Merge branch 'jn/libperl-git-config'
[git] / builtin / pack-objects.c
1 #include "builtin.h"
2 #include "cache.h"
3 #include "attr.h"
4 #include "object.h"
5 #include "blob.h"
6 #include "commit.h"
7 #include "tag.h"
8 #include "tree.h"
9 #include "delta.h"
10 #include "pack.h"
11 #include "pack-revindex.h"
12 #include "csum-file.h"
13 #include "tree-walk.h"
14 #include "diff.h"
15 #include "revision.h"
16 #include "list-objects.h"
17 #include "progress.h"
18 #include "refs.h"
19 #include "thread-utils.h"
20
21 static const char pack_usage[] =
22   "git pack-objects [ -q | --progress | --all-progress ]\n"
23   "        [--all-progress-implied]\n"
24   "        [--max-pack-size=<n>] [--local] [--incremental]\n"
25   "        [--window=<n>] [--window-memory=<n>] [--depth=<n>]\n"
26   "        [--no-reuse-delta] [--no-reuse-object] [--delta-base-offset]\n"
27   "        [--threads=<n>] [--non-empty] [--revs [--unpacked | --all]]\n"
28   "        [--reflog] [--stdout | base-name] [--include-tag]\n"
29   "        [--keep-unreachable | --unpack-unreachable]\n"
30   "        [< ref-list | < object-list]";
31
32 struct object_entry {
33         struct pack_idx_entry idx;
34         unsigned long size;     /* uncompressed size */
35         struct packed_git *in_pack;     /* already in pack */
36         off_t in_pack_offset;
37         struct object_entry *delta;     /* delta base object */
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         void *delta_data;       /* cached delta (uncompressed) */
43         unsigned long delta_size;       /* delta data size (uncompressed) */
44         unsigned long z_delta_size;     /* delta data size (compressed) */
45         unsigned int hash;      /* name hint hash */
46         enum object_type type;
47         enum object_type in_pack_type;  /* could be delta */
48         unsigned char in_pack_header_size;
49         unsigned char preferred_base; /* we do not pack this, but is available
50                                        * to be used as the base object to delta
51                                        * objects against.
52                                        */
53         unsigned char no_try_delta;
54         unsigned char tagged; /* near the very tip of refs */
55         unsigned char filled; /* assigned write-order */
56 };
57
58 /*
59  * Objects we are going to pack are collected in objects array (dynamically
60  * expanded).  nr_objects & nr_alloc controls this array.  They are stored
61  * in the order we see -- typically rev-list --objects order that gives us
62  * nice "minimum seek" order.
63  */
64 static struct object_entry *objects;
65 static struct pack_idx_entry **written_list;
66 static uint32_t nr_objects, nr_alloc, nr_result, nr_written;
67
68 static int non_empty;
69 static int reuse_delta = 1, reuse_object = 1;
70 static int keep_unreachable, unpack_unreachable, include_tag;
71 static int local;
72 static int incremental;
73 static int ignore_packed_keep;
74 static int allow_ofs_delta;
75 static struct pack_idx_option pack_idx_opts;
76 static const char *base_name;
77 static int progress = 1;
78 static int window = 10;
79 static unsigned long pack_size_limit, pack_size_limit_cfg;
80 static int depth = 50;
81 static int delta_search_threads;
82 static int pack_to_stdout;
83 static int num_preferred_base;
84 static struct progress *progress_state;
85 static int pack_compression_level = Z_DEFAULT_COMPRESSION;
86 static int pack_compression_seen;
87
88 static unsigned long delta_cache_size = 0;
89 static unsigned long max_delta_cache_size = 256 * 1024 * 1024;
90 static unsigned long cache_max_small_delta_size = 1000;
91
92 static unsigned long window_memory_limit = 0;
93
94 /*
95  * The object names in objects array are hashed with this hashtable,
96  * to help looking up the entry by object name.
97  * This hashtable is built after all the objects are seen.
98  */
99 static int *object_ix;
100 static int object_ix_hashsz;
101 static struct object_entry *locate_object_entry(const unsigned char *sha1);
102
103 /*
104  * stats
105  */
106 static uint32_t written, written_delta;
107 static uint32_t reused, reused_delta;
108
109
110 static void *get_delta(struct object_entry *entry)
111 {
112         unsigned long size, base_size, delta_size;
113         void *buf, *base_buf, *delta_buf;
114         enum object_type type;
115
116         buf = read_sha1_file(entry->idx.sha1, &type, &size);
117         if (!buf)
118                 die("unable to read %s", sha1_to_hex(entry->idx.sha1));
119         base_buf = read_sha1_file(entry->delta->idx.sha1, &type, &base_size);
120         if (!base_buf)
121                 die("unable to read %s", sha1_to_hex(entry->delta->idx.sha1));
122         delta_buf = diff_delta(base_buf, base_size,
123                                buf, size, &delta_size, 0);
124         if (!delta_buf || delta_size != entry->delta_size)
125                 die("delta size changed");
126         free(buf);
127         free(base_buf);
128         return delta_buf;
129 }
130
131 static unsigned long do_compress(void **pptr, unsigned long size)
132 {
133         git_zstream stream;
134         void *in, *out;
135         unsigned long maxsize;
136
137         memset(&stream, 0, sizeof(stream));
138         git_deflate_init(&stream, pack_compression_level);
139         maxsize = git_deflate_bound(&stream, size);
140
141         in = *pptr;
142         out = xmalloc(maxsize);
143         *pptr = out;
144
145         stream.next_in = in;
146         stream.avail_in = size;
147         stream.next_out = out;
148         stream.avail_out = maxsize;
149         while (git_deflate(&stream, Z_FINISH) == Z_OK)
150                 ; /* nothing */
151         git_deflate_end(&stream);
152
153         free(in);
154         return stream.total_out;
155 }
156
157 /*
158  * we are going to reuse the existing object data as is.  make
159  * sure it is not corrupt.
160  */
161 static int check_pack_inflate(struct packed_git *p,
162                 struct pack_window **w_curs,
163                 off_t offset,
164                 off_t len,
165                 unsigned long expect)
166 {
167         git_zstream stream;
168         unsigned char fakebuf[4096], *in;
169         int st;
170
171         memset(&stream, 0, sizeof(stream));
172         git_inflate_init(&stream);
173         do {
174                 in = use_pack(p, w_curs, offset, &stream.avail_in);
175                 stream.next_in = in;
176                 stream.next_out = fakebuf;
177                 stream.avail_out = sizeof(fakebuf);
178                 st = git_inflate(&stream, Z_FINISH);
179                 offset += stream.next_in - in;
180         } while (st == Z_OK || st == Z_BUF_ERROR);
181         git_inflate_end(&stream);
182         return (st == Z_STREAM_END &&
183                 stream.total_out == expect &&
184                 stream.total_in == len) ? 0 : -1;
185 }
186
187 static void copy_pack_data(struct sha1file *f,
188                 struct packed_git *p,
189                 struct pack_window **w_curs,
190                 off_t offset,
191                 off_t len)
192 {
193         unsigned char *in;
194         unsigned long avail;
195
196         while (len) {
197                 in = use_pack(p, w_curs, offset, &avail);
198                 if (avail > len)
199                         avail = (unsigned long)len;
200                 sha1write(f, in, avail);
201                 offset += avail;
202                 len -= avail;
203         }
204 }
205
206 /* Return 0 if we will bust the pack-size limit */
207 static unsigned long write_object(struct sha1file *f,
208                                   struct object_entry *entry,
209                                   off_t write_offset)
210 {
211         unsigned long size, limit, datalen;
212         void *buf;
213         unsigned char header[10], dheader[10];
214         unsigned hdrlen;
215         enum object_type type;
216         int usable_delta, to_reuse;
217
218         if (!pack_to_stdout)
219                 crc32_begin(f);
220
221         type = entry->type;
222
223         /* apply size limit if limited packsize and not first object */
224         if (!pack_size_limit || !nr_written)
225                 limit = 0;
226         else if (pack_size_limit <= write_offset)
227                 /*
228                  * the earlier object did not fit the limit; avoid
229                  * mistaking this with unlimited (i.e. limit = 0).
230                  */
231                 limit = 1;
232         else
233                 limit = pack_size_limit - write_offset;
234
235         if (!entry->delta)
236                 usable_delta = 0;       /* no delta */
237         else if (!pack_size_limit)
238                usable_delta = 1;        /* unlimited packfile */
239         else if (entry->delta->idx.offset == (off_t)-1)
240                 usable_delta = 0;       /* base was written to another pack */
241         else if (entry->delta->idx.offset)
242                 usable_delta = 1;       /* base already exists in this pack */
243         else
244                 usable_delta = 0;       /* base could end up in another pack */
245
246         if (!reuse_object)
247                 to_reuse = 0;   /* explicit */
248         else if (!entry->in_pack)
249                 to_reuse = 0;   /* can't reuse what we don't have */
250         else if (type == OBJ_REF_DELTA || type == OBJ_OFS_DELTA)
251                                 /* check_object() decided it for us ... */
252                 to_reuse = usable_delta;
253                                 /* ... but pack split may override that */
254         else if (type != entry->in_pack_type)
255                 to_reuse = 0;   /* pack has delta which is unusable */
256         else if (entry->delta)
257                 to_reuse = 0;   /* we want to pack afresh */
258         else
259                 to_reuse = 1;   /* we have it in-pack undeltified,
260                                  * and we do not need to deltify it.
261                                  */
262
263         if (!to_reuse) {
264                 no_reuse:
265                 if (!usable_delta) {
266                         buf = read_sha1_file(entry->idx.sha1, &type, &size);
267                         if (!buf)
268                                 die("unable to read %s", sha1_to_hex(entry->idx.sha1));
269                         /*
270                          * make sure no cached delta data remains from a
271                          * previous attempt before a pack split occurred.
272                          */
273                         free(entry->delta_data);
274                         entry->delta_data = NULL;
275                         entry->z_delta_size = 0;
276                 } else if (entry->delta_data) {
277                         size = entry->delta_size;
278                         buf = entry->delta_data;
279                         entry->delta_data = NULL;
280                         type = (allow_ofs_delta && entry->delta->idx.offset) ?
281                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
282                 } else {
283                         buf = get_delta(entry);
284                         size = entry->delta_size;
285                         type = (allow_ofs_delta && entry->delta->idx.offset) ?
286                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
287                 }
288
289                 if (entry->z_delta_size)
290                         datalen = entry->z_delta_size;
291                 else
292                         datalen = do_compress(&buf, size);
293
294                 /*
295                  * The object header is a byte of 'type' followed by zero or
296                  * more bytes of length.
297                  */
298                 hdrlen = encode_in_pack_object_header(type, size, header);
299
300                 if (type == OBJ_OFS_DELTA) {
301                         /*
302                          * Deltas with relative base contain an additional
303                          * encoding of the relative offset for the delta
304                          * base from this object's position in the pack.
305                          */
306                         off_t ofs = entry->idx.offset - entry->delta->idx.offset;
307                         unsigned pos = sizeof(dheader) - 1;
308                         dheader[pos] = ofs & 127;
309                         while (ofs >>= 7)
310                                 dheader[--pos] = 128 | (--ofs & 127);
311                         if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit) {
312                                 free(buf);
313                                 return 0;
314                         }
315                         sha1write(f, header, hdrlen);
316                         sha1write(f, dheader + pos, sizeof(dheader) - pos);
317                         hdrlen += sizeof(dheader) - pos;
318                 } else if (type == OBJ_REF_DELTA) {
319                         /*
320                          * Deltas with a base reference contain
321                          * an additional 20 bytes for the base sha1.
322                          */
323                         if (limit && hdrlen + 20 + datalen + 20 >= limit) {
324                                 free(buf);
325                                 return 0;
326                         }
327                         sha1write(f, header, hdrlen);
328                         sha1write(f, entry->delta->idx.sha1, 20);
329                         hdrlen += 20;
330                 } else {
331                         if (limit && hdrlen + datalen + 20 >= limit) {
332                                 free(buf);
333                                 return 0;
334                         }
335                         sha1write(f, header, hdrlen);
336                 }
337                 sha1write(f, buf, datalen);
338                 free(buf);
339         }
340         else {
341                 struct packed_git *p = entry->in_pack;
342                 struct pack_window *w_curs = NULL;
343                 struct revindex_entry *revidx;
344                 off_t offset;
345
346                 if (entry->delta)
347                         type = (allow_ofs_delta && entry->delta->idx.offset) ?
348                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
349                 hdrlen = encode_in_pack_object_header(type, entry->size, header);
350
351                 offset = entry->in_pack_offset;
352                 revidx = find_pack_revindex(p, offset);
353                 datalen = revidx[1].offset - offset;
354                 if (!pack_to_stdout && p->index_version > 1 &&
355                     check_pack_crc(p, &w_curs, offset, datalen, revidx->nr)) {
356                         error("bad packed object CRC for %s", sha1_to_hex(entry->idx.sha1));
357                         unuse_pack(&w_curs);
358                         goto no_reuse;
359                 }
360
361                 offset += entry->in_pack_header_size;
362                 datalen -= entry->in_pack_header_size;
363                 if (!pack_to_stdout && p->index_version == 1 &&
364                     check_pack_inflate(p, &w_curs, offset, datalen, entry->size)) {
365                         error("corrupt packed object for %s", sha1_to_hex(entry->idx.sha1));
366                         unuse_pack(&w_curs);
367                         goto no_reuse;
368                 }
369
370                 if (type == OBJ_OFS_DELTA) {
371                         off_t ofs = entry->idx.offset - entry->delta->idx.offset;
372                         unsigned pos = sizeof(dheader) - 1;
373                         dheader[pos] = ofs & 127;
374                         while (ofs >>= 7)
375                                 dheader[--pos] = 128 | (--ofs & 127);
376                         if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit) {
377                                 unuse_pack(&w_curs);
378                                 return 0;
379                         }
380                         sha1write(f, header, hdrlen);
381                         sha1write(f, dheader + pos, sizeof(dheader) - pos);
382                         hdrlen += sizeof(dheader) - pos;
383                         reused_delta++;
384                 } else if (type == OBJ_REF_DELTA) {
385                         if (limit && hdrlen + 20 + datalen + 20 >= limit) {
386                                 unuse_pack(&w_curs);
387                                 return 0;
388                         }
389                         sha1write(f, header, hdrlen);
390                         sha1write(f, entry->delta->idx.sha1, 20);
391                         hdrlen += 20;
392                         reused_delta++;
393                 } else {
394                         if (limit && hdrlen + datalen + 20 >= limit) {
395                                 unuse_pack(&w_curs);
396                                 return 0;
397                         }
398                         sha1write(f, header, hdrlen);
399                 }
400                 copy_pack_data(f, p, &w_curs, offset, datalen);
401                 unuse_pack(&w_curs);
402                 reused++;
403         }
404         if (usable_delta)
405                 written_delta++;
406         written++;
407         if (!pack_to_stdout)
408                 entry->idx.crc32 = crc32_end(f);
409         return hdrlen + datalen;
410 }
411
412 static int write_one(struct sha1file *f,
413                                struct object_entry *e,
414                                off_t *offset)
415 {
416         unsigned long size;
417
418         /* offset is non zero if object is written already. */
419         if (e->idx.offset || e->preferred_base)
420                 return -1;
421
422         /* if we are deltified, write out base object first. */
423         if (e->delta && !write_one(f, e->delta, offset))
424                 return 0;
425
426         e->idx.offset = *offset;
427         size = write_object(f, e, *offset);
428         if (!size) {
429                 e->idx.offset = 0;
430                 return 0;
431         }
432         written_list[nr_written++] = &e->idx;
433
434         /* make sure off_t is sufficiently large not to wrap */
435         if (signed_add_overflows(*offset, size))
436                 die("pack too large for current definition of off_t");
437         *offset += size;
438         return 1;
439 }
440
441 static int mark_tagged(const char *path, const unsigned char *sha1, int flag,
442                        void *cb_data)
443 {
444         unsigned char peeled[20];
445         struct object_entry *entry = locate_object_entry(sha1);
446
447         if (entry)
448                 entry->tagged = 1;
449         if (!peel_ref(path, peeled)) {
450                 entry = locate_object_entry(peeled);
451                 if (entry)
452                         entry->tagged = 1;
453         }
454         return 0;
455 }
456
457 static void add_to_write_order(struct object_entry **wo,
458                                int *endp,
459                                struct object_entry *e)
460 {
461         if (e->filled)
462                 return;
463         wo[(*endp)++] = e;
464         e->filled = 1;
465 }
466
467 static void add_descendants_to_write_order(struct object_entry **wo,
468                                            int *endp,
469                                            struct object_entry *e)
470 {
471         struct object_entry *child;
472
473         for (child = e->delta_child; child; child = child->delta_sibling)
474                 add_to_write_order(wo, endp, child);
475         for (child = e->delta_child; child; child = child->delta_sibling)
476                 add_descendants_to_write_order(wo, endp, child);
477 }
478
479 static void add_family_to_write_order(struct object_entry **wo,
480                                       int *endp,
481                                       struct object_entry *e)
482 {
483         struct object_entry *root;
484
485         for (root = e; root->delta; root = root->delta)
486                 ; /* nothing */
487         add_to_write_order(wo, endp, root);
488         add_descendants_to_write_order(wo, endp, root);
489 }
490
491 static struct object_entry **compute_write_order(void)
492 {
493         int i, wo_end;
494
495         struct object_entry **wo = xmalloc(nr_objects * sizeof(*wo));
496
497         for (i = 0; i < nr_objects; i++) {
498                 objects[i].tagged = 0;
499                 objects[i].filled = 0;
500                 objects[i].delta_child = NULL;
501                 objects[i].delta_sibling = NULL;
502         }
503
504         /*
505          * Fully connect delta_child/delta_sibling network.
506          * Make sure delta_sibling is sorted in the original
507          * recency order.
508          */
509         for (i = nr_objects - 1; 0 <= i; i--) {
510                 struct object_entry *e = &objects[i];
511                 if (!e->delta)
512                         continue;
513                 /* Mark me as the first child */
514                 e->delta_sibling = e->delta->delta_child;
515                 e->delta->delta_child = e;
516         }
517
518         /*
519          * Mark objects that are at the tip of tags.
520          */
521         for_each_tag_ref(mark_tagged, NULL);
522
523         /*
524          * Give the commits in the original recency order until
525          * we see a tagged tip.
526          */
527         for (i = wo_end = 0; i < nr_objects; i++) {
528                 if (objects[i].tagged)
529                         break;
530                 add_to_write_order(wo, &wo_end, &objects[i]);
531         }
532
533         /*
534          * Then fill all the tagged tips.
535          */
536         for (; i < nr_objects; i++) {
537                 if (objects[i].tagged)
538                         add_to_write_order(wo, &wo_end, &objects[i]);
539         }
540
541         /*
542          * And then all remaining commits and tags.
543          */
544         for (i = 0; i < nr_objects; i++) {
545                 if (objects[i].type != OBJ_COMMIT &&
546                     objects[i].type != OBJ_TAG)
547                         continue;
548                 add_to_write_order(wo, &wo_end, &objects[i]);
549         }
550
551         /*
552          * And then all the trees.
553          */
554         for (i = 0; i < nr_objects; i++) {
555                 if (objects[i].type != OBJ_TREE)
556                         continue;
557                 add_to_write_order(wo, &wo_end, &objects[i]);
558         }
559
560         /*
561          * Finally all the rest in really tight order
562          */
563         for (i = 0; i < nr_objects; i++)
564                 add_family_to_write_order(wo, &wo_end, &objects[i]);
565
566         return wo;
567 }
568
569 static void write_pack_file(void)
570 {
571         uint32_t i = 0, j;
572         struct sha1file *f;
573         off_t offset;
574         struct pack_header hdr;
575         uint32_t nr_remaining = nr_result;
576         time_t last_mtime = 0;
577         struct object_entry **write_order;
578
579         if (progress > pack_to_stdout)
580                 progress_state = start_progress("Writing objects", nr_result);
581         written_list = xmalloc(nr_objects * sizeof(*written_list));
582         write_order = compute_write_order();
583
584         do {
585                 unsigned char sha1[20];
586                 char *pack_tmp_name = NULL;
587
588                 if (pack_to_stdout) {
589                         f = sha1fd_throughput(1, "<stdout>", progress_state);
590                 } else {
591                         char tmpname[PATH_MAX];
592                         int fd;
593                         fd = odb_mkstemp(tmpname, sizeof(tmpname),
594                                          "pack/tmp_pack_XXXXXX");
595                         pack_tmp_name = xstrdup(tmpname);
596                         f = sha1fd(fd, pack_tmp_name);
597                 }
598
599                 hdr.hdr_signature = htonl(PACK_SIGNATURE);
600                 hdr.hdr_version = htonl(PACK_VERSION);
601                 hdr.hdr_entries = htonl(nr_remaining);
602                 sha1write(f, &hdr, sizeof(hdr));
603                 offset = sizeof(hdr);
604                 nr_written = 0;
605                 for (; i < nr_objects; i++) {
606                         struct object_entry *e = write_order[i];
607                         if (!write_one(f, e, &offset))
608                                 break;
609                         display_progress(progress_state, written);
610                 }
611
612                 /*
613                  * Did we write the wrong # entries in the header?
614                  * If so, rewrite it like in fast-import
615                  */
616                 if (pack_to_stdout) {
617                         sha1close(f, sha1, CSUM_CLOSE);
618                 } else if (nr_written == nr_remaining) {
619                         sha1close(f, sha1, CSUM_FSYNC);
620                 } else {
621                         int fd = sha1close(f, sha1, 0);
622                         fixup_pack_header_footer(fd, sha1, pack_tmp_name,
623                                                  nr_written, sha1, offset);
624                         close(fd);
625                 }
626
627                 if (!pack_to_stdout) {
628                         struct stat st;
629                         const char *idx_tmp_name;
630                         char tmpname[PATH_MAX];
631
632                         idx_tmp_name = write_idx_file(NULL, written_list, nr_written,
633                                                       &pack_idx_opts, sha1);
634
635                         snprintf(tmpname, sizeof(tmpname), "%s-%s.pack",
636                                  base_name, sha1_to_hex(sha1));
637                         free_pack_by_name(tmpname);
638                         if (adjust_shared_perm(pack_tmp_name))
639                                 die_errno("unable to make temporary pack file readable");
640                         if (rename(pack_tmp_name, tmpname))
641                                 die_errno("unable to rename temporary pack file");
642
643                         /*
644                          * Packs are runtime accessed in their mtime
645                          * order since newer packs are more likely to contain
646                          * younger objects.  So if we are creating multiple
647                          * packs then we should modify the mtime of later ones
648                          * to preserve this property.
649                          */
650                         if (stat(tmpname, &st) < 0) {
651                                 warning("failed to stat %s: %s",
652                                         tmpname, strerror(errno));
653                         } else if (!last_mtime) {
654                                 last_mtime = st.st_mtime;
655                         } else {
656                                 struct utimbuf utb;
657                                 utb.actime = st.st_atime;
658                                 utb.modtime = --last_mtime;
659                                 if (utime(tmpname, &utb) < 0)
660                                         warning("failed utime() on %s: %s",
661                                                 tmpname, strerror(errno));
662                         }
663
664                         snprintf(tmpname, sizeof(tmpname), "%s-%s.idx",
665                                  base_name, sha1_to_hex(sha1));
666                         if (adjust_shared_perm(idx_tmp_name))
667                                 die_errno("unable to make temporary index file readable");
668                         if (rename(idx_tmp_name, tmpname))
669                                 die_errno("unable to rename temporary index file");
670
671                         free((void *) idx_tmp_name);
672                         free(pack_tmp_name);
673                         puts(sha1_to_hex(sha1));
674                 }
675
676                 /* mark written objects as written to previous pack */
677                 for (j = 0; j < nr_written; j++) {
678                         written_list[j]->offset = (off_t)-1;
679                 }
680                 nr_remaining -= nr_written;
681         } while (nr_remaining && i < nr_objects);
682
683         free(written_list);
684         free(write_order);
685         stop_progress(&progress_state);
686         if (written != nr_result)
687                 die("wrote %"PRIu32" objects while expecting %"PRIu32,
688                         written, nr_result);
689 }
690
691 static int locate_object_entry_hash(const unsigned char *sha1)
692 {
693         int i;
694         unsigned int ui;
695         memcpy(&ui, sha1, sizeof(unsigned int));
696         i = ui % object_ix_hashsz;
697         while (0 < object_ix[i]) {
698                 if (!hashcmp(sha1, objects[object_ix[i] - 1].idx.sha1))
699                         return i;
700                 if (++i == object_ix_hashsz)
701                         i = 0;
702         }
703         return -1 - i;
704 }
705
706 static struct object_entry *locate_object_entry(const unsigned char *sha1)
707 {
708         int i;
709
710         if (!object_ix_hashsz)
711                 return NULL;
712
713         i = locate_object_entry_hash(sha1);
714         if (0 <= i)
715                 return &objects[object_ix[i]-1];
716         return NULL;
717 }
718
719 static void rehash_objects(void)
720 {
721         uint32_t i;
722         struct object_entry *oe;
723
724         object_ix_hashsz = nr_objects * 3;
725         if (object_ix_hashsz < 1024)
726                 object_ix_hashsz = 1024;
727         object_ix = xrealloc(object_ix, sizeof(int) * object_ix_hashsz);
728         memset(object_ix, 0, sizeof(int) * object_ix_hashsz);
729         for (i = 0, oe = objects; i < nr_objects; i++, oe++) {
730                 int ix = locate_object_entry_hash(oe->idx.sha1);
731                 if (0 <= ix)
732                         continue;
733                 ix = -1 - ix;
734                 object_ix[ix] = i + 1;
735         }
736 }
737
738 static unsigned name_hash(const char *name)
739 {
740         unsigned c, hash = 0;
741
742         if (!name)
743                 return 0;
744
745         /*
746          * This effectively just creates a sortable number from the
747          * last sixteen non-whitespace characters. Last characters
748          * count "most", so things that end in ".c" sort together.
749          */
750         while ((c = *name++) != 0) {
751                 if (isspace(c))
752                         continue;
753                 hash = (hash >> 2) + (c << 24);
754         }
755         return hash;
756 }
757
758 static void setup_delta_attr_check(struct git_attr_check *check)
759 {
760         static struct git_attr *attr_delta;
761
762         if (!attr_delta)
763                 attr_delta = git_attr("delta");
764
765         check[0].attr = attr_delta;
766 }
767
768 static int no_try_delta(const char *path)
769 {
770         struct git_attr_check check[1];
771
772         setup_delta_attr_check(check);
773         if (git_check_attr(path, ARRAY_SIZE(check), check))
774                 return 0;
775         if (ATTR_FALSE(check->value))
776                 return 1;
777         return 0;
778 }
779
780 static int add_object_entry(const unsigned char *sha1, enum object_type type,
781                             const char *name, int exclude)
782 {
783         struct object_entry *entry;
784         struct packed_git *p, *found_pack = NULL;
785         off_t found_offset = 0;
786         int ix;
787         unsigned hash = name_hash(name);
788
789         ix = nr_objects ? locate_object_entry_hash(sha1) : -1;
790         if (ix >= 0) {
791                 if (exclude) {
792                         entry = objects + object_ix[ix] - 1;
793                         if (!entry->preferred_base)
794                                 nr_result--;
795                         entry->preferred_base = 1;
796                 }
797                 return 0;
798         }
799
800         if (!exclude && local && has_loose_object_nonlocal(sha1))
801                 return 0;
802
803         for (p = packed_git; p; p = p->next) {
804                 off_t offset = find_pack_entry_one(sha1, p);
805                 if (offset) {
806                         if (!found_pack) {
807                                 if (!is_pack_valid(p)) {
808                                         warning("packfile %s cannot be accessed", p->pack_name);
809                                         continue;
810                                 }
811                                 found_offset = offset;
812                                 found_pack = p;
813                         }
814                         if (exclude)
815                                 break;
816                         if (incremental)
817                                 return 0;
818                         if (local && !p->pack_local)
819                                 return 0;
820                         if (ignore_packed_keep && p->pack_local && p->pack_keep)
821                                 return 0;
822                 }
823         }
824
825         if (nr_objects >= nr_alloc) {
826                 nr_alloc = (nr_alloc  + 1024) * 3 / 2;
827                 objects = xrealloc(objects, nr_alloc * sizeof(*entry));
828         }
829
830         entry = objects + nr_objects++;
831         memset(entry, 0, sizeof(*entry));
832         hashcpy(entry->idx.sha1, sha1);
833         entry->hash = hash;
834         if (type)
835                 entry->type = type;
836         if (exclude)
837                 entry->preferred_base = 1;
838         else
839                 nr_result++;
840         if (found_pack) {
841                 entry->in_pack = found_pack;
842                 entry->in_pack_offset = found_offset;
843         }
844
845         if (object_ix_hashsz * 3 <= nr_objects * 4)
846                 rehash_objects();
847         else
848                 object_ix[-1 - ix] = nr_objects;
849
850         display_progress(progress_state, nr_objects);
851
852         if (name && no_try_delta(name))
853                 entry->no_try_delta = 1;
854
855         return 1;
856 }
857
858 struct pbase_tree_cache {
859         unsigned char sha1[20];
860         int ref;
861         int temporary;
862         void *tree_data;
863         unsigned long tree_size;
864 };
865
866 static struct pbase_tree_cache *(pbase_tree_cache[256]);
867 static int pbase_tree_cache_ix(const unsigned char *sha1)
868 {
869         return sha1[0] % ARRAY_SIZE(pbase_tree_cache);
870 }
871 static int pbase_tree_cache_ix_incr(int ix)
872 {
873         return (ix+1) % ARRAY_SIZE(pbase_tree_cache);
874 }
875
876 static struct pbase_tree {
877         struct pbase_tree *next;
878         /* This is a phony "cache" entry; we are not
879          * going to evict it nor find it through _get()
880          * mechanism -- this is for the toplevel node that
881          * would almost always change with any commit.
882          */
883         struct pbase_tree_cache pcache;
884 } *pbase_tree;
885
886 static struct pbase_tree_cache *pbase_tree_get(const unsigned char *sha1)
887 {
888         struct pbase_tree_cache *ent, *nent;
889         void *data;
890         unsigned long size;
891         enum object_type type;
892         int neigh;
893         int my_ix = pbase_tree_cache_ix(sha1);
894         int available_ix = -1;
895
896         /* pbase-tree-cache acts as a limited hashtable.
897          * your object will be found at your index or within a few
898          * slots after that slot if it is cached.
899          */
900         for (neigh = 0; neigh < 8; neigh++) {
901                 ent = pbase_tree_cache[my_ix];
902                 if (ent && !hashcmp(ent->sha1, sha1)) {
903                         ent->ref++;
904                         return ent;
905                 }
906                 else if (((available_ix < 0) && (!ent || !ent->ref)) ||
907                          ((0 <= available_ix) &&
908                           (!ent && pbase_tree_cache[available_ix])))
909                         available_ix = my_ix;
910                 if (!ent)
911                         break;
912                 my_ix = pbase_tree_cache_ix_incr(my_ix);
913         }
914
915         /* Did not find one.  Either we got a bogus request or
916          * we need to read and perhaps cache.
917          */
918         data = read_sha1_file(sha1, &type, &size);
919         if (!data)
920                 return NULL;
921         if (type != OBJ_TREE) {
922                 free(data);
923                 return NULL;
924         }
925
926         /* We need to either cache or return a throwaway copy */
927
928         if (available_ix < 0)
929                 ent = NULL;
930         else {
931                 ent = pbase_tree_cache[available_ix];
932                 my_ix = available_ix;
933         }
934
935         if (!ent) {
936                 nent = xmalloc(sizeof(*nent));
937                 nent->temporary = (available_ix < 0);
938         }
939         else {
940                 /* evict and reuse */
941                 free(ent->tree_data);
942                 nent = ent;
943         }
944         hashcpy(nent->sha1, sha1);
945         nent->tree_data = data;
946         nent->tree_size = size;
947         nent->ref = 1;
948         if (!nent->temporary)
949                 pbase_tree_cache[my_ix] = nent;
950         return nent;
951 }
952
953 static void pbase_tree_put(struct pbase_tree_cache *cache)
954 {
955         if (!cache->temporary) {
956                 cache->ref--;
957                 return;
958         }
959         free(cache->tree_data);
960         free(cache);
961 }
962
963 static int name_cmp_len(const char *name)
964 {
965         int i;
966         for (i = 0; name[i] && name[i] != '\n' && name[i] != '/'; i++)
967                 ;
968         return i;
969 }
970
971 static void add_pbase_object(struct tree_desc *tree,
972                              const char *name,
973                              int cmplen,
974                              const char *fullname)
975 {
976         struct name_entry entry;
977         int cmp;
978
979         while (tree_entry(tree,&entry)) {
980                 if (S_ISGITLINK(entry.mode))
981                         continue;
982                 cmp = tree_entry_len(entry.path, entry.sha1) != cmplen ? 1 :
983                       memcmp(name, entry.path, cmplen);
984                 if (cmp > 0)
985                         continue;
986                 if (cmp < 0)
987                         return;
988                 if (name[cmplen] != '/') {
989                         add_object_entry(entry.sha1,
990                                          object_type(entry.mode),
991                                          fullname, 1);
992                         return;
993                 }
994                 if (S_ISDIR(entry.mode)) {
995                         struct tree_desc sub;
996                         struct pbase_tree_cache *tree;
997                         const char *down = name+cmplen+1;
998                         int downlen = name_cmp_len(down);
999
1000                         tree = pbase_tree_get(entry.sha1);
1001                         if (!tree)
1002                                 return;
1003                         init_tree_desc(&sub, tree->tree_data, tree->tree_size);
1004
1005                         add_pbase_object(&sub, down, downlen, fullname);
1006                         pbase_tree_put(tree);
1007                 }
1008         }
1009 }
1010
1011 static unsigned *done_pbase_paths;
1012 static int done_pbase_paths_num;
1013 static int done_pbase_paths_alloc;
1014 static int done_pbase_path_pos(unsigned hash)
1015 {
1016         int lo = 0;
1017         int hi = done_pbase_paths_num;
1018         while (lo < hi) {
1019                 int mi = (hi + lo) / 2;
1020                 if (done_pbase_paths[mi] == hash)
1021                         return mi;
1022                 if (done_pbase_paths[mi] < hash)
1023                         hi = mi;
1024                 else
1025                         lo = mi + 1;
1026         }
1027         return -lo-1;
1028 }
1029
1030 static int check_pbase_path(unsigned hash)
1031 {
1032         int pos = (!done_pbase_paths) ? -1 : done_pbase_path_pos(hash);
1033         if (0 <= pos)
1034                 return 1;
1035         pos = -pos - 1;
1036         if (done_pbase_paths_alloc <= done_pbase_paths_num) {
1037                 done_pbase_paths_alloc = alloc_nr(done_pbase_paths_alloc);
1038                 done_pbase_paths = xrealloc(done_pbase_paths,
1039                                             done_pbase_paths_alloc *
1040                                             sizeof(unsigned));
1041         }
1042         done_pbase_paths_num++;
1043         if (pos < done_pbase_paths_num)
1044                 memmove(done_pbase_paths + pos + 1,
1045                         done_pbase_paths + pos,
1046                         (done_pbase_paths_num - pos - 1) * sizeof(unsigned));
1047         done_pbase_paths[pos] = hash;
1048         return 0;
1049 }
1050
1051 static void add_preferred_base_object(const char *name)
1052 {
1053         struct pbase_tree *it;
1054         int cmplen;
1055         unsigned hash = name_hash(name);
1056
1057         if (!num_preferred_base || check_pbase_path(hash))
1058                 return;
1059
1060         cmplen = name_cmp_len(name);
1061         for (it = pbase_tree; it; it = it->next) {
1062                 if (cmplen == 0) {
1063                         add_object_entry(it->pcache.sha1, OBJ_TREE, NULL, 1);
1064                 }
1065                 else {
1066                         struct tree_desc tree;
1067                         init_tree_desc(&tree, it->pcache.tree_data, it->pcache.tree_size);
1068                         add_pbase_object(&tree, name, cmplen, name);
1069                 }
1070         }
1071 }
1072
1073 static void add_preferred_base(unsigned char *sha1)
1074 {
1075         struct pbase_tree *it;
1076         void *data;
1077         unsigned long size;
1078         unsigned char tree_sha1[20];
1079
1080         if (window <= num_preferred_base++)
1081                 return;
1082
1083         data = read_object_with_reference(sha1, tree_type, &size, tree_sha1);
1084         if (!data)
1085                 return;
1086
1087         for (it = pbase_tree; it; it = it->next) {
1088                 if (!hashcmp(it->pcache.sha1, tree_sha1)) {
1089                         free(data);
1090                         return;
1091                 }
1092         }
1093
1094         it = xcalloc(1, sizeof(*it));
1095         it->next = pbase_tree;
1096         pbase_tree = it;
1097
1098         hashcpy(it->pcache.sha1, tree_sha1);
1099         it->pcache.tree_data = data;
1100         it->pcache.tree_size = size;
1101 }
1102
1103 static void cleanup_preferred_base(void)
1104 {
1105         struct pbase_tree *it;
1106         unsigned i;
1107
1108         it = pbase_tree;
1109         pbase_tree = NULL;
1110         while (it) {
1111                 struct pbase_tree *this = it;
1112                 it = this->next;
1113                 free(this->pcache.tree_data);
1114                 free(this);
1115         }
1116
1117         for (i = 0; i < ARRAY_SIZE(pbase_tree_cache); i++) {
1118                 if (!pbase_tree_cache[i])
1119                         continue;
1120                 free(pbase_tree_cache[i]->tree_data);
1121                 free(pbase_tree_cache[i]);
1122                 pbase_tree_cache[i] = NULL;
1123         }
1124
1125         free(done_pbase_paths);
1126         done_pbase_paths = NULL;
1127         done_pbase_paths_num = done_pbase_paths_alloc = 0;
1128 }
1129
1130 static void check_object(struct object_entry *entry)
1131 {
1132         if (entry->in_pack) {
1133                 struct packed_git *p = entry->in_pack;
1134                 struct pack_window *w_curs = NULL;
1135                 const unsigned char *base_ref = NULL;
1136                 struct object_entry *base_entry;
1137                 unsigned long used, used_0;
1138                 unsigned long avail;
1139                 off_t ofs;
1140                 unsigned char *buf, c;
1141
1142                 buf = use_pack(p, &w_curs, entry->in_pack_offset, &avail);
1143
1144                 /*
1145                  * We want in_pack_type even if we do not reuse delta
1146                  * since non-delta representations could still be reused.
1147                  */
1148                 used = unpack_object_header_buffer(buf, avail,
1149                                                    &entry->in_pack_type,
1150                                                    &entry->size);
1151                 if (used == 0)
1152                         goto give_up;
1153
1154                 /*
1155                  * Determine if this is a delta and if so whether we can
1156                  * reuse it or not.  Otherwise let's find out as cheaply as
1157                  * possible what the actual type and size for this object is.
1158                  */
1159                 switch (entry->in_pack_type) {
1160                 default:
1161                         /* Not a delta hence we've already got all we need. */
1162                         entry->type = entry->in_pack_type;
1163                         entry->in_pack_header_size = used;
1164                         if (entry->type < OBJ_COMMIT || entry->type > OBJ_BLOB)
1165                                 goto give_up;
1166                         unuse_pack(&w_curs);
1167                         return;
1168                 case OBJ_REF_DELTA:
1169                         if (reuse_delta && !entry->preferred_base)
1170                                 base_ref = use_pack(p, &w_curs,
1171                                                 entry->in_pack_offset + used, NULL);
1172                         entry->in_pack_header_size = used + 20;
1173                         break;
1174                 case OBJ_OFS_DELTA:
1175                         buf = use_pack(p, &w_curs,
1176                                        entry->in_pack_offset + used, NULL);
1177                         used_0 = 0;
1178                         c = buf[used_0++];
1179                         ofs = c & 127;
1180                         while (c & 128) {
1181                                 ofs += 1;
1182                                 if (!ofs || MSB(ofs, 7)) {
1183                                         error("delta base offset overflow in pack for %s",
1184                                               sha1_to_hex(entry->idx.sha1));
1185                                         goto give_up;
1186                                 }
1187                                 c = buf[used_0++];
1188                                 ofs = (ofs << 7) + (c & 127);
1189                         }
1190                         ofs = entry->in_pack_offset - ofs;
1191                         if (ofs <= 0 || ofs >= entry->in_pack_offset) {
1192                                 error("delta base offset out of bound for %s",
1193                                       sha1_to_hex(entry->idx.sha1));
1194                                 goto give_up;
1195                         }
1196                         if (reuse_delta && !entry->preferred_base) {
1197                                 struct revindex_entry *revidx;
1198                                 revidx = find_pack_revindex(p, ofs);
1199                                 if (!revidx)
1200                                         goto give_up;
1201                                 base_ref = nth_packed_object_sha1(p, revidx->nr);
1202                         }
1203                         entry->in_pack_header_size = used + used_0;
1204                         break;
1205                 }
1206
1207                 if (base_ref && (base_entry = locate_object_entry(base_ref))) {
1208                         /*
1209                          * If base_ref was set above that means we wish to
1210                          * reuse delta data, and we even found that base
1211                          * in the list of objects we want to pack. Goodie!
1212                          *
1213                          * Depth value does not matter - find_deltas() will
1214                          * never consider reused delta as the base object to
1215                          * deltify other objects against, in order to avoid
1216                          * circular deltas.
1217                          */
1218                         entry->type = entry->in_pack_type;
1219                         entry->delta = base_entry;
1220                         entry->delta_size = entry->size;
1221                         entry->delta_sibling = base_entry->delta_child;
1222                         base_entry->delta_child = entry;
1223                         unuse_pack(&w_curs);
1224                         return;
1225                 }
1226
1227                 if (entry->type) {
1228                         /*
1229                          * This must be a delta and we already know what the
1230                          * final object type is.  Let's extract the actual
1231                          * object size from the delta header.
1232                          */
1233                         entry->size = get_size_from_delta(p, &w_curs,
1234                                         entry->in_pack_offset + entry->in_pack_header_size);
1235                         if (entry->size == 0)
1236                                 goto give_up;
1237                         unuse_pack(&w_curs);
1238                         return;
1239                 }
1240
1241                 /*
1242                  * No choice but to fall back to the recursive delta walk
1243                  * with sha1_object_info() to find about the object type
1244                  * at this point...
1245                  */
1246                 give_up:
1247                 unuse_pack(&w_curs);
1248         }
1249
1250         entry->type = sha1_object_info(entry->idx.sha1, &entry->size);
1251         /*
1252          * The error condition is checked in prepare_pack().  This is
1253          * to permit a missing preferred base object to be ignored
1254          * as a preferred base.  Doing so can result in a larger
1255          * pack file, but the transfer will still take place.
1256          */
1257 }
1258
1259 static int pack_offset_sort(const void *_a, const void *_b)
1260 {
1261         const struct object_entry *a = *(struct object_entry **)_a;
1262         const struct object_entry *b = *(struct object_entry **)_b;
1263
1264         /* avoid filesystem trashing with loose objects */
1265         if (!a->in_pack && !b->in_pack)
1266                 return hashcmp(a->idx.sha1, b->idx.sha1);
1267
1268         if (a->in_pack < b->in_pack)
1269                 return -1;
1270         if (a->in_pack > b->in_pack)
1271                 return 1;
1272         return a->in_pack_offset < b->in_pack_offset ? -1 :
1273                         (a->in_pack_offset > b->in_pack_offset);
1274 }
1275
1276 static void get_object_details(void)
1277 {
1278         uint32_t i;
1279         struct object_entry **sorted_by_offset;
1280
1281         sorted_by_offset = xcalloc(nr_objects, sizeof(struct object_entry *));
1282         for (i = 0; i < nr_objects; i++)
1283                 sorted_by_offset[i] = objects + i;
1284         qsort(sorted_by_offset, nr_objects, sizeof(*sorted_by_offset), pack_offset_sort);
1285
1286         for (i = 0; i < nr_objects; i++) {
1287                 struct object_entry *entry = sorted_by_offset[i];
1288                 check_object(entry);
1289                 if (big_file_threshold <= entry->size)
1290                         entry->no_try_delta = 1;
1291         }
1292
1293         free(sorted_by_offset);
1294 }
1295
1296 /*
1297  * We search for deltas in a list sorted by type, by filename hash, and then
1298  * by size, so that we see progressively smaller and smaller files.
1299  * That's because we prefer deltas to be from the bigger file
1300  * to the smaller -- deletes are potentially cheaper, but perhaps
1301  * more importantly, the bigger file is likely the more recent
1302  * one.  The deepest deltas are therefore the oldest objects which are
1303  * less susceptible to be accessed often.
1304  */
1305 static int type_size_sort(const void *_a, const void *_b)
1306 {
1307         const struct object_entry *a = *(struct object_entry **)_a;
1308         const struct object_entry *b = *(struct object_entry **)_b;
1309
1310         if (a->type > b->type)
1311                 return -1;
1312         if (a->type < b->type)
1313                 return 1;
1314         if (a->hash > b->hash)
1315                 return -1;
1316         if (a->hash < b->hash)
1317                 return 1;
1318         if (a->preferred_base > b->preferred_base)
1319                 return -1;
1320         if (a->preferred_base < b->preferred_base)
1321                 return 1;
1322         if (a->size > b->size)
1323                 return -1;
1324         if (a->size < b->size)
1325                 return 1;
1326         return a < b ? -1 : (a > b);  /* newest first */
1327 }
1328
1329 struct unpacked {
1330         struct object_entry *entry;
1331         void *data;
1332         struct delta_index *index;
1333         unsigned depth;
1334 };
1335
1336 static int delta_cacheable(unsigned long src_size, unsigned long trg_size,
1337                            unsigned long delta_size)
1338 {
1339         if (max_delta_cache_size && delta_cache_size + delta_size > max_delta_cache_size)
1340                 return 0;
1341
1342         if (delta_size < cache_max_small_delta_size)
1343                 return 1;
1344
1345         /* cache delta, if objects are large enough compared to delta size */
1346         if ((src_size >> 20) + (trg_size >> 21) > (delta_size >> 10))
1347                 return 1;
1348
1349         return 0;
1350 }
1351
1352 #ifndef NO_PTHREADS
1353
1354 static pthread_mutex_t read_mutex;
1355 #define read_lock()             pthread_mutex_lock(&read_mutex)
1356 #define read_unlock()           pthread_mutex_unlock(&read_mutex)
1357
1358 static pthread_mutex_t cache_mutex;
1359 #define cache_lock()            pthread_mutex_lock(&cache_mutex)
1360 #define cache_unlock()          pthread_mutex_unlock(&cache_mutex)
1361
1362 static pthread_mutex_t progress_mutex;
1363 #define progress_lock()         pthread_mutex_lock(&progress_mutex)
1364 #define progress_unlock()       pthread_mutex_unlock(&progress_mutex)
1365
1366 #else
1367
1368 #define read_lock()             (void)0
1369 #define read_unlock()           (void)0
1370 #define cache_lock()            (void)0
1371 #define cache_unlock()          (void)0
1372 #define progress_lock()         (void)0
1373 #define progress_unlock()       (void)0
1374
1375 #endif
1376
1377 static int try_delta(struct unpacked *trg, struct unpacked *src,
1378                      unsigned max_depth, unsigned long *mem_usage)
1379 {
1380         struct object_entry *trg_entry = trg->entry;
1381         struct object_entry *src_entry = src->entry;
1382         unsigned long trg_size, src_size, delta_size, sizediff, max_size, sz;
1383         unsigned ref_depth;
1384         enum object_type type;
1385         void *delta_buf;
1386
1387         /* Don't bother doing diffs between different types */
1388         if (trg_entry->type != src_entry->type)
1389                 return -1;
1390
1391         /*
1392          * We do not bother to try a delta that we discarded
1393          * on an earlier try, but only when reusing delta data.
1394          */
1395         if (reuse_delta && trg_entry->in_pack &&
1396             trg_entry->in_pack == src_entry->in_pack &&
1397             trg_entry->in_pack_type != OBJ_REF_DELTA &&
1398             trg_entry->in_pack_type != OBJ_OFS_DELTA)
1399                 return 0;
1400
1401         /* Let's not bust the allowed depth. */
1402         if (src->depth >= max_depth)
1403                 return 0;
1404
1405         /* Now some size filtering heuristics. */
1406         trg_size = trg_entry->size;
1407         if (!trg_entry->delta) {
1408                 max_size = trg_size/2 - 20;
1409                 ref_depth = 1;
1410         } else {
1411                 max_size = trg_entry->delta_size;
1412                 ref_depth = trg->depth;
1413         }
1414         max_size = (uint64_t)max_size * (max_depth - src->depth) /
1415                                                 (max_depth - ref_depth + 1);
1416         if (max_size == 0)
1417                 return 0;
1418         src_size = src_entry->size;
1419         sizediff = src_size < trg_size ? trg_size - src_size : 0;
1420         if (sizediff >= max_size)
1421                 return 0;
1422         if (trg_size < src_size / 32)
1423                 return 0;
1424
1425         /* Load data if not already done */
1426         if (!trg->data) {
1427                 read_lock();
1428                 trg->data = read_sha1_file(trg_entry->idx.sha1, &type, &sz);
1429                 read_unlock();
1430                 if (!trg->data)
1431                         die("object %s cannot be read",
1432                             sha1_to_hex(trg_entry->idx.sha1));
1433                 if (sz != trg_size)
1434                         die("object %s inconsistent object length (%lu vs %lu)",
1435                             sha1_to_hex(trg_entry->idx.sha1), sz, trg_size);
1436                 *mem_usage += sz;
1437         }
1438         if (!src->data) {
1439                 read_lock();
1440                 src->data = read_sha1_file(src_entry->idx.sha1, &type, &sz);
1441                 read_unlock();
1442                 if (!src->data) {
1443                         if (src_entry->preferred_base) {
1444                                 static int warned = 0;
1445                                 if (!warned++)
1446                                         warning("object %s cannot be read",
1447                                                 sha1_to_hex(src_entry->idx.sha1));
1448                                 /*
1449                                  * Those objects are not included in the
1450                                  * resulting pack.  Be resilient and ignore
1451                                  * them if they can't be read, in case the
1452                                  * pack could be created nevertheless.
1453                                  */
1454                                 return 0;
1455                         }
1456                         die("object %s cannot be read",
1457                             sha1_to_hex(src_entry->idx.sha1));
1458                 }
1459                 if (sz != src_size)
1460                         die("object %s inconsistent object length (%lu vs %lu)",
1461                             sha1_to_hex(src_entry->idx.sha1), sz, src_size);
1462                 *mem_usage += sz;
1463         }
1464         if (!src->index) {
1465                 src->index = create_delta_index(src->data, src_size);
1466                 if (!src->index) {
1467                         static int warned = 0;
1468                         if (!warned++)
1469                                 warning("suboptimal pack - out of memory");
1470                         return 0;
1471                 }
1472                 *mem_usage += sizeof_delta_index(src->index);
1473         }
1474
1475         delta_buf = create_delta(src->index, trg->data, trg_size, &delta_size, max_size);
1476         if (!delta_buf)
1477                 return 0;
1478
1479         if (trg_entry->delta) {
1480                 /* Prefer only shallower same-sized deltas. */
1481                 if (delta_size == trg_entry->delta_size &&
1482                     src->depth + 1 >= trg->depth) {
1483                         free(delta_buf);
1484                         return 0;
1485                 }
1486         }
1487
1488         /*
1489          * Handle memory allocation outside of the cache
1490          * accounting lock.  Compiler will optimize the strangeness
1491          * away when NO_PTHREADS is defined.
1492          */
1493         free(trg_entry->delta_data);
1494         cache_lock();
1495         if (trg_entry->delta_data) {
1496                 delta_cache_size -= trg_entry->delta_size;
1497                 trg_entry->delta_data = NULL;
1498         }
1499         if (delta_cacheable(src_size, trg_size, delta_size)) {
1500                 delta_cache_size += delta_size;
1501                 cache_unlock();
1502                 trg_entry->delta_data = xrealloc(delta_buf, delta_size);
1503         } else {
1504                 cache_unlock();
1505                 free(delta_buf);
1506         }
1507
1508         trg_entry->delta = src_entry;
1509         trg_entry->delta_size = delta_size;
1510         trg->depth = src->depth + 1;
1511
1512         return 1;
1513 }
1514
1515 static unsigned int check_delta_limit(struct object_entry *me, unsigned int n)
1516 {
1517         struct object_entry *child = me->delta_child;
1518         unsigned int m = n;
1519         while (child) {
1520                 unsigned int c = check_delta_limit(child, n + 1);
1521                 if (m < c)
1522                         m = c;
1523                 child = child->delta_sibling;
1524         }
1525         return m;
1526 }
1527
1528 static unsigned long free_unpacked(struct unpacked *n)
1529 {
1530         unsigned long freed_mem = sizeof_delta_index(n->index);
1531         free_delta_index(n->index);
1532         n->index = NULL;
1533         if (n->data) {
1534                 freed_mem += n->entry->size;
1535                 free(n->data);
1536                 n->data = NULL;
1537         }
1538         n->entry = NULL;
1539         n->depth = 0;
1540         return freed_mem;
1541 }
1542
1543 static void find_deltas(struct object_entry **list, unsigned *list_size,
1544                         int window, int depth, unsigned *processed)
1545 {
1546         uint32_t i, idx = 0, count = 0;
1547         struct unpacked *array;
1548         unsigned long mem_usage = 0;
1549
1550         array = xcalloc(window, sizeof(struct unpacked));
1551
1552         for (;;) {
1553                 struct object_entry *entry;
1554                 struct unpacked *n = array + idx;
1555                 int j, max_depth, best_base = -1;
1556
1557                 progress_lock();
1558                 if (!*list_size) {
1559                         progress_unlock();
1560                         break;
1561                 }
1562                 entry = *list++;
1563                 (*list_size)--;
1564                 if (!entry->preferred_base) {
1565                         (*processed)++;
1566                         display_progress(progress_state, *processed);
1567                 }
1568                 progress_unlock();
1569
1570                 mem_usage -= free_unpacked(n);
1571                 n->entry = entry;
1572
1573                 while (window_memory_limit &&
1574                        mem_usage > window_memory_limit &&
1575                        count > 1) {
1576                         uint32_t tail = (idx + window - count) % window;
1577                         mem_usage -= free_unpacked(array + tail);
1578                         count--;
1579                 }
1580
1581                 /* We do not compute delta to *create* objects we are not
1582                  * going to pack.
1583                  */
1584                 if (entry->preferred_base)
1585                         goto next;
1586
1587                 /*
1588                  * If the current object is at pack edge, take the depth the
1589                  * objects that depend on the current object into account
1590                  * otherwise they would become too deep.
1591                  */
1592                 max_depth = depth;
1593                 if (entry->delta_child) {
1594                         max_depth -= check_delta_limit(entry, 0);
1595                         if (max_depth <= 0)
1596                                 goto next;
1597                 }
1598
1599                 j = window;
1600                 while (--j > 0) {
1601                         int ret;
1602                         uint32_t other_idx = idx + j;
1603                         struct unpacked *m;
1604                         if (other_idx >= window)
1605                                 other_idx -= window;
1606                         m = array + other_idx;
1607                         if (!m->entry)
1608                                 break;
1609                         ret = try_delta(n, m, max_depth, &mem_usage);
1610                         if (ret < 0)
1611                                 break;
1612                         else if (ret > 0)
1613                                 best_base = other_idx;
1614                 }
1615
1616                 /*
1617                  * If we decided to cache the delta data, then it is best
1618                  * to compress it right away.  First because we have to do
1619                  * it anyway, and doing it here while we're threaded will
1620                  * save a lot of time in the non threaded write phase,
1621                  * as well as allow for caching more deltas within
1622                  * the same cache size limit.
1623                  * ...
1624                  * But only if not writing to stdout, since in that case
1625                  * the network is most likely throttling writes anyway,
1626                  * and therefore it is best to go to the write phase ASAP
1627                  * instead, as we can afford spending more time compressing
1628                  * between writes at that moment.
1629                  */
1630                 if (entry->delta_data && !pack_to_stdout) {
1631                         entry->z_delta_size = do_compress(&entry->delta_data,
1632                                                           entry->delta_size);
1633                         cache_lock();
1634                         delta_cache_size -= entry->delta_size;
1635                         delta_cache_size += entry->z_delta_size;
1636                         cache_unlock();
1637                 }
1638
1639                 /* if we made n a delta, and if n is already at max
1640                  * depth, leaving it in the window is pointless.  we
1641                  * should evict it first.
1642                  */
1643                 if (entry->delta && max_depth <= n->depth)
1644                         continue;
1645
1646                 /*
1647                  * Move the best delta base up in the window, after the
1648                  * currently deltified object, to keep it longer.  It will
1649                  * be the first base object to be attempted next.
1650                  */
1651                 if (entry->delta) {
1652                         struct unpacked swap = array[best_base];
1653                         int dist = (window + idx - best_base) % window;
1654                         int dst = best_base;
1655                         while (dist--) {
1656                                 int src = (dst + 1) % window;
1657                                 array[dst] = array[src];
1658                                 dst = src;
1659                         }
1660                         array[dst] = swap;
1661                 }
1662
1663                 next:
1664                 idx++;
1665                 if (count + 1 < window)
1666                         count++;
1667                 if (idx >= window)
1668                         idx = 0;
1669         }
1670
1671         for (i = 0; i < window; ++i) {
1672                 free_delta_index(array[i].index);
1673                 free(array[i].data);
1674         }
1675         free(array);
1676 }
1677
1678 #ifndef NO_PTHREADS
1679
1680 static void try_to_free_from_threads(size_t size)
1681 {
1682         read_lock();
1683         release_pack_memory(size, -1);
1684         read_unlock();
1685 }
1686
1687 static try_to_free_t old_try_to_free_routine;
1688
1689 /*
1690  * The main thread waits on the condition that (at least) one of the workers
1691  * has stopped working (which is indicated in the .working member of
1692  * struct thread_params).
1693  * When a work thread has completed its work, it sets .working to 0 and
1694  * signals the main thread and waits on the condition that .data_ready
1695  * becomes 1.
1696  */
1697
1698 struct thread_params {
1699         pthread_t thread;
1700         struct object_entry **list;
1701         unsigned list_size;
1702         unsigned remaining;
1703         int window;
1704         int depth;
1705         int working;
1706         int data_ready;
1707         pthread_mutex_t mutex;
1708         pthread_cond_t cond;
1709         unsigned *processed;
1710 };
1711
1712 static pthread_cond_t progress_cond;
1713
1714 /*
1715  * Mutex and conditional variable can't be statically-initialized on Windows.
1716  */
1717 static void init_threaded_search(void)
1718 {
1719         init_recursive_mutex(&read_mutex);
1720         pthread_mutex_init(&cache_mutex, NULL);
1721         pthread_mutex_init(&progress_mutex, NULL);
1722         pthread_cond_init(&progress_cond, NULL);
1723         old_try_to_free_routine = set_try_to_free_routine(try_to_free_from_threads);
1724 }
1725
1726 static void cleanup_threaded_search(void)
1727 {
1728         set_try_to_free_routine(old_try_to_free_routine);
1729         pthread_cond_destroy(&progress_cond);
1730         pthread_mutex_destroy(&read_mutex);
1731         pthread_mutex_destroy(&cache_mutex);
1732         pthread_mutex_destroy(&progress_mutex);
1733 }
1734
1735 static void *threaded_find_deltas(void *arg)
1736 {
1737         struct thread_params *me = arg;
1738
1739         while (me->remaining) {
1740                 find_deltas(me->list, &me->remaining,
1741                             me->window, me->depth, me->processed);
1742
1743                 progress_lock();
1744                 me->working = 0;
1745                 pthread_cond_signal(&progress_cond);
1746                 progress_unlock();
1747
1748                 /*
1749                  * We must not set ->data_ready before we wait on the
1750                  * condition because the main thread may have set it to 1
1751                  * before we get here. In order to be sure that new
1752                  * work is available if we see 1 in ->data_ready, it
1753                  * was initialized to 0 before this thread was spawned
1754                  * and we reset it to 0 right away.
1755                  */
1756                 pthread_mutex_lock(&me->mutex);
1757                 while (!me->data_ready)
1758                         pthread_cond_wait(&me->cond, &me->mutex);
1759                 me->data_ready = 0;
1760                 pthread_mutex_unlock(&me->mutex);
1761         }
1762         /* leave ->working 1 so that this doesn't get more work assigned */
1763         return NULL;
1764 }
1765
1766 static void ll_find_deltas(struct object_entry **list, unsigned list_size,
1767                            int window, int depth, unsigned *processed)
1768 {
1769         struct thread_params *p;
1770         int i, ret, active_threads = 0;
1771
1772         init_threaded_search();
1773
1774         if (!delta_search_threads)      /* --threads=0 means autodetect */
1775                 delta_search_threads = online_cpus();
1776         if (delta_search_threads <= 1) {
1777                 find_deltas(list, &list_size, window, depth, processed);
1778                 cleanup_threaded_search();
1779                 return;
1780         }
1781         if (progress > pack_to_stdout)
1782                 fprintf(stderr, "Delta compression using up to %d threads.\n",
1783                                 delta_search_threads);
1784         p = xcalloc(delta_search_threads, sizeof(*p));
1785
1786         /* Partition the work amongst work threads. */
1787         for (i = 0; i < delta_search_threads; i++) {
1788                 unsigned sub_size = list_size / (delta_search_threads - i);
1789
1790                 /* don't use too small segments or no deltas will be found */
1791                 if (sub_size < 2*window && i+1 < delta_search_threads)
1792                         sub_size = 0;
1793
1794                 p[i].window = window;
1795                 p[i].depth = depth;
1796                 p[i].processed = processed;
1797                 p[i].working = 1;
1798                 p[i].data_ready = 0;
1799
1800                 /* try to split chunks on "path" boundaries */
1801                 while (sub_size && sub_size < list_size &&
1802                        list[sub_size]->hash &&
1803                        list[sub_size]->hash == list[sub_size-1]->hash)
1804                         sub_size++;
1805
1806                 p[i].list = list;
1807                 p[i].list_size = sub_size;
1808                 p[i].remaining = sub_size;
1809
1810                 list += sub_size;
1811                 list_size -= sub_size;
1812         }
1813
1814         /* Start work threads. */
1815         for (i = 0; i < delta_search_threads; i++) {
1816                 if (!p[i].list_size)
1817                         continue;
1818                 pthread_mutex_init(&p[i].mutex, NULL);
1819                 pthread_cond_init(&p[i].cond, NULL);
1820                 ret = pthread_create(&p[i].thread, NULL,
1821                                      threaded_find_deltas, &p[i]);
1822                 if (ret)
1823                         die("unable to create thread: %s", strerror(ret));
1824                 active_threads++;
1825         }
1826
1827         /*
1828          * Now let's wait for work completion.  Each time a thread is done
1829          * with its work, we steal half of the remaining work from the
1830          * thread with the largest number of unprocessed objects and give
1831          * it to that newly idle thread.  This ensure good load balancing
1832          * until the remaining object list segments are simply too short
1833          * to be worth splitting anymore.
1834          */
1835         while (active_threads) {
1836                 struct thread_params *target = NULL;
1837                 struct thread_params *victim = NULL;
1838                 unsigned sub_size = 0;
1839
1840                 progress_lock();
1841                 for (;;) {
1842                         for (i = 0; !target && i < delta_search_threads; i++)
1843                                 if (!p[i].working)
1844                                         target = &p[i];
1845                         if (target)
1846                                 break;
1847                         pthread_cond_wait(&progress_cond, &progress_mutex);
1848                 }
1849
1850                 for (i = 0; i < delta_search_threads; i++)
1851                         if (p[i].remaining > 2*window &&
1852                             (!victim || victim->remaining < p[i].remaining))
1853                                 victim = &p[i];
1854                 if (victim) {
1855                         sub_size = victim->remaining / 2;
1856                         list = victim->list + victim->list_size - sub_size;
1857                         while (sub_size && list[0]->hash &&
1858                                list[0]->hash == list[-1]->hash) {
1859                                 list++;
1860                                 sub_size--;
1861                         }
1862                         if (!sub_size) {
1863                                 /*
1864                                  * It is possible for some "paths" to have
1865                                  * so many objects that no hash boundary
1866                                  * might be found.  Let's just steal the
1867                                  * exact half in that case.
1868                                  */
1869                                 sub_size = victim->remaining / 2;
1870                                 list -= sub_size;
1871                         }
1872                         target->list = list;
1873                         victim->list_size -= sub_size;
1874                         victim->remaining -= sub_size;
1875                 }
1876                 target->list_size = sub_size;
1877                 target->remaining = sub_size;
1878                 target->working = 1;
1879                 progress_unlock();
1880
1881                 pthread_mutex_lock(&target->mutex);
1882                 target->data_ready = 1;
1883                 pthread_cond_signal(&target->cond);
1884                 pthread_mutex_unlock(&target->mutex);
1885
1886                 if (!sub_size) {
1887                         pthread_join(target->thread, NULL);
1888                         pthread_cond_destroy(&target->cond);
1889                         pthread_mutex_destroy(&target->mutex);
1890                         active_threads--;
1891                 }
1892         }
1893         cleanup_threaded_search();
1894         free(p);
1895 }
1896
1897 #else
1898 #define ll_find_deltas(l, s, w, d, p)   find_deltas(l, &s, w, d, p)
1899 #endif
1900
1901 static int add_ref_tag(const char *path, const unsigned char *sha1, int flag, void *cb_data)
1902 {
1903         unsigned char peeled[20];
1904
1905         if (!prefixcmp(path, "refs/tags/") && /* is a tag? */
1906             !peel_ref(path, peeled)        && /* peelable? */
1907             !is_null_sha1(peeled)          && /* annotated tag? */
1908             locate_object_entry(peeled))      /* object packed? */
1909                 add_object_entry(sha1, OBJ_TAG, NULL, 0);
1910         return 0;
1911 }
1912
1913 static void prepare_pack(int window, int depth)
1914 {
1915         struct object_entry **delta_list;
1916         uint32_t i, nr_deltas;
1917         unsigned n;
1918
1919         get_object_details();
1920
1921         /*
1922          * If we're locally repacking then we need to be doubly careful
1923          * from now on in order to make sure no stealth corruption gets
1924          * propagated to the new pack.  Clients receiving streamed packs
1925          * should validate everything they get anyway so no need to incur
1926          * the additional cost here in that case.
1927          */
1928         if (!pack_to_stdout)
1929                 do_check_packed_object_crc = 1;
1930
1931         if (!nr_objects || !window || !depth)
1932                 return;
1933
1934         delta_list = xmalloc(nr_objects * sizeof(*delta_list));
1935         nr_deltas = n = 0;
1936
1937         for (i = 0; i < nr_objects; i++) {
1938                 struct object_entry *entry = objects + i;
1939
1940                 if (entry->delta)
1941                         /* This happens if we decided to reuse existing
1942                          * delta from a pack.  "reuse_delta &&" is implied.
1943                          */
1944                         continue;
1945
1946                 if (entry->size < 50)
1947                         continue;
1948
1949                 if (entry->no_try_delta)
1950                         continue;
1951
1952                 if (!entry->preferred_base) {
1953                         nr_deltas++;
1954                         if (entry->type < 0)
1955                                 die("unable to get type of object %s",
1956                                     sha1_to_hex(entry->idx.sha1));
1957                 } else {
1958                         if (entry->type < 0) {
1959                                 /*
1960                                  * This object is not found, but we
1961                                  * don't have to include it anyway.
1962                                  */
1963                                 continue;
1964                         }
1965                 }
1966
1967                 delta_list[n++] = entry;
1968         }
1969
1970         if (nr_deltas && n > 1) {
1971                 unsigned nr_done = 0;
1972                 if (progress)
1973                         progress_state = start_progress("Compressing objects",
1974                                                         nr_deltas);
1975                 qsort(delta_list, n, sizeof(*delta_list), type_size_sort);
1976                 ll_find_deltas(delta_list, n, window+1, depth, &nr_done);
1977                 stop_progress(&progress_state);
1978                 if (nr_done != nr_deltas)
1979                         die("inconsistency with delta count");
1980         }
1981         free(delta_list);
1982 }
1983
1984 static int git_pack_config(const char *k, const char *v, void *cb)
1985 {
1986         if (!strcmp(k, "pack.window")) {
1987                 window = git_config_int(k, v);
1988                 return 0;
1989         }
1990         if (!strcmp(k, "pack.windowmemory")) {
1991                 window_memory_limit = git_config_ulong(k, v);
1992                 return 0;
1993         }
1994         if (!strcmp(k, "pack.depth")) {
1995                 depth = git_config_int(k, v);
1996                 return 0;
1997         }
1998         if (!strcmp(k, "pack.compression")) {
1999                 int level = git_config_int(k, v);
2000                 if (level == -1)
2001                         level = Z_DEFAULT_COMPRESSION;
2002                 else if (level < 0 || level > Z_BEST_COMPRESSION)
2003                         die("bad pack compression level %d", level);
2004                 pack_compression_level = level;
2005                 pack_compression_seen = 1;
2006                 return 0;
2007         }
2008         if (!strcmp(k, "pack.deltacachesize")) {
2009                 max_delta_cache_size = git_config_int(k, v);
2010                 return 0;
2011         }
2012         if (!strcmp(k, "pack.deltacachelimit")) {
2013                 cache_max_small_delta_size = git_config_int(k, v);
2014                 return 0;
2015         }
2016         if (!strcmp(k, "pack.threads")) {
2017                 delta_search_threads = git_config_int(k, v);
2018                 if (delta_search_threads < 0)
2019                         die("invalid number of threads specified (%d)",
2020                             delta_search_threads);
2021 #ifdef NO_PTHREADS
2022                 if (delta_search_threads != 1)
2023                         warning("no threads support, ignoring %s", k);
2024 #endif
2025                 return 0;
2026         }
2027         if (!strcmp(k, "pack.indexversion")) {
2028                 pack_idx_opts.version = git_config_int(k, v);
2029                 if (pack_idx_opts.version > 2)
2030                         die("bad pack.indexversion=%"PRIu32,
2031                             pack_idx_opts.version);
2032                 return 0;
2033         }
2034         if (!strcmp(k, "pack.packsizelimit")) {
2035                 pack_size_limit_cfg = git_config_ulong(k, v);
2036                 return 0;
2037         }
2038         return git_default_config(k, v, cb);
2039 }
2040
2041 static void read_object_list_from_stdin(void)
2042 {
2043         char line[40 + 1 + PATH_MAX + 2];
2044         unsigned char sha1[20];
2045
2046         for (;;) {
2047                 if (!fgets(line, sizeof(line), stdin)) {
2048                         if (feof(stdin))
2049                                 break;
2050                         if (!ferror(stdin))
2051                                 die("fgets returned NULL, not EOF, not error!");
2052                         if (errno != EINTR)
2053                                 die_errno("fgets");
2054                         clearerr(stdin);
2055                         continue;
2056                 }
2057                 if (line[0] == '-') {
2058                         if (get_sha1_hex(line+1, sha1))
2059                                 die("expected edge sha1, got garbage:\n %s",
2060                                     line);
2061                         add_preferred_base(sha1);
2062                         continue;
2063                 }
2064                 if (get_sha1_hex(line, sha1))
2065                         die("expected sha1, got garbage:\n %s", line);
2066
2067                 add_preferred_base_object(line+41);
2068                 add_object_entry(sha1, 0, line+41, 0);
2069         }
2070 }
2071
2072 #define OBJECT_ADDED (1u<<20)
2073
2074 static void show_commit(struct commit *commit, void *data)
2075 {
2076         add_object_entry(commit->object.sha1, OBJ_COMMIT, NULL, 0);
2077         commit->object.flags |= OBJECT_ADDED;
2078 }
2079
2080 static void show_object(struct object *obj,
2081                         const struct name_path *path, const char *last,
2082                         void *data)
2083 {
2084         char *name = path_name(path, last);
2085
2086         add_preferred_base_object(name);
2087         add_object_entry(obj->sha1, obj->type, name, 0);
2088         obj->flags |= OBJECT_ADDED;
2089
2090         /*
2091          * We will have generated the hash from the name,
2092          * but not saved a pointer to it - we can free it
2093          */
2094         free((char *)name);
2095 }
2096
2097 static void show_edge(struct commit *commit)
2098 {
2099         add_preferred_base(commit->object.sha1);
2100 }
2101
2102 struct in_pack_object {
2103         off_t offset;
2104         struct object *object;
2105 };
2106
2107 struct in_pack {
2108         int alloc;
2109         int nr;
2110         struct in_pack_object *array;
2111 };
2112
2113 static void mark_in_pack_object(struct object *object, struct packed_git *p, struct in_pack *in_pack)
2114 {
2115         in_pack->array[in_pack->nr].offset = find_pack_entry_one(object->sha1, p);
2116         in_pack->array[in_pack->nr].object = object;
2117         in_pack->nr++;
2118 }
2119
2120 /*
2121  * Compare the objects in the offset order, in order to emulate the
2122  * "git rev-list --objects" output that produced the pack originally.
2123  */
2124 static int ofscmp(const void *a_, const void *b_)
2125 {
2126         struct in_pack_object *a = (struct in_pack_object *)a_;
2127         struct in_pack_object *b = (struct in_pack_object *)b_;
2128
2129         if (a->offset < b->offset)
2130                 return -1;
2131         else if (a->offset > b->offset)
2132                 return 1;
2133         else
2134                 return hashcmp(a->object->sha1, b->object->sha1);
2135 }
2136
2137 static void add_objects_in_unpacked_packs(struct rev_info *revs)
2138 {
2139         struct packed_git *p;
2140         struct in_pack in_pack;
2141         uint32_t i;
2142
2143         memset(&in_pack, 0, sizeof(in_pack));
2144
2145         for (p = packed_git; p; p = p->next) {
2146                 const unsigned char *sha1;
2147                 struct object *o;
2148
2149                 if (!p->pack_local || p->pack_keep)
2150                         continue;
2151                 if (open_pack_index(p))
2152                         die("cannot open pack index");
2153
2154                 ALLOC_GROW(in_pack.array,
2155                            in_pack.nr + p->num_objects,
2156                            in_pack.alloc);
2157
2158                 for (i = 0; i < p->num_objects; i++) {
2159                         sha1 = nth_packed_object_sha1(p, i);
2160                         o = lookup_unknown_object(sha1);
2161                         if (!(o->flags & OBJECT_ADDED))
2162                                 mark_in_pack_object(o, p, &in_pack);
2163                         o->flags |= OBJECT_ADDED;
2164                 }
2165         }
2166
2167         if (in_pack.nr) {
2168                 qsort(in_pack.array, in_pack.nr, sizeof(in_pack.array[0]),
2169                       ofscmp);
2170                 for (i = 0; i < in_pack.nr; i++) {
2171                         struct object *o = in_pack.array[i].object;
2172                         add_object_entry(o->sha1, o->type, "", 0);
2173                 }
2174         }
2175         free(in_pack.array);
2176 }
2177
2178 static int has_sha1_pack_kept_or_nonlocal(const unsigned char *sha1)
2179 {
2180         static struct packed_git *last_found = (void *)1;
2181         struct packed_git *p;
2182
2183         p = (last_found != (void *)1) ? last_found : packed_git;
2184
2185         while (p) {
2186                 if ((!p->pack_local || p->pack_keep) &&
2187                         find_pack_entry_one(sha1, p)) {
2188                         last_found = p;
2189                         return 1;
2190                 }
2191                 if (p == last_found)
2192                         p = packed_git;
2193                 else
2194                         p = p->next;
2195                 if (p == last_found)
2196                         p = p->next;
2197         }
2198         return 0;
2199 }
2200
2201 static void loosen_unused_packed_objects(struct rev_info *revs)
2202 {
2203         struct packed_git *p;
2204         uint32_t i;
2205         const unsigned char *sha1;
2206
2207         for (p = packed_git; p; p = p->next) {
2208                 if (!p->pack_local || p->pack_keep)
2209                         continue;
2210
2211                 if (open_pack_index(p))
2212                         die("cannot open pack index");
2213
2214                 for (i = 0; i < p->num_objects; i++) {
2215                         sha1 = nth_packed_object_sha1(p, i);
2216                         if (!locate_object_entry(sha1) &&
2217                                 !has_sha1_pack_kept_or_nonlocal(sha1))
2218                                 if (force_object_loose(sha1, p->mtime))
2219                                         die("unable to force loose object");
2220                 }
2221         }
2222 }
2223
2224 static void get_object_list(int ac, const char **av)
2225 {
2226         struct rev_info revs;
2227         char line[1000];
2228         int flags = 0;
2229
2230         init_revisions(&revs, NULL);
2231         save_commit_buffer = 0;
2232         setup_revisions(ac, av, &revs, NULL);
2233
2234         while (fgets(line, sizeof(line), stdin) != NULL) {
2235                 int len = strlen(line);
2236                 if (len && line[len - 1] == '\n')
2237                         line[--len] = 0;
2238                 if (!len)
2239                         break;
2240                 if (*line == '-') {
2241                         if (!strcmp(line, "--not")) {
2242                                 flags ^= UNINTERESTING;
2243                                 continue;
2244                         }
2245                         die("not a rev '%s'", line);
2246                 }
2247                 if (handle_revision_arg(line, &revs, flags, 1))
2248                         die("bad revision '%s'", line);
2249         }
2250
2251         if (prepare_revision_walk(&revs))
2252                 die("revision walk setup failed");
2253         mark_edges_uninteresting(revs.commits, &revs, show_edge);
2254         traverse_commit_list(&revs, show_commit, show_object, NULL);
2255
2256         if (keep_unreachable)
2257                 add_objects_in_unpacked_packs(&revs);
2258         if (unpack_unreachable)
2259                 loosen_unused_packed_objects(&revs);
2260 }
2261
2262 int cmd_pack_objects(int argc, const char **argv, const char *prefix)
2263 {
2264         int use_internal_rev_list = 0;
2265         int thin = 0;
2266         int all_progress_implied = 0;
2267         uint32_t i;
2268         const char **rp_av;
2269         int rp_ac_alloc = 64;
2270         int rp_ac;
2271
2272         read_replace_refs = 0;
2273
2274         rp_av = xcalloc(rp_ac_alloc, sizeof(*rp_av));
2275
2276         rp_av[0] = "pack-objects";
2277         rp_av[1] = "--objects"; /* --thin will make it --objects-edge */
2278         rp_ac = 2;
2279
2280         reset_pack_idx_option(&pack_idx_opts);
2281         git_config(git_pack_config, NULL);
2282         if (!pack_compression_seen && core_compression_seen)
2283                 pack_compression_level = core_compression_level;
2284
2285         progress = isatty(2);
2286         for (i = 1; i < argc; i++) {
2287                 const char *arg = argv[i];
2288
2289                 if (*arg != '-')
2290                         break;
2291
2292                 if (!strcmp("--non-empty", arg)) {
2293                         non_empty = 1;
2294                         continue;
2295                 }
2296                 if (!strcmp("--local", arg)) {
2297                         local = 1;
2298                         continue;
2299                 }
2300                 if (!strcmp("--incremental", arg)) {
2301                         incremental = 1;
2302                         continue;
2303                 }
2304                 if (!strcmp("--honor-pack-keep", arg)) {
2305                         ignore_packed_keep = 1;
2306                         continue;
2307                 }
2308                 if (!prefixcmp(arg, "--compression=")) {
2309                         char *end;
2310                         int level = strtoul(arg+14, &end, 0);
2311                         if (!arg[14] || *end)
2312                                 usage(pack_usage);
2313                         if (level == -1)
2314                                 level = Z_DEFAULT_COMPRESSION;
2315                         else if (level < 0 || level > Z_BEST_COMPRESSION)
2316                                 die("bad pack compression level %d", level);
2317                         pack_compression_level = level;
2318                         continue;
2319                 }
2320                 if (!prefixcmp(arg, "--max-pack-size=")) {
2321                         pack_size_limit_cfg = 0;
2322                         if (!git_parse_ulong(arg+16, &pack_size_limit))
2323                                 usage(pack_usage);
2324                         continue;
2325                 }
2326                 if (!prefixcmp(arg, "--window=")) {
2327                         char *end;
2328                         window = strtoul(arg+9, &end, 0);
2329                         if (!arg[9] || *end)
2330                                 usage(pack_usage);
2331                         continue;
2332                 }
2333                 if (!prefixcmp(arg, "--window-memory=")) {
2334                         if (!git_parse_ulong(arg+16, &window_memory_limit))
2335                                 usage(pack_usage);
2336                         continue;
2337                 }
2338                 if (!prefixcmp(arg, "--threads=")) {
2339                         char *end;
2340                         delta_search_threads = strtoul(arg+10, &end, 0);
2341                         if (!arg[10] || *end || delta_search_threads < 0)
2342                                 usage(pack_usage);
2343 #ifdef NO_PTHREADS
2344                         if (delta_search_threads != 1)
2345                                 warning("no threads support, "
2346                                         "ignoring %s", arg);
2347 #endif
2348                         continue;
2349                 }
2350                 if (!prefixcmp(arg, "--depth=")) {
2351                         char *end;
2352                         depth = strtoul(arg+8, &end, 0);
2353                         if (!arg[8] || *end)
2354                                 usage(pack_usage);
2355                         continue;
2356                 }
2357                 if (!strcmp("--progress", arg)) {
2358                         progress = 1;
2359                         continue;
2360                 }
2361                 if (!strcmp("--all-progress", arg)) {
2362                         progress = 2;
2363                         continue;
2364                 }
2365                 if (!strcmp("--all-progress-implied", arg)) {
2366                         all_progress_implied = 1;
2367                         continue;
2368                 }
2369                 if (!strcmp("-q", arg)) {
2370                         progress = 0;
2371                         continue;
2372                 }
2373                 if (!strcmp("--no-reuse-delta", arg)) {
2374                         reuse_delta = 0;
2375                         continue;
2376                 }
2377                 if (!strcmp("--no-reuse-object", arg)) {
2378                         reuse_object = reuse_delta = 0;
2379                         continue;
2380                 }
2381                 if (!strcmp("--delta-base-offset", arg)) {
2382                         allow_ofs_delta = 1;
2383                         continue;
2384                 }
2385                 if (!strcmp("--stdout", arg)) {
2386                         pack_to_stdout = 1;
2387                         continue;
2388                 }
2389                 if (!strcmp("--revs", arg)) {
2390                         use_internal_rev_list = 1;
2391                         continue;
2392                 }
2393                 if (!strcmp("--keep-unreachable", arg)) {
2394                         keep_unreachable = 1;
2395                         continue;
2396                 }
2397                 if (!strcmp("--unpack-unreachable", arg)) {
2398                         unpack_unreachable = 1;
2399                         continue;
2400                 }
2401                 if (!strcmp("--include-tag", arg)) {
2402                         include_tag = 1;
2403                         continue;
2404                 }
2405                 if (!strcmp("--unpacked", arg) ||
2406                     !strcmp("--reflog", arg) ||
2407                     !strcmp("--all", arg)) {
2408                         use_internal_rev_list = 1;
2409                         if (rp_ac >= rp_ac_alloc - 1) {
2410                                 rp_ac_alloc = alloc_nr(rp_ac_alloc);
2411                                 rp_av = xrealloc(rp_av,
2412                                                  rp_ac_alloc * sizeof(*rp_av));
2413                         }
2414                         rp_av[rp_ac++] = arg;
2415                         continue;
2416                 }
2417                 if (!strcmp("--thin", arg)) {
2418                         use_internal_rev_list = 1;
2419                         thin = 1;
2420                         rp_av[1] = "--objects-edge";
2421                         continue;
2422                 }
2423                 if (!prefixcmp(arg, "--index-version=")) {
2424                         char *c;
2425                         pack_idx_opts.version = strtoul(arg + 16, &c, 10);
2426                         if (pack_idx_opts.version > 2)
2427                                 die("bad %s", arg);
2428                         if (*c == ',')
2429                                 pack_idx_opts.off32_limit = strtoul(c+1, &c, 0);
2430                         if (*c || pack_idx_opts.off32_limit & 0x80000000)
2431                                 die("bad %s", arg);
2432                         continue;
2433                 }
2434                 if (!strcmp(arg, "--keep-true-parents")) {
2435                         grafts_replace_parents = 0;
2436                         continue;
2437                 }
2438                 usage(pack_usage);
2439         }
2440
2441         /* Traditionally "pack-objects [options] base extra" failed;
2442          * we would however want to take refs parameter that would
2443          * have been given to upstream rev-list ourselves, which means
2444          * we somehow want to say what the base name is.  So the
2445          * syntax would be:
2446          *
2447          * pack-objects [options] base <refs...>
2448          *
2449          * in other words, we would treat the first non-option as the
2450          * base_name and send everything else to the internal revision
2451          * walker.
2452          */
2453
2454         if (!pack_to_stdout)
2455                 base_name = argv[i++];
2456
2457         if (pack_to_stdout != !base_name)
2458                 usage(pack_usage);
2459
2460         if (!pack_to_stdout && !pack_size_limit)
2461                 pack_size_limit = pack_size_limit_cfg;
2462         if (pack_to_stdout && pack_size_limit)
2463                 die("--max-pack-size cannot be used to build a pack for transfer.");
2464         if (pack_size_limit && pack_size_limit < 1024*1024) {
2465                 warning("minimum pack size limit is 1 MiB");
2466                 pack_size_limit = 1024*1024;
2467         }
2468
2469         if (!pack_to_stdout && thin)
2470                 die("--thin cannot be used to build an indexable pack.");
2471
2472         if (keep_unreachable && unpack_unreachable)
2473                 die("--keep-unreachable and --unpack-unreachable are incompatible.");
2474
2475         if (progress && all_progress_implied)
2476                 progress = 2;
2477
2478         prepare_packed_git();
2479
2480         if (progress)
2481                 progress_state = start_progress("Counting objects", 0);
2482         if (!use_internal_rev_list)
2483                 read_object_list_from_stdin();
2484         else {
2485                 rp_av[rp_ac] = NULL;
2486                 get_object_list(rp_ac, rp_av);
2487         }
2488         cleanup_preferred_base();
2489         if (include_tag && nr_result)
2490                 for_each_ref(add_ref_tag, NULL);
2491         stop_progress(&progress_state);
2492
2493         if (non_empty && !nr_result)
2494                 return 0;
2495         if (nr_result)
2496                 prepare_pack(window, depth);
2497         write_pack_file();
2498         if (progress)
2499                 fprintf(stderr, "Total %"PRIu32" (delta %"PRIu32"),"
2500                         " reused %"PRIu32" (delta %"PRIu32")\n",
2501                         written, written_delta, reused, reused_delta);
2502         return 0;
2503 }