Actually handle some-low memory conditions
[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 size_t mapsz;
353 struct stat st;
354 char path[PATH_MAX];
355 int fd;
356
357 sprintf(path, "%s/info/alternates", relative_base);
358 fd = open(path, O_RDONLY);
359 if (fd < 0)
360 return;
361 if (fstat(fd, &st) || (st.st_size == 0)) {
362 close(fd);
363 return;
364 }
365 mapsz = xsize_t(st.st_size);
366 map = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, fd, 0);
367 close(fd);
368
369 link_alt_odb_entries(map, map + mapsz, '\n', relative_base, depth);
370
371 munmap(map, mapsz);
372 }
373
374 void prepare_alt_odb(void)
375 {
376 const char *alt;
377
378 alt = getenv(ALTERNATE_DB_ENVIRONMENT);
379 if (!alt) alt = "";
380
381 if (alt_odb_tail)
382 return;
383 alt_odb_tail = &alt_odb_list;
384 link_alt_odb_entries(alt, alt + strlen(alt), ':', NULL, 0);
385
386 read_info_alternates(get_object_directory(), 0);
387 }
388
389 static char *find_sha1_file(const unsigned char *sha1, struct stat *st)
390 {
391 char *name = sha1_file_name(sha1);
392 struct alternate_object_database *alt;
393
394 if (!stat(name, st))
395 return name;
396 prepare_alt_odb();
397 for (alt = alt_odb_list; alt; alt = alt->next) {
398 name = alt->name;
399 fill_sha1_path(name, sha1);
400 if (!stat(alt->base, st))
401 return alt->base;
402 }
403 return NULL;
404 }
405
406 static unsigned int pack_used_ctr;
407 static unsigned int pack_mmap_calls;
408 static unsigned int peak_pack_open_windows;
409 static unsigned int pack_open_windows;
410 static size_t peak_pack_mapped;
411 static size_t pack_mapped;
412 struct packed_git *packed_git;
413
414 void pack_report()
415 {
416 fprintf(stderr,
417 "pack_report: getpagesize() = %10" SZ_FMT "\n"
418 "pack_report: core.packedGitWindowSize = %10" SZ_FMT "\n"
419 "pack_report: core.packedGitLimit = %10" SZ_FMT "\n",
420 (size_t) getpagesize(),
421 packed_git_window_size,
422 packed_git_limit);
423 fprintf(stderr,
424 "pack_report: pack_used_ctr = %10u\n"
425 "pack_report: pack_mmap_calls = %10u\n"
426 "pack_report: pack_open_windows = %10u / %10u\n"
427 "pack_report: pack_mapped = "
428 "%10" SZ_FMT " / %10" SZ_FMT "\n",
429 pack_used_ctr,
430 pack_mmap_calls,
431 pack_open_windows, peak_pack_open_windows,
432 pack_mapped, peak_pack_mapped);
433 }
434
435 static int check_packed_git_idx(const char *path, struct packed_git *p)
436 {
437 void *idx_map;
438 struct pack_idx_header *hdr;
439 size_t idx_size;
440 uint32_t nr, i, *index;
441 int fd = open(path, O_RDONLY);
442 struct stat st;
443
444 if (fd < 0)
445 return -1;
446 if (fstat(fd, &st)) {
447 close(fd);
448 return -1;
449 }
450 idx_size = xsize_t(st.st_size);
451 if (idx_size < 4 * 256 + 20 + 20) {
452 close(fd);
453 return error("index file %s is too small", path);
454 }
455 idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
456 close(fd);
457
458 /* a future index format would start with this, as older git
459 * binaries would fail the non-monotonic index check below.
460 * give a nicer warning to the user if we can.
461 */
462 hdr = idx_map;
463 if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) {
464 munmap(idx_map, idx_size);
465 return error("index file %s is a newer version"
466 " and is not supported by this binary"
467 " (try upgrading GIT to a newer version)",
468 path);
469 }
470
471 nr = 0;
472 index = idx_map;
473 for (i = 0; i < 256; i++) {
474 uint32_t n = ntohl(index[i]);
475 if (n < nr) {
476 munmap(idx_map, idx_size);
477 return error("non-monotonic index %s", path);
478 }
479 nr = n;
480 }
481
482 /*
483 * Total size:
484 * - 256 index entries 4 bytes each
485 * - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
486 * - 20-byte SHA1 of the packfile
487 * - 20-byte SHA1 file checksum
488 */
489 if (idx_size != 4*256 + nr * 24 + 20 + 20) {
490 munmap(idx_map, idx_size);
491 return error("wrong index file size in %s", path);
492 }
493
494 p->index_version = 1;
495 p->index_data = idx_map;
496 p->index_size = idx_size;
497 return 0;
498 }
499
500 static void scan_windows(struct packed_git *p,
501 struct packed_git **lru_p,
502 struct pack_window **lru_w,
503 struct pack_window **lru_l)
504 {
505 struct pack_window *w, *w_l;
506
507 for (w_l = NULL, w = p->windows; w; w = w->next) {
508 if (!w->inuse_cnt) {
509 if (!*lru_w || w->last_used < (*lru_w)->last_used) {
510 *lru_p = p;
511 *lru_w = w;
512 *lru_l = w_l;
513 }
514 }
515 w_l = w;
516 }
517 }
518
519 static int unuse_one_window(struct packed_git *current, int keep_fd)
520 {
521 struct packed_git *p, *lru_p = NULL;
522 struct pack_window *lru_w = NULL, *lru_l = NULL;
523
524 if (current)
525 scan_windows(current, &lru_p, &lru_w, &lru_l);
526 for (p = packed_git; p; p = p->next)
527 scan_windows(p, &lru_p, &lru_w, &lru_l);
528 if (lru_p) {
529 munmap(lru_w->base, lru_w->len);
530 pack_mapped -= lru_w->len;
531 if (lru_l)
532 lru_l->next = lru_w->next;
533 else {
534 lru_p->windows = lru_w->next;
535 if (!lru_p->windows && lru_p->pack_fd != keep_fd) {
536 close(lru_p->pack_fd);
537 lru_p->pack_fd = -1;
538 }
539 }
540 free(lru_w);
541 pack_open_windows--;
542 return 1;
543 }
544 return 0;
545 }
546
547 void release_pack_memory(size_t need, int fd)
548 {
549 size_t cur = pack_mapped;
550 while (need >= (cur - pack_mapped) && unuse_one_window(NULL, fd))
551 ; /* nothing */
552 }
553
554 void unuse_pack(struct pack_window **w_cursor)
555 {
556 struct pack_window *w = *w_cursor;
557 if (w) {
558 w->inuse_cnt--;
559 *w_cursor = NULL;
560 }
561 }
562
563 /*
564 * Do not call this directly as this leaks p->pack_fd on error return;
565 * call open_packed_git() instead.
566 */
567 static int open_packed_git_1(struct packed_git *p)
568 {
569 struct stat st;
570 struct pack_header hdr;
571 unsigned char sha1[20];
572 unsigned char *idx_sha1;
573 long fd_flag;
574
575 p->pack_fd = open(p->pack_name, O_RDONLY);
576 if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
577 return -1;
578
579 /* If we created the struct before we had the pack we lack size. */
580 if (!p->pack_size) {
581 if (!S_ISREG(st.st_mode))
582 return error("packfile %s not a regular file", p->pack_name);
583 p->pack_size = st.st_size;
584 } else if (p->pack_size != st.st_size)
585 return error("packfile %s size changed", p->pack_name);
586
587 /* We leave these file descriptors open with sliding mmap;
588 * there is no point keeping them open across exec(), though.
589 */
590 fd_flag = fcntl(p->pack_fd, F_GETFD, 0);
591 if (fd_flag < 0)
592 return error("cannot determine file descriptor flags");
593 fd_flag |= FD_CLOEXEC;
594 if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1)
595 return error("cannot set FD_CLOEXEC");
596
597 /* Verify we recognize this pack file format. */
598 if (read_in_full(p->pack_fd, &hdr, sizeof(hdr)) != sizeof(hdr))
599 return error("file %s is far too short to be a packfile", p->pack_name);
600 if (hdr.hdr_signature != htonl(PACK_SIGNATURE))
601 return error("file %s is not a GIT packfile", p->pack_name);
602 if (!pack_version_ok(hdr.hdr_version))
603 return error("packfile %s is version %u and not supported"
604 " (try upgrading GIT to a newer version)",
605 p->pack_name, ntohl(hdr.hdr_version));
606
607 /* Verify the pack matches its index. */
608 if (num_packed_objects(p) != ntohl(hdr.hdr_entries))
609 return error("packfile %s claims to have %u objects"
610 " while index size indicates %u objects",
611 p->pack_name, ntohl(hdr.hdr_entries),
612 num_packed_objects(p));
613 if (lseek(p->pack_fd, p->pack_size - sizeof(sha1), SEEK_SET) == -1)
614 return error("end of packfile %s is unavailable", p->pack_name);
615 if (read_in_full(p->pack_fd, sha1, sizeof(sha1)) != sizeof(sha1))
616 return error("packfile %s signature is unavailable", p->pack_name);
617 idx_sha1 = ((unsigned char *)p->index_data) + p->index_size - 40;
618 if (hashcmp(sha1, idx_sha1))
619 return error("packfile %s does not match index", p->pack_name);
620 return 0;
621 }
622
623 static int open_packed_git(struct packed_git *p)
624 {
625 if (!open_packed_git_1(p))
626 return 0;
627 if (p->pack_fd != -1) {
628 close(p->pack_fd);
629 p->pack_fd = -1;
630 }
631 return -1;
632 }
633
634 static int in_window(struct pack_window *win, off_t offset)
635 {
636 /* We must promise at least 20 bytes (one hash) after the
637 * offset is available from this window, otherwise the offset
638 * is not actually in this window and a different window (which
639 * has that one hash excess) must be used. This is to support
640 * the object header and delta base parsing routines below.
641 */
642 off_t win_off = win->offset;
643 return win_off <= offset
644 && (offset + 20) <= (win_off + win->len);
645 }
646
647 unsigned char* use_pack(struct packed_git *p,
648 struct pack_window **w_cursor,
649 off_t offset,
650 unsigned int *left)
651 {
652 struct pack_window *win = *w_cursor;
653
654 if (p->pack_fd == -1 && open_packed_git(p))
655 die("packfile %s cannot be accessed", p->pack_name);
656
657 /* Since packfiles end in a hash of their content and its
658 * pointless to ask for an offset into the middle of that
659 * hash, and the in_window function above wouldn't match
660 * don't allow an offset too close to the end of the file.
661 */
662 if (offset > (p->pack_size - 20))
663 die("offset beyond end of packfile (truncated pack?)");
664
665 if (!win || !in_window(win, offset)) {
666 if (win)
667 win->inuse_cnt--;
668 for (win = p->windows; win; win = win->next) {
669 if (in_window(win, offset))
670 break;
671 }
672 if (!win) {
673 size_t window_align = packed_git_window_size / 2;
674 off_t len;
675 win = xcalloc(1, sizeof(*win));
676 win->offset = (offset / window_align) * window_align;
677 len = p->pack_size - win->offset;
678 if (len > packed_git_window_size)
679 len = packed_git_window_size;
680 win->len = (size_t)len;
681 pack_mapped += win->len;
682 while (packed_git_limit < pack_mapped
683 && unuse_one_window(p, p->pack_fd))
684 ; /* nothing */
685 win->base = xmmap(NULL, win->len,
686 PROT_READ, MAP_PRIVATE,
687 p->pack_fd, win->offset);
688 if (win->base == MAP_FAILED)
689 die("packfile %s cannot be mapped: %s",
690 p->pack_name,
691 strerror(errno));
692 pack_mmap_calls++;
693 pack_open_windows++;
694 if (pack_mapped > peak_pack_mapped)
695 peak_pack_mapped = pack_mapped;
696 if (pack_open_windows > peak_pack_open_windows)
697 peak_pack_open_windows = pack_open_windows;
698 win->next = p->windows;
699 p->windows = win;
700 }
701 }
702 if (win != *w_cursor) {
703 win->last_used = pack_used_ctr++;
704 win->inuse_cnt++;
705 *w_cursor = win;
706 }
707 offset -= win->offset;
708 if (left)
709 *left = win->len - xsize_t(offset);
710 return win->base + offset;
711 }
712
713 struct packed_git *add_packed_git(const char *path, int path_len, int local)
714 {
715 struct stat st;
716 struct packed_git *p = xmalloc(sizeof(*p) + path_len + 2);
717
718 /*
719 * Make sure a corresponding .pack file exists and that
720 * the index looks sane.
721 */
722 path_len -= strlen(".idx");
723 if (path_len < 1)
724 return NULL;
725 memcpy(p->pack_name, path, path_len);
726 strcpy(p->pack_name + path_len, ".pack");
727 if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode) ||
728 check_packed_git_idx(path, p)) {
729 free(p);
730 return NULL;
731 }
732
733 /* ok, it looks sane as far as we can check without
734 * actually mapping the pack file.
735 */
736 p->pack_size = st.st_size;
737 p->next = NULL;
738 p->windows = NULL;
739 p->pack_fd = -1;
740 p->pack_local = local;
741 p->mtime = st.st_mtime;
742 if (path_len < 40 || get_sha1_hex(path + path_len - 40, p->sha1))
743 hashclr(p->sha1);
744 return p;
745 }
746
747 struct packed_git *parse_pack_index(unsigned char *sha1)
748 {
749 char *path = sha1_pack_index_name(sha1);
750 return parse_pack_index_file(sha1, path);
751 }
752
753 struct packed_git *parse_pack_index_file(const unsigned char *sha1,
754 const char *idx_path)
755 {
756 const char *path = sha1_pack_name(sha1);
757 struct packed_git *p = xmalloc(sizeof(*p) + strlen(path) + 2);
758
759 if (check_packed_git_idx(idx_path, p)) {
760 free(p);
761 return NULL;
762 }
763
764 strcpy(p->pack_name, path);
765 p->pack_size = 0;
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 sort_pack(const void *a_, const void *b_)
823 {
824 struct packed_git *a = *((struct packed_git **)a_);
825 struct packed_git *b = *((struct packed_git **)b_);
826 int st;
827
828 /*
829 * Local packs tend to contain objects specific to our
830 * variant of the project than remote ones. In addition,
831 * remote ones could be on a network mounted filesystem.
832 * Favor local ones for these reasons.
833 */
834 st = a->pack_local - b->pack_local;
835 if (st)
836 return -st;
837
838 /*
839 * Younger packs tend to contain more recent objects,
840 * and more recent objects tend to get accessed more
841 * often.
842 */
843 if (a->mtime < b->mtime)
844 return 1;
845 else if (a->mtime == b->mtime)
846 return 0;
847 return -1;
848 }
849
850 static void rearrange_packed_git(void)
851 {
852 struct packed_git **ary, *p;
853 int i, n;
854
855 for (n = 0, p = packed_git; p; p = p->next)
856 n++;
857 if (n < 2)
858 return;
859
860 /* prepare an array of packed_git for easier sorting */
861 ary = xcalloc(n, sizeof(struct packed_git *));
862 for (n = 0, p = packed_git; p; p = p->next)
863 ary[n++] = p;
864
865 qsort(ary, n, sizeof(struct packed_git *), sort_pack);
866
867 /* link them back again */
868 for (i = 0; i < n - 1; i++)
869 ary[i]->next = ary[i + 1];
870 ary[n - 1]->next = NULL;
871 packed_git = ary[0];
872
873 free(ary);
874 }
875
876 static int prepare_packed_git_run_once = 0;
877 void prepare_packed_git(void)
878 {
879 struct alternate_object_database *alt;
880
881 if (prepare_packed_git_run_once)
882 return;
883 prepare_packed_git_one(get_object_directory(), 1);
884 prepare_alt_odb();
885 for (alt = alt_odb_list; alt; alt = alt->next) {
886 alt->name[-1] = 0;
887 prepare_packed_git_one(alt->base, 0);
888 alt->name[-1] = '/';
889 }
890 rearrange_packed_git();
891 prepare_packed_git_run_once = 1;
892 }
893
894 void reprepare_packed_git(void)
895 {
896 prepare_packed_git_run_once = 0;
897 prepare_packed_git();
898 }
899
900 int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long size, const char *type)
901 {
902 unsigned char real_sha1[20];
903 hash_sha1_file(map, size, type, real_sha1);
904 return hashcmp(sha1, real_sha1) ? -1 : 0;
905 }
906
907 void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
908 {
909 struct stat st;
910 void *map;
911 int fd;
912 char *filename = find_sha1_file(sha1, &st);
913
914 if (!filename) {
915 return NULL;
916 }
917
918 fd = open(filename, O_RDONLY | sha1_file_open_flag);
919 if (fd < 0) {
920 /* See if it works without O_NOATIME */
921 switch (sha1_file_open_flag) {
922 default:
923 fd = open(filename, O_RDONLY);
924 if (fd >= 0)
925 break;
926 /* Fallthrough */
927 case 0:
928 return NULL;
929 }
930
931 /* If it failed once, it will probably fail again.
932 * Stop using O_NOATIME
933 */
934 sha1_file_open_flag = 0;
935 }
936 *size = xsize_t(st.st_size);
937 map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
938 close(fd);
939 return map;
940 }
941
942 int legacy_loose_object(unsigned char *map)
943 {
944 unsigned int word;
945
946 /*
947 * Is it a zlib-compressed buffer? If so, the first byte
948 * must be 0x78 (15-bit window size, deflated), and the
949 * first 16-bit word is evenly divisible by 31
950 */
951 word = (map[0] << 8) + map[1];
952 if (map[0] == 0x78 && !(word % 31))
953 return 1;
954 else
955 return 0;
956 }
957
958 unsigned long unpack_object_header_gently(const unsigned char *buf, unsigned long len, enum object_type *type, unsigned long *sizep)
959 {
960 unsigned shift;
961 unsigned char c;
962 unsigned long size;
963 unsigned long used = 0;
964
965 c = buf[used++];
966 *type = (c >> 4) & 7;
967 size = c & 15;
968 shift = 4;
969 while (c & 0x80) {
970 if (len <= used)
971 return 0;
972 if (sizeof(long) * 8 <= shift)
973 return 0;
974 c = buf[used++];
975 size += (c & 0x7f) << shift;
976 shift += 7;
977 }
978 *sizep = size;
979 return used;
980 }
981
982 static int unpack_sha1_header(z_stream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz)
983 {
984 unsigned long size, used;
985 static const char valid_loose_object_type[8] = {
986 0, /* OBJ_EXT */
987 1, 1, 1, 1, /* "commit", "tree", "blob", "tag" */
988 0, /* "delta" and others are invalid in a loose object */
989 };
990 enum object_type type;
991
992 /* Get the data stream */
993 memset(stream, 0, sizeof(*stream));
994 stream->next_in = map;
995 stream->avail_in = mapsize;
996 stream->next_out = buffer;
997 stream->avail_out = bufsiz;
998
999 if (legacy_loose_object(map)) {
1000 inflateInit(stream);
1001 return inflate(stream, 0);
1002 }
1003
1004 used = unpack_object_header_gently(map, mapsize, &type, &size);
1005 if (!used || !valid_loose_object_type[type])
1006 return -1;
1007 map += used;
1008 mapsize -= used;
1009
1010 /* Set up the stream for the rest.. */
1011 stream->next_in = map;
1012 stream->avail_in = mapsize;
1013 inflateInit(stream);
1014
1015 /* And generate the fake traditional header */
1016 stream->total_out = 1 + snprintf(buffer, bufsiz, "%s %lu",
1017 typename(type), size);
1018 return 0;
1019 }
1020
1021 static void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size, const unsigned char *sha1)
1022 {
1023 int bytes = strlen(buffer) + 1;
1024 unsigned char *buf = xmalloc(1+size);
1025 unsigned long n;
1026 int status = Z_OK;
1027
1028 n = stream->total_out - bytes;
1029 if (n > size)
1030 n = size;
1031 memcpy(buf, (char *) buffer + bytes, n);
1032 bytes = n;
1033 if (bytes <= size) {
1034 /*
1035 * The above condition must be (bytes <= size), not
1036 * (bytes < size). In other words, even though we
1037 * expect no more output and set avail_out to zer0,
1038 * the input zlib stream may have bytes that express
1039 * "this concludes the stream", and we *do* want to
1040 * eat that input.
1041 *
1042 * Otherwise we would not be able to test that we
1043 * consumed all the input to reach the expected size;
1044 * we also want to check that zlib tells us that all
1045 * went well with status == Z_STREAM_END at the end.
1046 */
1047 stream->next_out = buf + bytes;
1048 stream->avail_out = size - bytes;
1049 while (status == Z_OK)
1050 status = inflate(stream, Z_FINISH);
1051 }
1052 buf[size] = 0;
1053 if (status == Z_STREAM_END && !stream->avail_in) {
1054 inflateEnd(stream);
1055 return buf;
1056 }
1057
1058 if (status < 0)
1059 error("corrupt loose object '%s'", sha1_to_hex(sha1));
1060 else if (stream->avail_in)
1061 error("garbage at end of loose object '%s'",
1062 sha1_to_hex(sha1));
1063 free(buf);
1064 return NULL;
1065 }
1066
1067 /*
1068 * We used to just use "sscanf()", but that's actually way
1069 * too permissive for what we want to check. So do an anal
1070 * object header parse by hand.
1071 */
1072 static int parse_sha1_header(const char *hdr, unsigned long *sizep)
1073 {
1074 char type[10];
1075 int i;
1076 unsigned long size;
1077
1078 /*
1079 * The type can be at most ten bytes (including the
1080 * terminating '\0' that we add), and is followed by
1081 * a space.
1082 */
1083 i = 0;
1084 for (;;) {
1085 char c = *hdr++;
1086 if (c == ' ')
1087 break;
1088 type[i++] = c;
1089 if (i >= sizeof(type))
1090 return -1;
1091 }
1092 type[i] = 0;
1093
1094 /*
1095 * The length must follow immediately, and be in canonical
1096 * decimal format (ie "010" is not valid).
1097 */
1098 size = *hdr++ - '0';
1099 if (size > 9)
1100 return -1;
1101 if (size) {
1102 for (;;) {
1103 unsigned long c = *hdr - '0';
1104 if (c > 9)
1105 break;
1106 hdr++;
1107 size = size * 10 + c;
1108 }
1109 }
1110 *sizep = size;
1111
1112 /*
1113 * The length must be followed by a zero byte
1114 */
1115 return *hdr ? -1 : type_from_string(type);
1116 }
1117
1118 static void *unpack_sha1_file(void *map, unsigned long mapsize, enum object_type *type, unsigned long *size, const unsigned char *sha1)
1119 {
1120 int ret;
1121 z_stream stream;
1122 char hdr[8192];
1123
1124 ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
1125 if (ret < Z_OK || (*type = parse_sha1_header(hdr, size)) < 0)
1126 return NULL;
1127
1128 return unpack_sha1_rest(&stream, hdr, *size, sha1);
1129 }
1130
1131 static off_t get_delta_base(struct packed_git *p,
1132 struct pack_window **w_curs,
1133 off_t *curpos,
1134 enum object_type type,
1135 off_t delta_obj_offset)
1136 {
1137 unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL);
1138 off_t base_offset;
1139
1140 /* use_pack() assured us we have [base_info, base_info + 20)
1141 * as a range that we can look at without walking off the
1142 * end of the mapped window. Its actually the hash size
1143 * that is assured. An OFS_DELTA longer than the hash size
1144 * is stupid, as then a REF_DELTA would be smaller to store.
1145 */
1146 if (type == OBJ_OFS_DELTA) {
1147 unsigned used = 0;
1148 unsigned char c = base_info[used++];
1149 base_offset = c & 127;
1150 while (c & 128) {
1151 base_offset += 1;
1152 if (!base_offset || base_offset & ~(~0UL >> 7))
1153 die("offset value overflow for delta base object");
1154 c = base_info[used++];
1155 base_offset = (base_offset << 7) + (c & 127);
1156 }
1157 base_offset = delta_obj_offset - base_offset;
1158 if (base_offset >= delta_obj_offset)
1159 die("delta base offset out of bound");
1160 *curpos += used;
1161 } else if (type == OBJ_REF_DELTA) {
1162 /* The base entry _must_ be in the same pack */
1163 base_offset = find_pack_entry_one(base_info, p);
1164 if (!base_offset)
1165 die("failed to find delta-pack base object %s",
1166 sha1_to_hex(base_info));
1167 *curpos += 20;
1168 } else
1169 die("I am totally screwed");
1170 return base_offset;
1171 }
1172
1173 /* forward declaration for a mutually recursive function */
1174 static int packed_object_info(struct packed_git *p, off_t offset,
1175 unsigned long *sizep);
1176
1177 static int packed_delta_info(struct packed_git *p,
1178 struct pack_window **w_curs,
1179 off_t curpos,
1180 enum object_type type,
1181 off_t obj_offset,
1182 unsigned long *sizep)
1183 {
1184 off_t base_offset;
1185
1186 base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
1187 type = packed_object_info(p, base_offset, NULL);
1188
1189 /* We choose to only get the type of the base object and
1190 * ignore potentially corrupt pack file that expects the delta
1191 * based on a base with a wrong size. This saves tons of
1192 * inflate() calls.
1193 */
1194 if (sizep) {
1195 const unsigned char *data;
1196 unsigned char delta_head[20], *in;
1197 z_stream stream;
1198 int st;
1199
1200 memset(&stream, 0, sizeof(stream));
1201 stream.next_out = delta_head;
1202 stream.avail_out = sizeof(delta_head);
1203
1204 inflateInit(&stream);
1205 do {
1206 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1207 stream.next_in = in;
1208 st = inflate(&stream, Z_FINISH);
1209 curpos += stream.next_in - in;
1210 } while ((st == Z_OK || st == Z_BUF_ERROR)
1211 && stream.total_out < sizeof(delta_head));
1212 inflateEnd(&stream);
1213 if ((st != Z_STREAM_END) &&
1214 stream.total_out != sizeof(delta_head))
1215 die("delta data unpack-initial failed");
1216
1217 /* Examine the initial part of the delta to figure out
1218 * the result size.
1219 */
1220 data = delta_head;
1221
1222 /* ignore base size */
1223 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1224
1225 /* Read the result size */
1226 *sizep = get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1227 }
1228
1229 return type;
1230 }
1231
1232 static int unpack_object_header(struct packed_git *p,
1233 struct pack_window **w_curs,
1234 off_t *curpos,
1235 unsigned long *sizep)
1236 {
1237 unsigned char *base;
1238 unsigned int left;
1239 unsigned long used;
1240 enum object_type type;
1241
1242 /* use_pack() assures us we have [base, base + 20) available
1243 * as a range that we can look at at. (Its actually the hash
1244 * size that is assured.) With our object header encoding
1245 * the maximum deflated object size is 2^137, which is just
1246 * insane, so we know won't exceed what we have been given.
1247 */
1248 base = use_pack(p, w_curs, *curpos, &left);
1249 used = unpack_object_header_gently(base, left, &type, sizep);
1250 if (!used)
1251 die("object offset outside of pack file");
1252 *curpos += used;
1253
1254 return type;
1255 }
1256
1257 const char *packed_object_info_detail(struct packed_git *p,
1258 off_t obj_offset,
1259 unsigned long *size,
1260 unsigned long *store_size,
1261 unsigned int *delta_chain_length,
1262 unsigned char *base_sha1)
1263 {
1264 struct pack_window *w_curs = NULL;
1265 off_t curpos;
1266 unsigned long dummy;
1267 unsigned char *next_sha1;
1268 enum object_type type;
1269
1270 *delta_chain_length = 0;
1271 curpos = obj_offset;
1272 type = unpack_object_header(p, &w_curs, &curpos, size);
1273
1274 for (;;) {
1275 switch (type) {
1276 default:
1277 die("pack %s contains unknown object type %d",
1278 p->pack_name, type);
1279 case OBJ_COMMIT:
1280 case OBJ_TREE:
1281 case OBJ_BLOB:
1282 case OBJ_TAG:
1283 *store_size = 0; /* notyet */
1284 unuse_pack(&w_curs);
1285 return typename(type);
1286 case OBJ_OFS_DELTA:
1287 obj_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
1288 if (*delta_chain_length == 0) {
1289 /* TODO: find base_sha1 as pointed by curpos */
1290 hashclr(base_sha1);
1291 }
1292 break;
1293 case OBJ_REF_DELTA:
1294 next_sha1 = use_pack(p, &w_curs, curpos, NULL);
1295 if (*delta_chain_length == 0)
1296 hashcpy(base_sha1, next_sha1);
1297 obj_offset = find_pack_entry_one(next_sha1, p);
1298 break;
1299 }
1300 (*delta_chain_length)++;
1301 curpos = obj_offset;
1302 type = unpack_object_header(p, &w_curs, &curpos, &dummy);
1303 }
1304 }
1305
1306 static int packed_object_info(struct packed_git *p, off_t obj_offset,
1307 unsigned long *sizep)
1308 {
1309 struct pack_window *w_curs = NULL;
1310 unsigned long size;
1311 off_t curpos = obj_offset;
1312 enum object_type type;
1313
1314 type = unpack_object_header(p, &w_curs, &curpos, &size);
1315
1316 switch (type) {
1317 case OBJ_OFS_DELTA:
1318 case OBJ_REF_DELTA:
1319 type = packed_delta_info(p, &w_curs, curpos,
1320 type, obj_offset, sizep);
1321 break;
1322 case OBJ_COMMIT:
1323 case OBJ_TREE:
1324 case OBJ_BLOB:
1325 case OBJ_TAG:
1326 if (sizep)
1327 *sizep = size;
1328 break;
1329 default:
1330 die("pack %s contains unknown object type %d",
1331 p->pack_name, type);
1332 }
1333 unuse_pack(&w_curs);
1334 return type;
1335 }
1336
1337 static void *unpack_compressed_entry(struct packed_git *p,
1338 struct pack_window **w_curs,
1339 off_t curpos,
1340 unsigned long size)
1341 {
1342 int st;
1343 z_stream stream;
1344 unsigned char *buffer, *in;
1345
1346 buffer = xmalloc(size + 1);
1347 buffer[size] = 0;
1348 memset(&stream, 0, sizeof(stream));
1349 stream.next_out = buffer;
1350 stream.avail_out = size;
1351
1352 inflateInit(&stream);
1353 do {
1354 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1355 stream.next_in = in;
1356 st = inflate(&stream, Z_FINISH);
1357 curpos += stream.next_in - in;
1358 } while (st == Z_OK || st == Z_BUF_ERROR);
1359 inflateEnd(&stream);
1360 if ((st != Z_STREAM_END) || stream.total_out != size) {
1361 free(buffer);
1362 return NULL;
1363 }
1364
1365 return buffer;
1366 }
1367
1368 #define MAX_DELTA_CACHE (256)
1369
1370 static size_t delta_base_cached;
1371
1372 static struct delta_base_cache_lru_list {
1373 struct delta_base_cache_lru_list *prev;
1374 struct delta_base_cache_lru_list *next;
1375 } delta_base_cache_lru = { &delta_base_cache_lru, &delta_base_cache_lru };
1376
1377 static struct delta_base_cache_entry {
1378 struct delta_base_cache_lru_list lru;
1379 void *data;
1380 struct packed_git *p;
1381 off_t base_offset;
1382 unsigned long size;
1383 enum object_type type;
1384 } delta_base_cache[MAX_DELTA_CACHE];
1385
1386 static unsigned long pack_entry_hash(struct packed_git *p, off_t base_offset)
1387 {
1388 unsigned long hash;
1389
1390 hash = (unsigned long)p + (unsigned long)base_offset;
1391 hash += (hash >> 8) + (hash >> 16);
1392 return hash % MAX_DELTA_CACHE;
1393 }
1394
1395 static void *cache_or_unpack_entry(struct packed_git *p, off_t base_offset,
1396 unsigned long *base_size, enum object_type *type, int keep_cache)
1397 {
1398 void *ret;
1399 unsigned long hash = pack_entry_hash(p, base_offset);
1400 struct delta_base_cache_entry *ent = delta_base_cache + hash;
1401
1402 ret = ent->data;
1403 if (ret && ent->p == p && ent->base_offset == base_offset)
1404 goto found_cache_entry;
1405 return unpack_entry(p, base_offset, type, base_size);
1406
1407 found_cache_entry:
1408 if (!keep_cache) {
1409 ent->data = NULL;
1410 ent->lru.next->prev = ent->lru.prev;
1411 ent->lru.prev->next = ent->lru.next;
1412 delta_base_cached -= ent->size;
1413 }
1414 else {
1415 ret = xmalloc(ent->size + 1);
1416 memcpy(ret, ent->data, ent->size);
1417 ((char *)ret)[ent->size] = 0;
1418 }
1419 *type = ent->type;
1420 *base_size = ent->size;
1421 return ret;
1422 }
1423
1424 static inline void release_delta_base_cache(struct delta_base_cache_entry *ent)
1425 {
1426 if (ent->data) {
1427 free(ent->data);
1428 ent->data = NULL;
1429 ent->lru.next->prev = ent->lru.prev;
1430 ent->lru.prev->next = ent->lru.next;
1431 delta_base_cached -= ent->size;
1432 }
1433 }
1434
1435 static void add_delta_base_cache(struct packed_git *p, off_t base_offset,
1436 void *base, unsigned long base_size, enum object_type type)
1437 {
1438 unsigned long hash = pack_entry_hash(p, base_offset);
1439 struct delta_base_cache_entry *ent = delta_base_cache + hash;
1440 struct delta_base_cache_lru_list *lru;
1441
1442 release_delta_base_cache(ent);
1443 delta_base_cached += base_size;
1444
1445 for (lru = delta_base_cache_lru.next;
1446 delta_base_cached > delta_base_cache_limit
1447 && lru != &delta_base_cache_lru;
1448 lru = lru->next) {
1449 struct delta_base_cache_entry *f = (void *)lru;
1450 if (f->type == OBJ_BLOB)
1451 release_delta_base_cache(f);
1452 }
1453 for (lru = delta_base_cache_lru.next;
1454 delta_base_cached > delta_base_cache_limit
1455 && lru != &delta_base_cache_lru;
1456 lru = lru->next) {
1457 struct delta_base_cache_entry *f = (void *)lru;
1458 release_delta_base_cache(f);
1459 }
1460
1461 ent->p = p;
1462 ent->base_offset = base_offset;
1463 ent->type = type;
1464 ent->data = base;
1465 ent->size = base_size;
1466 ent->lru.next = &delta_base_cache_lru;
1467 ent->lru.prev = delta_base_cache_lru.prev;
1468 delta_base_cache_lru.prev->next = &ent->lru;
1469 delta_base_cache_lru.prev = &ent->lru;
1470 }
1471
1472 static void *unpack_delta_entry(struct packed_git *p,
1473 struct pack_window **w_curs,
1474 off_t curpos,
1475 unsigned long delta_size,
1476 off_t obj_offset,
1477 enum object_type *type,
1478 unsigned long *sizep)
1479 {
1480 void *delta_data, *result, *base;
1481 unsigned long base_size;
1482 off_t base_offset;
1483
1484 base_offset = get_delta_base(p, w_curs, &curpos, *type, obj_offset);
1485 base = cache_or_unpack_entry(p, base_offset, &base_size, type, 0);
1486 if (!base)
1487 die("failed to read delta base object"
1488 " at %"PRIuMAX" from %s",
1489 (uintmax_t)base_offset, p->pack_name);
1490
1491 delta_data = unpack_compressed_entry(p, w_curs, curpos, delta_size);
1492 result = patch_delta(base, base_size,
1493 delta_data, delta_size,
1494 sizep);
1495 if (!result)
1496 die("failed to apply delta");
1497 free(delta_data);
1498 add_delta_base_cache(p, base_offset, base, base_size, *type);
1499 return result;
1500 }
1501
1502 void *unpack_entry(struct packed_git *p, off_t obj_offset,
1503 enum object_type *type, unsigned long *sizep)
1504 {
1505 struct pack_window *w_curs = NULL;
1506 off_t curpos = obj_offset;
1507 void *data;
1508
1509 *type = unpack_object_header(p, &w_curs, &curpos, sizep);
1510 switch (*type) {
1511 case OBJ_OFS_DELTA:
1512 case OBJ_REF_DELTA:
1513 data = unpack_delta_entry(p, &w_curs, curpos, *sizep,
1514 obj_offset, type, sizep);
1515 break;
1516 case OBJ_COMMIT:
1517 case OBJ_TREE:
1518 case OBJ_BLOB:
1519 case OBJ_TAG:
1520 data = unpack_compressed_entry(p, &w_curs, curpos, *sizep);
1521 break;
1522 default:
1523 die("unknown object type %i in %s", *type, p->pack_name);
1524 }
1525 unuse_pack(&w_curs);
1526 return data;
1527 }
1528
1529 uint32_t num_packed_objects(const struct packed_git *p)
1530 {
1531 /* See check_packed_git_idx() */
1532 return (uint32_t)((p->index_size - 20 - 20 - 4*256) / 24);
1533 }
1534
1535 int nth_packed_object_sha1(const struct packed_git *p, uint32_t n,
1536 unsigned char* sha1)
1537 {
1538 const unsigned char *index = p->index_data;
1539 index += 4 * 256;
1540 if (num_packed_objects(p) <= n)
1541 return -1;
1542 hashcpy(sha1, index + 24 * n + 4);
1543 return 0;
1544 }
1545
1546 off_t find_pack_entry_one(const unsigned char *sha1,
1547 struct packed_git *p)
1548 {
1549 const uint32_t *level1_ofs = p->index_data;
1550 int hi = ntohl(level1_ofs[*sha1]);
1551 int lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
1552 const unsigned char *index = p->index_data;
1553
1554 index += 4 * 256;
1555
1556 do {
1557 int mi = (lo + hi) / 2;
1558 int cmp = hashcmp(index + 24 * mi + 4, sha1);
1559 if (!cmp)
1560 return ntohl(*((uint32_t *)((char *)index + (24 * mi))));
1561 if (cmp > 0)
1562 hi = mi;
1563 else
1564 lo = mi+1;
1565 } while (lo < hi);
1566 return 0;
1567 }
1568
1569 static int matches_pack_name(struct packed_git *p, const char *ig)
1570 {
1571 const char *last_c, *c;
1572
1573 if (!strcmp(p->pack_name, ig))
1574 return 0;
1575
1576 for (c = p->pack_name, last_c = c; *c;)
1577 if (*c == '/')
1578 last_c = ++c;
1579 else
1580 ++c;
1581 if (!strcmp(last_c, ig))
1582 return 0;
1583
1584 return 1;
1585 }
1586
1587 static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e, const char **ignore_packed)
1588 {
1589 struct packed_git *p;
1590 off_t offset;
1591
1592 prepare_packed_git();
1593
1594 for (p = packed_git; p; p = p->next) {
1595 if (ignore_packed) {
1596 const char **ig;
1597 for (ig = ignore_packed; *ig; ig++)
1598 if (!matches_pack_name(p, *ig))
1599 break;
1600 if (*ig)
1601 continue;
1602 }
1603 offset = find_pack_entry_one(sha1, p);
1604 if (offset) {
1605 /*
1606 * We are about to tell the caller where they can
1607 * locate the requested object. We better make
1608 * sure the packfile is still here and can be
1609 * accessed before supplying that answer, as
1610 * it may have been deleted since the index
1611 * was loaded!
1612 */
1613 if (p->pack_fd == -1 && open_packed_git(p)) {
1614 error("packfile %s cannot be accessed", p->pack_name);
1615 continue;
1616 }
1617 e->offset = offset;
1618 e->p = p;
1619 hashcpy(e->sha1, sha1);
1620 return 1;
1621 }
1622 }
1623 return 0;
1624 }
1625
1626 struct packed_git *find_sha1_pack(const unsigned char *sha1,
1627 struct packed_git *packs)
1628 {
1629 struct packed_git *p;
1630
1631 for (p = packs; p; p = p->next) {
1632 if (find_pack_entry_one(sha1, p))
1633 return p;
1634 }
1635 return NULL;
1636
1637 }
1638
1639 static int sha1_loose_object_info(const unsigned char *sha1, unsigned long *sizep)
1640 {
1641 int status;
1642 unsigned long mapsize, size;
1643 void *map;
1644 z_stream stream;
1645 char hdr[32];
1646
1647 map = map_sha1_file(sha1, &mapsize);
1648 if (!map)
1649 return error("unable to find %s", sha1_to_hex(sha1));
1650 if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
1651 status = error("unable to unpack %s header",
1652 sha1_to_hex(sha1));
1653 else if ((status = parse_sha1_header(hdr, &size)) < 0)
1654 status = error("unable to parse %s header", sha1_to_hex(sha1));
1655 else if (sizep)
1656 *sizep = size;
1657 inflateEnd(&stream);
1658 munmap(map, mapsize);
1659 return status;
1660 }
1661
1662 int sha1_object_info(const unsigned char *sha1, unsigned long *sizep)
1663 {
1664 struct pack_entry e;
1665
1666 if (!find_pack_entry(sha1, &e, NULL)) {
1667 reprepare_packed_git();
1668 if (!find_pack_entry(sha1, &e, NULL))
1669 return sha1_loose_object_info(sha1, sizep);
1670 }
1671 return packed_object_info(e.p, e.offset, sizep);
1672 }
1673
1674 static void *read_packed_sha1(const unsigned char *sha1,
1675 enum object_type *type, unsigned long *size)
1676 {
1677 struct pack_entry e;
1678
1679 if (!find_pack_entry(sha1, &e, NULL))
1680 return NULL;
1681 else
1682 return cache_or_unpack_entry(e.p, e.offset, size, type, 1);
1683 }
1684
1685 /*
1686 * This is meant to hold a *small* number of objects that you would
1687 * want read_sha1_file() to be able to return, but yet you do not want
1688 * to write them into the object store (e.g. a browse-only
1689 * application).
1690 */
1691 static struct cached_object {
1692 unsigned char sha1[20];
1693 enum object_type type;
1694 void *buf;
1695 unsigned long size;
1696 } *cached_objects;
1697 static int cached_object_nr, cached_object_alloc;
1698
1699 static struct cached_object *find_cached_object(const unsigned char *sha1)
1700 {
1701 int i;
1702 struct cached_object *co = cached_objects;
1703
1704 for (i = 0; i < cached_object_nr; i++, co++) {
1705 if (!hashcmp(co->sha1, sha1))
1706 return co;
1707 }
1708 return NULL;
1709 }
1710
1711 int pretend_sha1_file(void *buf, unsigned long len, enum object_type type,
1712 unsigned char *sha1)
1713 {
1714 struct cached_object *co;
1715
1716 hash_sha1_file(buf, len, typename(type), sha1);
1717 if (has_sha1_file(sha1) || find_cached_object(sha1))
1718 return 0;
1719 if (cached_object_alloc <= cached_object_nr) {
1720 cached_object_alloc = alloc_nr(cached_object_alloc);
1721 cached_objects = xrealloc(cached_objects,
1722 sizeof(*cached_objects) *
1723 cached_object_alloc);
1724 }
1725 co = &cached_objects[cached_object_nr++];
1726 co->size = len;
1727 co->type = type;
1728 co->buf = xmalloc(len);
1729 memcpy(co->buf, buf, len);
1730 hashcpy(co->sha1, sha1);
1731 return 0;
1732 }
1733
1734 void *read_sha1_file(const unsigned char *sha1, enum object_type *type,
1735 unsigned long *size)
1736 {
1737 unsigned long mapsize;
1738 void *map, *buf;
1739 struct cached_object *co;
1740
1741 co = find_cached_object(sha1);
1742 if (co) {
1743 buf = xmalloc(co->size + 1);
1744 memcpy(buf, co->buf, co->size);
1745 ((char*)buf)[co->size] = 0;
1746 *type = co->type;
1747 *size = co->size;
1748 return buf;
1749 }
1750
1751 buf = read_packed_sha1(sha1, type, size);
1752 if (buf)
1753 return buf;
1754 map = map_sha1_file(sha1, &mapsize);
1755 if (map) {
1756 buf = unpack_sha1_file(map, mapsize, type, size, sha1);
1757 munmap(map, mapsize);
1758 return buf;
1759 }
1760 reprepare_packed_git();
1761 return read_packed_sha1(sha1, type, size);
1762 }
1763
1764 void *read_object_with_reference(const unsigned char *sha1,
1765 const char *required_type_name,
1766 unsigned long *size,
1767 unsigned char *actual_sha1_return)
1768 {
1769 enum object_type type, required_type;
1770 void *buffer;
1771 unsigned long isize;
1772 unsigned char actual_sha1[20];
1773
1774 required_type = type_from_string(required_type_name);
1775 hashcpy(actual_sha1, sha1);
1776 while (1) {
1777 int ref_length = -1;
1778 const char *ref_type = NULL;
1779
1780 buffer = read_sha1_file(actual_sha1, &type, &isize);
1781 if (!buffer)
1782 return NULL;
1783 if (type == required_type) {
1784 *size = isize;
1785 if (actual_sha1_return)
1786 hashcpy(actual_sha1_return, actual_sha1);
1787 return buffer;
1788 }
1789 /* Handle references */
1790 else if (type == OBJ_COMMIT)
1791 ref_type = "tree ";
1792 else if (type == OBJ_TAG)
1793 ref_type = "object ";
1794 else {
1795 free(buffer);
1796 return NULL;
1797 }
1798 ref_length = strlen(ref_type);
1799
1800 if (memcmp(buffer, ref_type, ref_length) ||
1801 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
1802 free(buffer);
1803 return NULL;
1804 }
1805 free(buffer);
1806 /* Now we have the ID of the referred-to object in
1807 * actual_sha1. Check again. */
1808 }
1809 }
1810
1811 static void write_sha1_file_prepare(const void *buf, unsigned long len,
1812 const char *type, unsigned char *sha1,
1813 char *hdr, int *hdrlen)
1814 {
1815 SHA_CTX c;
1816
1817 /* Generate the header */
1818 *hdrlen = sprintf(hdr, "%s %lu", type, len)+1;
1819
1820 /* Sha1.. */
1821 SHA1_Init(&c);
1822 SHA1_Update(&c, hdr, *hdrlen);
1823 SHA1_Update(&c, buf, len);
1824 SHA1_Final(sha1, &c);
1825 }
1826
1827 /*
1828 * Link the tempfile to the final place, possibly creating the
1829 * last directory level as you do so.
1830 *
1831 * Returns the errno on failure, 0 on success.
1832 */
1833 static int link_temp_to_file(const char *tmpfile, const char *filename)
1834 {
1835 int ret;
1836 char *dir;
1837
1838 if (!link(tmpfile, filename))
1839 return 0;
1840
1841 /*
1842 * Try to mkdir the last path component if that failed.
1843 *
1844 * Re-try the "link()" regardless of whether the mkdir
1845 * succeeds, since a race might mean that somebody
1846 * else succeeded.
1847 */
1848 ret = errno;
1849 dir = strrchr(filename, '/');
1850 if (dir) {
1851 *dir = 0;
1852 if (!mkdir(filename, 0777) && adjust_shared_perm(filename)) {
1853 *dir = '/';
1854 return -2;
1855 }
1856 *dir = '/';
1857 if (!link(tmpfile, filename))
1858 return 0;
1859 ret = errno;
1860 }
1861 return ret;
1862 }
1863
1864 /*
1865 * Move the just written object into its final resting place
1866 */
1867 int move_temp_to_file(const char *tmpfile, const char *filename)
1868 {
1869 int ret = link_temp_to_file(tmpfile, filename);
1870
1871 /*
1872 * Coda hack - coda doesn't like cross-directory links,
1873 * so we fall back to a rename, which will mean that it
1874 * won't be able to check collisions, but that's not a
1875 * big deal.
1876 *
1877 * The same holds for FAT formatted media.
1878 *
1879 * When this succeeds, we just return 0. We have nothing
1880 * left to unlink.
1881 */
1882 if (ret && ret != EEXIST) {
1883 if (!rename(tmpfile, filename))
1884 return 0;
1885 ret = errno;
1886 }
1887 unlink(tmpfile);
1888 if (ret) {
1889 if (ret != EEXIST) {
1890 return error("unable to write sha1 filename %s: %s\n", filename, strerror(ret));
1891 }
1892 /* FIXME!!! Collision check here ? */
1893 }
1894
1895 return 0;
1896 }
1897
1898 static int write_buffer(int fd, const void *buf, size_t len)
1899 {
1900 if (write_in_full(fd, buf, len) < 0)
1901 return error("file write error (%s)", strerror(errno));
1902 return 0;
1903 }
1904
1905 static int write_binary_header(unsigned char *hdr, enum object_type type, unsigned long len)
1906 {
1907 int hdr_len;
1908 unsigned char c;
1909
1910 c = (type << 4) | (len & 15);
1911 len >>= 4;
1912 hdr_len = 1;
1913 while (len) {
1914 *hdr++ = c | 0x80;
1915 hdr_len++;
1916 c = (len & 0x7f);
1917 len >>= 7;
1918 }
1919 *hdr = c;
1920 return hdr_len;
1921 }
1922
1923 static void setup_object_header(z_stream *stream, const char *type, unsigned long len)
1924 {
1925 int obj_type, hdrlen;
1926
1927 if (use_legacy_headers) {
1928 while (deflate(stream, 0) == Z_OK)
1929 /* nothing */;
1930 return;
1931 }
1932 obj_type = type_from_string(type);
1933 hdrlen = write_binary_header(stream->next_out, obj_type, len);
1934 stream->total_out = hdrlen;
1935 stream->next_out += hdrlen;
1936 stream->avail_out -= hdrlen;
1937 }
1938
1939 int hash_sha1_file(const void *buf, unsigned long len, const char *type,
1940 unsigned char *sha1)
1941 {
1942 char hdr[32];
1943 int hdrlen;
1944 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
1945 return 0;
1946 }
1947
1948 int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
1949 {
1950 int size, ret;
1951 unsigned char *compressed;
1952 z_stream stream;
1953 unsigned char sha1[20];
1954 char *filename;
1955 static char tmpfile[PATH_MAX];
1956 char hdr[32];
1957 int fd, hdrlen;
1958
1959 /* Normally if we have it in the pack then we do not bother writing
1960 * it out into .git/objects/??/?{38} file.
1961 */
1962 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
1963 filename = sha1_file_name(sha1);
1964 if (returnsha1)
1965 hashcpy(returnsha1, sha1);
1966 if (has_sha1_file(sha1))
1967 return 0;
1968 fd = open(filename, O_RDONLY);
1969 if (fd >= 0) {
1970 /*
1971 * FIXME!!! We might do collision checking here, but we'd
1972 * need to uncompress the old file and check it. Later.
1973 */
1974 close(fd);
1975 return 0;
1976 }
1977
1978 if (errno != ENOENT) {
1979 return error("sha1 file %s: %s\n", filename, strerror(errno));
1980 }
1981
1982 snprintf(tmpfile, sizeof(tmpfile), "%s/tmp_obj_XXXXXX", get_object_directory());
1983
1984 fd = mkstemp(tmpfile);
1985 if (fd < 0) {
1986 if (errno == EPERM)
1987 return error("insufficient permission for adding an object to repository database %s\n", get_object_directory());
1988 else
1989 return error("unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
1990 }
1991
1992 /* Set it up */
1993 memset(&stream, 0, sizeof(stream));
1994 deflateInit(&stream, zlib_compression_level);
1995 size = 8 + deflateBound(&stream, len+hdrlen);
1996 compressed = xmalloc(size);
1997
1998 /* Compress it */
1999 stream.next_out = compressed;
2000 stream.avail_out = size;
2001
2002 /* First header.. */
2003 stream.next_in = (unsigned char *)hdr;
2004 stream.avail_in = hdrlen;
2005 setup_object_header(&stream, type, len);
2006
2007 /* Then the data itself.. */
2008 stream.next_in = buf;
2009 stream.avail_in = len;
2010 ret = deflate(&stream, Z_FINISH);
2011 if (ret != Z_STREAM_END)
2012 die("unable to deflate new object %s (%d)", sha1_to_hex(sha1), ret);
2013
2014 ret = deflateEnd(&stream);
2015 if (ret != Z_OK)
2016 die("deflateEnd on object %s failed (%d)", sha1_to_hex(sha1), ret);
2017
2018 size = stream.total_out;
2019
2020 if (write_buffer(fd, compressed, size) < 0)
2021 die("unable to write sha1 file");
2022 fchmod(fd, 0444);
2023 if (close(fd))
2024 die("unable to write sha1 file");
2025 free(compressed);
2026
2027 return move_temp_to_file(tmpfile, filename);
2028 }
2029
2030 /*
2031 * We need to unpack and recompress the object for writing
2032 * it out to a different file.
2033 */
2034 static void *repack_object(const unsigned char *sha1, unsigned long *objsize)
2035 {
2036 size_t size;
2037 z_stream stream;
2038 unsigned char *unpacked;
2039 unsigned long len;
2040 enum object_type type;
2041 char hdr[32];
2042 int hdrlen;
2043 void *buf;
2044
2045 /* need to unpack and recompress it by itself */
2046 unpacked = read_packed_sha1(sha1, &type, &len);
2047 if (!unpacked)
2048 error("cannot read sha1_file for %s", sha1_to_hex(sha1));
2049
2050 hdrlen = sprintf(hdr, "%s %lu", typename(type), len) + 1;
2051
2052 /* Set it up */
2053 memset(&stream, 0, sizeof(stream));
2054 deflateInit(&stream, zlib_compression_level);
2055 size = deflateBound(&stream, len + hdrlen);
2056 buf = xmalloc(size);
2057
2058 /* Compress it */
2059 stream.next_out = buf;
2060 stream.avail_out = size;
2061
2062 /* First header.. */
2063 stream.next_in = (void *)hdr;
2064 stream.avail_in = hdrlen;
2065 while (deflate(&stream, 0) == Z_OK)
2066 /* nothing */;
2067
2068 /* Then the data itself.. */
2069 stream.next_in = unpacked;
2070 stream.avail_in = len;
2071 while (deflate(&stream, Z_FINISH) == Z_OK)
2072 /* nothing */;
2073 deflateEnd(&stream);
2074 free(unpacked);
2075
2076 *objsize = stream.total_out;
2077 return buf;
2078 }
2079
2080 int write_sha1_to_fd(int fd, const unsigned char *sha1)
2081 {
2082 int retval;
2083 unsigned long objsize;
2084 void *buf = map_sha1_file(sha1, &objsize);
2085
2086 if (buf) {
2087 retval = write_buffer(fd, buf, objsize);
2088 munmap(buf, objsize);
2089 return retval;
2090 }
2091
2092 buf = repack_object(sha1, &objsize);
2093 retval = write_buffer(fd, buf, objsize);
2094 free(buf);
2095 return retval;
2096 }
2097
2098 int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
2099 size_t bufsize, size_t *bufposn)
2100 {
2101 char tmpfile[PATH_MAX];
2102 int local;
2103 z_stream stream;
2104 unsigned char real_sha1[20];
2105 unsigned char discard[4096];
2106 int ret;
2107 SHA_CTX c;
2108
2109 snprintf(tmpfile, sizeof(tmpfile), "%s/tmp_obj_XXXXXX", get_object_directory());
2110
2111 local = mkstemp(tmpfile);
2112 if (local < 0) {
2113 if (errno == EPERM)
2114 return error("insufficient permission for adding an object to repository database %s\n", get_object_directory());
2115 else
2116 return error("unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
2117 }
2118
2119 memset(&stream, 0, sizeof(stream));
2120
2121 inflateInit(&stream);
2122
2123 SHA1_Init(&c);
2124
2125 do {
2126 ssize_t size;
2127 if (*bufposn) {
2128 stream.avail_in = *bufposn;
2129 stream.next_in = (unsigned char *) buffer;
2130 do {
2131 stream.next_out = discard;
2132 stream.avail_out = sizeof(discard);
2133 ret = inflate(&stream, Z_SYNC_FLUSH);
2134 SHA1_Update(&c, discard, sizeof(discard) -
2135 stream.avail_out);
2136 } while (stream.avail_in && ret == Z_OK);
2137 if (write_buffer(local, buffer, *bufposn - stream.avail_in) < 0)
2138 die("unable to write sha1 file");
2139 memmove(buffer, buffer + *bufposn - stream.avail_in,
2140 stream.avail_in);
2141 *bufposn = stream.avail_in;
2142 if (ret != Z_OK)
2143 break;
2144 }
2145 size = xread(fd, buffer + *bufposn, bufsize - *bufposn);
2146 if (size <= 0) {
2147 close(local);
2148 unlink(tmpfile);
2149 if (!size)
2150 return error("Connection closed?");
2151 perror("Reading from connection");
2152 return -1;
2153 }
2154 *bufposn += size;
2155 } while (1);
2156 inflateEnd(&stream);
2157
2158 fchmod(local, 0444);
2159 if (close(local) != 0)
2160 die("unable to write sha1 file");
2161 SHA1_Final(real_sha1, &c);
2162 if (ret != Z_STREAM_END) {
2163 unlink(tmpfile);
2164 return error("File %s corrupted", sha1_to_hex(sha1));
2165 }
2166 if (hashcmp(sha1, real_sha1)) {
2167 unlink(tmpfile);
2168 return error("File %s has bad hash", sha1_to_hex(sha1));
2169 }
2170
2171 return move_temp_to_file(tmpfile, sha1_file_name(sha1));
2172 }
2173
2174 int has_pack_index(const unsigned char *sha1)
2175 {
2176 struct stat st;
2177 if (stat(sha1_pack_index_name(sha1), &st))
2178 return 0;
2179 return 1;
2180 }
2181
2182 int has_pack_file(const unsigned char *sha1)
2183 {
2184 struct stat st;
2185 if (stat(sha1_pack_name(sha1), &st))
2186 return 0;
2187 return 1;
2188 }
2189
2190 int has_sha1_pack(const unsigned char *sha1, const char **ignore_packed)
2191 {
2192 struct pack_entry e;
2193 return find_pack_entry(sha1, &e, ignore_packed);
2194 }
2195
2196 int has_sha1_file(const unsigned char *sha1)
2197 {
2198 struct stat st;
2199 struct pack_entry e;
2200
2201 if (find_pack_entry(sha1, &e, NULL))
2202 return 1;
2203 return find_sha1_file(sha1, &st) ? 1 : 0;
2204 }
2205
2206 /*
2207 * reads from fd as long as possible into a supplied buffer of size bytes.
2208 * If necessary the buffer's size is increased using realloc()
2209 *
2210 * returns 0 if anything went fine and -1 otherwise
2211 *
2212 * NOTE: both buf and size may change, but even when -1 is returned
2213 * you still have to free() it yourself.
2214 */
2215 int read_pipe(int fd, char** return_buf, unsigned long* return_size)
2216 {
2217 char* buf = *return_buf;
2218 unsigned long size = *return_size;
2219 int iret;
2220 unsigned long off = 0;
2221
2222 do {
2223 iret = xread(fd, buf + off, size - off);
2224 if (iret > 0) {
2225 off += iret;
2226 if (off == size) {
2227 size *= 2;
2228 buf = xrealloc(buf, size);
2229 }
2230 }
2231 } while (iret > 0);
2232
2233 *return_buf = buf;
2234 *return_size = off;
2235
2236 if (iret < 0)
2237 return -1;
2238 return 0;
2239 }
2240
2241 int index_pipe(unsigned char *sha1, int fd, const char *type, int write_object)
2242 {
2243 unsigned long size = 4096;
2244 char *buf = xmalloc(size);
2245 int ret;
2246
2247 if (read_pipe(fd, &buf, &size)) {
2248 free(buf);
2249 return -1;
2250 }
2251
2252 if (!type)
2253 type = blob_type;
2254 if (write_object)
2255 ret = write_sha1_file(buf, size, type, sha1);
2256 else
2257 ret = hash_sha1_file(buf, size, type, sha1);
2258 free(buf);
2259 return ret;
2260 }
2261
2262 int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object,
2263 enum object_type type, const char *path)
2264 {
2265 size_t size = xsize_t(st->st_size);
2266 void *buf = NULL;
2267 int ret, re_allocated = 0;
2268
2269 if (size)
2270 buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
2271 close(fd);
2272
2273 if (!type)
2274 type = OBJ_BLOB;
2275
2276 /*
2277 * Convert blobs to git internal format
2278 */
2279 if ((type == OBJ_BLOB) && S_ISREG(st->st_mode)) {
2280 unsigned long nsize = size;
2281 char *nbuf = buf;
2282 if (convert_to_git(path, &nbuf, &nsize)) {
2283 if (size)
2284 munmap(buf, size);
2285 size = nsize;
2286 buf = nbuf;
2287 re_allocated = 1;
2288 }
2289 }
2290
2291 if (write_object)
2292 ret = write_sha1_file(buf, size, typename(type), sha1);
2293 else
2294 ret = hash_sha1_file(buf, size, typename(type), sha1);
2295 if (re_allocated) {
2296 free(buf);
2297 return ret;
2298 }
2299 if (size)
2300 munmap(buf, size);
2301 return ret;
2302 }
2303
2304 int index_path(unsigned char *sha1, const char *path, struct stat *st, int write_object)
2305 {
2306 int fd;
2307 char *target;
2308 size_t len;
2309
2310 switch (st->st_mode & S_IFMT) {
2311 case S_IFREG:
2312 fd = open(path, O_RDONLY);
2313 if (fd < 0)
2314 return error("open(\"%s\"): %s", path,
2315 strerror(errno));
2316 if (index_fd(sha1, fd, st, write_object, OBJ_BLOB, path) < 0)
2317 return error("%s: failed to insert into database",
2318 path);
2319 break;
2320 case S_IFLNK:
2321 len = xsize_t(st->st_size);
2322 target = xmalloc(len + 1);
2323 if (readlink(path, target, len + 1) != st->st_size) {
2324 char *errstr = strerror(errno);
2325 free(target);
2326 return error("readlink(\"%s\"): %s", path,
2327 errstr);
2328 }
2329 if (!write_object)
2330 hash_sha1_file(target, len, blob_type, sha1);
2331 else if (write_sha1_file(target, len, blob_type, sha1))
2332 return error("%s: failed to insert into database",
2333 path);
2334 free(target);
2335 break;
2336 default:
2337 return error("%s: unsupported file type", path);
2338 }
2339 return 0;
2340 }
2341
2342 int read_pack_header(int fd, struct pack_header *header)
2343 {
2344 char *c = (char*)header;
2345 ssize_t remaining = sizeof(struct pack_header);
2346 do {
2347 ssize_t r = xread(fd, c, remaining);
2348 if (r <= 0)
2349 /* "eof before pack header was fully read" */
2350 return PH_ERROR_EOF;
2351 remaining -= r;
2352 c += r;
2353 } while (remaining > 0);
2354 if (header->hdr_signature != htonl(PACK_SIGNATURE))
2355 /* "protocol error (pack signature mismatch detected)" */
2356 return PH_ERROR_PACK_SIGNATURE;
2357 if (!pack_version_ok(header->hdr_version))
2358 /* "protocol error (pack version unsupported)" */
2359 return PH_ERROR_PROTOCOL;
2360 return 0;
2361 }