#include "cache.h" #include "delta.h" #include "pack.h" #include "csum-file.h" #include "blob.h" #include "commit.h" #include "tag.h" #include "tree.h" #include "progress.h" static const char index_pack_usage[] = "git-index-pack [-v] [-o ] [{ ---keep | --keep= }] { | --stdin [--fix-thin] [] }"; struct object_entry { struct pack_idx_entry idx; unsigned long size; unsigned int hdr_size; enum object_type type; enum object_type real_type; }; union delta_base { unsigned char sha1[20]; off_t offset; }; /* * Even if sizeof(union delta_base) == 24 on 64-bit archs, we really want * to memcmp() only the first 20 bytes. */ #define UNION_BASE_SZ 20 struct delta_entry { union delta_base base; int obj_no; }; static struct object_entry *objects; static struct delta_entry *deltas; static int nr_objects; static int nr_deltas; static int nr_resolved_deltas; static int from_stdin; static int verbose; static struct progress *progress; /* We always read in 4kB chunks. */ static unsigned char input_buffer[4096]; static unsigned int input_offset, input_len; static off_t consumed_bytes; static SHA_CTX input_ctx; static uint32_t input_crc32; static int input_fd, output_fd, pack_fd; /* Discard current buffer used content. */ static void flush(void) { if (input_offset) { if (output_fd >= 0) write_or_die(output_fd, input_buffer, input_offset); SHA1_Update(&input_ctx, input_buffer, input_offset); memmove(input_buffer, input_buffer + input_offset, input_len); input_offset = 0; } } /* * Make sure at least "min" bytes are available in the buffer, and * return the pointer to the buffer. */ static void *fill(int min) { if (min <= input_len) return input_buffer + input_offset; if (min > sizeof(input_buffer)) die("cannot fill %d bytes", min); flush(); do { ssize_t ret = xread(input_fd, input_buffer + input_len, sizeof(input_buffer) - input_len); if (ret <= 0) { if (!ret) die("early EOF"); die("read error on input: %s", strerror(errno)); } input_len += ret; if (from_stdin) display_throughput(progress, consumed_bytes + input_len); } while (input_len < min); return input_buffer; } static void use(int bytes) { if (bytes > input_len) die("used more bytes than were available"); input_crc32 = crc32(input_crc32, input_buffer + input_offset, bytes); input_len -= bytes; input_offset += bytes; /* make sure off_t is sufficiently large not to wrap */ if (consumed_bytes > consumed_bytes + bytes) die("pack too large for current definition of off_t"); consumed_bytes += bytes; } static char *open_pack_file(char *pack_name) { if (from_stdin) { input_fd = 0; if (!pack_name) { static char tmpfile[PATH_MAX]; snprintf(tmpfile, sizeof(tmpfile), "%s/tmp_pack_XXXXXX", get_object_directory()); output_fd = xmkstemp(tmpfile); pack_name = xstrdup(tmpfile); } else output_fd = open(pack_name, O_CREAT|O_EXCL|O_RDWR, 0600); if (output_fd < 0) die("unable to create %s: %s\n", pack_name, strerror(errno)); pack_fd = output_fd; } else { input_fd = open(pack_name, O_RDONLY); if (input_fd < 0) die("cannot open packfile '%s': %s", pack_name, strerror(errno)); output_fd = -1; pack_fd = input_fd; } SHA1_Init(&input_ctx); return pack_name; } static void parse_pack_header(void) { struct pack_header *hdr = fill(sizeof(struct pack_header)); /* Header consistency check */ if (hdr->hdr_signature != htonl(PACK_SIGNATURE)) die("pack signature mismatch"); if (!pack_version_ok(hdr->hdr_version)) die("pack version %d unsupported", ntohl(hdr->hdr_version)); nr_objects = ntohl(hdr->hdr_entries); use(sizeof(struct pack_header)); } static void bad_object(unsigned long offset, const char *format, ...) NORETURN __attribute__((format (printf, 2, 3))); static void bad_object(unsigned long offset, const char *format, ...) { va_list params; char buf[1024]; va_start(params, format); vsnprintf(buf, sizeof(buf), format, params); va_end(params); die("pack has bad object at offset %lu: %s", offset, buf); } static void *unpack_entry_data(unsigned long offset, unsigned long size) { z_stream stream; void *buf = xmalloc(size); memset(&stream, 0, sizeof(stream)); stream.next_out = buf; stream.avail_out = size; stream.next_in = fill(1); stream.avail_in = input_len; inflateInit(&stream); for (;;) { int ret = inflate(&stream, 0); use(input_len - stream.avail_in); if (stream.total_out == size && ret == Z_STREAM_END) break; if (ret != Z_OK) bad_object(offset, "inflate returned %d", ret); stream.next_in = fill(1); stream.avail_in = input_len; } inflateEnd(&stream); return buf; } static void *unpack_raw_entry(struct object_entry *obj, union delta_base *delta_base) { unsigned char *p, c; unsigned long size; off_t base_offset; unsigned shift; void *data; obj->idx.offset = consumed_bytes; input_crc32 = crc32(0, Z_NULL, 0); p = fill(1); c = *p; use(1); obj->type = (c >> 4) & 7; size = (c & 15); shift = 4; while (c & 0x80) { p = fill(1); c = *p; use(1); size += (c & 0x7fUL) << shift; shift += 7; } obj->size = size; switch (obj->type) { case OBJ_REF_DELTA: hashcpy(delta_base->sha1, fill(20)); use(20); break; case OBJ_OFS_DELTA: memset(delta_base, 0, sizeof(*delta_base)); p = fill(1); c = *p; use(1); base_offset = c & 127; while (c & 128) { base_offset += 1; if (!base_offset || MSB(base_offset, 7)) bad_object(obj->idx.offset, "offset value overflow for delta base object"); p = fill(1); c = *p; use(1); base_offset = (base_offset << 7) + (c & 127); } delta_base->offset = obj->idx.offset - base_offset; if (delta_base->offset >= obj->idx.offset) bad_object(obj->idx.offset, "delta base offset is out of bound"); break; case OBJ_COMMIT: case OBJ_TREE: case OBJ_BLOB: case OBJ_TAG: break; default: bad_object(obj->idx.offset, "unknown object type %d", obj->type); } obj->hdr_size = consumed_bytes - obj->idx.offset; data = unpack_entry_data(obj->idx.offset, obj->size); obj->idx.crc32 = input_crc32; return data; } static void *get_data_from_pack(struct object_entry *obj) { off_t from = obj[0].idx.offset + obj[0].hdr_size; unsigned long len = obj[1].idx.offset - from; unsigned long rdy = 0; unsigned char *src, *data; z_stream stream; int st; src = xmalloc(len); data = src; do { ssize_t n = pread(pack_fd, data + rdy, len - rdy, from + rdy); if (n <= 0) die("cannot pread pack file: %s", strerror(errno)); rdy += n; } while (rdy < len); data = xmalloc(obj->size); memset(&stream, 0, sizeof(stream)); stream.next_out = data; stream.avail_out = obj->size; stream.next_in = src; stream.avail_in = len; inflateInit(&stream); while ((st = inflate(&stream, Z_FINISH)) == Z_OK); inflateEnd(&stream); if (st != Z_STREAM_END || stream.total_out != obj->size) die("serious inflate inconsistency"); free(src); return data; } static int find_delta(const union delta_base *base) { int first = 0, last = nr_deltas; while (first < last) { int next = (first + last) / 2; struct delta_entry *delta = &deltas[next]; int cmp; cmp = memcmp(base, &delta->base, UNION_BASE_SZ); if (!cmp) return next; if (cmp < 0) { last = next; continue; } first = next+1; } return -first-1; } static int find_delta_children(const union delta_base *base, int *first_index, int *last_index) { int first = find_delta(base); int last = first; int end = nr_deltas - 1; if (first < 0) return -1; while (first > 0 && !memcmp(&deltas[first - 1].base, base, UNION_BASE_SZ)) --first; while (last < end && !memcmp(&deltas[last + 1].base, base, UNION_BASE_SZ)) ++last; *first_index = first; *last_index = last; return 0; } static void sha1_object(const void *data, unsigned long size, enum object_type type, unsigned char *sha1) { hash_sha1_file(data, size, typename(type), sha1); if (has_sha1_file(sha1)) { void *has_data; enum object_type has_type; unsigned long has_size; has_data = read_sha1_file(sha1, &has_type, &has_size); if (!has_data) die("cannot read existing object %s", sha1_to_hex(sha1)); if (size != has_size || type != has_type || memcmp(data, has_data, size) != 0) die("SHA1 COLLISION FOUND WITH %s !", sha1_to_hex(sha1)); free(has_data); } } static void resolve_delta(struct object_entry *delta_obj, void *base_data, unsigned long base_size, enum object_type type) { void *delta_data; unsigned long delta_size; void *result; unsigned long result_size; union delta_base delta_base; int j, first, last; delta_obj->real_type = type; delta_data = get_data_from_pack(delta_obj); delta_size = delta_obj->size; result = patch_delta(base_data, base_size, delta_data, delta_size, &result_size); free(delta_data); if (!result) bad_object(delta_obj->idx.offset, "failed to apply delta"); sha1_object(result, result_size, type, delta_obj->idx.sha1); nr_resolved_deltas++; hashcpy(delta_base.sha1, delta_obj->idx.sha1); if (!find_delta_children(&delta_base, &first, &last)) { for (j = first; j <= last; j++) { struct object_entry *child = objects + deltas[j].obj_no; if (child->real_type == OBJ_REF_DELTA) resolve_delta(child, result, result_size, type); } } memset(&delta_base, 0, sizeof(delta_base)); delta_base.offset = delta_obj->idx.offset; if (!find_delta_children(&delta_base, &first, &last)) { for (j = first; j <= last; j++) { struct object_entry *child = objects + deltas[j].obj_no; if (child->real_type == OBJ_OFS_DELTA) resolve_delta(child, result, result_size, type); } } free(result); } static int compare_delta_entry(const void *a, const void *b) { const struct delta_entry *delta_a = a; const struct delta_entry *delta_b = b; return memcmp(&delta_a->base, &delta_b->base, UNION_BASE_SZ); } /* Parse all objects and return the pack content SHA1 hash */ static void parse_pack_objects(unsigned char *sha1) { int i; struct delta_entry *delta = deltas; void *data; struct stat st; /* * First pass: * - find locations of all objects; * - calculate SHA1 of all non-delta objects; * - remember base (SHA1 or offset) for all deltas. */ if (verbose) progress = start_progress( from_stdin ? "Receiving objects" : "Indexing objects", nr_objects); for (i = 0; i < nr_objects; i++) { struct object_entry *obj = &objects[i]; data = unpack_raw_entry(obj, &delta->base); obj->real_type = obj->type; if (obj->type == OBJ_REF_DELTA || obj->type == OBJ_OFS_DELTA) { nr_deltas++; delta->obj_no = i; delta++; } else sha1_object(data, obj->size, obj->type, obj->idx.sha1); free(data); display_progress(progress, i+1); } objects[i].idx.offset = consumed_bytes; stop_progress(&progress); /* Check pack integrity */ flush(); SHA1_Final(sha1, &input_ctx); if (hashcmp(fill(20), sha1)) die("pack is corrupted (SHA1 mismatch)"); use(20); /* If input_fd is a file, we should have reached its end now. */ if (fstat(input_fd, &st)) die("cannot fstat packfile: %s", strerror(errno)); if (S_ISREG(st.st_mode) && lseek(input_fd, 0, SEEK_CUR) - input_len != st.st_size) die("pack has junk at the end"); if (!nr_deltas) return; /* Sort deltas by base SHA1/offset for fast searching */ qsort(deltas, nr_deltas, sizeof(struct delta_entry), compare_delta_entry); /* * Second pass: * - for all non-delta objects, look if it is used as a base for * deltas; * - if used as a base, uncompress the object and apply all deltas, * recursively checking if the resulting object is used as a base * for some more deltas. */ if (verbose) progress = start_progress("Resolving deltas", nr_deltas); for (i = 0; i < nr_objects; i++) { struct object_entry *obj = &objects[i]; union delta_base base; int j, ref, ref_first, ref_last, ofs, ofs_first, ofs_last; if (obj->type == OBJ_REF_DELTA || obj->type == OBJ_OFS_DELTA) continue; hashcpy(base.sha1, obj->idx.sha1); ref = !find_delta_children(&base, &ref_first, &ref_last); memset(&base, 0, sizeof(base)); base.offset = obj->idx.offset; ofs = !find_delta_children(&base, &ofs_first, &ofs_last); if (!ref && !ofs) continue; data = get_data_from_pack(obj); if (ref) for (j = ref_first; j <= ref_last; j++) { struct object_entry *child = objects + deltas[j].obj_no; if (child->real_type == OBJ_REF_DELTA) resolve_delta(child, data, obj->size, obj->type); } if (ofs) for (j = ofs_first; j <= ofs_last; j++) { struct object_entry *child = objects + deltas[j].obj_no; if (child->real_type == OBJ_OFS_DELTA) resolve_delta(child, data, obj->size, obj->type); } free(data); display_progress(progress, nr_resolved_deltas); } } static int write_compressed(int fd, void *in, unsigned int size, uint32_t *obj_crc) { z_stream stream; unsigned long maxsize; void *out; memset(&stream, 0, sizeof(stream)); deflateInit(&stream, zlib_compression_level); maxsize = deflateBound(&stream, size); out = xmalloc(maxsize); /* Compress it */ stream.next_in = in; stream.avail_in = size; stream.next_out = out; stream.avail_out = maxsize; while (deflate(&stream, Z_FINISH) == Z_OK); deflateEnd(&stream); size = stream.total_out; write_or_die(fd, out, size); *obj_crc = crc32(*obj_crc, out, size); free(out); return size; } static void append_obj_to_pack(const unsigned char *sha1, void *buf, unsigned long size, enum object_type type) { struct object_entry *obj = &objects[nr_objects++]; unsigned char header[10]; unsigned long s = size; int n = 0; unsigned char c = (type << 4) | (s & 15); s >>= 4; while (s) { header[n++] = c | 0x80; c = s & 0x7f; s >>= 7; } header[n++] = c; write_or_die(output_fd, header, n); obj[0].idx.crc32 = crc32(0, Z_NULL, 0); obj[0].idx.crc32 = crc32(obj[0].idx.crc32, header, n); obj[1].idx.offset = obj[0].idx.offset + n; obj[1].idx.offset += write_compressed(output_fd, buf, size, &obj[0].idx.crc32); hashcpy(obj->idx.sha1, sha1); } static int delta_pos_compare(const void *_a, const void *_b) { struct delta_entry *a = *(struct delta_entry **)_a; struct delta_entry *b = *(struct delta_entry **)_b; return a->obj_no - b->obj_no; } static void fix_unresolved_deltas(int nr_unresolved) { struct delta_entry **sorted_by_pos; int i, n = 0; /* * Since many unresolved deltas may well be themselves base objects * for more unresolved deltas, we really want to include the * smallest number of base objects that would cover as much delta * as possible by picking the * trunc deltas first, allowing for other deltas to resolve without * additional base objects. Since most base objects are to be found * before deltas depending on them, a good heuristic is to start * resolving deltas in the same order as their position in the pack. */ sorted_by_pos = xmalloc(nr_unresolved * sizeof(*sorted_by_pos)); for (i = 0; i < nr_deltas; i++) { if (objects[deltas[i].obj_no].real_type != OBJ_REF_DELTA) continue; sorted_by_pos[n++] = &deltas[i]; } qsort(sorted_by_pos, n, sizeof(*sorted_by_pos), delta_pos_compare); for (i = 0; i < n; i++) { struct delta_entry *d = sorted_by_pos[i]; void *data; unsigned long size; enum object_type type; int j, first, last; if (objects[d->obj_no].real_type != OBJ_REF_DELTA) continue; data = read_sha1_file(d->base.sha1, &type, &size); if (!data) continue; find_delta_children(&d->base, &first, &last); for (j = first; j <= last; j++) { struct object_entry *child = objects + deltas[j].obj_no; if (child->real_type == OBJ_REF_DELTA) resolve_delta(child, data, size, type); } if (check_sha1_signature(d->base.sha1, data, size, typename(type))) die("local object %s is corrupt", sha1_to_hex(d->base.sha1)); append_obj_to_pack(d->base.sha1, data, size, type); free(data); display_progress(progress, nr_resolved_deltas); } free(sorted_by_pos); } static void final(const char *final_pack_name, const char *curr_pack_name, const char *final_index_name, const char *curr_index_name, const char *keep_name, const char *keep_msg, unsigned char *sha1) { const char *report = "pack"; char name[PATH_MAX]; int err; if (!from_stdin) { close(input_fd); } else { err = close(output_fd); if (err) die("error while closing pack file: %s", strerror(errno)); chmod(curr_pack_name, 0444); } if (keep_msg) { int keep_fd, keep_msg_len = strlen(keep_msg); if (!keep_name) { snprintf(name, sizeof(name), "%s/pack/pack-%s.keep", get_object_directory(), sha1_to_hex(sha1)); keep_name = name; } keep_fd = open(keep_name, O_RDWR|O_CREAT|O_EXCL, 0600); if (keep_fd < 0) { if (errno != EEXIST) die("cannot write keep file"); } else { if (keep_msg_len > 0) { write_or_die(keep_fd, keep_msg, keep_msg_len); write_or_die(keep_fd, "\n", 1); } if (close(keep_fd) != 0) die("cannot write keep file"); report = "keep"; } } if (final_pack_name != curr_pack_name) { if (!final_pack_name) { snprintf(name, sizeof(name), "%s/pack/pack-%s.pack", get_object_directory(), sha1_to_hex(sha1)); final_pack_name = name; } if (move_temp_to_file(curr_pack_name, final_pack_name)) die("cannot store pack file"); } chmod(curr_index_name, 0444); if (final_index_name != curr_index_name) { if (!final_index_name) { snprintf(name, sizeof(name), "%s/pack/pack-%s.idx", get_object_directory(), sha1_to_hex(sha1)); final_index_name = name; } if (move_temp_to_file(curr_index_name, final_index_name)) die("cannot store index file"); } if (!from_stdin) { printf("%s\n", sha1_to_hex(sha1)); } else { char buf[48]; int len = snprintf(buf, sizeof(buf), "%s\t%s\n", report, sha1_to_hex(sha1)); write_or_die(1, buf, len); /* * Let's just mimic git-unpack-objects here and write * the last part of the input buffer to stdout. */ while (input_len) { err = xwrite(1, input_buffer + input_offset, input_len); if (err <= 0) break; input_len -= err; input_offset += err; } } } static int git_index_pack_config(const char *k, const char *v) { if (!strcmp(k, "pack.indexversion")) { pack_idx_default_version = git_config_int(k, v); if (pack_idx_default_version > 2) die("bad pack.indexversion=%d", pack_idx_default_version); return 0; } return git_default_config(k, v); } int main(int argc, char **argv) { int i, fix_thin_pack = 0; char *curr_pack, *pack_name = NULL; char *curr_index, *index_name = NULL; const char *keep_name = NULL, *keep_msg = NULL; char *index_name_buf = NULL, *keep_name_buf = NULL; struct pack_idx_entry **idx_objects; unsigned char sha1[20]; git_config(git_index_pack_config); for (i = 1; i < argc; i++) { char *arg = argv[i]; if (*arg == '-') { if (!strcmp(arg, "--stdin")) { from_stdin = 1; } else if (!strcmp(arg, "--fix-thin")) { fix_thin_pack = 1; } else if (!strcmp(arg, "--keep")) { keep_msg = ""; } else if (!prefixcmp(arg, "--keep=")) { keep_msg = arg + 7; } else if (!prefixcmp(arg, "--pack_header=")) { struct pack_header *hdr; char *c; hdr = (struct pack_header *)input_buffer; hdr->hdr_signature = htonl(PACK_SIGNATURE); hdr->hdr_version = htonl(strtoul(arg + 14, &c, 10)); if (*c != ',') die("bad %s", arg); hdr->hdr_entries = htonl(strtoul(c + 1, &c, 10)); if (*c) die("bad %s", arg); input_len = sizeof(*hdr); } else if (!strcmp(arg, "-v")) { verbose = 1; } else if (!strcmp(arg, "-o")) { if (index_name || (i+1) >= argc) usage(index_pack_usage); index_name = argv[++i]; } else if (!prefixcmp(arg, "--index-version=")) { char *c; pack_idx_default_version = strtoul(arg + 16, &c, 10); if (pack_idx_default_version > 2) die("bad %s", arg); if (*c == ',') pack_idx_off32_limit = strtoul(c+1, &c, 0); if (*c || pack_idx_off32_limit & 0x80000000) die("bad %s", arg); } else usage(index_pack_usage); continue; } if (pack_name) usage(index_pack_usage); pack_name = arg; } if (!pack_name && !from_stdin) usage(index_pack_usage); if (fix_thin_pack && !from_stdin) die("--fix-thin cannot be used without --stdin"); if (!index_name && pack_name) { int len = strlen(pack_name); if (!has_extension(pack_name, ".pack")) die("packfile name '%s' does not end with '.pack'", pack_name); index_name_buf = xmalloc(len); memcpy(index_name_buf, pack_name, len - 5); strcpy(index_name_buf + len - 5, ".idx"); index_name = index_name_buf; } if (keep_msg && !keep_name && pack_name) { int len = strlen(pack_name); if (!has_extension(pack_name, ".pack")) die("packfile name '%s' does not end with '.pack'", pack_name); keep_name_buf = xmalloc(len); memcpy(keep_name_buf, pack_name, len - 5); strcpy(keep_name_buf + len - 5, ".keep"); keep_name = keep_name_buf; } curr_pack = open_pack_file(pack_name); parse_pack_header(); objects = xmalloc((nr_objects + 1) * sizeof(struct object_entry)); deltas = xmalloc(nr_objects * sizeof(struct delta_entry)); parse_pack_objects(sha1); if (nr_deltas == nr_resolved_deltas) { stop_progress(&progress); /* Flush remaining pack final 20-byte SHA1. */ flush(); } else { if (fix_thin_pack) { char msg[48]; int nr_unresolved = nr_deltas - nr_resolved_deltas; int nr_objects_initial = nr_objects; if (nr_unresolved <= 0) die("confusion beyond insanity"); objects = xrealloc(objects, (nr_objects + nr_unresolved + 1) * sizeof(*objects)); fix_unresolved_deltas(nr_unresolved); sprintf(msg, "completed with %d local objects", nr_objects - nr_objects_initial); stop_progress_msg(&progress, msg); fixup_pack_header_footer(output_fd, sha1, curr_pack, nr_objects); } if (nr_deltas != nr_resolved_deltas) die("pack has %d unresolved deltas", nr_deltas - nr_resolved_deltas); } free(deltas); idx_objects = xmalloc((nr_objects) * sizeof(struct pack_idx_entry *)); for (i = 0; i < nr_objects; i++) idx_objects[i] = &objects[i].idx; curr_index = write_idx_file(index_name, idx_objects, nr_objects, sha1); free(idx_objects); final(pack_name, curr_pack, index_name, curr_index, keep_name, keep_msg, sha1); free(objects); free(index_name_buf); free(keep_name_buf); if (pack_name == NULL) free(curr_pack); if (index_name == NULL) free(curr_index); return 0; }