1#ifndef CACHE_H
2#define CACHE_H
3#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#include SHA1_HEADER
18#include <zlib.h>
19#if ZLIB_VERNUM < 0x1200
21#define deflateBound(c,s) ((s) + (((s) + 7) >> 3) + (((s) + 63) >> 6) + 11)
22#endif
23#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/*
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#define CACHE_SIGNATURE 0x44495243 /* "DIRC" */
42struct cache_header {
43 unsigned int hdr_signature;
44 unsigned int hdr_version;
45 unsigned int hdr_entries;
46};
47/*
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/*
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 */
66struct 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#define CE_NAMEMASK (0x0fff)
81#define CE_STAGEMASK (0x3000)
82#define CE_STAGESHIFT 12
83#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#define ce_permissions(mode) (((mode) & 0100) ? 0755 : 0644)
90static inline unsigned int create_ce_mode(unsigned int mode)
91{
92 if (S_ISREG(mode))
93 return htonl(S_IFREG | ce_permissions(mode));
94 if (S_ISLNK(mode))
95 return htonl(S_IFLNK);
96 return htonl(mode);
97}
98#define cache_entry_size(len) ((offsetof(struct cache_entry,name) + (len) + 8) & ~7)
100const char *sha1_file_directory;
102struct cache_entry **active_cache;
103unsigned int active_nr, active_alloc;
104#define DB_ENVIRONMENT "SHA1_FILE_DIRECTORY"
106#define DEFAULT_DB_ENVIRONMENT ".git/objects"
107#define get_object_directory() (getenv(DB_ENVIRONMENT) ? : DEFAULT_DB_ENVIRONMENT)
109#define INDEX_ENVIRONMENT "GIT_INDEX_FILE"
111#define DEFAULT_INDEX_ENVIRONMENT ".git/index"
112#define get_index_file() (getenv(INDEX_ENVIRONMENT) ? : DEFAULT_INDEX_ENVIRONMENT)
114#define alloc_nr(x) (((x)+16)*3/2)
116/* Initialize and use the cache information */
118extern int read_cache(void);
119extern int write_cache(int newfd, struct cache_entry **cache, int entries);
120extern int cache_name_pos(const char *name, int namelen);
121extern int add_cache_entry(struct cache_entry *ce, int ok_to_add);
122extern int remove_entry_at(int pos);
123extern int remove_file_from_cache(char *path);
124extern int same_name(struct cache_entry *a, struct cache_entry *b);
125extern int cache_match_stat(struct cache_entry *ce, struct stat *st);
126extern int index_fd(unsigned char *sha1, int fd, struct stat *st);
127#define MTIME_CHANGED 0x0001
129#define CTIME_CHANGED 0x0002
130#define OWNER_CHANGED 0x0004
131#define MODE_CHANGED 0x0008
132#define INODE_CHANGED 0x0010
133#define DATA_CHANGED 0x0020
134#define TYPE_CHANGED 0x0040
135/* Return a statically allocated filename matching the sha1 signature */
137extern char *sha1_file_name(const unsigned char *sha1);
138/* Read and unpack a sha1 file into memory, write memory to a sha1 file */
140extern void * map_sha1_file(const unsigned char *sha1, unsigned long *size);
141extern void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size);
142extern void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size);
143extern int write_sha1_file(char *buf, unsigned long len, const char *type, unsigned char *return_sha1);
144extern int check_sha1_signature(unsigned char *sha1, void *buf, unsigned long size, const char *type);
146/* Read a tree into the cache */
148extern int read_tree(void *buffer, unsigned long size, int stage);
149extern int write_sha1_from_fd(const unsigned char *sha1, int fd);
151extern int has_sha1_file(const unsigned char *sha1);
153/* Convert to/from hex/sha1 representation */
155extern int get_sha1(const char *str, unsigned char *sha1);
156extern int get_sha1_hex(const char *hex, unsigned char *sha1);
157extern char *sha1_to_hex(const unsigned char *sha1); /* static buffer result! */
158/* General helper functions */
160extern void usage(const char *err);
161extern void die(const char *err, ...);
162extern int error(const char *err, ...);
163extern int cache_name_compare(const char *name1, int len1, const char *name2, int len2);
165extern void *read_object_with_reference(const unsigned char *sha1,
167 const unsigned char *required_type,
168 unsigned long *size,
169 unsigned char *sha1_ret);
170void parse_date(char *date, char *buf, int bufsize);
172void datestamp(char *buf, int bufsize);
173static inline void *xmalloc(int size)
175{
176 void *ret = malloc(size);
177 if (!ret)
178 die("Out of memory, malloc failed");
179 return ret;
180}
181static inline void *xrealloc(void *ptr, int size)
183{
184 void *ret = realloc(ptr, size);
185 if (!ret)
186 die("Out of memory, realloc failed");
187 return ret;
188}
189#endif /* CACHE_H */