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 #include <sys/types.h>
  18 #include <dirent.h>
  19
  20 #include SHA1_HEADER
  21 #include <zlib.h>
  22
  23 #if ZLIB_VERNUM < 0x1200
  24 #define deflateBound(c,s)  ((s) + (((s) + 7) >> 3) + (((s) + 63) >> 6) + 11)
  25 #endif
  26
  27 #ifdef DT_UNKNOWN
  28 #define DTYPE(de)       ((de)->d_type)
  29 #else
  30 #define DT_UNKNOWN      0
  31 #define DT_DIR          1
  32 #define DT_REG          2
  33 #define DT_LNK          3
  34 #define DTYPE(de)       DT_UNKNOWN
  35 #endif
  36
  37 #ifdef __GNUC__
  38 #define NORETURN __attribute__((__noreturn__))
  39 #else
  40 #define NORETURN
  41 #endif
  42
  43 /*
  44  * Intensive research over the course of many years has shown that
  45  * port 9418 is totally unused by anything else. Or
  46  *
  47  *      Your search - "port 9418" - did not match any documents.
  48  *
  49  * as www.google.com puts it.
  50  */
  51 #define DEFAULT_GIT_PORT 9418
  52
  53 /*
  54  * Environment variables transition.
  55  * We accept older names for now but warn.
  56  */
  57 extern char *gitenv_bc(const char *);
  58 #define gitenv(e) (getenv(e) ? : gitenv_bc(e))
  59
  60 /*
  61  * Basic data structures for the directory cache
  62  */
  63
  64 #define CACHE_SIGNATURE 0x44495243      /* "DIRC" */
  65 struct cache_header {
  66         unsigned int hdr_signature;
  67         unsigned int hdr_version;
  68         unsigned int hdr_entries;
  69 };
  70
  71 /*
  72  * The "cache_time" is just the low 32 bits of the
  73  * time. It doesn't matter if it overflows - we only
  74  * check it for equality in the 32 bits we save.
  75  */
  76 struct cache_time {
  77         unsigned int sec;
  78         unsigned int nsec;
  79 };
  80
  81 /*
  82  * dev/ino/uid/gid/size are also just tracked to the low 32 bits
  83  * Again - this is just a (very strong in practice) heuristic that
  84  * the inode hasn't changed.
  85  *
  86  * We save the fields in big-endian order to allow using the
  87  * index file over NFS transparently.
  88  */
  89 struct cache_entry {
  90         struct cache_time ce_ctime;
  91         struct cache_time ce_mtime;
  92         unsigned int ce_dev;
  93         unsigned int ce_ino;
  94         unsigned int ce_mode;
  95         unsigned int ce_uid;
  96         unsigned int ce_gid;
  97         unsigned int ce_size;
  98         unsigned char sha1[20];
  99         unsigned short ce_flags;
 100         char name[0];
 101 };
 102
 103 #define CE_NAMEMASK  (0x0fff)
 104 #define CE_STAGEMASK (0x3000)
 105 #define CE_UPDATE    (0x4000)
 106 #define CE_STAGESHIFT 12
 107
 108 #define create_ce_flags(len, stage) htons((len) | ((stage) << CE_STAGESHIFT))
 109 #define ce_namelen(ce) (CE_NAMEMASK & ntohs((ce)->ce_flags))
 110 #define ce_size(ce) cache_entry_size(ce_namelen(ce))
 111 #define ce_stage(ce) ((CE_STAGEMASK & ntohs((ce)->ce_flags)) >> CE_STAGESHIFT)
 112
 113 #define ce_permissions(mode) (((mode) & 0100) ? 0755 : 0644)
 114 static inline unsigned int create_ce_mode(unsigned int mode)
 115 {
 116         if (S_ISLNK(mode))
 117                 return htonl(S_IFLNK);
 118         return htonl(S_IFREG | ce_permissions(mode));
 119 }
 120
 121 #define cache_entry_size(len) ((offsetof(struct cache_entry,name) + (len) + 8) & ~7)
 122
 123 extern struct cache_entry **active_cache;
 124 extern unsigned int active_nr, active_alloc, active_cache_changed;
 125
 126 #define GIT_DIR_ENVIRONMENT "GIT_DIR"
 127 #define DEFAULT_GIT_DIR_ENVIRONMENT ".git"
 128 #define DB_ENVIRONMENT "GIT_OBJECT_DIRECTORY"
 129 #define INDEX_ENVIRONMENT "GIT_INDEX_FILE"
 130 #define GRAFT_ENVIRONMENT "GIT_GRAFT_FILE"
 131 #define TEMPLATE_DIR_ENVIRONMENT "GIT_TEMPLATE_DIRECTORY"
 132 #ifndef DEFAULT_GIT_TEMPLATE_ENVIRONMENT
 133 #define DEFAULT_GIT_TEMPLATE_ENVIRONMENT "/etc/git-core/templates"
 134 #endif
 135
 136 extern char *get_object_directory(void);
 137 extern char *get_refs_directory(void);
 138 extern char *get_index_file(void);
 139 extern char *get_graft_file(void);
 140
 141 #define ALTERNATE_DB_ENVIRONMENT "GIT_ALTERNATE_OBJECT_DIRECTORIES"
 142
 143 #define alloc_nr(x) (((x)+16)*3/2)
 144
 145 /* Initialize and use the cache information */
 146 extern int read_cache(void);
 147 extern int write_cache(int newfd, struct cache_entry **cache, int entries);
 148 extern int cache_name_pos(const char *name, int namelen);
 149 #define ADD_CACHE_OK_TO_ADD 1           /* Ok to add */
 150 #define ADD_CACHE_OK_TO_REPLACE 2       /* Ok to replace file/directory */
 151 #define ADD_CACHE_SKIP_DFCHECK 4        /* Ok to skip DF conflict checks */
 152 extern int add_cache_entry(struct cache_entry *ce, int option);
 153 extern int remove_cache_entry_at(int pos);
 154 extern int remove_file_from_cache(char *path);
 155 extern int ce_same_name(struct cache_entry *a, struct cache_entry *b);
 156 extern int ce_match_stat(struct cache_entry *ce, struct stat *st);
 157 extern int ce_path_match(const struct cache_entry *ce, const char **pathspec);
 158 extern int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object, const char *type);
 159 extern void fill_stat_cache_info(struct cache_entry *ce, struct stat *st);
 160
 161 struct cache_file {
 162         struct cache_file *next;
 163         char lockfile[PATH_MAX];
 164 };
 165 extern int hold_index_file_for_update(struct cache_file *, const char *path);
 166 extern int commit_index_file(struct cache_file *);
 167 extern void rollback_index_file(struct cache_file *);
 168
 169 #define MTIME_CHANGED   0x0001
 170 #define CTIME_CHANGED   0x0002
 171 #define OWNER_CHANGED   0x0004
 172 #define MODE_CHANGED    0x0008
 173 #define INODE_CHANGED   0x0010
 174 #define DATA_CHANGED    0x0020
 175 #define TYPE_CHANGED    0x0040
 176
 177 /* Return a statically allocated filename matching the sha1 signature */
 178 extern char *mkpath(const char *fmt, ...);
 179 extern char *git_path(const char *fmt, ...);
 180 extern char *sha1_file_name(const unsigned char *sha1);
 181 extern char *sha1_pack_name(const unsigned char *sha1);
 182 extern char *sha1_pack_index_name(const unsigned char *sha1);
 183
 184 int git_mkstemp(char *path, size_t n, const char *template);
 185
 186 int safe_create_leading_directories(char *path);
 187 char *safe_strncpy(char *, const char *, size_t);
 188
 189 /* Read and unpack a sha1 file into memory, write memory to a sha1 file */
 190 extern int unpack_sha1_header(z_stream *stream, void *map, unsigned long mapsize, void *buffer, unsigned long size);
 191 extern int parse_sha1_header(char *hdr, char *type, unsigned long *sizep);
 192 extern int sha1_object_info(const unsigned char *, char *, unsigned long *);
 193 extern void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size);
 194 extern void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size);
 195 extern int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *return_sha1);
 196 extern char *write_sha1_file_prepare(void *buf,
 197                                      unsigned long len,
 198                                      const char *type,
 199                                      unsigned char *sha1,
 200                                      unsigned char *hdr,
 201                                      int *hdrlen);
 202
 203 extern int check_sha1_signature(const unsigned char *sha1, void *buf, unsigned long size, const char *type);
 204
 205 /* Read a tree into the cache */
 206 extern int read_tree(void *buffer, unsigned long size, int stage, const char **paths);
 207
 208 extern int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
 209                               size_t bufsize, size_t *bufposn);
 210 extern int write_sha1_to_fd(int fd, const unsigned char *sha1);
 211
 212 extern int has_sha1_pack(const unsigned char *sha1);
 213 extern int has_sha1_file(const unsigned char *sha1);
 214
 215 extern int has_pack_file(const unsigned char *sha1);
 216 extern int has_pack_index(const unsigned char *sha1);
 217
 218 /* Convert to/from hex/sha1 representation */
 219 extern int get_sha1(const char *str, unsigned char *sha1);
 220 extern int get_sha1_hex(const char *hex, unsigned char *sha1);
 221 extern char *sha1_to_hex(const unsigned char *sha1);    /* static buffer result! */
 222
 223 /* General helper functions */
 224 extern void usage(const char *err) NORETURN;
 225 extern void die(const char *err, ...) NORETURN;
 226 extern int error(const char *err, ...);
 227
 228 extern int base_name_compare(const char *name1, int len1, int mode1, const char *name2, int len2, int mode2);
 229 extern int cache_name_compare(const char *name1, int len1, const char *name2, int len2);
 230
 231 extern void *read_object_with_reference(const unsigned char *sha1,
 232                                         const char *required_type,
 233                                         unsigned long *size,
 234                                         unsigned char *sha1_ret);
 235
 236 const char *show_date(unsigned long time, int timezone);
 237 void parse_date(const char *date, char *buf, int bufsize);
 238 void datestamp(char *buf, int bufsize);
 239
 240 extern int setup_ident(void);
 241 extern char *get_ident(const char *name, const char *email, const char *date_str);
 242 extern char *git_author_info(void);
 243 extern char *git_committer_info(void);
 244
 245 static inline void *xmalloc(size_t size)
 246 {
 247         void *ret = malloc(size);
 248         if (!ret)
 249                 die("Out of memory, malloc failed");
 250         return ret;
 251 }
 252
 253 static inline void *xrealloc(void *ptr, size_t size)
 254 {
 255         void *ret = realloc(ptr, size);
 256         if (!ret)
 257                 die("Out of memory, realloc failed");
 258         return ret;
 259 }
 260
 261 static inline void *xcalloc(size_t nmemb, size_t size)
 262 {
 263         void *ret = calloc(nmemb, size);
 264         if (!ret)
 265                 die("Out of memory, calloc failed");
 266         return ret;
 267 }
 268
 269 struct checkout {
 270         const char *base_dir;
 271         int base_dir_len;
 272         unsigned force:1,
 273                  quiet:1,
 274                  not_new:1,
 275                  refresh_cache:1;
 276 };
 277
 278 extern int checkout_entry(struct cache_entry *ce, struct checkout *state);
 279
 280 extern struct alternate_object_database {
 281         char *base;
 282         char *name;
 283 } *alt_odb;
 284 extern void prepare_alt_odb(void);
 285
 286 extern struct packed_git {
 287         struct packed_git *next;
 288         unsigned long index_size;
 289         unsigned long pack_size;
 290         unsigned int *index_base;
 291         void *pack_base;
 292         unsigned int pack_last_used;
 293         unsigned int pack_use_cnt;
 294         unsigned char sha1[20];
 295         char pack_name[0]; /* something like ".git/objects/pack/xxxxx.pack" */
 296 } *packed_git;
 297
 298 struct pack_entry {
 299         unsigned int offset;
 300         unsigned char sha1[20];
 301         struct packed_git *p;
 302 };
 303
 304 struct ref {
 305         struct ref *next;
 306         unsigned char old_sha1[20];
 307         unsigned char new_sha1[20];
 308         struct ref *peer_ref; /* when renaming */
 309         char name[0];
 310 };
 311
 312 extern int git_connect(int fd[2], char *url, const char *prog);
 313 extern int finish_connect(pid_t pid);
 314 extern int path_match(const char *path, int nr, char **match);
 315 extern int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail,
 316                       int nr_refspec, char **refspec, int all);
 317 extern int get_ack(int fd, unsigned char *result_sha1);
 318 extern struct ref **get_remote_heads(int in, struct ref **list, int nr_match, char **match);
 319
 320 extern struct packed_git *parse_pack_index(unsigned char *sha1);
 321
 322 extern void prepare_packed_git(void);
 323 extern void install_packed_git(struct packed_git *pack);
 324
 325 extern struct packed_git *find_sha1_pack(const unsigned char *sha1,
 326                                          struct packed_git *packs);
 327
 328 extern int use_packed_git(struct packed_git *);
 329 extern void unuse_packed_git(struct packed_git *);
 330 extern struct packed_git *add_packed_git(char *, int);
 331 extern int num_packed_objects(const struct packed_git *p);
 332 extern int nth_packed_object_sha1(const struct packed_git *, int, unsigned char*);
 333 extern int find_pack_entry_one(const unsigned char *, struct pack_entry *, struct packed_git *);
 334 extern void *unpack_entry_gently(struct pack_entry *, char *, unsigned long *);
 335 extern void packed_object_info_detail(struct pack_entry *, char *, unsigned long *, unsigned long *, int *, unsigned char *);
 336
 337 /* Dumb servers support */
 338 extern int update_server_info(int);
 339
 340 #endif /* CACHE_H */