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 extern int trust_executable_bit;
 182 extern int only_use_symrefs;
 183 extern int diff_rename_limit_default;
 184
 185 #define MTIME_CHANGED   0x0001
 186 #define CTIME_CHANGED   0x0002
 187 #define OWNER_CHANGED   0x0004
 188 #define MODE_CHANGED    0x0008
 189 #define INODE_CHANGED   0x0010
 190 #define DATA_CHANGED    0x0020
 191 #define TYPE_CHANGED    0x0040
 192
 193 /* Return a statically allocated filename matching the sha1 signature */
 194 extern char *mkpath(const char *fmt, ...) __attribute__((format (printf, 1, 2)));
 195 extern char *enter_repo(char *path, int strict);
 196 extern char *git_path(const char *fmt, ...) __attribute__((format (printf, 1, 2)));
 197 extern char *sha1_file_name(const unsigned char *sha1);
 198 extern char *sha1_pack_name(const unsigned char *sha1);
 199 extern char *sha1_pack_index_name(const unsigned char *sha1);
 200 extern const char *find_unique_abbrev(const unsigned char *sha1, int);
 201 extern const unsigned char null_sha1[20];
 202
 203 int git_mkstemp(char *path, size_t n, const char *template);
 204
 205 int safe_create_leading_directories(char *path);
 206 char *safe_strncpy(char *, const char *, size_t);
 207
 208 /* Read and unpack a sha1 file into memory, write memory to a sha1 file */
 209 extern int unpack_sha1_header(z_stream *stream, void *map, unsigned long mapsize, void *buffer, unsigned long size);
 210 extern int parse_sha1_header(char *hdr, char *type, unsigned long *sizep);
 211 extern int sha1_object_info(const unsigned char *, char *, unsigned long *);
 212 extern void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size);
 213 extern void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size);
 214 extern int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *return_sha1);
 215 extern char *write_sha1_file_prepare(void *buf,
 216                                      unsigned long len,
 217                                      const char *type,
 218                                      unsigned char *sha1,
 219                                      unsigned char *hdr,
 220                                      int *hdrlen);
 221
 222 extern int check_sha1_signature(const unsigned char *sha1, void *buf, unsigned long size, const char *type);
 223
 224 /* Read a tree into the cache */
 225 extern int read_tree(void *buffer, unsigned long size, int stage, const char **paths);
 226
 227 extern int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
 228                               size_t bufsize, size_t *bufposn);
 229 extern int write_sha1_to_fd(int fd, const unsigned char *sha1);
 230 extern int move_temp_to_file(const char *tmpfile, char *filename);
 231
 232 extern int has_sha1_pack(const unsigned char *sha1);
 233 extern int has_sha1_file(const unsigned char *sha1);
 234
 235 extern int has_pack_file(const unsigned char *sha1);
 236 extern int has_pack_index(const unsigned char *sha1);
 237
 238 /* Convert to/from hex/sha1 representation */
 239 extern int get_sha1(const char *str, unsigned char *sha1);
 240 extern int get_sha1_hex(const char *hex, unsigned char *sha1);
 241 extern char *sha1_to_hex(const unsigned char *sha1);    /* static buffer result! */
 242 extern int read_ref(const char *filename, unsigned char *sha1);
 243 extern const char *resolve_ref(const char *path, unsigned char *sha1, int);
 244 extern int create_symref(const char *git_HEAD, const char *refs_heads_master);
 245 extern int validate_symref(const char *git_HEAD);
 246
 247 /* General helper functions */
 248 extern void usage(const char *err) NORETURN;
 249 extern void die(const char *err, ...) NORETURN __attribute__((format (printf, 1, 2)));
 250 extern int error(const char *err, ...) __attribute__((format (printf, 1, 2)));
 251
 252 extern int base_name_compare(const char *name1, int len1, int mode1, const char *name2, int len2, int mode2);
 253 extern int cache_name_compare(const char *name1, int len1, const char *name2, int len2);
 254
 255 extern void *read_object_with_reference(const unsigned char *sha1,
 256                                         const char *required_type,
 257                                         unsigned long *size,
 258                                         unsigned char *sha1_ret);
 259
 260 const char *show_date(unsigned long time, int timezone);
 261 int parse_date(const char *date, char *buf, int bufsize);
 262 void datestamp(char *buf, int bufsize);
 263 unsigned long approxidate(const char *);
 264
 265 extern int setup_ident(void);
 266 extern char *get_ident(const char *name, const char *email, const char *date_str);
 267 extern char *git_author_info(void);
 268 extern char *git_committer_info(void);
 269
 270 static inline void *xmalloc(size_t size)
 271 {
 272         void *ret = malloc(size);
 273         if (!ret)
 274                 die("Out of memory, malloc failed");
 275         return ret;
 276 }
 277
 278 static inline void *xrealloc(void *ptr, size_t size)
 279 {
 280         void *ret = realloc(ptr, size);
 281         if (!ret)
 282                 die("Out of memory, realloc failed");
 283         return ret;
 284 }
 285
 286 static inline void *xcalloc(size_t nmemb, size_t size)
 287 {
 288         void *ret = calloc(nmemb, size);
 289         if (!ret)
 290                 die("Out of memory, calloc failed");
 291         return ret;
 292 }
 293
 294 struct checkout {
 295         const char *base_dir;
 296         int base_dir_len;
 297         unsigned force:1,
 298                  quiet:1,
 299                  not_new:1,
 300                  refresh_cache:1;
 301 };
 302
 303 extern int checkout_entry(struct cache_entry *ce, struct checkout *state);
 304
 305 extern struct alternate_object_database {
 306         struct alternate_object_database *next;
 307         char *name;
 308         char base[0]; /* more */
 309 } *alt_odb_list;
 310 extern void prepare_alt_odb(void);
 311
 312 extern struct packed_git {
 313         struct packed_git *next;
 314         unsigned long index_size;
 315         unsigned long pack_size;
 316         unsigned int *index_base;
 317         void *pack_base;
 318         unsigned int pack_last_used;
 319         unsigned int pack_use_cnt;
 320         int pack_local;
 321         unsigned char sha1[20];
 322         char pack_name[0]; /* something like ".git/objects/pack/xxxxx.pack" */
 323 } *packed_git;
 324
 325 struct pack_entry {
 326         unsigned int offset;
 327         unsigned char sha1[20];
 328         struct packed_git *p;
 329 };
 330
 331 struct ref {
 332         struct ref *next;
 333         unsigned char old_sha1[20];
 334         unsigned char new_sha1[20];
 335         unsigned char force;
 336         struct ref *peer_ref; /* when renaming */
 337         char name[0];
 338 };
 339
 340 extern int git_connect(int fd[2], char *url, const char *prog);
 341 extern int finish_connect(pid_t pid);
 342 extern int path_match(const char *path, int nr, char **match);
 343 extern int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail,
 344                       int nr_refspec, char **refspec, int all);
 345 extern int get_ack(int fd, unsigned char *result_sha1);
 346 extern struct ref **get_remote_heads(int in, struct ref **list, int nr_match, char **match, int ignore_funny);
 347 extern int server_supports(const char *feature);
 348
 349 extern struct packed_git *parse_pack_index(unsigned char *sha1);
 350 extern struct packed_git *parse_pack_index_file(const unsigned char *sha1,
 351                                                 char *idx_path);
 352
 353 extern void prepare_packed_git(void);
 354 extern void install_packed_git(struct packed_git *pack);
 355
 356 extern struct packed_git *find_sha1_pack(const unsigned char *sha1,
 357                                          struct packed_git *packs);
 358
 359 extern int use_packed_git(struct packed_git *);
 360 extern void unuse_packed_git(struct packed_git *);
 361 extern struct packed_git *add_packed_git(char *, int, int);
 362 extern int num_packed_objects(const struct packed_git *p);
 363 extern int nth_packed_object_sha1(const struct packed_git *, int, unsigned char*);
 364 extern int find_pack_entry_one(const unsigned char *, struct pack_entry *, struct packed_git *);
 365 extern void *unpack_entry_gently(struct pack_entry *, char *, unsigned long *);
 366 extern void packed_object_info_detail(struct pack_entry *, char *, unsigned long *, unsigned long *, int *, unsigned char *);
 367
 368 /* Dumb servers support */
 369 extern int update_server_info(int);
 370
 371 #ifdef NO_MMAP
 372
 373 #ifndef PROT_READ
 374 #define PROT_READ 1
 375 #define PROT_WRITE 2
 376 #define MAP_PRIVATE 1
 377 #define MAP_FAILED ((void*)-1)
 378 #endif
 379
 380 extern void *gitfakemmap(void *start, size_t length, int prot , int flags, int fd, off_t offset);
 381 extern int gitfakemunmap(void *start, size_t length);
 382
 383 #endif
 384
 385 typedef int (*config_fn_t)(const char *, const char *);
 386 extern int git_default_config(const char *, const char *);
 387 extern int git_config(config_fn_t fn);
 388 extern int git_config_int(const char *, const char *);
 389 extern int git_config_bool(const char *, const char *);
 390 extern int git_config_set(const char *, const char *);
 391 extern int git_config_set_multivar(const char *, const char *, const char *);
 392
 393 #define MAX_GITNAME (1000)
 394 extern char git_default_email[MAX_GITNAME];
 395 extern char git_default_name[MAX_GITNAME];
 396
 397 /* Sane ctype - no locale, and works with signed chars */
 398 #undef isspace
 399 #undef isdigit
 400 #undef isalpha
 401 #undef isalnum
 402 #undef tolower
 403 #undef toupper
 404 extern unsigned char sane_ctype[256];
 405 #define GIT_SPACE 0x01
 406 #define GIT_DIGIT 0x02
 407 #define GIT_ALPHA 0x04
 408 #define sane_istest(x,mask) ((sane_ctype[(unsigned char)(x)] & (mask)) != 0)
 409 #define isspace(x) sane_istest(x,GIT_SPACE)
 410 #define isdigit(x) sane_istest(x,GIT_DIGIT)
 411 #define isalpha(x) sane_istest(x,GIT_ALPHA)
 412 #define isalnum(x) sane_istest(x,GIT_ALPHA | GIT_DIGIT)
 413 #define tolower(x) sane_case((unsigned char)(x), 0x20)
 414 #define toupper(x) sane_case((unsigned char)(x), 0)
 415
 416 static inline int sane_case(int x, int high)
 417 {
 418         if (sane_istest(x, GIT_ALPHA))
 419                 x = (x & ~0x20) | high;
 420         return x;
 421 }
 422
 423 extern int copy_fd(int ifd, int ofd);
 424 #endif /* CACHE_H */