from the command line also to the precomposed form, to ensure that all pathnames used in Git are always in the precomposed form. This behaviour can be requested by setting "core.precomposedunicode" configuration variable to true. The code in compat/precomposed_utf8.c implements basically 4 new functions: precomposed_utf8_opendir(), precomposed_utf8_readdir(), precomposed_utf8_closedir() and precompose_argv(). The first three are to wrap opendir(3), readdir(3), and closedir(3) functions. The argv[] conversion allows to use the TAB filename completion done by the shell on command line. It tolerates other tools which use readdir() to feed decomposed file names into git. When creating a new git repository with "git init" or "git clone", "core.precomposedunicode" will be set "false". The user needs to activate this feature manually. She typically sets core.precomposedunicode to "true" on HFS and VFAT, or file systems mounted via SAMBA. Helped-by: Junio C Hamano <gitster@pobox.com> Signed-off-by: Torsten Bögershausen <tboegi@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-07-08 21:50:25 +08:00
extern int precomposed_unicode;
extern int protect_hfs;
extern int protect_ntfs;
/*
* Include broken refs in all ref iterations, which will
* generally choke dangerous operations rather than letting
* them silently proceed without taking the broken ref into
* account.
*/
extern int ref_paranoia;
/*
* The character that begins a commented line in user-editable file
* that is subject to stripspace.
*/
extern char comment_line_char;
extern int auto_comment_line_char;
mingw: introduce the 'core.hideDotFiles' setting On Unix (and Linux), files and directories whose names start with a dot are usually not shown by default. This convention is used by Git: the .git/ directory should be left alone by regular users, and only accessed through Git itself. On Windows, no such convention exists. Instead, there is an explicit flag to mark files or directories as hidden. In the early days, Git for Windows did not mark the .git/ directory (or for that matter, any file or directory whose name starts with a dot) hidden. This lead to quite a bit of confusion, and even loss of data. Consequently, Git for Windows introduced the core.hideDotFiles setting, with three possible values: true, false, and dotGitOnly, defaulting to marking only the .git/ directory as hidden. The rationale: users do not need to access .git/ directly, and indeed (as was demonstrated) should not really see that directory, either. However, not all dot files should be hidden by default, as e.g. Eclipse does not show them (and the user would therefore be unable to see, say, a .gitattributes file). In over five years since the last attempt to bring this patch into core Git, a slightly buggy version of this patch has served Git for Windows' users well: no single report indicated problems with the hidden .git/ directory, and the stream of problems caused by the previously non-hidden .git/ directory simply stopped. The bugs have been fixed during the process of getting this patch upstream. Note that there is a funny quirk we have to pay attention to when creating hidden files: we use Win32's _wopen() function which transmogrifies its arguments and hands off to Win32's CreateFile() function. That latter function errors out with ERROR_ACCESS_DENIED (the equivalent of EACCES) when the equivalent of the O_CREAT flag was passed and the file attributes (including the hidden flag) do not match an existing file's. And _wopen() accepts no parameter that would be transmogrified into said hidden flag. Therefore, we simply try again without O_CREAT. A slightly different method is required for our fopen()/freopen() function as we cannot even *remove* the implicit O_CREAT flag. Therefore, we briefly mark existing files as unhidden when opening them via fopen()/freopen(). The ERROR_ACCESS_DENIED error can also be triggered by opening a file that is marked as a system file (which is unlikely to be tracked in Git), and by trying to create a file that has *just* been deleted and is awaiting the last open handles to be released (which would be handled better by the "Try again?" logic, a story for a different patch series, though). In both cases, it does not matter much if we try again without the O_CREAT flag, read: it does not hurt, either. For details how ERROR_ACCESS_DENIED can be triggered, see https://msdn.microsoft.com/en-us/library/windows/desktop/aa363858 Original-patch-by: Erik Faye-Lund <kusmabite@gmail.com> Initial-Test-By: Pat Thoyts <patthoyts@users.sourceforge.net> Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-05-11 16:43:37 +08:00
/* Windows only */
enum hide_dotfiles_type {
HIDE_DOTFILES_FALSE = 0,
HIDE_DOTFILES_TRUE,
HIDE_DOTFILES_DOTGITONLY
};
extern enum hide_dotfiles_type hide_dotfiles;
enum log_refs_config {
LOG_REFS_UNSET = -1,
LOG_REFS_NONE = 0,
LOG_REFS_NORMAL,
LOG_REFS_ALWAYS
};
extern enum log_refs_config log_all_ref_updates;
enum branch_track {
BRANCH_TRACK_UNSPECIFIED = -1,
BRANCH_TRACK_NEVER = 0,
BRANCH_TRACK_REMOTE,
BRANCH_TRACK_ALWAYS,
BRANCH_TRACK_EXPLICIT,
BRANCH_TRACK_OVERRIDE
};
enum rebase_setup_type {
AUTOREBASE_NEVER = 0,
AUTOREBASE_LOCAL,
AUTOREBASE_REMOTE,
AUTOREBASE_ALWAYS
};
enum push_default_type {
PUSH_DEFAULT_NOTHING = 0,
PUSH_DEFAULT_MATCHING,
PUSH_DEFAULT_SIMPLE,
PUSH_DEFAULT_UPSTREAM,
push: Provide situational hints for non-fast-forward errors Pushing a non-fast-forward update to a remote repository will result in an error, but the hint text doesn't provide the correct resolution in every case. Give better resolution advice in three push scenarios: 1) If you push your current branch and it triggers a non-fast-forward error, you should merge remote changes with 'git pull' before pushing again. 2) If you push to a shared repository others push to, and your local tracking branches are not kept up to date, the 'matching refs' default will generate non-fast-forward errors on outdated branches. If this is your workflow, the 'matching refs' default is not for you. Consider setting the 'push.default' configuration variable to 'current' or 'upstream' to ensure only your current branch is pushed. 3) If you explicitly specify a ref that is not your current branch or push matching branches with ':', you will generate a non-fast-forward error if any pushed branch tip is out of date. You should checkout the offending branch and merge remote changes before pushing again. Teach transport.c to recognize these scenarios and configure push.c to hint for them. If 'git push's default behavior changes or we discover more scenarios, extension is easy. Standardize on the advice API and add three new advice variables, 'pushNonFFCurrent', 'pushNonFFDefault', and 'pushNonFFMatching'. Setting any of these to 'false' will disable their affiliated advice. Setting 'pushNonFastForward' to false will disable all three, thus preserving the config option for users who already set it, but guaranteeing new users won't disable push advice accidentally. Based-on-patch-by: Junio C Hamano <gitster@pobox.com> Signed-off-by: Christopher Tiwald <christiwald@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-03-20 12:31:33 +08:00
PUSH_DEFAULT_CURRENT,
PUSH_DEFAULT_UNSPECIFIED
};
extern enum branch_track git_branch_track;
extern enum rebase_setup_type autorebase;
extern enum push_default_type push_default;
enum object_creation_mode {
OBJECT_CREATION_USES_HARDLINKS = 0,
OBJECT_CREATION_USES_RENAMES = 1
};
extern enum object_creation_mode object_creation_mode;
extern char *notes_ref_name;
extern int grafts_replace_parents;
introduce "extensions" form of core.repositoryformatversion Normally we try to avoid bumps of the whole-repository core.repositoryformatversion field. However, it is unavoidable if we want to safely change certain aspects of git in a backwards-incompatible way (e.g., modifying the set of ref tips that we must traverse to generate a list of unreachable, safe-to-prune objects). If we were to bump the repository version for every such change, then any implementation understanding version `X` would also have to understand `X-1`, `X-2`, and so forth, even though the incompatibilities may be in orthogonal parts of the system, and there is otherwise no reason we cannot implement one without the other (or more importantly, that the user cannot choose to use one feature without the other, weighing the tradeoff in compatibility only for that particular feature). This patch documents the existing repositoryformatversion strategy and introduces a new format, "1", which lets a repository specify that it must run with an arbitrary set of extensions. This can be used, for example: - to inform git that the objects should not be pruned based only on the reachability of the ref tips (e.g, because it has "clone --shared" children) - that the refs are stored in a format besides the usual "refs" and "packed-refs" directories Because we bump to format "1", and because format "1" requires that a running git knows about any extensions mentioned, we know that older versions of the code will not do something dangerous when confronted with these new formats. For example, if the user chooses to use database storage for refs, they may set the "extensions.refbackend" config to "db". Older versions of git will not understand format "1" and bail. Versions of git which understand "1" but do not know about "refbackend", or which know about "refbackend" but not about the "db" backend, will refuse to run. This is annoying, of course, but much better than the alternative of claiming that there are no refs in the repository, or writing to a location that other implementations will not read. Note that we are only defining the rules for format 1 here. We do not ever write format 1 ourselves; it is a tool that is meant to be used by users and future extensions to provide safety with older implementations. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-06-23 18:53:58 +08:00
/*
* GIT_REPO_VERSION is the version we write by default. The
* _READ variant is the highest number we know how to
* handle.
*/
#define GIT_REPO_VERSION 0
introduce "extensions" form of core.repositoryformatversion Normally we try to avoid bumps of the whole-repository core.repositoryformatversion field. However, it is unavoidable if we want to safely change certain aspects of git in a backwards-incompatible way (e.g., modifying the set of ref tips that we must traverse to generate a list of unreachable, safe-to-prune objects). If we were to bump the repository version for every such change, then any implementation understanding version `X` would also have to understand `X-1`, `X-2`, and so forth, even though the incompatibilities may be in orthogonal parts of the system, and there is otherwise no reason we cannot implement one without the other (or more importantly, that the user cannot choose to use one feature without the other, weighing the tradeoff in compatibility only for that particular feature). This patch documents the existing repositoryformatversion strategy and introduces a new format, "1", which lets a repository specify that it must run with an arbitrary set of extensions. This can be used, for example: - to inform git that the objects should not be pruned based only on the reachability of the ref tips (e.g, because it has "clone --shared" children) - that the refs are stored in a format besides the usual "refs" and "packed-refs" directories Because we bump to format "1", and because format "1" requires that a running git knows about any extensions mentioned, we know that older versions of the code will not do something dangerous when confronted with these new formats. For example, if the user chooses to use database storage for refs, they may set the "extensions.refbackend" config to "db". Older versions of git will not understand format "1" and bail. Versions of git which understand "1" but do not know about "refbackend", or which know about "refbackend" but not about the "db" backend, will refuse to run. This is annoying, of course, but much better than the alternative of claiming that there are no refs in the repository, or writing to a location that other implementations will not read. Note that we are only defining the rules for format 1 here. We do not ever write format 1 ourselves; it is a tool that is meant to be used by users and future extensions to provide safety with older implementations. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-06-23 18:53:58 +08:00
#define GIT_REPO_VERSION_READ 1
extern int repository_format_precious_objects;
setup: refactor repo format reading and verification When we want to know if we're in a git repository of reasonable vintage, we can call check_repository_format_gently(), which does three things: 1. Reads the config from the .git/config file. 2. Verifies that the version info we read is sane. 3. Writes some global variables based on this. There are a few things we could improve here. One is that steps 1 and 3 happen together. So if the verification in step 2 fails, we still clobber the global variables. This is especially bad if we go on to try another repository directory; we may end up with a state of mixed config variables. The second is there's no way to ask about the repository version for anything besides the main repository we're in. git-init wants to do this, and it's possible that we would want to start doing so for submodules (e.g., to find out which ref backend they're using). We can improve both by splitting the first two steps into separate functions. Now check_repository_format_gently() calls out to steps 1 and 2, and does 3 only if step 2 succeeds. Note that the public interface for read_repository_format() and what check_repository_format_gently() needs from it are not quite the same, leading us to have an extra read_repository_format_1() helper. The extra needs from check_repository_format_gently() will go away in a future patch, and we can simplify this then to just the public interface. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-03-12 06:37:07 +08:00
struct repository_format {
int version;
int precious_objects;
int is_bare;
char *work_tree;
struct string_list unknown_extensions;
};
/*
* Read the repository format characteristics from the config file "path" into
* "format" struct. Returns the numeric version. On error, -1 is returned,
* format->version is set to -1, and all other fields in the struct are
* undefined.
*/
int read_repository_format(struct repository_format *format, const char *path);
/*
* Verify that the repository described by repository_format is something we
* can read. If it is, return 0. Otherwise, return -1, and "err" will describe
* any errors encountered.
*/
int verify_repository_format(const struct repository_format *format,
struct strbuf *err);
/*
* Check the repository format version in the path found in get_git_dir(),
* and die if it is a version we don't understand. Generally one would
* set_git_dir() before calling this, and use it only for "are we in a valid
* repo?".
*/
extern void check_repository_format(void);
#define MTIME_CHANGED 0x0001
#define CTIME_CHANGED 0x0002
#define OWNER_CHANGED 0x0004
#define MODE_CHANGED 0x0008
#define INODE_CHANGED 0x0010
#define DATA_CHANGED 0x0020
#define TYPE_CHANGED 0x0040
/*
* Return the name of the file in the local object database that would
* be used to store a loose object with the specified sha1. The
* return value is a pointer to a statically allocated buffer that is
* overwritten each time the function is called.
*/
extern const char *sha1_file_name(const unsigned char *sha1);
/*
* Return the name of the (local) packfile with the specified sha1 in
* its name. The return value is a pointer to memory that is
* overwritten each time this function is called.
*/
extern char *sha1_pack_name(const unsigned char *sha1);
/*
* Return the name of the (local) pack index file with the specified
* sha1 in its name. The return value is a pointer to memory that is
* overwritten each time this function is called.
*/
extern char *sha1_pack_index_name(const unsigned char *sha1);
/*
* Return an abbreviated sha1 unique within this repository's object database.
* The result will be at least `len` characters long, and will be NUL
* terminated.
*
* The non-`_r` version returns a static buffer which remains valid until 4
* more calls to find_unique_abbrev are made.
*
* The `_r` variant writes to a buffer supplied by the caller, which must be at
* least `GIT_SHA1_HEXSZ + 1` bytes. The return value is the number of bytes
* written (excluding the NUL terminator).
*
* Note that while this version avoids the static buffer, it is not fully
* reentrant, as it calls into other non-reentrant git code.
*/
extern const char *find_unique_abbrev(const unsigned char *sha1, int len);
extern int find_unique_abbrev_r(char *hex, const unsigned char *sha1, int len);
extern const unsigned char null_sha1[GIT_MAX_RAWSZ];
extern const struct object_id null_oid;
static inline int hashcmp(const unsigned char *sha1, const unsigned char *sha2)
{
int i;
for (i = 0; i < GIT_SHA1_RAWSZ; i++, sha1++, sha2++) {
if (*sha1 != *sha2)
return *sha1 - *sha2;
}
return 0;
}
static inline int oidcmp(const struct object_id *oid1, const struct object_id *oid2)
{
return hashcmp(oid1->hash, oid2->hash);
}
static inline int is_null_sha1(const unsigned char *sha1)
{
return !hashcmp(sha1, null_sha1);
}
static inline int is_null_oid(const struct object_id *oid)
{
return !hashcmp(oid->hash, null_sha1);
}
static inline void hashcpy(unsigned char *sha_dst, const unsigned char *sha_src)
{
memcpy(sha_dst, sha_src, GIT_SHA1_RAWSZ);
}
static inline void oidcpy(struct object_id *dst, const struct object_id *src)
{
hashcpy(dst->hash, src->hash);
}
static inline struct object_id *oiddup(const struct object_id *src)
{
struct object_id *dst = xmalloc(sizeof(struct object_id));
oidcpy(dst, src);
return dst;
}
static inline void hashclr(unsigned char *hash)
{
memset(hash, 0, GIT_SHA1_RAWSZ);
}
static inline void oidclr(struct object_id *oid)
{
hashclr(oid->hash);
}
#define EMPTY_TREE_SHA1_HEX \
"4b825dc642cb6eb9a060e54bf8d69288fbee4904"
#define EMPTY_TREE_SHA1_BIN_LITERAL \
"\x4b\x82\x5d\xc6\x42\xcb\x6e\xb9\xa0\x60" \
"\xe5\x4b\xf8\xd6\x92\x88\xfb\xee\x49\x04"
extern const struct object_id empty_tree_oid;
#define EMPTY_TREE_SHA1_BIN (empty_tree_oid.hash)
#define EMPTY_BLOB_SHA1_HEX \
"e69de29bb2d1d6434b8b29ae775ad8c2e48c5391"
#define EMPTY_BLOB_SHA1_BIN_LITERAL \
"\xe6\x9d\xe2\x9b\xb2\xd1\xd6\x43\x4b\x8b" \
"\x29\xae\x77\x5a\xd8\xc2\xe4\x8c\x53\x91"
extern const struct object_id empty_blob_oid;
#define EMPTY_BLOB_SHA1_BIN (empty_blob_oid.hash)
static inline int is_empty_blob_sha1(const unsigned char *sha1)
{
return !hashcmp(sha1, EMPTY_BLOB_SHA1_BIN);
}
static inline int is_empty_blob_oid(const struct object_id *oid)
{
return !hashcmp(oid->hash, EMPTY_BLOB_SHA1_BIN);
}
static inline int is_empty_tree_sha1(const unsigned char *sha1)
{
return !hashcmp(sha1, EMPTY_TREE_SHA1_BIN);
}
static inline int is_empty_tree_oid(const struct object_id *oid)
{
return !hashcmp(oid->hash, EMPTY_TREE_SHA1_BIN);
}
/* set default permissions by passing mode arguments to open(2) */
int git_mkstemps_mode(char *pattern, int suffix_len, int mode);
int git_mkstemp_mode(char *pattern, int mode);
/*
* NOTE NOTE NOTE!!
*
* PERM_UMASK, OLD_PERM_GROUP and OLD_PERM_EVERYBODY enumerations must
* not be changed. Old repositories have core.sharedrepository written in
* numeric format, and therefore these values are preserved for compatibility
* reasons.
*/
enum sharedrepo {
PERM_UMASK = 0,
OLD_PERM_GROUP = 1,
OLD_PERM_EVERYBODY = 2,
PERM_GROUP = 0660,
PERM_EVERYBODY = 0664
};
int git_config_perm(const char *var, const char *value);
int adjust_shared_perm(const char *path);
/*
* Create the directory containing the named path, using care to be
* somewhat safe against races. Return one of the scld_error values to
* indicate success/failure. On error, set errno to describe the
* problem.
*
* SCLD_VANISHED indicates that one of the ancestor directories of the
* path existed at one point during the function call and then
* suddenly vanished, probably because another process pruned the
* directory while we were working. To be robust against this kind of
* race, callers might want to try invoking the function again when it
* returns SCLD_VANISHED.
*
* safe_create_leading_directories() temporarily changes path while it
* is working but restores it before returning.
* safe_create_leading_directories_const() doesn't modify path, even
* temporarily.
*/
enum scld_error {
SCLD_OK = 0,
SCLD_FAILED = -1,
SCLD_PERMS = -2,
SCLD_EXISTS = -3,
SCLD_VANISHED = -4
};
enum scld_error safe_create_leading_directories(char *path);
enum scld_error safe_create_leading_directories_const(const char *path);
/*
* Callback function for raceproof_create_file(). This function is
* expected to do something that makes dirname(path) permanent despite
* the fact that other processes might be cleaning up empty
* directories at the same time. Usually it will create a file named
* path, but alternatively it could create another file in that
* directory, or even chdir() into that directory. The function should
* return 0 if the action was completed successfully. On error, it
* should return a nonzero result and set errno.
* raceproof_create_file() treats two errno values specially:
*
* - ENOENT -- dirname(path) does not exist. In this case,
* raceproof_create_file() tries creating dirname(path)
* (and any parent directories, if necessary) and calls
* the function again.
*
* - EISDIR -- the file already exists and is a directory. In this
* case, raceproof_create_file() removes the directory if
* it is empty (and recursively any empty directories that
* it contains) and calls the function again.
*
* Any other errno causes raceproof_create_file() to fail with the
* callback's return value and errno.
*
* Obviously, this function should be OK with being called again if it
* fails with ENOENT or EISDIR. In other scenarios it will not be
* called again.
*/
typedef int create_file_fn(const char *path, void *cb);
/*
* Create a file in dirname(path) by calling fn, creating leading
* directories if necessary. Retry a few times in case we are racing
* with another process that is trying to clean up the directory that
* contains path. See the documentation for create_file_fn for more
* details.
*
* Return the value and set the errno that resulted from the most
* recent call of fn. fn is always called at least once, and will be
* called more than once if it returns ENOENT or EISDIR.
*/
int raceproof_create_file(const char *path, create_file_fn fn, void *cb);
rerere: make sure it works even in a workdir attached to a young repository The git-new-workdir script in contrib/ makes a new work tree by sharing many subdirectories of the .git directory with the original repository. When rerere.enabled is set in the original repository, but the user has not encountered any conflicts yet, the original repository may not yet have .git/rr-cache directory. When rerere wants to run in a new work tree created from such a young original repository, it fails to mkdir(2) .git/rr-cache that is a symlink to a yet-to-be-created directory. There are three possible approaches to this: - A naive solution is not to create a symlink in the git-new-workdir script to a directory the original does not have (yet). This is not a solution, as we tend to lazily create subdirectories of .git/, and having rerere.enabled configuration set is a strong indication that the user _wants_ to have this lazy creation to happen; - We could always create .git/rr-cache upon repository creation. This is tempting but will not help people with existing repositories. - Detect this case by seeing that mkdir(2) failed with EEXIST, checking that the path is a symlink, and try running mkdir(2) on the link target. This patch solves the issue by doing the third one. Strictly speaking, this is incomplete. It does not attempt to handle relative symbolic link that points into the original repository, but this is good enough to help people who use contrib/workdir/git-new-workdir script. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2011-03-11 08:02:50 +08:00
int mkdir_in_gitdir(const char *path);
extern char *expand_user_path(const char *path, int real_home);
const char *enter_repo(const char *path, int strict);
static inline int is_absolute_path(const char *path)
{
return is_dir_sep(path[0]) || has_dos_drive_prefix(path);
}
int is_directory(const char *);
char *strbuf_realpath(struct strbuf *resolved, const char *path,
int die_on_error);
const char *real_path(const char *path);
const char *real_path_if_valid(const char *path);
char *real_pathdup(const char *path, int die_on_error);
const char *absolute_path(const char *path);
char *absolute_pathdup(const char *path);
const char *remove_leading_path(const char *in, const char *prefix);
path.c: refactor relative_path(), not only strip prefix Original design of relative_path() is simple, just strip the prefix (*base) from the absolute path (*abs). In most cases, we need a real relative path, such as: ../foo, ../../bar. That's why there is another reimplementation (path_relative()) in quote.c. Borrow some codes from path_relative() in quote.c to refactor relative_path() in path.c, so that it could return real relative path, and user can reuse this function without reimplementing his/her own. The function path_relative() in quote.c will be substituted, and I would use the new relative_path() function when implementing the interactive git-clean later. Different results for relative_path() before and after this refactor: abs path base path relative (original) relative (refactor) ======== ========= =================== =================== /a/b /a/b . ./ /a/b/ /a/b . ./ /a /a/b/ /a ../ / /a/b/ / ../../ /a/c /a/b/ /a/c ../c /x/y /a/b/ /x/y ../../x/y a/b/ a/b/ . ./ a/b/ a/b . ./ a a/b a ../ x/y a/b/ x/y ../../x/y a/c a/b a/c ../c (empty) (null) (empty) ./ (empty) (empty) (empty) ./ (empty) /a/b (empty) ./ (null) (null) (null) ./ (null) (empty) (null) ./ (null) /a/b (segfault) ./ You may notice that return value "." has been changed to "./". It is because: * Function quote_path_relative() in quote.c will show the relative path as "./" if abs(in) and base(prefix) are the same. * Function relative_path() is called only once (in setup.c), and it will be OK for the return value as "./" instead of ".". Signed-off-by: Jiang Xin <worldhello.net@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-25 23:53:43 +08:00
const char *relative_path(const char *in, const char *prefix, struct strbuf *sb);
int normalize_path_copy_len(char *dst, const char *src, int *prefix_len);
int normalize_path_copy(char *dst, const char *src);
int longest_ancestor_length(const char *path, struct string_list *prefixes);
char *strip_path_suffix(const char *path, const char *suffix);
int daemon_avoid_alias(const char *path);
path: add is_ntfs_dotgit() helper We do not allow paths with a ".git" component to be added to the index, as that would mean repository contents could overwrite our repository files. However, asking "is this path the same as .git" is not as simple as strcmp() on some filesystems. On NTFS (and FAT32), there exist so-called "short names" for backwards-compatibility: 8.3 compliant names that refer to the same files as their long names. As ".git" is not an 8.3 compliant name, a short name is generated automatically, typically "git~1". Depending on the Windows version, any combination of trailing spaces and periods are ignored, too, so that both "git~1." and ".git." still refer to the Git directory. The reason is that 8.3 stores file names shorter than 8 characters with trailing spaces. So literally, it does not matter for the short name whether it is padded with spaces or whether it is shorter than 8 characters, it is considered to be the exact same. The period is the separator between file name and file extension, and again, an empty extension consists just of spaces in 8.3 format. So technically, we would need only take care of the equivalent of this regex: (\.git {0,4}|git~1 {0,3})\. {0,3} However, there are indications that at least some Windows versions might be more lenient and accept arbitrary combinations of trailing spaces and periods and strip them out. So we're playing it real safe here. Besides, there can be little doubt about the intention behind using file names matching even the more lenient pattern specified above, therefore we should be fine with disallowing such patterns. Extra care is taken to catch names such as '.\\.git\\booh' because the backslash is marked as a directory separator only on Windows, and we want to use this new helper function also in fsck on other platforms. A big thank you goes to Ed Thomson and an unnamed Microsoft engineer for the detailed analysis performed to come up with the corresponding fixes for libgit2. This commit adds a function to detect whether a given file name can refer to the Git directory by mistake. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-12-17 06:31:03 +08:00
extern int is_ntfs_dotgit(const char *name);
2015-04-21 12:06:27 +08:00
/**
* Return a newly allocated string with the evaluation of
* "$XDG_CONFIG_HOME/git/$filename" if $XDG_CONFIG_HOME is non-empty, otherwise
* "$HOME/.config/git/$filename". Return NULL upon error.
*/
extern char *xdg_config_home(const char *filename);
/**
* Return a newly allocated string with the evaluation of
* "$XDG_CACHE_HOME/git/$filename" if $XDG_CACHE_HOME is non-empty, otherwise
* "$HOME/.cache/git/$filename". Return NULL upon error.
*/
extern char *xdg_cache_home(const char *filename);
extern void *read_sha1_file_extended(const unsigned char *sha1,
enum object_type *type,
unsigned long *size, int lookup_replace);
static inline void *read_sha1_file(const unsigned char *sha1, enum object_type *type, unsigned long *size)
{
return read_sha1_file_extended(sha1, type, size, 1);
}
/*
* This internal function is only declared here for the benefit of
* lookup_replace_object(). Please do not call it directly.
*/
extern const unsigned char *do_lookup_replace_object(const unsigned char *sha1);
/*
* If object sha1 should be replaced, return the replacement object's
* name (replaced recursively, if necessary). The return value is
* either sha1 or a pointer to a permanently-allocated value. When
* object replacement is suppressed, always return sha1.
*/
static inline const unsigned char *lookup_replace_object(const unsigned char *sha1)
{
if (!check_replace_refs)
return sha1;
return do_lookup_replace_object(sha1);
}
/* Read and unpack a sha1 file into memory, write memory to a sha1 file */
extern int sha1_object_info(const unsigned char *, unsigned long *);
extern int hash_sha1_file(const void *buf, unsigned long len, const char *type, unsigned char *sha1);
extern int write_sha1_file(const void *buf, unsigned long len, const char *type, unsigned char *return_sha1);
extern int hash_sha1_file_literally(const void *buf, unsigned long len, const char *type, unsigned char *sha1, unsigned flags);
extern int pretend_sha1_file(void *, unsigned long, enum object_type, unsigned char *);
extern int force_object_loose(const unsigned char *sha1, time_t mtime);
extern int git_open_cloexec(const char *name, int flags);
#define git_open(name) git_open_cloexec(name, O_RDONLY)
extern void *map_sha1_file(const unsigned char *sha1, unsigned long *size);
extern int unpack_sha1_header(git_zstream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz);
extern int parse_sha1_header(const char *hdr, unsigned long *sizep);
close another possibility for propagating pack corruption Abstract -------- With index v2 we have a per object CRC to allow quick and safe reuse of pack data when repacking. This, however, doesn't currently prevent a stealth corruption from being propagated into a new pack when _not_ reusing pack data as demonstrated by the modification to t5302 included here. The Context ----------- The Git database is all checksummed with SHA1 hashes. Any kind of corruption can be confirmed by verifying this per object hash against corresponding data. However this can be costly to perform systematically and therefore this check is often not performed at run time when accessing the object database. First, the loose object format is entirely compressed with zlib which already provide a CRC verification of its own when inflating data. Any disk corruption would be caught already in this case. Then, packed objects are also compressed with zlib but only for their actual payload. The object headers and delta base references are not deflated for obvious performance reasons, however this leave them vulnerable to potentially undetected disk corruptions. Object types are often validated against the expected type when they're requested, and deflated size must always match the size recorded in the object header, so those cases are pretty much covered as well. Where corruptions could go unnoticed is in the delta base reference. Of course, in the OBJ_REF_DELTA case, the odds for a SHA1 reference to get corrupted so it actually matches the SHA1 of another object with the same size (the delta header stores the expected size of the base object to apply against) are virtually zero. In the OBJ_OFS_DELTA case, the reference is a pack offset which would have to match the start boundary of a different base object but still with the same size, and although this is relatively much more "probable" than in the OBJ_REF_DELTA case, the probability is also about zero in absolute terms. Still, the possibility exists as demonstrated in t5302 and is certainly greater than a SHA1 collision, especially in the OBJ_OFS_DELTA case which is now the default when repacking. Again, repacking by reusing existing pack data is OK since the per object CRC provided by index v2 guards against any such corruptions. What t5302 failed to test is a full repack in such case. The Solution ------------ As unlikely as this kind of stealth corruption can be in practice, it certainly isn't acceptable to propagate it into a freshly created pack. But, because this is so unlikely, we don't want to pay the run time cost associated with extra validation checks all the time either. Furthermore, consequences of such corruption in anything but repacking should be rather visible, and even if it could be quite unpleasant, it still has far less severe consequences than actively creating bad packs. So the best compromize is to check packed object CRC when unpacking objects, and only during the compression/writing phase of a repack, and only when not streaming the result. The cost of this is minimal (less than 1% CPU time), and visible only with a full repack. Someone with a stats background could provide an objective evaluation of this, but I suspect that it's bad RAM that has more potential for data corruptions at this point, even in those cases where this extra check is not performed. Still, it is best to prevent a known hole for corruption when recreating object data into a new pack. What about the streamed pack case? Well, any client receiving a pack must always consider that pack as untrusty and perform full validation anyway, hence no such stealth corruption could be propagated to remote repositoryes already. It is therefore worthless doing local validation in that case. Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-10-31 23:31:08 +08:00
/* global flag to enable extra checks when accessing packed objects */
extern int do_check_packed_object_crc;
extern int check_sha1_signature(const unsigned char *sha1, void *buf, unsigned long size, const char *type);
extern int finalize_object_file(const char *tmpfile, const char *filename);
extern int has_sha1_pack(const unsigned char *sha1);
/*
* Open the loose object at path, check its sha1, and return the contents,
* type, and size. If the object is a blob, then "contents" may return NULL,
* to allow streaming of large blobs.
*
* Returns 0 on success, negative on error (details may be written to stderr).
*/
int read_loose_object(const char *path,
const unsigned char *expected_sha1,
enum object_type *type,
unsigned long *size,
void **contents);
/*
* Convenience for sha1_object_info_extended() with a NULL struct
* object_info. OBJECT_INFO_SKIP_CACHED is automatically set; pass
* nonzero flags to also set other flags.
*/
extern int has_sha1_file_with_flags(const unsigned char *sha1, int flags);
static inline int has_sha1_file(const unsigned char *sha1)
{
return has_sha1_file_with_flags(sha1, 0);
}
/* Same as the above, except for struct object_id. */
extern int has_object_file(const struct object_id *oid);
fetch: use "quick" has_sha1_file for tag following When we auto-follow tags in a fetch, we look at all of the tags advertised by the remote and fetch ones where we don't already have the tag, but we do have the object it peels to. This involves a lot of calls to has_sha1_file(), some of which we can reasonably expect to fail. Since 45e8a74 (has_sha1_file: re-check pack directory before giving up, 2013-08-30), this may cause many calls to reprepare_packed_git(), which is potentially expensive. This has gone unnoticed for several years because it requires a fairly unique setup to matter: 1. You need to have a lot of packs on the client side to make reprepare_packed_git() expensive (the most expensive part is finding duplicates in an unsorted list, which is currently quadratic). 2. You need a large number of tag refs on the server side that are candidates for auto-following (i.e., that the client doesn't have). Each one triggers a re-read of the pack directory. 3. Under normal circumstances, the client would auto-follow those tags and after one large fetch, (2) would no longer be true. But if those tags point to history which is disconnected from what the client otherwise fetches, then it will never auto-follow, and those candidates will impact it on every fetch. So when all three are true, each fetch pays an extra O(nr_tags * nr_packs^2) cost, mostly in string comparisons on the pack names. This was exacerbated by 47bf4b0 (prepare_packed_git_one: refactor duplicate-pack check, 2014-06-30) which uses a slightly more expensive string check, under the assumption that the duplicate check doesn't happen very often (and it shouldn't; the real problem here is how often we are calling reprepare_packed_git()). This patch teaches fetch to use HAS_SHA1_QUICK to sacrifice accuracy for speed, in cases where we might be racy with a simultaneous repack. This is similar to the fix in 0eeb077 (index-pack: avoid excessive re-reading of pack directory, 2015-06-09). As with that case, it's OK for has_sha1_file() occasionally say "no I don't have it" when we do, because the worst case is not a corruption, but simply that we may fail to auto-follow a tag that points to it. Here are results from the included perf script, which sets up a situation similar to the one described above: Test HEAD^ HEAD ---------------------------------------------------------- 5550.4: fetch 11.21(10.42+0.78) 0.08(0.04+0.02) -99.3% Reported-by: Vegard Nossum <vegard.nossum@oracle.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-10-14 00:53:44 +08:00
extern int has_object_file_with_flags(const struct object_id *oid, int flags);
/*
* Return true iff an alternate object database has a loose object
* with the specified name. This function does not respect replace
* references.
*/
extern int has_loose_object_nonlocal(const unsigned char *sha1);
extern int has_pack_index(const unsigned char *sha1);
extern void assert_sha1_type(const unsigned char *sha1, enum object_type expect);
/* Helper to check and "touch" a file */
extern int check_and_freshen_file(const char *fn, int freshen);
extern const signed char hexval_table[256];
static inline unsigned int hexval(unsigned char c)
{
return hexval_table[c];
}
/*
* Convert two consecutive hexadecimal digits into a char. Return a
* negative value on error. Don't run over the end of short strings.
*/
static inline int hex2chr(const char *s)
{
int val = hexval(s[0]);
return (val < 0) ? val : (val << 4) | hexval(s[1]);
}
/* Convert to/from hex/sha1 representation */
#define MINIMUM_ABBREV minimum_abbrev
#define DEFAULT_ABBREV default_abbrev
/* used when the code does not know or care what the default abbrev is */
#define FALLBACK_DEFAULT_ABBREV 7
struct object_context {
unsigned char tree[20];
unsigned mode;
/*
* symlink_path is only used by get_tree_entry_follow_symlinks,
* and only for symlinks that point outside the repository.
*/
struct strbuf symlink_path;
/*
* If GET_SHA1_RECORD_PATH is set, this will record path (if any)
* found when resolving the name. The caller is responsible for
* releasing the memory.
*/
char *path;
};
#define GET_SHA1_QUIETLY 01
#define GET_SHA1_COMMIT 02
#define GET_SHA1_COMMITTISH 04
#define GET_SHA1_TREE 010
#define GET_SHA1_TREEISH 020
#define GET_SHA1_BLOB 040
#define GET_SHA1_FOLLOW_SYMLINKS 0100
#define GET_SHA1_RECORD_PATH 0200
#define GET_SHA1_ONLY_TO_DIE 04000
#define GET_SHA1_DISAMBIGUATORS \
(GET_SHA1_COMMIT | GET_SHA1_COMMITTISH | \
GET_SHA1_TREE | GET_SHA1_TREEISH | \
GET_SHA1_BLOB)
extern int get_sha1(const char *str, unsigned char *sha1);
extern int get_sha1_commit(const char *str, unsigned char *sha1);
extern int get_sha1_committish(const char *str, unsigned char *sha1);
extern int get_sha1_tree(const char *str, unsigned char *sha1);
extern int get_sha1_treeish(const char *str, unsigned char *sha1);
extern int get_sha1_blob(const char *str, unsigned char *sha1);
extern void maybe_die_on_misspelt_object_name(const char *name, const char *prefix);
extern int get_sha1_with_context(const char *str, unsigned flags, unsigned char *sha1, struct object_context *oc);
extern int get_oid(const char *str, struct object_id *oid);
typedef int each_abbrev_fn(const struct object_id *oid, void *);
extern int for_each_abbrev(const char *prefix, each_abbrev_fn, void *);
extern int set_disambiguate_hint_config(const char *var, const char *value);
/*
* Try to read a SHA1 in hexadecimal format from the 40 characters
* starting at hex. Write the 20-byte result to sha1 in binary form.
* Return 0 on success. Reading stops if a NUL is encountered in the
* input, so it is safe to pass this function an arbitrary
* null-terminated string.
*/
extern int get_sha1_hex(const char *hex, unsigned char *sha1);
extern int get_oid_hex(const char *hex, struct object_id *sha1);
/*
* Convert a binary sha1 to its hex equivalent. The `_r` variant is reentrant,
* and writes the NUL-terminated output to the buffer `out`, which must be at
* least `GIT_SHA1_HEXSZ + 1` bytes, and returns a pointer to out for
* convenience.
*
* The non-`_r` variant returns a static buffer, but uses a ring of 4
* buffers, making it safe to make multiple calls for a single statement, like:
*
* printf("%s -> %s", sha1_to_hex(one), sha1_to_hex(two));
*/
extern char *sha1_to_hex_r(char *out, const unsigned char *sha1);
extern char *oid_to_hex_r(char *out, const struct object_id *oid);
extern char *sha1_to_hex(const unsigned char *sha1); /* static buffer result! */
extern char *oid_to_hex(const struct object_id *oid); /* same static buffer as sha1_to_hex */
/*
* Parse a 40-character hexadecimal object ID starting from hex, updating the
* pointer specified by end when parsing stops. The resulting object ID is
* stored in oid. Returns 0 on success. Parsing will stop on the first NUL or
* other invalid character. end is only updated on success; otherwise, it is
* unmodified.
*/
extern int parse_oid_hex(const char *hex, struct object_id *oid, const char **end);
/*
* This reads short-hand syntax that not only evaluates to a commit
* object name, but also can act as if the end user spelled the name
* of the branch from the command line.
*
* - "@{-N}" finds the name of the Nth previous branch we were on, and
* places the name of the branch in the given buf and returns the
* number of characters parsed if successful.
*
* - "<branch>@{upstream}" finds the name of the other ref that
* <branch> is configured to merge with (missing <branch> defaults
* to the current branch), and places the name of the branch in the
* given buf and returns the number of characters parsed if
* successful.
*
* If the input is not of the accepted format, it returns a negative
* number to signal an error.
*
* If the input was ok but there are not N branch switches in the
* reflog, it returns 0.
interpret_branch_name: allow callers to restrict expansions The interpret_branch_name() function converts names like @{-1} and @{upstream} into branch names. The expanded ref names are not fully qualified, and may be outside of the refs/heads/ namespace (e.g., "@" expands to "HEAD", and "@{upstream}" is likely to be in "refs/remotes/"). This is OK for callers like dwim_ref() which are primarily interested in resolving the resulting name, no matter where it is. But callers like "git branch" treat the result as a branch name in refs/heads/. When we expand to a ref outside that namespace, the results are very confusing (e.g., "git branch @" tries to create refs/heads/HEAD, which is nonsense). Callers can't know from the returned string how the expansion happened (e.g., did the user really ask for a branch named "HEAD", or did we do a bogus expansion?). One fix would be to return some out-parameters describing the types of expansion that occurred. This has the benefit that the caller can generate precise error messages ("I understood @{upstream} to mean origin/master, but that is a remote tracking branch, so you cannot create it as a local name"). However, out-parameters make the function interface somewhat cumbersome. Instead, let's do the opposite: let the caller tell us which elements to expand. That's easier to pass in, and none of the callers give more precise error messages than "@{upstream} isn't a valid branch name" anyway (which should be sufficient). The strbuf_branchname() function needs a similar parameter, as most of the callers access interpret_branch_name() through it. We can break the callers down into two groups: 1. Callers that are happy with any kind of ref in the result. We pass "0" here, so they continue to work without restrictions. This includes merge_name(), the reflog handling in add_pending_object_with_path(), and substitute_branch_name(). This last is what powers dwim_ref(). 2. Callers that have funny corner cases (mostly in git-branch and git-checkout). These need to make use of the new parameter, but I've left them as "0" in this patch, and will address them individually in follow-on patches. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-03-02 16:23:01 +08:00
*
* If "allowed" is non-zero, it is a treated as a bitfield of allowable
* expansions: local branches ("refs/heads/"), remote branches
* ("refs/remotes/"), or "HEAD". If no "allowed" bits are set, any expansion is
* allowed, even ones to refs outside of those namespaces.
*/
interpret_branch_name: allow callers to restrict expansions The interpret_branch_name() function converts names like @{-1} and @{upstream} into branch names. The expanded ref names are not fully qualified, and may be outside of the refs/heads/ namespace (e.g., "@" expands to "HEAD", and "@{upstream}" is likely to be in "refs/remotes/"). This is OK for callers like dwim_ref() which are primarily interested in resolving the resulting name, no matter where it is. But callers like "git branch" treat the result as a branch name in refs/heads/. When we expand to a ref outside that namespace, the results are very confusing (e.g., "git branch @" tries to create refs/heads/HEAD, which is nonsense). Callers can't know from the returned string how the expansion happened (e.g., did the user really ask for a branch named "HEAD", or did we do a bogus expansion?). One fix would be to return some out-parameters describing the types of expansion that occurred. This has the benefit that the caller can generate precise error messages ("I understood @{upstream} to mean origin/master, but that is a remote tracking branch, so you cannot create it as a local name"). However, out-parameters make the function interface somewhat cumbersome. Instead, let's do the opposite: let the caller tell us which elements to expand. That's easier to pass in, and none of the callers give more precise error messages than "@{upstream} isn't a valid branch name" anyway (which should be sufficient). The strbuf_branchname() function needs a similar parameter, as most of the callers access interpret_branch_name() through it. We can break the callers down into two groups: 1. Callers that are happy with any kind of ref in the result. We pass "0" here, so they continue to work without restrictions. This includes merge_name(), the reflog handling in add_pending_object_with_path(), and substitute_branch_name(). This last is what powers dwim_ref(). 2. Callers that have funny corner cases (mostly in git-branch and git-checkout). These need to make use of the new parameter, but I've left them as "0" in this patch, and will address them individually in follow-on patches. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-03-02 16:23:01 +08:00
#define INTERPRET_BRANCH_LOCAL (1<<0)
#define INTERPRET_BRANCH_REMOTE (1<<1)
#define INTERPRET_BRANCH_HEAD (1<<2)
extern int interpret_branch_name(const char *str, int len, struct strbuf *,
unsigned allowed);
extern int get_oid_mb(const char *str, struct object_id *oid);
extern int validate_headref(const char *ref);
extern int base_name_compare(const char *name1, int len1, int mode1, const char *name2, int len2, int mode2);
extern int df_name_compare(const char *name1, int len1, int mode1, const char *name2, int len2, int mode2);
extern int name_compare(const char *name1, size_t len1, const char *name2, size_t len2);
extern int cache_name_stage_compare(const char *name1, int len1, int stage1, const char *name2, int len2, int stage2);
extern void *read_object_with_reference(const unsigned char *sha1,
const char *required_type,
unsigned long *size,
unsigned char *sha1_ret);
extern struct object *peel_to_type(const char *name, int namelen,
struct object *o, enum object_type);
convert "enum date_mode" into a struct In preparation for adding date modes that may carry extra information beyond the mode itself, this patch converts the date_mode enum into a struct. Most of the conversion is fairly straightforward; we pass the struct as a pointer and dereference the type field where necessary. Locations that declare a date_mode can use a "{}" constructor. However, the tricky case is where we use the enum labels as constants, like: show_date(t, tz, DATE_NORMAL); Ideally we could say: show_date(t, tz, &{ DATE_NORMAL }); but of course C does not allow that. Likewise, we cannot cast the constant to a struct, because we need to pass an actual address. Our options are basically: 1. Manually add a "struct date_mode d = { DATE_NORMAL }" definition to each caller, and pass "&d". This makes the callers uglier, because they sometimes do not even have their own scope (e.g., they are inside a switch statement). 2. Provide a pre-made global "date_normal" struct that can be passed by address. We'd also need "date_rfc2822", "date_iso8601", and so forth. But at least the ugliness is defined in one place. 3. Provide a wrapper that generates the correct struct on the fly. The big downside is that we end up pointing to a single global, which makes our wrapper non-reentrant. But show_date is already not reentrant, so it does not matter. This patch implements 3, along with a minor macro to keep the size of the callers sane. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-06-26 00:55:02 +08:00
struct date_mode {
enum date_mode_type {
DATE_NORMAL = 0,
DATE_RELATIVE,
DATE_SHORT,
DATE_ISO8601,
DATE_ISO8601_STRICT,
DATE_RFC2822,
DATE_STRFTIME,
DATE_RAW,
DATE_UNIX
convert "enum date_mode" into a struct In preparation for adding date modes that may carry extra information beyond the mode itself, this patch converts the date_mode enum into a struct. Most of the conversion is fairly straightforward; we pass the struct as a pointer and dereference the type field where necessary. Locations that declare a date_mode can use a "{}" constructor. However, the tricky case is where we use the enum labels as constants, like: show_date(t, tz, DATE_NORMAL); Ideally we could say: show_date(t, tz, &{ DATE_NORMAL }); but of course C does not allow that. Likewise, we cannot cast the constant to a struct, because we need to pass an actual address. Our options are basically: 1. Manually add a "struct date_mode d = { DATE_NORMAL }" definition to each caller, and pass "&d". This makes the callers uglier, because they sometimes do not even have their own scope (e.g., they are inside a switch statement). 2. Provide a pre-made global "date_normal" struct that can be passed by address. We'd also need "date_rfc2822", "date_iso8601", and so forth. But at least the ugliness is defined in one place. 3. Provide a wrapper that generates the correct struct on the fly. The big downside is that we end up pointing to a single global, which makes our wrapper non-reentrant. But show_date is already not reentrant, so it does not matter. This patch implements 3, along with a minor macro to keep the size of the callers sane. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-06-26 00:55:02 +08:00
} type;
const char *strftime_fmt;
int local;
};
convert "enum date_mode" into a struct In preparation for adding date modes that may carry extra information beyond the mode itself, this patch converts the date_mode enum into a struct. Most of the conversion is fairly straightforward; we pass the struct as a pointer and dereference the type field where necessary. Locations that declare a date_mode can use a "{}" constructor. However, the tricky case is where we use the enum labels as constants, like: show_date(t, tz, DATE_NORMAL); Ideally we could say: show_date(t, tz, &{ DATE_NORMAL }); but of course C does not allow that. Likewise, we cannot cast the constant to a struct, because we need to pass an actual address. Our options are basically: 1. Manually add a "struct date_mode d = { DATE_NORMAL }" definition to each caller, and pass "&d". This makes the callers uglier, because they sometimes do not even have their own scope (e.g., they are inside a switch statement). 2. Provide a pre-made global "date_normal" struct that can be passed by address. We'd also need "date_rfc2822", "date_iso8601", and so forth. But at least the ugliness is defined in one place. 3. Provide a wrapper that generates the correct struct on the fly. The big downside is that we end up pointing to a single global, which makes our wrapper non-reentrant. But show_date is already not reentrant, so it does not matter. This patch implements 3, along with a minor macro to keep the size of the callers sane. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-06-26 00:55:02 +08:00
/*
* Convenience helper for passing a constant type, like:
*
* show_date(t, tz, DATE_MODE(NORMAL));
*/
#define DATE_MODE(t) date_mode_from_type(DATE_##t)
struct date_mode *date_mode_from_type(enum date_mode_type type);
const char *show_date(timestamp_t time, int timezone, const struct date_mode *mode);
void show_date_relative(timestamp_t time, int tz, const struct timeval *now,
struct strbuf *timebuf);
int parse_date(const char *date, struct strbuf *out);
int parse_date_basic(const char *date, timestamp_t *timestamp, int *offset);
int parse_expiry_date(const char *date, timestamp_t *timestamp);
void datestamp(struct strbuf *out);
#define approxidate(s) approxidate_careful((s), NULL)
timestamp_t approxidate_careful(const char *, int *);
timestamp_t approxidate_relative(const char *date, const struct timeval *now);
convert "enum date_mode" into a struct In preparation for adding date modes that may carry extra information beyond the mode itself, this patch converts the date_mode enum into a struct. Most of the conversion is fairly straightforward; we pass the struct as a pointer and dereference the type field where necessary. Locations that declare a date_mode can use a "{}" constructor. However, the tricky case is where we use the enum labels as constants, like: show_date(t, tz, DATE_NORMAL); Ideally we could say: show_date(t, tz, &{ DATE_NORMAL }); but of course C does not allow that. Likewise, we cannot cast the constant to a struct, because we need to pass an actual address. Our options are basically: 1. Manually add a "struct date_mode d = { DATE_NORMAL }" definition to each caller, and pass "&d". This makes the callers uglier, because they sometimes do not even have their own scope (e.g., they are inside a switch statement). 2. Provide a pre-made global "date_normal" struct that can be passed by address. We'd also need "date_rfc2822", "date_iso8601", and so forth. But at least the ugliness is defined in one place. 3. Provide a wrapper that generates the correct struct on the fly. The big downside is that we end up pointing to a single global, which makes our wrapper non-reentrant. But show_date is already not reentrant, so it does not matter. This patch implements 3, along with a minor macro to keep the size of the callers sane. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-06-26 00:55:02 +08:00
void parse_date_format(const char *format, struct date_mode *mode);
int date_overflows(timestamp_t date);
#define IDENT_STRICT 1
#define IDENT_NO_DATE 2
#define IDENT_NO_NAME 4
extern const char *git_author_info(int);
extern const char *git_committer_info(int);
extern const char *fmt_ident(const char *name, const char *email, const char *date_str, int);
extern const char *fmt_name(const char *name, const char *email);
extern const char *ident_default_name(void);
extern const char *ident_default_email(void);
extern const char *git_editor(void);
extern const char *git_pager(int stdout_is_tty);
extern int git_ident_config(const char *, const char *, void *);
am: reset cached ident date for each patch When we compute the date to go in author/committer lines of commits, or tagger lines of tags, we get the current date once and then cache it for the rest of the program. This is a good thing in some cases, like "git commit", because it means we do not racily assign different times to the author/committer fields of a single commit object. But as more programs start to make many commits in a single process (e.g., the recently builtin "git am"), it means that you'll get long strings of commits with identical committer timestamps (whereas before, we invoked "git commit" many times and got true timestamps). This patch addresses it by letting callers reset the cached time, which means they'll get a fresh time on their next call to git_committer_info() or git_author_info(). The first caller to do so is "git am", which resets the time for each patch it applies. It would be nice if we could just do this automatically before filling in the ident fields of commit and tag objects. Unfortunately, it's hard to know where a particular logical operation begins and ends. For instance, if commit_tree_extended() were to call reset_ident_date() before getting the committer/author ident, that doesn't quite work; sometimes the author info is passed in to us as a parameter, and it may or may not have come from a previous call to ident_default_date(). So in those cases, we lose the property that the committer and the author timestamp always match. You could similarly put a date-reset at the end of commit_tree_extended(). That actually works in the current code base, but it's fragile. It makes the assumption that after commit_tree_extended() finishes, the caller has no other operations that would logically want to fall into the same timestamp. So instead we provide the tool to easily do the reset, and let the high-level callers use it to annotate their own logical operations. There's no automated test, because it would be inherently racy (it depends on whether the program takes multiple seconds to run). But you can see the effect with something like: # make a fake 100-patch series top=$(git rev-parse HEAD) bottom=$(git rev-list --first-parent -100 HEAD | tail -n 1) git log --format=email --reverse --first-parent \ --binary -m -p $bottom..$top >patch # now apply it; this presumably takes multiple seconds git checkout --detach $bottom git am <patch # now count the number of distinct committer times; # prior to this patch, there would only be one, but # now we'd typically see several. git log --format=%ct $bottom.. | sort -u Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Helped-by: Paul Tan <pyokagan@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-08-02 03:37:00 +08:00
extern void reset_ident_date(void);
struct ident_split {
const char *name_begin;
const char *name_end;
const char *mail_begin;
const char *mail_end;
const char *date_begin;
const char *date_end;
const char *tz_begin;
const char *tz_end;
};
/*
* Signals an success with 0, but time part of the result may be NULL
* if the input lacks timestamp and zone
*/
extern int split_ident_line(struct ident_split *, const char *, int);
/*
* Like show_date, but pull the timestamp and tz parameters from
* the ident_split. It will also sanity-check the values and produce
* a well-known sentinel date if they appear bogus.
*/
convert "enum date_mode" into a struct In preparation for adding date modes that may carry extra information beyond the mode itself, this patch converts the date_mode enum into a struct. Most of the conversion is fairly straightforward; we pass the struct as a pointer and dereference the type field where necessary. Locations that declare a date_mode can use a "{}" constructor. However, the tricky case is where we use the enum labels as constants, like: show_date(t, tz, DATE_NORMAL); Ideally we could say: show_date(t, tz, &{ DATE_NORMAL }); but of course C does not allow that. Likewise, we cannot cast the constant to a struct, because we need to pass an actual address. Our options are basically: 1. Manually add a "struct date_mode d = { DATE_NORMAL }" definition to each caller, and pass "&d". This makes the callers uglier, because they sometimes do not even have their own scope (e.g., they are inside a switch statement). 2. Provide a pre-made global "date_normal" struct that can be passed by address. We'd also need "date_rfc2822", "date_iso8601", and so forth. But at least the ugliness is defined in one place. 3. Provide a wrapper that generates the correct struct on the fly. The big downside is that we end up pointing to a single global, which makes our wrapper non-reentrant. But show_date is already not reentrant, so it does not matter. This patch implements 3, along with a minor macro to keep the size of the callers sane. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-06-26 00:55:02 +08:00
const char *show_ident_date(const struct ident_split *id,
const struct date_mode *mode);
/*
* Compare split idents for equality or strict ordering. Note that we
* compare only the ident part of the line, ignoring any timestamp.
*
* Because there are two fields, we must choose one as the primary key; we
* currently arbitrarily pick the email.
*/
extern int ident_cmp(const struct ident_split *, const struct ident_split *);
struct checkout {
struct index_state *istate;
const char *base_dir;
int base_dir_len;
unsigned force:1,
quiet:1,
not_new:1,
refresh_cache:1;
};
#define CHECKOUT_INIT { NULL, "" }
#define TEMPORARY_FILENAME_LENGTH 25
extern int checkout_entry(struct cache_entry *ce, const struct checkout *state, char *topath);
struct cache_def {
struct strbuf path;
int flags;
int track_flags;
int prefix_len_stat_func;
};
#define CACHE_DEF_INIT { STRBUF_INIT, 0, 0, 0 }
static inline void cache_def_clear(struct cache_def *cache)
{
strbuf_release(&cache->path);
}
extern int has_symlink_leading_path(const char *name, int len);
extern int threaded_has_symlink_leading_path(struct cache_def *, const char *, int);
extern int check_leading_path(const char *name, int len);
extern int has_dirs_only_path(const char *name, int len, int prefix_len);
extern void schedule_dir_for_removal(const char *name, int len);
extern void remove_scheduled_dirs(void);
extern struct alternate_object_database {
struct alternate_object_database *next;
/* see alt_scratch_buf() */
struct strbuf scratch;
size_t base_len;
/*
* Used to store the results of readdir(3) calls when searching
* for unique abbreviated hashes. This cache is never
* invalidated, thus it's racy and not necessarily accurate.
* That's fine for its purpose; don't use it for tasks requiring
* greater accuracy!
*/
char loose_objects_subdir_seen[256];
struct oid_array loose_objects_cache;
char path[FLEX_ARRAY];
} *alt_odb_list;
extern void prepare_alt_odb(void);
extern void read_info_alternates(const char * relative_base, int depth);
extern char *compute_alternate_path(const char *path, struct strbuf *err);
typedef int alt_odb_fn(struct alternate_object_database *, void *);
extern int foreach_alt_odb(alt_odb_fn, void*);
/*
* Allocate a "struct alternate_object_database" but do _not_ actually
* add it to the list of alternates.
*/
struct alternate_object_database *alloc_alt_odb(const char *dir);
/*
* Add the directory to the on-disk alternates file; the new entry will also
* take effect in the current process.
*/
extern void add_to_alternates_file(const char *dir);
/*
* Add the directory to the in-memory list of alternates (along with any
* recursive alternates it points to), but do not modify the on-disk alternates
* file.
*/
extern void add_to_alternates_memory(const char *dir);
/*
* Returns a scratch strbuf pre-filled with the alternate object directory,
* including a trailing slash, which can be used to access paths in the
* alternate. Always use this over direct access to alt->scratch, as it
* cleans up any previous use of the scratch buffer.
*/
extern struct strbuf *alt_scratch_buf(struct alternate_object_database *alt);
struct pack_window {
struct pack_window *next;
unsigned char *base;
off_t offset;
size_t len;
unsigned int last_used;
unsigned int inuse_cnt;
};
extern struct packed_git {
struct packed_git *next;
struct pack_window *windows;
off_t pack_size;
const void *index_data;
size_t index_size;
uint32_t num_objects;
uint32_t num_bad_objects;
unsigned char *bad_object_sha1;
int index_version;
time_t mtime;
int pack_fd;
unsigned pack_local:1,
pack_keep:1,
freshened:1,
do_not_close:1;
unsigned char sha1[20];
struct revindex_entry *revindex;
/* something like ".git/objects/pack/xxxxx.pack" */
char pack_name[FLEX_ARRAY]; /* more */
} *packed_git;
find_pack_entry: replace last_found_pack with MRU cache Each pack has an index for looking up entries in O(log n) time, but if we have multiple packs, we have to scan through them linearly. This can produce a measurable overhead for some operations. We dealt with this long ago in f7c22cc (always start looking up objects in the last used pack first, 2007-05-30), which keeps what is essentially a 1-element most-recently-used cache. In theory, we should be able to do better by keeping a similar but longer cache, that is the same length as the pack-list itself. Since we now have a convenient generic MRU structure, we can plug it in and measure. Here are the numbers for running p5303 against linux.git: Test HEAD^ HEAD ------------------------------------------------------------------------ 5303.3: rev-list (1) 31.56(31.28+0.27) 31.30(31.08+0.20) -0.8% 5303.4: repack (1) 40.62(39.35+2.36) 40.60(39.27+2.44) -0.0% 5303.6: rev-list (50) 31.31(31.06+0.23) 31.23(31.00+0.22) -0.3% 5303.7: repack (50) 58.65(69.12+1.94) 58.27(68.64+2.05) -0.6% 5303.9: rev-list (1000) 38.74(38.40+0.33) 31.87(31.62+0.24) -17.7% 5303.10: repack (1000) 367.20(441.80+4.62) 342.00(414.04+3.72) -6.9% The main numbers of interest here are the rev-list ones (since that is exercising the normal object lookup code path). The single-pack case shouldn't improve at all; the 260ms speedup there is just part of the run-to-run noise (but it's important to note that we didn't make anything worse with the overhead of maintaining our cache). In the 50-pack case, we see similar results. There may be a slight improvement, but it's mostly within the noise. The 1000-pack case does show a big improvement, though. That carries over to the repack case, as well. Even though we haven't touched its pack-search loop yet, it does still do a lot of normal object lookups (e.g., for the internal revision walk), and so improves. As a point of reference, I also ran the 1000-pack test against a version of HEAD^ with the last_found_pack optimization disabled. It takes ~60s, so that gives an indication of how much even the single-element cache is helping. For comparison, here's a smaller repository, git.git: Test HEAD^ HEAD --------------------------------------------------------------------- 5303.3: rev-list (1) 1.56(1.54+0.01) 1.54(1.51+0.02) -1.3% 5303.4: repack (1) 1.84(1.80+0.10) 1.82(1.80+0.09) -1.1% 5303.6: rev-list (50) 1.58(1.55+0.02) 1.59(1.57+0.01) +0.6% 5303.7: repack (50) 2.50(3.18+0.04) 2.50(3.14+0.04) +0.0% 5303.9: rev-list (1000) 2.76(2.71+0.04) 2.24(2.21+0.02) -18.8% 5303.10: repack (1000) 13.21(19.56+0.25) 11.66(18.01+0.21) -11.7% You can see that the percentage improvement is similar. That's because the lookup we are optimizing is roughly O(nr_objects * nr_packs). Since the number of packs is constant in both tests, we'd expect the improvement to be linear in the number of objects. But the whole process is also linear in the number of objects, so the improvement is a constant factor. The exact improvement does also depend on the contents of the packs. In p5303, the extra packs all have 5 first-parent commits in them, which is a reasonable simulation of a pushed-to repository. But it also means that only 250 first-parent commits are in those packs (compared to almost 50,000 total in linux.git), and the rest are in the huge "base" pack. So once we start looking at history in taht big pack, that's where we'll find most everything, and even the 1-element cache gets close to 100% cache hits. You could almost certainly show better numbers with a more pathological case (e.g., distributing the objects more evenly across the packs). But that's simply not that realistic a scenario, so it makes more sense to focus on these numbers. The implementation itself is a straightforward application of the MRU code. We provide an MRU-ordered list of packs that shadows the packed_git list. This is easy to do because we only create and revise the pack list in one place. The "reprepare" code path actually drops the whole MRU and replaces it for simplicity. It would be more efficient to just add new entries, but there's not much point in optimizing here; repreparing happens rarely, and only after doing a lot of other expensive work. The key things to keep optimized are traversal (which is just a normal linked list, albeit with one extra level of indirection over the regular packed_git list), and marking (which is a constant number of pointer assignments, though slightly more than the old last_found_pack was; it doesn't seem to create a measurable slowdown, though). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-07-29 12:09:46 +08:00
/*
* A most-recently-used ordered version of the packed_git list, which can
* be iterated instead of packed_git (and marked via mru_mark).
*/
struct mru;
extern struct mru *packed_git_mru;
struct pack_entry {
off_t offset;
unsigned char sha1[20];
struct packed_git *p;
};
extern struct packed_git *parse_pack_index(unsigned char *sha1, const char *idx_path);
/* A hook to report invalid files in pack directory */
#define PACKDIR_FILE_PACK 1
#define PACKDIR_FILE_IDX 2
#define PACKDIR_FILE_GARBAGE 4
extern void (*report_garbage)(unsigned seen_bits, const char *path);
extern void prepare_packed_git(void);
extern void reprepare_packed_git(void);
extern void install_packed_git(struct packed_git *pack);
/*
* Give a rough count of objects in the repository. This sacrifices accuracy
* for speed.
*/
unsigned long approximate_object_count(void);
extern struct packed_git *find_sha1_pack(const unsigned char *sha1,
struct packed_git *packs);
extern void pack_report(void);
/*
* Create a temporary file rooted in the object database directory, or
* die on failure. The filename is taken from "pattern", which should have the
* usual "XXXXXX" trailer, and the resulting filename is written into the
* "template" buffer. Returns the open descriptor.
*/
extern int odb_mkstemp(struct strbuf *template, const char *pattern);
/*
* Generate the filename to be used for a pack file with checksum "sha1" and
* extension "ext". The result is written into the strbuf "buf", overwriting
* any existing contents. A pointer to buf->buf is returned as a convenience.
*
* Example: odb_pack_name(out, sha1, "idx") => ".git/objects/pack/pack-1234..idx"
*/
extern char *odb_pack_name(struct strbuf *buf, const unsigned char *sha1, const char *ext);
/*
* Create a pack .keep file named "name" (which should generally be the output
* of odb_pack_name). Returns a file descriptor opened for writing, or -1 on
* error.
*/
extern int odb_pack_keep(const char *name);
/*
* mmap the index file for the specified packfile (if it is not
* already mmapped). Return 0 on success.
*/
extern int open_pack_index(struct packed_git *);
/*
* munmap the index file for the specified packfile (if it is
* currently mmapped).
*/
extern void close_pack_index(struct packed_git *);
2011-06-11 02:52:15 +08:00
extern unsigned char *use_pack(struct packed_git *, struct pack_window **, off_t, unsigned long *);
Fix random fast-import errors when compiled with NO_MMAP fast-import was relying on the fact that on most systems mmap() and write() are synchronized by the filesystem's buffer cache. We were relying on the ability to mmap() 20 bytes beyond the current end of the file, then later fill in those bytes with a future write() call, then read them through the previously obtained mmap() address. This isn't always true with some implementations of NFS, but it is especially not true with our NO_MMAP=YesPlease build time option used on some platforms. If fast-import was built with NO_MMAP=YesPlease we used the malloc()+pread() emulation and the subsequent write() call does not update the trailing 20 bytes of a previously obtained "mmap()" (aka malloc'd) address. Under NO_MMAP that behavior causes unpack_entry() in sha1_file.c to be unable to read an object header (or data) that has been unlucky enough to be written to the packfile at a location such that it is in the trailing 20 bytes of a window previously opened on that same packfile. This bug has gone unnoticed for a very long time as it is highly data dependent. Not only does the object have to be placed at the right position, but it also needs to be positioned behind some other object that has been accessed due to a branch cache invalidation. In other words the stars had to align just right, and if you did run into this bug you probably should also have purchased a lottery ticket. Fortunately the workaround is a lot easier than the bug explanation. Before we allow unpack_entry() to read data from a pack window that has also (possibly) been modified through write() we force all existing windows on that packfile to be closed. By closing the windows we ensure that any new access via the emulated mmap() will reread the packfile, updating to the current file content. This comes at a slight performance degredation as we cannot reuse previously cached windows when we update the packfile. But it is a fairly minor difference as the window closes happen at only two points: - When the packfile is finalized and its .idx is generated: At this stage we are getting ready to update the refs and any data access into the packfile is going to be random, and is going after only the branch tips (to ensure they are valid). Our existing windows (if any) are not likely to be positioned at useful locations to access those final tip commits so we probably were closing them before anyway. - When the branch cache missed and we need to reload: At this point fast-import is getting change commands for the next commit and it needs to go re-read a tree object it previously had written out to the packfile. What windows we had (if any) are not likely to cover the tree in question so we probably were closing them before anyway. We do try to avoid unnecessarily closing windows in the second case by checking to see if the packfile size has increased since the last time we called unpack_entry() on that packfile. If the size has not changed then we have not written additional data, and any existing window is still vaild. This nicely handles the cases where fast-import is going through a branch cache reload and needs to read many trees at once. During such an event we are not likely to be updating the packfile so we do not cycle the windows between reads. With this change in place t9301-fast-export.sh (which was broken by c3b0dec509fe136c5417422f31898b5a4e2d5e02) finally works again. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-01-18 11:57:00 +08:00
extern void close_pack_windows(struct packed_git *);
extern void close_all_packs(void);
Replace use_packed_git with window cursors. Part of the implementation concept of the sliding mmap window for pack access is to permit multiple windows per pack to be mapped independently. Since the inuse_cnt is associated with the mmap and not with the file, this value is in struct pack_window and needs to be incremented/decremented for each pack_window accessed by any code. To faciliate that implementation we need to replace all uses of use_packed_git() and unuse_packed_git() with a different API that follows struct pack_window objects rather than struct packed_git. The way this works is when we need to start accessing a pack for the first time we should setup a new window 'cursor' by declaring a local and setting it to NULL: struct pack_windows *w_curs = NULL; To obtain the memory region which contains a specific section of the pack file we invoke use_pack(), supplying the address of our current window cursor: unsigned int len; unsigned char *addr = use_pack(p, &w_curs, offset, &len); the returned address `addr` will be the first byte at `offset` within the pack file. The optional variable len will also be updated with the number of bytes remaining following the address. Multiple calls to use_pack() with the same window cursor will update the window cursor, moving it from one window to another when necessary. In this way each window cursor variable maintains only one struct pack_window inuse at a time. Finally before exiting the scope which originally declared the window cursor we must invoke unuse_pack() to unuse the current window (which may be different from the one that was first obtained from use_pack): unuse_pack(&w_curs); This implementation is still not complete with regards to multiple windows, as only one window per pack file is supported right now. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-12-23 15:34:08 +08:00
extern void unuse_pack(struct pack_window **);
extern void clear_delta_base_cache(void);
extern struct packed_git *add_packed_git(const char *path, size_t path_len, int local);
/*
* Make sure that a pointer access into an mmap'd index file is within bounds,
* and can provide at least 8 bytes of data.
*
* Note that this is only necessary for variable-length segments of the file
* (like the 64-bit extended offset table), as we compare the size to the
* fixed-length parts when we open the file.
*/
extern void check_pack_index_ptr(const struct packed_git *p, const void *ptr);
/*
* Return the SHA-1 of the nth object within the specified packfile.
* Open the index if it is not already open. The return value points
* at the SHA-1 within the mmapped index. Return NULL if there is an
* error.
*/
extern const unsigned char *nth_packed_object_sha1(struct packed_git *, uint32_t n);
/*
* Like nth_packed_object_sha1, but write the data into the object specified by
* the the first argument. Returns the first argument on success, and NULL on
* error.
*/
extern const struct object_id *nth_packed_object_oid(struct object_id *, struct packed_git *, uint32_t n);
/*
* Return the offset of the nth object within the specified packfile.
* The index must already be opened.
*/
extern off_t nth_packed_object_offset(const struct packed_git *, uint32_t n);
/*
* If the object named sha1 is present in the specified packfile,
* return its offset within the packfile; otherwise, return 0.
*/
extern off_t find_pack_entry_one(const unsigned char *sha1, struct packed_git *);
pack-objects: protect against disappearing packs It's possible that while pack-objects is running, a simultaneously running prune process might delete a pack that we are interested in. Because we load the pack indices early on, we know that the pack contains our item, but by the time we try to open and map it, it is gone. Since c715f78, we already protect against this in the normal object access code path, but pack-objects accesses the packs at a lower level. In the normal access path, we call find_pack_entry, which will call find_pack_entry_one on each pack index, which does the actual lookup. If it gets a hit, we will actually open and verify the validity of the matching packfile (using c715f78's is_pack_valid). If we can't open it, we'll issue a warning and pretend that we didn't find it, causing us to go on to the next pack (or on to loose objects). Furthermore, we will cache the descriptor to the opened packfile. Which means that later, when we actually try to access the object, we are likely to still have that packfile opened, and won't care if it has been unlinked from the filesystem. Notice the "likely" above. If there is another pack access in the interim, and we run out of descriptors, we could close the pack. And then a later attempt to access the closed pack could fail (we'll try to re-open it, of course, but it may have been deleted). In practice, this doesn't happen because we tend to look up items and then access them immediately. Pack-objects does not follow this code path. Instead, it accesses the packs at a much lower level, using find_pack_entry_one directly. This means we skip the is_pack_valid check, and may end up with the name of a packfile, but no open descriptor. We can add the same is_pack_valid check here. Unfortunately, the access patterns of pack-objects are not quite as nice for keeping lookup and object access together. We look up each object as we find out about it, and the only later when writing the packfile do we necessarily access it. Which means that the opened packfile may be closed in the interim. In practice, however, adding this check still has value, for three reasons. 1. If you have a reasonable number of packs and/or a reasonable file descriptor limit, you can keep all of your packs open simultaneously. If this is the case, then the race is impossible to trigger. 2. Even if you can't keep all packs open at once, you may end up keeping the deleted one open (i.e., you may get lucky). 3. The race window is shortened. You may notice early that the pack is gone, and not try to access it. Triggering the problem without this check means deleting the pack any time after we read the list of index files, but before we access the looked-up objects. Triggering it with this check means deleting the pack means deleting the pack after we do a lookup (and successfully access the packfile), but before we access the object. Which is a smaller window. Acked-by: Nicolas Pitre <nico@fluxnic.net> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2011-10-15 02:03:48 +08:00
extern int is_pack_valid(struct packed_git *);
extern void *unpack_entry(struct packed_git *, off_t, enum object_type *, unsigned long *);
extern unsigned long unpack_object_header_buffer(const unsigned char *buf, unsigned long len, enum object_type *type, unsigned long *sizep);
extern unsigned long get_size_from_delta(struct packed_git *, struct pack_window **, off_t);
extern int unpack_object_header(struct packed_git *, struct pack_window **, off_t *, unsigned long *);
/*
* Iterate over the files in the loose-object parts of the object
* directory "path", triggering the following callbacks:
*
* - loose_object is called for each loose object we find.
*
* - loose_cruft is called for any files that do not appear to be
* loose objects. Note that we only look in the loose object
* directories "objects/[0-9a-f]{2}/", so we will not report
* "objects/foobar" as cruft.
*
* - loose_subdir is called for each top-level hashed subdirectory
* of the object directory (e.g., "$OBJDIR/f0"). It is called
* after the objects in the directory are processed.
*
* Any callback that is NULL will be ignored. Callbacks returning non-zero
* will end the iteration.
*
* In the "buf" variant, "path" is a strbuf which will also be used as a
* scratch buffer, but restored to its original contents before
* the function returns.
*/
typedef int each_loose_object_fn(const struct object_id *oid,
const char *path,
void *data);
typedef int each_loose_cruft_fn(const char *basename,
const char *path,
void *data);
typedef int each_loose_subdir_fn(unsigned int nr,
const char *path,
void *data);
int for_each_file_in_obj_subdir(unsigned int subdir_nr,
struct strbuf *path,
each_loose_object_fn obj_cb,
each_loose_cruft_fn cruft_cb,
each_loose_subdir_fn subdir_cb,
void *data);
int for_each_loose_file_in_objdir(const char *path,
each_loose_object_fn obj_cb,
each_loose_cruft_fn cruft_cb,
each_loose_subdir_fn subdir_cb,
void *data);
int for_each_loose_file_in_objdir_buf(struct strbuf *path,
each_loose_object_fn obj_cb,
each_loose_cruft_fn cruft_cb,
each_loose_subdir_fn subdir_cb,
void *data);
/*
* Iterate over loose and packed objects in both the local
reachable: only mark local objects as recent When pruning and repacking a repository that has an alternate object store configured, we may traverse a large number of objects in the alternate. This serves no purpose, and may be expensive to do. A longer explanation is below. Commits d3038d2 and abcb865 taught prune and pack-objects (respectively) to treat "recent" objects as tips for reachability, so that we keep whole chunks of history. They built on the object traversal in 660c889 (sha1_file: add for_each iterators for loose and packed objects, 2014-10-15), which covers both local and alternate objects. In both cases, covering alternate objects is unnecessary, as both commands can only drop objects from the local repository. In the case of prune, we traverse only the local object directory. And in the case of repacking, while we may or may not include local objects in our pack, we will never reach into the alternate with "repack -d". The "-l" option is only a question of whether we are migrating objects from the alternate into our repository, or leaving them untouched. It is possible that we may drop an object that is depended upon by another object in the alternate. For example, imagine two repositories, A and B, with A pointing to B as an alternate. Now imagine a commit that is in B which references a tree that is only in A. Traversing from recent objects in B might prevent A from dropping that tree. But this case isn't worth covering. Repo B should take responsibility for its own objects. It would never have had the commit in the first place if it did not also have the tree, and assuming it is using the same "keep recent chunks of history" scheme, then it would itself keep the tree, as well. So checking the alternate objects is not worth doing, and come with a significant performance impact. In both cases, we skip any recent objects that have already been marked SEEN (i.e., that we know are already reachable for prune, or included in the pack for a repack). So there is a slight waste of time in opening the alternate packs at all, only to notice that we have already considered each object. But much worse, the alternate repository may have a large number of objects that are not reachable from the local repository at all, and we end up adding them to the traversal. We can fix this by considering only local unseen objects. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-03-27 19:32:41 +08:00
* repository and any alternates repositories (unless the
* LOCAL_ONLY flag is set).
*/
reachable: only mark local objects as recent When pruning and repacking a repository that has an alternate object store configured, we may traverse a large number of objects in the alternate. This serves no purpose, and may be expensive to do. A longer explanation is below. Commits d3038d2 and abcb865 taught prune and pack-objects (respectively) to treat "recent" objects as tips for reachability, so that we keep whole chunks of history. They built on the object traversal in 660c889 (sha1_file: add for_each iterators for loose and packed objects, 2014-10-15), which covers both local and alternate objects. In both cases, covering alternate objects is unnecessary, as both commands can only drop objects from the local repository. In the case of prune, we traverse only the local object directory. And in the case of repacking, while we may or may not include local objects in our pack, we will never reach into the alternate with "repack -d". The "-l" option is only a question of whether we are migrating objects from the alternate into our repository, or leaving them untouched. It is possible that we may drop an object that is depended upon by another object in the alternate. For example, imagine two repositories, A and B, with A pointing to B as an alternate. Now imagine a commit that is in B which references a tree that is only in A. Traversing from recent objects in B might prevent A from dropping that tree. But this case isn't worth covering. Repo B should take responsibility for its own objects. It would never have had the commit in the first place if it did not also have the tree, and assuming it is using the same "keep recent chunks of history" scheme, then it would itself keep the tree, as well. So checking the alternate objects is not worth doing, and come with a significant performance impact. In both cases, we skip any recent objects that have already been marked SEEN (i.e., that we know are already reachable for prune, or included in the pack for a repack). So there is a slight waste of time in opening the alternate packs at all, only to notice that we have already considered each object. But much worse, the alternate repository may have a large number of objects that are not reachable from the local repository at all, and we end up adding them to the traversal. We can fix this by considering only local unseen objects. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-03-27 19:32:41 +08:00
#define FOR_EACH_OBJECT_LOCAL_ONLY 0x1
typedef int each_packed_object_fn(const struct object_id *oid,
struct packed_git *pack,
uint32_t pos,
void *data);
reachable: only mark local objects as recent When pruning and repacking a repository that has an alternate object store configured, we may traverse a large number of objects in the alternate. This serves no purpose, and may be expensive to do. A longer explanation is below. Commits d3038d2 and abcb865 taught prune and pack-objects (respectively) to treat "recent" objects as tips for reachability, so that we keep whole chunks of history. They built on the object traversal in 660c889 (sha1_file: add for_each iterators for loose and packed objects, 2014-10-15), which covers both local and alternate objects. In both cases, covering alternate objects is unnecessary, as both commands can only drop objects from the local repository. In the case of prune, we traverse only the local object directory. And in the case of repacking, while we may or may not include local objects in our pack, we will never reach into the alternate with "repack -d". The "-l" option is only a question of whether we are migrating objects from the alternate into our repository, or leaving them untouched. It is possible that we may drop an object that is depended upon by another object in the alternate. For example, imagine two repositories, A and B, with A pointing to B as an alternate. Now imagine a commit that is in B which references a tree that is only in A. Traversing from recent objects in B might prevent A from dropping that tree. But this case isn't worth covering. Repo B should take responsibility for its own objects. It would never have had the commit in the first place if it did not also have the tree, and assuming it is using the same "keep recent chunks of history" scheme, then it would itself keep the tree, as well. So checking the alternate objects is not worth doing, and come with a significant performance impact. In both cases, we skip any recent objects that have already been marked SEEN (i.e., that we know are already reachable for prune, or included in the pack for a repack). So there is a slight waste of time in opening the alternate packs at all, only to notice that we have already considered each object. But much worse, the alternate repository may have a large number of objects that are not reachable from the local repository at all, and we end up adding them to the traversal. We can fix this by considering only local unseen objects. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-03-27 19:32:41 +08:00
extern int for_each_loose_object(each_loose_object_fn, void *, unsigned flags);
extern int for_each_packed_object(each_packed_object_fn, void *, unsigned flags);
struct object_info {
/* Request */
sha1_object_info_extended: make type calculation optional Each caller of sha1_object_info_extended sets up an object_info struct to tell the function which elements of the object it wants to get. Until now, getting the type of the object has always been required (and it is returned via the return type rather than a pointer in object_info). This can involve actually opening a loose object file to determine its type, or following delta chains to determine a packed file's base type. These effects produce a measurable slow-down when doing a "cat-file --batch-check" that does not include %(objecttype). This patch adds a "typep" query to struct object_info, so that it can be optionally queried just like size and disk_size. As a result, the return type of the function is no longer the object type, but rather 0/-1 for success/error. As there are only three callers total, we just fix up each caller rather than keep a compatibility wrapper: 1. The simpler sha1_object_info wrapper continues to always ask for and return the type field. 2. The istream_source function wants to know the type, and so always asks for it. 3. The cat-file batch code asks for the type only when %(objecttype) is part of the format string. On linux.git, the best-of-five for running: $ git rev-list --objects --all >objects $ time git cat-file --batch-check='%(objectsize:disk)' on a fully packed repository goes from: real 0m8.680s user 0m8.160s sys 0m0.512s to: real 0m7.205s user 0m6.580s sys 0m0.608s Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-07-12 14:34:57 +08:00
enum object_type *typep;
unsigned long *sizep;
off_t *disk_sizep;
unsigned char *delta_base_sha1;
struct strbuf *typename;
void **contentp;
/* Response */
enum {
OI_CACHED,
OI_LOOSE,
OI_PACKED,
OI_DBCACHED
} whence;
union {
/*
* struct {
* ... Nothing to expose in this case
* } cached;
* struct {
* ... Nothing to expose in this case
* } loose;
*/
struct {
struct packed_git *pack;
off_t offset;
unsigned int is_delta;
} packed;
} u;
};
provide an initializer for "struct object_info" An all-zero initializer is fine for this struct, but because the first element is a pointer, call sites need to know to use "NULL" instead of "0". Otherwise some static checkers like "sparse" will complain; see d099b71 (Fix some sparse warnings, 2013-07-18) for example. So let's provide an initializer to make this easier to get right. But let's also comment that memset() to zero is explicitly OK[1]. One of the callers embeds object_info in another struct which is initialized via memset (expand_data in builtin/cat-file.c). Since our subset of C doesn't allow assignment from a compound literal, handling this in any other way is awkward, so we'd like to keep the ability to initialize by memset(). By documenting this property, it should make anybody who wants to change the initializer think twice before doing so. There's one other caller of interest. In parse_sha1_header(), we did not initialize the struct fully in the first place. This turned out not to be a bug because the sub-function it calls does not look at any other fields except the ones we did initialize. But that assumption might not hold in the future, so it's a dangerous construct. This patch switches it to initializing the whole struct, which protects us against unexpected reads of the other fields. [1] Obviously using memset() to initialize a pointer violates the C standard, but we long ago decided that it was an acceptable tradeoff in the real world. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-08-11 17:24:35 +08:00
/*
* Initializer for a "struct object_info" that wants no items. You may
* also memset() the memory to all-zeroes.
*/
#define OBJECT_INFO_INIT {NULL}
/* Invoke lookup_replace_object() on the given hash */
#define OBJECT_INFO_LOOKUP_REPLACE 1
/* Allow reading from a loose object file of unknown/bogus type */
#define OBJECT_INFO_ALLOW_UNKNOWN_TYPE 2
/* Do not check cached storage */
#define OBJECT_INFO_SKIP_CACHED 4
/* Do not retry packed storage after checking packed and loose storage */
#define OBJECT_INFO_QUICK 8
extern int sha1_object_info_extended(const unsigned char *, struct object_info *, unsigned flags);
extern int packed_object_info(struct packed_git *pack, off_t offset, struct object_info *);
/* Dumb servers support */
extern int update_server_info(int);
extern const char *get_log_output_encoding(void);
extern const char *get_commit_output_encoding(void);
/*
* This is a hack for test programs like test-dump-untracked-cache to
* ensure that they do not modify the untracked cache when reading it.
* Do not use it otherwise!
*/
extern int ignore_untracked_cache_config;
add `config_set` API for caching config-like files Currently `git_config()` uses a callback mechanism and file rereads for config values. Due to this approach, it is not uncommon for the config files to be parsed several times during the run of a git program, with different callbacks picking out different variables useful to themselves. Add a `config_set`, that can be used to construct an in-memory cache for config-like files that the caller specifies (i.e., files like `.gitmodules`, `~/.gitconfig` etc.). Add two external functions `git_configset_get_value` and `git_configset_get_value_multi` for querying from the config sets. `git_configset_get_value` follows `last one wins` semantic (i.e. if there are multiple matches for the queried key in the files of the configset the value returned will be the last entry in `value_list`). `git_configset_get_value_multi` returns a list of values sorted in order of increasing priority (i.e. last match will be at the end of the list). Add type specific query functions like `git_configset_get_bool` and similar. Add a default `config_set`, `the_config_set` to cache all key-value pairs read from usual config files (repo specific .git/config, user wide ~/.gitconfig, XDG config and the global /etc/gitconfig). `the_config_set` is populated using `git_config()`. Add two external functions `git_config_get_value` and `git_config_get_value_multi` for querying in a non-callback manner from `the_config_set`. Also, add type specific query functions that are implemented as a thin wrapper around the `config_set` API. Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr> Signed-off-by: Tanay Abhra <tanayabh@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-07-28 18:10:38 +08:00
extern int committer_ident_sufficiently_given(void);
extern int author_ident_sufficiently_given(void);
extern const char *git_commit_encoding;
extern const char *git_log_output_encoding;
extern const char *git_mailmap_file;
extern const char *git_mailmap_blob;
/* IO helper functions */
extern void maybe_flush_or_die(FILE *, const char *);
__attribute__((format (printf, 2, 3)))
extern void fprintf_or_die(FILE *, const char *fmt, ...);
#define COPY_READ_ERROR (-2)
#define COPY_WRITE_ERROR (-3)
extern int copy_fd(int ifd, int ofd);
extern int copy_file(const char *dst, const char *src, int mode);
extern int copy_file_with_time(const char *dst, const char *src, int mode);
extern void write_or_die(int fd, const void *buf, size_t count);
extern void fsync_or_die(int fd, const char *);
extern ssize_t read_in_full(int fd, void *buf, size_t count);
extern ssize_t write_in_full(int fd, const void *buf, size_t count);
extern ssize_t pread_in_full(int fd, void *buf, size_t count, off_t offset);
static inline ssize_t write_str_in_full(int fd, const char *str)
{
return write_in_full(fd, str, strlen(str));
}
/**
* Open (and truncate) the file at path, write the contents of buf to it,
* and close it. Dies if any errors are encountered.
*/
extern void write_file_buf(const char *path, const char *buf, size_t len);
/**
* Like write_file_buf(), but format the contents into a buffer first.
* Additionally, write_file() will append a newline if one is not already
* present, making it convenient to write text files:
*
* write_file(path, "counter: %d", ctr);
*/
__attribute__((format (printf, 2, 3)))
extern void write_file(const char *path, const char *fmt, ...);
/* pager.c */
extern void setup_pager(void);
extern int pager_in_use(void);
extern int pager_use_color;
extern int term_columns(void);
decimal_width: avoid integer overflow The decimal_width function originally appeared in blame.c as "lineno_width", and was designed for calculating the print-width of small-ish integer values (line numbers in text files). In ec7ff5b, it was made into a reusable function, and in dc801e7, we started using it to align diffstats. Binary files in a diffstat show byte counts rather than line numbers, meaning they can be quite large (e.g., consider adding or removing a 2GB file). decimal_width is not up to the challenge for two reasons: 1. It takes the value as an "int", whereas large files may easily surpass this. The value may be truncated, in which case we will produce an incorrect value. 2. It counts "up" by repeatedly multiplying another integer by 10 until it surpasses the value. This can cause an infinite loop when the value is close to the largest representable integer. For example, consider using a 32-bit signed integer, and a value of 2,140,000,000 (just shy of 2^31-1). We will count up and eventually see that 1,000,000,000 is smaller than our value. The next step would be to multiply by 10 and see that 10,000,000,000 is too large, ending the loop. But we can't represent that value, and we have signed overflow. This is technically undefined behavior, but a common behavior is to lose the high bits, in which case our iterator will certainly be less than the number. So we'll keep multiplying, overflow again, and so on. This patch changes the argument to a uintmax_t (the same type we use to store the diffstat information for binary filese), and counts "down" by repeatedly dividing our value by 10. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-02-05 16:14:19 +08:00
extern int decimal_width(uintmax_t);
extern int check_pager_config(const char *cmd);
extern void prepare_pager_args(struct child_process *, const char *pager);
extern const char *editor_program;
extern const char *askpass_program;
extern const char *excludes_file;
binary patch. This adds "binary patch" to the diff output and teaches apply what to do with them. On the diff generation side, traditionally, we said "Binary files differ\n" without giving anything other than the preimage and postimage object name on the index line. This was good enough for applying a patch generated from your own repository (very useful while rebasing), because the postimage would be available in such a case. However, this was not useful when the recipient of such a patch via e-mail were to apply it, even if the preimage was available. This patch allows the diff to generate "binary" patch when operating under --full-index option. The binary patch follows the usual extended git diff headers, and looks like this: "GIT binary patch\n" <length byte><data>"\n" ... "\n" Each line is prefixed with a "length-byte", whose value is upper or lowercase alphabet that encodes number of bytes that the data on the line decodes to (1..52 -- 'A' means 1, 'B' means 2, ..., 'Z' means 26, 'a' means 27, ...). <data> is 1 or more groups of 5-byte sequence, each of which encodes up to 4 bytes in base85 encoding. Because 52 / 4 * 5 = 65 and we have the length byte, an output line is capped to 66 characters. The payload is the same diff-delta as we use in the packfiles. On the consumption side, git-apply now can decode and apply the binary patch when --allow-binary-replacement is given, the diff was generated with --full-index, and the receiving repository has the preimage blob, which is the same condition as it always required when accepting an "Binary files differ\n" patch. Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-05-05 07:51:44 +08:00
/* base85 */
int decode_85(char *dst, const char *line, int linelen);
void encode_85(char *buf, const unsigned char *data, int bytes);
binary patch. This adds "binary patch" to the diff output and teaches apply what to do with them. On the diff generation side, traditionally, we said "Binary files differ\n" without giving anything other than the preimage and postimage object name on the index line. This was good enough for applying a patch generated from your own repository (very useful while rebasing), because the postimage would be available in such a case. However, this was not useful when the recipient of such a patch via e-mail were to apply it, even if the preimage was available. This patch allows the diff to generate "binary" patch when operating under --full-index option. The binary patch follows the usual extended git diff headers, and looks like this: "GIT binary patch\n" <length byte><data>"\n" ... "\n" Each line is prefixed with a "length-byte", whose value is upper or lowercase alphabet that encodes number of bytes that the data on the line decodes to (1..52 -- 'A' means 1, 'B' means 2, ..., 'Z' means 26, 'a' means 27, ...). <data> is 1 or more groups of 5-byte sequence, each of which encodes up to 4 bytes in base85 encoding. Because 52 / 4 * 5 = 65 and we have the length byte, an output line is capped to 66 characters. The payload is the same diff-delta as we use in the packfiles. On the consumption side, git-apply now can decode and apply the binary patch when --allow-binary-replacement is given, the diff was generated with --full-index, and the receiving repository has the preimage blob, which is the same condition as it always required when accepting an "Binary files differ\n" patch. Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-05-05 07:51:44 +08:00
Add specialized object allocator This creates a simple specialized object allocator for basic objects. This avoids wasting space with malloc overhead (metadata and extra alignment), since the specialized allocator knows the alignment, and that objects, once allocated, are never freed. It also allows us to track some basic statistics about object allocations. For example, for the mozilla import, it shows object usage as follows: blobs: 627629 (14710 kB) trees: 1119035 (34969 kB) commits: 196423 (8440 kB) tags: 1336 (46 kB) and the simpler allocator shaves off about 2.5% off the memory footprint off a "git-rev-list --all --objects", and is a bit faster too. [ Side note: this concludes the series of "save memory in object storage". The thing is, there simply isn't much more to be saved on the objects. Doing "git-rev-list --all --objects" on the mozilla archive has a final total RSS of 131498 pages for me: that's about 513MB. Of that, the object overhead is now just 56MB, the rest is going somewhere else (put another way: the fact that this patch shaves off 2.5% of the total memory overhead, considering that objects are now not much more than 10% of the total shows how big the wasted space really was: this makes object allocations much more memory- and time-efficient). I haven't looked at where the rest is, but I suspect the bulk of it is just the pack-file loading. It may be that we should pack the tree objects separately from the blob objects: for git-rev-list --objects, we don't actually ever need to even look at the blobs, but since trees and blobs are interspersed in the pack-file, we end up not being dense in the tree accesses, so we end up looking at more pages than we strictly need to. So with a 535MB pack-file, it's entirely possible - even likely - that most of the remaining RSS is just the mmap of the pack-file itself. We don't need to map in _all_ of it, but we do end up mapping a fair amount. ] Signed-off-by: Linus Torvalds <torvalds@osdl.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-06-20 01:44:15 +08:00
/* alloc.c */
extern void *alloc_blob_node(void);
extern void *alloc_tree_node(void);
extern void *alloc_commit_node(void);
extern void *alloc_tag_node(void);
extern void *alloc_object_node(void);
Add specialized object allocator This creates a simple specialized object allocator for basic objects. This avoids wasting space with malloc overhead (metadata and extra alignment), since the specialized allocator knows the alignment, and that objects, once allocated, are never freed. It also allows us to track some basic statistics about object allocations. For example, for the mozilla import, it shows object usage as follows: blobs: 627629 (14710 kB) trees: 1119035 (34969 kB) commits: 196423 (8440 kB) tags: 1336 (46 kB) and the simpler allocator shaves off about 2.5% off the memory footprint off a "git-rev-list --all --objects", and is a bit faster too. [ Side note: this concludes the series of "save memory in object storage". The thing is, there simply isn't much more to be saved on the objects. Doing "git-rev-list --all --objects" on the mozilla archive has a final total RSS of 131498 pages for me: that's about 513MB. Of that, the object overhead is now just 56MB, the rest is going somewhere else (put another way: the fact that this patch shaves off 2.5% of the total memory overhead, considering that objects are now not much more than 10% of the total shows how big the wasted space really was: this makes object allocations much more memory- and time-efficient). I haven't looked at where the rest is, but I suspect the bulk of it is just the pack-file loading. It may be that we should pack the tree objects separately from the blob objects: for git-rev-list --objects, we don't actually ever need to even look at the blobs, but since trees and blobs are interspersed in the pack-file, we end up not being dense in the tree accesses, so we end up looking at more pages than we strictly need to. So with a 535MB pack-file, it's entirely possible - even likely - that most of the remaining RSS is just the mmap of the pack-file itself. We don't need to map in _all_ of it, but we do end up mapping a fair amount. ] Signed-off-by: Linus Torvalds <torvalds@osdl.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-06-20 01:44:15 +08:00
extern void alloc_report(void);
extern unsigned int alloc_commit_index(void);
Add specialized object allocator This creates a simple specialized object allocator for basic objects. This avoids wasting space with malloc overhead (metadata and extra alignment), since the specialized allocator knows the alignment, and that objects, once allocated, are never freed. It also allows us to track some basic statistics about object allocations. For example, for the mozilla import, it shows object usage as follows: blobs: 627629 (14710 kB) trees: 1119035 (34969 kB) commits: 196423 (8440 kB) tags: 1336 (46 kB) and the simpler allocator shaves off about 2.5% off the memory footprint off a "git-rev-list --all --objects", and is a bit faster too. [ Side note: this concludes the series of "save memory in object storage". The thing is, there simply isn't much more to be saved on the objects. Doing "git-rev-list --all --objects" on the mozilla archive has a final total RSS of 131498 pages for me: that's about 513MB. Of that, the object overhead is now just 56MB, the rest is going somewhere else (put another way: the fact that this patch shaves off 2.5% of the total memory overhead, considering that objects are now not much more than 10% of the total shows how big the wasted space really was: this makes object allocations much more memory- and time-efficient). I haven't looked at where the rest is, but I suspect the bulk of it is just the pack-file loading. It may be that we should pack the tree objects separately from the blob objects: for git-rev-list --objects, we don't actually ever need to even look at the blobs, but since trees and blobs are interspersed in the pack-file, we end up not being dense in the tree accesses, so we end up looking at more pages than we strictly need to. So with a 535MB pack-file, it's entirely possible - even likely - that most of the remaining RSS is just the mmap of the pack-file itself. We don't need to map in _all_ of it, but we do end up mapping a fair amount. ] Signed-off-by: Linus Torvalds <torvalds@osdl.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-06-20 01:44:15 +08:00
/* pkt-line.c */
void packet_trace_identity(const char *prog);
/* add */
/*
* return 0 if success, 1 - if addition of a file failed and
* ADD_FILES_IGNORE_ERRORS was specified in flags
*/
int add_files_to_cache(const char *prefix, const struct pathspec *pathspec, int flags);
/* diff.c */
extern int diff_auto_refresh_index;
/* match-trees.c */
void shift_tree(const struct object_id *, const struct object_id *, struct object_id *, int);
void shift_tree_by(const struct object_id *, const struct object_id *, struct object_id *, const char *);
/*
* whitespace rules.
* used by both diff and apply
* last two digits are tab width
*/
#define WS_BLANK_AT_EOL 0100
#define WS_SPACE_BEFORE_TAB 0200
#define WS_INDENT_WITH_NON_TAB 0400
#define WS_CR_AT_EOL 01000
#define WS_BLANK_AT_EOF 02000
#define WS_TAB_IN_INDENT 04000
#define WS_TRAILING_SPACE (WS_BLANK_AT_EOL|WS_BLANK_AT_EOF)
#define WS_DEFAULT_RULE (WS_TRAILING_SPACE|WS_SPACE_BEFORE_TAB|8)
#define WS_TAB_WIDTH_MASK 077
extern unsigned whitespace_rule_cfg;
extern unsigned whitespace_rule(const char *);
extern unsigned parse_whitespace_rule(const char *);
extern unsigned ws_check(const char *line, int len, unsigned ws_rule);
extern void ws_check_emit(const char *line, int len, unsigned ws_rule, FILE *stream, const char *set, const char *reset, const char *ws);
extern char *whitespace_error_string(unsigned ws);
extern void ws_fix_copy(struct strbuf *, const char *, int, unsigned, int *);
extern int ws_blank_line(const char *line, int len, unsigned ws_rule);
#define ws_tab_width(rule) ((rule) & WS_TAB_WIDTH_MASK)
/* ls-files */
void overlay_tree_on_index(struct index_state *istate,
const char *tree_name, const char *prefix);
char *alias_lookup(const char *alias);
int split_cmdline(char *cmdline, const char ***argv);
/* Takes a negative value returned by split_cmdline */
const char *split_cmdline_strerror(int cmdline_errno);
setup: make startup_info available everywhere Commit a60645f (setup: remember whether repository was found, 2010-08-05) introduced the startup_info structure, which records some parts of the setup_git_directory() process (notably, whether we actually found a repository or not). One of the uses of this data is for functions to behave appropriately based on whether we are in a repo. But the startup_info struct is just a pointer to storage provided by the main program, and the only program that sets it up is the git.c wrapper. Thus builtins have access to startup_info, but externally linked programs do not. Worse, library code which is accessible from both has to be careful about accessing startup_info. This can be used to trigger a die("BUG") via get_sha1(): $ git fast-import <<-\EOF tag foo from HEAD:./whatever EOF fatal: BUG: startup_info struct is not initialized. Obviously that's fairly nonsensical input to feed to fast-import, but we should never hit a die("BUG"). And there may be other ways to trigger it if other non-builtins resolve sha1s. So let's point the storage for startup_info to a static variable in setup.c, making it available to all users of the library code. We _could_ turn startup_info into a regular extern struct, but doing so would mean tweaking all of the existing use sites. So let's leave the pointer indirection in place. We can, however, drop any checks for NULL, as they will always be false (and likewise, we can drop the test covering this case, which was a rather artificial situation using one of the test-* programs). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-03-06 06:10:27 +08:00
/* setup.c */
struct startup_info {
int have_repository;
const char *prefix;
};
extern struct startup_info *startup_info;
/* merge.c */
struct commit_list;
int try_merge_command(const char *strategy, size_t xopts_nr,
const char **xopts, struct commit_list *common,
const char *head_arg, struct commit_list *remotes);
int checkout_fast_forward(const struct object_id *from,
const struct object_id *to,
int overwrite_ignore);
int sane_execvp(const char *file, char *const argv[]);
/*
* A struct to encapsulate the concept of whether a file has changed
* since we last checked it. This uses criteria similar to those used
* for the index.
*/
struct stat_validity {
struct stat_data *sd;
};
void stat_validity_clear(struct stat_validity *sv);
/*
* Returns 1 if the path is a regular file (or a symlink to a regular
* file) and matches the saved stat_validity, 0 otherwise. A missing
* or inaccessible file is considered a match if the struct was just
* initialized, or if the previous update found an inaccessible file.
*/
int stat_validity_check(struct stat_validity *sv, const char *path);
/*
* Update the stat_validity from a file opened at descriptor fd. If
* the file is missing, inaccessible, or not a regular file, then
* future calls to stat_validity_check will match iff one of those
* conditions continues to be true.
*/
void stat_validity_update(struct stat_validity *sv, int fd);
int versioncmp(const char *s1, const char *s2);
void sleep_millisec(int millisec);
/*
* Create a directory and (if share is nonzero) adjust its permissions
* according to the shared_repository setting. Only use this for
* directories under $GIT_DIR. Don't use it for working tree
* directories.
*/
void safe_create_dir(const char *dir, int share);
#endif /* CACHE_H */