2 * GIT - The information manager from hell
4 * Copyright (C) Linus Torvalds, 2005
9 struct cache_entry
**active_cache
= NULL
;
10 unsigned int active_nr
= 0, active_alloc
= 0, active_cache_changed
= 0;
12 int cache_match_stat(struct cache_entry
*ce
, struct stat
*st
)
14 unsigned int changed
= 0;
16 switch (ntohl(ce
->ce_mode
) & S_IFMT
) {
18 changed
|= !S_ISREG(st
->st_mode
) ? TYPE_CHANGED
: 0;
19 /* We consider only the owner x bit to be relevant for "mode changes" */
20 if (0100 & (ntohl(ce
->ce_mode
) ^ st
->st_mode
))
21 changed
|= MODE_CHANGED
;
24 changed
|= !S_ISLNK(st
->st_mode
) ? TYPE_CHANGED
: 0;
27 die("internal error: ce_mode is %o", ntohl(ce
->ce_mode
));
29 if (ce
->ce_mtime
.sec
!= htonl(st
->st_mtime
))
30 changed
|= MTIME_CHANGED
;
31 if (ce
->ce_ctime
.sec
!= htonl(st
->st_ctime
))
32 changed
|= CTIME_CHANGED
;
36 * nsec seems unreliable - not all filesystems support it, so
37 * as long as it is in the inode cache you get right nsec
38 * but after it gets flushed, you get zero nsec.
40 if (ce
->ce_mtime
.nsec
!= htonl(st
->st_mtim
.tv_nsec
))
41 changed
|= MTIME_CHANGED
;
42 if (ce
->ce_ctime
.nsec
!= htonl(st
->st_ctim
.tv_nsec
))
43 changed
|= CTIME_CHANGED
;
46 if (ce
->ce_uid
!= htonl(st
->st_uid
) ||
47 ce
->ce_gid
!= htonl(st
->st_gid
))
48 changed
|= OWNER_CHANGED
;
49 if (ce
->ce_dev
!= htonl(st
->st_dev
) ||
50 ce
->ce_ino
!= htonl(st
->st_ino
))
51 changed
|= INODE_CHANGED
;
52 if (ce
->ce_size
!= htonl(st
->st_size
))
53 changed
|= DATA_CHANGED
;
57 int cache_name_compare(const char *name1
, int flags1
, const char *name2
, int flags2
)
59 int len1
= flags1
& CE_NAMEMASK
;
60 int len2
= flags2
& CE_NAMEMASK
;
61 int len
= len1
< len2
? len1
: len2
;
64 cmp
= memcmp(name1
, name2
, len
);
78 int cache_name_pos(const char *name
, int namelen
)
84 while (last
> first
) {
85 int next
= (last
+ first
) >> 1;
86 struct cache_entry
*ce
= active_cache
[next
];
87 int cmp
= cache_name_compare(name
, namelen
, ce
->name
, htons(ce
->ce_flags
));
99 /* Remove entry, return true if there are more entries to go.. */
100 int remove_entry_at(int pos
)
102 active_cache_changed
= 1;
104 if (pos
>= active_nr
)
106 memmove(active_cache
+ pos
, active_cache
+ pos
+ 1, (active_nr
- pos
) * sizeof(struct cache_entry
*));
110 int remove_file_from_cache(char *path
)
112 int pos
= cache_name_pos(path
, strlen(path
));
115 while (pos
< active_nr
&& !strcmp(active_cache
[pos
]->name
, path
))
116 remove_entry_at(pos
);
120 int same_name(struct cache_entry
*a
, struct cache_entry
*b
)
122 int len
= ce_namelen(a
);
123 return ce_namelen(b
) == len
&& !memcmp(a
->name
, b
->name
, len
);
126 /* We may be in a situation where we already have path/file and path
127 * is being added, or we already have path and path/file is being
128 * added. Either one would result in a nonsense tree that has path
129 * twice when git-write-tree tries to write it out. Prevent it.
131 static int check_file_directory_conflict(const struct cache_entry
*ce
)
134 const char *path
= ce
->name
;
135 int namelen
= strlen(path
);
136 int stage
= ce_stage(ce
);
137 char *pathbuf
= xmalloc(namelen
+ 1);
140 memcpy(pathbuf
, path
, namelen
+ 1);
143 * We are inserting path/file. Do they have path registered at
144 * the same stage? We need to do this for all the levels of our
149 char *ep
= strchr(cp
, '/');
152 *ep
= 0; /* first cut it at slash */
153 pos
= cache_name_pos(pathbuf
,
154 htons(create_ce_flags(ep
-cp
, stage
)));
156 /* Our leading path component is registered as a file,
157 * and we are trying to make it a directory. This is
163 *ep
= '/'; /* then restore it and go downwards */
168 /* Do we have an entry in the cache that makes our path a prefix
169 * of it? That is, are we creating a file where they already expect
172 pos
= cache_name_pos(path
,
173 htons(create_ce_flags(namelen
, stage
)));
175 /* (0 <= pos) cannot happen because add_cache_entry()
176 * should have taken care of that case.
180 /* pos would point at an existing entry that would come immediately
181 * after our path. It could be the same as our path in higher stage,
182 * or different path but in a lower stage.
184 * E.g. when we are inserting path at stage 2,
191 * We need to examine pos, ignore it because it is at different
192 * stage, examine next to find the path/file at stage 2, and
196 while (pos
< active_nr
) {
197 struct cache_entry
*other
= active_cache
[pos
];
198 if (strncmp(other
->name
, path
, namelen
))
199 break; /* it is not our "subdirectory" anymore */
200 if ((ce_stage(other
) == stage
) && other
->name
[namelen
] == '/')
208 int add_cache_entry(struct cache_entry
*ce
, int ok_to_add
)
212 pos
= cache_name_pos(ce
->name
, htons(ce
->ce_flags
));
214 /* existing match? Just replace it */
216 active_cache_changed
= 1;
217 active_cache
[pos
] = ce
;
223 * Inserting a merged entry ("stage 0") into the index
224 * will always replace all non-merged entries..
226 if (pos
< active_nr
&& ce_stage(ce
) == 0) {
227 while (same_name(active_cache
[pos
], ce
)) {
229 if (!remove_entry_at(pos
))
237 if (check_file_directory_conflict(ce
))
240 /* Make sure the array is big enough .. */
241 if (active_nr
== active_alloc
) {
242 active_alloc
= alloc_nr(active_alloc
);
243 active_cache
= xrealloc(active_cache
, active_alloc
* sizeof(struct cache_entry
*));
249 memmove(active_cache
+ pos
+ 1, active_cache
+ pos
, (active_nr
- pos
- 1) * sizeof(ce
));
250 active_cache
[pos
] = ce
;
251 active_cache_changed
= 1;
255 static int verify_hdr(struct cache_header
*hdr
, unsigned long size
)
258 unsigned char sha1
[20];
260 if (hdr
->hdr_signature
!= htonl(CACHE_SIGNATURE
))
261 return error("bad signature");
262 if (hdr
->hdr_version
!= htonl(2))
263 return error("bad index version");
265 SHA1_Update(&c
, hdr
, size
- 20);
266 SHA1_Final(sha1
, &c
);
267 if (memcmp(sha1
, (void *)hdr
+ size
- 20, 20))
268 return error("bad index file sha1 signature");
276 unsigned long size
, offset
;
278 struct cache_header
*hdr
;
282 return error("more than one cachefile");
284 fd
= open(get_index_file(), O_RDONLY
);
286 return (errno
== ENOENT
) ? 0 : error("open failed");
288 size
= 0; // avoid gcc warning
290 if (!fstat(fd
, &st
)) {
293 if (size
>= sizeof(struct cache_header
) + 20)
294 map
= mmap(NULL
, size
, PROT_READ
| PROT_WRITE
, MAP_PRIVATE
, fd
, 0);
297 if (-1 == (int)(long)map
)
298 return error("mmap failed");
301 if (verify_hdr(hdr
, size
) < 0)
304 active_nr
= ntohl(hdr
->hdr_entries
);
305 active_alloc
= alloc_nr(active_nr
);
306 active_cache
= calloc(active_alloc
, sizeof(struct cache_entry
*));
308 offset
= sizeof(*hdr
);
309 for (i
= 0; i
< active_nr
; i
++) {
310 struct cache_entry
*ce
= map
+ offset
;
311 offset
= offset
+ ce_size(ce
);
312 active_cache
[i
] = ce
;
319 return error("verify header failed");
322 #define WRITE_BUFFER_SIZE 8192
323 static char write_buffer
[WRITE_BUFFER_SIZE
];
324 static unsigned long write_buffer_len
;
326 static int ce_write(SHA_CTX
*context
, int fd
, void *data
, unsigned int len
)
329 unsigned int buffered
= write_buffer_len
;
330 unsigned int partial
= WRITE_BUFFER_SIZE
- buffered
;
333 memcpy(write_buffer
+ buffered
, data
, partial
);
335 if (buffered
== WRITE_BUFFER_SIZE
) {
336 SHA1_Update(context
, write_buffer
, WRITE_BUFFER_SIZE
);
337 if (write(fd
, write_buffer
, WRITE_BUFFER_SIZE
) != WRITE_BUFFER_SIZE
)
341 write_buffer_len
= buffered
;
348 static int ce_flush(SHA_CTX
*context
, int fd
)
350 unsigned int left
= write_buffer_len
;
353 write_buffer_len
= 0;
354 SHA1_Update(context
, write_buffer
, left
);
357 /* Append the SHA1 signature at the end */
358 SHA1_Final(write_buffer
+ left
, context
);
360 if (write(fd
, write_buffer
, left
) != left
)
365 int write_cache(int newfd
, struct cache_entry
**cache
, int entries
)
368 struct cache_header hdr
;
371 hdr
.hdr_signature
= htonl(CACHE_SIGNATURE
);
372 hdr
.hdr_version
= htonl(2);
373 hdr
.hdr_entries
= htonl(entries
);
376 if (ce_write(&c
, newfd
, &hdr
, sizeof(hdr
)) < 0)
379 for (i
= 0; i
< entries
; i
++) {
380 struct cache_entry
*ce
= cache
[i
];
381 if (ce_write(&c
, newfd
, ce
, ce_size(ce
)) < 0)
384 return ce_flush(&c
, newfd
);