diff options
Diffstat (limited to 'server-info.c')
| -rw-r--r-- | server-info.c | 367 |
1 files changed, 367 insertions, 0 deletions
diff --git a/server-info.c b/server-info.c new file mode 100644 index 0000000..bae2cdf --- /dev/null +++ b/server-info.c @@ -0,0 +1,367 @@ +#include "cache.h" +#include "dir.h" +#include "repository.h" +#include "refs.h" +#include "object.h" +#include "commit.h" +#include "tag.h" +#include "packfile.h" +#include "object-store.h" +#include "strbuf.h" + +struct update_info_ctx { + FILE *cur_fp; + FILE *old_fp; /* becomes NULL if it differs from cur_fp */ + struct strbuf cur_sb; + struct strbuf old_sb; +}; + +static void uic_mark_stale(struct update_info_ctx *uic) +{ + fclose(uic->old_fp); + uic->old_fp = NULL; +} + +static int uic_is_stale(const struct update_info_ctx *uic) +{ + return uic->old_fp == NULL; +} + +static int uic_printf(struct update_info_ctx *uic, const char *fmt, ...) +{ + va_list ap; + int ret = -1; + + va_start(ap, fmt); + + if (uic_is_stale(uic)) { + ret = vfprintf(uic->cur_fp, fmt, ap); + } else { + ssize_t r; + struct strbuf *cur = &uic->cur_sb; + struct strbuf *old = &uic->old_sb; + + strbuf_reset(cur); + strbuf_vinsertf(cur, 0, fmt, ap); + + strbuf_reset(old); + strbuf_grow(old, cur->len); + r = fread(old->buf, 1, cur->len, uic->old_fp); + if (r != cur->len || memcmp(old->buf, cur->buf, r)) + uic_mark_stale(uic); + + if (fwrite(cur->buf, 1, cur->len, uic->cur_fp) == cur->len) + ret = 0; + } + + va_end(ap); + + return ret; +} + +/* + * Create the file "path" by writing to a temporary file and renaming + * it into place. The contents of the file come from "generate", which + * should return non-zero if it encounters an error. + */ +static int update_info_file(char *path, + int (*generate)(struct update_info_ctx *), + int force) +{ + char *tmp = mkpathdup("%s_XXXXXX", path); + int ret = -1; + int fd = -1; + FILE *to_close; + struct update_info_ctx uic = { + .cur_fp = NULL, + .old_fp = NULL, + .cur_sb = STRBUF_INIT, + .old_sb = STRBUF_INIT + }; + + safe_create_leading_directories(path); + fd = git_mkstemp_mode(tmp, 0666); + if (fd < 0) + goto out; + to_close = uic.cur_fp = fdopen(fd, "w"); + if (!uic.cur_fp) + goto out; + fd = -1; + + /* no problem on ENOENT and old_fp == NULL, it's stale, now */ + if (!force) + uic.old_fp = fopen_or_warn(path, "r"); + + /* + * uic_printf will compare incremental comparison against old_fp + * and mark uic as stale if needed + */ + ret = generate(&uic); + if (ret) + goto out; + + /* new file may be shorter than the old one, check here */ + if (!uic_is_stale(&uic)) { + struct stat st; + long new_len = ftell(uic.cur_fp); + int old_fd = fileno(uic.old_fp); + + if (new_len < 0) { + ret = -1; + goto out; + } + if (fstat(old_fd, &st) || (st.st_size != (size_t)new_len)) + uic_mark_stale(&uic); + } + + uic.cur_fp = NULL; + if (fclose(to_close)) + goto out; + + if (uic_is_stale(&uic)) { + if (adjust_shared_perm(tmp) < 0) + goto out; + if (rename(tmp, path) < 0) + goto out; + } else { + unlink(tmp); + } + ret = 0; + +out: + if (ret) { + error_errno("unable to update %s", path); + if (uic.cur_fp) + fclose(uic.cur_fp); + else if (fd >= 0) + close(fd); + unlink(tmp); + } + free(tmp); + if (uic.old_fp) + fclose(uic.old_fp); + strbuf_release(&uic.old_sb); + strbuf_release(&uic.cur_sb); + return ret; +} + +static int add_info_ref(const char *path, const struct object_id *oid, + int flag, void *cb_data) +{ + struct update_info_ctx *uic = cb_data; + struct object *o = parse_object(the_repository, oid); + if (!o) + return -1; + + if (uic_printf(uic, "%s %s\n", oid_to_hex(oid), path) < 0) + return -1; + + if (o->type == OBJ_TAG) { + o = deref_tag(the_repository, o, path, 0); + if (o) + if (uic_printf(uic, "%s %s^{}\n", + oid_to_hex(&o->oid), path) < 0) + return -1; + } + return 0; +} + +static int generate_info_refs(struct update_info_ctx *uic) +{ + return for_each_ref(add_info_ref, uic); +} + +static int update_info_refs(int force) +{ + char *path = git_pathdup("info/refs"); + int ret = update_info_file(path, generate_info_refs, force); + free(path); + return ret; +} + +/* packs */ +static struct pack_info { + struct packed_git *p; + int old_num; + int new_num; +} **info; +static int num_pack; + +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; + if (!strcmp(pack_basename(p), name)) + return info[i]; + } + return NULL; +} + +/* Returns non-zero when we detect that the info in the + * old file is useless. + */ +static int parse_pack_def(const char *packname, int old_cnt) +{ + struct pack_info *i = find_pack_by_name(packname); + if (i) { + i->old_num = old_cnt; + return 0; + } + else { + /* The file describes a pack that is no longer here */ + return 1; + } +} + +/* 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; + struct strbuf line = STRBUF_INIT; + int old_cnt = 0; + int stale = 1; + + fp = fopen_or_warn(infofile, "r"); + if (!fp) + return 1; /* nonexistent is not an error. */ + + while (strbuf_getline(&line, fp) != EOF) { + const char *arg; + + if (!line.len) + continue; + + if (skip_prefix(line.buf, "P ", &arg)) { + /* P name */ + if (parse_pack_def(arg, old_cnt++)) + goto out_stale; + } else if (line.buf[0] == 'D') { + /* we used to emit D but that was misguided. */ + goto out_stale; + } else if (line.buf[0] == 'T') { + /* we used to emit T but nobody uses it. */ + goto out_stale; + } else { + error("unrecognized: %s", line.buf); + } + } + stale = 0; + + out_stale: + strbuf_release(&line); + fclose(fp); + return stale; +} + +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; + + /* then it does not matter but at least keep the comparison stable */ + if ((*a)->p == (*b)->p) + return 0; + else if ((*a)->p < (*b)->p) + return -1; + else + return 1; +} + +static void init_pack_info(const char *infofile, int force) +{ + struct packed_git *p; + int stale; + int i; + size_t alloc = 0; + + for (p = get_all_packs(the_repository); p; p = p->next) { + /* we ignore things on alternate path since they are + * not available to the pullers in general. + */ + if (!p->pack_local || !file_exists(p->pack_name)) + continue; + + i = num_pack++; + ALLOC_GROW(info, num_pack, alloc); + info[i] = xcalloc(1, sizeof(struct pack_info)); + info[i]->p = p; + info[i]->old_num = -1; + } + + 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; + + /* renumber them */ + QSORT(info, num_pack, compare_info); + for (i = 0; i < num_pack; i++) + info[i]->new_num = i; +} + +static void free_pack_info(void) +{ + int i; + for (i = 0; i < num_pack; i++) + free(info[i]); + free(info); +} + +static int write_pack_info_file(struct update_info_ctx *uic) +{ + int i; + for (i = 0; i < num_pack; i++) { + if (uic_printf(uic, "P %s\n", pack_basename(info[i]->p)) < 0) + return -1; + } + if (uic_printf(uic, "\n") < 0) + return -1; + return 0; +} + +static int update_info_packs(int force) +{ + char *infofile = mkpathdup("%s/info/packs", get_object_directory()); + int ret; + + init_pack_info(infofile, force); + ret = update_info_file(infofile, write_pack_info_file, force); + free_pack_info(); + free(infofile); + return ret; +} + +/* 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); + + /* remove leftover rev-cache file if there is any */ + unlink_or_warn(git_path("info/rev-cache")); + + return errs; +} |