diff options
Diffstat (limited to 'server-info.c')
| -rw-r--r-- | server-info.c | 565 |
1 files changed, 565 insertions, 0 deletions
diff --git a/server-info.c b/server-info.c new file mode 100644 index 0000000000..00f8ca0c58 --- /dev/null +++ b/server-info.c @@ -0,0 +1,565 @@ +#include "cache.h" +#include "refs.h" +#include "object.h" +#include "commit.h" +#include "rev-cache.h" + +/* refs */ +static FILE *info_ref_fp; +static unsigned long info_ref_time; +static int info_ref_is_stale = 0; + +static int stat_ref(const char *path, const unsigned char *sha1) +{ + struct stat st; + if (!stat(path, &st) && info_ref_time < st.st_mtime) + info_ref_is_stale = 1; + return 0; +} + +static int add_info_ref(const char *path, const unsigned char *sha1) +{ + fprintf(info_ref_fp, "%s %s\n", sha1_to_hex(sha1), path); + return 0; +} + +static int update_info_refs(int force) +{ + struct stat st; + char *path0 = strdup(git_path("info/refs")); + int len = strlen(path0); + char *path1 = xmalloc(len + 2); + + strcpy(path1, path0); + strcpy(path1 + len, "+"); + + if (!force) { + if (stat(path0, &st)) { + if (errno == ENOENT) + info_ref_is_stale = 1; + else + return error("cannot stat %s", path0); + } + else { + info_ref_time = st.st_mtime; + for_each_ref(stat_ref); + } + if (!info_ref_is_stale) + return 0; + } + + safe_create_leading_directories(path0); + info_ref_fp = fopen(path1, "w"); + if (!info_ref_fp) + return error("unable to update %s", path0); + for_each_ref(add_info_ref); + fclose(info_ref_fp); + rename(path1, path0); + free(path0); + free(path1); + return 0; +} + +/* packs */ +struct pack_info { + unsigned long latest; + struct packed_git *p; + int old_num; + int new_num; + int nr_alloc; + int nr_heads; + unsigned char (*head)[20]; + char dep[0]; /* more */ +} **info; +static int num_pack; +static const char *objdir; +static int objdirlen; + +static struct object *parse_object_cheap(const unsigned char *sha1) +{ + struct object *o; + + if ((o = parse_object(sha1)) == NULL) + return NULL; + if (o->type == commit_type) { + struct commit *commit = (struct commit *)o; + free(commit->buffer); + commit->buffer = NULL; + } + return o; +} + +static struct pack_info *find_pack_by_name(const char *name) +{ + int i; + for (i = 0; i < num_pack; i++) { + struct packed_git *p = info[i]->p; + /* skip "/pack/" after ".git/objects" */ + if (!strcmp(p->pack_name + objdirlen + 6, name)) + return info[i]; + } + return NULL; +} + +static struct pack_info *find_pack_by_old_num(int old_num) +{ + int i; + for (i = 0; i < num_pack; i++) + if (info[i]->old_num == old_num) + return info[i]; + return NULL; +} + +static int add_head_def(struct pack_info *this, unsigned char *sha1) +{ + if (this->nr_alloc <= this->nr_heads) { + this->nr_alloc = alloc_nr(this->nr_alloc); + this->head = xrealloc(this->head, this->nr_alloc * 20); + } + memcpy(this->head[this->nr_heads++], sha1, 20); + return 0; +} + +/* Returns non-zero when we detect that the info in the + * old file is useless. + */ +static int parse_pack_def(const char *line, int old_cnt) +{ + struct pack_info *i = find_pack_by_name(line + 2); + if (i) { + i->old_num = old_cnt; + return 0; + } + else { + /* The file describes a pack that is no longer here; + * dependencies between packs needs to be recalculated. + */ + return 1; + } +} + +/* Returns non-zero when we detect that the info in the + * old file is useless. + */ +static int parse_depend_def(char *line) +{ + unsigned long num; + char *cp, *ep; + struct pack_info *this, *that; + + cp = line + 2; + num = strtoul(cp, &ep, 10); + if (ep == cp) + return error("invalid input %s", line); + this = find_pack_by_old_num(num); + if (!this) + return 0; + while (ep && *(cp = ep)) { + num = strtoul(cp, &ep, 10); + if (ep == cp) + break; + that = find_pack_by_old_num(num); + if (!that) + /* The pack this one depends on does not + * exist; this should not happen because + * we write out the list of packs first and + * then dependency information, but it means + * the file is useless anyway. + */ + return 1; + this->dep[that->new_num] = 1; + } + return 0; +} + +/* Returns non-zero when we detect that the info in the + * old file is useless. + */ +static int parse_head_def(char *line) +{ + unsigned char sha1[20]; + unsigned long num; + char *cp, *ep; + struct pack_info *this; + struct object *o; + + cp = line + 2; + num = strtoul(cp, &ep, 10); + if (ep == cp || *ep++ != ' ') + return error("invalid input ix %s", line); + this = find_pack_by_old_num(num); + if (!this) + return 1; /* You know the drill. */ + if (get_sha1_hex(ep, sha1) || ep[40] != ' ') + return error("invalid input sha1 %s (%s)", line, ep); + if ((o = parse_object_cheap(sha1)) == NULL) + return error("no such object: %s", line); + return add_head_def(this, sha1); +} + +/* Returns non-zero when we detect that the info in the + * old file is useless. + */ +static int read_pack_info_file(const char *infofile) +{ + FILE *fp; + char line[1000]; + int old_cnt = 0; + + fp = fopen(infofile, "r"); + if (!fp) + return 1; /* nonexisting is not an error. */ + + while (fgets(line, sizeof(line), fp)) { + int len = strlen(line); + if (line[len-1] == '\n') + line[len-1] = 0; + + switch (line[0]) { + case 'P': /* P name */ + if (parse_pack_def(line, old_cnt++)) + goto out_stale; + break; + case 'D': /* D ix dep-ix1 dep-ix2... */ + if (parse_depend_def(line)) + goto out_stale; + break; + case 'T': /* T ix sha1 type */ + if (parse_head_def(line)) + goto out_stale; + break; + default: + error("unrecognized: %s", line); + break; + } + } + fclose(fp); + return 0; + out_stale: + fclose(fp); + return 1; +} + +/* We sort the packs according to the date of the latest commit. That + * in turn indicates how young the pack is, and in general we would + * want to depend on younger packs. + */ +static unsigned long get_latest_commit_date(struct packed_git *p) +{ + unsigned char sha1[20]; + struct object *o; + int num = num_packed_objects(p); + int i; + unsigned long latest = 0; + + for (i = 0; i < num; i++) { + if (nth_packed_object_sha1(p, i, sha1)) + die("corrupt pack file %s?", p->pack_name); + if ((o = parse_object_cheap(sha1)) == NULL) + die("cannot parse %s", sha1_to_hex(sha1)); + if (o->type == commit_type) { + struct commit *commit = (struct commit *)o; + if (latest < commit->date) + latest = commit->date; + } + } + return latest; +} + +static int compare_info(const void *a_, const void *b_) +{ + struct pack_info * const* a = a_; + struct pack_info * const* b = b_; + + if (0 <= (*a)->old_num && 0 <= (*b)->old_num) + /* Keep the order in the original */ + return (*a)->old_num - (*b)->old_num; + else if (0 <= (*a)->old_num) + /* Only A existed in the original so B is obviously newer */ + return -1; + else if (0 <= (*b)->old_num) + /* The other way around. */ + return 1; + + if ((*a)->latest < (*b)->latest) + return -1; + else if ((*a)->latest == (*b)->latest) + return 0; + else + return 1; +} + +static void init_pack_info(const char *infofile, int force) +{ + struct packed_git *p; + int stale; + int i = 0; + char *dep_temp; + + objdir = get_object_directory(); + objdirlen = strlen(objdir); + + prepare_packed_git(); + for (p = packed_git; p; p = p->next) { + /* we ignore things on alternate path since they are + * not available to the pullers in general. + */ + if (strncmp(p->pack_name, objdir, objdirlen) || + strncmp(p->pack_name + objdirlen, "/pack/", 6)) + continue; + i++; + } + num_pack = i; + info = xcalloc(num_pack, sizeof(struct pack_info *)); + for (i = 0, p = packed_git; p; p = p->next) { + if (strncmp(p->pack_name, objdir, objdirlen) || + p->pack_name[objdirlen] != '/') + continue; + info[i] = xcalloc(1, sizeof(struct pack_info) + num_pack); + info[i]->p = p; + info[i]->old_num = -1; + i++; + } + + if (infofile && !force) + stale = read_pack_info_file(infofile); + else + stale = 1; + + for (i = 0; i < num_pack; i++) { + if (stale) { + info[i]->old_num = -1; + memset(info[i]->dep, 0, num_pack); + info[i]->nr_heads = 0; + } + if (info[i]->old_num < 0) + info[i]->latest = get_latest_commit_date(info[i]->p); + } + + qsort(info, num_pack, sizeof(info[0]), compare_info); + for (i = 0; i < num_pack; i++) + info[i]->new_num = i; + + /* we need to fix up the dependency information + * for the old ones. + */ + dep_temp = NULL; + for (i = 0; i < num_pack; i++) { + int old; + + if (info[i]->old_num < 0) + continue; + if (! dep_temp) + dep_temp = xmalloc(num_pack); + memset(dep_temp, 0, num_pack); + for (old = 0; old < num_pack; old++) { + struct pack_info *base; + if (!info[i]->dep[old]) + continue; + base = find_pack_by_old_num(old); + if (!base) + die("internal error renumbering"); + dep_temp[base->new_num] = 1; + } + memcpy(info[i]->dep, dep_temp, num_pack); + } + free(dep_temp); +} + +static void write_pack_info_file(FILE *fp) +{ + int i, j; + for (i = 0; i < num_pack; i++) + fprintf(fp, "P %s\n", info[i]->p->pack_name + objdirlen + 6); + + for (i = 0; i < num_pack; i++) { + fprintf(fp, "D %1d", i); + for (j = 0; j < num_pack; j++) { + if ((i == j) || !(info[i]->dep[j])) + continue; + fprintf(fp, " %1d", j); + } + fputc('\n', fp); + } + + for (i = 0; i < num_pack; i++) { + struct pack_info *this = info[i]; + for (j = 0; j < this->nr_heads; j++) { + struct object *o = lookup_object(this->head[j]); + fprintf(fp, "T %1d %s %s\n", + i, sha1_to_hex(this->head[j]), o->type); + } + } + +} + +#define REFERENCED 01 +#define INTERNAL 02 +#define EMITTED 04 + +static void show(struct object *o, int pack_ix) +{ + /* + * We are interested in objects that are not referenced, + * and objects that are referenced but not internal. + */ + if (o->flags & EMITTED) + return; + + if (!(o->flags & REFERENCED)) + add_head_def(info[pack_ix], o->sha1); + else if ((o->flags & REFERENCED) && !(o->flags & INTERNAL)) { + int i; + + /* Which pack contains this object? That is what + * pack_ix can depend on. We earlier sorted info + * array from youngest to oldest, so try newer packs + * first to favor them here. + */ + for (i = num_pack - 1; 0 <= i; i--) { + struct packed_git *p = info[i]->p; + struct pack_entry ent; + if (find_pack_entry_one(o->sha1, &ent, p)) { + info[pack_ix]->dep[i] = 1; + break; + } + } + } + o->flags |= EMITTED; +} + +static void find_pack_info_one(int pack_ix) +{ + unsigned char sha1[20]; + struct object *o; + struct object_list *ref; + int i; + struct packed_git *p = info[pack_ix]->p; + int num = num_packed_objects(p); + + /* Scan objects, clear flags from all the edge ones and + * internal ones, possibly marked in the previous round. + */ + for (i = 0; i < num; i++) { + if (nth_packed_object_sha1(p, i, sha1)) + die("corrupt pack file %s?", p->pack_name); + if ((o = lookup_object(sha1)) == NULL) + die("cannot parse %s", sha1_to_hex(sha1)); + for (ref = o->refs; ref; ref = ref->next) + ref->item->flags = 0; + o->flags = 0; + } + + /* Mark all the internal ones */ + for (i = 0; i < num; i++) { + if (nth_packed_object_sha1(p, i, sha1)) + die("corrupt pack file %s?", p->pack_name); + if ((o = lookup_object(sha1)) == NULL) + die("cannot find %s", sha1_to_hex(sha1)); + for (ref = o->refs; ref; ref = ref->next) + ref->item->flags |= REFERENCED; + o->flags |= INTERNAL; + } + + for (i = 0; i < num; i++) { + if (nth_packed_object_sha1(p, i, sha1)) + die("corrupt pack file %s?", p->pack_name); + if ((o = lookup_object(sha1)) == NULL) + die("cannot find %s", sha1_to_hex(sha1)); + + show(o, pack_ix); + for (ref = o->refs; ref; ref = ref->next) + show(ref->item, pack_ix); + } + +} + +static void find_pack_info(void) +{ + int i; + for (i = 0; i < num_pack; i++) { + /* The packed objects are cast in stone, and a head + * in a pack will stay as head, so is the set of missing + * objects. If the repo has been reorganized and we + * are missing some packs available back then, we have + * already discarded the info read from the file, so + * we will find (old_num < 0) in that case. + */ + if (0 <= info[i]->old_num) + continue; + find_pack_info_one(i); + } +} + +static int update_info_packs(int force) +{ + char infofile[PATH_MAX]; + char name[PATH_MAX]; + int namelen; + FILE *fp; + + namelen = sprintf(infofile, "%s/info/packs", get_object_directory()); + strcpy(name, infofile); + strcpy(name + namelen, "+"); + + init_pack_info(infofile, force); + find_pack_info(); + + safe_create_leading_directories(name); + fp = fopen(name, "w"); + if (!fp) + return error("cannot open %s", name); + write_pack_info_file(fp); + fclose(fp); + rename(name, infofile); + return 0; +} + +/* rev-cache */ +static int record_rev_cache_ref(const char *path, const unsigned char *sha1) +{ + struct commit *commit; + if (!(commit = lookup_commit_reference(sha1))) + return error("not a commit: %s", sha1_to_hex(sha1)); + return record_rev_cache(commit->object.sha1, NULL); +} + +static int update_info_revs(int force) +{ + char *path0 = strdup(git_path("info/rev-cache")); + int len = strlen(path0); + char *path1 = xmalloc(len + 2); + + strcpy(path1, path0); + strcpy(path1 + len, "+"); + + /* read existing rev-cache */ + if (!force) + read_rev_cache(path0, NULL, 0); + safe_create_leading_directories(path0); + + for_each_ref(record_rev_cache_ref); + + /* update the rev-cache database */ + write_rev_cache(path1, force ? "/dev/null" : path0); + rename(path1, path0); + free(path1); + free(path0); + return 0; +} + +/* public */ +int update_server_info(int force) +{ + /* We would add more dumb-server support files later, + * including index of available pack files and their + * intended audiences. + */ + int errs = 0; + + errs = errs | update_info_refs(force); + errs = errs | update_info_packs(force); + errs = errs | update_info_revs(force); + + return errs; +} |