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git/cache-tree.h

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Add cache-tree. The cache_tree data structure is to cache tree object names that would result from the current index file. The idea is to have an optional file to record each tree object name that corresponds to a directory path in the cache when we run write_cache(), and read it back when we run read_cache(). During various index manupulations, we selectively invalidate the parts so that the next write-tree can bypass regenerating tree objects for unchanged parts of the directory hierarchy. We could perhaps make the cache-tree data an optional part of the index file, but that would involve the index format updates, so unless we need it for performance reasons, the current plan is to use a separate file, $GIT_DIR/index.aux to store this information and link it with the index file with the checksum that is already used for index file integrity check. Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-04-24 07:52:20 +08:00
#ifndef CACHE_TREE_H
#define CACHE_TREE_H
Move prime_cache_tree() to cache-tree.c The interface to build cache-tree belongs there. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-04-20 18:58:18 +08:00
#include "tree.h"
Optimize "diff-index --cached" using cache-tree When running "diff-index --cached" after making a change to only a small portion of the index, there is no point unpacking unchanged subtrees into the index recursively, only to find that all entries match anyway. Tweak unpack_trees() logic that is used to read in the tree object to catch the case where the tree entry we are looking at matches the index as a whole by looking at the cache-tree. As an exercise, after modifying a few paths in the kernel tree, here are a few numbers on my Athlon 64X2 3800+: (without patch, hot cache) $ /usr/bin/time git diff --cached --raw :100644 100644 b57e1f5... e69de29... M Makefile :100644 000000 8c86b72... 0000000... D arch/x86/Makefile :000000 100644 0000000... e69de29... A arche 0.07user 0.02system 0:00.09elapsed 102%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+0outputs (0major+9407minor)pagefaults 0swaps (with patch, hot cache) $ /usr/bin/time ../git.git/git-diff --cached --raw :100644 100644 b57e1f5... e69de29... M Makefile :100644 000000 8c86b72... 0000000... D arch/x86/Makefile :000000 100644 0000000... e69de29... A arche 0.02user 0.00system 0:00.02elapsed 103%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+0outputs (0major+2446minor)pagefaults 0swaps Cold cache numbers are very impressive, but it does not matter very much in practice: (without patch, cold cache) $ su root sh -c 'echo 3 >/proc/sys/vm/drop_caches' $ /usr/bin/time git diff --cached --raw :100644 100644 b57e1f5... e69de29... M Makefile :100644 000000 8c86b72... 0000000... D arch/x86/Makefile :000000 100644 0000000... e69de29... A arche 0.06user 0.17system 0:10.26elapsed 2%CPU (0avgtext+0avgdata 0maxresident)k 247032inputs+0outputs (1172major+8237minor)pagefaults 0swaps (with patch, cold cache) $ su root sh -c 'echo 3 >/proc/sys/vm/drop_caches' $ /usr/bin/time ../git.git/git-diff --cached --raw :100644 100644 b57e1f5... e69de29... M Makefile :100644 000000 8c86b72... 0000000... D arch/x86/Makefile :000000 100644 0000000... e69de29... A arche 0.02user 0.01system 0:01.01elapsed 3%CPU (0avgtext+0avgdata 0maxresident)k 18440inputs+0outputs (79major+2369minor)pagefaults 0swaps This of course helps "git status" as well. (without patch, hot cache) $ /usr/bin/time ../git.git/git-status >/dev/null 0.17user 0.18system 0:00.35elapsed 100%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+5336outputs (0major+10970minor)pagefaults 0swaps (with patch, hot cache) $ /usr/bin/time ../git.git/git-status >/dev/null 0.10user 0.16system 0:00.27elapsed 99%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+5336outputs (0major+3921minor)pagefaults 0swaps Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-05-21 06:57:22 +08:00
#include "tree-walk.h"
Move prime_cache_tree() to cache-tree.c The interface to build cache-tree belongs there. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-04-20 18:58:18 +08:00
Add cache-tree. The cache_tree data structure is to cache tree object names that would result from the current index file. The idea is to have an optional file to record each tree object name that corresponds to a directory path in the cache when we run write_cache(), and read it back when we run read_cache(). During various index manupulations, we selectively invalidate the parts so that the next write-tree can bypass regenerating tree objects for unchanged parts of the directory hierarchy. We could perhaps make the cache-tree data an optional part of the index file, but that would involve the index format updates, so unless we need it for performance reasons, the current plan is to use a separate file, $GIT_DIR/index.aux to store this information and link it with the index file with the checksum that is already used for index file integrity check. Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-04-24 07:52:20 +08:00
struct cache_tree;
struct cache_tree_sub {
struct cache_tree *cache_tree;
cache-tree: fix writing cache-tree when CE_REMOVE is present entry_count is used in update_one() for two purposes: 1. to skip through the number of processed entries in in-memory index 2. to record the number of entries this cache-tree covers on disk Unfortunately when CE_REMOVE is present these numbers are not the same because CE_REMOVE entries are automatically removed before writing to disk but entry_count is not adjusted and still counts CE_REMOVE entries. Separate the two use cases into two different variables. #1 is taken care by the new field count in struct cache_tree_sub and entry_count is prepared for #2. Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-12-16 12:15:27 +08:00
int count; /* internally used by update_one() */
Add cache-tree. The cache_tree data structure is to cache tree object names that would result from the current index file. The idea is to have an optional file to record each tree object name that corresponds to a directory path in the cache when we run write_cache(), and read it back when we run read_cache(). During various index manupulations, we selectively invalidate the parts so that the next write-tree can bypass regenerating tree objects for unchanged parts of the directory hierarchy. We could perhaps make the cache-tree data an optional part of the index file, but that would involve the index format updates, so unless we need it for performance reasons, the current plan is to use a separate file, $GIT_DIR/index.aux to store this information and link it with the index file with the checksum that is already used for index file integrity check. Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-04-24 07:52:20 +08:00
int namelen;
int used;
char name[FLEX_ARRAY];
};
struct cache_tree {
int entry_count; /* negative means "invalid" */
unsigned char sha1[20];
int subtree_nr;
int subtree_alloc;
struct cache_tree_sub **down;
};
struct cache_tree *cache_tree(void);
index: make the index file format extensible. ... and move the cache-tree data into it. Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-04-25 12:18:58 +08:00
void cache_tree_free(struct cache_tree **);
Add cache-tree. The cache_tree data structure is to cache tree object names that would result from the current index file. The idea is to have an optional file to record each tree object name that corresponds to a directory path in the cache when we run write_cache(), and read it back when we run read_cache(). During various index manupulations, we selectively invalidate the parts so that the next write-tree can bypass regenerating tree objects for unchanged parts of the directory hierarchy. We could perhaps make the cache-tree data an optional part of the index file, but that would involve the index format updates, so unless we need it for performance reasons, the current plan is to use a separate file, $GIT_DIR/index.aux to store this information and link it with the index file with the checksum that is already used for index file integrity check. Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-04-24 07:52:20 +08:00
void cache_tree_invalidate_path(struct cache_tree *, const char *);
read-tree: teach 1-way merege and plain read to prime cache-tree. This teaches read-tree to fully populate valid cache-tree when reading a tree from scratch, or reading a single tree into an existing index, reusing only the cached stat information (i.e. one-way merge). We have already taught update-index about cache-tree, so "git checkout" followed by updates to a few path followed by a "git commit" would become very efficient. Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-04-27 16:33:07 +08:00
struct cache_tree_sub *cache_tree_sub(struct cache_tree *, const char *);
Add cache-tree. The cache_tree data structure is to cache tree object names that would result from the current index file. The idea is to have an optional file to record each tree object name that corresponds to a directory path in the cache when we run write_cache(), and read it back when we run read_cache(). During various index manupulations, we selectively invalidate the parts so that the next write-tree can bypass regenerating tree objects for unchanged parts of the directory hierarchy. We could perhaps make the cache-tree data an optional part of the index file, but that would involve the index format updates, so unless we need it for performance reasons, the current plan is to use a separate file, $GIT_DIR/index.aux to store this information and link it with the index file with the checksum that is already used for index file integrity check. Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-04-24 07:52:20 +08:00
Small cache_tree_write refactor. This function cannot fail, make it void. Also make write_one act on a const char* instead of a char*. Signed-off-by: Pierre Habouzit <madcoder@debian.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-09-25 16:22:44 +08:00
void cache_tree_write(struct strbuf *, struct cache_tree *root);
index: make the index file format extensible. ... and move the cache-tree data into it. Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-04-25 12:18:58 +08:00
struct cache_tree *cache_tree_read(const char *buffer, unsigned long size);
Add cache-tree. The cache_tree data structure is to cache tree object names that would result from the current index file. The idea is to have an optional file to record each tree object name that corresponds to a directory path in the cache when we run write_cache(), and read it back when we run read_cache(). During various index manupulations, we selectively invalidate the parts so that the next write-tree can bypass regenerating tree objects for unchanged parts of the directory hierarchy. We could perhaps make the cache-tree data an optional part of the index file, but that would involve the index format updates, so unless we need it for performance reasons, the current plan is to use a separate file, $GIT_DIR/index.aux to store this information and link it with the index file with the checksum that is already used for index file integrity check. Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-04-24 07:52:20 +08:00
index: make the index file format extensible. ... and move the cache-tree data into it. Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-04-25 12:18:58 +08:00
int cache_tree_fully_valid(struct cache_tree *);
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
int cache_tree_update(struct cache_tree *, const struct cache_entry * const *, int, int);
Refactor cache_tree_update idiom from commit We'll need to safely create or update the cache-tree data of the_index from other places. While at it, give it an argument that lets us silence the messages produced by unmerged entries (which prevent it from working). Signed-off-by: Thomas Rast <trast@student.ethz.ch> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2011-12-07 01:43:37 +08:00
int update_main_cache_tree(int);
Add cache-tree. The cache_tree data structure is to cache tree object names that would result from the current index file. The idea is to have an optional file to record each tree object name that corresponds to a directory path in the cache when we run write_cache(), and read it back when we run read_cache(). During various index manupulations, we selectively invalidate the parts so that the next write-tree can bypass regenerating tree objects for unchanged parts of the directory hierarchy. We could perhaps make the cache-tree data an optional part of the index file, but that would involve the index format updates, so unless we need it for performance reasons, the current plan is to use a separate file, $GIT_DIR/index.aux to store this information and link it with the index file with the checksum that is already used for index file integrity check. Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-04-24 07:52:20 +08:00
write-tree --ignore-cache-tree This allows you to discard the cache-tree information before writing the tree out of the index (i.e. it always recomputes the tree object names for all the subtrees). This is only useful as a debug option, so I did not bother documenting it. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-05-21 02:04:35 +08:00
/* bitmasks to write_cache_as_tree flags */
#define WRITE_TREE_MISSING_OK 1
#define WRITE_TREE_IGNORE_CACHE_TREE 2
cache-tree: update API to take abitrary flags Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-01-16 10:36:46 +08:00
#define WRITE_TREE_DRY_RUN 4
#define WRITE_TREE_SILENT 8
write-tree --ignore-cache-tree This allows you to discard the cache-tree information before writing the tree out of the index (i.e. it always recomputes the tree object names for all the subtrees). This is only useful as a debug option, so I did not bother documenting it. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-05-21 02:04:35 +08:00
/* error return codes */
Make error messages from cherry-pick/revert more sensible The original "rewrite in C" did somewhat a sloppy job while stealing code from git-write-tree. The caller pretends as if the write_tree() function would return an error code and being able to issue a sensible error message itself, but write_tree() function just calls die() and never returns an error. Worse yet, the function claims that it was running git-write-tree (which is no longer true after cherry-pick stole it). Tested-by: Björn Steinbrink <B.Steinbrink@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-01-11 14:49:35 +08:00
#define WRITE_TREE_UNREADABLE_INDEX (-1)
#define WRITE_TREE_UNMERGED_INDEX (-2)
#define WRITE_TREE_PREFIX_ERROR (-3)
write-tree --ignore-cache-tree This allows you to discard the cache-tree information before writing the tree out of the index (i.e. it always recomputes the tree object names for all the subtrees). This is only useful as a debug option, so I did not bother documenting it. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-05-21 02:04:35 +08:00
int write_cache_as_tree(unsigned char *sha1, int flags, const char *prefix);
Move prime_cache_tree() to cache-tree.c The interface to build cache-tree belongs there. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-04-20 18:58:18 +08:00
void prime_cache_tree(struct cache_tree **, struct tree *);
Optimize "diff-index --cached" using cache-tree When running "diff-index --cached" after making a change to only a small portion of the index, there is no point unpacking unchanged subtrees into the index recursively, only to find that all entries match anyway. Tweak unpack_trees() logic that is used to read in the tree object to catch the case where the tree entry we are looking at matches the index as a whole by looking at the cache-tree. As an exercise, after modifying a few paths in the kernel tree, here are a few numbers on my Athlon 64X2 3800+: (without patch, hot cache) $ /usr/bin/time git diff --cached --raw :100644 100644 b57e1f5... e69de29... M Makefile :100644 000000 8c86b72... 0000000... D arch/x86/Makefile :000000 100644 0000000... e69de29... A arche 0.07user 0.02system 0:00.09elapsed 102%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+0outputs (0major+9407minor)pagefaults 0swaps (with patch, hot cache) $ /usr/bin/time ../git.git/git-diff --cached --raw :100644 100644 b57e1f5... e69de29... M Makefile :100644 000000 8c86b72... 0000000... D arch/x86/Makefile :000000 100644 0000000... e69de29... A arche 0.02user 0.00system 0:00.02elapsed 103%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+0outputs (0major+2446minor)pagefaults 0swaps Cold cache numbers are very impressive, but it does not matter very much in practice: (without patch, cold cache) $ su root sh -c 'echo 3 >/proc/sys/vm/drop_caches' $ /usr/bin/time git diff --cached --raw :100644 100644 b57e1f5... e69de29... M Makefile :100644 000000 8c86b72... 0000000... D arch/x86/Makefile :000000 100644 0000000... e69de29... A arche 0.06user 0.17system 0:10.26elapsed 2%CPU (0avgtext+0avgdata 0maxresident)k 247032inputs+0outputs (1172major+8237minor)pagefaults 0swaps (with patch, cold cache) $ su root sh -c 'echo 3 >/proc/sys/vm/drop_caches' $ /usr/bin/time ../git.git/git-diff --cached --raw :100644 100644 b57e1f5... e69de29... M Makefile :100644 000000 8c86b72... 0000000... D arch/x86/Makefile :000000 100644 0000000... e69de29... A arche 0.02user 0.01system 0:01.01elapsed 3%CPU (0avgtext+0avgdata 0maxresident)k 18440inputs+0outputs (79major+2369minor)pagefaults 0swaps This of course helps "git status" as well. (without patch, hot cache) $ /usr/bin/time ../git.git/git-status >/dev/null 0.17user 0.18system 0:00.35elapsed 100%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+5336outputs (0major+10970minor)pagefaults 0swaps (with patch, hot cache) $ /usr/bin/time ../git.git/git-status >/dev/null 0.10user 0.16system 0:00.27elapsed 99%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+5336outputs (0major+3921minor)pagefaults 0swaps Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-05-21 06:57:22 +08:00
extern int cache_tree_matches_traversal(struct cache_tree *, struct name_entry *ent, struct traverse_info *info);
Add cache-tree. The cache_tree data structure is to cache tree object names that would result from the current index file. The idea is to have an optional file to record each tree object name that corresponds to a directory path in the cache when we run write_cache(), and read it back when we run read_cache(). During various index manupulations, we selectively invalidate the parts so that the next write-tree can bypass regenerating tree objects for unchanged parts of the directory hierarchy. We could perhaps make the cache-tree data an optional part of the index file, but that would involve the index format updates, so unless we need it for performance reasons, the current plan is to use a separate file, $GIT_DIR/index.aux to store this information and link it with the index file with the checksum that is already used for index file integrity check. Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-04-24 07:52:20 +08:00
#endif
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