Support receiving server capabilities
[git/git.git] / cache.h
1 #ifndef CACHE_H
2 #define CACHE_H
3
4 #include <unistd.h>
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>
11 #include <string.h>
12 #include <errno.h>
13 #include <limits.h>
14 #ifndef NO_MMAP
15 #include <sys/mman.h>
16 #endif
17 #include <sys/param.h>
18 #include <netinet/in.h>
19 #include <sys/types.h>
20 #include <dirent.h>
21
22 #include SHA1_HEADER
23 #include <zlib.h>
24
25 #if ZLIB_VERNUM < 0x1200
26 #define deflateBound(c,s) ((s) + (((s) + 7) >> 3) + (((s) + 63) >> 6) + 11)
27 #endif
28
29 #ifdef DT_UNKNOWN
30 #define DTYPE(de) ((de)->d_type)
31 #else
32 #define DT_UNKNOWN 0
33 #define DT_DIR 1
34 #define DT_REG 2
35 #define DT_LNK 3
36 #define DTYPE(de) DT_UNKNOWN
37 #endif
38
39 #ifdef __GNUC__
40 #define NORETURN __attribute__((__noreturn__))
41 #else
42 #define NORETURN
43 #ifndef __attribute__
44 #define __attribute__(x)
45 #endif
46 #endif
47
48 /*
49 * Intensive research over the course of many years has shown that
50 * port 9418 is totally unused by anything else. Or
51 *
52 * Your search - "port 9418" - did not match any documents.
53 *
54 * as www.google.com puts it.
55 *
56 * This port has been properly assigned for git use by IANA:
57 * git (Assigned-9418) [I06-050728-0001].
58 *
59 * git 9418/tcp git pack transfer service
60 * git 9418/udp git pack transfer service
61 *
62 * with Linus Torvalds <torvalds@osdl.org> as the point of
63 * contact. September 2005.
64 *
65 * See http://www.iana.org/assignments/port-numbers
66 */
67 #define DEFAULT_GIT_PORT 9418
68
69 /*
70 * Basic data structures for the directory cache
71 */
72
73 #define CACHE_SIGNATURE 0x44495243 /* "DIRC" */
74 struct cache_header {
75 unsigned int hdr_signature;
76 unsigned int hdr_version;
77 unsigned int hdr_entries;
78 };
79
80 /*
81 * The "cache_time" is just the low 32 bits of the
82 * time. It doesn't matter if it overflows - we only
83 * check it for equality in the 32 bits we save.
84 */
85 struct cache_time {
86 unsigned int sec;
87 unsigned int nsec;
88 };
89
90 /*
91 * dev/ino/uid/gid/size are also just tracked to the low 32 bits
92 * Again - this is just a (very strong in practice) heuristic that
93 * the inode hasn't changed.
94 *
95 * We save the fields in big-endian order to allow using the
96 * index file over NFS transparently.
97 */
98 struct cache_entry {
99 struct cache_time ce_ctime;
100 struct cache_time ce_mtime;
101 unsigned int ce_dev;
102 unsigned int ce_ino;
103 unsigned int ce_mode;
104 unsigned int ce_uid;
105 unsigned int ce_gid;
106 unsigned int ce_size;
107 unsigned char sha1[20];
108 unsigned short ce_flags;
109 char name[0];
110 };
111
112 #define CE_NAMEMASK (0x0fff)
113 #define CE_STAGEMASK (0x3000)
114 #define CE_UPDATE (0x4000)
115 #define CE_STAGESHIFT 12
116
117 #define create_ce_flags(len, stage) htons((len) | ((stage) << CE_STAGESHIFT))
118 #define ce_namelen(ce) (CE_NAMEMASK & ntohs((ce)->ce_flags))
119 #define ce_size(ce) cache_entry_size(ce_namelen(ce))
120 #define ce_stage(ce) ((CE_STAGEMASK & ntohs((ce)->ce_flags)) >> CE_STAGESHIFT)
121
122 #define ce_permissions(mode) (((mode) & 0100) ? 0755 : 0644)
123 static inline unsigned int create_ce_mode(unsigned int mode)
124 {
125 if (S_ISLNK(mode))
126 return htonl(S_IFLNK);
127 return htonl(S_IFREG | ce_permissions(mode));
128 }
129
130 #define cache_entry_size(len) ((offsetof(struct cache_entry,name) + (len) + 8) & ~7)
131
132 extern struct cache_entry **active_cache;
133 extern unsigned int active_nr, active_alloc, active_cache_changed;
134
135 #define GIT_DIR_ENVIRONMENT "GIT_DIR"
136 #define DEFAULT_GIT_DIR_ENVIRONMENT ".git"
137 #define DB_ENVIRONMENT "GIT_OBJECT_DIRECTORY"
138 #define INDEX_ENVIRONMENT "GIT_INDEX_FILE"
139 #define GRAFT_ENVIRONMENT "GIT_GRAFT_FILE"
140
141 extern char *get_git_dir(void);
142 extern char *get_object_directory(void);
143 extern char *get_refs_directory(void);
144 extern char *get_index_file(void);
145 extern char *get_graft_file(void);
146
147 #define ALTERNATE_DB_ENVIRONMENT "GIT_ALTERNATE_OBJECT_DIRECTORIES"
148
149 extern const char **get_pathspec(const char *prefix, const char **pathspec);
150 extern const char *setup_git_directory(void);
151 extern const char *prefix_path(const char *prefix, int len, const char *path);
152
153 #define alloc_nr(x) (((x)+16)*3/2)
154
155 /* Initialize and use the cache information */
156 extern int read_cache(void);
157 extern int write_cache(int newfd, struct cache_entry **cache, int entries);
158 extern int cache_name_pos(const char *name, int namelen);
159 #define ADD_CACHE_OK_TO_ADD 1 /* Ok to add */
160 #define ADD_CACHE_OK_TO_REPLACE 2 /* Ok to replace file/directory */
161 #define ADD_CACHE_SKIP_DFCHECK 4 /* Ok to skip DF conflict checks */
162 extern int add_cache_entry(struct cache_entry *ce, int option);
163 extern int remove_cache_entry_at(int pos);
164 extern int remove_file_from_cache(const char *path);
165 extern int ce_same_name(struct cache_entry *a, struct cache_entry *b);
166 extern int ce_match_stat(struct cache_entry *ce, struct stat *st);
167 extern int ce_modified(struct cache_entry *ce, struct stat *st);
168 extern int ce_path_match(const struct cache_entry *ce, const char **pathspec);
169 extern int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object, const char *type);
170 extern int index_path(unsigned char *sha1, const char *path, struct stat *st, int write_object);
171 extern void fill_stat_cache_info(struct cache_entry *ce, struct stat *st);
172
173 struct cache_file {
174 struct cache_file *next;
175 char lockfile[PATH_MAX];
176 };
177 extern int hold_index_file_for_update(struct cache_file *, const char *path);
178 extern int commit_index_file(struct cache_file *);
179 extern void rollback_index_file(struct cache_file *);
180
181 extern int trust_executable_bit;
182
183 #define MTIME_CHANGED 0x0001
184 #define CTIME_CHANGED 0x0002
185 #define OWNER_CHANGED 0x0004
186 #define MODE_CHANGED 0x0008
187 #define INODE_CHANGED 0x0010
188 #define DATA_CHANGED 0x0020
189 #define TYPE_CHANGED 0x0040
190
191 /* Return a statically allocated filename matching the sha1 signature */
192 extern char *mkpath(const char *fmt, ...) __attribute__((format (printf, 1, 2)));
193 extern char *git_path(const char *fmt, ...) __attribute__((format (printf, 1, 2)));
194 extern char *sha1_file_name(const unsigned char *sha1);
195 extern char *sha1_pack_name(const unsigned char *sha1);
196 extern char *sha1_pack_index_name(const unsigned char *sha1);
197 extern const char *find_unique_abbrev(const unsigned char *sha1, int);
198 extern const unsigned char null_sha1[20];
199
200 int git_mkstemp(char *path, size_t n, const char *template);
201
202 int safe_create_leading_directories(char *path);
203 char *safe_strncpy(char *, const char *, size_t);
204
205 /* Read and unpack a sha1 file into memory, write memory to a sha1 file */
206 extern int unpack_sha1_header(z_stream *stream, void *map, unsigned long mapsize, void *buffer, unsigned long size);
207 extern int parse_sha1_header(char *hdr, char *type, unsigned long *sizep);
208 extern int sha1_object_info(const unsigned char *, char *, unsigned long *);
209 extern void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size);
210 extern void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size);
211 extern int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *return_sha1);
212 extern char *write_sha1_file_prepare(void *buf,
213 unsigned long len,
214 const char *type,
215 unsigned char *sha1,
216 unsigned char *hdr,
217 int *hdrlen);
218
219 extern int check_sha1_signature(const unsigned char *sha1, void *buf, unsigned long size, const char *type);
220
221 /* Read a tree into the cache */
222 extern int read_tree(void *buffer, unsigned long size, int stage, const char **paths);
223
224 extern int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
225 size_t bufsize, size_t *bufposn);
226 extern int write_sha1_to_fd(int fd, const unsigned char *sha1);
227 extern int move_temp_to_file(const char *tmpfile, char *filename);
228
229 extern int has_sha1_pack(const unsigned char *sha1);
230 extern int has_sha1_file(const unsigned char *sha1);
231
232 extern int has_pack_file(const unsigned char *sha1);
233 extern int has_pack_index(const unsigned char *sha1);
234
235 /* Convert to/from hex/sha1 representation */
236 extern int get_sha1(const char *str, unsigned char *sha1);
237 extern int get_sha1_hex(const char *hex, unsigned char *sha1);
238 extern char *sha1_to_hex(const unsigned char *sha1); /* static buffer result! */
239 extern int read_ref(const char *filename, unsigned char *sha1);
240 extern const char *resolve_ref(const char *path, unsigned char *sha1, int);
241 extern int create_symref(const char *git_HEAD, const char *refs_heads_master);
242 extern int validate_symref(const char *git_HEAD);
243
244 /* General helper functions */
245 extern void usage(const char *err) NORETURN;
246 extern void die(const char *err, ...) NORETURN __attribute__((format (printf, 1, 2)));
247 extern int error(const char *err, ...) __attribute__((format (printf, 1, 2)));
248
249 extern int base_name_compare(const char *name1, int len1, int mode1, const char *name2, int len2, int mode2);
250 extern int cache_name_compare(const char *name1, int len1, const char *name2, int len2);
251
252 extern void *read_object_with_reference(const unsigned char *sha1,
253 const char *required_type,
254 unsigned long *size,
255 unsigned char *sha1_ret);
256
257 const char *show_date(unsigned long time, int timezone);
258 int parse_date(const char *date, char *buf, int bufsize);
259 void datestamp(char *buf, int bufsize);
260
261 extern int setup_ident(void);
262 extern char *get_ident(const char *name, const char *email, const char *date_str);
263 extern char *git_author_info(void);
264 extern char *git_committer_info(void);
265
266 static inline void *xmalloc(size_t size)
267 {
268 void *ret = malloc(size);
269 if (!ret)
270 die("Out of memory, malloc failed");
271 return ret;
272 }
273
274 static inline void *xrealloc(void *ptr, size_t size)
275 {
276 void *ret = realloc(ptr, size);
277 if (!ret)
278 die("Out of memory, realloc failed");
279 return ret;
280 }
281
282 static inline void *xcalloc(size_t nmemb, size_t size)
283 {
284 void *ret = calloc(nmemb, size);
285 if (!ret)
286 die("Out of memory, calloc failed");
287 return ret;
288 }
289
290 struct checkout {
291 const char *base_dir;
292 int base_dir_len;
293 unsigned force:1,
294 quiet:1,
295 not_new:1,
296 refresh_cache:1;
297 };
298
299 extern int checkout_entry(struct cache_entry *ce, struct checkout *state);
300
301 extern struct alternate_object_database {
302 struct alternate_object_database *next;
303 char *name;
304 char base[0]; /* more */
305 } *alt_odb_list;
306 extern void prepare_alt_odb(void);
307
308 extern struct packed_git {
309 struct packed_git *next;
310 unsigned long index_size;
311 unsigned long pack_size;
312 unsigned int *index_base;
313 void *pack_base;
314 unsigned int pack_last_used;
315 unsigned int pack_use_cnt;
316 int pack_local;
317 unsigned char sha1[20];
318 char pack_name[0]; /* something like ".git/objects/pack/xxxxx.pack" */
319 } *packed_git;
320
321 struct pack_entry {
322 unsigned int offset;
323 unsigned char sha1[20];
324 struct packed_git *p;
325 };
326
327 struct ref {
328 struct ref *next;
329 unsigned char old_sha1[20];
330 unsigned char new_sha1[20];
331 unsigned char force;
332 struct ref *peer_ref; /* when renaming */
333 char name[0];
334 };
335
336 extern int git_connect(int fd[2], char *url, const char *prog);
337 extern int finish_connect(pid_t pid);
338 extern int path_match(const char *path, int nr, char **match);
339 extern int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail,
340 int nr_refspec, char **refspec, int all);
341 extern int get_ack(int fd, unsigned char *result_sha1);
342 extern struct ref **get_remote_heads(int in, struct ref **list, int nr_match, char **match, int ignore_funny);
343 extern int server_supports(const char *feature);
344
345 extern struct packed_git *parse_pack_index(unsigned char *sha1);
346 extern struct packed_git *parse_pack_index_file(const unsigned char *sha1,
347 char *idx_path);
348
349 extern void prepare_packed_git(void);
350 extern void install_packed_git(struct packed_git *pack);
351
352 extern struct packed_git *find_sha1_pack(const unsigned char *sha1,
353 struct packed_git *packs);
354
355 extern int use_packed_git(struct packed_git *);
356 extern void unuse_packed_git(struct packed_git *);
357 extern struct packed_git *add_packed_git(char *, int, int);
358 extern int num_packed_objects(const struct packed_git *p);
359 extern int nth_packed_object_sha1(const struct packed_git *, int, unsigned char*);
360 extern int find_pack_entry_one(const unsigned char *, struct pack_entry *, struct packed_git *);
361 extern void *unpack_entry_gently(struct pack_entry *, char *, unsigned long *);
362 extern void packed_object_info_detail(struct pack_entry *, char *, unsigned long *, unsigned long *, int *, unsigned char *);
363
364 /* Dumb servers support */
365 extern int update_server_info(int);
366
367 #ifdef NO_MMAP
368
369 #ifndef PROT_READ
370 #define PROT_READ 1
371 #define PROT_WRITE 2
372 #define MAP_PRIVATE 1
373 #define MAP_FAILED ((void*)-1)
374 #endif
375
376 extern void *gitfakemmap(void *start, size_t length, int prot , int flags, int fd, off_t offset);
377 extern int gitfakemunmap(void *start, size_t length);
378
379 #endif
380
381 typedef int (*config_fn_t)(const char *, const char *);
382 extern int git_default_config(const char *, const char *);
383 extern int git_config(config_fn_t fn);
384 extern int git_config_int(const char *, const char *);
385 extern int git_config_bool(const char *, const char *);
386
387 #define MAX_GITNAME (1000)
388 extern char git_default_email[MAX_GITNAME];
389 extern char git_default_name[MAX_GITNAME];
390
391 /* Sane ctype - no locale, and works with signed chars */
392 #undef isspace
393 #undef isdigit
394 #undef isalpha
395 #undef isalnum
396 #undef tolower
397 #undef toupper
398 extern unsigned char sane_ctype[256];
399 #define GIT_SPACE 0x01
400 #define GIT_DIGIT 0x02
401 #define GIT_ALPHA 0x04
402 #define sane_istest(x,mask) ((sane_ctype[(unsigned char)(x)] & (mask)) != 0)
403 #define isspace(x) sane_istest(x,GIT_SPACE)
404 #define isdigit(x) sane_istest(x,GIT_DIGIT)
405 #define isalpha(x) sane_istest(x,GIT_ALPHA)
406 #define isalnum(x) sane_istest(x,GIT_ALPHA | GIT_DIGIT)
407 #define tolower(x) sane_case((unsigned char)(x), 0x20)
408 #define toupper(x) sane_case((unsigned char)(x), 0)
409
410 static inline int sane_case(int x, int high)
411 {
412 if (sane_istest(x, GIT_ALPHA))
413 x = (x & ~0x20) | high;
414 return x;
415 }
416
417 extern int copy_fd(int ifd, int ofd);
418 #endif /* CACHE_H */