[PATCH] Fix warning in convert-cache
[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 #define create_ce_mode(mode) htonl(S_IFREG | ce_permissions(mode))
91
92 #define cache_entry_size(len) ((offsetof(struct cache_entry,name) + (len) + 8) & ~7)
93
94 const char *sha1_file_directory;
95 struct cache_entry **active_cache;
96 unsigned int active_nr, active_alloc;
97
98 #define DB_ENVIRONMENT "SHA1_FILE_DIRECTORY"
99 #define DEFAULT_DB_ENVIRONMENT ".git/objects"
100
101 #define get_object_directory() (getenv(DB_ENVIRONMENT) ? : DEFAULT_DB_ENVIRONMENT)
102
103 #define INDEX_ENVIRONMENT "GIT_INDEX_FILE"
104 #define DEFAULT_INDEX_ENVIRONMENT ".git/index"
105
106 #define get_index_file() (getenv(INDEX_ENVIRONMENT) ? : DEFAULT_INDEX_ENVIRONMENT)
107
108 #define alloc_nr(x) (((x)+16)*3/2)
109
110 /* Initialize and use the cache information */
111 extern int read_cache(void);
112 extern int write_cache(int newfd, struct cache_entry **cache, int entries);
113 extern int cache_name_pos(const char *name, int namelen);
114 extern int add_cache_entry(struct cache_entry *ce, int ok_to_add);
115 extern int remove_entry_at(int pos);
116 extern int remove_file_from_cache(char *path);
117 extern int same_name(struct cache_entry *a, struct cache_entry *b);
118 extern int cache_match_stat(struct cache_entry *ce, struct stat *st);
119
120 #define MTIME_CHANGED 0x0001
121 #define CTIME_CHANGED 0x0002
122 #define OWNER_CHANGED 0x0004
123 #define MODE_CHANGED 0x0008
124 #define INODE_CHANGED 0x0010
125 #define DATA_CHANGED 0x0020
126
127 /* Return a statically allocated filename matching the sha1 signature */
128 extern char *sha1_file_name(const unsigned char *sha1);
129
130 /* Write a memory buffer out to the sha file */
131 extern int write_sha1_buffer(const unsigned char *sha1, void *buf, unsigned int size);
132
133 /* Read and unpack a sha1 file into memory, write memory to a sha1 file */
134 extern void * map_sha1_file(const unsigned char *sha1, unsigned long *size);
135 extern void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size);
136 extern void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size);
137 extern int write_sha1_file(char *buf, unsigned long len, const char *type, unsigned char *return_sha1);
138
139 extern int check_sha1_signature(unsigned char *sha1, void *buf, unsigned long size, const char *type);
140
141 /* Read a tree into the cache */
142 extern int read_tree(void *buffer, unsigned long size, int stage);
143
144 extern int write_sha1_from_fd(const unsigned char *sha1, int fd);
145
146 extern int has_sha1_file(const unsigned char *sha1);
147
148 /* Convert to/from hex/sha1 representation */
149 extern int get_sha1(const char *str, unsigned char *sha1);
150 extern int get_sha1_hex(const char *hex, unsigned char *sha1);
151 extern char *sha1_to_hex(const unsigned char *sha1); /* static buffer result! */
152
153 /* General helper functions */
154 extern void usage(const char *err);
155 extern void die(const char *err, ...);
156 extern int error(const char *err, ...);
157
158 extern int cache_name_compare(const char *name1, int len1, const char *name2, int len2);
159
160 extern void *read_object_with_reference(const unsigned char *sha1,
161 const unsigned char *required_type,
162 unsigned long *size,
163 unsigned char *sha1_ret);
164
165 void parse_date(char *date, char *buf, int bufsize);
166 void datestamp(char *buf, int bufsize);
167
168 static inline void *xmalloc(int size)
169 {
170 void *ret = malloc(size);
171 if (!ret)
172 die("Out of memory, malloc failed");
173 return ret;
174 }
175
176 static inline void *xrealloc(void *ptr, int size)
177 {
178 void *ret = realloc(ptr, size);
179 if (!ret)
180 die("Out of memory, realloc failed");
181 return ret;
182 }
183
184 #endif /* CACHE_H */