a4be4a65670600c6c412ef6d9b51713899cfab2a
1#include "builtin.h"
2#include "delta.h"
3#include "pack.h"
4#include "csum-file.h"
5#include "blob.h"
6#include "commit.h"
7#include "tag.h"
8#include "tree.h"
9#include "progress.h"
10#include "fsck.h"
11#include "exec_cmd.h"
12static const char index_pack_usage[] =
14"git index-pack [-v] [-o <index-file>] [--keep | --keep=<msg>] [--verify] [--strict] (<pack-file> | --stdin [--fix-thin] [<pack-file>])";
15struct object_entry {
17 struct pack_idx_entry idx;
18 unsigned long size;
19 unsigned int hdr_size;
20 enum object_type type;
21 enum object_type real_type;
22 unsigned delta_depth;
23 int base_object_no;
24};
25union delta_base {
27 unsigned char sha1[20];
28 off_t offset;
29};
30struct base_data {
32 struct base_data *base;
33 struct base_data *child;
34 struct object_entry *obj;
35 void *data;
36 unsigned long size;
37 int ref_first, ref_last;
38 int ofs_first, ofs_last;
39};
40/*
42 * Even if sizeof(union delta_base) == 24 on 64-bit archs, we really want
43 * to memcmp() only the first 20 bytes.
44 */
45#define UNION_BASE_SZ 20
46#define FLAG_LINK (1u<<20)
48#define FLAG_CHECKED (1u<<21)
49struct delta_entry {
51 union delta_base base;
52 int obj_no;
53};
54static struct object_entry *objects;
56static struct delta_entry *deltas;
57static struct base_data *base_cache;
58static size_t base_cache_used;
59static int nr_objects;
60static int nr_deltas;
61static int nr_resolved_deltas;
62static int from_stdin;
64static int strict;
65static int verbose;
66static struct progress *progress;
68/* We always read in 4kB chunks. */
70static unsigned char input_buffer[4096];
71static unsigned int input_offset, input_len;
72static off_t consumed_bytes;
73static unsigned deepest_delta;
74static git_SHA_CTX input_ctx;
75static uint32_t input_crc32;
76static int input_fd, output_fd, pack_fd;
77static int mark_link(struct object *obj, int type, void *data)
79{
80 if (!obj)
81 return -1;
82 if (type != OBJ_ANY && obj->type != type)
84 die("object type mismatch at %s", sha1_to_hex(obj->sha1));
85 obj->flags |= FLAG_LINK;
87 return 0;
88}
89/* The content of each linked object must have been checked
91 or it must be already present in the object database */
92static void check_object(struct object *obj)
93{
94 if (!obj)
95 return;
96 if (!(obj->flags & FLAG_LINK))
98 return;
99 if (!(obj->flags & FLAG_CHECKED)) {
101 unsigned long size;
102 int type = sha1_object_info(obj->sha1, &size);
103 if (type != obj->type || type <= 0)
104 die("object of unexpected type");
105 obj->flags |= FLAG_CHECKED;
106 return;
107 }
108}
109static void check_objects(void)
111{
112 unsigned i, max;
113 max = get_max_object_index();
115 for (i = 0; i < max; i++)
116 check_object(get_indexed_object(i));
117}
118/* Discard current buffer used content. */
121static void flush(void)
122{
123 if (input_offset) {
124 if (output_fd >= 0)
125 write_or_die(output_fd, input_buffer, input_offset);
126 git_SHA1_Update(&input_ctx, input_buffer, input_offset);
127 memmove(input_buffer, input_buffer + input_offset, input_len);
128 input_offset = 0;
129 }
130}
131/*
133 * Make sure at least "min" bytes are available in the buffer, and
134 * return the pointer to the buffer.
135 */
136static void *fill(int min)
137{
138 if (min <= input_len)
139 return input_buffer + input_offset;
140 if (min > sizeof(input_buffer))
141 die("cannot fill %d bytes", min);
142 flush();
143 do {
144 ssize_t ret = xread(input_fd, input_buffer + input_len,
145 sizeof(input_buffer) - input_len);
146 if (ret <= 0) {
147 if (!ret)
148 die("early EOF");
149 die_errno("read error on input");
150 }
151 input_len += ret;
152 if (from_stdin)
153 display_throughput(progress, consumed_bytes + input_len);
154 } while (input_len < min);
155 return input_buffer;
156}
157static void use(int bytes)
159{
160 if (bytes > input_len)
161 die("used more bytes than were available");
162 input_crc32 = crc32(input_crc32, input_buffer + input_offset, bytes);
163 input_len -= bytes;
164 input_offset += bytes;
165 /* make sure off_t is sufficiently large not to wrap */
167 if (signed_add_overflows(consumed_bytes, bytes))
168 die("pack too large for current definition of off_t");
169 consumed_bytes += bytes;
170}
171static const char *open_pack_file(const char *pack_name)
173{
174 if (from_stdin) {
175 input_fd = 0;
176 if (!pack_name) {
177 static char tmp_file[PATH_MAX];
178 output_fd = odb_mkstemp(tmp_file, sizeof(tmp_file),
179 "pack/tmp_pack_XXXXXX");
180 pack_name = xstrdup(tmp_file);
181 } else
182 output_fd = open(pack_name, O_CREAT|O_EXCL|O_RDWR, 0600);
183 if (output_fd < 0)
184 die_errno("unable to create '%s'", pack_name);
185 pack_fd = output_fd;
186 } else {
187 input_fd = open(pack_name, O_RDONLY);
188 if (input_fd < 0)
189 die_errno("cannot open packfile '%s'", pack_name);
190 output_fd = -1;
191 pack_fd = input_fd;
192 }
193 git_SHA1_Init(&input_ctx);
194 return pack_name;
195}
196static void parse_pack_header(void)
198{
199 struct pack_header *hdr = fill(sizeof(struct pack_header));
200 /* Header consistency check */
202 if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
203 die("pack signature mismatch");
204 if (!pack_version_ok(hdr->hdr_version))
205 die("pack version %"PRIu32" unsupported",
206 ntohl(hdr->hdr_version));
207 nr_objects = ntohl(hdr->hdr_entries);
209 use(sizeof(struct pack_header));
210}
211static NORETURN void bad_object(unsigned long offset, const char *format,
213 ...) __attribute__((format (printf, 2, 3)));
214static NORETURN void bad_object(unsigned long offset, const char *format, ...)
216{
217 va_list params;
218 char buf[1024];
219 va_start(params, format);
221 vsnprintf(buf, sizeof(buf), format, params);
222 va_end(params);
223 die("pack has bad object at offset %lu: %s", offset, buf);
224}
225static struct base_data *alloc_base_data(void)
227{
228 struct base_data *base = xmalloc(sizeof(struct base_data));
229 memset(base, 0, sizeof(*base));
230 base->ref_last = -1;
231 base->ofs_last = -1;
232 return base;
233}
234static void free_base_data(struct base_data *c)
236{
237 if (c->data) {
238 free(c->data);
239 c->data = NULL;
240 base_cache_used -= c->size;
241 }
242}
243static void prune_base_data(struct base_data *retain)
245{
246 struct base_data *b;
247 for (b = base_cache;
248 base_cache_used > delta_base_cache_limit && b;
249 b = b->child) {
250 if (b->data && b != retain)
251 free_base_data(b);
252 }
253}
254static void link_base_data(struct base_data *base, struct base_data *c)
256{
257 if (base)
258 base->child = c;
259 else
260 base_cache = c;
261 c->base = base;
263 c->child = NULL;
264 if (c->data)
265 base_cache_used += c->size;
266 prune_base_data(c);
267}
268static void unlink_base_data(struct base_data *c)
270{
271 struct base_data *base = c->base;
272 if (base)
273 base->child = NULL;
274 else
275 base_cache = NULL;
276 free_base_data(c);
277}
278static void *unpack_entry_data(unsigned long offset, unsigned long size)
280{
281 int status;
282 git_zstream stream;
283 void *buf = xmalloc(size);
284 memset(&stream, 0, sizeof(stream));
286 git_inflate_init(&stream);
287 stream.next_out = buf;
288 stream.avail_out = size;
289 do {
291 stream.next_in = fill(1);
292 stream.avail_in = input_len;
293 status = git_inflate(&stream, 0);
294 use(input_len - stream.avail_in);
295 } while (status == Z_OK);
296 if (stream.total_out != size || status != Z_STREAM_END)
297 bad_object(offset, "inflate returned %d", status);
298 git_inflate_end(&stream);
299 return buf;
300}
301static void *unpack_raw_entry(struct object_entry *obj, union delta_base *delta_base)
303{
304 unsigned char *p;
305 unsigned long size, c;
306 off_t base_offset;
307 unsigned shift;
308 void *data;
309 obj->idx.offset = consumed_bytes;
311 input_crc32 = crc32(0, NULL, 0);
312 p = fill(1);
314 c = *p;
315 use(1);
316 obj->type = (c >> 4) & 7;
317 size = (c & 15);
318 shift = 4;
319 while (c & 0x80) {
320 p = fill(1);
321 c = *p;
322 use(1);
323 size += (c & 0x7f) << shift;
324 shift += 7;
325 }
326 obj->size = size;
327 switch (obj->type) {
329 case OBJ_REF_DELTA:
330 hashcpy(delta_base->sha1, fill(20));
331 use(20);
332 break;
333 case OBJ_OFS_DELTA:
334 memset(delta_base, 0, sizeof(*delta_base));
335 p = fill(1);
336 c = *p;
337 use(1);
338 base_offset = c & 127;
339 while (c & 128) {
340 base_offset += 1;
341 if (!base_offset || MSB(base_offset, 7))
342 bad_object(obj->idx.offset, "offset value overflow for delta base object");
343 p = fill(1);
344 c = *p;
345 use(1);
346 base_offset = (base_offset << 7) + (c & 127);
347 }
348 delta_base->offset = obj->idx.offset - base_offset;
349 if (delta_base->offset <= 0 || delta_base->offset >= obj->idx.offset)
350 bad_object(obj->idx.offset, "delta base offset is out of bound");
351 break;
352 case OBJ_COMMIT:
353 case OBJ_TREE:
354 case OBJ_BLOB:
355 case OBJ_TAG:
356 break;
357 default:
358 bad_object(obj->idx.offset, "unknown object type %d", obj->type);
359 }
360 obj->hdr_size = consumed_bytes - obj->idx.offset;
361 data = unpack_entry_data(obj->idx.offset, obj->size);
363 obj->idx.crc32 = input_crc32;
364 return data;
365}
366static void *get_data_from_pack(struct object_entry *obj)
368{
369 off_t from = obj[0].idx.offset + obj[0].hdr_size;
370 unsigned long len = obj[1].idx.offset - from;
371 unsigned char *data, *inbuf;
372 git_zstream stream;
373 int status;
374 data = xmalloc(obj->size);
376 inbuf = xmalloc((len < 64*1024) ? len : 64*1024);
377 memset(&stream, 0, sizeof(stream));
379 git_inflate_init(&stream);
380 stream.next_out = data;
381 stream.avail_out = obj->size;
382 do {
384 ssize_t n = (len < 64*1024) ? len : 64*1024;
385 n = pread(pack_fd, inbuf, n, from);
386 if (n < 0)
387 die_errno("cannot pread pack file");
388 if (!n)
389 die("premature end of pack file, %lu bytes missing", len);
390 from += n;
391 len -= n;
392 stream.next_in = inbuf;
393 stream.avail_in = n;
394 status = git_inflate(&stream, 0);
395 } while (len && status == Z_OK && !stream.avail_in);
396 /* This has been inflated OK when first encountered, so... */
398 if (status != Z_STREAM_END || stream.total_out != obj->size)
399 die("serious inflate inconsistency");
400 git_inflate_end(&stream);
402 free(inbuf);
403 return data;
404}
405static int compare_delta_bases(const union delta_base *base1,
407 const union delta_base *base2,
408 enum object_type type1,
409 enum object_type type2)
410{
411 int cmp = type1 - type2;
412 if (cmp)
413 return cmp;
414 return memcmp(base1, base2, UNION_BASE_SZ);
415}
416static int find_delta(const union delta_base *base, enum object_type type)
418{
419 int first = 0, last = nr_deltas;
420 while (first < last) {
422 int next = (first + last) / 2;
423 struct delta_entry *delta = &deltas[next];
424 int cmp;
425 cmp = compare_delta_bases(base, &delta->base,
427 type, objects[delta->obj_no].type);
428 if (!cmp)
429 return next;
430 if (cmp < 0) {
431 last = next;
432 continue;
433 }
434 first = next+1;
435 }
436 return -first-1;
437}
438static void find_delta_children(const union delta_base *base,
440 int *first_index, int *last_index,
441 enum object_type type)
442{
443 int first = find_delta(base, type);
444 int last = first;
445 int end = nr_deltas - 1;
446 if (first < 0) {
448 *first_index = 0;
449 *last_index = -1;
450 return;
451 }
452 while (first > 0 && !memcmp(&deltas[first - 1].base, base, UNION_BASE_SZ))
453 --first;
454 while (last < end && !memcmp(&deltas[last + 1].base, base, UNION_BASE_SZ))
455 ++last;
456 *first_index = first;
457 *last_index = last;
458}
459static void sha1_object(const void *data, unsigned long size,
461 enum object_type type, unsigned char *sha1)
462{
463 hash_sha1_file(data, size, typename(type), sha1);
464 if (has_sha1_file(sha1)) {
465 void *has_data;
466 enum object_type has_type;
467 unsigned long has_size;
468 has_data = read_sha1_file(sha1, &has_type, &has_size);
469 if (!has_data)
470 die("cannot read existing object %s", sha1_to_hex(sha1));
471 if (size != has_size || type != has_type ||
472 memcmp(data, has_data, size) != 0)
473 die("SHA1 COLLISION FOUND WITH %s !", sha1_to_hex(sha1));
474 free(has_data);
475 }
476 if (strict) {
477 if (type == OBJ_BLOB) {
478 struct blob *blob = lookup_blob(sha1);
479 if (blob)
480 blob->object.flags |= FLAG_CHECKED;
481 else
482 die("invalid blob object %s", sha1_to_hex(sha1));
483 } else {
484 struct object *obj;
485 int eaten;
486 void *buf = (void *) data;
487 /*
489 * we do not need to free the memory here, as the
490 * buf is deleted by the caller.
491 */
492 obj = parse_object_buffer(sha1, type, size, buf, &eaten);
493 if (!obj)
494 die("invalid %s", typename(type));
495 if (fsck_object(obj, 1, fsck_error_function))
496 die("Error in object");
497 if (fsck_walk(obj, mark_link, NULL))
498 die("Not all child objects of %s are reachable", sha1_to_hex(obj->sha1));
499 if (obj->type == OBJ_TREE) {
501 struct tree *item = (struct tree *) obj;
502 item->buffer = NULL;
503 }
504 if (obj->type == OBJ_COMMIT) {
505 struct commit *commit = (struct commit *) obj;
506 commit->buffer = NULL;
507 }
508 obj->flags |= FLAG_CHECKED;
509 }
510 }
511}
512static int is_delta_type(enum object_type type)
514{
515 return (type == OBJ_REF_DELTA || type == OBJ_OFS_DELTA);
516}
517/*
519 * This function is part of find_unresolved_deltas(). There are two
520 * walkers going in the opposite ways.
521 *
522 * The first one in find_unresolved_deltas() traverses down from
523 * parent node to children, deflating nodes along the way. However,
524 * memory for deflated nodes is limited by delta_base_cache_limit, so
525 * at some point parent node's deflated content may be freed.
526 *
527 * The second walker is this function, which goes from current node up
528 * to top parent if necessary to deflate the node. In normal
529 * situation, its parent node would be already deflated, so it just
530 * needs to apply delta.
531 *
532 * In the worst case scenario, parent node is no longer deflated because
533 * we're running out of delta_base_cache_limit; we need to re-deflate
534 * parents, possibly up to the top base.
535 *
536 * All deflated objects here are subject to be freed if we exceed
537 * delta_base_cache_limit, just like in find_unresolved_deltas(), we
538 * just need to make sure the last node is not freed.
539 */
540static void *get_base_data(struct base_data *c)
541{
542 if (!c->data) {
543 struct object_entry *obj = c->obj;
544 struct base_data **delta = NULL;
545 int delta_nr = 0, delta_alloc = 0;
546 while (is_delta_type(c->obj->type) && !c->data) {
548 ALLOC_GROW(delta, delta_nr + 1, delta_alloc);
549 delta[delta_nr++] = c;
550 c = c->base;
551 }
552 if (!delta_nr) {
553 c->data = get_data_from_pack(obj);
554 c->size = obj->size;
555 base_cache_used += c->size;
556 prune_base_data(c);
557 }
558 for (; delta_nr > 0; delta_nr--) {
559 void *base, *raw;
560 c = delta[delta_nr - 1];
561 obj = c->obj;
562 base = get_base_data(c->base);
563 raw = get_data_from_pack(obj);
564 c->data = patch_delta(
565 base, c->base->size,
566 raw, obj->size,
567 &c->size);
568 free(raw);
569 if (!c->data)
570 bad_object(obj->idx.offset, "failed to apply delta");
571 base_cache_used += c->size;
572 prune_base_data(c);
573 }
574 free(delta);
575 }
576 return c->data;
577}
578static void resolve_delta(struct object_entry *delta_obj,
580 struct base_data *base, struct base_data *result)
581{
582 void *base_data, *delta_data;
583 delta_obj->real_type = base->obj->real_type;
585 delta_obj->delta_depth = base->obj->delta_depth + 1;
586 if (deepest_delta < delta_obj->delta_depth)
587 deepest_delta = delta_obj->delta_depth;
588 delta_obj->base_object_no = base->obj - objects;
589 delta_data = get_data_from_pack(delta_obj);
590 base_data = get_base_data(base);
591 result->obj = delta_obj;
592 result->data = patch_delta(base_data, base->size,
593 delta_data, delta_obj->size, &result->size);
594 free(delta_data);
595 if (!result->data)
596 bad_object(delta_obj->idx.offset, "failed to apply delta");
597 sha1_object(result->data, result->size, delta_obj->real_type,
598 delta_obj->idx.sha1);
599 nr_resolved_deltas++;
600}
601static struct base_data *find_unresolved_deltas_1(struct base_data *base,
603 struct base_data *prev_base)
604{
605 if (base->ref_last == -1 && base->ofs_last == -1) {
606 union delta_base base_spec;
607 hashcpy(base_spec.sha1, base->obj->idx.sha1);
609 find_delta_children(&base_spec,
610 &base->ref_first, &base->ref_last, OBJ_REF_DELTA);
611 memset(&base_spec, 0, sizeof(base_spec));
613 base_spec.offset = base->obj->idx.offset;
614 find_delta_children(&base_spec,
615 &base->ofs_first, &base->ofs_last, OBJ_OFS_DELTA);
616 if (base->ref_last == -1 && base->ofs_last == -1) {
618 free(base->data);
619 return NULL;
620 }
621 link_base_data(prev_base, base);
623 }
624 if (base->ref_first <= base->ref_last) {
626 struct object_entry *child = objects + deltas[base->ref_first].obj_no;
627 struct base_data *result = alloc_base_data();
628 assert(child->real_type == OBJ_REF_DELTA);
630 resolve_delta(child, base, result);
631 if (base->ref_first == base->ref_last && base->ofs_last == -1)
632 free_base_data(base);
633 base->ref_first++;
635 return result;
636 }
637 if (base->ofs_first <= base->ofs_last) {
639 struct object_entry *child = objects + deltas[base->ofs_first].obj_no;
640 struct base_data *result = alloc_base_data();
641 assert(child->real_type == OBJ_OFS_DELTA);
643 resolve_delta(child, base, result);
644 if (base->ofs_first == base->ofs_last)
645 free_base_data(base);
646 base->ofs_first++;
648 return result;
649 }
650 unlink_base_data(base);
652 return NULL;
653}
654static void find_unresolved_deltas(struct base_data *base)
656{
657 struct base_data *new_base, *prev_base = NULL;
658 for (;;) {
659 new_base = find_unresolved_deltas_1(base, prev_base);
660 if (new_base) {
662 prev_base = base;
663 base = new_base;
664 } else {
665 free(base);
666 base = prev_base;
667 if (!base)
668 return;
669 prev_base = base->base;
670 }
671 }
672}
673static int compare_delta_entry(const void *a, const void *b)
675{
676 const struct delta_entry *delta_a = a;
677 const struct delta_entry *delta_b = b;
678 /* group by type (ref vs ofs) and then by value (sha-1 or offset) */
680 return compare_delta_bases(&delta_a->base, &delta_b->base,
681 objects[delta_a->obj_no].type,
682 objects[delta_b->obj_no].type);
683}
684static void resolve_base(struct object_entry *obj)
686{
687 struct base_data *base_obj = alloc_base_data();
688 base_obj->obj = obj;
689 base_obj->data = NULL;
690 find_unresolved_deltas(base_obj);
691}
692/*
694 * First pass:
695 * - find locations of all objects;
696 * - calculate SHA1 of all non-delta objects;
697 * - remember base (SHA1 or offset) for all deltas.
698 */
699static void parse_pack_objects(unsigned char *sha1)
700{
701 int i;
702 struct delta_entry *delta = deltas;
703 struct stat st;
704 if (verbose)
706 progress = start_progress(
707 from_stdin ? "Receiving objects" : "Indexing objects",
708 nr_objects);
709 for (i = 0; i < nr_objects; i++) {
710 struct object_entry *obj = &objects[i];
711 void *data = unpack_raw_entry(obj, &delta->base);
712 obj->real_type = obj->type;
713 if (is_delta_type(obj->type)) {
714 nr_deltas++;
715 delta->obj_no = i;
716 delta++;
717 } else
718 sha1_object(data, obj->size, obj->type, obj->idx.sha1);
719 free(data);
720 display_progress(progress, i+1);
721 }
722 objects[i].idx.offset = consumed_bytes;
723 stop_progress(&progress);
724 /* Check pack integrity */
726 flush();
727 git_SHA1_Final(sha1, &input_ctx);
728 if (hashcmp(fill(20), sha1))
729 die("pack is corrupted (SHA1 mismatch)");
730 use(20);
731 /* If input_fd is a file, we should have reached its end now. */
733 if (fstat(input_fd, &st))
734 die_errno("cannot fstat packfile");
735 if (S_ISREG(st.st_mode) &&
736 lseek(input_fd, 0, SEEK_CUR) - input_len != st.st_size)
737 die("pack has junk at the end");
738}
739/*
741 * Second pass:
742 * - for all non-delta objects, look if it is used as a base for
743 * deltas;
744 * - if used as a base, uncompress the object and apply all deltas,
745 * recursively checking if the resulting object is used as a base
746 * for some more deltas.
747 */
748static void resolve_deltas(void)
749{
750 int i;
751 if (!nr_deltas)
753 return;
754 /* Sort deltas by base SHA1/offset for fast searching */
756 qsort(deltas, nr_deltas, sizeof(struct delta_entry),
757 compare_delta_entry);
758 if (verbose)
760 progress = start_progress("Resolving deltas", nr_deltas);
761 for (i = 0; i < nr_objects; i++) {
762 struct object_entry *obj = &objects[i];
763 if (is_delta_type(obj->type))
765 continue;
766 resolve_base(obj);
767 display_progress(progress, nr_resolved_deltas);
768 }
769}
770/*
772 * Third pass:
773 * - append objects to convert thin pack to full pack if required
774 * - write the final 20-byte SHA-1
775 */
776static void fix_unresolved_deltas(struct sha1file *f, int nr_unresolved);
777static void conclude_pack(int fix_thin_pack, const char *curr_pack, unsigned char *pack_sha1)
778{
779 if (nr_deltas == nr_resolved_deltas) {
780 stop_progress(&progress);
781 /* Flush remaining pack final 20-byte SHA1. */
782 flush();
783 return;
784 }
785 if (fix_thin_pack) {
787 struct sha1file *f;
788 unsigned char read_sha1[20], tail_sha1[20];
789 char msg[48];
790 int nr_unresolved = nr_deltas - nr_resolved_deltas;
791 int nr_objects_initial = nr_objects;
792 if (nr_unresolved <= 0)
793 die("confusion beyond insanity");
794 objects = xrealloc(objects,
795 (nr_objects + nr_unresolved + 1)
796 * sizeof(*objects));
797 f = sha1fd(output_fd, curr_pack);
798 fix_unresolved_deltas(f, nr_unresolved);
799 sprintf(msg, "completed with %d local objects",
800 nr_objects - nr_objects_initial);
801 stop_progress_msg(&progress, msg);
802 sha1close(f, tail_sha1, 0);
803 hashcpy(read_sha1, pack_sha1);
804 fixup_pack_header_footer(output_fd, pack_sha1,
805 curr_pack, nr_objects,
806 read_sha1, consumed_bytes-20);
807 if (hashcmp(read_sha1, tail_sha1) != 0)
808 die("Unexpected tail checksum for %s "
809 "(disk corruption?)", curr_pack);
810 }
811 if (nr_deltas != nr_resolved_deltas)
812 die("pack has %d unresolved deltas",
813 nr_deltas - nr_resolved_deltas);
814}
815static int write_compressed(struct sha1file *f, void *in, unsigned int size)
817{
818 git_zstream stream;
819 int status;
820 unsigned char outbuf[4096];
821 memset(&stream, 0, sizeof(stream));
823 git_deflate_init(&stream, zlib_compression_level);
824 stream.next_in = in;
825 stream.avail_in = size;
826 do {
828 stream.next_out = outbuf;
829 stream.avail_out = sizeof(outbuf);
830 status = git_deflate(&stream, Z_FINISH);
831 sha1write(f, outbuf, sizeof(outbuf) - stream.avail_out);
832 } while (status == Z_OK);
833 if (status != Z_STREAM_END)
835 die("unable to deflate appended object (%d)", status);
836 size = stream.total_out;
837 git_deflate_end(&stream);
838 return size;
839}
840static struct object_entry *append_obj_to_pack(struct sha1file *f,
842 const unsigned char *sha1, void *buf,
843 unsigned long size, enum object_type type)
844{
845 struct object_entry *obj = &objects[nr_objects++];
846 unsigned char header[10];
847 unsigned long s = size;
848 int n = 0;
849 unsigned char c = (type << 4) | (s & 15);
850 s >>= 4;
851 while (s) {
852 header[n++] = c | 0x80;
853 c = s & 0x7f;
854 s >>= 7;
855 }
856 header[n++] = c;
857 crc32_begin(f);
858 sha1write(f, header, n);
859 obj[0].size = size;
860 obj[0].hdr_size = n;
861 obj[0].type = type;
862 obj[0].real_type = type;
863 obj[1].idx.offset = obj[0].idx.offset + n;
864 obj[1].idx.offset += write_compressed(f, buf, size);
865 obj[0].idx.crc32 = crc32_end(f);
866 sha1flush(f);
867 hashcpy(obj->idx.sha1, sha1);
868 return obj;
869}
870static int delta_pos_compare(const void *_a, const void *_b)
872{
873 struct delta_entry *a = *(struct delta_entry **)_a;
874 struct delta_entry *b = *(struct delta_entry **)_b;
875 return a->obj_no - b->obj_no;
876}
877static void fix_unresolved_deltas(struct sha1file *f, int nr_unresolved)
879{
880 struct delta_entry **sorted_by_pos;
881 int i, n = 0;
882 /*
884 * Since many unresolved deltas may well be themselves base objects
885 * for more unresolved deltas, we really want to include the
886 * smallest number of base objects that would cover as much delta
887 * as possible by picking the
888 * trunc deltas first, allowing for other deltas to resolve without
889 * additional base objects. Since most base objects are to be found
890 * before deltas depending on them, a good heuristic is to start
891 * resolving deltas in the same order as their position in the pack.
892 */
893 sorted_by_pos = xmalloc(nr_unresolved * sizeof(*sorted_by_pos));
894 for (i = 0; i < nr_deltas; i++) {
895 if (objects[deltas[i].obj_no].real_type != OBJ_REF_DELTA)
896 continue;
897 sorted_by_pos[n++] = &deltas[i];
898 }
899 qsort(sorted_by_pos, n, sizeof(*sorted_by_pos), delta_pos_compare);
900 for (i = 0; i < n; i++) {
902 struct delta_entry *d = sorted_by_pos[i];
903 enum object_type type;
904 struct base_data *base_obj = alloc_base_data();
905 if (objects[d->obj_no].real_type != OBJ_REF_DELTA)
907 continue;
908 base_obj->data = read_sha1_file(d->base.sha1, &type, &base_obj->size);
909 if (!base_obj->data)
910 continue;
911 if (check_sha1_signature(d->base.sha1, base_obj->data,
913 base_obj->size, typename(type)))
914 die("local object %s is corrupt", sha1_to_hex(d->base.sha1));
915 base_obj->obj = append_obj_to_pack(f, d->base.sha1,
916 base_obj->data, base_obj->size, type);
917 find_unresolved_deltas(base_obj);
918 display_progress(progress, nr_resolved_deltas);
919 }
920 free(sorted_by_pos);
921}
922static void final(const char *final_pack_name, const char *curr_pack_name,
924 const char *final_index_name, const char *curr_index_name,
925 const char *keep_name, const char *keep_msg,
926 unsigned char *sha1)
927{
928 const char *report = "pack";
929 char name[PATH_MAX];
930 int err;
931 if (!from_stdin) {
933 close(input_fd);
934 } else {
935 fsync_or_die(output_fd, curr_pack_name);
936 err = close(output_fd);
937 if (err)
938 die_errno("error while closing pack file");
939 }
940 if (keep_msg) {
942 int keep_fd, keep_msg_len = strlen(keep_msg);
943 if (!keep_name)
945 keep_fd = odb_pack_keep(name, sizeof(name), sha1);
946 else
947 keep_fd = open(keep_name, O_RDWR|O_CREAT|O_EXCL, 0600);
948 if (keep_fd < 0) {
950 if (errno != EEXIST)
951 die_errno("cannot write keep file '%s'",
952 keep_name);
953 } else {
954 if (keep_msg_len > 0) {
955 write_or_die(keep_fd, keep_msg, keep_msg_len);
956 write_or_die(keep_fd, "\n", 1);
957 }
958 if (close(keep_fd) != 0)
959 die_errno("cannot close written keep file '%s'",
960 keep_name);
961 report = "keep";
962 }
963 }
964 if (final_pack_name != curr_pack_name) {
966 if (!final_pack_name) {
967 snprintf(name, sizeof(name), "%s/pack/pack-%s.pack",
968 get_object_directory(), sha1_to_hex(sha1));
969 final_pack_name = name;
970 }
971 if (move_temp_to_file(curr_pack_name, final_pack_name))
972 die("cannot store pack file");
973 } else if (from_stdin)
974 chmod(final_pack_name, 0444);
975 if (final_index_name != curr_index_name) {
977 if (!final_index_name) {
978 snprintf(name, sizeof(name), "%s/pack/pack-%s.idx",
979 get_object_directory(), sha1_to_hex(sha1));
980 final_index_name = name;
981 }
982 if (move_temp_to_file(curr_index_name, final_index_name))
983 die("cannot store index file");
984 } else
985 chmod(final_index_name, 0444);
986 if (!from_stdin) {
988 printf("%s\n", sha1_to_hex(sha1));
989 } else {
990 char buf[48];
991 int len = snprintf(buf, sizeof(buf), "%s\t%s\n",
992 report, sha1_to_hex(sha1));
993 write_or_die(1, buf, len);
994 /*
996 * Let's just mimic git-unpack-objects here and write
997 * the last part of the input buffer to stdout.
998 */
999 while (input_len) {
1000 err = xwrite(1, input_buffer + input_offset, input_len);
1001 if (err <= 0)
1002 break;
1003 input_len -= err;
1004 input_offset += err;
1005 }
1006 }
1007}
1008static int git_index_pack_config(const char *k, const char *v, void *cb)
1010{
1011 struct pack_idx_option *opts = cb;
1012 if (!strcmp(k, "pack.indexversion")) {
1014 opts->version = git_config_int(k, v);
1015 if (opts->version > 2)
1016 die("bad pack.indexversion=%"PRIu32, opts->version);
1017 return 0;
1018 }
1019 return git_default_config(k, v, cb);
1020}
1021static int cmp_uint32(const void *a_, const void *b_)
1023{
1024 uint32_t a = *((uint32_t *)a_);
1025 uint32_t b = *((uint32_t *)b_);
1026 return (a < b) ? -1 : (a != b);
1028}
1029static void read_v2_anomalous_offsets(struct packed_git *p,
1031 struct pack_idx_option *opts)
1032{
1033 const uint32_t *idx1, *idx2;
1034 uint32_t i;
1035 /* The address of the 4-byte offset table */
1037 idx1 = (((const uint32_t *)p->index_data)
1038 + 2 /* 8-byte header */
1039 + 256 /* fan out */
1040 + 5 * p->num_objects /* 20-byte SHA-1 table */
1041 + p->num_objects /* CRC32 table */
1042 );
1043 /* The address of the 8-byte offset table */
1045 idx2 = idx1 + p->num_objects;
1046 for (i = 0; i < p->num_objects; i++) {
1048 uint32_t off = ntohl(idx1[i]);
1049 if (!(off & 0x80000000))
1050 continue;
1051 off = off & 0x7fffffff;
1052 if (idx2[off * 2])
1053 continue;
1054 /*
1055 * The real offset is ntohl(idx2[off * 2]) in high 4
1056 * octets, and ntohl(idx2[off * 2 + 1]) in low 4
1057 * octets. But idx2[off * 2] is Zero!!!
1058 */
1059 ALLOC_GROW(opts->anomaly, opts->anomaly_nr + 1, opts->anomaly_alloc);
1060 opts->anomaly[opts->anomaly_nr++] = ntohl(idx2[off * 2 + 1]);
1061 }
1062 if (1 < opts->anomaly_nr)
1064 qsort(opts->anomaly, opts->anomaly_nr, sizeof(uint32_t), cmp_uint32);
1065}
1066static void read_idx_option(struct pack_idx_option *opts, const char *pack_name)
1068{
1069 struct packed_git *p = add_packed_git(pack_name, strlen(pack_name), 1);
1070 if (!p)
1072 die("Cannot open existing pack file '%s'", pack_name);
1073 if (open_pack_index(p))
1074 die("Cannot open existing pack idx file for '%s'", pack_name);
1075 /* Read the attributes from the existing idx file */
1077 opts->version = p->index_version;
1078 if (opts->version == 2)
1080 read_v2_anomalous_offsets(p, opts);
1081 /*
1083 * Get rid of the idx file as we do not need it anymore.
1084 * NEEDSWORK: extract this bit from free_pack_by_name() in
1085 * sha1_file.c, perhaps? It shouldn't matter very much as we
1086 * know we haven't installed this pack (hence we never have
1087 * read anything from it).
1088 */
1089 close_pack_index(p);
1090 free(p);
1091}
1092static void show_pack_info(int stat_only)
1094{
1095 int i, baseobjects = nr_objects - nr_deltas;
1096 unsigned long *chain_histogram = NULL;
1097 if (deepest_delta)
1099 chain_histogram = xcalloc(deepest_delta, sizeof(unsigned long));
1100 for (i = 0; i < nr_objects; i++) {
1102 struct object_entry *obj = &objects[i];
1103 if (is_delta_type(obj->type))
1105 chain_histogram[obj->delta_depth - 1]++;
1106 if (stat_only)
1107 continue;
1108 printf("%s %-6s %lu %lu %"PRIuMAX,
1109 sha1_to_hex(obj->idx.sha1),
1110 typename(obj->real_type), obj->size,
1111 (unsigned long)(obj[1].idx.offset - obj->idx.offset),
1112 (uintmax_t)obj->idx.offset);
1113 if (is_delta_type(obj->type)) {
1114 struct object_entry *bobj = &objects[obj->base_object_no];
1115 printf(" %u %s", obj->delta_depth, sha1_to_hex(bobj->idx.sha1));
1116 }
1117 putchar('\n');
1118 }
1119 if (baseobjects)
1121 printf("non delta: %d object%s\n",
1122 baseobjects, baseobjects > 1 ? "s" : "");
1123 for (i = 0; i < deepest_delta; i++) {
1124 if (!chain_histogram[i])
1125 continue;
1126 printf("chain length = %d: %lu object%s\n",
1127 i + 1,
1128 chain_histogram[i],
1129 chain_histogram[i] > 1 ? "s" : "");
1130 }
1131}
1132int cmd_index_pack(int argc, const char **argv, const char *prefix)
1134{
1135 int i, fix_thin_pack = 0, verify = 0, stat_only = 0, stat = 0;
1136 const char *curr_pack, *curr_index;
1137 const char *index_name = NULL, *pack_name = NULL;
1138 const char *keep_name = NULL, *keep_msg = NULL;
1139 char *index_name_buf = NULL, *keep_name_buf = NULL;
1140 struct pack_idx_entry **idx_objects;
1141 struct pack_idx_option opts;
1142 unsigned char pack_sha1[20];
1143 if (argc == 2 && !strcmp(argv[1], "-h"))
1145 usage(index_pack_usage);
1146 read_replace_refs = 0;
1148 reset_pack_idx_option(&opts);
1150 git_config(git_index_pack_config, &opts);
1151 if (prefix && chdir(prefix))
1152 die("Cannot come back to cwd");
1153 for (i = 1; i < argc; i++) {
1155 const char *arg = argv[i];
1156 if (*arg == '-') {
1158 if (!strcmp(arg, "--stdin")) {
1159 from_stdin = 1;
1160 } else if (!strcmp(arg, "--fix-thin")) {
1161 fix_thin_pack = 1;
1162 } else if (!strcmp(arg, "--strict")) {
1163 strict = 1;
1164 } else if (!strcmp(arg, "--verify")) {
1165 verify = 1;
1166 } else if (!strcmp(arg, "--verify-stat")) {
1167 verify = 1;
1168 stat = 1;
1169 } else if (!strcmp(arg, "--verify-stat-only")) {
1170 verify = 1;
1171 stat = 1;
1172 stat_only = 1;
1173 } else if (!strcmp(arg, "--keep")) {
1174 keep_msg = "";
1175 } else if (!prefixcmp(arg, "--keep=")) {
1176 keep_msg = arg + 7;
1177 } else if (!prefixcmp(arg, "--pack_header=")) {
1178 struct pack_header *hdr;
1179 char *c;
1180 hdr = (struct pack_header *)input_buffer;
1182 hdr->hdr_signature = htonl(PACK_SIGNATURE);
1183 hdr->hdr_version = htonl(strtoul(arg + 14, &c, 10));
1184 if (*c != ',')
1185 die("bad %s", arg);
1186 hdr->hdr_entries = htonl(strtoul(c + 1, &c, 10));
1187 if (*c)
1188 die("bad %s", arg);
1189 input_len = sizeof(*hdr);
1190 } else if (!strcmp(arg, "-v")) {
1191 verbose = 1;
1192 } else if (!strcmp(arg, "-o")) {
1193 if (index_name || (i+1) >= argc)
1194 usage(index_pack_usage);
1195 index_name = argv[++i];
1196 } else if (!prefixcmp(arg, "--index-version=")) {
1197 char *c;
1198 opts.version = strtoul(arg + 16, &c, 10);
1199 if (opts.version > 2)
1200 die("bad %s", arg);
1201 if (*c == ',')
1202 opts.off32_limit = strtoul(c+1, &c, 0);
1203 if (*c || opts.off32_limit & 0x80000000)
1204 die("bad %s", arg);
1205 } else
1206 usage(index_pack_usage);
1207 continue;
1208 }
1209 if (pack_name)
1211 usage(index_pack_usage);
1212 pack_name = arg;
1213 }
1214 if (!pack_name && !from_stdin)
1216 usage(index_pack_usage);
1217 if (fix_thin_pack && !from_stdin)
1218 die("--fix-thin cannot be used without --stdin");
1219 if (!index_name && pack_name) {
1220 int len = strlen(pack_name);
1221 if (!has_extension(pack_name, ".pack"))
1222 die("packfile name '%s' does not end with '.pack'",
1223 pack_name);
1224 index_name_buf = xmalloc(len);
1225 memcpy(index_name_buf, pack_name, len - 5);
1226 strcpy(index_name_buf + len - 5, ".idx");
1227 index_name = index_name_buf;
1228 }
1229 if (keep_msg && !keep_name && pack_name) {
1230 int len = strlen(pack_name);
1231 if (!has_extension(pack_name, ".pack"))
1232 die("packfile name '%s' does not end with '.pack'",
1233 pack_name);
1234 keep_name_buf = xmalloc(len);
1235 memcpy(keep_name_buf, pack_name, len - 5);
1236 strcpy(keep_name_buf + len - 5, ".keep");
1237 keep_name = keep_name_buf;
1238 }
1239 if (verify) {
1240 if (!index_name)
1241 die("--verify with no packfile name given");
1242 read_idx_option(&opts, index_name);
1243 opts.flags |= WRITE_IDX_VERIFY | WRITE_IDX_STRICT;
1244 }
1245 if (strict)
1246 opts.flags |= WRITE_IDX_STRICT;
1247 curr_pack = open_pack_file(pack_name);
1249 parse_pack_header();
1250 objects = xcalloc(nr_objects + 1, sizeof(struct object_entry));
1251 deltas = xcalloc(nr_objects, sizeof(struct delta_entry));
1252 parse_pack_objects(pack_sha1);
1253 resolve_deltas();
1254 conclude_pack(fix_thin_pack, curr_pack, pack_sha1);
1255 free(deltas);
1256 if (strict)
1257 check_objects();
1258 if (stat)
1260 show_pack_info(stat_only);
1261 idx_objects = xmalloc((nr_objects) * sizeof(struct pack_idx_entry *));
1263 for (i = 0; i < nr_objects; i++)
1264 idx_objects[i] = &objects[i].idx;
1265 curr_index = write_idx_file(index_name, idx_objects, nr_objects, &opts, pack_sha1);
1266 free(idx_objects);
1267 if (!verify)
1269 final(pack_name, curr_pack,
1270 index_name, curr_index,
1271 keep_name, keep_msg,
1272 pack_sha1);
1273 else
1274 close(input_fd);
1275 free(objects);
1276 free(index_name_buf);
1277 free(keep_name_buf);
1278 if (pack_name == NULL)
1279 free((void *) curr_pack);
1280 if (index_name == NULL)
1281 free((void *) curr_index);
1282 return 0;
1284}