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 DT_LNK 3
31#define DTYPE(de) DT_UNKNOWN
32#endif
33
34/*
35 * Environment variables transition.
36 * We accept older names for now but warn.
37 */
38extern char *gitenv_bc(const char *);
39#define gitenv(e) (getenv(e) ? : gitenv_bc(e))
40
41/*
42 * Basic data structures for the directory cache
43 */
44
45#define CACHE_SIGNATURE 0x44495243 /* "DIRC" */
46struct cache_header {
47 unsigned int hdr_signature;
48 unsigned int hdr_version;
49 unsigned int hdr_entries;
50};
51
52/*
53 * The "cache_time" is just the low 32 bits of the
54 * time. It doesn't matter if it overflows - we only
55 * check it for equality in the 32 bits we save.
56 */
57struct cache_time {
58 unsigned int sec;
59 unsigned int nsec;
60};
61
62/*
63 * dev/ino/uid/gid/size are also just tracked to the low 32 bits
64 * Again - this is just a (very strong in practice) heuristic that
65 * the inode hasn't changed.
66 *
67 * We save the fields in big-endian order to allow using the
68 * index file over NFS transparently.
69 */
70struct cache_entry {
71 struct cache_time ce_ctime;
72 struct cache_time ce_mtime;
73 unsigned int ce_dev;
74 unsigned int ce_ino;
75 unsigned int ce_mode;
76 unsigned int ce_uid;
77 unsigned int ce_gid;
78 unsigned int ce_size;
79 unsigned char sha1[20];
80 unsigned short ce_flags;
81 char name[0];
82};
83
84#define CE_NAMEMASK (0x0fff)
85#define CE_STAGEMASK (0x3000)
86#define CE_STAGESHIFT 12
87
88#define create_ce_flags(len, stage) htons((len) | ((stage) << CE_STAGESHIFT))
89#define ce_namelen(ce) (CE_NAMEMASK & ntohs((ce)->ce_flags))
90#define ce_size(ce) cache_entry_size(ce_namelen(ce))
91#define ce_stage(ce) ((CE_STAGEMASK & ntohs((ce)->ce_flags)) >> CE_STAGESHIFT)
92
93#define ce_permissions(mode) (((mode) & 0100) ? 0755 : 0644)
94static inline unsigned int create_ce_mode(unsigned int mode)
95{
96 if (S_ISLNK(mode))
97 return htonl(S_IFLNK);
98 return htonl(S_IFREG | ce_permissions(mode));
99}
100
101#define cache_entry_size(len) ((offsetof(struct cache_entry,name) + (len) + 8) & ~7)
102
103extern struct cache_entry **active_cache;
104extern unsigned int active_nr, active_alloc, active_cache_changed;
105
106#define GIT_DIR_ENVIRONMENT "GIT_DIR"
107#define DEFAULT_GIT_DIR_ENVIRONMENT ".git"
108#define DB_ENVIRONMENT "GIT_OBJECT_DIRECTORY"
109#define INDEX_ENVIRONMENT "GIT_INDEX_FILE"
110
111extern char *get_object_directory(void);
112extern char *get_index_file(void);
113
114#define ALTERNATE_DB_ENVIRONMENT "GIT_ALTERNATE_OBJECT_DIRECTORIES"
115
116#define alloc_nr(x) (((x)+16)*3/2)
117
118/* Initialize and use the cache information */
119extern int read_cache(void);
120extern int write_cache(int newfd, struct cache_entry **cache, int entries);
121extern int cache_name_pos(const char *name, int namelen);
122#define ADD_CACHE_OK_TO_ADD 1 /* Ok to add */
123#define ADD_CACHE_OK_TO_REPLACE 2 /* Ok to replace file/directory */
124extern int add_cache_entry(struct cache_entry *ce, int option);
125extern int remove_cache_entry_at(int pos);
126extern int remove_file_from_cache(char *path);
127extern int ce_same_name(struct cache_entry *a, struct cache_entry *b);
128extern int ce_match_stat(struct cache_entry *ce, struct stat *st);
129extern int index_fd(unsigned char *sha1, int fd, struct stat *st);
130extern void fill_stat_cache_info(struct cache_entry *ce, struct stat *st);
131
132struct cache_file {
133 struct cache_file *next;
134 char lockfile[PATH_MAX];
135};
136extern int hold_index_file_for_update(struct cache_file *, const char *path);
137extern int commit_index_file(struct cache_file *);
138extern void rollback_index_file(struct cache_file *);
139
140#define MTIME_CHANGED 0x0001
141#define CTIME_CHANGED 0x0002
142#define OWNER_CHANGED 0x0004
143#define MODE_CHANGED 0x0008
144#define INODE_CHANGED 0x0010
145#define DATA_CHANGED 0x0020
146#define TYPE_CHANGED 0x0040
147
148/* Return a statically allocated filename matching the sha1 signature */
149extern char *sha1_file_name(const unsigned char *sha1);
150
151/* Read and unpack a sha1 file into memory, write memory to a sha1 file */
152extern void * map_sha1_file(const unsigned char *sha1, unsigned long *size);
153extern void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size);
154extern void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size);
155extern int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *return_sha1);
156
157extern int check_sha1_signature(unsigned char *sha1, void *buf, unsigned long size, const char *type);
158
159/* Read a tree into the cache */
160extern int read_tree(void *buffer, unsigned long size, int stage);
161
162extern int write_sha1_from_fd(const unsigned char *sha1, int fd);
163
164extern int has_sha1_file(const unsigned char *sha1);
165
166/* Convert to/from hex/sha1 representation */
167extern int get_sha1(const char *str, unsigned char *sha1);
168extern int get_sha1_hex(const char *hex, unsigned char *sha1);
169extern char *sha1_to_hex(const unsigned char *sha1); /* static buffer result! */
170
171/* General helper functions */
172extern void usage(const char *err);
173extern void die(const char *err, ...);
174extern int error(const char *err, ...);
175
176extern int base_name_compare(const char *name1, int len1, int mode1, const char *name2, int len2, int mode2);
177extern int cache_name_compare(const char *name1, int len1, const char *name2, int len2);
178
179extern void *read_object_with_reference(const unsigned char *sha1,
180 const char *required_type,
181 unsigned long *size,
182 unsigned char *sha1_ret);
183
184const char *show_date(unsigned long time, int timezone);
185void parse_date(char *date, char *buf, int bufsize);
186void datestamp(char *buf, int bufsize);
187
188static inline void *xmalloc(size_t size)
189{
190 void *ret = malloc(size);
191 if (!ret)
192 die("Out of memory, malloc failed");
193 return ret;
194}
195
196static inline void *xrealloc(void *ptr, size_t size)
197{
198 void *ret = realloc(ptr, size);
199 if (!ret)
200 die("Out of memory, realloc failed");
201 return ret;
202}
203
204static inline void *xcalloc(size_t nmemb, size_t size)
205{
206 void *ret = calloc(nmemb, size);
207 if (!ret)
208 die("Out of memory, calloc failed");
209 return ret;
210}
211
212#endif /* CACHE_H */