Improve sha1 object file writing.
[git/git.git] / cache.h
CommitLineData
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>
e83c5163 16
cef661fc 17#include SHA1_HEADER
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18#include <zlib.h>
19
9da3acfb
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20#if ZLIB_VERNUM < 0x1200
21#define deflateBound(c,s) ((s) + (((s) + 7) >> 3) + (((s) + 63) >> 6) + 11)
22#endif
23
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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
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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" */
42struct cache_header {
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43 unsigned int hdr_signature;
44 unsigned int hdr_version;
45 unsigned int hdr_entries;
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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 */
53struct 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.
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62 *
63 * We save the fields in big-endian order to allow using the
64 * index file over NFS transparently.
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65 */
66struct cache_entry {
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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;
e83c5163 75 unsigned char sha1[20];
f5cabd13 76 unsigned short ce_flags;
59c1e249 77 char name[0];
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78};
79
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80#define CE_NAMEMASK (0x0fff)
81#define CE_STAGEMASK (0x3000)
aee46198 82#define CE_STAGESHIFT 12
95fd5bf8 83
aee46198
JH
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
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89#define ce_permissions(mode) (((mode) & 0100) ? 0755 : 0644)
90#define create_ce_mode(mode) htonl(S_IFREG | ce_permissions(mode))
91
aee46198 92#define cache_entry_size(len) ((offsetof(struct cache_entry,name) + (len) + 8) & ~7)
f5cabd13 93
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94const char *sha1_file_directory;
95struct cache_entry **active_cache;
96unsigned int active_nr, active_alloc;
97
98#define DB_ENVIRONMENT "SHA1_FILE_DIRECTORY"
4bb04f21 99#define DEFAULT_DB_ENVIRONMENT ".git/objects"
e83c5163 100
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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
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108#define alloc_nr(x) (((x)+16)*3/2)
109
734aab75 110/* Initialize and use the cache information */
e83c5163 111extern int read_cache(void);
197ee8c9 112extern int write_cache(int newfd, struct cache_entry **cache, int entries);
eb38c22f 113extern int cache_name_pos(const char *name, int namelen);
121481ab 114extern int add_cache_entry(struct cache_entry *ce, int ok_to_add);
b5af9107 115extern int remove_entry_at(int pos);
197ee8c9 116extern int remove_file_from_cache(char *path);
b5af9107 117extern int same_name(struct cache_entry *a, struct cache_entry *b);
734aab75 118extern int cache_match_stat(struct cache_entry *ce, struct stat *st);
74400e71 119extern int index_fd(unsigned char *sha1, int fd, struct stat *st);
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120
121#define MTIME_CHANGED 0x0001
122#define CTIME_CHANGED 0x0002
123#define OWNER_CHANGED 0x0004
124#define MODE_CHANGED 0x0008
125#define INODE_CHANGED 0x0010
126#define DATA_CHANGED 0x0020
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127
128/* Return a statically allocated filename matching the sha1 signature */
73134b6d 129extern char *sha1_file_name(const unsigned char *sha1);
e83c5163 130
e83c5163 131/* Read and unpack a sha1 file into memory, write memory to a sha1 file */
73134b6d 132extern void * map_sha1_file(const unsigned char *sha1, unsigned long *size);
2ade9340 133extern void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size);
73134b6d 134extern void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size);
f5b913c9 135extern int write_sha1_file(char *buf, unsigned long len, const char *type, unsigned char *return_sha1);
8237b185 136
d98b46f8 137extern int check_sha1_signature(unsigned char *sha1, void *buf, unsigned long size, const char *type);
e83c5163 138
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139/* Read a tree into the cache */
140extern int read_tree(void *buffer, unsigned long size, int stage);
141
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DB
142extern int write_sha1_from_fd(const unsigned char *sha1, int fd);
143
144extern int has_sha1_file(const unsigned char *sha1);
145
e83c5163 146/* Convert to/from hex/sha1 representation */
3c249c95 147extern int get_sha1(const char *str, unsigned char *sha1);
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148extern int get_sha1_hex(const char *hex, unsigned char *sha1);
149extern char *sha1_to_hex(const unsigned char *sha1); /* static buffer result! */
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150
151/* General helper functions */
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PB
152extern void usage(const char *err);
153extern void die(const char *err, ...);
154extern int error(const char *err, ...);
155
79517a06 156extern int cache_name_compare(const char *name1, int len1, const char *name2, int len2);
e83c5163 157
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JH
158extern void *read_object_with_reference(const unsigned char *sha1,
159 const unsigned char *required_type,
160 unsigned long *size,
161 unsigned char *sha1_ret);
f4913f91 162
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163void parse_date(char *date, char *buf, int bufsize);
164void datestamp(char *buf, int bufsize);
165
812666c8
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166static inline void *xmalloc(int size)
167{
168 void *ret = malloc(size);
169 if (!ret)
170 die("Out of memory, malloc failed");
171 return ret;
172}
173
174static inline void *xrealloc(void *ptr, int size)
175{
176 void *ret = realloc(ptr, size);
177 if (!ret)
178 die("Out of memory, realloc failed");
179 return ret;
180}
181
e83c5163 182#endif /* CACHE_H */