cache.h

   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 <limits.h>
  14 #include <sys/mman.h>
  15 #include <sys/param.h>
  16 #include <netinet/in.h>
  17
  18 #include SHA1_HEADER
  19 #include <zlib.h>
  20
  21 #if ZLIB_VERNUM < 0x1200
  22 #define deflateBound(c,s)  ((s) + (((s) + 7) >> 3) + (((s) + 63) >> 6) + 11)
  23 #endif
  24
  25 #ifdef DT_UNKNOWN
  26 #define DTYPE(de)       ((de)->d_type)
  27 #else
  28 #define DT_UNKNOWN      0
  29 #define DT_DIR          1
  30 #define DT_REG          2
  31 #define DT_LNK          3
  32 #define DTYPE(de)       DT_UNKNOWN
  33 #endif
  34
  35 /*
  36  * Environment variables transition.
  37  * We accept older names for now but warn.
  38  */
  39 extern char *gitenv_bc(const char *);
  40 #define gitenv(e) (getenv(e) ? : gitenv_bc(e))
  41
  42 /*
  43  * Basic data structures for the directory cache
  44  */
  45
  46 #define CACHE_SIGNATURE 0x44495243      /* "DIRC" */
  47 struct cache_header {
  48         unsigned int hdr_signature;
  49         unsigned int hdr_version;
  50         unsigned int hdr_entries;
  51 };
  52
  53 /*
  54  * The "cache_time" is just the low 32 bits of the
  55  * time. It doesn't matter if it overflows - we only
  56  * check it for equality in the 32 bits we save.
  57  */
  58 struct cache_time {
  59         unsigned int sec;
  60         unsigned int nsec;
  61 };
  62
  63 /*
  64  * dev/ino/uid/gid/size are also just tracked to the low 32 bits
  65  * Again - this is just a (very strong in practice) heuristic that
  66  * the inode hasn't changed.
  67  *
  68  * We save the fields in big-endian order to allow using the
  69  * index file over NFS transparently.
  70  */
  71 struct cache_entry {
  72         struct cache_time ce_ctime;
  73         struct cache_time ce_mtime;
  74         unsigned int ce_dev;
  75         unsigned int ce_ino;
  76         unsigned int ce_mode;
  77         unsigned int ce_uid;
  78         unsigned int ce_gid;
  79         unsigned int ce_size;
  80         unsigned char sha1[20];
  81         unsigned short ce_flags;
  82         char name[0];
  83 };
  84
  85 #define CE_NAMEMASK  (0x0fff)
  86 #define CE_STAGEMASK (0x3000)
  87 #define CE_UPDATE    (0x4000)
  88 #define CE_STAGESHIFT 12
  89
  90 #define create_ce_flags(len, stage) htons((len) | ((stage) << CE_STAGESHIFT))
  91 #define ce_namelen(ce) (CE_NAMEMASK & ntohs((ce)->ce_flags))
  92 #define ce_size(ce) cache_entry_size(ce_namelen(ce))
  93 #define ce_stage(ce) ((CE_STAGEMASK & ntohs((ce)->ce_flags)) >> CE_STAGESHIFT)
  94
  95 #define ce_permissions(mode) (((mode) & 0100) ? 0755 : 0644)
  96 static inline unsigned int create_ce_mode(unsigned int mode)
  97 {
  98         if (S_ISLNK(mode))
  99                 return htonl(S_IFLNK);
 100         return htonl(S_IFREG | ce_permissions(mode));
 101 }
 102
 103 #define cache_entry_size(len) ((offsetof(struct cache_entry,name) + (len) + 8) & ~7)
 104
 105 extern struct cache_entry **active_cache;
 106 extern unsigned int active_nr, active_alloc, active_cache_changed;
 107
 108 #define GIT_DIR_ENVIRONMENT "GIT_DIR"
 109 #define DEFAULT_GIT_DIR_ENVIRONMENT ".git"
 110 #define DB_ENVIRONMENT "GIT_OBJECT_DIRECTORY"
 111 #define INDEX_ENVIRONMENT "GIT_INDEX_FILE"
 112
 113 extern char *get_object_directory(void);
 114 extern char *get_index_file(void);
 115
 116 #define ALTERNATE_DB_ENVIRONMENT "GIT_ALTERNATE_OBJECT_DIRECTORIES"
 117
 118 #define alloc_nr(x) (((x)+16)*3/2)
 119
 120 /* Initialize and use the cache information */
 121 extern int read_cache(void);
 122 extern int write_cache(int newfd, struct cache_entry **cache, int entries);
 123 extern int cache_name_pos(const char *name, int namelen);
 124 #define ADD_CACHE_OK_TO_ADD 1           /* Ok to add */
 125 #define ADD_CACHE_OK_TO_REPLACE 2       /* Ok to replace file/directory */
 126 extern int add_cache_entry(struct cache_entry *ce, int option);
 127 extern int remove_cache_entry_at(int pos);
 128 extern int remove_file_from_cache(char *path);
 129 extern int ce_same_name(struct cache_entry *a, struct cache_entry *b);
 130 extern int ce_match_stat(struct cache_entry *ce, struct stat *st);
 131 extern int index_fd(unsigned char *sha1, int fd, struct stat *st);
 132 extern void fill_stat_cache_info(struct cache_entry *ce, struct stat *st);
 133
 134 struct cache_file {
 135         struct cache_file *next;
 136         char lockfile[PATH_MAX];
 137 };
 138 extern int hold_index_file_for_update(struct cache_file *, const char *path);
 139 extern int commit_index_file(struct cache_file *);
 140 extern void rollback_index_file(struct cache_file *);
 141
 142 #define MTIME_CHANGED   0x0001
 143 #define CTIME_CHANGED   0x0002
 144 #define OWNER_CHANGED   0x0004
 145 #define MODE_CHANGED    0x0008
 146 #define INODE_CHANGED   0x0010
 147 #define DATA_CHANGED    0x0020
 148 #define TYPE_CHANGED    0x0040
 149
 150 /* Return a statically allocated filename matching the sha1 signature */
 151 extern char *sha1_file_name(const unsigned char *sha1);
 152
 153 /* Read and unpack a sha1 file into memory, write memory to a sha1 file */
 154 extern void * map_sha1_file(const unsigned char *sha1, unsigned long *size);
 155 extern int unpack_sha1_header(z_stream *stream, void *map, unsigned long mapsize, void *buffer, unsigned long size);
 156 extern int parse_sha1_header(char *hdr, char *type, unsigned long *sizep);
 157 extern int sha1_delta_base(const unsigned char *, unsigned char *);
 158 extern int sha1_file_size(const unsigned char *, unsigned long *);
 159 extern void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size);
 160 extern void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size);
 161 extern int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *return_sha1);
 162
 163 extern int check_sha1_signature(unsigned char *sha1, void *buf, unsigned long size, const char *type);
 164
 165 /* Read a tree into the cache */
 166 extern int read_tree(void *buffer, unsigned long size, int stage);
 167
 168 extern int write_sha1_from_fd(const unsigned char *sha1, int fd);
 169
 170 extern int has_sha1_file(const unsigned char *sha1);
 171
 172 /* Convert to/from hex/sha1 representation */
 173 extern int get_sha1(const char *str, unsigned char *sha1);
 174 extern int get_sha1_hex(const char *hex, unsigned char *sha1);
 175 extern char *sha1_to_hex(const unsigned char *sha1);    /* static buffer result! */
 176
 177 /* General helper functions */
 178 extern void usage(const char *err);
 179 extern void die(const char *err, ...);
 180 extern int error(const char *err, ...);
 181
 182 extern int base_name_compare(const char *name1, int len1, int mode1, const char *name2, int len2, int mode2);
 183 extern int cache_name_compare(const char *name1, int len1, const char *name2, int len2);
 184
 185 extern void *read_object_with_reference(const unsigned char *sha1,
 186                                         const char *required_type,
 187                                         unsigned long *size,
 188                                         unsigned char *sha1_ret);
 189
 190 const char *show_date(unsigned long time, int timezone);
 191 void parse_date(char *date, char *buf, int bufsize);
 192 void datestamp(char *buf, int bufsize);
 193
 194 static inline void *xmalloc(size_t size)
 195 {
 196         void *ret = malloc(size);
 197         if (!ret)
 198                 die("Out of memory, malloc failed");
 199         return ret;
 200 }
 201
 202 static inline void *xrealloc(void *ptr, size_t size)
 203 {
 204         void *ret = realloc(ptr, size);
 205         if (!ret)
 206                 die("Out of memory, realloc failed");
 207         return ret;
 208 }
 209
 210 static inline void *xcalloc(size_t nmemb, size_t size)
 211 {
 212         void *ret = calloc(nmemb, size);
 213         if (!ret)
 214                 die("Out of memory, calloc failed");
 215         return ret;
 216 }
 217
 218 struct checkout {
 219         const char *base_dir;
 220         int base_dir_len;
 221         unsigned force:1,
 222                  quiet:1,
 223                  not_new:1,
 224                  refresh_cache:1;
 225 };
 226
 227 extern int checkout_entry(struct cache_entry *ce, struct checkout *state);
 228
 229 #endif /* CACHE_H */