t: make 'test_i18ngrep' more informative on failure
[git/git.git] / builtin / unpack-objects.c
1 #include "builtin.h"
2 #include "cache.h"
3 #include "config.h"
4 #include "object.h"
5 #include "delta.h"
6 #include "pack.h"
7 #include "blob.h"
8 #include "commit.h"
9 #include "tag.h"
10 #include "tree.h"
11 #include "tree-walk.h"
12 #include "progress.h"
13 #include "decorate.h"
14 #include "fsck.h"
15
16 static int dry_run, quiet, recover, has_errors, strict;
17 static const char unpack_usage[] = "git unpack-objects [-n] [-q] [-r] [--strict]";
18
19 /* We always read in 4kB chunks. */
20 static unsigned char buffer[4096];
21 static unsigned int offset, len;
22 static off_t consumed_bytes;
23 static off_t max_input_size;
24 static git_SHA_CTX ctx;
25 static struct fsck_options fsck_options = FSCK_OPTIONS_STRICT;
26
27 /*
28 * When running under --strict mode, objects whose reachability are
29 * suspect are kept in core without getting written in the object
30 * store.
31 */
32 struct obj_buffer {
33 char *buffer;
34 unsigned long size;
35 };
36
37 static struct decoration obj_decorate;
38
39 static struct obj_buffer *lookup_object_buffer(struct object *base)
40 {
41 return lookup_decoration(&obj_decorate, base);
42 }
43
44 static void add_object_buffer(struct object *object, char *buffer, unsigned long size)
45 {
46 struct obj_buffer *obj;
47 obj = xcalloc(1, sizeof(struct obj_buffer));
48 obj->buffer = buffer;
49 obj->size = size;
50 if (add_decoration(&obj_decorate, object, obj))
51 die("object %s tried to add buffer twice!", oid_to_hex(&object->oid));
52 }
53
54 /*
55 * Make sure at least "min" bytes are available in the buffer, and
56 * return the pointer to the buffer.
57 */
58 static void *fill(int min)
59 {
60 if (min <= len)
61 return buffer + offset;
62 if (min > sizeof(buffer))
63 die("cannot fill %d bytes", min);
64 if (offset) {
65 git_SHA1_Update(&ctx, buffer, offset);
66 memmove(buffer, buffer + offset, len);
67 offset = 0;
68 }
69 do {
70 ssize_t ret = xread(0, buffer + len, sizeof(buffer) - len);
71 if (ret <= 0) {
72 if (!ret)
73 die("early EOF");
74 die_errno("read error on input");
75 }
76 len += ret;
77 } while (len < min);
78 return buffer;
79 }
80
81 static void use(int bytes)
82 {
83 if (bytes > len)
84 die("used more bytes than were available");
85 len -= bytes;
86 offset += bytes;
87
88 /* make sure off_t is sufficiently large not to wrap */
89 if (signed_add_overflows(consumed_bytes, bytes))
90 die("pack too large for current definition of off_t");
91 consumed_bytes += bytes;
92 if (max_input_size && consumed_bytes > max_input_size)
93 die(_("pack exceeds maximum allowed size"));
94 }
95
96 static void *get_data(unsigned long size)
97 {
98 git_zstream stream;
99 void *buf = xmallocz(size);
100
101 memset(&stream, 0, sizeof(stream));
102
103 stream.next_out = buf;
104 stream.avail_out = size;
105 stream.next_in = fill(1);
106 stream.avail_in = len;
107 git_inflate_init(&stream);
108
109 for (;;) {
110 int ret = git_inflate(&stream, 0);
111 use(len - stream.avail_in);
112 if (stream.total_out == size && ret == Z_STREAM_END)
113 break;
114 if (ret != Z_OK) {
115 error("inflate returned %d", ret);
116 FREE_AND_NULL(buf);
117 if (!recover)
118 exit(1);
119 has_errors = 1;
120 break;
121 }
122 stream.next_in = fill(1);
123 stream.avail_in = len;
124 }
125 git_inflate_end(&stream);
126 return buf;
127 }
128
129 struct delta_info {
130 struct object_id base_oid;
131 unsigned nr;
132 off_t base_offset;
133 unsigned long size;
134 void *delta;
135 struct delta_info *next;
136 };
137
138 static struct delta_info *delta_list;
139
140 static void add_delta_to_list(unsigned nr, const struct object_id *base_oid,
141 off_t base_offset,
142 void *delta, unsigned long size)
143 {
144 struct delta_info *info = xmalloc(sizeof(*info));
145
146 oidcpy(&info->base_oid, base_oid);
147 info->base_offset = base_offset;
148 info->size = size;
149 info->delta = delta;
150 info->nr = nr;
151 info->next = delta_list;
152 delta_list = info;
153 }
154
155 struct obj_info {
156 off_t offset;
157 struct object_id oid;
158 struct object *obj;
159 };
160
161 #define FLAG_OPEN (1u<<20)
162 #define FLAG_WRITTEN (1u<<21)
163
164 static struct obj_info *obj_list;
165 static unsigned nr_objects;
166
167 /*
168 * Called only from check_object() after it verified this object
169 * is Ok.
170 */
171 static void write_cached_object(struct object *obj, struct obj_buffer *obj_buf)
172 {
173 struct object_id oid;
174
175 if (write_sha1_file(obj_buf->buffer, obj_buf->size, typename(obj->type), oid.hash) < 0)
176 die("failed to write object %s", oid_to_hex(&obj->oid));
177 obj->flags |= FLAG_WRITTEN;
178 }
179
180 /*
181 * At the very end of the processing, write_rest() scans the objects
182 * that have reachability requirements and calls this function.
183 * Verify its reachability and validity recursively and write it out.
184 */
185 static int check_object(struct object *obj, int type, void *data, struct fsck_options *options)
186 {
187 struct obj_buffer *obj_buf;
188
189 if (!obj)
190 return 1;
191
192 if (obj->flags & FLAG_WRITTEN)
193 return 0;
194
195 if (type != OBJ_ANY && obj->type != type)
196 die("object type mismatch");
197
198 if (!(obj->flags & FLAG_OPEN)) {
199 unsigned long size;
200 int type = sha1_object_info(obj->oid.hash, &size);
201 if (type != obj->type || type <= 0)
202 die("object of unexpected type");
203 obj->flags |= FLAG_WRITTEN;
204 return 0;
205 }
206
207 obj_buf = lookup_object_buffer(obj);
208 if (!obj_buf)
209 die("Whoops! Cannot find object '%s'", oid_to_hex(&obj->oid));
210 if (fsck_object(obj, obj_buf->buffer, obj_buf->size, &fsck_options))
211 die("Error in object");
212 fsck_options.walk = check_object;
213 if (fsck_walk(obj, NULL, &fsck_options))
214 die("Error on reachable objects of %s", oid_to_hex(&obj->oid));
215 write_cached_object(obj, obj_buf);
216 return 0;
217 }
218
219 static void write_rest(void)
220 {
221 unsigned i;
222 for (i = 0; i < nr_objects; i++) {
223 if (obj_list[i].obj)
224 check_object(obj_list[i].obj, OBJ_ANY, NULL, NULL);
225 }
226 }
227
228 static void added_object(unsigned nr, enum object_type type,
229 void *data, unsigned long size);
230
231 /*
232 * Write out nr-th object from the list, now we know the contents
233 * of it. Under --strict, this buffers structured objects in-core,
234 * to be checked at the end.
235 */
236 static void write_object(unsigned nr, enum object_type type,
237 void *buf, unsigned long size)
238 {
239 if (!strict) {
240 if (write_sha1_file(buf, size, typename(type), obj_list[nr].oid.hash) < 0)
241 die("failed to write object");
242 added_object(nr, type, buf, size);
243 free(buf);
244 obj_list[nr].obj = NULL;
245 } else if (type == OBJ_BLOB) {
246 struct blob *blob;
247 if (write_sha1_file(buf, size, typename(type), obj_list[nr].oid.hash) < 0)
248 die("failed to write object");
249 added_object(nr, type, buf, size);
250 free(buf);
251
252 blob = lookup_blob(&obj_list[nr].oid);
253 if (blob)
254 blob->object.flags |= FLAG_WRITTEN;
255 else
256 die("invalid blob object");
257 obj_list[nr].obj = NULL;
258 } else {
259 struct object *obj;
260 int eaten;
261 hash_sha1_file(buf, size, typename(type), obj_list[nr].oid.hash);
262 added_object(nr, type, buf, size);
263 obj = parse_object_buffer(&obj_list[nr].oid, type, size, buf,
264 &eaten);
265 if (!obj)
266 die("invalid %s", typename(type));
267 add_object_buffer(obj, buf, size);
268 obj->flags |= FLAG_OPEN;
269 obj_list[nr].obj = obj;
270 }
271 }
272
273 static void resolve_delta(unsigned nr, enum object_type type,
274 void *base, unsigned long base_size,
275 void *delta, unsigned long delta_size)
276 {
277 void *result;
278 unsigned long result_size;
279
280 result = patch_delta(base, base_size,
281 delta, delta_size,
282 &result_size);
283 if (!result)
284 die("failed to apply delta");
285 free(delta);
286 write_object(nr, type, result, result_size);
287 }
288
289 /*
290 * We now know the contents of an object (which is nr-th in the pack);
291 * resolve all the deltified objects that are based on it.
292 */
293 static void added_object(unsigned nr, enum object_type type,
294 void *data, unsigned long size)
295 {
296 struct delta_info **p = &delta_list;
297 struct delta_info *info;
298
299 while ((info = *p) != NULL) {
300 if (!oidcmp(&info->base_oid, &obj_list[nr].oid) ||
301 info->base_offset == obj_list[nr].offset) {
302 *p = info->next;
303 p = &delta_list;
304 resolve_delta(info->nr, type, data, size,
305 info->delta, info->size);
306 free(info);
307 continue;
308 }
309 p = &info->next;
310 }
311 }
312
313 static void unpack_non_delta_entry(enum object_type type, unsigned long size,
314 unsigned nr)
315 {
316 void *buf = get_data(size);
317
318 if (!dry_run && buf)
319 write_object(nr, type, buf, size);
320 else
321 free(buf);
322 }
323
324 static int resolve_against_held(unsigned nr, const struct object_id *base,
325 void *delta_data, unsigned long delta_size)
326 {
327 struct object *obj;
328 struct obj_buffer *obj_buffer;
329 obj = lookup_object(base->hash);
330 if (!obj)
331 return 0;
332 obj_buffer = lookup_object_buffer(obj);
333 if (!obj_buffer)
334 return 0;
335 resolve_delta(nr, obj->type, obj_buffer->buffer,
336 obj_buffer->size, delta_data, delta_size);
337 return 1;
338 }
339
340 static void unpack_delta_entry(enum object_type type, unsigned long delta_size,
341 unsigned nr)
342 {
343 void *delta_data, *base;
344 unsigned long base_size;
345 struct object_id base_oid;
346
347 if (type == OBJ_REF_DELTA) {
348 hashcpy(base_oid.hash, fill(GIT_SHA1_RAWSZ));
349 use(GIT_SHA1_RAWSZ);
350 delta_data = get_data(delta_size);
351 if (dry_run || !delta_data) {
352 free(delta_data);
353 return;
354 }
355 if (has_object_file(&base_oid))
356 ; /* Ok we have this one */
357 else if (resolve_against_held(nr, &base_oid,
358 delta_data, delta_size))
359 return; /* we are done */
360 else {
361 /* cannot resolve yet --- queue it */
362 oidclr(&obj_list[nr].oid);
363 add_delta_to_list(nr, &base_oid, 0, delta_data, delta_size);
364 return;
365 }
366 } else {
367 unsigned base_found = 0;
368 unsigned char *pack, c;
369 off_t base_offset;
370 unsigned lo, mid, hi;
371
372 pack = fill(1);
373 c = *pack;
374 use(1);
375 base_offset = c & 127;
376 while (c & 128) {
377 base_offset += 1;
378 if (!base_offset || MSB(base_offset, 7))
379 die("offset value overflow for delta base object");
380 pack = fill(1);
381 c = *pack;
382 use(1);
383 base_offset = (base_offset << 7) + (c & 127);
384 }
385 base_offset = obj_list[nr].offset - base_offset;
386 if (base_offset <= 0 || base_offset >= obj_list[nr].offset)
387 die("offset value out of bound for delta base object");
388
389 delta_data = get_data(delta_size);
390 if (dry_run || !delta_data) {
391 free(delta_data);
392 return;
393 }
394 lo = 0;
395 hi = nr;
396 while (lo < hi) {
397 mid = lo + (hi - lo) / 2;
398 if (base_offset < obj_list[mid].offset) {
399 hi = mid;
400 } else if (base_offset > obj_list[mid].offset) {
401 lo = mid + 1;
402 } else {
403 oidcpy(&base_oid, &obj_list[mid].oid);
404 base_found = !is_null_oid(&base_oid);
405 break;
406 }
407 }
408 if (!base_found) {
409 /*
410 * The delta base object is itself a delta that
411 * has not been resolved yet.
412 */
413 oidclr(&obj_list[nr].oid);
414 add_delta_to_list(nr, &null_oid, base_offset, delta_data, delta_size);
415 return;
416 }
417 }
418
419 if (resolve_against_held(nr, &base_oid, delta_data, delta_size))
420 return;
421
422 base = read_sha1_file(base_oid.hash, &type, &base_size);
423 if (!base) {
424 error("failed to read delta-pack base object %s",
425 oid_to_hex(&base_oid));
426 if (!recover)
427 exit(1);
428 has_errors = 1;
429 return;
430 }
431 resolve_delta(nr, type, base, base_size, delta_data, delta_size);
432 free(base);
433 }
434
435 static void unpack_one(unsigned nr)
436 {
437 unsigned shift;
438 unsigned char *pack;
439 unsigned long size, c;
440 enum object_type type;
441
442 obj_list[nr].offset = consumed_bytes;
443
444 pack = fill(1);
445 c = *pack;
446 use(1);
447 type = (c >> 4) & 7;
448 size = (c & 15);
449 shift = 4;
450 while (c & 0x80) {
451 pack = fill(1);
452 c = *pack;
453 use(1);
454 size += (c & 0x7f) << shift;
455 shift += 7;
456 }
457
458 switch (type) {
459 case OBJ_COMMIT:
460 case OBJ_TREE:
461 case OBJ_BLOB:
462 case OBJ_TAG:
463 unpack_non_delta_entry(type, size, nr);
464 return;
465 case OBJ_REF_DELTA:
466 case OBJ_OFS_DELTA:
467 unpack_delta_entry(type, size, nr);
468 return;
469 default:
470 error("bad object type %d", type);
471 has_errors = 1;
472 if (recover)
473 return;
474 exit(1);
475 }
476 }
477
478 static void unpack_all(void)
479 {
480 int i;
481 struct progress *progress = NULL;
482 struct pack_header *hdr = fill(sizeof(struct pack_header));
483
484 nr_objects = ntohl(hdr->hdr_entries);
485
486 if (ntohl(hdr->hdr_signature) != PACK_SIGNATURE)
487 die("bad pack file");
488 if (!pack_version_ok(hdr->hdr_version))
489 die("unknown pack file version %"PRIu32,
490 ntohl(hdr->hdr_version));
491 use(sizeof(struct pack_header));
492
493 if (!quiet)
494 progress = start_progress(_("Unpacking objects"), nr_objects);
495 obj_list = xcalloc(nr_objects, sizeof(*obj_list));
496 for (i = 0; i < nr_objects; i++) {
497 unpack_one(i);
498 display_progress(progress, i + 1);
499 }
500 stop_progress(&progress);
501
502 if (delta_list)
503 die("unresolved deltas left after unpacking");
504 }
505
506 int cmd_unpack_objects(int argc, const char **argv, const char *prefix)
507 {
508 int i;
509 struct object_id oid;
510
511 check_replace_refs = 0;
512
513 git_config(git_default_config, NULL);
514
515 quiet = !isatty(2);
516
517 for (i = 1 ; i < argc; i++) {
518 const char *arg = argv[i];
519
520 if (*arg == '-') {
521 if (!strcmp(arg, "-n")) {
522 dry_run = 1;
523 continue;
524 }
525 if (!strcmp(arg, "-q")) {
526 quiet = 1;
527 continue;
528 }
529 if (!strcmp(arg, "-r")) {
530 recover = 1;
531 continue;
532 }
533 if (!strcmp(arg, "--strict")) {
534 strict = 1;
535 continue;
536 }
537 if (skip_prefix(arg, "--strict=", &arg)) {
538 strict = 1;
539 fsck_set_msg_types(&fsck_options, arg);
540 continue;
541 }
542 if (starts_with(arg, "--pack_header=")) {
543 struct pack_header *hdr;
544 char *c;
545
546 hdr = (struct pack_header *)buffer;
547 hdr->hdr_signature = htonl(PACK_SIGNATURE);
548 hdr->hdr_version = htonl(strtoul(arg + 14, &c, 10));
549 if (*c != ',')
550 die("bad %s", arg);
551 hdr->hdr_entries = htonl(strtoul(c + 1, &c, 10));
552 if (*c)
553 die("bad %s", arg);
554 len = sizeof(*hdr);
555 continue;
556 }
557 if (skip_prefix(arg, "--max-input-size=", &arg)) {
558 max_input_size = strtoumax(arg, NULL, 10);
559 continue;
560 }
561 usage(unpack_usage);
562 }
563
564 /* We don't take any non-flag arguments now.. Maybe some day */
565 usage(unpack_usage);
566 }
567 git_SHA1_Init(&ctx);
568 unpack_all();
569 git_SHA1_Update(&ctx, buffer, offset);
570 git_SHA1_Final(oid.hash, &ctx);
571 if (strict)
572 write_rest();
573 if (hashcmp(fill(GIT_SHA1_RAWSZ), oid.hash))
574 die("final sha1 did not match");
575 use(GIT_SHA1_RAWSZ);
576
577 /* Write the last part of the buffer to stdout */
578 while (len) {
579 int ret = xwrite(1, buffer + offset, len);
580 if (ret <= 0)
581 break;
582 len -= ret;
583 offset += ret;
584 }
585
586 /* All done */
587 return has_errors;
588 }