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