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git.ipfire.org Git - thirdparty/git.git/blob - cache.h
14 #include <sys/param.h>
15 #include <netinet/in.h>
20 #if ZLIB_VERNUM < 0x1200
21 #define deflateBound(c,s) ((s) + (((s) + 7) >> 3) + (((s) + 63) >> 6) + 11)
25 * Basic data structures for the directory cache
27 * NOTE NOTE NOTE! This is all in the native CPU byte format. It's
28 * not even trying to be portable. It's trying to be efficient. It's
29 * just a cache, after all.
32 #define CACHE_SIGNATURE 0x44495243 /* "DIRC" */
34 unsigned int hdr_signature
;
35 unsigned int hdr_version
;
36 unsigned int hdr_entries
;
40 * The "cache_time" is just the low 32 bits of the
41 * time. It doesn't matter if it overflows - we only
42 * check it for equality in the 32 bits we save.
50 * dev/ino/uid/gid/size are also just tracked to the low 32 bits
51 * Again - this is just a (very strong in practice) heuristic that
52 * the inode hasn't changed.
54 * We save the fields in big-endian order to allow using the
55 * index file over NFS transparently.
58 struct cache_time ce_ctime
;
59 struct cache_time ce_mtime
;
66 unsigned char sha1
[20];
67 unsigned short ce_flags
;
71 #define CE_NAMEMASK (0x0fff)
72 #define CE_STAGEMASK (0x3000)
73 #define CE_STAGESHIFT 12
75 #define create_ce_flags(len, stage) htons((len) | ((stage) << CE_STAGESHIFT))
76 #define ce_namelen(ce) (CE_NAMEMASK & ntohs((ce)->ce_flags))
77 #define ce_size(ce) cache_entry_size(ce_namelen(ce))
78 #define ce_stage(ce) ((CE_STAGEMASK & ntohs((ce)->ce_flags)) >> CE_STAGESHIFT)
80 #define ce_permissions(mode) (((mode) & 0100) ? 0755 : 0644)
81 #define create_ce_mode(mode) htonl(S_IFREG | ce_permissions(mode))
83 #define cache_entry_size(len) ((offsetof(struct cache_entry,name) + (len) + 8) & ~7)
85 const char *sha1_file_directory
;
86 struct cache_entry
**active_cache
;
87 unsigned int active_nr
, active_alloc
;
89 #define DB_ENVIRONMENT "SHA1_FILE_DIRECTORY"
90 #define DEFAULT_DB_ENVIRONMENT ".git/objects"
92 #define get_object_directory() (getenv(DB_ENVIRONMENT) ? : DEFAULT_DB_ENVIRONMENT)
94 #define INDEX_ENVIRONMENT "GIT_INDEX_FILE"
95 #define DEFAULT_INDEX_ENVIRONMENT ".git/index"
97 #define get_index_file() (getenv(INDEX_ENVIRONMENT) ? : DEFAULT_INDEX_ENVIRONMENT)
99 #define alloc_nr(x) (((x)+16)*3/2)
101 /* Initialize and use the cache information */
102 extern int read_cache(void);
103 extern int write_cache(int newfd
, struct cache_entry
**cache
, int entries
);
104 extern int cache_name_pos(const char *name
, int namelen
);
105 extern int add_cache_entry(struct cache_entry
*ce
, int ok_to_add
);
106 extern int remove_entry_at(int pos
);
107 extern int remove_file_from_cache(char *path
);
108 extern int same_name(struct cache_entry
*a
, struct cache_entry
*b
);
109 extern int cache_match_stat(struct cache_entry
*ce
, struct stat
*st
);
111 #define MTIME_CHANGED 0x0001
112 #define CTIME_CHANGED 0x0002
113 #define OWNER_CHANGED 0x0004
114 #define MODE_CHANGED 0x0008
115 #define INODE_CHANGED 0x0010
116 #define DATA_CHANGED 0x0020
118 /* Return a statically allocated filename matching the sha1 signature */
119 extern char *sha1_file_name(const unsigned char *sha1
);
121 /* Write a memory buffer out to the sha file */
122 extern int write_sha1_buffer(const unsigned char *sha1
, void *buf
, unsigned int size
);
124 /* Read and unpack a sha1 file into memory, write memory to a sha1 file */
125 extern void * map_sha1_file(const unsigned char *sha1
, unsigned long *size
);
126 extern void * unpack_sha1_file(void *map
, unsigned long mapsize
, char *type
, unsigned long *size
);
127 extern void * read_sha1_file(const unsigned char *sha1
, char *type
, unsigned long *size
);
128 extern int write_sha1_file(char *buf
, unsigned long len
, const char *type
, unsigned char *return_sha1
);
130 extern int check_sha1_signature(unsigned char *sha1
, void *buf
, unsigned long size
, const char *type
);
132 /* Read a tree into the cache */
133 extern int read_tree(void *buffer
, unsigned long size
, int stage
);
135 extern int write_sha1_from_fd(const unsigned char *sha1
, int fd
);
137 extern int has_sha1_file(const unsigned char *sha1
);
139 /* Convert to/from hex/sha1 representation */
140 extern int get_sha1_hex(const char *hex
, unsigned char *sha1
);
141 extern char *sha1_to_hex(const unsigned char *sha1
); /* static buffer result! */
143 /* General helper functions */
144 extern void usage(const char *err
);
145 extern void die(const char *err
, ...);
146 extern int error(const char *err
, ...);
148 extern int cache_name_compare(const char *name1
, int len1
, const char *name2
, int len2
);
150 extern void *read_object_with_reference(const unsigned char *sha1
,
151 const unsigned char *required_type
,
153 unsigned char *sha1_ret
);
155 void parse_date(char *date
, char *buf
, int bufsize
);
156 void datestamp(char *buf
, int bufsize
);
158 static inline void *xmalloc(int size
)
160 void *ret
= malloc(size
);
162 die("Out of memory, malloc failed");
166 static inline void *xrealloc(void *ptr
, int size
)
168 void *ret
= realloc(ptr
, size
);
170 die("Out of memory, realloc failed");