7 static const char unpack_usage[] = "git-unpack-objects < pack-file";
9 /* We always read in 4kB chunks. */
10 static unsigned char buffer[4096];
11 static unsigned long offset, len, eof;
15 * Make sure at least "min" bytes are available in the buffer, and
16 * return the pointer to the buffer.
18 static void * fill(int min)
21 return buffer + offset;
23 die("unable to fill input");
24 if (min > sizeof(buffer))
25 die("cannot fill %d bytes", min);
27 SHA1_Update(&ctx, buffer, offset);
28 memcpy(buffer, buffer + offset, len);
32 int ret = read(0, buffer + len, sizeof(buffer) - len);
36 if (errno == EAGAIN || errno == EINTR)
38 die("read error on input: %s", strerror(errno));
45 static void use(int bytes)
48 die("used more bytes than were available");
53 static void *get_data(unsigned long size)
56 void *buf = xmalloc(size);
60 memset(&stream, 0, sizeof(stream));
62 stream.next_out = buf;
63 stream.avail_out = size;
64 stream.next_in = fill(1);
65 stream.avail_in = len;
69 int ret = inflate(&stream, 0);
70 use(len - stream.avail_in);
71 if (stream.total_out == size && ret == Z_STREAM_END)
74 die("inflate returned %d\n", ret);
75 stream.next_in = fill(1);
76 stream.avail_in = len;
82 unsigned char base_sha1[20];
85 struct delta_info *next;
88 static struct delta_info *delta_list;
90 static void add_delta_to_list(unsigned char *base_sha1, void *delta, unsigned long size)
92 struct delta_info *info = xmalloc(sizeof(*info));
94 memcpy(info->base_sha1, base_sha1, 20);
97 info->next = delta_list;
101 static void added_object(unsigned char *sha1, char *type, void *data, unsigned long size);
103 static int resolve_delta(char *type,
104 void *base, unsigned long base_size,
105 void *delta, unsigned long delta_size)
108 unsigned long result_size;
109 unsigned char sha1[20];
111 result = patch_delta(base, base_size,
115 die("failed to apply delta");
118 if (write_sha1_file(result, result_size, type, sha1) < 0)
119 die("failed to write object");
120 added_object(sha1, type, result, result_size);
125 static void added_object(unsigned char *sha1, char *type, void *data, unsigned long size)
127 struct delta_info **p = &delta_list;
128 struct delta_info *info;
130 while ((info = *p) != NULL) {
131 if (!memcmp(info->base_sha1, sha1, 20)) {
134 resolve_delta(type, data, size, info->delta, info->size);
142 static int unpack_non_delta_entry(enum object_type kind, unsigned long size)
144 void *buf = get_data(size);
145 unsigned char sha1[20];
149 case OBJ_COMMIT: type = "commit"; break;
150 case OBJ_TREE: type = "tree"; break;
151 case OBJ_BLOB: type = "blob"; break;
152 case OBJ_TAG: type = "tag"; break;
153 default: die("bad type %d", kind);
155 if (write_sha1_file(buf, size, type, sha1) < 0)
156 die("failed to write object");
157 added_object(sha1, type, buf, size);
162 static int unpack_delta_entry(unsigned long delta_size)
164 void *delta_data, *base;
165 unsigned long base_size;
167 unsigned char base_sha1[20];
169 memcpy(base_sha1, fill(20), 20);
172 delta_data = get_data(delta_size);
174 if (!has_sha1_file(base_sha1)) {
175 add_delta_to_list(base_sha1, delta_data, delta_size);
178 base = read_sha1_file(base_sha1, type, &base_size);
180 die("failed to read delta-pack base object %s", sha1_to_hex(base_sha1));
181 return resolve_delta(type, base, base_size, delta_data, delta_size);
184 static void unpack_one(void)
187 unsigned char *pack, c;
189 enum object_type type;
201 size += (c & 0x7f) << shift;
209 unpack_non_delta_entry(type, size);
212 unpack_delta_entry(size);
215 die("bad object type %d", type);
220 * We unpack from the end, older files first. Now, usually
221 * there are deltas etc, so we'll not actually write the
222 * objects in that order, but we might as well try..
224 static void unpack_all(void)
227 struct pack_header *hdr = fill(sizeof(struct pack_header));
228 unsigned version = ntohl(hdr->hdr_version);
229 unsigned nr_objects = ntohl(hdr->hdr_entries);
231 if (ntohl(hdr->hdr_signature) != PACK_SIGNATURE)
232 die("bad pack file");
233 if (version != PACK_VERSION)
234 die("unable to handle pack file version %d", version);
235 fprintf(stderr, "Unpacking %d objects\n", nr_objects);
237 use(sizeof(struct pack_header));
238 for (i = 0; i < nr_objects; i++)
241 die("unresolved deltas left after unpacking");
244 int main(int argc, char **argv)
247 unsigned char sha1[20];
249 for (i = 1 ; i < argc; i++) {
250 const char *arg = argv[i];
253 if (!strcmp(arg, "-n")) {
260 /* We don't take any non-flag arguments now.. Maybe some day */
265 SHA1_Update(&ctx, buffer, offset);
266 SHA1_Final(sha1, &ctx);
267 if (memcmp(fill(20), sha1, 20))
268 die("final sha1 did not match");
271 /* Write the last part of the buffer to stdout */
273 int ret = write(1, buffer + offset, len);
277 if (errno == EAGAIN || errno == EINTR)