From e1e22e37f47e3f4d741d28920e1d27e3775c31ad Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Mon, 11 Sep 2006 16:37:32 -0700 Subject: [PATCH] Start handling references internally as a sorted in-memory list This also adds some very rudimentary support for the notion of packed refs. HOWEVER! At this point it isn't used to actually look up a ref yet, only for listing them (ie "for_each_ref()" and friends see the packed refs, but none of the other single-ref lookup routines). Note how we keep two separate lists: one for the loose refs, and one for the packed refs we read. That's so that we can easily keep the two apart, and read only one set or the other (and still always make sure that the loose refs take precedence). [ From this, it's not actually obvious why we'd keep the two separate lists, but it's important to have the packed refs on their own list later on, when I add support for looking up a single loose one. For that case, we will want to read _just_ the packed refs in case the single-ref lookup fails, yet we may end up needing the other list at some point in the future, so keeping them separated is important ] Signed-off-by: Linus Torvalds Signed-off-by: Junio C Hamano --- Makefile | 3 +- builtin-pack-refs.c | 41 ++++++++ builtin.h | 1 + git.c | 1 + refs.c | 226 +++++++++++++++++++++++++++++++++----------- 5 files changed, 218 insertions(+), 54 deletions(-) create mode 100644 builtin-pack-refs.c diff --git a/Makefile b/Makefile index 8467447da..cdbb566d4 100644 --- a/Makefile +++ b/Makefile @@ -301,7 +301,8 @@ BUILTIN_OBJS = \ builtin-upload-tar.o \ builtin-verify-pack.o \ builtin-write-tree.o \ - builtin-zip-tree.o + builtin-zip-tree.o \ + builtin-pack-refs.o GITLIBS = $(LIB_FILE) $(XDIFF_LIB) LIBS = $(GITLIBS) -lz diff --git a/builtin-pack-refs.c b/builtin-pack-refs.c new file mode 100644 index 000000000..0f5d827c2 --- /dev/null +++ b/builtin-pack-refs.c @@ -0,0 +1,41 @@ +#include "cache.h" +#include "refs.h" + +static FILE *refs_file; +static const char *result_path, *lock_path; + +static void remove_lock_file(void) +{ + if (lock_path) + unlink(lock_path); +} + +static int handle_one_ref(const char *path, const unsigned char *sha1) +{ + fprintf(refs_file, "%s %s\n", sha1_to_hex(sha1), path); + return 0; +} + +int cmd_pack_refs(int argc, const char **argv, const char *prefix) +{ + int fd; + + result_path = xstrdup(git_path("packed-refs")); + lock_path = xstrdup(mkpath("%s.lock", result_path)); + + fd = open(lock_path, O_CREAT | O_EXCL | O_WRONLY, 0666); + if (fd < 0) + die("unable to create new ref-pack file (%s)", strerror(errno)); + atexit(remove_lock_file); + + refs_file = fdopen(fd, "w"); + if (!refs_file) + die("unable to create ref-pack file structure (%s)", strerror(errno)); + for_each_ref(handle_one_ref); + fsync(fd); + fclose(refs_file); + if (rename(lock_path, result_path) < 0) + die("unable to overwrite old ref-pack file (%s)", strerror(errno)); + lock_path = NULL; + return 0; +} diff --git a/builtin.h b/builtin.h index ccade94e2..4b11f52f1 100644 --- a/builtin.h +++ b/builtin.h @@ -63,5 +63,6 @@ extern int cmd_version(int argc, const char **argv, const char *prefix); extern int cmd_whatchanged(int argc, const char **argv, const char *prefix); extern int cmd_write_tree(int argc, const char **argv, const char *prefix); extern int cmd_verify_pack(int argc, const char **argv, const char *prefix); +extern int cmd_pack_refs(int argc, const char **argv, const char *prefix); #endif diff --git a/git.c b/git.c index 44ab0de94..de2a06b97 100644 --- a/git.c +++ b/git.c @@ -269,6 +269,7 @@ static void handle_internal_command(int argc, const char **argv, char **envp) { "whatchanged", cmd_whatchanged, RUN_SETUP | USE_PAGER }, { "write-tree", cmd_write_tree, RUN_SETUP }, { "verify-pack", cmd_verify_pack }, + { "pack-refs", cmd_pack_refs, RUN_SETUP }, }; int i; diff --git a/refs.c b/refs.c index 5e653141c..5f80a6892 100644 --- a/refs.c +++ b/refs.c @@ -3,6 +3,145 @@ #include +struct ref_list { + struct ref_list *next; + unsigned char sha1[20]; + char name[FLEX_ARRAY]; +}; + +static const char *parse_ref_line(char *line, unsigned char *sha1) +{ + /* + * 42: the answer to everything. + * + * In this case, it happens to be the answer to + * 40 (length of sha1 hex representation) + * +1 (space in between hex and name) + * +1 (newline at the end of the line) + */ + int len = strlen(line) - 42; + + if (len <= 0) + return NULL; + if (get_sha1_hex(line, sha1) < 0) + return NULL; + if (!isspace(line[40])) + return NULL; + line += 41; + if (line[len] != '\n') + return NULL; + line[len] = 0; + return line; +} + +static struct ref_list *add_ref(const char *name, const unsigned char *sha1, struct ref_list *list) +{ + int len; + struct ref_list **p = &list, *entry; + + /* Find the place to insert the ref into.. */ + while ((entry = *p) != NULL) { + int cmp = strcmp(entry->name, name); + if (cmp > 0) + break; + + /* Same as existing entry? */ + if (!cmp) + return list; + p = &entry->next; + } + + /* Allocate it and add it in.. */ + len = strlen(name) + 1; + entry = xmalloc(sizeof(struct ref_list) + len); + hashcpy(entry->sha1, sha1); + memcpy(entry->name, name, len); + entry->next = *p; + *p = entry; + return list; +} + +static struct ref_list *get_packed_refs(void) +{ + static int did_refs = 0; + static struct ref_list *refs = NULL; + + if (!did_refs) { + FILE *f = fopen(git_path("packed-refs"), "r"); + if (f) { + struct ref_list *list = NULL; + char refline[PATH_MAX]; + while (fgets(refline, sizeof(refline), f)) { + unsigned char sha1[20]; + const char *name = parse_ref_line(refline, sha1); + if (!name) + continue; + list = add_ref(name, sha1, list); + } + fclose(f); + refs = list; + } + did_refs = 1; + } + return refs; +} + +static struct ref_list *get_ref_dir(const char *base, struct ref_list *list) +{ + DIR *dir = opendir(git_path("%s", base)); + + if (dir) { + struct dirent *de; + int baselen = strlen(base); + char *path = xmalloc(baselen + 257); + + memcpy(path, base, baselen); + if (baselen && base[baselen-1] != '/') + path[baselen++] = '/'; + + while ((de = readdir(dir)) != NULL) { + unsigned char sha1[20]; + struct stat st; + int namelen; + + if (de->d_name[0] == '.') + continue; + namelen = strlen(de->d_name); + if (namelen > 255) + continue; + if (has_extension(de->d_name, ".lock")) + continue; + memcpy(path + baselen, de->d_name, namelen+1); + if (stat(git_path("%s", path), &st) < 0) + continue; + if (S_ISDIR(st.st_mode)) { + list = get_ref_dir(path, list); + continue; + } + if (read_ref(git_path("%s", path), sha1) < 0) { + error("%s points nowhere!", path); + continue; + } + list = add_ref(path, sha1, list); + } + free(path); + closedir(dir); + } + return list; +} + +static struct ref_list *get_loose_refs(void) +{ + static int did_refs = 0; + static struct ref_list *refs = NULL; + + if (!did_refs) { + refs = get_ref_dir("refs", NULL); + did_refs = 1; + } + return refs; +} + /* We allow "recursive" symbolic refs. Only within reason, though */ #define MAXDEPTH 5 @@ -121,60 +260,41 @@ int read_ref(const char *filename, unsigned char *sha1) static int do_for_each_ref(const char *base, int (*fn)(const char *path, const unsigned char *sha1), int trim) { - int retval = 0; - DIR *dir = opendir(git_path("%s", base)); - - if (dir) { - struct dirent *de; - int baselen = strlen(base); - char *path = xmalloc(baselen + 257); - - if (!strncmp(base, "./", 2)) { - base += 2; - baselen -= 2; + int retval; + struct ref_list *packed = get_packed_refs(); + struct ref_list *loose = get_loose_refs(); + + while (packed && loose) { + struct ref_list *entry; + int cmp = strcmp(packed->name, loose->name); + if (!cmp) { + packed = packed->next; + continue; } - memcpy(path, base, baselen); - if (baselen && base[baselen-1] != '/') - path[baselen++] = '/'; - - while ((de = readdir(dir)) != NULL) { - unsigned char sha1[20]; - struct stat st; - int namelen; + if (cmp > 0) { + entry = loose; + loose = loose->next; + } else { + entry = packed; + packed = packed->next; + } + if (strncmp(base, entry->name, trim)) + continue; + retval = fn(entry->name + trim, entry->sha1); + if (retval) + return retval; + } - if (de->d_name[0] == '.') - continue; - namelen = strlen(de->d_name); - if (namelen > 255) - continue; - if (has_extension(de->d_name, ".lock")) - continue; - memcpy(path + baselen, de->d_name, namelen+1); - if (stat(git_path("%s", path), &st) < 0) - continue; - if (S_ISDIR(st.st_mode)) { - retval = do_for_each_ref(path, fn, trim); - if (retval) - break; - continue; - } - if (read_ref(git_path("%s", path), sha1) < 0) { - error("%s points nowhere!", path); - continue; - } - if (!has_sha1_file(sha1)) { - error("%s does not point to a valid " - "commit object!", path); - continue; - } - retval = fn(path + trim, sha1); + packed = packed ? packed : loose; + while (packed) { + if (!strncmp(base, packed->name, trim)) { + retval = fn(packed->name + trim, packed->sha1); if (retval) - break; + return retval; } - free(path); - closedir(dir); + packed = packed->next; } - return retval; + return 0; } int head_ref(int (*fn)(const char *path, const unsigned char *sha1)) @@ -187,22 +307,22 @@ int head_ref(int (*fn)(const char *path, const unsigned char *sha1)) int for_each_ref(int (*fn)(const char *path, const unsigned char *sha1)) { - return do_for_each_ref("refs", fn, 0); + return do_for_each_ref("refs/", fn, 0); } int for_each_tag_ref(int (*fn)(const char *path, const unsigned char *sha1)) { - return do_for_each_ref("refs/tags", fn, 10); + return do_for_each_ref("refs/tags/", fn, 10); } int for_each_branch_ref(int (*fn)(const char *path, const unsigned char *sha1)) { - return do_for_each_ref("refs/heads", fn, 11); + return do_for_each_ref("refs/heads/", fn, 11); } int for_each_remote_ref(int (*fn)(const char *path, const unsigned char *sha1)) { - return do_for_each_ref("refs/remotes", fn, 13); + return do_for_each_ref("refs/remotes/", fn, 13); } int get_ref_sha1(const char *ref, unsigned char *sha1) -- 2.26.2