sort_in_topological_order(): avoid setting a commit flag
[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
12 static const char index_pack_usage[] =
13 "git-index-pack [-v] [-o <index-file>] [{ ---keep | --keep=<msg> }] [--strict] { <pack-file> | --stdin [--fix-thin] [<pack-file>] }";
14
15 struct object_entry
16 {
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 };
23
24 union delta_base {
25         unsigned char sha1[20];
26         off_t offset;
27 };
28
29 struct base_data {
30         struct base_data *base;
31         struct base_data *child;
32         struct object_entry *obj;
33         void *data;
34         unsigned long size;
35 };
36
37 /*
38  * Even if sizeof(union delta_base) == 24 on 64-bit archs, we really want
39  * to memcmp() only the first 20 bytes.
40  */
41 #define UNION_BASE_SZ   20
42
43 #define FLAG_LINK (1u<<20)
44 #define FLAG_CHECKED (1u<<21)
45
46 struct delta_entry
47 {
48         union delta_base base;
49         int obj_no;
50 };
51
52 static struct object_entry *objects;
53 static struct delta_entry *deltas;
54 static struct base_data *base_cache;
55 static size_t base_cache_used;
56 static int nr_objects;
57 static int nr_deltas;
58 static int nr_resolved_deltas;
59
60 static int from_stdin;
61 static int strict;
62 static int verbose;
63
64 static struct progress *progress;
65
66 /* We always read in 4kB chunks. */
67 static unsigned char input_buffer[4096];
68 static unsigned int input_offset, input_len;
69 static off_t consumed_bytes;
70 static SHA_CTX input_ctx;
71 static uint32_t input_crc32;
72 static int input_fd, output_fd, pack_fd;
73
74 static int mark_link(struct object *obj, int type, void *data)
75 {
76         if (!obj)
77                 return -1;
78
79         if (type != OBJ_ANY && obj->type != type)
80                 die("object type mismatch at %s", sha1_to_hex(obj->sha1));
81
82         obj->flags |= FLAG_LINK;
83         return 0;
84 }
85
86 /* The content of each linked object must have been checked
87    or it must be already present in the object database */
88 static void check_object(struct object *obj)
89 {
90         if (!obj)
91                 return;
92
93         if (!(obj->flags & FLAG_LINK))
94                 return;
95
96         if (!(obj->flags & FLAG_CHECKED)) {
97                 unsigned long size;
98                 int type = sha1_object_info(obj->sha1, &size);
99                 if (type != obj->type || type <= 0)
100                         die("object of unexpected type");
101                 obj->flags |= FLAG_CHECKED;
102                 return;
103         }
104 }
105
106 static void check_objects(void)
107 {
108         unsigned i, max;
109
110         max = get_max_object_index();
111         for (i = 0; i < max; i++)
112                 check_object(get_indexed_object(i));
113 }
114
115
116 /* Discard current buffer used content. */
117 static void flush(void)
118 {
119         if (input_offset) {
120                 if (output_fd >= 0)
121                         write_or_die(output_fd, input_buffer, input_offset);
122                 SHA1_Update(&input_ctx, input_buffer, input_offset);
123                 memmove(input_buffer, input_buffer + input_offset, input_len);
124                 input_offset = 0;
125         }
126 }
127
128 /*
129  * Make sure at least "min" bytes are available in the buffer, and
130  * return the pointer to the buffer.
131  */
132 static void *fill(int min)
133 {
134         if (min <= input_len)
135                 return input_buffer + input_offset;
136         if (min > sizeof(input_buffer))
137                 die("cannot fill %d bytes", min);
138         flush();
139         do {
140                 ssize_t ret = xread(input_fd, input_buffer + input_len,
141                                 sizeof(input_buffer) - input_len);
142                 if (ret <= 0) {
143                         if (!ret)
144                                 die("early EOF");
145                         die("read error on input: %s", strerror(errno));
146                 }
147                 input_len += ret;
148                 if (from_stdin)
149                         display_throughput(progress, consumed_bytes + input_len);
150         } while (input_len < min);
151         return input_buffer;
152 }
153
154 static void use(int bytes)
155 {
156         if (bytes > input_len)
157                 die("used more bytes than were available");
158         input_crc32 = crc32(input_crc32, input_buffer + input_offset, bytes);
159         input_len -= bytes;
160         input_offset += bytes;
161
162         /* make sure off_t is sufficiently large not to wrap */
163         if (consumed_bytes > consumed_bytes + bytes)
164                 die("pack too large for current definition of off_t");
165         consumed_bytes += bytes;
166 }
167
168 static char *open_pack_file(char *pack_name)
169 {
170         if (from_stdin) {
171                 input_fd = 0;
172                 if (!pack_name) {
173                         static char tmpfile[PATH_MAX];
174                         snprintf(tmpfile, sizeof(tmpfile),
175                                  "%s/tmp_pack_XXXXXX", get_object_directory());
176                         output_fd = xmkstemp(tmpfile);
177                         pack_name = xstrdup(tmpfile);
178                 } else
179                         output_fd = open(pack_name, O_CREAT|O_EXCL|O_RDWR, 0600);
180                 if (output_fd < 0)
181                         die("unable to create %s: %s\n", pack_name, strerror(errno));
182                 pack_fd = output_fd;
183         } else {
184                 input_fd = open(pack_name, O_RDONLY);
185                 if (input_fd < 0)
186                         die("cannot open packfile '%s': %s",
187                             pack_name, strerror(errno));
188                 output_fd = -1;
189                 pack_fd = input_fd;
190         }
191         SHA1_Init(&input_ctx);
192         return pack_name;
193 }
194
195 static void parse_pack_header(void)
196 {
197         struct pack_header *hdr = fill(sizeof(struct pack_header));
198
199         /* Header consistency check */
200         if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
201                 die("pack signature mismatch");
202         if (!pack_version_ok(hdr->hdr_version))
203                 die("pack version %d unsupported", ntohl(hdr->hdr_version));
204
205         nr_objects = ntohl(hdr->hdr_entries);
206         use(sizeof(struct pack_header));
207 }
208
209 static void bad_object(unsigned long offset, const char *format,
210                        ...) NORETURN __attribute__((format (printf, 2, 3)));
211
212 static void bad_object(unsigned long offset, const char *format, ...)
213 {
214         va_list params;
215         char buf[1024];
216
217         va_start(params, format);
218         vsnprintf(buf, sizeof(buf), format, params);
219         va_end(params);
220         die("pack has bad object at offset %lu: %s", offset, buf);
221 }
222
223 static void prune_base_data(struct base_data *retain)
224 {
225         struct base_data *b = base_cache;
226         for (b = base_cache;
227              base_cache_used > delta_base_cache_limit && b;
228              b = b->child) {
229                 if (b->data && b != retain) {
230                         free(b->data);
231                         b->data = NULL;
232                         base_cache_used -= b->size;
233                 }
234         }
235 }
236
237 static void link_base_data(struct base_data *base, struct base_data *c)
238 {
239         if (base)
240                 base->child = c;
241         else
242                 base_cache = c;
243
244         c->base = base;
245         c->child = NULL;
246         base_cache_used += c->size;
247         prune_base_data(c);
248 }
249
250 static void unlink_base_data(struct base_data *c)
251 {
252         struct base_data *base = c->base;
253         if (base)
254                 base->child = NULL;
255         else
256                 base_cache = NULL;
257         if (c->data) {
258                 free(c->data);
259                 base_cache_used -= c->size;
260         }
261 }
262
263 static void *unpack_entry_data(unsigned long offset, unsigned long size)
264 {
265         z_stream stream;
266         void *buf = xmalloc(size);
267
268         memset(&stream, 0, sizeof(stream));
269         stream.next_out = buf;
270         stream.avail_out = size;
271         stream.next_in = fill(1);
272         stream.avail_in = input_len;
273         inflateInit(&stream);
274
275         for (;;) {
276                 int ret = inflate(&stream, 0);
277                 use(input_len - stream.avail_in);
278                 if (stream.total_out == size && ret == Z_STREAM_END)
279                         break;
280                 if (ret != Z_OK)
281                         bad_object(offset, "inflate returned %d", ret);
282                 stream.next_in = fill(1);
283                 stream.avail_in = input_len;
284         }
285         inflateEnd(&stream);
286         return buf;
287 }
288
289 static void *unpack_raw_entry(struct object_entry *obj, union delta_base *delta_base)
290 {
291         unsigned char *p, c;
292         unsigned long size;
293         off_t base_offset;
294         unsigned shift;
295         void *data;
296
297         obj->idx.offset = consumed_bytes;
298         input_crc32 = crc32(0, Z_NULL, 0);
299
300         p = fill(1);
301         c = *p;
302         use(1);
303         obj->type = (c >> 4) & 7;
304         size = (c & 15);
305         shift = 4;
306         while (c & 0x80) {
307                 p = fill(1);
308                 c = *p;
309                 use(1);
310                 size += (c & 0x7fUL) << shift;
311                 shift += 7;
312         }
313         obj->size = size;
314
315         switch (obj->type) {
316         case OBJ_REF_DELTA:
317                 hashcpy(delta_base->sha1, fill(20));
318                 use(20);
319                 break;
320         case OBJ_OFS_DELTA:
321                 memset(delta_base, 0, sizeof(*delta_base));
322                 p = fill(1);
323                 c = *p;
324                 use(1);
325                 base_offset = c & 127;
326                 while (c & 128) {
327                         base_offset += 1;
328                         if (!base_offset || MSB(base_offset, 7))
329                                 bad_object(obj->idx.offset, "offset value overflow for delta base object");
330                         p = fill(1);
331                         c = *p;
332                         use(1);
333                         base_offset = (base_offset << 7) + (c & 127);
334                 }
335                 delta_base->offset = obj->idx.offset - base_offset;
336                 if (delta_base->offset >= obj->idx.offset)
337                         bad_object(obj->idx.offset, "delta base offset is out of bound");
338                 break;
339         case OBJ_COMMIT:
340         case OBJ_TREE:
341         case OBJ_BLOB:
342         case OBJ_TAG:
343                 break;
344         default:
345                 bad_object(obj->idx.offset, "unknown object type %d", obj->type);
346         }
347         obj->hdr_size = consumed_bytes - obj->idx.offset;
348
349         data = unpack_entry_data(obj->idx.offset, obj->size);
350         obj->idx.crc32 = input_crc32;
351         return data;
352 }
353
354 static void *get_data_from_pack(struct object_entry *obj)
355 {
356         off_t from = obj[0].idx.offset + obj[0].hdr_size;
357         unsigned long len = obj[1].idx.offset - from;
358         unsigned long rdy = 0;
359         unsigned char *src, *data;
360         z_stream stream;
361         int st;
362
363         src = xmalloc(len);
364         data = src;
365         do {
366                 ssize_t n = pread(pack_fd, data + rdy, len - rdy, from + rdy);
367                 if (n <= 0)
368                         die("cannot pread pack file: %s", strerror(errno));
369                 rdy += n;
370         } while (rdy < len);
371         data = xmalloc(obj->size);
372         memset(&stream, 0, sizeof(stream));
373         stream.next_out = data;
374         stream.avail_out = obj->size;
375         stream.next_in = src;
376         stream.avail_in = len;
377         inflateInit(&stream);
378         while ((st = inflate(&stream, Z_FINISH)) == Z_OK);
379         inflateEnd(&stream);
380         if (st != Z_STREAM_END || stream.total_out != obj->size)
381                 die("serious inflate inconsistency");
382         free(src);
383         return data;
384 }
385
386 static int find_delta(const union delta_base *base)
387 {
388         int first = 0, last = nr_deltas;
389
390         while (first < last) {
391                 int next = (first + last) / 2;
392                 struct delta_entry *delta = &deltas[next];
393                 int cmp;
394
395                 cmp = memcmp(base, &delta->base, UNION_BASE_SZ);
396                 if (!cmp)
397                         return next;
398                 if (cmp < 0) {
399                         last = next;
400                         continue;
401                 }
402                 first = next+1;
403         }
404         return -first-1;
405 }
406
407 static int find_delta_children(const union delta_base *base,
408                                int *first_index, int *last_index)
409 {
410         int first = find_delta(base);
411         int last = first;
412         int end = nr_deltas - 1;
413
414         if (first < 0)
415                 return -1;
416         while (first > 0 && !memcmp(&deltas[first - 1].base, base, UNION_BASE_SZ))
417                 --first;
418         while (last < end && !memcmp(&deltas[last + 1].base, base, UNION_BASE_SZ))
419                 ++last;
420         *first_index = first;
421         *last_index = last;
422         return 0;
423 }
424
425 static void sha1_object(const void *data, unsigned long size,
426                         enum object_type type, unsigned char *sha1)
427 {
428         hash_sha1_file(data, size, typename(type), sha1);
429         if (has_sha1_file(sha1)) {
430                 void *has_data;
431                 enum object_type has_type;
432                 unsigned long has_size;
433                 has_data = read_sha1_file(sha1, &has_type, &has_size);
434                 if (!has_data)
435                         die("cannot read existing object %s", sha1_to_hex(sha1));
436                 if (size != has_size || type != has_type ||
437                     memcmp(data, has_data, size) != 0)
438                         die("SHA1 COLLISION FOUND WITH %s !", sha1_to_hex(sha1));
439                 free(has_data);
440         }
441         if (strict) {
442                 if (type == OBJ_BLOB) {
443                         struct blob *blob = lookup_blob(sha1);
444                         if (blob)
445                                 blob->object.flags |= FLAG_CHECKED;
446                         else
447                                 die("invalid blob object %s", sha1_to_hex(sha1));
448                 } else {
449                         struct object *obj;
450                         int eaten;
451                         void *buf = (void *) data;
452
453                         /*
454                          * we do not need to free the memory here, as the
455                          * buf is deleted by the caller.
456                          */
457                         obj = parse_object_buffer(sha1, type, size, buf, &eaten);
458                         if (!obj)
459                                 die("invalid %s", typename(type));
460                         if (fsck_object(obj, 1, fsck_error_function))
461                                 die("Error in object");
462                         if (fsck_walk(obj, mark_link, 0))
463                                 die("Not all child objects of %s are reachable", sha1_to_hex(obj->sha1));
464
465                         if (obj->type == OBJ_TREE) {
466                                 struct tree *item = (struct tree *) obj;
467                                 item->buffer = NULL;
468                         }
469                         if (obj->type == OBJ_COMMIT) {
470                                 struct commit *commit = (struct commit *) obj;
471                                 commit->buffer = NULL;
472                         }
473                         obj->flags |= FLAG_CHECKED;
474                 }
475         }
476 }
477
478 static void *get_base_data(struct base_data *c)
479 {
480         if (!c->data) {
481                 struct object_entry *obj = c->obj;
482
483                 if (obj->type == OBJ_REF_DELTA || obj->type == OBJ_OFS_DELTA) {
484                         void *base = get_base_data(c->base);
485                         void *raw = get_data_from_pack(obj);
486                         c->data = patch_delta(
487                                 base, c->base->size,
488                                 raw, obj->size,
489                                 &c->size);
490                         free(raw);
491                         if (!c->data)
492                                 bad_object(obj->idx.offset, "failed to apply delta");
493                 } else
494                         c->data = get_data_from_pack(obj);
495
496                 base_cache_used += c->size;
497                 prune_base_data(c);
498         }
499         return c->data;
500 }
501
502 static void resolve_delta(struct object_entry *delta_obj,
503                           struct base_data *base_obj, enum object_type type)
504 {
505         void *delta_data;
506         unsigned long delta_size;
507         union delta_base delta_base;
508         int j, first, last;
509         struct base_data result;
510
511         delta_obj->real_type = type;
512         delta_data = get_data_from_pack(delta_obj);
513         delta_size = delta_obj->size;
514         result.data = patch_delta(get_base_data(base_obj), base_obj->size,
515                              delta_data, delta_size,
516                              &result.size);
517         free(delta_data);
518         if (!result.data)
519                 bad_object(delta_obj->idx.offset, "failed to apply delta");
520         sha1_object(result.data, result.size, type, delta_obj->idx.sha1);
521         nr_resolved_deltas++;
522
523         result.obj = delta_obj;
524         link_base_data(base_obj, &result);
525
526         hashcpy(delta_base.sha1, delta_obj->idx.sha1);
527         if (!find_delta_children(&delta_base, &first, &last)) {
528                 for (j = first; j <= last; j++) {
529                         struct object_entry *child = objects + deltas[j].obj_no;
530                         if (child->real_type == OBJ_REF_DELTA)
531                                 resolve_delta(child, &result, type);
532                 }
533         }
534
535         memset(&delta_base, 0, sizeof(delta_base));
536         delta_base.offset = delta_obj->idx.offset;
537         if (!find_delta_children(&delta_base, &first, &last)) {
538                 for (j = first; j <= last; j++) {
539                         struct object_entry *child = objects + deltas[j].obj_no;
540                         if (child->real_type == OBJ_OFS_DELTA)
541                                 resolve_delta(child, &result, type);
542                 }
543         }
544
545         unlink_base_data(&result);
546 }
547
548 static int compare_delta_entry(const void *a, const void *b)
549 {
550         const struct delta_entry *delta_a = a;
551         const struct delta_entry *delta_b = b;
552         return memcmp(&delta_a->base, &delta_b->base, UNION_BASE_SZ);
553 }
554
555 /* Parse all objects and return the pack content SHA1 hash */
556 static void parse_pack_objects(unsigned char *sha1)
557 {
558         int i;
559         struct delta_entry *delta = deltas;
560         struct stat st;
561
562         /*
563          * First pass:
564          * - find locations of all objects;
565          * - calculate SHA1 of all non-delta objects;
566          * - remember base (SHA1 or offset) for all deltas.
567          */
568         if (verbose)
569                 progress = start_progress(
570                                 from_stdin ? "Receiving objects" : "Indexing objects",
571                                 nr_objects);
572         for (i = 0; i < nr_objects; i++) {
573                 struct object_entry *obj = &objects[i];
574                 void *data = unpack_raw_entry(obj, &delta->base);
575                 obj->real_type = obj->type;
576                 if (obj->type == OBJ_REF_DELTA || obj->type == OBJ_OFS_DELTA) {
577                         nr_deltas++;
578                         delta->obj_no = i;
579                         delta++;
580                 } else
581                         sha1_object(data, obj->size, obj->type, obj->idx.sha1);
582                 free(data);
583                 display_progress(progress, i+1);
584         }
585         objects[i].idx.offset = consumed_bytes;
586         stop_progress(&progress);
587
588         /* Check pack integrity */
589         flush();
590         SHA1_Final(sha1, &input_ctx);
591         if (hashcmp(fill(20), sha1))
592                 die("pack is corrupted (SHA1 mismatch)");
593         use(20);
594
595         /* If input_fd is a file, we should have reached its end now. */
596         if (fstat(input_fd, &st))
597                 die("cannot fstat packfile: %s", strerror(errno));
598         if (S_ISREG(st.st_mode) &&
599                         lseek(input_fd, 0, SEEK_CUR) - input_len != st.st_size)
600                 die("pack has junk at the end");
601
602         if (!nr_deltas)
603                 return;
604
605         /* Sort deltas by base SHA1/offset for fast searching */
606         qsort(deltas, nr_deltas, sizeof(struct delta_entry),
607               compare_delta_entry);
608
609         /*
610          * Second pass:
611          * - for all non-delta objects, look if it is used as a base for
612          *   deltas;
613          * - if used as a base, uncompress the object and apply all deltas,
614          *   recursively checking if the resulting object is used as a base
615          *   for some more deltas.
616          */
617         if (verbose)
618                 progress = start_progress("Resolving deltas", nr_deltas);
619         for (i = 0; i < nr_objects; i++) {
620                 struct object_entry *obj = &objects[i];
621                 union delta_base base;
622                 int j, ref, ref_first, ref_last, ofs, ofs_first, ofs_last;
623                 struct base_data base_obj;
624
625                 if (obj->type == OBJ_REF_DELTA || obj->type == OBJ_OFS_DELTA)
626                         continue;
627                 hashcpy(base.sha1, obj->idx.sha1);
628                 ref = !find_delta_children(&base, &ref_first, &ref_last);
629                 memset(&base, 0, sizeof(base));
630                 base.offset = obj->idx.offset;
631                 ofs = !find_delta_children(&base, &ofs_first, &ofs_last);
632                 if (!ref && !ofs)
633                         continue;
634                 base_obj.data = get_data_from_pack(obj);
635                 base_obj.size = obj->size;
636                 base_obj.obj = obj;
637                 link_base_data(NULL, &base_obj);
638
639                 if (ref)
640                         for (j = ref_first; j <= ref_last; j++) {
641                                 struct object_entry *child = objects + deltas[j].obj_no;
642                                 if (child->real_type == OBJ_REF_DELTA)
643                                         resolve_delta(child, &base_obj, obj->type);
644                         }
645                 if (ofs)
646                         for (j = ofs_first; j <= ofs_last; j++) {
647                                 struct object_entry *child = objects + deltas[j].obj_no;
648                                 if (child->real_type == OBJ_OFS_DELTA)
649                                         resolve_delta(child, &base_obj, obj->type);
650                         }
651                 unlink_base_data(&base_obj);
652                 display_progress(progress, nr_resolved_deltas);
653         }
654 }
655
656 static int write_compressed(int fd, void *in, unsigned int size, uint32_t *obj_crc)
657 {
658         z_stream stream;
659         unsigned long maxsize;
660         void *out;
661
662         memset(&stream, 0, sizeof(stream));
663         deflateInit(&stream, zlib_compression_level);
664         maxsize = deflateBound(&stream, size);
665         out = xmalloc(maxsize);
666
667         /* Compress it */
668         stream.next_in = in;
669         stream.avail_in = size;
670         stream.next_out = out;
671         stream.avail_out = maxsize;
672         while (deflate(&stream, Z_FINISH) == Z_OK);
673         deflateEnd(&stream);
674
675         size = stream.total_out;
676         write_or_die(fd, out, size);
677         *obj_crc = crc32(*obj_crc, out, size);
678         free(out);
679         return size;
680 }
681
682 static struct object_entry *append_obj_to_pack(
683                                const unsigned char *sha1, void *buf,
684                                unsigned long size, enum object_type type)
685 {
686         struct object_entry *obj = &objects[nr_objects++];
687         unsigned char header[10];
688         unsigned long s = size;
689         int n = 0;
690         unsigned char c = (type << 4) | (s & 15);
691         s >>= 4;
692         while (s) {
693                 header[n++] = c | 0x80;
694                 c = s & 0x7f;
695                 s >>= 7;
696         }
697         header[n++] = c;
698         write_or_die(output_fd, header, n);
699         obj[0].idx.crc32 = crc32(0, Z_NULL, 0);
700         obj[0].idx.crc32 = crc32(obj[0].idx.crc32, header, n);
701         obj[0].size = size;
702         obj[0].hdr_size = n;
703         obj[0].type = type;
704         obj[0].real_type = type;
705         obj[1].idx.offset = obj[0].idx.offset + n;
706         obj[1].idx.offset += write_compressed(output_fd, buf, size, &obj[0].idx.crc32);
707         hashcpy(obj->idx.sha1, sha1);
708         return obj;
709 }
710
711 static int delta_pos_compare(const void *_a, const void *_b)
712 {
713         struct delta_entry *a = *(struct delta_entry **)_a;
714         struct delta_entry *b = *(struct delta_entry **)_b;
715         return a->obj_no - b->obj_no;
716 }
717
718 static void fix_unresolved_deltas(int nr_unresolved)
719 {
720         struct delta_entry **sorted_by_pos;
721         int i, n = 0;
722
723         /*
724          * Since many unresolved deltas may well be themselves base objects
725          * for more unresolved deltas, we really want to include the
726          * smallest number of base objects that would cover as much delta
727          * as possible by picking the
728          * trunc deltas first, allowing for other deltas to resolve without
729          * additional base objects.  Since most base objects are to be found
730          * before deltas depending on them, a good heuristic is to start
731          * resolving deltas in the same order as their position in the pack.
732          */
733         sorted_by_pos = xmalloc(nr_unresolved * sizeof(*sorted_by_pos));
734         for (i = 0; i < nr_deltas; i++) {
735                 if (objects[deltas[i].obj_no].real_type != OBJ_REF_DELTA)
736                         continue;
737                 sorted_by_pos[n++] = &deltas[i];
738         }
739         qsort(sorted_by_pos, n, sizeof(*sorted_by_pos), delta_pos_compare);
740
741         for (i = 0; i < n; i++) {
742                 struct delta_entry *d = sorted_by_pos[i];
743                 enum object_type type;
744                 int j, first, last;
745                 struct base_data base_obj;
746
747                 if (objects[d->obj_no].real_type != OBJ_REF_DELTA)
748                         continue;
749                 base_obj.data = read_sha1_file(d->base.sha1, &type, &base_obj.size);
750                 if (!base_obj.data)
751                         continue;
752
753                 if (check_sha1_signature(d->base.sha1, base_obj.data,
754                                 base_obj.size, typename(type)))
755                         die("local object %s is corrupt", sha1_to_hex(d->base.sha1));
756                 base_obj.obj = append_obj_to_pack(d->base.sha1, base_obj.data,
757                         base_obj.size, type);
758                 link_base_data(NULL, &base_obj);
759
760                 find_delta_children(&d->base, &first, &last);
761                 for (j = first; j <= last; j++) {
762                         struct object_entry *child = objects + deltas[j].obj_no;
763                         if (child->real_type == OBJ_REF_DELTA)
764                                 resolve_delta(child, &base_obj, type);
765                 }
766
767                 unlink_base_data(&base_obj);
768                 display_progress(progress, nr_resolved_deltas);
769         }
770         free(sorted_by_pos);
771 }
772
773 static void final(const char *final_pack_name, const char *curr_pack_name,
774                   const char *final_index_name, const char *curr_index_name,
775                   const char *keep_name, const char *keep_msg,
776                   unsigned char *sha1)
777 {
778         const char *report = "pack";
779         char name[PATH_MAX];
780         int err;
781
782         if (!from_stdin) {
783                 close(input_fd);
784         } else {
785                 fsync_or_die(output_fd, curr_pack_name);
786                 err = close(output_fd);
787                 if (err)
788                         die("error while closing pack file: %s", strerror(errno));
789                 chmod(curr_pack_name, 0444);
790         }
791
792         if (keep_msg) {
793                 int keep_fd, keep_msg_len = strlen(keep_msg);
794                 if (!keep_name) {
795                         snprintf(name, sizeof(name), "%s/pack/pack-%s.keep",
796                                  get_object_directory(), sha1_to_hex(sha1));
797                         keep_name = name;
798                 }
799                 keep_fd = open(keep_name, O_RDWR|O_CREAT|O_EXCL, 0600);
800                 if (keep_fd < 0) {
801                         if (errno != EEXIST)
802                                 die("cannot write keep file");
803                 } else {
804                         if (keep_msg_len > 0) {
805                                 write_or_die(keep_fd, keep_msg, keep_msg_len);
806                                 write_or_die(keep_fd, "\n", 1);
807                         }
808                         if (close(keep_fd) != 0)
809                                 die("cannot write keep file");
810                         report = "keep";
811                 }
812         }
813
814         if (final_pack_name != curr_pack_name) {
815                 if (!final_pack_name) {
816                         snprintf(name, sizeof(name), "%s/pack/pack-%s.pack",
817                                  get_object_directory(), sha1_to_hex(sha1));
818                         final_pack_name = name;
819                 }
820                 if (move_temp_to_file(curr_pack_name, final_pack_name))
821                         die("cannot store pack file");
822         }
823
824         chmod(curr_index_name, 0444);
825         if (final_index_name != curr_index_name) {
826                 if (!final_index_name) {
827                         snprintf(name, sizeof(name), "%s/pack/pack-%s.idx",
828                                  get_object_directory(), sha1_to_hex(sha1));
829                         final_index_name = name;
830                 }
831                 if (move_temp_to_file(curr_index_name, final_index_name))
832                         die("cannot store index file");
833         }
834
835         if (!from_stdin) {
836                 printf("%s\n", sha1_to_hex(sha1));
837         } else {
838                 char buf[48];
839                 int len = snprintf(buf, sizeof(buf), "%s\t%s\n",
840                                    report, sha1_to_hex(sha1));
841                 write_or_die(1, buf, len);
842
843                 /*
844                  * Let's just mimic git-unpack-objects here and write
845                  * the last part of the input buffer to stdout.
846                  */
847                 while (input_len) {
848                         err = xwrite(1, input_buffer + input_offset, input_len);
849                         if (err <= 0)
850                                 break;
851                         input_len -= err;
852                         input_offset += err;
853                 }
854         }
855 }
856
857 static int git_index_pack_config(const char *k, const char *v, void *cb)
858 {
859         if (!strcmp(k, "pack.indexversion")) {
860                 pack_idx_default_version = git_config_int(k, v);
861                 if (pack_idx_default_version > 2)
862                         die("bad pack.indexversion=%d", pack_idx_default_version);
863                 return 0;
864         }
865         return git_default_config(k, v, cb);
866 }
867
868 int main(int argc, char **argv)
869 {
870         int i, fix_thin_pack = 0;
871         char *curr_pack, *pack_name = NULL;
872         char *curr_index, *index_name = NULL;
873         const char *keep_name = NULL, *keep_msg = NULL;
874         char *index_name_buf = NULL, *keep_name_buf = NULL;
875         struct pack_idx_entry **idx_objects;
876         unsigned char sha1[20];
877
878         git_config(git_index_pack_config, NULL);
879
880         for (i = 1; i < argc; i++) {
881                 char *arg = argv[i];
882
883                 if (*arg == '-') {
884                         if (!strcmp(arg, "--stdin")) {
885                                 from_stdin = 1;
886                         } else if (!strcmp(arg, "--fix-thin")) {
887                                 fix_thin_pack = 1;
888                         } else if (!strcmp(arg, "--strict")) {
889                                 strict = 1;
890                         } else if (!strcmp(arg, "--keep")) {
891                                 keep_msg = "";
892                         } else if (!prefixcmp(arg, "--keep=")) {
893                                 keep_msg = arg + 7;
894                         } else if (!prefixcmp(arg, "--pack_header=")) {
895                                 struct pack_header *hdr;
896                                 char *c;
897
898                                 hdr = (struct pack_header *)input_buffer;
899                                 hdr->hdr_signature = htonl(PACK_SIGNATURE);
900                                 hdr->hdr_version = htonl(strtoul(arg + 14, &c, 10));
901                                 if (*c != ',')
902                                         die("bad %s", arg);
903                                 hdr->hdr_entries = htonl(strtoul(c + 1, &c, 10));
904                                 if (*c)
905                                         die("bad %s", arg);
906                                 input_len = sizeof(*hdr);
907                         } else if (!strcmp(arg, "-v")) {
908                                 verbose = 1;
909                         } else if (!strcmp(arg, "-o")) {
910                                 if (index_name || (i+1) >= argc)
911                                         usage(index_pack_usage);
912                                 index_name = argv[++i];
913                         } else if (!prefixcmp(arg, "--index-version=")) {
914                                 char *c;
915                                 pack_idx_default_version = strtoul(arg + 16, &c, 10);
916                                 if (pack_idx_default_version > 2)
917                                         die("bad %s", arg);
918                                 if (*c == ',')
919                                         pack_idx_off32_limit = strtoul(c+1, &c, 0);
920                                 if (*c || pack_idx_off32_limit & 0x80000000)
921                                         die("bad %s", arg);
922                         } else
923                                 usage(index_pack_usage);
924                         continue;
925                 }
926
927                 if (pack_name)
928                         usage(index_pack_usage);
929                 pack_name = arg;
930         }
931
932         if (!pack_name && !from_stdin)
933                 usage(index_pack_usage);
934         if (fix_thin_pack && !from_stdin)
935                 die("--fix-thin cannot be used without --stdin");
936         if (!index_name && pack_name) {
937                 int len = strlen(pack_name);
938                 if (!has_extension(pack_name, ".pack"))
939                         die("packfile name '%s' does not end with '.pack'",
940                             pack_name);
941                 index_name_buf = xmalloc(len);
942                 memcpy(index_name_buf, pack_name, len - 5);
943                 strcpy(index_name_buf + len - 5, ".idx");
944                 index_name = index_name_buf;
945         }
946         if (keep_msg && !keep_name && pack_name) {
947                 int len = strlen(pack_name);
948                 if (!has_extension(pack_name, ".pack"))
949                         die("packfile name '%s' does not end with '.pack'",
950                             pack_name);
951                 keep_name_buf = xmalloc(len);
952                 memcpy(keep_name_buf, pack_name, len - 5);
953                 strcpy(keep_name_buf + len - 5, ".keep");
954                 keep_name = keep_name_buf;
955         }
956
957         curr_pack = open_pack_file(pack_name);
958         parse_pack_header();
959         objects = xmalloc((nr_objects + 1) * sizeof(struct object_entry));
960         deltas = xmalloc(nr_objects * sizeof(struct delta_entry));
961         parse_pack_objects(sha1);
962         if (nr_deltas == nr_resolved_deltas) {
963                 stop_progress(&progress);
964                 /* Flush remaining pack final 20-byte SHA1. */
965                 flush();
966         } else {
967                 if (fix_thin_pack) {
968                         char msg[48];
969                         int nr_unresolved = nr_deltas - nr_resolved_deltas;
970                         int nr_objects_initial = nr_objects;
971                         if (nr_unresolved <= 0)
972                                 die("confusion beyond insanity");
973                         objects = xrealloc(objects,
974                                            (nr_objects + nr_unresolved + 1)
975                                            * sizeof(*objects));
976                         fix_unresolved_deltas(nr_unresolved);
977                         sprintf(msg, "completed with %d local objects",
978                                 nr_objects - nr_objects_initial);
979                         stop_progress_msg(&progress, msg);
980                         fixup_pack_header_footer(output_fd, sha1,
981                                                  curr_pack, nr_objects);
982                 }
983                 if (nr_deltas != nr_resolved_deltas)
984                         die("pack has %d unresolved deltas",
985                             nr_deltas - nr_resolved_deltas);
986         }
987         free(deltas);
988         if (strict)
989                 check_objects();
990
991         idx_objects = xmalloc((nr_objects) * sizeof(struct pack_idx_entry *));
992         for (i = 0; i < nr_objects; i++)
993                 idx_objects[i] = &objects[i].idx;
994         curr_index = write_idx_file(index_name, idx_objects, nr_objects, sha1);
995         free(idx_objects);
996
997         final(pack_name, curr_pack,
998                 index_name, curr_index,
999                 keep_name, keep_msg,
1000                 sha1);
1001         free(objects);
1002         free(index_name_buf);
1003         free(keep_name_buf);
1004         if (pack_name == NULL)
1005                 free(curr_pack);
1006         if (index_name == NULL)
1007                 free(curr_index);
1008
1009         return 0;
1010 }