Use uint32_t for all packed object counts.
[git/git.git] / sha1_file.c
1 /*
2 * GIT - The information manager from hell
3 *
4 * Copyright (C) Linus Torvalds, 2005
5 *
6 * This handles basic git sha1 object files - packing, unpacking,
7 * creation etc.
8 */
9 #include "cache.h"
10 #include "delta.h"
11 #include "pack.h"
12 #include "blob.h"
13 #include "commit.h"
14 #include "tag.h"
15 #include "tree.h"
16
17 #ifndef O_NOATIME
18 #if defined(__linux__) && (defined(__i386__) || defined(__PPC__))
19 #define O_NOATIME 01000000
20 #else
21 #define O_NOATIME 0
22 #endif
23 #endif
24
25 #ifdef NO_C99_FORMAT
26 #define SZ_FMT "lu"
27 #else
28 #define SZ_FMT "zu"
29 #endif
30
31 const unsigned char null_sha1[20];
32
33 static unsigned int sha1_file_open_flag = O_NOATIME;
34
35 signed char hexval_table[256] = {
36 -1, -1, -1, -1, -1, -1, -1, -1, /* 00-07 */
37 -1, -1, -1, -1, -1, -1, -1, -1, /* 08-0f */
38 -1, -1, -1, -1, -1, -1, -1, -1, /* 10-17 */
39 -1, -1, -1, -1, -1, -1, -1, -1, /* 18-1f */
40 -1, -1, -1, -1, -1, -1, -1, -1, /* 20-27 */
41 -1, -1, -1, -1, -1, -1, -1, -1, /* 28-2f */
42 0, 1, 2, 3, 4, 5, 6, 7, /* 30-37 */
43 8, 9, -1, -1, -1, -1, -1, -1, /* 38-3f */
44 -1, 10, 11, 12, 13, 14, 15, -1, /* 40-47 */
45 -1, -1, -1, -1, -1, -1, -1, -1, /* 48-4f */
46 -1, -1, -1, -1, -1, -1, -1, -1, /* 50-57 */
47 -1, -1, -1, -1, -1, -1, -1, -1, /* 58-5f */
48 -1, 10, 11, 12, 13, 14, 15, -1, /* 60-67 */
49 -1, -1, -1, -1, -1, -1, -1, -1, /* 68-67 */
50 -1, -1, -1, -1, -1, -1, -1, -1, /* 70-77 */
51 -1, -1, -1, -1, -1, -1, -1, -1, /* 78-7f */
52 -1, -1, -1, -1, -1, -1, -1, -1, /* 80-87 */
53 -1, -1, -1, -1, -1, -1, -1, -1, /* 88-8f */
54 -1, -1, -1, -1, -1, -1, -1, -1, /* 90-97 */
55 -1, -1, -1, -1, -1, -1, -1, -1, /* 98-9f */
56 -1, -1, -1, -1, -1, -1, -1, -1, /* a0-a7 */
57 -1, -1, -1, -1, -1, -1, -1, -1, /* a8-af */
58 -1, -1, -1, -1, -1, -1, -1, -1, /* b0-b7 */
59 -1, -1, -1, -1, -1, -1, -1, -1, /* b8-bf */
60 -1, -1, -1, -1, -1, -1, -1, -1, /* c0-c7 */
61 -1, -1, -1, -1, -1, -1, -1, -1, /* c8-cf */
62 -1, -1, -1, -1, -1, -1, -1, -1, /* d0-d7 */
63 -1, -1, -1, -1, -1, -1, -1, -1, /* d8-df */
64 -1, -1, -1, -1, -1, -1, -1, -1, /* e0-e7 */
65 -1, -1, -1, -1, -1, -1, -1, -1, /* e8-ef */
66 -1, -1, -1, -1, -1, -1, -1, -1, /* f0-f7 */
67 -1, -1, -1, -1, -1, -1, -1, -1, /* f8-ff */
68 };
69
70 int get_sha1_hex(const char *hex, unsigned char *sha1)
71 {
72 int i;
73 for (i = 0; i < 20; i++) {
74 unsigned int val = (hexval(hex[0]) << 4) | hexval(hex[1]);
75 if (val & ~0xff)
76 return -1;
77 *sha1++ = val;
78 hex += 2;
79 }
80 return 0;
81 }
82
83 int safe_create_leading_directories(char *path)
84 {
85 char *pos = path;
86 struct stat st;
87
88 if (*pos == '/')
89 pos++;
90
91 while (pos) {
92 pos = strchr(pos, '/');
93 if (!pos)
94 break;
95 *pos = 0;
96 if (!stat(path, &st)) {
97 /* path exists */
98 if (!S_ISDIR(st.st_mode)) {
99 *pos = '/';
100 return -3;
101 }
102 }
103 else if (mkdir(path, 0777)) {
104 *pos = '/';
105 return -1;
106 }
107 else if (adjust_shared_perm(path)) {
108 *pos = '/';
109 return -2;
110 }
111 *pos++ = '/';
112 }
113 return 0;
114 }
115
116 char * sha1_to_hex(const unsigned char *sha1)
117 {
118 static int bufno;
119 static char hexbuffer[4][50];
120 static const char hex[] = "0123456789abcdef";
121 char *buffer = hexbuffer[3 & ++bufno], *buf = buffer;
122 int i;
123
124 for (i = 0; i < 20; i++) {
125 unsigned int val = *sha1++;
126 *buf++ = hex[val >> 4];
127 *buf++ = hex[val & 0xf];
128 }
129 *buf = '\0';
130
131 return buffer;
132 }
133
134 static void fill_sha1_path(char *pathbuf, const unsigned char *sha1)
135 {
136 int i;
137 for (i = 0; i < 20; i++) {
138 static char hex[] = "0123456789abcdef";
139 unsigned int val = sha1[i];
140 char *pos = pathbuf + i*2 + (i > 0);
141 *pos++ = hex[val >> 4];
142 *pos = hex[val & 0xf];
143 }
144 }
145
146 /*
147 * NOTE! This returns a statically allocated buffer, so you have to be
148 * careful about using it. Do a "xstrdup()" if you need to save the
149 * filename.
150 *
151 * Also note that this returns the location for creating. Reading
152 * SHA1 file can happen from any alternate directory listed in the
153 * DB_ENVIRONMENT environment variable if it is not found in
154 * the primary object database.
155 */
156 char *sha1_file_name(const unsigned char *sha1)
157 {
158 static char *name, *base;
159
160 if (!base) {
161 const char *sha1_file_directory = get_object_directory();
162 int len = strlen(sha1_file_directory);
163 base = xmalloc(len + 60);
164 memcpy(base, sha1_file_directory, len);
165 memset(base+len, 0, 60);
166 base[len] = '/';
167 base[len+3] = '/';
168 name = base + len + 1;
169 }
170 fill_sha1_path(name, sha1);
171 return base;
172 }
173
174 char *sha1_pack_name(const unsigned char *sha1)
175 {
176 static const char hex[] = "0123456789abcdef";
177 static char *name, *base, *buf;
178 int i;
179
180 if (!base) {
181 const char *sha1_file_directory = get_object_directory();
182 int len = strlen(sha1_file_directory);
183 base = xmalloc(len + 60);
184 sprintf(base, "%s/pack/pack-1234567890123456789012345678901234567890.pack", sha1_file_directory);
185 name = base + len + 11;
186 }
187
188 buf = name;
189
190 for (i = 0; i < 20; i++) {
191 unsigned int val = *sha1++;
192 *buf++ = hex[val >> 4];
193 *buf++ = hex[val & 0xf];
194 }
195
196 return base;
197 }
198
199 char *sha1_pack_index_name(const unsigned char *sha1)
200 {
201 static const char hex[] = "0123456789abcdef";
202 static char *name, *base, *buf;
203 int i;
204
205 if (!base) {
206 const char *sha1_file_directory = get_object_directory();
207 int len = strlen(sha1_file_directory);
208 base = xmalloc(len + 60);
209 sprintf(base, "%s/pack/pack-1234567890123456789012345678901234567890.idx", sha1_file_directory);
210 name = base + len + 11;
211 }
212
213 buf = name;
214
215 for (i = 0; i < 20; i++) {
216 unsigned int val = *sha1++;
217 *buf++ = hex[val >> 4];
218 *buf++ = hex[val & 0xf];
219 }
220
221 return base;
222 }
223
224 struct alternate_object_database *alt_odb_list;
225 static struct alternate_object_database **alt_odb_tail;
226
227 static void read_info_alternates(const char * alternates, int depth);
228
229 /*
230 * Prepare alternate object database registry.
231 *
232 * The variable alt_odb_list points at the list of struct
233 * alternate_object_database. The elements on this list come from
234 * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
235 * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
236 * whose contents is similar to that environment variable but can be
237 * LF separated. Its base points at a statically allocated buffer that
238 * contains "/the/directory/corresponding/to/.git/objects/...", while
239 * its name points just after the slash at the end of ".git/objects/"
240 * in the example above, and has enough space to hold 40-byte hex
241 * SHA1, an extra slash for the first level indirection, and the
242 * terminating NUL.
243 */
244 static int link_alt_odb_entry(const char * entry, int len, const char * relative_base, int depth)
245 {
246 struct stat st;
247 const char *objdir = get_object_directory();
248 struct alternate_object_database *ent;
249 struct alternate_object_database *alt;
250 /* 43 = 40-byte + 2 '/' + terminating NUL */
251 int pfxlen = len;
252 int entlen = pfxlen + 43;
253 int base_len = -1;
254
255 if (*entry != '/' && relative_base) {
256 /* Relative alt-odb */
257 if (base_len < 0)
258 base_len = strlen(relative_base) + 1;
259 entlen += base_len;
260 pfxlen += base_len;
261 }
262 ent = xmalloc(sizeof(*ent) + entlen);
263
264 if (*entry != '/' && relative_base) {
265 memcpy(ent->base, relative_base, base_len - 1);
266 ent->base[base_len - 1] = '/';
267 memcpy(ent->base + base_len, entry, len);
268 }
269 else
270 memcpy(ent->base, entry, pfxlen);
271
272 ent->name = ent->base + pfxlen + 1;
273 ent->base[pfxlen + 3] = '/';
274 ent->base[pfxlen] = ent->base[entlen-1] = 0;
275
276 /* Detect cases where alternate disappeared */
277 if (stat(ent->base, &st) || !S_ISDIR(st.st_mode)) {
278 error("object directory %s does not exist; "
279 "check .git/objects/info/alternates.",
280 ent->base);
281 free(ent);
282 return -1;
283 }
284
285 /* Prevent the common mistake of listing the same
286 * thing twice, or object directory itself.
287 */
288 for (alt = alt_odb_list; alt; alt = alt->next) {
289 if (!memcmp(ent->base, alt->base, pfxlen)) {
290 free(ent);
291 return -1;
292 }
293 }
294 if (!memcmp(ent->base, objdir, pfxlen)) {
295 free(ent);
296 return -1;
297 }
298
299 /* add the alternate entry */
300 *alt_odb_tail = ent;
301 alt_odb_tail = &(ent->next);
302 ent->next = NULL;
303
304 /* recursively add alternates */
305 read_info_alternates(ent->base, depth + 1);
306
307 ent->base[pfxlen] = '/';
308
309 return 0;
310 }
311
312 static void link_alt_odb_entries(const char *alt, const char *ep, int sep,
313 const char *relative_base, int depth)
314 {
315 const char *cp, *last;
316
317 if (depth > 5) {
318 error("%s: ignoring alternate object stores, nesting too deep.",
319 relative_base);
320 return;
321 }
322
323 last = alt;
324 while (last < ep) {
325 cp = last;
326 if (cp < ep && *cp == '#') {
327 while (cp < ep && *cp != sep)
328 cp++;
329 last = cp + 1;
330 continue;
331 }
332 while (cp < ep && *cp != sep)
333 cp++;
334 if (last != cp) {
335 if ((*last != '/') && depth) {
336 error("%s: ignoring relative alternate object store %s",
337 relative_base, last);
338 } else {
339 link_alt_odb_entry(last, cp - last,
340 relative_base, depth);
341 }
342 }
343 while (cp < ep && *cp == sep)
344 cp++;
345 last = cp;
346 }
347 }
348
349 static void read_info_alternates(const char * relative_base, int depth)
350 {
351 char *map;
352 struct stat st;
353 char path[PATH_MAX];
354 int fd;
355
356 sprintf(path, "%s/info/alternates", relative_base);
357 fd = open(path, O_RDONLY);
358 if (fd < 0)
359 return;
360 if (fstat(fd, &st) || (st.st_size == 0)) {
361 close(fd);
362 return;
363 }
364 map = xmmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
365 close(fd);
366
367 link_alt_odb_entries(map, map + st.st_size, '\n', relative_base, depth);
368
369 munmap(map, st.st_size);
370 }
371
372 void prepare_alt_odb(void)
373 {
374 const char *alt;
375
376 alt = getenv(ALTERNATE_DB_ENVIRONMENT);
377 if (!alt) alt = "";
378
379 if (alt_odb_tail)
380 return;
381 alt_odb_tail = &alt_odb_list;
382 link_alt_odb_entries(alt, alt + strlen(alt), ':', NULL, 0);
383
384 read_info_alternates(get_object_directory(), 0);
385 }
386
387 static char *find_sha1_file(const unsigned char *sha1, struct stat *st)
388 {
389 char *name = sha1_file_name(sha1);
390 struct alternate_object_database *alt;
391
392 if (!stat(name, st))
393 return name;
394 prepare_alt_odb();
395 for (alt = alt_odb_list; alt; alt = alt->next) {
396 name = alt->name;
397 fill_sha1_path(name, sha1);
398 if (!stat(alt->base, st))
399 return alt->base;
400 }
401 return NULL;
402 }
403
404 static unsigned int pack_used_ctr;
405 static unsigned int pack_mmap_calls;
406 static unsigned int peak_pack_open_windows;
407 static unsigned int pack_open_windows;
408 static size_t peak_pack_mapped;
409 static size_t pack_mapped;
410 struct packed_git *packed_git;
411
412 void pack_report()
413 {
414 fprintf(stderr,
415 "pack_report: getpagesize() = %10" SZ_FMT "\n"
416 "pack_report: core.packedGitWindowSize = %10" SZ_FMT "\n"
417 "pack_report: core.packedGitLimit = %10" SZ_FMT "\n",
418 (size_t) getpagesize(),
419 packed_git_window_size,
420 packed_git_limit);
421 fprintf(stderr,
422 "pack_report: pack_used_ctr = %10u\n"
423 "pack_report: pack_mmap_calls = %10u\n"
424 "pack_report: pack_open_windows = %10u / %10u\n"
425 "pack_report: pack_mapped = "
426 "%10" SZ_FMT " / %10" SZ_FMT "\n",
427 pack_used_ctr,
428 pack_mmap_calls,
429 pack_open_windows, peak_pack_open_windows,
430 pack_mapped, peak_pack_mapped);
431 }
432
433 static int check_packed_git_idx(const char *path,
434 unsigned long *idx_size_,
435 void **idx_map_)
436 {
437 void *idx_map;
438 uint32_t *index;
439 unsigned long idx_size;
440 uint32_t nr, i;
441 int fd = open(path, O_RDONLY);
442 struct stat st;
443 if (fd < 0)
444 return -1;
445 if (fstat(fd, &st)) {
446 close(fd);
447 return -1;
448 }
449 idx_size = st.st_size;
450 if (idx_size < 4 * 256 + 20 + 20) {
451 close(fd);
452 return error("index file %s is too small", path);
453 }
454 idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
455 close(fd);
456
457 index = idx_map;
458 *idx_map_ = idx_map;
459 *idx_size_ = idx_size;
460
461 /* a future index format would start with this, as older git
462 * binaries would fail the non-monotonic index check below.
463 * give a nicer warning to the user if we can.
464 */
465 if (index[0] == htonl(PACK_IDX_SIGNATURE)) {
466 munmap(idx_map, idx_size);
467 return error("index file %s is a newer version"
468 " and is not supported by this binary"
469 " (try upgrading GIT to a newer version)",
470 path);
471 }
472
473 nr = 0;
474 for (i = 0; i < 256; i++) {
475 uint32_t n = ntohl(index[i]);
476 if (n < nr) {
477 munmap(idx_map, idx_size);
478 return error("non-monotonic index %s", path);
479 }
480 nr = n;
481 }
482
483 /*
484 * Total size:
485 * - 256 index entries 4 bytes each
486 * - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
487 * - 20-byte SHA1 of the packfile
488 * - 20-byte SHA1 file checksum
489 */
490 if (idx_size != 4*256 + nr * 24 + 20 + 20) {
491 munmap(idx_map, idx_size);
492 return error("wrong index file size in %s", path);
493 }
494
495 return 0;
496 }
497
498 static void scan_windows(struct packed_git *p,
499 struct packed_git **lru_p,
500 struct pack_window **lru_w,
501 struct pack_window **lru_l)
502 {
503 struct pack_window *w, *w_l;
504
505 for (w_l = NULL, w = p->windows; w; w = w->next) {
506 if (!w->inuse_cnt) {
507 if (!*lru_w || w->last_used < (*lru_w)->last_used) {
508 *lru_p = p;
509 *lru_w = w;
510 *lru_l = w_l;
511 }
512 }
513 w_l = w;
514 }
515 }
516
517 static int unuse_one_window(struct packed_git *current)
518 {
519 struct packed_git *p, *lru_p = NULL;
520 struct pack_window *lru_w = NULL, *lru_l = NULL;
521
522 if (current)
523 scan_windows(current, &lru_p, &lru_w, &lru_l);
524 for (p = packed_git; p; p = p->next)
525 scan_windows(p, &lru_p, &lru_w, &lru_l);
526 if (lru_p) {
527 munmap(lru_w->base, lru_w->len);
528 pack_mapped -= lru_w->len;
529 if (lru_l)
530 lru_l->next = lru_w->next;
531 else {
532 lru_p->windows = lru_w->next;
533 if (!lru_p->windows && lru_p != current) {
534 close(lru_p->pack_fd);
535 lru_p->pack_fd = -1;
536 }
537 }
538 free(lru_w);
539 pack_open_windows--;
540 return 1;
541 }
542 return 0;
543 }
544
545 void release_pack_memory(size_t need)
546 {
547 size_t cur = pack_mapped;
548 while (need >= (cur - pack_mapped) && unuse_one_window(NULL))
549 ; /* nothing */
550 }
551
552 void unuse_pack(struct pack_window **w_cursor)
553 {
554 struct pack_window *w = *w_cursor;
555 if (w) {
556 w->inuse_cnt--;
557 *w_cursor = NULL;
558 }
559 }
560
561 /*
562 * Do not call this directly as this leaks p->pack_fd on error return;
563 * call open_packed_git() instead.
564 */
565 static int open_packed_git_1(struct packed_git *p)
566 {
567 struct stat st;
568 struct pack_header hdr;
569 unsigned char sha1[20];
570 unsigned char *idx_sha1;
571 long fd_flag;
572
573 p->pack_fd = open(p->pack_name, O_RDONLY);
574 if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
575 return -1;
576
577 /* If we created the struct before we had the pack we lack size. */
578 if (!p->pack_size) {
579 if (!S_ISREG(st.st_mode))
580 return error("packfile %s not a regular file", p->pack_name);
581 p->pack_size = st.st_size;
582 } else if (p->pack_size != st.st_size)
583 return error("packfile %s size changed", p->pack_name);
584
585 /* We leave these file descriptors open with sliding mmap;
586 * there is no point keeping them open across exec(), though.
587 */
588 fd_flag = fcntl(p->pack_fd, F_GETFD, 0);
589 if (fd_flag < 0)
590 return error("cannot determine file descriptor flags");
591 fd_flag |= FD_CLOEXEC;
592 if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1)
593 return error("cannot set FD_CLOEXEC");
594
595 /* Verify we recognize this pack file format. */
596 if (read_in_full(p->pack_fd, &hdr, sizeof(hdr)) != sizeof(hdr))
597 return error("file %s is far too short to be a packfile", p->pack_name);
598 if (hdr.hdr_signature != htonl(PACK_SIGNATURE))
599 return error("file %s is not a GIT packfile", p->pack_name);
600 if (!pack_version_ok(hdr.hdr_version))
601 return error("packfile %s is version %u and not supported"
602 " (try upgrading GIT to a newer version)",
603 p->pack_name, ntohl(hdr.hdr_version));
604
605 /* Verify the pack matches its index. */
606 if (num_packed_objects(p) != ntohl(hdr.hdr_entries))
607 return error("packfile %s claims to have %u objects"
608 " while index size indicates %u objects",
609 p->pack_name, ntohl(hdr.hdr_entries),
610 num_packed_objects(p));
611 if (lseek(p->pack_fd, p->pack_size - sizeof(sha1), SEEK_SET) == -1)
612 return error("end of packfile %s is unavailable", p->pack_name);
613 if (read_in_full(p->pack_fd, sha1, sizeof(sha1)) != sizeof(sha1))
614 return error("packfile %s signature is unavailable", p->pack_name);
615 idx_sha1 = ((unsigned char *)p->index_base) + p->index_size - 40;
616 if (hashcmp(sha1, idx_sha1))
617 return error("packfile %s does not match index", p->pack_name);
618 return 0;
619 }
620
621 static int open_packed_git(struct packed_git *p)
622 {
623 if (!open_packed_git_1(p))
624 return 0;
625 if (p->pack_fd != -1) {
626 close(p->pack_fd);
627 p->pack_fd = -1;
628 }
629 return -1;
630 }
631
632 static int in_window(struct pack_window *win, unsigned long offset)
633 {
634 /* We must promise at least 20 bytes (one hash) after the
635 * offset is available from this window, otherwise the offset
636 * is not actually in this window and a different window (which
637 * has that one hash excess) must be used. This is to support
638 * the object header and delta base parsing routines below.
639 */
640 off_t win_off = win->offset;
641 return win_off <= offset
642 && (offset + 20) <= (win_off + win->len);
643 }
644
645 unsigned char* use_pack(struct packed_git *p,
646 struct pack_window **w_cursor,
647 unsigned long offset,
648 unsigned int *left)
649 {
650 struct pack_window *win = *w_cursor;
651
652 if (p->pack_fd == -1 && open_packed_git(p))
653 die("packfile %s cannot be accessed", p->pack_name);
654
655 /* Since packfiles end in a hash of their content and its
656 * pointless to ask for an offset into the middle of that
657 * hash, and the in_window function above wouldn't match
658 * don't allow an offset too close to the end of the file.
659 */
660 if (offset > (p->pack_size - 20))
661 die("offset beyond end of packfile (truncated pack?)");
662
663 if (!win || !in_window(win, offset)) {
664 if (win)
665 win->inuse_cnt--;
666 for (win = p->windows; win; win = win->next) {
667 if (in_window(win, offset))
668 break;
669 }
670 if (!win) {
671 size_t window_align = packed_git_window_size / 2;
672 win = xcalloc(1, sizeof(*win));
673 win->offset = (offset / window_align) * window_align;
674 win->len = p->pack_size - win->offset;
675 if (win->len > packed_git_window_size)
676 win->len = packed_git_window_size;
677 pack_mapped += win->len;
678 while (packed_git_limit < pack_mapped
679 && unuse_one_window(p))
680 ; /* nothing */
681 win->base = xmmap(NULL, win->len,
682 PROT_READ, MAP_PRIVATE,
683 p->pack_fd, win->offset);
684 if (win->base == MAP_FAILED)
685 die("packfile %s cannot be mapped: %s",
686 p->pack_name,
687 strerror(errno));
688 pack_mmap_calls++;
689 pack_open_windows++;
690 if (pack_mapped > peak_pack_mapped)
691 peak_pack_mapped = pack_mapped;
692 if (pack_open_windows > peak_pack_open_windows)
693 peak_pack_open_windows = pack_open_windows;
694 win->next = p->windows;
695 p->windows = win;
696 }
697 }
698 if (win != *w_cursor) {
699 win->last_used = pack_used_ctr++;
700 win->inuse_cnt++;
701 *w_cursor = win;
702 }
703 offset -= win->offset;
704 if (left)
705 *left = win->len - offset;
706 return win->base + offset;
707 }
708
709 struct packed_git *add_packed_git(char *path, int path_len, int local)
710 {
711 struct stat st;
712 struct packed_git *p;
713 unsigned long idx_size;
714 void *idx_map;
715 unsigned char sha1[20];
716
717 if (check_packed_git_idx(path, &idx_size, &idx_map))
718 return NULL;
719
720 /* do we have a corresponding .pack file? */
721 strcpy(path + path_len - 4, ".pack");
722 if (stat(path, &st) || !S_ISREG(st.st_mode)) {
723 munmap(idx_map, idx_size);
724 return NULL;
725 }
726 /* ok, it looks sane as far as we can check without
727 * actually mapping the pack file.
728 */
729 p = xmalloc(sizeof(*p) + path_len + 2);
730 strcpy(p->pack_name, path);
731 p->index_size = idx_size;
732 p->pack_size = st.st_size;
733 p->index_base = idx_map;
734 p->next = NULL;
735 p->windows = NULL;
736 p->pack_fd = -1;
737 p->pack_local = local;
738 if ((path_len > 44) && !get_sha1_hex(path + path_len - 44, sha1))
739 hashcpy(p->sha1, sha1);
740 return p;
741 }
742
743 struct packed_git *parse_pack_index(unsigned char *sha1)
744 {
745 char *path = sha1_pack_index_name(sha1);
746 return parse_pack_index_file(sha1, path);
747 }
748
749 struct packed_git *parse_pack_index_file(const unsigned char *sha1, char *idx_path)
750 {
751 struct packed_git *p;
752 unsigned long idx_size;
753 void *idx_map;
754 char *path;
755
756 if (check_packed_git_idx(idx_path, &idx_size, &idx_map))
757 return NULL;
758
759 path = sha1_pack_name(sha1);
760
761 p = xmalloc(sizeof(*p) + strlen(path) + 2);
762 strcpy(p->pack_name, path);
763 p->index_size = idx_size;
764 p->pack_size = 0;
765 p->index_base = idx_map;
766 p->next = NULL;
767 p->windows = NULL;
768 p->pack_fd = -1;
769 hashcpy(p->sha1, sha1);
770 return p;
771 }
772
773 void install_packed_git(struct packed_git *pack)
774 {
775 pack->next = packed_git;
776 packed_git = pack;
777 }
778
779 static void prepare_packed_git_one(char *objdir, int local)
780 {
781 char path[PATH_MAX];
782 int len;
783 DIR *dir;
784 struct dirent *de;
785
786 sprintf(path, "%s/pack", objdir);
787 len = strlen(path);
788 dir = opendir(path);
789 if (!dir) {
790 if (errno != ENOENT)
791 error("unable to open object pack directory: %s: %s",
792 path, strerror(errno));
793 return;
794 }
795 path[len++] = '/';
796 while ((de = readdir(dir)) != NULL) {
797 int namelen = strlen(de->d_name);
798 struct packed_git *p;
799
800 if (!has_extension(de->d_name, ".idx"))
801 continue;
802
803 /* Don't reopen a pack we already have. */
804 strcpy(path + len, de->d_name);
805 for (p = packed_git; p; p = p->next) {
806 if (!memcmp(path, p->pack_name, len + namelen - 4))
807 break;
808 }
809 if (p)
810 continue;
811 /* See if it really is a valid .idx file with corresponding
812 * .pack file that we can map.
813 */
814 p = add_packed_git(path, len + namelen, local);
815 if (!p)
816 continue;
817 install_packed_git(p);
818 }
819 closedir(dir);
820 }
821
822 static int prepare_packed_git_run_once = 0;
823 void prepare_packed_git(void)
824 {
825 struct alternate_object_database *alt;
826
827 if (prepare_packed_git_run_once)
828 return;
829 prepare_packed_git_one(get_object_directory(), 1);
830 prepare_alt_odb();
831 for (alt = alt_odb_list; alt; alt = alt->next) {
832 alt->name[-1] = 0;
833 prepare_packed_git_one(alt->base, 0);
834 alt->name[-1] = '/';
835 }
836 prepare_packed_git_run_once = 1;
837 }
838
839 void reprepare_packed_git(void)
840 {
841 prepare_packed_git_run_once = 0;
842 prepare_packed_git();
843 }
844
845 int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long size, const char *type)
846 {
847 unsigned char real_sha1[20];
848 hash_sha1_file(map, size, type, real_sha1);
849 return hashcmp(sha1, real_sha1) ? -1 : 0;
850 }
851
852 void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
853 {
854 struct stat st;
855 void *map;
856 int fd;
857 char *filename = find_sha1_file(sha1, &st);
858
859 if (!filename) {
860 return NULL;
861 }
862
863 fd = open(filename, O_RDONLY | sha1_file_open_flag);
864 if (fd < 0) {
865 /* See if it works without O_NOATIME */
866 switch (sha1_file_open_flag) {
867 default:
868 fd = open(filename, O_RDONLY);
869 if (fd >= 0)
870 break;
871 /* Fallthrough */
872 case 0:
873 return NULL;
874 }
875
876 /* If it failed once, it will probably fail again.
877 * Stop using O_NOATIME
878 */
879 sha1_file_open_flag = 0;
880 }
881 map = xmmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
882 close(fd);
883 *size = st.st_size;
884 return map;
885 }
886
887 int legacy_loose_object(unsigned char *map)
888 {
889 unsigned int word;
890
891 /*
892 * Is it a zlib-compressed buffer? If so, the first byte
893 * must be 0x78 (15-bit window size, deflated), and the
894 * first 16-bit word is evenly divisible by 31
895 */
896 word = (map[0] << 8) + map[1];
897 if (map[0] == 0x78 && !(word % 31))
898 return 1;
899 else
900 return 0;
901 }
902
903 unsigned long unpack_object_header_gently(const unsigned char *buf, unsigned long len, enum object_type *type, unsigned long *sizep)
904 {
905 unsigned shift;
906 unsigned char c;
907 unsigned long size;
908 unsigned long used = 0;
909
910 c = buf[used++];
911 *type = (c >> 4) & 7;
912 size = c & 15;
913 shift = 4;
914 while (c & 0x80) {
915 if (len <= used)
916 return 0;
917 if (sizeof(long) * 8 <= shift)
918 return 0;
919 c = buf[used++];
920 size += (c & 0x7f) << shift;
921 shift += 7;
922 }
923 *sizep = size;
924 return used;
925 }
926
927 static int unpack_sha1_header(z_stream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz)
928 {
929 unsigned long size, used;
930 static const char valid_loose_object_type[8] = {
931 0, /* OBJ_EXT */
932 1, 1, 1, 1, /* "commit", "tree", "blob", "tag" */
933 0, /* "delta" and others are invalid in a loose object */
934 };
935 enum object_type type;
936
937 /* Get the data stream */
938 memset(stream, 0, sizeof(*stream));
939 stream->next_in = map;
940 stream->avail_in = mapsize;
941 stream->next_out = buffer;
942 stream->avail_out = bufsiz;
943
944 if (legacy_loose_object(map)) {
945 inflateInit(stream);
946 return inflate(stream, 0);
947 }
948
949 used = unpack_object_header_gently(map, mapsize, &type, &size);
950 if (!used || !valid_loose_object_type[type])
951 return -1;
952 map += used;
953 mapsize -= used;
954
955 /* Set up the stream for the rest.. */
956 stream->next_in = map;
957 stream->avail_in = mapsize;
958 inflateInit(stream);
959
960 /* And generate the fake traditional header */
961 stream->total_out = 1 + snprintf(buffer, bufsiz, "%s %lu",
962 typename(type), size);
963 return 0;
964 }
965
966 static void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size)
967 {
968 int bytes = strlen(buffer) + 1;
969 unsigned char *buf = xmalloc(1+size);
970 unsigned long n;
971
972 n = stream->total_out - bytes;
973 if (n > size)
974 n = size;
975 memcpy(buf, (char *) buffer + bytes, n);
976 bytes = n;
977 if (bytes < size) {
978 stream->next_out = buf + bytes;
979 stream->avail_out = size - bytes;
980 while (inflate(stream, Z_FINISH) == Z_OK)
981 /* nothing */;
982 }
983 buf[size] = 0;
984 inflateEnd(stream);
985 return buf;
986 }
987
988 /*
989 * We used to just use "sscanf()", but that's actually way
990 * too permissive for what we want to check. So do an anal
991 * object header parse by hand.
992 */
993 static int parse_sha1_header(const char *hdr, unsigned long *sizep)
994 {
995 char type[10];
996 int i;
997 unsigned long size;
998
999 /*
1000 * The type can be at most ten bytes (including the
1001 * terminating '\0' that we add), and is followed by
1002 * a space.
1003 */
1004 i = 0;
1005 for (;;) {
1006 char c = *hdr++;
1007 if (c == ' ')
1008 break;
1009 type[i++] = c;
1010 if (i >= sizeof(type))
1011 return -1;
1012 }
1013 type[i] = 0;
1014
1015 /*
1016 * The length must follow immediately, and be in canonical
1017 * decimal format (ie "010" is not valid).
1018 */
1019 size = *hdr++ - '0';
1020 if (size > 9)
1021 return -1;
1022 if (size) {
1023 for (;;) {
1024 unsigned long c = *hdr - '0';
1025 if (c > 9)
1026 break;
1027 hdr++;
1028 size = size * 10 + c;
1029 }
1030 }
1031 *sizep = size;
1032
1033 /*
1034 * The length must be followed by a zero byte
1035 */
1036 return *hdr ? -1 : type_from_string(type);
1037 }
1038
1039 void * unpack_sha1_file(void *map, unsigned long mapsize, enum object_type *type, unsigned long *size)
1040 {
1041 int ret;
1042 z_stream stream;
1043 char hdr[8192];
1044
1045 ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
1046 if (ret < Z_OK || (*type = parse_sha1_header(hdr, size)) < 0)
1047 return NULL;
1048
1049 return unpack_sha1_rest(&stream, hdr, *size);
1050 }
1051
1052 static unsigned long get_delta_base(struct packed_git *p,
1053 struct pack_window **w_curs,
1054 unsigned long *curpos,
1055 enum object_type type,
1056 unsigned long delta_obj_offset)
1057 {
1058 unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL);
1059 unsigned long base_offset;
1060
1061 /* use_pack() assured us we have [base_info, base_info + 20)
1062 * as a range that we can look at without walking off the
1063 * end of the mapped window. Its actually the hash size
1064 * that is assured. An OFS_DELTA longer than the hash size
1065 * is stupid, as then a REF_DELTA would be smaller to store.
1066 */
1067 if (type == OBJ_OFS_DELTA) {
1068 unsigned used = 0;
1069 unsigned char c = base_info[used++];
1070 base_offset = c & 127;
1071 while (c & 128) {
1072 base_offset += 1;
1073 if (!base_offset || base_offset & ~(~0UL >> 7))
1074 die("offset value overflow for delta base object");
1075 c = base_info[used++];
1076 base_offset = (base_offset << 7) + (c & 127);
1077 }
1078 base_offset = delta_obj_offset - base_offset;
1079 if (base_offset >= delta_obj_offset)
1080 die("delta base offset out of bound");
1081 *curpos += used;
1082 } else if (type == OBJ_REF_DELTA) {
1083 /* The base entry _must_ be in the same pack */
1084 base_offset = find_pack_entry_one(base_info, p);
1085 if (!base_offset)
1086 die("failed to find delta-pack base object %s",
1087 sha1_to_hex(base_info));
1088 *curpos += 20;
1089 } else
1090 die("I am totally screwed");
1091 return base_offset;
1092 }
1093
1094 /* forward declaration for a mutually recursive function */
1095 static int packed_object_info(struct packed_git *p, unsigned long offset,
1096 unsigned long *sizep);
1097
1098 static int packed_delta_info(struct packed_git *p,
1099 struct pack_window **w_curs,
1100 unsigned long curpos,
1101 enum object_type type,
1102 unsigned long obj_offset,
1103 unsigned long *sizep)
1104 {
1105 unsigned long base_offset;
1106
1107 base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
1108 type = packed_object_info(p, base_offset, NULL);
1109
1110 /* We choose to only get the type of the base object and
1111 * ignore potentially corrupt pack file that expects the delta
1112 * based on a base with a wrong size. This saves tons of
1113 * inflate() calls.
1114 */
1115 if (sizep) {
1116 const unsigned char *data;
1117 unsigned char delta_head[20], *in;
1118 z_stream stream;
1119 int st;
1120
1121 memset(&stream, 0, sizeof(stream));
1122 stream.next_out = delta_head;
1123 stream.avail_out = sizeof(delta_head);
1124
1125 inflateInit(&stream);
1126 do {
1127 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1128 stream.next_in = in;
1129 st = inflate(&stream, Z_FINISH);
1130 curpos += stream.next_in - in;
1131 } while ((st == Z_OK || st == Z_BUF_ERROR)
1132 && stream.total_out < sizeof(delta_head));
1133 inflateEnd(&stream);
1134 if ((st != Z_STREAM_END) &&
1135 stream.total_out != sizeof(delta_head))
1136 die("delta data unpack-initial failed");
1137
1138 /* Examine the initial part of the delta to figure out
1139 * the result size.
1140 */
1141 data = delta_head;
1142
1143 /* ignore base size */
1144 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1145
1146 /* Read the result size */
1147 *sizep = get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1148 }
1149
1150 return type;
1151 }
1152
1153 static int unpack_object_header(struct packed_git *p,
1154 struct pack_window **w_curs,
1155 unsigned long *curpos,
1156 unsigned long *sizep)
1157 {
1158 unsigned char *base;
1159 unsigned int left;
1160 unsigned long used;
1161 enum object_type type;
1162
1163 /* use_pack() assures us we have [base, base + 20) available
1164 * as a range that we can look at at. (Its actually the hash
1165 * size that is assured.) With our object header encoding
1166 * the maximum deflated object size is 2^137, which is just
1167 * insane, so we know won't exceed what we have been given.
1168 */
1169 base = use_pack(p, w_curs, *curpos, &left);
1170 used = unpack_object_header_gently(base, left, &type, sizep);
1171 if (!used)
1172 die("object offset outside of pack file");
1173 *curpos += used;
1174
1175 return type;
1176 }
1177
1178 const char *packed_object_info_detail(struct packed_git *p,
1179 unsigned long obj_offset,
1180 unsigned long *size,
1181 unsigned long *store_size,
1182 unsigned int *delta_chain_length,
1183 unsigned char *base_sha1)
1184 {
1185 struct pack_window *w_curs = NULL;
1186 unsigned long curpos, dummy;
1187 unsigned char *next_sha1;
1188 enum object_type type;
1189
1190 *delta_chain_length = 0;
1191 curpos = obj_offset;
1192 type = unpack_object_header(p, &w_curs, &curpos, size);
1193
1194 for (;;) {
1195 switch (type) {
1196 default:
1197 die("pack %s contains unknown object type %d",
1198 p->pack_name, type);
1199 case OBJ_COMMIT:
1200 case OBJ_TREE:
1201 case OBJ_BLOB:
1202 case OBJ_TAG:
1203 *store_size = 0; /* notyet */
1204 unuse_pack(&w_curs);
1205 return typename(type);
1206 case OBJ_OFS_DELTA:
1207 obj_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
1208 if (*delta_chain_length == 0) {
1209 /* TODO: find base_sha1 as pointed by curpos */
1210 hashclr(base_sha1);
1211 }
1212 break;
1213 case OBJ_REF_DELTA:
1214 next_sha1 = use_pack(p, &w_curs, curpos, NULL);
1215 if (*delta_chain_length == 0)
1216 hashcpy(base_sha1, next_sha1);
1217 obj_offset = find_pack_entry_one(next_sha1, p);
1218 break;
1219 }
1220 (*delta_chain_length)++;
1221 curpos = obj_offset;
1222 type = unpack_object_header(p, &w_curs, &curpos, &dummy);
1223 }
1224 }
1225
1226 static int packed_object_info(struct packed_git *p, unsigned long obj_offset,
1227 unsigned long *sizep)
1228 {
1229 struct pack_window *w_curs = NULL;
1230 unsigned long size, curpos = obj_offset;
1231 enum object_type type;
1232
1233 type = unpack_object_header(p, &w_curs, &curpos, &size);
1234
1235 switch (type) {
1236 case OBJ_OFS_DELTA:
1237 case OBJ_REF_DELTA:
1238 type = packed_delta_info(p, &w_curs, curpos,
1239 type, obj_offset, sizep);
1240 break;
1241 case OBJ_COMMIT:
1242 case OBJ_TREE:
1243 case OBJ_BLOB:
1244 case OBJ_TAG:
1245 if (sizep)
1246 *sizep = size;
1247 break;
1248 default:
1249 die("pack %s contains unknown object type %d",
1250 p->pack_name, type);
1251 }
1252 unuse_pack(&w_curs);
1253 return type;
1254 }
1255
1256 static void *unpack_compressed_entry(struct packed_git *p,
1257 struct pack_window **w_curs,
1258 unsigned long curpos,
1259 unsigned long size)
1260 {
1261 int st;
1262 z_stream stream;
1263 unsigned char *buffer, *in;
1264
1265 buffer = xmalloc(size + 1);
1266 buffer[size] = 0;
1267 memset(&stream, 0, sizeof(stream));
1268 stream.next_out = buffer;
1269 stream.avail_out = size;
1270
1271 inflateInit(&stream);
1272 do {
1273 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1274 stream.next_in = in;
1275 st = inflate(&stream, Z_FINISH);
1276 curpos += stream.next_in - in;
1277 } while (st == Z_OK || st == Z_BUF_ERROR);
1278 inflateEnd(&stream);
1279 if ((st != Z_STREAM_END) || stream.total_out != size) {
1280 free(buffer);
1281 return NULL;
1282 }
1283
1284 return buffer;
1285 }
1286
1287 static void *unpack_delta_entry(struct packed_git *p,
1288 struct pack_window **w_curs,
1289 unsigned long curpos,
1290 unsigned long delta_size,
1291 unsigned long obj_offset,
1292 enum object_type *type,
1293 unsigned long *sizep)
1294 {
1295 void *delta_data, *result, *base;
1296 unsigned long base_size, base_offset;
1297
1298 base_offset = get_delta_base(p, w_curs, &curpos, *type, obj_offset);
1299 base = unpack_entry(p, base_offset, type, &base_size);
1300 if (!base)
1301 die("failed to read delta base object at %lu from %s",
1302 base_offset, p->pack_name);
1303
1304 delta_data = unpack_compressed_entry(p, w_curs, curpos, delta_size);
1305 result = patch_delta(base, base_size,
1306 delta_data, delta_size,
1307 sizep);
1308 if (!result)
1309 die("failed to apply delta");
1310 free(delta_data);
1311 free(base);
1312 return result;
1313 }
1314
1315 void *unpack_entry(struct packed_git *p, unsigned long obj_offset,
1316 enum object_type *type, unsigned long *sizep)
1317 {
1318 struct pack_window *w_curs = NULL;
1319 unsigned long curpos = obj_offset;
1320 void *data;
1321
1322 *type = unpack_object_header(p, &w_curs, &curpos, sizep);
1323 switch (*type) {
1324 case OBJ_OFS_DELTA:
1325 case OBJ_REF_DELTA:
1326 data = unpack_delta_entry(p, &w_curs, curpos, *sizep,
1327 obj_offset, type, sizep);
1328 break;
1329 case OBJ_COMMIT:
1330 case OBJ_TREE:
1331 case OBJ_BLOB:
1332 case OBJ_TAG:
1333 data = unpack_compressed_entry(p, &w_curs, curpos, *sizep);
1334 break;
1335 default:
1336 die("unknown object type %i in %s", *type, p->pack_name);
1337 }
1338 unuse_pack(&w_curs);
1339 return data;
1340 }
1341
1342 uint32_t num_packed_objects(const struct packed_git *p)
1343 {
1344 /* See check_packed_git_idx() */
1345 return (p->index_size - 20 - 20 - 4*256) / 24;
1346 }
1347
1348 int nth_packed_object_sha1(const struct packed_git *p, uint32_t n,
1349 unsigned char* sha1)
1350 {
1351 void *index = p->index_base + 256;
1352 if (num_packed_objects(p) <= n)
1353 return -1;
1354 hashcpy(sha1, (unsigned char *) index + (24 * n) + 4);
1355 return 0;
1356 }
1357
1358 unsigned long find_pack_entry_one(const unsigned char *sha1,
1359 struct packed_git *p)
1360 {
1361 uint32_t *level1_ofs = p->index_base;
1362 int hi = ntohl(level1_ofs[*sha1]);
1363 int lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
1364 void *index = p->index_base + 256;
1365
1366 do {
1367 int mi = (lo + hi) / 2;
1368 int cmp = hashcmp((unsigned char *)index + (24 * mi) + 4, sha1);
1369 if (!cmp)
1370 return ntohl(*((uint32_t *)((char *)index + (24 * mi))));
1371 if (cmp > 0)
1372 hi = mi;
1373 else
1374 lo = mi+1;
1375 } while (lo < hi);
1376 return 0;
1377 }
1378
1379 static int matches_pack_name(struct packed_git *p, const char *ig)
1380 {
1381 const char *last_c, *c;
1382
1383 if (!strcmp(p->pack_name, ig))
1384 return 0;
1385
1386 for (c = p->pack_name, last_c = c; *c;)
1387 if (*c == '/')
1388 last_c = ++c;
1389 else
1390 ++c;
1391 if (!strcmp(last_c, ig))
1392 return 0;
1393
1394 return 1;
1395 }
1396
1397 static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e, const char **ignore_packed)
1398 {
1399 struct packed_git *p;
1400 unsigned long offset;
1401
1402 prepare_packed_git();
1403
1404 for (p = packed_git; p; p = p->next) {
1405 if (ignore_packed) {
1406 const char **ig;
1407 for (ig = ignore_packed; *ig; ig++)
1408 if (!matches_pack_name(p, *ig))
1409 break;
1410 if (*ig)
1411 continue;
1412 }
1413 offset = find_pack_entry_one(sha1, p);
1414 if (offset) {
1415 /*
1416 * We are about to tell the caller where they can
1417 * locate the requested object. We better make
1418 * sure the packfile is still here and can be
1419 * accessed before supplying that answer, as
1420 * it may have been deleted since the index
1421 * was loaded!
1422 */
1423 if (p->pack_fd == -1 && open_packed_git(p)) {
1424 error("packfile %s cannot be accessed", p->pack_name);
1425 continue;
1426 }
1427 e->offset = offset;
1428 e->p = p;
1429 hashcpy(e->sha1, sha1);
1430 return 1;
1431 }
1432 }
1433 return 0;
1434 }
1435
1436 struct packed_git *find_sha1_pack(const unsigned char *sha1,
1437 struct packed_git *packs)
1438 {
1439 struct packed_git *p;
1440
1441 for (p = packs; p; p = p->next) {
1442 if (find_pack_entry_one(sha1, p))
1443 return p;
1444 }
1445 return NULL;
1446
1447 }
1448
1449 static int sha1_loose_object_info(const unsigned char *sha1, unsigned long *sizep)
1450 {
1451 int status;
1452 unsigned long mapsize, size;
1453 void *map;
1454 z_stream stream;
1455 char hdr[32];
1456
1457 map = map_sha1_file(sha1, &mapsize);
1458 if (!map)
1459 return error("unable to find %s", sha1_to_hex(sha1));
1460 if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
1461 status = error("unable to unpack %s header",
1462 sha1_to_hex(sha1));
1463 else if ((status = parse_sha1_header(hdr, &size)) < 0)
1464 status = error("unable to parse %s header", sha1_to_hex(sha1));
1465 else if (sizep)
1466 *sizep = size;
1467 inflateEnd(&stream);
1468 munmap(map, mapsize);
1469 return status;
1470 }
1471
1472 int sha1_object_info(const unsigned char *sha1, unsigned long *sizep)
1473 {
1474 struct pack_entry e;
1475
1476 if (!find_pack_entry(sha1, &e, NULL)) {
1477 reprepare_packed_git();
1478 if (!find_pack_entry(sha1, &e, NULL))
1479 return sha1_loose_object_info(sha1, sizep);
1480 }
1481 return packed_object_info(e.p, e.offset, sizep);
1482 }
1483
1484 static void *read_packed_sha1(const unsigned char *sha1,
1485 enum object_type *type, unsigned long *size)
1486 {
1487 struct pack_entry e;
1488
1489 if (!find_pack_entry(sha1, &e, NULL))
1490 return NULL;
1491 else
1492 return unpack_entry(e.p, e.offset, type, size);
1493 }
1494
1495 /*
1496 * This is meant to hold a *small* number of objects that you would
1497 * want read_sha1_file() to be able to return, but yet you do not want
1498 * to write them into the object store (e.g. a browse-only
1499 * application).
1500 */
1501 static struct cached_object {
1502 unsigned char sha1[20];
1503 enum object_type type;
1504 void *buf;
1505 unsigned long size;
1506 } *cached_objects;
1507 static int cached_object_nr, cached_object_alloc;
1508
1509 static struct cached_object *find_cached_object(const unsigned char *sha1)
1510 {
1511 int i;
1512 struct cached_object *co = cached_objects;
1513
1514 for (i = 0; i < cached_object_nr; i++, co++) {
1515 if (!hashcmp(co->sha1, sha1))
1516 return co;
1517 }
1518 return NULL;
1519 }
1520
1521 int pretend_sha1_file(void *buf, unsigned long len, enum object_type type,
1522 unsigned char *sha1)
1523 {
1524 struct cached_object *co;
1525
1526 hash_sha1_file(buf, len, typename(type), sha1);
1527 if (has_sha1_file(sha1) || find_cached_object(sha1))
1528 return 0;
1529 if (cached_object_alloc <= cached_object_nr) {
1530 cached_object_alloc = alloc_nr(cached_object_alloc);
1531 cached_objects = xrealloc(cached_objects,
1532 sizeof(*cached_objects) *
1533 cached_object_alloc);
1534 }
1535 co = &cached_objects[cached_object_nr++];
1536 co->size = len;
1537 co->type = type;
1538 co->buf = xmalloc(len);
1539 memcpy(co->buf, buf, len);
1540 hashcpy(co->sha1, sha1);
1541 return 0;
1542 }
1543
1544 void *read_sha1_file(const unsigned char *sha1, enum object_type *type,
1545 unsigned long *size)
1546 {
1547 unsigned long mapsize;
1548 void *map, *buf;
1549 struct cached_object *co;
1550
1551 co = find_cached_object(sha1);
1552 if (co) {
1553 buf = xmalloc(co->size + 1);
1554 memcpy(buf, co->buf, co->size);
1555 ((char*)buf)[co->size] = 0;
1556 *type = co->type;
1557 *size = co->size;
1558 return buf;
1559 }
1560
1561 buf = read_packed_sha1(sha1, type, size);
1562 if (buf)
1563 return buf;
1564 map = map_sha1_file(sha1, &mapsize);
1565 if (map) {
1566 buf = unpack_sha1_file(map, mapsize, type, size);
1567 munmap(map, mapsize);
1568 return buf;
1569 }
1570 reprepare_packed_git();
1571 return read_packed_sha1(sha1, type, size);
1572 }
1573
1574 void *read_object_with_reference(const unsigned char *sha1,
1575 const char *required_type_name,
1576 unsigned long *size,
1577 unsigned char *actual_sha1_return)
1578 {
1579 enum object_type type, required_type;
1580 void *buffer;
1581 unsigned long isize;
1582 unsigned char actual_sha1[20];
1583
1584 required_type = type_from_string(required_type_name);
1585 hashcpy(actual_sha1, sha1);
1586 while (1) {
1587 int ref_length = -1;
1588 const char *ref_type = NULL;
1589
1590 buffer = read_sha1_file(actual_sha1, &type, &isize);
1591 if (!buffer)
1592 return NULL;
1593 if (type == required_type) {
1594 *size = isize;
1595 if (actual_sha1_return)
1596 hashcpy(actual_sha1_return, actual_sha1);
1597 return buffer;
1598 }
1599 /* Handle references */
1600 else if (type == OBJ_COMMIT)
1601 ref_type = "tree ";
1602 else if (type == OBJ_TAG)
1603 ref_type = "object ";
1604 else {
1605 free(buffer);
1606 return NULL;
1607 }
1608 ref_length = strlen(ref_type);
1609
1610 if (memcmp(buffer, ref_type, ref_length) ||
1611 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
1612 free(buffer);
1613 return NULL;
1614 }
1615 free(buffer);
1616 /* Now we have the ID of the referred-to object in
1617 * actual_sha1. Check again. */
1618 }
1619 }
1620
1621 static void write_sha1_file_prepare(void *buf, unsigned long len,
1622 const char *type, unsigned char *sha1,
1623 char *hdr, int *hdrlen)
1624 {
1625 SHA_CTX c;
1626
1627 /* Generate the header */
1628 *hdrlen = sprintf(hdr, "%s %lu", type, len)+1;
1629
1630 /* Sha1.. */
1631 SHA1_Init(&c);
1632 SHA1_Update(&c, hdr, *hdrlen);
1633 SHA1_Update(&c, buf, len);
1634 SHA1_Final(sha1, &c);
1635 }
1636
1637 /*
1638 * Link the tempfile to the final place, possibly creating the
1639 * last directory level as you do so.
1640 *
1641 * Returns the errno on failure, 0 on success.
1642 */
1643 static int link_temp_to_file(const char *tmpfile, const char *filename)
1644 {
1645 int ret;
1646 char *dir;
1647
1648 if (!link(tmpfile, filename))
1649 return 0;
1650
1651 /*
1652 * Try to mkdir the last path component if that failed.
1653 *
1654 * Re-try the "link()" regardless of whether the mkdir
1655 * succeeds, since a race might mean that somebody
1656 * else succeeded.
1657 */
1658 ret = errno;
1659 dir = strrchr(filename, '/');
1660 if (dir) {
1661 *dir = 0;
1662 if (!mkdir(filename, 0777) && adjust_shared_perm(filename)) {
1663 *dir = '/';
1664 return -2;
1665 }
1666 *dir = '/';
1667 if (!link(tmpfile, filename))
1668 return 0;
1669 ret = errno;
1670 }
1671 return ret;
1672 }
1673
1674 /*
1675 * Move the just written object into its final resting place
1676 */
1677 int move_temp_to_file(const char *tmpfile, const char *filename)
1678 {
1679 int ret = link_temp_to_file(tmpfile, filename);
1680
1681 /*
1682 * Coda hack - coda doesn't like cross-directory links,
1683 * so we fall back to a rename, which will mean that it
1684 * won't be able to check collisions, but that's not a
1685 * big deal.
1686 *
1687 * The same holds for FAT formatted media.
1688 *
1689 * When this succeeds, we just return 0. We have nothing
1690 * left to unlink.
1691 */
1692 if (ret && ret != EEXIST) {
1693 if (!rename(tmpfile, filename))
1694 return 0;
1695 ret = errno;
1696 }
1697 unlink(tmpfile);
1698 if (ret) {
1699 if (ret != EEXIST) {
1700 return error("unable to write sha1 filename %s: %s\n", filename, strerror(ret));
1701 }
1702 /* FIXME!!! Collision check here ? */
1703 }
1704
1705 return 0;
1706 }
1707
1708 static int write_buffer(int fd, const void *buf, size_t len)
1709 {
1710 if (write_in_full(fd, buf, len) < 0)
1711 return error("file write error (%s)", strerror(errno));
1712 return 0;
1713 }
1714
1715 static int write_binary_header(unsigned char *hdr, enum object_type type, unsigned long len)
1716 {
1717 int hdr_len;
1718 unsigned char c;
1719
1720 c = (type << 4) | (len & 15);
1721 len >>= 4;
1722 hdr_len = 1;
1723 while (len) {
1724 *hdr++ = c | 0x80;
1725 hdr_len++;
1726 c = (len & 0x7f);
1727 len >>= 7;
1728 }
1729 *hdr = c;
1730 return hdr_len;
1731 }
1732
1733 static void setup_object_header(z_stream *stream, const char *type, unsigned long len)
1734 {
1735 int obj_type, hdrlen;
1736
1737 if (use_legacy_headers) {
1738 while (deflate(stream, 0) == Z_OK)
1739 /* nothing */;
1740 return;
1741 }
1742 obj_type = type_from_string(type);
1743 hdrlen = write_binary_header(stream->next_out, obj_type, len);
1744 stream->total_out = hdrlen;
1745 stream->next_out += hdrlen;
1746 stream->avail_out -= hdrlen;
1747 }
1748
1749 int hash_sha1_file(void *buf, unsigned long len, const char *type,
1750 unsigned char *sha1)
1751 {
1752 char hdr[32];
1753 int hdrlen;
1754 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
1755 return 0;
1756 }
1757
1758 int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
1759 {
1760 int size;
1761 unsigned char *compressed;
1762 z_stream stream;
1763 unsigned char sha1[20];
1764 char *filename;
1765 static char tmpfile[PATH_MAX];
1766 char hdr[32];
1767 int fd, hdrlen;
1768
1769 /* Normally if we have it in the pack then we do not bother writing
1770 * it out into .git/objects/??/?{38} file.
1771 */
1772 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
1773 filename = sha1_file_name(sha1);
1774 if (returnsha1)
1775 hashcpy(returnsha1, sha1);
1776 if (has_sha1_file(sha1))
1777 return 0;
1778 fd = open(filename, O_RDONLY);
1779 if (fd >= 0) {
1780 /*
1781 * FIXME!!! We might do collision checking here, but we'd
1782 * need to uncompress the old file and check it. Later.
1783 */
1784 close(fd);
1785 return 0;
1786 }
1787
1788 if (errno != ENOENT) {
1789 return error("sha1 file %s: %s\n", filename, strerror(errno));
1790 }
1791
1792 snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
1793
1794 fd = mkstemp(tmpfile);
1795 if (fd < 0) {
1796 if (errno == EPERM)
1797 return error("insufficient permission for adding an object to repository database %s\n", get_object_directory());
1798 else
1799 return error("unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
1800 }
1801
1802 /* Set it up */
1803 memset(&stream, 0, sizeof(stream));
1804 deflateInit(&stream, zlib_compression_level);
1805 size = 8 + deflateBound(&stream, len+hdrlen);
1806 compressed = xmalloc(size);
1807
1808 /* Compress it */
1809 stream.next_out = compressed;
1810 stream.avail_out = size;
1811
1812 /* First header.. */
1813 stream.next_in = (unsigned char *)hdr;
1814 stream.avail_in = hdrlen;
1815 setup_object_header(&stream, type, len);
1816
1817 /* Then the data itself.. */
1818 stream.next_in = buf;
1819 stream.avail_in = len;
1820 while (deflate(&stream, Z_FINISH) == Z_OK)
1821 /* nothing */;
1822 deflateEnd(&stream);
1823 size = stream.total_out;
1824
1825 if (write_buffer(fd, compressed, size) < 0)
1826 die("unable to write sha1 file");
1827 fchmod(fd, 0444);
1828 close(fd);
1829 free(compressed);
1830
1831 return move_temp_to_file(tmpfile, filename);
1832 }
1833
1834 /*
1835 * We need to unpack and recompress the object for writing
1836 * it out to a different file.
1837 */
1838 static void *repack_object(const unsigned char *sha1, unsigned long *objsize)
1839 {
1840 size_t size;
1841 z_stream stream;
1842 unsigned char *unpacked;
1843 unsigned long len;
1844 enum object_type type;
1845 char hdr[32];
1846 int hdrlen;
1847 void *buf;
1848
1849 /* need to unpack and recompress it by itself */
1850 unpacked = read_packed_sha1(sha1, &type, &len);
1851 if (!unpacked)
1852 error("cannot read sha1_file for %s", sha1_to_hex(sha1));
1853
1854 hdrlen = sprintf(hdr, "%s %lu", typename(type), len) + 1;
1855
1856 /* Set it up */
1857 memset(&stream, 0, sizeof(stream));
1858 deflateInit(&stream, zlib_compression_level);
1859 size = deflateBound(&stream, len + hdrlen);
1860 buf = xmalloc(size);
1861
1862 /* Compress it */
1863 stream.next_out = buf;
1864 stream.avail_out = size;
1865
1866 /* First header.. */
1867 stream.next_in = (void *)hdr;
1868 stream.avail_in = hdrlen;
1869 while (deflate(&stream, 0) == Z_OK)
1870 /* nothing */;
1871
1872 /* Then the data itself.. */
1873 stream.next_in = unpacked;
1874 stream.avail_in = len;
1875 while (deflate(&stream, Z_FINISH) == Z_OK)
1876 /* nothing */;
1877 deflateEnd(&stream);
1878 free(unpacked);
1879
1880 *objsize = stream.total_out;
1881 return buf;
1882 }
1883
1884 int write_sha1_to_fd(int fd, const unsigned char *sha1)
1885 {
1886 int retval;
1887 unsigned long objsize;
1888 void *buf = map_sha1_file(sha1, &objsize);
1889
1890 if (buf) {
1891 retval = write_buffer(fd, buf, objsize);
1892 munmap(buf, objsize);
1893 return retval;
1894 }
1895
1896 buf = repack_object(sha1, &objsize);
1897 retval = write_buffer(fd, buf, objsize);
1898 free(buf);
1899 return retval;
1900 }
1901
1902 int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
1903 size_t bufsize, size_t *bufposn)
1904 {
1905 char tmpfile[PATH_MAX];
1906 int local;
1907 z_stream stream;
1908 unsigned char real_sha1[20];
1909 unsigned char discard[4096];
1910 int ret;
1911 SHA_CTX c;
1912
1913 snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
1914
1915 local = mkstemp(tmpfile);
1916 if (local < 0) {
1917 if (errno == EPERM)
1918 return error("insufficient permission for adding an object to repository database %s\n", get_object_directory());
1919 else
1920 return error("unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
1921 }
1922
1923 memset(&stream, 0, sizeof(stream));
1924
1925 inflateInit(&stream);
1926
1927 SHA1_Init(&c);
1928
1929 do {
1930 ssize_t size;
1931 if (*bufposn) {
1932 stream.avail_in = *bufposn;
1933 stream.next_in = (unsigned char *) buffer;
1934 do {
1935 stream.next_out = discard;
1936 stream.avail_out = sizeof(discard);
1937 ret = inflate(&stream, Z_SYNC_FLUSH);
1938 SHA1_Update(&c, discard, sizeof(discard) -
1939 stream.avail_out);
1940 } while (stream.avail_in && ret == Z_OK);
1941 if (write_buffer(local, buffer, *bufposn - stream.avail_in) < 0)
1942 die("unable to write sha1 file");
1943 memmove(buffer, buffer + *bufposn - stream.avail_in,
1944 stream.avail_in);
1945 *bufposn = stream.avail_in;
1946 if (ret != Z_OK)
1947 break;
1948 }
1949 size = xread(fd, buffer + *bufposn, bufsize - *bufposn);
1950 if (size <= 0) {
1951 close(local);
1952 unlink(tmpfile);
1953 if (!size)
1954 return error("Connection closed?");
1955 perror("Reading from connection");
1956 return -1;
1957 }
1958 *bufposn += size;
1959 } while (1);
1960 inflateEnd(&stream);
1961
1962 close(local);
1963 SHA1_Final(real_sha1, &c);
1964 if (ret != Z_STREAM_END) {
1965 unlink(tmpfile);
1966 return error("File %s corrupted", sha1_to_hex(sha1));
1967 }
1968 if (hashcmp(sha1, real_sha1)) {
1969 unlink(tmpfile);
1970 return error("File %s has bad hash", sha1_to_hex(sha1));
1971 }
1972
1973 return move_temp_to_file(tmpfile, sha1_file_name(sha1));
1974 }
1975
1976 int has_pack_index(const unsigned char *sha1)
1977 {
1978 struct stat st;
1979 if (stat(sha1_pack_index_name(sha1), &st))
1980 return 0;
1981 return 1;
1982 }
1983
1984 int has_pack_file(const unsigned char *sha1)
1985 {
1986 struct stat st;
1987 if (stat(sha1_pack_name(sha1), &st))
1988 return 0;
1989 return 1;
1990 }
1991
1992 int has_sha1_pack(const unsigned char *sha1, const char **ignore_packed)
1993 {
1994 struct pack_entry e;
1995 return find_pack_entry(sha1, &e, ignore_packed);
1996 }
1997
1998 int has_sha1_file(const unsigned char *sha1)
1999 {
2000 struct stat st;
2001 struct pack_entry e;
2002
2003 if (find_pack_entry(sha1, &e, NULL))
2004 return 1;
2005 return find_sha1_file(sha1, &st) ? 1 : 0;
2006 }
2007
2008 /*
2009 * reads from fd as long as possible into a supplied buffer of size bytes.
2010 * If necessary the buffer's size is increased using realloc()
2011 *
2012 * returns 0 if anything went fine and -1 otherwise
2013 *
2014 * NOTE: both buf and size may change, but even when -1 is returned
2015 * you still have to free() it yourself.
2016 */
2017 int read_pipe(int fd, char** return_buf, unsigned long* return_size)
2018 {
2019 char* buf = *return_buf;
2020 unsigned long size = *return_size;
2021 int iret;
2022 unsigned long off = 0;
2023
2024 do {
2025 iret = xread(fd, buf + off, size - off);
2026 if (iret > 0) {
2027 off += iret;
2028 if (off == size) {
2029 size *= 2;
2030 buf = xrealloc(buf, size);
2031 }
2032 }
2033 } while (iret > 0);
2034
2035 *return_buf = buf;
2036 *return_size = off;
2037
2038 if (iret < 0)
2039 return -1;
2040 return 0;
2041 }
2042
2043 int index_pipe(unsigned char *sha1, int fd, const char *type, int write_object)
2044 {
2045 unsigned long size = 4096;
2046 char *buf = xmalloc(size);
2047 int ret;
2048
2049 if (read_pipe(fd, &buf, &size)) {
2050 free(buf);
2051 return -1;
2052 }
2053
2054 if (!type)
2055 type = blob_type;
2056 if (write_object)
2057 ret = write_sha1_file(buf, size, type, sha1);
2058 else
2059 ret = hash_sha1_file(buf, size, type, sha1);
2060 free(buf);
2061 return ret;
2062 }
2063
2064 int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object,
2065 enum object_type type, const char *path)
2066 {
2067 unsigned long size = st->st_size;
2068 void *buf = NULL;
2069 int ret, re_allocated = 0;
2070
2071 if (size)
2072 buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
2073 close(fd);
2074
2075 if (!type)
2076 type = OBJ_BLOB;
2077
2078 /*
2079 * Convert blobs to git internal format
2080 */
2081 if ((type == OBJ_BLOB) && S_ISREG(st->st_mode)) {
2082 unsigned long nsize = size;
2083 char *nbuf = buf;
2084 if (convert_to_git(path, &nbuf, &nsize)) {
2085 if (size)
2086 munmap(buf, size);
2087 size = nsize;
2088 buf = nbuf;
2089 re_allocated = 1;
2090 }
2091 }
2092
2093 if (write_object)
2094 ret = write_sha1_file(buf, size, typename(type), sha1);
2095 else
2096 ret = hash_sha1_file(buf, size, typename(type), sha1);
2097 if (re_allocated) {
2098 free(buf);
2099 return ret;
2100 }
2101 if (size)
2102 munmap(buf, size);
2103 return ret;
2104 }
2105
2106 int index_path(unsigned char *sha1, const char *path, struct stat *st, int write_object)
2107 {
2108 int fd;
2109 char *target;
2110
2111 switch (st->st_mode & S_IFMT) {
2112 case S_IFREG:
2113 fd = open(path, O_RDONLY);
2114 if (fd < 0)
2115 return error("open(\"%s\"): %s", path,
2116 strerror(errno));
2117 if (index_fd(sha1, fd, st, write_object, OBJ_BLOB, path) < 0)
2118 return error("%s: failed to insert into database",
2119 path);
2120 break;
2121 case S_IFLNK:
2122 target = xmalloc(st->st_size+1);
2123 if (readlink(path, target, st->st_size+1) != st->st_size) {
2124 char *errstr = strerror(errno);
2125 free(target);
2126 return error("readlink(\"%s\"): %s", path,
2127 errstr);
2128 }
2129 if (!write_object)
2130 hash_sha1_file(target, st->st_size, blob_type, sha1);
2131 else if (write_sha1_file(target, st->st_size, blob_type, sha1))
2132 return error("%s: failed to insert into database",
2133 path);
2134 free(target);
2135 break;
2136 default:
2137 return error("%s: unsupported file type", path);
2138 }
2139 return 0;
2140 }
2141
2142 int read_pack_header(int fd, struct pack_header *header)
2143 {
2144 char *c = (char*)header;
2145 ssize_t remaining = sizeof(struct pack_header);
2146 do {
2147 ssize_t r = xread(fd, c, remaining);
2148 if (r <= 0)
2149 /* "eof before pack header was fully read" */
2150 return PH_ERROR_EOF;
2151 remaining -= r;
2152 c += r;
2153 } while (remaining > 0);
2154 if (header->hdr_signature != htonl(PACK_SIGNATURE))
2155 /* "protocol error (pack signature mismatch detected)" */
2156 return PH_ERROR_PACK_SIGNATURE;
2157 if (!pack_version_ok(header->hdr_version))
2158 /* "protocol error (pack version unsupported)" */
2159 return PH_ERROR_PROTOCOL;
2160 return 0;
2161 }