Enable threaded async procedures whenever pthreads is available
[git/dscho.git] / builtin-pack-objects.c
blob6b2f65c6db833df59f8b7ab50244f630a828c9a1
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 "thread-utils.h"
22 #include <pthread.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  * we are going to reuse the existing object data as is.  make
159  * sure it is not corrupt.
160  */
161 static int check_pack_inflate(struct packed_git *p,
162                 struct pack_window **w_curs,
163                 off_t offset,
164                 off_t len,
165                 unsigned long expect)
167         z_stream stream;
168         unsigned char fakebuf[4096], *in;
169         int st;
171         memset(&stream, 0, sizeof(stream));
172         git_inflate_init(&stream);
173         do {
174                 in = use_pack(p, w_curs, offset, &stream.avail_in);
175                 stream.next_in = in;
176                 stream.next_out = fakebuf;
177                 stream.avail_out = sizeof(fakebuf);
178                 st = git_inflate(&stream, Z_FINISH);
179                 offset += stream.next_in - in;
180         } while (st == Z_OK || st == Z_BUF_ERROR);
181         git_inflate_end(&stream);
182         return (st == Z_STREAM_END &&
183                 stream.total_out == expect &&
184                 stream.total_in == len) ? 0 : -1;
187 static void copy_pack_data(struct sha1file *f,
188                 struct packed_git *p,
189                 struct pack_window **w_curs,
190                 off_t offset,
191                 off_t len)
193         unsigned char *in;
194         unsigned int avail;
196         while (len) {
197                 in = use_pack(p, w_curs, offset, &avail);
198                 if (avail > len)
199                         avail = (unsigned int)len;
200                 sha1write(f, in, avail);
201                 offset += avail;
202                 len -= avail;
203         }
206 static unsigned long write_object(struct sha1file *f,
207                                   struct object_entry *entry,
208                                   off_t write_offset)
210         unsigned long size, limit, datalen;
211         void *buf;
212         unsigned char header[10], dheader[10];
213         unsigned hdrlen;
214         enum object_type type;
215         int usable_delta, to_reuse;
217         if (!pack_to_stdout)
218                 crc32_begin(f);
220         type = entry->type;
222         /* apply size limit if limited packsize and not first object */
223         if (!pack_size_limit || !nr_written)
224                 limit = 0;
225         else if (pack_size_limit <= write_offset)
226                 /*
227                  * the earlier object did not fit the limit; avoid
228                  * mistaking this with unlimited (i.e. limit = 0).
229                  */
230                 limit = 1;
231         else
232                 limit = pack_size_limit - write_offset;
234         if (!entry->delta)
235                 usable_delta = 0;       /* no delta */
236         else if (!pack_size_limit)
237                usable_delta = 1;        /* unlimited packfile */
238         else if (entry->delta->idx.offset == (off_t)-1)
239                 usable_delta = 0;       /* base was written to another pack */
240         else if (entry->delta->idx.offset)
241                 usable_delta = 1;       /* base already exists in this pack */
242         else
243                 usable_delta = 0;       /* base could end up in another pack */
245         if (!reuse_object)
246                 to_reuse = 0;   /* explicit */
247         else if (!entry->in_pack)
248                 to_reuse = 0;   /* can't reuse what we don't have */
249         else if (type == OBJ_REF_DELTA || type == OBJ_OFS_DELTA)
250                                 /* check_object() decided it for us ... */
251                 to_reuse = usable_delta;
252                                 /* ... but pack split may override that */
253         else if (type != entry->in_pack_type)
254                 to_reuse = 0;   /* pack has delta which is unusable */
255         else if (entry->delta)
256                 to_reuse = 0;   /* we want to pack afresh */
257         else
258                 to_reuse = 1;   /* we have it in-pack undeltified,
259                                  * and we do not need to deltify it.
260                                  */
262         if (!to_reuse) {
263                 no_reuse:
264                 if (!usable_delta) {
265                         buf = read_sha1_file(entry->idx.sha1, &type, &size);
266                         if (!buf)
267                                 die("unable to read %s", sha1_to_hex(entry->idx.sha1));
268                         /*
269                          * make sure no cached delta data remains from a
270                          * previous attempt before a pack split occurred.
271                          */
272                         free(entry->delta_data);
273                         entry->delta_data = NULL;
274                         entry->z_delta_size = 0;
275                 } else if (entry->delta_data) {
276                         size = entry->delta_size;
277                         buf = entry->delta_data;
278                         entry->delta_data = NULL;
279                         type = (allow_ofs_delta && entry->delta->idx.offset) ?
280                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
281                 } else {
282                         buf = get_delta(entry);
283                         size = entry->delta_size;
284                         type = (allow_ofs_delta && entry->delta->idx.offset) ?
285                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
286                 }
288                 if (entry->z_delta_size)
289                         datalen = entry->z_delta_size;
290                 else
291                         datalen = do_compress(&buf, size);
293                 /*
294                  * The object header is a byte of 'type' followed by zero or
295                  * more bytes of length.
296                  */
297                 hdrlen = encode_in_pack_object_header(type, size, header);
299                 if (type == OBJ_OFS_DELTA) {
300                         /*
301                          * Deltas with relative base contain an additional
302                          * encoding of the relative offset for the delta
303                          * base from this object's position in the pack.
304                          */
305                         off_t ofs = entry->idx.offset - entry->delta->idx.offset;
306                         unsigned pos = sizeof(dheader) - 1;
307                         dheader[pos] = ofs & 127;
308                         while (ofs >>= 7)
309                                 dheader[--pos] = 128 | (--ofs & 127);
310                         if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit) {
311                                 free(buf);
312                                 return 0;
313                         }
314                         sha1write(f, header, hdrlen);
315                         sha1write(f, dheader + pos, sizeof(dheader) - pos);
316                         hdrlen += sizeof(dheader) - pos;
317                 } else if (type == OBJ_REF_DELTA) {
318                         /*
319                          * Deltas with a base reference contain
320                          * an additional 20 bytes for the base sha1.
321                          */
322                         if (limit && hdrlen + 20 + datalen + 20 >= limit) {
323                                 free(buf);
324                                 return 0;
325                         }
326                         sha1write(f, header, hdrlen);
327                         sha1write(f, entry->delta->idx.sha1, 20);
328                         hdrlen += 20;
329                 } else {
330                         if (limit && hdrlen + datalen + 20 >= limit) {
331                                 free(buf);
332                                 return 0;
333                         }
334                         sha1write(f, header, hdrlen);
335                 }
336                 sha1write(f, buf, datalen);
337                 free(buf);
338         }
339         else {
340                 struct packed_git *p = entry->in_pack;
341                 struct pack_window *w_curs = NULL;
342                 struct revindex_entry *revidx;
343                 off_t offset;
345                 if (entry->delta)
346                         type = (allow_ofs_delta && entry->delta->idx.offset) ?
347                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
348                 hdrlen = encode_in_pack_object_header(type, entry->size, header);
350                 offset = entry->in_pack_offset;
351                 revidx = find_pack_revindex(p, offset);
352                 datalen = revidx[1].offset - offset;
353                 if (!pack_to_stdout && p->index_version > 1 &&
354                     check_pack_crc(p, &w_curs, offset, datalen, revidx->nr)) {
355                         error("bad packed object CRC for %s", sha1_to_hex(entry->idx.sha1));
356                         unuse_pack(&w_curs);
357                         goto no_reuse;
358                 }
360                 offset += entry->in_pack_header_size;
361                 datalen -= entry->in_pack_header_size;
362                 if (!pack_to_stdout && p->index_version == 1 &&
363                     check_pack_inflate(p, &w_curs, offset, datalen, entry->size)) {
364                         error("corrupt packed object for %s", sha1_to_hex(entry->idx.sha1));
365                         unuse_pack(&w_curs);
366                         goto no_reuse;
367                 }
369                 if (type == OBJ_OFS_DELTA) {
370                         off_t ofs = entry->idx.offset - entry->delta->idx.offset;
371                         unsigned pos = sizeof(dheader) - 1;
372                         dheader[pos] = ofs & 127;
373                         while (ofs >>= 7)
374                                 dheader[--pos] = 128 | (--ofs & 127);
375                         if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit) {
376                                 unuse_pack(&w_curs);
377                                 return 0;
378                         }
379                         sha1write(f, header, hdrlen);
380                         sha1write(f, dheader + pos, sizeof(dheader) - pos);
381                         hdrlen += sizeof(dheader) - pos;
382                         reused_delta++;
383                 } else if (type == OBJ_REF_DELTA) {
384                         if (limit && hdrlen + 20 + datalen + 20 >= limit) {
385                                 unuse_pack(&w_curs);
386                                 return 0;
387                         }
388                         sha1write(f, header, hdrlen);
389                         sha1write(f, entry->delta->idx.sha1, 20);
390                         hdrlen += 20;
391                         reused_delta++;
392                 } else {
393                         if (limit && hdrlen + datalen + 20 >= limit) {
394                                 unuse_pack(&w_curs);
395                                 return 0;
396                         }
397                         sha1write(f, header, hdrlen);
398                 }
399                 copy_pack_data(f, p, &w_curs, offset, datalen);
400                 unuse_pack(&w_curs);
401                 reused++;
402         }
403         if (usable_delta)
404                 written_delta++;
405         written++;
406         if (!pack_to_stdout)
407                 entry->idx.crc32 = crc32_end(f);
408         return hdrlen + datalen;
411 static int write_one(struct sha1file *f,
412                                struct object_entry *e,
413                                off_t *offset)
415         unsigned long size;
417         /* offset is non zero if object is written already. */
418         if (e->idx.offset || e->preferred_base)
419                 return -1;
421         /* if we are deltified, write out base object first. */
422         if (e->delta && !write_one(f, e->delta, offset))
423                 return 0;
425         e->idx.offset = *offset;
426         size = write_object(f, e, *offset);
427         if (!size) {
428                 e->idx.offset = 0;
429                 return 0;
430         }
431         written_list[nr_written++] = &e->idx;
433         /* make sure off_t is sufficiently large not to wrap */
434         if (*offset > *offset + size)
435                 die("pack too large for current definition of off_t");
436         *offset += size;
437         return 1;
440 /* forward declaration for write_pack_file */
441 static int adjust_perm(const char *path, mode_t mode);
443 static void write_pack_file(void)
445         uint32_t i = 0, j;
446         struct sha1file *f;
447         off_t offset;
448         struct pack_header hdr;
449         uint32_t nr_remaining = nr_result;
450         time_t last_mtime = 0;
452         if (progress > pack_to_stdout)
453                 progress_state = start_progress("Writing objects", nr_result);
454         written_list = xmalloc(nr_objects * sizeof(*written_list));
456         do {
457                 unsigned char sha1[20];
458                 char *pack_tmp_name = NULL;
460                 if (pack_to_stdout) {
461                         f = sha1fd_throughput(1, "<stdout>", progress_state);
462                 } else {
463                         char tmpname[PATH_MAX];
464                         int fd;
465                         fd = odb_mkstemp(tmpname, sizeof(tmpname),
466                                          "pack/tmp_pack_XXXXXX");
467                         pack_tmp_name = xstrdup(tmpname);
468                         f = sha1fd(fd, pack_tmp_name);
469                 }
471                 hdr.hdr_signature = htonl(PACK_SIGNATURE);
472                 hdr.hdr_version = htonl(PACK_VERSION);
473                 hdr.hdr_entries = htonl(nr_remaining);
474                 sha1write(f, &hdr, sizeof(hdr));
475                 offset = sizeof(hdr);
476                 nr_written = 0;
477                 for (; i < nr_objects; i++) {
478                         if (!write_one(f, objects + i, &offset))
479                                 break;
480                         display_progress(progress_state, written);
481                 }
483                 /*
484                  * Did we write the wrong # entries in the header?
485                  * If so, rewrite it like in fast-import
486                  */
487                 if (pack_to_stdout) {
488                         sha1close(f, sha1, CSUM_CLOSE);
489                 } else if (nr_written == nr_remaining) {
490                         sha1close(f, sha1, CSUM_FSYNC);
491                 } else {
492                         int fd = sha1close(f, sha1, 0);
493                         fixup_pack_header_footer(fd, sha1, pack_tmp_name,
494                                                  nr_written, sha1, offset);
495                         close(fd);
496                 }
498                 if (!pack_to_stdout) {
499                         mode_t mode = umask(0);
500                         struct stat st;
501                         const char *idx_tmp_name;
502                         char tmpname[PATH_MAX];
504                         umask(mode);
505                         mode = 0444 & ~mode;
507                         idx_tmp_name = write_idx_file(NULL, written_list,
508                                                       nr_written, sha1);
510                         snprintf(tmpname, sizeof(tmpname), "%s-%s.pack",
511                                  base_name, sha1_to_hex(sha1));
512                         free_pack_by_name(tmpname);
513                         if (adjust_perm(pack_tmp_name, mode))
514                                 die_errno("unable to make temporary pack file readable");
515                         if (rename(pack_tmp_name, tmpname))
516                                 die_errno("unable to rename temporary pack file");
518                         /*
519                          * Packs are runtime accessed in their mtime
520                          * order since newer packs are more likely to contain
521                          * younger objects.  So if we are creating multiple
522                          * packs then we should modify the mtime of later ones
523                          * to preserve this property.
524                          */
525                         if (stat(tmpname, &st) < 0) {
526                                 warning("failed to stat %s: %s",
527                                         tmpname, strerror(errno));
528                         } else if (!last_mtime) {
529                                 last_mtime = st.st_mtime;
530                         } else {
531                                 struct utimbuf utb;
532                                 utb.actime = st.st_atime;
533                                 utb.modtime = --last_mtime;
534                                 if (utime(tmpname, &utb) < 0)
535                                         warning("failed utime() on %s: %s",
536                                                 tmpname, strerror(errno));
537                         }
539                         snprintf(tmpname, sizeof(tmpname), "%s-%s.idx",
540                                  base_name, sha1_to_hex(sha1));
541                         if (adjust_perm(idx_tmp_name, mode))
542                                 die_errno("unable to make temporary index file readable");
543                         if (rename(idx_tmp_name, tmpname))
544                                 die_errno("unable to rename temporary index file");
546                         free((void *) idx_tmp_name);
547                         free(pack_tmp_name);
548                         puts(sha1_to_hex(sha1));
549                 }
551                 /* mark written objects as written to previous pack */
552                 for (j = 0; j < nr_written; j++) {
553                         written_list[j]->offset = (off_t)-1;
554                 }
555                 nr_remaining -= nr_written;
556         } while (nr_remaining && i < nr_objects);
558         free(written_list);
559         stop_progress(&progress_state);
560         if (written != nr_result)
561                 die("wrote %"PRIu32" objects while expecting %"PRIu32,
562                         written, nr_result);
565 static int locate_object_entry_hash(const unsigned char *sha1)
567         int i;
568         unsigned int ui;
569         memcpy(&ui, sha1, sizeof(unsigned int));
570         i = ui % object_ix_hashsz;
571         while (0 < object_ix[i]) {
572                 if (!hashcmp(sha1, objects[object_ix[i] - 1].idx.sha1))
573                         return i;
574                 if (++i == object_ix_hashsz)
575                         i = 0;
576         }
577         return -1 - i;
580 static struct object_entry *locate_object_entry(const unsigned char *sha1)
582         int i;
584         if (!object_ix_hashsz)
585                 return NULL;
587         i = locate_object_entry_hash(sha1);
588         if (0 <= i)
589                 return &objects[object_ix[i]-1];
590         return NULL;
593 static void rehash_objects(void)
595         uint32_t i;
596         struct object_entry *oe;
598         object_ix_hashsz = nr_objects * 3;
599         if (object_ix_hashsz < 1024)
600                 object_ix_hashsz = 1024;
601         object_ix = xrealloc(object_ix, sizeof(int) * object_ix_hashsz);
602         memset(object_ix, 0, sizeof(int) * object_ix_hashsz);
603         for (i = 0, oe = objects; i < nr_objects; i++, oe++) {
604                 int ix = locate_object_entry_hash(oe->idx.sha1);
605                 if (0 <= ix)
606                         continue;
607                 ix = -1 - ix;
608                 object_ix[ix] = i + 1;
609         }
612 static unsigned name_hash(const char *name)
614         unsigned c, hash = 0;
616         if (!name)
617                 return 0;
619         /*
620          * This effectively just creates a sortable number from the
621          * last sixteen non-whitespace characters. Last characters
622          * count "most", so things that end in ".c" sort together.
623          */
624         while ((c = *name++) != 0) {
625                 if (isspace(c))
626                         continue;
627                 hash = (hash >> 2) + (c << 24);
628         }
629         return hash;
632 static void setup_delta_attr_check(struct git_attr_check *check)
634         static struct git_attr *attr_delta;
636         if (!attr_delta)
637                 attr_delta = git_attr("delta");
639         check[0].attr = attr_delta;
642 static int no_try_delta(const char *path)
644         struct git_attr_check check[1];
646         setup_delta_attr_check(check);
647         if (git_checkattr(path, ARRAY_SIZE(check), check))
648                 return 0;
649         if (ATTR_FALSE(check->value))
650                 return 1;
651         return 0;
654 static int add_object_entry(const unsigned char *sha1, enum object_type type,
655                             const char *name, int exclude)
657         struct object_entry *entry;
658         struct packed_git *p, *found_pack = NULL;
659         off_t found_offset = 0;
660         int ix;
661         unsigned hash = name_hash(name);
663         ix = nr_objects ? locate_object_entry_hash(sha1) : -1;
664         if (ix >= 0) {
665                 if (exclude) {
666                         entry = objects + object_ix[ix] - 1;
667                         if (!entry->preferred_base)
668                                 nr_result--;
669                         entry->preferred_base = 1;
670                 }
671                 return 0;
672         }
674         if (!exclude && local && has_loose_object_nonlocal(sha1))
675                 return 0;
677         for (p = packed_git; p; p = p->next) {
678                 off_t offset = find_pack_entry_one(sha1, p);
679                 if (offset) {
680                         if (!found_pack) {
681                                 found_offset = offset;
682                                 found_pack = p;
683                         }
684                         if (exclude)
685                                 break;
686                         if (incremental)
687                                 return 0;
688                         if (local && !p->pack_local)
689                                 return 0;
690                         if (ignore_packed_keep && p->pack_local && p->pack_keep)
691                                 return 0;
692                 }
693         }
695         if (nr_objects >= nr_alloc) {
696                 nr_alloc = (nr_alloc  + 1024) * 3 / 2;
697                 objects = xrealloc(objects, nr_alloc * sizeof(*entry));
698         }
700         entry = objects + nr_objects++;
701         memset(entry, 0, sizeof(*entry));
702         hashcpy(entry->idx.sha1, sha1);
703         entry->hash = hash;
704         if (type)
705                 entry->type = type;
706         if (exclude)
707                 entry->preferred_base = 1;
708         else
709                 nr_result++;
710         if (found_pack) {
711                 entry->in_pack = found_pack;
712                 entry->in_pack_offset = found_offset;
713         }
715         if (object_ix_hashsz * 3 <= nr_objects * 4)
716                 rehash_objects();
717         else
718                 object_ix[-1 - ix] = nr_objects;
720         display_progress(progress_state, nr_objects);
722         if (name && no_try_delta(name))
723                 entry->no_try_delta = 1;
725         return 1;
728 struct pbase_tree_cache {
729         unsigned char sha1[20];
730         int ref;
731         int temporary;
732         void *tree_data;
733         unsigned long tree_size;
736 static struct pbase_tree_cache *(pbase_tree_cache[256]);
737 static int pbase_tree_cache_ix(const unsigned char *sha1)
739         return sha1[0] % ARRAY_SIZE(pbase_tree_cache);
741 static int pbase_tree_cache_ix_incr(int ix)
743         return (ix+1) % ARRAY_SIZE(pbase_tree_cache);
746 static struct pbase_tree {
747         struct pbase_tree *next;
748         /* This is a phony "cache" entry; we are not
749          * going to evict it nor find it through _get()
750          * mechanism -- this is for the toplevel node that
751          * would almost always change with any commit.
752          */
753         struct pbase_tree_cache pcache;
754 } *pbase_tree;
756 static struct pbase_tree_cache *pbase_tree_get(const unsigned char *sha1)
758         struct pbase_tree_cache *ent, *nent;
759         void *data;
760         unsigned long size;
761         enum object_type type;
762         int neigh;
763         int my_ix = pbase_tree_cache_ix(sha1);
764         int available_ix = -1;
766         /* pbase-tree-cache acts as a limited hashtable.
767          * your object will be found at your index or within a few
768          * slots after that slot if it is cached.
769          */
770         for (neigh = 0; neigh < 8; neigh++) {
771                 ent = pbase_tree_cache[my_ix];
772                 if (ent && !hashcmp(ent->sha1, sha1)) {
773                         ent->ref++;
774                         return ent;
775                 }
776                 else if (((available_ix < 0) && (!ent || !ent->ref)) ||
777                          ((0 <= available_ix) &&
778                           (!ent && pbase_tree_cache[available_ix])))
779                         available_ix = my_ix;
780                 if (!ent)
781                         break;
782                 my_ix = pbase_tree_cache_ix_incr(my_ix);
783         }
785         /* Did not find one.  Either we got a bogus request or
786          * we need to read and perhaps cache.
787          */
788         data = read_sha1_file(sha1, &type, &size);
789         if (!data)
790                 return NULL;
791         if (type != OBJ_TREE) {
792                 free(data);
793                 return NULL;
794         }
796         /* We need to either cache or return a throwaway copy */
798         if (available_ix < 0)
799                 ent = NULL;
800         else {
801                 ent = pbase_tree_cache[available_ix];
802                 my_ix = available_ix;
803         }
805         if (!ent) {
806                 nent = xmalloc(sizeof(*nent));
807                 nent->temporary = (available_ix < 0);
808         }
809         else {
810                 /* evict and reuse */
811                 free(ent->tree_data);
812                 nent = ent;
813         }
814         hashcpy(nent->sha1, sha1);
815         nent->tree_data = data;
816         nent->tree_size = size;
817         nent->ref = 1;
818         if (!nent->temporary)
819                 pbase_tree_cache[my_ix] = nent;
820         return nent;
823 static void pbase_tree_put(struct pbase_tree_cache *cache)
825         if (!cache->temporary) {
826                 cache->ref--;
827                 return;
828         }
829         free(cache->tree_data);
830         free(cache);
833 static int name_cmp_len(const char *name)
835         int i;
836         for (i = 0; name[i] && name[i] != '\n' && name[i] != '/'; i++)
837                 ;
838         return i;
841 static void add_pbase_object(struct tree_desc *tree,
842                              const char *name,
843                              int cmplen,
844                              const char *fullname)
846         struct name_entry entry;
847         int cmp;
849         while (tree_entry(tree,&entry)) {
850                 if (S_ISGITLINK(entry.mode))
851                         continue;
852                 cmp = tree_entry_len(entry.path, entry.sha1) != cmplen ? 1 :
853                       memcmp(name, entry.path, cmplen);
854                 if (cmp > 0)
855                         continue;
856                 if (cmp < 0)
857                         return;
858                 if (name[cmplen] != '/') {
859                         add_object_entry(entry.sha1,
860                                          object_type(entry.mode),
861                                          fullname, 1);
862                         return;
863                 }
864                 if (S_ISDIR(entry.mode)) {
865                         struct tree_desc sub;
866                         struct pbase_tree_cache *tree;
867                         const char *down = name+cmplen+1;
868                         int downlen = name_cmp_len(down);
870                         tree = pbase_tree_get(entry.sha1);
871                         if (!tree)
872                                 return;
873                         init_tree_desc(&sub, tree->tree_data, tree->tree_size);
875                         add_pbase_object(&sub, down, downlen, fullname);
876                         pbase_tree_put(tree);
877                 }
878         }
881 static unsigned *done_pbase_paths;
882 static int done_pbase_paths_num;
883 static int done_pbase_paths_alloc;
884 static int done_pbase_path_pos(unsigned hash)
886         int lo = 0;
887         int hi = done_pbase_paths_num;
888         while (lo < hi) {
889                 int mi = (hi + lo) / 2;
890                 if (done_pbase_paths[mi] == hash)
891                         return mi;
892                 if (done_pbase_paths[mi] < hash)
893                         hi = mi;
894                 else
895                         lo = mi + 1;
896         }
897         return -lo-1;
900 static int check_pbase_path(unsigned hash)
902         int pos = (!done_pbase_paths) ? -1 : done_pbase_path_pos(hash);
903         if (0 <= pos)
904                 return 1;
905         pos = -pos - 1;
906         if (done_pbase_paths_alloc <= done_pbase_paths_num) {
907                 done_pbase_paths_alloc = alloc_nr(done_pbase_paths_alloc);
908                 done_pbase_paths = xrealloc(done_pbase_paths,
909                                             done_pbase_paths_alloc *
910                                             sizeof(unsigned));
911         }
912         done_pbase_paths_num++;
913         if (pos < done_pbase_paths_num)
914                 memmove(done_pbase_paths + pos + 1,
915                         done_pbase_paths + pos,
916                         (done_pbase_paths_num - pos - 1) * sizeof(unsigned));
917         done_pbase_paths[pos] = hash;
918         return 0;
921 static void add_preferred_base_object(const char *name)
923         struct pbase_tree *it;
924         int cmplen;
925         unsigned hash = name_hash(name);
927         if (!num_preferred_base || check_pbase_path(hash))
928                 return;
930         cmplen = name_cmp_len(name);
931         for (it = pbase_tree; it; it = it->next) {
932                 if (cmplen == 0) {
933                         add_object_entry(it->pcache.sha1, OBJ_TREE, NULL, 1);
934                 }
935                 else {
936                         struct tree_desc tree;
937                         init_tree_desc(&tree, it->pcache.tree_data, it->pcache.tree_size);
938                         add_pbase_object(&tree, name, cmplen, name);
939                 }
940         }
943 static void add_preferred_base(unsigned char *sha1)
945         struct pbase_tree *it;
946         void *data;
947         unsigned long size;
948         unsigned char tree_sha1[20];
950         if (window <= num_preferred_base++)
951                 return;
953         data = read_object_with_reference(sha1, tree_type, &size, tree_sha1);
954         if (!data)
955                 return;
957         for (it = pbase_tree; it; it = it->next) {
958                 if (!hashcmp(it->pcache.sha1, tree_sha1)) {
959                         free(data);
960                         return;
961                 }
962         }
964         it = xcalloc(1, sizeof(*it));
965         it->next = pbase_tree;
966         pbase_tree = it;
968         hashcpy(it->pcache.sha1, tree_sha1);
969         it->pcache.tree_data = data;
970         it->pcache.tree_size = size;
973 static void cleanup_preferred_base(void)
975         struct pbase_tree *it;
976         unsigned i;
978         it = pbase_tree;
979         pbase_tree = NULL;
980         while (it) {
981                 struct pbase_tree *this = it;
982                 it = this->next;
983                 free(this->pcache.tree_data);
984                 free(this);
985         }
987         for (i = 0; i < ARRAY_SIZE(pbase_tree_cache); i++) {
988                 if (!pbase_tree_cache[i])
989                         continue;
990                 free(pbase_tree_cache[i]->tree_data);
991                 free(pbase_tree_cache[i]);
992                 pbase_tree_cache[i] = NULL;
993         }
995         free(done_pbase_paths);
996         done_pbase_paths = NULL;
997         done_pbase_paths_num = done_pbase_paths_alloc = 0;
1000 static void check_object(struct object_entry *entry)
1002         if (entry->in_pack) {
1003                 struct packed_git *p = entry->in_pack;
1004                 struct pack_window *w_curs = NULL;
1005                 const unsigned char *base_ref = NULL;
1006                 struct object_entry *base_entry;
1007                 unsigned long used, used_0;
1008                 unsigned int avail;
1009                 off_t ofs;
1010                 unsigned char *buf, c;
1012                 buf = use_pack(p, &w_curs, entry->in_pack_offset, &avail);
1014                 /*
1015                  * We want in_pack_type even if we do not reuse delta
1016                  * since non-delta representations could still be reused.
1017                  */
1018                 used = unpack_object_header_buffer(buf, avail,
1019                                                    &entry->in_pack_type,
1020                                                    &entry->size);
1021                 if (used == 0)
1022                         goto give_up;
1024                 /*
1025                  * Determine if this is a delta and if so whether we can
1026                  * reuse it or not.  Otherwise let's find out as cheaply as
1027                  * possible what the actual type and size for this object is.
1028                  */
1029                 switch (entry->in_pack_type) {
1030                 default:
1031                         /* Not a delta hence we've already got all we need. */
1032                         entry->type = entry->in_pack_type;
1033                         entry->in_pack_header_size = used;
1034                         if (entry->type < OBJ_COMMIT || entry->type > OBJ_BLOB)
1035                                 goto give_up;
1036                         unuse_pack(&w_curs);
1037                         return;
1038                 case OBJ_REF_DELTA:
1039                         if (reuse_delta && !entry->preferred_base)
1040                                 base_ref = use_pack(p, &w_curs,
1041                                                 entry->in_pack_offset + used, NULL);
1042                         entry->in_pack_header_size = used + 20;
1043                         break;
1044                 case OBJ_OFS_DELTA:
1045                         buf = use_pack(p, &w_curs,
1046                                        entry->in_pack_offset + used, NULL);
1047                         used_0 = 0;
1048                         c = buf[used_0++];
1049                         ofs = c & 127;
1050                         while (c & 128) {
1051                                 ofs += 1;
1052                                 if (!ofs || MSB(ofs, 7)) {
1053                                         error("delta base offset overflow in pack for %s",
1054                                               sha1_to_hex(entry->idx.sha1));
1055                                         goto give_up;
1056                                 }
1057                                 c = buf[used_0++];
1058                                 ofs = (ofs << 7) + (c & 127);
1059                         }
1060                         ofs = entry->in_pack_offset - ofs;
1061                         if (ofs <= 0 || ofs >= entry->in_pack_offset) {
1062                                 error("delta base offset out of bound for %s",
1063                                       sha1_to_hex(entry->idx.sha1));
1064                                 goto give_up;
1065                         }
1066                         if (reuse_delta && !entry->preferred_base) {
1067                                 struct revindex_entry *revidx;
1068                                 revidx = find_pack_revindex(p, ofs);
1069                                 if (!revidx)
1070                                         goto give_up;
1071                                 base_ref = nth_packed_object_sha1(p, revidx->nr);
1072                         }
1073                         entry->in_pack_header_size = used + used_0;
1074                         break;
1075                 }
1077                 if (base_ref && (base_entry = locate_object_entry(base_ref))) {
1078                         /*
1079                          * If base_ref was set above that means we wish to
1080                          * reuse delta data, and we even found that base
1081                          * in the list of objects we want to pack. Goodie!
1082                          *
1083                          * Depth value does not matter - find_deltas() will
1084                          * never consider reused delta as the base object to
1085                          * deltify other objects against, in order to avoid
1086                          * circular deltas.
1087                          */
1088                         entry->type = entry->in_pack_type;
1089                         entry->delta = base_entry;
1090                         entry->delta_size = entry->size;
1091                         entry->delta_sibling = base_entry->delta_child;
1092                         base_entry->delta_child = entry;
1093                         unuse_pack(&w_curs);
1094                         return;
1095                 }
1097                 if (entry->type) {
1098                         /*
1099                          * This must be a delta and we already know what the
1100                          * final object type is.  Let's extract the actual
1101                          * object size from the delta header.
1102                          */
1103                         entry->size = get_size_from_delta(p, &w_curs,
1104                                         entry->in_pack_offset + entry->in_pack_header_size);
1105                         if (entry->size == 0)
1106                                 goto give_up;
1107                         unuse_pack(&w_curs);
1108                         return;
1109                 }
1111                 /*
1112                  * No choice but to fall back to the recursive delta walk
1113                  * with sha1_object_info() to find about the object type
1114                  * at this point...
1115                  */
1116                 give_up:
1117                 unuse_pack(&w_curs);
1118         }
1120         entry->type = sha1_object_info(entry->idx.sha1, &entry->size);
1121         /*
1122          * The error condition is checked in prepare_pack().  This is
1123          * to permit a missing preferred base object to be ignored
1124          * as a preferred base.  Doing so can result in a larger
1125          * pack file, but the transfer will still take place.
1126          */
1129 static int pack_offset_sort(const void *_a, const void *_b)
1131         const struct object_entry *a = *(struct object_entry **)_a;
1132         const struct object_entry *b = *(struct object_entry **)_b;
1134         /* avoid filesystem trashing with loose objects */
1135         if (!a->in_pack && !b->in_pack)
1136                 return hashcmp(a->idx.sha1, b->idx.sha1);
1138         if (a->in_pack < b->in_pack)
1139                 return -1;
1140         if (a->in_pack > b->in_pack)
1141                 return 1;
1142         return a->in_pack_offset < b->in_pack_offset ? -1 :
1143                         (a->in_pack_offset > b->in_pack_offset);
1146 static void get_object_details(void)
1148         uint32_t i;
1149         struct object_entry **sorted_by_offset;
1151         sorted_by_offset = xcalloc(nr_objects, sizeof(struct object_entry *));
1152         for (i = 0; i < nr_objects; i++)
1153                 sorted_by_offset[i] = objects + i;
1154         qsort(sorted_by_offset, nr_objects, sizeof(*sorted_by_offset), pack_offset_sort);
1156         for (i = 0; i < nr_objects; i++)
1157                 check_object(sorted_by_offset[i]);
1159         free(sorted_by_offset);
1163  * We search for deltas in a list sorted by type, by filename hash, and then
1164  * by size, so that we see progressively smaller and smaller files.
1165  * That's because we prefer deltas to be from the bigger file
1166  * to the smaller -- deletes are potentially cheaper, but perhaps
1167  * more importantly, the bigger file is likely the more recent
1168  * one.  The deepest deltas are therefore the oldest objects which are
1169  * less susceptible to be accessed often.
1170  */
1171 static int type_size_sort(const void *_a, const void *_b)
1173         const struct object_entry *a = *(struct object_entry **)_a;
1174         const struct object_entry *b = *(struct object_entry **)_b;
1176         if (a->type > b->type)
1177                 return -1;
1178         if (a->type < b->type)
1179                 return 1;
1180         if (a->hash > b->hash)
1181                 return -1;
1182         if (a->hash < b->hash)
1183                 return 1;
1184         if (a->preferred_base > b->preferred_base)
1185                 return -1;
1186         if (a->preferred_base < b->preferred_base)
1187                 return 1;
1188         if (a->size > b->size)
1189                 return -1;
1190         if (a->size < b->size)
1191                 return 1;
1192         return a < b ? -1 : (a > b);  /* newest first */
1195 struct unpacked {
1196         struct object_entry *entry;
1197         void *data;
1198         struct delta_index *index;
1199         unsigned depth;
1202 static int delta_cacheable(unsigned long src_size, unsigned long trg_size,
1203                            unsigned long delta_size)
1205         if (max_delta_cache_size && delta_cache_size + delta_size > max_delta_cache_size)
1206                 return 0;
1208         if (delta_size < cache_max_small_delta_size)
1209                 return 1;
1211         /* cache delta, if objects are large enough compared to delta size */
1212         if ((src_size >> 20) + (trg_size >> 21) > (delta_size >> 10))
1213                 return 1;
1215         return 0;
1218 #ifndef NO_PTHREADS
1220 static pthread_mutex_t read_mutex;
1221 #define read_lock()             pthread_mutex_lock(&read_mutex)
1222 #define read_unlock()           pthread_mutex_unlock(&read_mutex)
1224 static pthread_mutex_t cache_mutex;
1225 #define cache_lock()            pthread_mutex_lock(&cache_mutex)
1226 #define cache_unlock()          pthread_mutex_unlock(&cache_mutex)
1228 static pthread_mutex_t progress_mutex;
1229 #define progress_lock()         pthread_mutex_lock(&progress_mutex)
1230 #define progress_unlock()       pthread_mutex_unlock(&progress_mutex)
1232 #else
1234 #define read_lock()             (void)0
1235 #define read_unlock()           (void)0
1236 #define cache_lock()            (void)0
1237 #define cache_unlock()          (void)0
1238 #define progress_lock()         (void)0
1239 #define progress_unlock()       (void)0
1241 #endif
1243 static int try_delta(struct unpacked *trg, struct unpacked *src,
1244                      unsigned max_depth, unsigned long *mem_usage)
1246         struct object_entry *trg_entry = trg->entry;
1247         struct object_entry *src_entry = src->entry;
1248         unsigned long trg_size, src_size, delta_size, sizediff, max_size, sz;
1249         unsigned ref_depth;
1250         enum object_type type;
1251         void *delta_buf;
1253         /* Don't bother doing diffs between different types */
1254         if (trg_entry->type != src_entry->type)
1255                 return -1;
1257         /*
1258          * We do not bother to try a delta that we discarded
1259          * on an earlier try, but only when reusing delta data.
1260          */
1261         if (reuse_delta && trg_entry->in_pack &&
1262             trg_entry->in_pack == src_entry->in_pack &&
1263             trg_entry->in_pack_type != OBJ_REF_DELTA &&
1264             trg_entry->in_pack_type != OBJ_OFS_DELTA)
1265                 return 0;
1267         /* Let's not bust the allowed depth. */
1268         if (src->depth >= max_depth)
1269                 return 0;
1271         /* Now some size filtering heuristics. */
1272         trg_size = trg_entry->size;
1273         if (!trg_entry->delta) {
1274                 max_size = trg_size/2 - 20;
1275                 ref_depth = 1;
1276         } else {
1277                 max_size = trg_entry->delta_size;
1278                 ref_depth = trg->depth;
1279         }
1280         max_size = (uint64_t)max_size * (max_depth - src->depth) /
1281                                                 (max_depth - ref_depth + 1);
1282         if (max_size == 0)
1283                 return 0;
1284         src_size = src_entry->size;
1285         sizediff = src_size < trg_size ? trg_size - src_size : 0;
1286         if (sizediff >= max_size)
1287                 return 0;
1288         if (trg_size < src_size / 32)
1289                 return 0;
1291         /* Load data if not already done */
1292         if (!trg->data) {
1293                 read_lock();
1294                 trg->data = read_sha1_file(trg_entry->idx.sha1, &type, &sz);
1295                 read_unlock();
1296                 if (!trg->data)
1297                         die("object %s cannot be read",
1298                             sha1_to_hex(trg_entry->idx.sha1));
1299                 if (sz != trg_size)
1300                         die("object %s inconsistent object length (%lu vs %lu)",
1301                             sha1_to_hex(trg_entry->idx.sha1), sz, trg_size);
1302                 *mem_usage += sz;
1303         }
1304         if (!src->data) {
1305                 read_lock();
1306                 src->data = read_sha1_file(src_entry->idx.sha1, &type, &sz);
1307                 read_unlock();
1308                 if (!src->data)
1309                         die("object %s cannot be read",
1310                             sha1_to_hex(src_entry->idx.sha1));
1311                 if (sz != src_size)
1312                         die("object %s inconsistent object length (%lu vs %lu)",
1313                             sha1_to_hex(src_entry->idx.sha1), sz, src_size);
1314                 *mem_usage += sz;
1315         }
1316         if (!src->index) {
1317                 src->index = create_delta_index(src->data, src_size);
1318                 if (!src->index) {
1319                         static int warned = 0;
1320                         if (!warned++)
1321                                 warning("suboptimal pack - out of memory");
1322                         return 0;
1323                 }
1324                 *mem_usage += sizeof_delta_index(src->index);
1325         }
1327         delta_buf = create_delta(src->index, trg->data, trg_size, &delta_size, max_size);
1328         if (!delta_buf)
1329                 return 0;
1331         if (trg_entry->delta) {
1332                 /* Prefer only shallower same-sized deltas. */
1333                 if (delta_size == trg_entry->delta_size &&
1334                     src->depth + 1 >= trg->depth) {
1335                         free(delta_buf);
1336                         return 0;
1337                 }
1338         }
1340         /*
1341          * Handle memory allocation outside of the cache
1342          * accounting lock.  Compiler will optimize the strangeness
1343          * away when NO_PTHREADS is defined.
1344          */
1345         free(trg_entry->delta_data);
1346         cache_lock();
1347         if (trg_entry->delta_data) {
1348                 delta_cache_size -= trg_entry->delta_size;
1349                 trg_entry->delta_data = NULL;
1350         }
1351         if (delta_cacheable(src_size, trg_size, delta_size)) {
1352                 delta_cache_size += delta_size;
1353                 cache_unlock();
1354                 trg_entry->delta_data = xrealloc(delta_buf, delta_size);
1355         } else {
1356                 cache_unlock();
1357                 free(delta_buf);
1358         }
1360         trg_entry->delta = src_entry;
1361         trg_entry->delta_size = delta_size;
1362         trg->depth = src->depth + 1;
1364         return 1;
1367 static unsigned int check_delta_limit(struct object_entry *me, unsigned int n)
1369         struct object_entry *child = me->delta_child;
1370         unsigned int m = n;
1371         while (child) {
1372                 unsigned int c = check_delta_limit(child, n + 1);
1373                 if (m < c)
1374                         m = c;
1375                 child = child->delta_sibling;
1376         }
1377         return m;
1380 static unsigned long free_unpacked(struct unpacked *n)
1382         unsigned long freed_mem = sizeof_delta_index(n->index);
1383         free_delta_index(n->index);
1384         n->index = NULL;
1385         if (n->data) {
1386                 freed_mem += n->entry->size;
1387                 free(n->data);
1388                 n->data = NULL;
1389         }
1390         n->entry = NULL;
1391         n->depth = 0;
1392         return freed_mem;
1395 static void find_deltas(struct object_entry **list, unsigned *list_size,
1396                         int window, int depth, unsigned *processed)
1398         uint32_t i, idx = 0, count = 0;
1399         struct unpacked *array;
1400         unsigned long mem_usage = 0;
1402         array = xcalloc(window, sizeof(struct unpacked));
1404         for (;;) {
1405                 struct object_entry *entry;
1406                 struct unpacked *n = array + idx;
1407                 int j, max_depth, best_base = -1;
1409                 progress_lock();
1410                 if (!*list_size) {
1411                         progress_unlock();
1412                         break;
1413                 }
1414                 entry = *list++;
1415                 (*list_size)--;
1416                 if (!entry->preferred_base) {
1417                         (*processed)++;
1418                         display_progress(progress_state, *processed);
1419                 }
1420                 progress_unlock();
1422                 mem_usage -= free_unpacked(n);
1423                 n->entry = entry;
1425                 while (window_memory_limit &&
1426                        mem_usage > window_memory_limit &&
1427                        count > 1) {
1428                         uint32_t tail = (idx + window - count) % window;
1429                         mem_usage -= free_unpacked(array + tail);
1430                         count--;
1431                 }
1433                 /* We do not compute delta to *create* objects we are not
1434                  * going to pack.
1435                  */
1436                 if (entry->preferred_base)
1437                         goto next;
1439                 /*
1440                  * If the current object is at pack edge, take the depth the
1441                  * objects that depend on the current object into account
1442                  * otherwise they would become too deep.
1443                  */
1444                 max_depth = depth;
1445                 if (entry->delta_child) {
1446                         max_depth -= check_delta_limit(entry, 0);
1447                         if (max_depth <= 0)
1448                                 goto next;
1449                 }
1451                 j = window;
1452                 while (--j > 0) {
1453                         int ret;
1454                         uint32_t other_idx = idx + j;
1455                         struct unpacked *m;
1456                         if (other_idx >= window)
1457                                 other_idx -= window;
1458                         m = array + other_idx;
1459                         if (!m->entry)
1460                                 break;
1461                         ret = try_delta(n, m, max_depth, &mem_usage);
1462                         if (ret < 0)
1463                                 break;
1464                         else if (ret > 0)
1465                                 best_base = other_idx;
1466                 }
1468                 /*
1469                  * If we decided to cache the delta data, then it is best
1470                  * to compress it right away.  First because we have to do
1471                  * it anyway, and doing it here while we're threaded will
1472                  * save a lot of time in the non threaded write phase,
1473                  * as well as allow for caching more deltas within
1474                  * the same cache size limit.
1475                  * ...
1476                  * But only if not writing to stdout, since in that case
1477                  * the network is most likely throttling writes anyway,
1478                  * and therefore it is best to go to the write phase ASAP
1479                  * instead, as we can afford spending more time compressing
1480                  * between writes at that moment.
1481                  */
1482                 if (entry->delta_data && !pack_to_stdout) {
1483                         entry->z_delta_size = do_compress(&entry->delta_data,
1484                                                           entry->delta_size);
1485                         cache_lock();
1486                         delta_cache_size -= entry->delta_size;
1487                         delta_cache_size += entry->z_delta_size;
1488                         cache_unlock();
1489                 }
1491                 /* if we made n a delta, and if n is already at max
1492                  * depth, leaving it in the window is pointless.  we
1493                  * should evict it first.
1494                  */
1495                 if (entry->delta && max_depth <= n->depth)
1496                         continue;
1498                 /*
1499                  * Move the best delta base up in the window, after the
1500                  * currently deltified object, to keep it longer.  It will
1501                  * be the first base object to be attempted next.
1502                  */
1503                 if (entry->delta) {
1504                         struct unpacked swap = array[best_base];
1505                         int dist = (window + idx - best_base) % window;
1506                         int dst = best_base;
1507                         while (dist--) {
1508                                 int src = (dst + 1) % window;
1509                                 array[dst] = array[src];
1510                                 dst = src;
1511                         }
1512                         array[dst] = swap;
1513                 }
1515                 next:
1516                 idx++;
1517                 if (count + 1 < window)
1518                         count++;
1519                 if (idx >= window)
1520                         idx = 0;
1521         }
1523         for (i = 0; i < window; ++i) {
1524                 free_delta_index(array[i].index);
1525                 free(array[i].data);
1526         }
1527         free(array);
1530 #ifndef NO_PTHREADS
1533  * The main thread waits on the condition that (at least) one of the workers
1534  * has stopped working (which is indicated in the .working member of
1535  * struct thread_params).
1536  * When a work thread has completed its work, it sets .working to 0 and
1537  * signals the main thread and waits on the condition that .data_ready
1538  * becomes 1.
1539  */
1541 struct thread_params {
1542         pthread_t thread;
1543         struct object_entry **list;
1544         unsigned list_size;
1545         unsigned remaining;
1546         int window;
1547         int depth;
1548         int working;
1549         int data_ready;
1550         pthread_mutex_t mutex;
1551         pthread_cond_t cond;
1552         unsigned *processed;
1555 static pthread_cond_t progress_cond;
1558  * Mutex and conditional variable can't be statically-initialized on Windows.
1559  */
1560 static void init_threaded_search(void)
1562         pthread_mutex_init(&read_mutex, NULL);
1563         pthread_mutex_init(&cache_mutex, NULL);
1564         pthread_mutex_init(&progress_mutex, NULL);
1565         pthread_cond_init(&progress_cond, NULL);
1568 static void cleanup_threaded_search(void)
1570         pthread_cond_destroy(&progress_cond);
1571         pthread_mutex_destroy(&read_mutex);
1572         pthread_mutex_destroy(&cache_mutex);
1573         pthread_mutex_destroy(&progress_mutex);
1576 static void *threaded_find_deltas(void *arg)
1578         struct thread_params *me = arg;
1580         while (me->remaining) {
1581                 find_deltas(me->list, &me->remaining,
1582                             me->window, me->depth, me->processed);
1584                 progress_lock();
1585                 me->working = 0;
1586                 pthread_cond_signal(&progress_cond);
1587                 progress_unlock();
1589                 /*
1590                  * We must not set ->data_ready before we wait on the
1591                  * condition because the main thread may have set it to 1
1592                  * before we get here. In order to be sure that new
1593                  * work is available if we see 1 in ->data_ready, it
1594                  * was initialized to 0 before this thread was spawned
1595                  * and we reset it to 0 right away.
1596                  */
1597                 pthread_mutex_lock(&me->mutex);
1598                 while (!me->data_ready)
1599                         pthread_cond_wait(&me->cond, &me->mutex);
1600                 me->data_ready = 0;
1601                 pthread_mutex_unlock(&me->mutex);
1602         }
1603         /* leave ->working 1 so that this doesn't get more work assigned */
1604         return NULL;
1607 static void ll_find_deltas(struct object_entry **list, unsigned list_size,
1608                            int window, int depth, unsigned *processed)
1610         struct thread_params *p;
1611         int i, ret, active_threads = 0;
1613         init_threaded_search();
1615         if (!delta_search_threads)      /* --threads=0 means autodetect */
1616                 delta_search_threads = online_cpus();
1617         if (delta_search_threads <= 1) {
1618                 find_deltas(list, &list_size, window, depth, processed);
1619                 cleanup_threaded_search();
1620                 return;
1621         }
1622         if (progress > pack_to_stdout)
1623                 fprintf(stderr, "Delta compression using up to %d threads.\n",
1624                                 delta_search_threads);
1625         p = xcalloc(delta_search_threads, sizeof(*p));
1627         /* Partition the work amongst work threads. */
1628         for (i = 0; i < delta_search_threads; i++) {
1629                 unsigned sub_size = list_size / (delta_search_threads - i);
1631                 /* don't use too small segments or no deltas will be found */
1632                 if (sub_size < 2*window && i+1 < delta_search_threads)
1633                         sub_size = 0;
1635                 p[i].window = window;
1636                 p[i].depth = depth;
1637                 p[i].processed = processed;
1638                 p[i].working = 1;
1639                 p[i].data_ready = 0;
1641                 /* try to split chunks on "path" boundaries */
1642                 while (sub_size && sub_size < list_size &&
1643                        list[sub_size]->hash &&
1644                        list[sub_size]->hash == list[sub_size-1]->hash)
1645                         sub_size++;
1647                 p[i].list = list;
1648                 p[i].list_size = sub_size;
1649                 p[i].remaining = sub_size;
1651                 list += sub_size;
1652                 list_size -= sub_size;
1653         }
1655         /* Start work threads. */
1656         for (i = 0; i < delta_search_threads; i++) {
1657                 if (!p[i].list_size)
1658                         continue;
1659                 pthread_mutex_init(&p[i].mutex, NULL);
1660                 pthread_cond_init(&p[i].cond, NULL);
1661                 ret = pthread_create(&p[i].thread, NULL,
1662                                      threaded_find_deltas, &p[i]);
1663                 if (ret)
1664                         die("unable to create thread: %s", strerror(ret));
1665                 active_threads++;
1666         }
1668         /*
1669          * Now let's wait for work completion.  Each time a thread is done
1670          * with its work, we steal half of the remaining work from the
1671          * thread with the largest number of unprocessed objects and give
1672          * it to that newly idle thread.  This ensure good load balancing
1673          * until the remaining object list segments are simply too short
1674          * to be worth splitting anymore.
1675          */
1676         while (active_threads) {
1677                 struct thread_params *target = NULL;
1678                 struct thread_params *victim = NULL;
1679                 unsigned sub_size = 0;
1681                 progress_lock();
1682                 for (;;) {
1683                         for (i = 0; !target && i < delta_search_threads; i++)
1684                                 if (!p[i].working)
1685                                         target = &p[i];
1686                         if (target)
1687                                 break;
1688                         pthread_cond_wait(&progress_cond, &progress_mutex);
1689                 }
1691                 for (i = 0; i < delta_search_threads; i++)
1692                         if (p[i].remaining > 2*window &&
1693                             (!victim || victim->remaining < p[i].remaining))
1694                                 victim = &p[i];
1695                 if (victim) {
1696                         sub_size = victim->remaining / 2;
1697                         list = victim->list + victim->list_size - sub_size;
1698                         while (sub_size && list[0]->hash &&
1699                                list[0]->hash == list[-1]->hash) {
1700                                 list++;
1701                                 sub_size--;
1702                         }
1703                         if (!sub_size) {
1704                                 /*
1705                                  * It is possible for some "paths" to have
1706                                  * so many objects that no hash boundary
1707                                  * might be found.  Let's just steal the
1708                                  * exact half in that case.
1709                                  */
1710                                 sub_size = victim->remaining / 2;
1711                                 list -= sub_size;
1712                         }
1713                         target->list = list;
1714                         victim->list_size -= sub_size;
1715                         victim->remaining -= sub_size;
1716                 }
1717                 target->list_size = sub_size;
1718                 target->remaining = sub_size;
1719                 target->working = 1;
1720                 progress_unlock();
1722                 pthread_mutex_lock(&target->mutex);
1723                 target->data_ready = 1;
1724                 pthread_cond_signal(&target->cond);
1725                 pthread_mutex_unlock(&target->mutex);
1727                 if (!sub_size) {
1728                         pthread_join(target->thread, NULL);
1729                         pthread_cond_destroy(&target->cond);
1730                         pthread_mutex_destroy(&target->mutex);
1731                         active_threads--;
1732                 }
1733         }
1734         cleanup_threaded_search();
1735         free(p);
1738 #else
1739 #define ll_find_deltas(l, s, w, d, p)   find_deltas(l, &s, w, d, p)
1740 #endif
1742 static int add_ref_tag(const char *path, const unsigned char *sha1, int flag, void *cb_data)
1744         unsigned char peeled[20];
1746         if (!prefixcmp(path, "refs/tags/") && /* is a tag? */
1747             !peel_ref(path, peeled)        && /* peelable? */
1748             !is_null_sha1(peeled)          && /* annotated tag? */
1749             locate_object_entry(peeled))      /* object packed? */
1750                 add_object_entry(sha1, OBJ_TAG, NULL, 0);
1751         return 0;
1754 static void prepare_pack(int window, int depth)
1756         struct object_entry **delta_list;
1757         uint32_t i, nr_deltas;
1758         unsigned n;
1760         get_object_details();
1762         /*
1763          * If we're locally repacking then we need to be doubly careful
1764          * from now on in order to make sure no stealth corruption gets
1765          * propagated to the new pack.  Clients receiving streamed packs
1766          * should validate everything they get anyway so no need to incur
1767          * the additional cost here in that case.
1768          */
1769         if (!pack_to_stdout)
1770                 do_check_packed_object_crc = 1;
1772         if (!nr_objects || !window || !depth)
1773                 return;
1775         delta_list = xmalloc(nr_objects * sizeof(*delta_list));
1776         nr_deltas = n = 0;
1778         for (i = 0; i < nr_objects; i++) {
1779                 struct object_entry *entry = objects + i;
1781                 if (entry->delta)
1782                         /* This happens if we decided to reuse existing
1783                          * delta from a pack.  "reuse_delta &&" is implied.
1784                          */
1785                         continue;
1787                 if (entry->size < 50)
1788                         continue;
1790                 if (entry->no_try_delta)
1791                         continue;
1793                 if (!entry->preferred_base) {
1794                         nr_deltas++;
1795                         if (entry->type < 0)
1796                                 die("unable to get type of object %s",
1797                                     sha1_to_hex(entry->idx.sha1));
1798                 } else {
1799                         if (entry->type < 0) {
1800                                 /*
1801                                  * This object is not found, but we
1802                                  * don't have to include it anyway.
1803                                  */
1804                                 continue;
1805                         }
1806                 }
1808                 delta_list[n++] = entry;
1809         }
1811         if (nr_deltas && n > 1) {
1812                 unsigned nr_done = 0;
1813                 if (progress)
1814                         progress_state = start_progress("Compressing objects",
1815                                                         nr_deltas);
1816                 qsort(delta_list, n, sizeof(*delta_list), type_size_sort);
1817                 ll_find_deltas(delta_list, n, window+1, depth, &nr_done);
1818                 stop_progress(&progress_state);
1819                 if (nr_done != nr_deltas)
1820                         die("inconsistency with delta count");
1821         }
1822         free(delta_list);
1825 static int git_pack_config(const char *k, const char *v, void *cb)
1827         if (!strcmp(k, "pack.window")) {
1828                 window = git_config_int(k, v);
1829                 return 0;
1830         }
1831         if (!strcmp(k, "pack.windowmemory")) {
1832                 window_memory_limit = git_config_ulong(k, v);
1833                 return 0;
1834         }
1835         if (!strcmp(k, "pack.depth")) {
1836                 depth = git_config_int(k, v);
1837                 return 0;
1838         }
1839         if (!strcmp(k, "pack.compression")) {
1840                 int level = git_config_int(k, v);
1841                 if (level == -1)
1842                         level = Z_DEFAULT_COMPRESSION;
1843                 else if (level < 0 || level > Z_BEST_COMPRESSION)
1844                         die("bad pack compression level %d", level);
1845                 pack_compression_level = level;
1846                 pack_compression_seen = 1;
1847                 return 0;
1848         }
1849         if (!strcmp(k, "pack.deltacachesize")) {
1850                 max_delta_cache_size = git_config_int(k, v);
1851                 return 0;
1852         }
1853         if (!strcmp(k, "pack.deltacachelimit")) {
1854                 cache_max_small_delta_size = git_config_int(k, v);
1855                 return 0;
1856         }
1857         if (!strcmp(k, "pack.threads")) {
1858                 delta_search_threads = git_config_int(k, v);
1859                 if (delta_search_threads < 0)
1860                         die("invalid number of threads specified (%d)",
1861                             delta_search_threads);
1862 #ifdef NO_PTHREADS
1863                 if (delta_search_threads != 1)
1864                         warning("no threads support, ignoring %s", k);
1865 #endif
1866                 return 0;
1867         }
1868         if (!strcmp(k, "pack.indexversion")) {
1869                 pack_idx_default_version = git_config_int(k, v);
1870                 if (pack_idx_default_version > 2)
1871                         die("bad pack.indexversion=%"PRIu32,
1872                                 pack_idx_default_version);
1873                 return 0;
1874         }
1875         if (!strcmp(k, "pack.packsizelimit")) {
1876                 pack_size_limit_cfg = git_config_ulong(k, v);
1877                 return 0;
1878         }
1879         return git_default_config(k, v, cb);
1882 static void read_object_list_from_stdin(void)
1884         char line[40 + 1 + PATH_MAX + 2];
1885         unsigned char sha1[20];
1887         for (;;) {
1888                 if (!fgets(line, sizeof(line), stdin)) {
1889                         if (feof(stdin))
1890                                 break;
1891                         if (!ferror(stdin))
1892                                 die("fgets returned NULL, not EOF, not error!");
1893                         if (errno != EINTR)
1894                                 die_errno("fgets");
1895                         clearerr(stdin);
1896                         continue;
1897                 }
1898                 if (line[0] == '-') {
1899                         if (get_sha1_hex(line+1, sha1))
1900                                 die("expected edge sha1, got garbage:\n %s",
1901                                     line);
1902                         add_preferred_base(sha1);
1903                         continue;
1904                 }
1905                 if (get_sha1_hex(line, sha1))
1906                         die("expected sha1, got garbage:\n %s", line);
1908                 add_preferred_base_object(line+41);
1909                 add_object_entry(sha1, 0, line+41, 0);
1910         }
1913 #define OBJECT_ADDED (1u<<20)
1915 static void show_commit(struct commit *commit, void *data)
1917         add_object_entry(commit->object.sha1, OBJ_COMMIT, NULL, 0);
1918         commit->object.flags |= OBJECT_ADDED;
1921 static void show_object(struct object *obj, const struct name_path *path, const char *last)
1923         char *name = path_name(path, last);
1925         add_preferred_base_object(name);
1926         add_object_entry(obj->sha1, obj->type, name, 0);
1927         obj->flags |= OBJECT_ADDED;
1929         /*
1930          * We will have generated the hash from the name,
1931          * but not saved a pointer to it - we can free it
1932          */
1933         free((char *)name);
1936 static void show_edge(struct commit *commit)
1938         add_preferred_base(commit->object.sha1);
1941 struct in_pack_object {
1942         off_t offset;
1943         struct object *object;
1946 struct in_pack {
1947         int alloc;
1948         int nr;
1949         struct in_pack_object *array;
1952 static void mark_in_pack_object(struct object *object, struct packed_git *p, struct in_pack *in_pack)
1954         in_pack->array[in_pack->nr].offset = find_pack_entry_one(object->sha1, p);
1955         in_pack->array[in_pack->nr].object = object;
1956         in_pack->nr++;
1960  * Compare the objects in the offset order, in order to emulate the
1961  * "git rev-list --objects" output that produced the pack originally.
1962  */
1963 static int ofscmp(const void *a_, const void *b_)
1965         struct in_pack_object *a = (struct in_pack_object *)a_;
1966         struct in_pack_object *b = (struct in_pack_object *)b_;
1968         if (a->offset < b->offset)
1969                 return -1;
1970         else if (a->offset > b->offset)
1971                 return 1;
1972         else
1973                 return hashcmp(a->object->sha1, b->object->sha1);
1976 static void add_objects_in_unpacked_packs(struct rev_info *revs)
1978         struct packed_git *p;
1979         struct in_pack in_pack;
1980         uint32_t i;
1982         memset(&in_pack, 0, sizeof(in_pack));
1984         for (p = packed_git; p; p = p->next) {
1985                 const unsigned char *sha1;
1986                 struct object *o;
1988                 if (!p->pack_local || p->pack_keep)
1989                         continue;
1990                 if (open_pack_index(p))
1991                         die("cannot open pack index");
1993                 ALLOC_GROW(in_pack.array,
1994                            in_pack.nr + p->num_objects,
1995                            in_pack.alloc);
1997                 for (i = 0; i < p->num_objects; i++) {
1998                         sha1 = nth_packed_object_sha1(p, i);
1999                         o = lookup_unknown_object(sha1);
2000                         if (!(o->flags & OBJECT_ADDED))
2001                                 mark_in_pack_object(o, p, &in_pack);
2002                         o->flags |= OBJECT_ADDED;
2003                 }
2004         }
2006         if (in_pack.nr) {
2007                 qsort(in_pack.array, in_pack.nr, sizeof(in_pack.array[0]),
2008                       ofscmp);
2009                 for (i = 0; i < in_pack.nr; i++) {
2010                         struct object *o = in_pack.array[i].object;
2011                         add_object_entry(o->sha1, o->type, "", 0);
2012                 }
2013         }
2014         free(in_pack.array);
2017 static int has_sha1_pack_kept_or_nonlocal(const unsigned char *sha1)
2019         static struct packed_git *last_found = (void *)1;
2020         struct packed_git *p;
2022         p = (last_found != (void *)1) ? last_found : packed_git;
2024         while (p) {
2025                 if ((!p->pack_local || p->pack_keep) &&
2026                         find_pack_entry_one(sha1, p)) {
2027                         last_found = p;
2028                         return 1;
2029                 }
2030                 if (p == last_found)
2031                         p = packed_git;
2032                 else
2033                         p = p->next;
2034                 if (p == last_found)
2035                         p = p->next;
2036         }
2037         return 0;
2040 static void loosen_unused_packed_objects(struct rev_info *revs)
2042         struct packed_git *p;
2043         uint32_t i;
2044         const unsigned char *sha1;
2046         for (p = packed_git; p; p = p->next) {
2047                 if (!p->pack_local || p->pack_keep)
2048                         continue;
2050                 if (open_pack_index(p))
2051                         die("cannot open pack index");
2053                 for (i = 0; i < p->num_objects; i++) {
2054                         sha1 = nth_packed_object_sha1(p, i);
2055                         if (!locate_object_entry(sha1) &&
2056                                 !has_sha1_pack_kept_or_nonlocal(sha1))
2057                                 if (force_object_loose(sha1, p->mtime))
2058                                         die("unable to force loose object");
2059                 }
2060         }
2063 static void get_object_list(int ac, const char **av)
2065         struct rev_info revs;
2066         char line[1000];
2067         int flags = 0;
2069         init_revisions(&revs, NULL);
2070         save_commit_buffer = 0;
2071         setup_revisions(ac, av, &revs, NULL);
2073         while (fgets(line, sizeof(line), stdin) != NULL) {
2074                 int len = strlen(line);
2075                 if (len && line[len - 1] == '\n')
2076                         line[--len] = 0;
2077                 if (!len)
2078                         break;
2079                 if (*line == '-') {
2080                         if (!strcmp(line, "--not")) {
2081                                 flags ^= UNINTERESTING;
2082                                 continue;
2083                         }
2084                         die("not a rev '%s'", line);
2085                 }
2086                 if (handle_revision_arg(line, &revs, flags, 1))
2087                         die("bad revision '%s'", line);
2088         }
2090         if (prepare_revision_walk(&revs))
2091                 die("revision walk setup failed");
2092         mark_edges_uninteresting(revs.commits, &revs, show_edge);
2093         traverse_commit_list(&revs, show_commit, show_object, NULL);
2095         if (keep_unreachable)
2096                 add_objects_in_unpacked_packs(&revs);
2097         if (unpack_unreachable)
2098                 loosen_unused_packed_objects(&revs);
2101 static int adjust_perm(const char *path, mode_t mode)
2103         if (chmod(path, mode))
2104                 return -1;
2105         return adjust_shared_perm(path);
2108 int cmd_pack_objects(int argc, const char **argv, const char *prefix)
2110         int use_internal_rev_list = 0;
2111         int thin = 0;
2112         int all_progress_implied = 0;
2113         uint32_t i;
2114         const char **rp_av;
2115         int rp_ac_alloc = 64;
2116         int rp_ac;
2118         read_replace_refs = 0;
2120         rp_av = xcalloc(rp_ac_alloc, sizeof(*rp_av));
2122         rp_av[0] = "pack-objects";
2123         rp_av[1] = "--objects"; /* --thin will make it --objects-edge */
2124         rp_ac = 2;
2126         git_config(git_pack_config, NULL);
2127         if (!pack_compression_seen && core_compression_seen)
2128                 pack_compression_level = core_compression_level;
2130         progress = isatty(2);
2131         for (i = 1; i < argc; i++) {
2132                 const char *arg = argv[i];
2134                 if (*arg != '-')
2135                         break;
2137                 if (!strcmp("--non-empty", arg)) {
2138                         non_empty = 1;
2139                         continue;
2140                 }
2141                 if (!strcmp("--local", arg)) {
2142                         local = 1;
2143                         continue;
2144                 }
2145                 if (!strcmp("--incremental", arg)) {
2146                         incremental = 1;
2147                         continue;
2148                 }
2149                 if (!strcmp("--honor-pack-keep", arg)) {
2150                         ignore_packed_keep = 1;
2151                         continue;
2152                 }
2153                 if (!prefixcmp(arg, "--compression=")) {
2154                         char *end;
2155                         int level = strtoul(arg+14, &end, 0);
2156                         if (!arg[14] || *end)
2157                                 usage(pack_usage);
2158                         if (level == -1)
2159                                 level = Z_DEFAULT_COMPRESSION;
2160                         else if (level < 0 || level > Z_BEST_COMPRESSION)
2161                                 die("bad pack compression level %d", level);
2162                         pack_compression_level = level;
2163                         continue;
2164                 }
2165                 if (!prefixcmp(arg, "--max-pack-size=")) {
2166                         pack_size_limit_cfg = 0;
2167                         if (!git_parse_ulong(arg+16, &pack_size_limit))
2168                                 usage(pack_usage);
2169                         continue;
2170                 }
2171                 if (!prefixcmp(arg, "--window=")) {
2172                         char *end;
2173                         window = strtoul(arg+9, &end, 0);
2174                         if (!arg[9] || *end)
2175                                 usage(pack_usage);
2176                         continue;
2177                 }
2178                 if (!prefixcmp(arg, "--window-memory=")) {
2179                         if (!git_parse_ulong(arg+16, &window_memory_limit))
2180                                 usage(pack_usage);
2181                         continue;
2182                 }
2183                 if (!prefixcmp(arg, "--threads=")) {
2184                         char *end;
2185                         delta_search_threads = strtoul(arg+10, &end, 0);
2186                         if (!arg[10] || *end || delta_search_threads < 0)
2187                                 usage(pack_usage);
2188 #ifdef NO_PTHREADS
2189                         if (delta_search_threads != 1)
2190                                 warning("no threads support, "
2191                                         "ignoring %s", arg);
2192 #endif
2193                         continue;
2194                 }
2195                 if (!prefixcmp(arg, "--depth=")) {
2196                         char *end;
2197                         depth = strtoul(arg+8, &end, 0);
2198                         if (!arg[8] || *end)
2199                                 usage(pack_usage);
2200                         continue;
2201                 }
2202                 if (!strcmp("--progress", arg)) {
2203                         progress = 1;
2204                         continue;
2205                 }
2206                 if (!strcmp("--all-progress", arg)) {
2207                         progress = 2;
2208                         continue;
2209                 }
2210                 if (!strcmp("--all-progress-implied", arg)) {
2211                         all_progress_implied = 1;
2212                         continue;
2213                 }
2214                 if (!strcmp("-q", arg)) {
2215                         progress = 0;
2216                         continue;
2217                 }
2218                 if (!strcmp("--no-reuse-delta", arg)) {
2219                         reuse_delta = 0;
2220                         continue;
2221                 }
2222                 if (!strcmp("--no-reuse-object", arg)) {
2223                         reuse_object = reuse_delta = 0;
2224                         continue;
2225                 }
2226                 if (!strcmp("--delta-base-offset", arg)) {
2227                         allow_ofs_delta = 1;
2228                         continue;
2229                 }
2230                 if (!strcmp("--stdout", arg)) {
2231                         pack_to_stdout = 1;
2232                         continue;
2233                 }
2234                 if (!strcmp("--revs", arg)) {
2235                         use_internal_rev_list = 1;
2236                         continue;
2237                 }
2238                 if (!strcmp("--keep-unreachable", arg)) {
2239                         keep_unreachable = 1;
2240                         continue;
2241                 }
2242                 if (!strcmp("--unpack-unreachable", arg)) {
2243                         unpack_unreachable = 1;
2244                         continue;
2245                 }
2246                 if (!strcmp("--include-tag", arg)) {
2247                         include_tag = 1;
2248                         continue;
2249                 }
2250                 if (!strcmp("--unpacked", arg) ||
2251                     !strcmp("--reflog", arg) ||
2252                     !strcmp("--all", arg)) {
2253                         use_internal_rev_list = 1;
2254                         if (rp_ac >= rp_ac_alloc - 1) {
2255                                 rp_ac_alloc = alloc_nr(rp_ac_alloc);
2256                                 rp_av = xrealloc(rp_av,
2257                                                  rp_ac_alloc * sizeof(*rp_av));
2258                         }
2259                         rp_av[rp_ac++] = arg;
2260                         continue;
2261                 }
2262                 if (!strcmp("--thin", arg)) {
2263                         use_internal_rev_list = 1;
2264                         thin = 1;
2265                         rp_av[1] = "--objects-edge";
2266                         continue;
2267                 }
2268                 if (!prefixcmp(arg, "--index-version=")) {
2269                         char *c;
2270                         pack_idx_default_version = strtoul(arg + 16, &c, 10);
2271                         if (pack_idx_default_version > 2)
2272                                 die("bad %s", arg);
2273                         if (*c == ',')
2274                                 pack_idx_off32_limit = strtoul(c+1, &c, 0);
2275                         if (*c || pack_idx_off32_limit & 0x80000000)
2276                                 die("bad %s", arg);
2277                         continue;
2278                 }
2279                 if (!strcmp(arg, "--keep-true-parents")) {
2280                         grafts_replace_parents = 0;
2281                         continue;
2282                 }
2283                 usage(pack_usage);
2284         }
2286         /* Traditionally "pack-objects [options] base extra" failed;
2287          * we would however want to take refs parameter that would
2288          * have been given to upstream rev-list ourselves, which means
2289          * we somehow want to say what the base name is.  So the
2290          * syntax would be:
2291          *
2292          * pack-objects [options] base <refs...>
2293          *
2294          * in other words, we would treat the first non-option as the
2295          * base_name and send everything else to the internal revision
2296          * walker.
2297          */
2299         if (!pack_to_stdout)
2300                 base_name = argv[i++];
2302         if (pack_to_stdout != !base_name)
2303                 usage(pack_usage);
2305         if (!pack_to_stdout && !pack_size_limit)
2306                 pack_size_limit = pack_size_limit_cfg;
2307         if (pack_to_stdout && pack_size_limit)
2308                 die("--max-pack-size cannot be used to build a pack for transfer.");
2309         if (pack_size_limit && pack_size_limit < 1024*1024) {
2310                 warning("minimum pack size limit is 1 MiB");
2311                 pack_size_limit = 1024*1024;
2312         }
2314         if (!pack_to_stdout && thin)
2315                 die("--thin cannot be used to build an indexable pack.");
2317         if (keep_unreachable && unpack_unreachable)
2318                 die("--keep-unreachable and --unpack-unreachable are incompatible.");
2320         if (progress && all_progress_implied)
2321                 progress = 2;
2323         prepare_packed_git();
2325         if (progress)
2326                 progress_state = start_progress("Counting objects", 0);
2327         if (!use_internal_rev_list)
2328                 read_object_list_from_stdin();
2329         else {
2330                 rp_av[rp_ac] = NULL;
2331                 get_object_list(rp_ac, rp_av);
2332         }
2333         cleanup_preferred_base();
2334         if (include_tag && nr_result)
2335                 for_each_ref(add_ref_tag, NULL);
2336         stop_progress(&progress_state);
2338         if (non_empty && !nr_result)
2339                 return 0;
2340         if (nr_result)
2341                 prepare_pack(window, depth);
2342         write_pack_file();
2343         if (progress)
2344                 fprintf(stderr, "Total %"PRIu32" (delta %"PRIu32"),"
2345                         " reused %"PRIu32" (delta %"PRIu32")\n",
2346                         written, written_delta, reused, reused_delta);
2347         return 0;