merge-recursive: do not use on-file index when not needed.
This revamps the merge-recursive implementation following the
outline in:
Message-ID: <7v8xgileza.fsf@assigned-by-dhcp.cox.net>
There is no need to write out the index until the very end just
once from merge-recursive. Also there is no need to write out
the resulting tree object for the simple case of merging with a
single merge base.
Signed-off-by: Junio C Hamano <junkio@cox.net>
diff --git a/merge-recursive.c b/merge-recursive.c
index aab4c34..5237021 100644
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -110,35 +110,6 @@
}
}
-static const char *current_index_file = NULL;
-static const char *original_index_file;
-static const char *temporary_index_file;
-static int cache_dirty = 0;
-
-static int flush_cache(void)
-{
- /* flush temporary index */
- struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
- int fd = hold_lock_file_for_update(lock, current_index_file, 1);
- if (write_cache(fd, active_cache, active_nr) ||
- close(fd) || commit_lock_file(lock))
- die ("unable to write %s", current_index_file);
- discard_cache();
- cache_dirty = 0;
- return 0;
-}
-
-static void setup_index(int temp)
-{
- current_index_file = temp ? temporary_index_file: original_index_file;
- if (cache_dirty) {
- discard_cache();
- cache_dirty = 0;
- }
- unlink(temporary_index_file);
- discard_cache();
-}
-
static struct cache_entry *make_cache_entry(unsigned int mode,
const unsigned char *sha1, const char *path, int stage, int refresh)
{
@@ -167,9 +138,6 @@
const char *path, int stage, int refresh, int options)
{
struct cache_entry *ce;
- if (!cache_dirty)
- read_cache_from(current_index_file);
- cache_dirty++;
ce = make_cache_entry(mode, sha1 ? sha1 : null_sha1, path, stage, refresh);
if (!ce)
return error("cache_addinfo failed: %s", strerror(cache_errno));
@@ -187,26 +155,6 @@
*/
static int index_only = 0;
-static int git_read_tree(struct tree *tree)
-{
- int rc;
- struct object_list *trees = NULL;
- struct unpack_trees_options opts;
-
- if (cache_dirty)
- die("read-tree with dirty cache");
-
- memset(&opts, 0, sizeof(opts));
- object_list_append(&tree->object, &trees);
- rc = unpack_trees(trees, &opts);
- cache_tree_free(&active_cache_tree);
-
- if (rc == 0)
- cache_dirty = 1;
-
- return rc;
-}
-
static int git_merge_trees(int index_only,
struct tree *common,
struct tree *head,
@@ -216,11 +164,6 @@
struct object_list *trees = NULL;
struct unpack_trees_options opts;
- if (!cache_dirty) {
- read_cache_from(current_index_file);
- cache_dirty = 1;
- }
-
memset(&opts, 0, sizeof(opts));
if (index_only)
opts.index_only = 1;
@@ -236,39 +179,37 @@
rc = unpack_trees(trees, &opts);
cache_tree_free(&active_cache_tree);
-
- cache_dirty = 1;
-
return rc;
}
+static int unmerged_index(void)
+{
+ int i;
+ for (i = 0; i < active_nr; i++) {
+ struct cache_entry *ce = active_cache[i];
+ if (ce_stage(ce))
+ return 1;
+ }
+ return 0;
+}
+
static struct tree *git_write_tree(void)
{
struct tree *result = NULL;
- if (cache_dirty) {
- unsigned i;
- for (i = 0; i < active_nr; i++) {
- struct cache_entry *ce = active_cache[i];
- if (ce_stage(ce))
- return NULL;
- }
- } else
- read_cache_from(current_index_file);
+ if (unmerged_index())
+ return NULL;
if (!active_cache_tree)
active_cache_tree = cache_tree();
if (!cache_tree_fully_valid(active_cache_tree) &&
- cache_tree_update(active_cache_tree,
- active_cache, active_nr, 0, 0) < 0)
+ cache_tree_update(active_cache_tree,
+ active_cache, active_nr, 0, 0) < 0)
die("error building trees");
result = lookup_tree(active_cache_tree->sha1);
- flush_cache();
- cache_dirty = 0;
-
return result;
}
@@ -331,10 +272,7 @@
int i;
unmerged->strdup_paths = 1;
- if (!cache_dirty) {
- read_cache_from(current_index_file);
- cache_dirty++;
- }
+
for (i = 0; i < active_nr; i++) {
struct path_list_item *item;
struct stage_data *e;
@@ -469,9 +407,6 @@
int update_working_directory = !index_only && !no_wd;
if (update_cache) {
- if (!cache_dirty)
- read_cache_from(current_index_file);
- cache_dirty++;
if (remove_file_from_cache(path))
return -1;
}
@@ -1105,9 +1040,7 @@
sha1_to_hex(head->object.sha1),
sha1_to_hex(merge->object.sha1));
- *result = git_write_tree();
-
- if (!*result) {
+ if (unmerged_index()) {
struct path_list *entries, *re_head, *re_merge;
int i;
path_list_clear(¤t_file_set, 1);
@@ -1128,17 +1061,11 @@
if (!process_entry(path, e, branch1, branch2))
clean = 0;
}
- if (cache_dirty)
- flush_cache();
path_list_clear(re_merge, 0);
path_list_clear(re_head, 0);
path_list_clear(entries, 1);
- if (clean || index_only)
- *result = git_write_tree();
- else
- *result = NULL;
} else {
clean = 1;
printf("merging of trees %s and %s resulted in %s\n",
@@ -1146,6 +1073,8 @@
sha1_to_hex(merge->object.sha1),
sha1_to_hex((*result)->object.sha1));
}
+ if (index_only)
+ *result = git_write_tree();
return clean;
}
@@ -1170,10 +1099,10 @@
const char *branch1,
const char *branch2,
int call_depth /* =0 */,
- struct commit *ancestor /* =None */,
+ struct commit_list *ca,
struct commit **result)
{
- struct commit_list *ca = NULL, *iter;
+ struct commit_list *iter;
struct commit *merged_common_ancestors;
struct tree *mrtree;
int clean;
@@ -1182,10 +1111,10 @@
output_commit_title(h1);
output_commit_title(h2);
- if (ancestor)
- commit_list_insert(ancestor, &ca);
- else
- ca = reverse_commit_list(get_merge_bases(h1, h2, 1));
+ if (!ca) {
+ ca = get_merge_bases(h1, h2, 1);
+ ca = reverse_commit_list(ca);
+ }
output("found %u common ancestor(s):", commit_list_count(ca));
for (iter = ca; iter; iter = iter->next)
@@ -1211,6 +1140,7 @@
* merge_trees has always overwritten it: the commited
* "conflicts" were already resolved.
*/
+ discard_cache();
merge(merged_common_ancestors, iter->item,
"Temporary merge branch 1",
"Temporary merge branch 2",
@@ -1223,25 +1153,21 @@
die("merge returned no commit");
}
+ discard_cache();
if (call_depth == 0) {
- setup_index(0 /* $GIT_DIR/index */);
+ read_cache();
index_only = 0;
- } else {
- setup_index(1 /* temporary index */);
- git_read_tree(h1->tree);
+ } else
index_only = 1;
- }
clean = merge_trees(h1->tree, h2->tree, merged_common_ancestors->tree,
branch1, branch2, &mrtree);
- if (!ancestor && (clean || index_only)) {
+ if (index_only) {
*result = make_virtual_commit(mrtree, "merged tree");
commit_list_insert(h1, &(*result)->parents);
commit_list_insert(h2, &(*result)->parents->next);
- } else
- *result = NULL;
-
+ }
return clean;
}
@@ -1277,19 +1203,16 @@
int main(int argc, char *argv[])
{
- static const char *bases[2];
+ static const char *bases[20];
static unsigned bases_count = 0;
int i, clean;
const char *branch1, *branch2;
struct commit *result, *h1, *h2;
+ struct commit_list *ca = NULL;
+ struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
+ int index_fd;
git_config(git_default_config); /* core.filemode */
- original_index_file = getenv(INDEX_ENVIRONMENT);
-
- if (!original_index_file)
- original_index_file = xstrdup(git_path("index"));
-
- temporary_index_file = xstrdup(git_path("mrg-rcrsv-tmp-idx"));
if (argc < 4)
die("Usage: %s <base>... -- <head> <remote> ...\n", argv[0]);
@@ -1313,18 +1236,18 @@
branch2 = better_branch_name(branch2);
printf("Merging %s with %s\n", branch1, branch2);
- if (bases_count == 1) {
- struct commit *ancestor = get_ref(bases[0]);
- clean = merge(h1, h2, branch1, branch2, 0, ancestor, &result);
- } else
- clean = merge(h1, h2, branch1, branch2, 0, NULL, &result);
+ index_fd = hold_lock_file_for_update(lock, get_index_file(), 1);
- if (cache_dirty)
- flush_cache();
+ for (i = 0; i < bases_count; i++) {
+ struct commit *ancestor = get_ref(bases[i]);
+ ca = commit_list_insert(ancestor, &ca);
+ }
+ clean = merge(h1, h2, branch1, branch2, 0, ca, &result);
+
+ if (active_cache_changed &&
+ (write_cache(index_fd, active_cache, active_nr) ||
+ close(index_fd) || commit_lock_file(lock)))
+ die ("unable to write %s", get_index_file());
return clean ? 0: 1;
}
-
-/*
-vim: sw=8 noet
-*/
