Merge part of 'sp/checkout'
[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
13 #ifndef O_NOATIME
14 #if defined(__linux__) && (defined(__i386__) || defined(__PPC__))
15 #define O_NOATIME 01000000
16 #else
17 #define O_NOATIME 0
18 #endif
19 #endif
20
21 const unsigned char null_sha1[20] = { 0, };
22
23 static unsigned int sha1_file_open_flag = O_NOATIME;
24
25 static unsigned hexval(char c)
26 {
27         if (c >= '0' && c <= '9')
28                 return c - '0';
29         if (c >= 'a' && c <= 'f')
30                 return c - 'a' + 10;
31         if (c >= 'A' && c <= 'F')
32                 return c - 'A' + 10;
33         return ~0;
34 }
35
36 int get_sha1_hex(const char *hex, unsigned char *sha1)
37 {
38         int i;
39         for (i = 0; i < 20; i++) {
40                 unsigned int val = (hexval(hex[0]) << 4) | hexval(hex[1]);
41                 if (val & ~0xff)
42                         return -1;
43                 *sha1++ = val;
44                 hex += 2;
45         }
46         return 0;
47 }
48
49 int adjust_shared_perm(const char *path)
50 {
51         struct stat st;
52         int mode;
53
54         if (!shared_repository)
55                 return 0;
56         if (lstat(path, &st) < 0)
57                 return -1;
58         mode = st.st_mode;
59         if (mode & S_IRUSR)
60                 mode |= S_IRGRP;
61         if (mode & S_IWUSR)
62                 mode |= S_IWGRP;
63         if (mode & S_IXUSR)
64                 mode |= S_IXGRP;
65         if (S_ISDIR(mode))
66                 mode |= S_ISGID;
67         if (chmod(path, mode) < 0)
68                 return -2;
69         return 0;
70 }
71
72 int safe_create_leading_directories(char *path)
73 {
74         char *pos = path;
75         struct stat st;
76
77         if (*pos == '/')
78                 pos++;
79
80         while (pos) {
81                 pos = strchr(pos, '/');
82                 if (!pos)
83                         break;
84                 *pos = 0;
85                 if (!stat(path, &st)) {
86                         /* path exists */
87                         if (!S_ISDIR(st.st_mode)) {
88                                 *pos = '/';
89                                 return -3;
90                         }
91                 }
92                 else if (mkdir(path, 0777)) {
93                         *pos = '/';
94                         return -1;
95                 }
96                 else if (adjust_shared_perm(path)) {
97                         *pos = '/';
98                         return -2;
99                 }
100                 *pos++ = '/';
101         }
102         return 0;
103 }
104
105 char * sha1_to_hex(const unsigned char *sha1)
106 {
107         static char buffer[50];
108         static const char hex[] = "0123456789abcdef";
109         char *buf = buffer;
110         int i;
111
112         for (i = 0; i < 20; i++) {
113                 unsigned int val = *sha1++;
114                 *buf++ = hex[val >> 4];
115                 *buf++ = hex[val & 0xf];
116         }
117         *buf = '\0';
118
119         return buffer;
120 }
121
122 static void fill_sha1_path(char *pathbuf, const unsigned char *sha1)
123 {
124         int i;
125         for (i = 0; i < 20; i++) {
126                 static char hex[] = "0123456789abcdef";
127                 unsigned int val = sha1[i];
128                 char *pos = pathbuf + i*2 + (i > 0);
129                 *pos++ = hex[val >> 4];
130                 *pos = hex[val & 0xf];
131         }
132 }
133
134 /*
135  * NOTE! This returns a statically allocated buffer, so you have to be
136  * careful about using it. Do a "strdup()" if you need to save the
137  * filename.
138  *
139  * Also note that this returns the location for creating.  Reading
140  * SHA1 file can happen from any alternate directory listed in the
141  * DB_ENVIRONMENT environment variable if it is not found in
142  * the primary object database.
143  */
144 char *sha1_file_name(const unsigned char *sha1)
145 {
146         static char *name, *base;
147
148         if (!base) {
149                 const char *sha1_file_directory = get_object_directory();
150                 int len = strlen(sha1_file_directory);
151                 base = xmalloc(len + 60);
152                 memcpy(base, sha1_file_directory, len);
153                 memset(base+len, 0, 60);
154                 base[len] = '/';
155                 base[len+3] = '/';
156                 name = base + len + 1;
157         }
158         fill_sha1_path(name, sha1);
159         return base;
160 }
161
162 char *sha1_pack_name(const unsigned char *sha1)
163 {
164         static const char hex[] = "0123456789abcdef";
165         static char *name, *base, *buf;
166         int i;
167
168         if (!base) {
169                 const char *sha1_file_directory = get_object_directory();
170                 int len = strlen(sha1_file_directory);
171                 base = xmalloc(len + 60);
172                 sprintf(base, "%s/pack/pack-1234567890123456789012345678901234567890.pack", sha1_file_directory);
173                 name = base + len + 11;
174         }
175
176         buf = name;
177
178         for (i = 0; i < 20; i++) {
179                 unsigned int val = *sha1++;
180                 *buf++ = hex[val >> 4];
181                 *buf++ = hex[val & 0xf];
182         }
183         
184         return base;
185 }
186
187 char *sha1_pack_index_name(const unsigned char *sha1)
188 {
189         static const char hex[] = "0123456789abcdef";
190         static char *name, *base, *buf;
191         int i;
192
193         if (!base) {
194                 const char *sha1_file_directory = get_object_directory();
195                 int len = strlen(sha1_file_directory);
196                 base = xmalloc(len + 60);
197                 sprintf(base, "%s/pack/pack-1234567890123456789012345678901234567890.idx", sha1_file_directory);
198                 name = base + len + 11;
199         }
200
201         buf = name;
202
203         for (i = 0; i < 20; i++) {
204                 unsigned int val = *sha1++;
205                 *buf++ = hex[val >> 4];
206                 *buf++ = hex[val & 0xf];
207         }
208         
209         return base;
210 }
211
212 struct alternate_object_database *alt_odb_list;
213 static struct alternate_object_database **alt_odb_tail;
214
215 /*
216  * Prepare alternate object database registry.
217  *
218  * The variable alt_odb_list points at the list of struct
219  * alternate_object_database.  The elements on this list come from
220  * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
221  * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
222  * whose contents is similar to that environment variable but can be
223  * LF separated.  Its base points at a statically allocated buffer that
224  * contains "/the/directory/corresponding/to/.git/objects/...", while
225  * its name points just after the slash at the end of ".git/objects/"
226  * in the example above, and has enough space to hold 40-byte hex
227  * SHA1, an extra slash for the first level indirection, and the
228  * terminating NUL.
229  */
230 static void link_alt_odb_entries(const char *alt, const char *ep, int sep,
231                                  const char *relative_base)
232 {
233         const char *cp, *last;
234         struct alternate_object_database *ent;
235         const char *objdir = get_object_directory();
236         int base_len = -1;
237
238         last = alt;
239         while (last < ep) {
240                 cp = last;
241                 if (cp < ep && *cp == '#') {
242                         while (cp < ep && *cp != sep)
243                                 cp++;
244                         last = cp + 1;
245                         continue;
246                 }
247                 for ( ; cp < ep && *cp != sep; cp++)
248                         ;
249                 if (last != cp) {
250                         struct stat st;
251                         struct alternate_object_database *alt;
252                         /* 43 = 40-byte + 2 '/' + terminating NUL */
253                         int pfxlen = cp - last;
254                         int entlen = pfxlen + 43;
255
256                         if (*last != '/' && relative_base) {
257                                 /* Relative alt-odb */
258                                 if (base_len < 0)
259                                         base_len = strlen(relative_base) + 1;
260                                 entlen += base_len;
261                                 pfxlen += base_len;
262                         }
263                         ent = xmalloc(sizeof(*ent) + entlen);
264
265                         if (*last != '/' && relative_base) {
266                                 memcpy(ent->base, relative_base, base_len - 1);
267                                 ent->base[base_len - 1] = '/';
268                                 memcpy(ent->base + base_len,
269                                        last, cp - last);
270                         }
271                         else
272                                 memcpy(ent->base, last, pfxlen);
273
274                         ent->name = ent->base + pfxlen + 1;
275                         ent->base[pfxlen + 3] = '/';
276                         ent->base[pfxlen] = ent->base[entlen-1] = 0;
277
278                         /* Detect cases where alternate disappeared */
279                         if (stat(ent->base, &st) || !S_ISDIR(st.st_mode)) {
280                                 error("object directory %s does not exist; "
281                                       "check .git/objects/info/alternates.",
282                                       ent->base);
283                                 goto bad;
284                         }
285                         ent->base[pfxlen] = '/';
286
287                         /* Prevent the common mistake of listing the same
288                          * thing twice, or object directory itself.
289                          */
290                         for (alt = alt_odb_list; alt; alt = alt->next)
291                                 if (!memcmp(ent->base, alt->base, pfxlen))
292                                         goto bad;
293                         if (!memcmp(ent->base, objdir, pfxlen)) {
294                         bad:
295                                 free(ent);
296                         }
297                         else {
298                                 *alt_odb_tail = ent;
299                                 alt_odb_tail = &(ent->next);
300                                 ent->next = NULL;
301                         }
302                 }
303                 while (cp < ep && *cp == sep)
304                         cp++;
305                 last = cp;
306         }
307 }
308
309 void prepare_alt_odb(void)
310 {
311         char path[PATH_MAX];
312         char *map;
313         int fd;
314         struct stat st;
315         char *alt;
316
317         alt = getenv(ALTERNATE_DB_ENVIRONMENT);
318         if (!alt) alt = "";
319
320         if (alt_odb_tail)
321                 return;
322         alt_odb_tail = &alt_odb_list;
323         link_alt_odb_entries(alt, alt + strlen(alt), ':', NULL);
324
325         sprintf(path, "%s/info/alternates", get_object_directory());
326         fd = open(path, O_RDONLY);
327         if (fd < 0)
328                 return;
329         if (fstat(fd, &st) || (st.st_size == 0)) {
330                 close(fd);
331                 return;
332         }
333         map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
334         close(fd);
335         if (map == MAP_FAILED)
336                 return;
337
338         link_alt_odb_entries(map, map + st.st_size, '\n',
339                              get_object_directory());
340         munmap(map, st.st_size);
341 }
342
343 static char *find_sha1_file(const unsigned char *sha1, struct stat *st)
344 {
345         char *name = sha1_file_name(sha1);
346         struct alternate_object_database *alt;
347
348         if (!stat(name, st))
349                 return name;
350         prepare_alt_odb();
351         for (alt = alt_odb_list; alt; alt = alt->next) {
352                 name = alt->name;
353                 fill_sha1_path(name, sha1);
354                 if (!stat(alt->base, st))
355                         return alt->base;
356         }
357         return NULL;
358 }
359
360 #define PACK_MAX_SZ (1<<26)
361 static int pack_used_ctr;
362 static unsigned long pack_mapped;
363 struct packed_git *packed_git;
364
365 static int check_packed_git_idx(const char *path, unsigned long *idx_size_,
366                                 void **idx_map_)
367 {
368         void *idx_map;
369         unsigned int *index;
370         unsigned long idx_size;
371         int nr, i;
372         int fd = open(path, O_RDONLY);
373         struct stat st;
374         if (fd < 0)
375                 return -1;
376         if (fstat(fd, &st)) {
377                 close(fd);
378                 return -1;
379         }
380         idx_size = st.st_size;
381         idx_map = mmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
382         close(fd);
383         if (idx_map == MAP_FAILED)
384                 return -1;
385
386         index = idx_map;
387         *idx_map_ = idx_map;
388         *idx_size_ = idx_size;
389
390         /* check index map */
391         if (idx_size < 4*256 + 20 + 20)
392                 return error("index file too small");
393         nr = 0;
394         for (i = 0; i < 256; i++) {
395                 unsigned int n = ntohl(index[i]);
396                 if (n < nr)
397                         return error("non-monotonic index");
398                 nr = n;
399         }
400
401         /*
402          * Total size:
403          *  - 256 index entries 4 bytes each
404          *  - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
405          *  - 20-byte SHA1 of the packfile
406          *  - 20-byte SHA1 file checksum
407          */
408         if (idx_size != 4*256 + nr * 24 + 20 + 20)
409                 return error("wrong index file size");
410
411         return 0;
412 }
413
414 static int unuse_one_packed_git(void)
415 {
416         struct packed_git *p, *lru = NULL;
417
418         for (p = packed_git; p; p = p->next) {
419                 if (p->pack_use_cnt || !p->pack_base)
420                         continue;
421                 if (!lru || p->pack_last_used < lru->pack_last_used)
422                         lru = p;
423         }
424         if (!lru)
425                 return 0;
426         munmap(lru->pack_base, lru->pack_size);
427         lru->pack_base = NULL;
428         return 1;
429 }
430
431 void unuse_packed_git(struct packed_git *p)
432 {
433         p->pack_use_cnt--;
434 }
435
436 int use_packed_git(struct packed_git *p)
437 {
438         if (!p->pack_size) {
439                 struct stat st;
440                 // We created the struct before we had the pack
441                 stat(p->pack_name, &st);
442                 if (!S_ISREG(st.st_mode))
443                         die("packfile %s not a regular file", p->pack_name);
444                 p->pack_size = st.st_size;
445         }
446         if (!p->pack_base) {
447                 int fd;
448                 struct stat st;
449                 void *map;
450
451                 pack_mapped += p->pack_size;
452                 while (PACK_MAX_SZ < pack_mapped && unuse_one_packed_git())
453                         ; /* nothing */
454                 fd = open(p->pack_name, O_RDONLY);
455                 if (fd < 0)
456                         die("packfile %s cannot be opened", p->pack_name);
457                 if (fstat(fd, &st)) {
458                         close(fd);
459                         die("packfile %s cannot be opened", p->pack_name);
460                 }
461                 if (st.st_size != p->pack_size)
462                         die("packfile %s size mismatch.", p->pack_name);
463                 map = mmap(NULL, p->pack_size, PROT_READ, MAP_PRIVATE, fd, 0);
464                 close(fd);
465                 if (map == MAP_FAILED)
466                         die("packfile %s cannot be mapped.", p->pack_name);
467                 p->pack_base = map;
468
469                 /* Check if the pack file matches with the index file.
470                  * this is cheap.
471                  */
472                 if (memcmp((char*)(p->index_base) + p->index_size - 40,
473                            p->pack_base + p->pack_size - 20, 20)) {
474                               
475                         die("packfile %s does not match index.", p->pack_name);
476                 }
477         }
478         p->pack_last_used = pack_used_ctr++;
479         p->pack_use_cnt++;
480         return 0;
481 }
482
483 struct packed_git *add_packed_git(char *path, int path_len, int local)
484 {
485         struct stat st;
486         struct packed_git *p;
487         unsigned long idx_size;
488         void *idx_map;
489         unsigned char sha1[20];
490
491         if (check_packed_git_idx(path, &idx_size, &idx_map))
492                 return NULL;
493
494         /* do we have a corresponding .pack file? */
495         strcpy(path + path_len - 4, ".pack");
496         if (stat(path, &st) || !S_ISREG(st.st_mode)) {
497                 munmap(idx_map, idx_size);
498                 return NULL;
499         }
500         /* ok, it looks sane as far as we can check without
501          * actually mapping the pack file.
502          */
503         p = xmalloc(sizeof(*p) + path_len + 2);
504         strcpy(p->pack_name, path);
505         p->index_size = idx_size;
506         p->pack_size = st.st_size;
507         p->index_base = idx_map;
508         p->next = NULL;
509         p->pack_base = NULL;
510         p->pack_last_used = 0;
511         p->pack_use_cnt = 0;
512         p->pack_local = local;
513         if ((path_len > 44) && !get_sha1_hex(path + path_len - 44, sha1))
514                 memcpy(p->sha1, sha1, 20);
515         return p;
516 }
517
518 struct packed_git *parse_pack_index(unsigned char *sha1)
519 {
520         char *path = sha1_pack_index_name(sha1);
521         return parse_pack_index_file(sha1, path);
522 }
523
524 struct packed_git *parse_pack_index_file(const unsigned char *sha1, char *idx_path)
525 {
526         struct packed_git *p;
527         unsigned long idx_size;
528         void *idx_map;
529         char *path;
530
531         if (check_packed_git_idx(idx_path, &idx_size, &idx_map))
532                 return NULL;
533
534         path = sha1_pack_name(sha1);
535
536         p = xmalloc(sizeof(*p) + strlen(path) + 2);
537         strcpy(p->pack_name, path);
538         p->index_size = idx_size;
539         p->pack_size = 0;
540         p->index_base = idx_map;
541         p->next = NULL;
542         p->pack_base = NULL;
543         p->pack_last_used = 0;
544         p->pack_use_cnt = 0;
545         memcpy(p->sha1, sha1, 20);
546         return p;
547 }
548
549 void install_packed_git(struct packed_git *pack)
550 {
551         pack->next = packed_git;
552         packed_git = pack;
553 }
554
555 static void prepare_packed_git_one(char *objdir, int local)
556 {
557         char path[PATH_MAX];
558         int len;
559         DIR *dir;
560         struct dirent *de;
561
562         sprintf(path, "%s/pack", objdir);
563         len = strlen(path);
564         dir = opendir(path);
565         if (!dir) {
566                 if (errno != ENOENT)
567                         error("unable to open object pack directory: %s: %s",
568                               path, strerror(errno));
569                 return;
570         }
571         path[len++] = '/';
572         while ((de = readdir(dir)) != NULL) {
573                 int namelen = strlen(de->d_name);
574                 struct packed_git *p;
575
576                 if (strcmp(de->d_name + namelen - 4, ".idx"))
577                         continue;
578
579                 /* we have .idx.  Is it a file we can map? */
580                 strcpy(path + len, de->d_name);
581                 p = add_packed_git(path, len + namelen, local);
582                 if (!p)
583                         continue;
584                 p->next = packed_git;
585                 packed_git = p;
586         }
587         closedir(dir);
588 }
589
590 void prepare_packed_git(void)
591 {
592         static int run_once = 0;
593         struct alternate_object_database *alt;
594
595         if (run_once)
596                 return;
597         prepare_packed_git_one(get_object_directory(), 1);
598         prepare_alt_odb();
599         for (alt = alt_odb_list; alt; alt = alt->next) {
600                 alt->name[-1] = 0;
601                 prepare_packed_git_one(alt->base, 0);
602                 alt->name[-1] = '/';
603         }
604         run_once = 1;
605 }
606
607 int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long size, const char *type)
608 {
609         char header[100];
610         unsigned char real_sha1[20];
611         SHA_CTX c;
612
613         SHA1_Init(&c);
614         SHA1_Update(&c, header, 1+sprintf(header, "%s %lu", type, size));
615         SHA1_Update(&c, map, size);
616         SHA1_Final(real_sha1, &c);
617         return memcmp(sha1, real_sha1, 20) ? -1 : 0;
618 }
619
620 static void *map_sha1_file_internal(const unsigned char *sha1,
621                                     unsigned long *size)
622 {
623         struct stat st;
624         void *map;
625         int fd;
626         char *filename = find_sha1_file(sha1, &st);
627
628         if (!filename) {
629                 return NULL;
630         }
631
632         fd = open(filename, O_RDONLY | sha1_file_open_flag);
633         if (fd < 0) {
634                 /* See if it works without O_NOATIME */
635                 switch (sha1_file_open_flag) {
636                 default:
637                         fd = open(filename, O_RDONLY);
638                         if (fd >= 0)
639                                 break;
640                 /* Fallthrough */
641                 case 0:
642                         return NULL;
643                 }
644
645                 /* If it failed once, it will probably fail again.
646                  * Stop using O_NOATIME
647                  */
648                 sha1_file_open_flag = 0;
649         }
650         map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
651         close(fd);
652         if (map == MAP_FAILED)
653                 return NULL;
654         *size = st.st_size;
655         return map;
656 }
657
658 int unpack_sha1_header(z_stream *stream, void *map, unsigned long mapsize, void *buffer, unsigned long size)
659 {
660         /* Get the data stream */
661         memset(stream, 0, sizeof(*stream));
662         stream->next_in = map;
663         stream->avail_in = mapsize;
664         stream->next_out = buffer;
665         stream->avail_out = size;
666
667         inflateInit(stream);
668         return inflate(stream, 0);
669 }
670
671 static void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size)
672 {
673         int bytes = strlen(buffer) + 1;
674         unsigned char *buf = xmalloc(1+size);
675
676         memcpy(buf, buffer + bytes, stream->total_out - bytes);
677         bytes = stream->total_out - bytes;
678         if (bytes < size) {
679                 stream->next_out = buf + bytes;
680                 stream->avail_out = size - bytes;
681                 while (inflate(stream, Z_FINISH) == Z_OK)
682                         /* nothing */;
683         }
684         buf[size] = 0;
685         inflateEnd(stream);
686         return buf;
687 }
688
689 /*
690  * We used to just use "sscanf()", but that's actually way
691  * too permissive for what we want to check. So do an anal
692  * object header parse by hand.
693  */
694 int parse_sha1_header(char *hdr, char *type, unsigned long *sizep)
695 {
696         int i;
697         unsigned long size;
698
699         /*
700          * The type can be at most ten bytes (including the 
701          * terminating '\0' that we add), and is followed by
702          * a space. 
703          */
704         i = 10;
705         for (;;) {
706                 char c = *hdr++;
707                 if (c == ' ')
708                         break;
709                 if (!--i)
710                         return -1;
711                 *type++ = c;
712         }
713         *type = 0;
714
715         /*
716          * The length must follow immediately, and be in canonical
717          * decimal format (ie "010" is not valid).
718          */
719         size = *hdr++ - '0';
720         if (size > 9)
721                 return -1;
722         if (size) {
723                 for (;;) {
724                         unsigned long c = *hdr - '0';
725                         if (c > 9)
726                                 break;
727                         hdr++;
728                         size = size * 10 + c;
729                 }
730         }
731         *sizep = size;
732
733         /*
734          * The length must be followed by a zero byte
735          */
736         return *hdr ? -1 : 0;
737 }
738
739 void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size)
740 {
741         int ret;
742         z_stream stream;
743         char hdr[8192];
744
745         ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
746         if (ret < Z_OK || parse_sha1_header(hdr, type, size) < 0)
747                 return NULL;
748
749         return unpack_sha1_rest(&stream, hdr, *size);
750 }
751
752 /* forward declaration for a mutually recursive function */
753 static int packed_object_info(struct pack_entry *entry,
754                               char *type, unsigned long *sizep);
755
756 static int packed_delta_info(unsigned char *base_sha1,
757                              unsigned long delta_size,
758                              unsigned long left,
759                              char *type,
760                              unsigned long *sizep,
761                              struct packed_git *p)
762 {
763         struct pack_entry base_ent;
764
765         if (left < 20)
766                 die("truncated pack file");
767
768         /* The base entry _must_ be in the same pack */
769         if (!find_pack_entry_one(base_sha1, &base_ent, p))
770                 die("failed to find delta-pack base object %s",
771                     sha1_to_hex(base_sha1));
772
773         /* We choose to only get the type of the base object and
774          * ignore potentially corrupt pack file that expects the delta
775          * based on a base with a wrong size.  This saves tons of
776          * inflate() calls.
777          */
778
779         if (packed_object_info(&base_ent, type, NULL))
780                 die("cannot get info for delta-pack base");
781
782         if (sizep) {
783                 const unsigned char *data;
784                 unsigned char delta_head[64];
785                 unsigned long result_size;
786                 z_stream stream;
787                 int st;
788
789                 memset(&stream, 0, sizeof(stream));
790
791                 data = stream.next_in = base_sha1 + 20;
792                 stream.avail_in = left - 20;
793                 stream.next_out = delta_head;
794                 stream.avail_out = sizeof(delta_head);
795
796                 inflateInit(&stream);
797                 st = inflate(&stream, Z_FINISH);
798                 inflateEnd(&stream);
799                 if ((st != Z_STREAM_END) &&
800                     stream.total_out != sizeof(delta_head))
801                         die("delta data unpack-initial failed");
802
803                 /* Examine the initial part of the delta to figure out
804                  * the result size.
805                  */
806                 data = delta_head;
807                 get_delta_hdr_size(&data); /* ignore base size */
808
809                 /* Read the result size */
810                 result_size = get_delta_hdr_size(&data);
811                 *sizep = result_size;
812         }
813         return 0;
814 }
815
816 static unsigned long unpack_object_header(struct packed_git *p, unsigned long offset,
817         enum object_type *type, unsigned long *sizep)
818 {
819         unsigned shift;
820         unsigned char *pack, c;
821         unsigned long size;
822
823         if (offset >= p->pack_size)
824                 die("object offset outside of pack file");
825
826         pack =  p->pack_base + offset;
827         c = *pack++;
828         offset++;
829         *type = (c >> 4) & 7;
830         size = c & 15;
831         shift = 4;
832         while (c & 0x80) {
833                 if (offset >= p->pack_size)
834                         die("object offset outside of pack file");
835                 c = *pack++;
836                 offset++;
837                 size += (c & 0x7f) << shift;
838                 shift += 7;
839         }
840         *sizep = size;
841         return offset;
842 }
843
844 int check_reuse_pack_delta(struct packed_git *p, unsigned long offset,
845                            unsigned char *base, unsigned long *sizep,
846                            enum object_type *kindp)
847 {
848         unsigned long ptr;
849         int status = -1;
850
851         use_packed_git(p);
852         ptr = offset;
853         ptr = unpack_object_header(p, ptr, kindp, sizep);
854         if (*kindp != OBJ_DELTA)
855                 goto done;
856         memcpy(base, p->pack_base + ptr, 20);
857         status = 0;
858  done:
859         unuse_packed_git(p);
860         return status;
861 }
862
863 void packed_object_info_detail(struct pack_entry *e,
864                                char *type,
865                                unsigned long *size,
866                                unsigned long *store_size,
867                                unsigned int *delta_chain_length,
868                                unsigned char *base_sha1)
869 {
870         struct packed_git *p = e->p;
871         unsigned long offset, left;
872         unsigned char *pack;
873         enum object_type kind;
874
875         offset = unpack_object_header(p, e->offset, &kind, size);
876         pack = p->pack_base + offset;
877         left = p->pack_size - offset;
878         if (kind != OBJ_DELTA)
879                 *delta_chain_length = 0;
880         else {
881                 unsigned int chain_length = 0;
882                 memcpy(base_sha1, pack, 20);
883                 do {
884                         struct pack_entry base_ent;
885                         unsigned long junk;
886
887                         find_pack_entry_one(pack, &base_ent, p);
888                         offset = unpack_object_header(p, base_ent.offset,
889                                                       &kind, &junk);
890                         pack = p->pack_base + offset;
891                         chain_length++;
892                 } while (kind == OBJ_DELTA);
893                 *delta_chain_length = chain_length;
894         }
895         switch (kind) {
896         case OBJ_COMMIT:
897                 strcpy(type, "commit");
898                 break;
899         case OBJ_TREE:
900                 strcpy(type, "tree");
901                 break;
902         case OBJ_BLOB:
903                 strcpy(type, "blob");
904                 break;
905         case OBJ_TAG:
906                 strcpy(type, "tag");
907                 break;
908         default:
909                 die("corrupted pack file %s containing object of kind %d",
910                     p->pack_name, kind);
911         }
912         *store_size = 0; /* notyet */
913 }
914
915 static int packed_object_info(struct pack_entry *entry,
916                               char *type, unsigned long *sizep)
917 {
918         struct packed_git *p = entry->p;
919         unsigned long offset, size, left;
920         unsigned char *pack;
921         enum object_type kind;
922         int retval;
923
924         if (use_packed_git(p))
925                 die("cannot map packed file");
926
927         offset = unpack_object_header(p, entry->offset, &kind, &size);
928         pack = p->pack_base + offset;
929         left = p->pack_size - offset;
930
931         switch (kind) {
932         case OBJ_DELTA:
933                 retval = packed_delta_info(pack, size, left, type, sizep, p);
934                 unuse_packed_git(p);
935                 return retval;
936         case OBJ_COMMIT:
937                 strcpy(type, "commit");
938                 break;
939         case OBJ_TREE:
940                 strcpy(type, "tree");
941                 break;
942         case OBJ_BLOB:
943                 strcpy(type, "blob");
944                 break;
945         case OBJ_TAG:
946                 strcpy(type, "tag");
947                 break;
948         default:
949                 die("corrupted pack file %s containing object of kind %d",
950                     p->pack_name, kind);
951         }
952         if (sizep)
953                 *sizep = size;
954         unuse_packed_git(p);
955         return 0;
956 }
957
958 /* forward declaration for a mutually recursive function */
959 static void *unpack_entry(struct pack_entry *, char *, unsigned long *);
960
961 static void *unpack_delta_entry(unsigned char *base_sha1,
962                                 unsigned long delta_size,
963                                 unsigned long left,
964                                 char *type,
965                                 unsigned long *sizep,
966                                 struct packed_git *p)
967 {
968         struct pack_entry base_ent;
969         void *data, *delta_data, *result, *base;
970         unsigned long data_size, result_size, base_size;
971         z_stream stream;
972         int st;
973
974         if (left < 20)
975                 die("truncated pack file");
976         data = base_sha1 + 20;
977         data_size = left - 20;
978         delta_data = xmalloc(delta_size);
979
980         memset(&stream, 0, sizeof(stream));
981
982         stream.next_in = data;
983         stream.avail_in = data_size;
984         stream.next_out = delta_data;
985         stream.avail_out = delta_size;
986
987         inflateInit(&stream);
988         st = inflate(&stream, Z_FINISH);
989         inflateEnd(&stream);
990         if ((st != Z_STREAM_END) || stream.total_out != delta_size)
991                 die("delta data unpack failed");
992
993         /* The base entry _must_ be in the same pack */
994         if (!find_pack_entry_one(base_sha1, &base_ent, p))
995                 die("failed to find delta-pack base object %s",
996                     sha1_to_hex(base_sha1));
997         base = unpack_entry_gently(&base_ent, type, &base_size);
998         if (!base)
999                 die("failed to read delta-pack base object %s",
1000                     sha1_to_hex(base_sha1));
1001         result = patch_delta(base, base_size,
1002                              delta_data, delta_size,
1003                              &result_size);
1004         if (!result)
1005                 die("failed to apply delta");
1006         free(delta_data);
1007         free(base);
1008         *sizep = result_size;
1009         return result;
1010 }
1011
1012 static void *unpack_non_delta_entry(unsigned char *data,
1013                                     unsigned long size,
1014                                     unsigned long left)
1015 {
1016         int st;
1017         z_stream stream;
1018         unsigned char *buffer;
1019
1020         buffer = xmalloc(size + 1);
1021         buffer[size] = 0;
1022         memset(&stream, 0, sizeof(stream));
1023         stream.next_in = data;
1024         stream.avail_in = left;
1025         stream.next_out = buffer;
1026         stream.avail_out = size;
1027
1028         inflateInit(&stream);
1029         st = inflate(&stream, Z_FINISH);
1030         inflateEnd(&stream);
1031         if ((st != Z_STREAM_END) || stream.total_out != size) {
1032                 free(buffer);
1033                 return NULL;
1034         }
1035
1036         return buffer;
1037 }
1038
1039 static void *unpack_entry(struct pack_entry *entry,
1040                           char *type, unsigned long *sizep)
1041 {
1042         struct packed_git *p = entry->p;
1043         void *retval;
1044
1045         if (use_packed_git(p))
1046                 die("cannot map packed file");
1047         retval = unpack_entry_gently(entry, type, sizep);
1048         unuse_packed_git(p);
1049         if (!retval)
1050                 die("corrupted pack file %s", p->pack_name);
1051         return retval;
1052 }
1053
1054 /* The caller is responsible for use_packed_git()/unuse_packed_git() pair */
1055 void *unpack_entry_gently(struct pack_entry *entry,
1056                           char *type, unsigned long *sizep)
1057 {
1058         struct packed_git *p = entry->p;
1059         unsigned long offset, size, left;
1060         unsigned char *pack;
1061         enum object_type kind;
1062         void *retval;
1063
1064         offset = unpack_object_header(p, entry->offset, &kind, &size);
1065         pack = p->pack_base + offset;
1066         left = p->pack_size - offset;
1067         switch (kind) {
1068         case OBJ_DELTA:
1069                 retval = unpack_delta_entry(pack, size, left, type, sizep, p);
1070                 return retval;
1071         case OBJ_COMMIT:
1072                 strcpy(type, "commit");
1073                 break;
1074         case OBJ_TREE:
1075                 strcpy(type, "tree");
1076                 break;
1077         case OBJ_BLOB:
1078                 strcpy(type, "blob");
1079                 break;
1080         case OBJ_TAG:
1081                 strcpy(type, "tag");
1082                 break;
1083         default:
1084                 return NULL;
1085         }
1086         *sizep = size;
1087         retval = unpack_non_delta_entry(pack, size, left);
1088         return retval;
1089 }
1090
1091 int num_packed_objects(const struct packed_git *p)
1092 {
1093         /* See check_packed_git_idx() */
1094         return (p->index_size - 20 - 20 - 4*256) / 24;
1095 }
1096
1097 int nth_packed_object_sha1(const struct packed_git *p, int n,
1098                            unsigned char* sha1)
1099 {
1100         void *index = p->index_base + 256;
1101         if (n < 0 || num_packed_objects(p) <= n)
1102                 return -1;
1103         memcpy(sha1, (index + 24 * n + 4), 20);
1104         return 0;
1105 }
1106
1107 int find_pack_entry_one(const unsigned char *sha1,
1108                         struct pack_entry *e, struct packed_git *p)
1109 {
1110         unsigned int *level1_ofs = p->index_base;
1111         int hi = ntohl(level1_ofs[*sha1]);
1112         int lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
1113         void *index = p->index_base + 256;
1114
1115         do {
1116                 int mi = (lo + hi) / 2;
1117                 int cmp = memcmp(index + 24 * mi + 4, sha1, 20);
1118                 if (!cmp) {
1119                         e->offset = ntohl(*((int*)(index + 24 * mi)));
1120                         memcpy(e->sha1, sha1, 20);
1121                         e->p = p;
1122                         return 1;
1123                 }
1124                 if (cmp > 0)
1125                         hi = mi;
1126                 else
1127                         lo = mi+1;
1128         } while (lo < hi);
1129         return 0;
1130 }
1131
1132 static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
1133 {
1134         struct packed_git *p;
1135         prepare_packed_git();
1136
1137         for (p = packed_git; p; p = p->next) {
1138                 if (find_pack_entry_one(sha1, e, p))
1139                         return 1;
1140         }
1141         return 0;
1142 }
1143
1144 struct packed_git *find_sha1_pack(const unsigned char *sha1, 
1145                                   struct packed_git *packs)
1146 {
1147         struct packed_git *p;
1148         struct pack_entry e;
1149
1150         for (p = packs; p; p = p->next) {
1151                 if (find_pack_entry_one(sha1, &e, p))
1152                         return p;
1153         }
1154         return NULL;
1155         
1156 }
1157
1158 int sha1_object_info(const unsigned char *sha1, char *type, unsigned long *sizep)
1159 {
1160         int status;
1161         unsigned long mapsize, size;
1162         void *map;
1163         z_stream stream;
1164         char hdr[128];
1165
1166         map = map_sha1_file_internal(sha1, &mapsize);
1167         if (!map) {
1168                 struct pack_entry e;
1169
1170                 if (!find_pack_entry(sha1, &e))
1171                         return error("unable to find %s", sha1_to_hex(sha1));
1172                 return packed_object_info(&e, type, sizep);
1173         }
1174         if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
1175                 status = error("unable to unpack %s header",
1176                                sha1_to_hex(sha1));
1177         if (parse_sha1_header(hdr, type, &size) < 0)
1178                 status = error("unable to parse %s header", sha1_to_hex(sha1));
1179         else {
1180                 status = 0;
1181                 if (sizep)
1182                         *sizep = size;
1183         }
1184         inflateEnd(&stream);
1185         munmap(map, mapsize);
1186         return status;
1187 }
1188
1189 static void *read_packed_sha1(const unsigned char *sha1, char *type, unsigned long *size)
1190 {
1191         struct pack_entry e;
1192
1193         if (!find_pack_entry(sha1, &e)) {
1194                 error("cannot read sha1_file for %s", sha1_to_hex(sha1));
1195                 return NULL;
1196         }
1197         return unpack_entry(&e, type, size);
1198 }
1199
1200 void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size)
1201 {
1202         unsigned long mapsize;
1203         void *map, *buf;
1204         struct pack_entry e;
1205
1206         if (find_pack_entry(sha1, &e))
1207                 return read_packed_sha1(sha1, type, size);
1208         map = map_sha1_file_internal(sha1, &mapsize);
1209         if (map) {
1210                 buf = unpack_sha1_file(map, mapsize, type, size);
1211                 munmap(map, mapsize);
1212                 return buf;
1213         }
1214         return NULL;
1215 }
1216
1217 void *read_object_with_reference(const unsigned char *sha1,
1218                                  const char *required_type,
1219                                  unsigned long *size,
1220                                  unsigned char *actual_sha1_return)
1221 {
1222         char type[20];
1223         void *buffer;
1224         unsigned long isize;
1225         unsigned char actual_sha1[20];
1226
1227         memcpy(actual_sha1, sha1, 20);
1228         while (1) {
1229                 int ref_length = -1;
1230                 const char *ref_type = NULL;
1231
1232                 buffer = read_sha1_file(actual_sha1, type, &isize);
1233                 if (!buffer)
1234                         return NULL;
1235                 if (!strcmp(type, required_type)) {
1236                         *size = isize;
1237                         if (actual_sha1_return)
1238                                 memcpy(actual_sha1_return, actual_sha1, 20);
1239                         return buffer;
1240                 }
1241                 /* Handle references */
1242                 else if (!strcmp(type, "commit"))
1243                         ref_type = "tree ";
1244                 else if (!strcmp(type, "tag"))
1245                         ref_type = "object ";
1246                 else {
1247                         free(buffer);
1248                         return NULL;
1249                 }
1250                 ref_length = strlen(ref_type);
1251
1252                 if (memcmp(buffer, ref_type, ref_length) ||
1253                     get_sha1_hex(buffer + ref_length, actual_sha1)) {
1254                         free(buffer);
1255                         return NULL;
1256                 }
1257                 free(buffer);
1258                 /* Now we have the ID of the referred-to object in
1259                  * actual_sha1.  Check again. */
1260         }
1261 }
1262
1263 char *write_sha1_file_prepare(void *buf,
1264                               unsigned long len,
1265                               const char *type,
1266                               unsigned char *sha1,
1267                               unsigned char *hdr,
1268                               int *hdrlen)
1269 {
1270         SHA_CTX c;
1271
1272         /* Generate the header */
1273         *hdrlen = sprintf((char *)hdr, "%s %lu", type, len)+1;
1274
1275         /* Sha1.. */
1276         SHA1_Init(&c);
1277         SHA1_Update(&c, hdr, *hdrlen);
1278         SHA1_Update(&c, buf, len);
1279         SHA1_Final(sha1, &c);
1280
1281         return sha1_file_name(sha1);
1282 }
1283
1284 /*
1285  * Link the tempfile to the final place, possibly creating the
1286  * last directory level as you do so.
1287  *
1288  * Returns the errno on failure, 0 on success.
1289  */
1290 static int link_temp_to_file(const char *tmpfile, char *filename)
1291 {
1292         int ret;
1293
1294         if (!link(tmpfile, filename))
1295                 return 0;
1296
1297         /*
1298          * Try to mkdir the last path component if that failed
1299          * with an ENOENT.
1300          *
1301          * Re-try the "link()" regardless of whether the mkdir
1302          * succeeds, since a race might mean that somebody
1303          * else succeeded.
1304          */
1305         ret = errno;
1306         if (ret == ENOENT) {
1307                 char *dir = strrchr(filename, '/');
1308                 if (dir) {
1309                         *dir = 0;
1310                         mkdir(filename, 0777);
1311                         if (adjust_shared_perm(filename))
1312                                 return -2;
1313                         *dir = '/';
1314                         if (!link(tmpfile, filename))
1315                                 return 0;
1316                         ret = errno;
1317                 }
1318         }
1319         return ret;
1320 }
1321
1322 /*
1323  * Move the just written object into its final resting place
1324  */
1325 int move_temp_to_file(const char *tmpfile, char *filename)
1326 {
1327         int ret = link_temp_to_file(tmpfile, filename);
1328
1329         /*
1330          * Coda hack - coda doesn't like cross-directory links,
1331          * so we fall back to a rename, which will mean that it
1332          * won't be able to check collisions, but that's not a
1333          * big deal.
1334          *
1335          * The same holds for FAT formatted media.
1336          *
1337          * When this succeeds, we just return 0. We have nothing
1338          * left to unlink.
1339          */
1340         if (ret && ret != EEXIST) {
1341                 if (!rename(tmpfile, filename))
1342                         return 0;
1343                 ret = errno;
1344         }
1345         unlink(tmpfile);
1346         if (ret) {
1347                 if (ret != EEXIST) {
1348                         fprintf(stderr, "unable to write sha1 filename %s: %s\n", filename, strerror(ret));
1349                         return -1;
1350                 }
1351                 /* FIXME!!! Collision check here ? */
1352         }
1353
1354         return 0;
1355 }
1356
1357 int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
1358 {
1359         int size;
1360         unsigned char *compressed;
1361         z_stream stream;
1362         unsigned char sha1[20];
1363         char *filename;
1364         static char tmpfile[PATH_MAX];
1365         unsigned char hdr[50];
1366         int fd, hdrlen;
1367
1368         /* Normally if we have it in the pack then we do not bother writing
1369          * it out into .git/objects/??/?{38} file.
1370          */
1371         filename = write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
1372         if (returnsha1)
1373                 memcpy(returnsha1, sha1, 20);
1374         if (has_sha1_file(sha1))
1375                 return 0;
1376         fd = open(filename, O_RDONLY);
1377         if (fd >= 0) {
1378                 /*
1379                  * FIXME!!! We might do collision checking here, but we'd
1380                  * need to uncompress the old file and check it. Later.
1381                  */
1382                 close(fd);
1383                 return 0;
1384         }
1385
1386         if (errno != ENOENT) {
1387                 fprintf(stderr, "sha1 file %s: %s\n", filename, strerror(errno));
1388                 return -1;
1389         }
1390
1391         snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
1392
1393         fd = mkstemp(tmpfile);
1394         if (fd < 0) {
1395                 fprintf(stderr, "unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
1396                 return -1;
1397         }
1398
1399         /* Set it up */
1400         memset(&stream, 0, sizeof(stream));
1401         deflateInit(&stream, Z_BEST_COMPRESSION);
1402         size = deflateBound(&stream, len+hdrlen);
1403         compressed = xmalloc(size);
1404
1405         /* Compress it */
1406         stream.next_out = compressed;
1407         stream.avail_out = size;
1408
1409         /* First header.. */
1410         stream.next_in = hdr;
1411         stream.avail_in = hdrlen;
1412         while (deflate(&stream, 0) == Z_OK)
1413                 /* nothing */;
1414
1415         /* Then the data itself.. */
1416         stream.next_in = buf;
1417         stream.avail_in = len;
1418         while (deflate(&stream, Z_FINISH) == Z_OK)
1419                 /* nothing */;
1420         deflateEnd(&stream);
1421         size = stream.total_out;
1422
1423         if (write(fd, compressed, size) != size)
1424                 die("unable to write file");
1425         fchmod(fd, 0444);
1426         close(fd);
1427         free(compressed);
1428
1429         return move_temp_to_file(tmpfile, filename);
1430 }
1431
1432 int write_sha1_to_fd(int fd, const unsigned char *sha1)
1433 {
1434         ssize_t size;
1435         unsigned long objsize;
1436         int posn = 0;
1437         void *map = map_sha1_file_internal(sha1, &objsize);
1438         void *buf = map;
1439         void *temp_obj = NULL;
1440         z_stream stream;
1441
1442         if (!buf) {
1443                 unsigned char *unpacked;
1444                 unsigned long len;
1445                 char type[20];
1446                 char hdr[50];
1447                 int hdrlen;
1448                 // need to unpack and recompress it by itself
1449                 unpacked = read_packed_sha1(sha1, type, &len);
1450
1451                 hdrlen = sprintf(hdr, "%s %lu", type, len) + 1;
1452
1453                 /* Set it up */
1454                 memset(&stream, 0, sizeof(stream));
1455                 deflateInit(&stream, Z_BEST_COMPRESSION);
1456                 size = deflateBound(&stream, len + hdrlen);
1457                 temp_obj = buf = xmalloc(size);
1458
1459                 /* Compress it */
1460                 stream.next_out = buf;
1461                 stream.avail_out = size;
1462                 
1463                 /* First header.. */
1464                 stream.next_in = (void *)hdr;
1465                 stream.avail_in = hdrlen;
1466                 while (deflate(&stream, 0) == Z_OK)
1467                         /* nothing */;
1468
1469                 /* Then the data itself.. */
1470                 stream.next_in = unpacked;
1471                 stream.avail_in = len;
1472                 while (deflate(&stream, Z_FINISH) == Z_OK)
1473                         /* nothing */;
1474                 deflateEnd(&stream);
1475                 free(unpacked);
1476                 
1477                 objsize = stream.total_out;
1478         }
1479
1480         do {
1481                 size = write(fd, buf + posn, objsize - posn);
1482                 if (size <= 0) {
1483                         if (!size) {
1484                                 fprintf(stderr, "write closed\n");
1485                         } else {
1486                                 perror("write ");
1487                         }
1488                         return -1;
1489                 }
1490                 posn += size;
1491         } while (posn < objsize);
1492
1493         if (map)
1494                 munmap(map, objsize);
1495         if (temp_obj)
1496                 free(temp_obj);
1497
1498         return 0;
1499 }
1500
1501 int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
1502                        size_t bufsize, size_t *bufposn)
1503 {
1504         char tmpfile[PATH_MAX];
1505         int local;
1506         z_stream stream;
1507         unsigned char real_sha1[20];
1508         unsigned char discard[4096];
1509         int ret;
1510         SHA_CTX c;
1511
1512         snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
1513
1514         local = mkstemp(tmpfile);
1515         if (local < 0)
1516                 return error("Couldn't open %s for %s",
1517                              tmpfile, sha1_to_hex(sha1));
1518
1519         memset(&stream, 0, sizeof(stream));
1520
1521         inflateInit(&stream);
1522
1523         SHA1_Init(&c);
1524
1525         do {
1526                 ssize_t size;
1527                 if (*bufposn) {
1528                         stream.avail_in = *bufposn;
1529                         stream.next_in = (unsigned char *) buffer;
1530                         do {
1531                                 stream.next_out = discard;
1532                                 stream.avail_out = sizeof(discard);
1533                                 ret = inflate(&stream, Z_SYNC_FLUSH);
1534                                 SHA1_Update(&c, discard, sizeof(discard) -
1535                                             stream.avail_out);
1536                         } while (stream.avail_in && ret == Z_OK);
1537                         write(local, buffer, *bufposn - stream.avail_in);
1538                         memmove(buffer, buffer + *bufposn - stream.avail_in,
1539                                 stream.avail_in);
1540                         *bufposn = stream.avail_in;
1541                         if (ret != Z_OK)
1542                                 break;
1543                 }
1544                 size = read(fd, buffer + *bufposn, bufsize - *bufposn);
1545                 if (size <= 0) {
1546                         close(local);
1547                         unlink(tmpfile);
1548                         if (!size)
1549                                 return error("Connection closed?");
1550                         perror("Reading from connection");
1551                         return -1;
1552                 }
1553                 *bufposn += size;
1554         } while (1);
1555         inflateEnd(&stream);
1556
1557         close(local);
1558         SHA1_Final(real_sha1, &c);
1559         if (ret != Z_STREAM_END) {
1560                 unlink(tmpfile);
1561                 return error("File %s corrupted", sha1_to_hex(sha1));
1562         }
1563         if (memcmp(sha1, real_sha1, 20)) {
1564                 unlink(tmpfile);
1565                 return error("File %s has bad hash", sha1_to_hex(sha1));
1566         }
1567
1568         return move_temp_to_file(tmpfile, sha1_file_name(sha1));
1569 }
1570
1571 int has_pack_index(const unsigned char *sha1)
1572 {
1573         struct stat st;
1574         if (stat(sha1_pack_index_name(sha1), &st))
1575                 return 0;
1576         return 1;
1577 }
1578
1579 int has_pack_file(const unsigned char *sha1)
1580 {
1581         struct stat st;
1582         if (stat(sha1_pack_name(sha1), &st))
1583                 return 0;
1584         return 1;
1585 }
1586
1587 int has_sha1_pack(const unsigned char *sha1)
1588 {
1589         struct pack_entry e;
1590         return find_pack_entry(sha1, &e);
1591 }
1592
1593 int has_sha1_file(const unsigned char *sha1)
1594 {
1595         struct stat st;
1596         struct pack_entry e;
1597
1598         if (find_pack_entry(sha1, &e))
1599                 return 1;
1600         return find_sha1_file(sha1, &st) ? 1 : 0;
1601 }
1602
1603 int index_pipe(unsigned char *sha1, int fd, const char *type, int write_object)
1604 {
1605         unsigned long size = 4096;
1606         char *buf = malloc(size);
1607         int iret, ret;
1608         unsigned long off = 0;
1609         unsigned char hdr[50];
1610         int hdrlen;
1611         do {
1612                 iret = read(fd, buf + off, size - off);
1613                 if (iret > 0) {
1614                         off += iret;
1615                         if (off == size) {
1616                                 size *= 2;
1617                                 buf = realloc(buf, size);
1618                         }
1619                 }
1620         } while (iret > 0);
1621         if (iret < 0) {
1622                 free(buf);
1623                 return -1;
1624         }
1625         if (!type)
1626                 type = "blob";
1627         if (write_object)
1628                 ret = write_sha1_file(buf, off, type, sha1);
1629         else {
1630                 write_sha1_file_prepare(buf, off, type, sha1, hdr, &hdrlen);
1631                 ret = 0;
1632         }
1633         free(buf);
1634         return ret;
1635 }
1636
1637 int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object, const char *type)
1638 {
1639         unsigned long size = st->st_size;
1640         void *buf;
1641         int ret;
1642         unsigned char hdr[50];
1643         int hdrlen;
1644
1645         buf = "";
1646         if (size)
1647                 buf = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
1648         close(fd);
1649         if (buf == MAP_FAILED)
1650                 return -1;
1651
1652         if (!type)
1653                 type = "blob";
1654         if (write_object)
1655                 ret = write_sha1_file(buf, size, type, sha1);
1656         else {
1657                 write_sha1_file_prepare(buf, size, type, sha1, hdr, &hdrlen);
1658                 ret = 0;
1659         }
1660         if (size)
1661                 munmap(buf, size);
1662         return ret;
1663 }
1664
1665 int index_path(unsigned char *sha1, const char *path, struct stat *st, int write_object)
1666 {
1667         int fd;
1668         char *target;
1669
1670         switch (st->st_mode & S_IFMT) {
1671         case S_IFREG:
1672                 fd = open(path, O_RDONLY);
1673                 if (fd < 0)
1674                         return error("open(\"%s\"): %s", path,
1675                                      strerror(errno));
1676                 if (index_fd(sha1, fd, st, write_object, NULL) < 0)
1677                         return error("%s: failed to insert into database",
1678                                      path);
1679                 break;
1680         case S_IFLNK:
1681                 target = xmalloc(st->st_size+1);
1682                 if (readlink(path, target, st->st_size+1) != st->st_size) {
1683                         char *errstr = strerror(errno);
1684                         free(target);
1685                         return error("readlink(\"%s\"): %s", path,
1686                                      errstr);
1687                 }
1688                 if (!write_object) {
1689                         unsigned char hdr[50];
1690                         int hdrlen;
1691                         write_sha1_file_prepare(target, st->st_size, "blob",
1692                                                 sha1, hdr, &hdrlen);
1693                 } else if (write_sha1_file(target, st->st_size, "blob", sha1))
1694                         return error("%s: failed to insert into database",
1695                                      path);
1696                 free(target);
1697                 break;
1698         default:
1699                 return error("%s: unsupported file type", path);
1700         }
1701         return 0;
1702 }