Mark the variable declarations in .h files as extern
[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 <sys/mman.h>
14 #include <sys/param.h>
15 #include <netinet/in.h>
16
17 #include SHA1_HEADER
18 #include <zlib.h>
19
20 #if ZLIB_VERNUM < 0x1200
21 #define deflateBound(c,s) ((s) + (((s) + 7) >> 3) + (((s) + 63) >> 6) + 11)
22 #endif
23
24 #ifdef DT_UNKNOWN
25 #define DTYPE(de) ((de)->d_type)
26 #else
27 #define DT_UNKNOWN 0
28 #define DT_DIR 1
29 #define DT_REG 2
30 #define DTYPE(de) DT_UNKNOWN
31 #endif
32
33 /*
34 * Basic data structures for the directory cache
35 *
36 * NOTE NOTE NOTE! This is all in the native CPU byte format. It's
37 * not even trying to be portable. It's trying to be efficient. It's
38 * just a cache, after all.
39 */
40
41 #define CACHE_SIGNATURE 0x44495243 /* "DIRC" */
42 struct cache_header {
43 unsigned int hdr_signature;
44 unsigned int hdr_version;
45 unsigned int hdr_entries;
46 };
47
48 /*
49 * The "cache_time" is just the low 32 bits of the
50 * time. It doesn't matter if it overflows - we only
51 * check it for equality in the 32 bits we save.
52 */
53 struct cache_time {
54 unsigned int sec;
55 unsigned int nsec;
56 };
57
58 /*
59 * dev/ino/uid/gid/size are also just tracked to the low 32 bits
60 * Again - this is just a (very strong in practice) heuristic that
61 * the inode hasn't changed.
62 *
63 * We save the fields in big-endian order to allow using the
64 * index file over NFS transparently.
65 */
66 struct cache_entry {
67 struct cache_time ce_ctime;
68 struct cache_time ce_mtime;
69 unsigned int ce_dev;
70 unsigned int ce_ino;
71 unsigned int ce_mode;
72 unsigned int ce_uid;
73 unsigned int ce_gid;
74 unsigned int ce_size;
75 unsigned char sha1[20];
76 unsigned short ce_flags;
77 char name[0];
78 };
79
80 #define CE_NAMEMASK (0x0fff)
81 #define CE_STAGEMASK (0x3000)
82 #define CE_STAGESHIFT 12
83
84 #define create_ce_flags(len, stage) htons((len) | ((stage) << CE_STAGESHIFT))
85 #define ce_namelen(ce) (CE_NAMEMASK & ntohs((ce)->ce_flags))
86 #define ce_size(ce) cache_entry_size(ce_namelen(ce))
87 #define ce_stage(ce) ((CE_STAGEMASK & ntohs((ce)->ce_flags)) >> CE_STAGESHIFT)
88
89 #define ce_permissions(mode) (((mode) & 0100) ? 0755 : 0644)
90 static inline unsigned int create_ce_mode(unsigned int mode)
91 {
92 if (S_ISLNK(mode))
93 return htonl(S_IFLNK);
94 return htonl(S_IFREG | ce_permissions(mode));
95 }
96
97 #define cache_entry_size(len) ((offsetof(struct cache_entry,name) + (len) + 8) & ~7)
98
99 extern struct cache_entry **active_cache;
100 extern unsigned int active_nr, active_alloc, active_cache_changed;
101
102 #define DB_ENVIRONMENT "SHA1_FILE_DIRECTORY"
103 #define DEFAULT_DB_ENVIRONMENT ".git/objects"
104
105 #define get_object_directory() (getenv(DB_ENVIRONMENT) ? : DEFAULT_DB_ENVIRONMENT)
106
107 #define INDEX_ENVIRONMENT "GIT_INDEX_FILE"
108 #define DEFAULT_INDEX_ENVIRONMENT ".git/index"
109
110 #define get_index_file() (getenv(INDEX_ENVIRONMENT) ? : DEFAULT_INDEX_ENVIRONMENT)
111
112 #define alloc_nr(x) (((x)+16)*3/2)
113
114 /* Initialize and use the cache information */
115 extern int read_cache(void);
116 extern int write_cache(int newfd, struct cache_entry **cache, int entries);
117 extern int cache_name_pos(const char *name, int namelen);
118 extern int add_cache_entry(struct cache_entry *ce, int ok_to_add);
119 extern int remove_entry_at(int pos);
120 extern int remove_file_from_cache(char *path);
121 extern int same_name(struct cache_entry *a, struct cache_entry *b);
122 extern int cache_match_stat(struct cache_entry *ce, struct stat *st);
123 extern int index_fd(unsigned char *sha1, int fd, struct stat *st);
124
125 #define MTIME_CHANGED 0x0001
126 #define CTIME_CHANGED 0x0002
127 #define OWNER_CHANGED 0x0004
128 #define MODE_CHANGED 0x0008
129 #define INODE_CHANGED 0x0010
130 #define DATA_CHANGED 0x0020
131 #define TYPE_CHANGED 0x0040
132
133 /* Return a statically allocated filename matching the sha1 signature */
134 extern char *sha1_file_name(const unsigned char *sha1);
135
136 /* Read and unpack a sha1 file into memory, write memory to a sha1 file */
137 extern void * map_sha1_file(const unsigned char *sha1, unsigned long *size);
138 extern void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size);
139 extern void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size);
140 extern int write_sha1_file(char *buf, unsigned long len, const char *type, unsigned char *return_sha1);
141
142 extern int check_sha1_signature(unsigned char *sha1, void *buf, unsigned long size, const char *type);
143
144 /* Read a tree into the cache */
145 extern int read_tree(void *buffer, unsigned long size, int stage);
146
147 extern int write_sha1_from_fd(const unsigned char *sha1, int fd);
148
149 extern int has_sha1_file(const unsigned char *sha1);
150
151 /* Convert to/from hex/sha1 representation */
152 extern int get_sha1(const char *str, unsigned char *sha1);
153 extern int get_sha1_hex(const char *hex, unsigned char *sha1);
154 extern char *sha1_to_hex(const unsigned char *sha1); /* static buffer result! */
155
156 /* General helper functions */
157 extern void usage(const char *err);
158 extern void die(const char *err, ...);
159 extern int error(const char *err, ...);
160
161 extern int cache_name_compare(const char *name1, int len1, const char *name2, int len2);
162
163 extern void *read_object_with_reference(const unsigned char *sha1,
164 const unsigned char *required_type,
165 unsigned long *size,
166 unsigned char *sha1_ret);
167
168 const char *show_date(unsigned long time, int timezone);
169 void parse_date(char *date, char *buf, int bufsize);
170 void datestamp(char *buf, int bufsize);
171
172 static inline void *xmalloc(int size)
173 {
174 void *ret = malloc(size);
175 if (!ret)
176 die("Out of memory, malloc failed");
177 return ret;
178 }
179
180 static inline void *xrealloc(void *ptr, int size)
181 {
182 void *ret = realloc(ptr, size);
183 if (!ret)
184 die("Out of memory, realloc failed");
185 return ret;
186 }
187
188 #endif /* CACHE_H */