Split up Makefile library list handling with separate entries for
[git/git.git] / cache.h
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e83c5163
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1#ifndef CACHE_H
2#define CACHE_H
3
2dee0609 4#include <unistd.h>
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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>
bf0c6e83 11#include <string.h>
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12#include <errno.h>
13#include <sys/mman.h>
bb233d69 14#include <sys/param.h>
ccc4feb5 15#include <netinet/in.h>
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16
17#include <openssl/sha.h>
18#include <zlib.h>
19
20/*
21 * Basic data structures for the directory cache
22 *
23 * NOTE NOTE NOTE! This is all in the native CPU byte format. It's
24 * not even trying to be portable. It's trying to be efficient. It's
25 * just a cache, after all.
26 */
27
28#define CACHE_SIGNATURE 0x44495243 /* "DIRC" */
29struct cache_header {
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30 unsigned int hdr_signature;
31 unsigned int hdr_version;
32 unsigned int hdr_entries;
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33};
34
35/*
36 * The "cache_time" is just the low 32 bits of the
37 * time. It doesn't matter if it overflows - we only
38 * check it for equality in the 32 bits we save.
39 */
40struct cache_time {
41 unsigned int sec;
42 unsigned int nsec;
43};
44
45/*
46 * dev/ino/uid/gid/size are also just tracked to the low 32 bits
47 * Again - this is just a (very strong in practice) heuristic that
48 * the inode hasn't changed.
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49 *
50 * We save the fields in big-endian order to allow using the
51 * index file over NFS transparently.
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52 */
53struct cache_entry {
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54 struct cache_time ce_ctime;
55 struct cache_time ce_mtime;
56 unsigned int ce_dev;
57 unsigned int ce_ino;
58 unsigned int ce_mode;
59 unsigned int ce_uid;
60 unsigned int ce_gid;
61 unsigned int ce_size;
e83c5163 62 unsigned char sha1[20];
f5cabd13 63 unsigned short ce_flags;
59c1e249 64 char name[0];
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65};
66
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67#define CE_NAMEMASK (0x0fff)
68#define CE_STAGEMASK (0x3000)
aee46198 69#define CE_STAGESHIFT 12
95fd5bf8 70
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71#define create_ce_flags(len, stage) htons((len) | ((stage) << CE_STAGESHIFT))
72#define ce_namelen(ce) (CE_NAMEMASK & ntohs((ce)->ce_flags))
73#define ce_size(ce) cache_entry_size(ce_namelen(ce))
74#define ce_stage(ce) ((CE_STAGEMASK & ntohs((ce)->ce_flags)) >> CE_STAGESHIFT)
75
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76#define ce_permissions(mode) (((mode) & 0100) ? 0755 : 0644)
77#define create_ce_mode(mode) htonl(S_IFREG | ce_permissions(mode))
78
aee46198 79#define cache_entry_size(len) ((offsetof(struct cache_entry,name) + (len) + 8) & ~7)
f5cabd13 80
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81const char *sha1_file_directory;
82struct cache_entry **active_cache;
83unsigned int active_nr, active_alloc;
84
85#define DB_ENVIRONMENT "SHA1_FILE_DIRECTORY"
4bb04f21 86#define DEFAULT_DB_ENVIRONMENT ".git/objects"
e83c5163 87
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88#define get_object_directory() (getenv(DB_ENVIRONMENT) ? : DEFAULT_DB_ENVIRONMENT)
89
90#define INDEX_ENVIRONMENT "GIT_INDEX_FILE"
91#define DEFAULT_INDEX_ENVIRONMENT ".git/index"
92
93#define get_index_file() (getenv(INDEX_ENVIRONMENT) ? : DEFAULT_INDEX_ENVIRONMENT)
94
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95#define alloc_nr(x) (((x)+16)*3/2)
96
734aab75 97/* Initialize and use the cache information */
e83c5163 98extern int read_cache(void);
197ee8c9 99extern int write_cache(int newfd, struct cache_entry **cache, int entries);
eb38c22f 100extern int cache_name_pos(const char *name, int namelen);
121481ab 101extern int add_cache_entry(struct cache_entry *ce, int ok_to_add);
197ee8c9 102extern int remove_file_from_cache(char *path);
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103extern int cache_match_stat(struct cache_entry *ce, struct stat *st);
104
105#define MTIME_CHANGED 0x0001
106#define CTIME_CHANGED 0x0002
107#define OWNER_CHANGED 0x0004
108#define MODE_CHANGED 0x0008
109#define INODE_CHANGED 0x0010
110#define DATA_CHANGED 0x0020
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111
112/* Return a statically allocated filename matching the sha1 signature */
73134b6d 113extern char *sha1_file_name(const unsigned char *sha1);
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114
115/* Write a memory buffer out to the sha file */
73134b6d 116extern int write_sha1_buffer(const unsigned char *sha1, void *buf, unsigned int size);
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117
118/* Read and unpack a sha1 file into memory, write memory to a sha1 file */
73134b6d 119extern void * map_sha1_file(const unsigned char *sha1, unsigned long *size);
2ade9340 120extern void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size);
73134b6d 121extern void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size);
d6d3f9d0 122extern int write_sha1_file(char *buf, unsigned len, unsigned char *return_sha1);
d98b46f8 123extern int check_sha1_signature(unsigned char *sha1, void *buf, unsigned long size, const char *type);
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124
125/* Convert to/from hex/sha1 representation */
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126extern int get_sha1_hex(const char *hex, unsigned char *sha1);
127extern char *sha1_to_hex(const unsigned char *sha1); /* static buffer result! */
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128
129/* General helper functions */
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130extern void usage(const char *err);
131extern void die(const char *err, ...);
132extern int error(const char *err, ...);
133
79517a06 134extern int cache_name_compare(const char *name1, int len1, const char *name2, int len2);
e83c5163 135
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136extern void *read_tree_with_tree_or_commit_sha1(const unsigned char *sha1,
137 unsigned long *size,
138 unsigned char *tree_sha1_ret);
139
e83c5163 140#endif /* CACHE_H */