git/builtin-read-tree.c

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/*
* GIT - The information manager from hell
*
* Copyright (C) Linus Torvalds, 2005
*/
#include "cache.h"
#include "object.h"
#include "tree.h"
#include "tree-walk.h"
#include "cache-tree.h"
#include "unpack-trees.h"
#include "builtin.h"
static struct object_list *trees;
static int list_tree(unsigned char *sha1)
{
struct tree *tree = parse_tree_indirect(sha1);
if (!tree)
return -1;
object_list_append(&tree->object, &trees);
return 0;
}
static int read_cache_unmerged(void)
{
int i;
struct cache_entry **dst;
struct cache_entry *last = NULL;
read_cache();
dst = active_cache;
for (i = 0; i < active_nr; i++) {
struct cache_entry *ce = active_cache[i];
if (ce_stage(ce)) {
if (last && !strcmp(ce->name, last->name))
continue;
cache_tree_invalidate_path(active_cache_tree, ce->name);
last = ce;
ce->ce_mode = 0;
ce->ce_flags &= ~htons(CE_STAGEMASK);
}
*dst++ = ce;
}
active_nr = dst - active_cache;
return !!last;
}
static void prime_cache_tree_rec(struct cache_tree *it, struct tree *tree)
{
struct tree_desc desc;
tree_entry(): new tree-walking helper function This adds a "tree_entry()" function that combines the common operation of doing a "tree_entry_extract()" + "update_tree_entry()". It also has a simplified calling convention, designed for simple loops that traverse over a whole tree: the arguments are pointers to the tree descriptor and a name_entry structure to fill in, and it returns a boolean "true" if there was an entry left to be gotten in the tree. This allows tree traversal with struct tree_desc desc; struct name_entry entry; desc.buf = tree->buffer; desc.size = tree->size; while (tree_entry(&desc, &entry) { ... use "entry.{path, sha1, mode, pathlen}" ... } which is not only shorter than writing it out in full, it's hopefully less error prone too. [ It's actually a tad faster too - we don't need to recalculate the entry pathlength in both extract and update, but need to do it only once. Also, some callers can avoid doing a "strlen()" on the result, since it's returned as part of the name_entry structure. However, by now we're talking just 1% speedup on "git-rev-list --objects --all", and we're definitely at the point where tree walking is no longer the issue any more. ] NOTE! Not everybody wants to use this new helper function, since some of the tree walkers very much on purpose do the descriptor update separately from the entry extraction. So the "extract + update" sequence still remains as the core sequence, this is just a simplified interface. We should probably add a silly two-line inline helper function for initializing the descriptor from the "struct tree" too, just to cut down on the noise from that common "desc" initializer. Signed-off-by: Linus Torvalds <torvalds@osdl.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-05-31 00:45:45 +08:00
struct name_entry entry;
int cnt;
hashcpy(it->sha1, tree->object.sha1);
desc.buf = tree->buffer;
desc.size = tree->size;
cnt = 0;
tree_entry(): new tree-walking helper function This adds a "tree_entry()" function that combines the common operation of doing a "tree_entry_extract()" + "update_tree_entry()". It also has a simplified calling convention, designed for simple loops that traverse over a whole tree: the arguments are pointers to the tree descriptor and a name_entry structure to fill in, and it returns a boolean "true" if there was an entry left to be gotten in the tree. This allows tree traversal with struct tree_desc desc; struct name_entry entry; desc.buf = tree->buffer; desc.size = tree->size; while (tree_entry(&desc, &entry) { ... use "entry.{path, sha1, mode, pathlen}" ... } which is not only shorter than writing it out in full, it's hopefully less error prone too. [ It's actually a tad faster too - we don't need to recalculate the entry pathlength in both extract and update, but need to do it only once. Also, some callers can avoid doing a "strlen()" on the result, since it's returned as part of the name_entry structure. However, by now we're talking just 1% speedup on "git-rev-list --objects --all", and we're definitely at the point where tree walking is no longer the issue any more. ] NOTE! Not everybody wants to use this new helper function, since some of the tree walkers very much on purpose do the descriptor update separately from the entry extraction. So the "extract + update" sequence still remains as the core sequence, this is just a simplified interface. We should probably add a silly two-line inline helper function for initializing the descriptor from the "struct tree" too, just to cut down on the noise from that common "desc" initializer. Signed-off-by: Linus Torvalds <torvalds@osdl.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-05-31 00:45:45 +08:00
while (tree_entry(&desc, &entry)) {
if (!S_ISDIR(entry.mode))
cnt++;
else {
struct cache_tree_sub *sub;
tree_entry(): new tree-walking helper function This adds a "tree_entry()" function that combines the common operation of doing a "tree_entry_extract()" + "update_tree_entry()". It also has a simplified calling convention, designed for simple loops that traverse over a whole tree: the arguments are pointers to the tree descriptor and a name_entry structure to fill in, and it returns a boolean "true" if there was an entry left to be gotten in the tree. This allows tree traversal with struct tree_desc desc; struct name_entry entry; desc.buf = tree->buffer; desc.size = tree->size; while (tree_entry(&desc, &entry) { ... use "entry.{path, sha1, mode, pathlen}" ... } which is not only shorter than writing it out in full, it's hopefully less error prone too. [ It's actually a tad faster too - we don't need to recalculate the entry pathlength in both extract and update, but need to do it only once. Also, some callers can avoid doing a "strlen()" on the result, since it's returned as part of the name_entry structure. However, by now we're talking just 1% speedup on "git-rev-list --objects --all", and we're definitely at the point where tree walking is no longer the issue any more. ] NOTE! Not everybody wants to use this new helper function, since some of the tree walkers very much on purpose do the descriptor update separately from the entry extraction. So the "extract + update" sequence still remains as the core sequence, this is just a simplified interface. We should probably add a silly two-line inline helper function for initializing the descriptor from the "struct tree" too, just to cut down on the noise from that common "desc" initializer. Signed-off-by: Linus Torvalds <torvalds@osdl.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-05-31 00:45:45 +08:00
struct tree *subtree = lookup_tree(entry.sha1);
if (!subtree->object.parsed)
parse_tree(subtree);
tree_entry(): new tree-walking helper function This adds a "tree_entry()" function that combines the common operation of doing a "tree_entry_extract()" + "update_tree_entry()". It also has a simplified calling convention, designed for simple loops that traverse over a whole tree: the arguments are pointers to the tree descriptor and a name_entry structure to fill in, and it returns a boolean "true" if there was an entry left to be gotten in the tree. This allows tree traversal with struct tree_desc desc; struct name_entry entry; desc.buf = tree->buffer; desc.size = tree->size; while (tree_entry(&desc, &entry) { ... use "entry.{path, sha1, mode, pathlen}" ... } which is not only shorter than writing it out in full, it's hopefully less error prone too. [ It's actually a tad faster too - we don't need to recalculate the entry pathlength in both extract and update, but need to do it only once. Also, some callers can avoid doing a "strlen()" on the result, since it's returned as part of the name_entry structure. However, by now we're talking just 1% speedup on "git-rev-list --objects --all", and we're definitely at the point where tree walking is no longer the issue any more. ] NOTE! Not everybody wants to use this new helper function, since some of the tree walkers very much on purpose do the descriptor update separately from the entry extraction. So the "extract + update" sequence still remains as the core sequence, this is just a simplified interface. We should probably add a silly two-line inline helper function for initializing the descriptor from the "struct tree" too, just to cut down on the noise from that common "desc" initializer. Signed-off-by: Linus Torvalds <torvalds@osdl.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-05-31 00:45:45 +08:00
sub = cache_tree_sub(it, entry.path);
sub->cache_tree = cache_tree();
prime_cache_tree_rec(sub->cache_tree, subtree);
cnt += sub->cache_tree->entry_count;
}
}
it->entry_count = cnt;
}
static void prime_cache_tree(void)
{
struct tree *tree = (struct tree *)trees->item;
if (!tree)
return;
active_cache_tree = cache_tree();
prime_cache_tree_rec(active_cache_tree, tree);
}
static const char read_tree_usage[] = "git-read-tree (<sha> | [[-m [--aggressive] | --reset | --prefix=<prefix>] [-u | -i]] <sha1> [<sha2> [<sha3>]])";
static struct lock_file lock_file;
int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
{
int i, newfd, stage = 0;
unsigned char sha1[20];
struct unpack_trees_options opts;
memset(&opts, 0, sizeof(opts));
opts.head_idx = -1;
setup_git_directory();
git_config(git_default_config);
newfd = hold_lock_file_for_update(&lock_file, get_index_file(), 1);
git_config(git_default_config);
for (i = 1; i < argc; i++) {
const char *arg = argv[i];
/* "-u" means "update", meaning that a merge will update
* the working tree.
*/
if (!strcmp(arg, "-u")) {
opts.update = 1;
continue;
}
if (!strcmp(arg, "-v")) {
opts.verbose_update = 1;
continue;
}
/* "-i" means "index only", meaning that a merge will
* not even look at the working tree.
*/
if (!strcmp(arg, "-i")) {
opts.index_only = 1;
continue;
}
/* "--prefix=<subdirectory>/" means keep the current index
* entries and put the entries from the tree under the
* given subdirectory.
*/
if (!strncmp(arg, "--prefix=", 9)) {
if (stage || opts.merge || opts.prefix)
usage(read_tree_usage);
opts.prefix = arg + 9;
opts.merge = 1;
stage = 1;
if (read_cache_unmerged())
die("you need to resolve your current index first");
continue;
}
/* This differs from "-m" in that we'll silently ignore
* unmerged entries and overwrite working tree files that
* correspond to them.
*/
if (!strcmp(arg, "--reset")) {
if (stage || opts.merge || opts.prefix)
usage(read_tree_usage);
opts.reset = 1;
opts.merge = 1;
stage = 1;
read_cache_unmerged();
2005-06-16 01:25:46 +08:00
continue;
}
if (!strcmp(arg, "--trivial")) {
opts.trivial_merges_only = 1;
continue;
}
if (!strcmp(arg, "--aggressive")) {
opts.aggressive = 1;
continue;
}
/* "-m" stands for "merge", meaning we start in stage 1 */
if (!strcmp(arg, "-m")) {
if (stage || opts.merge || opts.prefix)
usage(read_tree_usage);
if (read_cache_unmerged())
die("you need to resolve your current index first");
stage = 1;
opts.merge = 1;
continue;
}
/* using -u and -i at the same time makes no sense */
if (1 < opts.index_only + opts.update)
usage(read_tree_usage);
if (get_sha1(arg, sha1))
die("Not a valid object name %s", arg);
if (list_tree(sha1) < 0)
die("failed to unpack tree object %s", arg);
stage++;
}
if ((opts.update||opts.index_only) && !opts.merge)
usage(read_tree_usage);
if (opts.prefix) {
int pfxlen = strlen(opts.prefix);
int pos;
if (opts.prefix[pfxlen-1] != '/')
die("prefix must end with /");
if (stage != 2)
die("binding merge takes only one tree");
pos = cache_name_pos(opts.prefix, pfxlen);
if (0 <= pos)
die("corrupt index file");
pos = -pos-1;
if (pos < active_nr &&
!strncmp(active_cache[pos]->name, opts.prefix, pfxlen))
die("subdirectory '%s' already exists.", opts.prefix);
pos = cache_name_pos(opts.prefix, pfxlen-1);
if (0 <= pos)
die("file '%.*s' already exists.",
pfxlen-1, opts.prefix);
}
if (opts.merge) {
if (stage < 2)
die("just how do you expect me to merge %d trees?", stage-1);
switch (stage - 1) {
case 1:
opts.fn = opts.prefix ? bind_merge : oneway_merge;
break;
case 2:
opts.fn = twoway_merge;
break;
case 3:
default:
opts.fn = threeway_merge;
cache_tree_free(&active_cache_tree);
break;
}
if (stage - 1 >= 3)
opts.head_idx = stage - 2;
else
opts.head_idx = 1;
}
unpack_trees(trees, &opts);
/*
* When reading only one tree (either the most basic form,
* "-m ent" or "--reset ent" form), we can obtain a fully
* valid cache-tree because the index must match exactly
* what came from the tree.
*/
if (trees && trees->item && !opts.prefix && (!opts.merge || (stage == 2))) {
cache_tree_free(&active_cache_tree);
prime_cache_tree();
}
if (write_cache(newfd, active_cache, active_nr) ||
close(newfd) || commit_lock_file(&lock_file))
die("unable to write new index file");
return 0;
}