| /* |
| * Copyright (C) the libgit2 contributors. All rights reserved. |
| * |
| * This file is part of libgit2, distributed under the GNU GPL v2 with |
| * a Linking Exception. For full terms see the included COPYING file. |
| */ |
| |
| #include "common.h" |
| #include "odb.h" |
| #include "pack.h" |
| #include "delta-apply.h" |
| #include "sha1_lookup.h" |
| #include "mwindow.h" |
| #include "fileops.h" |
| #include "oid.h" |
| |
| #include <zlib.h> |
| |
| static int packfile_open(struct git_pack_file *p); |
| static git_off_t nth_packed_object_offset(const struct git_pack_file *p, uint32_t n); |
| int packfile_unpack_compressed( |
| git_rawobj *obj, |
| struct git_pack_file *p, |
| git_mwindow **w_curs, |
| git_off_t *curpos, |
| size_t size, |
| git_otype type); |
| |
| /* Can find the offset of an object given |
| * a prefix of an identifier. |
| * Throws GIT_EAMBIGUOUSOIDPREFIX if short oid |
| * is ambiguous within the pack. |
| * This method assumes that len is between |
| * GIT_OID_MINPREFIXLEN and GIT_OID_HEXSZ. |
| */ |
| static int pack_entry_find_offset( |
| git_off_t *offset_out, |
| git_oid *found_oid, |
| struct git_pack_file *p, |
| const git_oid *short_oid, |
| size_t len); |
| |
| static int packfile_error(const char *message) |
| { |
| giterr_set(GITERR_ODB, "Invalid pack file - %s", message); |
| return -1; |
| } |
| |
| /******************** |
| * Delta base cache |
| ********************/ |
| |
| static git_pack_cache_entry *new_cache_object(git_rawobj *source) |
| { |
| git_pack_cache_entry *e = git__calloc(1, sizeof(git_pack_cache_entry)); |
| if (!e) |
| return NULL; |
| |
| memcpy(&e->raw, source, sizeof(git_rawobj)); |
| |
| return e; |
| } |
| |
| static void free_cache_object(void *o) |
| { |
| git_pack_cache_entry *e = (git_pack_cache_entry *)o; |
| |
| if (e != NULL) { |
| assert(e->refcount.val == 0); |
| git__free(e->raw.data); |
| git__free(e); |
| } |
| } |
| |
| static void cache_free(git_pack_cache *cache) |
| { |
| khiter_t k; |
| |
| if (cache->entries) { |
| for (k = kh_begin(cache->entries); k != kh_end(cache->entries); k++) { |
| if (kh_exist(cache->entries, k)) |
| free_cache_object(kh_value(cache->entries, k)); |
| } |
| |
| git_offmap_free(cache->entries); |
| git_mutex_free(&cache->lock); |
| } |
| |
| memset(cache, 0, sizeof(*cache)); |
| } |
| |
| static int cache_init(git_pack_cache *cache) |
| { |
| memset(cache, 0, sizeof(*cache)); |
| |
| cache->entries = git_offmap_alloc(); |
| GITERR_CHECK_ALLOC(cache->entries); |
| |
| cache->memory_limit = GIT_PACK_CACHE_MEMORY_LIMIT; |
| |
| if (git_mutex_init(&cache->lock)) { |
| giterr_set(GITERR_OS, "Failed to initialize pack cache mutex"); |
| |
| git__free(cache->entries); |
| cache->entries = NULL; |
| |
| return -1; |
| } |
| |
| return 0; |
| } |
| |
| static git_pack_cache_entry *cache_get(git_pack_cache *cache, git_off_t offset) |
| { |
| khiter_t k; |
| git_pack_cache_entry *entry = NULL; |
| |
| if (git_mutex_lock(&cache->lock) < 0) |
| return NULL; |
| |
| k = kh_get(off, cache->entries, offset); |
| if (k != kh_end(cache->entries)) { /* found it */ |
| entry = kh_value(cache->entries, k); |
| git_atomic_inc(&entry->refcount); |
| entry->last_usage = cache->use_ctr++; |
| } |
| git_mutex_unlock(&cache->lock); |
| |
| return entry; |
| } |
| |
| /* Run with the cache lock held */ |
| static void free_lowest_entry(git_pack_cache *cache) |
| { |
| git_pack_cache_entry *entry; |
| khiter_t k; |
| |
| for (k = kh_begin(cache->entries); k != kh_end(cache->entries); k++) { |
| if (!kh_exist(cache->entries, k)) |
| continue; |
| |
| entry = kh_value(cache->entries, k); |
| |
| if (entry && entry->refcount.val == 0) { |
| cache->memory_used -= entry->raw.len; |
| kh_del(off, cache->entries, k); |
| free_cache_object(entry); |
| } |
| } |
| } |
| |
| static int cache_add(git_pack_cache *cache, git_rawobj *base, git_off_t offset) |
| { |
| git_pack_cache_entry *entry; |
| int error, exists = 0; |
| khiter_t k; |
| |
| if (base->len > GIT_PACK_CACHE_SIZE_LIMIT) |
| return -1; |
| |
| entry = new_cache_object(base); |
| if (entry) { |
| if (git_mutex_lock(&cache->lock) < 0) { |
| giterr_set(GITERR_OS, "failed to lock cache"); |
| return -1; |
| } |
| /* Add it to the cache if nobody else has */ |
| exists = kh_get(off, cache->entries, offset) != kh_end(cache->entries); |
| if (!exists) { |
| while (cache->memory_used + base->len > cache->memory_limit) |
| free_lowest_entry(cache); |
| |
| k = kh_put(off, cache->entries, offset, &error); |
| assert(error != 0); |
| kh_value(cache->entries, k) = entry; |
| cache->memory_used += entry->raw.len; |
| } |
| git_mutex_unlock(&cache->lock); |
| /* Somebody beat us to adding it into the cache */ |
| if (exists) { |
| git__free(entry); |
| return -1; |
| } |
| } |
| |
| return 0; |
| } |
| |
| /*********************************************************** |
| * |
| * PACK INDEX METHODS |
| * |
| ***********************************************************/ |
| |
| static void pack_index_free(struct git_pack_file *p) |
| { |
| if (p->oids) { |
| git__free(p->oids); |
| p->oids = NULL; |
| } |
| if (p->index_map.data) { |
| git_futils_mmap_free(&p->index_map); |
| p->index_map.data = NULL; |
| } |
| } |
| |
| static int pack_index_check(const char *path, struct git_pack_file *p) |
| { |
| struct git_pack_idx_header *hdr; |
| uint32_t version, nr, i, *index; |
| void *idx_map; |
| size_t idx_size; |
| struct stat st; |
| int error; |
| /* TODO: properly open the file without access time using O_NOATIME */ |
| git_file fd = git_futils_open_ro(path); |
| if (fd < 0) |
| return fd; |
| |
| if (p_fstat(fd, &st) < 0) { |
| p_close(fd); |
| giterr_set(GITERR_OS, "Unable to stat pack index '%s'", path); |
| return -1; |
| } |
| |
| if (!S_ISREG(st.st_mode) || |
| !git__is_sizet(st.st_size) || |
| (idx_size = (size_t)st.st_size) < 4 * 256 + 20 + 20) |
| { |
| p_close(fd); |
| giterr_set(GITERR_ODB, "Invalid pack index '%s'", path); |
| return -1; |
| } |
| |
| error = git_futils_mmap_ro(&p->index_map, fd, 0, idx_size); |
| |
| p_close(fd); |
| |
| if (error < 0) |
| return error; |
| |
| hdr = idx_map = p->index_map.data; |
| |
| if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) { |
| version = ntohl(hdr->idx_version); |
| |
| if (version < 2 || version > 2) { |
| git_futils_mmap_free(&p->index_map); |
| return packfile_error("unsupported index 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) { |
| git_futils_mmap_free(&p->index_map); |
| return packfile_error("index is non-monotonic"); |
| } |
| 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) { |
| git_futils_mmap_free(&p->index_map); |
| return packfile_error("index is corrupted"); |
| } |
| } 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) { |
| git_futils_mmap_free(&p->index_map); |
| return packfile_error("wrong index size"); |
| } |
| } |
| |
| p->num_objects = nr; |
| p->index_version = version; |
| return 0; |
| } |
| |
| static int pack_index_open(struct git_pack_file *p) |
| { |
| char *idx_name; |
| int error = 0; |
| size_t name_len, base_len; |
| |
| if (p->index_version > -1) |
| return 0; |
| |
| name_len = strlen(p->pack_name); |
| assert(name_len > strlen(".pack")); /* checked by git_pack_file alloc */ |
| |
| if ((idx_name = git__malloc(name_len)) == NULL) |
| return -1; |
| |
| base_len = name_len - strlen(".pack"); |
| memcpy(idx_name, p->pack_name, base_len); |
| memcpy(idx_name + base_len, ".idx", sizeof(".idx")); |
| |
| if ((error = git_mutex_lock(&p->lock)) < 0) |
| return error; |
| |
| if (p->index_version == -1) |
| error = pack_index_check(idx_name, p); |
| |
| git__free(idx_name); |
| |
| git_mutex_unlock(&p->lock); |
| |
| return error; |
| } |
| |
| static unsigned char *pack_window_open( |
| struct git_pack_file *p, |
| git_mwindow **w_cursor, |
| git_off_t offset, |
| unsigned int *left) |
| { |
| if (p->mwf.fd == -1 && packfile_open(p) < 0) |
| return NULL; |
| |
| /* 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 pack_window_contains function above wouldn't match |
| * don't allow an offset too close to the end of the file. |
| */ |
| if (offset > (p->mwf.size - 20)) |
| return NULL; |
| |
| return git_mwindow_open(&p->mwf, w_cursor, offset, 20, left); |
| } |
| |
| static int packfile_unpack_header1( |
| unsigned long *usedp, |
| size_t *sizep, |
| git_otype *type, |
| const unsigned char *buf, |
| unsigned long len) |
| { |
| 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) |
| return GIT_EBUFS; |
| |
| if (bitsizeof(long) <= shift) { |
| *usedp = 0; |
| return -1; |
| } |
| |
| c = buf[used++]; |
| size += (c & 0x7f) << shift; |
| shift += 7; |
| } |
| |
| *sizep = (size_t)size; |
| *usedp = used; |
| return 0; |
| } |
| |
| int git_packfile_unpack_header( |
| size_t *size_p, |
| git_otype *type_p, |
| git_mwindow_file *mwf, |
| git_mwindow **w_curs, |
| git_off_t *curpos) |
| { |
| unsigned char *base; |
| unsigned int left; |
| unsigned long used; |
| int ret; |
| |
| /* pack_window_open() assures us we have [base, base + 20) available |
| * as a range that we can look at 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 = pack_window_open(p, w_curs, *curpos, &left); */ |
| base = git_mwindow_open(mwf, w_curs, *curpos, 20, &left); |
| if (base == NULL) |
| return GIT_EBUFS; |
| |
| ret = packfile_unpack_header1(&used, size_p, type_p, base, left); |
| git_mwindow_close(w_curs); |
| if (ret == GIT_EBUFS) |
| return ret; |
| else if (ret < 0) |
| return packfile_error("header length is zero"); |
| |
| *curpos += used; |
| return 0; |
| } |
| |
| int git_packfile_resolve_header( |
| size_t *size_p, |
| git_otype *type_p, |
| struct git_pack_file *p, |
| git_off_t offset) |
| { |
| git_mwindow *w_curs = NULL; |
| git_off_t curpos = offset; |
| size_t size; |
| git_otype type; |
| git_off_t base_offset; |
| int error; |
| |
| error = git_packfile_unpack_header(&size, &type, &p->mwf, &w_curs, &curpos); |
| git_mwindow_close(&w_curs); |
| if (error < 0) |
| return error; |
| |
| if (type == GIT_OBJ_OFS_DELTA || type == GIT_OBJ_REF_DELTA) { |
| size_t base_size; |
| git_rawobj delta; |
| base_offset = get_delta_base(p, &w_curs, &curpos, type, offset); |
| git_mwindow_close(&w_curs); |
| error = packfile_unpack_compressed(&delta, p, &w_curs, &curpos, size, type); |
| git_mwindow_close(&w_curs); |
| if (error < 0) |
| return error; |
| error = git__delta_read_header(delta.data, delta.len, &base_size, size_p); |
| git__free(delta.data); |
| if (error < 0) |
| return error; |
| } else |
| *size_p = size; |
| |
| while (type == GIT_OBJ_OFS_DELTA || type == GIT_OBJ_REF_DELTA) { |
| curpos = base_offset; |
| error = git_packfile_unpack_header(&size, &type, &p->mwf, &w_curs, &curpos); |
| git_mwindow_close(&w_curs); |
| if (error < 0) |
| return error; |
| if (type != GIT_OBJ_OFS_DELTA && type != GIT_OBJ_REF_DELTA) |
| break; |
| base_offset = get_delta_base(p, &w_curs, &curpos, type, base_offset); |
| git_mwindow_close(&w_curs); |
| } |
| *type_p = type; |
| |
| return error; |
| } |
| |
| static int packfile_unpack_delta( |
| git_rawobj *obj, |
| struct git_pack_file *p, |
| git_mwindow **w_curs, |
| git_off_t *curpos, |
| size_t delta_size, |
| git_otype delta_type, |
| git_off_t obj_offset) |
| { |
| git_off_t base_offset, base_key; |
| git_rawobj base, delta; |
| git_pack_cache_entry *cached = NULL; |
| int error, found_base = 0; |
| |
| base_offset = get_delta_base(p, w_curs, curpos, delta_type, obj_offset); |
| git_mwindow_close(w_curs); |
| if (base_offset == 0) |
| return packfile_error("delta offset is zero"); |
| if (base_offset < 0) /* must actually be an error code */ |
| return (int)base_offset; |
| |
| if (!p->bases.entries && (cache_init(&p->bases) < 0)) |
| return -1; |
| |
| base_key = base_offset; /* git_packfile_unpack modifies base_offset */ |
| if ((cached = cache_get(&p->bases, base_offset)) != NULL) { |
| memcpy(&base, &cached->raw, sizeof(git_rawobj)); |
| found_base = 1; |
| } |
| |
| if (!cached) { /* have to inflate it */ |
| error = git_packfile_unpack(&base, p, &base_offset); |
| |
| /* |
| * TODO: git.git tries to load the base from other packfiles |
| * or loose objects. |
| * |
| * We'll need to do this in order to support thin packs. |
| */ |
| if (error < 0) |
| return error; |
| } |
| |
| error = packfile_unpack_compressed(&delta, p, w_curs, curpos, delta_size, delta_type); |
| git_mwindow_close(w_curs); |
| |
| if (error < 0) { |
| if (!found_base) |
| git__free(base.data); |
| return error; |
| } |
| |
| obj->type = base.type; |
| error = git__delta_apply(obj, base.data, base.len, delta.data, delta.len); |
| if (error < 0) |
| goto on_error; |
| |
| if (found_base) |
| git_atomic_dec(&cached->refcount); |
| else if (cache_add(&p->bases, &base, base_key) < 0) |
| git__free(base.data); |
| |
| on_error: |
| git__free(delta.data); |
| |
| return error; /* error set by git__delta_apply */ |
| } |
| |
| int git_packfile_unpack( |
| git_rawobj *obj, |
| struct git_pack_file *p, |
| git_off_t *obj_offset) |
| { |
| git_mwindow *w_curs = NULL; |
| git_off_t curpos = *obj_offset; |
| int error; |
| |
| size_t size = 0; |
| git_otype type; |
| |
| /* |
| * TODO: optionally check the CRC on the packfile |
| */ |
| |
| obj->data = NULL; |
| obj->len = 0; |
| obj->type = GIT_OBJ_BAD; |
| |
| error = git_packfile_unpack_header(&size, &type, &p->mwf, &w_curs, &curpos); |
| git_mwindow_close(&w_curs); |
| |
| if (error < 0) |
| return error; |
| |
| switch (type) { |
| case GIT_OBJ_OFS_DELTA: |
| case GIT_OBJ_REF_DELTA: |
| error = packfile_unpack_delta( |
| obj, p, &w_curs, &curpos, |
| size, type, *obj_offset); |
| break; |
| |
| case GIT_OBJ_COMMIT: |
| case GIT_OBJ_TREE: |
| case GIT_OBJ_BLOB: |
| case GIT_OBJ_TAG: |
| error = packfile_unpack_compressed( |
| obj, p, &w_curs, &curpos, |
| size, type); |
| break; |
| |
| default: |
| error = packfile_error("invalid packfile type in header");; |
| break; |
| } |
| |
| *obj_offset = curpos; |
| return error; |
| } |
| |
| static void *use_git_alloc(void *opaq, unsigned int count, unsigned int size) |
| { |
| GIT_UNUSED(opaq); |
| return git__calloc(count, size); |
| } |
| |
| static void use_git_free(void *opaq, void *ptr) |
| { |
| GIT_UNUSED(opaq); |
| git__free(ptr); |
| } |
| |
| int git_packfile_stream_open(git_packfile_stream *obj, struct git_pack_file *p, git_off_t curpos) |
| { |
| int st; |
| |
| memset(obj, 0, sizeof(git_packfile_stream)); |
| obj->curpos = curpos; |
| obj->p = p; |
| obj->zstream.zalloc = use_git_alloc; |
| obj->zstream.zfree = use_git_free; |
| obj->zstream.next_in = Z_NULL; |
| obj->zstream.next_out = Z_NULL; |
| st = inflateInit(&obj->zstream); |
| if (st != Z_OK) { |
| git__free(obj); |
| giterr_set(GITERR_ZLIB, "Failed to inflate packfile"); |
| return -1; |
| } |
| |
| return 0; |
| } |
| |
| ssize_t git_packfile_stream_read(git_packfile_stream *obj, void *buffer, size_t len) |
| { |
| unsigned char *in; |
| size_t written; |
| int st; |
| |
| if (obj->done) |
| return 0; |
| |
| in = pack_window_open(obj->p, &obj->mw, obj->curpos, &obj->zstream.avail_in); |
| if (in == NULL) |
| return GIT_EBUFS; |
| |
| obj->zstream.next_out = buffer; |
| obj->zstream.avail_out = (unsigned int)len; |
| obj->zstream.next_in = in; |
| |
| st = inflate(&obj->zstream, Z_SYNC_FLUSH); |
| git_mwindow_close(&obj->mw); |
| |
| obj->curpos += obj->zstream.next_in - in; |
| written = len - obj->zstream.avail_out; |
| |
| if (st != Z_OK && st != Z_STREAM_END) { |
| giterr_set(GITERR_ZLIB, "Failed to inflate packfile"); |
| return -1; |
| } |
| |
| if (st == Z_STREAM_END) |
| obj->done = 1; |
| |
| |
| /* If we didn't write anything out but we're not done, we need more data */ |
| if (!written && st != Z_STREAM_END) |
| return GIT_EBUFS; |
| |
| return written; |
| |
| } |
| |
| void git_packfile_stream_free(git_packfile_stream *obj) |
| { |
| inflateEnd(&obj->zstream); |
| } |
| |
| int packfile_unpack_compressed( |
| git_rawobj *obj, |
| struct git_pack_file *p, |
| git_mwindow **w_curs, |
| git_off_t *curpos, |
| size_t size, |
| git_otype type) |
| { |
| int st; |
| z_stream stream; |
| unsigned char *buffer, *in; |
| |
| buffer = git__calloc(1, size + 1); |
| GITERR_CHECK_ALLOC(buffer); |
| |
| memset(&stream, 0, sizeof(stream)); |
| stream.next_out = buffer; |
| stream.avail_out = (uInt)size + 1; |
| stream.zalloc = use_git_alloc; |
| stream.zfree = use_git_free; |
| |
| st = inflateInit(&stream); |
| if (st != Z_OK) { |
| git__free(buffer); |
| giterr_set(GITERR_ZLIB, "Failed to inflate packfile"); |
| |
| return -1; |
| } |
| |
| do { |
| in = pack_window_open(p, w_curs, *curpos, &stream.avail_in); |
| stream.next_in = in; |
| st = inflate(&stream, Z_FINISH); |
| git_mwindow_close(w_curs); |
| |
| if (!stream.avail_out) |
| break; /* the payload is larger than it should be */ |
| |
| if (st == Z_BUF_ERROR && in == NULL) { |
| inflateEnd(&stream); |
| git__free(buffer); |
| return GIT_EBUFS; |
| } |
| |
| *curpos += stream.next_in - in; |
| } while (st == Z_OK || st == Z_BUF_ERROR); |
| |
| inflateEnd(&stream); |
| |
| if ((st != Z_STREAM_END) || stream.total_out != size) { |
| git__free(buffer); |
| giterr_set(GITERR_ZLIB, "Failed to inflate packfile"); |
| return -1; |
| } |
| |
| obj->type = type; |
| obj->len = size; |
| obj->data = buffer; |
| return 0; |
| } |
| |
| /* |
| * curpos is where the data starts, delta_obj_offset is the where the |
| * header starts |
| */ |
| git_off_t get_delta_base( |
| struct git_pack_file *p, |
| git_mwindow **w_curs, |
| git_off_t *curpos, |
| git_otype type, |
| git_off_t delta_obj_offset) |
| { |
| unsigned int left = 0; |
| unsigned char *base_info; |
| git_off_t base_offset; |
| git_oid unused; |
| |
| base_info = pack_window_open(p, w_curs, *curpos, &left); |
| /* Assumption: the only reason this would fail is because the file is too small */ |
| if (base_info == NULL) |
| return GIT_EBUFS; |
| /* pack_window_open() 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 == GIT_OBJ_OFS_DELTA) { |
| unsigned used = 0; |
| unsigned char c = base_info[used++]; |
| base_offset = c & 127; |
| while (c & 128) { |
| if (left <= used) |
| return GIT_EBUFS; |
| 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 == GIT_OBJ_REF_DELTA) { |
| /* If we have the cooperative cache, search in it first */ |
| if (p->has_cache) { |
| khiter_t k; |
| git_oid oid; |
| |
| git_oid_fromraw(&oid, base_info); |
| k = kh_get(oid, p->idx_cache, &oid); |
| if (k != kh_end(p->idx_cache)) { |
| *curpos += 20; |
| return ((struct git_pack_entry *)kh_value(p->idx_cache, k))->offset; |
| } |
| } |
| /* The base entry _must_ be in the same pack */ |
| if (pack_entry_find_offset(&base_offset, &unused, p, (git_oid *)base_info, GIT_OID_HEXSZ) < 0) |
| return packfile_error("base entry delta is not in the same pack"); |
| *curpos += 20; |
| } else |
| return 0; |
| |
| return base_offset; |
| } |
| |
| /*********************************************************** |
| * |
| * PACKFILE METHODS |
| * |
| ***********************************************************/ |
| |
| void git_packfile_free(struct git_pack_file *p) |
| { |
| if (!p) |
| return; |
| |
| cache_free(&p->bases); |
| |
| git_mwindow_free_all(&p->mwf); |
| |
| if (p->mwf.fd != -1) |
| p_close(p->mwf.fd); |
| |
| pack_index_free(p); |
| |
| git__free(p->bad_object_sha1); |
| |
| git_mutex_free(&p->lock); |
| git__free(p); |
| } |
| |
| static int packfile_open(struct git_pack_file *p) |
| { |
| struct stat st; |
| struct git_pack_header hdr; |
| git_oid sha1; |
| unsigned char *idx_sha1; |
| |
| if (p->index_version == -1 && pack_index_open(p) < 0) |
| return git_odb__error_notfound("failed to open packfile", NULL); |
| |
| /* if mwf opened by another thread, return now */ |
| if (git_mutex_lock(&p->lock) < 0) |
| return packfile_error("failed to get lock for open"); |
| |
| if (p->mwf.fd >= 0) { |
| git_mutex_unlock(&p->lock); |
| return 0; |
| } |
| |
| /* TODO: open with noatime */ |
| p->mwf.fd = git_futils_open_ro(p->pack_name); |
| if (p->mwf.fd < 0) |
| goto cleanup; |
| |
| if (p_fstat(p->mwf.fd, &st) < 0 || |
| git_mwindow_file_register(&p->mwf) < 0) |
| goto cleanup; |
| |
| /* If we created the struct before we had the pack we lack size. */ |
| if (!p->mwf.size) { |
| if (!S_ISREG(st.st_mode)) |
| goto cleanup; |
| p->mwf.size = (git_off_t)st.st_size; |
| } else if (p->mwf.size != st.st_size) |
| goto cleanup; |
| |
| #if 0 |
| /* We leave these file descriptors open with sliding mmap; |
| * there is no point keeping them open across exec(), though. |
| */ |
| fd_flag = fcntl(p->mwf.fd, F_GETFD, 0); |
| if (fd_flag < 0) |
| goto cleanup; |
| |
| fd_flag |= FD_CLOEXEC; |
| if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1) |
| goto cleanup; |
| #endif |
| |
| /* Verify we recognize this pack file format. */ |
| if (p_read(p->mwf.fd, &hdr, sizeof(hdr)) < 0 || |
| hdr.hdr_signature != htonl(PACK_SIGNATURE) || |
| !pack_version_ok(hdr.hdr_version)) |
| goto cleanup; |
| |
| /* Verify the pack matches its index. */ |
| if (p->num_objects != ntohl(hdr.hdr_entries) || |
| p_lseek(p->mwf.fd, p->mwf.size - GIT_OID_RAWSZ, SEEK_SET) == -1 || |
| p_read(p->mwf.fd, sha1.id, GIT_OID_RAWSZ) < 0) |
| goto cleanup; |
| |
| idx_sha1 = ((unsigned char *)p->index_map.data) + p->index_map.len - 40; |
| |
| if (git_oid__cmp(&sha1, (git_oid *)idx_sha1) != 0) |
| goto cleanup; |
| |
| git_mutex_unlock(&p->lock); |
| return 0; |
| |
| cleanup: |
| giterr_set(GITERR_OS, "Invalid packfile '%s'", p->pack_name); |
| |
| p_close(p->mwf.fd); |
| p->mwf.fd = -1; |
| |
| git_mutex_unlock(&p->lock); |
| |
| return -1; |
| } |
| |
| int git_packfile_alloc(struct git_pack_file **pack_out, const char *path) |
| { |
| struct stat st; |
| struct git_pack_file *p; |
| size_t path_len = path ? strlen(path) : 0; |
| |
| *pack_out = NULL; |
| |
| if (path_len < strlen(".idx")) |
| return git_odb__error_notfound("invalid packfile path", NULL); |
| |
| p = git__calloc(1, sizeof(*p) + path_len + 2); |
| GITERR_CHECK_ALLOC(p); |
| |
| memcpy(p->pack_name, path, path_len + 1); |
| |
| /* |
| * Make sure a corresponding .pack file exists and that |
| * the index looks sane. |
| */ |
| if (git__suffixcmp(path, ".idx") == 0) { |
| size_t root_len = path_len - strlen(".idx"); |
| |
| memcpy(p->pack_name + root_len, ".keep", sizeof(".keep")); |
| if (git_path_exists(p->pack_name) == true) |
| p->pack_keep = 1; |
| |
| memcpy(p->pack_name + root_len, ".pack", sizeof(".pack")); |
| path_len = path_len - strlen(".idx") + strlen(".pack"); |
| } |
| |
| if (p_stat(p->pack_name, &st) < 0 || !S_ISREG(st.st_mode)) { |
| git__free(p); |
| return git_odb__error_notfound("packfile not found", NULL); |
| } |
| |
| /* ok, it looks sane as far as we can check without |
| * actually mapping the pack file. |
| */ |
| p->mwf.fd = -1; |
| p->mwf.size = st.st_size; |
| p->pack_local = 1; |
| p->mtime = (git_time_t)st.st_mtime; |
| p->index_version = -1; |
| |
| if (git_mutex_init(&p->lock)) { |
| giterr_set(GITERR_OS, "Failed to initialize packfile mutex"); |
| git__free(p); |
| return -1; |
| } |
| |
| /* see if we can parse the sha1 oid in the packfile name */ |
| if (path_len < 40 || |
| git_oid_fromstr(&p->sha1, path + path_len - GIT_OID_HEXSZ) < 0) |
| memset(&p->sha1, 0x0, GIT_OID_RAWSZ); |
| |
| *pack_out = p; |
| |
| return 0; |
| } |
| |
| /*********************************************************** |
| * |
| * PACKFILE ENTRY SEARCH INTERNALS |
| * |
| ***********************************************************/ |
| |
| static git_off_t nth_packed_object_offset(const struct git_pack_file *p, uint32_t n) |
| { |
| const unsigned char *index = p->index_map.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; |
| return (((uint64_t)ntohl(*((uint32_t *)(index + 0)))) << 32) | |
| ntohl(*((uint32_t *)(index + 4))); |
| } |
| } |
| |
| static int git__memcmp4(const void *a, const void *b) { |
| return memcmp(a, b, 4); |
| } |
| |
| int git_pack_foreach_entry( |
| struct git_pack_file *p, |
| git_odb_foreach_cb cb, |
| void *data) |
| { |
| const unsigned char *index = p->index_map.data, *current; |
| uint32_t i; |
| |
| if (index == NULL) { |
| int error; |
| |
| if ((error = pack_index_open(p)) < 0) |
| return error; |
| |
| assert(p->index_map.data); |
| |
| index = p->index_map.data; |
| } |
| |
| if (p->index_version > 1) { |
| index += 8; |
| } |
| |
| index += 4 * 256; |
| |
| if (p->oids == NULL) { |
| git_vector offsets, oids; |
| int error; |
| |
| if ((error = git_vector_init(&oids, p->num_objects, NULL))) |
| return error; |
| |
| if ((error = git_vector_init(&offsets, p->num_objects, git__memcmp4))) |
| return error; |
| |
| if (p->index_version > 1) { |
| const unsigned char *off = index + 24 * p->num_objects; |
| for (i = 0; i < p->num_objects; i++) |
| git_vector_insert(&offsets, (void*)&off[4 * i]); |
| git_vector_sort(&offsets); |
| git_vector_foreach(&offsets, i, current) |
| git_vector_insert(&oids, (void*)&index[5 * (current - off)]); |
| } else { |
| for (i = 0; i < p->num_objects; i++) |
| git_vector_insert(&offsets, (void*)&index[24 * i]); |
| git_vector_sort(&offsets); |
| git_vector_foreach(&offsets, i, current) |
| git_vector_insert(&oids, (void*)¤t[4]); |
| } |
| git_vector_free(&offsets); |
| p->oids = (git_oid **)oids.contents; |
| } |
| |
| for (i = 0; i < p->num_objects; i++) |
| if (cb(p->oids[i], data)) |
| return GIT_EUSER; |
| |
| return 0; |
| } |
| |
| static int pack_entry_find_offset( |
| git_off_t *offset_out, |
| git_oid *found_oid, |
| struct git_pack_file *p, |
| const git_oid *short_oid, |
| size_t len) |
| { |
| const uint32_t *level1_ofs = p->index_map.data; |
| const unsigned char *index = p->index_map.data; |
| unsigned hi, lo, stride; |
| int pos, found = 0; |
| const unsigned char *current = 0; |
| |
| *offset_out = 0; |
| |
| if (p->index_version == -1) { |
| int error; |
| |
| if ((error = pack_index_open(p)) < 0) |
| return error; |
| assert(p->index_map.data); |
| |
| index = p->index_map.data; |
| level1_ofs = p->index_map.data; |
| } |
| |
| if (p->index_version > 1) { |
| level1_ofs += 2; |
| index += 8; |
| } |
| |
| index += 4 * 256; |
| hi = ntohl(level1_ofs[(int)short_oid->id[0]]); |
| lo = ((short_oid->id[0] == 0x0) ? 0 : ntohl(level1_ofs[(int)short_oid->id[0] - 1])); |
| |
| if (p->index_version > 1) { |
| stride = 20; |
| } else { |
| stride = 24; |
| index += 4; |
| } |
| |
| #ifdef INDEX_DEBUG_LOOKUP |
| printf("%02x%02x%02x... lo %u hi %u nr %d\n", |
| short_oid->id[0], short_oid->id[1], short_oid->id[2], lo, hi, p->num_objects); |
| #endif |
| |
| /* Use git.git lookup code */ |
| pos = sha1_entry_pos(index, stride, 0, lo, hi, p->num_objects, short_oid->id); |
| |
| if (pos >= 0) { |
| /* An object matching exactly the oid was found */ |
| found = 1; |
| current = index + pos * stride; |
| } else { |
| /* No object was found */ |
| /* pos refers to the object with the "closest" oid to short_oid */ |
| pos = - 1 - pos; |
| if (pos < (int)p->num_objects) { |
| current = index + pos * stride; |
| |
| if (!git_oid_ncmp(short_oid, (const git_oid *)current, len)) |
| found = 1; |
| } |
| } |
| |
| if (found && len != GIT_OID_HEXSZ && pos + 1 < (int)p->num_objects) { |
| /* Check for ambiguousity */ |
| const unsigned char *next = current + stride; |
| |
| if (!git_oid_ncmp(short_oid, (const git_oid *)next, len)) { |
| found = 2; |
| } |
| } |
| |
| if (!found) |
| return git_odb__error_notfound("failed to find offset for pack entry", short_oid); |
| if (found > 1) |
| return git_odb__error_ambiguous("found multiple offsets for pack entry"); |
| |
| *offset_out = nth_packed_object_offset(p, pos); |
| git_oid_fromraw(found_oid, current); |
| |
| #ifdef INDEX_DEBUG_LOOKUP |
| { |
| unsigned char hex_sha1[GIT_OID_HEXSZ + 1]; |
| git_oid_fmt(hex_sha1, found_oid); |
| hex_sha1[GIT_OID_HEXSZ] = '\0'; |
| printf("found lo=%d %s\n", lo, hex_sha1); |
| } |
| #endif |
| |
| return 0; |
| } |
| |
| int git_pack_entry_find( |
| struct git_pack_entry *e, |
| struct git_pack_file *p, |
| const git_oid *short_oid, |
| size_t len) |
| { |
| git_off_t offset; |
| git_oid found_oid; |
| int error; |
| |
| assert(p); |
| |
| if (len == GIT_OID_HEXSZ && p->num_bad_objects) { |
| unsigned i; |
| for (i = 0; i < p->num_bad_objects; i++) |
| if (git_oid__cmp(short_oid, &p->bad_object_sha1[i]) == 0) |
| return packfile_error("bad object found in packfile"); |
| } |
| |
| error = pack_entry_find_offset(&offset, &found_oid, p, short_oid, len); |
| if (error < 0) |
| return error; |
| |
| /* we found a unique entry in the index; |
| * make sure the packfile backing the index |
| * still exists on disk */ |
| if (p->mwf.fd == -1 && (error = packfile_open(p)) < 0) |
| return error; |
| |
| e->offset = offset; |
| e->p = p; |
| |
| git_oid_cpy(&e->sha1, &found_oid); |
| return 0; |
| } |