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Commit | Line | Data |
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9cf6d335 SV |
1 | #include "cache.h" |
2 | #include "delta.h" | |
3 | #include "pack.h" | |
4 | #include "csum-file.h" | |
8e440259 PE |
5 | #include "blob.h" |
6 | #include "commit.h" | |
7 | #include "tag.h" | |
8 | #include "tree.h" | |
9cf6d335 SV |
9 | |
10 | static const char index_pack_usage[] = | |
11 | "git-index-pack [-o index-file] pack-file"; | |
12 | ||
13 | struct object_entry | |
14 | { | |
15 | unsigned long offset; | |
16 | enum object_type type; | |
17 | enum object_type real_type; | |
18 | unsigned char sha1[20]; | |
19 | }; | |
20 | ||
53dda6ff NP |
21 | union delta_base { |
22 | unsigned char sha1[20]; | |
23 | unsigned long offset; | |
24 | }; | |
25 | ||
3c552873 NP |
26 | /* |
27 | * Even if sizeof(union delta_base) == 24 on 64-bit archs, we really want | |
28 | * to memcmp() only the first 20 bytes. | |
29 | */ | |
30 | #define UNION_BASE_SZ 20 | |
31 | ||
9cf6d335 SV |
32 | struct delta_entry |
33 | { | |
34 | struct object_entry *obj; | |
53dda6ff | 35 | union delta_base base; |
9cf6d335 SV |
36 | }; |
37 | ||
38 | static const char *pack_name; | |
39 | static unsigned char *pack_base; | |
40 | static unsigned long pack_size; | |
41 | static struct object_entry *objects; | |
42 | static struct delta_entry *deltas; | |
43 | static int nr_objects; | |
44 | static int nr_deltas; | |
45 | ||
46 | static void open_pack_file(void) | |
47 | { | |
48 | int fd; | |
49 | struct stat st; | |
50 | ||
51 | fd = open(pack_name, O_RDONLY); | |
52 | if (fd < 0) | |
53 | die("cannot open packfile '%s': %s", pack_name, | |
54 | strerror(errno)); | |
55 | if (fstat(fd, &st)) { | |
56 | int err = errno; | |
57 | close(fd); | |
58 | die("cannot fstat packfile '%s': %s", pack_name, | |
59 | strerror(err)); | |
60 | } | |
61 | pack_size = st.st_size; | |
62 | pack_base = mmap(NULL, pack_size, PROT_READ, MAP_PRIVATE, fd, 0); | |
63 | if (pack_base == MAP_FAILED) { | |
64 | int err = errno; | |
65 | close(fd); | |
66 | die("cannot mmap packfile '%s': %s", pack_name, | |
67 | strerror(err)); | |
68 | } | |
69 | close(fd); | |
70 | } | |
71 | ||
72 | static void parse_pack_header(void) | |
73 | { | |
74 | const struct pack_header *hdr; | |
75 | unsigned char sha1[20]; | |
76 | SHA_CTX ctx; | |
77 | ||
78 | /* Ensure there are enough bytes for the header and final SHA1 */ | |
79 | if (pack_size < sizeof(struct pack_header) + 20) | |
80 | die("packfile '%s' is too small", pack_name); | |
81 | ||
82 | /* Header consistency check */ | |
83 | hdr = (void *)pack_base; | |
84 | if (hdr->hdr_signature != htonl(PACK_SIGNATURE)) | |
85 | die("packfile '%s' signature mismatch", pack_name); | |
d60fc1c8 NP |
86 | if (!pack_version_ok(hdr->hdr_version)) |
87 | die("packfile '%s' version %d unsupported", | |
88 | pack_name, ntohl(hdr->hdr_version)); | |
9cf6d335 SV |
89 | |
90 | nr_objects = ntohl(hdr->hdr_entries); | |
91 | ||
92 | /* Check packfile integrity */ | |
93 | SHA1_Init(&ctx); | |
94 | SHA1_Update(&ctx, pack_base, pack_size - 20); | |
95 | SHA1_Final(sha1, &ctx); | |
a89fccd2 | 96 | if (hashcmp(sha1, pack_base + pack_size - 20)) |
9cf6d335 SV |
97 | die("packfile '%s' SHA1 mismatch", pack_name); |
98 | } | |
99 | ||
100 | static void bad_object(unsigned long offset, const char *format, | |
101 | ...) NORETURN __attribute__((format (printf, 2, 3))); | |
102 | ||
103 | static void bad_object(unsigned long offset, const char *format, ...) | |
104 | { | |
105 | va_list params; | |
106 | char buf[1024]; | |
107 | ||
108 | va_start(params, format); | |
109 | vsnprintf(buf, sizeof(buf), format, params); | |
110 | va_end(params); | |
111 | die("packfile '%s': bad object at offset %lu: %s", | |
112 | pack_name, offset, buf); | |
113 | } | |
114 | ||
115 | static void *unpack_entry_data(unsigned long offset, | |
116 | unsigned long *current_pos, unsigned long size) | |
117 | { | |
118 | unsigned long pack_limit = pack_size - 20; | |
119 | unsigned long pos = *current_pos; | |
120 | z_stream stream; | |
121 | void *buf = xmalloc(size); | |
122 | ||
123 | memset(&stream, 0, sizeof(stream)); | |
124 | stream.next_out = buf; | |
125 | stream.avail_out = size; | |
126 | stream.next_in = pack_base + pos; | |
127 | stream.avail_in = pack_limit - pos; | |
128 | inflateInit(&stream); | |
129 | ||
130 | for (;;) { | |
131 | int ret = inflate(&stream, 0); | |
132 | if (ret == Z_STREAM_END) | |
133 | break; | |
134 | if (ret != Z_OK) | |
135 | bad_object(offset, "inflate returned %d", ret); | |
136 | } | |
137 | inflateEnd(&stream); | |
138 | if (stream.total_out != size) | |
139 | bad_object(offset, "size mismatch (expected %lu, got %lu)", | |
140 | size, stream.total_out); | |
141 | *current_pos = pack_limit - stream.avail_in; | |
142 | return buf; | |
143 | } | |
144 | ||
145 | static void *unpack_raw_entry(unsigned long offset, | |
146 | enum object_type *obj_type, | |
147 | unsigned long *obj_size, | |
53dda6ff | 148 | union delta_base *delta_base, |
9cf6d335 SV |
149 | unsigned long *next_obj_offset) |
150 | { | |
151 | unsigned long pack_limit = pack_size - 20; | |
152 | unsigned long pos = offset; | |
153 | unsigned char c; | |
53dda6ff | 154 | unsigned long size, base_offset; |
9cf6d335 SV |
155 | unsigned shift; |
156 | enum object_type type; | |
157 | void *data; | |
158 | ||
159 | c = pack_base[pos++]; | |
160 | type = (c >> 4) & 7; | |
161 | size = (c & 15); | |
162 | shift = 4; | |
163 | while (c & 0x80) { | |
164 | if (pos >= pack_limit) | |
165 | bad_object(offset, "object extends past end of pack"); | |
166 | c = pack_base[pos++]; | |
167 | size += (c & 0x7fUL) << shift; | |
168 | shift += 7; | |
169 | } | |
170 | ||
171 | switch (type) { | |
eb32d236 | 172 | case OBJ_REF_DELTA: |
9cf6d335 SV |
173 | if (pos + 20 >= pack_limit) |
174 | bad_object(offset, "object extends past end of pack"); | |
53dda6ff | 175 | hashcpy(delta_base->sha1, pack_base + pos); |
9cf6d335 | 176 | pos += 20; |
53dda6ff NP |
177 | break; |
178 | case OBJ_OFS_DELTA: | |
179 | memset(delta_base, 0, sizeof(*delta_base)); | |
180 | c = pack_base[pos++]; | |
181 | base_offset = c & 127; | |
182 | while (c & 128) { | |
183 | base_offset += 1; | |
184 | if (!base_offset || base_offset & ~(~0UL >> 7)) | |
185 | bad_object(offset, "offset value overflow for delta base object"); | |
186 | if (pos >= pack_limit) | |
187 | bad_object(offset, "object extends past end of pack"); | |
188 | c = pack_base[pos++]; | |
189 | base_offset = (base_offset << 7) + (c & 127); | |
190 | } | |
191 | delta_base->offset = offset - base_offset; | |
192 | if (delta_base->offset >= offset) | |
193 | bad_object(offset, "delta base offset is out of bound"); | |
194 | break; | |
9cf6d335 SV |
195 | case OBJ_COMMIT: |
196 | case OBJ_TREE: | |
197 | case OBJ_BLOB: | |
198 | case OBJ_TAG: | |
9cf6d335 SV |
199 | break; |
200 | default: | |
201 | bad_object(offset, "bad object type %d", type); | |
202 | } | |
203 | ||
53dda6ff | 204 | data = unpack_entry_data(offset, &pos, size); |
9cf6d335 SV |
205 | *obj_type = type; |
206 | *obj_size = size; | |
207 | *next_obj_offset = pos; | |
208 | return data; | |
209 | } | |
210 | ||
53dda6ff | 211 | static int find_delta(const union delta_base *base) |
9cf6d335 SV |
212 | { |
213 | int first = 0, last = nr_deltas; | |
214 | ||
215 | while (first < last) { | |
216 | int next = (first + last) / 2; | |
217 | struct delta_entry *delta = &deltas[next]; | |
218 | int cmp; | |
219 | ||
3c552873 | 220 | cmp = memcmp(base, &delta->base, UNION_BASE_SZ); |
9cf6d335 SV |
221 | if (!cmp) |
222 | return next; | |
223 | if (cmp < 0) { | |
224 | last = next; | |
225 | continue; | |
226 | } | |
227 | first = next+1; | |
228 | } | |
229 | return -first-1; | |
230 | } | |
231 | ||
53dda6ff NP |
232 | static int find_delta_childs(const union delta_base *base, |
233 | int *first_index, int *last_index) | |
9cf6d335 | 234 | { |
53dda6ff | 235 | int first = find_delta(base); |
9cf6d335 SV |
236 | int last = first; |
237 | int end = nr_deltas - 1; | |
238 | ||
239 | if (first < 0) | |
240 | return -1; | |
3c552873 | 241 | while (first > 0 && !memcmp(&deltas[first - 1].base, base, UNION_BASE_SZ)) |
9cf6d335 | 242 | --first; |
3c552873 | 243 | while (last < end && !memcmp(&deltas[last + 1].base, base, UNION_BASE_SZ)) |
9cf6d335 SV |
244 | ++last; |
245 | *first_index = first; | |
246 | *last_index = last; | |
247 | return 0; | |
248 | } | |
249 | ||
250 | static void sha1_object(const void *data, unsigned long size, | |
251 | enum object_type type, unsigned char *sha1) | |
252 | { | |
253 | SHA_CTX ctx; | |
254 | char header[50]; | |
255 | int header_size; | |
256 | const char *type_str; | |
257 | ||
258 | switch (type) { | |
8e440259 PE |
259 | case OBJ_COMMIT: type_str = commit_type; break; |
260 | case OBJ_TREE: type_str = tree_type; break; | |
261 | case OBJ_BLOB: type_str = blob_type; break; | |
262 | case OBJ_TAG: type_str = tag_type; break; | |
9cf6d335 SV |
263 | default: |
264 | die("bad type %d", type); | |
265 | } | |
266 | ||
267 | header_size = sprintf(header, "%s %lu", type_str, size) + 1; | |
268 | ||
269 | SHA1_Init(&ctx); | |
270 | SHA1_Update(&ctx, header, header_size); | |
271 | SHA1_Update(&ctx, data, size); | |
272 | SHA1_Final(sha1, &ctx); | |
273 | } | |
274 | ||
275 | static void resolve_delta(struct delta_entry *delta, void *base_data, | |
276 | unsigned long base_size, enum object_type type) | |
277 | { | |
278 | struct object_entry *obj = delta->obj; | |
279 | void *delta_data; | |
280 | unsigned long delta_size; | |
281 | void *result; | |
282 | unsigned long result_size; | |
283 | enum object_type delta_type; | |
53dda6ff | 284 | union delta_base delta_base; |
9cf6d335 SV |
285 | unsigned long next_obj_offset; |
286 | int j, first, last; | |
287 | ||
288 | obj->real_type = type; | |
289 | delta_data = unpack_raw_entry(obj->offset, &delta_type, | |
53dda6ff | 290 | &delta_size, &delta_base, |
9cf6d335 SV |
291 | &next_obj_offset); |
292 | result = patch_delta(base_data, base_size, delta_data, delta_size, | |
293 | &result_size); | |
294 | free(delta_data); | |
295 | if (!result) | |
296 | bad_object(obj->offset, "failed to apply delta"); | |
297 | sha1_object(result, result_size, type, obj->sha1); | |
53dda6ff NP |
298 | |
299 | hashcpy(delta_base.sha1, obj->sha1); | |
300 | if (!find_delta_childs(&delta_base, &first, &last)) { | |
301 | for (j = first; j <= last; j++) | |
302 | if (deltas[j].obj->type == OBJ_REF_DELTA) | |
303 | resolve_delta(&deltas[j], result, result_size, type); | |
304 | } | |
305 | ||
306 | memset(&delta_base, 0, sizeof(delta_base)); | |
307 | delta_base.offset = obj->offset; | |
308 | if (!find_delta_childs(&delta_base, &first, &last)) { | |
9cf6d335 | 309 | for (j = first; j <= last; j++) |
53dda6ff NP |
310 | if (deltas[j].obj->type == OBJ_OFS_DELTA) |
311 | resolve_delta(&deltas[j], result, result_size, type); | |
9cf6d335 | 312 | } |
53dda6ff | 313 | |
9cf6d335 SV |
314 | free(result); |
315 | } | |
316 | ||
317 | static int compare_delta_entry(const void *a, const void *b) | |
318 | { | |
319 | const struct delta_entry *delta_a = a; | |
320 | const struct delta_entry *delta_b = b; | |
3c552873 | 321 | return memcmp(&delta_a->base, &delta_b->base, UNION_BASE_SZ); |
9cf6d335 SV |
322 | } |
323 | ||
324 | static void parse_pack_objects(void) | |
325 | { | |
326 | int i; | |
327 | unsigned long offset = sizeof(struct pack_header); | |
53dda6ff | 328 | struct delta_entry *delta = deltas; |
9cf6d335 SV |
329 | void *data; |
330 | unsigned long data_size; | |
331 | ||
332 | /* | |
333 | * First pass: | |
334 | * - find locations of all objects; | |
335 | * - calculate SHA1 of all non-delta objects; | |
336 | * - remember base SHA1 for all deltas. | |
337 | */ | |
338 | for (i = 0; i < nr_objects; i++) { | |
339 | struct object_entry *obj = &objects[i]; | |
340 | obj->offset = offset; | |
341 | data = unpack_raw_entry(offset, &obj->type, &data_size, | |
53dda6ff | 342 | &delta->base, &offset); |
9cf6d335 | 343 | obj->real_type = obj->type; |
53dda6ff NP |
344 | if (obj->type == OBJ_REF_DELTA || obj->type == OBJ_OFS_DELTA) { |
345 | nr_deltas++; | |
9cf6d335 | 346 | delta->obj = obj; |
53dda6ff | 347 | delta++; |
9cf6d335 SV |
348 | } else |
349 | sha1_object(data, data_size, obj->type, obj->sha1); | |
350 | free(data); | |
351 | } | |
352 | if (offset != pack_size - 20) | |
353 | die("packfile '%s' has junk at the end", pack_name); | |
354 | ||
53dda6ff | 355 | /* Sort deltas by base SHA1/offset for fast searching */ |
9cf6d335 SV |
356 | qsort(deltas, nr_deltas, sizeof(struct delta_entry), |
357 | compare_delta_entry); | |
358 | ||
359 | /* | |
360 | * Second pass: | |
361 | * - for all non-delta objects, look if it is used as a base for | |
362 | * deltas; | |
363 | * - if used as a base, uncompress the object and apply all deltas, | |
364 | * recursively checking if the resulting object is used as a base | |
365 | * for some more deltas. | |
366 | */ | |
367 | for (i = 0; i < nr_objects; i++) { | |
368 | struct object_entry *obj = &objects[i]; | |
53dda6ff NP |
369 | union delta_base base; |
370 | int j, ref, ref_first, ref_last, ofs, ofs_first, ofs_last; | |
9cf6d335 | 371 | |
53dda6ff | 372 | if (obj->type == OBJ_REF_DELTA || obj->type == OBJ_OFS_DELTA) |
9cf6d335 | 373 | continue; |
53dda6ff NP |
374 | hashcpy(base.sha1, obj->sha1); |
375 | ref = !find_delta_childs(&base, &ref_first, &ref_last); | |
376 | memset(&base, 0, sizeof(base)); | |
377 | base.offset = obj->offset; | |
378 | ofs = !find_delta_childs(&base, &ofs_first, &ofs_last); | |
379 | if (!ref && !ofs) | |
9cf6d335 SV |
380 | continue; |
381 | data = unpack_raw_entry(obj->offset, &obj->type, &data_size, | |
53dda6ff NP |
382 | &base, &offset); |
383 | if (ref) | |
384 | for (j = ref_first; j <= ref_last; j++) | |
385 | if (deltas[j].obj->type == OBJ_REF_DELTA) | |
386 | resolve_delta(&deltas[j], data, | |
387 | data_size, obj->type); | |
388 | if (ofs) | |
389 | for (j = ofs_first; j <= ofs_last; j++) | |
390 | if (deltas[j].obj->type == OBJ_OFS_DELTA) | |
391 | resolve_delta(&deltas[j], data, | |
392 | data_size, obj->type); | |
9cf6d335 SV |
393 | free(data); |
394 | } | |
395 | ||
396 | /* Check for unresolved deltas */ | |
397 | for (i = 0; i < nr_deltas; i++) { | |
53dda6ff NP |
398 | if (deltas[i].obj->real_type == OBJ_REF_DELTA || |
399 | deltas[i].obj->real_type == OBJ_OFS_DELTA) | |
9cf6d335 SV |
400 | die("packfile '%s' has unresolved deltas", pack_name); |
401 | } | |
402 | } | |
403 | ||
404 | static int sha1_compare(const void *_a, const void *_b) | |
405 | { | |
406 | struct object_entry *a = *(struct object_entry **)_a; | |
407 | struct object_entry *b = *(struct object_entry **)_b; | |
a89fccd2 | 408 | return hashcmp(a->sha1, b->sha1); |
9cf6d335 SV |
409 | } |
410 | ||
84c8d8ae | 411 | static void write_index_file(const char *index_name, unsigned char *sha1) |
9cf6d335 SV |
412 | { |
413 | struct sha1file *f; | |
7e4a2a84 | 414 | struct object_entry **sorted_by_sha, **list, **last; |
9cf6d335 SV |
415 | unsigned int array[256]; |
416 | int i; | |
84c8d8ae | 417 | SHA_CTX ctx; |
9cf6d335 | 418 | |
7e4a2a84 JH |
419 | if (nr_objects) { |
420 | sorted_by_sha = | |
421 | xcalloc(nr_objects, sizeof(struct object_entry *)); | |
422 | list = sorted_by_sha; | |
423 | last = sorted_by_sha + nr_objects; | |
424 | for (i = 0; i < nr_objects; ++i) | |
425 | sorted_by_sha[i] = &objects[i]; | |
426 | qsort(sorted_by_sha, nr_objects, sizeof(sorted_by_sha[0]), | |
427 | sha1_compare); | |
428 | ||
429 | } | |
430 | else | |
431 | sorted_by_sha = list = last = NULL; | |
9cf6d335 SV |
432 | |
433 | unlink(index_name); | |
434 | f = sha1create("%s", index_name); | |
435 | ||
436 | /* | |
437 | * Write the first-level table (the list is sorted, | |
438 | * but we use a 256-entry lookup to be able to avoid | |
439 | * having to do eight extra binary search iterations). | |
440 | */ | |
441 | for (i = 0; i < 256; i++) { | |
442 | struct object_entry **next = list; | |
443 | while (next < last) { | |
444 | struct object_entry *obj = *next; | |
445 | if (obj->sha1[0] != i) | |
446 | break; | |
447 | next++; | |
448 | } | |
449 | array[i] = htonl(next - sorted_by_sha); | |
450 | list = next; | |
451 | } | |
452 | sha1write(f, array, 256 * sizeof(int)); | |
453 | ||
84c8d8ae JH |
454 | /* recompute the SHA1 hash of sorted object names. |
455 | * currently pack-objects does not do this, but that | |
456 | * can be fixed. | |
457 | */ | |
458 | SHA1_Init(&ctx); | |
9cf6d335 SV |
459 | /* |
460 | * Write the actual SHA1 entries.. | |
461 | */ | |
462 | list = sorted_by_sha; | |
463 | for (i = 0; i < nr_objects; i++) { | |
464 | struct object_entry *obj = *list++; | |
465 | unsigned int offset = htonl(obj->offset); | |
466 | sha1write(f, &offset, 4); | |
467 | sha1write(f, obj->sha1, 20); | |
84c8d8ae | 468 | SHA1_Update(&ctx, obj->sha1, 20); |
9cf6d335 SV |
469 | } |
470 | sha1write(f, pack_base + pack_size - 20, 20); | |
471 | sha1close(f, NULL, 1); | |
472 | free(sorted_by_sha); | |
84c8d8ae | 473 | SHA1_Final(sha1, &ctx); |
9cf6d335 SV |
474 | } |
475 | ||
476 | int main(int argc, char **argv) | |
477 | { | |
478 | int i; | |
479 | char *index_name = NULL; | |
480 | char *index_name_buf = NULL; | |
84c8d8ae | 481 | unsigned char sha1[20]; |
9cf6d335 SV |
482 | |
483 | for (i = 1; i < argc; i++) { | |
484 | const char *arg = argv[i]; | |
485 | ||
486 | if (*arg == '-') { | |
487 | if (!strcmp(arg, "-o")) { | |
488 | if (index_name || (i+1) >= argc) | |
489 | usage(index_pack_usage); | |
490 | index_name = argv[++i]; | |
491 | } else | |
492 | usage(index_pack_usage); | |
493 | continue; | |
494 | } | |
495 | ||
496 | if (pack_name) | |
497 | usage(index_pack_usage); | |
498 | pack_name = arg; | |
499 | } | |
500 | ||
501 | if (!pack_name) | |
502 | usage(index_pack_usage); | |
503 | if (!index_name) { | |
504 | int len = strlen(pack_name); | |
5bb1cda5 | 505 | if (!has_extension(pack_name, ".pack")) |
9cf6d335 SV |
506 | die("packfile name '%s' does not end with '.pack'", |
507 | pack_name); | |
6689f087 | 508 | index_name_buf = xmalloc(len); |
9cf6d335 SV |
509 | memcpy(index_name_buf, pack_name, len - 5); |
510 | strcpy(index_name_buf + len - 5, ".idx"); | |
511 | index_name = index_name_buf; | |
512 | } | |
513 | ||
514 | open_pack_file(); | |
515 | parse_pack_header(); | |
516 | objects = xcalloc(nr_objects, sizeof(struct object_entry)); | |
517 | deltas = xcalloc(nr_objects, sizeof(struct delta_entry)); | |
518 | parse_pack_objects(); | |
519 | free(deltas); | |
84c8d8ae | 520 | write_index_file(index_name, sha1); |
9cf6d335 SV |
521 | free(objects); |
522 | free(index_name_buf); | |
523 | ||
84c8d8ae JH |
524 | printf("%s\n", sha1_to_hex(sha1)); |
525 | ||
9cf6d335 SV |
526 | return 0; |
527 | } |