[PATCH] git-branch: only traverse the requested refs

[Lars Hjemli <hjemli@gmail.com>]

This avoids looking at every single file below .git/refs when git-branch
is fetching the list of refs to display.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>
---

This patch should make git-branch much more efficient when there exists
many files below .git/refs, but it does require two passes through
.git/packed-refs when -a is specified.

No benchmarking performed...

 builtin-branch.c |   28 +++++++++-------------------
 1 files changed, 9 insertions(+), 19 deletions(-)

diff --git a/builtin-branch.c b/builtin-branch.c
index 3da8b55..466e1e0 100644
--- a/builtin-branch.c
+++ b/builtin-branch.c
@@ -185,25 +185,8 @@ static int append_ref(const char *refname, const unsigned char *sha1, int flags,
 {
 	struct ref_list *ref_list = (struct ref_list*)(cb_data);
 	struct ref_item *newitem;
-	int kind = REF_UNKNOWN_TYPE;
 	int len;
 
-	/* Detect kind */
-	if (!prefixcmp(refname, "refs/heads/")) {
-		kind = REF_LOCAL_BRANCH;
-		refname += 11;
-	} else if (!prefixcmp(refname, "refs/remotes/")) {
-		kind = REF_REMOTE_BRANCH;
-		refname += 13;
-	} else if (!prefixcmp(refname, "refs/tags/")) {
-		kind = REF_TAG;
-		refname += 10;
-	}
-
-	/* Don't add types the caller doesn't want */
-	if ((kind & ref_list->kinds) == 0)
-		return 0;
-
 	/* Resize buffer */
 	if (ref_list->index >= ref_list->alloc) {
 		ref_list->alloc = alloc_nr(ref_list->alloc);
@@ -214,7 +197,7 @@ static int append_ref(const char *refname, const unsigned char *sha1, int flags,
 	/* Record the new item */
 	newitem = &(ref_list->list[ref_list->index++]);
 	newitem->name = xstrdup(refname);
-	newitem->kind = kind;
+	newitem->kind = ref_list->kinds;
 	hashcpy(newitem->sha1, sha1);
 	len = strlen(newitem->name);
 	if (len > ref_list->maxwidth)
@@ -296,8 +279,15 @@ static void print_ref_list(int kinds, int detached, int verbose, int abbrev)
 	struct ref_list ref_list;
 
 	memset(&ref_list, 0, sizeof(ref_list));
+	if (kinds & REF_LOCAL_BRANCH) {
+		ref_list.kinds = REF_LOCAL_BRANCH;
+		for_each_branch_ref(append_ref, &ref_list);
+	}
+	if (kinds & REF_REMOTE_BRANCH) {
+		ref_list.kinds = REF_REMOTE_BRANCH;
+		for_each_remote_ref(append_ref, &ref_list);
+	}
 	ref_list.kinds = kinds;
-	for_each_ref(append_ref, &ref_list);
 
 	qsort(ref_list.list, ref_list.index, sizeof(struct ref_item), ref_cmp);
 
-- 
1.5.3.4.206.g58ba4