Documentation: expand preface and todo's
[git/jrn.git] / cache.h
blob31b0819e83d7f76ed52db7771cf274e74b2156dc
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 #if defined(DT_UNKNOWN) && !defined(NO_D_TYPE_IN_DIRENT)
14 #define DTYPE(de) ((de)->d_type)
15 #else
16 #undef DT_UNKNOWN
17 #undef DT_DIR
18 #undef DT_REG
19 #undef DT_LNK
20 #define DT_UNKNOWN 0
21 #define DT_DIR 1
22 #define DT_REG 2
23 #define DT_LNK 3
24 #define DTYPE(de) DT_UNKNOWN
25 #endif
28 * Intensive research over the course of many years has shown that
29 * port 9418 is totally unused by anything else. Or
31 * Your search - "port 9418" - did not match any documents.
33 * as www.google.com puts it.
35 * This port has been properly assigned for git use by IANA:
36 * git (Assigned-9418) [I06-050728-0001].
38 * git 9418/tcp git pack transfer service
39 * git 9418/udp git pack transfer service
41 * with Linus Torvalds <torvalds@osdl.org> as the point of
42 * contact. September 2005.
44 * See http://www.iana.org/assignments/port-numbers
46 #define DEFAULT_GIT_PORT 9418
49 * Basic data structures for the directory cache
52 #define CACHE_SIGNATURE 0x44495243 /* "DIRC" */
53 struct cache_header {
54 unsigned int hdr_signature;
55 unsigned int hdr_version;
56 unsigned int hdr_entries;
60 * The "cache_time" is just the low 32 bits of the
61 * time. It doesn't matter if it overflows - we only
62 * check it for equality in the 32 bits we save.
64 struct cache_time {
65 unsigned int sec;
66 unsigned int nsec;
70 * dev/ino/uid/gid/size are also just tracked to the low 32 bits
71 * Again - this is just a (very strong in practice) heuristic that
72 * the inode hasn't changed.
74 * We save the fields in big-endian order to allow using the
75 * index file over NFS transparently.
77 struct cache_entry {
78 struct cache_time ce_ctime;
79 struct cache_time ce_mtime;
80 unsigned int ce_dev;
81 unsigned int ce_ino;
82 unsigned int ce_mode;
83 unsigned int ce_uid;
84 unsigned int ce_gid;
85 unsigned int ce_size;
86 unsigned char sha1[20];
87 unsigned short ce_flags;
88 char name[FLEX_ARRAY]; /* more */
91 #define CE_NAMEMASK (0x0fff)
92 #define CE_STAGEMASK (0x3000)
93 #define CE_UPDATE (0x4000)
94 #define CE_VALID (0x8000)
95 #define CE_STAGESHIFT 12
97 #define create_ce_flags(len, stage) htons((len) | ((stage) << CE_STAGESHIFT))
98 #define ce_namelen(ce) (CE_NAMEMASK & ntohs((ce)->ce_flags))
99 #define ce_size(ce) cache_entry_size(ce_namelen(ce))
100 #define ce_stage(ce) ((CE_STAGEMASK & ntohs((ce)->ce_flags)) >> CE_STAGESHIFT)
102 #define ce_permissions(mode) (((mode) & 0100) ? 0755 : 0644)
103 static inline unsigned int create_ce_mode(unsigned int mode)
105 if (S_ISLNK(mode))
106 return htonl(S_IFLNK);
107 return htonl(S_IFREG | ce_permissions(mode));
109 #define canon_mode(mode) \
110 (S_ISREG(mode) ? (S_IFREG | ce_permissions(mode)) : \
111 S_ISLNK(mode) ? S_IFLNK : S_IFDIR)
113 #define cache_entry_size(len) ((offsetof(struct cache_entry,name) + (len) + 8) & ~7)
115 extern struct cache_entry **active_cache;
116 extern unsigned int active_nr, active_alloc, active_cache_changed;
117 extern struct cache_tree *active_cache_tree;
118 extern int cache_errno;
120 #define GIT_DIR_ENVIRONMENT "GIT_DIR"
121 #define DEFAULT_GIT_DIR_ENVIRONMENT ".git"
122 #define DB_ENVIRONMENT "GIT_OBJECT_DIRECTORY"
123 #define INDEX_ENVIRONMENT "GIT_INDEX_FILE"
124 #define GRAFT_ENVIRONMENT "GIT_GRAFT_FILE"
125 #define TEMPLATE_DIR_ENVIRONMENT "GIT_TEMPLATE_DIR"
126 #define CONFIG_ENVIRONMENT "GIT_CONFIG"
127 #define CONFIG_LOCAL_ENVIRONMENT "GIT_CONFIG_LOCAL"
128 #define EXEC_PATH_ENVIRONMENT "GIT_EXEC_PATH"
130 extern int is_bare_git_dir(const char *dir);
131 extern const char *get_git_dir(void);
132 extern char *get_object_directory(void);
133 extern char *get_refs_directory(void);
134 extern char *get_index_file(void);
135 extern char *get_graft_file(void);
137 #define ALTERNATE_DB_ENVIRONMENT "GIT_ALTERNATE_OBJECT_DIRECTORIES"
139 extern const char **get_pathspec(const char *prefix, const char **pathspec);
140 extern const char *setup_git_directory_gently(int *);
141 extern const char *setup_git_directory(void);
142 extern const char *prefix_path(const char *prefix, int len, const char *path);
143 extern const char *prefix_filename(const char *prefix, int len, const char *path);
144 extern void verify_filename(const char *prefix, const char *name);
145 extern void verify_non_filename(const char *prefix, const char *name);
147 #define alloc_nr(x) (((x)+16)*3/2)
149 /* Initialize and use the cache information */
150 extern int read_cache(void);
151 extern int read_cache_from(const char *path);
152 extern int write_cache(int newfd, struct cache_entry **cache, int entries);
153 extern int discard_cache(void);
154 extern int verify_path(const char *path);
155 extern int cache_name_pos(const char *name, int namelen);
156 #define ADD_CACHE_OK_TO_ADD 1 /* Ok to add */
157 #define ADD_CACHE_OK_TO_REPLACE 2 /* Ok to replace file/directory */
158 #define ADD_CACHE_SKIP_DFCHECK 4 /* Ok to skip DF conflict checks */
159 extern int add_cache_entry(struct cache_entry *ce, int option);
160 extern struct cache_entry *refresh_cache_entry(struct cache_entry *ce, int really);
161 extern int remove_cache_entry_at(int pos);
162 extern int remove_file_from_cache(const char *path);
163 extern int add_file_to_index(const char *path, int verbose);
164 extern int ce_same_name(struct cache_entry *a, struct cache_entry *b);
165 extern int ce_match_stat(struct cache_entry *ce, struct stat *st, int);
166 extern int ce_modified(struct cache_entry *ce, struct stat *st, int);
167 extern int ce_path_match(const struct cache_entry *ce, const char **pathspec);
168 extern int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object, const char *type);
169 extern int read_pipe(int fd, char** return_buf, unsigned long* return_size);
170 extern int index_pipe(unsigned char *sha1, int fd, const char *type, int write_object);
171 extern int index_path(unsigned char *sha1, const char *path, struct stat *st, int write_object);
172 extern void fill_stat_cache_info(struct cache_entry *ce, struct stat *st);
174 #define REFRESH_REALLY 0x0001 /* ignore_valid */
175 #define REFRESH_UNMERGED 0x0002 /* allow unmerged */
176 #define REFRESH_QUIET 0x0004 /* be quiet about it */
177 #define REFRESH_IGNORE_MISSING 0x0008 /* ignore non-existent */
178 extern int refresh_cache(unsigned int flags);
180 struct lock_file {
181 struct lock_file *next;
182 char on_list;
183 char filename[PATH_MAX];
185 extern int hold_lock_file_for_update(struct lock_file *, const char *path, int);
186 extern int commit_lock_file(struct lock_file *);
187 extern void rollback_lock_file(struct lock_file *);
188 extern int delete_ref(const char *, unsigned char *sha1);
190 /* Environment bits from configuration mechanism */
191 extern int use_legacy_headers;
192 extern int trust_executable_bit;
193 extern int assume_unchanged;
194 extern int prefer_symlink_refs;
195 extern int log_all_ref_updates;
196 extern int warn_ambiguous_refs;
197 extern int shared_repository;
198 extern const char *apply_default_whitespace;
199 extern int zlib_compression_level;
201 #define GIT_REPO_VERSION 0
202 extern int repository_format_version;
203 extern int check_repository_format(void);
205 #define MTIME_CHANGED 0x0001
206 #define CTIME_CHANGED 0x0002
207 #define OWNER_CHANGED 0x0004
208 #define MODE_CHANGED 0x0008
209 #define INODE_CHANGED 0x0010
210 #define DATA_CHANGED 0x0020
211 #define TYPE_CHANGED 0x0040
213 /* Return a statically allocated filename matching the sha1 signature */
214 extern char *mkpath(const char *fmt, ...) __attribute__((format (printf, 1, 2)));
215 extern char *git_path(const char *fmt, ...) __attribute__((format (printf, 1, 2)));
216 extern char *sha1_file_name(const unsigned char *sha1);
217 extern char *sha1_pack_name(const unsigned char *sha1);
218 extern char *sha1_pack_index_name(const unsigned char *sha1);
219 extern const char *find_unique_abbrev(const unsigned char *sha1, int);
220 extern const unsigned char null_sha1[20];
221 static inline int is_null_sha1(const unsigned char *sha1)
223 return !memcmp(sha1, null_sha1, 20);
225 static inline int hashcmp(const unsigned char *sha1, const unsigned char *sha2)
227 return memcmp(sha1, sha2, 20);
229 static inline void hashcpy(unsigned char *sha_dst, const unsigned char *sha_src)
231 memcpy(sha_dst, sha_src, 20);
233 static inline void hashclr(unsigned char *hash)
235 memset(hash, 0, 20);
238 int git_mkstemp(char *path, size_t n, const char *template);
240 enum sharedrepo {
241 PERM_UMASK = 0,
242 PERM_GROUP,
243 PERM_EVERYBODY
245 int git_config_perm(const char *var, const char *value);
246 int adjust_shared_perm(const char *path);
247 int safe_create_leading_directories(char *path);
248 char *enter_repo(char *path, int strict);
250 /* Read and unpack a sha1 file into memory, write memory to a sha1 file */
251 extern int sha1_object_info(const unsigned char *, char *, unsigned long *);
252 extern void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size);
253 extern void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size);
254 extern int hash_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *sha1);
255 extern int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *return_sha1);
257 extern int check_sha1_signature(const unsigned char *sha1, void *buf, unsigned long size, const char *type);
259 extern int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
260 size_t bufsize, size_t *bufposn);
261 extern int write_sha1_to_fd(int fd, const unsigned char *sha1);
262 extern int move_temp_to_file(const char *tmpfile, const char *filename);
264 extern int has_sha1_pack(const unsigned char *sha1, const char **ignore);
265 extern int has_sha1_file(const unsigned char *sha1);
266 extern void *map_sha1_file(const unsigned char *sha1, unsigned long *);
267 extern int legacy_loose_object(unsigned char *);
269 extern int has_pack_file(const unsigned char *sha1);
270 extern int has_pack_index(const unsigned char *sha1);
272 enum object_type {
273 OBJ_NONE = 0,
274 OBJ_COMMIT = 1,
275 OBJ_TREE = 2,
276 OBJ_BLOB = 3,
277 OBJ_TAG = 4,
278 /* 5 for future expansion */
279 OBJ_OFS_DELTA = 6,
280 OBJ_REF_DELTA = 7,
281 OBJ_BAD,
284 extern signed char hexval_table[256];
285 static inline unsigned int hexval(unsigned int c)
287 return hexval_table[c];
290 /* Convert to/from hex/sha1 representation */
291 #define MINIMUM_ABBREV 4
292 #define DEFAULT_ABBREV 7
294 extern int get_sha1(const char *str, unsigned char *sha1);
295 extern int get_sha1_hex(const char *hex, unsigned char *sha1);
296 extern char *sha1_to_hex(const unsigned char *sha1); /* static buffer result! */
297 extern int read_ref(const char *filename, unsigned char *sha1);
298 extern const char *resolve_ref(const char *path, unsigned char *sha1, int, int *);
299 extern int create_symref(const char *ref, const char *refs_heads_master);
300 extern int validate_symref(const char *ref);
302 extern int base_name_compare(const char *name1, int len1, int mode1, const char *name2, int len2, int mode2);
303 extern int cache_name_compare(const char *name1, int len1, const char *name2, int len2);
305 extern void *read_object_with_reference(const unsigned char *sha1,
306 const char *required_type,
307 unsigned long *size,
308 unsigned char *sha1_ret);
310 const char *show_date(unsigned long time, int timezone, int relative);
311 const char *show_rfc2822_date(unsigned long time, int timezone);
312 int parse_date(const char *date, char *buf, int bufsize);
313 void datestamp(char *buf, int bufsize);
314 unsigned long approxidate(const char *);
316 extern int setup_ident(void);
317 extern void ignore_missing_committer_name();
318 extern const char *git_author_info(int);
319 extern const char *git_committer_info(int);
321 struct checkout {
322 const char *base_dir;
323 int base_dir_len;
324 unsigned force:1,
325 quiet:1,
326 not_new:1,
327 refresh_cache:1;
330 extern int checkout_entry(struct cache_entry *ce, struct checkout *state, char *topath);
332 extern struct alternate_object_database {
333 struct alternate_object_database *next;
334 char *name;
335 char base[FLEX_ARRAY]; /* more */
336 } *alt_odb_list;
337 extern void prepare_alt_odb(void);
339 extern struct packed_git {
340 struct packed_git *next;
341 unsigned long index_size;
342 unsigned long pack_size;
343 unsigned int *index_base;
344 void *pack_base;
345 unsigned int pack_last_used;
346 unsigned int pack_use_cnt;
347 int pack_local;
348 unsigned char sha1[20];
349 /* something like ".git/objects/pack/xxxxx.pack" */
350 char pack_name[FLEX_ARRAY]; /* more */
351 } *packed_git;
353 struct pack_entry {
354 unsigned int offset;
355 unsigned char sha1[20];
356 struct packed_git *p;
359 struct ref {
360 struct ref *next;
361 unsigned char old_sha1[20];
362 unsigned char new_sha1[20];
363 unsigned char force;
364 struct ref *peer_ref; /* when renaming */
365 char name[FLEX_ARRAY]; /* more */
368 #define REF_NORMAL (1u << 0)
369 #define REF_HEADS (1u << 1)
370 #define REF_TAGS (1u << 2)
372 extern pid_t git_connect(int fd[2], char *url, const char *prog);
373 extern int finish_connect(pid_t pid);
374 extern int path_match(const char *path, int nr, char **match);
375 extern int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail,
376 int nr_refspec, char **refspec, int all);
377 extern int get_ack(int fd, unsigned char *result_sha1);
378 extern struct ref **get_remote_heads(int in, struct ref **list, int nr_match, char **match, unsigned int flags);
379 extern int server_supports(const char *feature);
381 extern struct packed_git *parse_pack_index(unsigned char *sha1);
382 extern struct packed_git *parse_pack_index_file(const unsigned char *sha1,
383 char *idx_path);
385 extern void prepare_packed_git(void);
386 extern void reprepare_packed_git(void);
387 extern void install_packed_git(struct packed_git *pack);
389 extern struct packed_git *find_sha1_pack(const unsigned char *sha1,
390 struct packed_git *packs);
392 extern int use_packed_git(struct packed_git *);
393 extern void unuse_packed_git(struct packed_git *);
394 extern struct packed_git *add_packed_git(char *, int, int);
395 extern int num_packed_objects(const struct packed_git *p);
396 extern int nth_packed_object_sha1(const struct packed_git *, int, unsigned char*);
397 extern unsigned long find_pack_entry_one(const unsigned char *, struct packed_git *);
398 extern void *unpack_entry_gently(struct packed_git *, unsigned long, char *, unsigned long *);
399 extern unsigned long unpack_object_header_gently(const unsigned char *buf, unsigned long len, enum object_type *type, unsigned long *sizep);
400 extern void packed_object_info_detail(struct packed_git *, unsigned long, char *, unsigned long *, unsigned long *, unsigned int *, unsigned char *);
402 /* Dumb servers support */
403 extern int update_server_info(int);
405 typedef int (*config_fn_t)(const char *, const char *);
406 extern int git_default_config(const char *, const char *);
407 extern int git_config_from_file(config_fn_t fn, const char *);
408 extern int git_config(config_fn_t fn);
409 extern int git_config_int(const char *, const char *);
410 extern int git_config_bool(const char *, const char *);
411 extern int git_config_set(const char *, const char *);
412 extern int git_config_set_multivar(const char *, const char *, const char *, int);
413 extern int git_config_rename_section(const char *, const char *);
414 extern int check_repository_format_version(const char *var, const char *value);
416 #define MAX_GITNAME (1000)
417 extern char git_default_email[MAX_GITNAME];
418 extern char git_default_name[MAX_GITNAME];
420 extern char *git_commit_encoding;
421 extern char *git_log_output_encoding;
423 extern int copy_fd(int ifd, int ofd);
424 extern int write_in_full(int fd, const void *buf, size_t count, const char *);
425 extern void write_or_die(int fd, const void *buf, size_t count);
426 extern int write_or_whine(int fd, const void *buf, size_t count, const char *msg);
428 /* pager.c */
429 extern void setup_pager(void);
430 extern int pager_in_use;
431 extern int pager_use_color;
433 /* base85 */
434 int decode_85(char *dst, char *line, int linelen);
435 void encode_85(char *buf, unsigned char *data, int bytes);
437 /* alloc.c */
438 struct blob;
439 struct tree;
440 struct commit;
441 struct tag;
442 extern struct blob *alloc_blob_node(void);
443 extern struct tree *alloc_tree_node(void);
444 extern struct commit *alloc_commit_node(void);
445 extern struct tag *alloc_tag_node(void);
446 extern void alloc_report(void);
448 /* trace.c */
449 extern int nfvasprintf(char **str, const char *fmt, va_list va);
450 extern void trace_printf(const char *format, ...);
451 extern void trace_argv_printf(const char **argv, int count, const char *format, ...);
453 #endif /* CACHE_H */