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authorJunio C Hamano <junkio@cox.net>2006-11-21 23:36:35 -0800
committerJunio C Hamano <junkio@cox.net>2006-11-21 23:37:35 -0800
commitf4204ab9f6a192cdb9a68150e031d7183688bfeb (patch)
tree3c9402e5a9e55dadf6477e44904fcc86fac7c8be /refs.c
parentcf0adba7885342e1bbcf0689fece9d13e39784b4 (diff)
downloadgit-f4204ab9f6a192cdb9a68150e031d7183688bfeb.tar.gz
Store peeled refs in packed-refs (take 2).
This fixes the previous implementation which failed to optimize repositories with tons of lightweight tags. The updated packed-refs format begins with "# packed-refs with:" line that lists the kind of extended data the file records. Currently, there is only one such extension defined, "peeled". This stores the "peeled tag" on a line that immediately follows a line for a tag object itself in the format "^<sha-1>". The header line itself and any extended data are ignored by older implementation, so packed-refs file generated with this version can still be used by older git. packed-refs made by older git can of course be used with this version. Signed-off-by: Junio C Hamano <junkio@cox.net>
Diffstat (limited to 'refs.c')
-rw-r--r--refs.c111
1 files changed, 64 insertions, 47 deletions
diff --git a/refs.c b/refs.c
index 75cbc0e7ef..96ea8b6907 100644
--- a/refs.c
+++ b/refs.c
@@ -5,14 +5,18 @@
#include <errno.h>
+/* ISSYMREF=01 and ISPACKED=02 are public interfaces */
+#define REF_KNOWS_PEELED 04
+
struct ref_list {
struct ref_list *next;
- unsigned char flag; /* ISSYMREF? ISPACKED? ISPEELED? */
+ unsigned char flag; /* ISSYMREF? ISPACKED? */
unsigned char sha1[20];
+ unsigned char peeled[20];
char name[FLEX_ARRAY];
};
-static const char *parse_ref_line(char *line, unsigned char *sha1, int *flag)
+static const char *parse_ref_line(char *line, unsigned char *sha1)
{
/*
* 42: the answer to everything.
@@ -23,7 +27,6 @@ static const char *parse_ref_line(char *line, unsigned char *sha1, int *flag)
* +1 (newline at the end of the line)
*/
int len = strlen(line) - 42;
- int peeled = 0;
if (len <= 0)
return NULL;
@@ -32,29 +35,18 @@ static const char *parse_ref_line(char *line, unsigned char *sha1, int *flag)
if (!isspace(line[40]))
return NULL;
line += 41;
-
- if (isspace(*line)) {
- /* "SHA-1 SP SP refs/tags/tagname^{} LF"? */
- line++;
- len--;
- peeled = 1;
- }
+ if (isspace(*line))
+ return NULL;
if (line[len] != '\n')
return NULL;
line[len] = 0;
- if (peeled && (len < 3 || strcmp(line + len - 3, "^{}")))
- return NULL;
-
- if (!peeled)
- *flag &= ~REF_ISPEELED;
- else
- *flag |= REF_ISPEELED;
return line;
}
static struct ref_list *add_ref(const char *name, const unsigned char *sha1,
- int flag, struct ref_list *list)
+ int flag, struct ref_list *list,
+ struct ref_list **new_entry)
{
int len;
struct ref_list **p = &list, *entry;
@@ -66,8 +58,11 @@ static struct ref_list *add_ref(const char *name, const unsigned char *sha1,
break;
/* Same as existing entry? */
- if (!cmp)
+ if (!cmp) {
+ if (new_entry)
+ *new_entry = entry;
return list;
+ }
p = &entry->next;
}
@@ -75,10 +70,13 @@ static struct ref_list *add_ref(const char *name, const unsigned char *sha1,
len = strlen(name) + 1;
entry = xmalloc(sizeof(struct ref_list) + len);
hashcpy(entry->sha1, sha1);
+ hashclr(entry->peeled);
memcpy(entry->name, name, len);
entry->flag = flag;
entry->next = *p;
*p = entry;
+ if (new_entry)
+ *new_entry = entry;
return list;
}
@@ -114,27 +112,50 @@ static void invalidate_cached_refs(void)
ca->did_loose = ca->did_packed = 0;
}
+static void read_packed_refs(FILE *f, struct cached_refs *cached_refs)
+{
+ struct ref_list *list = NULL;
+ struct ref_list *last = NULL;
+ char refline[PATH_MAX];
+ int flag = REF_ISPACKED;
+
+ while (fgets(refline, sizeof(refline), f)) {
+ unsigned char sha1[20];
+ const char *name;
+ static const char header[] = "# pack-refs with:";
+
+ if (!strncmp(refline, header, sizeof(header)-1)) {
+ const char *traits = refline + sizeof(header) - 1;
+ if (strstr(traits, " peeled "))
+ flag |= REF_KNOWS_PEELED;
+ /* perhaps other traits later as well */
+ continue;
+ }
+
+ name = parse_ref_line(refline, sha1);
+ if (name) {
+ list = add_ref(name, sha1, flag, list, &last);
+ continue;
+ }
+ if (last &&
+ refline[0] == '^' &&
+ strlen(refline) == 42 &&
+ refline[41] == '\n' &&
+ !get_sha1_hex(refline + 1, sha1))
+ hashcpy(last->peeled, sha1);
+ }
+ cached_refs->packed = list;
+}
+
static struct ref_list *get_packed_refs(void)
{
if (!cached_refs.did_packed) {
- struct ref_list *refs = NULL;
FILE *f = fopen(git_path("packed-refs"), "r");
+ cached_refs.packed = NULL;
if (f) {
- struct ref_list *list = NULL;
- char refline[PATH_MAX];
- while (fgets(refline, sizeof(refline), f)) {
- unsigned char sha1[20];
- int flag = REF_ISPACKED;
- const char *name =
- parse_ref_line(refline, sha1, &flag);
- if (!name)
- continue;
- list = add_ref(name, sha1, flag, list);
- }
+ read_packed_refs(f, &cached_refs);
fclose(f);
- refs = list;
}
- cached_refs.packed = refs;
cached_refs.did_packed = 1;
}
return cached_refs.packed;
@@ -177,7 +198,7 @@ static struct ref_list *get_ref_dir(const char *base, struct ref_list *list)
error("%s points nowhere!", ref);
continue;
}
- list = add_ref(ref, sha1, flag, list);
+ list = add_ref(ref, sha1, flag, list, NULL);
}
free(ref);
closedir(dir);
@@ -225,8 +246,7 @@ const char *resolve_ref(const char *ref, unsigned char *sha1, int reading, int *
if (lstat(path, &st) < 0) {
struct ref_list *list = get_packed_refs();
while (list) {
- if (!(list->flag & REF_ISPEELED) &&
- !strcmp(ref, list->name)) {
+ if (!strcmp(ref, list->name)) {
hashcpy(sha1, list->sha1);
if (flag)
*flag |= REF_ISPACKED;
@@ -348,8 +368,6 @@ static int do_one_ref(const char *base, each_ref_fn fn, int trim,
return 0;
if (is_null_sha1(entry->sha1))
return 0;
- if (entry->flag & REF_ISPEELED)
- return 0;
if (!has_sha1_file(entry->sha1)) {
error("%s does not point to a valid object!", entry->name);
return 0;
@@ -368,22 +386,21 @@ int peel_ref(const char *ref, unsigned char *sha1)
if ((flag & REF_ISPACKED)) {
struct ref_list *list = get_packed_refs();
- int len = strlen(ref);
while (list) {
- if ((list->flag & REF_ISPEELED) &&
- !strncmp(list->name, ref, len) &&
- strlen(list->name) == len + 3 &&
- !strcmp(list->name + len, "^{}")) {
- hashcpy(sha1, list->sha1);
- return 0;
+ if (!strcmp(list->name, ref)) {
+ if (list->flag & REF_KNOWS_PEELED) {
+ hashcpy(sha1, list->peeled);
+ return 0;
+ }
+ /* older pack-refs did not leave peeled ones */
+ break;
}
list = list->next;
}
- /* older pack-refs did not leave peeled ones in */
}
- /* otherwise ... */
+ /* fallback - callers should not call this for unpacked refs */
o = parse_object(base);
if (o->type == OBJ_TAG) {
o = deref_tag(o, ref, 0);