From f4204ab9f6a192cdb9a68150e031d7183688bfeb Mon Sep 17 00:00:00 2001 From: Junio C Hamano Date: Tue, 21 Nov 2006 23:36:35 -0800 Subject: [PATCH] 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 "^". 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 --- builtin-pack-refs.c | 8 +++- builtin-show-ref.c | 6 ++- refs.c | 111 +++++++++++++++++++++++++------------------- refs.h | 7 ++- 4 files changed, 77 insertions(+), 55 deletions(-) diff --git a/builtin-pack-refs.c b/builtin-pack-refs.c index ee5a5565a..8dc5b9eff 100644 --- a/builtin-pack-refs.c +++ b/builtin-pack-refs.c @@ -46,8 +46,8 @@ static int handle_one_ref(const char *path, const unsigned char *sha1, if (o->type == OBJ_TAG) { o = deref_tag(o, path, 0); if (o) - fprintf(cb->refs_file, "%s %s^{}\n", - sha1_to_hex(o->sha1), path); + fprintf(cb->refs_file, "^%s\n", + sha1_to_hex(o->sha1)); } } @@ -111,6 +111,10 @@ int cmd_pack_refs(int argc, const char **argv, const char *prefix) if (!cbdata.refs_file) die("unable to create ref-pack file structure (%s)", strerror(errno)); + + /* perhaps other traits later as well */ + fprintf(cbdata.refs_file, "# pack-refs with: peeled \n"); + for_each_ref(handle_one_ref, &cbdata); fflush(cbdata.refs_file); fsync(fd); diff --git a/builtin-show-ref.c b/builtin-show-ref.c index 9ae3d0854..073979855 100644 --- a/builtin-show-ref.c +++ b/builtin-show-ref.c @@ -67,8 +67,10 @@ match: return 0; if ((flag & REF_ISPACKED) && !peel_ref(refname, peeled)) { - hex = find_unique_abbrev(peeled, abbrev); - printf("%s %s^{}\n", hex, refname); + if (!is_null_sha1(peeled)) { + hex = find_unique_abbrev(peeled, abbrev); + printf("%s %s^{}\n", hex, refname); + } } else { obj = parse_object(sha1); diff --git a/refs.c b/refs.c index 75cbc0e7e..96ea8b690 100644 --- a/refs.c +++ b/refs.c @@ -5,14 +5,18 @@ #include +/* 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); diff --git a/refs.h b/refs.h index 40048a691..cd1e1d620 100644 --- a/refs.h +++ b/refs.h @@ -10,14 +10,13 @@ struct ref_lock { int force_write; }; +#define REF_ISSYMREF 01 +#define REF_ISPACKED 02 + /* * Calls the specified function for each ref file until it returns nonzero, * and returns the value */ -#define REF_ISSYMREF 01 -#define REF_ISPACKED 02 -#define REF_ISPEELED 04 /* internal use */ - typedef int each_ref_fn(const char *refname, const unsigned char *sha1, int flags, void *cb_data); extern int head_ref(each_ref_fn, void *); extern int for_each_ref(each_ref_fn, void *); -- 2.26.2