8 static const char pack_usage[] = "git-pack-objects [-q] [--non-empty] [--local] [--incremental] [--window=N] [--depth=N] {--stdout | base-name} < object-list";
11 unsigned char sha1[20];
16 enum object_type type;
17 unsigned long delta_size;
18 struct object_entry *delta;
21 static unsigned char object_list_sha1[20];
22 static int non_empty = 0;
24 static int incremental = 0;
25 static struct object_entry **sorted_by_sha, **sorted_by_type;
26 static struct object_entry *objects = NULL;
27 static int nr_objects = 0, nr_alloc = 0;
28 static const char *base_name;
29 static unsigned char pack_file_sha1[20];
30 static int progress = 1;
32 static void *delta_against(void *buf, unsigned long size, struct object_entry *entry)
34 unsigned long othersize, delta_size;
36 void *otherbuf = read_sha1_file(entry->delta->sha1, type, &othersize);
40 die("unable to read %s", sha1_to_hex(entry->delta->sha1));
41 delta_buf = diff_delta(otherbuf, othersize,
42 buf, size, &delta_size, 0);
43 if (!delta_buf || delta_size != entry->delta_size)
44 die("delta size changed");
51 * The per-object header is a pretty dense thing, which is
52 * - first byte: low four bits are "size", then three bits of "type",
53 * and the high bit is "size continues".
54 * - each byte afterwards: low seven bits are size continuation,
55 * with the high bit being "size continues"
57 static int encode_header(enum object_type type, unsigned long size, unsigned char *hdr)
62 if (type < OBJ_COMMIT || type > OBJ_DELTA)
63 die("bad type %d", type);
65 c = (type << 4) | (size & 15);
77 static unsigned long write_object(struct sha1file *f, struct object_entry *entry)
81 void *buf = read_sha1_file(entry->sha1, type, &size);
82 unsigned char header[10];
83 unsigned hdrlen, datalen;
84 enum object_type obj_type;
87 die("unable to read %s", sha1_to_hex(entry->sha1));
88 if (size != entry->size)
89 die("object %s size inconsistency (%lu vs %lu)", sha1_to_hex(entry->sha1), size, entry->size);
92 * The object header is a byte of 'type' followed by zero or
93 * more bytes of length. For deltas, the 20 bytes of delta sha1
96 obj_type = entry->type;
98 buf = delta_against(buf, size, entry);
99 size = entry->delta_size;
100 obj_type = OBJ_DELTA;
102 hdrlen = encode_header(obj_type, size, header);
103 sha1write(f, header, hdrlen);
105 sha1write(f, entry->delta, 20);
108 datalen = sha1write_compressed(f, buf, size);
110 return hdrlen + datalen;
113 static unsigned long write_one(struct sha1file *f,
114 struct object_entry *e,
115 unsigned long offset)
118 /* offset starts from header size and cannot be zero
119 * if it is written already.
123 offset += write_object(f, e);
124 /* if we are deltified, write out its base object. */
126 offset = write_one(f, e->delta, offset);
130 static void write_pack_file(void)
134 unsigned long offset;
136 struct pack_header hdr;
139 f = sha1fd(1, "<stdout>");
141 f = sha1create("%s-%s.%s", base_name, sha1_to_hex(object_list_sha1), "pack");
142 hdr.hdr_signature = htonl(PACK_SIGNATURE);
143 hdr.hdr_version = htonl(PACK_VERSION);
144 hdr.hdr_entries = htonl(nr_objects);
145 sha1write(f, &hdr, sizeof(hdr));
146 offset = sizeof(hdr);
147 for (i = 0; i < nr_objects; i++)
148 offset = write_one(f, objects + i, offset);
150 sha1close(f, pack_file_sha1, 1);
155 static void write_index_file(void)
158 struct sha1file *f = sha1create("%s-%s.%s", base_name, sha1_to_hex(object_list_sha1), "idx");
159 struct object_entry **list = sorted_by_sha;
160 struct object_entry **last = list + nr_objects;
161 unsigned int array[256];
164 * Write the first-level table (the list is sorted,
165 * but we use a 256-entry lookup to be able to avoid
166 * having to do eight extra binary search iterations).
168 for (i = 0; i < 256; i++) {
169 struct object_entry **next = list;
170 while (next < last) {
171 struct object_entry *entry = *next;
172 if (entry->sha1[0] != i)
176 array[i] = htonl(next - sorted_by_sha);
179 sha1write(f, array, 256 * sizeof(int));
182 * Write the actual SHA1 entries..
184 list = sorted_by_sha;
185 for (i = 0; i < nr_objects; i++) {
186 struct object_entry *entry = *list++;
187 unsigned int offset = htonl(entry->offset);
188 sha1write(f, &offset, 4);
189 sha1write(f, entry->sha1, 20);
191 sha1write(f, pack_file_sha1, 20);
192 sha1close(f, NULL, 1);
195 static int add_object_entry(unsigned char *sha1, unsigned int hash)
197 unsigned int idx = nr_objects;
198 struct object_entry *entry;
200 if (incremental || local) {
201 struct packed_git *p;
203 for (p = packed_git; p; p = p->next) {
206 if (find_pack_entry_one(sha1, &e, p)) {
209 if (local && !p->pack_local)
215 if (idx >= nr_alloc) {
216 unsigned int needed = (idx + 1024) * 3 / 2;
217 objects = xrealloc(objects, needed * sizeof(*entry));
220 entry = objects + idx;
221 memset(entry, 0, sizeof(*entry));
222 memcpy(entry->sha1, sha1, 20);
228 static void check_object(struct object_entry *entry)
232 if (!sha1_object_info(entry->sha1, type, &entry->size)) {
233 if (!strcmp(type, "commit")) {
234 entry->type = OBJ_COMMIT;
235 } else if (!strcmp(type, "tree")) {
236 entry->type = OBJ_TREE;
237 } else if (!strcmp(type, "blob")) {
238 entry->type = OBJ_BLOB;
239 } else if (!strcmp(type, "tag")) {
240 entry->type = OBJ_TAG;
242 die("unable to pack object %s of type %s",
243 sha1_to_hex(entry->sha1), type);
246 die("unable to get type of object %s",
247 sha1_to_hex(entry->sha1));
250 static void get_object_details(void)
253 struct object_entry *entry = objects;
255 for (i = 0; i < nr_objects; i++)
256 check_object(entry++);
259 typedef int (*entry_sort_t)(const struct object_entry *, const struct object_entry *);
261 static entry_sort_t current_sort;
263 static int sort_comparator(const void *_a, const void *_b)
265 struct object_entry *a = *(struct object_entry **)_a;
266 struct object_entry *b = *(struct object_entry **)_b;
267 return current_sort(a,b);
270 static struct object_entry **create_sorted_list(entry_sort_t sort)
272 struct object_entry **list = xmalloc(nr_objects * sizeof(struct object_entry *));
275 for (i = 0; i < nr_objects; i++)
276 list[i] = objects + i;
278 qsort(list, nr_objects, sizeof(struct object_entry *), sort_comparator);
282 static int sha1_sort(const struct object_entry *a, const struct object_entry *b)
284 return memcmp(a->sha1, b->sha1, 20);
287 static int type_size_sort(const struct object_entry *a, const struct object_entry *b)
289 if (a->type < b->type)
291 if (a->type > b->type)
293 if (a->hash < b->hash)
295 if (a->hash > b->hash)
297 if (a->size < b->size)
299 if (a->size > b->size)
301 return a < b ? -1 : (a > b);
305 struct object_entry *entry;
310 * We search for deltas _backwards_ in a list sorted by type and
311 * by size, so that we see progressively smaller and smaller files.
312 * That's because we prefer deltas to be from the bigger file
313 * to the smaller - deletes are potentially cheaper, but perhaps
314 * more importantly, the bigger file is likely the more recent
317 static int try_delta(struct unpacked *cur, struct unpacked *old, unsigned max_depth)
319 struct object_entry *cur_entry = cur->entry;
320 struct object_entry *old_entry = old->entry;
321 unsigned long size, oldsize, delta_size, sizediff;
325 /* Don't bother doing diffs between different types */
326 if (cur_entry->type != old_entry->type)
329 size = cur_entry->size;
332 oldsize = old_entry->size;
333 sizediff = oldsize > size ? oldsize - size : size - oldsize;
334 if (sizediff > size / 8)
336 if (old_entry->depth >= max_depth)
342 * We always delta from the bigger to the smaller, since that's
343 * more space-efficient (deletes don't have to say _what_ they
346 max_size = size / 2 - 20;
347 if (cur_entry->delta)
348 max_size = cur_entry->delta_size-1;
349 if (sizediff >= max_size)
351 delta_buf = diff_delta(old->data, oldsize,
352 cur->data, size, &delta_size, max_size);
355 cur_entry->delta = old_entry;
356 cur_entry->delta_size = delta_size;
357 cur_entry->depth = old_entry->depth + 1;
362 static void find_deltas(struct object_entry **list, int window, int depth)
365 unsigned int array_size = window * sizeof(struct unpacked);
366 struct unpacked *array = xmalloc(array_size);
369 memset(array, 0, array_size);
372 eye_candy = i - (nr_objects / 20);
375 struct object_entry *entry = list[i];
376 struct unpacked *n = array + idx;
381 if (progress && i <= eye_candy) {
382 eye_candy -= nr_objects / 20;
387 n->data = read_sha1_file(entry->sha1, type, &size);
388 if (size != entry->size)
389 die("object %s inconsistent object length (%lu vs %lu)", sha1_to_hex(entry->sha1), size, entry->size);
392 unsigned int other_idx = idx + j;
394 if (other_idx >= window)
396 m = array + other_idx;
399 if (try_delta(n, m, depth) < 0)
407 for (i = 0; i < window; ++i)
412 static void prepare_pack(int window, int depth)
414 get_object_details();
417 fprintf(stderr, "Packing %d objects", nr_objects);
418 sorted_by_type = create_sorted_list(type_size_sort);
420 find_deltas(sorted_by_type, window+1, depth);
426 static int reuse_cached_pack(unsigned char *sha1, int pack_to_stdout)
428 static const char cache[] = "pack-cache/pack-%s.%s";
429 char *cached_pack, *cached_idx;
430 int ifd, ofd, ifd_ix = -1;
432 cached_pack = git_path(cache, sha1_to_hex(sha1), "pack");
433 ifd = open(cached_pack, O_RDONLY);
437 if (!pack_to_stdout) {
438 cached_idx = git_path(cache, sha1_to_hex(sha1), "idx");
439 ifd_ix = open(cached_idx, O_RDONLY);
446 fprintf(stderr, "Reusing %d objects pack %s\n", nr_objects,
449 if (pack_to_stdout) {
456 snprintf(name, sizeof(name),
457 "%s-%s.%s", base_name, sha1_to_hex(sha1), "pack");
458 ofd = open(name, O_CREAT | O_EXCL | O_WRONLY, 0666);
460 die("unable to open %s (%s)", name, strerror(errno));
461 if (copy_fd(ifd, ofd))
465 snprintf(name, sizeof(name),
466 "%s-%s.%s", base_name, sha1_to_hex(sha1), "idx");
467 ofd = open(name, O_CREAT | O_EXCL | O_WRONLY, 0666);
469 die("unable to open %s (%s)", name, strerror(errno));
470 if (copy_fd(ifd_ix, ofd))
473 puts(sha1_to_hex(sha1));
479 int main(int argc, char **argv)
482 char line[PATH_MAX + 20];
483 int window = 10, depth = 10, pack_to_stdout = 0;
484 struct object_entry **list;
486 struct timeval prev_tv;
488 int eye_candy_incr = 500;
491 setup_git_directory();
493 for (i = 1; i < argc; i++) {
494 const char *arg = argv[i];
497 if (!strcmp("--non-empty", arg)) {
501 if (!strcmp("--local", arg)) {
505 if (!strcmp("--incremental", arg)) {
509 if (!strncmp("--window=", arg, 9)) {
511 window = strtoul(arg+9, &end, 0);
516 if (!strncmp("--depth=", arg, 8)) {
518 depth = strtoul(arg+8, &end, 0);
523 if (!strcmp("-q", arg)) {
527 if (!strcmp("--stdout", arg)) {
538 if (pack_to_stdout != !base_name)
541 prepare_packed_git();
543 fprintf(stderr, "Generating pack...\n");
544 gettimeofday(&prev_tv, NULL);
546 while (fgets(line, sizeof(line), stdin) != NULL) {
549 unsigned char sha1[20];
551 if (progress && (eye_candy <= nr_objects)) {
552 fprintf(stderr, "Counting objects...%d\r", nr_objects);
553 if (eye_candy && (50 <= eye_candy_incr)) {
556 gettimeofday(&tv, NULL);
557 time_diff = (tv.tv_sec - prev_tv.tv_sec);
559 time_diff += (tv.tv_usec - prev_tv.tv_usec);
560 if ((1 << 9) < time_diff)
561 eye_candy_incr += 50;
562 else if (50 < eye_candy_incr)
563 eye_candy_incr -= 50;
565 eye_candy += eye_candy_incr;
567 if (get_sha1_hex(line, sha1))
568 die("expected sha1, got garbage:\n %s", line);
572 unsigned char c = *p++;
575 hash = hash * 11 + c;
577 add_object_entry(sha1, hash);
580 fprintf(stderr, "Done counting %d objects.\n", nr_objects);
581 if (non_empty && !nr_objects)
584 sorted_by_sha = create_sorted_list(sha1_sort);
586 list = sorted_by_sha;
587 for (i = 0; i < nr_objects; i++) {
588 struct object_entry *entry = *list++;
589 SHA1_Update(&ctx, entry->sha1, 20);
591 SHA1_Final(object_list_sha1, &ctx);
593 if (reuse_cached_pack(object_list_sha1, pack_to_stdout))
596 prepare_pack(window, depth);
597 if (!pack_to_stdout) {
599 puts(sha1_to_hex(object_list_sha1));