[PATCH] verify-pack updates.
[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 #include <sys/mman.h>
15 #include <sys/param.h>
16 #include <netinet/in.h>
17 #include <sys/types.h>
18 #include <dirent.h>
19
20 #include SHA1_HEADER
21 #include <zlib.h>
22
23 #if ZLIB_VERNUM < 0x1200
24 #define deflateBound(c,s) ((s) + (((s) + 7) >> 3) + (((s) + 63) >> 6) + 11)
25 #endif
26
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
33 #define DT_LNK 3
34 #define DTYPE(de) DT_UNKNOWN
35 #endif
36
37 #ifdef __GNUC__
38 #define NORETURN __attribute__((__noreturn__))
39 #else
40 #define NORETURN
41 #endif
42
43 /*
44 * Environment variables transition.
45 * We accept older names for now but warn.
46 */
47 extern char *gitenv_bc(const char *);
48 #define gitenv(e) (getenv(e) ? : gitenv_bc(e))
49
50 /*
51 * Basic data structures for the directory cache
52 */
53
54 #define CACHE_SIGNATURE 0x44495243 /* "DIRC" */
55 struct cache_header {
56 unsigned int hdr_signature;
57 unsigned int hdr_version;
58 unsigned int hdr_entries;
59 };
60
61 /*
62 * The "cache_time" is just the low 32 bits of the
63 * time. It doesn't matter if it overflows - we only
64 * check it for equality in the 32 bits we save.
65 */
66 struct cache_time {
67 unsigned int sec;
68 unsigned int nsec;
69 };
70
71 /*
72 * dev/ino/uid/gid/size are also just tracked to the low 32 bits
73 * Again - this is just a (very strong in practice) heuristic that
74 * the inode hasn't changed.
75 *
76 * We save the fields in big-endian order to allow using the
77 * index file over NFS transparently.
78 */
79 struct cache_entry {
80 struct cache_time ce_ctime;
81 struct cache_time ce_mtime;
82 unsigned int ce_dev;
83 unsigned int ce_ino;
84 unsigned int ce_mode;
85 unsigned int ce_uid;
86 unsigned int ce_gid;
87 unsigned int ce_size;
88 unsigned char sha1[20];
89 unsigned short ce_flags;
90 char name[0];
91 };
92
93 #define CE_NAMEMASK (0x0fff)
94 #define CE_STAGEMASK (0x3000)
95 #define CE_UPDATE (0x4000)
96 #define CE_STAGESHIFT 12
97
98 #define create_ce_flags(len, stage) htons((len) | ((stage) << CE_STAGESHIFT))
99 #define ce_namelen(ce) (CE_NAMEMASK & ntohs((ce)->ce_flags))
100 #define ce_size(ce) cache_entry_size(ce_namelen(ce))
101 #define ce_stage(ce) ((CE_STAGEMASK & ntohs((ce)->ce_flags)) >> CE_STAGESHIFT)
102
103 #define ce_permissions(mode) (((mode) & 0100) ? 0755 : 0644)
104 static inline unsigned int create_ce_mode(unsigned int mode)
105 {
106 if (S_ISLNK(mode))
107 return htonl(S_IFLNK);
108 return htonl(S_IFREG | ce_permissions(mode));
109 }
110
111 #define cache_entry_size(len) ((offsetof(struct cache_entry,name) + (len) + 8) & ~7)
112
113 extern struct cache_entry **active_cache;
114 extern unsigned int active_nr, active_alloc, active_cache_changed;
115
116 #define GIT_DIR_ENVIRONMENT "GIT_DIR"
117 #define DEFAULT_GIT_DIR_ENVIRONMENT ".git"
118 #define DB_ENVIRONMENT "GIT_OBJECT_DIRECTORY"
119 #define INDEX_ENVIRONMENT "GIT_INDEX_FILE"
120
121 extern char *get_object_directory(void);
122 extern char *get_refs_directory(void);
123 extern char *get_index_file(void);
124
125 #define ALTERNATE_DB_ENVIRONMENT "GIT_ALTERNATE_OBJECT_DIRECTORIES"
126
127 #define alloc_nr(x) (((x)+16)*3/2)
128
129 /* Initialize and use the cache information */
130 extern int read_cache(void);
131 extern int write_cache(int newfd, struct cache_entry **cache, int entries);
132 extern int cache_name_pos(const char *name, int namelen);
133 #define ADD_CACHE_OK_TO_ADD 1 /* Ok to add */
134 #define ADD_CACHE_OK_TO_REPLACE 2 /* Ok to replace file/directory */
135 #define ADD_CACHE_SKIP_DFCHECK 4 /* Ok to skip DF conflict checks */
136 extern int add_cache_entry(struct cache_entry *ce, int option);
137 extern int remove_cache_entry_at(int pos);
138 extern int remove_file_from_cache(char *path);
139 extern int ce_same_name(struct cache_entry *a, struct cache_entry *b);
140 extern int ce_match_stat(struct cache_entry *ce, struct stat *st);
141 extern int index_fd(unsigned char *sha1, int fd, struct stat *st);
142 extern void fill_stat_cache_info(struct cache_entry *ce, struct stat *st);
143
144 struct cache_file {
145 struct cache_file *next;
146 char lockfile[PATH_MAX];
147 };
148 extern int hold_index_file_for_update(struct cache_file *, const char *path);
149 extern int commit_index_file(struct cache_file *);
150 extern void rollback_index_file(struct cache_file *);
151
152 #define MTIME_CHANGED 0x0001
153 #define CTIME_CHANGED 0x0002
154 #define OWNER_CHANGED 0x0004
155 #define MODE_CHANGED 0x0008
156 #define INODE_CHANGED 0x0010
157 #define DATA_CHANGED 0x0020
158 #define TYPE_CHANGED 0x0040
159
160 /* Return a statically allocated filename matching the sha1 signature */
161 extern char *sha1_file_name(const unsigned char *sha1);
162
163 /* Read and unpack a sha1 file into memory, write memory to a sha1 file */
164 extern void * map_sha1_file(const unsigned char *sha1, unsigned long *size);
165 extern int unpack_sha1_header(z_stream *stream, void *map, unsigned long mapsize, void *buffer, unsigned long size);
166 extern int parse_sha1_header(char *hdr, char *type, unsigned long *sizep);
167 extern int sha1_object_info(const unsigned char *, char *, unsigned long *);
168 extern void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size);
169 extern void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size);
170 extern int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *return_sha1);
171
172 extern int check_sha1_signature(const unsigned char *sha1, void *buf, unsigned long size, const char *type);
173
174 /* Read a tree into the cache */
175 extern int read_tree(void *buffer, unsigned long size, int stage);
176
177 extern int write_sha1_from_fd(const unsigned char *sha1, int fd);
178
179 extern int has_sha1_file(const unsigned char *sha1);
180
181 /* Convert to/from hex/sha1 representation */
182 extern int get_sha1(const char *str, unsigned char *sha1);
183 extern int get_sha1_hex(const char *hex, unsigned char *sha1);
184 extern char *sha1_to_hex(const unsigned char *sha1); /* static buffer result! */
185
186 /* General helper functions */
187 extern void usage(const char *err) NORETURN;
188 extern void die(const char *err, ...) NORETURN;
189 extern int error(const char *err, ...);
190
191 extern int base_name_compare(const char *name1, int len1, int mode1, const char *name2, int len2, int mode2);
192 extern int cache_name_compare(const char *name1, int len1, const char *name2, int len2);
193
194 extern void *read_object_with_reference(const unsigned char *sha1,
195 const char *required_type,
196 unsigned long *size,
197 unsigned char *sha1_ret);
198
199 const char *show_date(unsigned long time, int timezone);
200 void parse_date(char *date, char *buf, int bufsize);
201 void datestamp(char *buf, int bufsize);
202
203 static inline void *xmalloc(size_t size)
204 {
205 void *ret = malloc(size);
206 if (!ret)
207 die("Out of memory, malloc failed");
208 return ret;
209 }
210
211 static inline void *xrealloc(void *ptr, size_t size)
212 {
213 void *ret = realloc(ptr, size);
214 if (!ret)
215 die("Out of memory, realloc failed");
216 return ret;
217 }
218
219 static inline void *xcalloc(size_t nmemb, size_t size)
220 {
221 void *ret = calloc(nmemb, size);
222 if (!ret)
223 die("Out of memory, calloc failed");
224 return ret;
225 }
226
227 struct checkout {
228 const char *base_dir;
229 int base_dir_len;
230 unsigned force:1,
231 quiet:1,
232 not_new:1,
233 refresh_cache:1;
234 };
235
236 extern int checkout_entry(struct cache_entry *ce, struct checkout *state);
237
238 extern struct alternate_object_database {
239 char *base;
240 char *name;
241 } *alt_odb;
242 extern void prepare_alt_odb(void);
243
244 extern struct packed_git {
245 struct packed_git *next;
246 unsigned long index_size;
247 unsigned long pack_size;
248 unsigned int *index_base;
249 void *pack_base;
250 unsigned int pack_last_used;
251 unsigned int pack_use_cnt;
252 char pack_name[0]; /* something like ".git/objects/pack/xxxxx.pack" */
253 } *packed_git;
254
255 struct pack_entry {
256 unsigned int offset;
257 unsigned char sha1[20];
258 struct packed_git *p;
259 };
260
261 extern void prepare_packed_git(void);
262 extern int use_packed_git(struct packed_git *);
263 extern void unuse_packed_git(struct packed_git *);
264 extern struct packed_git *add_packed_git(char *, int);
265 extern int num_packed_objects(const struct packed_git *p);
266 extern int nth_packed_object_sha1(const struct packed_git *, int, unsigned char*);
267 extern int find_pack_entry_one(const unsigned char *, struct pack_entry *, struct packed_git *);
268 extern void *unpack_entry_gently(struct pack_entry *, char *, unsigned long *);
269
270 #endif /* CACHE_H */