Merge branch 'maint'
[git] / index-pack.c
1 #include "cache.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"
12
13 static const char index_pack_usage[] =
14 "git index-pack [-v] [-o <index-file>] [{ ---keep | --keep=<msg> }] [--strict] { <pack-file> | --stdin [--fix-thin] [<pack-file>] }";
15
16 struct object_entry
17 {
18         struct pack_idx_entry idx;
19         unsigned long size;
20         unsigned int hdr_size;
21         enum object_type type;
22         enum object_type real_type;
23 };
24
25 union delta_base {
26         unsigned char sha1[20];
27         off_t offset;
28 };
29
30 struct base_data {
31         struct base_data *base;
32         struct base_data *child;
33         struct object_entry *obj;
34         void *data;
35         unsigned long size;
36 };
37
38 /*
39  * Even if sizeof(union delta_base) == 24 on 64-bit archs, we really want
40  * to memcmp() only the first 20 bytes.
41  */
42 #define UNION_BASE_SZ   20
43
44 #define FLAG_LINK (1u<<20)
45 #define FLAG_CHECKED (1u<<21)
46
47 struct delta_entry
48 {
49         union delta_base base;
50         int obj_no;
51 };
52
53 static struct object_entry *objects;
54 static struct delta_entry *deltas;
55 static struct base_data *base_cache;
56 static size_t base_cache_used;
57 static int nr_objects;
58 static int nr_deltas;
59 static int nr_resolved_deltas;
60
61 static int from_stdin;
62 static int strict;
63 static int verbose;
64
65 static struct progress *progress;
66
67 /* We always read in 4kB chunks. */
68 static unsigned char input_buffer[4096];
69 static unsigned int input_offset, input_len;
70 static off_t consumed_bytes;
71 static git_SHA_CTX input_ctx;
72 static uint32_t input_crc32;
73 static int input_fd, output_fd, pack_fd;
74
75 static int mark_link(struct object *obj, int type, void *data)
76 {
77         if (!obj)
78                 return -1;
79
80         if (type != OBJ_ANY && obj->type != type)
81                 die("object type mismatch at %s", sha1_to_hex(obj->sha1));
82
83         obj->flags |= FLAG_LINK;
84         return 0;
85 }
86
87 /* The content of each linked object must have been checked
88    or it must be already present in the object database */
89 static void check_object(struct object *obj)
90 {
91         if (!obj)
92                 return;
93
94         if (!(obj->flags & FLAG_LINK))
95                 return;
96
97         if (!(obj->flags & FLAG_CHECKED)) {
98                 unsigned long size;
99                 int type = sha1_object_info(obj->sha1, &size);
100                 if (type != obj->type || type <= 0)
101                         die("object of unexpected type");
102                 obj->flags |= FLAG_CHECKED;
103                 return;
104         }
105 }
106
107 static void check_objects(void)
108 {
109         unsigned i, max;
110
111         max = get_max_object_index();
112         for (i = 0; i < max; i++)
113                 check_object(get_indexed_object(i));
114 }
115
116
117 /* Discard current buffer used content. */
118 static void flush(void)
119 {
120         if (input_offset) {
121                 if (output_fd >= 0)
122                         write_or_die(output_fd, input_buffer, input_offset);
123                 git_SHA1_Update(&input_ctx, input_buffer, input_offset);
124                 memmove(input_buffer, input_buffer + input_offset, input_len);
125                 input_offset = 0;
126         }
127 }
128
129 /*
130  * Make sure at least "min" bytes are available in the buffer, and
131  * return the pointer to the buffer.
132  */
133 static void *fill(int min)
134 {
135         if (min <= input_len)
136                 return input_buffer + input_offset;
137         if (min > sizeof(input_buffer))
138                 die("cannot fill %d bytes", min);
139         flush();
140         do {
141                 ssize_t ret = xread(input_fd, input_buffer + input_len,
142                                 sizeof(input_buffer) - input_len);
143                 if (ret <= 0) {
144                         if (!ret)
145                                 die("early EOF");
146                         die("read error on input: %s", strerror(errno));
147                 }
148                 input_len += ret;
149                 if (from_stdin)
150                         display_throughput(progress, consumed_bytes + input_len);
151         } while (input_len < min);
152         return input_buffer;
153 }
154
155 static void use(int bytes)
156 {
157         if (bytes > input_len)
158                 die("used more bytes than were available");
159         input_crc32 = crc32(input_crc32, input_buffer + input_offset, bytes);
160         input_len -= bytes;
161         input_offset += bytes;
162
163         /* make sure off_t is sufficiently large not to wrap */
164         if (consumed_bytes > consumed_bytes + bytes)
165                 die("pack too large for current definition of off_t");
166         consumed_bytes += bytes;
167 }
168
169 static char *open_pack_file(char *pack_name)
170 {
171         if (from_stdin) {
172                 input_fd = 0;
173                 if (!pack_name) {
174                         static char tmpfile[PATH_MAX];
175                         snprintf(tmpfile, sizeof(tmpfile),
176                                  "%s/pack/tmp_pack_XXXXXX", get_object_directory());
177                         output_fd = xmkstemp(tmpfile);
178                         pack_name = xstrdup(tmpfile);
179                 } else
180                         output_fd = open(pack_name, O_CREAT|O_EXCL|O_RDWR, 0600);
181                 if (output_fd < 0)
182                         die("unable to create %s: %s", pack_name, strerror(errno));
183                 pack_fd = output_fd;
184         } else {
185                 input_fd = open(pack_name, O_RDONLY);
186                 if (input_fd < 0)
187                         die("cannot open packfile '%s': %s",
188                             pack_name, strerror(errno));
189                 output_fd = -1;
190                 pack_fd = input_fd;
191         }
192         git_SHA1_Init(&input_ctx);
193         return pack_name;
194 }
195
196 static void parse_pack_header(void)
197 {
198         struct pack_header *hdr = fill(sizeof(struct pack_header));
199
200         /* Header consistency check */
201         if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
202                 die("pack signature mismatch");
203         if (!pack_version_ok(hdr->hdr_version))
204                 die("pack version %"PRIu32" unsupported",
205                         ntohl(hdr->hdr_version));
206
207         nr_objects = ntohl(hdr->hdr_entries);
208         use(sizeof(struct pack_header));
209 }
210
211 static void bad_object(unsigned long offset, const char *format,
212                        ...) NORETURN __attribute__((format (printf, 2, 3)));
213
214 static void bad_object(unsigned long offset, const char *format, ...)
215 {
216         va_list params;
217         char buf[1024];
218
219         va_start(params, format);
220         vsnprintf(buf, sizeof(buf), format, params);
221         va_end(params);
222         die("pack has bad object at offset %lu: %s", offset, buf);
223 }
224
225 static void free_base_data(struct base_data *c)
226 {
227         if (c->data) {
228                 free(c->data);
229                 c->data = NULL;
230                 base_cache_used -= c->size;
231         }
232 }
233
234 static void prune_base_data(struct base_data *retain)
235 {
236         struct base_data *b = base_cache;
237         for (b = base_cache;
238              base_cache_used > delta_base_cache_limit && b;
239              b = b->child) {
240                 if (b->data && b != retain)
241                         free_base_data(b);
242         }
243 }
244
245 static void link_base_data(struct base_data *base, struct base_data *c)
246 {
247         if (base)
248                 base->child = c;
249         else
250                 base_cache = c;
251
252         c->base = base;
253         c->child = NULL;
254         if (c->data)
255                 base_cache_used += c->size;
256         prune_base_data(c);
257 }
258
259 static void unlink_base_data(struct base_data *c)
260 {
261         struct base_data *base = c->base;
262         if (base)
263                 base->child = NULL;
264         else
265                 base_cache = NULL;
266         free_base_data(c);
267 }
268
269 static void *unpack_entry_data(unsigned long offset, unsigned long size)
270 {
271         z_stream stream;
272         void *buf = xmalloc(size);
273
274         memset(&stream, 0, sizeof(stream));
275         stream.next_out = buf;
276         stream.avail_out = size;
277         stream.next_in = fill(1);
278         stream.avail_in = input_len;
279         git_inflate_init(&stream);
280
281         for (;;) {
282                 int ret = git_inflate(&stream, 0);
283                 use(input_len - stream.avail_in);
284                 if (stream.total_out == size && ret == Z_STREAM_END)
285                         break;
286                 if (ret != Z_OK)
287                         bad_object(offset, "inflate returned %d", ret);
288                 stream.next_in = fill(1);
289                 stream.avail_in = input_len;
290         }
291         git_inflate_end(&stream);
292         return buf;
293 }
294
295 static void *unpack_raw_entry(struct object_entry *obj, union delta_base *delta_base)
296 {
297         unsigned char *p, c;
298         unsigned long size;
299         off_t base_offset;
300         unsigned shift;
301         void *data;
302
303         obj->idx.offset = consumed_bytes;
304         input_crc32 = crc32(0, Z_NULL, 0);
305
306         p = fill(1);
307         c = *p;
308         use(1);
309         obj->type = (c >> 4) & 7;
310         size = (c & 15);
311         shift = 4;
312         while (c & 0x80) {
313                 p = fill(1);
314                 c = *p;
315                 use(1);
316                 size += (c & 0x7fUL) << shift;
317                 shift += 7;
318         }
319         obj->size = size;
320
321         switch (obj->type) {
322         case OBJ_REF_DELTA:
323                 hashcpy(delta_base->sha1, fill(20));
324                 use(20);
325                 break;
326         case OBJ_OFS_DELTA:
327                 memset(delta_base, 0, sizeof(*delta_base));
328                 p = fill(1);
329                 c = *p;
330                 use(1);
331                 base_offset = c & 127;
332                 while (c & 128) {
333                         base_offset += 1;
334                         if (!base_offset || MSB(base_offset, 7))
335                                 bad_object(obj->idx.offset, "offset value overflow for delta base object");
336                         p = fill(1);
337                         c = *p;
338                         use(1);
339                         base_offset = (base_offset << 7) + (c & 127);
340                 }
341                 delta_base->offset = obj->idx.offset - base_offset;
342                 if (delta_base->offset <= 0 || delta_base->offset >= obj->idx.offset)
343                         bad_object(obj->idx.offset, "delta base offset is out of bound");
344                 break;
345         case OBJ_COMMIT:
346         case OBJ_TREE:
347         case OBJ_BLOB:
348         case OBJ_TAG:
349                 break;
350         default:
351                 bad_object(obj->idx.offset, "unknown object type %d", obj->type);
352         }
353         obj->hdr_size = consumed_bytes - obj->idx.offset;
354
355         data = unpack_entry_data(obj->idx.offset, obj->size);
356         obj->idx.crc32 = input_crc32;
357         return data;
358 }
359
360 static void *get_data_from_pack(struct object_entry *obj)
361 {
362         off_t from = obj[0].idx.offset + obj[0].hdr_size;
363         unsigned long len = obj[1].idx.offset - from;
364         unsigned long rdy = 0;
365         unsigned char *src, *data;
366         z_stream stream;
367         int st;
368
369         src = xmalloc(len);
370         data = src;
371         do {
372                 ssize_t n = pread(pack_fd, data + rdy, len - rdy, from + rdy);
373                 if (n < 0)
374                         die("cannot pread pack file: %s", strerror(errno));
375                 if (!n)
376                         die("premature end of pack file, %lu bytes missing",
377                             len - rdy);
378                 rdy += n;
379         } while (rdy < len);
380         data = xmalloc(obj->size);
381         memset(&stream, 0, sizeof(stream));
382         stream.next_out = data;
383         stream.avail_out = obj->size;
384         stream.next_in = src;
385         stream.avail_in = len;
386         git_inflate_init(&stream);
387         while ((st = git_inflate(&stream, Z_FINISH)) == Z_OK);
388         git_inflate_end(&stream);
389         if (st != Z_STREAM_END || stream.total_out != obj->size)
390                 die("serious inflate inconsistency");
391         free(src);
392         return data;
393 }
394
395 static int find_delta(const union delta_base *base)
396 {
397         int first = 0, last = nr_deltas;
398
399         while (first < last) {
400                 int next = (first + last) / 2;
401                 struct delta_entry *delta = &deltas[next];
402                 int cmp;
403
404                 cmp = memcmp(base, &delta->base, UNION_BASE_SZ);
405                 if (!cmp)
406                         return next;
407                 if (cmp < 0) {
408                         last = next;
409                         continue;
410                 }
411                 first = next+1;
412         }
413         return -first-1;
414 }
415
416 static void find_delta_children(const union delta_base *base,
417                                 int *first_index, int *last_index)
418 {
419         int first = find_delta(base);
420         int last = first;
421         int end = nr_deltas - 1;
422
423         if (first < 0) {
424                 *first_index = 0;
425                 *last_index = -1;
426                 return;
427         }
428         while (first > 0 && !memcmp(&deltas[first - 1].base, base, UNION_BASE_SZ))
429                 --first;
430         while (last < end && !memcmp(&deltas[last + 1].base, base, UNION_BASE_SZ))
431                 ++last;
432         *first_index = first;
433         *last_index = last;
434 }
435
436 static void sha1_object(const void *data, unsigned long size,
437                         enum object_type type, unsigned char *sha1)
438 {
439         hash_sha1_file(data, size, typename(type), sha1);
440         if (has_sha1_file(sha1)) {
441                 void *has_data;
442                 enum object_type has_type;
443                 unsigned long has_size;
444                 has_data = read_sha1_file(sha1, &has_type, &has_size);
445                 if (!has_data)
446                         die("cannot read existing object %s", sha1_to_hex(sha1));
447                 if (size != has_size || type != has_type ||
448                     memcmp(data, has_data, size) != 0)
449                         die("SHA1 COLLISION FOUND WITH %s !", sha1_to_hex(sha1));
450                 free(has_data);
451         }
452         if (strict) {
453                 if (type == OBJ_BLOB) {
454                         struct blob *blob = lookup_blob(sha1);
455                         if (blob)
456                                 blob->object.flags |= FLAG_CHECKED;
457                         else
458                                 die("invalid blob object %s", sha1_to_hex(sha1));
459                 } else {
460                         struct object *obj;
461                         int eaten;
462                         void *buf = (void *) data;
463
464                         /*
465                          * we do not need to free the memory here, as the
466                          * buf is deleted by the caller.
467                          */
468                         obj = parse_object_buffer(sha1, type, size, buf, &eaten);
469                         if (!obj)
470                                 die("invalid %s", typename(type));
471                         if (fsck_object(obj, 1, fsck_error_function))
472                                 die("Error in object");
473                         if (fsck_walk(obj, mark_link, 0))
474                                 die("Not all child objects of %s are reachable", sha1_to_hex(obj->sha1));
475
476                         if (obj->type == OBJ_TREE) {
477                                 struct tree *item = (struct tree *) obj;
478                                 item->buffer = NULL;
479                         }
480                         if (obj->type == OBJ_COMMIT) {
481                                 struct commit *commit = (struct commit *) obj;
482                                 commit->buffer = NULL;
483                         }
484                         obj->flags |= FLAG_CHECKED;
485                 }
486         }
487 }
488
489 static void *get_base_data(struct base_data *c)
490 {
491         if (!c->data) {
492                 struct object_entry *obj = c->obj;
493
494                 if (obj->type == OBJ_REF_DELTA || obj->type == OBJ_OFS_DELTA) {
495                         void *base = get_base_data(c->base);
496                         void *raw = get_data_from_pack(obj);
497                         c->data = patch_delta(
498                                 base, c->base->size,
499                                 raw, obj->size,
500                                 &c->size);
501                         free(raw);
502                         if (!c->data)
503                                 bad_object(obj->idx.offset, "failed to apply delta");
504                 } else {
505                         c->data = get_data_from_pack(obj);
506                         c->size = obj->size;
507                 }
508
509                 base_cache_used += c->size;
510                 prune_base_data(c);
511         }
512         return c->data;
513 }
514
515 static void resolve_delta(struct object_entry *delta_obj,
516                           struct base_data *base, struct base_data *result)
517 {
518         void *base_data, *delta_data;
519
520         delta_obj->real_type = base->obj->real_type;
521         delta_data = get_data_from_pack(delta_obj);
522         base_data = get_base_data(base);
523         result->obj = delta_obj;
524         result->data = patch_delta(base_data, base->size,
525                                    delta_data, delta_obj->size, &result->size);
526         free(delta_data);
527         if (!result->data)
528                 bad_object(delta_obj->idx.offset, "failed to apply delta");
529         sha1_object(result->data, result->size, delta_obj->real_type,
530                     delta_obj->idx.sha1);
531         nr_resolved_deltas++;
532 }
533
534 static void find_unresolved_deltas(struct base_data *base,
535                                    struct base_data *prev_base)
536 {
537         int i, ref_first, ref_last, ofs_first, ofs_last;
538
539         /*
540          * This is a recursive function. Those brackets should help reducing
541          * stack usage by limiting the scope of the delta_base union.
542          */
543         {
544                 union delta_base base_spec;
545
546                 hashcpy(base_spec.sha1, base->obj->idx.sha1);
547                 find_delta_children(&base_spec, &ref_first, &ref_last);
548
549                 memset(&base_spec, 0, sizeof(base_spec));
550                 base_spec.offset = base->obj->idx.offset;
551                 find_delta_children(&base_spec, &ofs_first, &ofs_last);
552         }
553
554         if (ref_last == -1 && ofs_last == -1) {
555                 free(base->data);
556                 return;
557         }
558
559         link_base_data(prev_base, base);
560
561         for (i = ref_first; i <= ref_last; i++) {
562                 struct object_entry *child = objects + deltas[i].obj_no;
563                 if (child->real_type == OBJ_REF_DELTA) {
564                         struct base_data result;
565                         resolve_delta(child, base, &result);
566                         if (i == ref_last && ofs_last == -1)
567                                 free_base_data(base);
568                         find_unresolved_deltas(&result, base);
569                 }
570         }
571
572         for (i = ofs_first; i <= ofs_last; i++) {
573                 struct object_entry *child = objects + deltas[i].obj_no;
574                 if (child->real_type == OBJ_OFS_DELTA) {
575                         struct base_data result;
576                         resolve_delta(child, base, &result);
577                         if (i == ofs_last)
578                                 free_base_data(base);
579                         find_unresolved_deltas(&result, base);
580                 }
581         }
582
583         unlink_base_data(base);
584 }
585
586 static int compare_delta_entry(const void *a, const void *b)
587 {
588         const struct delta_entry *delta_a = a;
589         const struct delta_entry *delta_b = b;
590         return memcmp(&delta_a->base, &delta_b->base, UNION_BASE_SZ);
591 }
592
593 /* Parse all objects and return the pack content SHA1 hash */
594 static void parse_pack_objects(unsigned char *sha1)
595 {
596         int i;
597         struct delta_entry *delta = deltas;
598         struct stat st;
599
600         /*
601          * First pass:
602          * - find locations of all objects;
603          * - calculate SHA1 of all non-delta objects;
604          * - remember base (SHA1 or offset) for all deltas.
605          */
606         if (verbose)
607                 progress = start_progress(
608                                 from_stdin ? "Receiving objects" : "Indexing objects",
609                                 nr_objects);
610         for (i = 0; i < nr_objects; i++) {
611                 struct object_entry *obj = &objects[i];
612                 void *data = unpack_raw_entry(obj, &delta->base);
613                 obj->real_type = obj->type;
614                 if (obj->type == OBJ_REF_DELTA || obj->type == OBJ_OFS_DELTA) {
615                         nr_deltas++;
616                         delta->obj_no = i;
617                         delta++;
618                 } else
619                         sha1_object(data, obj->size, obj->type, obj->idx.sha1);
620                 free(data);
621                 display_progress(progress, i+1);
622         }
623         objects[i].idx.offset = consumed_bytes;
624         stop_progress(&progress);
625
626         /* Check pack integrity */
627         flush();
628         git_SHA1_Final(sha1, &input_ctx);
629         if (hashcmp(fill(20), sha1))
630                 die("pack is corrupted (SHA1 mismatch)");
631         use(20);
632
633         /* If input_fd is a file, we should have reached its end now. */
634         if (fstat(input_fd, &st))
635                 die("cannot fstat packfile: %s", strerror(errno));
636         if (S_ISREG(st.st_mode) &&
637                         lseek(input_fd, 0, SEEK_CUR) - input_len != st.st_size)
638                 die("pack has junk at the end");
639
640         if (!nr_deltas)
641                 return;
642
643         /* Sort deltas by base SHA1/offset for fast searching */
644         qsort(deltas, nr_deltas, sizeof(struct delta_entry),
645               compare_delta_entry);
646
647         /*
648          * Second pass:
649          * - for all non-delta objects, look if it is used as a base for
650          *   deltas;
651          * - if used as a base, uncompress the object and apply all deltas,
652          *   recursively checking if the resulting object is used as a base
653          *   for some more deltas.
654          */
655         if (verbose)
656                 progress = start_progress("Resolving deltas", nr_deltas);
657         for (i = 0; i < nr_objects; i++) {
658                 struct object_entry *obj = &objects[i];
659                 struct base_data base_obj;
660
661                 if (obj->type == OBJ_REF_DELTA || obj->type == OBJ_OFS_DELTA)
662                         continue;
663                 base_obj.obj = obj;
664                 base_obj.data = NULL;
665                 find_unresolved_deltas(&base_obj, NULL);
666                 display_progress(progress, nr_resolved_deltas);
667         }
668 }
669
670 static int write_compressed(struct sha1file *f, void *in, unsigned int size)
671 {
672         z_stream stream;
673         unsigned long maxsize;
674         void *out;
675
676         memset(&stream, 0, sizeof(stream));
677         deflateInit(&stream, zlib_compression_level);
678         maxsize = deflateBound(&stream, size);
679         out = xmalloc(maxsize);
680
681         /* Compress it */
682         stream.next_in = in;
683         stream.avail_in = size;
684         stream.next_out = out;
685         stream.avail_out = maxsize;
686         while (deflate(&stream, Z_FINISH) == Z_OK);
687         deflateEnd(&stream);
688
689         size = stream.total_out;
690         sha1write(f, out, size);
691         free(out);
692         return size;
693 }
694
695 static struct object_entry *append_obj_to_pack(struct sha1file *f,
696                                const unsigned char *sha1, void *buf,
697                                unsigned long size, enum object_type type)
698 {
699         struct object_entry *obj = &objects[nr_objects++];
700         unsigned char header[10];
701         unsigned long s = size;
702         int n = 0;
703         unsigned char c = (type << 4) | (s & 15);
704         s >>= 4;
705         while (s) {
706                 header[n++] = c | 0x80;
707                 c = s & 0x7f;
708                 s >>= 7;
709         }
710         header[n++] = c;
711         crc32_begin(f);
712         sha1write(f, header, n);
713         obj[0].size = size;
714         obj[0].hdr_size = n;
715         obj[0].type = type;
716         obj[0].real_type = type;
717         obj[1].idx.offset = obj[0].idx.offset + n;
718         obj[1].idx.offset += write_compressed(f, buf, size);
719         obj[0].idx.crc32 = crc32_end(f);
720         sha1flush(f);
721         hashcpy(obj->idx.sha1, sha1);
722         return obj;
723 }
724
725 static int delta_pos_compare(const void *_a, const void *_b)
726 {
727         struct delta_entry *a = *(struct delta_entry **)_a;
728         struct delta_entry *b = *(struct delta_entry **)_b;
729         return a->obj_no - b->obj_no;
730 }
731
732 static void fix_unresolved_deltas(struct sha1file *f, int nr_unresolved)
733 {
734         struct delta_entry **sorted_by_pos;
735         int i, n = 0;
736
737         /*
738          * Since many unresolved deltas may well be themselves base objects
739          * for more unresolved deltas, we really want to include the
740          * smallest number of base objects that would cover as much delta
741          * as possible by picking the
742          * trunc deltas first, allowing for other deltas to resolve without
743          * additional base objects.  Since most base objects are to be found
744          * before deltas depending on them, a good heuristic is to start
745          * resolving deltas in the same order as their position in the pack.
746          */
747         sorted_by_pos = xmalloc(nr_unresolved * sizeof(*sorted_by_pos));
748         for (i = 0; i < nr_deltas; i++) {
749                 if (objects[deltas[i].obj_no].real_type != OBJ_REF_DELTA)
750                         continue;
751                 sorted_by_pos[n++] = &deltas[i];
752         }
753         qsort(sorted_by_pos, n, sizeof(*sorted_by_pos), delta_pos_compare);
754
755         for (i = 0; i < n; i++) {
756                 struct delta_entry *d = sorted_by_pos[i];
757                 enum object_type type;
758                 struct base_data base_obj;
759
760                 if (objects[d->obj_no].real_type != OBJ_REF_DELTA)
761                         continue;
762                 base_obj.data = read_sha1_file(d->base.sha1, &type, &base_obj.size);
763                 if (!base_obj.data)
764                         continue;
765
766                 if (check_sha1_signature(d->base.sha1, base_obj.data,
767                                 base_obj.size, typename(type)))
768                         die("local object %s is corrupt", sha1_to_hex(d->base.sha1));
769                 base_obj.obj = append_obj_to_pack(f, d->base.sha1,
770                                         base_obj.data, base_obj.size, type);
771                 find_unresolved_deltas(&base_obj, NULL);
772                 display_progress(progress, nr_resolved_deltas);
773         }
774         free(sorted_by_pos);
775 }
776
777 static void final(const char *final_pack_name, const char *curr_pack_name,
778                   const char *final_index_name, const char *curr_index_name,
779                   const char *keep_name, const char *keep_msg,
780                   unsigned char *sha1)
781 {
782         const char *report = "pack";
783         char name[PATH_MAX];
784         int err;
785
786         if (!from_stdin) {
787                 close(input_fd);
788         } else {
789                 fsync_or_die(output_fd, curr_pack_name);
790                 err = close(output_fd);
791                 if (err)
792                         die("error while closing pack file: %s", strerror(errno));
793         }
794
795         if (keep_msg) {
796                 int keep_fd, keep_msg_len = strlen(keep_msg);
797                 if (!keep_name) {
798                         snprintf(name, sizeof(name), "%s/pack/pack-%s.keep",
799                                  get_object_directory(), sha1_to_hex(sha1));
800                         keep_name = name;
801                 }
802                 keep_fd = open(keep_name, O_RDWR|O_CREAT|O_EXCL, 0600);
803                 if (keep_fd < 0) {
804                         if (errno != EEXIST)
805                                 die("cannot write keep file");
806                 } else {
807                         if (keep_msg_len > 0) {
808                                 write_or_die(keep_fd, keep_msg, keep_msg_len);
809                                 write_or_die(keep_fd, "\n", 1);
810                         }
811                         if (close(keep_fd) != 0)
812                                 die("cannot write keep file");
813                         report = "keep";
814                 }
815         }
816
817         if (final_pack_name != curr_pack_name) {
818                 if (!final_pack_name) {
819                         snprintf(name, sizeof(name), "%s/pack/pack-%s.pack",
820                                  get_object_directory(), sha1_to_hex(sha1));
821                         final_pack_name = name;
822                 }
823                 if (move_temp_to_file(curr_pack_name, final_pack_name))
824                         die("cannot store pack file");
825         }
826         if (from_stdin)
827                 chmod(final_pack_name, 0444);
828
829         if (final_index_name != curr_index_name) {
830                 if (!final_index_name) {
831                         snprintf(name, sizeof(name), "%s/pack/pack-%s.idx",
832                                  get_object_directory(), sha1_to_hex(sha1));
833                         final_index_name = name;
834                 }
835                 if (move_temp_to_file(curr_index_name, final_index_name))
836                         die("cannot store index file");
837         }
838         chmod(final_index_name, 0444);
839
840         if (!from_stdin) {
841                 printf("%s\n", sha1_to_hex(sha1));
842         } else {
843                 char buf[48];
844                 int len = snprintf(buf, sizeof(buf), "%s\t%s\n",
845                                    report, sha1_to_hex(sha1));
846                 write_or_die(1, buf, len);
847
848                 /*
849                  * Let's just mimic git-unpack-objects here and write
850                  * the last part of the input buffer to stdout.
851                  */
852                 while (input_len) {
853                         err = xwrite(1, input_buffer + input_offset, input_len);
854                         if (err <= 0)
855                                 break;
856                         input_len -= err;
857                         input_offset += err;
858                 }
859         }
860 }
861
862 static int git_index_pack_config(const char *k, const char *v, void *cb)
863 {
864         if (!strcmp(k, "pack.indexversion")) {
865                 pack_idx_default_version = git_config_int(k, v);
866                 if (pack_idx_default_version > 2)
867                         die("bad pack.indexversion=%"PRIu32,
868                                 pack_idx_default_version);
869                 return 0;
870         }
871         return git_default_config(k, v, cb);
872 }
873
874 int main(int argc, char **argv)
875 {
876         int i, fix_thin_pack = 0;
877         char *curr_pack, *pack_name = NULL;
878         char *curr_index, *index_name = NULL;
879         const char *keep_name = NULL, *keep_msg = NULL;
880         char *index_name_buf = NULL, *keep_name_buf = NULL;
881         struct pack_idx_entry **idx_objects;
882         unsigned char pack_sha1[20];
883
884         git_extract_argv0_path(argv[0]);
885
886         /*
887          * We wish to read the repository's config file if any, and
888          * for that it is necessary to call setup_git_directory_gently().
889          * However if the cwd was inside .git/objects/pack/ then we need
890          * to go back there or all the pack name arguments will be wrong.
891          * And in that case we cannot rely on any prefix returned by
892          * setup_git_directory_gently() either.
893          */
894         {
895                 char cwd[PATH_MAX+1];
896                 int nongit;
897
898                 if (!getcwd(cwd, sizeof(cwd)-1))
899                         die("Unable to get current working directory");
900                 setup_git_directory_gently(&nongit);
901                 git_config(git_index_pack_config, NULL);
902                 if (chdir(cwd))
903                         die("Cannot come back to cwd");
904         }
905
906         for (i = 1; i < argc; i++) {
907                 char *arg = argv[i];
908
909                 if (*arg == '-') {
910                         if (!strcmp(arg, "--stdin")) {
911                                 from_stdin = 1;
912                         } else if (!strcmp(arg, "--fix-thin")) {
913                                 fix_thin_pack = 1;
914                         } else if (!strcmp(arg, "--strict")) {
915                                 strict = 1;
916                         } else if (!strcmp(arg, "--keep")) {
917                                 keep_msg = "";
918                         } else if (!prefixcmp(arg, "--keep=")) {
919                                 keep_msg = arg + 7;
920                         } else if (!prefixcmp(arg, "--pack_header=")) {
921                                 struct pack_header *hdr;
922                                 char *c;
923
924                                 hdr = (struct pack_header *)input_buffer;
925                                 hdr->hdr_signature = htonl(PACK_SIGNATURE);
926                                 hdr->hdr_version = htonl(strtoul(arg + 14, &c, 10));
927                                 if (*c != ',')
928                                         die("bad %s", arg);
929                                 hdr->hdr_entries = htonl(strtoul(c + 1, &c, 10));
930                                 if (*c)
931                                         die("bad %s", arg);
932                                 input_len = sizeof(*hdr);
933                         } else if (!strcmp(arg, "-v")) {
934                                 verbose = 1;
935                         } else if (!strcmp(arg, "-o")) {
936                                 if (index_name || (i+1) >= argc)
937                                         usage(index_pack_usage);
938                                 index_name = argv[++i];
939                         } else if (!prefixcmp(arg, "--index-version=")) {
940                                 char *c;
941                                 pack_idx_default_version = strtoul(arg + 16, &c, 10);
942                                 if (pack_idx_default_version > 2)
943                                         die("bad %s", arg);
944                                 if (*c == ',')
945                                         pack_idx_off32_limit = strtoul(c+1, &c, 0);
946                                 if (*c || pack_idx_off32_limit & 0x80000000)
947                                         die("bad %s", arg);
948                         } else
949                                 usage(index_pack_usage);
950                         continue;
951                 }
952
953                 if (pack_name)
954                         usage(index_pack_usage);
955                 pack_name = arg;
956         }
957
958         if (!pack_name && !from_stdin)
959                 usage(index_pack_usage);
960         if (fix_thin_pack && !from_stdin)
961                 die("--fix-thin cannot be used without --stdin");
962         if (!index_name && pack_name) {
963                 int len = strlen(pack_name);
964                 if (!has_extension(pack_name, ".pack"))
965                         die("packfile name '%s' does not end with '.pack'",
966                             pack_name);
967                 index_name_buf = xmalloc(len);
968                 memcpy(index_name_buf, pack_name, len - 5);
969                 strcpy(index_name_buf + len - 5, ".idx");
970                 index_name = index_name_buf;
971         }
972         if (keep_msg && !keep_name && pack_name) {
973                 int len = strlen(pack_name);
974                 if (!has_extension(pack_name, ".pack"))
975                         die("packfile name '%s' does not end with '.pack'",
976                             pack_name);
977                 keep_name_buf = xmalloc(len);
978                 memcpy(keep_name_buf, pack_name, len - 5);
979                 strcpy(keep_name_buf + len - 5, ".keep");
980                 keep_name = keep_name_buf;
981         }
982
983         curr_pack = open_pack_file(pack_name);
984         parse_pack_header();
985         objects = xmalloc((nr_objects + 1) * sizeof(struct object_entry));
986         deltas = xmalloc(nr_objects * sizeof(struct delta_entry));
987         parse_pack_objects(pack_sha1);
988         if (nr_deltas == nr_resolved_deltas) {
989                 stop_progress(&progress);
990                 /* Flush remaining pack final 20-byte SHA1. */
991                 flush();
992         } else {
993                 if (fix_thin_pack) {
994                         struct sha1file *f;
995                         unsigned char read_sha1[20], tail_sha1[20];
996                         char msg[48];
997                         int nr_unresolved = nr_deltas - nr_resolved_deltas;
998                         int nr_objects_initial = nr_objects;
999                         if (nr_unresolved <= 0)
1000                                 die("confusion beyond insanity");
1001                         objects = xrealloc(objects,
1002                                            (nr_objects + nr_unresolved + 1)
1003                                            * sizeof(*objects));
1004                         f = sha1fd(output_fd, curr_pack);
1005                         fix_unresolved_deltas(f, nr_unresolved);
1006                         sprintf(msg, "completed with %d local objects",
1007                                 nr_objects - nr_objects_initial);
1008                         stop_progress_msg(&progress, msg);
1009                         sha1close(f, tail_sha1, 0);
1010                         hashcpy(read_sha1, pack_sha1);
1011                         fixup_pack_header_footer(output_fd, pack_sha1,
1012                                                  curr_pack, nr_objects,
1013                                                  read_sha1, consumed_bytes-20);
1014                         if (hashcmp(read_sha1, tail_sha1) != 0)
1015                                 die("Unexpected tail checksum for %s "
1016                                     "(disk corruption?)", curr_pack);
1017                 }
1018                 if (nr_deltas != nr_resolved_deltas)
1019                         die("pack has %d unresolved deltas",
1020                             nr_deltas - nr_resolved_deltas);
1021         }
1022         free(deltas);
1023         if (strict)
1024                 check_objects();
1025
1026         idx_objects = xmalloc((nr_objects) * sizeof(struct pack_idx_entry *));
1027         for (i = 0; i < nr_objects; i++)
1028                 idx_objects[i] = &objects[i].idx;
1029         curr_index = write_idx_file(index_name, idx_objects, nr_objects, pack_sha1);
1030         free(idx_objects);
1031
1032         final(pack_name, curr_pack,
1033                 index_name, curr_index,
1034                 keep_name, keep_msg,
1035                 pack_sha1);
1036         free(objects);
1037         free(index_name_buf);
1038         free(keep_name_buf);
1039         if (pack_name == NULL)
1040                 free(curr_pack);
1041         if (index_name == NULL)
1042                 free(curr_index);
1043
1044         return 0;
1045 }