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