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 #ifndef NO_MMAP
  15 #include <sys/mman.h>
  16 #endif
  17 #include <sys/param.h>
  18 #include <netinet/in.h>
  19 #include <sys/types.h>
  20 #include <dirent.h>
  21
  22 #include SHA1_HEADER
  23 #include <zlib.h>
  24
  25 #if ZLIB_VERNUM < 0x1200
  26 #define deflateBound(c,s)  ((s) + (((s) + 7) >> 3) + (((s) + 63) >> 6) + 11)
  27 #endif
  28
  29 #ifdef DT_UNKNOWN
  30 #define DTYPE(de)       ((de)->d_type)
  31 #else
  32 #define DT_UNKNOWN      0
  33 #define DT_DIR          1
  34 #define DT_REG          2
  35 #define DT_LNK          3
  36 #define DTYPE(de)       DT_UNKNOWN
  37 #endif
  38
  39 #ifdef __GNUC__
  40 #define NORETURN __attribute__((__noreturn__))
  41 #else
  42 #define NORETURN
  43 #ifndef __attribute__
  44 #define __attribute__(x)
  45 #endif
  46 #endif
  47
  48 /*
  49  * Intensive research over the course of many years has shown that
  50  * port 9418 is totally unused by anything else. Or
  51  *
  52  *      Your search - "port 9418" - did not match any documents.
  53  *
  54  * as www.google.com puts it.
  55  *
  56  * This port has been properly assigned for git use by IANA:
  57  * git (Assigned-9418) [I06-050728-0001].
  58  *
  59  *      git  9418/tcp   git pack transfer service
  60  *      git  9418/udp   git pack transfer service
  61  *
  62  * with Linus Torvalds <torvalds@osdl.org> as the point of
  63  * contact. September 2005.
  64  *
  65  * See http://www.iana.org/assignments/port-numbers
  66  */
  67 #define DEFAULT_GIT_PORT 9418
  68
  69 /*
  70  * Basic data structures for the directory cache
  71  */
  72
  73 #define CACHE_SIGNATURE 0x44495243      /* "DIRC" */
  74 struct cache_header {
  75         unsigned int hdr_signature;
  76         unsigned int hdr_version;
  77         unsigned int hdr_entries;
  78 };
  79
  80 /*
  81  * The "cache_time" is just the low 32 bits of the
  82  * time. It doesn't matter if it overflows - we only
  83  * check it for equality in the 32 bits we save.
  84  */
  85 struct cache_time {
  86         unsigned int sec;
  87         unsigned int nsec;
  88 };
  89
  90 /*
  91  * dev/ino/uid/gid/size are also just tracked to the low 32 bits
  92  * Again - this is just a (very strong in practice) heuristic that
  93  * the inode hasn't changed.
  94  *
  95  * We save the fields in big-endian order to allow using the
  96  * index file over NFS transparently.
  97  */
  98 struct cache_entry {
  99         struct cache_time ce_ctime;
 100         struct cache_time ce_mtime;
 101         unsigned int ce_dev;
 102         unsigned int ce_ino;
 103         unsigned int ce_mode;
 104         unsigned int ce_uid;
 105         unsigned int ce_gid;
 106         unsigned int ce_size;
 107         unsigned char sha1[20];
 108         unsigned short ce_flags;
 109         char name[0];
 110 };
 111
 112 #define CE_NAMEMASK  (0x0fff)
 113 #define CE_STAGEMASK (0x3000)
 114 #define CE_UPDATE    (0x4000)
 115 #define CE_STAGESHIFT 12
 116
 117 #define create_ce_flags(len, stage) htons((len) | ((stage) << CE_STAGESHIFT))
 118 #define ce_namelen(ce) (CE_NAMEMASK & ntohs((ce)->ce_flags))
 119 #define ce_size(ce) cache_entry_size(ce_namelen(ce))
 120 #define ce_stage(ce) ((CE_STAGEMASK & ntohs((ce)->ce_flags)) >> CE_STAGESHIFT)
 121
 122 #define ce_permissions(mode) (((mode) & 0100) ? 0755 : 0644)
 123 static inline unsigned int create_ce_mode(unsigned int mode)
 124 {
 125         if (S_ISLNK(mode))
 126                 return htonl(S_IFLNK);
 127         return htonl(S_IFREG | ce_permissions(mode));
 128 }
 129
 130 #define cache_entry_size(len) ((offsetof(struct cache_entry,name) + (len) + 8) & ~7)
 131
 132 extern struct cache_entry **active_cache;
 133 extern unsigned int active_nr, active_alloc, active_cache_changed;
 134
 135 #define GIT_DIR_ENVIRONMENT "GIT_DIR"
 136 #define DEFAULT_GIT_DIR_ENVIRONMENT ".git"
 137 #define DB_ENVIRONMENT "GIT_OBJECT_DIRECTORY"
 138 #define INDEX_ENVIRONMENT "GIT_INDEX_FILE"
 139 #define GRAFT_ENVIRONMENT "GIT_GRAFT_FILE"
 140
 141 extern char *get_git_dir(void);
 142 extern char *get_object_directory(void);
 143 extern char *get_refs_directory(void);
 144 extern char *get_index_file(void);
 145 extern char *get_graft_file(void);
 146
 147 #define ALTERNATE_DB_ENVIRONMENT "GIT_ALTERNATE_OBJECT_DIRECTORIES"
 148
 149 extern const char **get_pathspec(const char *prefix, const char **pathspec);
 150 extern const char *setup_git_directory(void);
 151 extern const char *prefix_path(const char *prefix, int len, const char *path);
 152
 153 #define alloc_nr(x) (((x)+16)*3/2)
 154
 155 /* Initialize and use the cache information */
 156 extern int read_cache(void);
 157 extern int write_cache(int newfd, struct cache_entry **cache, int entries);
 158 extern int cache_name_pos(const char *name, int namelen);
 159 #define ADD_CACHE_OK_TO_ADD 1           /* Ok to add */
 160 #define ADD_CACHE_OK_TO_REPLACE 2       /* Ok to replace file/directory */
 161 #define ADD_CACHE_SKIP_DFCHECK 4        /* Ok to skip DF conflict checks */
 162 extern int add_cache_entry(struct cache_entry *ce, int option);
 163 extern int remove_cache_entry_at(int pos);
 164 extern int remove_file_from_cache(const char *path);
 165 extern int ce_same_name(struct cache_entry *a, struct cache_entry *b);
 166 extern int ce_match_stat(struct cache_entry *ce, struct stat *st);
 167 extern int ce_modified(struct cache_entry *ce, struct stat *st);
 168 extern int ce_path_match(const struct cache_entry *ce, const char **pathspec);
 169 extern int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object, const char *type);
 170 extern int index_path(unsigned char *sha1, const char *path, struct stat *st, int write_object);
 171 extern void fill_stat_cache_info(struct cache_entry *ce, struct stat *st);
 172
 173 struct cache_file {
 174         struct cache_file *next;
 175         char lockfile[PATH_MAX];
 176 };
 177 extern int hold_index_file_for_update(struct cache_file *, const char *path);
 178 extern int commit_index_file(struct cache_file *);
 179 extern void rollback_index_file(struct cache_file *);
 180
 181 #define MTIME_CHANGED   0x0001
 182 #define CTIME_CHANGED   0x0002
 183 #define OWNER_CHANGED   0x0004
 184 #define MODE_CHANGED    0x0008
 185 #define INODE_CHANGED   0x0010
 186 #define DATA_CHANGED    0x0020
 187 #define TYPE_CHANGED    0x0040
 188
 189 /* Return a statically allocated filename matching the sha1 signature */
 190 extern char *mkpath(const char *fmt, ...) __attribute__((format (printf, 1, 2)));
 191 extern char *git_path(const char *fmt, ...) __attribute__((format (printf, 1, 2)));
 192 extern char *sha1_file_name(const unsigned char *sha1);
 193 extern char *sha1_pack_name(const unsigned char *sha1);
 194 extern char *sha1_pack_index_name(const unsigned char *sha1);
 195 extern const unsigned char null_sha1[20];
 196
 197 int git_mkstemp(char *path, size_t n, const char *template);
 198
 199 int safe_create_leading_directories(char *path);
 200 char *safe_strncpy(char *, const char *, size_t);
 201
 202 /* Read and unpack a sha1 file into memory, write memory to a sha1 file */
 203 extern int unpack_sha1_header(z_stream *stream, void *map, unsigned long mapsize, void *buffer, unsigned long size);
 204 extern int parse_sha1_header(char *hdr, char *type, unsigned long *sizep);
 205 extern int sha1_object_info(const unsigned char *, char *, unsigned long *);
 206 extern void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size);
 207 extern void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size);
 208 extern int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *return_sha1);
 209 extern char *write_sha1_file_prepare(void *buf,
 210                                      unsigned long len,
 211                                      const char *type,
 212                                      unsigned char *sha1,
 213                                      unsigned char *hdr,
 214                                      int *hdrlen);
 215
 216 extern int check_sha1_signature(const unsigned char *sha1, void *buf, unsigned long size, const char *type);
 217
 218 /* Read a tree into the cache */
 219 extern int read_tree(void *buffer, unsigned long size, int stage, const char **paths);
 220
 221 extern int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
 222                               size_t bufsize, size_t *bufposn);
 223 extern int write_sha1_to_fd(int fd, const unsigned char *sha1);
 224
 225 extern int has_sha1_pack(const unsigned char *sha1);
 226 extern int has_sha1_file(const unsigned char *sha1);
 227
 228 extern int has_pack_file(const unsigned char *sha1);
 229 extern int has_pack_index(const unsigned char *sha1);
 230
 231 /* Convert to/from hex/sha1 representation */
 232 extern int get_sha1(const char *str, unsigned char *sha1);
 233 extern int get_sha1_hex(const char *hex, unsigned char *sha1);
 234 extern char *sha1_to_hex(const unsigned char *sha1);    /* static buffer result! */
 235 extern int read_ref(const char *filename, unsigned char *sha1);
 236 extern const char *resolve_ref(const char *path, unsigned char *sha1, int);
 237 extern int create_symref(const char *git_HEAD, const char *refs_heads_master);
 238 extern int validate_symref(const char *git_HEAD);
 239
 240 /* General helper functions */
 241 extern void usage(const char *err) NORETURN;
 242 extern void die(const char *err, ...) NORETURN __attribute__((format (printf, 1, 2)));
 243 extern int error(const char *err, ...) __attribute__((format (printf, 1, 2)));
 244
 245 extern int base_name_compare(const char *name1, int len1, int mode1, const char *name2, int len2, int mode2);
 246 extern int cache_name_compare(const char *name1, int len1, const char *name2, int len2);
 247
 248 extern void *read_object_with_reference(const unsigned char *sha1,
 249                                         const char *required_type,
 250                                         unsigned long *size,
 251                                         unsigned char *sha1_ret);
 252
 253 const char *show_date(unsigned long time, int timezone);
 254 int parse_date(const char *date, char *buf, int bufsize);
 255 void datestamp(char *buf, int bufsize);
 256
 257 extern int setup_ident(void);
 258 extern char *get_ident(const char *name, const char *email, const char *date_str);
 259 extern char *git_author_info(void);
 260 extern char *git_committer_info(void);
 261
 262 static inline void *xmalloc(size_t size)
 263 {
 264         void *ret = malloc(size);
 265         if (!ret)
 266                 die("Out of memory, malloc failed");
 267         return ret;
 268 }
 269
 270 static inline void *xrealloc(void *ptr, size_t size)
 271 {
 272         void *ret = realloc(ptr, size);
 273         if (!ret)
 274                 die("Out of memory, realloc failed");
 275         return ret;
 276 }
 277
 278 static inline void *xcalloc(size_t nmemb, size_t size)
 279 {
 280         void *ret = calloc(nmemb, size);
 281         if (!ret)
 282                 die("Out of memory, calloc failed");
 283         return ret;
 284 }
 285
 286 struct checkout {
 287         const char *base_dir;
 288         int base_dir_len;
 289         unsigned force:1,
 290                  quiet:1,
 291                  not_new:1,
 292                  refresh_cache:1;
 293 };
 294
 295 extern int checkout_entry(struct cache_entry *ce, struct checkout *state);
 296
 297 extern struct alternate_object_database {
 298         struct alternate_object_database *next;
 299         char *name;
 300         char base[0]; /* more */
 301 } *alt_odb_list;
 302 extern void prepare_alt_odb(void);
 303
 304 extern struct packed_git {
 305         struct packed_git *next;
 306         unsigned long index_size;
 307         unsigned long pack_size;
 308         unsigned int *index_base;
 309         void *pack_base;
 310         unsigned int pack_last_used;
 311         unsigned int pack_use_cnt;
 312         unsigned char sha1[20];
 313         char pack_name[0]; /* something like ".git/objects/pack/xxxxx.pack" */
 314 } *packed_git;
 315
 316 struct pack_entry {
 317         unsigned int offset;
 318         unsigned char sha1[20];
 319         struct packed_git *p;
 320 };
 321
 322 struct ref {
 323         struct ref *next;
 324         unsigned char old_sha1[20];
 325         unsigned char new_sha1[20];
 326         unsigned char force;
 327         struct ref *peer_ref; /* when renaming */
 328         char name[0];
 329 };
 330
 331 extern int git_connect(int fd[2], char *url, const char *prog);
 332 extern int finish_connect(pid_t pid);
 333 extern int path_match(const char *path, int nr, char **match);
 334 extern int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail,
 335                       int nr_refspec, char **refspec, int all);
 336 extern int get_ack(int fd, unsigned char *result_sha1);
 337 extern struct ref **get_remote_heads(int in, struct ref **list, int nr_match, char **match);
 338
 339 extern struct packed_git *parse_pack_index(unsigned char *sha1);
 340 extern struct packed_git *parse_pack_index_file(const unsigned char *sha1,
 341                                                 char *idx_path);
 342
 343 extern void prepare_packed_git(void);
 344 extern void install_packed_git(struct packed_git *pack);
 345
 346 extern struct packed_git *find_sha1_pack(const unsigned char *sha1,
 347                                          struct packed_git *packs);
 348
 349 extern int use_packed_git(struct packed_git *);
 350 extern void unuse_packed_git(struct packed_git *);
 351 extern struct packed_git *add_packed_git(char *, int);
 352 extern int num_packed_objects(const struct packed_git *p);
 353 extern int nth_packed_object_sha1(const struct packed_git *, int, unsigned char*);
 354 extern int find_pack_entry_one(const unsigned char *, struct pack_entry *, struct packed_git *);
 355 extern void *unpack_entry_gently(struct pack_entry *, char *, unsigned long *);
 356 extern void packed_object_info_detail(struct pack_entry *, char *, unsigned long *, unsigned long *, int *, unsigned char *);
 357
 358 /* Dumb servers support */
 359 extern int update_server_info(int);
 360
 361 #ifdef NO_MMAP
 362
 363 #ifndef PROT_READ
 364 #define PROT_READ 1
 365 #define PROT_WRITE 2
 366 #define MAP_PRIVATE 1
 367 #define MAP_FAILED ((void*)-1)
 368 #endif
 369
 370 extern void *gitfakemmap(void *start, size_t length, int prot , int flags, int fd, off_t offset);
 371 extern int gitfakemunmap(void *start, size_t length);
 372
 373 #endif
 374
 375 #endif /* CACHE_H */