Merge branch 'jk/maint-break-rename-reduce-memory'
[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
20 #ifdef THREADED_DELTA_SEARCH
21 #include "thread-utils.h"
22 #include <pthread.h>
23 #endif
24
25 static const char pack_usage[] =
26   "git pack-objects [{ -q | --progress | --all-progress }]\n"
27   "        [--max-pack-size=N] [--local] [--incremental]\n"
28   "        [--window=N] [--window-memory=N] [--depth=N]\n"
29   "        [--no-reuse-delta] [--no-reuse-object] [--delta-base-offset]\n"
30   "        [--threads=N] [--non-empty] [--revs [--unpacked | --all]*]\n"
31   "        [--reflog] [--stdout | base-name] [--include-tag]\n"
32   "        [--keep-unreachable | --unpack-unreachable \n"
33   "        [<ref-list | <object-list]";
34
35 struct object_entry {
36         struct pack_idx_entry idx;
37         unsigned long size;     /* uncompressed size */
38         struct packed_git *in_pack;     /* already in pack */
39         off_t in_pack_offset;
40         struct object_entry *delta;     /* delta base object */
41         struct object_entry *delta_child; /* deltified objects who bases me */
42         struct object_entry *delta_sibling; /* other deltified objects who
43                                              * uses the same base as me
44                                              */
45         void *delta_data;       /* cached delta (uncompressed) */
46         unsigned long delta_size;       /* delta data size (uncompressed) */
47         unsigned long z_delta_size;     /* delta data size (compressed) */
48         unsigned int hash;      /* name hint hash */
49         enum object_type type;
50         enum object_type in_pack_type;  /* could be delta */
51         unsigned char in_pack_header_size;
52         unsigned char preferred_base; /* we do not pack this, but is available
53                                        * to be used as the base object to delta
54                                        * objects against.
55                                        */
56         unsigned char no_try_delta;
57 };
58
59 /*
60  * Objects we are going to pack are collected in objects array (dynamically
61  * expanded).  nr_objects & nr_alloc controls this array.  They are stored
62  * in the order we see -- typically rev-list --objects order that gives us
63  * nice "minimum seek" order.
64  */
65 static struct object_entry *objects;
66 static struct pack_idx_entry **written_list;
67 static uint32_t nr_objects, nr_alloc, nr_result, nr_written;
68
69 static int non_empty;
70 static int reuse_delta = 1, reuse_object = 1;
71 static int keep_unreachable, unpack_unreachable, include_tag;
72 static int local;
73 static int incremental;
74 static int ignore_packed_keep;
75 static int allow_ofs_delta;
76 static const char *base_name;
77 static int progress = 1;
78 static int window = 10;
79 static uint32_t 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
102 /*
103  * stats
104  */
105 static uint32_t written, written_delta;
106 static uint32_t reused, reused_delta;
107
108
109 static void *get_delta(struct object_entry *entry)
110 {
111         unsigned long size, base_size, delta_size;
112         void *buf, *base_buf, *delta_buf;
113         enum object_type type;
114
115         buf = read_sha1_file(entry->idx.sha1, &type, &size);
116         if (!buf)
117                 die("unable to read %s", sha1_to_hex(entry->idx.sha1));
118         base_buf = read_sha1_file(entry->delta->idx.sha1, &type, &base_size);
119         if (!base_buf)
120                 die("unable to read %s", sha1_to_hex(entry->delta->idx.sha1));
121         delta_buf = diff_delta(base_buf, base_size,
122                                buf, size, &delta_size, 0);
123         if (!delta_buf || delta_size != entry->delta_size)
124                 die("delta size changed");
125         free(buf);
126         free(base_buf);
127         return delta_buf;
128 }
129
130 static unsigned long do_compress(void **pptr, unsigned long size)
131 {
132         z_stream stream;
133         void *in, *out;
134         unsigned long maxsize;
135
136         memset(&stream, 0, sizeof(stream));
137         deflateInit(&stream, pack_compression_level);
138         maxsize = deflateBound(&stream, size);
139
140         in = *pptr;
141         out = xmalloc(maxsize);
142         *pptr = out;
143
144         stream.next_in = in;
145         stream.avail_in = size;
146         stream.next_out = out;
147         stream.avail_out = maxsize;
148         while (deflate(&stream, Z_FINISH) == Z_OK)
149                 ; /* nothing */
150         deflateEnd(&stream);
151
152         free(in);
153         return stream.total_out;
154 }
155
156 /*
157  * The per-object header is a pretty dense thing, which is
158  *  - first byte: low four bits are "size", then three bits of "type",
159  *    and the high bit is "size continues".
160  *  - each byte afterwards: low seven bits are size continuation,
161  *    with the high bit being "size continues"
162  */
163 static int encode_header(enum object_type type, unsigned long size, unsigned char *hdr)
164 {
165         int n = 1;
166         unsigned char c;
167
168         if (type < OBJ_COMMIT || type > OBJ_REF_DELTA)
169                 die("bad type %d", type);
170
171         c = (type << 4) | (size & 15);
172         size >>= 4;
173         while (size) {
174                 *hdr++ = c | 0x80;
175                 c = size & 0x7f;
176                 size >>= 7;
177                 n++;
178         }
179         *hdr = c;
180         return n;
181 }
182
183 /*
184  * we are going to reuse the existing object data as is.  make
185  * sure it is not corrupt.
186  */
187 static int check_pack_inflate(struct packed_git *p,
188                 struct pack_window **w_curs,
189                 off_t offset,
190                 off_t len,
191                 unsigned long expect)
192 {
193         z_stream stream;
194         unsigned char fakebuf[4096], *in;
195         int st;
196
197         memset(&stream, 0, sizeof(stream));
198         git_inflate_init(&stream);
199         do {
200                 in = use_pack(p, w_curs, offset, &stream.avail_in);
201                 stream.next_in = in;
202                 stream.next_out = fakebuf;
203                 stream.avail_out = sizeof(fakebuf);
204                 st = git_inflate(&stream, Z_FINISH);
205                 offset += stream.next_in - in;
206         } while (st == Z_OK || st == Z_BUF_ERROR);
207         git_inflate_end(&stream);
208         return (st == Z_STREAM_END &&
209                 stream.total_out == expect &&
210                 stream.total_in == len) ? 0 : -1;
211 }
212
213 static void copy_pack_data(struct sha1file *f,
214                 struct packed_git *p,
215                 struct pack_window **w_curs,
216                 off_t offset,
217                 off_t len)
218 {
219         unsigned char *in;
220         unsigned int avail;
221
222         while (len) {
223                 in = use_pack(p, w_curs, offset, &avail);
224                 if (avail > len)
225                         avail = (unsigned int)len;
226                 sha1write(f, in, avail);
227                 offset += avail;
228                 len -= avail;
229         }
230 }
231
232 static unsigned long write_object(struct sha1file *f,
233                                   struct object_entry *entry,
234                                   off_t write_offset)
235 {
236         unsigned long size, limit, datalen;
237         void *buf;
238         unsigned char header[10], dheader[10];
239         unsigned hdrlen;
240         enum object_type type;
241         int usable_delta, to_reuse;
242
243         if (!pack_to_stdout)
244                 crc32_begin(f);
245
246         type = entry->type;
247
248         /* write limit if limited packsize and not first object */
249         if (!pack_size_limit || !nr_written)
250                 limit = 0;
251         else if (pack_size_limit <= write_offset)
252                 /*
253                  * the earlier object did not fit the limit; avoid
254                  * mistaking this with unlimited (i.e. limit = 0).
255                  */
256                 limit = 1;
257         else
258                 limit = pack_size_limit - write_offset;
259
260         if (!entry->delta)
261                 usable_delta = 0;       /* no delta */
262         else if (!pack_size_limit)
263                usable_delta = 1;        /* unlimited packfile */
264         else if (entry->delta->idx.offset == (off_t)-1)
265                 usable_delta = 0;       /* base was written to another pack */
266         else if (entry->delta->idx.offset)
267                 usable_delta = 1;       /* base already exists in this pack */
268         else
269                 usable_delta = 0;       /* base could end up in another pack */
270
271         if (!reuse_object)
272                 to_reuse = 0;   /* explicit */
273         else if (!entry->in_pack)
274                 to_reuse = 0;   /* can't reuse what we don't have */
275         else if (type == OBJ_REF_DELTA || type == OBJ_OFS_DELTA)
276                                 /* check_object() decided it for us ... */
277                 to_reuse = usable_delta;
278                                 /* ... but pack split may override that */
279         else if (type != entry->in_pack_type)
280                 to_reuse = 0;   /* pack has delta which is unusable */
281         else if (entry->delta)
282                 to_reuse = 0;   /* we want to pack afresh */
283         else
284                 to_reuse = 1;   /* we have it in-pack undeltified,
285                                  * and we do not need to deltify it.
286                                  */
287
288         if (!to_reuse) {
289                 no_reuse:
290                 if (!usable_delta) {
291                         buf = read_sha1_file(entry->idx.sha1, &type, &size);
292                         if (!buf)
293                                 die("unable to read %s", sha1_to_hex(entry->idx.sha1));
294                         /*
295                          * make sure no cached delta data remains from a
296                          * previous attempt before a pack split occurred.
297                          */
298                         free(entry->delta_data);
299                         entry->delta_data = NULL;
300                         entry->z_delta_size = 0;
301                 } else if (entry->delta_data) {
302                         size = entry->delta_size;
303                         buf = entry->delta_data;
304                         entry->delta_data = NULL;
305                         type = (allow_ofs_delta && entry->delta->idx.offset) ?
306                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
307                 } else {
308                         buf = get_delta(entry);
309                         size = entry->delta_size;
310                         type = (allow_ofs_delta && entry->delta->idx.offset) ?
311                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
312                 }
313
314                 if (entry->z_delta_size)
315                         datalen = entry->z_delta_size;
316                 else
317                         datalen = do_compress(&buf, size);
318
319                 /*
320                  * The object header is a byte of 'type' followed by zero or
321                  * more bytes of length.
322                  */
323                 hdrlen = encode_header(type, size, header);
324
325                 if (type == OBJ_OFS_DELTA) {
326                         /*
327                          * Deltas with relative base contain an additional
328                          * encoding of the relative offset for the delta
329                          * base from this object's position in the pack.
330                          */
331                         off_t ofs = entry->idx.offset - entry->delta->idx.offset;
332                         unsigned pos = sizeof(dheader) - 1;
333                         dheader[pos] = ofs & 127;
334                         while (ofs >>= 7)
335                                 dheader[--pos] = 128 | (--ofs & 127);
336                         if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit) {
337                                 free(buf);
338                                 return 0;
339                         }
340                         sha1write(f, header, hdrlen);
341                         sha1write(f, dheader + pos, sizeof(dheader) - pos);
342                         hdrlen += sizeof(dheader) - pos;
343                 } else if (type == OBJ_REF_DELTA) {
344                         /*
345                          * Deltas with a base reference contain
346                          * an additional 20 bytes for the base sha1.
347                          */
348                         if (limit && hdrlen + 20 + datalen + 20 >= limit) {
349                                 free(buf);
350                                 return 0;
351                         }
352                         sha1write(f, header, hdrlen);
353                         sha1write(f, entry->delta->idx.sha1, 20);
354                         hdrlen += 20;
355                 } else {
356                         if (limit && hdrlen + datalen + 20 >= limit) {
357                                 free(buf);
358                                 return 0;
359                         }
360                         sha1write(f, header, hdrlen);
361                 }
362                 sha1write(f, buf, datalen);
363                 free(buf);
364         }
365         else {
366                 struct packed_git *p = entry->in_pack;
367                 struct pack_window *w_curs = NULL;
368                 struct revindex_entry *revidx;
369                 off_t offset;
370
371                 if (entry->delta)
372                         type = (allow_ofs_delta && entry->delta->idx.offset) ?
373                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
374                 hdrlen = encode_header(type, entry->size, header);
375
376                 offset = entry->in_pack_offset;
377                 revidx = find_pack_revindex(p, offset);
378                 datalen = revidx[1].offset - offset;
379                 if (!pack_to_stdout && p->index_version > 1 &&
380                     check_pack_crc(p, &w_curs, offset, datalen, revidx->nr)) {
381                         error("bad packed object CRC for %s", sha1_to_hex(entry->idx.sha1));
382                         unuse_pack(&w_curs);
383                         goto no_reuse;
384                 }
385
386                 offset += entry->in_pack_header_size;
387                 datalen -= entry->in_pack_header_size;
388                 if (!pack_to_stdout && p->index_version == 1 &&
389                     check_pack_inflate(p, &w_curs, offset, datalen, entry->size)) {
390                         error("corrupt packed object for %s", sha1_to_hex(entry->idx.sha1));
391                         unuse_pack(&w_curs);
392                         goto no_reuse;
393                 }
394
395                 if (type == OBJ_OFS_DELTA) {
396                         off_t ofs = entry->idx.offset - entry->delta->idx.offset;
397                         unsigned pos = sizeof(dheader) - 1;
398                         dheader[pos] = ofs & 127;
399                         while (ofs >>= 7)
400                                 dheader[--pos] = 128 | (--ofs & 127);
401                         if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit) {
402                                 unuse_pack(&w_curs);
403                                 return 0;
404                         }
405                         sha1write(f, header, hdrlen);
406                         sha1write(f, dheader + pos, sizeof(dheader) - pos);
407                         hdrlen += sizeof(dheader) - pos;
408                         reused_delta++;
409                 } else if (type == OBJ_REF_DELTA) {
410                         if (limit && hdrlen + 20 + datalen + 20 >= limit) {
411                                 unuse_pack(&w_curs);
412                                 return 0;
413                         }
414                         sha1write(f, header, hdrlen);
415                         sha1write(f, entry->delta->idx.sha1, 20);
416                         hdrlen += 20;
417                         reused_delta++;
418                 } else {
419                         if (limit && hdrlen + datalen + 20 >= limit) {
420                                 unuse_pack(&w_curs);
421                                 return 0;
422                         }
423                         sha1write(f, header, hdrlen);
424                 }
425                 copy_pack_data(f, p, &w_curs, offset, datalen);
426                 unuse_pack(&w_curs);
427                 reused++;
428         }
429         if (usable_delta)
430                 written_delta++;
431         written++;
432         if (!pack_to_stdout)
433                 entry->idx.crc32 = crc32_end(f);
434         return hdrlen + datalen;
435 }
436
437 static int write_one(struct sha1file *f,
438                                struct object_entry *e,
439                                off_t *offset)
440 {
441         unsigned long size;
442
443         /* offset is non zero if object is written already. */
444         if (e->idx.offset || e->preferred_base)
445                 return 1;
446
447         /* if we are deltified, write out base object first. */
448         if (e->delta && !write_one(f, e->delta, offset))
449                 return 0;
450
451         e->idx.offset = *offset;
452         size = write_object(f, e, *offset);
453         if (!size) {
454                 e->idx.offset = 0;
455                 return 0;
456         }
457         written_list[nr_written++] = &e->idx;
458
459         /* make sure off_t is sufficiently large not to wrap */
460         if (*offset > *offset + size)
461                 die("pack too large for current definition of off_t");
462         *offset += size;
463         return 1;
464 }
465
466 /* forward declaration for write_pack_file */
467 static int adjust_perm(const char *path, mode_t mode);
468
469 static void write_pack_file(void)
470 {
471         uint32_t i = 0, j;
472         struct sha1file *f;
473         off_t offset;
474         struct pack_header hdr;
475         uint32_t nr_remaining = nr_result;
476         time_t last_mtime = 0;
477
478         if (progress > pack_to_stdout)
479                 progress_state = start_progress("Writing objects", nr_result);
480         written_list = xmalloc(nr_objects * sizeof(*written_list));
481
482         do {
483                 unsigned char sha1[20];
484                 char *pack_tmp_name = NULL;
485
486                 if (pack_to_stdout) {
487                         f = sha1fd_throughput(1, "<stdout>", progress_state);
488                 } else {
489                         char tmpname[PATH_MAX];
490                         int fd;
491                         fd = odb_mkstemp(tmpname, sizeof(tmpname),
492                                          "pack/tmp_pack_XXXXXX");
493                         pack_tmp_name = xstrdup(tmpname);
494                         f = sha1fd(fd, pack_tmp_name);
495                 }
496
497                 hdr.hdr_signature = htonl(PACK_SIGNATURE);
498                 hdr.hdr_version = htonl(PACK_VERSION);
499                 hdr.hdr_entries = htonl(nr_remaining);
500                 sha1write(f, &hdr, sizeof(hdr));
501                 offset = sizeof(hdr);
502                 nr_written = 0;
503                 for (; i < nr_objects; i++) {
504                         if (!write_one(f, objects + i, &offset))
505                                 break;
506                         display_progress(progress_state, written);
507                 }
508
509                 /*
510                  * Did we write the wrong # entries in the header?
511                  * If so, rewrite it like in fast-import
512                  */
513                 if (pack_to_stdout) {
514                         sha1close(f, sha1, CSUM_CLOSE);
515                 } else if (nr_written == nr_remaining) {
516                         sha1close(f, sha1, CSUM_FSYNC);
517                 } else {
518                         int fd = sha1close(f, sha1, 0);
519                         fixup_pack_header_footer(fd, sha1, pack_tmp_name,
520                                                  nr_written, sha1, offset);
521                         close(fd);
522                 }
523
524                 if (!pack_to_stdout) {
525                         mode_t mode = umask(0);
526                         struct stat st;
527                         char *idx_tmp_name, tmpname[PATH_MAX];
528
529                         umask(mode);
530                         mode = 0444 & ~mode;
531
532                         idx_tmp_name = write_idx_file(NULL, written_list,
533                                                       nr_written, sha1);
534
535                         snprintf(tmpname, sizeof(tmpname), "%s-%s.pack",
536                                  base_name, sha1_to_hex(sha1));
537                         free_pack_by_name(tmpname);
538                         if (adjust_perm(pack_tmp_name, mode))
539                                 die_errno("unable to make temporary pack file readable");
540                         if (rename(pack_tmp_name, tmpname))
541                                 die_errno("unable to rename temporary pack file");
542
543                         /*
544                          * Packs are runtime accessed in their mtime
545                          * order since newer packs are more likely to contain
546                          * younger objects.  So if we are creating multiple
547                          * packs then we should modify the mtime of later ones
548                          * to preserve this property.
549                          */
550                         if (stat(tmpname, &st) < 0) {
551                                 warning("failed to stat %s: %s",
552                                         tmpname, strerror(errno));
553                         } else if (!last_mtime) {
554                                 last_mtime = st.st_mtime;
555                         } else {
556                                 struct utimbuf utb;
557                                 utb.actime = st.st_atime;
558                                 utb.modtime = --last_mtime;
559                                 if (utime(tmpname, &utb) < 0)
560                                         warning("failed utime() on %s: %s",
561                                                 tmpname, strerror(errno));
562                         }
563
564                         snprintf(tmpname, sizeof(tmpname), "%s-%s.idx",
565                                  base_name, sha1_to_hex(sha1));
566                         if (adjust_perm(idx_tmp_name, mode))
567                                 die_errno("unable to make temporary index file readable");
568                         if (rename(idx_tmp_name, tmpname))
569                                 die_errno("unable to rename temporary index file");
570
571                         free(idx_tmp_name);
572                         free(pack_tmp_name);
573                         puts(sha1_to_hex(sha1));
574                 }
575
576                 /* mark written objects as written to previous pack */
577                 for (j = 0; j < nr_written; j++) {
578                         written_list[j]->offset = (off_t)-1;
579                 }
580                 nr_remaining -= nr_written;
581         } while (nr_remaining && i < nr_objects);
582
583         free(written_list);
584         stop_progress(&progress_state);
585         if (written != nr_result)
586                 die("wrote %"PRIu32" objects while expecting %"PRIu32,
587                         written, nr_result);
588         /*
589          * We have scanned through [0 ... i).  Since we have written
590          * the correct number of objects,  the remaining [i ... nr_objects)
591          * items must be either already written (due to out-of-order delta base)
592          * or a preferred base.  Count those which are neither and complain if any.
593          */
594         for (j = 0; i < nr_objects; i++) {
595                 struct object_entry *e = objects + i;
596                 j += !e->idx.offset && !e->preferred_base;
597         }
598         if (j)
599                 die("wrote %"PRIu32" objects as expected but %"PRIu32
600                         " unwritten", written, j);
601 }
602
603 static int locate_object_entry_hash(const unsigned char *sha1)
604 {
605         int i;
606         unsigned int ui;
607         memcpy(&ui, sha1, sizeof(unsigned int));
608         i = ui % object_ix_hashsz;
609         while (0 < object_ix[i]) {
610                 if (!hashcmp(sha1, objects[object_ix[i] - 1].idx.sha1))
611                         return i;
612                 if (++i == object_ix_hashsz)
613                         i = 0;
614         }
615         return -1 - i;
616 }
617
618 static struct object_entry *locate_object_entry(const unsigned char *sha1)
619 {
620         int i;
621
622         if (!object_ix_hashsz)
623                 return NULL;
624
625         i = locate_object_entry_hash(sha1);
626         if (0 <= i)
627                 return &objects[object_ix[i]-1];
628         return NULL;
629 }
630
631 static void rehash_objects(void)
632 {
633         uint32_t i;
634         struct object_entry *oe;
635
636         object_ix_hashsz = nr_objects * 3;
637         if (object_ix_hashsz < 1024)
638                 object_ix_hashsz = 1024;
639         object_ix = xrealloc(object_ix, sizeof(int) * object_ix_hashsz);
640         memset(object_ix, 0, sizeof(int) * object_ix_hashsz);
641         for (i = 0, oe = objects; i < nr_objects; i++, oe++) {
642                 int ix = locate_object_entry_hash(oe->idx.sha1);
643                 if (0 <= ix)
644                         continue;
645                 ix = -1 - ix;
646                 object_ix[ix] = i + 1;
647         }
648 }
649
650 static unsigned name_hash(const char *name)
651 {
652         unsigned c, hash = 0;
653
654         if (!name)
655                 return 0;
656
657         /*
658          * This effectively just creates a sortable number from the
659          * last sixteen non-whitespace characters. Last characters
660          * count "most", so things that end in ".c" sort together.
661          */
662         while ((c = *name++) != 0) {
663                 if (isspace(c))
664                         continue;
665                 hash = (hash >> 2) + (c << 24);
666         }
667         return hash;
668 }
669
670 static void setup_delta_attr_check(struct git_attr_check *check)
671 {
672         static struct git_attr *attr_delta;
673
674         if (!attr_delta)
675                 attr_delta = git_attr("delta", 5);
676
677         check[0].attr = attr_delta;
678 }
679
680 static int no_try_delta(const char *path)
681 {
682         struct git_attr_check check[1];
683
684         setup_delta_attr_check(check);
685         if (git_checkattr(path, ARRAY_SIZE(check), check))
686                 return 0;
687         if (ATTR_FALSE(check->value))
688                 return 1;
689         return 0;
690 }
691
692 static int add_object_entry(const unsigned char *sha1, enum object_type type,
693                             const char *name, int exclude)
694 {
695         struct object_entry *entry;
696         struct packed_git *p, *found_pack = NULL;
697         off_t found_offset = 0;
698         int ix;
699         unsigned hash = name_hash(name);
700
701         ix = nr_objects ? locate_object_entry_hash(sha1) : -1;
702         if (ix >= 0) {
703                 if (exclude) {
704                         entry = objects + object_ix[ix] - 1;
705                         if (!entry->preferred_base)
706                                 nr_result--;
707                         entry->preferred_base = 1;
708                 }
709                 return 0;
710         }
711
712         if (!exclude && local && has_loose_object_nonlocal(sha1))
713                 return 0;
714
715         for (p = packed_git; p; p = p->next) {
716                 off_t offset = find_pack_entry_one(sha1, p);
717                 if (offset) {
718                         if (!found_pack) {
719                                 found_offset = offset;
720                                 found_pack = p;
721                         }
722                         if (exclude)
723                                 break;
724                         if (incremental)
725                                 return 0;
726                         if (local && !p->pack_local)
727                                 return 0;
728                         if (ignore_packed_keep && p->pack_local && p->pack_keep)
729                                 return 0;
730                 }
731         }
732
733         if (nr_objects >= nr_alloc) {
734                 nr_alloc = (nr_alloc  + 1024) * 3 / 2;
735                 objects = xrealloc(objects, nr_alloc * sizeof(*entry));
736         }
737
738         entry = objects + nr_objects++;
739         memset(entry, 0, sizeof(*entry));
740         hashcpy(entry->idx.sha1, sha1);
741         entry->hash = hash;
742         if (type)
743                 entry->type = type;
744         if (exclude)
745                 entry->preferred_base = 1;
746         else
747                 nr_result++;
748         if (found_pack) {
749                 entry->in_pack = found_pack;
750                 entry->in_pack_offset = found_offset;
751         }
752
753         if (object_ix_hashsz * 3 <= nr_objects * 4)
754                 rehash_objects();
755         else
756                 object_ix[-1 - ix] = nr_objects;
757
758         display_progress(progress_state, nr_objects);
759
760         if (name && no_try_delta(name))
761                 entry->no_try_delta = 1;
762
763         return 1;
764 }
765
766 struct pbase_tree_cache {
767         unsigned char sha1[20];
768         int ref;
769         int temporary;
770         void *tree_data;
771         unsigned long tree_size;
772 };
773
774 static struct pbase_tree_cache *(pbase_tree_cache[256]);
775 static int pbase_tree_cache_ix(const unsigned char *sha1)
776 {
777         return sha1[0] % ARRAY_SIZE(pbase_tree_cache);
778 }
779 static int pbase_tree_cache_ix_incr(int ix)
780 {
781         return (ix+1) % ARRAY_SIZE(pbase_tree_cache);
782 }
783
784 static struct pbase_tree {
785         struct pbase_tree *next;
786         /* This is a phony "cache" entry; we are not
787          * going to evict it nor find it through _get()
788          * mechanism -- this is for the toplevel node that
789          * would almost always change with any commit.
790          */
791         struct pbase_tree_cache pcache;
792 } *pbase_tree;
793
794 static struct pbase_tree_cache *pbase_tree_get(const unsigned char *sha1)
795 {
796         struct pbase_tree_cache *ent, *nent;
797         void *data;
798         unsigned long size;
799         enum object_type type;
800         int neigh;
801         int my_ix = pbase_tree_cache_ix(sha1);
802         int available_ix = -1;
803
804         /* pbase-tree-cache acts as a limited hashtable.
805          * your object will be found at your index or within a few
806          * slots after that slot if it is cached.
807          */
808         for (neigh = 0; neigh < 8; neigh++) {
809                 ent = pbase_tree_cache[my_ix];
810                 if (ent && !hashcmp(ent->sha1, sha1)) {
811                         ent->ref++;
812                         return ent;
813                 }
814                 else if (((available_ix < 0) && (!ent || !ent->ref)) ||
815                          ((0 <= available_ix) &&
816                           (!ent && pbase_tree_cache[available_ix])))
817                         available_ix = my_ix;
818                 if (!ent)
819                         break;
820                 my_ix = pbase_tree_cache_ix_incr(my_ix);
821         }
822
823         /* Did not find one.  Either we got a bogus request or
824          * we need to read and perhaps cache.
825          */
826         data = read_sha1_file(sha1, &type, &size);
827         if (!data)
828                 return NULL;
829         if (type != OBJ_TREE) {
830                 free(data);
831                 return NULL;
832         }
833
834         /* We need to either cache or return a throwaway copy */
835
836         if (available_ix < 0)
837                 ent = NULL;
838         else {
839                 ent = pbase_tree_cache[available_ix];
840                 my_ix = available_ix;
841         }
842
843         if (!ent) {
844                 nent = xmalloc(sizeof(*nent));
845                 nent->temporary = (available_ix < 0);
846         }
847         else {
848                 /* evict and reuse */
849                 free(ent->tree_data);
850                 nent = ent;
851         }
852         hashcpy(nent->sha1, sha1);
853         nent->tree_data = data;
854         nent->tree_size = size;
855         nent->ref = 1;
856         if (!nent->temporary)
857                 pbase_tree_cache[my_ix] = nent;
858         return nent;
859 }
860
861 static void pbase_tree_put(struct pbase_tree_cache *cache)
862 {
863         if (!cache->temporary) {
864                 cache->ref--;
865                 return;
866         }
867         free(cache->tree_data);
868         free(cache);
869 }
870
871 static int name_cmp_len(const char *name)
872 {
873         int i;
874         for (i = 0; name[i] && name[i] != '\n' && name[i] != '/'; i++)
875                 ;
876         return i;
877 }
878
879 static void add_pbase_object(struct tree_desc *tree,
880                              const char *name,
881                              int cmplen,
882                              const char *fullname)
883 {
884         struct name_entry entry;
885         int cmp;
886
887         while (tree_entry(tree,&entry)) {
888                 if (S_ISGITLINK(entry.mode))
889                         continue;
890                 cmp = tree_entry_len(entry.path, entry.sha1) != cmplen ? 1 :
891                       memcmp(name, entry.path, cmplen);
892                 if (cmp > 0)
893                         continue;
894                 if (cmp < 0)
895                         return;
896                 if (name[cmplen] != '/') {
897                         add_object_entry(entry.sha1,
898                                          object_type(entry.mode),
899                                          fullname, 1);
900                         return;
901                 }
902                 if (S_ISDIR(entry.mode)) {
903                         struct tree_desc sub;
904                         struct pbase_tree_cache *tree;
905                         const char *down = name+cmplen+1;
906                         int downlen = name_cmp_len(down);
907
908                         tree = pbase_tree_get(entry.sha1);
909                         if (!tree)
910                                 return;
911                         init_tree_desc(&sub, tree->tree_data, tree->tree_size);
912
913                         add_pbase_object(&sub, down, downlen, fullname);
914                         pbase_tree_put(tree);
915                 }
916         }
917 }
918
919 static unsigned *done_pbase_paths;
920 static int done_pbase_paths_num;
921 static int done_pbase_paths_alloc;
922 static int done_pbase_path_pos(unsigned hash)
923 {
924         int lo = 0;
925         int hi = done_pbase_paths_num;
926         while (lo < hi) {
927                 int mi = (hi + lo) / 2;
928                 if (done_pbase_paths[mi] == hash)
929                         return mi;
930                 if (done_pbase_paths[mi] < hash)
931                         hi = mi;
932                 else
933                         lo = mi + 1;
934         }
935         return -lo-1;
936 }
937
938 static int check_pbase_path(unsigned hash)
939 {
940         int pos = (!done_pbase_paths) ? -1 : done_pbase_path_pos(hash);
941         if (0 <= pos)
942                 return 1;
943         pos = -pos - 1;
944         if (done_pbase_paths_alloc <= done_pbase_paths_num) {
945                 done_pbase_paths_alloc = alloc_nr(done_pbase_paths_alloc);
946                 done_pbase_paths = xrealloc(done_pbase_paths,
947                                             done_pbase_paths_alloc *
948                                             sizeof(unsigned));
949         }
950         done_pbase_paths_num++;
951         if (pos < done_pbase_paths_num)
952                 memmove(done_pbase_paths + pos + 1,
953                         done_pbase_paths + pos,
954                         (done_pbase_paths_num - pos - 1) * sizeof(unsigned));
955         done_pbase_paths[pos] = hash;
956         return 0;
957 }
958
959 static void add_preferred_base_object(const char *name)
960 {
961         struct pbase_tree *it;
962         int cmplen;
963         unsigned hash = name_hash(name);
964
965         if (!num_preferred_base || check_pbase_path(hash))
966                 return;
967
968         cmplen = name_cmp_len(name);
969         for (it = pbase_tree; it; it = it->next) {
970                 if (cmplen == 0) {
971                         add_object_entry(it->pcache.sha1, OBJ_TREE, NULL, 1);
972                 }
973                 else {
974                         struct tree_desc tree;
975                         init_tree_desc(&tree, it->pcache.tree_data, it->pcache.tree_size);
976                         add_pbase_object(&tree, name, cmplen, name);
977                 }
978         }
979 }
980
981 static void add_preferred_base(unsigned char *sha1)
982 {
983         struct pbase_tree *it;
984         void *data;
985         unsigned long size;
986         unsigned char tree_sha1[20];
987
988         if (window <= num_preferred_base++)
989                 return;
990
991         data = read_object_with_reference(sha1, tree_type, &size, tree_sha1);
992         if (!data)
993                 return;
994
995         for (it = pbase_tree; it; it = it->next) {
996                 if (!hashcmp(it->pcache.sha1, tree_sha1)) {
997                         free(data);
998                         return;
999                 }
1000         }
1001
1002         it = xcalloc(1, sizeof(*it));
1003         it->next = pbase_tree;
1004         pbase_tree = it;
1005
1006         hashcpy(it->pcache.sha1, tree_sha1);
1007         it->pcache.tree_data = data;
1008         it->pcache.tree_size = size;
1009 }
1010
1011 static void cleanup_preferred_base(void)
1012 {
1013         struct pbase_tree *it;
1014         unsigned i;
1015
1016         it = pbase_tree;
1017         pbase_tree = NULL;
1018         while (it) {
1019                 struct pbase_tree *this = it;
1020                 it = this->next;
1021                 free(this->pcache.tree_data);
1022                 free(this);
1023         }
1024
1025         for (i = 0; i < ARRAY_SIZE(pbase_tree_cache); i++) {
1026                 if (!pbase_tree_cache[i])
1027                         continue;
1028                 free(pbase_tree_cache[i]->tree_data);
1029                 free(pbase_tree_cache[i]);
1030                 pbase_tree_cache[i] = NULL;
1031         }
1032
1033         free(done_pbase_paths);
1034         done_pbase_paths = NULL;
1035         done_pbase_paths_num = done_pbase_paths_alloc = 0;
1036 }
1037
1038 static void check_object(struct object_entry *entry)
1039 {
1040         if (entry->in_pack) {
1041                 struct packed_git *p = entry->in_pack;
1042                 struct pack_window *w_curs = NULL;
1043                 const unsigned char *base_ref = NULL;
1044                 struct object_entry *base_entry;
1045                 unsigned long used, used_0;
1046                 unsigned int avail;
1047                 off_t ofs;
1048                 unsigned char *buf, c;
1049
1050                 buf = use_pack(p, &w_curs, entry->in_pack_offset, &avail);
1051
1052                 /*
1053                  * We want in_pack_type even if we do not reuse delta
1054                  * since non-delta representations could still be reused.
1055                  */
1056                 used = unpack_object_header_buffer(buf, avail,
1057                                                    &entry->in_pack_type,
1058                                                    &entry->size);
1059                 if (used == 0)
1060                         goto give_up;
1061
1062                 /*
1063                  * Determine if this is a delta and if so whether we can
1064                  * reuse it or not.  Otherwise let's find out as cheaply as
1065                  * possible what the actual type and size for this object is.
1066                  */
1067                 switch (entry->in_pack_type) {
1068                 default:
1069                         /* Not a delta hence we've already got all we need. */
1070                         entry->type = entry->in_pack_type;
1071                         entry->in_pack_header_size = used;
1072                         if (entry->type < OBJ_COMMIT || entry->type > OBJ_BLOB)
1073                                 goto give_up;
1074                         unuse_pack(&w_curs);
1075                         return;
1076                 case OBJ_REF_DELTA:
1077                         if (reuse_delta && !entry->preferred_base)
1078                                 base_ref = use_pack(p, &w_curs,
1079                                                 entry->in_pack_offset + used, NULL);
1080                         entry->in_pack_header_size = used + 20;
1081                         break;
1082                 case OBJ_OFS_DELTA:
1083                         buf = use_pack(p, &w_curs,
1084                                        entry->in_pack_offset + used, NULL);
1085                         used_0 = 0;
1086                         c = buf[used_0++];
1087                         ofs = c & 127;
1088                         while (c & 128) {
1089                                 ofs += 1;
1090                                 if (!ofs || MSB(ofs, 7)) {
1091                                         error("delta base offset overflow in pack for %s",
1092                                               sha1_to_hex(entry->idx.sha1));
1093                                         goto give_up;
1094                                 }
1095                                 c = buf[used_0++];
1096                                 ofs = (ofs << 7) + (c & 127);
1097                         }
1098                         ofs = entry->in_pack_offset - ofs;
1099                         if (ofs <= 0 || ofs >= entry->in_pack_offset) {
1100                                 error("delta base offset out of bound for %s",
1101                                       sha1_to_hex(entry->idx.sha1));
1102                                 goto give_up;
1103                         }
1104                         if (reuse_delta && !entry->preferred_base) {
1105                                 struct revindex_entry *revidx;
1106                                 revidx = find_pack_revindex(p, ofs);
1107                                 if (!revidx)
1108                                         goto give_up;
1109                                 base_ref = nth_packed_object_sha1(p, revidx->nr);
1110                         }
1111                         entry->in_pack_header_size = used + used_0;
1112                         break;
1113                 }
1114
1115                 if (base_ref && (base_entry = locate_object_entry(base_ref))) {
1116                         /*
1117                          * If base_ref was set above that means we wish to
1118                          * reuse delta data, and we even found that base
1119                          * in the list of objects we want to pack. Goodie!
1120                          *
1121                          * Depth value does not matter - find_deltas() will
1122                          * never consider reused delta as the base object to
1123                          * deltify other objects against, in order to avoid
1124                          * circular deltas.
1125                          */
1126                         entry->type = entry->in_pack_type;
1127                         entry->delta = base_entry;
1128                         entry->delta_size = entry->size;
1129                         entry->delta_sibling = base_entry->delta_child;
1130                         base_entry->delta_child = entry;
1131                         unuse_pack(&w_curs);
1132                         return;
1133                 }
1134
1135                 if (entry->type) {
1136                         /*
1137                          * This must be a delta and we already know what the
1138                          * final object type is.  Let's extract the actual
1139                          * object size from the delta header.
1140                          */
1141                         entry->size = get_size_from_delta(p, &w_curs,
1142                                         entry->in_pack_offset + entry->in_pack_header_size);
1143                         if (entry->size == 0)
1144                                 goto give_up;
1145                         unuse_pack(&w_curs);
1146                         return;
1147                 }
1148
1149                 /*
1150                  * No choice but to fall back to the recursive delta walk
1151                  * with sha1_object_info() to find about the object type
1152                  * at this point...
1153                  */
1154                 give_up:
1155                 unuse_pack(&w_curs);
1156         }
1157
1158         entry->type = sha1_object_info(entry->idx.sha1, &entry->size);
1159         /*
1160          * The error condition is checked in prepare_pack().  This is
1161          * to permit a missing preferred base object to be ignored
1162          * as a preferred base.  Doing so can result in a larger
1163          * pack file, but the transfer will still take place.
1164          */
1165 }
1166
1167 static int pack_offset_sort(const void *_a, const void *_b)
1168 {
1169         const struct object_entry *a = *(struct object_entry **)_a;
1170         const struct object_entry *b = *(struct object_entry **)_b;
1171
1172         /* avoid filesystem trashing with loose objects */
1173         if (!a->in_pack && !b->in_pack)
1174                 return hashcmp(a->idx.sha1, b->idx.sha1);
1175
1176         if (a->in_pack < b->in_pack)
1177                 return -1;
1178         if (a->in_pack > b->in_pack)
1179                 return 1;
1180         return a->in_pack_offset < b->in_pack_offset ? -1 :
1181                         (a->in_pack_offset > b->in_pack_offset);
1182 }
1183
1184 static void get_object_details(void)
1185 {
1186         uint32_t i;
1187         struct object_entry **sorted_by_offset;
1188
1189         sorted_by_offset = xcalloc(nr_objects, sizeof(struct object_entry *));
1190         for (i = 0; i < nr_objects; i++)
1191                 sorted_by_offset[i] = objects + i;
1192         qsort(sorted_by_offset, nr_objects, sizeof(*sorted_by_offset), pack_offset_sort);
1193
1194         for (i = 0; i < nr_objects; i++)
1195                 check_object(sorted_by_offset[i]);
1196
1197         free(sorted_by_offset);
1198 }
1199
1200 /*
1201  * We search for deltas in a list sorted by type, by filename hash, and then
1202  * by size, so that we see progressively smaller and smaller files.
1203  * That's because we prefer deltas to be from the bigger file
1204  * to the smaller -- deletes are potentially cheaper, but perhaps
1205  * more importantly, the bigger file is likely the more recent
1206  * one.  The deepest deltas are therefore the oldest objects which are
1207  * less susceptible to be accessed often.
1208  */
1209 static int type_size_sort(const void *_a, const void *_b)
1210 {
1211         const struct object_entry *a = *(struct object_entry **)_a;
1212         const struct object_entry *b = *(struct object_entry **)_b;
1213
1214         if (a->type > b->type)
1215                 return -1;
1216         if (a->type < b->type)
1217                 return 1;
1218         if (a->hash > b->hash)
1219                 return -1;
1220         if (a->hash < b->hash)
1221                 return 1;
1222         if (a->preferred_base > b->preferred_base)
1223                 return -1;
1224         if (a->preferred_base < b->preferred_base)
1225                 return 1;
1226         if (a->size > b->size)
1227                 return -1;
1228         if (a->size < b->size)
1229                 return 1;
1230         return a < b ? -1 : (a > b);  /* newest first */
1231 }
1232
1233 struct unpacked {
1234         struct object_entry *entry;
1235         void *data;
1236         struct delta_index *index;
1237         unsigned depth;
1238 };
1239
1240 static int delta_cacheable(unsigned long src_size, unsigned long trg_size,
1241                            unsigned long delta_size)
1242 {
1243         if (max_delta_cache_size && delta_cache_size + delta_size > max_delta_cache_size)
1244                 return 0;
1245
1246         if (delta_size < cache_max_small_delta_size)
1247                 return 1;
1248
1249         /* cache delta, if objects are large enough compared to delta size */
1250         if ((src_size >> 20) + (trg_size >> 21) > (delta_size >> 10))
1251                 return 1;
1252
1253         return 0;
1254 }
1255
1256 #ifdef THREADED_DELTA_SEARCH
1257
1258 static pthread_mutex_t read_mutex = PTHREAD_MUTEX_INITIALIZER;
1259 #define read_lock()             pthread_mutex_lock(&read_mutex)
1260 #define read_unlock()           pthread_mutex_unlock(&read_mutex)
1261
1262 static pthread_mutex_t cache_mutex = PTHREAD_MUTEX_INITIALIZER;
1263 #define cache_lock()            pthread_mutex_lock(&cache_mutex)
1264 #define cache_unlock()          pthread_mutex_unlock(&cache_mutex)
1265
1266 static pthread_mutex_t progress_mutex = PTHREAD_MUTEX_INITIALIZER;
1267 #define progress_lock()         pthread_mutex_lock(&progress_mutex)
1268 #define progress_unlock()       pthread_mutex_unlock(&progress_mutex)
1269
1270 #else
1271
1272 #define read_lock()             (void)0
1273 #define read_unlock()           (void)0
1274 #define cache_lock()            (void)0
1275 #define cache_unlock()          (void)0
1276 #define progress_lock()         (void)0
1277 #define progress_unlock()       (void)0
1278
1279 #endif
1280
1281 static int try_delta(struct unpacked *trg, struct unpacked *src,
1282                      unsigned max_depth, unsigned long *mem_usage)
1283 {
1284         struct object_entry *trg_entry = trg->entry;
1285         struct object_entry *src_entry = src->entry;
1286         unsigned long trg_size, src_size, delta_size, sizediff, max_size, sz;
1287         unsigned ref_depth;
1288         enum object_type type;
1289         void *delta_buf;
1290
1291         /* Don't bother doing diffs between different types */
1292         if (trg_entry->type != src_entry->type)
1293                 return -1;
1294
1295         /*
1296          * We do not bother to try a delta that we discarded
1297          * on an earlier try, but only when reusing delta data.
1298          */
1299         if (reuse_delta && trg_entry->in_pack &&
1300             trg_entry->in_pack == src_entry->in_pack &&
1301             trg_entry->in_pack_type != OBJ_REF_DELTA &&
1302             trg_entry->in_pack_type != OBJ_OFS_DELTA)
1303                 return 0;
1304
1305         /* Let's not bust the allowed depth. */
1306         if (src->depth >= max_depth)
1307                 return 0;
1308
1309         /* Now some size filtering heuristics. */
1310         trg_size = trg_entry->size;
1311         if (!trg_entry->delta) {
1312                 max_size = trg_size/2 - 20;
1313                 ref_depth = 1;
1314         } else {
1315                 max_size = trg_entry->delta_size;
1316                 ref_depth = trg->depth;
1317         }
1318         max_size = (uint64_t)max_size * (max_depth - src->depth) /
1319                                                 (max_depth - ref_depth + 1);
1320         if (max_size == 0)
1321                 return 0;
1322         src_size = src_entry->size;
1323         sizediff = src_size < trg_size ? trg_size - src_size : 0;
1324         if (sizediff >= max_size)
1325                 return 0;
1326         if (trg_size < src_size / 32)
1327                 return 0;
1328
1329         /* Load data if not already done */
1330         if (!trg->data) {
1331                 read_lock();
1332                 trg->data = read_sha1_file(trg_entry->idx.sha1, &type, &sz);
1333                 read_unlock();
1334                 if (!trg->data)
1335                         die("object %s cannot be read",
1336                             sha1_to_hex(trg_entry->idx.sha1));
1337                 if (sz != trg_size)
1338                         die("object %s inconsistent object length (%lu vs %lu)",
1339                             sha1_to_hex(trg_entry->idx.sha1), sz, trg_size);
1340                 *mem_usage += sz;
1341         }
1342         if (!src->data) {
1343                 read_lock();
1344                 src->data = read_sha1_file(src_entry->idx.sha1, &type, &sz);
1345                 read_unlock();
1346                 if (!src->data)
1347                         die("object %s cannot be read",
1348                             sha1_to_hex(src_entry->idx.sha1));
1349                 if (sz != src_size)
1350                         die("object %s inconsistent object length (%lu vs %lu)",
1351                             sha1_to_hex(src_entry->idx.sha1), sz, src_size);
1352                 *mem_usage += sz;
1353         }
1354         if (!src->index) {
1355                 src->index = create_delta_index(src->data, src_size);
1356                 if (!src->index) {
1357                         static int warned = 0;
1358                         if (!warned++)
1359                                 warning("suboptimal pack - out of memory");
1360                         return 0;
1361                 }
1362                 *mem_usage += sizeof_delta_index(src->index);
1363         }
1364
1365         delta_buf = create_delta(src->index, trg->data, trg_size, &delta_size, max_size);
1366         if (!delta_buf)
1367                 return 0;
1368
1369         if (trg_entry->delta) {
1370                 /* Prefer only shallower same-sized deltas. */
1371                 if (delta_size == trg_entry->delta_size &&
1372                     src->depth + 1 >= trg->depth) {
1373                         free(delta_buf);
1374                         return 0;
1375                 }
1376         }
1377
1378         /*
1379          * Handle memory allocation outside of the cache
1380          * accounting lock.  Compiler will optimize the strangeness
1381          * away when THREADED_DELTA_SEARCH is not defined.
1382          */
1383         free(trg_entry->delta_data);
1384         cache_lock();
1385         if (trg_entry->delta_data) {
1386                 delta_cache_size -= trg_entry->delta_size;
1387                 trg_entry->delta_data = NULL;
1388         }
1389         if (delta_cacheable(src_size, trg_size, delta_size)) {
1390                 delta_cache_size += delta_size;
1391                 cache_unlock();
1392                 trg_entry->delta_data = xrealloc(delta_buf, delta_size);
1393         } else {
1394                 cache_unlock();
1395                 free(delta_buf);
1396         }
1397
1398         trg_entry->delta = src_entry;
1399         trg_entry->delta_size = delta_size;
1400         trg->depth = src->depth + 1;
1401
1402         return 1;
1403 }
1404
1405 static unsigned int check_delta_limit(struct object_entry *me, unsigned int n)
1406 {
1407         struct object_entry *child = me->delta_child;
1408         unsigned int m = n;
1409         while (child) {
1410                 unsigned int c = check_delta_limit(child, n + 1);
1411                 if (m < c)
1412                         m = c;
1413                 child = child->delta_sibling;
1414         }
1415         return m;
1416 }
1417
1418 static unsigned long free_unpacked(struct unpacked *n)
1419 {
1420         unsigned long freed_mem = sizeof_delta_index(n->index);
1421         free_delta_index(n->index);
1422         n->index = NULL;
1423         if (n->data) {
1424                 freed_mem += n->entry->size;
1425                 free(n->data);
1426                 n->data = NULL;
1427         }
1428         n->entry = NULL;
1429         n->depth = 0;
1430         return freed_mem;
1431 }
1432
1433 static void find_deltas(struct object_entry **list, unsigned *list_size,
1434                         int window, int depth, unsigned *processed)
1435 {
1436         uint32_t i, idx = 0, count = 0;
1437         struct unpacked *array;
1438         unsigned long mem_usage = 0;
1439
1440         array = xcalloc(window, sizeof(struct unpacked));
1441
1442         for (;;) {
1443                 struct object_entry *entry;
1444                 struct unpacked *n = array + idx;
1445                 int j, max_depth, best_base = -1;
1446
1447                 progress_lock();
1448                 if (!*list_size) {
1449                         progress_unlock();
1450                         break;
1451                 }
1452                 entry = *list++;
1453                 (*list_size)--;
1454                 if (!entry->preferred_base) {
1455                         (*processed)++;
1456                         display_progress(progress_state, *processed);
1457                 }
1458                 progress_unlock();
1459
1460                 mem_usage -= free_unpacked(n);
1461                 n->entry = entry;
1462
1463                 while (window_memory_limit &&
1464                        mem_usage > window_memory_limit &&
1465                        count > 1) {
1466                         uint32_t tail = (idx + window - count) % window;
1467                         mem_usage -= free_unpacked(array + tail);
1468                         count--;
1469                 }
1470
1471                 /* We do not compute delta to *create* objects we are not
1472                  * going to pack.
1473                  */
1474                 if (entry->preferred_base)
1475                         goto next;
1476
1477                 /*
1478                  * If the current object is at pack edge, take the depth the
1479                  * objects that depend on the current object into account
1480                  * otherwise they would become too deep.
1481                  */
1482                 max_depth = depth;
1483                 if (entry->delta_child) {
1484                         max_depth -= check_delta_limit(entry, 0);
1485                         if (max_depth <= 0)
1486                                 goto next;
1487                 }
1488
1489                 j = window;
1490                 while (--j > 0) {
1491                         int ret;
1492                         uint32_t other_idx = idx + j;
1493                         struct unpacked *m;
1494                         if (other_idx >= window)
1495                                 other_idx -= window;
1496                         m = array + other_idx;
1497                         if (!m->entry)
1498                                 break;
1499                         ret = try_delta(n, m, max_depth, &mem_usage);
1500                         if (ret < 0)
1501                                 break;
1502                         else if (ret > 0)
1503                                 best_base = other_idx;
1504                 }
1505
1506                 /*
1507                  * If we decided to cache the delta data, then it is best
1508                  * to compress it right away.  First because we have to do
1509                  * it anyway, and doing it here while we're threaded will
1510                  * save a lot of time in the non threaded write phase,
1511                  * as well as allow for caching more deltas within
1512                  * the same cache size limit.
1513                  * ...
1514                  * But only if not writing to stdout, since in that case
1515                  * the network is most likely throttling writes anyway,
1516                  * and therefore it is best to go to the write phase ASAP
1517                  * instead, as we can afford spending more time compressing
1518                  * between writes at that moment.
1519                  */
1520                 if (entry->delta_data && !pack_to_stdout) {
1521                         entry->z_delta_size = do_compress(&entry->delta_data,
1522                                                           entry->delta_size);
1523                         cache_lock();
1524                         delta_cache_size -= entry->delta_size;
1525                         delta_cache_size += entry->z_delta_size;
1526                         cache_unlock();
1527                 }
1528
1529                 /* if we made n a delta, and if n is already at max
1530                  * depth, leaving it in the window is pointless.  we
1531                  * should evict it first.
1532                  */
1533                 if (entry->delta && max_depth <= n->depth)
1534                         continue;
1535
1536                 /*
1537                  * Move the best delta base up in the window, after the
1538                  * currently deltified object, to keep it longer.  It will
1539                  * be the first base object to be attempted next.
1540                  */
1541                 if (entry->delta) {
1542                         struct unpacked swap = array[best_base];
1543                         int dist = (window + idx - best_base) % window;
1544                         int dst = best_base;
1545                         while (dist--) {
1546                                 int src = (dst + 1) % window;
1547                                 array[dst] = array[src];
1548                                 dst = src;
1549                         }
1550                         array[dst] = swap;
1551                 }
1552
1553                 next:
1554                 idx++;
1555                 if (count + 1 < window)
1556                         count++;
1557                 if (idx >= window)
1558                         idx = 0;
1559         }
1560
1561         for (i = 0; i < window; ++i) {
1562                 free_delta_index(array[i].index);
1563                 free(array[i].data);
1564         }
1565         free(array);
1566 }
1567
1568 #ifdef THREADED_DELTA_SEARCH
1569
1570 /*
1571  * The main thread waits on the condition that (at least) one of the workers
1572  * has stopped working (which is indicated in the .working member of
1573  * struct thread_params).
1574  * When a work thread has completed its work, it sets .working to 0 and
1575  * signals the main thread and waits on the condition that .data_ready
1576  * becomes 1.
1577  */
1578
1579 struct thread_params {
1580         pthread_t thread;
1581         struct object_entry **list;
1582         unsigned list_size;
1583         unsigned remaining;
1584         int window;
1585         int depth;
1586         int working;
1587         int data_ready;
1588         pthread_mutex_t mutex;
1589         pthread_cond_t cond;
1590         unsigned *processed;
1591 };
1592
1593 static pthread_cond_t progress_cond = PTHREAD_COND_INITIALIZER;
1594
1595 static void *threaded_find_deltas(void *arg)
1596 {
1597         struct thread_params *me = arg;
1598
1599         while (me->remaining) {
1600                 find_deltas(me->list, &me->remaining,
1601                             me->window, me->depth, me->processed);
1602
1603                 progress_lock();
1604                 me->working = 0;
1605                 pthread_cond_signal(&progress_cond);
1606                 progress_unlock();
1607
1608                 /*
1609                  * We must not set ->data_ready before we wait on the
1610                  * condition because the main thread may have set it to 1
1611                  * before we get here. In order to be sure that new
1612                  * work is available if we see 1 in ->data_ready, it
1613                  * was initialized to 0 before this thread was spawned
1614                  * and we reset it to 0 right away.
1615                  */
1616                 pthread_mutex_lock(&me->mutex);
1617                 while (!me->data_ready)
1618                         pthread_cond_wait(&me->cond, &me->mutex);
1619                 me->data_ready = 0;
1620                 pthread_mutex_unlock(&me->mutex);
1621         }
1622         /* leave ->working 1 so that this doesn't get more work assigned */
1623         return NULL;
1624 }
1625
1626 static void ll_find_deltas(struct object_entry **list, unsigned list_size,
1627                            int window, int depth, unsigned *processed)
1628 {
1629         struct thread_params *p;
1630         int i, ret, active_threads = 0;
1631
1632         if (!delta_search_threads)      /* --threads=0 means autodetect */
1633                 delta_search_threads = online_cpus();
1634         if (delta_search_threads <= 1) {
1635                 find_deltas(list, &list_size, window, depth, processed);
1636                 return;
1637         }
1638         if (progress > pack_to_stdout)
1639                 fprintf(stderr, "Delta compression using up to %d threads.\n",
1640                                 delta_search_threads);
1641         p = xcalloc(delta_search_threads, sizeof(*p));
1642
1643         /* Partition the work amongst work threads. */
1644         for (i = 0; i < delta_search_threads; i++) {
1645                 unsigned sub_size = list_size / (delta_search_threads - i);
1646
1647                 /* don't use too small segments or no deltas will be found */
1648                 if (sub_size < 2*window && i+1 < delta_search_threads)
1649                         sub_size = 0;
1650
1651                 p[i].window = window;
1652                 p[i].depth = depth;
1653                 p[i].processed = processed;
1654                 p[i].working = 1;
1655                 p[i].data_ready = 0;
1656
1657                 /* try to split chunks on "path" boundaries */
1658                 while (sub_size && sub_size < list_size &&
1659                        list[sub_size]->hash &&
1660                        list[sub_size]->hash == list[sub_size-1]->hash)
1661                         sub_size++;
1662
1663                 p[i].list = list;
1664                 p[i].list_size = sub_size;
1665                 p[i].remaining = sub_size;
1666
1667                 list += sub_size;
1668                 list_size -= sub_size;
1669         }
1670
1671         /* Start work threads. */
1672         for (i = 0; i < delta_search_threads; i++) {
1673                 if (!p[i].list_size)
1674                         continue;
1675                 pthread_mutex_init(&p[i].mutex, NULL);
1676                 pthread_cond_init(&p[i].cond, NULL);
1677                 ret = pthread_create(&p[i].thread, NULL,
1678                                      threaded_find_deltas, &p[i]);
1679                 if (ret)
1680                         die("unable to create thread: %s", strerror(ret));
1681                 active_threads++;
1682         }
1683
1684         /*
1685          * Now let's wait for work completion.  Each time a thread is done
1686          * with its work, we steal half of the remaining work from the
1687          * thread with the largest number of unprocessed objects and give
1688          * it to that newly idle thread.  This ensure good load balancing
1689          * until the remaining object list segments are simply too short
1690          * to be worth splitting anymore.
1691          */
1692         while (active_threads) {
1693                 struct thread_params *target = NULL;
1694                 struct thread_params *victim = NULL;
1695                 unsigned sub_size = 0;
1696
1697                 progress_lock();
1698                 for (;;) {
1699                         for (i = 0; !target && i < delta_search_threads; i++)
1700                                 if (!p[i].working)
1701                                         target = &p[i];
1702                         if (target)
1703                                 break;
1704                         pthread_cond_wait(&progress_cond, &progress_mutex);
1705                 }
1706
1707                 for (i = 0; i < delta_search_threads; i++)
1708                         if (p[i].remaining > 2*window &&
1709                             (!victim || victim->remaining < p[i].remaining))
1710                                 victim = &p[i];
1711                 if (victim) {
1712                         sub_size = victim->remaining / 2;
1713                         list = victim->list + victim->list_size - sub_size;
1714                         while (sub_size && list[0]->hash &&
1715                                list[0]->hash == list[-1]->hash) {
1716                                 list++;
1717                                 sub_size--;
1718                         }
1719                         if (!sub_size) {
1720                                 /*
1721                                  * It is possible for some "paths" to have
1722                                  * so many objects that no hash boundary
1723                                  * might be found.  Let's just steal the
1724                                  * exact half in that case.
1725                                  */
1726                                 sub_size = victim->remaining / 2;
1727                                 list -= sub_size;
1728                         }
1729                         target->list = list;
1730                         victim->list_size -= sub_size;
1731                         victim->remaining -= sub_size;
1732                 }
1733                 target->list_size = sub_size;
1734                 target->remaining = sub_size;
1735                 target->working = 1;
1736                 progress_unlock();
1737
1738                 pthread_mutex_lock(&target->mutex);
1739                 target->data_ready = 1;
1740                 pthread_cond_signal(&target->cond);
1741                 pthread_mutex_unlock(&target->mutex);
1742
1743                 if (!sub_size) {
1744                         pthread_join(target->thread, NULL);
1745                         pthread_cond_destroy(&target->cond);
1746                         pthread_mutex_destroy(&target->mutex);
1747                         active_threads--;
1748                 }
1749         }
1750         free(p);
1751 }
1752
1753 #else
1754 #define ll_find_deltas(l, s, w, d, p)   find_deltas(l, &s, w, d, p)
1755 #endif
1756
1757 static int add_ref_tag(const char *path, const unsigned char *sha1, int flag, void *cb_data)
1758 {
1759         unsigned char peeled[20];
1760
1761         if (!prefixcmp(path, "refs/tags/") && /* is a tag? */
1762             !peel_ref(path, peeled)        && /* peelable? */
1763             !is_null_sha1(peeled)          && /* annotated tag? */
1764             locate_object_entry(peeled))      /* object packed? */
1765                 add_object_entry(sha1, OBJ_TAG, NULL, 0);
1766         return 0;
1767 }
1768
1769 static void prepare_pack(int window, int depth)
1770 {
1771         struct object_entry **delta_list;
1772         uint32_t i, nr_deltas;
1773         unsigned n;
1774
1775         get_object_details();
1776
1777         /*
1778          * If we're locally repacking then we need to be doubly careful
1779          * from now on in order to make sure no stealth corruption gets
1780          * propagated to the new pack.  Clients receiving streamed packs
1781          * should validate everything they get anyway so no need to incur
1782          * the additional cost here in that case.
1783          */
1784         if (!pack_to_stdout)
1785                 do_check_packed_object_crc = 1;
1786
1787         if (!nr_objects || !window || !depth)
1788                 return;
1789
1790         delta_list = xmalloc(nr_objects * sizeof(*delta_list));
1791         nr_deltas = n = 0;
1792
1793         for (i = 0; i < nr_objects; i++) {
1794                 struct object_entry *entry = objects + i;
1795
1796                 if (entry->delta)
1797                         /* This happens if we decided to reuse existing
1798                          * delta from a pack.  "reuse_delta &&" is implied.
1799                          */
1800                         continue;
1801
1802                 if (entry->size < 50)
1803                         continue;
1804
1805                 if (entry->no_try_delta)
1806                         continue;
1807
1808                 if (!entry->preferred_base) {
1809                         nr_deltas++;
1810                         if (entry->type < 0)
1811                                 die("unable to get type of object %s",
1812                                     sha1_to_hex(entry->idx.sha1));
1813                 } else {
1814                         if (entry->type < 0) {
1815                                 /*
1816                                  * This object is not found, but we
1817                                  * don't have to include it anyway.
1818                                  */
1819                                 continue;
1820                         }
1821                 }
1822
1823                 delta_list[n++] = entry;
1824         }
1825
1826         if (nr_deltas && n > 1) {
1827                 unsigned nr_done = 0;
1828                 if (progress)
1829                         progress_state = start_progress("Compressing objects",
1830                                                         nr_deltas);
1831                 qsort(delta_list, n, sizeof(*delta_list), type_size_sort);
1832                 ll_find_deltas(delta_list, n, window+1, depth, &nr_done);
1833                 stop_progress(&progress_state);
1834                 if (nr_done != nr_deltas)
1835                         die("inconsistency with delta count");
1836         }
1837         free(delta_list);
1838 }
1839
1840 static int git_pack_config(const char *k, const char *v, void *cb)
1841 {
1842         if (!strcmp(k, "pack.window")) {
1843                 window = git_config_int(k, v);
1844                 return 0;
1845         }
1846         if (!strcmp(k, "pack.windowmemory")) {
1847                 window_memory_limit = git_config_ulong(k, v);
1848                 return 0;
1849         }
1850         if (!strcmp(k, "pack.depth")) {
1851                 depth = git_config_int(k, v);
1852                 return 0;
1853         }
1854         if (!strcmp(k, "pack.compression")) {
1855                 int level = git_config_int(k, v);
1856                 if (level == -1)
1857                         level = Z_DEFAULT_COMPRESSION;
1858                 else if (level < 0 || level > Z_BEST_COMPRESSION)
1859                         die("bad pack compression level %d", level);
1860                 pack_compression_level = level;
1861                 pack_compression_seen = 1;
1862                 return 0;
1863         }
1864         if (!strcmp(k, "pack.deltacachesize")) {
1865                 max_delta_cache_size = git_config_int(k, v);
1866                 return 0;
1867         }
1868         if (!strcmp(k, "pack.deltacachelimit")) {
1869                 cache_max_small_delta_size = git_config_int(k, v);
1870                 return 0;
1871         }
1872         if (!strcmp(k, "pack.threads")) {
1873                 delta_search_threads = git_config_int(k, v);
1874                 if (delta_search_threads < 0)
1875                         die("invalid number of threads specified (%d)",
1876                             delta_search_threads);
1877 #ifndef THREADED_DELTA_SEARCH
1878                 if (delta_search_threads != 1)
1879                         warning("no threads support, ignoring %s", k);
1880 #endif
1881                 return 0;
1882         }
1883         if (!strcmp(k, "pack.indexversion")) {
1884                 pack_idx_default_version = git_config_int(k, v);
1885                 if (pack_idx_default_version > 2)
1886                         die("bad pack.indexversion=%"PRIu32,
1887                                 pack_idx_default_version);
1888                 return 0;
1889         }
1890         if (!strcmp(k, "pack.packsizelimit")) {
1891                 pack_size_limit_cfg = git_config_ulong(k, v);
1892                 return 0;
1893         }
1894         return git_default_config(k, v, cb);
1895 }
1896
1897 static void read_object_list_from_stdin(void)
1898 {
1899         char line[40 + 1 + PATH_MAX + 2];
1900         unsigned char sha1[20];
1901
1902         for (;;) {
1903                 if (!fgets(line, sizeof(line), stdin)) {
1904                         if (feof(stdin))
1905                                 break;
1906                         if (!ferror(stdin))
1907                                 die("fgets returned NULL, not EOF, not error!");
1908                         if (errno != EINTR)
1909                                 die_errno("fgets");
1910                         clearerr(stdin);
1911                         continue;
1912                 }
1913                 if (line[0] == '-') {
1914                         if (get_sha1_hex(line+1, sha1))
1915                                 die("expected edge sha1, got garbage:\n %s",
1916                                     line);
1917                         add_preferred_base(sha1);
1918                         continue;
1919                 }
1920                 if (get_sha1_hex(line, sha1))
1921                         die("expected sha1, got garbage:\n %s", line);
1922
1923                 add_preferred_base_object(line+41);
1924                 add_object_entry(sha1, 0, line+41, 0);
1925         }
1926 }
1927
1928 #define OBJECT_ADDED (1u<<20)
1929
1930 static void show_commit(struct commit *commit, void *data)
1931 {
1932         add_object_entry(commit->object.sha1, OBJ_COMMIT, NULL, 0);
1933         commit->object.flags |= OBJECT_ADDED;
1934 }
1935
1936 static void show_object(struct object *obj, const struct name_path *path, const char *last)
1937 {
1938         char *name = path_name(path, last);
1939
1940         add_preferred_base_object(name);
1941         add_object_entry(obj->sha1, obj->type, name, 0);
1942         obj->flags |= OBJECT_ADDED;
1943
1944         /*
1945          * We will have generated the hash from the name,
1946          * but not saved a pointer to it - we can free it
1947          */
1948         free((char *)name);
1949 }
1950
1951 static void show_edge(struct commit *commit)
1952 {
1953         add_preferred_base(commit->object.sha1);
1954 }
1955
1956 struct in_pack_object {
1957         off_t offset;
1958         struct object *object;
1959 };
1960
1961 struct in_pack {
1962         int alloc;
1963         int nr;
1964         struct in_pack_object *array;
1965 };
1966
1967 static void mark_in_pack_object(struct object *object, struct packed_git *p, struct in_pack *in_pack)
1968 {
1969         in_pack->array[in_pack->nr].offset = find_pack_entry_one(object->sha1, p);
1970         in_pack->array[in_pack->nr].object = object;
1971         in_pack->nr++;
1972 }
1973
1974 /*
1975  * Compare the objects in the offset order, in order to emulate the
1976  * "git rev-list --objects" output that produced the pack originally.
1977  */
1978 static int ofscmp(const void *a_, const void *b_)
1979 {
1980         struct in_pack_object *a = (struct in_pack_object *)a_;
1981         struct in_pack_object *b = (struct in_pack_object *)b_;
1982
1983         if (a->offset < b->offset)
1984                 return -1;
1985         else if (a->offset > b->offset)
1986                 return 1;
1987         else
1988                 return hashcmp(a->object->sha1, b->object->sha1);
1989 }
1990
1991 static void add_objects_in_unpacked_packs(struct rev_info *revs)
1992 {
1993         struct packed_git *p;
1994         struct in_pack in_pack;
1995         uint32_t i;
1996
1997         memset(&in_pack, 0, sizeof(in_pack));
1998
1999         for (p = packed_git; p; p = p->next) {
2000                 const unsigned char *sha1;
2001                 struct object *o;
2002
2003                 if (!p->pack_local || p->pack_keep)
2004                         continue;
2005                 if (open_pack_index(p))
2006                         die("cannot open pack index");
2007
2008                 ALLOC_GROW(in_pack.array,
2009                            in_pack.nr + p->num_objects,
2010                            in_pack.alloc);
2011
2012                 for (i = 0; i < p->num_objects; i++) {
2013                         sha1 = nth_packed_object_sha1(p, i);
2014                         o = lookup_unknown_object(sha1);
2015                         if (!(o->flags & OBJECT_ADDED))
2016                                 mark_in_pack_object(o, p, &in_pack);
2017                         o->flags |= OBJECT_ADDED;
2018                 }
2019         }
2020
2021         if (in_pack.nr) {
2022                 qsort(in_pack.array, in_pack.nr, sizeof(in_pack.array[0]),
2023                       ofscmp);
2024                 for (i = 0; i < in_pack.nr; i++) {
2025                         struct object *o = in_pack.array[i].object;
2026                         add_object_entry(o->sha1, o->type, "", 0);
2027                 }
2028         }
2029         free(in_pack.array);
2030 }
2031
2032 static int has_sha1_pack_kept_or_nonlocal(const unsigned char *sha1)
2033 {
2034         static struct packed_git *last_found = (void *)1;
2035         struct packed_git *p;
2036
2037         p = (last_found != (void *)1) ? last_found : packed_git;
2038
2039         while (p) {
2040                 if ((!p->pack_local || p->pack_keep) &&
2041                         find_pack_entry_one(sha1, p)) {
2042                         last_found = p;
2043                         return 1;
2044                 }
2045                 if (p == last_found)
2046                         p = packed_git;
2047                 else
2048                         p = p->next;
2049                 if (p == last_found)
2050                         p = p->next;
2051         }
2052         return 0;
2053 }
2054
2055 static void loosen_unused_packed_objects(struct rev_info *revs)
2056 {
2057         struct packed_git *p;
2058         uint32_t i;
2059         const unsigned char *sha1;
2060
2061         for (p = packed_git; p; p = p->next) {
2062                 if (!p->pack_local || p->pack_keep)
2063                         continue;
2064
2065                 if (open_pack_index(p))
2066                         die("cannot open pack index");
2067
2068                 for (i = 0; i < p->num_objects; i++) {
2069                         sha1 = nth_packed_object_sha1(p, i);
2070                         if (!locate_object_entry(sha1) &&
2071                                 !has_sha1_pack_kept_or_nonlocal(sha1))
2072                                 if (force_object_loose(sha1, p->mtime))
2073                                         die("unable to force loose object");
2074                 }
2075         }
2076 }
2077
2078 static void get_object_list(int ac, const char **av)
2079 {
2080         struct rev_info revs;
2081         char line[1000];
2082         int flags = 0;
2083
2084         init_revisions(&revs, NULL);
2085         save_commit_buffer = 0;
2086         setup_revisions(ac, av, &revs, NULL);
2087
2088         while (fgets(line, sizeof(line), stdin) != NULL) {
2089                 int len = strlen(line);
2090                 if (len && line[len - 1] == '\n')
2091                         line[--len] = 0;
2092                 if (!len)
2093                         break;
2094                 if (*line == '-') {
2095                         if (!strcmp(line, "--not")) {
2096                                 flags ^= UNINTERESTING;
2097                                 continue;
2098                         }
2099                         die("not a rev '%s'", line);
2100                 }
2101                 if (handle_revision_arg(line, &revs, flags, 1))
2102                         die("bad revision '%s'", line);
2103         }
2104
2105         if (prepare_revision_walk(&revs))
2106                 die("revision walk setup failed");
2107         mark_edges_uninteresting(revs.commits, &revs, show_edge);
2108         traverse_commit_list(&revs, show_commit, show_object, NULL);
2109
2110         if (keep_unreachable)
2111                 add_objects_in_unpacked_packs(&revs);
2112         if (unpack_unreachable)
2113                 loosen_unused_packed_objects(&revs);
2114 }
2115
2116 static int adjust_perm(const char *path, mode_t mode)
2117 {
2118         if (chmod(path, mode))
2119                 return -1;
2120         return adjust_shared_perm(path);
2121 }
2122
2123 int cmd_pack_objects(int argc, const char **argv, const char *prefix)
2124 {
2125         int use_internal_rev_list = 0;
2126         int thin = 0;
2127         uint32_t i;
2128         const char **rp_av;
2129         int rp_ac_alloc = 64;
2130         int rp_ac;
2131
2132         read_replace_refs = 0;
2133
2134         rp_av = xcalloc(rp_ac_alloc, sizeof(*rp_av));
2135
2136         rp_av[0] = "pack-objects";
2137         rp_av[1] = "--objects"; /* --thin will make it --objects-edge */
2138         rp_ac = 2;
2139
2140         git_config(git_pack_config, NULL);
2141         if (!pack_compression_seen && core_compression_seen)
2142                 pack_compression_level = core_compression_level;
2143
2144         progress = isatty(2);
2145         for (i = 1; i < argc; i++) {
2146                 const char *arg = argv[i];
2147
2148                 if (*arg != '-')
2149                         break;
2150
2151                 if (!strcmp("--non-empty", arg)) {
2152                         non_empty = 1;
2153                         continue;
2154                 }
2155                 if (!strcmp("--local", arg)) {
2156                         local = 1;
2157                         continue;
2158                 }
2159                 if (!strcmp("--incremental", arg)) {
2160                         incremental = 1;
2161                         continue;
2162                 }
2163                 if (!strcmp("--honor-pack-keep", arg)) {
2164                         ignore_packed_keep = 1;
2165                         continue;
2166                 }
2167                 if (!prefixcmp(arg, "--compression=")) {
2168                         char *end;
2169                         int level = strtoul(arg+14, &end, 0);
2170                         if (!arg[14] || *end)
2171                                 usage(pack_usage);
2172                         if (level == -1)
2173                                 level = Z_DEFAULT_COMPRESSION;
2174                         else if (level < 0 || level > Z_BEST_COMPRESSION)
2175                                 die("bad pack compression level %d", level);
2176                         pack_compression_level = level;
2177                         continue;
2178                 }
2179                 if (!prefixcmp(arg, "--max-pack-size=")) {
2180                         char *end;
2181                         pack_size_limit_cfg = 0;
2182                         pack_size_limit = strtoul(arg+16, &end, 0) * 1024 * 1024;
2183                         if (!arg[16] || *end)
2184                                 usage(pack_usage);
2185                         continue;
2186                 }
2187                 if (!prefixcmp(arg, "--window=")) {
2188                         char *end;
2189                         window = strtoul(arg+9, &end, 0);
2190                         if (!arg[9] || *end)
2191                                 usage(pack_usage);
2192                         continue;
2193                 }
2194                 if (!prefixcmp(arg, "--window-memory=")) {
2195                         if (!git_parse_ulong(arg+16, &window_memory_limit))
2196                                 usage(pack_usage);
2197                         continue;
2198                 }
2199                 if (!prefixcmp(arg, "--threads=")) {
2200                         char *end;
2201                         delta_search_threads = strtoul(arg+10, &end, 0);
2202                         if (!arg[10] || *end || delta_search_threads < 0)
2203                                 usage(pack_usage);
2204 #ifndef THREADED_DELTA_SEARCH
2205                         if (delta_search_threads != 1)
2206                                 warning("no threads support, "
2207                                         "ignoring %s", arg);
2208 #endif
2209                         continue;
2210                 }
2211                 if (!prefixcmp(arg, "--depth=")) {
2212                         char *end;
2213                         depth = strtoul(arg+8, &end, 0);
2214                         if (!arg[8] || *end)
2215                                 usage(pack_usage);
2216                         continue;
2217                 }
2218                 if (!strcmp("--progress", arg)) {
2219                         progress = 1;
2220                         continue;
2221                 }
2222                 if (!strcmp("--all-progress", arg)) {
2223                         progress = 2;
2224                         continue;
2225                 }
2226                 if (!strcmp("-q", arg)) {
2227                         progress = 0;
2228                         continue;
2229                 }
2230                 if (!strcmp("--no-reuse-delta", arg)) {
2231                         reuse_delta = 0;
2232                         continue;
2233                 }
2234                 if (!strcmp("--no-reuse-object", arg)) {
2235                         reuse_object = reuse_delta = 0;
2236                         continue;
2237                 }
2238                 if (!strcmp("--delta-base-offset", arg)) {
2239                         allow_ofs_delta = 1;
2240                         continue;
2241                 }
2242                 if (!strcmp("--stdout", arg)) {
2243                         pack_to_stdout = 1;
2244                         continue;
2245                 }
2246                 if (!strcmp("--revs", arg)) {
2247                         use_internal_rev_list = 1;
2248                         continue;
2249                 }
2250                 if (!strcmp("--keep-unreachable", arg)) {
2251                         keep_unreachable = 1;
2252                         continue;
2253                 }
2254                 if (!strcmp("--unpack-unreachable", arg)) {
2255                         unpack_unreachable = 1;
2256                         continue;
2257                 }
2258                 if (!strcmp("--include-tag", arg)) {
2259                         include_tag = 1;
2260                         continue;
2261                 }
2262                 if (!strcmp("--unpacked", arg) ||
2263                     !strcmp("--reflog", arg) ||
2264                     !strcmp("--all", arg)) {
2265                         use_internal_rev_list = 1;
2266                         if (rp_ac >= rp_ac_alloc - 1) {
2267                                 rp_ac_alloc = alloc_nr(rp_ac_alloc);
2268                                 rp_av = xrealloc(rp_av,
2269                                                  rp_ac_alloc * sizeof(*rp_av));
2270                         }
2271                         rp_av[rp_ac++] = arg;
2272                         continue;
2273                 }
2274                 if (!strcmp("--thin", arg)) {
2275                         use_internal_rev_list = 1;
2276                         thin = 1;
2277                         rp_av[1] = "--objects-edge";
2278                         continue;
2279                 }
2280                 if (!prefixcmp(arg, "--index-version=")) {
2281                         char *c;
2282                         pack_idx_default_version = strtoul(arg + 16, &c, 10);
2283                         if (pack_idx_default_version > 2)
2284                                 die("bad %s", arg);
2285                         if (*c == ',')
2286                                 pack_idx_off32_limit = strtoul(c+1, &c, 0);
2287                         if (*c || pack_idx_off32_limit & 0x80000000)
2288                                 die("bad %s", arg);
2289                         continue;
2290                 }
2291                 if (!strcmp(arg, "--keep-true-parents")) {
2292                         grafts_replace_parents = 0;
2293                         continue;
2294                 }
2295                 usage(pack_usage);
2296         }
2297
2298         /* Traditionally "pack-objects [options] base extra" failed;
2299          * we would however want to take refs parameter that would
2300          * have been given to upstream rev-list ourselves, which means
2301          * we somehow want to say what the base name is.  So the
2302          * syntax would be:
2303          *
2304          * pack-objects [options] base <refs...>
2305          *
2306          * in other words, we would treat the first non-option as the
2307          * base_name and send everything else to the internal revision
2308          * walker.
2309          */
2310
2311         if (!pack_to_stdout)
2312                 base_name = argv[i++];
2313
2314         if (pack_to_stdout != !base_name)
2315                 usage(pack_usage);
2316
2317         if (!pack_to_stdout && !pack_size_limit)
2318                 pack_size_limit = pack_size_limit_cfg;
2319
2320         if (pack_to_stdout && pack_size_limit)
2321                 die("--max-pack-size cannot be used to build a pack for transfer.");
2322
2323         if (!pack_to_stdout && thin)
2324                 die("--thin cannot be used to build an indexable pack.");
2325
2326         if (keep_unreachable && unpack_unreachable)
2327                 die("--keep-unreachable and --unpack-unreachable are incompatible.");
2328
2329         prepare_packed_git();
2330
2331         if (progress)
2332                 progress_state = start_progress("Counting objects", 0);
2333         if (!use_internal_rev_list)
2334                 read_object_list_from_stdin();
2335         else {
2336                 rp_av[rp_ac] = NULL;
2337                 get_object_list(rp_ac, rp_av);
2338         }
2339         cleanup_preferred_base();
2340         if (include_tag && nr_result)
2341                 for_each_ref(add_ref_tag, NULL);
2342         stop_progress(&progress_state);
2343
2344         if (non_empty && !nr_result)
2345                 return 0;
2346         if (nr_result)
2347                 prepare_pack(window, depth);
2348         write_pack_file();
2349         if (progress)
2350                 fprintf(stderr, "Total %"PRIu32" (delta %"PRIu32"),"
2351                         " reused %"PRIu32" (delta %"PRIu32")\n",
2352                         written, written_delta, reused, reused_delta);
2353         return 0;
2354 }