4183f595edfe6086f5097a430cb48202db00c5c1
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
25const unsigned char null_sha1[20];
26
27static unsigned int sha1_file_open_flag = O_NOATIME;
28
29signed char hexval_table[256] = {
30 -1, -1, -1, -1, -1, -1, -1, -1, /* 00-07 */
31 -1, -1, -1, -1, -1, -1, -1, -1, /* 08-0f */
32 -1, -1, -1, -1, -1, -1, -1, -1, /* 10-17 */
33 -1, -1, -1, -1, -1, -1, -1, -1, /* 18-1f */
34 -1, -1, -1, -1, -1, -1, -1, -1, /* 20-27 */
35 -1, -1, -1, -1, -1, -1, -1, -1, /* 28-2f */
36 0, 1, 2, 3, 4, 5, 6, 7, /* 30-37 */
37 8, 9, -1, -1, -1, -1, -1, -1, /* 38-3f */
38 -1, 10, 11, 12, 13, 14, 15, -1, /* 40-47 */
39 -1, -1, -1, -1, -1, -1, -1, -1, /* 48-4f */
40 -1, -1, -1, -1, -1, -1, -1, -1, /* 50-57 */
41 -1, -1, -1, -1, -1, -1, -1, -1, /* 58-5f */
42 -1, 10, 11, 12, 13, 14, 15, -1, /* 60-67 */
43 -1, -1, -1, -1, -1, -1, -1, -1, /* 68-67 */
44 -1, -1, -1, -1, -1, -1, -1, -1, /* 70-77 */
45 -1, -1, -1, -1, -1, -1, -1, -1, /* 78-7f */
46 -1, -1, -1, -1, -1, -1, -1, -1, /* 80-87 */
47 -1, -1, -1, -1, -1, -1, -1, -1, /* 88-8f */
48 -1, -1, -1, -1, -1, -1, -1, -1, /* 90-97 */
49 -1, -1, -1, -1, -1, -1, -1, -1, /* 98-9f */
50 -1, -1, -1, -1, -1, -1, -1, -1, /* a0-a7 */
51 -1, -1, -1, -1, -1, -1, -1, -1, /* a8-af */
52 -1, -1, -1, -1, -1, -1, -1, -1, /* b0-b7 */
53 -1, -1, -1, -1, -1, -1, -1, -1, /* b8-bf */
54 -1, -1, -1, -1, -1, -1, -1, -1, /* c0-c7 */
55 -1, -1, -1, -1, -1, -1, -1, -1, /* c8-cf */
56 -1, -1, -1, -1, -1, -1, -1, -1, /* d0-d7 */
57 -1, -1, -1, -1, -1, -1, -1, -1, /* d8-df */
58 -1, -1, -1, -1, -1, -1, -1, -1, /* e0-e7 */
59 -1, -1, -1, -1, -1, -1, -1, -1, /* e8-ef */
60 -1, -1, -1, -1, -1, -1, -1, -1, /* f0-f7 */
61 -1, -1, -1, -1, -1, -1, -1, -1, /* f8-ff */
62};
63
64int get_sha1_hex(const char *hex, unsigned char *sha1)
65{
66 int i;
67 for (i = 0; i < 20; i++) {
68 unsigned int val = (hexval(hex[0]) << 4) | hexval(hex[1]);
69 if (val & ~0xff)
70 return -1;
71 *sha1++ = val;
72 hex += 2;
73 }
74 return 0;
75}
76
77int safe_create_leading_directories(char *path)
78{
79 char *pos = path;
80 struct stat st;
81
82 if (*pos == '/')
83 pos++;
84
85 while (pos) {
86 pos = strchr(pos, '/');
87 if (!pos)
88 break;
89 *pos = 0;
90 if (!stat(path, &st)) {
91 /* path exists */
92 if (!S_ISDIR(st.st_mode)) {
93 *pos = '/';
94 return -3;
95 }
96 }
97 else if (mkdir(path, 0777)) {
98 *pos = '/';
99 return -1;
100 }
101 else if (adjust_shared_perm(path)) {
102 *pos = '/';
103 return -2;
104 }
105 *pos++ = '/';
106 }
107 return 0;
108}
109
110char * sha1_to_hex(const unsigned char *sha1)
111{
112 static int bufno;
113 static char hexbuffer[4][50];
114 static const char hex[] = "0123456789abcdef";
115 char *buffer = hexbuffer[3 & ++bufno], *buf = buffer;
116 int i;
117
118 for (i = 0; i < 20; i++) {
119 unsigned int val = *sha1++;
120 *buf++ = hex[val >> 4];
121 *buf++ = hex[val & 0xf];
122 }
123 *buf = '\0';
124
125 return buffer;
126}
127
128static void fill_sha1_path(char *pathbuf, const unsigned char *sha1)
129{
130 int i;
131 for (i = 0; i < 20; i++) {
132 static char hex[] = "0123456789abcdef";
133 unsigned int val = sha1[i];
134 char *pos = pathbuf + i*2 + (i > 0);
135 *pos++ = hex[val >> 4];
136 *pos = hex[val & 0xf];
137 }
138}
139
140/*
141 * NOTE! This returns a statically allocated buffer, so you have to be
142 * careful about using it. Do a "xstrdup()" if you need to save the
143 * filename.
144 *
145 * Also note that this returns the location for creating. Reading
146 * SHA1 file can happen from any alternate directory listed in the
147 * DB_ENVIRONMENT environment variable if it is not found in
148 * the primary object database.
149 */
150char *sha1_file_name(const unsigned char *sha1)
151{
152 static char *name, *base;
153
154 if (!base) {
155 const char *sha1_file_directory = get_object_directory();
156 int len = strlen(sha1_file_directory);
157 base = xmalloc(len + 60);
158 memcpy(base, sha1_file_directory, len);
159 memset(base+len, 0, 60);
160 base[len] = '/';
161 base[len+3] = '/';
162 name = base + len + 1;
163 }
164 fill_sha1_path(name, sha1);
165 return base;
166}
167
168char *sha1_pack_name(const unsigned char *sha1)
169{
170 static const char hex[] = "0123456789abcdef";
171 static char *name, *base, *buf;
172 int i;
173
174 if (!base) {
175 const char *sha1_file_directory = get_object_directory();
176 int len = strlen(sha1_file_directory);
177 base = xmalloc(len + 60);
178 sprintf(base, "%s/pack/pack-1234567890123456789012345678901234567890.pack", sha1_file_directory);
179 name = base + len + 11;
180 }
181
182 buf = name;
183
184 for (i = 0; i < 20; i++) {
185 unsigned int val = *sha1++;
186 *buf++ = hex[val >> 4];
187 *buf++ = hex[val & 0xf];
188 }
189
190 return base;
191}
192
193char *sha1_pack_index_name(const unsigned char *sha1)
194{
195 static const char hex[] = "0123456789abcdef";
196 static char *name, *base, *buf;
197 int i;
198
199 if (!base) {
200 const char *sha1_file_directory = get_object_directory();
201 int len = strlen(sha1_file_directory);
202 base = xmalloc(len + 60);
203 sprintf(base, "%s/pack/pack-1234567890123456789012345678901234567890.idx", sha1_file_directory);
204 name = base + len + 11;
205 }
206
207 buf = name;
208
209 for (i = 0; i < 20; i++) {
210 unsigned int val = *sha1++;
211 *buf++ = hex[val >> 4];
212 *buf++ = hex[val & 0xf];
213 }
214
215 return base;
216}
217
218struct alternate_object_database *alt_odb_list;
219static struct alternate_object_database **alt_odb_tail;
220
221static void read_info_alternates(const char * alternates, int depth);
222
223/*
224 * Prepare alternate object database registry.
225 *
226 * The variable alt_odb_list points at the list of struct
227 * alternate_object_database. The elements on this list come from
228 * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
229 * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
230 * whose contents is similar to that environment variable but can be
231 * LF separated. Its base points at a statically allocated buffer that
232 * contains "/the/directory/corresponding/to/.git/objects/...", while
233 * its name points just after the slash at the end of ".git/objects/"
234 * in the example above, and has enough space to hold 40-byte hex
235 * SHA1, an extra slash for the first level indirection, and the
236 * terminating NUL.
237 */
238static int link_alt_odb_entry(const char * entry, int len, const char * relative_base, int depth)
239{
240 struct stat st;
241 const char *objdir = get_object_directory();
242 struct alternate_object_database *ent;
243 struct alternate_object_database *alt;
244 /* 43 = 40-byte + 2 '/' + terminating NUL */
245 int pfxlen = len;
246 int entlen = pfxlen + 43;
247 int base_len = -1;
248
249 if (*entry != '/' && relative_base) {
250 /* Relative alt-odb */
251 if (base_len < 0)
252 base_len = strlen(relative_base) + 1;
253 entlen += base_len;
254 pfxlen += base_len;
255 }
256 ent = xmalloc(sizeof(*ent) + entlen);
257
258 if (*entry != '/' && relative_base) {
259 memcpy(ent->base, relative_base, base_len - 1);
260 ent->base[base_len - 1] = '/';
261 memcpy(ent->base + base_len, entry, len);
262 }
263 else
264 memcpy(ent->base, entry, pfxlen);
265
266 ent->name = ent->base + pfxlen + 1;
267 ent->base[pfxlen + 3] = '/';
268 ent->base[pfxlen] = ent->base[entlen-1] = 0;
269
270 /* Detect cases where alternate disappeared */
271 if (stat(ent->base, &st) || !S_ISDIR(st.st_mode)) {
272 error("object directory %s does not exist; "
273 "check .git/objects/info/alternates.",
274 ent->base);
275 free(ent);
276 return -1;
277 }
278
279 /* Prevent the common mistake of listing the same
280 * thing twice, or object directory itself.
281 */
282 for (alt = alt_odb_list; alt; alt = alt->next) {
283 if (!memcmp(ent->base, alt->base, pfxlen)) {
284 free(ent);
285 return -1;
286 }
287 }
288 if (!memcmp(ent->base, objdir, pfxlen)) {
289 free(ent);
290 return -1;
291 }
292
293 /* add the alternate entry */
294 *alt_odb_tail = ent;
295 alt_odb_tail = &(ent->next);
296 ent->next = NULL;
297
298 /* recursively add alternates */
299 read_info_alternates(ent->base, depth + 1);
300
301 ent->base[pfxlen] = '/';
302
303 return 0;
304}
305
306static void link_alt_odb_entries(const char *alt, const char *ep, int sep,
307 const char *relative_base, int depth)
308{
309 const char *cp, *last;
310
311 if (depth > 5) {
312 error("%s: ignoring alternate object stores, nesting too deep.",
313 relative_base);
314 return;
315 }
316
317 last = alt;
318 while (last < ep) {
319 cp = last;
320 if (cp < ep && *cp == '#') {
321 while (cp < ep && *cp != sep)
322 cp++;
323 last = cp + 1;
324 continue;
325 }
326 while (cp < ep && *cp != sep)
327 cp++;
328 if (last != cp) {
329 if ((*last != '/') && depth) {
330 error("%s: ignoring relative alternate object store %s",
331 relative_base, last);
332 } else {
333 link_alt_odb_entry(last, cp - last,
334 relative_base, depth);
335 }
336 }
337 while (cp < ep && *cp == sep)
338 cp++;
339 last = cp;
340 }
341}
342
343static void read_info_alternates(const char * relative_base, int depth)
344{
345 char *map;
346 struct stat st;
347 char path[PATH_MAX];
348 int fd;
349
350 sprintf(path, "%s/info/alternates", relative_base);
351 fd = open(path, O_RDONLY);
352 if (fd < 0)
353 return;
354 if (fstat(fd, &st) || (st.st_size == 0)) {
355 close(fd);
356 return;
357 }
358 map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
359 close(fd);
360 if (map == MAP_FAILED)
361 return;
362
363 link_alt_odb_entries(map, map + st.st_size, '\n', relative_base, depth);
364
365 munmap(map, st.st_size);
366}
367
368void prepare_alt_odb(void)
369{
370 const char *alt;
371
372 alt = getenv(ALTERNATE_DB_ENVIRONMENT);
373 if (!alt) alt = "";
374
375 if (alt_odb_tail)
376 return;
377 alt_odb_tail = &alt_odb_list;
378 link_alt_odb_entries(alt, alt + strlen(alt), ':', NULL, 0);
379
380 read_info_alternates(get_object_directory(), 0);
381}
382
383static char *find_sha1_file(const unsigned char *sha1, struct stat *st)
384{
385 char *name = sha1_file_name(sha1);
386 struct alternate_object_database *alt;
387
388 if (!stat(name, st))
389 return name;
390 prepare_alt_odb();
391 for (alt = alt_odb_list; alt; alt = alt->next) {
392 name = alt->name;
393 fill_sha1_path(name, sha1);
394 if (!stat(alt->base, st))
395 return alt->base;
396 }
397 return NULL;
398}
399
400static int pack_used_ctr;
401static unsigned long pack_mapped;
402struct packed_git *packed_git;
403
404static int check_packed_git_idx(const char *path, unsigned long *idx_size_,
405 void **idx_map_)
406{
407 void *idx_map;
408 unsigned int *index;
409 unsigned long idx_size;
410 int nr, i;
411 int fd = open(path, O_RDONLY);
412 struct stat st;
413 if (fd < 0)
414 return -1;
415 if (fstat(fd, &st)) {
416 close(fd);
417 return -1;
418 }
419 idx_size = st.st_size;
420 idx_map = mmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
421 close(fd);
422 if (idx_map == MAP_FAILED)
423 return -1;
424
425 index = idx_map;
426 *idx_map_ = idx_map;
427 *idx_size_ = idx_size;
428
429 /* check index map */
430 if (idx_size < 4*256 + 20 + 20)
431 return error("index file too small");
432 nr = 0;
433 for (i = 0; i < 256; i++) {
434 unsigned int n = ntohl(index[i]);
435 if (n < nr)
436 return error("non-monotonic index");
437 nr = n;
438 }
439
440 /*
441 * Total size:
442 * - 256 index entries 4 bytes each
443 * - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
444 * - 20-byte SHA1 of the packfile
445 * - 20-byte SHA1 file checksum
446 */
447 if (idx_size != 4*256 + nr * 24 + 20 + 20)
448 return error("wrong index file size");
449
450 return 0;
451}
452
453static int unuse_one_packed_git(void)
454{
455 struct packed_git *p, *lru = NULL;
456
457 for (p = packed_git; p; p = p->next) {
458 if (p->pack_use_cnt || !p->pack_base)
459 continue;
460 if (!lru || p->pack_last_used < lru->pack_last_used)
461 lru = p;
462 }
463 if (!lru)
464 return 0;
465 munmap(lru->pack_base, lru->pack_size);
466 lru->pack_base = NULL;
467 return 1;
468}
469
470void unuse_packed_git(struct packed_git *p)
471{
472 p->pack_use_cnt--;
473}
474
475int use_packed_git(struct packed_git *p)
476{
477 if (!p->pack_size) {
478 struct stat st;
479 /* We created the struct before we had the pack */
480 stat(p->pack_name, &st);
481 if (!S_ISREG(st.st_mode))
482 die("packfile %s not a regular file", p->pack_name);
483 p->pack_size = st.st_size;
484 }
485 if (!p->pack_base) {
486 int fd;
487 struct stat st;
488 void *map;
489 struct pack_header *hdr;
490
491 pack_mapped += p->pack_size;
492 while (packed_git_limit < pack_mapped && unuse_one_packed_git())
493 ; /* nothing */
494 fd = open(p->pack_name, O_RDONLY);
495 if (fd < 0)
496 die("packfile %s cannot be opened", p->pack_name);
497 if (fstat(fd, &st)) {
498 close(fd);
499 die("packfile %s cannot be opened", p->pack_name);
500 }
501 if (st.st_size != p->pack_size)
502 die("packfile %s size mismatch.", p->pack_name);
503 map = mmap(NULL, p->pack_size, PROT_READ, MAP_PRIVATE, fd, 0);
504 close(fd);
505 if (map == MAP_FAILED)
506 die("packfile %s cannot be mapped.", p->pack_name);
507 p->pack_base = map;
508
509 /* Check if we understand this pack file. If we don't we're
510 * likely too old to handle it.
511 */
512 hdr = map;
513 if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
514 die("packfile %s isn't actually a pack.", p->pack_name);
515 if (!pack_version_ok(hdr->hdr_version))
516 die("packfile %s is version %i and not supported"
517 " (try upgrading GIT to a newer version)",
518 p->pack_name, ntohl(hdr->hdr_version));
519
520 /* Check if the pack file matches with the index file.
521 * this is cheap.
522 */
523 if (hashcmp((unsigned char *)(p->index_base) +
524 p->index_size - 40,
525 (unsigned char *)p->pack_base +
526 p->pack_size - 20)) {
527 die("packfile %s does not match index.", p->pack_name);
528 }
529 }
530 p->pack_last_used = pack_used_ctr++;
531 p->pack_use_cnt++;
532 return 0;
533}
534
535struct packed_git *add_packed_git(char *path, int path_len, int local)
536{
537 struct stat st;
538 struct packed_git *p;
539 unsigned long idx_size;
540 void *idx_map;
541 unsigned char sha1[20];
542
543 if (check_packed_git_idx(path, &idx_size, &idx_map))
544 return NULL;
545
546 /* do we have a corresponding .pack file? */
547 strcpy(path + path_len - 4, ".pack");
548 if (stat(path, &st) || !S_ISREG(st.st_mode)) {
549 munmap(idx_map, idx_size);
550 return NULL;
551 }
552 /* ok, it looks sane as far as we can check without
553 * actually mapping the pack file.
554 */
555 p = xmalloc(sizeof(*p) + path_len + 2);
556 strcpy(p->pack_name, path);
557 p->index_size = idx_size;
558 p->pack_size = st.st_size;
559 p->index_base = idx_map;
560 p->next = NULL;
561 p->pack_base = NULL;
562 p->pack_last_used = 0;
563 p->pack_use_cnt = 0;
564 p->pack_local = local;
565 if ((path_len > 44) && !get_sha1_hex(path + path_len - 44, sha1))
566 hashcpy(p->sha1, sha1);
567 return p;
568}
569
570struct packed_git *parse_pack_index(unsigned char *sha1)
571{
572 char *path = sha1_pack_index_name(sha1);
573 return parse_pack_index_file(sha1, path);
574}
575
576struct packed_git *parse_pack_index_file(const unsigned char *sha1, char *idx_path)
577{
578 struct packed_git *p;
579 unsigned long idx_size;
580 void *idx_map;
581 char *path;
582
583 if (check_packed_git_idx(idx_path, &idx_size, &idx_map))
584 return NULL;
585
586 path = sha1_pack_name(sha1);
587
588 p = xmalloc(sizeof(*p) + strlen(path) + 2);
589 strcpy(p->pack_name, path);
590 p->index_size = idx_size;
591 p->pack_size = 0;
592 p->index_base = idx_map;
593 p->next = NULL;
594 p->pack_base = NULL;
595 p->pack_last_used = 0;
596 p->pack_use_cnt = 0;
597 hashcpy(p->sha1, sha1);
598 return p;
599}
600
601void install_packed_git(struct packed_git *pack)
602{
603 pack->next = packed_git;
604 packed_git = pack;
605}
606
607static void prepare_packed_git_one(char *objdir, int local)
608{
609 char path[PATH_MAX];
610 int len;
611 DIR *dir;
612 struct dirent *de;
613
614 sprintf(path, "%s/pack", objdir);
615 len = strlen(path);
616 dir = opendir(path);
617 if (!dir) {
618 if (errno != ENOENT)
619 error("unable to open object pack directory: %s: %s",
620 path, strerror(errno));
621 return;
622 }
623 path[len++] = '/';
624 while ((de = readdir(dir)) != NULL) {
625 int namelen = strlen(de->d_name);
626 struct packed_git *p;
627
628 if (!has_extension(de->d_name, ".idx"))
629 continue;
630
631 /* we have .idx. Is it a file we can map? */
632 strcpy(path + len, de->d_name);
633 for (p = packed_git; p; p = p->next) {
634 if (!memcmp(path, p->pack_name, len + namelen - 4))
635 break;
636 }
637 if (p)
638 continue;
639 p = add_packed_git(path, len + namelen, local);
640 if (!p)
641 continue;
642 p->next = packed_git;
643 packed_git = p;
644 }
645 closedir(dir);
646}
647
648static int prepare_packed_git_run_once = 0;
649void prepare_packed_git(void)
650{
651 struct alternate_object_database *alt;
652
653 if (prepare_packed_git_run_once)
654 return;
655 prepare_packed_git_one(get_object_directory(), 1);
656 prepare_alt_odb();
657 for (alt = alt_odb_list; alt; alt = alt->next) {
658 alt->name[-1] = 0;
659 prepare_packed_git_one(alt->base, 0);
660 alt->name[-1] = '/';
661 }
662 prepare_packed_git_run_once = 1;
663}
664
665void reprepare_packed_git(void)
666{
667 prepare_packed_git_run_once = 0;
668 prepare_packed_git();
669}
670
671int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long size, const char *type)
672{
673 unsigned char real_sha1[20];
674 hash_sha1_file(map, size, type, real_sha1);
675 return hashcmp(sha1, real_sha1) ? -1 : 0;
676}
677
678void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
679{
680 struct stat st;
681 void *map;
682 int fd;
683 char *filename = find_sha1_file(sha1, &st);
684
685 if (!filename) {
686 return NULL;
687 }
688
689 fd = open(filename, O_RDONLY | sha1_file_open_flag);
690 if (fd < 0) {
691 /* See if it works without O_NOATIME */
692 switch (sha1_file_open_flag) {
693 default:
694 fd = open(filename, O_RDONLY);
695 if (fd >= 0)
696 break;
697 /* Fallthrough */
698 case 0:
699 return NULL;
700 }
701
702 /* If it failed once, it will probably fail again.
703 * Stop using O_NOATIME
704 */
705 sha1_file_open_flag = 0;
706 }
707 map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
708 close(fd);
709 if (map == MAP_FAILED)
710 return NULL;
711 *size = st.st_size;
712 return map;
713}
714
715int legacy_loose_object(unsigned char *map)
716{
717 unsigned int word;
718
719 /*
720 * Is it a zlib-compressed buffer? If so, the first byte
721 * must be 0x78 (15-bit window size, deflated), and the
722 * first 16-bit word is evenly divisible by 31
723 */
724 word = (map[0] << 8) + map[1];
725 if (map[0] == 0x78 && !(word % 31))
726 return 1;
727 else
728 return 0;
729}
730
731unsigned long unpack_object_header_gently(const unsigned char *buf, unsigned long len, enum object_type *type, unsigned long *sizep)
732{
733 unsigned shift;
734 unsigned char c;
735 unsigned long size;
736 unsigned long used = 0;
737
738 c = buf[used++];
739 *type = (c >> 4) & 7;
740 size = c & 15;
741 shift = 4;
742 while (c & 0x80) {
743 if (len <= used)
744 return 0;
745 if (sizeof(long) * 8 <= shift)
746 return 0;
747 c = buf[used++];
748 size += (c & 0x7f) << shift;
749 shift += 7;
750 }
751 *sizep = size;
752 return used;
753}
754
755static int unpack_sha1_header(z_stream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz)
756{
757 unsigned long size, used;
758 static const char valid_loose_object_type[8] = {
759 0, /* OBJ_EXT */
760 1, 1, 1, 1, /* "commit", "tree", "blob", "tag" */
761 0, /* "delta" and others are invalid in a loose object */
762 };
763 enum object_type type;
764
765 /* Get the data stream */
766 memset(stream, 0, sizeof(*stream));
767 stream->next_in = map;
768 stream->avail_in = mapsize;
769 stream->next_out = buffer;
770 stream->avail_out = bufsiz;
771
772 if (legacy_loose_object(map)) {
773 inflateInit(stream);
774 return inflate(stream, 0);
775 }
776
777 used = unpack_object_header_gently(map, mapsize, &type, &size);
778 if (!used || !valid_loose_object_type[type])
779 return -1;
780 map += used;
781 mapsize -= used;
782
783 /* Set up the stream for the rest.. */
784 stream->next_in = map;
785 stream->avail_in = mapsize;
786 inflateInit(stream);
787
788 /* And generate the fake traditional header */
789 stream->total_out = 1 + snprintf(buffer, bufsiz, "%s %lu",
790 type_names[type], size);
791 return 0;
792}
793
794static void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size)
795{
796 int bytes = strlen(buffer) + 1;
797 unsigned char *buf = xmalloc(1+size);
798 unsigned long n;
799
800 n = stream->total_out - bytes;
801 if (n > size)
802 n = size;
803 memcpy(buf, (char *) buffer + bytes, n);
804 bytes = n;
805 if (bytes < size) {
806 stream->next_out = buf + bytes;
807 stream->avail_out = size - bytes;
808 while (inflate(stream, Z_FINISH) == Z_OK)
809 /* nothing */;
810 }
811 buf[size] = 0;
812 inflateEnd(stream);
813 return buf;
814}
815
816/*
817 * We used to just use "sscanf()", but that's actually way
818 * too permissive for what we want to check. So do an anal
819 * object header parse by hand.
820 */
821static int parse_sha1_header(char *hdr, char *type, unsigned long *sizep)
822{
823 int i;
824 unsigned long size;
825
826 /*
827 * The type can be at most ten bytes (including the
828 * terminating '\0' that we add), and is followed by
829 * a space.
830 */
831 i = 10;
832 for (;;) {
833 char c = *hdr++;
834 if (c == ' ')
835 break;
836 if (!--i)
837 return -1;
838 *type++ = c;
839 }
840 *type = 0;
841
842 /*
843 * The length must follow immediately, and be in canonical
844 * decimal format (ie "010" is not valid).
845 */
846 size = *hdr++ - '0';
847 if (size > 9)
848 return -1;
849 if (size) {
850 for (;;) {
851 unsigned long c = *hdr - '0';
852 if (c > 9)
853 break;
854 hdr++;
855 size = size * 10 + c;
856 }
857 }
858 *sizep = size;
859
860 /*
861 * The length must be followed by a zero byte
862 */
863 return *hdr ? -1 : 0;
864}
865
866void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size)
867{
868 int ret;
869 z_stream stream;
870 char hdr[8192];
871
872 ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
873 if (ret < Z_OK || parse_sha1_header(hdr, type, size) < 0)
874 return NULL;
875
876 return unpack_sha1_rest(&stream, hdr, *size);
877}
878
879static unsigned long get_delta_base(struct packed_git *p,
880 unsigned long offset,
881 enum object_type kind,
882 unsigned long delta_obj_offset,
883 unsigned long *base_obj_offset)
884{
885 unsigned char *base_info = (unsigned char *) p->pack_base + offset;
886 unsigned long base_offset;
887
888 /* there must be at least 20 bytes left regardless of delta type */
889 if (p->pack_size <= offset + 20)
890 die("truncated pack file");
891
892 if (kind == OBJ_OFS_DELTA) {
893 unsigned used = 0;
894 unsigned char c = base_info[used++];
895 base_offset = c & 127;
896 while (c & 128) {
897 base_offset += 1;
898 if (!base_offset || base_offset & ~(~0UL >> 7))
899 die("offset value overflow for delta base object");
900 c = base_info[used++];
901 base_offset = (base_offset << 7) + (c & 127);
902 }
903 base_offset = delta_obj_offset - base_offset;
904 if (base_offset >= delta_obj_offset)
905 die("delta base offset out of bound");
906 offset += used;
907 } else if (kind == OBJ_REF_DELTA) {
908 /* The base entry _must_ be in the same pack */
909 base_offset = find_pack_entry_one(base_info, p);
910 if (!base_offset)
911 die("failed to find delta-pack base object %s",
912 sha1_to_hex(base_info));
913 offset += 20;
914 } else
915 die("I am totally screwed");
916 *base_obj_offset = base_offset;
917 return offset;
918}
919
920/* forward declaration for a mutually recursive function */
921static int packed_object_info(struct packed_git *p, unsigned long offset,
922 char *type, unsigned long *sizep);
923
924static int packed_delta_info(struct packed_git *p,
925 unsigned long offset,
926 enum object_type kind,
927 unsigned long obj_offset,
928 char *type,
929 unsigned long *sizep)
930{
931 unsigned long base_offset;
932
933 offset = get_delta_base(p, offset, kind, obj_offset, &base_offset);
934
935 /* We choose to only get the type of the base object and
936 * ignore potentially corrupt pack file that expects the delta
937 * based on a base with a wrong size. This saves tons of
938 * inflate() calls.
939 */
940 if (packed_object_info(p, base_offset, type, NULL))
941 die("cannot get info for delta-pack base");
942
943 if (sizep) {
944 const unsigned char *data;
945 unsigned char delta_head[20];
946 unsigned long result_size;
947 z_stream stream;
948 int st;
949
950 memset(&stream, 0, sizeof(stream));
951
952 stream.next_in = (unsigned char *) p->pack_base + offset;
953 stream.avail_in = p->pack_size - offset;
954 stream.next_out = delta_head;
955 stream.avail_out = sizeof(delta_head);
956
957 inflateInit(&stream);
958 st = inflate(&stream, Z_FINISH);
959 inflateEnd(&stream);
960 if ((st != Z_STREAM_END) &&
961 stream.total_out != sizeof(delta_head))
962 die("delta data unpack-initial failed");
963
964 /* Examine the initial part of the delta to figure out
965 * the result size.
966 */
967 data = delta_head;
968
969 /* ignore base size */
970 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
971
972 /* Read the result size */
973 result_size = get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
974 *sizep = result_size;
975 }
976 return 0;
977}
978
979static unsigned long unpack_object_header(struct packed_git *p, unsigned long offset,
980 enum object_type *type, unsigned long *sizep)
981{
982 unsigned long used;
983
984 if (p->pack_size <= offset)
985 die("object offset outside of pack file");
986
987 used = unpack_object_header_gently((unsigned char *)p->pack_base +
988 offset,
989 p->pack_size - offset, type, sizep);
990 if (!used)
991 die("object offset outside of pack file");
992
993 return offset + used;
994}
995
996void packed_object_info_detail(struct packed_git *p,
997 unsigned long offset,
998 char *type,
999 unsigned long *size,
1000 unsigned long *store_size,
1001 unsigned int *delta_chain_length,
1002 unsigned char *base_sha1)
1003{
1004 unsigned long obj_offset, val;
1005 unsigned char *next_sha1;
1006 enum object_type kind;
1007
1008 *delta_chain_length = 0;
1009 obj_offset = offset;
1010 offset = unpack_object_header(p, offset, &kind, size);
1011
1012 for (;;) {
1013 switch (kind) {
1014 default:
1015 die("pack %s contains unknown object type %d",
1016 p->pack_name, kind);
1017 case OBJ_COMMIT:
1018 case OBJ_TREE:
1019 case OBJ_BLOB:
1020 case OBJ_TAG:
1021 strcpy(type, type_names[kind]);
1022 *store_size = 0; /* notyet */
1023 return;
1024 case OBJ_OFS_DELTA:
1025 get_delta_base(p, offset, kind, obj_offset, &offset);
1026 if (*delta_chain_length == 0) {
1027 /* TODO: find base_sha1 as pointed by offset */
1028 }
1029 break;
1030 case OBJ_REF_DELTA:
1031 if (p->pack_size <= offset + 20)
1032 die("pack file %s records an incomplete delta base",
1033 p->pack_name);
1034 next_sha1 = (unsigned char *) p->pack_base + offset;
1035 if (*delta_chain_length == 0)
1036 hashcpy(base_sha1, next_sha1);
1037 offset = find_pack_entry_one(next_sha1, p);
1038 break;
1039 }
1040 obj_offset = offset;
1041 offset = unpack_object_header(p, offset, &kind, &val);
1042 (*delta_chain_length)++;
1043 }
1044}
1045
1046static int packed_object_info(struct packed_git *p, unsigned long offset,
1047 char *type, unsigned long *sizep)
1048{
1049 unsigned long size, obj_offset = offset;
1050 enum object_type kind;
1051
1052 offset = unpack_object_header(p, offset, &kind, &size);
1053
1054 switch (kind) {
1055 case OBJ_OFS_DELTA:
1056 case OBJ_REF_DELTA:
1057 return packed_delta_info(p, offset, kind, obj_offset, type, sizep);
1058 case OBJ_COMMIT:
1059 case OBJ_TREE:
1060 case OBJ_BLOB:
1061 case OBJ_TAG:
1062 strcpy(type, type_names[kind]);
1063 break;
1064 default:
1065 die("pack %s contains unknown object type %d",
1066 p->pack_name, kind);
1067 }
1068 if (sizep)
1069 *sizep = size;
1070 return 0;
1071}
1072
1073static void *unpack_compressed_entry(struct packed_git *p,
1074 unsigned long offset,
1075 unsigned long size)
1076{
1077 int st;
1078 z_stream stream;
1079 unsigned char *buffer;
1080
1081 buffer = xmalloc(size + 1);
1082 buffer[size] = 0;
1083 memset(&stream, 0, sizeof(stream));
1084 stream.next_in = (unsigned char*)p->pack_base + offset;
1085 stream.avail_in = p->pack_size - offset;
1086 stream.next_out = buffer;
1087 stream.avail_out = size;
1088
1089 inflateInit(&stream);
1090 st = inflate(&stream, Z_FINISH);
1091 inflateEnd(&stream);
1092 if ((st != Z_STREAM_END) || stream.total_out != size) {
1093 free(buffer);
1094 return NULL;
1095 }
1096
1097 return buffer;
1098}
1099
1100static void *unpack_delta_entry(struct packed_git *p,
1101 unsigned long offset,
1102 unsigned long delta_size,
1103 enum object_type kind,
1104 unsigned long obj_offset,
1105 char *type,
1106 unsigned long *sizep)
1107{
1108 void *delta_data, *result, *base;
1109 unsigned long result_size, base_size, base_offset;
1110
1111 offset = get_delta_base(p, offset, kind, obj_offset, &base_offset);
1112 base = unpack_entry(p, base_offset, type, &base_size);
1113 if (!base)
1114 die("failed to read delta base object at %lu from %s",
1115 base_offset, p->pack_name);
1116
1117 delta_data = unpack_compressed_entry(p, offset, delta_size);
1118 result = patch_delta(base, base_size,
1119 delta_data, delta_size,
1120 &result_size);
1121 if (!result)
1122 die("failed to apply delta");
1123 free(delta_data);
1124 free(base);
1125 *sizep = result_size;
1126 return result;
1127}
1128
1129void *unpack_entry(struct packed_git *p, unsigned long offset,
1130 char *type, unsigned long *sizep)
1131{
1132 unsigned long size, obj_offset = offset;
1133 enum object_type kind;
1134 void *retval;
1135
1136 if (use_packed_git(p))
1137 die("cannot map packed file");
1138 offset = unpack_object_header(p, offset, &kind, &size);
1139 switch (kind) {
1140 case OBJ_OFS_DELTA:
1141 case OBJ_REF_DELTA:
1142 retval = unpack_delta_entry(p, offset, size, kind, obj_offset, type, sizep);
1143 break;
1144 case OBJ_COMMIT:
1145 case OBJ_TREE:
1146 case OBJ_BLOB:
1147 case OBJ_TAG:
1148 strcpy(type, type_names[kind]);
1149 *sizep = size;
1150 retval = unpack_compressed_entry(p, offset, size);
1151 break;
1152 default:
1153 die("unknown object type %i in %s", kind, p->pack_name);
1154 }
1155 unuse_packed_git(p);
1156 return retval;
1157}
1158
1159int num_packed_objects(const struct packed_git *p)
1160{
1161 /* See check_packed_git_idx() */
1162 return (p->index_size - 20 - 20 - 4*256) / 24;
1163}
1164
1165int nth_packed_object_sha1(const struct packed_git *p, int n,
1166 unsigned char* sha1)
1167{
1168 void *index = p->index_base + 256;
1169 if (n < 0 || num_packed_objects(p) <= n)
1170 return -1;
1171 hashcpy(sha1, (unsigned char *) index + (24 * n) + 4);
1172 return 0;
1173}
1174
1175unsigned long find_pack_entry_one(const unsigned char *sha1,
1176 struct packed_git *p)
1177{
1178 unsigned int *level1_ofs = p->index_base;
1179 int hi = ntohl(level1_ofs[*sha1]);
1180 int lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
1181 void *index = p->index_base + 256;
1182
1183 do {
1184 int mi = (lo + hi) / 2;
1185 int cmp = hashcmp((unsigned char *)index + (24 * mi) + 4, sha1);
1186 if (!cmp)
1187 return ntohl(*((unsigned int *) ((char *) index + (24 * mi))));
1188 if (cmp > 0)
1189 hi = mi;
1190 else
1191 lo = mi+1;
1192 } while (lo < hi);
1193 return 0;
1194}
1195
1196static int matches_pack_name(struct packed_git *p, const char *ig)
1197{
1198 const char *last_c, *c;
1199
1200 if (!strcmp(p->pack_name, ig))
1201 return 0;
1202
1203 for (c = p->pack_name, last_c = c; *c;)
1204 if (*c == '/')
1205 last_c = ++c;
1206 else
1207 ++c;
1208 if (!strcmp(last_c, ig))
1209 return 0;
1210
1211 return 1;
1212}
1213
1214static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e, const char **ignore_packed)
1215{
1216 struct packed_git *p;
1217 unsigned long offset;
1218
1219 prepare_packed_git();
1220
1221 for (p = packed_git; p; p = p->next) {
1222 if (ignore_packed) {
1223 const char **ig;
1224 for (ig = ignore_packed; *ig; ig++)
1225 if (!matches_pack_name(p, *ig))
1226 break;
1227 if (*ig)
1228 continue;
1229 }
1230 offset = find_pack_entry_one(sha1, p);
1231 if (offset) {
1232 e->offset = offset;
1233 e->p = p;
1234 hashcpy(e->sha1, sha1);
1235 return 1;
1236 }
1237 }
1238 return 0;
1239}
1240
1241struct packed_git *find_sha1_pack(const unsigned char *sha1,
1242 struct packed_git *packs)
1243{
1244 struct packed_git *p;
1245
1246 for (p = packs; p; p = p->next) {
1247 if (find_pack_entry_one(sha1, p))
1248 return p;
1249 }
1250 return NULL;
1251
1252}
1253
1254static int sha1_loose_object_info(const unsigned char *sha1, char *type, unsigned long *sizep)
1255{
1256 int status;
1257 unsigned long mapsize, size;
1258 void *map;
1259 z_stream stream;
1260 char hdr[128];
1261
1262 map = map_sha1_file(sha1, &mapsize);
1263 if (!map)
1264 return error("unable to find %s", sha1_to_hex(sha1));
1265 if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
1266 status = error("unable to unpack %s header",
1267 sha1_to_hex(sha1));
1268 if (parse_sha1_header(hdr, type, &size) < 0)
1269 status = error("unable to parse %s header", sha1_to_hex(sha1));
1270 else {
1271 status = 0;
1272 if (sizep)
1273 *sizep = size;
1274 }
1275 inflateEnd(&stream);
1276 munmap(map, mapsize);
1277 return status;
1278}
1279
1280int sha1_object_info(const unsigned char *sha1, char *type, unsigned long *sizep)
1281{
1282 int status;
1283 struct pack_entry e;
1284
1285 if (!find_pack_entry(sha1, &e, NULL)) {
1286 reprepare_packed_git();
1287 if (!find_pack_entry(sha1, &e, NULL))
1288 return sha1_loose_object_info(sha1, type, sizep);
1289 }
1290 if (use_packed_git(e.p))
1291 die("cannot map packed file");
1292 status = packed_object_info(e.p, e.offset, type, sizep);
1293 unuse_packed_git(e.p);
1294 return status;
1295}
1296
1297static void *read_packed_sha1(const unsigned char *sha1, char *type, unsigned long *size)
1298{
1299 struct pack_entry e;
1300
1301 if (!find_pack_entry(sha1, &e, NULL)) {
1302 error("cannot read sha1_file for %s", sha1_to_hex(sha1));
1303 return NULL;
1304 }
1305 return unpack_entry(e.p, e.offset, type, size);
1306}
1307
1308void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size)
1309{
1310 unsigned long mapsize;
1311 void *map, *buf;
1312 struct pack_entry e;
1313
1314 if (find_pack_entry(sha1, &e, NULL))
1315 return read_packed_sha1(sha1, type, size);
1316 map = map_sha1_file(sha1, &mapsize);
1317 if (map) {
1318 buf = unpack_sha1_file(map, mapsize, type, size);
1319 munmap(map, mapsize);
1320 return buf;
1321 }
1322 reprepare_packed_git();
1323 if (find_pack_entry(sha1, &e, NULL))
1324 return read_packed_sha1(sha1, type, size);
1325 return NULL;
1326}
1327
1328void *read_object_with_reference(const unsigned char *sha1,
1329 const char *required_type,
1330 unsigned long *size,
1331 unsigned char *actual_sha1_return)
1332{
1333 char type[20];
1334 void *buffer;
1335 unsigned long isize;
1336 unsigned char actual_sha1[20];
1337
1338 hashcpy(actual_sha1, sha1);
1339 while (1) {
1340 int ref_length = -1;
1341 const char *ref_type = NULL;
1342
1343 buffer = read_sha1_file(actual_sha1, type, &isize);
1344 if (!buffer)
1345 return NULL;
1346 if (!strcmp(type, required_type)) {
1347 *size = isize;
1348 if (actual_sha1_return)
1349 hashcpy(actual_sha1_return, actual_sha1);
1350 return buffer;
1351 }
1352 /* Handle references */
1353 else if (!strcmp(type, commit_type))
1354 ref_type = "tree ";
1355 else if (!strcmp(type, tag_type))
1356 ref_type = "object ";
1357 else {
1358 free(buffer);
1359 return NULL;
1360 }
1361 ref_length = strlen(ref_type);
1362
1363 if (memcmp(buffer, ref_type, ref_length) ||
1364 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
1365 free(buffer);
1366 return NULL;
1367 }
1368 free(buffer);
1369 /* Now we have the ID of the referred-to object in
1370 * actual_sha1. Check again. */
1371 }
1372}
1373
1374static void write_sha1_file_prepare(void *buf, unsigned long len,
1375 const char *type, unsigned char *sha1,
1376 unsigned char *hdr, int *hdrlen)
1377{
1378 SHA_CTX c;
1379
1380 /* Generate the header */
1381 *hdrlen = sprintf((char *)hdr, "%s %lu", type, len)+1;
1382
1383 /* Sha1.. */
1384 SHA1_Init(&c);
1385 SHA1_Update(&c, hdr, *hdrlen);
1386 SHA1_Update(&c, buf, len);
1387 SHA1_Final(sha1, &c);
1388}
1389
1390/*
1391 * Link the tempfile to the final place, possibly creating the
1392 * last directory level as you do so.
1393 *
1394 * Returns the errno on failure, 0 on success.
1395 */
1396static int link_temp_to_file(const char *tmpfile, const char *filename)
1397{
1398 int ret;
1399 char *dir;
1400
1401 if (!link(tmpfile, filename))
1402 return 0;
1403
1404 /*
1405 * Try to mkdir the last path component if that failed.
1406 *
1407 * Re-try the "link()" regardless of whether the mkdir
1408 * succeeds, since a race might mean that somebody
1409 * else succeeded.
1410 */
1411 ret = errno;
1412 dir = strrchr(filename, '/');
1413 if (dir) {
1414 *dir = 0;
1415 if (!mkdir(filename, 0777) && adjust_shared_perm(filename)) {
1416 *dir = '/';
1417 return -2;
1418 }
1419 *dir = '/';
1420 if (!link(tmpfile, filename))
1421 return 0;
1422 ret = errno;
1423 }
1424 return ret;
1425}
1426
1427/*
1428 * Move the just written object into its final resting place
1429 */
1430int move_temp_to_file(const char *tmpfile, const char *filename)
1431{
1432 int ret = link_temp_to_file(tmpfile, filename);
1433
1434 /*
1435 * Coda hack - coda doesn't like cross-directory links,
1436 * so we fall back to a rename, which will mean that it
1437 * won't be able to check collisions, but that's not a
1438 * big deal.
1439 *
1440 * The same holds for FAT formatted media.
1441 *
1442 * When this succeeds, we just return 0. We have nothing
1443 * left to unlink.
1444 */
1445 if (ret && ret != EEXIST) {
1446 if (!rename(tmpfile, filename))
1447 return 0;
1448 ret = errno;
1449 }
1450 unlink(tmpfile);
1451 if (ret) {
1452 if (ret != EEXIST) {
1453 return error("unable to write sha1 filename %s: %s\n", filename, strerror(ret));
1454 }
1455 /* FIXME!!! Collision check here ? */
1456 }
1457
1458 return 0;
1459}
1460
1461static int write_buffer(int fd, const void *buf, size_t len)
1462{
1463 while (len) {
1464 ssize_t size;
1465
1466 size = write(fd, buf, len);
1467 if (!size)
1468 return error("file write: disk full");
1469 if (size < 0) {
1470 if (errno == EINTR || errno == EAGAIN)
1471 continue;
1472 return error("file write error (%s)", strerror(errno));
1473 }
1474 len -= size;
1475 buf = (char *) buf + size;
1476 }
1477 return 0;
1478}
1479
1480static int write_binary_header(unsigned char *hdr, enum object_type type, unsigned long len)
1481{
1482 int hdr_len;
1483 unsigned char c;
1484
1485 c = (type << 4) | (len & 15);
1486 len >>= 4;
1487 hdr_len = 1;
1488 while (len) {
1489 *hdr++ = c | 0x80;
1490 hdr_len++;
1491 c = (len & 0x7f);
1492 len >>= 7;
1493 }
1494 *hdr = c;
1495 return hdr_len;
1496}
1497
1498static void setup_object_header(z_stream *stream, const char *type, unsigned long len)
1499{
1500 int obj_type, hdr;
1501
1502 if (use_legacy_headers) {
1503 while (deflate(stream, 0) == Z_OK)
1504 /* nothing */;
1505 return;
1506 }
1507 if (!strcmp(type, blob_type))
1508 obj_type = OBJ_BLOB;
1509 else if (!strcmp(type, tree_type))
1510 obj_type = OBJ_TREE;
1511 else if (!strcmp(type, commit_type))
1512 obj_type = OBJ_COMMIT;
1513 else if (!strcmp(type, tag_type))
1514 obj_type = OBJ_TAG;
1515 else
1516 die("trying to generate bogus object of type '%s'", type);
1517 hdr = write_binary_header(stream->next_out, obj_type, len);
1518 stream->total_out = hdr;
1519 stream->next_out += hdr;
1520 stream->avail_out -= hdr;
1521}
1522
1523int hash_sha1_file(void *buf, unsigned long len, const char *type,
1524 unsigned char *sha1)
1525{
1526 unsigned char hdr[50];
1527 int hdrlen;
1528 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
1529 return 0;
1530}
1531
1532int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
1533{
1534 int size;
1535 unsigned char *compressed;
1536 z_stream stream;
1537 unsigned char sha1[20];
1538 char *filename;
1539 static char tmpfile[PATH_MAX];
1540 unsigned char hdr[50];
1541 int fd, hdrlen;
1542
1543 /* Normally if we have it in the pack then we do not bother writing
1544 * it out into .git/objects/??/?{38} file.
1545 */
1546 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
1547 filename = sha1_file_name(sha1);
1548 if (returnsha1)
1549 hashcpy(returnsha1, sha1);
1550 if (has_sha1_file(sha1))
1551 return 0;
1552 fd = open(filename, O_RDONLY);
1553 if (fd >= 0) {
1554 /*
1555 * FIXME!!! We might do collision checking here, but we'd
1556 * need to uncompress the old file and check it. Later.
1557 */
1558 close(fd);
1559 return 0;
1560 }
1561
1562 if (errno != ENOENT) {
1563 return error("sha1 file %s: %s\n", filename, strerror(errno));
1564 }
1565
1566 snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
1567
1568 fd = mkstemp(tmpfile);
1569 if (fd < 0) {
1570 if (errno == EPERM)
1571 return error("insufficient permission for adding an object to repository database %s\n", get_object_directory());
1572 else
1573 return error("unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
1574 }
1575
1576 /* Set it up */
1577 memset(&stream, 0, sizeof(stream));
1578 deflateInit(&stream, zlib_compression_level);
1579 size = 8 + deflateBound(&stream, len+hdrlen);
1580 compressed = xmalloc(size);
1581
1582 /* Compress it */
1583 stream.next_out = compressed;
1584 stream.avail_out = size;
1585
1586 /* First header.. */
1587 stream.next_in = hdr;
1588 stream.avail_in = hdrlen;
1589 setup_object_header(&stream, type, len);
1590
1591 /* Then the data itself.. */
1592 stream.next_in = buf;
1593 stream.avail_in = len;
1594 while (deflate(&stream, Z_FINISH) == Z_OK)
1595 /* nothing */;
1596 deflateEnd(&stream);
1597 size = stream.total_out;
1598
1599 if (write_buffer(fd, compressed, size) < 0)
1600 die("unable to write sha1 file");
1601 fchmod(fd, 0444);
1602 close(fd);
1603 free(compressed);
1604
1605 return move_temp_to_file(tmpfile, filename);
1606}
1607
1608/*
1609 * We need to unpack and recompress the object for writing
1610 * it out to a different file.
1611 */
1612static void *repack_object(const unsigned char *sha1, unsigned long *objsize)
1613{
1614 size_t size;
1615 z_stream stream;
1616 unsigned char *unpacked;
1617 unsigned long len;
1618 char type[20];
1619 char hdr[50];
1620 int hdrlen;
1621 void *buf;
1622
1623 /* need to unpack and recompress it by itself */
1624 unpacked = read_packed_sha1(sha1, type, &len);
1625
1626 hdrlen = sprintf(hdr, "%s %lu", type, len) + 1;
1627
1628 /* Set it up */
1629 memset(&stream, 0, sizeof(stream));
1630 deflateInit(&stream, zlib_compression_level);
1631 size = deflateBound(&stream, len + hdrlen);
1632 buf = xmalloc(size);
1633
1634 /* Compress it */
1635 stream.next_out = buf;
1636 stream.avail_out = size;
1637
1638 /* First header.. */
1639 stream.next_in = (void *)hdr;
1640 stream.avail_in = hdrlen;
1641 while (deflate(&stream, 0) == Z_OK)
1642 /* nothing */;
1643
1644 /* Then the data itself.. */
1645 stream.next_in = unpacked;
1646 stream.avail_in = len;
1647 while (deflate(&stream, Z_FINISH) == Z_OK)
1648 /* nothing */;
1649 deflateEnd(&stream);
1650 free(unpacked);
1651
1652 *objsize = stream.total_out;
1653 return buf;
1654}
1655
1656int write_sha1_to_fd(int fd, const unsigned char *sha1)
1657{
1658 int retval;
1659 unsigned long objsize;
1660 void *buf = map_sha1_file(sha1, &objsize);
1661
1662 if (buf) {
1663 retval = write_buffer(fd, buf, objsize);
1664 munmap(buf, objsize);
1665 return retval;
1666 }
1667
1668 buf = repack_object(sha1, &objsize);
1669 retval = write_buffer(fd, buf, objsize);
1670 free(buf);
1671 return retval;
1672}
1673
1674int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
1675 size_t bufsize, size_t *bufposn)
1676{
1677 char tmpfile[PATH_MAX];
1678 int local;
1679 z_stream stream;
1680 unsigned char real_sha1[20];
1681 unsigned char discard[4096];
1682 int ret;
1683 SHA_CTX c;
1684
1685 snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
1686
1687 local = mkstemp(tmpfile);
1688 if (local < 0) {
1689 if (errno == EPERM)
1690 return error("insufficient permission for adding an object to repository database %s\n", get_object_directory());
1691 else
1692 return error("unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
1693 }
1694
1695 memset(&stream, 0, sizeof(stream));
1696
1697 inflateInit(&stream);
1698
1699 SHA1_Init(&c);
1700
1701 do {
1702 ssize_t size;
1703 if (*bufposn) {
1704 stream.avail_in = *bufposn;
1705 stream.next_in = (unsigned char *) buffer;
1706 do {
1707 stream.next_out = discard;
1708 stream.avail_out = sizeof(discard);
1709 ret = inflate(&stream, Z_SYNC_FLUSH);
1710 SHA1_Update(&c, discard, sizeof(discard) -
1711 stream.avail_out);
1712 } while (stream.avail_in && ret == Z_OK);
1713 if (write_buffer(local, buffer, *bufposn - stream.avail_in) < 0)
1714 die("unable to write sha1 file");
1715 memmove(buffer, buffer + *bufposn - stream.avail_in,
1716 stream.avail_in);
1717 *bufposn = stream.avail_in;
1718 if (ret != Z_OK)
1719 break;
1720 }
1721 size = read(fd, buffer + *bufposn, bufsize - *bufposn);
1722 if (size <= 0) {
1723 close(local);
1724 unlink(tmpfile);
1725 if (!size)
1726 return error("Connection closed?");
1727 perror("Reading from connection");
1728 return -1;
1729 }
1730 *bufposn += size;
1731 } while (1);
1732 inflateEnd(&stream);
1733
1734 close(local);
1735 SHA1_Final(real_sha1, &c);
1736 if (ret != Z_STREAM_END) {
1737 unlink(tmpfile);
1738 return error("File %s corrupted", sha1_to_hex(sha1));
1739 }
1740 if (hashcmp(sha1, real_sha1)) {
1741 unlink(tmpfile);
1742 return error("File %s has bad hash", sha1_to_hex(sha1));
1743 }
1744
1745 return move_temp_to_file(tmpfile, sha1_file_name(sha1));
1746}
1747
1748int has_pack_index(const unsigned char *sha1)
1749{
1750 struct stat st;
1751 if (stat(sha1_pack_index_name(sha1), &st))
1752 return 0;
1753 return 1;
1754}
1755
1756int has_pack_file(const unsigned char *sha1)
1757{
1758 struct stat st;
1759 if (stat(sha1_pack_name(sha1), &st))
1760 return 0;
1761 return 1;
1762}
1763
1764int has_sha1_pack(const unsigned char *sha1, const char **ignore_packed)
1765{
1766 struct pack_entry e;
1767 return find_pack_entry(sha1, &e, ignore_packed);
1768}
1769
1770int has_sha1_file(const unsigned char *sha1)
1771{
1772 struct stat st;
1773 struct pack_entry e;
1774
1775 if (find_pack_entry(sha1, &e, NULL))
1776 return 1;
1777 return find_sha1_file(sha1, &st) ? 1 : 0;
1778}
1779
1780/*
1781 * reads from fd as long as possible into a supplied buffer of size bytes.
1782 * If necessary the buffer's size is increased using realloc()
1783 *
1784 * returns 0 if anything went fine and -1 otherwise
1785 *
1786 * NOTE: both buf and size may change, but even when -1 is returned
1787 * you still have to free() it yourself.
1788 */
1789int read_pipe(int fd, char** return_buf, unsigned long* return_size)
1790{
1791 char* buf = *return_buf;
1792 unsigned long size = *return_size;
1793 int iret;
1794 unsigned long off = 0;
1795
1796 do {
1797 iret = xread(fd, buf + off, size - off);
1798 if (iret > 0) {
1799 off += iret;
1800 if (off == size) {
1801 size *= 2;
1802 buf = xrealloc(buf, size);
1803 }
1804 }
1805 } while (iret > 0);
1806
1807 *return_buf = buf;
1808 *return_size = off;
1809
1810 if (iret < 0)
1811 return -1;
1812 return 0;
1813}
1814
1815int index_pipe(unsigned char *sha1, int fd, const char *type, int write_object)
1816{
1817 unsigned long size = 4096;
1818 char *buf = xmalloc(size);
1819 int ret;
1820
1821 if (read_pipe(fd, &buf, &size)) {
1822 free(buf);
1823 return -1;
1824 }
1825
1826 if (!type)
1827 type = blob_type;
1828 if (write_object)
1829 ret = write_sha1_file(buf, size, type, sha1);
1830 else
1831 ret = hash_sha1_file(buf, size, type, sha1);
1832 free(buf);
1833 return ret;
1834}
1835
1836int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object, const char *type)
1837{
1838 unsigned long size = st->st_size;
1839 void *buf;
1840 int ret;
1841
1842 buf = "";
1843 if (size)
1844 buf = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
1845 close(fd);
1846 if (buf == MAP_FAILED)
1847 return -1;
1848
1849 if (!type)
1850 type = blob_type;
1851 if (write_object)
1852 ret = write_sha1_file(buf, size, type, sha1);
1853 else
1854 ret = hash_sha1_file(buf, size, type, sha1);
1855 if (size)
1856 munmap(buf, size);
1857 return ret;
1858}
1859
1860int index_path(unsigned char *sha1, const char *path, struct stat *st, int write_object)
1861{
1862 int fd;
1863 char *target;
1864
1865 switch (st->st_mode & S_IFMT) {
1866 case S_IFREG:
1867 fd = open(path, O_RDONLY);
1868 if (fd < 0)
1869 return error("open(\"%s\"): %s", path,
1870 strerror(errno));
1871 if (index_fd(sha1, fd, st, write_object, NULL) < 0)
1872 return error("%s: failed to insert into database",
1873 path);
1874 break;
1875 case S_IFLNK:
1876 target = xmalloc(st->st_size+1);
1877 if (readlink(path, target, st->st_size+1) != st->st_size) {
1878 char *errstr = strerror(errno);
1879 free(target);
1880 return error("readlink(\"%s\"): %s", path,
1881 errstr);
1882 }
1883 if (!write_object)
1884 hash_sha1_file(target, st->st_size, blob_type, sha1);
1885 else if (write_sha1_file(target, st->st_size, blob_type, sha1))
1886 return error("%s: failed to insert into database",
1887 path);
1888 free(target);
1889 break;
1890 default:
1891 return error("%s: unsupported file type", path);
1892 }
1893 return 0;
1894}