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 #ifdef __GNUC__
  36 #define NORETURN __attribute__((__noreturn__))
  37 #else
  38 #define NORETURN
  39 #endif
  40
  41 /*
  42  * Environment variables transition.
  43  * We accept older names for now but warn.
  44  */
  45 extern char *gitenv_bc(const char *);
  46 #define gitenv(e) (getenv(e) ? : gitenv_bc(e))
  47
  48 /*
  49  * Basic data structures for the directory cache
  50  */
  51
  52 #define CACHE_SIGNATURE 0x44495243      /* "DIRC" */
  53 struct cache_header {
  54         unsigned int hdr_signature;
  55         unsigned int hdr_version;
  56         unsigned int hdr_entries;
  57 };
  58
  59 /*
  60  * The "cache_time" is just the low 32 bits of the
  61  * time. It doesn't matter if it overflows - we only
  62  * check it for equality in the 32 bits we save.
  63  */
  64 struct cache_time {
  65         unsigned int sec;
  66         unsigned int nsec;
  67 };
  68
  69 /*
  70  * dev/ino/uid/gid/size are also just tracked to the low 32 bits
  71  * Again - this is just a (very strong in practice) heuristic that
  72  * the inode hasn't changed.
  73  *
  74  * We save the fields in big-endian order to allow using the
  75  * index file over NFS transparently.
  76  */
  77 struct cache_entry {
  78         struct cache_time ce_ctime;
  79         struct cache_time ce_mtime;
  80         unsigned int ce_dev;
  81         unsigned int ce_ino;
  82         unsigned int ce_mode;
  83         unsigned int ce_uid;
  84         unsigned int ce_gid;
  85         unsigned int ce_size;
  86         unsigned char sha1[20];
  87         unsigned short ce_flags;
  88         char name[0];
  89 };
  90
  91 #define CE_NAMEMASK  (0x0fff)
  92 #define CE_STAGEMASK (0x3000)
  93 #define CE_UPDATE    (0x4000)
  94 #define CE_STAGESHIFT 12
  95
  96 #define create_ce_flags(len, stage) htons((len) | ((stage) << CE_STAGESHIFT))
  97 #define ce_namelen(ce) (CE_NAMEMASK & ntohs((ce)->ce_flags))
  98 #define ce_size(ce) cache_entry_size(ce_namelen(ce))
  99 #define ce_stage(ce) ((CE_STAGEMASK & ntohs((ce)->ce_flags)) >> CE_STAGESHIFT)
 100
 101 #define ce_permissions(mode) (((mode) & 0100) ? 0755 : 0644)
 102 static inline unsigned int create_ce_mode(unsigned int mode)
 103 {
 104         if (S_ISLNK(mode))
 105                 return htonl(S_IFLNK);
 106         return htonl(S_IFREG | ce_permissions(mode));
 107 }
 108
 109 #define cache_entry_size(len) ((offsetof(struct cache_entry,name) + (len) + 8) & ~7)
 110
 111 extern struct cache_entry **active_cache;
 112 extern unsigned int active_nr, active_alloc, active_cache_changed;
 113
 114 #define GIT_DIR_ENVIRONMENT "GIT_DIR"
 115 #define DEFAULT_GIT_DIR_ENVIRONMENT ".git"
 116 #define DB_ENVIRONMENT "GIT_OBJECT_DIRECTORY"
 117 #define INDEX_ENVIRONMENT "GIT_INDEX_FILE"
 118
 119 extern char *get_object_directory(void);
 120 extern char *get_refs_directory(void);
 121 extern char *get_index_file(void);
 122
 123 #define ALTERNATE_DB_ENVIRONMENT "GIT_ALTERNATE_OBJECT_DIRECTORIES"
 124
 125 #define alloc_nr(x) (((x)+16)*3/2)
 126
 127 /* Initialize and use the cache information */
 128 extern int read_cache(void);
 129 extern int write_cache(int newfd, struct cache_entry **cache, int entries);
 130 extern int cache_name_pos(const char *name, int namelen);
 131 #define ADD_CACHE_OK_TO_ADD 1           /* Ok to add */
 132 #define ADD_CACHE_OK_TO_REPLACE 2       /* Ok to replace file/directory */
 133 #define ADD_CACHE_SKIP_DFCHECK 4        /* Ok to skip DF conflict checks */
 134 extern int add_cache_entry(struct cache_entry *ce, int option);
 135 extern int remove_cache_entry_at(int pos);
 136 extern int remove_file_from_cache(char *path);
 137 extern int ce_same_name(struct cache_entry *a, struct cache_entry *b);
 138 extern int ce_match_stat(struct cache_entry *ce, struct stat *st);
 139 extern int index_fd(unsigned char *sha1, int fd, struct stat *st);
 140 extern void fill_stat_cache_info(struct cache_entry *ce, struct stat *st);
 141
 142 struct cache_file {
 143         struct cache_file *next;
 144         char lockfile[PATH_MAX];
 145 };
 146 extern int hold_index_file_for_update(struct cache_file *, const char *path);
 147 extern int commit_index_file(struct cache_file *);
 148 extern void rollback_index_file(struct cache_file *);
 149
 150 #define MTIME_CHANGED   0x0001
 151 #define CTIME_CHANGED   0x0002
 152 #define OWNER_CHANGED   0x0004
 153 #define MODE_CHANGED    0x0008
 154 #define INODE_CHANGED   0x0010
 155 #define DATA_CHANGED    0x0020
 156 #define TYPE_CHANGED    0x0040
 157
 158 /* Return a statically allocated filename matching the sha1 signature */
 159 extern char *sha1_file_name(const unsigned char *sha1);
 160
 161 /* Read and unpack a sha1 file into memory, write memory to a sha1 file */
 162 extern void * map_sha1_file(const unsigned char *sha1, unsigned long *size);
 163 extern int unpack_sha1_header(z_stream *stream, void *map, unsigned long mapsize, void *buffer, unsigned long size);
 164 extern int parse_sha1_header(char *hdr, char *type, unsigned long *sizep);
 165 extern int sha1_delta_base(const unsigned char *, unsigned char *);
 166 extern int sha1_file_size(const unsigned char *, unsigned long *);
 167 extern void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size);
 168 extern void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size);
 169 extern int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *return_sha1);
 170
 171 extern int check_sha1_signature(const unsigned char *sha1, void *buf, unsigned long size, const char *type);
 172
 173 /* Read a tree into the cache */
 174 extern int read_tree(void *buffer, unsigned long size, int stage);
 175
 176 extern int write_sha1_from_fd(const unsigned char *sha1, int fd);
 177
 178 extern int has_sha1_file(const unsigned char *sha1);
 179
 180 /* Convert to/from hex/sha1 representation */
 181 extern int get_sha1(const char *str, unsigned char *sha1);
 182 extern int get_sha1_hex(const char *hex, unsigned char *sha1);
 183 extern char *sha1_to_hex(const unsigned char *sha1);    /* static buffer result! */
 184
 185 /* General helper functions */
 186 extern void usage(const char *err) NORETURN;
 187 extern void die(const char *err, ...) NORETURN;
 188 extern int error(const char *err, ...);
 189
 190 extern int base_name_compare(const char *name1, int len1, int mode1, const char *name2, int len2, int mode2);
 191 extern int cache_name_compare(const char *name1, int len1, const char *name2, int len2);
 192
 193 extern void *read_object_with_reference(const unsigned char *sha1,
 194                                         const char *required_type,
 195                                         unsigned long *size,
 196                                         unsigned char *sha1_ret);
 197
 198 const char *show_date(unsigned long time, int timezone);
 199 void parse_date(char *date, char *buf, int bufsize);
 200 void datestamp(char *buf, int bufsize);
 201
 202 static inline void *xmalloc(size_t size)
 203 {
 204         void *ret = malloc(size);
 205         if (!ret)
 206                 die("Out of memory, malloc failed");
 207         return ret;
 208 }
 209
 210 static inline void *xrealloc(void *ptr, size_t size)
 211 {
 212         void *ret = realloc(ptr, size);
 213         if (!ret)
 214                 die("Out of memory, realloc failed");
 215         return ret;
 216 }
 217
 218 static inline void *xcalloc(size_t nmemb, size_t size)
 219 {
 220         void *ret = calloc(nmemb, size);
 221         if (!ret)
 222                 die("Out of memory, calloc failed");
 223         return ret;
 224 }
 225
 226 struct checkout {
 227         const char *base_dir;
 228         int base_dir_len;
 229         unsigned force:1,
 230                  quiet:1,
 231                  not_new:1,
 232                  refresh_cache:1;
 233 };
 234
 235 extern int checkout_entry(struct cache_entry *ce, struct checkout *state);
 236
 237 #endif /* CACHE_H */