Code

pack-objects: get rid of reuse_cached_pack
[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"
16 static const char pack_usage[] = "\
17 git-pack-objects [{ -q | --progress | --all-progress }] \n\
18         [--local] [--incremental] [--window=N] [--depth=N] \n\
19         [--no-reuse-delta] [--delta-base-offset] [--non-empty] \n\
20         [--revs [--unpacked | --all]*] [--reflog] [--stdout | base-name] \n\
21         [<ref-list | <object-list]";
23 struct object_entry {
24         unsigned char sha1[20];
25         unsigned long size;     /* uncompressed size */
26         off_t offset;   /* offset into the final pack file;
27                                  * nonzero if already written.
28                                  */
29         unsigned int depth;     /* delta depth */
30         unsigned int hash;      /* name hint hash */
31         enum object_type type;
32         enum object_type in_pack_type;  /* could be delta */
33         unsigned long delta_size;       /* delta data size (uncompressed) */
34 #define in_pack_header_size delta_size  /* only when reusing pack data */
35         struct object_entry *delta;     /* delta base object */
36         struct packed_git *in_pack;     /* already in pack */
37         off_t in_pack_offset;
38         struct object_entry *delta_child; /* deltified objects who bases me */
39         struct object_entry *delta_sibling; /* other deltified objects who
40                                              * uses the same base as me
41                                              */
42         int preferred_base;     /* we do not pack this, but is encouraged to
43                                  * be used as the base objectto delta huge
44                                  * objects against.
45                                  */
46         uint32_t crc32;         /* crc of raw pack data for this object */
47 };
49 /*
50  * Objects we are going to pack are collected in objects array (dynamically
51  * expanded).  nr_objects & nr_alloc controls this array.  They are stored
52  * in the order we see -- typically rev-list --objects order that gives us
53  * nice "minimum seek" order.
54  *
55  * sorted-by-sha ans sorted-by-type are arrays of pointers that point at
56  * elements in the objects array.  The former is used to build the pack
57  * index (lists object names in the ascending order to help offset lookup),
58  * and the latter is used to group similar things together by try_delta()
59  * heuristics.
60  */
62 static unsigned char object_list_sha1[20];
63 static int non_empty;
64 static int no_reuse_delta;
65 static int local;
66 static int incremental;
67 static int allow_ofs_delta;
69 static struct object_entry **sorted_by_sha;
70 static struct object_entry *objects;
71 static uint32_t nr_objects, nr_alloc, nr_result;
72 static const char *base_name;
73 static unsigned char pack_file_sha1[20];
74 static int progress = 1;
75 static volatile sig_atomic_t progress_update;
76 static int window = 10;
77 static int pack_to_stdout;
78 static int num_preferred_base;
80 /*
81  * The object names in objects array are hashed with this hashtable,
82  * to help looking up the entry by object name.  Binary search from
83  * sorted_by_sha is also possible but this was easier to code and faster.
84  * This hashtable is built after all the objects are seen.
85  */
86 static int *object_ix;
87 static int object_ix_hashsz;
89 /*
90  * Pack index for existing packs give us easy access to the offsets into
91  * corresponding pack file where each object's data starts, but the entries
92  * do not store the size of the compressed representation (uncompressed
93  * size is easily available by examining the pack entry header).  It is
94  * also rather expensive to find the sha1 for an object given its offset.
95  *
96  * We build a hashtable of existing packs (pack_revindex), and keep reverse
97  * index here -- pack index file is sorted by object name mapping to offset;
98  * this pack_revindex[].revindex array is a list of offset/index_nr pairs
99  * ordered by offset, so if you know the offset of an object, next offset
100  * is where its packed representation ends and the index_nr can be used to
101  * get the object sha1 from the main index.
102  */
103 struct revindex_entry {
104         off_t offset;
105         unsigned int nr;
106 };
107 struct pack_revindex {
108         struct packed_git *p;
109         struct revindex_entry *revindex;
110 };
111 static struct  pack_revindex *pack_revindex;
112 static int pack_revindex_hashsz;
114 /*
115  * stats
116  */
117 static uint32_t written, written_delta;
118 static uint32_t reused, reused_delta;
120 static int pack_revindex_ix(struct packed_git *p)
122         unsigned long ui = (unsigned long)p;
123         int i;
125         ui = ui ^ (ui >> 16); /* defeat structure alignment */
126         i = (int)(ui % pack_revindex_hashsz);
127         while (pack_revindex[i].p) {
128                 if (pack_revindex[i].p == p)
129                         return i;
130                 if (++i == pack_revindex_hashsz)
131                         i = 0;
132         }
133         return -1 - i;
136 static void prepare_pack_ix(void)
138         int num;
139         struct packed_git *p;
140         for (num = 0, p = packed_git; p; p = p->next)
141                 num++;
142         if (!num)
143                 return;
144         pack_revindex_hashsz = num * 11;
145         pack_revindex = xcalloc(sizeof(*pack_revindex), pack_revindex_hashsz);
146         for (p = packed_git; p; p = p->next) {
147                 num = pack_revindex_ix(p);
148                 num = - 1 - num;
149                 pack_revindex[num].p = p;
150         }
151         /* revindex elements are lazily initialized */
154 static int cmp_offset(const void *a_, const void *b_)
156         const struct revindex_entry *a = a_;
157         const struct revindex_entry *b = b_;
158         return (a->offset < b->offset) ? -1 : (a->offset > b->offset) ? 1 : 0;
161 /*
162  * Ordered list of offsets of objects in the pack.
163  */
164 static void prepare_pack_revindex(struct pack_revindex *rix)
166         struct packed_git *p = rix->p;
167         int num_ent = p->num_objects;
168         int i;
169         const char *index = p->index_data;
171         rix->revindex = xmalloc(sizeof(*rix->revindex) * (num_ent + 1));
172         index += 4 * 256;
174         if (p->index_version > 1) {
175                 const uint32_t *off_32 =
176                         (uint32_t *)(index + 8 + p->num_objects * (20 + 4));
177                 const uint32_t *off_64 = off_32 + p->num_objects;
178                 for (i = 0; i < num_ent; i++) {
179                         uint32_t off = ntohl(*off_32++);
180                         if (!(off & 0x80000000)) {
181                                 rix->revindex[i].offset = off;
182                         } else {
183                                 rix->revindex[i].offset =
184                                         ((uint64_t)ntohl(*off_64++)) << 32;
185                                 rix->revindex[i].offset |=
186                                         ntohl(*off_64++);
187                         }
188                         rix->revindex[i].nr = i;
189                 }
190         } else {
191                 for (i = 0; i < num_ent; i++) {
192                         uint32_t hl = *((uint32_t *)(index + 24 * i));
193                         rix->revindex[i].offset = ntohl(hl);
194                         rix->revindex[i].nr = i;
195                 }
196         }
198         /* This knows the pack format -- the 20-byte trailer
199          * follows immediately after the last object data.
200          */
201         rix->revindex[num_ent].offset = p->pack_size - 20;
202         rix->revindex[num_ent].nr = -1;
203         qsort(rix->revindex, num_ent, sizeof(*rix->revindex), cmp_offset);
206 static struct revindex_entry * find_packed_object(struct packed_git *p,
207                                                   off_t ofs)
209         int num;
210         int lo, hi;
211         struct pack_revindex *rix;
212         struct revindex_entry *revindex;
213         num = pack_revindex_ix(p);
214         if (num < 0)
215                 die("internal error: pack revindex uninitialized");
216         rix = &pack_revindex[num];
217         if (!rix->revindex)
218                 prepare_pack_revindex(rix);
219         revindex = rix->revindex;
220         lo = 0;
221         hi = p->num_objects + 1;
222         do {
223                 int mi = (lo + hi) / 2;
224                 if (revindex[mi].offset == ofs) {
225                         return revindex + mi;
226                 }
227                 else if (ofs < revindex[mi].offset)
228                         hi = mi;
229                 else
230                         lo = mi + 1;
231         } while (lo < hi);
232         die("internal error: pack revindex corrupt");
235 static const unsigned char *find_packed_object_name(struct packed_git *p,
236                                                     off_t ofs)
238         struct revindex_entry *entry = find_packed_object(p, ofs);
239         return nth_packed_object_sha1(p, entry->nr);
242 static void *delta_against(void *buf, unsigned long size, struct object_entry *entry)
244         unsigned long othersize, delta_size;
245         enum object_type type;
246         void *otherbuf = read_sha1_file(entry->delta->sha1, &type, &othersize);
247         void *delta_buf;
249         if (!otherbuf)
250                 die("unable to read %s", sha1_to_hex(entry->delta->sha1));
251         delta_buf = diff_delta(otherbuf, othersize,
252                                buf, size, &delta_size, 0);
253         if (!delta_buf || delta_size != entry->delta_size)
254                 die("delta size changed");
255         free(buf);
256         free(otherbuf);
257         return delta_buf;
260 /*
261  * The per-object header is a pretty dense thing, which is
262  *  - first byte: low four bits are "size", then three bits of "type",
263  *    and the high bit is "size continues".
264  *  - each byte afterwards: low seven bits are size continuation,
265  *    with the high bit being "size continues"
266  */
267 static int encode_header(enum object_type type, unsigned long size, unsigned char *hdr)
269         int n = 1;
270         unsigned char c;
272         if (type < OBJ_COMMIT || type > OBJ_REF_DELTA)
273                 die("bad type %d", type);
275         c = (type << 4) | (size & 15);
276         size >>= 4;
277         while (size) {
278                 *hdr++ = c | 0x80;
279                 c = size & 0x7f;
280                 size >>= 7;
281                 n++;
282         }
283         *hdr = c;
284         return n;
287 /*
288  * we are going to reuse the existing object data as is.  make
289  * sure it is not corrupt.
290  */
291 static int check_pack_inflate(struct packed_git *p,
292                 struct pack_window **w_curs,
293                 off_t offset,
294                 off_t len,
295                 unsigned long expect)
297         z_stream stream;
298         unsigned char fakebuf[4096], *in;
299         int st;
301         memset(&stream, 0, sizeof(stream));
302         inflateInit(&stream);
303         do {
304                 in = use_pack(p, w_curs, offset, &stream.avail_in);
305                 stream.next_in = in;
306                 stream.next_out = fakebuf;
307                 stream.avail_out = sizeof(fakebuf);
308                 st = inflate(&stream, Z_FINISH);
309                 offset += stream.next_in - in;
310         } while (st == Z_OK || st == Z_BUF_ERROR);
311         inflateEnd(&stream);
312         return (st == Z_STREAM_END &&
313                 stream.total_out == expect &&
314                 stream.total_in == len) ? 0 : -1;
317 static int check_pack_crc(struct packed_git *p, struct pack_window **w_curs,
318                           off_t offset, off_t len, unsigned int nr)
320         const uint32_t *index_crc;
321         uint32_t data_crc = crc32(0, Z_NULL, 0);
323         do {
324                 unsigned int avail;
325                 void *data = use_pack(p, w_curs, offset, &avail);
326                 if (avail > len)
327                         avail = len;
328                 data_crc = crc32(data_crc, data, avail);
329                 offset += avail;
330                 len -= avail;
331         } while (len);
333         index_crc = p->index_data;
334         index_crc += 2 + 256 + p->num_objects * (20/4) + nr;
336         return data_crc != ntohl(*index_crc);
339 static void copy_pack_data(struct sha1file *f,
340                 struct packed_git *p,
341                 struct pack_window **w_curs,
342                 off_t offset,
343                 off_t len)
345         unsigned char *in;
346         unsigned int avail;
348         while (len) {
349                 in = use_pack(p, w_curs, offset, &avail);
350                 if (avail > len)
351                         avail = (unsigned int)len;
352                 sha1write(f, in, avail);
353                 offset += avail;
354                 len -= avail;
355         }
358 static int check_loose_inflate(unsigned char *data, unsigned long len, unsigned long expect)
360         z_stream stream;
361         unsigned char fakebuf[4096];
362         int st;
364         memset(&stream, 0, sizeof(stream));
365         stream.next_in = data;
366         stream.avail_in = len;
367         stream.next_out = fakebuf;
368         stream.avail_out = sizeof(fakebuf);
369         inflateInit(&stream);
371         while (1) {
372                 st = inflate(&stream, Z_FINISH);
373                 if (st == Z_STREAM_END || st == Z_OK) {
374                         st = (stream.total_out == expect &&
375                               stream.total_in == len) ? 0 : -1;
376                         break;
377                 }
378                 if (st != Z_BUF_ERROR) {
379                         st = -1;
380                         break;
381                 }
382                 stream.next_out = fakebuf;
383                 stream.avail_out = sizeof(fakebuf);
384         }
385         inflateEnd(&stream);
386         return st;
389 static int revalidate_loose_object(struct object_entry *entry,
390                                    unsigned char *map,
391                                    unsigned long mapsize)
393         /* we already know this is a loose object with new type header. */
394         enum object_type type;
395         unsigned long size, used;
397         if (pack_to_stdout)
398                 return 0;
400         used = unpack_object_header_gently(map, mapsize, &type, &size);
401         if (!used)
402                 return -1;
403         map += used;
404         mapsize -= used;
405         return check_loose_inflate(map, mapsize, size);
408 static unsigned long write_object(struct sha1file *f,
409                                   struct object_entry *entry)
411         unsigned long size;
412         enum object_type type;
413         void *buf;
414         unsigned char header[10];
415         unsigned hdrlen;
416         off_t datalen;
417         enum object_type obj_type;
418         int to_reuse = 0;
420         if (!pack_to_stdout)
421                 crc32_begin(f);
423         obj_type = entry->type;
424         if (! entry->in_pack)
425                 to_reuse = 0;   /* can't reuse what we don't have */
426         else if (obj_type == OBJ_REF_DELTA || obj_type == OBJ_OFS_DELTA)
427                 to_reuse = 1;   /* check_object() decided it for us */
428         else if (obj_type != entry->in_pack_type)
429                 to_reuse = 0;   /* pack has delta which is unusable */
430         else if (entry->delta)
431                 to_reuse = 0;   /* we want to pack afresh */
432         else
433                 to_reuse = 1;   /* we have it in-pack undeltified,
434                                  * and we do not need to deltify it.
435                                  */
437         if (!entry->in_pack && !entry->delta) {
438                 unsigned char *map;
439                 unsigned long mapsize;
440                 map = map_sha1_file(entry->sha1, &mapsize);
441                 if (map && !legacy_loose_object(map)) {
442                         /* We can copy straight into the pack file */
443                         if (revalidate_loose_object(entry, map, mapsize))
444                                 die("corrupt loose object %s",
445                                     sha1_to_hex(entry->sha1));
446                         sha1write(f, map, mapsize);
447                         munmap(map, mapsize);
448                         written++;
449                         reused++;
450                         return mapsize;
451                 }
452                 if (map)
453                         munmap(map, mapsize);
454         }
456         if (!to_reuse) {
457                 buf = read_sha1_file(entry->sha1, &type, &size);
458                 if (!buf)
459                         die("unable to read %s", sha1_to_hex(entry->sha1));
460                 if (size != entry->size)
461                         die("object %s size inconsistency (%lu vs %lu)",
462                             sha1_to_hex(entry->sha1), size, entry->size);
463                 if (entry->delta) {
464                         buf = delta_against(buf, size, entry);
465                         size = entry->delta_size;
466                         obj_type = (allow_ofs_delta && entry->delta->offset) ?
467                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
468                 }
469                 /*
470                  * The object header is a byte of 'type' followed by zero or
471                  * more bytes of length.
472                  */
473                 hdrlen = encode_header(obj_type, size, header);
474                 sha1write(f, header, hdrlen);
476                 if (obj_type == OBJ_OFS_DELTA) {
477                         /*
478                          * Deltas with relative base contain an additional
479                          * encoding of the relative offset for the delta
480                          * base from this object's position in the pack.
481                          */
482                         off_t ofs = entry->offset - entry->delta->offset;
483                         unsigned pos = sizeof(header) - 1;
484                         header[pos] = ofs & 127;
485                         while (ofs >>= 7)
486                                 header[--pos] = 128 | (--ofs & 127);
487                         sha1write(f, header + pos, sizeof(header) - pos);
488                         hdrlen += sizeof(header) - pos;
489                 } else if (obj_type == OBJ_REF_DELTA) {
490                         /*
491                          * Deltas with a base reference contain
492                          * an additional 20 bytes for the base sha1.
493                          */
494                         sha1write(f, entry->delta->sha1, 20);
495                         hdrlen += 20;
496                 }
497                 datalen = sha1write_compressed(f, buf, size);
498                 free(buf);
499         }
500         else {
501                 struct packed_git *p = entry->in_pack;
502                 struct pack_window *w_curs = NULL;
503                 struct revindex_entry *revidx;
504                 off_t offset;
506                 if (entry->delta) {
507                         obj_type = (allow_ofs_delta && entry->delta->offset) ?
508                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
509                         reused_delta++;
510                 }
511                 hdrlen = encode_header(obj_type, entry->size, header);
512                 sha1write(f, header, hdrlen);
513                 if (obj_type == OBJ_OFS_DELTA) {
514                         off_t ofs = entry->offset - entry->delta->offset;
515                         unsigned pos = sizeof(header) - 1;
516                         header[pos] = ofs & 127;
517                         while (ofs >>= 7)
518                                 header[--pos] = 128 | (--ofs & 127);
519                         sha1write(f, header + pos, sizeof(header) - pos);
520                         hdrlen += sizeof(header) - pos;
521                 } else if (obj_type == OBJ_REF_DELTA) {
522                         sha1write(f, entry->delta->sha1, 20);
523                         hdrlen += 20;
524                 }
526                 offset = entry->in_pack_offset;
527                 revidx = find_packed_object(p, offset);
528                 datalen = revidx[1].offset - offset;
529                 if (!pack_to_stdout && p->index_version > 1 &&
530                     check_pack_crc(p, &w_curs, offset, datalen, revidx->nr))
531                         die("bad packed object CRC for %s", sha1_to_hex(entry->sha1));
532                 offset += entry->in_pack_header_size;
533                 datalen -= entry->in_pack_header_size;
534                 if (!pack_to_stdout && p->index_version == 1 &&
535                     check_pack_inflate(p, &w_curs, offset, datalen, entry->size))
536                         die("corrupt packed object for %s", sha1_to_hex(entry->sha1));
537                 copy_pack_data(f, p, &w_curs, offset, datalen);
538                 unuse_pack(&w_curs);
539                 reused++;
540         }
541         if (entry->delta)
542                 written_delta++;
543         written++;
544         if (!pack_to_stdout)
545                 entry->crc32 = crc32_end(f);
546         return hdrlen + datalen;
549 static off_t write_one(struct sha1file *f,
550                                struct object_entry *e,
551                                off_t offset)
553         unsigned long size;
555         /* offset is non zero if object is written already. */
556         if (e->offset || e->preferred_base)
557                 return offset;
559         /* if we are deltified, write out base object first. */
560         if (e->delta)
561                 offset = write_one(f, e->delta, offset);
563         e->offset = offset;
564         size = write_object(f, e);
566         /* make sure off_t is sufficiently large not to wrap */
567         if (offset > offset + size)
568                 die("pack too large for current definition of off_t");
569         return offset + size;
572 static off_t write_pack_file(void)
574         uint32_t i;
575         struct sha1file *f;
576         off_t offset, last_obj_offset = 0;
577         struct pack_header hdr;
578         unsigned last_percent = 999;
579         int do_progress = progress;
581         if (!base_name) {
582                 f = sha1fd(1, "<stdout>");
583                 do_progress >>= 1;
584         }
585         else
586                 f = sha1create("%s-%s.%s", base_name,
587                                sha1_to_hex(object_list_sha1), "pack");
588         if (do_progress)
589                 fprintf(stderr, "Writing %u objects.\n", nr_result);
591         hdr.hdr_signature = htonl(PACK_SIGNATURE);
592         hdr.hdr_version = htonl(PACK_VERSION);
593         hdr.hdr_entries = htonl(nr_result);
594         sha1write(f, &hdr, sizeof(hdr));
595         offset = sizeof(hdr);
596         if (!nr_result)
597                 goto done;
598         for (i = 0; i < nr_objects; i++) {
599                 last_obj_offset = offset;
600                 offset = write_one(f, objects + i, offset);
601                 if (do_progress) {
602                         unsigned percent = written * 100 / nr_result;
603                         if (progress_update || percent != last_percent) {
604                                 fprintf(stderr, "%4u%% (%u/%u) done\r",
605                                         percent, written, nr_result);
606                                 progress_update = 0;
607                                 last_percent = percent;
608                         }
609                 }
610         }
611         if (do_progress)
612                 fputc('\n', stderr);
613  done:
614         if (written != nr_result)
615                 die("wrote %u objects while expecting %u", written, nr_result);
616         sha1close(f, pack_file_sha1, 1);
618         return last_obj_offset;
621 static uint32_t index_default_version = 1;
622 static uint32_t index_off32_limit = 0x7fffffff;
624 static void write_index_file(off_t last_obj_offset)
626         uint32_t i;
627         struct sha1file *f = sha1create("%s-%s.%s", base_name,
628                                         sha1_to_hex(object_list_sha1), "idx");
629         struct object_entry **list = sorted_by_sha;
630         struct object_entry **last = list + nr_result;
631         uint32_t array[256];
632         uint32_t index_version;
634         /* if last object's offset is >= 2^31 we should use index V2 */
635         index_version = (last_obj_offset >> 31) ? 2 : index_default_version;
637         /* index versions 2 and above need a header */
638         if (index_version >= 2) {
639                 struct pack_idx_header hdr;
640                 hdr.idx_signature = htonl(PACK_IDX_SIGNATURE);
641                 hdr.idx_version = htonl(index_version);
642                 sha1write(f, &hdr, sizeof(hdr));
643         }
645         /*
646          * Write the first-level table (the list is sorted,
647          * but we use a 256-entry lookup to be able to avoid
648          * having to do eight extra binary search iterations).
649          */
650         for (i = 0; i < 256; i++) {
651                 struct object_entry **next = list;
652                 while (next < last) {
653                         struct object_entry *entry = *next;
654                         if (entry->sha1[0] != i)
655                                 break;
656                         next++;
657                 }
658                 array[i] = htonl(next - sorted_by_sha);
659                 list = next;
660         }
661         sha1write(f, array, 256 * 4);
663         /*
664          * Write the actual SHA1 entries..
665          */
666         list = sorted_by_sha;
667         for (i = 0; i < nr_result; i++) {
668                 struct object_entry *entry = *list++;
669                 if (index_version < 2) {
670                         uint32_t offset = htonl(entry->offset);
671                         sha1write(f, &offset, 4);
672                 }
673                 sha1write(f, entry->sha1, 20);
674         }
676         if (index_version >= 2) {
677                 unsigned int nr_large_offset = 0;
679                 /* write the crc32 table */
680                 list = sorted_by_sha;
681                 for (i = 0; i < nr_objects; i++) {
682                         struct object_entry *entry = *list++;
683                         uint32_t crc32_val = htonl(entry->crc32);
684                         sha1write(f, &crc32_val, 4);
685                 }
687                 /* write the 32-bit offset table */
688                 list = sorted_by_sha;
689                 for (i = 0; i < nr_objects; i++) {
690                         struct object_entry *entry = *list++;
691                         uint32_t offset = (entry->offset <= index_off32_limit) ?
692                                 entry->offset : (0x80000000 | nr_large_offset++);
693                         offset = htonl(offset);
694                         sha1write(f, &offset, 4);
695                 }
697                 /* write the large offset table */
698                 list = sorted_by_sha;
699                 while (nr_large_offset) {
700                         struct object_entry *entry = *list++;
701                         uint64_t offset = entry->offset;
702                         if (offset > index_off32_limit) {
703                                 uint32_t split[2];
704                                 split[0]        = htonl(offset >> 32);
705                                 split[1] = htonl(offset & 0xffffffff);
706                                 sha1write(f, split, 8);
707                                 nr_large_offset--;
708                         }
709                 }
710         }
712         sha1write(f, pack_file_sha1, 20);
713         sha1close(f, NULL, 1);
716 static int locate_object_entry_hash(const unsigned char *sha1)
718         int i;
719         unsigned int ui;
720         memcpy(&ui, sha1, sizeof(unsigned int));
721         i = ui % object_ix_hashsz;
722         while (0 < object_ix[i]) {
723                 if (!hashcmp(sha1, objects[object_ix[i] - 1].sha1))
724                         return i;
725                 if (++i == object_ix_hashsz)
726                         i = 0;
727         }
728         return -1 - i;
731 static struct object_entry *locate_object_entry(const unsigned char *sha1)
733         int i;
735         if (!object_ix_hashsz)
736                 return NULL;
738         i = locate_object_entry_hash(sha1);
739         if (0 <= i)
740                 return &objects[object_ix[i]-1];
741         return NULL;
744 static void rehash_objects(void)
746         uint32_t i;
747         struct object_entry *oe;
749         object_ix_hashsz = nr_objects * 3;
750         if (object_ix_hashsz < 1024)
751                 object_ix_hashsz = 1024;
752         object_ix = xrealloc(object_ix, sizeof(int) * object_ix_hashsz);
753         memset(object_ix, 0, sizeof(int) * object_ix_hashsz);
754         for (i = 0, oe = objects; i < nr_objects; i++, oe++) {
755                 int ix = locate_object_entry_hash(oe->sha1);
756                 if (0 <= ix)
757                         continue;
758                 ix = -1 - ix;
759                 object_ix[ix] = i + 1;
760         }
763 static unsigned name_hash(const char *name)
765         unsigned char c;
766         unsigned hash = 0;
768         /*
769          * This effectively just creates a sortable number from the
770          * last sixteen non-whitespace characters. Last characters
771          * count "most", so things that end in ".c" sort together.
772          */
773         while ((c = *name++) != 0) {
774                 if (isspace(c))
775                         continue;
776                 hash = (hash >> 2) + (c << 24);
777         }
778         return hash;
781 static int add_object_entry(const unsigned char *sha1, unsigned hash, int exclude)
783         struct object_entry *entry;
784         struct packed_git *p, *found_pack = NULL;
785         off_t found_offset = 0;
786         int ix;
788         ix = nr_objects ? locate_object_entry_hash(sha1) : -1;
789         if (ix >= 0) {
790                 if (exclude) {
791                         entry = objects + object_ix[ix] - 1;
792                         entry->preferred_base = 1;
793                 }
794                 return 0;
795         }
797         if (!exclude) {
798                 for (p = packed_git; p; p = p->next) {
799                         off_t offset = find_pack_entry_one(sha1, p);
800                         if (offset) {
801                                 if (incremental)
802                                         return 0;
803                                 if (local && !p->pack_local)
804                                         return 0;
805                                 if (!found_pack) {
806                                         found_offset = offset;
807                                         found_pack = p;
808                                 }
809                         }
810                 }
811         }
813         if (nr_objects >= nr_alloc) {
814                 nr_alloc = (nr_alloc  + 1024) * 3 / 2;
815                 objects = xrealloc(objects, nr_alloc * sizeof(*entry));
816         }
818         entry = objects + nr_objects++;
819         memset(entry, 0, sizeof(*entry));
820         hashcpy(entry->sha1, sha1);
821         entry->hash = hash;
822         if (exclude)
823                 entry->preferred_base = 1;
824         if (found_pack) {
825                 entry->in_pack = found_pack;
826                 entry->in_pack_offset = found_offset;
827         }
829         if (object_ix_hashsz * 3 <= nr_objects * 4)
830                 rehash_objects();
831         else
832                 object_ix[-1 - ix] = nr_objects;
834         if (progress_update) {
835                 fprintf(stderr, "Counting objects...%u\r", nr_objects);
836                 progress_update = 0;
837         }
839         return 1;
842 struct pbase_tree_cache {
843         unsigned char sha1[20];
844         int ref;
845         int temporary;
846         void *tree_data;
847         unsigned long tree_size;
848 };
850 static struct pbase_tree_cache *(pbase_tree_cache[256]);
851 static int pbase_tree_cache_ix(const unsigned char *sha1)
853         return sha1[0] % ARRAY_SIZE(pbase_tree_cache);
855 static int pbase_tree_cache_ix_incr(int ix)
857         return (ix+1) % ARRAY_SIZE(pbase_tree_cache);
860 static struct pbase_tree {
861         struct pbase_tree *next;
862         /* This is a phony "cache" entry; we are not
863          * going to evict it nor find it through _get()
864          * mechanism -- this is for the toplevel node that
865          * would almost always change with any commit.
866          */
867         struct pbase_tree_cache pcache;
868 } *pbase_tree;
870 static struct pbase_tree_cache *pbase_tree_get(const unsigned char *sha1)
872         struct pbase_tree_cache *ent, *nent;
873         void *data;
874         unsigned long size;
875         enum object_type type;
876         int neigh;
877         int my_ix = pbase_tree_cache_ix(sha1);
878         int available_ix = -1;
880         /* pbase-tree-cache acts as a limited hashtable.
881          * your object will be found at your index or within a few
882          * slots after that slot if it is cached.
883          */
884         for (neigh = 0; neigh < 8; neigh++) {
885                 ent = pbase_tree_cache[my_ix];
886                 if (ent && !hashcmp(ent->sha1, sha1)) {
887                         ent->ref++;
888                         return ent;
889                 }
890                 else if (((available_ix < 0) && (!ent || !ent->ref)) ||
891                          ((0 <= available_ix) &&
892                           (!ent && pbase_tree_cache[available_ix])))
893                         available_ix = my_ix;
894                 if (!ent)
895                         break;
896                 my_ix = pbase_tree_cache_ix_incr(my_ix);
897         }
899         /* Did not find one.  Either we got a bogus request or
900          * we need to read and perhaps cache.
901          */
902         data = read_sha1_file(sha1, &type, &size);
903         if (!data)
904                 return NULL;
905         if (type != OBJ_TREE) {
906                 free(data);
907                 return NULL;
908         }
910         /* We need to either cache or return a throwaway copy */
912         if (available_ix < 0)
913                 ent = NULL;
914         else {
915                 ent = pbase_tree_cache[available_ix];
916                 my_ix = available_ix;
917         }
919         if (!ent) {
920                 nent = xmalloc(sizeof(*nent));
921                 nent->temporary = (available_ix < 0);
922         }
923         else {
924                 /* evict and reuse */
925                 free(ent->tree_data);
926                 nent = ent;
927         }
928         hashcpy(nent->sha1, sha1);
929         nent->tree_data = data;
930         nent->tree_size = size;
931         nent->ref = 1;
932         if (!nent->temporary)
933                 pbase_tree_cache[my_ix] = nent;
934         return nent;
937 static void pbase_tree_put(struct pbase_tree_cache *cache)
939         if (!cache->temporary) {
940                 cache->ref--;
941                 return;
942         }
943         free(cache->tree_data);
944         free(cache);
947 static int name_cmp_len(const char *name)
949         int i;
950         for (i = 0; name[i] && name[i] != '\n' && name[i] != '/'; i++)
951                 ;
952         return i;
955 static void add_pbase_object(struct tree_desc *tree,
956                              const char *name,
957                              int cmplen,
958                              const char *fullname)
960         struct name_entry entry;
961         int cmp;
963         while (tree_entry(tree,&entry)) {
964                 cmp = tree_entry_len(entry.path, entry.sha1) != cmplen ? 1 :
965                       memcmp(name, entry.path, cmplen);
966                 if (cmp > 0)
967                         continue;
968                 if (cmp < 0)
969                         return;
970                 if (name[cmplen] != '/') {
971                         unsigned hash = name_hash(fullname);
972                         add_object_entry(entry.sha1, hash, 1);
973                         return;
974                 }
975                 if (S_ISDIR(entry.mode)) {
976                         struct tree_desc sub;
977                         struct pbase_tree_cache *tree;
978                         const char *down = name+cmplen+1;
979                         int downlen = name_cmp_len(down);
981                         tree = pbase_tree_get(entry.sha1);
982                         if (!tree)
983                                 return;
984                         init_tree_desc(&sub, tree->tree_data, tree->tree_size);
986                         add_pbase_object(&sub, down, downlen, fullname);
987                         pbase_tree_put(tree);
988                 }
989         }
992 static unsigned *done_pbase_paths;
993 static int done_pbase_paths_num;
994 static int done_pbase_paths_alloc;
995 static int done_pbase_path_pos(unsigned hash)
997         int lo = 0;
998         int hi = done_pbase_paths_num;
999         while (lo < hi) {
1000                 int mi = (hi + lo) / 2;
1001                 if (done_pbase_paths[mi] == hash)
1002                         return mi;
1003                 if (done_pbase_paths[mi] < hash)
1004                         hi = mi;
1005                 else
1006                         lo = mi + 1;
1007         }
1008         return -lo-1;
1011 static int check_pbase_path(unsigned hash)
1013         int pos = (!done_pbase_paths) ? -1 : done_pbase_path_pos(hash);
1014         if (0 <= pos)
1015                 return 1;
1016         pos = -pos - 1;
1017         if (done_pbase_paths_alloc <= done_pbase_paths_num) {
1018                 done_pbase_paths_alloc = alloc_nr(done_pbase_paths_alloc);
1019                 done_pbase_paths = xrealloc(done_pbase_paths,
1020                                             done_pbase_paths_alloc *
1021                                             sizeof(unsigned));
1022         }
1023         done_pbase_paths_num++;
1024         if (pos < done_pbase_paths_num)
1025                 memmove(done_pbase_paths + pos + 1,
1026                         done_pbase_paths + pos,
1027                         (done_pbase_paths_num - pos - 1) * sizeof(unsigned));
1028         done_pbase_paths[pos] = hash;
1029         return 0;
1032 static void add_preferred_base_object(const char *name, unsigned hash)
1034         struct pbase_tree *it;
1035         int cmplen;
1037         if (!num_preferred_base || check_pbase_path(hash))
1038                 return;
1040         cmplen = name_cmp_len(name);
1041         for (it = pbase_tree; it; it = it->next) {
1042                 if (cmplen == 0) {
1043                         add_object_entry(it->pcache.sha1, 0, 1);
1044                 }
1045                 else {
1046                         struct tree_desc tree;
1047                         init_tree_desc(&tree, it->pcache.tree_data, it->pcache.tree_size);
1048                         add_pbase_object(&tree, name, cmplen, name);
1049                 }
1050         }
1053 static void add_preferred_base(unsigned char *sha1)
1055         struct pbase_tree *it;
1056         void *data;
1057         unsigned long size;
1058         unsigned char tree_sha1[20];
1060         if (window <= num_preferred_base++)
1061                 return;
1063         data = read_object_with_reference(sha1, tree_type, &size, tree_sha1);
1064         if (!data)
1065                 return;
1067         for (it = pbase_tree; it; it = it->next) {
1068                 if (!hashcmp(it->pcache.sha1, tree_sha1)) {
1069                         free(data);
1070                         return;
1071                 }
1072         }
1074         it = xcalloc(1, sizeof(*it));
1075         it->next = pbase_tree;
1076         pbase_tree = it;
1078         hashcpy(it->pcache.sha1, tree_sha1);
1079         it->pcache.tree_data = data;
1080         it->pcache.tree_size = size;
1083 static void check_object(struct object_entry *entry)
1085         if (entry->in_pack && !entry->preferred_base) {
1086                 struct packed_git *p = entry->in_pack;
1087                 struct pack_window *w_curs = NULL;
1088                 unsigned long size, used;
1089                 unsigned int avail;
1090                 unsigned char *buf;
1091                 struct object_entry *base_entry = NULL;
1093                 buf = use_pack(p, &w_curs, entry->in_pack_offset, &avail);
1095                 /* We want in_pack_type even if we do not reuse delta.
1096                  * There is no point not reusing non-delta representations.
1097                  */
1098                 used = unpack_object_header_gently(buf, avail,
1099                                                    &entry->in_pack_type, &size);
1101                 /* Check if it is delta, and the base is also an object
1102                  * we are going to pack.  If so we will reuse the existing
1103                  * delta.
1104                  */
1105                 if (!no_reuse_delta) {
1106                         unsigned char c;
1107                         const unsigned char *base_name;
1108                         off_t ofs;
1109                         unsigned long used_0;
1110                         /* there is at least 20 bytes left in the pack */
1111                         switch (entry->in_pack_type) {
1112                         case OBJ_REF_DELTA:
1113                                 base_name = use_pack(p, &w_curs,
1114                                         entry->in_pack_offset + used, NULL);
1115                                 used += 20;
1116                                 break;
1117                         case OBJ_OFS_DELTA:
1118                                 buf = use_pack(p, &w_curs,
1119                                         entry->in_pack_offset + used, NULL);
1120                                 used_0 = 0;
1121                                 c = buf[used_0++];
1122                                 ofs = c & 127;
1123                                 while (c & 128) {
1124                                         ofs += 1;
1125                                         if (!ofs || MSB(ofs, 7))
1126                                                 die("delta base offset overflow in pack for %s",
1127                                                     sha1_to_hex(entry->sha1));
1128                                         c = buf[used_0++];
1129                                         ofs = (ofs << 7) + (c & 127);
1130                                 }
1131                                 if (ofs >= entry->in_pack_offset)
1132                                         die("delta base offset out of bound for %s",
1133                                             sha1_to_hex(entry->sha1));
1134                                 ofs = entry->in_pack_offset - ofs;
1135                                 base_name = find_packed_object_name(p, ofs);
1136                                 used += used_0;
1137                                 break;
1138                         default:
1139                                 base_name = NULL;
1140                         }
1141                         if (base_name)
1142                                 base_entry = locate_object_entry(base_name);
1143                 }
1144                 unuse_pack(&w_curs);
1145                 entry->in_pack_header_size = used;
1147                 if (base_entry) {
1149                         /* Depth value does not matter - find_deltas()
1150                          * will never consider reused delta as the
1151                          * base object to deltify other objects
1152                          * against, in order to avoid circular deltas.
1153                          */
1155                         /* uncompressed size of the delta data */
1156                         entry->size = size;
1157                         entry->delta = base_entry;
1158                         entry->type = entry->in_pack_type;
1160                         entry->delta_sibling = base_entry->delta_child;
1161                         base_entry->delta_child = entry;
1163                         return;
1164                 }
1165                 /* Otherwise we would do the usual */
1166         }
1168         entry->type = sha1_object_info(entry->sha1, &entry->size);
1169         if (entry->type < 0)
1170                 die("unable to get type of object %s",
1171                     sha1_to_hex(entry->sha1));
1174 static void get_object_details(void)
1176         uint32_t i;
1177         struct object_entry *entry;
1179         prepare_pack_ix();
1180         for (i = 0, entry = objects; i < nr_objects; i++, entry++)
1181                 check_object(entry);
1184 static int sha1_sort(const void *_a, const void *_b)
1186         const struct object_entry *a = *(struct object_entry **)_a;
1187         const struct object_entry *b = *(struct object_entry **)_b;
1188         return hashcmp(a->sha1, b->sha1);
1191 static struct object_entry **create_final_object_list(void)
1193         struct object_entry **list;
1194         uint32_t i, j;
1196         for (i = nr_result = 0; i < nr_objects; i++)
1197                 if (!objects[i].preferred_base)
1198                         nr_result++;
1199         list = xmalloc(nr_result * sizeof(struct object_entry *));
1200         for (i = j = 0; i < nr_objects; i++) {
1201                 if (!objects[i].preferred_base)
1202                         list[j++] = objects + i;
1203         }
1204         qsort(list, nr_result, sizeof(struct object_entry *), sha1_sort);
1205         return list;
1208 static int type_size_sort(const void *_a, const void *_b)
1210         const struct object_entry *a = *(struct object_entry **)_a;
1211         const struct object_entry *b = *(struct object_entry **)_b;
1213         if (a->type < b->type)
1214                 return -1;
1215         if (a->type > b->type)
1216                 return 1;
1217         if (a->hash < b->hash)
1218                 return -1;
1219         if (a->hash > b->hash)
1220                 return 1;
1221         if (a->preferred_base < b->preferred_base)
1222                 return -1;
1223         if (a->preferred_base > b->preferred_base)
1224                 return 1;
1225         if (a->size < b->size)
1226                 return -1;
1227         if (a->size > b->size)
1228                 return 1;
1229         return a > b ? -1 : (a < b);  /* newest last */
1232 struct unpacked {
1233         struct object_entry *entry;
1234         void *data;
1235         struct delta_index *index;
1236 };
1238 /*
1239  * We search for deltas _backwards_ in a list sorted by type and
1240  * by size, so that we see progressively smaller and smaller files.
1241  * That's because we prefer deltas to be from the bigger file
1242  * to the smaller - deletes are potentially cheaper, but perhaps
1243  * more importantly, the bigger file is likely the more recent
1244  * one.
1245  */
1246 static int try_delta(struct unpacked *trg, struct unpacked *src,
1247                      unsigned max_depth)
1249         struct object_entry *trg_entry = trg->entry;
1250         struct object_entry *src_entry = src->entry;
1251         unsigned long trg_size, src_size, delta_size, sizediff, max_size, sz;
1252         enum object_type type;
1253         void *delta_buf;
1255         /* Don't bother doing diffs between different types */
1256         if (trg_entry->type != src_entry->type)
1257                 return -1;
1259         /* We do not compute delta to *create* objects we are not
1260          * going to pack.
1261          */
1262         if (trg_entry->preferred_base)
1263                 return -1;
1265         /*
1266          * We do not bother to try a delta that we discarded
1267          * on an earlier try, but only when reusing delta data.
1268          */
1269         if (!no_reuse_delta && trg_entry->in_pack &&
1270             trg_entry->in_pack == src_entry->in_pack &&
1271             trg_entry->in_pack_type != OBJ_REF_DELTA &&
1272             trg_entry->in_pack_type != OBJ_OFS_DELTA)
1273                 return 0;
1275         /* Let's not bust the allowed depth. */
1276         if (src_entry->depth >= max_depth)
1277                 return 0;
1279         /* Now some size filtering heuristics. */
1280         trg_size = trg_entry->size;
1281         max_size = trg_size/2 - 20;
1282         max_size = max_size * (max_depth - src_entry->depth) / max_depth;
1283         if (max_size == 0)
1284                 return 0;
1285         if (trg_entry->delta && trg_entry->delta_size <= max_size)
1286                 max_size = trg_entry->delta_size-1;
1287         src_size = src_entry->size;
1288         sizediff = src_size < trg_size ? trg_size - src_size : 0;
1289         if (sizediff >= max_size)
1290                 return 0;
1292         /* Load data if not already done */
1293         if (!trg->data) {
1294                 trg->data = read_sha1_file(trg_entry->sha1, &type, &sz);
1295                 if (sz != trg_size)
1296                         die("object %s inconsistent object length (%lu vs %lu)",
1297                             sha1_to_hex(trg_entry->sha1), sz, trg_size);
1298         }
1299         if (!src->data) {
1300                 src->data = read_sha1_file(src_entry->sha1, &type, &sz);
1301                 if (sz != src_size)
1302                         die("object %s inconsistent object length (%lu vs %lu)",
1303                             sha1_to_hex(src_entry->sha1), sz, src_size);
1304         }
1305         if (!src->index) {
1306                 src->index = create_delta_index(src->data, src_size);
1307                 if (!src->index)
1308                         die("out of memory");
1309         }
1311         delta_buf = create_delta(src->index, trg->data, trg_size, &delta_size, max_size);
1312         if (!delta_buf)
1313                 return 0;
1315         trg_entry->delta = src_entry;
1316         trg_entry->delta_size = delta_size;
1317         trg_entry->depth = src_entry->depth + 1;
1318         free(delta_buf);
1319         return 1;
1322 static unsigned int check_delta_limit(struct object_entry *me, unsigned int n)
1324         struct object_entry *child = me->delta_child;
1325         unsigned int m = n;
1326         while (child) {
1327                 unsigned int c = check_delta_limit(child, n + 1);
1328                 if (m < c)
1329                         m = c;
1330                 child = child->delta_sibling;
1331         }
1332         return m;
1335 static void find_deltas(struct object_entry **list, int window, int depth)
1337         uint32_t i = nr_objects, idx = 0, processed = 0;
1338         unsigned int array_size = window * sizeof(struct unpacked);
1339         struct unpacked *array;
1340         unsigned last_percent = 999;
1341         int max_depth;
1343         if (!nr_objects)
1344                 return;
1345         array = xmalloc(array_size);
1346         memset(array, 0, array_size);
1347         if (progress)
1348                 fprintf(stderr, "Deltifying %u objects.\n", nr_result);
1350         do {
1351                 struct object_entry *entry = list[--i];
1352                 struct unpacked *n = array + idx;
1353                 int j;
1355                 if (!entry->preferred_base)
1356                         processed++;
1358                 if (progress) {
1359                         unsigned percent = processed * 100 / nr_result;
1360                         if (percent != last_percent || progress_update) {
1361                                 fprintf(stderr, "%4u%% (%u/%u) done\r",
1362                                         percent, processed, nr_result);
1363                                 progress_update = 0;
1364                                 last_percent = percent;
1365                         }
1366                 }
1368                 if (entry->delta)
1369                         /* This happens if we decided to reuse existing
1370                          * delta from a pack.  "!no_reuse_delta &&" is implied.
1371                          */
1372                         continue;
1374                 if (entry->size < 50)
1375                         continue;
1376                 free_delta_index(n->index);
1377                 n->index = NULL;
1378                 free(n->data);
1379                 n->data = NULL;
1380                 n->entry = entry;
1382                 /*
1383                  * If the current object is at pack edge, take the depth the
1384                  * objects that depend on the current object into account
1385                  * otherwise they would become too deep.
1386                  */
1387                 max_depth = depth;
1388                 if (entry->delta_child) {
1389                         max_depth -= check_delta_limit(entry, 0);
1390                         if (max_depth <= 0)
1391                                 goto next;
1392                 }
1394                 j = window;
1395                 while (--j > 0) {
1396                         uint32_t other_idx = idx + j;
1397                         struct unpacked *m;
1398                         if (other_idx >= window)
1399                                 other_idx -= window;
1400                         m = array + other_idx;
1401                         if (!m->entry)
1402                                 break;
1403                         if (try_delta(n, m, max_depth) < 0)
1404                                 break;
1405                 }
1407                 /* if we made n a delta, and if n is already at max
1408                  * depth, leaving it in the window is pointless.  we
1409                  * should evict it first.
1410                  */
1411                 if (entry->delta && depth <= entry->depth)
1412                         continue;
1414                 next:
1415                 idx++;
1416                 if (idx >= window)
1417                         idx = 0;
1418         } while (i > 0);
1420         if (progress)
1421                 fputc('\n', stderr);
1423         for (i = 0; i < window; ++i) {
1424                 free_delta_index(array[i].index);
1425                 free(array[i].data);
1426         }
1427         free(array);
1430 static void prepare_pack(int window, int depth)
1432         struct object_entry **delta_list;
1433         uint32_t i;
1435         get_object_details();
1437         if (!window || !depth)
1438                 return;
1440         delta_list = xmalloc(nr_objects * sizeof(*delta_list));
1441         for (i = 0; i < nr_objects; i++)
1442                 delta_list[i] = objects + i;
1443         qsort(delta_list, nr_objects, sizeof(*delta_list), type_size_sort);
1444         find_deltas(delta_list, window+1, depth);
1445         free(delta_list);
1448 static void progress_interval(int signum)
1450         progress_update = 1;
1453 static void setup_progress_signal(void)
1455         struct sigaction sa;
1456         struct itimerval v;
1458         memset(&sa, 0, sizeof(sa));
1459         sa.sa_handler = progress_interval;
1460         sigemptyset(&sa.sa_mask);
1461         sa.sa_flags = SA_RESTART;
1462         sigaction(SIGALRM, &sa, NULL);
1464         v.it_interval.tv_sec = 1;
1465         v.it_interval.tv_usec = 0;
1466         v.it_value = v.it_interval;
1467         setitimer(ITIMER_REAL, &v, NULL);
1470 static int git_pack_config(const char *k, const char *v)
1472         if(!strcmp(k, "pack.window")) {
1473                 window = git_config_int(k, v);
1474                 return 0;
1475         }
1476         return git_default_config(k, v);
1479 static void read_object_list_from_stdin(void)
1481         char line[40 + 1 + PATH_MAX + 2];
1482         unsigned char sha1[20];
1483         unsigned hash;
1485         for (;;) {
1486                 if (!fgets(line, sizeof(line), stdin)) {
1487                         if (feof(stdin))
1488                                 break;
1489                         if (!ferror(stdin))
1490                                 die("fgets returned NULL, not EOF, not error!");
1491                         if (errno != EINTR)
1492                                 die("fgets: %s", strerror(errno));
1493                         clearerr(stdin);
1494                         continue;
1495                 }
1496                 if (line[0] == '-') {
1497                         if (get_sha1_hex(line+1, sha1))
1498                                 die("expected edge sha1, got garbage:\n %s",
1499                                     line);
1500                         add_preferred_base(sha1);
1501                         continue;
1502                 }
1503                 if (get_sha1_hex(line, sha1))
1504                         die("expected sha1, got garbage:\n %s", line);
1506                 hash = name_hash(line+41);
1507                 add_preferred_base_object(line+41, hash);
1508                 add_object_entry(sha1, hash, 0);
1509         }
1512 static void show_commit(struct commit *commit)
1514         add_object_entry(commit->object.sha1, 0, 0);
1517 static void show_object(struct object_array_entry *p)
1519         unsigned hash = name_hash(p->name);
1520         add_preferred_base_object(p->name, hash);
1521         add_object_entry(p->item->sha1, hash, 0);
1524 static void show_edge(struct commit *commit)
1526         add_preferred_base(commit->object.sha1);
1529 static void get_object_list(int ac, const char **av)
1531         struct rev_info revs;
1532         char line[1000];
1533         int flags = 0;
1535         init_revisions(&revs, NULL);
1536         save_commit_buffer = 0;
1537         track_object_refs = 0;
1538         setup_revisions(ac, av, &revs, NULL);
1540         while (fgets(line, sizeof(line), stdin) != NULL) {
1541                 int len = strlen(line);
1542                 if (line[len - 1] == '\n')
1543                         line[--len] = 0;
1544                 if (!len)
1545                         break;
1546                 if (*line == '-') {
1547                         if (!strcmp(line, "--not")) {
1548                                 flags ^= UNINTERESTING;
1549                                 continue;
1550                         }
1551                         die("not a rev '%s'", line);
1552                 }
1553                 if (handle_revision_arg(line, &revs, flags, 1))
1554                         die("bad revision '%s'", line);
1555         }
1557         prepare_revision_walk(&revs);
1558         mark_edges_uninteresting(revs.commits, &revs, show_edge);
1559         traverse_commit_list(&revs, show_commit, show_object);
1562 int cmd_pack_objects(int argc, const char **argv, const char *prefix)
1564         SHA_CTX ctx;
1565         int depth = 10;
1566         struct object_entry **list;
1567         off_t last_obj_offset;
1568         int use_internal_rev_list = 0;
1569         int thin = 0;
1570         uint32_t i;
1571         const char **rp_av;
1572         int rp_ac_alloc = 64;
1573         int rp_ac;
1575         rp_av = xcalloc(rp_ac_alloc, sizeof(*rp_av));
1577         rp_av[0] = "pack-objects";
1578         rp_av[1] = "--objects"; /* --thin will make it --objects-edge */
1579         rp_ac = 2;
1581         git_config(git_pack_config);
1583         progress = isatty(2);
1584         for (i = 1; i < argc; i++) {
1585                 const char *arg = argv[i];
1587                 if (*arg != '-')
1588                         break;
1590                 if (!strcmp("--non-empty", arg)) {
1591                         non_empty = 1;
1592                         continue;
1593                 }
1594                 if (!strcmp("--local", arg)) {
1595                         local = 1;
1596                         continue;
1597                 }
1598                 if (!strcmp("--incremental", arg)) {
1599                         incremental = 1;
1600                         continue;
1601                 }
1602                 if (!prefixcmp(arg, "--window=")) {
1603                         char *end;
1604                         window = strtoul(arg+9, &end, 0);
1605                         if (!arg[9] || *end)
1606                                 usage(pack_usage);
1607                         continue;
1608                 }
1609                 if (!prefixcmp(arg, "--depth=")) {
1610                         char *end;
1611                         depth = strtoul(arg+8, &end, 0);
1612                         if (!arg[8] || *end)
1613                                 usage(pack_usage);
1614                         continue;
1615                 }
1616                 if (!strcmp("--progress", arg)) {
1617                         progress = 1;
1618                         continue;
1619                 }
1620                 if (!strcmp("--all-progress", arg)) {
1621                         progress = 2;
1622                         continue;
1623                 }
1624                 if (!strcmp("-q", arg)) {
1625                         progress = 0;
1626                         continue;
1627                 }
1628                 if (!strcmp("--no-reuse-delta", arg)) {
1629                         no_reuse_delta = 1;
1630                         continue;
1631                 }
1632                 if (!strcmp("--delta-base-offset", arg)) {
1633                         allow_ofs_delta = 1;
1634                         continue;
1635                 }
1636                 if (!strcmp("--stdout", arg)) {
1637                         pack_to_stdout = 1;
1638                         continue;
1639                 }
1640                 if (!strcmp("--revs", arg)) {
1641                         use_internal_rev_list = 1;
1642                         continue;
1643                 }
1644                 if (!strcmp("--unpacked", arg) ||
1645                     !prefixcmp(arg, "--unpacked=") ||
1646                     !strcmp("--reflog", arg) ||
1647                     !strcmp("--all", arg)) {
1648                         use_internal_rev_list = 1;
1649                         if (rp_ac >= rp_ac_alloc - 1) {
1650                                 rp_ac_alloc = alloc_nr(rp_ac_alloc);
1651                                 rp_av = xrealloc(rp_av,
1652                                                  rp_ac_alloc * sizeof(*rp_av));
1653                         }
1654                         rp_av[rp_ac++] = arg;
1655                         continue;
1656                 }
1657                 if (!strcmp("--thin", arg)) {
1658                         use_internal_rev_list = 1;
1659                         thin = 1;
1660                         rp_av[1] = "--objects-edge";
1661                         continue;
1662                 }
1663                 if (!prefixcmp(arg, "--index-version=")) {
1664                         char *c;
1665                         index_default_version = strtoul(arg + 16, &c, 10);
1666                         if (index_default_version > 2)
1667                                 die("bad %s", arg);
1668                         if (*c == ',')
1669                                 index_off32_limit = strtoul(c+1, &c, 0);
1670                         if (*c || index_off32_limit & 0x80000000)
1671                                 die("bad %s", arg);
1672                         continue;
1673                 }
1674                 usage(pack_usage);
1675         }
1677         /* Traditionally "pack-objects [options] base extra" failed;
1678          * we would however want to take refs parameter that would
1679          * have been given to upstream rev-list ourselves, which means
1680          * we somehow want to say what the base name is.  So the
1681          * syntax would be:
1682          *
1683          * pack-objects [options] base <refs...>
1684          *
1685          * in other words, we would treat the first non-option as the
1686          * base_name and send everything else to the internal revision
1687          * walker.
1688          */
1690         if (!pack_to_stdout)
1691                 base_name = argv[i++];
1693         if (pack_to_stdout != !base_name)
1694                 usage(pack_usage);
1696         if (!pack_to_stdout && thin)
1697                 die("--thin cannot be used to build an indexable pack.");
1699         prepare_packed_git();
1701         if (progress) {
1702                 fprintf(stderr, "Generating pack...\n");
1703                 setup_progress_signal();
1704         }
1706         if (!use_internal_rev_list)
1707                 read_object_list_from_stdin();
1708         else {
1709                 rp_av[rp_ac] = NULL;
1710                 get_object_list(rp_ac, rp_av);
1711         }
1713         if (progress)
1714                 fprintf(stderr, "Done counting %u objects.\n", nr_objects);
1715         sorted_by_sha = create_final_object_list();
1716         if (non_empty && !nr_result)
1717                 return 0;
1719         SHA1_Init(&ctx);
1720         list = sorted_by_sha;
1721         for (i = 0; i < nr_result; i++) {
1722                 struct object_entry *entry = *list++;
1723                 SHA1_Update(&ctx, entry->sha1, 20);
1724         }
1725         SHA1_Final(object_list_sha1, &ctx);
1726         if (progress && (nr_objects != nr_result))
1727                 fprintf(stderr, "Result has %u objects.\n", nr_result);
1729         if (nr_result)
1730                 prepare_pack(window, depth);
1731         if (progress == 1 && pack_to_stdout) {
1732                 /* the other end usually displays progress itself */
1733                 struct itimerval v = {{0,},};
1734                 setitimer(ITIMER_REAL, &v, NULL);
1735                 signal(SIGALRM, SIG_IGN );
1736                 progress_update = 0;
1737         }
1738         last_obj_offset = write_pack_file();
1739         if (!pack_to_stdout) {
1740                 write_index_file(last_obj_offset);
1741                 puts(sha1_to_hex(object_list_sha1));
1742         }
1743         if (progress)
1744                 fprintf(stderr, "Total %u (delta %u), reused %u (delta %u)\n",
1745                         written, written_delta, reused, reused_delta);
1746         return 0;