Code

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