| /* |
| * GIT - The information manager from hell |
| * |
| * Copyright (C) Linus Torvalds, 2005 |
| * |
| * This handles basic git sha1 object files - packing, unpacking, |
| * creation etc. |
| */ |
| #include "cache.h" |
| #include "string-list.h" |
| #include "lockfile.h" |
| #include "delta.h" |
| #include "pack.h" |
| #include "blob.h" |
| #include "commit.h" |
| #include "run-command.h" |
| #include "tag.h" |
| #include "tree.h" |
| #include "tree-walk.h" |
| #include "refs.h" |
| #include "pack-revindex.h" |
| #include "sha1-lookup.h" |
| #include "bulk-checkin.h" |
| #include "streaming.h" |
| #include "dir.h" |
| #include "mru.h" |
| #include "list.h" |
| #include "mergesort.h" |
| |
| #ifndef O_NOATIME |
| #if defined(__linux__) && (defined(__i386__) || defined(__PPC__)) |
| #define O_NOATIME 01000000 |
| #else |
| #define O_NOATIME 0 |
| #endif |
| #endif |
| |
| #define SZ_FMT PRIuMAX |
| static inline uintmax_t sz_fmt(size_t s) { return s; } |
| |
| const unsigned char null_sha1[20]; |
| const struct object_id null_oid; |
| const struct object_id empty_tree_oid = { |
| EMPTY_TREE_SHA1_BIN_LITERAL |
| }; |
| const struct object_id empty_blob_oid = { |
| EMPTY_BLOB_SHA1_BIN_LITERAL |
| }; |
| |
| /* |
| * This is meant to hold a *small* number of objects that you would |
| * want read_sha1_file() to be able to return, but yet you do not want |
| * to write them into the object store (e.g. a browse-only |
| * application). |
| */ |
| static struct cached_object { |
| unsigned char sha1[20]; |
| enum object_type type; |
| void *buf; |
| unsigned long size; |
| } *cached_objects; |
| static int cached_object_nr, cached_object_alloc; |
| |
| static struct cached_object empty_tree = { |
| EMPTY_TREE_SHA1_BIN_LITERAL, |
| OBJ_TREE, |
| "", |
| 0 |
| }; |
| |
| static struct cached_object *find_cached_object(const unsigned char *sha1) |
| { |
| int i; |
| struct cached_object *co = cached_objects; |
| |
| for (i = 0; i < cached_object_nr; i++, co++) { |
| if (!hashcmp(co->sha1, sha1)) |
| return co; |
| } |
| if (!hashcmp(sha1, empty_tree.sha1)) |
| return &empty_tree; |
| return NULL; |
| } |
| |
| int mkdir_in_gitdir(const char *path) |
| { |
| if (mkdir(path, 0777)) { |
| int saved_errno = errno; |
| struct stat st; |
| struct strbuf sb = STRBUF_INIT; |
| |
| if (errno != EEXIST) |
| return -1; |
| /* |
| * Are we looking at a path in a symlinked worktree |
| * whose original repository does not yet have it? |
| * e.g. .git/rr-cache pointing at its original |
| * repository in which the user hasn't performed any |
| * conflict resolution yet? |
| */ |
| if (lstat(path, &st) || !S_ISLNK(st.st_mode) || |
| strbuf_readlink(&sb, path, st.st_size) || |
| !is_absolute_path(sb.buf) || |
| mkdir(sb.buf, 0777)) { |
| strbuf_release(&sb); |
| errno = saved_errno; |
| return -1; |
| } |
| strbuf_release(&sb); |
| } |
| return adjust_shared_perm(path); |
| } |
| |
| enum scld_error safe_create_leading_directories(char *path) |
| { |
| char *next_component = path + offset_1st_component(path); |
| enum scld_error ret = SCLD_OK; |
| |
| while (ret == SCLD_OK && next_component) { |
| struct stat st; |
| char *slash = next_component, slash_character; |
| |
| while (*slash && !is_dir_sep(*slash)) |
| slash++; |
| |
| if (!*slash) |
| break; |
| |
| next_component = slash + 1; |
| while (is_dir_sep(*next_component)) |
| next_component++; |
| if (!*next_component) |
| break; |
| |
| slash_character = *slash; |
| *slash = '\0'; |
| if (!stat(path, &st)) { |
| /* path exists */ |
| if (!S_ISDIR(st.st_mode)) |
| ret = SCLD_EXISTS; |
| } else if (mkdir(path, 0777)) { |
| if (errno == EEXIST && |
| !stat(path, &st) && S_ISDIR(st.st_mode)) |
| ; /* somebody created it since we checked */ |
| else if (errno == ENOENT) |
| /* |
| * Either mkdir() failed because |
| * somebody just pruned the containing |
| * directory, or stat() failed because |
| * the file that was in our way was |
| * just removed. Either way, inform |
| * the caller that it might be worth |
| * trying again: |
| */ |
| ret = SCLD_VANISHED; |
| else |
| ret = SCLD_FAILED; |
| } else if (adjust_shared_perm(path)) { |
| ret = SCLD_PERMS; |
| } |
| *slash = slash_character; |
| } |
| return ret; |
| } |
| |
| enum scld_error safe_create_leading_directories_const(const char *path) |
| { |
| /* path points to cache entries, so xstrdup before messing with it */ |
| char *buf = xstrdup(path); |
| enum scld_error result = safe_create_leading_directories(buf); |
| free(buf); |
| return result; |
| } |
| |
| static void fill_sha1_path(struct strbuf *buf, const unsigned char *sha1) |
| { |
| int i; |
| for (i = 0; i < 20; i++) { |
| static char hex[] = "0123456789abcdef"; |
| unsigned int val = sha1[i]; |
| strbuf_addch(buf, hex[val >> 4]); |
| strbuf_addch(buf, hex[val & 0xf]); |
| if (!i) |
| strbuf_addch(buf, '/'); |
| } |
| } |
| |
| const char *sha1_file_name(const unsigned char *sha1) |
| { |
| static struct strbuf buf = STRBUF_INIT; |
| |
| strbuf_reset(&buf); |
| strbuf_addf(&buf, "%s/", get_object_directory()); |
| |
| fill_sha1_path(&buf, sha1); |
| return buf.buf; |
| } |
| |
| struct strbuf *alt_scratch_buf(struct alternate_object_database *alt) |
| { |
| strbuf_setlen(&alt->scratch, alt->base_len); |
| return &alt->scratch; |
| } |
| |
| static const char *alt_sha1_path(struct alternate_object_database *alt, |
| const unsigned char *sha1) |
| { |
| struct strbuf *buf = alt_scratch_buf(alt); |
| fill_sha1_path(buf, sha1); |
| return buf->buf; |
| } |
| |
| /* |
| * Return the name of the pack or index file with the specified sha1 |
| * in its filename. *base and *name are scratch space that must be |
| * provided by the caller. which should be "pack" or "idx". |
| */ |
| static char *sha1_get_pack_name(const unsigned char *sha1, |
| struct strbuf *buf, |
| const char *which) |
| { |
| strbuf_reset(buf); |
| strbuf_addf(buf, "%s/pack/pack-%s.%s", get_object_directory(), |
| sha1_to_hex(sha1), which); |
| return buf->buf; |
| } |
| |
| char *sha1_pack_name(const unsigned char *sha1) |
| { |
| static struct strbuf buf = STRBUF_INIT; |
| return sha1_get_pack_name(sha1, &buf, "pack"); |
| } |
| |
| char *sha1_pack_index_name(const unsigned char *sha1) |
| { |
| static struct strbuf buf = STRBUF_INIT; |
| return sha1_get_pack_name(sha1, &buf, "idx"); |
| } |
| |
| struct alternate_object_database *alt_odb_list; |
| static struct alternate_object_database **alt_odb_tail; |
| |
| /* |
| * Return non-zero iff the path is usable as an alternate object database. |
| */ |
| static int alt_odb_usable(struct strbuf *path, const char *normalized_objdir) |
| { |
| struct alternate_object_database *alt; |
| |
| /* Detect cases where alternate disappeared */ |
| if (!is_directory(path->buf)) { |
| error("object directory %s does not exist; " |
| "check .git/objects/info/alternates.", |
| path->buf); |
| return 0; |
| } |
| |
| /* |
| * Prevent the common mistake of listing the same |
| * thing twice, or object directory itself. |
| */ |
| for (alt = alt_odb_list; alt; alt = alt->next) { |
| if (!fspathcmp(path->buf, alt->path)) |
| return 0; |
| } |
| if (!fspathcmp(path->buf, normalized_objdir)) |
| return 0; |
| |
| return 1; |
| } |
| |
| /* |
| * Prepare alternate object database registry. |
| * |
| * The variable alt_odb_list points at the list of struct |
| * alternate_object_database. The elements on this list come from |
| * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT |
| * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates, |
| * whose contents is similar to that environment variable but can be |
| * LF separated. Its base points at a statically allocated buffer that |
| * contains "/the/directory/corresponding/to/.git/objects/...", while |
| * its name points just after the slash at the end of ".git/objects/" |
| * in the example above, and has enough space to hold 40-byte hex |
| * SHA1, an extra slash for the first level indirection, and the |
| * terminating NUL. |
| */ |
| static int link_alt_odb_entry(const char *entry, const char *relative_base, |
| int depth, const char *normalized_objdir) |
| { |
| struct alternate_object_database *ent; |
| struct strbuf pathbuf = STRBUF_INIT; |
| |
| if (!is_absolute_path(entry) && relative_base) { |
| strbuf_addstr(&pathbuf, real_path(relative_base)); |
| strbuf_addch(&pathbuf, '/'); |
| } |
| strbuf_addstr(&pathbuf, entry); |
| |
| if (strbuf_normalize_path(&pathbuf) < 0 && relative_base) { |
| error("unable to normalize alternate object path: %s", |
| pathbuf.buf); |
| strbuf_release(&pathbuf); |
| return -1; |
| } |
| |
| /* |
| * The trailing slash after the directory name is given by |
| * this function at the end. Remove duplicates. |
| */ |
| while (pathbuf.len && pathbuf.buf[pathbuf.len - 1] == '/') |
| strbuf_setlen(&pathbuf, pathbuf.len - 1); |
| |
| if (!alt_odb_usable(&pathbuf, normalized_objdir)) { |
| strbuf_release(&pathbuf); |
| return -1; |
| } |
| |
| ent = alloc_alt_odb(pathbuf.buf); |
| |
| /* add the alternate entry */ |
| *alt_odb_tail = ent; |
| alt_odb_tail = &(ent->next); |
| ent->next = NULL; |
| |
| /* recursively add alternates */ |
| read_info_alternates(pathbuf.buf, depth + 1); |
| |
| strbuf_release(&pathbuf); |
| return 0; |
| } |
| |
| static void link_alt_odb_entries(const char *alt, int len, int sep, |
| const char *relative_base, int depth) |
| { |
| struct string_list entries = STRING_LIST_INIT_NODUP; |
| char *alt_copy; |
| int i; |
| struct strbuf objdirbuf = STRBUF_INIT; |
| |
| if (depth > 5) { |
| error("%s: ignoring alternate object stores, nesting too deep.", |
| relative_base); |
| return; |
| } |
| |
| strbuf_add_absolute_path(&objdirbuf, get_object_directory()); |
| if (strbuf_normalize_path(&objdirbuf) < 0) |
| die("unable to normalize object directory: %s", |
| objdirbuf.buf); |
| |
| alt_copy = xmemdupz(alt, len); |
| string_list_split_in_place(&entries, alt_copy, sep, -1); |
| for (i = 0; i < entries.nr; i++) { |
| const char *entry = entries.items[i].string; |
| if (entry[0] == '\0' || entry[0] == '#') |
| continue; |
| link_alt_odb_entry(entry, relative_base, depth, objdirbuf.buf); |
| } |
| string_list_clear(&entries, 0); |
| free(alt_copy); |
| strbuf_release(&objdirbuf); |
| } |
| |
| void read_info_alternates(const char * relative_base, int depth) |
| { |
| char *map; |
| size_t mapsz; |
| struct stat st; |
| char *path; |
| int fd; |
| |
| path = xstrfmt("%s/info/alternates", relative_base); |
| fd = git_open(path); |
| free(path); |
| if (fd < 0) |
| return; |
| if (fstat(fd, &st) || (st.st_size == 0)) { |
| close(fd); |
| return; |
| } |
| mapsz = xsize_t(st.st_size); |
| map = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, fd, 0); |
| close(fd); |
| |
| link_alt_odb_entries(map, mapsz, '\n', relative_base, depth); |
| |
| munmap(map, mapsz); |
| } |
| |
| struct alternate_object_database *alloc_alt_odb(const char *dir) |
| { |
| struct alternate_object_database *ent; |
| |
| FLEX_ALLOC_STR(ent, path, dir); |
| strbuf_init(&ent->scratch, 0); |
| strbuf_addf(&ent->scratch, "%s/", dir); |
| ent->base_len = ent->scratch.len; |
| |
| return ent; |
| } |
| |
| void add_to_alternates_file(const char *reference) |
| { |
| struct lock_file *lock = xcalloc(1, sizeof(struct lock_file)); |
| char *alts = git_pathdup("objects/info/alternates"); |
| FILE *in, *out; |
| |
| hold_lock_file_for_update(lock, alts, LOCK_DIE_ON_ERROR); |
| out = fdopen_lock_file(lock, "w"); |
| if (!out) |
| die_errno("unable to fdopen alternates lockfile"); |
| |
| in = fopen(alts, "r"); |
| if (in) { |
| struct strbuf line = STRBUF_INIT; |
| int found = 0; |
| |
| while (strbuf_getline(&line, in) != EOF) { |
| if (!strcmp(reference, line.buf)) { |
| found = 1; |
| break; |
| } |
| fprintf_or_die(out, "%s\n", line.buf); |
| } |
| |
| strbuf_release(&line); |
| fclose(in); |
| |
| if (found) { |
| rollback_lock_file(lock); |
| lock = NULL; |
| } |
| } |
| else if (errno != ENOENT) |
| die_errno("unable to read alternates file"); |
| |
| if (lock) { |
| fprintf_or_die(out, "%s\n", reference); |
| if (commit_lock_file(lock)) |
| die_errno("unable to move new alternates file into place"); |
| if (alt_odb_tail) |
| link_alt_odb_entries(reference, strlen(reference), '\n', NULL, 0); |
| } |
| free(alts); |
| } |
| |
| void add_to_alternates_memory(const char *reference) |
| { |
| /* |
| * Make sure alternates are initialized, or else our entry may be |
| * overwritten when they are. |
| */ |
| prepare_alt_odb(); |
| |
| link_alt_odb_entries(reference, strlen(reference), '\n', NULL, 0); |
| } |
| |
| /* |
| * Compute the exact path an alternate is at and returns it. In case of |
| * error NULL is returned and the human readable error is added to `err` |
| * `path` may be relative and should point to $GITDIR. |
| * `err` must not be null. |
| */ |
| char *compute_alternate_path(const char *path, struct strbuf *err) |
| { |
| char *ref_git = NULL; |
| const char *repo, *ref_git_s; |
| int seen_error = 0; |
| |
| ref_git_s = real_path_if_valid(path); |
| if (!ref_git_s) { |
| seen_error = 1; |
| strbuf_addf(err, _("path '%s' does not exist"), path); |
| goto out; |
| } else |
| /* |
| * Beware: read_gitfile(), real_path() and mkpath() |
| * return static buffer |
| */ |
| ref_git = xstrdup(ref_git_s); |
| |
| repo = read_gitfile(ref_git); |
| if (!repo) |
| repo = read_gitfile(mkpath("%s/.git", ref_git)); |
| if (repo) { |
| free(ref_git); |
| ref_git = xstrdup(repo); |
| } |
| |
| if (!repo && is_directory(mkpath("%s/.git/objects", ref_git))) { |
| char *ref_git_git = mkpathdup("%s/.git", ref_git); |
| free(ref_git); |
| ref_git = ref_git_git; |
| } else if (!is_directory(mkpath("%s/objects", ref_git))) { |
| struct strbuf sb = STRBUF_INIT; |
| seen_error = 1; |
| if (get_common_dir(&sb, ref_git)) { |
| strbuf_addf(err, |
| _("reference repository '%s' as a linked " |
| "checkout is not supported yet."), |
| path); |
| goto out; |
| } |
| |
| strbuf_addf(err, _("reference repository '%s' is not a " |
| "local repository."), path); |
| goto out; |
| } |
| |
| if (!access(mkpath("%s/shallow", ref_git), F_OK)) { |
| strbuf_addf(err, _("reference repository '%s' is shallow"), |
| path); |
| seen_error = 1; |
| goto out; |
| } |
| |
| if (!access(mkpath("%s/info/grafts", ref_git), F_OK)) { |
| strbuf_addf(err, |
| _("reference repository '%s' is grafted"), |
| path); |
| seen_error = 1; |
| goto out; |
| } |
| |
| out: |
| if (seen_error) { |
| free(ref_git); |
| ref_git = NULL; |
| } |
| |
| return ref_git; |
| } |
| |
| int foreach_alt_odb(alt_odb_fn fn, void *cb) |
| { |
| struct alternate_object_database *ent; |
| int r = 0; |
| |
| prepare_alt_odb(); |
| for (ent = alt_odb_list; ent; ent = ent->next) { |
| r = fn(ent, cb); |
| if (r) |
| break; |
| } |
| return r; |
| } |
| |
| void prepare_alt_odb(void) |
| { |
| const char *alt; |
| |
| if (alt_odb_tail) |
| return; |
| |
| alt = getenv(ALTERNATE_DB_ENVIRONMENT); |
| if (!alt) alt = ""; |
| |
| alt_odb_tail = &alt_odb_list; |
| link_alt_odb_entries(alt, strlen(alt), PATH_SEP, NULL, 0); |
| |
| read_info_alternates(get_object_directory(), 0); |
| } |
| |
| /* Returns 1 if we have successfully freshened the file, 0 otherwise. */ |
| static int freshen_file(const char *fn) |
| { |
| struct utimbuf t; |
| t.actime = t.modtime = time(NULL); |
| return !utime(fn, &t); |
| } |
| |
| /* |
| * All of the check_and_freshen functions return 1 if the file exists and was |
| * freshened (if freshening was requested), 0 otherwise. If they return |
| * 0, you should not assume that it is safe to skip a write of the object (it |
| * either does not exist on disk, or has a stale mtime and may be subject to |
| * pruning). |
| */ |
| static int check_and_freshen_file(const char *fn, int freshen) |
| { |
| if (access(fn, F_OK)) |
| return 0; |
| if (freshen && !freshen_file(fn)) |
| return 0; |
| return 1; |
| } |
| |
| static int check_and_freshen_local(const unsigned char *sha1, int freshen) |
| { |
| return check_and_freshen_file(sha1_file_name(sha1), freshen); |
| } |
| |
| static int check_and_freshen_nonlocal(const unsigned char *sha1, int freshen) |
| { |
| struct alternate_object_database *alt; |
| prepare_alt_odb(); |
| for (alt = alt_odb_list; alt; alt = alt->next) { |
| const char *path = alt_sha1_path(alt, sha1); |
| if (check_and_freshen_file(path, freshen)) |
| return 1; |
| } |
| return 0; |
| } |
| |
| static int check_and_freshen(const unsigned char *sha1, int freshen) |
| { |
| return check_and_freshen_local(sha1, freshen) || |
| check_and_freshen_nonlocal(sha1, freshen); |
| } |
| |
| int has_loose_object_nonlocal(const unsigned char *sha1) |
| { |
| return check_and_freshen_nonlocal(sha1, 0); |
| } |
| |
| static int has_loose_object(const unsigned char *sha1) |
| { |
| return check_and_freshen(sha1, 0); |
| } |
| |
| static unsigned int pack_used_ctr; |
| static unsigned int pack_mmap_calls; |
| static unsigned int peak_pack_open_windows; |
| static unsigned int pack_open_windows; |
| static unsigned int pack_open_fds; |
| static unsigned int pack_max_fds; |
| static size_t peak_pack_mapped; |
| static size_t pack_mapped; |
| struct packed_git *packed_git; |
| |
| static struct mru packed_git_mru_storage; |
| struct mru *packed_git_mru = &packed_git_mru_storage; |
| |
| void pack_report(void) |
| { |
| fprintf(stderr, |
| "pack_report: getpagesize() = %10" SZ_FMT "\n" |
| "pack_report: core.packedGitWindowSize = %10" SZ_FMT "\n" |
| "pack_report: core.packedGitLimit = %10" SZ_FMT "\n", |
| sz_fmt(getpagesize()), |
| sz_fmt(packed_git_window_size), |
| sz_fmt(packed_git_limit)); |
| fprintf(stderr, |
| "pack_report: pack_used_ctr = %10u\n" |
| "pack_report: pack_mmap_calls = %10u\n" |
| "pack_report: pack_open_windows = %10u / %10u\n" |
| "pack_report: pack_mapped = " |
| "%10" SZ_FMT " / %10" SZ_FMT "\n", |
| pack_used_ctr, |
| pack_mmap_calls, |
| pack_open_windows, peak_pack_open_windows, |
| sz_fmt(pack_mapped), sz_fmt(peak_pack_mapped)); |
| } |
| |
| /* |
| * Open and mmap the index file at path, perform a couple of |
| * consistency checks, then record its information to p. Return 0 on |
| * success. |
| */ |
| static int check_packed_git_idx(const char *path, struct packed_git *p) |
| { |
| void *idx_map; |
| struct pack_idx_header *hdr; |
| size_t idx_size; |
| uint32_t version, nr, i, *index; |
| int fd = git_open(path); |
| struct stat st; |
| |
| if (fd < 0) |
| return -1; |
| if (fstat(fd, &st)) { |
| close(fd); |
| return -1; |
| } |
| idx_size = xsize_t(st.st_size); |
| if (idx_size < 4 * 256 + 20 + 20) { |
| close(fd); |
| return error("index file %s is too small", path); |
| } |
| idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0); |
| close(fd); |
| |
| hdr = idx_map; |
| if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) { |
| version = ntohl(hdr->idx_version); |
| if (version < 2 || version > 2) { |
| munmap(idx_map, idx_size); |
| return error("index file %s is version %"PRIu32 |
| " and is not supported by this binary" |
| " (try upgrading GIT to a newer version)", |
| path, version); |
| } |
| } else |
| version = 1; |
| |
| nr = 0; |
| index = idx_map; |
| if (version > 1) |
| index += 2; /* skip index header */ |
| for (i = 0; i < 256; i++) { |
| uint32_t n = ntohl(index[i]); |
| if (n < nr) { |
| munmap(idx_map, idx_size); |
| return error("non-monotonic index %s", path); |
| } |
| nr = n; |
| } |
| |
| if (version == 1) { |
| /* |
| * Total size: |
| * - 256 index entries 4 bytes each |
| * - 24-byte entries * nr (20-byte sha1 + 4-byte offset) |
| * - 20-byte SHA1 of the packfile |
| * - 20-byte SHA1 file checksum |
| */ |
| if (idx_size != 4*256 + nr * 24 + 20 + 20) { |
| munmap(idx_map, idx_size); |
| return error("wrong index v1 file size in %s", path); |
| } |
| } else if (version == 2) { |
| /* |
| * Minimum size: |
| * - 8 bytes of header |
| * - 256 index entries 4 bytes each |
| * - 20-byte sha1 entry * nr |
| * - 4-byte crc entry * nr |
| * - 4-byte offset entry * nr |
| * - 20-byte SHA1 of the packfile |
| * - 20-byte SHA1 file checksum |
| * And after the 4-byte offset table might be a |
| * variable sized table containing 8-byte entries |
| * for offsets larger than 2^31. |
| */ |
| unsigned long min_size = 8 + 4*256 + nr*(20 + 4 + 4) + 20 + 20; |
| unsigned long max_size = min_size; |
| if (nr) |
| max_size += (nr - 1)*8; |
| if (idx_size < min_size || idx_size > max_size) { |
| munmap(idx_map, idx_size); |
| return error("wrong index v2 file size in %s", path); |
| } |
| if (idx_size != min_size && |
| /* |
| * make sure we can deal with large pack offsets. |
| * 31-bit signed offset won't be enough, neither |
| * 32-bit unsigned one will be. |
| */ |
| (sizeof(off_t) <= 4)) { |
| munmap(idx_map, idx_size); |
| return error("pack too large for current definition of off_t in %s", path); |
| } |
| } |
| |
| p->index_version = version; |
| p->index_data = idx_map; |
| p->index_size = idx_size; |
| p->num_objects = nr; |
| return 0; |
| } |
| |
| int open_pack_index(struct packed_git *p) |
| { |
| char *idx_name; |
| size_t len; |
| int ret; |
| |
| if (p->index_data) |
| return 0; |
| |
| if (!strip_suffix(p->pack_name, ".pack", &len)) |
| die("BUG: pack_name does not end in .pack"); |
| idx_name = xstrfmt("%.*s.idx", (int)len, p->pack_name); |
| ret = check_packed_git_idx(idx_name, p); |
| free(idx_name); |
| return ret; |
| } |
| |
| static void scan_windows(struct packed_git *p, |
| struct packed_git **lru_p, |
| struct pack_window **lru_w, |
| struct pack_window **lru_l) |
| { |
| struct pack_window *w, *w_l; |
| |
| for (w_l = NULL, w = p->windows; w; w = w->next) { |
| if (!w->inuse_cnt) { |
| if (!*lru_w || w->last_used < (*lru_w)->last_used) { |
| *lru_p = p; |
| *lru_w = w; |
| *lru_l = w_l; |
| } |
| } |
| w_l = w; |
| } |
| } |
| |
| static int unuse_one_window(struct packed_git *current) |
| { |
| struct packed_git *p, *lru_p = NULL; |
| struct pack_window *lru_w = NULL, *lru_l = NULL; |
| |
| if (current) |
| scan_windows(current, &lru_p, &lru_w, &lru_l); |
| for (p = packed_git; p; p = p->next) |
| scan_windows(p, &lru_p, &lru_w, &lru_l); |
| if (lru_p) { |
| munmap(lru_w->base, lru_w->len); |
| pack_mapped -= lru_w->len; |
| if (lru_l) |
| lru_l->next = lru_w->next; |
| else |
| lru_p->windows = lru_w->next; |
| free(lru_w); |
| pack_open_windows--; |
| return 1; |
| } |
| return 0; |
| } |
| |
| void release_pack_memory(size_t need) |
| { |
| size_t cur = pack_mapped; |
| while (need >= (cur - pack_mapped) && unuse_one_window(NULL)) |
| ; /* nothing */ |
| } |
| |
| static void mmap_limit_check(size_t length) |
| { |
| static size_t limit = 0; |
| if (!limit) { |
| limit = git_env_ulong("GIT_MMAP_LIMIT", 0); |
| if (!limit) |
| limit = SIZE_MAX; |
| } |
| if (length > limit) |
| die("attempting to mmap %"PRIuMAX" over limit %"PRIuMAX, |
| (uintmax_t)length, (uintmax_t)limit); |
| } |
| |
| void *xmmap_gently(void *start, size_t length, |
| int prot, int flags, int fd, off_t offset) |
| { |
| void *ret; |
| |
| mmap_limit_check(length); |
| ret = mmap(start, length, prot, flags, fd, offset); |
| if (ret == MAP_FAILED) { |
| if (!length) |
| return NULL; |
| release_pack_memory(length); |
| ret = mmap(start, length, prot, flags, fd, offset); |
| } |
| return ret; |
| } |
| |
| void *xmmap(void *start, size_t length, |
| int prot, int flags, int fd, off_t offset) |
| { |
| void *ret = xmmap_gently(start, length, prot, flags, fd, offset); |
| if (ret == MAP_FAILED) |
| die_errno("mmap failed"); |
| return ret; |
| } |
| |
| void close_pack_windows(struct packed_git *p) |
| { |
| while (p->windows) { |
| struct pack_window *w = p->windows; |
| |
| if (w->inuse_cnt) |
| die("pack '%s' still has open windows to it", |
| p->pack_name); |
| munmap(w->base, w->len); |
| pack_mapped -= w->len; |
| pack_open_windows--; |
| p->windows = w->next; |
| free(w); |
| } |
| } |
| |
| static int close_pack_fd(struct packed_git *p) |
| { |
| if (p->pack_fd < 0) |
| return 0; |
| |
| close(p->pack_fd); |
| pack_open_fds--; |
| p->pack_fd = -1; |
| |
| return 1; |
| } |
| |
| static void close_pack(struct packed_git *p) |
| { |
| close_pack_windows(p); |
| close_pack_fd(p); |
| close_pack_index(p); |
| } |
| |
| void close_all_packs(void) |
| { |
| struct packed_git *p; |
| |
| for (p = packed_git; p; p = p->next) |
| if (p->do_not_close) |
| die("BUG: want to close pack marked 'do-not-close'"); |
| else |
| close_pack(p); |
| } |
| |
| |
| /* |
| * The LRU pack is the one with the oldest MRU window, preferring packs |
| * with no used windows, or the oldest mtime if it has no windows allocated. |
| */ |
| static void find_lru_pack(struct packed_git *p, struct packed_git **lru_p, struct pack_window **mru_w, int *accept_windows_inuse) |
| { |
| struct pack_window *w, *this_mru_w; |
| int has_windows_inuse = 0; |
| |
| /* |
| * Reject this pack if it has windows and the previously selected |
| * one does not. If this pack does not have windows, reject |
| * it if the pack file is newer than the previously selected one. |
| */ |
| if (*lru_p && !*mru_w && (p->windows || p->mtime > (*lru_p)->mtime)) |
| return; |
| |
| for (w = this_mru_w = p->windows; w; w = w->next) { |
| /* |
| * Reject this pack if any of its windows are in use, |
| * but the previously selected pack did not have any |
| * inuse windows. Otherwise, record that this pack |
| * has windows in use. |
| */ |
| if (w->inuse_cnt) { |
| if (*accept_windows_inuse) |
| has_windows_inuse = 1; |
| else |
| return; |
| } |
| |
| if (w->last_used > this_mru_w->last_used) |
| this_mru_w = w; |
| |
| /* |
| * Reject this pack if it has windows that have been |
| * used more recently than the previously selected pack. |
| * If the previously selected pack had windows inuse and |
| * we have not encountered a window in this pack that is |
| * inuse, skip this check since we prefer a pack with no |
| * inuse windows to one that has inuse windows. |
| */ |
| if (*mru_w && *accept_windows_inuse == has_windows_inuse && |
| this_mru_w->last_used > (*mru_w)->last_used) |
| return; |
| } |
| |
| /* |
| * Select this pack. |
| */ |
| *mru_w = this_mru_w; |
| *lru_p = p; |
| *accept_windows_inuse = has_windows_inuse; |
| } |
| |
| static int close_one_pack(void) |
| { |
| struct packed_git *p, *lru_p = NULL; |
| struct pack_window *mru_w = NULL; |
| int accept_windows_inuse = 1; |
| |
| for (p = packed_git; p; p = p->next) { |
| if (p->pack_fd == -1) |
| continue; |
| find_lru_pack(p, &lru_p, &mru_w, &accept_windows_inuse); |
| } |
| |
| if (lru_p) |
| return close_pack_fd(lru_p); |
| |
| return 0; |
| } |
| |
| void unuse_pack(struct pack_window **w_cursor) |
| { |
| struct pack_window *w = *w_cursor; |
| if (w) { |
| w->inuse_cnt--; |
| *w_cursor = NULL; |
| } |
| } |
| |
| void close_pack_index(struct packed_git *p) |
| { |
| if (p->index_data) { |
| munmap((void *)p->index_data, p->index_size); |
| p->index_data = NULL; |
| } |
| } |
| |
| static unsigned int get_max_fd_limit(void) |
| { |
| #ifdef RLIMIT_NOFILE |
| { |
| struct rlimit lim; |
| |
| if (!getrlimit(RLIMIT_NOFILE, &lim)) |
| return lim.rlim_cur; |
| } |
| #endif |
| |
| #ifdef _SC_OPEN_MAX |
| { |
| long open_max = sysconf(_SC_OPEN_MAX); |
| if (0 < open_max) |
| return open_max; |
| /* |
| * Otherwise, we got -1 for one of the two |
| * reasons: |
| * |
| * (1) sysconf() did not understand _SC_OPEN_MAX |
| * and signaled an error with -1; or |
| * (2) sysconf() said there is no limit. |
| * |
| * We _could_ clear errno before calling sysconf() to |
| * tell these two cases apart and return a huge number |
| * in the latter case to let the caller cap it to a |
| * value that is not so selfish, but letting the |
| * fallback OPEN_MAX codepath take care of these cases |
| * is a lot simpler. |
| */ |
| } |
| #endif |
| |
| #ifdef OPEN_MAX |
| return OPEN_MAX; |
| #else |
| return 1; /* see the caller ;-) */ |
| #endif |
| } |
| |
| /* |
| * Do not call this directly as this leaks p->pack_fd on error return; |
| * call open_packed_git() instead. |
| */ |
| static int open_packed_git_1(struct packed_git *p) |
| { |
| struct stat st; |
| struct pack_header hdr; |
| unsigned char sha1[20]; |
| unsigned char *idx_sha1; |
| long fd_flag; |
| |
| if (!p->index_data && open_pack_index(p)) |
| return error("packfile %s index unavailable", p->pack_name); |
| |
| if (!pack_max_fds) { |
| unsigned int max_fds = get_max_fd_limit(); |
| |
| /* Save 3 for stdin/stdout/stderr, 22 for work */ |
| if (25 < max_fds) |
| pack_max_fds = max_fds - 25; |
| else |
| pack_max_fds = 1; |
| } |
| |
| while (pack_max_fds <= pack_open_fds && close_one_pack()) |
| ; /* nothing */ |
| |
| p->pack_fd = git_open(p->pack_name); |
| if (p->pack_fd < 0 || fstat(p->pack_fd, &st)) |
| return -1; |
| pack_open_fds++; |
| |
| /* If we created the struct before we had the pack we lack size. */ |
| if (!p->pack_size) { |
| if (!S_ISREG(st.st_mode)) |
| return error("packfile %s not a regular file", p->pack_name); |
| p->pack_size = st.st_size; |
| } else if (p->pack_size != st.st_size) |
| return error("packfile %s size changed", p->pack_name); |
| |
| /* We leave these file descriptors open with sliding mmap; |
| * there is no point keeping them open across exec(), though. |
| */ |
| fd_flag = fcntl(p->pack_fd, F_GETFD, 0); |
| if (fd_flag < 0) |
| return error("cannot determine file descriptor flags"); |
| fd_flag |= FD_CLOEXEC; |
| if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1) |
| return error("cannot set FD_CLOEXEC"); |
| |
| /* Verify we recognize this pack file format. */ |
| if (read_in_full(p->pack_fd, &hdr, sizeof(hdr)) != sizeof(hdr)) |
| return error("file %s is far too short to be a packfile", p->pack_name); |
| if (hdr.hdr_signature != htonl(PACK_SIGNATURE)) |
| return error("file %s is not a GIT packfile", p->pack_name); |
| if (!pack_version_ok(hdr.hdr_version)) |
| return error("packfile %s is version %"PRIu32" and not" |
| " supported (try upgrading GIT to a newer version)", |
| p->pack_name, ntohl(hdr.hdr_version)); |
| |
| /* Verify the pack matches its index. */ |
| if (p->num_objects != ntohl(hdr.hdr_entries)) |
| return error("packfile %s claims to have %"PRIu32" objects" |
| " while index indicates %"PRIu32" objects", |
| p->pack_name, ntohl(hdr.hdr_entries), |
| p->num_objects); |
| if (lseek(p->pack_fd, p->pack_size - sizeof(sha1), SEEK_SET) == -1) |
| return error("end of packfile %s is unavailable", p->pack_name); |
| if (read_in_full(p->pack_fd, sha1, sizeof(sha1)) != sizeof(sha1)) |
| return error("packfile %s signature is unavailable", p->pack_name); |
| idx_sha1 = ((unsigned char *)p->index_data) + p->index_size - 40; |
| if (hashcmp(sha1, idx_sha1)) |
| return error("packfile %s does not match index", p->pack_name); |
| return 0; |
| } |
| |
| static int open_packed_git(struct packed_git *p) |
| { |
| if (!open_packed_git_1(p)) |
| return 0; |
| close_pack_fd(p); |
| return -1; |
| } |
| |
| static int in_window(struct pack_window *win, off_t offset) |
| { |
| /* We must promise at least 20 bytes (one hash) after the |
| * offset is available from this window, otherwise the offset |
| * is not actually in this window and a different window (which |
| * has that one hash excess) must be used. This is to support |
| * the object header and delta base parsing routines below. |
| */ |
| off_t win_off = win->offset; |
| return win_off <= offset |
| && (offset + 20) <= (win_off + win->len); |
| } |
| |
| unsigned char *use_pack(struct packed_git *p, |
| struct pack_window **w_cursor, |
| off_t offset, |
| unsigned long *left) |
| { |
| struct pack_window *win = *w_cursor; |
| |
| /* Since packfiles end in a hash of their content and it's |
| * pointless to ask for an offset into the middle of that |
| * hash, and the in_window function above wouldn't match |
| * don't allow an offset too close to the end of the file. |
| */ |
| if (!p->pack_size && p->pack_fd == -1 && open_packed_git(p)) |
| die("packfile %s cannot be accessed", p->pack_name); |
| if (offset > (p->pack_size - 20)) |
| die("offset beyond end of packfile (truncated pack?)"); |
| if (offset < 0) |
| die(_("offset before end of packfile (broken .idx?)")); |
| |
| if (!win || !in_window(win, offset)) { |
| if (win) |
| win->inuse_cnt--; |
| for (win = p->windows; win; win = win->next) { |
| if (in_window(win, offset)) |
| break; |
| } |
| if (!win) { |
| size_t window_align = packed_git_window_size / 2; |
| off_t len; |
| |
| if (p->pack_fd == -1 && open_packed_git(p)) |
| die("packfile %s cannot be accessed", p->pack_name); |
| |
| win = xcalloc(1, sizeof(*win)); |
| win->offset = (offset / window_align) * window_align; |
| len = p->pack_size - win->offset; |
| if (len > packed_git_window_size) |
| len = packed_git_window_size; |
| win->len = (size_t)len; |
| pack_mapped += win->len; |
| while (packed_git_limit < pack_mapped |
| && unuse_one_window(p)) |
| ; /* nothing */ |
| win->base = xmmap(NULL, win->len, |
| PROT_READ, MAP_PRIVATE, |
| p->pack_fd, win->offset); |
| if (win->base == MAP_FAILED) |
| die_errno("packfile %s cannot be mapped", |
| p->pack_name); |
| if (!win->offset && win->len == p->pack_size |
| && !p->do_not_close) |
| close_pack_fd(p); |
| pack_mmap_calls++; |
| pack_open_windows++; |
| if (pack_mapped > peak_pack_mapped) |
| peak_pack_mapped = pack_mapped; |
| if (pack_open_windows > peak_pack_open_windows) |
| peak_pack_open_windows = pack_open_windows; |
| win->next = p->windows; |
| p->windows = win; |
| } |
| } |
| if (win != *w_cursor) { |
| win->last_used = pack_used_ctr++; |
| win->inuse_cnt++; |
| *w_cursor = win; |
| } |
| offset -= win->offset; |
| if (left) |
| *left = win->len - xsize_t(offset); |
| return win->base + offset; |
| } |
| |
| static struct packed_git *alloc_packed_git(int extra) |
| { |
| struct packed_git *p = xmalloc(st_add(sizeof(*p), extra)); |
| memset(p, 0, sizeof(*p)); |
| p->pack_fd = -1; |
| return p; |
| } |
| |
| static void try_to_free_pack_memory(size_t size) |
| { |
| release_pack_memory(size); |
| } |
| |
| struct packed_git *add_packed_git(const char *path, size_t path_len, int local) |
| { |
| static int have_set_try_to_free_routine; |
| struct stat st; |
| size_t alloc; |
| struct packed_git *p; |
| |
| if (!have_set_try_to_free_routine) { |
| have_set_try_to_free_routine = 1; |
| set_try_to_free_routine(try_to_free_pack_memory); |
| } |
| |
| /* |
| * Make sure a corresponding .pack file exists and that |
| * the index looks sane. |
| */ |
| if (!strip_suffix_mem(path, &path_len, ".idx")) |
| return NULL; |
| |
| /* |
| * ".pack" is long enough to hold any suffix we're adding (and |
| * the use xsnprintf double-checks that) |
| */ |
| alloc = st_add3(path_len, strlen(".pack"), 1); |
| p = alloc_packed_git(alloc); |
| memcpy(p->pack_name, path, path_len); |
| |
| xsnprintf(p->pack_name + path_len, alloc - path_len, ".keep"); |
| if (!access(p->pack_name, F_OK)) |
| p->pack_keep = 1; |
| |
| xsnprintf(p->pack_name + path_len, alloc - path_len, ".pack"); |
| if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) { |
| free(p); |
| return NULL; |
| } |
| |
| /* ok, it looks sane as far as we can check without |
| * actually mapping the pack file. |
| */ |
| p->pack_size = st.st_size; |
| p->pack_local = local; |
| p->mtime = st.st_mtime; |
| if (path_len < 40 || get_sha1_hex(path + path_len - 40, p->sha1)) |
| hashclr(p->sha1); |
| return p; |
| } |
| |
| struct packed_git *parse_pack_index(unsigned char *sha1, const char *idx_path) |
| { |
| const char *path = sha1_pack_name(sha1); |
| size_t alloc = st_add(strlen(path), 1); |
| struct packed_git *p = alloc_packed_git(alloc); |
| |
| memcpy(p->pack_name, path, alloc); /* includes NUL */ |
| hashcpy(p->sha1, sha1); |
| if (check_packed_git_idx(idx_path, p)) { |
| free(p); |
| return NULL; |
| } |
| |
| return p; |
| } |
| |
| void install_packed_git(struct packed_git *pack) |
| { |
| if (pack->pack_fd != -1) |
| pack_open_fds++; |
| |
| pack->next = packed_git; |
| packed_git = pack; |
| } |
| |
| void (*report_garbage)(unsigned seen_bits, const char *path); |
| |
| static void report_helper(const struct string_list *list, |
| int seen_bits, int first, int last) |
| { |
| if (seen_bits == (PACKDIR_FILE_PACK|PACKDIR_FILE_IDX)) |
| return; |
| |
| for (; first < last; first++) |
| report_garbage(seen_bits, list->items[first].string); |
| } |
| |
| static void report_pack_garbage(struct string_list *list) |
| { |
| int i, baselen = -1, first = 0, seen_bits = 0; |
| |
| if (!report_garbage) |
| return; |
| |
| string_list_sort(list); |
| |
| for (i = 0; i < list->nr; i++) { |
| const char *path = list->items[i].string; |
| if (baselen != -1 && |
| strncmp(path, list->items[first].string, baselen)) { |
| report_helper(list, seen_bits, first, i); |
| baselen = -1; |
| seen_bits = 0; |
| } |
| if (baselen == -1) { |
| const char *dot = strrchr(path, '.'); |
| if (!dot) { |
| report_garbage(PACKDIR_FILE_GARBAGE, path); |
| continue; |
| } |
| baselen = dot - path + 1; |
| first = i; |
| } |
| if (!strcmp(path + baselen, "pack")) |
| seen_bits |= 1; |
| else if (!strcmp(path + baselen, "idx")) |
| seen_bits |= 2; |
| } |
| report_helper(list, seen_bits, first, list->nr); |
| } |
| |
| static void prepare_packed_git_one(char *objdir, int local) |
| { |
| struct strbuf path = STRBUF_INIT; |
| size_t dirnamelen; |
| DIR *dir; |
| struct dirent *de; |
| struct string_list garbage = STRING_LIST_INIT_DUP; |
| |
| strbuf_addstr(&path, objdir); |
| strbuf_addstr(&path, "/pack"); |
| dir = opendir(path.buf); |
| if (!dir) { |
| if (errno != ENOENT) |
| error_errno("unable to open object pack directory: %s", |
| path.buf); |
| strbuf_release(&path); |
| return; |
| } |
| strbuf_addch(&path, '/'); |
| dirnamelen = path.len; |
| while ((de = readdir(dir)) != NULL) { |
| struct packed_git *p; |
| size_t base_len; |
| |
| if (is_dot_or_dotdot(de->d_name)) |
| continue; |
| |
| strbuf_setlen(&path, dirnamelen); |
| strbuf_addstr(&path, de->d_name); |
| |
| base_len = path.len; |
| if (strip_suffix_mem(path.buf, &base_len, ".idx")) { |
| /* Don't reopen a pack we already have. */ |
| for (p = packed_git; p; p = p->next) { |
| size_t len; |
| if (strip_suffix(p->pack_name, ".pack", &len) && |
| len == base_len && |
| !memcmp(p->pack_name, path.buf, len)) |
| break; |
| } |
| if (p == NULL && |
| /* |
| * See if it really is a valid .idx file with |
| * corresponding .pack file that we can map. |
| */ |
| (p = add_packed_git(path.buf, path.len, local)) != NULL) |
| install_packed_git(p); |
| } |
| |
| if (!report_garbage) |
| continue; |
| |
| if (ends_with(de->d_name, ".idx") || |
| ends_with(de->d_name, ".pack") || |
| ends_with(de->d_name, ".bitmap") || |
| ends_with(de->d_name, ".keep")) |
| string_list_append(&garbage, path.buf); |
| else |
| report_garbage(PACKDIR_FILE_GARBAGE, path.buf); |
| } |
| closedir(dir); |
| report_pack_garbage(&garbage); |
| string_list_clear(&garbage, 0); |
| strbuf_release(&path); |
| } |
| |
| static int approximate_object_count_valid; |
| |
| /* |
| * Give a fast, rough count of the number of objects in the repository. This |
| * ignores loose objects completely. If you have a lot of them, then either |
| * you should repack because your performance will be awful, or they are |
| * all unreachable objects about to be pruned, in which case they're not really |
| * interesting as a measure of repo size in the first place. |
| */ |
| unsigned long approximate_object_count(void) |
| { |
| static unsigned long count; |
| if (!approximate_object_count_valid) { |
| struct packed_git *p; |
| |
| prepare_packed_git(); |
| count = 0; |
| for (p = packed_git; p; p = p->next) { |
| if (open_pack_index(p)) |
| continue; |
| count += p->num_objects; |
| } |
| } |
| return count; |
| } |
| |
| static void *get_next_packed_git(const void *p) |
| { |
| return ((const struct packed_git *)p)->next; |
| } |
| |
| static void set_next_packed_git(void *p, void *next) |
| { |
| ((struct packed_git *)p)->next = next; |
| } |
| |
| static int sort_pack(const void *a_, const void *b_) |
| { |
| const struct packed_git *a = a_; |
| const struct packed_git *b = b_; |
| int st; |
| |
| /* |
| * Local packs tend to contain objects specific to our |
| * variant of the project than remote ones. In addition, |
| * remote ones could be on a network mounted filesystem. |
| * Favor local ones for these reasons. |
| */ |
| st = a->pack_local - b->pack_local; |
| if (st) |
| return -st; |
| |
| /* |
| * Younger packs tend to contain more recent objects, |
| * and more recent objects tend to get accessed more |
| * often. |
| */ |
| if (a->mtime < b->mtime) |
| return 1; |
| else if (a->mtime == b->mtime) |
| return 0; |
| return -1; |
| } |
| |
| static void rearrange_packed_git(void) |
| { |
| packed_git = llist_mergesort(packed_git, get_next_packed_git, |
| set_next_packed_git, sort_pack); |
| } |
| |
| static void prepare_packed_git_mru(void) |
| { |
| struct packed_git *p; |
| |
| mru_clear(packed_git_mru); |
| for (p = packed_git; p; p = p->next) |
| mru_append(packed_git_mru, p); |
| } |
| |
| static int prepare_packed_git_run_once = 0; |
| void prepare_packed_git(void) |
| { |
| struct alternate_object_database *alt; |
| |
| if (prepare_packed_git_run_once) |
| return; |
| prepare_packed_git_one(get_object_directory(), 1); |
| prepare_alt_odb(); |
| for (alt = alt_odb_list; alt; alt = alt->next) |
| prepare_packed_git_one(alt->path, 0); |
| rearrange_packed_git(); |
| prepare_packed_git_mru(); |
| prepare_packed_git_run_once = 1; |
| } |
| |
| void reprepare_packed_git(void) |
| { |
| approximate_object_count_valid = 0; |
| prepare_packed_git_run_once = 0; |
| prepare_packed_git(); |
| } |
| |
| static void mark_bad_packed_object(struct packed_git *p, |
| const unsigned char *sha1) |
| { |
| unsigned i; |
| for (i = 0; i < p->num_bad_objects; i++) |
| if (!hashcmp(sha1, p->bad_object_sha1 + GIT_SHA1_RAWSZ * i)) |
| return; |
| p->bad_object_sha1 = xrealloc(p->bad_object_sha1, |
| st_mult(GIT_SHA1_RAWSZ, |
| st_add(p->num_bad_objects, 1))); |
| hashcpy(p->bad_object_sha1 + GIT_SHA1_RAWSZ * p->num_bad_objects, sha1); |
| p->num_bad_objects++; |
| } |
| |
| static const struct packed_git *has_packed_and_bad(const unsigned char *sha1) |
| { |
| struct packed_git *p; |
| unsigned i; |
| |
| for (p = packed_git; p; p = p->next) |
| for (i = 0; i < p->num_bad_objects; i++) |
| if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i)) |
| return p; |
| return NULL; |
| } |
| |
| /* |
| * With an in-core object data in "map", rehash it to make sure the |
| * object name actually matches "sha1" to detect object corruption. |
| * With "map" == NULL, try reading the object named with "sha1" using |
| * the streaming interface and rehash it to do the same. |
| */ |
| int check_sha1_signature(const unsigned char *sha1, void *map, |
| unsigned long size, const char *type) |
| { |
| unsigned char real_sha1[20]; |
| enum object_type obj_type; |
| struct git_istream *st; |
| git_SHA_CTX c; |
| char hdr[32]; |
| int hdrlen; |
| |
| if (map) { |
| hash_sha1_file(map, size, type, real_sha1); |
| return hashcmp(sha1, real_sha1) ? -1 : 0; |
| } |
| |
| st = open_istream(sha1, &obj_type, &size, NULL); |
| if (!st) |
| return -1; |
| |
| /* Generate the header */ |
| hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %lu", typename(obj_type), size) + 1; |
| |
| /* Sha1.. */ |
| git_SHA1_Init(&c); |
| git_SHA1_Update(&c, hdr, hdrlen); |
| for (;;) { |
| char buf[1024 * 16]; |
| ssize_t readlen = read_istream(st, buf, sizeof(buf)); |
| |
| if (readlen < 0) { |
| close_istream(st); |
| return -1; |
| } |
| if (!readlen) |
| break; |
| git_SHA1_Update(&c, buf, readlen); |
| } |
| git_SHA1_Final(real_sha1, &c); |
| close_istream(st); |
| return hashcmp(sha1, real_sha1) ? -1 : 0; |
| } |
| |
| int git_open(const char *name) |
| { |
| static int sha1_file_open_flag = O_NOATIME | O_CLOEXEC; |
| |
| for (;;) { |
| int fd; |
| |
| errno = 0; |
| fd = open(name, O_RDONLY | sha1_file_open_flag); |
| if (fd >= 0) |
| return fd; |
| |
| /* Try again w/o O_CLOEXEC: the kernel might not support it */ |
| if ((sha1_file_open_flag & O_CLOEXEC) && errno == EINVAL) { |
| sha1_file_open_flag &= ~O_CLOEXEC; |
| continue; |
| } |
| |
| /* Might the failure be due to O_NOATIME? */ |
| if (errno != ENOENT && (sha1_file_open_flag & O_NOATIME)) { |
| sha1_file_open_flag &= ~O_NOATIME; |
| continue; |
| } |
| return -1; |
| } |
| } |
| |
| static int stat_sha1_file(const unsigned char *sha1, struct stat *st) |
| { |
| struct alternate_object_database *alt; |
| |
| if (!lstat(sha1_file_name(sha1), st)) |
| return 0; |
| |
| prepare_alt_odb(); |
| errno = ENOENT; |
| for (alt = alt_odb_list; alt; alt = alt->next) { |
| const char *path = alt_sha1_path(alt, sha1); |
| if (!lstat(path, st)) |
| return 0; |
| } |
| |
| return -1; |
| } |
| |
| static int open_sha1_file(const unsigned char *sha1) |
| { |
| int fd; |
| struct alternate_object_database *alt; |
| int most_interesting_errno; |
| |
| fd = git_open(sha1_file_name(sha1)); |
| if (fd >= 0) |
| return fd; |
| most_interesting_errno = errno; |
| |
| prepare_alt_odb(); |
| for (alt = alt_odb_list; alt; alt = alt->next) { |
| const char *path = alt_sha1_path(alt, sha1); |
| fd = git_open(path); |
| if (fd >= 0) |
| return fd; |
| if (most_interesting_errno == ENOENT) |
| most_interesting_errno = errno; |
| } |
| errno = most_interesting_errno; |
| return -1; |
| } |
| |
| void *map_sha1_file(const unsigned char *sha1, unsigned long *size) |
| { |
| void *map; |
| int fd; |
| |
| fd = open_sha1_file(sha1); |
| map = NULL; |
| if (fd >= 0) { |
| struct stat st; |
| |
| if (!fstat(fd, &st)) { |
| *size = xsize_t(st.st_size); |
| if (!*size) { |
| /* mmap() is forbidden on empty files */ |
| error("object file %s is empty", sha1_file_name(sha1)); |
| return NULL; |
| } |
| map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0); |
| } |
| close(fd); |
| } |
| return map; |
| } |
| |
| unsigned long unpack_object_header_buffer(const unsigned char *buf, |
| unsigned long len, enum object_type *type, unsigned long *sizep) |
| { |
| unsigned shift; |
| unsigned long size, c; |
| unsigned long used = 0; |
| |
| c = buf[used++]; |
| *type = (c >> 4) & 7; |
| size = c & 15; |
| shift = 4; |
| while (c & 0x80) { |
| if (len <= used || bitsizeof(long) <= shift) { |
| error("bad object header"); |
| size = used = 0; |
| break; |
| } |
| c = buf[used++]; |
| size += (c & 0x7f) << shift; |
| shift += 7; |
| } |
| *sizep = size; |
| return used; |
| } |
| |
| static int unpack_sha1_short_header(git_zstream *stream, |
| unsigned char *map, unsigned long mapsize, |
| void *buffer, unsigned long bufsiz) |
| { |
| /* Get the data stream */ |
| memset(stream, 0, sizeof(*stream)); |
| stream->next_in = map; |
| stream->avail_in = mapsize; |
| stream->next_out = buffer; |
| stream->avail_out = bufsiz; |
| |
| git_inflate_init(stream); |
| return git_inflate(stream, 0); |
| } |
| |
| int unpack_sha1_header(git_zstream *stream, |
| unsigned char *map, unsigned long mapsize, |
| void *buffer, unsigned long bufsiz) |
| { |
| int status = unpack_sha1_short_header(stream, map, mapsize, |
| buffer, bufsiz); |
| |
| if (status < Z_OK) |
| return status; |
| |
| /* Make sure we have the terminating NUL */ |
| if (!memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer)) |
| return -1; |
| return 0; |
| } |
| |
| static int unpack_sha1_header_to_strbuf(git_zstream *stream, unsigned char *map, |
| unsigned long mapsize, void *buffer, |
| unsigned long bufsiz, struct strbuf *header) |
| { |
| int status; |
| |
| status = unpack_sha1_short_header(stream, map, mapsize, buffer, bufsiz); |
| if (status < Z_OK) |
| return -1; |
| |
| /* |
| * Check if entire header is unpacked in the first iteration. |
| */ |
| if (memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer)) |
| return 0; |
| |
| /* |
| * buffer[0..bufsiz] was not large enough. Copy the partial |
| * result out to header, and then append the result of further |
| * reading the stream. |
| */ |
| strbuf_add(header, buffer, stream->next_out - (unsigned char *)buffer); |
| stream->next_out = buffer; |
| stream->avail_out = bufsiz; |
| |
| do { |
| status = git_inflate(stream, 0); |
| strbuf_add(header, buffer, stream->next_out - (unsigned char *)buffer); |
| if (memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer)) |
| return 0; |
| stream->next_out = buffer; |
| stream->avail_out = bufsiz; |
| } while (status != Z_STREAM_END); |
| return -1; |
| } |
| |
| static void *unpack_sha1_rest(git_zstream *stream, void *buffer, unsigned long size, const unsigned char *sha1) |
| { |
| int bytes = strlen(buffer) + 1; |
| unsigned char *buf = xmallocz(size); |
| unsigned long n; |
| int status = Z_OK; |
| |
| n = stream->total_out - bytes; |
| if (n > size) |
| n = size; |
| memcpy(buf, (char *) buffer + bytes, n); |
| bytes = n; |
| if (bytes <= size) { |
| /* |
| * The above condition must be (bytes <= size), not |
| * (bytes < size). In other words, even though we |
| * expect no more output and set avail_out to zero, |
| * the input zlib stream may have bytes that express |
| * "this concludes the stream", and we *do* want to |
| * eat that input. |
| * |
| * Otherwise we would not be able to test that we |
| * consumed all the input to reach the expected size; |
| * we also want to check that zlib tells us that all |
| * went well with status == Z_STREAM_END at the end. |
| */ |
| stream->next_out = buf + bytes; |
| stream->avail_out = size - bytes; |
| while (status == Z_OK) |
| status = git_inflate(stream, Z_FINISH); |
| } |
| if (status == Z_STREAM_END && !stream->avail_in) { |
| git_inflate_end(stream); |
| return buf; |
| } |
| |
| if (status < 0) |
| error("corrupt loose object '%s'", sha1_to_hex(sha1)); |
| else if (stream->avail_in) |
| error("garbage at end of loose object '%s'", |
| sha1_to_hex(sha1)); |
| free(buf); |
| return NULL; |
| } |
| |
| /* |
| * We used to just use "sscanf()", but that's actually way |
| * too permissive for what we want to check. So do an anal |
| * object header parse by hand. |
| */ |
| static int parse_sha1_header_extended(const char *hdr, struct object_info *oi, |
| unsigned int flags) |
| { |
| const char *type_buf = hdr; |
| unsigned long size; |
| int type, type_len = 0; |
| |
| /* |
| * The type can be of any size but is followed by |
| * a space. |
| */ |
| for (;;) { |
| char c = *hdr++; |
| if (!c) |
| return -1; |
| if (c == ' ') |
| break; |
| type_len++; |
| } |
| |
| type = type_from_string_gently(type_buf, type_len, 1); |
| if (oi->typename) |
| strbuf_add(oi->typename, type_buf, type_len); |
| /* |
| * Set type to 0 if its an unknown object and |
| * we're obtaining the type using '--allow-unknown-type' |
| * option. |
| */ |
| if ((flags & LOOKUP_UNKNOWN_OBJECT) && (type < 0)) |
| type = 0; |
| else if (type < 0) |
| die("invalid object type"); |
| if (oi->typep) |
| *oi->typep = type; |
| |
| /* |
| * The length must follow immediately, and be in canonical |
| * decimal format (ie "010" is not valid). |
| */ |
| size = *hdr++ - '0'; |
| if (size > 9) |
| return -1; |
| if (size) { |
| for (;;) { |
| unsigned long c = *hdr - '0'; |
| if (c > 9) |
| break; |
| hdr++; |
| size = size * 10 + c; |
| } |
| } |
| |
| if (oi->sizep) |
| *oi->sizep = size; |
| |
| /* |
| * The length must be followed by a zero byte |
| */ |
| return *hdr ? -1 : type; |
| } |
| |
| int parse_sha1_header(const char *hdr, unsigned long *sizep) |
| { |
| struct object_info oi = OBJECT_INFO_INIT; |
| |
| oi.sizep = sizep; |
| return parse_sha1_header_extended(hdr, &oi, LOOKUP_REPLACE_OBJECT); |
| } |
| |
| static void *unpack_sha1_file(void *map, unsigned long mapsize, enum object_type *type, unsigned long *size, const unsigned char *sha1) |
| { |
| int ret; |
| git_zstream stream; |
| char hdr[8192]; |
| |
| ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)); |
| if (ret < Z_OK || (*type = parse_sha1_header(hdr, size)) < 0) |
| return NULL; |
| |
| return unpack_sha1_rest(&stream, hdr, *size, sha1); |
| } |
| |
| unsigned long get_size_from_delta(struct packed_git *p, |
| struct pack_window **w_curs, |
| off_t curpos) |
| { |
| const unsigned char *data; |
| unsigned char delta_head[20], *in; |
| git_zstream stream; |
| int st; |
| |
| memset(&stream, 0, sizeof(stream)); |
| stream.next_out = delta_head; |
| stream.avail_out = sizeof(delta_head); |
| |
| git_inflate_init(&stream); |
| do { |
| in = use_pack(p, w_curs, curpos, &stream.avail_in); |
| stream.next_in = in; |
| st = git_inflate(&stream, Z_FINISH); |
| curpos += stream.next_in - in; |
| } while ((st == Z_OK || st == Z_BUF_ERROR) && |
| stream.total_out < sizeof(delta_head)); |
| git_inflate_end(&stream); |
| if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head)) { |
| error("delta data unpack-initial failed"); |
| return 0; |
| } |
| |
| /* Examine the initial part of the delta to figure out |
| * the result size. |
| */ |
| data = delta_head; |
| |
| /* ignore base size */ |
| get_delta_hdr_size(&data, delta_head+sizeof(delta_head)); |
| |
| /* Read the result size */ |
| return get_delta_hdr_size(&data, delta_head+sizeof(delta_head)); |
| } |
| |
| static off_t get_delta_base(struct packed_git *p, |
| struct pack_window **w_curs, |
| off_t *curpos, |
| enum object_type type, |
| off_t delta_obj_offset) |
| { |
| unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL); |
| off_t base_offset; |
| |
| /* use_pack() assured us we have [base_info, base_info + 20) |
| * as a range that we can look at without walking off the |
| * end of the mapped window. Its actually the hash size |
| * that is assured. An OFS_DELTA longer than the hash size |
| * is stupid, as then a REF_DELTA would be smaller to store. |
| */ |
| if (type == OBJ_OFS_DELTA) { |
| unsigned used = 0; |
| unsigned char c = base_info[used++]; |
| base_offset = c & 127; |
| while (c & 128) { |
| base_offset += 1; |
| if (!base_offset || MSB(base_offset, 7)) |
| return 0; /* overflow */ |
| c = base_info[used++]; |
| base_offset = (base_offset << 7) + (c & 127); |
| } |
| base_offset = delta_obj_offset - base_offset; |
| if (base_offset <= 0 || base_offset >= delta_obj_offset) |
| return 0; /* out of bound */ |
| *curpos += used; |
| } else if (type == OBJ_REF_DELTA) { |
| /* The base entry _must_ be in the same pack */ |
| base_offset = find_pack_entry_one(base_info, p); |
| *curpos += 20; |
| } else |
| die("I am totally screwed"); |
| return base_offset; |
| } |
| |
| /* |
| * Like get_delta_base above, but we return the sha1 instead of the pack |
| * offset. This means it is cheaper for REF deltas (we do not have to do |
| * the final object lookup), but more expensive for OFS deltas (we |
| * have to load the revidx to convert the offset back into a sha1). |
| */ |
| static const unsigned char *get_delta_base_sha1(struct packed_git *p, |
| struct pack_window **w_curs, |
| off_t curpos, |
| enum object_type type, |
| off_t delta_obj_offset) |
| { |
| if (type == OBJ_REF_DELTA) { |
| unsigned char *base = use_pack(p, w_curs, curpos, NULL); |
| return base; |
| } else if (type == OBJ_OFS_DELTA) { |
| struct revindex_entry *revidx; |
| off_t base_offset = get_delta_base(p, w_curs, &curpos, |
| type, delta_obj_offset); |
| |
| if (!base_offset) |
| return NULL; |
| |
| revidx = find_pack_revindex(p, base_offset); |
| if (!revidx) |
| return NULL; |
| |
| return nth_packed_object_sha1(p, revidx->nr); |
| } else |
| return NULL; |
| } |
| |
| int unpack_object_header(struct packed_git *p, |
| struct pack_window **w_curs, |
| off_t *curpos, |
| unsigned long *sizep) |
| { |
| unsigned char *base; |
| unsigned long left; |
| unsigned long used; |
| enum object_type type; |
| |
| /* use_pack() assures us we have [base, base + 20) available |
| * as a range that we can look at. (Its actually the hash |
| * size that is assured.) With our object header encoding |
| * the maximum deflated object size is 2^137, which is just |
| * insane, so we know won't exceed what we have been given. |
| */ |
| base = use_pack(p, w_curs, *curpos, &left); |
| used = unpack_object_header_buffer(base, left, &type, sizep); |
| if (!used) { |
| type = OBJ_BAD; |
| } else |
| *curpos += used; |
| |
| return type; |
| } |
| |
| static int retry_bad_packed_offset(struct packed_git *p, off_t obj_offset) |
| { |
| int type; |
| struct revindex_entry *revidx; |
| const unsigned char *sha1; |
| revidx = find_pack_revindex(p, obj_offset); |
| if (!revidx) |
| return OBJ_BAD; |
| sha1 = nth_packed_object_sha1(p, revidx->nr); |
| mark_bad_packed_object(p, sha1); |
| type = sha1_object_info(sha1, NULL); |
| if (type <= OBJ_NONE) |
| return OBJ_BAD; |
| return type; |
| } |
| |
| #define POI_STACK_PREALLOC 64 |
| |
| static enum object_type packed_to_object_type(struct packed_git *p, |
| off_t obj_offset, |
| enum object_type type, |
| struct pack_window **w_curs, |
| off_t curpos) |
| { |
| off_t small_poi_stack[POI_STACK_PREALLOC]; |
| off_t *poi_stack = small_poi_stack; |
| int poi_stack_nr = 0, poi_stack_alloc = POI_STACK_PREALLOC; |
| |
| while (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) { |
| off_t base_offset; |
| unsigned long size; |
| /* Push the object we're going to leave behind */ |
| if (poi_stack_nr >= poi_stack_alloc && poi_stack == small_poi_stack) { |
| poi_stack_alloc = alloc_nr(poi_stack_nr); |
| ALLOC_ARRAY(poi_stack, poi_stack_alloc); |
| memcpy(poi_stack, small_poi_stack, sizeof(off_t)*poi_stack_nr); |
| } else { |
| ALLOC_GROW(poi_stack, poi_stack_nr+1, poi_stack_alloc); |
| } |
| poi_stack[poi_stack_nr++] = obj_offset; |
| /* If parsing the base offset fails, just unwind */ |
| base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset); |
| if (!base_offset) |
| goto unwind; |
| curpos = obj_offset = base_offset; |
| type = unpack_object_header(p, w_curs, &curpos, &size); |
| if (type <= OBJ_NONE) { |
| /* If getting the base itself fails, we first |
| * retry the base, otherwise unwind */ |
| type = retry_bad_packed_offset(p, base_offset); |
| if (type > OBJ_NONE) |
| goto out; |
| goto unwind; |
| } |
| } |
| |
| switch (type) { |
| case OBJ_BAD: |
| case OBJ_COMMIT: |
| case OBJ_TREE: |
| case OBJ_BLOB: |
| case OBJ_TAG: |
| break; |
| default: |
| error("unknown object type %i at offset %"PRIuMAX" in %s", |
| type, (uintmax_t)obj_offset, p->pack_name); |
| type = OBJ_BAD; |
| } |
| |
| out: |
| if (poi_stack != small_poi_stack) |
| free(poi_stack); |
| return type; |
| |
| unwind: |
| while (poi_stack_nr) { |
| obj_offset = poi_stack[--poi_stack_nr]; |
| type = retry_bad_packed_offset(p, obj_offset); |
| if (type > OBJ_NONE) |
| goto out; |
| } |
| type = OBJ_BAD; |
| goto out; |
| } |
| |
| int packed_object_info(struct packed_git *p, off_t obj_offset, |
| struct object_info *oi) |
| { |
| struct pack_window *w_curs = NULL; |
| unsigned long size; |
| off_t curpos = obj_offset; |
| enum object_type type; |
| |
| /* |
| * We always get the representation type, but only convert it to |
| * a "real" type later if the caller is interested. |
| */ |
| type = unpack_object_header(p, &w_curs, &curpos, &size); |
| |
| if (oi->sizep) { |
| if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) { |
| off_t tmp_pos = curpos; |
| off_t base_offset = get_delta_base(p, &w_curs, &tmp_pos, |
| type, obj_offset); |
| if (!base_offset) { |
| type = OBJ_BAD; |
| goto out; |
| } |
| *oi->sizep = get_size_from_delta(p, &w_curs, tmp_pos); |
| if (*oi->sizep == 0) { |
| type = OBJ_BAD; |
| goto out; |
| } |
| } else { |
| *oi->sizep = size; |
| } |
| } |
| |
| if (oi->disk_sizep) { |
| struct revindex_entry *revidx = find_pack_revindex(p, obj_offset); |
| *oi->disk_sizep = revidx[1].offset - obj_offset; |
| } |
| |
| if (oi->typep) { |
| *oi->typep = packed_to_object_type(p, obj_offset, type, &w_curs, curpos); |
| if (*oi->typep < 0) { |
| type = OBJ_BAD; |
| goto out; |
| } |
| } |
| |
| if (oi->delta_base_sha1) { |
| if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) { |
| const unsigned char *base; |
| |
| base = get_delta_base_sha1(p, &w_curs, curpos, |
| type, obj_offset); |
| if (!base) { |
| type = OBJ_BAD; |
| goto out; |
| } |
| |
| hashcpy(oi->delta_base_sha1, base); |
| } else |
| hashclr(oi->delta_base_sha1); |
| } |
| |
| out: |
| unuse_pack(&w_curs); |
| return type; |
| } |
| |
| static void *unpack_compressed_entry(struct packed_git *p, |
| struct pack_window **w_curs, |
| off_t curpos, |
| unsigned long size) |
| { |
| int st; |
| git_zstream stream; |
| unsigned char *buffer, *in; |
| |
| buffer = xmallocz_gently(size); |
| if (!buffer) |
| return NULL; |
| memset(&stream, 0, sizeof(stream)); |
| stream.next_out = buffer; |
| stream.avail_out = size + 1; |
| |
| git_inflate_init(&stream); |
| do { |
| in = use_pack(p, w_curs, curpos, &stream.avail_in); |
| stream.next_in = in; |
| st = git_inflate(&stream, Z_FINISH); |
| if (!stream.avail_out) |
| break; /* the payload is larger than it should be */ |
| curpos += stream.next_in - in; |
| } while (st == Z_OK || st == Z_BUF_ERROR); |
| git_inflate_end(&stream); |
| if ((st != Z_STREAM_END) || stream.total_out != size) { |
| free(buffer); |
| return NULL; |
| } |
| |
| return buffer; |
| } |
| |
| static struct hashmap delta_base_cache; |
| static size_t delta_base_cached; |
| |
| static LIST_HEAD(delta_base_cache_lru); |
| |
| struct delta_base_cache_key { |
| struct packed_git *p; |
| off_t base_offset; |
| }; |
| |
| struct delta_base_cache_entry { |
| struct hashmap hash; |
| struct delta_base_cache_key key; |
| struct list_head lru; |
| void *data; |
| unsigned long size; |
| enum object_type type; |
| }; |
| |
| static unsigned int pack_entry_hash(struct packed_git *p, off_t base_offset) |
| { |
| unsigned int hash; |
| |
| hash = (unsigned int)(intptr_t)p + (unsigned int)base_offset; |
| hash += (hash >> 8) + (hash >> 16); |
| return hash; |
| } |
| |
| static struct delta_base_cache_entry * |
| get_delta_base_cache_entry(struct packed_git *p, off_t base_offset) |
| { |
| struct hashmap_entry entry; |
| struct delta_base_cache_key key; |
| |
| if (!delta_base_cache.cmpfn) |
| return NULL; |
| |
| hashmap_entry_init(&entry, pack_entry_hash(p, base_offset)); |
| key.p = p; |
| key.base_offset = base_offset; |
| return hashmap_get(&delta_base_cache, &entry, &key); |
| } |
| |
| static int delta_base_cache_key_eq(const struct delta_base_cache_key *a, |
| const struct delta_base_cache_key *b) |
| { |
| return a->p == b->p && a->base_offset == b->base_offset; |
| } |
| |
| static int delta_base_cache_hash_cmp(const void *va, const void *vb, |
| const void *vkey) |
| { |
| const struct delta_base_cache_entry *a = va, *b = vb; |
| const struct delta_base_cache_key *key = vkey; |
| if (key) |
| return !delta_base_cache_key_eq(&a->key, key); |
| else |
| return !delta_base_cache_key_eq(&a->key, &b->key); |
| } |
| |
| static int in_delta_base_cache(struct packed_git *p, off_t base_offset) |
| { |
| return !!get_delta_base_cache_entry(p, base_offset); |
| } |
| |
| /* |
| * Remove the entry from the cache, but do _not_ free the associated |
| * entry data. The caller takes ownership of the "data" buffer, and |
| * should copy out any fields it wants before detaching. |
| */ |
| static void detach_delta_base_cache_entry(struct delta_base_cache_entry *ent) |
| { |
| hashmap_remove(&delta_base_cache, ent, &ent->key); |
| list_del(&ent->lru); |
| delta_base_cached -= ent->size; |
| free(ent); |
| } |
| |
| static void *cache_or_unpack_entry(struct packed_git *p, off_t base_offset, |
| unsigned long *base_size, enum object_type *type) |
| { |
| struct delta_base_cache_entry *ent; |
| |
| ent = get_delta_base_cache_entry(p, base_offset); |
| if (!ent) |
| return unpack_entry(p, base_offset, type, base_size); |
| |
| *type = ent->type; |
| *base_size = ent->size; |
| return xmemdupz(ent->data, ent->size); |
| } |
| |
| static inline void release_delta_base_cache(struct delta_base_cache_entry *ent) |
| { |
| free(ent->data); |
| detach_delta_base_cache_entry(ent); |
| } |
| |
| void clear_delta_base_cache(void) |
| { |
| struct hashmap_iter iter; |
| struct delta_base_cache_entry *entry; |
| for (entry = hashmap_iter_first(&delta_base_cache, &iter); |
| entry; |
| entry = hashmap_iter_next(&iter)) { |
| release_delta_base_cache(entry); |
| } |
| } |
| |
| static void add_delta_base_cache(struct packed_git *p, off_t base_offset, |
| void *base, unsigned long base_size, enum object_type type) |
| { |
| struct delta_base_cache_entry *ent = xmalloc(sizeof(*ent)); |
| struct list_head *lru, *tmp; |
| |
| delta_base_cached += base_size; |
| |
| list_for_each_safe(lru, tmp, &delta_base_cache_lru) { |
| struct delta_base_cache_entry *f = |
| list_entry(lru, struct delta_base_cache_entry, lru); |
| if (delta_base_cached <= delta_base_cache_limit) |
| break; |
| release_delta_base_cache(f); |
| } |
| |
| ent->key.p = p; |
| ent->key.base_offset = base_offset; |
| ent->type = type; |
| ent->data = base; |
| ent->size = base_size; |
| list_add_tail(&ent->lru, &delta_base_cache_lru); |
| |
| if (!delta_base_cache.cmpfn) |
| hashmap_init(&delta_base_cache, delta_base_cache_hash_cmp, 0); |
| hashmap_entry_init(ent, pack_entry_hash(p, base_offset)); |
| hashmap_add(&delta_base_cache, ent); |
| } |
| |
| static void *read_object(const unsigned char *sha1, enum object_type *type, |
| unsigned long *size); |
| |
| static void write_pack_access_log(struct packed_git *p, off_t obj_offset) |
| { |
| static struct trace_key pack_access = TRACE_KEY_INIT(PACK_ACCESS); |
| trace_printf_key(&pack_access, "%s %"PRIuMAX"\n", |
| p->pack_name, (uintmax_t)obj_offset); |
| } |
| |
| int do_check_packed_object_crc; |
| |
| #define UNPACK_ENTRY_STACK_PREALLOC 64 |
| struct unpack_entry_stack_ent { |
| off_t obj_offset; |
| off_t curpos; |
| unsigned long size; |
| }; |
| |
| void *unpack_entry(struct packed_git *p, off_t obj_offset, |
| enum object_type *final_type, unsigned long *final_size) |
| { |
| struct pack_window *w_curs = NULL; |
| off_t curpos = obj_offset; |
| void *data = NULL; |
| unsigned long size; |
| enum object_type type; |
| struct unpack_entry_stack_ent small_delta_stack[UNPACK_ENTRY_STACK_PREALLOC]; |
| struct unpack_entry_stack_ent *delta_stack = small_delta_stack; |
| int delta_stack_nr = 0, delta_stack_alloc = UNPACK_ENTRY_STACK_PREALLOC; |
| int base_from_cache = 0; |
| |
| write_pack_access_log(p, obj_offset); |
| |
| /* PHASE 1: drill down to the innermost base object */ |
| for (;;) { |
| off_t base_offset; |
| int i; |
| struct delta_base_cache_entry *ent; |
| |
| ent = get_delta_base_cache_entry(p, curpos); |
| if (ent) { |
| type = ent->type; |
| data = ent->data; |
| size = ent->size; |
| detach_delta_base_cache_entry(ent); |
| base_from_cache = 1; |
| break; |
| } |
| |
| if (do_check_packed_object_crc && p->index_version > 1) { |
| struct revindex_entry *revidx = find_pack_revindex(p, obj_offset); |
| off_t len = revidx[1].offset - obj_offset; |
| if (check_pack_crc(p, &w_curs, obj_offset, len, revidx->nr)) { |
| const unsigned char *sha1 = |
| nth_packed_object_sha1(p, revidx->nr); |
| error("bad packed object CRC for %s", |
| sha1_to_hex(sha1)); |
| mark_bad_packed_object(p, sha1); |
| unuse_pack(&w_curs); |
| return NULL; |
| } |
| } |
| |
| type = unpack_object_header(p, &w_curs, &curpos, &size); |
| if (type != OBJ_OFS_DELTA && type != OBJ_REF_DELTA) |
| break; |
| |
| base_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset); |
| if (!base_offset) { |
| error("failed to validate delta base reference " |
| "at offset %"PRIuMAX" from %s", |
| (uintmax_t)curpos, p->pack_name); |
| /* bail to phase 2, in hopes of recovery */ |
| data = NULL; |
| break; |
| } |
| |
| /* push object, proceed to base */ |
| if (delta_stack_nr >= delta_stack_alloc |
| && delta_stack == small_delta_stack) { |
| delta_stack_alloc = alloc_nr(delta_stack_nr); |
| ALLOC_ARRAY(delta_stack, delta_stack_alloc); |
| memcpy(delta_stack, small_delta_stack, |
| sizeof(*delta_stack)*delta_stack_nr); |
| } else { |
| ALLOC_GROW(delta_stack, delta_stack_nr+1, delta_stack_alloc); |
| } |
| i = delta_stack_nr++; |
| delta_stack[i].obj_offset = obj_offset; |
| delta_stack[i].curpos = curpos; |
| delta_stack[i].size = size; |
| |
| curpos = obj_offset = base_offset; |
| } |
| |
| /* PHASE 2: handle the base */ |
| switch (type) { |
| case OBJ_OFS_DELTA: |
| case OBJ_REF_DELTA: |
| if (data) |
| die("BUG: unpack_entry: left loop at a valid delta"); |
| break; |
| case OBJ_COMMIT: |
| case OBJ_TREE: |
| case OBJ_BLOB: |
| case OBJ_TAG: |
| if (!base_from_cache) |
| data = unpack_compressed_entry(p, &w_curs, curpos, size); |
| break; |
| default: |
| data = NULL; |
| error("unknown object type %i at offset %"PRIuMAX" in %s", |
| type, (uintmax_t)obj_offset, p->pack_name); |
| } |
| |
| /* PHASE 3: apply deltas in order */ |
| |
| /* invariants: |
| * 'data' holds the base data, or NULL if there was corruption |
| */ |
| while (delta_stack_nr) { |
| void *delta_data; |
| void *base = data; |
| unsigned long delta_size, base_size = size; |
| int i; |
| |
| data = NULL; |
| |
| if (base) |
| add_delta_base_cache(p, obj_offset, base, base_size, type); |
| |
| if (!base) { |
| /* |
| * We're probably in deep shit, but let's try to fetch |
| * the required base anyway from another pack or loose. |
| * This is costly but should happen only in the presence |
| * of a corrupted pack, and is better than failing outright. |
| */ |
| struct revindex_entry *revidx; |
| const unsigned char *base_sha1; |
| revidx = find_pack_revindex(p, obj_offset); |
| if (revidx) { |
| base_sha1 = nth_packed_object_sha1(p, revidx->nr); |
| error("failed to read delta base object %s" |
| " at offset %"PRIuMAX" from %s", |
| sha1_to_hex(base_sha1), (uintmax_t)obj_offset, |
| p->pack_name); |
| mark_bad_packed_object(p, base_sha1); |
| base = read_object(base_sha1, &type, &base_size); |
| } |
| } |
| |
| i = --delta_stack_nr; |
| obj_offset = delta_stack[i].obj_offset; |
| curpos = delta_stack[i].curpos; |
| delta_size = delta_stack[i].size; |
| |
| if (!base) |
| continue; |
| |
| delta_data = unpack_compressed_entry(p, &w_curs, curpos, delta_size); |
| |
| if (!delta_data) { |
| error("failed to unpack compressed delta " |
| "at offset %"PRIuMAX" from %s", |
| (uintmax_t)curpos, p->pack_name); |
| data = NULL; |
| continue; |
| } |
| |
| data = patch_delta(base, base_size, |
| delta_data, delta_size, |
| &size); |
| |
| /* |
| * We could not apply the delta; warn the user, but keep going. |
| * Our failure will be noticed either in the next iteration of |
| * the loop, or if this is the final delta, in the caller when |
| * we return NULL. Those code paths will take care of making |
| * a more explicit warning and retrying with another copy of |
| * the object. |
| */ |
| if (!data) |
| error("failed to apply delta"); |
| |
| free(delta_data); |
| } |
| |
| *final_type = type; |
| *final_size = size; |
| |
| unuse_pack(&w_curs); |
| |
| if (delta_stack != small_delta_stack) |
| free(delta_stack); |
| |
| return data; |
| } |
| |
| const unsigned char *nth_packed_object_sha1(struct packed_git *p, |
| uint32_t n) |
| { |
| const unsigned char *index = p->index_data; |
| if (!index) { |
| if (open_pack_index(p)) |
| return NULL; |
| index = p->index_data; |
| } |
| if (n >= p->num_objects) |
| return NULL; |
| index += 4 * 256; |
| if (p->index_version == 1) { |
| return index + 24 * n + 4; |
| } else { |
| index += 8; |
| return index + 20 * n; |
| } |
| } |
| |
| void check_pack_index_ptr(const struct packed_git *p, const void *vptr) |
| { |
| const unsigned char *ptr = vptr; |
| const unsigned char *start = p->index_data; |
| const unsigned char *end = start + p->index_size; |
| if (ptr < start) |
| die(_("offset before start of pack index for %s (corrupt index?)"), |
| p->pack_name); |
| /* No need to check for underflow; .idx files must be at least 8 bytes */ |
| if (ptr >= end - 8) |
| die(_("offset beyond end of pack index for %s (truncated index?)"), |
| p->pack_name); |
| } |
| |
| off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n) |
| { |
| const unsigned char *index = p->index_data; |
| index += 4 * 256; |
| if (p->index_version == 1) { |
| return ntohl(*((uint32_t *)(index + 24 * n))); |
| } else { |
| uint32_t off; |
| index += 8 + p->num_objects * (20 + 4); |
| off = ntohl(*((uint32_t *)(index + 4 * n))); |
| if (!(off & 0x80000000)) |
| return off; |
| index += p->num_objects * 4 + (off & 0x7fffffff) * 8; |
| check_pack_index_ptr(p, index); |
| return (((uint64_t)ntohl(*((uint32_t *)(index + 0)))) << 32) | |
| ntohl(*((uint32_t *)(index + 4))); |
| } |
| } |
| |
| off_t find_pack_entry_one(const unsigned char *sha1, |
| struct packed_git *p) |
| { |
| const uint32_t *level1_ofs = p->index_data; |
| const unsigned char *index = p->index_data; |
| unsigned hi, lo, stride; |
| static int use_lookup = -1; |
| static int debug_lookup = -1; |
| |
| if (debug_lookup < 0) |
| debug_lookup = !!getenv("GIT_DEBUG_LOOKUP"); |
| |
| if (!index) { |
| if (open_pack_index(p)) |
| return 0; |
| level1_ofs = p->index_data; |
| index = p->index_data; |
| } |
| if (p->index_version > 1) { |
| level1_ofs += 2; |
| index += 8; |
| } |
| index += 4 * 256; |
| hi = ntohl(level1_ofs[*sha1]); |
| lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1])); |
| if (p->index_version > 1) { |
| stride = 20; |
| } else { |
| stride = 24; |
| index += 4; |
| } |
| |
| if (debug_lookup) |
| printf("%02x%02x%02x... lo %u hi %u nr %"PRIu32"\n", |
| sha1[0], sha1[1], sha1[2], lo, hi, p->num_objects); |
| |
| if (use_lookup < 0) |
| use_lookup = !!getenv("GIT_USE_LOOKUP"); |
| if (use_lookup) { |
| int pos = sha1_entry_pos(index, stride, 0, |
| lo, hi, p->num_objects, sha1); |
| if (pos < 0) |
| return 0; |
| return nth_packed_object_offset(p, pos); |
| } |
| |
| do { |
| unsigned mi = (lo + hi) / 2; |
| int cmp = hashcmp(index + mi * stride, sha1); |
| |
| if (debug_lookup) |
| printf("lo %u hi %u rg %u mi %u\n", |
| lo, hi, hi - lo, mi); |
| if (!cmp) |
| return nth_packed_object_offset(p, mi); |
| if (cmp > 0) |
| hi = mi; |
| else |
| lo = mi+1; |
| } while (lo < hi); |
| return 0; |
| } |
| |
| int is_pack_valid(struct packed_git *p) |
| { |
| /* An already open pack is known to be valid. */ |
| if (p->pack_fd != -1) |
| return 1; |
| |
| /* If the pack has one window completely covering the |
| * file size, the pack is known to be valid even if |
| * the descriptor is not currently open. |
| */ |
| if (p->windows) { |
| struct pack_window *w = p->windows; |
| |
| if (!w->offset && w->len == p->pack_size) |
| return 1; |
| } |
| |
| /* Force the pack to open to prove its valid. */ |
| return !open_packed_git(p); |
| } |
| |
| static int fill_pack_entry(const unsigned char *sha1, |
| struct pack_entry *e, |
| struct packed_git *p) |
| { |
| off_t offset; |
| |
| if (p->num_bad_objects) { |
| unsigned i; |
| for (i = 0; i < p->num_bad_objects; i++) |
| if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i)) |
| return 0; |
| } |
| |
| offset = find_pack_entry_one(sha1, p); |
| if (!offset) |
| return 0; |
| |
| /* |
| * We are about to tell the caller where they can locate the |
| * requested object. We better make sure the packfile is |
| * still here and can be accessed before supplying that |
| * answer, as it may have been deleted since the index was |
| * loaded! |
| */ |
| if (!is_pack_valid(p)) |
| return 0; |
| e->offset = offset; |
| e->p = p; |
| hashcpy(e->sha1, sha1); |
| return 1; |
| } |
| |
| /* |
| * Iff a pack file contains the object named by sha1, return true and |
| * store its location to e. |
| */ |
| static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e) |
| { |
| struct mru_entry *p; |
| |
| prepare_packed_git(); |
| if (!packed_git) |
| return 0; |
| |
| for (p = packed_git_mru->head; p; p = p->next) { |
| if (fill_pack_entry(sha1, e, p->item)) { |
| mru_mark(packed_git_mru, p); |
| return 1; |
| } |
| } |
| return 0; |
| } |
| |
| struct packed_git *find_sha1_pack(const unsigned char *sha1, |
| struct packed_git *packs) |
| { |
| struct packed_git *p; |
| |
| for (p = packs; p; p = p->next) { |
| if (find_pack_entry_one(sha1, p)) |
| return p; |
| } |
| return NULL; |
| |
| } |
| |
| static int sha1_loose_object_info(const unsigned char *sha1, |
| struct object_info *oi, |
| int flags) |
| { |
| int status = 0; |
| unsigned long mapsize; |
| void *map; |
| git_zstream stream; |
| char hdr[32]; |
| struct strbuf hdrbuf = STRBUF_INIT; |
| |
| if (oi->delta_base_sha1) |
| hashclr(oi->delta_base_sha1); |
| |
| /* |
| * If we don't care about type or size, then we don't |
| * need to look inside the object at all. Note that we |
| * do not optimize out the stat call, even if the |
| * caller doesn't care about the disk-size, since our |
| * return value implicitly indicates whether the |
| * object even exists. |
| */ |
| if (!oi->typep && !oi->typename && !oi->sizep) { |
| struct stat st; |
| if (stat_sha1_file(sha1, &st) < 0) |
| return -1; |
| if (oi->disk_sizep) |
| *oi->disk_sizep = st.st_size; |
| return 0; |
| } |
| |
| map = map_sha1_file(sha1, &mapsize); |
| if (!map) |
| return -1; |
| if (oi->disk_sizep) |
| *oi->disk_sizep = mapsize; |
| if ((flags & LOOKUP_UNKNOWN_OBJECT)) { |
| if (unpack_sha1_header_to_strbuf(&stream, map, mapsize, hdr, sizeof(hdr), &hdrbuf) < 0) |
| status = error("unable to unpack %s header with --allow-unknown-type", |
| sha1_to_hex(sha1)); |
| } else if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0) |
| status = error("unable to unpack %s header", |
| sha1_to_hex(sha1)); |
| if (status < 0) |
| ; /* Do nothing */ |
| else if (hdrbuf.len) { |
| if ((status = parse_sha1_header_extended(hdrbuf.buf, oi, flags)) < 0) |
| status = error("unable to parse %s header with --allow-unknown-type", |
| sha1_to_hex(sha1)); |
| } else if ((status = parse_sha1_header_extended(hdr, oi, flags)) < 0) |
| status = error("unable to parse %s header", sha1_to_hex(sha1)); |
| git_inflate_end(&stream); |
| munmap(map, mapsize); |
| if (status && oi->typep) |
| *oi->typep = status; |
| strbuf_release(&hdrbuf); |
| return 0; |
| } |
| |
| int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi, unsigned flags) |
| { |
| struct cached_object *co; |
| struct pack_entry e; |
| int rtype; |
| enum object_type real_type; |
| const unsigned char *real = lookup_replace_object_extended(sha1, flags); |
| |
| co = find_cached_object(real); |
| if (co) { |
| if (oi->typep) |
| *(oi->typep) = co->type; |
| if (oi->sizep) |
| *(oi->sizep) = co->size; |
| if (oi->disk_sizep) |
| *(oi->disk_sizep) = 0; |
| if (oi->delta_base_sha1) |
| hashclr(oi->delta_base_sha1); |
| if (oi->typename) |
| strbuf_addstr(oi->typename, typename(co->type)); |
| oi->whence = OI_CACHED; |
| return 0; |
| } |
| |
| if (!find_pack_entry(real, &e)) { |
| /* Most likely it's a loose object. */ |
| if (!sha1_loose_object_info(real, oi, flags)) { |
| oi->whence = OI_LOOSE; |
| return 0; |
| } |
| |
| /* Not a loose object; someone else may have just packed it. */ |
| reprepare_packed_git(); |
| if (!find_pack_entry(real, &e)) |
| return -1; |
| } |
| |
| /* |
| * packed_object_info() does not follow the delta chain to |
| * find out the real type, unless it is given oi->typep. |
| */ |
| if (oi->typename && !oi->typep) |
| oi->typep = &real_type; |
| |
| rtype = packed_object_info(e.p, e.offset, oi); |
| if (rtype < 0) { |
| mark_bad_packed_object(e.p, real); |
| if (oi->typep == &real_type) |
| oi->typep = NULL; |
| return sha1_object_info_extended(real, oi, 0); |
| } else if (in_delta_base_cache(e.p, e.offset)) { |
| oi->whence = OI_DBCACHED; |
| } else { |
| oi->whence = OI_PACKED; |
| oi->u.packed.offset = e.offset; |
| oi->u.packed.pack = e.p; |
| oi->u.packed.is_delta = (rtype == OBJ_REF_DELTA || |
| rtype == OBJ_OFS_DELTA); |
| } |
| if (oi->typename) |
| strbuf_addstr(oi->typename, typename(*oi->typep)); |
| if (oi->typep == &real_type) |
| oi->typep = NULL; |
| |
| return 0; |
| } |
| |
| /* returns enum object_type or negative */ |
| int sha1_object_info(const unsigned char *sha1, unsigned long *sizep) |
| { |
| enum object_type type; |
| struct object_info oi = OBJECT_INFO_INIT; |
| |
| oi.typep = &type; |
| oi.sizep = sizep; |
| if (sha1_object_info_extended(sha1, &oi, LOOKUP_REPLACE_OBJECT) < 0) |
| return -1; |
| return type; |
| } |
| |
| static void *read_packed_sha1(const unsigned char *sha1, |
| enum object_type *type, unsigned long *size) |
| { |
| struct pack_entry e; |
| void *data; |
| |
| if (!find_pack_entry(sha1, &e)) |
| return NULL; |
| data = cache_or_unpack_entry(e.p, e.offset, size, type); |
| if (!data) { |
| /* |
| * We're probably in deep shit, but let's try to fetch |
| * the required object anyway from another pack or loose. |
| * This should happen only in the presence of a corrupted |
| * pack, and is better than failing outright. |
| */ |
| error("failed to read object %s at offset %"PRIuMAX" from %s", |
| sha1_to_hex(sha1), (uintmax_t)e.offset, e.p->pack_name); |
| mark_bad_packed_object(e.p, sha1); |
| data = read_object(sha1, type, size); |
| } |
| return data; |
| } |
| |
| int pretend_sha1_file(void *buf, unsigned long len, enum object_type type, |
| unsigned char *sha1) |
| { |
| struct cached_object *co; |
| |
| hash_sha1_file(buf, len, typename(type), sha1); |
| if (has_sha1_file(sha1) || find_cached_object(sha1)) |
| return 0; |
| ALLOC_GROW(cached_objects, cached_object_nr + 1, cached_object_alloc); |
| co = &cached_objects[cached_object_nr++]; |
| co->size = len; |
| co->type = type; |
| co->buf = xmalloc(len); |
| memcpy(co->buf, buf, len); |
| hashcpy(co->sha1, sha1); |
| return 0; |
| } |
| |
| static void *read_object(const unsigned char *sha1, enum object_type *type, |
| unsigned long *size) |
| { |
| unsigned long mapsize; |
| void *map, *buf; |
| struct cached_object *co; |
| |
| co = find_cached_object(sha1); |
| if (co) { |
| *type = co->type; |
| *size = co->size; |
| return xmemdupz(co->buf, co->size); |
| } |
| |
| buf = read_packed_sha1(sha1, type, size); |
| if (buf) |
| return buf; |
| map = map_sha1_file(sha1, &mapsize); |
| if (map) { |
| buf = unpack_sha1_file(map, mapsize, type, size, sha1); |
| munmap(map, mapsize); |
| return buf; |
| } |
| reprepare_packed_git(); |
| return read_packed_sha1(sha1, type, size); |
| } |
| |
| /* |
| * This function dies on corrupt objects; the callers who want to |
| * deal with them should arrange to call read_object() and give error |
| * messages themselves. |
| */ |
| void *read_sha1_file_extended(const unsigned char *sha1, |
| enum object_type *type, |
| unsigned long *size, |
| unsigned flag) |
| { |
| void *data; |
| const |