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authorMike Hommey <mh@glandium.org>2015-07-09 15:50:09 +0900
committerJunio C Hamano <gitster@pobox.com>2015-07-13 09:36:05 -0700
commit0df3245721580a3d48c9766a311dd0e3367844b8 (patch)
tree185fe8c41e487da319169f0e9a9e2237718291a3 /fast-import.c
parent7ecec52d42a964c4a8e9f6ca41bb0b5ce00049b4 (diff)
downloadgit-0df3245721580a3d48c9766a311dd0e3367844b8.tar.gz
fast-import: do less work when given "from" matches current branch headmh/fast-import-optimize-current-from
When building a fast-import stream, it's easy to forget the fact that for non-merge commits happening on top of the current branch head, there is no need for a "from" command. That is corroborated by the fact that at least git-p4, hg-fast-export and felipec's git-remote-hg all unconditionally use a "from" command. Unfortunately, giving a "from" command always resets the branch tree, forcing it to be re-read, and in many cases, the pack is also closed and reopened through gfi_unpack_entry. Both are unnecessary overhead, and the latter is particularly slow at least on OSX. Avoid resetting the tree when it's unmodified, and avoid calling gfi_unpack_entry when the given mark points to the same commit as the current branch head. Signed-off-by: Mike Hommey <mh@glandium.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 'fast-import.c')
-rw-r--r--fast-import.c29
1 files changed, 17 insertions, 12 deletions
diff --git a/fast-import.c b/fast-import.c
index 6378726993..ece0096623 100644
--- a/fast-import.c
+++ b/fast-import.c
@@ -2588,14 +2588,12 @@ static int parse_from(struct branch *b)
{
const char *from;
struct branch *s;
+ unsigned char sha1[20];
if (!skip_prefix(command_buf.buf, "from ", &from))
return 0;
- if (b->branch_tree.tree) {
- release_tree_content_recursive(b->branch_tree.tree);
- b->branch_tree.tree = NULL;
- }
+ hashcpy(sha1, b->branch_tree.versions[1].sha1);
s = lookup_branch(from);
if (b == s)
@@ -2610,14 +2608,16 @@ static int parse_from(struct branch *b)
struct object_entry *oe = find_mark(idnum);
if (oe->type != OBJ_COMMIT)
die("Mark :%" PRIuMAX " not a commit", idnum);
- hashcpy(b->sha1, oe->idx.sha1);
- if (oe->pack_id != MAX_PACK_ID) {
- unsigned long size;
- char *buf = gfi_unpack_entry(oe, &size);
- parse_from_commit(b, buf, size);
- free(buf);
- } else
- parse_from_existing(b);
+ if (hashcmp(b->sha1, oe->idx.sha1)) {
+ hashcpy(b->sha1, oe->idx.sha1);
+ if (oe->pack_id != MAX_PACK_ID) {
+ unsigned long size;
+ char *buf = gfi_unpack_entry(oe, &size);
+ parse_from_commit(b, buf, size);
+ free(buf);
+ } else
+ parse_from_existing(b);
+ }
} else if (!get_sha1(from, b->sha1)) {
parse_from_existing(b);
if (is_null_sha1(b->sha1))
@@ -2626,6 +2626,11 @@ static int parse_from(struct branch *b)
else
die("Invalid ref name or SHA1 expression: %s", from);
+ if (b->branch_tree.tree && hashcmp(sha1, b->branch_tree.versions[1].sha1)) {
+ release_tree_content_recursive(b->branch_tree.tree);
+ b->branch_tree.tree = NULL;
+ }
+
read_next_command();
return 1;
}