Merge branch 'maint-1.7.0' into maint-1.7.1
[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 #ifndef NO_PTHREADS
21 #include <pthread.h>
22 #include "thread-utils.h"
23 #endif
24
25 static const char pack_usage[] =
26   "git pack-objects [{ -q | --progress | --all-progress }]\n"
27   "        [--all-progress-implied]\n"
28   "        [--max-pack-size=N] [--local] [--incremental]\n"
29   "        [--window=N] [--window-memory=N] [--depth=N]\n"
30   "        [--no-reuse-delta] [--no-reuse-object] [--delta-base-offset]\n"
31   "        [--threads=N] [--non-empty] [--revs [--unpacked | --all]*]\n"
32   "        [--reflog] [--stdout | base-name] [--include-tag]\n"
33   "        [--keep-unreachable | --unpack-unreachable \n"
34   "        [<ref-list | <object-list]";
35
36 struct object_entry {
37         struct pack_idx_entry idx;
38         unsigned long size;     /* uncompressed size */
39         struct packed_git *in_pack;     /* already in pack */
40         off_t in_pack_offset;
41         struct object_entry *delta;     /* delta base object */
42         struct object_entry *delta_child; /* deltified objects who bases me */
43         struct object_entry *delta_sibling; /* other deltified objects who
44                                              * uses the same base as me
45                                              */
46         void *delta_data;       /* cached delta (uncompressed) */
47         unsigned long delta_size;       /* delta data size (uncompressed) */
48         unsigned long z_delta_size;     /* delta data size (compressed) */
49         unsigned int hash;      /* name hint hash */
50         enum object_type type;
51         enum object_type in_pack_type;  /* could be delta */
52         unsigned char in_pack_header_size;
53         unsigned char preferred_base; /* we do not pack this, but is available
54                                        * to be used as the base object to delta
55                                        * objects against.
56                                        */
57         unsigned char no_try_delta;
58 };
59
60 /*
61  * Objects we are going to pack are collected in objects array (dynamically
62  * expanded).  nr_objects & nr_alloc controls this array.  They are stored
63  * in the order we see -- typically rev-list --objects order that gives us
64  * nice "minimum seek" order.
65  */
66 static struct object_entry *objects;
67 static struct pack_idx_entry **written_list;
68 static uint32_t nr_objects, nr_alloc, nr_result, nr_written;
69
70 static int non_empty;
71 static int reuse_delta = 1, reuse_object = 1;
72 static int keep_unreachable, unpack_unreachable, include_tag;
73 static int local;
74 static int incremental;
75 static int ignore_packed_keep;
76 static int allow_ofs_delta;
77 static const char *base_name;
78 static int progress = 1;
79 static int window = 10;
80 static unsigned long pack_size_limit, pack_size_limit_cfg;
81 static int depth = 50;
82 static int delta_search_threads;
83 static int pack_to_stdout;
84 static int num_preferred_base;
85 static struct progress *progress_state;
86 static int pack_compression_level = Z_DEFAULT_COMPRESSION;
87 static int pack_compression_seen;
88
89 static unsigned long delta_cache_size = 0;
90 static unsigned long max_delta_cache_size = 256 * 1024 * 1024;
91 static unsigned long cache_max_small_delta_size = 1000;
92
93 static unsigned long window_memory_limit = 0;
94
95 /*
96  * The object names in objects array are hashed with this hashtable,
97  * to help looking up the entry by object name.
98  * This hashtable is built after all the objects are seen.
99  */
100 static int *object_ix;
101 static int object_ix_hashsz;
102
103 /*
104  * stats
105  */
106 static uint32_t written, written_delta;
107 static uint32_t reused, reused_delta;
108
109
110 static void *get_delta(struct object_entry *entry)
111 {
112         unsigned long size, base_size, delta_size;
113         void *buf, *base_buf, *delta_buf;
114         enum object_type type;
115
116         buf = read_sha1_file(entry->idx.sha1, &type, &size);
117         if (!buf)
118                 die("unable to read %s", sha1_to_hex(entry->idx.sha1));
119         base_buf = read_sha1_file(entry->delta->idx.sha1, &type, &base_size);
120         if (!base_buf)
121                 die("unable to read %s", sha1_to_hex(entry->delta->idx.sha1));
122         delta_buf = diff_delta(base_buf, base_size,
123                                buf, size, &delta_size, 0);
124         if (!delta_buf || delta_size != entry->delta_size)
125                 die("delta size changed");
126         free(buf);
127         free(base_buf);
128         return delta_buf;
129 }
130
131 static unsigned long do_compress(void **pptr, unsigned long size)
132 {
133         z_stream stream;
134         void *in, *out;
135         unsigned long maxsize;
136
137         memset(&stream, 0, sizeof(stream));
138         deflateInit(&stream, pack_compression_level);
139         maxsize = deflateBound(&stream, size);
140
141         in = *pptr;
142         out = xmalloc(maxsize);
143         *pptr = out;
144
145         stream.next_in = in;
146         stream.avail_in = size;
147         stream.next_out = out;
148         stream.avail_out = maxsize;
149         while (deflate(&stream, Z_FINISH) == Z_OK)
150                 ; /* nothing */
151         deflateEnd(&stream);
152
153         free(in);
154         return stream.total_out;
155 }
156
157 /*
158  * we are going to reuse the existing object data as is.  make
159  * sure it is not corrupt.
160  */
161 static int check_pack_inflate(struct packed_git *p,
162                 struct pack_window **w_curs,
163                 off_t offset,
164                 off_t len,
165                 unsigned long expect)
166 {
167         z_stream stream;
168         unsigned char fakebuf[4096], *in;
169         int st;
170
171         memset(&stream, 0, sizeof(stream));
172         git_inflate_init(&stream);
173         do {
174                 in = use_pack(p, w_curs, offset, &stream.avail_in);
175                 stream.next_in = in;
176                 stream.next_out = fakebuf;
177                 stream.avail_out = sizeof(fakebuf);
178                 st = git_inflate(&stream, Z_FINISH);
179                 offset += stream.next_in - in;
180         } while (st == Z_OK || st == Z_BUF_ERROR);
181         git_inflate_end(&stream);
182         return (st == Z_STREAM_END &&
183                 stream.total_out == expect &&
184                 stream.total_in == len) ? 0 : -1;
185 }
186
187 static void copy_pack_data(struct sha1file *f,
188                 struct packed_git *p,
189                 struct pack_window **w_curs,
190                 off_t offset,
191                 off_t len)
192 {
193         unsigned char *in;
194         unsigned int avail;
195
196         while (len) {
197                 in = use_pack(p, w_curs, offset, &avail);
198                 if (avail > len)
199                         avail = (unsigned int)len;
200                 sha1write(f, in, avail);
201                 offset += avail;
202                 len -= avail;
203         }
204 }
205
206 static unsigned long write_object(struct sha1file *f,
207                                   struct object_entry *entry,
208                                   off_t write_offset)
209 {
210         unsigned long size, limit, datalen;
211         void *buf;
212         unsigned char header[10], dheader[10];
213         unsigned hdrlen;
214         enum object_type type;
215         int usable_delta, to_reuse;
216
217         if (!pack_to_stdout)
218                 crc32_begin(f);
219
220         type = entry->type;
221
222         /* apply size limit if limited packsize and not first object */
223         if (!pack_size_limit || !nr_written)
224                 limit = 0;
225         else if (pack_size_limit <= write_offset)
226                 /*
227                  * the earlier object did not fit the limit; avoid
228                  * mistaking this with unlimited (i.e. limit = 0).
229                  */
230                 limit = 1;
231         else
232                 limit = pack_size_limit - write_offset;
233
234         if (!entry->delta)
235                 usable_delta = 0;       /* no delta */
236         else if (!pack_size_limit)
237                usable_delta = 1;        /* unlimited packfile */
238         else if (entry->delta->idx.offset == (off_t)-1)
239                 usable_delta = 0;       /* base was written to another pack */
240         else if (entry->delta->idx.offset)
241                 usable_delta = 1;       /* base already exists in this pack */
242         else
243                 usable_delta = 0;       /* base could end up in another pack */
244
245         if (!reuse_object)
246                 to_reuse = 0;   /* explicit */
247         else if (!entry->in_pack)
248                 to_reuse = 0;   /* can't reuse what we don't have */
249         else if (type == OBJ_REF_DELTA || type == OBJ_OFS_DELTA)
250                                 /* check_object() decided it for us ... */
251                 to_reuse = usable_delta;
252                                 /* ... but pack split may override that */
253         else if (type != entry->in_pack_type)
254                 to_reuse = 0;   /* pack has delta which is unusable */
255         else if (entry->delta)
256                 to_reuse = 0;   /* we want to pack afresh */
257         else
258                 to_reuse = 1;   /* we have it in-pack undeltified,
259                                  * and we do not need to deltify it.
260                                  */
261
262         if (!to_reuse) {
263                 no_reuse:
264                 if (!usable_delta) {
265                         buf = read_sha1_file(entry->idx.sha1, &type, &size);
266                         if (!buf)
267                                 die("unable to read %s", sha1_to_hex(entry->idx.sha1));
268                         /*
269                          * make sure no cached delta data remains from a
270                          * previous attempt before a pack split occurred.
271                          */
272                         free(entry->delta_data);
273                         entry->delta_data = NULL;
274                         entry->z_delta_size = 0;
275                 } else if (entry->delta_data) {
276                         size = entry->delta_size;
277                         buf = entry->delta_data;
278                         entry->delta_data = NULL;
279                         type = (allow_ofs_delta && entry->delta->idx.offset) ?
280                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
281                 } else {
282                         buf = get_delta(entry);
283                         size = entry->delta_size;
284                         type = (allow_ofs_delta && entry->delta->idx.offset) ?
285                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
286                 }
287
288                 if (entry->z_delta_size)
289                         datalen = entry->z_delta_size;
290                 else
291                         datalen = do_compress(&buf, size);
292
293                 /*
294                  * The object header is a byte of 'type' followed by zero or
295                  * more bytes of length.
296                  */
297                 hdrlen = encode_in_pack_object_header(type, size, header);
298
299                 if (type == OBJ_OFS_DELTA) {
300                         /*
301                          * Deltas with relative base contain an additional
302                          * encoding of the relative offset for the delta
303                          * base from this object's position in the pack.
304                          */
305                         off_t ofs = entry->idx.offset - entry->delta->idx.offset;
306                         unsigned pos = sizeof(dheader) - 1;
307                         dheader[pos] = ofs & 127;
308                         while (ofs >>= 7)
309                                 dheader[--pos] = 128 | (--ofs & 127);
310                         if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit) {
311                                 free(buf);
312                                 return 0;
313                         }
314                         sha1write(f, header, hdrlen);
315                         sha1write(f, dheader + pos, sizeof(dheader) - pos);
316                         hdrlen += sizeof(dheader) - pos;
317                 } else if (type == OBJ_REF_DELTA) {
318                         /*
319                          * Deltas with a base reference contain
320                          * an additional 20 bytes for the base sha1.
321                          */
322                         if (limit && hdrlen + 20 + datalen + 20 >= limit) {
323                                 free(buf);
324                                 return 0;
325                         }
326                         sha1write(f, header, hdrlen);
327                         sha1write(f, entry->delta->idx.sha1, 20);
328                         hdrlen += 20;
329                 } else {
330                         if (limit && hdrlen + datalen + 20 >= limit) {
331                                 free(buf);
332                                 return 0;
333                         }
334                         sha1write(f, header, hdrlen);
335                 }
336                 sha1write(f, buf, datalen);
337                 free(buf);
338         }
339         else {
340                 struct packed_git *p = entry->in_pack;
341                 struct pack_window *w_curs = NULL;
342                 struct revindex_entry *revidx;
343                 off_t offset;
344
345                 if (entry->delta)
346                         type = (allow_ofs_delta && entry->delta->idx.offset) ?
347                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
348                 hdrlen = encode_in_pack_object_header(type, entry->size, header);
349
350                 offset = entry->in_pack_offset;
351                 revidx = find_pack_revindex(p, offset);
352                 datalen = revidx[1].offset - offset;
353                 if (!pack_to_stdout && p->index_version > 1 &&
354                     check_pack_crc(p, &w_curs, offset, datalen, revidx->nr)) {
355                         error("bad packed object CRC for %s", sha1_to_hex(entry->idx.sha1));
356                         unuse_pack(&w_curs);
357                         goto no_reuse;
358                 }
359
360                 offset += entry->in_pack_header_size;
361                 datalen -= entry->in_pack_header_size;
362                 if (!pack_to_stdout && p->index_version == 1 &&
363                     check_pack_inflate(p, &w_curs, offset, datalen, entry->size)) {
364                         error("corrupt packed object for %s", sha1_to_hex(entry->idx.sha1));
365                         unuse_pack(&w_curs);
366                         goto no_reuse;
367                 }
368
369                 if (type == OBJ_OFS_DELTA) {
370                         off_t ofs = entry->idx.offset - entry->delta->idx.offset;
371                         unsigned pos = sizeof(dheader) - 1;
372                         dheader[pos] = ofs & 127;
373                         while (ofs >>= 7)
374                                 dheader[--pos] = 128 | (--ofs & 127);
375                         if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit) {
376                                 unuse_pack(&w_curs);
377                                 return 0;
378                         }
379                         sha1write(f, header, hdrlen);
380                         sha1write(f, dheader + pos, sizeof(dheader) - pos);
381                         hdrlen += sizeof(dheader) - pos;
382                         reused_delta++;
383                 } else if (type == OBJ_REF_DELTA) {
384                         if (limit && hdrlen + 20 + datalen + 20 >= limit) {
385                                 unuse_pack(&w_curs);
386                                 return 0;
387                         }
388                         sha1write(f, header, hdrlen);
389                         sha1write(f, entry->delta->idx.sha1, 20);
390                         hdrlen += 20;
391                         reused_delta++;
392                 } else {
393                         if (limit && hdrlen + datalen + 20 >= limit) {
394                                 unuse_pack(&w_curs);
395                                 return 0;
396                         }
397                         sha1write(f, header, hdrlen);
398                 }
399                 copy_pack_data(f, p, &w_curs, offset, datalen);
400                 unuse_pack(&w_curs);
401                 reused++;
402         }
403         if (usable_delta)
404                 written_delta++;
405         written++;
406         if (!pack_to_stdout)
407                 entry->idx.crc32 = crc32_end(f);
408         return hdrlen + datalen;
409 }
410
411 static int write_one(struct sha1file *f,
412                                struct object_entry *e,
413                                off_t *offset)
414 {
415         unsigned long size;
416
417         /* offset is non zero if object is written already. */
418         if (e->idx.offset || e->preferred_base)
419                 return -1;
420
421         /* if we are deltified, write out base object first. */
422         if (e->delta && !write_one(f, e->delta, offset))
423                 return 0;
424
425         e->idx.offset = *offset;
426         size = write_object(f, e, *offset);
427         if (!size) {
428                 e->idx.offset = 0;
429                 return 0;
430         }
431         written_list[nr_written++] = &e->idx;
432
433         /* make sure off_t is sufficiently large not to wrap */
434         if (*offset > *offset + size)
435                 die("pack too large for current definition of off_t");
436         *offset += size;
437         return 1;
438 }
439
440 static void write_pack_file(void)
441 {
442         uint32_t i = 0, j;
443         struct sha1file *f;
444         off_t offset;
445         struct pack_header hdr;
446         uint32_t nr_remaining = nr_result;
447         time_t last_mtime = 0;
448
449         if (progress > pack_to_stdout)
450                 progress_state = start_progress("Writing objects", nr_result);
451         written_list = xmalloc(nr_objects * sizeof(*written_list));
452
453         do {
454                 unsigned char sha1[20];
455                 char *pack_tmp_name = NULL;
456
457                 if (pack_to_stdout) {
458                         f = sha1fd_throughput(1, "<stdout>", progress_state);
459                 } else {
460                         char tmpname[PATH_MAX];
461                         int fd;
462                         fd = odb_mkstemp(tmpname, sizeof(tmpname),
463                                          "pack/tmp_pack_XXXXXX");
464                         pack_tmp_name = xstrdup(tmpname);
465                         f = sha1fd(fd, pack_tmp_name);
466                 }
467
468                 hdr.hdr_signature = htonl(PACK_SIGNATURE);
469                 hdr.hdr_version = htonl(PACK_VERSION);
470                 hdr.hdr_entries = htonl(nr_remaining);
471                 sha1write(f, &hdr, sizeof(hdr));
472                 offset = sizeof(hdr);
473                 nr_written = 0;
474                 for (; i < nr_objects; i++) {
475                         if (!write_one(f, objects + i, &offset))
476                                 break;
477                         display_progress(progress_state, written);
478                 }
479
480                 /*
481                  * Did we write the wrong # entries in the header?
482                  * If so, rewrite it like in fast-import
483                  */
484                 if (pack_to_stdout) {
485                         sha1close(f, sha1, CSUM_CLOSE);
486                 } else if (nr_written == nr_remaining) {
487                         sha1close(f, sha1, CSUM_FSYNC);
488                 } else {
489                         int fd = sha1close(f, sha1, 0);
490                         fixup_pack_header_footer(fd, sha1, pack_tmp_name,
491                                                  nr_written, sha1, offset);
492                         close(fd);
493                 }
494
495                 if (!pack_to_stdout) {
496                         struct stat st;
497                         const char *idx_tmp_name;
498                         char tmpname[PATH_MAX];
499
500                         idx_tmp_name = write_idx_file(NULL, written_list,
501                                                       nr_written, sha1);
502
503                         snprintf(tmpname, sizeof(tmpname), "%s-%s.pack",
504                                  base_name, sha1_to_hex(sha1));
505                         free_pack_by_name(tmpname);
506                         if (adjust_shared_perm(pack_tmp_name))
507                                 die_errno("unable to make temporary pack file readable");
508                         if (rename(pack_tmp_name, tmpname))
509                                 die_errno("unable to rename temporary pack file");
510
511                         /*
512                          * Packs are runtime accessed in their mtime
513                          * order since newer packs are more likely to contain
514                          * younger objects.  So if we are creating multiple
515                          * packs then we should modify the mtime of later ones
516                          * to preserve this property.
517                          */
518                         if (stat(tmpname, &st) < 0) {
519                                 warning("failed to stat %s: %s",
520                                         tmpname, strerror(errno));
521                         } else if (!last_mtime) {
522                                 last_mtime = st.st_mtime;
523                         } else {
524                                 struct utimbuf utb;
525                                 utb.actime = st.st_atime;
526                                 utb.modtime = --last_mtime;
527                                 if (utime(tmpname, &utb) < 0)
528                                         warning("failed utime() on %s: %s",
529                                                 tmpname, strerror(errno));
530                         }
531
532                         snprintf(tmpname, sizeof(tmpname), "%s-%s.idx",
533                                  base_name, sha1_to_hex(sha1));
534                         if (adjust_shared_perm(idx_tmp_name))
535                                 die_errno("unable to make temporary index file readable");
536                         if (rename(idx_tmp_name, tmpname))
537                                 die_errno("unable to rename temporary index file");
538
539                         free((void *) idx_tmp_name);
540                         free(pack_tmp_name);
541                         puts(sha1_to_hex(sha1));
542                 }
543
544                 /* mark written objects as written to previous pack */
545                 for (j = 0; j < nr_written; j++) {
546                         written_list[j]->offset = (off_t)-1;
547                 }
548                 nr_remaining -= nr_written;
549         } while (nr_remaining && i < nr_objects);
550
551         free(written_list);
552         stop_progress(&progress_state);
553         if (written != nr_result)
554                 die("wrote %"PRIu32" objects while expecting %"PRIu32,
555                         written, nr_result);
556 }
557
558 static int locate_object_entry_hash(const unsigned char *sha1)
559 {
560         int i;
561         unsigned int ui;
562         memcpy(&ui, sha1, sizeof(unsigned int));
563         i = ui % object_ix_hashsz;
564         while (0 < object_ix[i]) {
565                 if (!hashcmp(sha1, objects[object_ix[i] - 1].idx.sha1))
566                         return i;
567                 if (++i == object_ix_hashsz)
568                         i = 0;
569         }
570         return -1 - i;
571 }
572
573 static struct object_entry *locate_object_entry(const unsigned char *sha1)
574 {
575         int i;
576
577         if (!object_ix_hashsz)
578                 return NULL;
579
580         i = locate_object_entry_hash(sha1);
581         if (0 <= i)
582                 return &objects[object_ix[i]-1];
583         return NULL;
584 }
585
586 static void rehash_objects(void)
587 {
588         uint32_t i;
589         struct object_entry *oe;
590
591         object_ix_hashsz = nr_objects * 3;
592         if (object_ix_hashsz < 1024)
593                 object_ix_hashsz = 1024;
594         object_ix = xrealloc(object_ix, sizeof(int) * object_ix_hashsz);
595         memset(object_ix, 0, sizeof(int) * object_ix_hashsz);
596         for (i = 0, oe = objects; i < nr_objects; i++, oe++) {
597                 int ix = locate_object_entry_hash(oe->idx.sha1);
598                 if (0 <= ix)
599                         continue;
600                 ix = -1 - ix;
601                 object_ix[ix] = i + 1;
602         }
603 }
604
605 static unsigned name_hash(const char *name)
606 {
607         unsigned c, hash = 0;
608
609         if (!name)
610                 return 0;
611
612         /*
613          * This effectively just creates a sortable number from the
614          * last sixteen non-whitespace characters. Last characters
615          * count "most", so things that end in ".c" sort together.
616          */
617         while ((c = *name++) != 0) {
618                 if (isspace(c))
619                         continue;
620                 hash = (hash >> 2) + (c << 24);
621         }
622         return hash;
623 }
624
625 static void setup_delta_attr_check(struct git_attr_check *check)
626 {
627         static struct git_attr *attr_delta;
628
629         if (!attr_delta)
630                 attr_delta = git_attr("delta");
631
632         check[0].attr = attr_delta;
633 }
634
635 static int no_try_delta(const char *path)
636 {
637         struct git_attr_check check[1];
638
639         setup_delta_attr_check(check);
640         if (git_checkattr(path, ARRAY_SIZE(check), check))
641                 return 0;
642         if (ATTR_FALSE(check->value))
643                 return 1;
644         return 0;
645 }
646
647 static int add_object_entry(const unsigned char *sha1, enum object_type type,
648                             const char *name, int exclude)
649 {
650         struct object_entry *entry;
651         struct packed_git *p, *found_pack = NULL;
652         off_t found_offset = 0;
653         int ix;
654         unsigned hash = name_hash(name);
655
656         ix = nr_objects ? locate_object_entry_hash(sha1) : -1;
657         if (ix >= 0) {
658                 if (exclude) {
659                         entry = objects + object_ix[ix] - 1;
660                         if (!entry->preferred_base)
661                                 nr_result--;
662                         entry->preferred_base = 1;
663                 }
664                 return 0;
665         }
666
667         if (!exclude && local && has_loose_object_nonlocal(sha1))
668                 return 0;
669
670         for (p = packed_git; p; p = p->next) {
671                 off_t offset = find_pack_entry_one(sha1, p);
672                 if (offset) {
673                         if (!found_pack) {
674                                 found_offset = offset;
675                                 found_pack = p;
676                         }
677                         if (exclude)
678                                 break;
679                         if (incremental)
680                                 return 0;
681                         if (local && !p->pack_local)
682                                 return 0;
683                         if (ignore_packed_keep && p->pack_local && p->pack_keep)
684                                 return 0;
685                 }
686         }
687
688         if (nr_objects >= nr_alloc) {
689                 nr_alloc = (nr_alloc  + 1024) * 3 / 2;
690                 objects = xrealloc(objects, nr_alloc * sizeof(*entry));
691         }
692
693         entry = objects + nr_objects++;
694         memset(entry, 0, sizeof(*entry));
695         hashcpy(entry->idx.sha1, sha1);
696         entry->hash = hash;
697         if (type)
698                 entry->type = type;
699         if (exclude)
700                 entry->preferred_base = 1;
701         else
702                 nr_result++;
703         if (found_pack) {
704                 entry->in_pack = found_pack;
705                 entry->in_pack_offset = found_offset;
706         }
707
708         if (object_ix_hashsz * 3 <= nr_objects * 4)
709                 rehash_objects();
710         else
711                 object_ix[-1 - ix] = nr_objects;
712
713         display_progress(progress_state, nr_objects);
714
715         if (name && no_try_delta(name))
716                 entry->no_try_delta = 1;
717
718         return 1;
719 }
720
721 struct pbase_tree_cache {
722         unsigned char sha1[20];
723         int ref;
724         int temporary;
725         void *tree_data;
726         unsigned long tree_size;
727 };
728
729 static struct pbase_tree_cache *(pbase_tree_cache[256]);
730 static int pbase_tree_cache_ix(const unsigned char *sha1)
731 {
732         return sha1[0] % ARRAY_SIZE(pbase_tree_cache);
733 }
734 static int pbase_tree_cache_ix_incr(int ix)
735 {
736         return (ix+1) % ARRAY_SIZE(pbase_tree_cache);
737 }
738
739 static struct pbase_tree {
740         struct pbase_tree *next;
741         /* This is a phony "cache" entry; we are not
742          * going to evict it nor find it through _get()
743          * mechanism -- this is for the toplevel node that
744          * would almost always change with any commit.
745          */
746         struct pbase_tree_cache pcache;
747 } *pbase_tree;
748
749 static struct pbase_tree_cache *pbase_tree_get(const unsigned char *sha1)
750 {
751         struct pbase_tree_cache *ent, *nent;
752         void *data;
753         unsigned long size;
754         enum object_type type;
755         int neigh;
756         int my_ix = pbase_tree_cache_ix(sha1);
757         int available_ix = -1;
758
759         /* pbase-tree-cache acts as a limited hashtable.
760          * your object will be found at your index or within a few
761          * slots after that slot if it is cached.
762          */
763         for (neigh = 0; neigh < 8; neigh++) {
764                 ent = pbase_tree_cache[my_ix];
765                 if (ent && !hashcmp(ent->sha1, sha1)) {
766                         ent->ref++;
767                         return ent;
768                 }
769                 else if (((available_ix < 0) && (!ent || !ent->ref)) ||
770                          ((0 <= available_ix) &&
771                           (!ent && pbase_tree_cache[available_ix])))
772                         available_ix = my_ix;
773                 if (!ent)
774                         break;
775                 my_ix = pbase_tree_cache_ix_incr(my_ix);
776         }
777
778         /* Did not find one.  Either we got a bogus request or
779          * we need to read and perhaps cache.
780          */
781         data = read_sha1_file(sha1, &type, &size);
782         if (!data)
783                 return NULL;
784         if (type != OBJ_TREE) {
785                 free(data);
786                 return NULL;
787         }
788
789         /* We need to either cache or return a throwaway copy */
790
791         if (available_ix < 0)
792                 ent = NULL;
793         else {
794                 ent = pbase_tree_cache[available_ix];
795                 my_ix = available_ix;
796         }
797
798         if (!ent) {
799                 nent = xmalloc(sizeof(*nent));
800                 nent->temporary = (available_ix < 0);
801         }
802         else {
803                 /* evict and reuse */
804                 free(ent->tree_data);
805                 nent = ent;
806         }
807         hashcpy(nent->sha1, sha1);
808         nent->tree_data = data;
809         nent->tree_size = size;
810         nent->ref = 1;
811         if (!nent->temporary)
812                 pbase_tree_cache[my_ix] = nent;
813         return nent;
814 }
815
816 static void pbase_tree_put(struct pbase_tree_cache *cache)
817 {
818         if (!cache->temporary) {
819                 cache->ref--;
820                 return;
821         }
822         free(cache->tree_data);
823         free(cache);
824 }
825
826 static int name_cmp_len(const char *name)
827 {
828         int i;
829         for (i = 0; name[i] && name[i] != '\n' && name[i] != '/'; i++)
830                 ;
831         return i;
832 }
833
834 static void add_pbase_object(struct tree_desc *tree,
835                              const char *name,
836                              int cmplen,
837                              const char *fullname)
838 {
839         struct name_entry entry;
840         int cmp;
841
842         while (tree_entry(tree,&entry)) {
843                 if (S_ISGITLINK(entry.mode))
844                         continue;
845                 cmp = tree_entry_len(entry.path, entry.sha1) != cmplen ? 1 :
846                       memcmp(name, entry.path, cmplen);
847                 if (cmp > 0)
848                         continue;
849                 if (cmp < 0)
850                         return;
851                 if (name[cmplen] != '/') {
852                         add_object_entry(entry.sha1,
853                                          object_type(entry.mode),
854                                          fullname, 1);
855                         return;
856                 }
857                 if (S_ISDIR(entry.mode)) {
858                         struct tree_desc sub;
859                         struct pbase_tree_cache *tree;
860                         const char *down = name+cmplen+1;
861                         int downlen = name_cmp_len(down);
862
863                         tree = pbase_tree_get(entry.sha1);
864                         if (!tree)
865                                 return;
866                         init_tree_desc(&sub, tree->tree_data, tree->tree_size);
867
868                         add_pbase_object(&sub, down, downlen, fullname);
869                         pbase_tree_put(tree);
870                 }
871         }
872 }
873
874 static unsigned *done_pbase_paths;
875 static int done_pbase_paths_num;
876 static int done_pbase_paths_alloc;
877 static int done_pbase_path_pos(unsigned hash)
878 {
879         int lo = 0;
880         int hi = done_pbase_paths_num;
881         while (lo < hi) {
882                 int mi = (hi + lo) / 2;
883                 if (done_pbase_paths[mi] == hash)
884                         return mi;
885                 if (done_pbase_paths[mi] < hash)
886                         hi = mi;
887                 else
888                         lo = mi + 1;
889         }
890         return -lo-1;
891 }
892
893 static int check_pbase_path(unsigned hash)
894 {
895         int pos = (!done_pbase_paths) ? -1 : done_pbase_path_pos(hash);
896         if (0 <= pos)
897                 return 1;
898         pos = -pos - 1;
899         if (done_pbase_paths_alloc <= done_pbase_paths_num) {
900                 done_pbase_paths_alloc = alloc_nr(done_pbase_paths_alloc);
901                 done_pbase_paths = xrealloc(done_pbase_paths,
902                                             done_pbase_paths_alloc *
903                                             sizeof(unsigned));
904         }
905         done_pbase_paths_num++;
906         if (pos < done_pbase_paths_num)
907                 memmove(done_pbase_paths + pos + 1,
908                         done_pbase_paths + pos,
909                         (done_pbase_paths_num - pos - 1) * sizeof(unsigned));
910         done_pbase_paths[pos] = hash;
911         return 0;
912 }
913
914 static void add_preferred_base_object(const char *name)
915 {
916         struct pbase_tree *it;
917         int cmplen;
918         unsigned hash = name_hash(name);
919
920         if (!num_preferred_base || check_pbase_path(hash))
921                 return;
922
923         cmplen = name_cmp_len(name);
924         for (it = pbase_tree; it; it = it->next) {
925                 if (cmplen == 0) {
926                         add_object_entry(it->pcache.sha1, OBJ_TREE, NULL, 1);
927                 }
928                 else {
929                         struct tree_desc tree;
930                         init_tree_desc(&tree, it->pcache.tree_data, it->pcache.tree_size);
931                         add_pbase_object(&tree, name, cmplen, name);
932                 }
933         }
934 }
935
936 static void add_preferred_base(unsigned char *sha1)
937 {
938         struct pbase_tree *it;
939         void *data;
940         unsigned long size;
941         unsigned char tree_sha1[20];
942
943         if (window <= num_preferred_base++)
944                 return;
945
946         data = read_object_with_reference(sha1, tree_type, &size, tree_sha1);
947         if (!data)
948                 return;
949
950         for (it = pbase_tree; it; it = it->next) {
951                 if (!hashcmp(it->pcache.sha1, tree_sha1)) {
952                         free(data);
953                         return;
954                 }
955         }
956
957         it = xcalloc(1, sizeof(*it));
958         it->next = pbase_tree;
959         pbase_tree = it;
960
961         hashcpy(it->pcache.sha1, tree_sha1);
962         it->pcache.tree_data = data;
963         it->pcache.tree_size = size;
964 }
965
966 static void cleanup_preferred_base(void)
967 {
968         struct pbase_tree *it;
969         unsigned i;
970
971         it = pbase_tree;
972         pbase_tree = NULL;
973         while (it) {
974                 struct pbase_tree *this = it;
975                 it = this->next;
976                 free(this->pcache.tree_data);
977                 free(this);
978         }
979
980         for (i = 0; i < ARRAY_SIZE(pbase_tree_cache); i++) {
981                 if (!pbase_tree_cache[i])
982                         continue;
983                 free(pbase_tree_cache[i]->tree_data);
984                 free(pbase_tree_cache[i]);
985                 pbase_tree_cache[i] = NULL;
986         }
987
988         free(done_pbase_paths);
989         done_pbase_paths = NULL;
990         done_pbase_paths_num = done_pbase_paths_alloc = 0;
991 }
992
993 static void check_object(struct object_entry *entry)
994 {
995         if (entry->in_pack) {
996                 struct packed_git *p = entry->in_pack;
997                 struct pack_window *w_curs = NULL;
998                 const unsigned char *base_ref = NULL;
999                 struct object_entry *base_entry;
1000                 unsigned long used, used_0;
1001                 unsigned int avail;
1002                 off_t ofs;
1003                 unsigned char *buf, c;
1004
1005                 buf = use_pack(p, &w_curs, entry->in_pack_offset, &avail);
1006
1007                 /*
1008                  * We want in_pack_type even if we do not reuse delta
1009                  * since non-delta representations could still be reused.
1010                  */
1011                 used = unpack_object_header_buffer(buf, avail,
1012                                                    &entry->in_pack_type,
1013                                                    &entry->size);
1014                 if (used == 0)
1015                         goto give_up;
1016
1017                 /*
1018                  * Determine if this is a delta and if so whether we can
1019                  * reuse it or not.  Otherwise let's find out as cheaply as
1020                  * possible what the actual type and size for this object is.
1021                  */
1022                 switch (entry->in_pack_type) {
1023                 default:
1024                         /* Not a delta hence we've already got all we need. */
1025                         entry->type = entry->in_pack_type;
1026                         entry->in_pack_header_size = used;
1027                         if (entry->type < OBJ_COMMIT || entry->type > OBJ_BLOB)
1028                                 goto give_up;
1029                         unuse_pack(&w_curs);
1030                         return;
1031                 case OBJ_REF_DELTA:
1032                         if (reuse_delta && !entry->preferred_base)
1033                                 base_ref = use_pack(p, &w_curs,
1034                                                 entry->in_pack_offset + used, NULL);
1035                         entry->in_pack_header_size = used + 20;
1036                         break;
1037                 case OBJ_OFS_DELTA:
1038                         buf = use_pack(p, &w_curs,
1039                                        entry->in_pack_offset + used, NULL);
1040                         used_0 = 0;
1041                         c = buf[used_0++];
1042                         ofs = c & 127;
1043                         while (c & 128) {
1044                                 ofs += 1;
1045                                 if (!ofs || MSB(ofs, 7)) {
1046                                         error("delta base offset overflow in pack for %s",
1047                                               sha1_to_hex(entry->idx.sha1));
1048                                         goto give_up;
1049                                 }
1050                                 c = buf[used_0++];
1051                                 ofs = (ofs << 7) + (c & 127);
1052                         }
1053                         ofs = entry->in_pack_offset - ofs;
1054                         if (ofs <= 0 || ofs >= entry->in_pack_offset) {
1055                                 error("delta base offset out of bound for %s",
1056                                       sha1_to_hex(entry->idx.sha1));
1057                                 goto give_up;
1058                         }
1059                         if (reuse_delta && !entry->preferred_base) {
1060                                 struct revindex_entry *revidx;
1061                                 revidx = find_pack_revindex(p, ofs);
1062                                 if (!revidx)
1063                                         goto give_up;
1064                                 base_ref = nth_packed_object_sha1(p, revidx->nr);
1065                         }
1066                         entry->in_pack_header_size = used + used_0;
1067                         break;
1068                 }
1069
1070                 if (base_ref && (base_entry = locate_object_entry(base_ref))) {
1071                         /*
1072                          * If base_ref was set above that means we wish to
1073                          * reuse delta data, and we even found that base
1074                          * in the list of objects we want to pack. Goodie!
1075                          *
1076                          * Depth value does not matter - find_deltas() will
1077                          * never consider reused delta as the base object to
1078                          * deltify other objects against, in order to avoid
1079                          * circular deltas.
1080                          */
1081                         entry->type = entry->in_pack_type;
1082                         entry->delta = base_entry;
1083                         entry->delta_size = entry->size;
1084                         entry->delta_sibling = base_entry->delta_child;
1085                         base_entry->delta_child = entry;
1086                         unuse_pack(&w_curs);
1087                         return;
1088                 }
1089
1090                 if (entry->type) {
1091                         /*
1092                          * This must be a delta and we already know what the
1093                          * final object type is.  Let's extract the actual
1094                          * object size from the delta header.
1095                          */
1096                         entry->size = get_size_from_delta(p, &w_curs,
1097                                         entry->in_pack_offset + entry->in_pack_header_size);
1098                         if (entry->size == 0)
1099                                 goto give_up;
1100                         unuse_pack(&w_curs);
1101                         return;
1102                 }
1103
1104                 /*
1105                  * No choice but to fall back to the recursive delta walk
1106                  * with sha1_object_info() to find about the object type
1107                  * at this point...
1108                  */
1109                 give_up:
1110                 unuse_pack(&w_curs);
1111         }
1112
1113         entry->type = sha1_object_info(entry->idx.sha1, &entry->size);
1114         /*
1115          * The error condition is checked in prepare_pack().  This is
1116          * to permit a missing preferred base object to be ignored
1117          * as a preferred base.  Doing so can result in a larger
1118          * pack file, but the transfer will still take place.
1119          */
1120 }
1121
1122 static int pack_offset_sort(const void *_a, const void *_b)
1123 {
1124         const struct object_entry *a = *(struct object_entry **)_a;
1125         const struct object_entry *b = *(struct object_entry **)_b;
1126
1127         /* avoid filesystem trashing with loose objects */
1128         if (!a->in_pack && !b->in_pack)
1129                 return hashcmp(a->idx.sha1, b->idx.sha1);
1130
1131         if (a->in_pack < b->in_pack)
1132                 return -1;
1133         if (a->in_pack > b->in_pack)
1134                 return 1;
1135         return a->in_pack_offset < b->in_pack_offset ? -1 :
1136                         (a->in_pack_offset > b->in_pack_offset);
1137 }
1138
1139 static void get_object_details(void)
1140 {
1141         uint32_t i;
1142         struct object_entry **sorted_by_offset;
1143
1144         sorted_by_offset = xcalloc(nr_objects, sizeof(struct object_entry *));
1145         for (i = 0; i < nr_objects; i++)
1146                 sorted_by_offset[i] = objects + i;
1147         qsort(sorted_by_offset, nr_objects, sizeof(*sorted_by_offset), pack_offset_sort);
1148
1149         for (i = 0; i < nr_objects; i++)
1150                 check_object(sorted_by_offset[i]);
1151
1152         free(sorted_by_offset);
1153 }
1154
1155 /*
1156  * We search for deltas in a list sorted by type, by filename hash, and then
1157  * by size, so that we see progressively smaller and smaller files.
1158  * That's because we prefer deltas to be from the bigger file
1159  * to the smaller -- deletes are potentially cheaper, but perhaps
1160  * more importantly, the bigger file is likely the more recent
1161  * one.  The deepest deltas are therefore the oldest objects which are
1162  * less susceptible to be accessed often.
1163  */
1164 static int type_size_sort(const void *_a, const void *_b)
1165 {
1166         const struct object_entry *a = *(struct object_entry **)_a;
1167         const struct object_entry *b = *(struct object_entry **)_b;
1168
1169         if (a->type > b->type)
1170                 return -1;
1171         if (a->type < b->type)
1172                 return 1;
1173         if (a->hash > b->hash)
1174                 return -1;
1175         if (a->hash < b->hash)
1176                 return 1;
1177         if (a->preferred_base > b->preferred_base)
1178                 return -1;
1179         if (a->preferred_base < b->preferred_base)
1180                 return 1;
1181         if (a->size > b->size)
1182                 return -1;
1183         if (a->size < b->size)
1184                 return 1;
1185         return a < b ? -1 : (a > b);  /* newest first */
1186 }
1187
1188 struct unpacked {
1189         struct object_entry *entry;
1190         void *data;
1191         struct delta_index *index;
1192         unsigned depth;
1193 };
1194
1195 static int delta_cacheable(unsigned long src_size, unsigned long trg_size,
1196                            unsigned long delta_size)
1197 {
1198         if (max_delta_cache_size && delta_cache_size + delta_size > max_delta_cache_size)
1199                 return 0;
1200
1201         if (delta_size < cache_max_small_delta_size)
1202                 return 1;
1203
1204         /* cache delta, if objects are large enough compared to delta size */
1205         if ((src_size >> 20) + (trg_size >> 21) > (delta_size >> 10))
1206                 return 1;
1207
1208         return 0;
1209 }
1210
1211 #ifndef NO_PTHREADS
1212
1213 static pthread_mutex_t read_mutex;
1214 #define read_lock()             pthread_mutex_lock(&read_mutex)
1215 #define read_unlock()           pthread_mutex_unlock(&read_mutex)
1216
1217 static pthread_mutex_t cache_mutex;
1218 #define cache_lock()            pthread_mutex_lock(&cache_mutex)
1219 #define cache_unlock()          pthread_mutex_unlock(&cache_mutex)
1220
1221 static pthread_mutex_t progress_mutex;
1222 #define progress_lock()         pthread_mutex_lock(&progress_mutex)
1223 #define progress_unlock()       pthread_mutex_unlock(&progress_mutex)
1224
1225 #else
1226
1227 #define read_lock()             (void)0
1228 #define read_unlock()           (void)0
1229 #define cache_lock()            (void)0
1230 #define cache_unlock()          (void)0
1231 #define progress_lock()         (void)0
1232 #define progress_unlock()       (void)0
1233
1234 #endif
1235
1236 static int try_delta(struct unpacked *trg, struct unpacked *src,
1237                      unsigned max_depth, unsigned long *mem_usage)
1238 {
1239         struct object_entry *trg_entry = trg->entry;
1240         struct object_entry *src_entry = src->entry;
1241         unsigned long trg_size, src_size, delta_size, sizediff, max_size, sz;
1242         unsigned ref_depth;
1243         enum object_type type;
1244         void *delta_buf;
1245
1246         /* Don't bother doing diffs between different types */
1247         if (trg_entry->type != src_entry->type)
1248                 return -1;
1249
1250         /*
1251          * We do not bother to try a delta that we discarded
1252          * on an earlier try, but only when reusing delta data.
1253          */
1254         if (reuse_delta && trg_entry->in_pack &&
1255             trg_entry->in_pack == src_entry->in_pack &&
1256             trg_entry->in_pack_type != OBJ_REF_DELTA &&
1257             trg_entry->in_pack_type != OBJ_OFS_DELTA)
1258                 return 0;
1259
1260         /* Let's not bust the allowed depth. */
1261         if (src->depth >= max_depth)
1262                 return 0;
1263
1264         /* Now some size filtering heuristics. */
1265         trg_size = trg_entry->size;
1266         if (!trg_entry->delta) {
1267                 max_size = trg_size/2 - 20;
1268                 ref_depth = 1;
1269         } else {
1270                 max_size = trg_entry->delta_size;
1271                 ref_depth = trg->depth;
1272         }
1273         max_size = (uint64_t)max_size * (max_depth - src->depth) /
1274                                                 (max_depth - ref_depth + 1);
1275         if (max_size == 0)
1276                 return 0;
1277         src_size = src_entry->size;
1278         sizediff = src_size < trg_size ? trg_size - src_size : 0;
1279         if (sizediff >= max_size)
1280                 return 0;
1281         if (trg_size < src_size / 32)
1282                 return 0;
1283
1284         /* Load data if not already done */
1285         if (!trg->data) {
1286                 read_lock();
1287                 trg->data = read_sha1_file(trg_entry->idx.sha1, &type, &sz);
1288                 read_unlock();
1289                 if (!trg->data)
1290                         die("object %s cannot be read",
1291                             sha1_to_hex(trg_entry->idx.sha1));
1292                 if (sz != trg_size)
1293                         die("object %s inconsistent object length (%lu vs %lu)",
1294                             sha1_to_hex(trg_entry->idx.sha1), sz, trg_size);
1295                 *mem_usage += sz;
1296         }
1297         if (!src->data) {
1298                 read_lock();
1299                 src->data = read_sha1_file(src_entry->idx.sha1, &type, &sz);
1300                 read_unlock();
1301                 if (!src->data)
1302                         die("object %s cannot be read",
1303                             sha1_to_hex(src_entry->idx.sha1));
1304                 if (sz != src_size)
1305                         die("object %s inconsistent object length (%lu vs %lu)",
1306                             sha1_to_hex(src_entry->idx.sha1), sz, src_size);
1307                 *mem_usage += sz;
1308         }
1309         if (!src->index) {
1310                 src->index = create_delta_index(src->data, src_size);
1311                 if (!src->index) {
1312                         static int warned = 0;
1313                         if (!warned++)
1314                                 warning("suboptimal pack - out of memory");
1315                         return 0;
1316                 }
1317                 *mem_usage += sizeof_delta_index(src->index);
1318         }
1319
1320         delta_buf = create_delta(src->index, trg->data, trg_size, &delta_size, max_size);
1321         if (!delta_buf)
1322                 return 0;
1323
1324         if (trg_entry->delta) {
1325                 /* Prefer only shallower same-sized deltas. */
1326                 if (delta_size == trg_entry->delta_size &&
1327                     src->depth + 1 >= trg->depth) {
1328                         free(delta_buf);
1329                         return 0;
1330                 }
1331         }
1332
1333         /*
1334          * Handle memory allocation outside of the cache
1335          * accounting lock.  Compiler will optimize the strangeness
1336          * away when NO_PTHREADS is defined.
1337          */
1338         free(trg_entry->delta_data);
1339         cache_lock();
1340         if (trg_entry->delta_data) {
1341                 delta_cache_size -= trg_entry->delta_size;
1342                 trg_entry->delta_data = NULL;
1343         }
1344         if (delta_cacheable(src_size, trg_size, delta_size)) {
1345                 delta_cache_size += delta_size;
1346                 cache_unlock();
1347                 trg_entry->delta_data = xrealloc(delta_buf, delta_size);
1348         } else {
1349                 cache_unlock();
1350                 free(delta_buf);
1351         }
1352
1353         trg_entry->delta = src_entry;
1354         trg_entry->delta_size = delta_size;
1355         trg->depth = src->depth + 1;
1356
1357         return 1;
1358 }
1359
1360 static unsigned int check_delta_limit(struct object_entry *me, unsigned int n)
1361 {
1362         struct object_entry *child = me->delta_child;
1363         unsigned int m = n;
1364         while (child) {
1365                 unsigned int c = check_delta_limit(child, n + 1);
1366                 if (m < c)
1367                         m = c;
1368                 child = child->delta_sibling;
1369         }
1370         return m;
1371 }
1372
1373 static unsigned long free_unpacked(struct unpacked *n)
1374 {
1375         unsigned long freed_mem = sizeof_delta_index(n->index);
1376         free_delta_index(n->index);
1377         n->index = NULL;
1378         if (n->data) {
1379                 freed_mem += n->entry->size;
1380                 free(n->data);
1381                 n->data = NULL;
1382         }
1383         n->entry = NULL;
1384         n->depth = 0;
1385         return freed_mem;
1386 }
1387
1388 static void find_deltas(struct object_entry **list, unsigned *list_size,
1389                         int window, int depth, unsigned *processed)
1390 {
1391         uint32_t i, idx = 0, count = 0;
1392         struct unpacked *array;
1393         unsigned long mem_usage = 0;
1394
1395         array = xcalloc(window, sizeof(struct unpacked));
1396
1397         for (;;) {
1398                 struct object_entry *entry;
1399                 struct unpacked *n = array + idx;
1400                 int j, max_depth, best_base = -1;
1401
1402                 progress_lock();
1403                 if (!*list_size) {
1404                         progress_unlock();
1405                         break;
1406                 }
1407                 entry = *list++;
1408                 (*list_size)--;
1409                 if (!entry->preferred_base) {
1410                         (*processed)++;
1411                         display_progress(progress_state, *processed);
1412                 }
1413                 progress_unlock();
1414
1415                 mem_usage -= free_unpacked(n);
1416                 n->entry = entry;
1417
1418                 while (window_memory_limit &&
1419                        mem_usage > window_memory_limit &&
1420                        count > 1) {
1421                         uint32_t tail = (idx + window - count) % window;
1422                         mem_usage -= free_unpacked(array + tail);
1423                         count--;
1424                 }
1425
1426                 /* We do not compute delta to *create* objects we are not
1427                  * going to pack.
1428                  */
1429                 if (entry->preferred_base)
1430                         goto next;
1431
1432                 /*
1433                  * If the current object is at pack edge, take the depth the
1434                  * objects that depend on the current object into account
1435                  * otherwise they would become too deep.
1436                  */
1437                 max_depth = depth;
1438                 if (entry->delta_child) {
1439                         max_depth -= check_delta_limit(entry, 0);
1440                         if (max_depth <= 0)
1441                                 goto next;
1442                 }
1443
1444                 j = window;
1445                 while (--j > 0) {
1446                         int ret;
1447                         uint32_t other_idx = idx + j;
1448                         struct unpacked *m;
1449                         if (other_idx >= window)
1450                                 other_idx -= window;
1451                         m = array + other_idx;
1452                         if (!m->entry)
1453                                 break;
1454                         ret = try_delta(n, m, max_depth, &mem_usage);
1455                         if (ret < 0)
1456                                 break;
1457                         else if (ret > 0)
1458                                 best_base = other_idx;
1459                 }
1460
1461                 /*
1462                  * If we decided to cache the delta data, then it is best
1463                  * to compress it right away.  First because we have to do
1464                  * it anyway, and doing it here while we're threaded will
1465                  * save a lot of time in the non threaded write phase,
1466                  * as well as allow for caching more deltas within
1467                  * the same cache size limit.
1468                  * ...
1469                  * But only if not writing to stdout, since in that case
1470                  * the network is most likely throttling writes anyway,
1471                  * and therefore it is best to go to the write phase ASAP
1472                  * instead, as we can afford spending more time compressing
1473                  * between writes at that moment.
1474                  */
1475                 if (entry->delta_data && !pack_to_stdout) {
1476                         entry->z_delta_size = do_compress(&entry->delta_data,
1477                                                           entry->delta_size);
1478                         cache_lock();
1479                         delta_cache_size -= entry->delta_size;
1480                         delta_cache_size += entry->z_delta_size;
1481                         cache_unlock();
1482                 }
1483
1484                 /* if we made n a delta, and if n is already at max
1485                  * depth, leaving it in the window is pointless.  we
1486                  * should evict it first.
1487                  */
1488                 if (entry->delta && max_depth <= n->depth)
1489                         continue;
1490
1491                 /*
1492                  * Move the best delta base up in the window, after the
1493                  * currently deltified object, to keep it longer.  It will
1494                  * be the first base object to be attempted next.
1495                  */
1496                 if (entry->delta) {
1497                         struct unpacked swap = array[best_base];
1498                         int dist = (window + idx - best_base) % window;
1499                         int dst = best_base;
1500                         while (dist--) {
1501                                 int src = (dst + 1) % window;
1502                                 array[dst] = array[src];
1503                                 dst = src;
1504                         }
1505                         array[dst] = swap;
1506                 }
1507
1508                 next:
1509                 idx++;
1510                 if (count + 1 < window)
1511                         count++;
1512                 if (idx >= window)
1513                         idx = 0;
1514         }
1515
1516         for (i = 0; i < window; ++i) {
1517                 free_delta_index(array[i].index);
1518                 free(array[i].data);
1519         }
1520         free(array);
1521 }
1522
1523 #ifndef NO_PTHREADS
1524
1525 static void try_to_free_from_threads(size_t size)
1526 {
1527         read_lock();
1528         release_pack_memory(size, -1);
1529         read_unlock();
1530 }
1531
1532 /*
1533  * The main thread waits on the condition that (at least) one of the workers
1534  * has stopped working (which is indicated in the .working member of
1535  * struct thread_params).
1536  * When a work thread has completed its work, it sets .working to 0 and
1537  * signals the main thread and waits on the condition that .data_ready
1538  * becomes 1.
1539  */
1540
1541 struct thread_params {
1542         pthread_t thread;
1543         struct object_entry **list;
1544         unsigned list_size;
1545         unsigned remaining;
1546         int window;
1547         int depth;
1548         int working;
1549         int data_ready;
1550         pthread_mutex_t mutex;
1551         pthread_cond_t cond;
1552         unsigned *processed;
1553 };
1554
1555 static pthread_cond_t progress_cond;
1556
1557 /*
1558  * Mutex and conditional variable can't be statically-initialized on Windows.
1559  */
1560 static void init_threaded_search(void)
1561 {
1562         init_recursive_mutex(&read_mutex);
1563         pthread_mutex_init(&cache_mutex, NULL);
1564         pthread_mutex_init(&progress_mutex, NULL);
1565         pthread_cond_init(&progress_cond, NULL);
1566         set_try_to_free_routine(try_to_free_from_threads);
1567 }
1568
1569 static void cleanup_threaded_search(void)
1570 {
1571         set_try_to_free_routine(NULL);
1572         pthread_cond_destroy(&progress_cond);
1573         pthread_mutex_destroy(&read_mutex);
1574         pthread_mutex_destroy(&cache_mutex);
1575         pthread_mutex_destroy(&progress_mutex);
1576 }
1577
1578 static void *threaded_find_deltas(void *arg)
1579 {
1580         struct thread_params *me = arg;
1581
1582         while (me->remaining) {
1583                 find_deltas(me->list, &me->remaining,
1584                             me->window, me->depth, me->processed);
1585
1586                 progress_lock();
1587                 me->working = 0;
1588                 pthread_cond_signal(&progress_cond);
1589                 progress_unlock();
1590
1591                 /*
1592                  * We must not set ->data_ready before we wait on the
1593                  * condition because the main thread may have set it to 1
1594                  * before we get here. In order to be sure that new
1595                  * work is available if we see 1 in ->data_ready, it
1596                  * was initialized to 0 before this thread was spawned
1597                  * and we reset it to 0 right away.
1598                  */
1599                 pthread_mutex_lock(&me->mutex);
1600                 while (!me->data_ready)
1601                         pthread_cond_wait(&me->cond, &me->mutex);
1602                 me->data_ready = 0;
1603                 pthread_mutex_unlock(&me->mutex);
1604         }
1605         /* leave ->working 1 so that this doesn't get more work assigned */
1606         return NULL;
1607 }
1608
1609 static void ll_find_deltas(struct object_entry **list, unsigned list_size,
1610                            int window, int depth, unsigned *processed)
1611 {
1612         struct thread_params *p;
1613         int i, ret, active_threads = 0;
1614
1615         init_threaded_search();
1616
1617         if (!delta_search_threads)      /* --threads=0 means autodetect */
1618                 delta_search_threads = online_cpus();
1619         if (delta_search_threads <= 1) {
1620                 find_deltas(list, &list_size, window, depth, processed);
1621                 cleanup_threaded_search();
1622                 return;
1623         }
1624         if (progress > pack_to_stdout)
1625                 fprintf(stderr, "Delta compression using up to %d threads.\n",
1626                                 delta_search_threads);
1627         p = xcalloc(delta_search_threads, sizeof(*p));
1628
1629         /* Partition the work amongst work threads. */
1630         for (i = 0; i < delta_search_threads; i++) {
1631                 unsigned sub_size = list_size / (delta_search_threads - i);
1632
1633                 /* don't use too small segments or no deltas will be found */
1634                 if (sub_size < 2*window && i+1 < delta_search_threads)
1635                         sub_size = 0;
1636
1637                 p[i].window = window;
1638                 p[i].depth = depth;
1639                 p[i].processed = processed;
1640                 p[i].working = 1;
1641                 p[i].data_ready = 0;
1642
1643                 /* try to split chunks on "path" boundaries */
1644                 while (sub_size && sub_size < list_size &&
1645                        list[sub_size]->hash &&
1646                        list[sub_size]->hash == list[sub_size-1]->hash)
1647                         sub_size++;
1648
1649                 p[i].list = list;
1650                 p[i].list_size = sub_size;
1651                 p[i].remaining = sub_size;
1652
1653                 list += sub_size;
1654                 list_size -= sub_size;
1655         }
1656
1657         /* Start work threads. */
1658         for (i = 0; i < delta_search_threads; i++) {
1659                 if (!p[i].list_size)
1660                         continue;
1661                 pthread_mutex_init(&p[i].mutex, NULL);
1662                 pthread_cond_init(&p[i].cond, NULL);
1663                 ret = pthread_create(&p[i].thread, NULL,
1664                                      threaded_find_deltas, &p[i]);
1665                 if (ret)
1666                         die("unable to create thread: %s", strerror(ret));
1667                 active_threads++;
1668         }
1669
1670         /*
1671          * Now let's wait for work completion.  Each time a thread is done
1672          * with its work, we steal half of the remaining work from the
1673          * thread with the largest number of unprocessed objects and give
1674          * it to that newly idle thread.  This ensure good load balancing
1675          * until the remaining object list segments are simply too short
1676          * to be worth splitting anymore.
1677          */
1678         while (active_threads) {
1679                 struct thread_params *target = NULL;
1680                 struct thread_params *victim = NULL;
1681                 unsigned sub_size = 0;
1682
1683                 progress_lock();
1684                 for (;;) {
1685                         for (i = 0; !target && i < delta_search_threads; i++)
1686                                 if (!p[i].working)
1687                                         target = &p[i];
1688                         if (target)
1689                                 break;
1690                         pthread_cond_wait(&progress_cond, &progress_mutex);
1691                 }
1692
1693                 for (i = 0; i < delta_search_threads; i++)
1694                         if (p[i].remaining > 2*window &&
1695                             (!victim || victim->remaining < p[i].remaining))
1696                                 victim = &p[i];
1697                 if (victim) {
1698                         sub_size = victim->remaining / 2;
1699                         list = victim->list + victim->list_size - sub_size;
1700                         while (sub_size && list[0]->hash &&
1701                                list[0]->hash == list[-1]->hash) {
1702                                 list++;
1703                                 sub_size--;
1704                         }
1705                         if (!sub_size) {
1706                                 /*
1707                                  * It is possible for some "paths" to have
1708                                  * so many objects that no hash boundary
1709                                  * might be found.  Let's just steal the
1710                                  * exact half in that case.
1711                                  */
1712                                 sub_size = victim->remaining / 2;
1713                                 list -= sub_size;
1714                         }
1715                         target->list = list;
1716                         victim->list_size -= sub_size;
1717                         victim->remaining -= sub_size;
1718                 }
1719                 target->list_size = sub_size;
1720                 target->remaining = sub_size;
1721                 target->working = 1;
1722                 progress_unlock();
1723
1724                 pthread_mutex_lock(&target->mutex);
1725                 target->data_ready = 1;
1726                 pthread_cond_signal(&target->cond);
1727                 pthread_mutex_unlock(&target->mutex);
1728
1729                 if (!sub_size) {
1730                         pthread_join(target->thread, NULL);
1731                         pthread_cond_destroy(&target->cond);
1732                         pthread_mutex_destroy(&target->mutex);
1733                         active_threads--;
1734                 }
1735         }
1736         cleanup_threaded_search();
1737         free(p);
1738 }
1739
1740 #else
1741 #define ll_find_deltas(l, s, w, d, p)   find_deltas(l, &s, w, d, p)
1742 #endif
1743
1744 static int add_ref_tag(const char *path, const unsigned char *sha1, int flag, void *cb_data)
1745 {
1746         unsigned char peeled[20];
1747
1748         if (!prefixcmp(path, "refs/tags/") && /* is a tag? */
1749             !peel_ref(path, peeled)        && /* peelable? */
1750             !is_null_sha1(peeled)          && /* annotated tag? */
1751             locate_object_entry(peeled))      /* object packed? */
1752                 add_object_entry(sha1, OBJ_TAG, NULL, 0);
1753         return 0;
1754 }
1755
1756 static void prepare_pack(int window, int depth)
1757 {
1758         struct object_entry **delta_list;
1759         uint32_t i, nr_deltas;
1760         unsigned n;
1761
1762         get_object_details();
1763
1764         /*
1765          * If we're locally repacking then we need to be doubly careful
1766          * from now on in order to make sure no stealth corruption gets
1767          * propagated to the new pack.  Clients receiving streamed packs
1768          * should validate everything they get anyway so no need to incur
1769          * the additional cost here in that case.
1770          */
1771         if (!pack_to_stdout)
1772                 do_check_packed_object_crc = 1;
1773
1774         if (!nr_objects || !window || !depth)
1775                 return;
1776
1777         delta_list = xmalloc(nr_objects * sizeof(*delta_list));
1778         nr_deltas = n = 0;
1779
1780         for (i = 0; i < nr_objects; i++) {
1781                 struct object_entry *entry = objects + i;
1782
1783                 if (entry->delta)
1784                         /* This happens if we decided to reuse existing
1785                          * delta from a pack.  "reuse_delta &&" is implied.
1786                          */
1787                         continue;
1788
1789                 if (entry->size < 50)
1790                         continue;
1791
1792                 if (entry->no_try_delta)
1793                         continue;
1794
1795                 if (!entry->preferred_base) {
1796                         nr_deltas++;
1797                         if (entry->type < 0)
1798                                 die("unable to get type of object %s",
1799                                     sha1_to_hex(entry->idx.sha1));
1800                 } else {
1801                         if (entry->type < 0) {
1802                                 /*
1803                                  * This object is not found, but we
1804                                  * don't have to include it anyway.
1805                                  */
1806                                 continue;
1807                         }
1808                 }
1809
1810                 delta_list[n++] = entry;
1811         }
1812
1813         if (nr_deltas && n > 1) {
1814                 unsigned nr_done = 0;
1815                 if (progress)
1816                         progress_state = start_progress("Compressing objects",
1817                                                         nr_deltas);
1818                 qsort(delta_list, n, sizeof(*delta_list), type_size_sort);
1819                 ll_find_deltas(delta_list, n, window+1, depth, &nr_done);
1820                 stop_progress(&progress_state);
1821                 if (nr_done != nr_deltas)
1822                         die("inconsistency with delta count");
1823         }
1824         free(delta_list);
1825 }
1826
1827 static int git_pack_config(const char *k, const char *v, void *cb)
1828 {
1829         if (!strcmp(k, "pack.window")) {
1830                 window = git_config_int(k, v);
1831                 return 0;
1832         }
1833         if (!strcmp(k, "pack.windowmemory")) {
1834                 window_memory_limit = git_config_ulong(k, v);
1835                 return 0;
1836         }
1837         if (!strcmp(k, "pack.depth")) {
1838                 depth = git_config_int(k, v);
1839                 return 0;
1840         }
1841         if (!strcmp(k, "pack.compression")) {
1842                 int level = git_config_int(k, v);
1843                 if (level == -1)
1844                         level = Z_DEFAULT_COMPRESSION;
1845                 else if (level < 0 || level > Z_BEST_COMPRESSION)
1846                         die("bad pack compression level %d", level);
1847                 pack_compression_level = level;
1848                 pack_compression_seen = 1;
1849                 return 0;
1850         }
1851         if (!strcmp(k, "pack.deltacachesize")) {
1852                 max_delta_cache_size = git_config_int(k, v);
1853                 return 0;
1854         }
1855         if (!strcmp(k, "pack.deltacachelimit")) {
1856                 cache_max_small_delta_size = git_config_int(k, v);
1857                 return 0;
1858         }
1859         if (!strcmp(k, "pack.threads")) {
1860                 delta_search_threads = git_config_int(k, v);
1861                 if (delta_search_threads < 0)
1862                         die("invalid number of threads specified (%d)",
1863                             delta_search_threads);
1864 #ifdef NO_PTHREADS
1865                 if (delta_search_threads != 1)
1866                         warning("no threads support, ignoring %s", k);
1867 #endif
1868                 return 0;
1869         }
1870         if (!strcmp(k, "pack.indexversion")) {
1871                 pack_idx_default_version = git_config_int(k, v);
1872                 if (pack_idx_default_version > 2)
1873                         die("bad pack.indexversion=%"PRIu32,
1874                                 pack_idx_default_version);
1875                 return 0;
1876         }
1877         if (!strcmp(k, "pack.packsizelimit")) {
1878                 pack_size_limit_cfg = git_config_ulong(k, v);
1879                 return 0;
1880         }
1881         return git_default_config(k, v, cb);
1882 }
1883
1884 static void read_object_list_from_stdin(void)
1885 {
1886         char line[40 + 1 + PATH_MAX + 2];
1887         unsigned char sha1[20];
1888
1889         for (;;) {
1890                 if (!fgets(line, sizeof(line), stdin)) {
1891                         if (feof(stdin))
1892                                 break;
1893                         if (!ferror(stdin))
1894                                 die("fgets returned NULL, not EOF, not error!");
1895                         if (errno != EINTR)
1896                                 die_errno("fgets");
1897                         clearerr(stdin);
1898                         continue;
1899                 }
1900                 if (line[0] == '-') {
1901                         if (get_sha1_hex(line+1, sha1))
1902                                 die("expected edge sha1, got garbage:\n %s",
1903                                     line);
1904                         add_preferred_base(sha1);
1905                         continue;
1906                 }
1907                 if (get_sha1_hex(line, sha1))
1908                         die("expected sha1, got garbage:\n %s", line);
1909
1910                 add_preferred_base_object(line+41);
1911                 add_object_entry(sha1, 0, line+41, 0);
1912         }
1913 }
1914
1915 #define OBJECT_ADDED (1u<<20)
1916
1917 static void show_commit(struct commit *commit, void *data)
1918 {
1919         add_object_entry(commit->object.sha1, OBJ_COMMIT, NULL, 0);
1920         commit->object.flags |= OBJECT_ADDED;
1921 }
1922
1923 static void show_object(struct object *obj, const struct name_path *path, const char *last)
1924 {
1925         char *name = path_name(path, last);
1926
1927         add_preferred_base_object(name);
1928         add_object_entry(obj->sha1, obj->type, name, 0);
1929         obj->flags |= OBJECT_ADDED;
1930
1931         /*
1932          * We will have generated the hash from the name,
1933          * but not saved a pointer to it - we can free it
1934          */
1935         free((char *)name);
1936 }
1937
1938 static void show_edge(struct commit *commit)
1939 {
1940         add_preferred_base(commit->object.sha1);
1941 }
1942
1943 struct in_pack_object {
1944         off_t offset;
1945         struct object *object;
1946 };
1947
1948 struct in_pack {
1949         int alloc;
1950         int nr;
1951         struct in_pack_object *array;
1952 };
1953
1954 static void mark_in_pack_object(struct object *object, struct packed_git *p, struct in_pack *in_pack)
1955 {
1956         in_pack->array[in_pack->nr].offset = find_pack_entry_one(object->sha1, p);
1957         in_pack->array[in_pack->nr].object = object;
1958         in_pack->nr++;
1959 }
1960
1961 /*
1962  * Compare the objects in the offset order, in order to emulate the
1963  * "git rev-list --objects" output that produced the pack originally.
1964  */
1965 static int ofscmp(const void *a_, const void *b_)
1966 {
1967         struct in_pack_object *a = (struct in_pack_object *)a_;
1968         struct in_pack_object *b = (struct in_pack_object *)b_;
1969
1970         if (a->offset < b->offset)
1971                 return -1;
1972         else if (a->offset > b->offset)
1973                 return 1;
1974         else
1975                 return hashcmp(a->object->sha1, b->object->sha1);
1976 }
1977
1978 static void add_objects_in_unpacked_packs(struct rev_info *revs)
1979 {
1980         struct packed_git *p;
1981         struct in_pack in_pack;
1982         uint32_t i;
1983
1984         memset(&in_pack, 0, sizeof(in_pack));
1985
1986         for (p = packed_git; p; p = p->next) {
1987                 const unsigned char *sha1;
1988                 struct object *o;
1989
1990                 if (!p->pack_local || p->pack_keep)
1991                         continue;
1992                 if (open_pack_index(p))
1993                         die("cannot open pack index");
1994
1995                 ALLOC_GROW(in_pack.array,
1996                            in_pack.nr + p->num_objects,
1997                            in_pack.alloc);
1998
1999                 for (i = 0; i < p->num_objects; i++) {
2000                         sha1 = nth_packed_object_sha1(p, i);
2001                         o = lookup_unknown_object(sha1);
2002                         if (!(o->flags & OBJECT_ADDED))
2003                                 mark_in_pack_object(o, p, &in_pack);
2004                         o->flags |= OBJECT_ADDED;
2005                 }
2006         }
2007
2008         if (in_pack.nr) {
2009                 qsort(in_pack.array, in_pack.nr, sizeof(in_pack.array[0]),
2010                       ofscmp);
2011                 for (i = 0; i < in_pack.nr; i++) {
2012                         struct object *o = in_pack.array[i].object;
2013                         add_object_entry(o->sha1, o->type, "", 0);
2014                 }
2015         }
2016         free(in_pack.array);
2017 }
2018
2019 static int has_sha1_pack_kept_or_nonlocal(const unsigned char *sha1)
2020 {
2021         static struct packed_git *last_found = (void *)1;
2022         struct packed_git *p;
2023
2024         p = (last_found != (void *)1) ? last_found : packed_git;
2025
2026         while (p) {
2027                 if ((!p->pack_local || p->pack_keep) &&
2028                         find_pack_entry_one(sha1, p)) {
2029                         last_found = p;
2030                         return 1;
2031                 }
2032                 if (p == last_found)
2033                         p = packed_git;
2034                 else
2035                         p = p->next;
2036                 if (p == last_found)
2037                         p = p->next;
2038         }
2039         return 0;
2040 }
2041
2042 static void loosen_unused_packed_objects(struct rev_info *revs)
2043 {
2044         struct packed_git *p;
2045         uint32_t i;
2046         const unsigned char *sha1;
2047
2048         for (p = packed_git; p; p = p->next) {
2049                 if (!p->pack_local || p->pack_keep)
2050                         continue;
2051
2052                 if (open_pack_index(p))
2053                         die("cannot open pack index");
2054
2055                 for (i = 0; i < p->num_objects; i++) {
2056                         sha1 = nth_packed_object_sha1(p, i);
2057                         if (!locate_object_entry(sha1) &&
2058                                 !has_sha1_pack_kept_or_nonlocal(sha1))
2059                                 if (force_object_loose(sha1, p->mtime))
2060                                         die("unable to force loose object");
2061                 }
2062         }
2063 }
2064
2065 static void get_object_list(int ac, const char **av)
2066 {
2067         struct rev_info revs;
2068         char line[1000];
2069         int flags = 0;
2070
2071         init_revisions(&revs, NULL);
2072         save_commit_buffer = 0;
2073         setup_revisions(ac, av, &revs, NULL);
2074
2075         while (fgets(line, sizeof(line), stdin) != NULL) {
2076                 int len = strlen(line);
2077                 if (len && line[len - 1] == '\n')
2078                         line[--len] = 0;
2079                 if (!len)
2080                         break;
2081                 if (*line == '-') {
2082                         if (!strcmp(line, "--not")) {
2083                                 flags ^= UNINTERESTING;
2084                                 continue;
2085                         }
2086                         die("not a rev '%s'", line);
2087                 }
2088                 if (handle_revision_arg(line, &revs, flags, 1))
2089                         die("bad revision '%s'", line);
2090         }
2091
2092         if (prepare_revision_walk(&revs))
2093                 die("revision walk setup failed");
2094         mark_edges_uninteresting(revs.commits, &revs, show_edge);
2095         traverse_commit_list(&revs, show_commit, show_object, NULL);
2096
2097         if (keep_unreachable)
2098                 add_objects_in_unpacked_packs(&revs);
2099         if (unpack_unreachable)
2100                 loosen_unused_packed_objects(&revs);
2101 }
2102
2103 int cmd_pack_objects(int argc, const char **argv, const char *prefix)
2104 {
2105         int use_internal_rev_list = 0;
2106         int thin = 0;
2107         int all_progress_implied = 0;
2108         uint32_t i;
2109         const char **rp_av;
2110         int rp_ac_alloc = 64;
2111         int rp_ac;
2112
2113         read_replace_refs = 0;
2114
2115         rp_av = xcalloc(rp_ac_alloc, sizeof(*rp_av));
2116
2117         rp_av[0] = "pack-objects";
2118         rp_av[1] = "--objects"; /* --thin will make it --objects-edge */
2119         rp_ac = 2;
2120
2121         git_config(git_pack_config, NULL);
2122         if (!pack_compression_seen && core_compression_seen)
2123                 pack_compression_level = core_compression_level;
2124
2125         progress = isatty(2);
2126         for (i = 1; i < argc; i++) {
2127                 const char *arg = argv[i];
2128
2129                 if (*arg != '-')
2130                         break;
2131
2132                 if (!strcmp("--non-empty", arg)) {
2133                         non_empty = 1;
2134                         continue;
2135                 }
2136                 if (!strcmp("--local", arg)) {
2137                         local = 1;
2138                         continue;
2139                 }
2140                 if (!strcmp("--incremental", arg)) {
2141                         incremental = 1;
2142                         continue;
2143                 }
2144                 if (!strcmp("--honor-pack-keep", arg)) {
2145                         ignore_packed_keep = 1;
2146                         continue;
2147                 }
2148                 if (!prefixcmp(arg, "--compression=")) {
2149                         char *end;
2150                         int level = strtoul(arg+14, &end, 0);
2151                         if (!arg[14] || *end)
2152                                 usage(pack_usage);
2153                         if (level == -1)
2154                                 level = Z_DEFAULT_COMPRESSION;
2155                         else if (level < 0 || level > Z_BEST_COMPRESSION)
2156                                 die("bad pack compression level %d", level);
2157                         pack_compression_level = level;
2158                         continue;
2159                 }
2160                 if (!prefixcmp(arg, "--max-pack-size=")) {
2161                         pack_size_limit_cfg = 0;
2162                         if (!git_parse_ulong(arg+16, &pack_size_limit))
2163                                 usage(pack_usage);
2164                         continue;
2165                 }
2166                 if (!prefixcmp(arg, "--window=")) {
2167                         char *end;
2168                         window = strtoul(arg+9, &end, 0);
2169                         if (!arg[9] || *end)
2170                                 usage(pack_usage);
2171                         continue;
2172                 }
2173                 if (!prefixcmp(arg, "--window-memory=")) {
2174                         if (!git_parse_ulong(arg+16, &window_memory_limit))
2175                                 usage(pack_usage);
2176                         continue;
2177                 }
2178                 if (!prefixcmp(arg, "--threads=")) {
2179                         char *end;
2180                         delta_search_threads = strtoul(arg+10, &end, 0);
2181                         if (!arg[10] || *end || delta_search_threads < 0)
2182                                 usage(pack_usage);
2183 #ifdef NO_PTHREADS
2184                         if (delta_search_threads != 1)
2185                                 warning("no threads support, "
2186                                         "ignoring %s", arg);
2187 #endif
2188                         continue;
2189                 }
2190                 if (!prefixcmp(arg, "--depth=")) {
2191                         char *end;
2192                         depth = strtoul(arg+8, &end, 0);
2193                         if (!arg[8] || *end)
2194                                 usage(pack_usage);
2195                         continue;
2196                 }
2197                 if (!strcmp("--progress", arg)) {
2198                         progress = 1;
2199                         continue;
2200                 }
2201                 if (!strcmp("--all-progress", arg)) {
2202                         progress = 2;
2203                         continue;
2204                 }
2205                 if (!strcmp("--all-progress-implied", arg)) {
2206                         all_progress_implied = 1;
2207                         continue;
2208                 }
2209                 if (!strcmp("-q", arg)) {
2210                         progress = 0;
2211                         continue;
2212                 }
2213                 if (!strcmp("--no-reuse-delta", arg)) {
2214                         reuse_delta = 0;
2215                         continue;
2216                 }
2217                 if (!strcmp("--no-reuse-object", arg)) {
2218                         reuse_object = reuse_delta = 0;
2219                         continue;
2220                 }
2221                 if (!strcmp("--delta-base-offset", arg)) {
2222                         allow_ofs_delta = 1;
2223                         continue;
2224                 }
2225                 if (!strcmp("--stdout", arg)) {
2226                         pack_to_stdout = 1;
2227                         continue;
2228                 }
2229                 if (!strcmp("--revs", arg)) {
2230                         use_internal_rev_list = 1;
2231                         continue;
2232                 }
2233                 if (!strcmp("--keep-unreachable", arg)) {
2234                         keep_unreachable = 1;
2235                         continue;
2236                 }
2237                 if (!strcmp("--unpack-unreachable", arg)) {
2238                         unpack_unreachable = 1;
2239                         continue;
2240                 }
2241                 if (!strcmp("--include-tag", arg)) {
2242                         include_tag = 1;
2243                         continue;
2244                 }
2245                 if (!strcmp("--unpacked", arg) ||
2246                     !strcmp("--reflog", arg) ||
2247                     !strcmp("--all", arg)) {
2248                         use_internal_rev_list = 1;
2249                         if (rp_ac >= rp_ac_alloc - 1) {
2250                                 rp_ac_alloc = alloc_nr(rp_ac_alloc);
2251                                 rp_av = xrealloc(rp_av,
2252                                                  rp_ac_alloc * sizeof(*rp_av));
2253                         }
2254                         rp_av[rp_ac++] = arg;
2255                         continue;
2256                 }
2257                 if (!strcmp("--thin", arg)) {
2258                         use_internal_rev_list = 1;
2259                         thin = 1;
2260                         rp_av[1] = "--objects-edge";
2261                         continue;
2262                 }
2263                 if (!prefixcmp(arg, "--index-version=")) {
2264                         char *c;
2265                         pack_idx_default_version = strtoul(arg + 16, &c, 10);
2266                         if (pack_idx_default_version > 2)
2267                                 die("bad %s", arg);
2268                         if (*c == ',')
2269                                 pack_idx_off32_limit = strtoul(c+1, &c, 0);
2270                         if (*c || pack_idx_off32_limit & 0x80000000)
2271                                 die("bad %s", arg);
2272                         continue;
2273                 }
2274                 if (!strcmp(arg, "--keep-true-parents")) {
2275                         grafts_replace_parents = 0;
2276                         continue;
2277                 }
2278                 usage(pack_usage);
2279         }
2280
2281         /* Traditionally "pack-objects [options] base extra" failed;
2282          * we would however want to take refs parameter that would
2283          * have been given to upstream rev-list ourselves, which means
2284          * we somehow want to say what the base name is.  So the
2285          * syntax would be:
2286          *
2287          * pack-objects [options] base <refs...>
2288          *
2289          * in other words, we would treat the first non-option as the
2290          * base_name and send everything else to the internal revision
2291          * walker.
2292          */
2293
2294         if (!pack_to_stdout)
2295                 base_name = argv[i++];
2296
2297         if (pack_to_stdout != !base_name)
2298                 usage(pack_usage);
2299
2300         if (!pack_to_stdout && !pack_size_limit)
2301                 pack_size_limit = pack_size_limit_cfg;
2302         if (pack_to_stdout && pack_size_limit)
2303                 die("--max-pack-size cannot be used to build a pack for transfer.");
2304         if (pack_size_limit && pack_size_limit < 1024*1024) {
2305                 warning("minimum pack size limit is 1 MiB");
2306                 pack_size_limit = 1024*1024;
2307         }
2308
2309         if (!pack_to_stdout && thin)
2310                 die("--thin cannot be used to build an indexable pack.");
2311
2312         if (keep_unreachable && unpack_unreachable)
2313                 die("--keep-unreachable and --unpack-unreachable are incompatible.");
2314
2315         if (progress && all_progress_implied)
2316                 progress = 2;
2317
2318         prepare_packed_git();
2319
2320         if (progress)
2321                 progress_state = start_progress("Counting objects", 0);
2322         if (!use_internal_rev_list)
2323                 read_object_list_from_stdin();
2324         else {
2325                 rp_av[rp_ac] = NULL;
2326                 get_object_list(rp_ac, rp_av);
2327         }
2328         cleanup_preferred_base();
2329         if (include_tag && nr_result)
2330                 for_each_ref(add_ref_tag, NULL);
2331         stop_progress(&progress_state);
2332
2333         if (non_empty && !nr_result)
2334                 return 0;
2335         if (nr_result)
2336                 prepare_pack(window, depth);
2337         write_pack_file();
2338         if (progress)
2339                 fprintf(stderr, "Total %"PRIu32" (delta %"PRIu32"),"
2340                         " reused %"PRIu32" (delta %"PRIu32")\n",
2341                         written, written_delta, reused, reused_delta);
2342         return 0;
2343 }