Documentation updates.
[git/git.git] / cache.h
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e83c5163
LT
1#ifndef CACHE_H
2#define CACHE_H
3
2dee0609 4#include <unistd.h>
e83c5163
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5#include <stdio.h>
6#include <sys/stat.h>
7#include <fcntl.h>
8#include <stddef.h>
9#include <stdlib.h>
10#include <stdarg.h>
bf0c6e83 11#include <string.h>
e83c5163 12#include <errno.h>
6b0c3121 13#include <limits.h>
e83c5163 14#include <sys/mman.h>
bb233d69 15#include <sys/param.h>
ccc4feb5 16#include <netinet/in.h>
575f4974
LT
17#include <sys/types.h>
18#include <dirent.h>
e83c5163 19
cef661fc 20#include SHA1_HEADER
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21#include <zlib.h>
22
9da3acfb
ET
23#if ZLIB_VERNUM < 0x1200
24#define deflateBound(c,s) ((s) + (((s) + 7) >> 3) + (((s) + 63) >> 6) + 11)
25#endif
26
b6829693
ET
27#ifdef DT_UNKNOWN
28#define DTYPE(de) ((de)->d_type)
29#else
30#define DT_UNKNOWN 0
31#define DT_DIR 1
32#define DT_REG 2
a15c1c60 33#define DT_LNK 3
b6829693
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34#define DTYPE(de) DT_UNKNOWN
35#endif
36
90334cf7
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37#ifdef __GNUC__
38#define NORETURN __attribute__((__noreturn__))
39#else
40#define NORETURN
41#endif
42
4ec99bf0
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43#ifndef __attribute__
44#define __attribute(x)
45#endif
46
2386d658
LT
47/*
48 * Intensive research over the course of many years has shown that
49 * port 9418 is totally unused by anything else. Or
50 *
51 * Your search - "port 9418" - did not match any documents.
52 *
53 * as www.google.com puts it.
54 */
55#define DEFAULT_GIT_PORT 9418
56
d19938ab
JH
57/*
58 * Environment variables transition.
59 * We accept older names for now but warn.
60 */
61extern char *gitenv_bc(const char *);
62#define gitenv(e) (getenv(e) ? : gitenv_bc(e))
63
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64/*
65 * Basic data structures for the directory cache
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66 */
67
68#define CACHE_SIGNATURE 0x44495243 /* "DIRC" */
69struct cache_header {
ccc4feb5
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70 unsigned int hdr_signature;
71 unsigned int hdr_version;
72 unsigned int hdr_entries;
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73};
74
75/*
76 * The "cache_time" is just the low 32 bits of the
77 * time. It doesn't matter if it overflows - we only
78 * check it for equality in the 32 bits we save.
79 */
80struct cache_time {
81 unsigned int sec;
82 unsigned int nsec;
83};
84
85/*
86 * dev/ino/uid/gid/size are also just tracked to the low 32 bits
87 * Again - this is just a (very strong in practice) heuristic that
88 * the inode hasn't changed.
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89 *
90 * We save the fields in big-endian order to allow using the
91 * index file over NFS transparently.
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92 */
93struct cache_entry {
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LT
94 struct cache_time ce_ctime;
95 struct cache_time ce_mtime;
96 unsigned int ce_dev;
97 unsigned int ce_ino;
98 unsigned int ce_mode;
99 unsigned int ce_uid;
100 unsigned int ce_gid;
101 unsigned int ce_size;
e83c5163 102 unsigned char sha1[20];
f5cabd13 103 unsigned short ce_flags;
59c1e249 104 char name[0];
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105};
106
95fd5bf8
LT
107#define CE_NAMEMASK (0x0fff)
108#define CE_STAGEMASK (0x3000)
220a0b52 109#define CE_UPDATE (0x4000)
aee46198 110#define CE_STAGESHIFT 12
95fd5bf8 111
aee46198
JH
112#define create_ce_flags(len, stage) htons((len) | ((stage) << CE_STAGESHIFT))
113#define ce_namelen(ce) (CE_NAMEMASK & ntohs((ce)->ce_flags))
114#define ce_size(ce) cache_entry_size(ce_namelen(ce))
115#define ce_stage(ce) ((CE_STAGEMASK & ntohs((ce)->ce_flags)) >> CE_STAGESHIFT)
116
e4479470 117#define ce_permissions(mode) (((mode) & 0100) ? 0755 : 0644)
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118static inline unsigned int create_ce_mode(unsigned int mode)
119{
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120 if (S_ISLNK(mode))
121 return htonl(S_IFLNK);
db823d4a 122 return htonl(S_IFREG | ce_permissions(mode));
8ae0a8c5 123}
e4479470 124
aee46198 125#define cache_entry_size(len) ((offsetof(struct cache_entry,name) + (len) + 8) & ~7)
f5cabd13 126
88355048
PB
127extern struct cache_entry **active_cache;
128extern unsigned int active_nr, active_alloc, active_cache_changed;
e83c5163 129
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130#define GIT_DIR_ENVIRONMENT "GIT_DIR"
131#define DEFAULT_GIT_DIR_ENVIRONMENT ".git"
d19938ab 132#define DB_ENVIRONMENT "GIT_OBJECT_DIRECTORY"
bb233d69 133#define INDEX_ENVIRONMENT "GIT_INDEX_FILE"
5da5c8f4 134#define GRAFT_ENVIRONMENT "GIT_GRAFT_FILE"
bb233d69 135
8ac069ac 136extern char *get_object_directory(void);
95fc7512 137extern char *get_refs_directory(void);
8ac069ac 138extern char *get_index_file(void);
5da5c8f4 139extern char *get_graft_file(void);
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140
141#define ALTERNATE_DB_ENVIRONMENT "GIT_ALTERNATE_OBJECT_DIRECTORIES"
bb233d69 142
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LT
143#define alloc_nr(x) (((x)+16)*3/2)
144
734aab75 145/* Initialize and use the cache information */
e83c5163 146extern int read_cache(void);
197ee8c9 147extern int write_cache(int newfd, struct cache_entry **cache, int entries);
eb38c22f 148extern int cache_name_pos(const char *name, int namelen);
192268c1
JH
149#define ADD_CACHE_OK_TO_ADD 1 /* Ok to add */
150#define ADD_CACHE_OK_TO_REPLACE 2 /* Ok to replace file/directory */
b155725d 151#define ADD_CACHE_SKIP_DFCHECK 4 /* Ok to skip DF conflict checks */
192268c1 152extern int add_cache_entry(struct cache_entry *ce, int option);
dbbce55b 153extern int remove_cache_entry_at(int pos);
197ee8c9 154extern int remove_file_from_cache(char *path);
dbbce55b 155extern int ce_same_name(struct cache_entry *a, struct cache_entry *b);
5d728c84 156extern int ce_match_stat(struct cache_entry *ce, struct stat *st);
c0fd1f51 157extern int ce_path_match(const struct cache_entry *ce, const char **pathspec);
7672db20 158extern int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object, const char *type);
415e96c8
JH
159extern void fill_stat_cache_info(struct cache_entry *ce, struct stat *st);
160
161struct cache_file {
162 struct cache_file *next;
163 char lockfile[PATH_MAX];
164};
165extern int hold_index_file_for_update(struct cache_file *, const char *path);
166extern int commit_index_file(struct cache_file *);
167extern void rollback_index_file(struct cache_file *);
734aab75
LT
168
169#define MTIME_CHANGED 0x0001
170#define CTIME_CHANGED 0x0002
171#define OWNER_CHANGED 0x0004
172#define MODE_CHANGED 0x0008
173#define INODE_CHANGED 0x0010
174#define DATA_CHANGED 0x0020
8ae0a8c5 175#define TYPE_CHANGED 0x0040
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176
177/* Return a statically allocated filename matching the sha1 signature */
4ec99bf0
TS
178extern char *mkpath(const char *fmt, ...) __attribute__((format (printf, 1, 2)));
179extern char *git_path(const char *fmt, ...) __attribute__((format (printf, 1, 2)));
73134b6d 180extern char *sha1_file_name(const unsigned char *sha1);
bf592c50
DB
181extern char *sha1_pack_name(const unsigned char *sha1);
182extern char *sha1_pack_index_name(const unsigned char *sha1);
e83c5163 183
f2db68ed
HE
184int git_mkstemp(char *path, size_t n, const char *template);
185
b2cb9425 186int safe_create_leading_directories(char *path);
f2db68ed 187char *safe_strncpy(char *, const char *, size_t);
b2cb9425 188
e83c5163 189/* Read and unpack a sha1 file into memory, write memory to a sha1 file */
c4483576 190extern int unpack_sha1_header(z_stream *stream, void *map, unsigned long mapsize, void *buffer, unsigned long size);
5180cacc 191extern int parse_sha1_header(char *hdr, char *type, unsigned long *sizep);
36e4d74a 192extern int sha1_object_info(const unsigned char *, char *, unsigned long *);
2ade9340 193extern void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size);
73134b6d 194extern void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size);
bf0f910d 195extern int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *return_sha1);
7672db20
BL
196extern char *write_sha1_file_prepare(void *buf,
197 unsigned long len,
198 const char *type,
199 unsigned char *sha1,
200 unsigned char *hdr,
201 int *hdrlen);
8237b185 202
5d6ccf5c 203extern int check_sha1_signature(const unsigned char *sha1, void *buf, unsigned long size, const char *type);
e83c5163 204
94537c78 205/* Read a tree into the cache */
3e587635 206extern int read_tree(void *buffer, unsigned long size, int stage, const char **paths);
94537c78 207
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DB
208extern int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
209 size_t bufsize, size_t *bufposn);
a5eda52b 210extern int write_sha1_to_fd(int fd, const unsigned char *sha1);
8237b185 211
dade09c2 212extern int has_sha1_pack(const unsigned char *sha1);
8237b185
DB
213extern int has_sha1_file(const unsigned char *sha1);
214
bf592c50
DB
215extern int has_pack_file(const unsigned char *sha1);
216extern int has_pack_index(const unsigned char *sha1);
217
e83c5163 218/* Convert to/from hex/sha1 representation */
3c249c95 219extern int get_sha1(const char *str, unsigned char *sha1);
197ee8c9
LT
220extern int get_sha1_hex(const char *hex, unsigned char *sha1);
221extern char *sha1_to_hex(const unsigned char *sha1); /* static buffer result! */
e83c5163
LT
222
223/* General helper functions */
90334cf7 224extern void usage(const char *err) NORETURN;
4ec99bf0
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225extern void die(const char *err, ...) NORETURN __attribute__((format (printf, 1, 2)));
226extern int error(const char *err, ...) __attribute__((format (printf, 1, 2)));
2de381f9 227
958ba6c9 228extern int base_name_compare(const char *name1, int len1, int mode1, const char *name2, int len2, int mode2);
79517a06 229extern int cache_name_compare(const char *name1, int len1, const char *name2, int len2);
e83c5163 230
40469ee9 231extern void *read_object_with_reference(const unsigned char *sha1,
bf0f910d 232 const char *required_type,
40469ee9
JH
233 unsigned long *size,
234 unsigned char *sha1_ret);
f4913f91 235
f80cd783 236const char *show_date(unsigned long time, int timezone);
26a2d8ae 237void parse_date(const char *date, char *buf, int bufsize);
ecee9d9e
ET
238void datestamp(char *buf, int bufsize);
239
6aa33f40
LT
240extern int setup_ident(void);
241extern char *get_ident(const char *name, const char *email, const char *date_str);
d289d136
EB
242extern char *git_author_info(void);
243extern char *git_committer_info(void);
6aa33f40 244
127cfd0d 245static inline void *xmalloc(size_t size)
812666c8
CL
246{
247 void *ret = malloc(size);
248 if (!ret)
249 die("Out of memory, malloc failed");
250 return ret;
251}
252
127cfd0d 253static inline void *xrealloc(void *ptr, size_t size)
812666c8
CL
254{
255 void *ret = realloc(ptr, size);
256 if (!ret)
257 die("Out of memory, realloc failed");
258 return ret;
259}
260
127cfd0d
BR
261static inline void *xcalloc(size_t nmemb, size_t size)
262{
263 void *ret = calloc(nmemb, size);
264 if (!ret)
265 die("Out of memory, calloc failed");
266 return ret;
267}
268
12dccc16
LT
269struct checkout {
270 const char *base_dir;
271 int base_dir_len;
272 unsigned force:1,
273 quiet:1,
274 not_new:1,
275 refresh_cache:1;
276};
277
278extern int checkout_entry(struct cache_entry *ce, struct checkout *state);
279
9a217f2a
JH
280extern struct alternate_object_database {
281 char *base;
282 char *name;
283} *alt_odb;
284extern void prepare_alt_odb(void);
285
286extern struct packed_git {
287 struct packed_git *next;
288 unsigned long index_size;
289 unsigned long pack_size;
290 unsigned int *index_base;
291 void *pack_base;
292 unsigned int pack_last_used;
f9253394 293 unsigned int pack_use_cnt;
bf592c50 294 unsigned char sha1[20];
9a217f2a
JH
295 char pack_name[0]; /* something like ".git/objects/pack/xxxxx.pack" */
296} *packed_git;
f3bf9224
JH
297
298struct pack_entry {
299 unsigned int offset;
300 unsigned char sha1[20];
301 struct packed_git *p;
302};
303
d1c133f5
LT
304struct ref {
305 struct ref *next;
306 unsigned char old_sha1[20];
307 unsigned char new_sha1[20];
f88395ac 308 struct ref *peer_ref; /* when renaming */
d1c133f5
LT
309 char name[0];
310};
311
f7192598
LT
312extern int git_connect(int fd[2], char *url, const char *prog);
313extern int finish_connect(pid_t pid);
013e7c7f 314extern int path_match(const char *path, int nr, char **match);
f88395ac
JH
315extern int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail,
316 int nr_refspec, char **refspec, int all);
41cb7488 317extern int get_ack(int fd, unsigned char *result_sha1);
d1c133f5 318extern struct ref **get_remote_heads(int in, struct ref **list, int nr_match, char **match);
f7192598 319
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DB
320extern struct packed_git *parse_pack_index(unsigned char *sha1);
321
9a217f2a 322extern void prepare_packed_git(void);
bf592c50
DB
323extern void install_packed_git(struct packed_git *pack);
324
325extern struct packed_git *find_sha1_pack(const unsigned char *sha1,
326 struct packed_git *packs);
327
f9253394
JH
328extern int use_packed_git(struct packed_git *);
329extern void unuse_packed_git(struct packed_git *);
330extern struct packed_git *add_packed_git(char *, int);
9a217f2a
JH
331extern int num_packed_objects(const struct packed_git *p);
332extern int nth_packed_object_sha1(const struct packed_git *, int, unsigned char*);
f3bf9224
JH
333extern int find_pack_entry_one(const unsigned char *, struct pack_entry *, struct packed_git *);
334extern void *unpack_entry_gently(struct pack_entry *, char *, unsigned long *);
ad8c80a5 335extern void packed_object_info_detail(struct pack_entry *, char *, unsigned long *, unsigned long *, int *, unsigned char *);
9a217f2a 336
8f3f9b09
JH
337/* Dumb servers support */
338extern int update_server_info(int);
339
e83c5163 340#endif /* CACHE_H */