Code

allow for undeltified objects not to be reused
[git.git] / builtin-pack-objects.c
1 #include "builtin.h"
2 #include "cache.h"
3 #include "object.h"
4 #include "blob.h"
5 #include "commit.h"
6 #include "tag.h"
7 #include "tree.h"
8 #include "delta.h"
9 #include "pack.h"
10 #include "csum-file.h"
11 #include "tree-walk.h"
12 #include "diff.h"
13 #include "revision.h"
14 #include "list-objects.h"
15 #include "progress.h"
17 static const char pack_usage[] = "\
18 git-pack-objects [{ -q | --progress | --all-progress }] \n\
19         [--local] [--incremental] [--window=N] [--depth=N] \n\
20         [--no-reuse-delta] [--no-reuse-object] [--delta-base-offset] \n\
21         [--non-empty] [--revs [--unpacked | --all]*] [--reflog] \n\
22         [--stdout | base-name] [<ref-list | <object-list]";
24 struct object_entry {
25         unsigned char sha1[20];
26         uint32_t crc32;         /* crc of raw pack data for this object */
27         off_t offset;           /* offset into the final pack file */
28         unsigned long size;     /* uncompressed size */
29         unsigned int hash;      /* name hint hash */
30         unsigned int depth;     /* delta depth */
31         struct packed_git *in_pack;     /* already in pack */
32         off_t in_pack_offset;
33         struct object_entry *delta;     /* delta base object */
34         struct object_entry *delta_child; /* deltified objects who bases me */
35         struct object_entry *delta_sibling; /* other deltified objects who
36                                              * uses the same base as me
37                                              */
38         unsigned long delta_size;       /* delta data size (uncompressed) */
39         enum object_type type;
40         enum object_type in_pack_type;  /* could be delta */
41         unsigned char in_pack_header_size;
42         unsigned char preferred_base; /* we do not pack this, but is available
43                                        * to be used as the base objectto delta
44                                        * objects against.
45                                        */
46 };
48 /*
49  * Objects we are going to pack are collected in objects array (dynamically
50  * expanded).  nr_objects & nr_alloc controls this array.  They are stored
51  * in the order we see -- typically rev-list --objects order that gives us
52  * nice "minimum seek" order.
53  */
54 static struct object_entry *objects;
55 static uint32_t nr_objects, nr_alloc, nr_result;
57 static int non_empty;
58 static int no_reuse_delta, no_reuse_object;
59 static int local;
60 static int incremental;
61 static int allow_ofs_delta;
62 static const char *pack_tmp_name, *idx_tmp_name;
63 static char tmpname[PATH_MAX];
64 static unsigned char pack_file_sha1[20];
65 static int progress = 1;
66 static int window = 10;
67 static int depth = 50;
68 static int pack_to_stdout;
69 static int num_preferred_base;
70 static struct progress progress_state;
72 /*
73  * The object names in objects array are hashed with this hashtable,
74  * to help looking up the entry by object name.
75  * This hashtable is built after all the objects are seen.
76  */
77 static int *object_ix;
78 static int object_ix_hashsz;
80 /*
81  * Pack index for existing packs give us easy access to the offsets into
82  * corresponding pack file where each object's data starts, but the entries
83  * do not store the size of the compressed representation (uncompressed
84  * size is easily available by examining the pack entry header).  It is
85  * also rather expensive to find the sha1 for an object given its offset.
86  *
87  * We build a hashtable of existing packs (pack_revindex), and keep reverse
88  * index here -- pack index file is sorted by object name mapping to offset;
89  * this pack_revindex[].revindex array is a list of offset/index_nr pairs
90  * ordered by offset, so if you know the offset of an object, next offset
91  * is where its packed representation ends and the index_nr can be used to
92  * get the object sha1 from the main index.
93  */
94 struct revindex_entry {
95         off_t offset;
96         unsigned int nr;
97 };
98 struct pack_revindex {
99         struct packed_git *p;
100         struct revindex_entry *revindex;
101 };
102 static struct  pack_revindex *pack_revindex;
103 static int pack_revindex_hashsz;
105 /*
106  * stats
107  */
108 static uint32_t written, written_delta;
109 static uint32_t reused, reused_delta;
111 static int pack_revindex_ix(struct packed_git *p)
113         unsigned long ui = (unsigned long)p;
114         int i;
116         ui = ui ^ (ui >> 16); /* defeat structure alignment */
117         i = (int)(ui % pack_revindex_hashsz);
118         while (pack_revindex[i].p) {
119                 if (pack_revindex[i].p == p)
120                         return i;
121                 if (++i == pack_revindex_hashsz)
122                         i = 0;
123         }
124         return -1 - i;
127 static void prepare_pack_ix(void)
129         int num;
130         struct packed_git *p;
131         for (num = 0, p = packed_git; p; p = p->next)
132                 num++;
133         if (!num)
134                 return;
135         pack_revindex_hashsz = num * 11;
136         pack_revindex = xcalloc(sizeof(*pack_revindex), pack_revindex_hashsz);
137         for (p = packed_git; p; p = p->next) {
138                 num = pack_revindex_ix(p);
139                 num = - 1 - num;
140                 pack_revindex[num].p = p;
141         }
142         /* revindex elements are lazily initialized */
145 static int cmp_offset(const void *a_, const void *b_)
147         const struct revindex_entry *a = a_;
148         const struct revindex_entry *b = b_;
149         return (a->offset < b->offset) ? -1 : (a->offset > b->offset) ? 1 : 0;
152 /*
153  * Ordered list of offsets of objects in the pack.
154  */
155 static void prepare_pack_revindex(struct pack_revindex *rix)
157         struct packed_git *p = rix->p;
158         int num_ent = p->num_objects;
159         int i;
160         const char *index = p->index_data;
162         rix->revindex = xmalloc(sizeof(*rix->revindex) * (num_ent + 1));
163         index += 4 * 256;
165         if (p->index_version > 1) {
166                 const uint32_t *off_32 =
167                         (uint32_t *)(index + 8 + p->num_objects * (20 + 4));
168                 const uint32_t *off_64 = off_32 + p->num_objects;
169                 for (i = 0; i < num_ent; i++) {
170                         uint32_t off = ntohl(*off_32++);
171                         if (!(off & 0x80000000)) {
172                                 rix->revindex[i].offset = off;
173                         } else {
174                                 rix->revindex[i].offset =
175                                         ((uint64_t)ntohl(*off_64++)) << 32;
176                                 rix->revindex[i].offset |=
177                                         ntohl(*off_64++);
178                         }
179                         rix->revindex[i].nr = i;
180                 }
181         } else {
182                 for (i = 0; i < num_ent; i++) {
183                         uint32_t hl = *((uint32_t *)(index + 24 * i));
184                         rix->revindex[i].offset = ntohl(hl);
185                         rix->revindex[i].nr = i;
186                 }
187         }
189         /* This knows the pack format -- the 20-byte trailer
190          * follows immediately after the last object data.
191          */
192         rix->revindex[num_ent].offset = p->pack_size - 20;
193         rix->revindex[num_ent].nr = -1;
194         qsort(rix->revindex, num_ent, sizeof(*rix->revindex), cmp_offset);
197 static struct revindex_entry * find_packed_object(struct packed_git *p,
198                                                   off_t ofs)
200         int num;
201         int lo, hi;
202         struct pack_revindex *rix;
203         struct revindex_entry *revindex;
204         num = pack_revindex_ix(p);
205         if (num < 0)
206                 die("internal error: pack revindex uninitialized");
207         rix = &pack_revindex[num];
208         if (!rix->revindex)
209                 prepare_pack_revindex(rix);
210         revindex = rix->revindex;
211         lo = 0;
212         hi = p->num_objects + 1;
213         do {
214                 int mi = (lo + hi) / 2;
215                 if (revindex[mi].offset == ofs) {
216                         return revindex + mi;
217                 }
218                 else if (ofs < revindex[mi].offset)
219                         hi = mi;
220                 else
221                         lo = mi + 1;
222         } while (lo < hi);
223         die("internal error: pack revindex corrupt");
226 static const unsigned char *find_packed_object_name(struct packed_git *p,
227                                                     off_t ofs)
229         struct revindex_entry *entry = find_packed_object(p, ofs);
230         return nth_packed_object_sha1(p, entry->nr);
233 static void *delta_against(void *buf, unsigned long size, struct object_entry *entry)
235         unsigned long othersize, delta_size;
236         enum object_type type;
237         void *otherbuf = read_sha1_file(entry->delta->sha1, &type, &othersize);
238         void *delta_buf;
240         if (!otherbuf)
241                 die("unable to read %s", sha1_to_hex(entry->delta->sha1));
242         delta_buf = diff_delta(otherbuf, othersize,
243                                buf, size, &delta_size, 0);
244         if (!delta_buf || delta_size != entry->delta_size)
245                 die("delta size changed");
246         free(buf);
247         free(otherbuf);
248         return delta_buf;
251 /*
252  * The per-object header is a pretty dense thing, which is
253  *  - first byte: low four bits are "size", then three bits of "type",
254  *    and the high bit is "size continues".
255  *  - each byte afterwards: low seven bits are size continuation,
256  *    with the high bit being "size continues"
257  */
258 static int encode_header(enum object_type type, unsigned long size, unsigned char *hdr)
260         int n = 1;
261         unsigned char c;
263         if (type < OBJ_COMMIT || type > OBJ_REF_DELTA)
264                 die("bad type %d", type);
266         c = (type << 4) | (size & 15);
267         size >>= 4;
268         while (size) {
269                 *hdr++ = c | 0x80;
270                 c = size & 0x7f;
271                 size >>= 7;
272                 n++;
273         }
274         *hdr = c;
275         return n;
278 /*
279  * we are going to reuse the existing object data as is.  make
280  * sure it is not corrupt.
281  */
282 static int check_pack_inflate(struct packed_git *p,
283                 struct pack_window **w_curs,
284                 off_t offset,
285                 off_t len,
286                 unsigned long expect)
288         z_stream stream;
289         unsigned char fakebuf[4096], *in;
290         int st;
292         memset(&stream, 0, sizeof(stream));
293         inflateInit(&stream);
294         do {
295                 in = use_pack(p, w_curs, offset, &stream.avail_in);
296                 stream.next_in = in;
297                 stream.next_out = fakebuf;
298                 stream.avail_out = sizeof(fakebuf);
299                 st = inflate(&stream, Z_FINISH);
300                 offset += stream.next_in - in;
301         } while (st == Z_OK || st == Z_BUF_ERROR);
302         inflateEnd(&stream);
303         return (st == Z_STREAM_END &&
304                 stream.total_out == expect &&
305                 stream.total_in == len) ? 0 : -1;
308 static int check_pack_crc(struct packed_git *p, struct pack_window **w_curs,
309                           off_t offset, off_t len, unsigned int nr)
311         const uint32_t *index_crc;
312         uint32_t data_crc = crc32(0, Z_NULL, 0);
314         do {
315                 unsigned int avail;
316                 void *data = use_pack(p, w_curs, offset, &avail);
317                 if (avail > len)
318                         avail = len;
319                 data_crc = crc32(data_crc, data, avail);
320                 offset += avail;
321                 len -= avail;
322         } while (len);
324         index_crc = p->index_data;
325         index_crc += 2 + 256 + p->num_objects * (20/4) + nr;
327         return data_crc != ntohl(*index_crc);
330 static void copy_pack_data(struct sha1file *f,
331                 struct packed_git *p,
332                 struct pack_window **w_curs,
333                 off_t offset,
334                 off_t len)
336         unsigned char *in;
337         unsigned int avail;
339         while (len) {
340                 in = use_pack(p, w_curs, offset, &avail);
341                 if (avail > len)
342                         avail = (unsigned int)len;
343                 sha1write(f, in, avail);
344                 offset += avail;
345                 len -= avail;
346         }
349 static int check_loose_inflate(unsigned char *data, unsigned long len, unsigned long expect)
351         z_stream stream;
352         unsigned char fakebuf[4096];
353         int st;
355         memset(&stream, 0, sizeof(stream));
356         stream.next_in = data;
357         stream.avail_in = len;
358         stream.next_out = fakebuf;
359         stream.avail_out = sizeof(fakebuf);
360         inflateInit(&stream);
362         while (1) {
363                 st = inflate(&stream, Z_FINISH);
364                 if (st == Z_STREAM_END || st == Z_OK) {
365                         st = (stream.total_out == expect &&
366                               stream.total_in == len) ? 0 : -1;
367                         break;
368                 }
369                 if (st != Z_BUF_ERROR) {
370                         st = -1;
371                         break;
372                 }
373                 stream.next_out = fakebuf;
374                 stream.avail_out = sizeof(fakebuf);
375         }
376         inflateEnd(&stream);
377         return st;
380 static int revalidate_loose_object(struct object_entry *entry,
381                                    unsigned char *map,
382                                    unsigned long mapsize)
384         /* we already know this is a loose object with new type header. */
385         enum object_type type;
386         unsigned long size, used;
388         if (pack_to_stdout)
389                 return 0;
391         used = unpack_object_header_gently(map, mapsize, &type, &size);
392         if (!used)
393                 return -1;
394         map += used;
395         mapsize -= used;
396         return check_loose_inflate(map, mapsize, size);
399 static unsigned long write_object(struct sha1file *f,
400                                   struct object_entry *entry)
402         unsigned long size;
403         enum object_type type;
404         void *buf;
405         unsigned char header[10];
406         unsigned hdrlen;
407         off_t datalen;
408         enum object_type obj_type;
409         int to_reuse = 0;
411         if (!pack_to_stdout)
412                 crc32_begin(f);
414         obj_type = entry->type;
415         if (no_reuse_object)
416                 to_reuse = 0;   /* explicit */
417         else if (!entry->in_pack)
418                 to_reuse = 0;   /* can't reuse what we don't have */
419         else if (obj_type == OBJ_REF_DELTA || obj_type == OBJ_OFS_DELTA)
420                 to_reuse = 1;   /* check_object() decided it for us */
421         else if (obj_type != entry->in_pack_type)
422                 to_reuse = 0;   /* pack has delta which is unusable */
423         else if (entry->delta)
424                 to_reuse = 0;   /* we want to pack afresh */
425         else
426                 to_reuse = 1;   /* we have it in-pack undeltified,
427                                  * and we do not need to deltify it.
428                                  */
430         if (!no_reuse_object && !entry->in_pack && !entry->delta) {
431                 unsigned char *map;
432                 unsigned long mapsize;
433                 map = map_sha1_file(entry->sha1, &mapsize);
434                 if (map && !legacy_loose_object(map)) {
435                         /* We can copy straight into the pack file */
436                         if (revalidate_loose_object(entry, map, mapsize))
437                                 die("corrupt loose object %s",
438                                     sha1_to_hex(entry->sha1));
439                         sha1write(f, map, mapsize);
440                         munmap(map, mapsize);
441                         written++;
442                         reused++;
443                         return mapsize;
444                 }
445                 if (map)
446                         munmap(map, mapsize);
447         }
449         if (!to_reuse) {
450                 buf = read_sha1_file(entry->sha1, &type, &size);
451                 if (!buf)
452                         die("unable to read %s", sha1_to_hex(entry->sha1));
453                 if (size != entry->size)
454                         die("object %s size inconsistency (%lu vs %lu)",
455                             sha1_to_hex(entry->sha1), size, entry->size);
456                 if (entry->delta) {
457                         buf = delta_against(buf, size, entry);
458                         size = entry->delta_size;
459                         obj_type = (allow_ofs_delta && entry->delta->offset) ?
460                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
461                 }
462                 /*
463                  * The object header is a byte of 'type' followed by zero or
464                  * more bytes of length.
465                  */
466                 hdrlen = encode_header(obj_type, size, header);
467                 sha1write(f, header, hdrlen);
469                 if (obj_type == OBJ_OFS_DELTA) {
470                         /*
471                          * Deltas with relative base contain an additional
472                          * encoding of the relative offset for the delta
473                          * base from this object's position in the pack.
474                          */
475                         off_t ofs = entry->offset - entry->delta->offset;
476                         unsigned pos = sizeof(header) - 1;
477                         header[pos] = ofs & 127;
478                         while (ofs >>= 7)
479                                 header[--pos] = 128 | (--ofs & 127);
480                         sha1write(f, header + pos, sizeof(header) - pos);
481                         hdrlen += sizeof(header) - pos;
482                 } else if (obj_type == OBJ_REF_DELTA) {
483                         /*
484                          * Deltas with a base reference contain
485                          * an additional 20 bytes for the base sha1.
486                          */
487                         sha1write(f, entry->delta->sha1, 20);
488                         hdrlen += 20;
489                 }
490                 datalen = sha1write_compressed(f, buf, size);
491                 free(buf);
492         }
493         else {
494                 struct packed_git *p = entry->in_pack;
495                 struct pack_window *w_curs = NULL;
496                 struct revindex_entry *revidx;
497                 off_t offset;
499                 if (entry->delta) {
500                         obj_type = (allow_ofs_delta && entry->delta->offset) ?
501                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
502                         reused_delta++;
503                 }
504                 hdrlen = encode_header(obj_type, entry->size, header);
505                 sha1write(f, header, hdrlen);
506                 if (obj_type == OBJ_OFS_DELTA) {
507                         off_t ofs = entry->offset - entry->delta->offset;
508                         unsigned pos = sizeof(header) - 1;
509                         header[pos] = ofs & 127;
510                         while (ofs >>= 7)
511                                 header[--pos] = 128 | (--ofs & 127);
512                         sha1write(f, header + pos, sizeof(header) - pos);
513                         hdrlen += sizeof(header) - pos;
514                 } else if (obj_type == OBJ_REF_DELTA) {
515                         sha1write(f, entry->delta->sha1, 20);
516                         hdrlen += 20;
517                 }
519                 offset = entry->in_pack_offset;
520                 revidx = find_packed_object(p, offset);
521                 datalen = revidx[1].offset - offset;
522                 if (!pack_to_stdout && p->index_version > 1 &&
523                     check_pack_crc(p, &w_curs, offset, datalen, revidx->nr))
524                         die("bad packed object CRC for %s", sha1_to_hex(entry->sha1));
525                 offset += entry->in_pack_header_size;
526                 datalen -= entry->in_pack_header_size;
527                 if (!pack_to_stdout && p->index_version == 1 &&
528                     check_pack_inflate(p, &w_curs, offset, datalen, entry->size))
529                         die("corrupt packed object for %s", sha1_to_hex(entry->sha1));
530                 copy_pack_data(f, p, &w_curs, offset, datalen);
531                 unuse_pack(&w_curs);
532                 reused++;
533         }
534         if (entry->delta)
535                 written_delta++;
536         written++;
537         if (!pack_to_stdout)
538                 entry->crc32 = crc32_end(f);
539         return hdrlen + datalen;
542 static off_t write_one(struct sha1file *f,
543                                struct object_entry *e,
544                                off_t offset)
546         unsigned long size;
548         /* offset is non zero if object is written already. */
549         if (e->offset || e->preferred_base)
550                 return offset;
552         /* if we are deltified, write out base object first. */
553         if (e->delta)
554                 offset = write_one(f, e->delta, offset);
556         e->offset = offset;
557         size = write_object(f, e);
559         /* make sure off_t is sufficiently large not to wrap */
560         if (offset > offset + size)
561                 die("pack too large for current definition of off_t");
562         return offset + size;
565 static int open_object_dir_tmp(const char *path)
567     snprintf(tmpname, sizeof(tmpname), "%s/%s", get_object_directory(), path);
568     return mkstemp(tmpname);
571 static off_t write_pack_file(void)
573         uint32_t i;
574         struct sha1file *f;
575         off_t offset, last_obj_offset = 0;
576         struct pack_header hdr;
577         int do_progress = progress;
579         if (pack_to_stdout) {
580                 f = sha1fd(1, "<stdout>");
581                 do_progress >>= 1;
582         } else {
583                 int fd = open_object_dir_tmp("tmp_pack_XXXXXX");
584                 if (fd < 0)
585                         die("unable to create %s: %s\n", tmpname, strerror(errno));
586                 pack_tmp_name = xstrdup(tmpname);
587                 f = sha1fd(fd, pack_tmp_name);
588         }
590         if (do_progress)
591                 start_progress(&progress_state, "Writing %u objects...", "", nr_result);
593         hdr.hdr_signature = htonl(PACK_SIGNATURE);
594         hdr.hdr_version = htonl(PACK_VERSION);
595         hdr.hdr_entries = htonl(nr_result);
596         sha1write(f, &hdr, sizeof(hdr));
597         offset = sizeof(hdr);
598         if (!nr_result)
599                 goto done;
600         for (i = 0; i < nr_objects; i++) {
601                 last_obj_offset = offset;
602                 offset = write_one(f, objects + i, offset);
603                 if (do_progress)
604                         display_progress(&progress_state, written);
605         }
606         if (do_progress)
607                 stop_progress(&progress_state);
608  done:
609         if (written != nr_result)
610                 die("wrote %u objects while expecting %u", written, nr_result);
611         sha1close(f, pack_file_sha1, 1);
613         return last_obj_offset;
616 static int sha1_sort(const void *_a, const void *_b)
618         const struct object_entry *a = *(struct object_entry **)_a;
619         const struct object_entry *b = *(struct object_entry **)_b;
620         return hashcmp(a->sha1, b->sha1);
623 static uint32_t index_default_version = 1;
624 static uint32_t index_off32_limit = 0x7fffffff;
626 static void write_index_file(off_t last_obj_offset, unsigned char *sha1)
628         struct sha1file *f;
629         struct object_entry **sorted_by_sha, **list, **last;
630         uint32_t array[256];
631         uint32_t i, index_version;
632         SHA_CTX ctx;
634         int fd = open_object_dir_tmp("tmp_idx_XXXXXX");
635         if (fd < 0)
636                 die("unable to create %s: %s\n", tmpname, strerror(errno));
637         idx_tmp_name = xstrdup(tmpname);
638         f = sha1fd(fd, idx_tmp_name);
640         if (nr_result) {
641                 uint32_t j = 0;
642                 sorted_by_sha =
643                         xcalloc(nr_result, sizeof(struct object_entry *));
644                 for (i = 0; i < nr_objects; i++)
645                         if (!objects[i].preferred_base)
646                                 sorted_by_sha[j++] = objects + i;
647                 if (j != nr_result)
648                         die("listed %u objects while expecting %u", j, nr_result);
649                 qsort(sorted_by_sha, nr_result, sizeof(*sorted_by_sha), sha1_sort);
650                 list = sorted_by_sha;
651                 last = sorted_by_sha + nr_result;
652         } else
653                 sorted_by_sha = list = last = NULL;
655         /* if last object's offset is >= 2^31 we should use index V2 */
656         index_version = (last_obj_offset >> 31) ? 2 : index_default_version;
658         /* index versions 2 and above need a header */
659         if (index_version >= 2) {
660                 struct pack_idx_header hdr;
661                 hdr.idx_signature = htonl(PACK_IDX_SIGNATURE);
662                 hdr.idx_version = htonl(index_version);
663                 sha1write(f, &hdr, sizeof(hdr));
664         }
666         /*
667          * Write the first-level table (the list is sorted,
668          * but we use a 256-entry lookup to be able to avoid
669          * having to do eight extra binary search iterations).
670          */
671         for (i = 0; i < 256; i++) {
672                 struct object_entry **next = list;
673                 while (next < last) {
674                         struct object_entry *entry = *next;
675                         if (entry->sha1[0] != i)
676                                 break;
677                         next++;
678                 }
679                 array[i] = htonl(next - sorted_by_sha);
680                 list = next;
681         }
682         sha1write(f, array, 256 * 4);
684         /* Compute the SHA1 hash of sorted object names. */
685         SHA1_Init(&ctx);
687         /* Write the actual SHA1 entries. */
688         list = sorted_by_sha;
689         for (i = 0; i < nr_result; i++) {
690                 struct object_entry *entry = *list++;
691                 if (index_version < 2) {
692                         uint32_t offset = htonl(entry->offset);
693                         sha1write(f, &offset, 4);
694                 }
695                 sha1write(f, entry->sha1, 20);
696                 SHA1_Update(&ctx, entry->sha1, 20);
697         }
699         if (index_version >= 2) {
700                 unsigned int nr_large_offset = 0;
702                 /* write the crc32 table */
703                 list = sorted_by_sha;
704                 for (i = 0; i < nr_objects; i++) {
705                         struct object_entry *entry = *list++;
706                         uint32_t crc32_val = htonl(entry->crc32);
707                         sha1write(f, &crc32_val, 4);
708                 }
710                 /* write the 32-bit offset table */
711                 list = sorted_by_sha;
712                 for (i = 0; i < nr_objects; i++) {
713                         struct object_entry *entry = *list++;
714                         uint32_t offset = (entry->offset <= index_off32_limit) ?
715                                 entry->offset : (0x80000000 | nr_large_offset++);
716                         offset = htonl(offset);
717                         sha1write(f, &offset, 4);
718                 }
720                 /* write the large offset table */
721                 list = sorted_by_sha;
722                 while (nr_large_offset) {
723                         struct object_entry *entry = *list++;
724                         uint64_t offset = entry->offset;
725                         if (offset > index_off32_limit) {
726                                 uint32_t split[2];
727                                 split[0]        = htonl(offset >> 32);
728                                 split[1] = htonl(offset & 0xffffffff);
729                                 sha1write(f, split, 8);
730                                 nr_large_offset--;
731                         }
732                 }
733         }
735         sha1write(f, pack_file_sha1, 20);
736         sha1close(f, NULL, 1);
737         free(sorted_by_sha);
738         SHA1_Final(sha1, &ctx);
741 static int locate_object_entry_hash(const unsigned char *sha1)
743         int i;
744         unsigned int ui;
745         memcpy(&ui, sha1, sizeof(unsigned int));
746         i = ui % object_ix_hashsz;
747         while (0 < object_ix[i]) {
748                 if (!hashcmp(sha1, objects[object_ix[i] - 1].sha1))
749                         return i;
750                 if (++i == object_ix_hashsz)
751                         i = 0;
752         }
753         return -1 - i;
756 static struct object_entry *locate_object_entry(const unsigned char *sha1)
758         int i;
760         if (!object_ix_hashsz)
761                 return NULL;
763         i = locate_object_entry_hash(sha1);
764         if (0 <= i)
765                 return &objects[object_ix[i]-1];
766         return NULL;
769 static void rehash_objects(void)
771         uint32_t i;
772         struct object_entry *oe;
774         object_ix_hashsz = nr_objects * 3;
775         if (object_ix_hashsz < 1024)
776                 object_ix_hashsz = 1024;
777         object_ix = xrealloc(object_ix, sizeof(int) * object_ix_hashsz);
778         memset(object_ix, 0, sizeof(int) * object_ix_hashsz);
779         for (i = 0, oe = objects; i < nr_objects; i++, oe++) {
780                 int ix = locate_object_entry_hash(oe->sha1);
781                 if (0 <= ix)
782                         continue;
783                 ix = -1 - ix;
784                 object_ix[ix] = i + 1;
785         }
788 static unsigned name_hash(const char *name)
790         unsigned char c;
791         unsigned hash = 0;
793         /*
794          * This effectively just creates a sortable number from the
795          * last sixteen non-whitespace characters. Last characters
796          * count "most", so things that end in ".c" sort together.
797          */
798         while ((c = *name++) != 0) {
799                 if (isspace(c))
800                         continue;
801                 hash = (hash >> 2) + (c << 24);
802         }
803         return hash;
806 static int add_object_entry(const unsigned char *sha1, enum object_type type,
807                             unsigned hash, int exclude)
809         struct object_entry *entry;
810         struct packed_git *p, *found_pack = NULL;
811         off_t found_offset = 0;
812         int ix;
814         ix = nr_objects ? locate_object_entry_hash(sha1) : -1;
815         if (ix >= 0) {
816                 if (exclude) {
817                         entry = objects + object_ix[ix] - 1;
818                         if (!entry->preferred_base)
819                                 nr_result--;
820                         entry->preferred_base = 1;
821                 }
822                 return 0;
823         }
825         for (p = packed_git; p; p = p->next) {
826                 off_t offset = find_pack_entry_one(sha1, p);
827                 if (offset) {
828                         if (!found_pack) {
829                                 found_offset = offset;
830                                 found_pack = p;
831                         }
832                         if (exclude)
833                                 break;
834                         if (incremental)
835                                 return 0;
836                         if (local && !p->pack_local)
837                                 return 0;
838                 }
839         }
841         if (nr_objects >= nr_alloc) {
842                 nr_alloc = (nr_alloc  + 1024) * 3 / 2;
843                 objects = xrealloc(objects, nr_alloc * sizeof(*entry));
844         }
846         entry = objects + nr_objects++;
847         memset(entry, 0, sizeof(*entry));
848         hashcpy(entry->sha1, sha1);
849         entry->hash = hash;
850         if (type)
851                 entry->type = type;
852         if (exclude)
853                 entry->preferred_base = 1;
854         else
855                 nr_result++;
856         if (found_pack) {
857                 entry->in_pack = found_pack;
858                 entry->in_pack_offset = found_offset;
859         }
861         if (object_ix_hashsz * 3 <= nr_objects * 4)
862                 rehash_objects();
863         else
864                 object_ix[-1 - ix] = nr_objects;
866         if (progress)
867                 display_progress(&progress_state, nr_objects);
869         return 1;
872 struct pbase_tree_cache {
873         unsigned char sha1[20];
874         int ref;
875         int temporary;
876         void *tree_data;
877         unsigned long tree_size;
878 };
880 static struct pbase_tree_cache *(pbase_tree_cache[256]);
881 static int pbase_tree_cache_ix(const unsigned char *sha1)
883         return sha1[0] % ARRAY_SIZE(pbase_tree_cache);
885 static int pbase_tree_cache_ix_incr(int ix)
887         return (ix+1) % ARRAY_SIZE(pbase_tree_cache);
890 static struct pbase_tree {
891         struct pbase_tree *next;
892         /* This is a phony "cache" entry; we are not
893          * going to evict it nor find it through _get()
894          * mechanism -- this is for the toplevel node that
895          * would almost always change with any commit.
896          */
897         struct pbase_tree_cache pcache;
898 } *pbase_tree;
900 static struct pbase_tree_cache *pbase_tree_get(const unsigned char *sha1)
902         struct pbase_tree_cache *ent, *nent;
903         void *data;
904         unsigned long size;
905         enum object_type type;
906         int neigh;
907         int my_ix = pbase_tree_cache_ix(sha1);
908         int available_ix = -1;
910         /* pbase-tree-cache acts as a limited hashtable.
911          * your object will be found at your index or within a few
912          * slots after that slot if it is cached.
913          */
914         for (neigh = 0; neigh < 8; neigh++) {
915                 ent = pbase_tree_cache[my_ix];
916                 if (ent && !hashcmp(ent->sha1, sha1)) {
917                         ent->ref++;
918                         return ent;
919                 }
920                 else if (((available_ix < 0) && (!ent || !ent->ref)) ||
921                          ((0 <= available_ix) &&
922                           (!ent && pbase_tree_cache[available_ix])))
923                         available_ix = my_ix;
924                 if (!ent)
925                         break;
926                 my_ix = pbase_tree_cache_ix_incr(my_ix);
927         }
929         /* Did not find one.  Either we got a bogus request or
930          * we need to read and perhaps cache.
931          */
932         data = read_sha1_file(sha1, &type, &size);
933         if (!data)
934                 return NULL;
935         if (type != OBJ_TREE) {
936                 free(data);
937                 return NULL;
938         }
940         /* We need to either cache or return a throwaway copy */
942         if (available_ix < 0)
943                 ent = NULL;
944         else {
945                 ent = pbase_tree_cache[available_ix];
946                 my_ix = available_ix;
947         }
949         if (!ent) {
950                 nent = xmalloc(sizeof(*nent));
951                 nent->temporary = (available_ix < 0);
952         }
953         else {
954                 /* evict and reuse */
955                 free(ent->tree_data);
956                 nent = ent;
957         }
958         hashcpy(nent->sha1, sha1);
959         nent->tree_data = data;
960         nent->tree_size = size;
961         nent->ref = 1;
962         if (!nent->temporary)
963                 pbase_tree_cache[my_ix] = nent;
964         return nent;
967 static void pbase_tree_put(struct pbase_tree_cache *cache)
969         if (!cache->temporary) {
970                 cache->ref--;
971                 return;
972         }
973         free(cache->tree_data);
974         free(cache);
977 static int name_cmp_len(const char *name)
979         int i;
980         for (i = 0; name[i] && name[i] != '\n' && name[i] != '/'; i++)
981                 ;
982         return i;
985 static void add_pbase_object(struct tree_desc *tree,
986                              const char *name,
987                              int cmplen,
988                              const char *fullname)
990         struct name_entry entry;
991         int cmp;
993         while (tree_entry(tree,&entry)) {
994                 cmp = tree_entry_len(entry.path, entry.sha1) != cmplen ? 1 :
995                       memcmp(name, entry.path, cmplen);
996                 if (cmp > 0)
997                         continue;
998                 if (cmp < 0)
999                         return;
1000                 if (name[cmplen] != '/') {
1001                         unsigned hash = name_hash(fullname);
1002                         add_object_entry(entry.sha1,
1003                                          S_ISDIR(entry.mode) ? OBJ_TREE : OBJ_BLOB,
1004                                          hash, 1);
1005                         return;
1006                 }
1007                 if (S_ISDIR(entry.mode)) {
1008                         struct tree_desc sub;
1009                         struct pbase_tree_cache *tree;
1010                         const char *down = name+cmplen+1;
1011                         int downlen = name_cmp_len(down);
1013                         tree = pbase_tree_get(entry.sha1);
1014                         if (!tree)
1015                                 return;
1016                         init_tree_desc(&sub, tree->tree_data, tree->tree_size);
1018                         add_pbase_object(&sub, down, downlen, fullname);
1019                         pbase_tree_put(tree);
1020                 }
1021         }
1024 static unsigned *done_pbase_paths;
1025 static int done_pbase_paths_num;
1026 static int done_pbase_paths_alloc;
1027 static int done_pbase_path_pos(unsigned hash)
1029         int lo = 0;
1030         int hi = done_pbase_paths_num;
1031         while (lo < hi) {
1032                 int mi = (hi + lo) / 2;
1033                 if (done_pbase_paths[mi] == hash)
1034                         return mi;
1035                 if (done_pbase_paths[mi] < hash)
1036                         hi = mi;
1037                 else
1038                         lo = mi + 1;
1039         }
1040         return -lo-1;
1043 static int check_pbase_path(unsigned hash)
1045         int pos = (!done_pbase_paths) ? -1 : done_pbase_path_pos(hash);
1046         if (0 <= pos)
1047                 return 1;
1048         pos = -pos - 1;
1049         if (done_pbase_paths_alloc <= done_pbase_paths_num) {
1050                 done_pbase_paths_alloc = alloc_nr(done_pbase_paths_alloc);
1051                 done_pbase_paths = xrealloc(done_pbase_paths,
1052                                             done_pbase_paths_alloc *
1053                                             sizeof(unsigned));
1054         }
1055         done_pbase_paths_num++;
1056         if (pos < done_pbase_paths_num)
1057                 memmove(done_pbase_paths + pos + 1,
1058                         done_pbase_paths + pos,
1059                         (done_pbase_paths_num - pos - 1) * sizeof(unsigned));
1060         done_pbase_paths[pos] = hash;
1061         return 0;
1064 static void add_preferred_base_object(const char *name, unsigned hash)
1066         struct pbase_tree *it;
1067         int cmplen;
1069         if (!num_preferred_base || check_pbase_path(hash))
1070                 return;
1072         cmplen = name_cmp_len(name);
1073         for (it = pbase_tree; it; it = it->next) {
1074                 if (cmplen == 0) {
1075                         add_object_entry(it->pcache.sha1, OBJ_TREE, 0, 1);
1076                 }
1077                 else {
1078                         struct tree_desc tree;
1079                         init_tree_desc(&tree, it->pcache.tree_data, it->pcache.tree_size);
1080                         add_pbase_object(&tree, name, cmplen, name);
1081                 }
1082         }
1085 static void add_preferred_base(unsigned char *sha1)
1087         struct pbase_tree *it;
1088         void *data;
1089         unsigned long size;
1090         unsigned char tree_sha1[20];
1092         if (window <= num_preferred_base++)
1093                 return;
1095         data = read_object_with_reference(sha1, tree_type, &size, tree_sha1);
1096         if (!data)
1097                 return;
1099         for (it = pbase_tree; it; it = it->next) {
1100                 if (!hashcmp(it->pcache.sha1, tree_sha1)) {
1101                         free(data);
1102                         return;
1103                 }
1104         }
1106         it = xcalloc(1, sizeof(*it));
1107         it->next = pbase_tree;
1108         pbase_tree = it;
1110         hashcpy(it->pcache.sha1, tree_sha1);
1111         it->pcache.tree_data = data;
1112         it->pcache.tree_size = size;
1115 static void check_object(struct object_entry *entry)
1117         if (entry->in_pack) {
1118                 struct packed_git *p = entry->in_pack;
1119                 struct pack_window *w_curs = NULL;
1120                 const unsigned char *base_ref = NULL;
1121                 struct object_entry *base_entry;
1122                 unsigned long used, used_0;
1123                 unsigned int avail;
1124                 off_t ofs;
1125                 unsigned char *buf, c;
1127                 buf = use_pack(p, &w_curs, entry->in_pack_offset, &avail);
1129                 /*
1130                  * We want in_pack_type even if we do not reuse delta
1131                  * since non-delta representations could still be reused.
1132                  */
1133                 used = unpack_object_header_gently(buf, avail,
1134                                                    &entry->in_pack_type,
1135                                                    &entry->size);
1137                 /*
1138                  * Determine if this is a delta and if so whether we can
1139                  * reuse it or not.  Otherwise let's find out as cheaply as
1140                  * possible what the actual type and size for this object is.
1141                  */
1142                 switch (entry->in_pack_type) {
1143                 default:
1144                         /* Not a delta hence we've already got all we need. */
1145                         entry->type = entry->in_pack_type;
1146                         entry->in_pack_header_size = used;
1147                         unuse_pack(&w_curs);
1148                         return;
1149                 case OBJ_REF_DELTA:
1150                         if (!no_reuse_delta && !entry->preferred_base)
1151                                 base_ref = use_pack(p, &w_curs,
1152                                                 entry->in_pack_offset + used, NULL);
1153                         entry->in_pack_header_size = used + 20;
1154                         break;
1155                 case OBJ_OFS_DELTA:
1156                         buf = use_pack(p, &w_curs,
1157                                        entry->in_pack_offset + used, NULL);
1158                         used_0 = 0;
1159                         c = buf[used_0++];
1160                         ofs = c & 127;
1161                         while (c & 128) {
1162                                 ofs += 1;
1163                                 if (!ofs || MSB(ofs, 7))
1164                                         die("delta base offset overflow in pack for %s",
1165                                             sha1_to_hex(entry->sha1));
1166                                 c = buf[used_0++];
1167                                 ofs = (ofs << 7) + (c & 127);
1168                         }
1169                         if (ofs >= entry->in_pack_offset)
1170                                 die("delta base offset out of bound for %s",
1171                                     sha1_to_hex(entry->sha1));
1172                         ofs = entry->in_pack_offset - ofs;
1173                         if (!no_reuse_delta && !entry->preferred_base)
1174                                 base_ref = find_packed_object_name(p, ofs);
1175                         entry->in_pack_header_size = used + used_0;
1176                         break;
1177                 }
1179                 if (base_ref && (base_entry = locate_object_entry(base_ref))) {
1180                         /*
1181                          * If base_ref was set above that means we wish to
1182                          * reuse delta data, and we even found that base
1183                          * in the list of objects we want to pack. Goodie!
1184                          *
1185                          * Depth value does not matter - find_deltas() will
1186                          * never consider reused delta as the base object to
1187                          * deltify other objects against, in order to avoid
1188                          * circular deltas.
1189                          */
1190                         entry->type = entry->in_pack_type;
1191                         entry->delta = base_entry;
1192                         entry->delta_sibling = base_entry->delta_child;
1193                         base_entry->delta_child = entry;
1194                         unuse_pack(&w_curs);
1195                         return;
1196                 }
1198                 if (entry->type) {
1199                         /*
1200                          * This must be a delta and we already know what the
1201                          * final object type is.  Let's extract the actual
1202                          * object size from the delta header.
1203                          */
1204                         entry->size = get_size_from_delta(p, &w_curs,
1205                                         entry->in_pack_offset + entry->in_pack_header_size);
1206                         unuse_pack(&w_curs);
1207                         return;
1208                 }
1210                 /*
1211                  * No choice but to fall back to the recursive delta walk
1212                  * with sha1_object_info() to find about the object type
1213                  * at this point...
1214                  */
1215                 unuse_pack(&w_curs);
1216         }
1218         entry->type = sha1_object_info(entry->sha1, &entry->size);
1219         if (entry->type < 0)
1220                 die("unable to get type of object %s",
1221                     sha1_to_hex(entry->sha1));
1224 static int pack_offset_sort(const void *_a, const void *_b)
1226         const struct object_entry *a = *(struct object_entry **)_a;
1227         const struct object_entry *b = *(struct object_entry **)_b;
1229         /* avoid filesystem trashing with loose objects */
1230         if (!a->in_pack && !b->in_pack)
1231                 return hashcmp(a->sha1, b->sha1);
1233         if (a->in_pack < b->in_pack)
1234                 return -1;
1235         if (a->in_pack > b->in_pack)
1236                 return 1;
1237         return a->in_pack_offset < b->in_pack_offset ? -1 :
1238                         (a->in_pack_offset > b->in_pack_offset);
1241 static void get_object_details(void)
1243         uint32_t i;
1244         struct object_entry **sorted_by_offset;
1246         sorted_by_offset = xcalloc(nr_objects, sizeof(struct object_entry *));
1247         for (i = 0; i < nr_objects; i++)
1248                 sorted_by_offset[i] = objects + i;
1249         qsort(sorted_by_offset, nr_objects, sizeof(*sorted_by_offset), pack_offset_sort);
1251         prepare_pack_ix();
1252         for (i = 0; i < nr_objects; i++)
1253                 check_object(sorted_by_offset[i]);
1254         free(sorted_by_offset);
1257 static int type_size_sort(const void *_a, const void *_b)
1259         const struct object_entry *a = *(struct object_entry **)_a;
1260         const struct object_entry *b = *(struct object_entry **)_b;
1262         if (a->type < b->type)
1263                 return -1;
1264         if (a->type > b->type)
1265                 return 1;
1266         if (a->hash < b->hash)
1267                 return -1;
1268         if (a->hash > b->hash)
1269                 return 1;
1270         if (a->preferred_base < b->preferred_base)
1271                 return -1;
1272         if (a->preferred_base > b->preferred_base)
1273                 return 1;
1274         if (a->size < b->size)
1275                 return -1;
1276         if (a->size > b->size)
1277                 return 1;
1278         return a > b ? -1 : (a < b);  /* newest last */
1281 struct unpacked {
1282         struct object_entry *entry;
1283         void *data;
1284         struct delta_index *index;
1285 };
1287 /*
1288  * We search for deltas _backwards_ in a list sorted by type and
1289  * by size, so that we see progressively smaller and smaller files.
1290  * That's because we prefer deltas to be from the bigger file
1291  * to the smaller - deletes are potentially cheaper, but perhaps
1292  * more importantly, the bigger file is likely the more recent
1293  * one.
1294  */
1295 static int try_delta(struct unpacked *trg, struct unpacked *src,
1296                      unsigned max_depth)
1298         struct object_entry *trg_entry = trg->entry;
1299         struct object_entry *src_entry = src->entry;
1300         unsigned long trg_size, src_size, delta_size, sizediff, max_size, sz;
1301         enum object_type type;
1302         void *delta_buf;
1304         /* Don't bother doing diffs between different types */
1305         if (trg_entry->type != src_entry->type)
1306                 return -1;
1308         /* We do not compute delta to *create* objects we are not
1309          * going to pack.
1310          */
1311         if (trg_entry->preferred_base)
1312                 return -1;
1314         /*
1315          * We do not bother to try a delta that we discarded
1316          * on an earlier try, but only when reusing delta data.
1317          */
1318         if (!no_reuse_delta && trg_entry->in_pack &&
1319             trg_entry->in_pack == src_entry->in_pack &&
1320             trg_entry->in_pack_type != OBJ_REF_DELTA &&
1321             trg_entry->in_pack_type != OBJ_OFS_DELTA)
1322                 return 0;
1324         /* Let's not bust the allowed depth. */
1325         if (src_entry->depth >= max_depth)
1326                 return 0;
1328         /* Now some size filtering heuristics. */
1329         trg_size = trg_entry->size;
1330         max_size = trg_size/2 - 20;
1331         max_size = max_size * (max_depth - src_entry->depth) / max_depth;
1332         if (max_size == 0)
1333                 return 0;
1334         if (trg_entry->delta && trg_entry->delta_size <= max_size)
1335                 max_size = trg_entry->delta_size-1;
1336         src_size = src_entry->size;
1337         sizediff = src_size < trg_size ? trg_size - src_size : 0;
1338         if (sizediff >= max_size)
1339                 return 0;
1341         /* Load data if not already done */
1342         if (!trg->data) {
1343                 trg->data = read_sha1_file(trg_entry->sha1, &type, &sz);
1344                 if (sz != trg_size)
1345                         die("object %s inconsistent object length (%lu vs %lu)",
1346                             sha1_to_hex(trg_entry->sha1), sz, trg_size);
1347         }
1348         if (!src->data) {
1349                 src->data = read_sha1_file(src_entry->sha1, &type, &sz);
1350                 if (sz != src_size)
1351                         die("object %s inconsistent object length (%lu vs %lu)",
1352                             sha1_to_hex(src_entry->sha1), sz, src_size);
1353         }
1354         if (!src->index) {
1355                 src->index = create_delta_index(src->data, src_size);
1356                 if (!src->index)
1357                         die("out of memory");
1358         }
1360         delta_buf = create_delta(src->index, trg->data, trg_size, &delta_size, max_size);
1361         if (!delta_buf)
1362                 return 0;
1364         trg_entry->delta = src_entry;
1365         trg_entry->delta_size = delta_size;
1366         trg_entry->depth = src_entry->depth + 1;
1367         free(delta_buf);
1368         return 1;
1371 static unsigned int check_delta_limit(struct object_entry *me, unsigned int n)
1373         struct object_entry *child = me->delta_child;
1374         unsigned int m = n;
1375         while (child) {
1376                 unsigned int c = check_delta_limit(child, n + 1);
1377                 if (m < c)
1378                         m = c;
1379                 child = child->delta_sibling;
1380         }
1381         return m;
1384 static void find_deltas(struct object_entry **list, int window, int depth)
1386         uint32_t i = nr_objects, idx = 0, processed = 0;
1387         unsigned int array_size = window * sizeof(struct unpacked);
1388         struct unpacked *array;
1389         int max_depth;
1391         if (!nr_objects)
1392                 return;
1393         array = xmalloc(array_size);
1394         memset(array, 0, array_size);
1395         if (progress)
1396                 start_progress(&progress_state, "Deltifying %u objects...", "", nr_result);
1398         do {
1399                 struct object_entry *entry = list[--i];
1400                 struct unpacked *n = array + idx;
1401                 int j;
1403                 if (!entry->preferred_base)
1404                         processed++;
1406                 if (progress)
1407                         display_progress(&progress_state, processed);
1409                 if (entry->delta)
1410                         /* This happens if we decided to reuse existing
1411                          * delta from a pack.  "!no_reuse_delta &&" is implied.
1412                          */
1413                         continue;
1415                 if (entry->size < 50)
1416                         continue;
1417                 free_delta_index(n->index);
1418                 n->index = NULL;
1419                 free(n->data);
1420                 n->data = NULL;
1421                 n->entry = entry;
1423                 /*
1424                  * If the current object is at pack edge, take the depth the
1425                  * objects that depend on the current object into account
1426                  * otherwise they would become too deep.
1427                  */
1428                 max_depth = depth;
1429                 if (entry->delta_child) {
1430                         max_depth -= check_delta_limit(entry, 0);
1431                         if (max_depth <= 0)
1432                                 goto next;
1433                 }
1435                 j = window;
1436                 while (--j > 0) {
1437                         uint32_t other_idx = idx + j;
1438                         struct unpacked *m;
1439                         if (other_idx >= window)
1440                                 other_idx -= window;
1441                         m = array + other_idx;
1442                         if (!m->entry)
1443                                 break;
1444                         if (try_delta(n, m, max_depth) < 0)
1445                                 break;
1446                 }
1448                 /* if we made n a delta, and if n is already at max
1449                  * depth, leaving it in the window is pointless.  we
1450                  * should evict it first.
1451                  */
1452                 if (entry->delta && depth <= entry->depth)
1453                         continue;
1455                 next:
1456                 idx++;
1457                 if (idx >= window)
1458                         idx = 0;
1459         } while (i > 0);
1461         if (progress)
1462                 stop_progress(&progress_state);
1464         for (i = 0; i < window; ++i) {
1465                 free_delta_index(array[i].index);
1466                 free(array[i].data);
1467         }
1468         free(array);
1471 static void prepare_pack(int window, int depth)
1473         struct object_entry **delta_list;
1474         uint32_t i;
1476         get_object_details();
1478         if (!window || !depth)
1479                 return;
1481         delta_list = xmalloc(nr_objects * sizeof(*delta_list));
1482         for (i = 0; i < nr_objects; i++)
1483                 delta_list[i] = objects + i;
1484         qsort(delta_list, nr_objects, sizeof(*delta_list), type_size_sort);
1485         find_deltas(delta_list, window+1, depth);
1486         free(delta_list);
1489 static int git_pack_config(const char *k, const char *v)
1491         if(!strcmp(k, "pack.window")) {
1492                 window = git_config_int(k, v);
1493                 return 0;
1494         }
1495         if(!strcmp(k, "pack.depth")) {
1496                 depth = git_config_int(k, v);
1497                 return 0;
1498         }
1499         return git_default_config(k, v);
1502 static void read_object_list_from_stdin(void)
1504         char line[40 + 1 + PATH_MAX + 2];
1505         unsigned char sha1[20];
1506         unsigned hash;
1508         for (;;) {
1509                 if (!fgets(line, sizeof(line), stdin)) {
1510                         if (feof(stdin))
1511                                 break;
1512                         if (!ferror(stdin))
1513                                 die("fgets returned NULL, not EOF, not error!");
1514                         if (errno != EINTR)
1515                                 die("fgets: %s", strerror(errno));
1516                         clearerr(stdin);
1517                         continue;
1518                 }
1519                 if (line[0] == '-') {
1520                         if (get_sha1_hex(line+1, sha1))
1521                                 die("expected edge sha1, got garbage:\n %s",
1522                                     line);
1523                         add_preferred_base(sha1);
1524                         continue;
1525                 }
1526                 if (get_sha1_hex(line, sha1))
1527                         die("expected sha1, got garbage:\n %s", line);
1529                 hash = name_hash(line+41);
1530                 add_preferred_base_object(line+41, hash);
1531                 add_object_entry(sha1, 0, hash, 0);
1532         }
1535 static void show_commit(struct commit *commit)
1537         add_object_entry(commit->object.sha1, OBJ_COMMIT, 0, 0);
1540 static void show_object(struct object_array_entry *p)
1542         unsigned hash = name_hash(p->name);
1543         add_preferred_base_object(p->name, hash);
1544         add_object_entry(p->item->sha1, p->item->type, hash, 0);
1547 static void show_edge(struct commit *commit)
1549         add_preferred_base(commit->object.sha1);
1552 static void get_object_list(int ac, const char **av)
1554         struct rev_info revs;
1555         char line[1000];
1556         int flags = 0;
1558         init_revisions(&revs, NULL);
1559         save_commit_buffer = 0;
1560         track_object_refs = 0;
1561         setup_revisions(ac, av, &revs, NULL);
1563         while (fgets(line, sizeof(line), stdin) != NULL) {
1564                 int len = strlen(line);
1565                 if (line[len - 1] == '\n')
1566                         line[--len] = 0;
1567                 if (!len)
1568                         break;
1569                 if (*line == '-') {
1570                         if (!strcmp(line, "--not")) {
1571                                 flags ^= UNINTERESTING;
1572                                 continue;
1573                         }
1574                         die("not a rev '%s'", line);
1575                 }
1576                 if (handle_revision_arg(line, &revs, flags, 1))
1577                         die("bad revision '%s'", line);
1578         }
1580         prepare_revision_walk(&revs);
1581         mark_edges_uninteresting(revs.commits, &revs, show_edge);
1582         traverse_commit_list(&revs, show_commit, show_object);
1585 static int adjust_perm(const char *path, mode_t mode)
1587         if (chmod(path, mode))
1588                 return -1;
1589         return adjust_shared_perm(path);
1592 int cmd_pack_objects(int argc, const char **argv, const char *prefix)
1594         int use_internal_rev_list = 0;
1595         int thin = 0;
1596         uint32_t i;
1597         off_t last_obj_offset;
1598         const char *base_name = NULL;
1599         const char **rp_av;
1600         int rp_ac_alloc = 64;
1601         int rp_ac;
1603         rp_av = xcalloc(rp_ac_alloc, sizeof(*rp_av));
1605         rp_av[0] = "pack-objects";
1606         rp_av[1] = "--objects"; /* --thin will make it --objects-edge */
1607         rp_ac = 2;
1609         git_config(git_pack_config);
1611         progress = isatty(2);
1612         for (i = 1; i < argc; i++) {
1613                 const char *arg = argv[i];
1615                 if (*arg != '-')
1616                         break;
1618                 if (!strcmp("--non-empty", arg)) {
1619                         non_empty = 1;
1620                         continue;
1621                 }
1622                 if (!strcmp("--local", arg)) {
1623                         local = 1;
1624                         continue;
1625                 }
1626                 if (!strcmp("--incremental", arg)) {
1627                         incremental = 1;
1628                         continue;
1629                 }
1630                 if (!prefixcmp(arg, "--window=")) {
1631                         char *end;
1632                         window = strtoul(arg+9, &end, 0);
1633                         if (!arg[9] || *end)
1634                                 usage(pack_usage);
1635                         continue;
1636                 }
1637                 if (!prefixcmp(arg, "--depth=")) {
1638                         char *end;
1639                         depth = strtoul(arg+8, &end, 0);
1640                         if (!arg[8] || *end)
1641                                 usage(pack_usage);
1642                         continue;
1643                 }
1644                 if (!strcmp("--progress", arg)) {
1645                         progress = 1;
1646                         continue;
1647                 }
1648                 if (!strcmp("--all-progress", arg)) {
1649                         progress = 2;
1650                         continue;
1651                 }
1652                 if (!strcmp("-q", arg)) {
1653                         progress = 0;
1654                         continue;
1655                 }
1656                 if (!strcmp("--no-reuse-delta", arg)) {
1657                         no_reuse_delta = 1;
1658                         continue;
1659                 }
1660                 if (!strcmp("--no-reuse-object", arg)) {
1661                         no_reuse_object = no_reuse_delta = 1;
1662                         continue;
1663                 }
1664                 if (!strcmp("--delta-base-offset", arg)) {
1665                         allow_ofs_delta = 1;
1666                         continue;
1667                 }
1668                 if (!strcmp("--stdout", arg)) {
1669                         pack_to_stdout = 1;
1670                         continue;
1671                 }
1672                 if (!strcmp("--revs", arg)) {
1673                         use_internal_rev_list = 1;
1674                         continue;
1675                 }
1676                 if (!strcmp("--unpacked", arg) ||
1677                     !prefixcmp(arg, "--unpacked=") ||
1678                     !strcmp("--reflog", arg) ||
1679                     !strcmp("--all", arg)) {
1680                         use_internal_rev_list = 1;
1681                         if (rp_ac >= rp_ac_alloc - 1) {
1682                                 rp_ac_alloc = alloc_nr(rp_ac_alloc);
1683                                 rp_av = xrealloc(rp_av,
1684                                                  rp_ac_alloc * sizeof(*rp_av));
1685                         }
1686                         rp_av[rp_ac++] = arg;
1687                         continue;
1688                 }
1689                 if (!strcmp("--thin", arg)) {
1690                         use_internal_rev_list = 1;
1691                         thin = 1;
1692                         rp_av[1] = "--objects-edge";
1693                         continue;
1694                 }
1695                 if (!prefixcmp(arg, "--index-version=")) {
1696                         char *c;
1697                         index_default_version = strtoul(arg + 16, &c, 10);
1698                         if (index_default_version > 2)
1699                                 die("bad %s", arg);
1700                         if (*c == ',')
1701                                 index_off32_limit = strtoul(c+1, &c, 0);
1702                         if (*c || index_off32_limit & 0x80000000)
1703                                 die("bad %s", arg);
1704                         continue;
1705                 }
1706                 usage(pack_usage);
1707         }
1709         /* Traditionally "pack-objects [options] base extra" failed;
1710          * we would however want to take refs parameter that would
1711          * have been given to upstream rev-list ourselves, which means
1712          * we somehow want to say what the base name is.  So the
1713          * syntax would be:
1714          *
1715          * pack-objects [options] base <refs...>
1716          *
1717          * in other words, we would treat the first non-option as the
1718          * base_name and send everything else to the internal revision
1719          * walker.
1720          */
1722         if (!pack_to_stdout)
1723                 base_name = argv[i++];
1725         if (pack_to_stdout != !base_name)
1726                 usage(pack_usage);
1728         if (!pack_to_stdout && thin)
1729                 die("--thin cannot be used to build an indexable pack.");
1731         prepare_packed_git();
1733         if (progress)
1734                 start_progress(&progress_state, "Generating pack...",
1735                                "Counting objects: ", 0);
1736         if (!use_internal_rev_list)
1737                 read_object_list_from_stdin();
1738         else {
1739                 rp_av[rp_ac] = NULL;
1740                 get_object_list(rp_ac, rp_av);
1741         }
1742         if (progress) {
1743                 stop_progress(&progress_state);
1744                 fprintf(stderr, "Done counting %u objects.\n", nr_objects);
1745         }
1747         if (non_empty && !nr_result)
1748                 return 0;
1749         if (progress && (nr_objects != nr_result))
1750                 fprintf(stderr, "Result has %u objects.\n", nr_result);
1751         if (nr_result)
1752                 prepare_pack(window, depth);
1753         last_obj_offset = write_pack_file();
1754         if (!pack_to_stdout) {
1755                 unsigned char object_list_sha1[20];
1756                 mode_t mode = umask(0);
1758                 umask(mode);
1759                 mode = 0444 & ~mode;
1761                 write_index_file(last_obj_offset, object_list_sha1);
1762                 snprintf(tmpname, sizeof(tmpname), "%s-%s.pack",
1763                          base_name, sha1_to_hex(object_list_sha1));
1764                 if (adjust_perm(pack_tmp_name, mode))
1765                         die("unable to make temporary pack file readable: %s",
1766                             strerror(errno));
1767                 if (rename(pack_tmp_name, tmpname))
1768                         die("unable to rename temporary pack file: %s",
1769                             strerror(errno));
1770                 snprintf(tmpname, sizeof(tmpname), "%s-%s.idx",
1771                          base_name, sha1_to_hex(object_list_sha1));
1772                 if (adjust_perm(idx_tmp_name, mode))
1773                         die("unable to make temporary index file readable: %s",
1774                             strerror(errno));
1775                 if (rename(idx_tmp_name, tmpname))
1776                         die("unable to rename temporary index file: %s",
1777                             strerror(errno));
1778                 puts(sha1_to_hex(object_list_sha1));
1779         }
1780         if (progress)
1781                 fprintf(stderr, "Total %u (delta %u), reused %u (delta %u)\n",
1782                         written, written_delta, reused, reused_delta);
1783         return 0;