?alloc: do not return NULL when asked for zero bytes
[git/dscho.git] / cache.h
blobcb87becb3aaea75915a65e99565c418d6765174b
1 #ifndef CACHE_H
2 #define CACHE_H
4 #include "git-compat-util.h"
6 #include SHA1_HEADER
7 #include <zlib.h>
9 #if ZLIB_VERNUM < 0x1200
10 #define deflateBound(c,s) ((s) + (((s) + 7) >> 3) + (((s) + 63) >> 6) + 11)
11 #endif
13 #ifdef DT_UNKNOWN
14 #define DTYPE(de) ((de)->d_type)
15 #else
16 #define DT_UNKNOWN 0
17 #define DT_DIR 1
18 #define DT_REG 2
19 #define DT_LNK 3
20 #define DTYPE(de) DT_UNKNOWN
21 #endif
24 * Intensive research over the course of many years has shown that
25 * port 9418 is totally unused by anything else. Or
27 * Your search - "port 9418" - did not match any documents.
29 * as www.google.com puts it.
31 * This port has been properly assigned for git use by IANA:
32 * git (Assigned-9418) [I06-050728-0001].
34 * git 9418/tcp git pack transfer service
35 * git 9418/udp git pack transfer service
37 * with Linus Torvalds <torvalds@osdl.org> as the point of
38 * contact. September 2005.
40 * See http://www.iana.org/assignments/port-numbers
42 #define DEFAULT_GIT_PORT 9418
45 * Basic data structures for the directory cache
48 #define CACHE_SIGNATURE 0x44495243 /* "DIRC" */
49 struct cache_header {
50 unsigned int hdr_signature;
51 unsigned int hdr_version;
52 unsigned int hdr_entries;
56 * The "cache_time" is just the low 32 bits of the
57 * time. It doesn't matter if it overflows - we only
58 * check it for equality in the 32 bits we save.
60 struct cache_time {
61 unsigned int sec;
62 unsigned int nsec;
66 * dev/ino/uid/gid/size are also just tracked to the low 32 bits
67 * Again - this is just a (very strong in practice) heuristic that
68 * the inode hasn't changed.
70 * We save the fields in big-endian order to allow using the
71 * index file over NFS transparently.
73 struct cache_entry {
74 struct cache_time ce_ctime;
75 struct cache_time ce_mtime;
76 unsigned int ce_dev;
77 unsigned int ce_ino;
78 unsigned int ce_mode;
79 unsigned int ce_uid;
80 unsigned int ce_gid;
81 unsigned int ce_size;
82 unsigned char sha1[20];
83 unsigned short ce_flags;
84 char name[0];
87 #define CE_NAMEMASK (0x0fff)
88 #define CE_STAGEMASK (0x3000)
89 #define CE_UPDATE (0x4000)
90 #define CE_STAGESHIFT 12
92 #define create_ce_flags(len, stage) htons((len) | ((stage) << CE_STAGESHIFT))
93 #define ce_namelen(ce) (CE_NAMEMASK & ntohs((ce)->ce_flags))
94 #define ce_size(ce) cache_entry_size(ce_namelen(ce))
95 #define ce_stage(ce) ((CE_STAGEMASK & ntohs((ce)->ce_flags)) >> CE_STAGESHIFT)
97 #define ce_permissions(mode) (((mode) & 0100) ? 0755 : 0644)
98 static inline unsigned int create_ce_mode(unsigned int mode)
100 if (S_ISLNK(mode))
101 return htonl(S_IFLNK);
102 return htonl(S_IFREG | ce_permissions(mode));
105 #define cache_entry_size(len) ((offsetof(struct cache_entry,name) + (len) + 8) & ~7)
107 extern struct cache_entry **active_cache;
108 extern unsigned int active_nr, active_alloc, active_cache_changed;
110 #define GIT_DIR_ENVIRONMENT "GIT_DIR"
111 #define DEFAULT_GIT_DIR_ENVIRONMENT ".git"
112 #define DB_ENVIRONMENT "GIT_OBJECT_DIRECTORY"
113 #define INDEX_ENVIRONMENT "GIT_INDEX_FILE"
114 #define GRAFT_ENVIRONMENT "GIT_GRAFT_FILE"
116 extern char *get_git_dir(void);
117 extern char *get_object_directory(void);
118 extern char *get_refs_directory(void);
119 extern char *get_index_file(void);
120 extern char *get_graft_file(void);
122 #define ALTERNATE_DB_ENVIRONMENT "GIT_ALTERNATE_OBJECT_DIRECTORIES"
124 extern const char **get_pathspec(const char *prefix, const char **pathspec);
125 extern const char *setup_git_directory_gently(int *);
126 extern const char *setup_git_directory(void);
127 extern const char *prefix_path(const char *prefix, int len, const char *path);
128 extern const char *prefix_filename(const char *prefix, int len, const char *path);
130 #define alloc_nr(x) (((x)+16)*3/2)
132 /* Initialize and use the cache information */
133 extern int read_cache(void);
134 extern int write_cache(int newfd, struct cache_entry **cache, int entries);
135 extern int cache_name_pos(const char *name, int namelen);
136 #define ADD_CACHE_OK_TO_ADD 1 /* Ok to add */
137 #define ADD_CACHE_OK_TO_REPLACE 2 /* Ok to replace file/directory */
138 #define ADD_CACHE_SKIP_DFCHECK 4 /* Ok to skip DF conflict checks */
139 extern int add_cache_entry(struct cache_entry *ce, int option);
140 extern int remove_cache_entry_at(int pos);
141 extern int remove_file_from_cache(const char *path);
142 extern int ce_same_name(struct cache_entry *a, struct cache_entry *b);
143 extern int ce_match_stat(struct cache_entry *ce, struct stat *st);
144 extern int ce_modified(struct cache_entry *ce, struct stat *st);
145 extern int ce_path_match(const struct cache_entry *ce, const char **pathspec);
146 extern int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object, const char *type);
147 extern int index_pipe(unsigned char *sha1, int fd, const char *type, int write_object);
148 extern int index_path(unsigned char *sha1, const char *path, struct stat *st, int write_object);
149 extern void fill_stat_cache_info(struct cache_entry *ce, struct stat *st);
151 struct cache_file {
152 struct cache_file *next;
153 char lockfile[PATH_MAX];
155 extern int hold_index_file_for_update(struct cache_file *, const char *path);
156 extern int commit_index_file(struct cache_file *);
157 extern void rollback_index_file(struct cache_file *);
159 extern int trust_executable_bit;
160 extern int only_use_symrefs;
161 extern int diff_rename_limit_default;
163 #define GIT_REPO_VERSION 0
164 extern int repository_format_version;
165 extern int check_repository_format(void);
167 #define MTIME_CHANGED 0x0001
168 #define CTIME_CHANGED 0x0002
169 #define OWNER_CHANGED 0x0004
170 #define MODE_CHANGED 0x0008
171 #define INODE_CHANGED 0x0010
172 #define DATA_CHANGED 0x0020
173 #define TYPE_CHANGED 0x0040
175 /* Return a statically allocated filename matching the sha1 signature */
176 extern char *mkpath(const char *fmt, ...) __attribute__((format (printf, 1, 2)));
177 extern char *git_path(const char *fmt, ...) __attribute__((format (printf, 1, 2)));
178 extern char *sha1_file_name(const unsigned char *sha1);
179 extern char *sha1_pack_name(const unsigned char *sha1);
180 extern char *sha1_pack_index_name(const unsigned char *sha1);
181 extern const char *find_unique_abbrev(const unsigned char *sha1, int);
182 extern const unsigned char null_sha1[20];
184 int git_mkstemp(char *path, size_t n, const char *template);
186 int safe_create_leading_directories(char *path);
187 char *safe_strncpy(char *, const char *, size_t);
188 char *enter_repo(char *path, int strict);
190 /* Read and unpack a sha1 file into memory, write memory to a sha1 file */
191 extern int unpack_sha1_header(z_stream *stream, void *map, unsigned long mapsize, void *buffer, unsigned long size);
192 extern int parse_sha1_header(char *hdr, char *type, unsigned long *sizep);
193 extern int sha1_object_info(const unsigned char *, char *, unsigned long *);
194 extern void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size);
195 extern void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size);
196 extern int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *return_sha1);
197 extern char *write_sha1_file_prepare(void *buf,
198 unsigned long len,
199 const char *type,
200 unsigned char *sha1,
201 unsigned char *hdr,
202 int *hdrlen);
204 extern int check_sha1_signature(const unsigned char *sha1, void *buf, unsigned long size, const char *type);
206 /* Read a tree into the cache */
207 extern int read_tree(void *buffer, unsigned long size, int stage, const char **paths);
209 extern int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
210 size_t bufsize, size_t *bufposn);
211 extern int write_sha1_to_fd(int fd, const unsigned char *sha1);
212 extern int move_temp_to_file(const char *tmpfile, char *filename);
214 extern int has_sha1_pack(const unsigned char *sha1);
215 extern int has_sha1_file(const unsigned char *sha1);
217 extern int has_pack_file(const unsigned char *sha1);
218 extern int has_pack_index(const unsigned char *sha1);
220 /* Convert to/from hex/sha1 representation */
221 extern int get_sha1(const char *str, unsigned char *sha1);
222 extern int get_sha1_hex(const char *hex, unsigned char *sha1);
223 extern char *sha1_to_hex(const unsigned char *sha1); /* static buffer result! */
224 extern int read_ref(const char *filename, unsigned char *sha1);
225 extern const char *resolve_ref(const char *path, unsigned char *sha1, int);
226 extern int create_symref(const char *git_HEAD, const char *refs_heads_master);
227 extern int validate_symref(const char *git_HEAD);
229 extern int base_name_compare(const char *name1, int len1, int mode1, const char *name2, int len2, int mode2);
230 extern int cache_name_compare(const char *name1, int len1, const char *name2, int len2);
232 extern void *read_object_with_reference(const unsigned char *sha1,
233 const char *required_type,
234 unsigned long *size,
235 unsigned char *sha1_ret);
237 const char *show_date(unsigned long time, int timezone);
238 int parse_date(const char *date, char *buf, int bufsize);
239 void datestamp(char *buf, int bufsize);
240 unsigned long approxidate(const char *);
242 extern int setup_ident(void);
243 extern const char *git_author_info(void);
244 extern const char *git_committer_info(void);
246 struct checkout {
247 const char *base_dir;
248 int base_dir_len;
249 unsigned force:1,
250 quiet:1,
251 not_new:1,
252 refresh_cache:1;
255 extern int checkout_entry(struct cache_entry *ce, struct checkout *state);
257 extern struct alternate_object_database {
258 struct alternate_object_database *next;
259 char *name;
260 char base[0]; /* more */
261 } *alt_odb_list;
262 extern void prepare_alt_odb(void);
264 extern struct packed_git {
265 struct packed_git *next;
266 unsigned long index_size;
267 unsigned long pack_size;
268 unsigned int *index_base;
269 void *pack_base;
270 unsigned int pack_last_used;
271 unsigned int pack_use_cnt;
272 int pack_local;
273 unsigned char sha1[20];
274 char pack_name[0]; /* something like ".git/objects/pack/xxxxx.pack" */
275 } *packed_git;
277 struct pack_entry {
278 unsigned int offset;
279 unsigned char sha1[20];
280 struct packed_git *p;
283 struct ref {
284 struct ref *next;
285 unsigned char old_sha1[20];
286 unsigned char new_sha1[20];
287 unsigned char force;
288 struct ref *peer_ref; /* when renaming */
289 char name[0];
292 extern int git_connect(int fd[2], char *url, const char *prog);
293 extern int finish_connect(pid_t pid);
294 extern int path_match(const char *path, int nr, char **match);
295 extern int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail,
296 int nr_refspec, char **refspec, int all);
297 extern int get_ack(int fd, unsigned char *result_sha1);
298 extern struct ref **get_remote_heads(int in, struct ref **list, int nr_match, char **match, int ignore_funny);
299 extern int server_supports(const char *feature);
301 extern struct packed_git *parse_pack_index(unsigned char *sha1);
302 extern struct packed_git *parse_pack_index_file(const unsigned char *sha1,
303 char *idx_path);
305 extern void prepare_packed_git(void);
306 extern void install_packed_git(struct packed_git *pack);
308 extern struct packed_git *find_sha1_pack(const unsigned char *sha1,
309 struct packed_git *packs);
311 extern int use_packed_git(struct packed_git *);
312 extern void unuse_packed_git(struct packed_git *);
313 extern struct packed_git *add_packed_git(char *, int, int);
314 extern int num_packed_objects(const struct packed_git *p);
315 extern int nth_packed_object_sha1(const struct packed_git *, int, unsigned char*);
316 extern int find_pack_entry_one(const unsigned char *, struct pack_entry *, struct packed_git *);
317 extern void *unpack_entry_gently(struct pack_entry *, char *, unsigned long *);
318 extern void packed_object_info_detail(struct pack_entry *, char *, unsigned long *, unsigned long *, int *, unsigned char *);
320 /* Dumb servers support */
321 extern int update_server_info(int);
323 typedef int (*config_fn_t)(const char *, const char *);
324 extern int git_default_config(const char *, const char *);
325 extern int git_config_from_file(config_fn_t fn, const char *);
326 extern int git_config(config_fn_t fn);
327 extern int git_config_int(const char *, const char *);
328 extern int git_config_bool(const char *, const char *);
329 extern int git_config_set(const char *, const char *);
330 extern int git_config_set_multivar(const char *, const char *, const char *, int);
331 extern int check_repository_format_version(const char *var, const char *value);
333 #define MAX_GITNAME (1000)
334 extern char git_default_email[MAX_GITNAME];
335 extern char git_default_name[MAX_GITNAME];
337 #define MAX_ENCODING_LENGTH 64
338 extern char git_commit_encoding[MAX_ENCODING_LENGTH];
340 extern int copy_fd(int ifd, int ofd);
342 /* Finish off pack transfer receiving end */
343 extern int receive_unpack_pack(int fd[2], const char *me, int quiet);
344 extern int receive_keep_pack(int fd[2], const char *me);
346 #endif /* CACHE_H */