Thread-safe xmalloc and xrealloc needs a recursive mutex
[git/dscho.git] / builtin-pack-objects.c
blob26fc7cd5a6f89ce8d8d8c3c56ff039c108ef12f1
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"
20 #ifndef NO_PTHREADS
21 #include <pthread.h>
22 #include "thread-utils.h"
23 #endif
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]";
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;
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;
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;
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;
93 static unsigned long window_memory_limit = 0;
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;
104  * stats
105  */
106 static uint32_t written, written_delta;
107 static uint32_t reused, reused_delta;
110 static void *get_delta(struct object_entry *entry)
112         unsigned long size, base_size, delta_size;
113         void *buf, *base_buf, *delta_buf;
114         enum object_type type;
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;
131 static unsigned long do_compress(void **pptr, unsigned long size)
133         z_stream stream;
134         void *in, *out;
135         unsigned long maxsize;
137         memset(&stream, 0, sizeof(stream));
138         deflateInit(&stream, pack_compression_level);
139         maxsize = deflateBound(&stream, size);
141         in = *pptr;
142         out = xmalloc(maxsize);
143         *pptr = out;
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);
153         free(in);
154         return stream.total_out;
158  * The per-object header is a pretty dense thing, which is
159  *  - first byte: low four bits are "size", then three bits of "type",
160  *    and the high bit is "size continues".
161  *  - each byte afterwards: low seven bits are size continuation,
162  *    with the high bit being "size continues"
163  */
164 static int encode_header(enum object_type type, unsigned long size, unsigned char *hdr)
166         int n = 1;
167         unsigned char c;
169         if (type < OBJ_COMMIT || type > OBJ_REF_DELTA)
170                 die("bad type %d", type);
172         c = (type << 4) | (size & 15);
173         size >>= 4;
174         while (size) {
175                 *hdr++ = c | 0x80;
176                 c = size & 0x7f;
177                 size >>= 7;
178                 n++;
179         }
180         *hdr = c;
181         return n;
185  * we are going to reuse the existing object data as is.  make
186  * sure it is not corrupt.
187  */
188 static int check_pack_inflate(struct packed_git *p,
189                 struct pack_window **w_curs,
190                 off_t offset,
191                 off_t len,
192                 unsigned long expect)
194         z_stream stream;
195         unsigned char fakebuf[4096], *in;
196         int st;
198         memset(&stream, 0, sizeof(stream));
199         git_inflate_init(&stream);
200         do {
201                 in = use_pack(p, w_curs, offset, &stream.avail_in);
202                 stream.next_in = in;
203                 stream.next_out = fakebuf;
204                 stream.avail_out = sizeof(fakebuf);
205                 st = git_inflate(&stream, Z_FINISH);
206                 offset += stream.next_in - in;
207         } while (st == Z_OK || st == Z_BUF_ERROR);
208         git_inflate_end(&stream);
209         return (st == Z_STREAM_END &&
210                 stream.total_out == expect &&
211                 stream.total_in == len) ? 0 : -1;
214 static void copy_pack_data(struct sha1file *f,
215                 struct packed_git *p,
216                 struct pack_window **w_curs,
217                 off_t offset,
218                 off_t len)
220         unsigned char *in;
221         unsigned int avail;
223         while (len) {
224                 in = use_pack(p, w_curs, offset, &avail);
225                 if (avail > len)
226                         avail = (unsigned int)len;
227                 sha1write(f, in, avail);
228                 offset += avail;
229                 len -= avail;
230         }
233 static unsigned long write_object(struct sha1file *f,
234                                   struct object_entry *entry,
235                                   off_t write_offset)
237         unsigned long size, limit, datalen;
238         void *buf;
239         unsigned char header[10], dheader[10];
240         unsigned hdrlen;
241         enum object_type type;
242         int usable_delta, to_reuse;
244         if (!pack_to_stdout)
245                 crc32_begin(f);
247         type = entry->type;
249         /* apply size limit if limited packsize and not first object */
250         if (!pack_size_limit || !nr_written)
251                 limit = 0;
252         else if (pack_size_limit <= write_offset)
253                 /*
254                  * the earlier object did not fit the limit; avoid
255                  * mistaking this with unlimited (i.e. limit = 0).
256                  */
257                 limit = 1;
258         else
259                 limit = pack_size_limit - write_offset;
261         if (!entry->delta)
262                 usable_delta = 0;       /* no delta */
263         else if (!pack_size_limit)
264                usable_delta = 1;        /* unlimited packfile */
265         else if (entry->delta->idx.offset == (off_t)-1)
266                 usable_delta = 0;       /* base was written to another pack */
267         else if (entry->delta->idx.offset)
268                 usable_delta = 1;       /* base already exists in this pack */
269         else
270                 usable_delta = 0;       /* base could end up in another pack */
272         if (!reuse_object)
273                 to_reuse = 0;   /* explicit */
274         else if (!entry->in_pack)
275                 to_reuse = 0;   /* can't reuse what we don't have */
276         else if (type == OBJ_REF_DELTA || type == OBJ_OFS_DELTA)
277                                 /* check_object() decided it for us ... */
278                 to_reuse = usable_delta;
279                                 /* ... but pack split may override that */
280         else if (type != entry->in_pack_type)
281                 to_reuse = 0;   /* pack has delta which is unusable */
282         else if (entry->delta)
283                 to_reuse = 0;   /* we want to pack afresh */
284         else
285                 to_reuse = 1;   /* we have it in-pack undeltified,
286                                  * and we do not need to deltify it.
287                                  */
289         if (!to_reuse) {
290                 no_reuse:
291                 if (!usable_delta) {
292                         buf = read_sha1_file(entry->idx.sha1, &type, &size);
293                         if (!buf)
294                                 die("unable to read %s", sha1_to_hex(entry->idx.sha1));
295                         /*
296                          * make sure no cached delta data remains from a
297                          * previous attempt before a pack split occurred.
298                          */
299                         free(entry->delta_data);
300                         entry->delta_data = NULL;
301                         entry->z_delta_size = 0;
302                 } else if (entry->delta_data) {
303                         size = entry->delta_size;
304                         buf = entry->delta_data;
305                         entry->delta_data = NULL;
306                         type = (allow_ofs_delta && entry->delta->idx.offset) ?
307                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
308                 } else {
309                         buf = get_delta(entry);
310                         size = entry->delta_size;
311                         type = (allow_ofs_delta && entry->delta->idx.offset) ?
312                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
313                 }
315                 if (entry->z_delta_size)
316                         datalen = entry->z_delta_size;
317                 else
318                         datalen = do_compress(&buf, size);
320                 /*
321                  * The object header is a byte of 'type' followed by zero or
322                  * more bytes of length.
323                  */
324                 hdrlen = encode_header(type, size, header);
326                 if (type == OBJ_OFS_DELTA) {
327                         /*
328                          * Deltas with relative base contain an additional
329                          * encoding of the relative offset for the delta
330                          * base from this object's position in the pack.
331                          */
332                         off_t ofs = entry->idx.offset - entry->delta->idx.offset;
333                         unsigned pos = sizeof(dheader) - 1;
334                         dheader[pos] = ofs & 127;
335                         while (ofs >>= 7)
336                                 dheader[--pos] = 128 | (--ofs & 127);
337                         if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit) {
338                                 free(buf);
339                                 return 0;
340                         }
341                         sha1write(f, header, hdrlen);
342                         sha1write(f, dheader + pos, sizeof(dheader) - pos);
343                         hdrlen += sizeof(dheader) - pos;
344                 } else if (type == OBJ_REF_DELTA) {
345                         /*
346                          * Deltas with a base reference contain
347                          * an additional 20 bytes for the base sha1.
348                          */
349                         if (limit && hdrlen + 20 + datalen + 20 >= limit) {
350                                 free(buf);
351                                 return 0;
352                         }
353                         sha1write(f, header, hdrlen);
354                         sha1write(f, entry->delta->idx.sha1, 20);
355                         hdrlen += 20;
356                 } else {
357                         if (limit && hdrlen + datalen + 20 >= limit) {
358                                 free(buf);
359                                 return 0;
360                         }
361                         sha1write(f, header, hdrlen);
362                 }
363                 sha1write(f, buf, datalen);
364                 free(buf);
365         }
366         else {
367                 struct packed_git *p = entry->in_pack;
368                 struct pack_window *w_curs = NULL;
369                 struct revindex_entry *revidx;
370                 off_t offset;
372                 if (entry->delta)
373                         type = (allow_ofs_delta && entry->delta->idx.offset) ?
374                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
375                 hdrlen = encode_header(type, entry->size, header);
377                 offset = entry->in_pack_offset;
378                 revidx = find_pack_revindex(p, offset);
379                 datalen = revidx[1].offset - offset;
380                 if (!pack_to_stdout && p->index_version > 1 &&
381                     check_pack_crc(p, &w_curs, offset, datalen, revidx->nr)) {
382                         error("bad packed object CRC for %s", sha1_to_hex(entry->idx.sha1));
383                         unuse_pack(&w_curs);
384                         goto no_reuse;
385                 }
387                 offset += entry->in_pack_header_size;
388                 datalen -= entry->in_pack_header_size;
389                 if (!pack_to_stdout && p->index_version == 1 &&
390                     check_pack_inflate(p, &w_curs, offset, datalen, entry->size)) {
391                         error("corrupt packed object for %s", sha1_to_hex(entry->idx.sha1));
392                         unuse_pack(&w_curs);
393                         goto no_reuse;
394                 }
396                 if (type == OBJ_OFS_DELTA) {
397                         off_t ofs = entry->idx.offset - entry->delta->idx.offset;
398                         unsigned pos = sizeof(dheader) - 1;
399                         dheader[pos] = ofs & 127;
400                         while (ofs >>= 7)
401                                 dheader[--pos] = 128 | (--ofs & 127);
402                         if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit) {
403                                 unuse_pack(&w_curs);
404                                 return 0;
405                         }
406                         sha1write(f, header, hdrlen);
407                         sha1write(f, dheader + pos, sizeof(dheader) - pos);
408                         hdrlen += sizeof(dheader) - pos;
409                         reused_delta++;
410                 } else if (type == OBJ_REF_DELTA) {
411                         if (limit && hdrlen + 20 + datalen + 20 >= limit) {
412                                 unuse_pack(&w_curs);
413                                 return 0;
414                         }
415                         sha1write(f, header, hdrlen);
416                         sha1write(f, entry->delta->idx.sha1, 20);
417                         hdrlen += 20;
418                         reused_delta++;
419                 } else {
420                         if (limit && hdrlen + datalen + 20 >= limit) {
421                                 unuse_pack(&w_curs);
422                                 return 0;
423                         }
424                         sha1write(f, header, hdrlen);
425                 }
426                 copy_pack_data(f, p, &w_curs, offset, datalen);
427                 unuse_pack(&w_curs);
428                 reused++;
429         }
430         if (usable_delta)
431                 written_delta++;
432         written++;
433         if (!pack_to_stdout)
434                 entry->idx.crc32 = crc32_end(f);
435         return hdrlen + datalen;
438 static int write_one(struct sha1file *f,
439                                struct object_entry *e,
440                                off_t *offset)
442         unsigned long size;
444         /* offset is non zero if object is written already. */
445         if (e->idx.offset || e->preferred_base)
446                 return -1;
448         /* if we are deltified, write out base object first. */
449         if (e->delta && !write_one(f, e->delta, offset))
450                 return 0;
452         e->idx.offset = *offset;
453         size = write_object(f, e, *offset);
454         if (!size) {
455                 e->idx.offset = 0;
456                 return 0;
457         }
458         written_list[nr_written++] = &e->idx;
460         /* make sure off_t is sufficiently large not to wrap */
461         if (*offset > *offset + size)
462                 die("pack too large for current definition of off_t");
463         *offset += size;
464         return 1;
467 static void write_pack_file(void)
469         uint32_t i = 0, j;
470         struct sha1file *f;
471         off_t offset;
472         struct pack_header hdr;
473         uint32_t nr_remaining = nr_result;
474         time_t last_mtime = 0;
476         if (progress > pack_to_stdout)
477                 progress_state = start_progress("Writing objects", nr_result);
478         written_list = xmalloc(nr_objects * sizeof(*written_list));
480         do {
481                 unsigned char sha1[20];
482                 char *pack_tmp_name = NULL;
484                 if (pack_to_stdout) {
485                         f = sha1fd_throughput(1, "<stdout>", progress_state);
486                 } else {
487                         char tmpname[PATH_MAX];
488                         int fd;
489                         fd = odb_mkstemp(tmpname, sizeof(tmpname),
490                                          "pack/tmp_pack_XXXXXX");
491                         pack_tmp_name = xstrdup(tmpname);
492                         f = sha1fd(fd, pack_tmp_name);
493                 }
495                 hdr.hdr_signature = htonl(PACK_SIGNATURE);
496                 hdr.hdr_version = htonl(PACK_VERSION);
497                 hdr.hdr_entries = htonl(nr_remaining);
498                 sha1write(f, &hdr, sizeof(hdr));
499                 offset = sizeof(hdr);
500                 nr_written = 0;
501                 for (; i < nr_objects; i++) {
502                         if (!write_one(f, objects + i, &offset))
503                                 break;
504                         display_progress(progress_state, written);
505                 }
507                 /*
508                  * Did we write the wrong # entries in the header?
509                  * If so, rewrite it like in fast-import
510                  */
511                 if (pack_to_stdout) {
512                         sha1close(f, sha1, CSUM_CLOSE);
513                 } else if (nr_written == nr_remaining) {
514                         sha1close(f, sha1, CSUM_FSYNC);
515                 } else {
516                         int fd = sha1close(f, sha1, 0);
517                         fixup_pack_header_footer(fd, sha1, pack_tmp_name,
518                                                  nr_written, sha1, offset);
519                         close(fd);
520                 }
522                 if (!pack_to_stdout) {
523                         struct stat st;
524                         const char *idx_tmp_name;
525                         char tmpname[PATH_MAX];
527                         idx_tmp_name = write_idx_file(NULL, written_list,
528                                                       nr_written, sha1);
530                         snprintf(tmpname, sizeof(tmpname), "%s-%s.pack",
531                                  base_name, sha1_to_hex(sha1));
532                         free_pack_by_name(tmpname);
533                         if (adjust_shared_perm(pack_tmp_name))
534                                 die_errno("unable to make temporary pack file readable");
535                         if (rename(pack_tmp_name, tmpname))
536                                 die_errno("unable to rename temporary pack file");
538                         /*
539                          * Packs are runtime accessed in their mtime
540                          * order since newer packs are more likely to contain
541                          * younger objects.  So if we are creating multiple
542                          * packs then we should modify the mtime of later ones
543                          * to preserve this property.
544                          */
545                         if (stat(tmpname, &st) < 0) {
546                                 warning("failed to stat %s: %s",
547                                         tmpname, strerror(errno));
548                         } else if (!last_mtime) {
549                                 last_mtime = st.st_mtime;
550                         } else {
551                                 struct utimbuf utb;
552                                 utb.actime = st.st_atime;
553                                 utb.modtime = --last_mtime;
554                                 if (utime(tmpname, &utb) < 0)
555                                         warning("failed utime() on %s: %s",
556                                                 tmpname, strerror(errno));
557                         }
559                         snprintf(tmpname, sizeof(tmpname), "%s-%s.idx",
560                                  base_name, sha1_to_hex(sha1));
561                         if (adjust_shared_perm(idx_tmp_name))
562                                 die_errno("unable to make temporary index file readable");
563                         if (rename(idx_tmp_name, tmpname))
564                                 die_errno("unable to rename temporary index file");
566                         free((void *) idx_tmp_name);
567                         free(pack_tmp_name);
568                         puts(sha1_to_hex(sha1));
569                 }
571                 /* mark written objects as written to previous pack */
572                 for (j = 0; j < nr_written; j++) {
573                         written_list[j]->offset = (off_t)-1;
574                 }
575                 nr_remaining -= nr_written;
576         } while (nr_remaining && i < nr_objects);
578         free(written_list);
579         stop_progress(&progress_state);
580         if (written != nr_result)
581                 die("wrote %"PRIu32" objects while expecting %"PRIu32,
582                         written, nr_result);
585 static int locate_object_entry_hash(const unsigned char *sha1)
587         int i;
588         unsigned int ui;
589         memcpy(&ui, sha1, sizeof(unsigned int));
590         i = ui % object_ix_hashsz;
591         while (0 < object_ix[i]) {
592                 if (!hashcmp(sha1, objects[object_ix[i] - 1].idx.sha1))
593                         return i;
594                 if (++i == object_ix_hashsz)
595                         i = 0;
596         }
597         return -1 - i;
600 static struct object_entry *locate_object_entry(const unsigned char *sha1)
602         int i;
604         if (!object_ix_hashsz)
605                 return NULL;
607         i = locate_object_entry_hash(sha1);
608         if (0 <= i)
609                 return &objects[object_ix[i]-1];
610         return NULL;
613 static void rehash_objects(void)
615         uint32_t i;
616         struct object_entry *oe;
618         object_ix_hashsz = nr_objects * 3;
619         if (object_ix_hashsz < 1024)
620                 object_ix_hashsz = 1024;
621         object_ix = xrealloc(object_ix, sizeof(int) * object_ix_hashsz);
622         memset(object_ix, 0, sizeof(int) * object_ix_hashsz);
623         for (i = 0, oe = objects; i < nr_objects; i++, oe++) {
624                 int ix = locate_object_entry_hash(oe->idx.sha1);
625                 if (0 <= ix)
626                         continue;
627                 ix = -1 - ix;
628                 object_ix[ix] = i + 1;
629         }
632 static unsigned name_hash(const char *name)
634         unsigned c, hash = 0;
636         if (!name)
637                 return 0;
639         /*
640          * This effectively just creates a sortable number from the
641          * last sixteen non-whitespace characters. Last characters
642          * count "most", so things that end in ".c" sort together.
643          */
644         while ((c = *name++) != 0) {
645                 if (isspace(c))
646                         continue;
647                 hash = (hash >> 2) + (c << 24);
648         }
649         return hash;
652 static void setup_delta_attr_check(struct git_attr_check *check)
654         static struct git_attr *attr_delta;
656         if (!attr_delta)
657                 attr_delta = git_attr("delta");
659         check[0].attr = attr_delta;
662 static int no_try_delta(const char *path)
664         struct git_attr_check check[1];
666         setup_delta_attr_check(check);
667         if (git_checkattr(path, ARRAY_SIZE(check), check))
668                 return 0;
669         if (ATTR_FALSE(check->value))
670                 return 1;
671         return 0;
674 static int add_object_entry(const unsigned char *sha1, enum object_type type,
675                             const char *name, int exclude)
677         struct object_entry *entry;
678         struct packed_git *p, *found_pack = NULL;
679         off_t found_offset = 0;
680         int ix;
681         unsigned hash = name_hash(name);
683         ix = nr_objects ? locate_object_entry_hash(sha1) : -1;
684         if (ix >= 0) {
685                 if (exclude) {
686                         entry = objects + object_ix[ix] - 1;
687                         if (!entry->preferred_base)
688                                 nr_result--;
689                         entry->preferred_base = 1;
690                 }
691                 return 0;
692         }
694         if (!exclude && local && has_loose_object_nonlocal(sha1))
695                 return 0;
697         for (p = packed_git; p; p = p->next) {
698                 off_t offset = find_pack_entry_one(sha1, p);
699                 if (offset) {
700                         if (!found_pack) {
701                                 found_offset = offset;
702                                 found_pack = p;
703                         }
704                         if (exclude)
705                                 break;
706                         if (incremental)
707                                 return 0;
708                         if (local && !p->pack_local)
709                                 return 0;
710                         if (ignore_packed_keep && p->pack_local && p->pack_keep)
711                                 return 0;
712                 }
713         }
715         if (nr_objects >= nr_alloc) {
716                 nr_alloc = (nr_alloc  + 1024) * 3 / 2;
717                 objects = xrealloc(objects, nr_alloc * sizeof(*entry));
718         }
720         entry = objects + nr_objects++;
721         memset(entry, 0, sizeof(*entry));
722         hashcpy(entry->idx.sha1, sha1);
723         entry->hash = hash;
724         if (type)
725                 entry->type = type;
726         if (exclude)
727                 entry->preferred_base = 1;
728         else
729                 nr_result++;
730         if (found_pack) {
731                 entry->in_pack = found_pack;
732                 entry->in_pack_offset = found_offset;
733         }
735         if (object_ix_hashsz * 3 <= nr_objects * 4)
736                 rehash_objects();
737         else
738                 object_ix[-1 - ix] = nr_objects;
740         display_progress(progress_state, nr_objects);
742         if (name && no_try_delta(name))
743                 entry->no_try_delta = 1;
745         return 1;
748 struct pbase_tree_cache {
749         unsigned char sha1[20];
750         int ref;
751         int temporary;
752         void *tree_data;
753         unsigned long tree_size;
756 static struct pbase_tree_cache *(pbase_tree_cache[256]);
757 static int pbase_tree_cache_ix(const unsigned char *sha1)
759         return sha1[0] % ARRAY_SIZE(pbase_tree_cache);
761 static int pbase_tree_cache_ix_incr(int ix)
763         return (ix+1) % ARRAY_SIZE(pbase_tree_cache);
766 static struct pbase_tree {
767         struct pbase_tree *next;
768         /* This is a phony "cache" entry; we are not
769          * going to evict it nor find it through _get()
770          * mechanism -- this is for the toplevel node that
771          * would almost always change with any commit.
772          */
773         struct pbase_tree_cache pcache;
774 } *pbase_tree;
776 static struct pbase_tree_cache *pbase_tree_get(const unsigned char *sha1)
778         struct pbase_tree_cache *ent, *nent;
779         void *data;
780         unsigned long size;
781         enum object_type type;
782         int neigh;
783         int my_ix = pbase_tree_cache_ix(sha1);
784         int available_ix = -1;
786         /* pbase-tree-cache acts as a limited hashtable.
787          * your object will be found at your index or within a few
788          * slots after that slot if it is cached.
789          */
790         for (neigh = 0; neigh < 8; neigh++) {
791                 ent = pbase_tree_cache[my_ix];
792                 if (ent && !hashcmp(ent->sha1, sha1)) {
793                         ent->ref++;
794                         return ent;
795                 }
796                 else if (((available_ix < 0) && (!ent || !ent->ref)) ||
797                          ((0 <= available_ix) &&
798                           (!ent && pbase_tree_cache[available_ix])))
799                         available_ix = my_ix;
800                 if (!ent)
801                         break;
802                 my_ix = pbase_tree_cache_ix_incr(my_ix);
803         }
805         /* Did not find one.  Either we got a bogus request or
806          * we need to read and perhaps cache.
807          */
808         data = read_sha1_file(sha1, &type, &size);
809         if (!data)
810                 return NULL;
811         if (type != OBJ_TREE) {
812                 free(data);
813                 return NULL;
814         }
816         /* We need to either cache or return a throwaway copy */
818         if (available_ix < 0)
819                 ent = NULL;
820         else {
821                 ent = pbase_tree_cache[available_ix];
822                 my_ix = available_ix;
823         }
825         if (!ent) {
826                 nent = xmalloc(sizeof(*nent));
827                 nent->temporary = (available_ix < 0);
828         }
829         else {
830                 /* evict and reuse */
831                 free(ent->tree_data);
832                 nent = ent;
833         }
834         hashcpy(nent->sha1, sha1);
835         nent->tree_data = data;
836         nent->tree_size = size;
837         nent->ref = 1;
838         if (!nent->temporary)
839                 pbase_tree_cache[my_ix] = nent;
840         return nent;
843 static void pbase_tree_put(struct pbase_tree_cache *cache)
845         if (!cache->temporary) {
846                 cache->ref--;
847                 return;
848         }
849         free(cache->tree_data);
850         free(cache);
853 static int name_cmp_len(const char *name)
855         int i;
856         for (i = 0; name[i] && name[i] != '\n' && name[i] != '/'; i++)
857                 ;
858         return i;
861 static void add_pbase_object(struct tree_desc *tree,
862                              const char *name,
863                              int cmplen,
864                              const char *fullname)
866         struct name_entry entry;
867         int cmp;
869         while (tree_entry(tree,&entry)) {
870                 if (S_ISGITLINK(entry.mode))
871                         continue;
872                 cmp = tree_entry_len(entry.path, entry.sha1) != cmplen ? 1 :
873                       memcmp(name, entry.path, cmplen);
874                 if (cmp > 0)
875                         continue;
876                 if (cmp < 0)
877                         return;
878                 if (name[cmplen] != '/') {
879                         add_object_entry(entry.sha1,
880                                          object_type(entry.mode),
881                                          fullname, 1);
882                         return;
883                 }
884                 if (S_ISDIR(entry.mode)) {
885                         struct tree_desc sub;
886                         struct pbase_tree_cache *tree;
887                         const char *down = name+cmplen+1;
888                         int downlen = name_cmp_len(down);
890                         tree = pbase_tree_get(entry.sha1);
891                         if (!tree)
892                                 return;
893                         init_tree_desc(&sub, tree->tree_data, tree->tree_size);
895                         add_pbase_object(&sub, down, downlen, fullname);
896                         pbase_tree_put(tree);
897                 }
898         }
901 static unsigned *done_pbase_paths;
902 static int done_pbase_paths_num;
903 static int done_pbase_paths_alloc;
904 static int done_pbase_path_pos(unsigned hash)
906         int lo = 0;
907         int hi = done_pbase_paths_num;
908         while (lo < hi) {
909                 int mi = (hi + lo) / 2;
910                 if (done_pbase_paths[mi] == hash)
911                         return mi;
912                 if (done_pbase_paths[mi] < hash)
913                         hi = mi;
914                 else
915                         lo = mi + 1;
916         }
917         return -lo-1;
920 static int check_pbase_path(unsigned hash)
922         int pos = (!done_pbase_paths) ? -1 : done_pbase_path_pos(hash);
923         if (0 <= pos)
924                 return 1;
925         pos = -pos - 1;
926         if (done_pbase_paths_alloc <= done_pbase_paths_num) {
927                 done_pbase_paths_alloc = alloc_nr(done_pbase_paths_alloc);
928                 done_pbase_paths = xrealloc(done_pbase_paths,
929                                             done_pbase_paths_alloc *
930                                             sizeof(unsigned));
931         }
932         done_pbase_paths_num++;
933         if (pos < done_pbase_paths_num)
934                 memmove(done_pbase_paths + pos + 1,
935                         done_pbase_paths + pos,
936                         (done_pbase_paths_num - pos - 1) * sizeof(unsigned));
937         done_pbase_paths[pos] = hash;
938         return 0;
941 static void add_preferred_base_object(const char *name)
943         struct pbase_tree *it;
944         int cmplen;
945         unsigned hash = name_hash(name);
947         if (!num_preferred_base || check_pbase_path(hash))
948                 return;
950         cmplen = name_cmp_len(name);
951         for (it = pbase_tree; it; it = it->next) {
952                 if (cmplen == 0) {
953                         add_object_entry(it->pcache.sha1, OBJ_TREE, NULL, 1);
954                 }
955                 else {
956                         struct tree_desc tree;
957                         init_tree_desc(&tree, it->pcache.tree_data, it->pcache.tree_size);
958                         add_pbase_object(&tree, name, cmplen, name);
959                 }
960         }
963 static void add_preferred_base(unsigned char *sha1)
965         struct pbase_tree *it;
966         void *data;
967         unsigned long size;
968         unsigned char tree_sha1[20];
970         if (window <= num_preferred_base++)
971                 return;
973         data = read_object_with_reference(sha1, tree_type, &size, tree_sha1);
974         if (!data)
975                 return;
977         for (it = pbase_tree; it; it = it->next) {
978                 if (!hashcmp(it->pcache.sha1, tree_sha1)) {
979                         free(data);
980                         return;
981                 }
982         }
984         it = xcalloc(1, sizeof(*it));
985         it->next = pbase_tree;
986         pbase_tree = it;
988         hashcpy(it->pcache.sha1, tree_sha1);
989         it->pcache.tree_data = data;
990         it->pcache.tree_size = size;
993 static void cleanup_preferred_base(void)
995         struct pbase_tree *it;
996         unsigned i;
998         it = pbase_tree;
999         pbase_tree = NULL;
1000         while (it) {
1001                 struct pbase_tree *this = it;
1002                 it = this->next;
1003                 free(this->pcache.tree_data);
1004                 free(this);
1005         }
1007         for (i = 0; i < ARRAY_SIZE(pbase_tree_cache); i++) {
1008                 if (!pbase_tree_cache[i])
1009                         continue;
1010                 free(pbase_tree_cache[i]->tree_data);
1011                 free(pbase_tree_cache[i]);
1012                 pbase_tree_cache[i] = NULL;
1013         }
1015         free(done_pbase_paths);
1016         done_pbase_paths = NULL;
1017         done_pbase_paths_num = done_pbase_paths_alloc = 0;
1020 static void check_object(struct object_entry *entry)
1022         if (entry->in_pack) {
1023                 struct packed_git *p = entry->in_pack;
1024                 struct pack_window *w_curs = NULL;
1025                 const unsigned char *base_ref = NULL;
1026                 struct object_entry *base_entry;
1027                 unsigned long used, used_0;
1028                 unsigned int avail;
1029                 off_t ofs;
1030                 unsigned char *buf, c;
1032                 buf = use_pack(p, &w_curs, entry->in_pack_offset, &avail);
1034                 /*
1035                  * We want in_pack_type even if we do not reuse delta
1036                  * since non-delta representations could still be reused.
1037                  */
1038                 used = unpack_object_header_buffer(buf, avail,
1039                                                    &entry->in_pack_type,
1040                                                    &entry->size);
1041                 if (used == 0)
1042                         goto give_up;
1044                 /*
1045                  * Determine if this is a delta and if so whether we can
1046                  * reuse it or not.  Otherwise let's find out as cheaply as
1047                  * possible what the actual type and size for this object is.
1048                  */
1049                 switch (entry->in_pack_type) {
1050                 default:
1051                         /* Not a delta hence we've already got all we need. */
1052                         entry->type = entry->in_pack_type;
1053                         entry->in_pack_header_size = used;
1054                         if (entry->type < OBJ_COMMIT || entry->type > OBJ_BLOB)
1055                                 goto give_up;
1056                         unuse_pack(&w_curs);
1057                         return;
1058                 case OBJ_REF_DELTA:
1059                         if (reuse_delta && !entry->preferred_base)
1060                                 base_ref = use_pack(p, &w_curs,
1061                                                 entry->in_pack_offset + used, NULL);
1062                         entry->in_pack_header_size = used + 20;
1063                         break;
1064                 case OBJ_OFS_DELTA:
1065                         buf = use_pack(p, &w_curs,
1066                                        entry->in_pack_offset + used, NULL);
1067                         used_0 = 0;
1068                         c = buf[used_0++];
1069                         ofs = c & 127;
1070                         while (c & 128) {
1071                                 ofs += 1;
1072                                 if (!ofs || MSB(ofs, 7)) {
1073                                         error("delta base offset overflow in pack for %s",
1074                                               sha1_to_hex(entry->idx.sha1));
1075                                         goto give_up;
1076                                 }
1077                                 c = buf[used_0++];
1078                                 ofs = (ofs << 7) + (c & 127);
1079                         }
1080                         ofs = entry->in_pack_offset - ofs;
1081                         if (ofs <= 0 || ofs >= entry->in_pack_offset) {
1082                                 error("delta base offset out of bound for %s",
1083                                       sha1_to_hex(entry->idx.sha1));
1084                                 goto give_up;
1085                         }
1086                         if (reuse_delta && !entry->preferred_base) {
1087                                 struct revindex_entry *revidx;
1088                                 revidx = find_pack_revindex(p, ofs);
1089                                 if (!revidx)
1090                                         goto give_up;
1091                                 base_ref = nth_packed_object_sha1(p, revidx->nr);
1092                         }
1093                         entry->in_pack_header_size = used + used_0;
1094                         break;
1095                 }
1097                 if (base_ref && (base_entry = locate_object_entry(base_ref))) {
1098                         /*
1099                          * If base_ref was set above that means we wish to
1100                          * reuse delta data, and we even found that base
1101                          * in the list of objects we want to pack. Goodie!
1102                          *
1103                          * Depth value does not matter - find_deltas() will
1104                          * never consider reused delta as the base object to
1105                          * deltify other objects against, in order to avoid
1106                          * circular deltas.
1107                          */
1108                         entry->type = entry->in_pack_type;
1109                         entry->delta = base_entry;
1110                         entry->delta_size = entry->size;
1111                         entry->delta_sibling = base_entry->delta_child;
1112                         base_entry->delta_child = entry;
1113                         unuse_pack(&w_curs);
1114                         return;
1115                 }
1117                 if (entry->type) {
1118                         /*
1119                          * This must be a delta and we already know what the
1120                          * final object type is.  Let's extract the actual
1121                          * object size from the delta header.
1122                          */
1123                         entry->size = get_size_from_delta(p, &w_curs,
1124                                         entry->in_pack_offset + entry->in_pack_header_size);
1125                         if (entry->size == 0)
1126                                 goto give_up;
1127                         unuse_pack(&w_curs);
1128                         return;
1129                 }
1131                 /*
1132                  * No choice but to fall back to the recursive delta walk
1133                  * with sha1_object_info() to find about the object type
1134                  * at this point...
1135                  */
1136                 give_up:
1137                 unuse_pack(&w_curs);
1138         }
1140         entry->type = sha1_object_info(entry->idx.sha1, &entry->size);
1141         /*
1142          * The error condition is checked in prepare_pack().  This is
1143          * to permit a missing preferred base object to be ignored
1144          * as a preferred base.  Doing so can result in a larger
1145          * pack file, but the transfer will still take place.
1146          */
1149 static int pack_offset_sort(const void *_a, const void *_b)
1151         const struct object_entry *a = *(struct object_entry **)_a;
1152         const struct object_entry *b = *(struct object_entry **)_b;
1154         /* avoid filesystem trashing with loose objects */
1155         if (!a->in_pack && !b->in_pack)
1156                 return hashcmp(a->idx.sha1, b->idx.sha1);
1158         if (a->in_pack < b->in_pack)
1159                 return -1;
1160         if (a->in_pack > b->in_pack)
1161                 return 1;
1162         return a->in_pack_offset < b->in_pack_offset ? -1 :
1163                         (a->in_pack_offset > b->in_pack_offset);
1166 static void get_object_details(void)
1168         uint32_t i;
1169         struct object_entry **sorted_by_offset;
1171         sorted_by_offset = xcalloc(nr_objects, sizeof(struct object_entry *));
1172         for (i = 0; i < nr_objects; i++)
1173                 sorted_by_offset[i] = objects + i;
1174         qsort(sorted_by_offset, nr_objects, sizeof(*sorted_by_offset), pack_offset_sort);
1176         for (i = 0; i < nr_objects; i++)
1177                 check_object(sorted_by_offset[i]);
1179         free(sorted_by_offset);
1183  * We search for deltas in a list sorted by type, by filename hash, and then
1184  * by size, so that we see progressively smaller and smaller files.
1185  * That's because we prefer deltas to be from the bigger file
1186  * to the smaller -- deletes are potentially cheaper, but perhaps
1187  * more importantly, the bigger file is likely the more recent
1188  * one.  The deepest deltas are therefore the oldest objects which are
1189  * less susceptible to be accessed often.
1190  */
1191 static int type_size_sort(const void *_a, const void *_b)
1193         const struct object_entry *a = *(struct object_entry **)_a;
1194         const struct object_entry *b = *(struct object_entry **)_b;
1196         if (a->type > b->type)
1197                 return -1;
1198         if (a->type < b->type)
1199                 return 1;
1200         if (a->hash > b->hash)
1201                 return -1;
1202         if (a->hash < b->hash)
1203                 return 1;
1204         if (a->preferred_base > b->preferred_base)
1205                 return -1;
1206         if (a->preferred_base < b->preferred_base)
1207                 return 1;
1208         if (a->size > b->size)
1209                 return -1;
1210         if (a->size < b->size)
1211                 return 1;
1212         return a < b ? -1 : (a > b);  /* newest first */
1215 struct unpacked {
1216         struct object_entry *entry;
1217         void *data;
1218         struct delta_index *index;
1219         unsigned depth;
1222 static int delta_cacheable(unsigned long src_size, unsigned long trg_size,
1223                            unsigned long delta_size)
1225         if (max_delta_cache_size && delta_cache_size + delta_size > max_delta_cache_size)
1226                 return 0;
1228         if (delta_size < cache_max_small_delta_size)
1229                 return 1;
1231         /* cache delta, if objects are large enough compared to delta size */
1232         if ((src_size >> 20) + (trg_size >> 21) > (delta_size >> 10))
1233                 return 1;
1235         return 0;
1238 #ifndef NO_PTHREADS
1240 static pthread_mutex_t read_mutex;
1241 #define read_lock()             pthread_mutex_lock(&read_mutex)
1242 #define read_unlock()           pthread_mutex_unlock(&read_mutex)
1244 static pthread_mutex_t cache_mutex;
1245 #define cache_lock()            pthread_mutex_lock(&cache_mutex)
1246 #define cache_unlock()          pthread_mutex_unlock(&cache_mutex)
1248 static pthread_mutex_t progress_mutex;
1249 #define progress_lock()         pthread_mutex_lock(&progress_mutex)
1250 #define progress_unlock()       pthread_mutex_unlock(&progress_mutex)
1252 #else
1254 #define read_lock()             (void)0
1255 #define read_unlock()           (void)0
1256 #define cache_lock()            (void)0
1257 #define cache_unlock()          (void)0
1258 #define progress_lock()         (void)0
1259 #define progress_unlock()       (void)0
1261 #endif
1263 static int try_delta(struct unpacked *trg, struct unpacked *src,
1264                      unsigned max_depth, unsigned long *mem_usage)
1266         struct object_entry *trg_entry = trg->entry;
1267         struct object_entry *src_entry = src->entry;
1268         unsigned long trg_size, src_size, delta_size, sizediff, max_size, sz;
1269         unsigned ref_depth;
1270         enum object_type type;
1271         void *delta_buf;
1273         /* Don't bother doing diffs between different types */
1274         if (trg_entry->type != src_entry->type)
1275                 return -1;
1277         /*
1278          * We do not bother to try a delta that we discarded
1279          * on an earlier try, but only when reusing delta data.
1280          */
1281         if (reuse_delta && trg_entry->in_pack &&
1282             trg_entry->in_pack == src_entry->in_pack &&
1283             trg_entry->in_pack_type != OBJ_REF_DELTA &&
1284             trg_entry->in_pack_type != OBJ_OFS_DELTA)
1285                 return 0;
1287         /* Let's not bust the allowed depth. */
1288         if (src->depth >= max_depth)
1289                 return 0;
1291         /* Now some size filtering heuristics. */
1292         trg_size = trg_entry->size;
1293         if (!trg_entry->delta) {
1294                 max_size = trg_size/2 - 20;
1295                 ref_depth = 1;
1296         } else {
1297                 max_size = trg_entry->delta_size;
1298                 ref_depth = trg->depth;
1299         }
1300         max_size = (uint64_t)max_size * (max_depth - src->depth) /
1301                                                 (max_depth - ref_depth + 1);
1302         if (max_size == 0)
1303                 return 0;
1304         src_size = src_entry->size;
1305         sizediff = src_size < trg_size ? trg_size - src_size : 0;
1306         if (sizediff >= max_size)
1307                 return 0;
1308         if (trg_size < src_size / 32)
1309                 return 0;
1311         /* Load data if not already done */
1312         if (!trg->data) {
1313                 read_lock();
1314                 trg->data = read_sha1_file(trg_entry->idx.sha1, &type, &sz);
1315                 read_unlock();
1316                 if (!trg->data)
1317                         die("object %s cannot be read",
1318                             sha1_to_hex(trg_entry->idx.sha1));
1319                 if (sz != trg_size)
1320                         die("object %s inconsistent object length (%lu vs %lu)",
1321                             sha1_to_hex(trg_entry->idx.sha1), sz, trg_size);
1322                 *mem_usage += sz;
1323         }
1324         if (!src->data) {
1325                 read_lock();
1326                 src->data = read_sha1_file(src_entry->idx.sha1, &type, &sz);
1327                 read_unlock();
1328                 if (!src->data)
1329                         die("object %s cannot be read",
1330                             sha1_to_hex(src_entry->idx.sha1));
1331                 if (sz != src_size)
1332                         die("object %s inconsistent object length (%lu vs %lu)",
1333                             sha1_to_hex(src_entry->idx.sha1), sz, src_size);
1334                 *mem_usage += sz;
1335         }
1336         if (!src->index) {
1337                 src->index = create_delta_index(src->data, src_size);
1338                 if (!src->index) {
1339                         static int warned = 0;
1340                         if (!warned++)
1341                                 warning("suboptimal pack - out of memory");
1342                         return 0;
1343                 }
1344                 *mem_usage += sizeof_delta_index(src->index);
1345         }
1347         delta_buf = create_delta(src->index, trg->data, trg_size, &delta_size, max_size);
1348         if (!delta_buf)
1349                 return 0;
1351         if (trg_entry->delta) {
1352                 /* Prefer only shallower same-sized deltas. */
1353                 if (delta_size == trg_entry->delta_size &&
1354                     src->depth + 1 >= trg->depth) {
1355                         free(delta_buf);
1356                         return 0;
1357                 }
1358         }
1360         /*
1361          * Handle memory allocation outside of the cache
1362          * accounting lock.  Compiler will optimize the strangeness
1363          * away when NO_PTHREADS is defined.
1364          */
1365         free(trg_entry->delta_data);
1366         cache_lock();
1367         if (trg_entry->delta_data) {
1368                 delta_cache_size -= trg_entry->delta_size;
1369                 trg_entry->delta_data = NULL;
1370         }
1371         if (delta_cacheable(src_size, trg_size, delta_size)) {
1372                 delta_cache_size += delta_size;
1373                 cache_unlock();
1374                 trg_entry->delta_data = xrealloc(delta_buf, delta_size);
1375         } else {
1376                 cache_unlock();
1377                 free(delta_buf);
1378         }
1380         trg_entry->delta = src_entry;
1381         trg_entry->delta_size = delta_size;
1382         trg->depth = src->depth + 1;
1384         return 1;
1387 static unsigned int check_delta_limit(struct object_entry *me, unsigned int n)
1389         struct object_entry *child = me->delta_child;
1390         unsigned int m = n;
1391         while (child) {
1392                 unsigned int c = check_delta_limit(child, n + 1);
1393                 if (m < c)
1394                         m = c;
1395                 child = child->delta_sibling;
1396         }
1397         return m;
1400 static unsigned long free_unpacked(struct unpacked *n)
1402         unsigned long freed_mem = sizeof_delta_index(n->index);
1403         free_delta_index(n->index);
1404         n->index = NULL;
1405         if (n->data) {
1406                 freed_mem += n->entry->size;
1407                 free(n->data);
1408                 n->data = NULL;
1409         }
1410         n->entry = NULL;
1411         n->depth = 0;
1412         return freed_mem;
1415 static void find_deltas(struct object_entry **list, unsigned *list_size,
1416                         int window, int depth, unsigned *processed)
1418         uint32_t i, idx = 0, count = 0;
1419         struct unpacked *array;
1420         unsigned long mem_usage = 0;
1422         array = xcalloc(window, sizeof(struct unpacked));
1424         for (;;) {
1425                 struct object_entry *entry;
1426                 struct unpacked *n = array + idx;
1427                 int j, max_depth, best_base = -1;
1429                 progress_lock();
1430                 if (!*list_size) {
1431                         progress_unlock();
1432                         break;
1433                 }
1434                 entry = *list++;
1435                 (*list_size)--;
1436                 if (!entry->preferred_base) {
1437                         (*processed)++;
1438                         display_progress(progress_state, *processed);
1439                 }
1440                 progress_unlock();
1442                 mem_usage -= free_unpacked(n);
1443                 n->entry = entry;
1445                 while (window_memory_limit &&
1446                        mem_usage > window_memory_limit &&
1447                        count > 1) {
1448                         uint32_t tail = (idx + window - count) % window;
1449                         mem_usage -= free_unpacked(array + tail);
1450                         count--;
1451                 }
1453                 /* We do not compute delta to *create* objects we are not
1454                  * going to pack.
1455                  */
1456                 if (entry->preferred_base)
1457                         goto next;
1459                 /*
1460                  * If the current object is at pack edge, take the depth the
1461                  * objects that depend on the current object into account
1462                  * otherwise they would become too deep.
1463                  */
1464                 max_depth = depth;
1465                 if (entry->delta_child) {
1466                         max_depth -= check_delta_limit(entry, 0);
1467                         if (max_depth <= 0)
1468                                 goto next;
1469                 }
1471                 j = window;
1472                 while (--j > 0) {
1473                         int ret;
1474                         uint32_t other_idx = idx + j;
1475                         struct unpacked *m;
1476                         if (other_idx >= window)
1477                                 other_idx -= window;
1478                         m = array + other_idx;
1479                         if (!m->entry)
1480                                 break;
1481                         ret = try_delta(n, m, max_depth, &mem_usage);
1482                         if (ret < 0)
1483                                 break;
1484                         else if (ret > 0)
1485                                 best_base = other_idx;
1486                 }
1488                 /*
1489                  * If we decided to cache the delta data, then it is best
1490                  * to compress it right away.  First because we have to do
1491                  * it anyway, and doing it here while we're threaded will
1492                  * save a lot of time in the non threaded write phase,
1493                  * as well as allow for caching more deltas within
1494                  * the same cache size limit.
1495                  * ...
1496                  * But only if not writing to stdout, since in that case
1497                  * the network is most likely throttling writes anyway,
1498                  * and therefore it is best to go to the write phase ASAP
1499                  * instead, as we can afford spending more time compressing
1500                  * between writes at that moment.
1501                  */
1502                 if (entry->delta_data && !pack_to_stdout) {
1503                         entry->z_delta_size = do_compress(&entry->delta_data,
1504                                                           entry->delta_size);
1505                         cache_lock();
1506                         delta_cache_size -= entry->delta_size;
1507                         delta_cache_size += entry->z_delta_size;
1508                         cache_unlock();
1509                 }
1511                 /* if we made n a delta, and if n is already at max
1512                  * depth, leaving it in the window is pointless.  we
1513                  * should evict it first.
1514                  */
1515                 if (entry->delta && max_depth <= n->depth)
1516                         continue;
1518                 /*
1519                  * Move the best delta base up in the window, after the
1520                  * currently deltified object, to keep it longer.  It will
1521                  * be the first base object to be attempted next.
1522                  */
1523                 if (entry->delta) {
1524                         struct unpacked swap = array[best_base];
1525                         int dist = (window + idx - best_base) % window;
1526                         int dst = best_base;
1527                         while (dist--) {
1528                                 int src = (dst + 1) % window;
1529                                 array[dst] = array[src];
1530                                 dst = src;
1531                         }
1532                         array[dst] = swap;
1533                 }
1535                 next:
1536                 idx++;
1537                 if (count + 1 < window)
1538                         count++;
1539                 if (idx >= window)
1540                         idx = 0;
1541         }
1543         for (i = 0; i < window; ++i) {
1544                 free_delta_index(array[i].index);
1545                 free(array[i].data);
1546         }
1547         free(array);
1550 #ifndef NO_PTHREADS
1552 static void try_to_free_from_threads(size_t size)
1554         read_lock();
1555         release_pack_memory(size, -1);
1556         read_unlock();
1560  * The main thread waits on the condition that (at least) one of the workers
1561  * has stopped working (which is indicated in the .working member of
1562  * struct thread_params).
1563  * When a work thread has completed its work, it sets .working to 0 and
1564  * signals the main thread and waits on the condition that .data_ready
1565  * becomes 1.
1566  */
1568 struct thread_params {
1569         pthread_t thread;
1570         struct object_entry **list;
1571         unsigned list_size;
1572         unsigned remaining;
1573         int window;
1574         int depth;
1575         int working;
1576         int data_ready;
1577         pthread_mutex_t mutex;
1578         pthread_cond_t cond;
1579         unsigned *processed;
1582 static pthread_cond_t progress_cond;
1585  * Mutex and conditional variable can't be statically-initialized on Windows.
1586  */
1587 static void init_threaded_search(void)
1589         init_recursive_mutex(&read_mutex);
1590         pthread_mutex_init(&cache_mutex, NULL);
1591         pthread_mutex_init(&progress_mutex, NULL);
1592         pthread_cond_init(&progress_cond, NULL);
1593         set_try_to_free_routine(try_to_free_from_threads);
1596 static void cleanup_threaded_search(void)
1598         set_try_to_free_routine(NULL);
1599         pthread_cond_destroy(&progress_cond);
1600         pthread_mutex_destroy(&read_mutex);
1601         pthread_mutex_destroy(&cache_mutex);
1602         pthread_mutex_destroy(&progress_mutex);
1605 static void *threaded_find_deltas(void *arg)
1607         struct thread_params *me = arg;
1609         while (me->remaining) {
1610                 find_deltas(me->list, &me->remaining,
1611                             me->window, me->depth, me->processed);
1613                 progress_lock();
1614                 me->working = 0;
1615                 pthread_cond_signal(&progress_cond);
1616                 progress_unlock();
1618                 /*
1619                  * We must not set ->data_ready before we wait on the
1620                  * condition because the main thread may have set it to 1
1621                  * before we get here. In order to be sure that new
1622                  * work is available if we see 1 in ->data_ready, it
1623                  * was initialized to 0 before this thread was spawned
1624                  * and we reset it to 0 right away.
1625                  */
1626                 pthread_mutex_lock(&me->mutex);
1627                 while (!me->data_ready)
1628                         pthread_cond_wait(&me->cond, &me->mutex);
1629                 me->data_ready = 0;
1630                 pthread_mutex_unlock(&me->mutex);
1631         }
1632         /* leave ->working 1 so that this doesn't get more work assigned */
1633         return NULL;
1636 static void ll_find_deltas(struct object_entry **list, unsigned list_size,
1637                            int window, int depth, unsigned *processed)
1639         struct thread_params *p;
1640         int i, ret, active_threads = 0;
1642         init_threaded_search();
1644         if (!delta_search_threads)      /* --threads=0 means autodetect */
1645                 delta_search_threads = online_cpus();
1646         if (delta_search_threads <= 1) {
1647                 find_deltas(list, &list_size, window, depth, processed);
1648                 cleanup_threaded_search();
1649                 return;
1650         }
1651         if (progress > pack_to_stdout)
1652                 fprintf(stderr, "Delta compression using up to %d threads.\n",
1653                                 delta_search_threads);
1654         p = xcalloc(delta_search_threads, sizeof(*p));
1656         /* Partition the work amongst work threads. */
1657         for (i = 0; i < delta_search_threads; i++) {
1658                 unsigned sub_size = list_size / (delta_search_threads - i);
1660                 /* don't use too small segments or no deltas will be found */
1661                 if (sub_size < 2*window && i+1 < delta_search_threads)
1662                         sub_size = 0;
1664                 p[i].window = window;
1665                 p[i].depth = depth;
1666                 p[i].processed = processed;
1667                 p[i].working = 1;
1668                 p[i].data_ready = 0;
1670                 /* try to split chunks on "path" boundaries */
1671                 while (sub_size && sub_size < list_size &&
1672                        list[sub_size]->hash &&
1673                        list[sub_size]->hash == list[sub_size-1]->hash)
1674                         sub_size++;
1676                 p[i].list = list;
1677                 p[i].list_size = sub_size;
1678                 p[i].remaining = sub_size;
1680                 list += sub_size;
1681                 list_size -= sub_size;
1682         }
1684         /* Start work threads. */
1685         for (i = 0; i < delta_search_threads; i++) {
1686                 if (!p[i].list_size)
1687                         continue;
1688                 pthread_mutex_init(&p[i].mutex, NULL);
1689                 pthread_cond_init(&p[i].cond, NULL);
1690                 ret = pthread_create(&p[i].thread, NULL,
1691                                      threaded_find_deltas, &p[i]);
1692                 if (ret)
1693                         die("unable to create thread: %s", strerror(ret));
1694                 active_threads++;
1695         }
1697         /*
1698          * Now let's wait for work completion.  Each time a thread is done
1699          * with its work, we steal half of the remaining work from the
1700          * thread with the largest number of unprocessed objects and give
1701          * it to that newly idle thread.  This ensure good load balancing
1702          * until the remaining object list segments are simply too short
1703          * to be worth splitting anymore.
1704          */
1705         while (active_threads) {
1706                 struct thread_params *target = NULL;
1707                 struct thread_params *victim = NULL;
1708                 unsigned sub_size = 0;
1710                 progress_lock();
1711                 for (;;) {
1712                         for (i = 0; !target && i < delta_search_threads; i++)
1713                                 if (!p[i].working)
1714                                         target = &p[i];
1715                         if (target)
1716                                 break;
1717                         pthread_cond_wait(&progress_cond, &progress_mutex);
1718                 }
1720                 for (i = 0; i < delta_search_threads; i++)
1721                         if (p[i].remaining > 2*window &&
1722                             (!victim || victim->remaining < p[i].remaining))
1723                                 victim = &p[i];
1724                 if (victim) {
1725                         sub_size = victim->remaining / 2;
1726                         list = victim->list + victim->list_size - sub_size;
1727                         while (sub_size && list[0]->hash &&
1728                                list[0]->hash == list[-1]->hash) {
1729                                 list++;
1730                                 sub_size--;
1731                         }
1732                         if (!sub_size) {
1733                                 /*
1734                                  * It is possible for some "paths" to have
1735                                  * so many objects that no hash boundary
1736                                  * might be found.  Let's just steal the
1737                                  * exact half in that case.
1738                                  */
1739                                 sub_size = victim->remaining / 2;
1740                                 list -= sub_size;
1741                         }
1742                         target->list = list;
1743                         victim->list_size -= sub_size;
1744                         victim->remaining -= sub_size;
1745                 }
1746                 target->list_size = sub_size;
1747                 target->remaining = sub_size;
1748                 target->working = 1;
1749                 progress_unlock();
1751                 pthread_mutex_lock(&target->mutex);
1752                 target->data_ready = 1;
1753                 pthread_cond_signal(&target->cond);
1754                 pthread_mutex_unlock(&target->mutex);
1756                 if (!sub_size) {
1757                         pthread_join(target->thread, NULL);
1758                         pthread_cond_destroy(&target->cond);
1759                         pthread_mutex_destroy(&target->mutex);
1760                         active_threads--;
1761                 }
1762         }
1763         cleanup_threaded_search();
1764         free(p);
1767 #else
1768 #define ll_find_deltas(l, s, w, d, p)   find_deltas(l, &s, w, d, p)
1769 #endif
1771 static int add_ref_tag(const char *path, const unsigned char *sha1, int flag, void *cb_data)
1773         unsigned char peeled[20];
1775         if (!prefixcmp(path, "refs/tags/") && /* is a tag? */
1776             !peel_ref(path, peeled)        && /* peelable? */
1777             !is_null_sha1(peeled)          && /* annotated tag? */
1778             locate_object_entry(peeled))      /* object packed? */
1779                 add_object_entry(sha1, OBJ_TAG, NULL, 0);
1780         return 0;
1783 static void prepare_pack(int window, int depth)
1785         struct object_entry **delta_list;
1786         uint32_t i, nr_deltas;
1787         unsigned n;
1789         get_object_details();
1791         /*
1792          * If we're locally repacking then we need to be doubly careful
1793          * from now on in order to make sure no stealth corruption gets
1794          * propagated to the new pack.  Clients receiving streamed packs
1795          * should validate everything they get anyway so no need to incur
1796          * the additional cost here in that case.
1797          */
1798         if (!pack_to_stdout)
1799                 do_check_packed_object_crc = 1;
1801         if (!nr_objects || !window || !depth)
1802                 return;
1804         delta_list = xmalloc(nr_objects * sizeof(*delta_list));
1805         nr_deltas = n = 0;
1807         for (i = 0; i < nr_objects; i++) {
1808                 struct object_entry *entry = objects + i;
1810                 if (entry->delta)
1811                         /* This happens if we decided to reuse existing
1812                          * delta from a pack.  "reuse_delta &&" is implied.
1813                          */
1814                         continue;
1816                 if (entry->size < 50)
1817                         continue;
1819                 if (entry->no_try_delta)
1820                         continue;
1822                 if (!entry->preferred_base) {
1823                         nr_deltas++;
1824                         if (entry->type < 0)
1825                                 die("unable to get type of object %s",
1826                                     sha1_to_hex(entry->idx.sha1));
1827                 } else {
1828                         if (entry->type < 0) {
1829                                 /*
1830                                  * This object is not found, but we
1831                                  * don't have to include it anyway.
1832                                  */
1833                                 continue;
1834                         }
1835                 }
1837                 delta_list[n++] = entry;
1838         }
1840         if (nr_deltas && n > 1) {
1841                 unsigned nr_done = 0;
1842                 if (progress)
1843                         progress_state = start_progress("Compressing objects",
1844                                                         nr_deltas);
1845                 qsort(delta_list, n, sizeof(*delta_list), type_size_sort);
1846                 ll_find_deltas(delta_list, n, window+1, depth, &nr_done);
1847                 stop_progress(&progress_state);
1848                 if (nr_done != nr_deltas)
1849                         die("inconsistency with delta count");
1850         }
1851         free(delta_list);
1854 static int git_pack_config(const char *k, const char *v, void *cb)
1856         if (!strcmp(k, "pack.window")) {
1857                 window = git_config_int(k, v);
1858                 return 0;
1859         }
1860         if (!strcmp(k, "pack.windowmemory")) {
1861                 window_memory_limit = git_config_ulong(k, v);
1862                 return 0;
1863         }
1864         if (!strcmp(k, "pack.depth")) {
1865                 depth = git_config_int(k, v);
1866                 return 0;
1867         }
1868         if (!strcmp(k, "pack.compression")) {
1869                 int level = git_config_int(k, v);
1870                 if (level == -1)
1871                         level = Z_DEFAULT_COMPRESSION;
1872                 else if (level < 0 || level > Z_BEST_COMPRESSION)
1873                         die("bad pack compression level %d", level);
1874                 pack_compression_level = level;
1875                 pack_compression_seen = 1;
1876                 return 0;
1877         }
1878         if (!strcmp(k, "pack.deltacachesize")) {
1879                 max_delta_cache_size = git_config_int(k, v);
1880                 return 0;
1881         }
1882         if (!strcmp(k, "pack.deltacachelimit")) {
1883                 cache_max_small_delta_size = git_config_int(k, v);
1884                 return 0;
1885         }
1886         if (!strcmp(k, "pack.threads")) {
1887                 delta_search_threads = git_config_int(k, v);
1888                 if (delta_search_threads < 0)
1889                         die("invalid number of threads specified (%d)",
1890                             delta_search_threads);
1891 #ifdef NO_PTHREADS
1892                 if (delta_search_threads != 1)
1893                         warning("no threads support, ignoring %s", k);
1894 #endif
1895                 return 0;
1896         }
1897         if (!strcmp(k, "pack.indexversion")) {
1898                 pack_idx_default_version = git_config_int(k, v);
1899                 if (pack_idx_default_version > 2)
1900                         die("bad pack.indexversion=%"PRIu32,
1901                                 pack_idx_default_version);
1902                 return 0;
1903         }
1904         if (!strcmp(k, "pack.packsizelimit")) {
1905                 pack_size_limit_cfg = git_config_ulong(k, v);
1906                 return 0;
1907         }
1908         return git_default_config(k, v, cb);
1911 static void read_object_list_from_stdin(void)
1913         char line[40 + 1 + PATH_MAX + 2];
1914         unsigned char sha1[20];
1916         for (;;) {
1917                 if (!fgets(line, sizeof(line), stdin)) {
1918                         if (feof(stdin))
1919                                 break;
1920                         if (!ferror(stdin))
1921                                 die("fgets returned NULL, not EOF, not error!");
1922                         if (errno != EINTR)
1923                                 die_errno("fgets");
1924                         clearerr(stdin);
1925                         continue;
1926                 }
1927                 if (line[0] == '-') {
1928                         if (get_sha1_hex(line+1, sha1))
1929                                 die("expected edge sha1, got garbage:\n %s",
1930                                     line);
1931                         add_preferred_base(sha1);
1932                         continue;
1933                 }
1934                 if (get_sha1_hex(line, sha1))
1935                         die("expected sha1, got garbage:\n %s", line);
1937                 add_preferred_base_object(line+41);
1938                 add_object_entry(sha1, 0, line+41, 0);
1939         }
1942 #define OBJECT_ADDED (1u<<20)
1944 static void show_commit(struct commit *commit, void *data)
1946         add_object_entry(commit->object.sha1, OBJ_COMMIT, NULL, 0);
1947         commit->object.flags |= OBJECT_ADDED;
1950 static void show_object(struct object *obj, const struct name_path *path, const char *last)
1952         char *name = path_name(path, last);
1954         add_preferred_base_object(name);
1955         add_object_entry(obj->sha1, obj->type, name, 0);
1956         obj->flags |= OBJECT_ADDED;
1958         /*
1959          * We will have generated the hash from the name,
1960          * but not saved a pointer to it - we can free it
1961          */
1962         free((char *)name);
1965 static void show_edge(struct commit *commit)
1967         add_preferred_base(commit->object.sha1);
1970 struct in_pack_object {
1971         off_t offset;
1972         struct object *object;
1975 struct in_pack {
1976         int alloc;
1977         int nr;
1978         struct in_pack_object *array;
1981 static void mark_in_pack_object(struct object *object, struct packed_git *p, struct in_pack *in_pack)
1983         in_pack->array[in_pack->nr].offset = find_pack_entry_one(object->sha1, p);
1984         in_pack->array[in_pack->nr].object = object;
1985         in_pack->nr++;
1989  * Compare the objects in the offset order, in order to emulate the
1990  * "git rev-list --objects" output that produced the pack originally.
1991  */
1992 static int ofscmp(const void *a_, const void *b_)
1994         struct in_pack_object *a = (struct in_pack_object *)a_;
1995         struct in_pack_object *b = (struct in_pack_object *)b_;
1997         if (a->offset < b->offset)
1998                 return -1;
1999         else if (a->offset > b->offset)
2000                 return 1;
2001         else
2002                 return hashcmp(a->object->sha1, b->object->sha1);
2005 static void add_objects_in_unpacked_packs(struct rev_info *revs)
2007         struct packed_git *p;
2008         struct in_pack in_pack;
2009         uint32_t i;
2011         memset(&in_pack, 0, sizeof(in_pack));
2013         for (p = packed_git; p; p = p->next) {
2014                 const unsigned char *sha1;
2015                 struct object *o;
2017                 if (!p->pack_local || p->pack_keep)
2018                         continue;
2019                 if (open_pack_index(p))
2020                         die("cannot open pack index");
2022                 ALLOC_GROW(in_pack.array,
2023                            in_pack.nr + p->num_objects,
2024                            in_pack.alloc);
2026                 for (i = 0; i < p->num_objects; i++) {
2027                         sha1 = nth_packed_object_sha1(p, i);
2028                         o = lookup_unknown_object(sha1);
2029                         if (!(o->flags & OBJECT_ADDED))
2030                                 mark_in_pack_object(o, p, &in_pack);
2031                         o->flags |= OBJECT_ADDED;
2032                 }
2033         }
2035         if (in_pack.nr) {
2036                 qsort(in_pack.array, in_pack.nr, sizeof(in_pack.array[0]),
2037                       ofscmp);
2038                 for (i = 0; i < in_pack.nr; i++) {
2039                         struct object *o = in_pack.array[i].object;
2040                         add_object_entry(o->sha1, o->type, "", 0);
2041                 }
2042         }
2043         free(in_pack.array);
2046 static int has_sha1_pack_kept_or_nonlocal(const unsigned char *sha1)
2048         static struct packed_git *last_found = (void *)1;
2049         struct packed_git *p;
2051         p = (last_found != (void *)1) ? last_found : packed_git;
2053         while (p) {
2054                 if ((!p->pack_local || p->pack_keep) &&
2055                         find_pack_entry_one(sha1, p)) {
2056                         last_found = p;
2057                         return 1;
2058                 }
2059                 if (p == last_found)
2060                         p = packed_git;
2061                 else
2062                         p = p->next;
2063                 if (p == last_found)
2064                         p = p->next;
2065         }
2066         return 0;
2069 static void loosen_unused_packed_objects(struct rev_info *revs)
2071         struct packed_git *p;
2072         uint32_t i;
2073         const unsigned char *sha1;
2075         for (p = packed_git; p; p = p->next) {
2076                 if (!p->pack_local || p->pack_keep)
2077                         continue;
2079                 if (open_pack_index(p))
2080                         die("cannot open pack index");
2082                 for (i = 0; i < p->num_objects; i++) {
2083                         sha1 = nth_packed_object_sha1(p, i);
2084                         if (!locate_object_entry(sha1) &&
2085                                 !has_sha1_pack_kept_or_nonlocal(sha1))
2086                                 if (force_object_loose(sha1, p->mtime))
2087                                         die("unable to force loose object");
2088                 }
2089         }
2092 static void get_object_list(int ac, const char **av)
2094         struct rev_info revs;
2095         char line[1000];
2096         int flags = 0;
2098         init_revisions(&revs, NULL);
2099         save_commit_buffer = 0;
2100         setup_revisions(ac, av, &revs, NULL);
2102         while (fgets(line, sizeof(line), stdin) != NULL) {
2103                 int len = strlen(line);
2104                 if (len && line[len - 1] == '\n')
2105                         line[--len] = 0;
2106                 if (!len)
2107                         break;
2108                 if (*line == '-') {
2109                         if (!strcmp(line, "--not")) {
2110                                 flags ^= UNINTERESTING;
2111                                 continue;
2112                         }
2113                         die("not a rev '%s'", line);
2114                 }
2115                 if (handle_revision_arg(line, &revs, flags, 1))
2116                         die("bad revision '%s'", line);
2117         }
2119         if (prepare_revision_walk(&revs))
2120                 die("revision walk setup failed");
2121         mark_edges_uninteresting(revs.commits, &revs, show_edge);
2122         traverse_commit_list(&revs, show_commit, show_object, NULL);
2124         if (keep_unreachable)
2125                 add_objects_in_unpacked_packs(&revs);
2126         if (unpack_unreachable)
2127                 loosen_unused_packed_objects(&revs);
2130 int cmd_pack_objects(int argc, const char **argv, const char *prefix)
2132         int use_internal_rev_list = 0;
2133         int thin = 0;
2134         int all_progress_implied = 0;
2135         uint32_t i;
2136         const char **rp_av;
2137         int rp_ac_alloc = 64;
2138         int rp_ac;
2140         read_replace_refs = 0;
2142         rp_av = xcalloc(rp_ac_alloc, sizeof(*rp_av));
2144         rp_av[0] = "pack-objects";
2145         rp_av[1] = "--objects"; /* --thin will make it --objects-edge */
2146         rp_ac = 2;
2148         git_config(git_pack_config, NULL);
2149         if (!pack_compression_seen && core_compression_seen)
2150                 pack_compression_level = core_compression_level;
2152         progress = isatty(2);
2153         for (i = 1; i < argc; i++) {
2154                 const char *arg = argv[i];
2156                 if (*arg != '-')
2157                         break;
2159                 if (!strcmp("--non-empty", arg)) {
2160                         non_empty = 1;
2161                         continue;
2162                 }
2163                 if (!strcmp("--local", arg)) {
2164                         local = 1;
2165                         continue;
2166                 }
2167                 if (!strcmp("--incremental", arg)) {
2168                         incremental = 1;
2169                         continue;
2170                 }
2171                 if (!strcmp("--honor-pack-keep", arg)) {
2172                         ignore_packed_keep = 1;
2173                         continue;
2174                 }
2175                 if (!prefixcmp(arg, "--compression=")) {
2176                         char *end;
2177                         int level = strtoul(arg+14, &end, 0);
2178                         if (!arg[14] || *end)
2179                                 usage(pack_usage);
2180                         if (level == -1)
2181                                 level = Z_DEFAULT_COMPRESSION;
2182                         else if (level < 0 || level > Z_BEST_COMPRESSION)
2183                                 die("bad pack compression level %d", level);
2184                         pack_compression_level = level;
2185                         continue;
2186                 }
2187                 if (!prefixcmp(arg, "--max-pack-size=")) {
2188                         pack_size_limit_cfg = 0;
2189                         if (!git_parse_ulong(arg+16, &pack_size_limit))
2190                                 usage(pack_usage);
2191                         continue;
2192                 }
2193                 if (!prefixcmp(arg, "--window=")) {
2194                         char *end;
2195                         window = strtoul(arg+9, &end, 0);
2196                         if (!arg[9] || *end)
2197                                 usage(pack_usage);
2198                         continue;
2199                 }
2200                 if (!prefixcmp(arg, "--window-memory=")) {
2201                         if (!git_parse_ulong(arg+16, &window_memory_limit))
2202                                 usage(pack_usage);
2203                         continue;
2204                 }
2205                 if (!prefixcmp(arg, "--threads=")) {
2206                         char *end;
2207                         delta_search_threads = strtoul(arg+10, &end, 0);
2208                         if (!arg[10] || *end || delta_search_threads < 0)
2209                                 usage(pack_usage);
2210 #ifdef NO_PTHREADS
2211                         if (delta_search_threads != 1)
2212                                 warning("no threads support, "
2213                                         "ignoring %s", arg);
2214 #endif
2215                         continue;
2216                 }
2217                 if (!prefixcmp(arg, "--depth=")) {
2218                         char *end;
2219                         depth = strtoul(arg+8, &end, 0);
2220                         if (!arg[8] || *end)
2221                                 usage(pack_usage);
2222                         continue;
2223                 }
2224                 if (!strcmp("--progress", arg)) {
2225                         progress = 1;
2226                         continue;
2227                 }
2228                 if (!strcmp("--all-progress", arg)) {
2229                         progress = 2;
2230                         continue;
2231                 }
2232                 if (!strcmp("--all-progress-implied", arg)) {
2233                         all_progress_implied = 1;
2234                         continue;
2235                 }
2236                 if (!strcmp("-q", arg)) {
2237                         progress = 0;
2238                         continue;
2239                 }
2240                 if (!strcmp("--no-reuse-delta", arg)) {
2241                         reuse_delta = 0;
2242                         continue;
2243                 }
2244                 if (!strcmp("--no-reuse-object", arg)) {
2245                         reuse_object = reuse_delta = 0;
2246                         continue;
2247                 }
2248                 if (!strcmp("--delta-base-offset", arg)) {
2249                         allow_ofs_delta = 1;
2250                         continue;
2251                 }
2252                 if (!strcmp("--stdout", arg)) {
2253                         pack_to_stdout = 1;
2254                         continue;
2255                 }
2256                 if (!strcmp("--revs", arg)) {
2257                         use_internal_rev_list = 1;
2258                         continue;
2259                 }
2260                 if (!strcmp("--keep-unreachable", arg)) {
2261                         keep_unreachable = 1;
2262                         continue;
2263                 }
2264                 if (!strcmp("--unpack-unreachable", arg)) {
2265                         unpack_unreachable = 1;
2266                         continue;
2267                 }
2268                 if (!strcmp("--include-tag", arg)) {
2269                         include_tag = 1;
2270                         continue;
2271                 }
2272                 if (!strcmp("--unpacked", arg) ||
2273                     !strcmp("--reflog", arg) ||
2274                     !strcmp("--all", arg)) {
2275                         use_internal_rev_list = 1;
2276                         if (rp_ac >= rp_ac_alloc - 1) {
2277                                 rp_ac_alloc = alloc_nr(rp_ac_alloc);
2278                                 rp_av = xrealloc(rp_av,
2279                                                  rp_ac_alloc * sizeof(*rp_av));
2280                         }
2281                         rp_av[rp_ac++] = arg;
2282                         continue;
2283                 }
2284                 if (!strcmp("--thin", arg)) {
2285                         use_internal_rev_list = 1;
2286                         thin = 1;
2287                         rp_av[1] = "--objects-edge";
2288                         continue;
2289                 }
2290                 if (!prefixcmp(arg, "--index-version=")) {
2291                         char *c;
2292                         pack_idx_default_version = strtoul(arg + 16, &c, 10);
2293                         if (pack_idx_default_version > 2)
2294                                 die("bad %s", arg);
2295                         if (*c == ',')
2296                                 pack_idx_off32_limit = strtoul(c+1, &c, 0);
2297                         if (*c || pack_idx_off32_limit & 0x80000000)
2298                                 die("bad %s", arg);
2299                         continue;
2300                 }
2301                 if (!strcmp(arg, "--keep-true-parents")) {
2302                         grafts_replace_parents = 0;
2303                         continue;
2304                 }
2305                 usage(pack_usage);
2306         }
2308         /* Traditionally "pack-objects [options] base extra" failed;
2309          * we would however want to take refs parameter that would
2310          * have been given to upstream rev-list ourselves, which means
2311          * we somehow want to say what the base name is.  So the
2312          * syntax would be:
2313          *
2314          * pack-objects [options] base <refs...>
2315          *
2316          * in other words, we would treat the first non-option as the
2317          * base_name and send everything else to the internal revision
2318          * walker.
2319          */
2321         if (!pack_to_stdout)
2322                 base_name = argv[i++];
2324         if (pack_to_stdout != !base_name)
2325                 usage(pack_usage);
2327         if (!pack_to_stdout && !pack_size_limit)
2328                 pack_size_limit = pack_size_limit_cfg;
2329         if (pack_to_stdout && pack_size_limit)
2330                 die("--max-pack-size cannot be used to build a pack for transfer.");
2331         if (pack_size_limit && pack_size_limit < 1024*1024) {
2332                 warning("minimum pack size limit is 1 MiB");
2333                 pack_size_limit = 1024*1024;
2334         }
2336         if (!pack_to_stdout && thin)
2337                 die("--thin cannot be used to build an indexable pack.");
2339         if (keep_unreachable && unpack_unreachable)
2340                 die("--keep-unreachable and --unpack-unreachable are incompatible.");
2342         if (progress && all_progress_implied)
2343                 progress = 2;
2345         prepare_packed_git();
2347         if (progress)
2348                 progress_state = start_progress("Counting objects", 0);
2349         if (!use_internal_rev_list)
2350                 read_object_list_from_stdin();
2351         else {
2352                 rp_av[rp_ac] = NULL;
2353                 get_object_list(rp_ac, rp_av);
2354         }
2355         cleanup_preferred_base();
2356         if (include_tag && nr_result)
2357                 for_each_ref(add_ref_tag, NULL);
2358         stop_progress(&progress_state);
2360         if (non_empty && !nr_result)
2361                 return 0;
2362         if (nr_result)
2363                 prepare_pack(window, depth);
2364         write_pack_file();
2365         if (progress)
2366                 fprintf(stderr, "Total %"PRIu32" (delta %"PRIu32"),"
2367                         " reused %"PRIu32" (delta %"PRIu32")\n",
2368                         written, written_delta, reused, reused_delta);
2369         return 0;