diff options
Diffstat (limited to 'sha1_file.c')
| -rw-r--r-- | sha1_file.c | 113 |
1 files changed, 65 insertions, 48 deletions
diff --git a/sha1_file.c b/sha1_file.c index 47e2a29abd..e89d24c015 100644 --- a/sha1_file.c +++ b/sha1_file.c @@ -877,26 +877,61 @@ void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned l return unpack_sha1_rest(&stream, hdr, *size); } +static unsigned long get_delta_base(struct packed_git *p, + unsigned long offset, + enum object_type kind, + unsigned long delta_obj_offset, + unsigned long *base_obj_offset) +{ + unsigned char *base_info = (unsigned char *) p->pack_base + offset; + unsigned long base_offset; + + /* there must be at least 20 bytes left regardless of delta type */ + if (p->pack_size <= offset + 20) + die("truncated pack file"); + + if (kind == 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 || base_offset & ~(~0UL >> 7)) + die("offset value overflow for delta base object"); + c = base_info[used++]; + base_offset = (base_offset << 7) + (c & 127); + } + base_offset = delta_obj_offset - base_offset; + if (base_offset >= delta_obj_offset) + die("delta base offset out of bound"); + offset += used; + } else if (kind == OBJ_REF_DELTA) { + /* The base entry _must_ be in the same pack */ + base_offset = find_pack_entry_one(base_info, p); + if (!base_offset) + die("failed to find delta-pack base object %s", + sha1_to_hex(base_info)); + offset += 20; + } else + die("I am totally screwed"); + *base_obj_offset = base_offset; + return offset; +} + /* forward declaration for a mutually recursive function */ static int packed_object_info(struct packed_git *p, unsigned long offset, char *type, unsigned long *sizep); static int packed_delta_info(struct packed_git *p, unsigned long offset, + enum object_type kind, + unsigned long obj_offset, char *type, unsigned long *sizep) { unsigned long base_offset; - unsigned char *base_sha1 = (unsigned char *) p->pack_base + offset; - if (p->pack_size < offset + 20) - die("truncated pack file"); - /* The base entry _must_ be in the same pack */ - base_offset = find_pack_entry_one(base_sha1, p); - if (!base_offset) - die("failed to find delta-pack base object %s", - sha1_to_hex(base_sha1)); - offset += 20; + offset = get_delta_base(p, offset, kind, obj_offset, &base_offset); /* We choose to only get the type of the base object and * ignore potentially corrupt pack file that expects the delta @@ -959,25 +994,6 @@ static unsigned long unpack_object_header(struct packed_git *p, unsigned long of return offset + used; } -int check_reuse_pack_delta(struct packed_git *p, unsigned long offset, - unsigned char *base, unsigned long *sizep, - enum object_type *kindp) -{ - unsigned long ptr; - int status = -1; - - use_packed_git(p); - ptr = offset; - ptr = unpack_object_header(p, ptr, kindp, sizep); - if (*kindp != OBJ_DELTA) - goto done; - hashcpy(base, (unsigned char *) p->pack_base + ptr); - status = 0; - done: - unuse_packed_git(p); - return status; -} - void packed_object_info_detail(struct packed_git *p, unsigned long offset, char *type, @@ -986,11 +1002,12 @@ void packed_object_info_detail(struct packed_git *p, unsigned int *delta_chain_length, unsigned char *base_sha1) { - unsigned long val; + unsigned long obj_offset, val; unsigned char *next_sha1; enum object_type kind; *delta_chain_length = 0; + obj_offset = offset; offset = unpack_object_header(p, offset, &kind, size); for (;;) { @@ -1005,7 +1022,13 @@ void packed_object_info_detail(struct packed_git *p, strcpy(type, type_names[kind]); *store_size = 0; /* notyet */ return; - case OBJ_DELTA: + case OBJ_OFS_DELTA: + get_delta_base(p, offset, kind, obj_offset, &offset); + if (*delta_chain_length == 0) { + /* TODO: find base_sha1 as pointed by offset */ + } + break; + case OBJ_REF_DELTA: if (p->pack_size <= offset + 20) die("pack file %s records an incomplete delta base", p->pack_name); @@ -1015,6 +1038,7 @@ void packed_object_info_detail(struct packed_git *p, offset = find_pack_entry_one(next_sha1, p); break; } + obj_offset = offset; offset = unpack_object_header(p, offset, &kind, &val); (*delta_chain_length)++; } @@ -1023,15 +1047,15 @@ void packed_object_info_detail(struct packed_git *p, static int packed_object_info(struct packed_git *p, unsigned long offset, char *type, unsigned long *sizep) { - unsigned long size; + unsigned long size, obj_offset = offset; enum object_type kind; offset = unpack_object_header(p, offset, &kind, &size); - if (kind == OBJ_DELTA) - return packed_delta_info(p, offset, type, sizep); - switch (kind) { + case OBJ_OFS_DELTA: + case OBJ_REF_DELTA: + return packed_delta_info(p, offset, kind, obj_offset, type, sizep); case OBJ_COMMIT: case OBJ_TREE: case OBJ_BLOB: @@ -1077,23 +1101,15 @@ static void *unpack_compressed_entry(struct packed_git *p, static void *unpack_delta_entry(struct packed_git *p, unsigned long offset, unsigned long delta_size, + enum object_type kind, + unsigned long obj_offset, char *type, unsigned long *sizep) { void *delta_data, *result, *base; unsigned long result_size, base_size, base_offset; - unsigned char *base_sha1; - - if (p->pack_size < offset + 20) - die("truncated pack file"); - /* The base entry _must_ be in the same pack */ - base_sha1 = (unsigned char*)p->pack_base + offset; - base_offset = find_pack_entry_one(base_sha1, p); - if (!base_offset) - die("failed to find delta-pack base object %s", - sha1_to_hex(base_sha1)); - offset += 20; + offset = get_delta_base(p, offset, kind, obj_offset, &base_offset); base = unpack_entry_gently(p, base_offset, type, &base_size); if (!base) die("failed to read delta base object at %lu from %s", @@ -1130,13 +1146,14 @@ static void *unpack_entry(struct pack_entry *entry, void *unpack_entry_gently(struct packed_git *p, unsigned long offset, char *type, unsigned long *sizep) { - unsigned long size; + unsigned long size, obj_offset = offset; enum object_type kind; offset = unpack_object_header(p, offset, &kind, &size); switch (kind) { - case OBJ_DELTA: - return unpack_delta_entry(p, offset, size, type, sizep); + case OBJ_OFS_DELTA: + case OBJ_REF_DELTA: + return unpack_delta_entry(p, offset, size, kind, obj_offset, type, sizep); case OBJ_COMMIT: case OBJ_TREE: case OBJ_BLOB: |