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
 131 extern char *get_object_directory(void);
 132 extern char *get_refs_directory(void);
 133 extern char *get_index_file(void);
 134
 135 #define ALTERNATE_DB_ENVIRONMENT "GIT_ALTERNATE_OBJECT_DIRECTORIES"
 136
 137 #define alloc_nr(x) (((x)+16)*3/2)
 138
 139 /* Initialize and use the cache information */
 140 extern int read_cache(void);
 141 extern int write_cache(int newfd, struct cache_entry **cache, int entries);
 142 extern int cache_name_pos(const char *name, int namelen);
 143 #define ADD_CACHE_OK_TO_ADD 1           /* Ok to add */
 144 #define ADD_CACHE_OK_TO_REPLACE 2       /* Ok to replace file/directory */
 145 #define ADD_CACHE_SKIP_DFCHECK 4        /* Ok to skip DF conflict checks */
 146 extern int add_cache_entry(struct cache_entry *ce, int option);
 147 extern int remove_cache_entry_at(int pos);
 148 extern int remove_file_from_cache(char *path);
 149 extern int ce_same_name(struct cache_entry *a, struct cache_entry *b);
 150 extern int ce_match_stat(struct cache_entry *ce, struct stat *st);
 151 extern int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object, const char *type);
 152 extern void fill_stat_cache_info(struct cache_entry *ce, struct stat *st);
 153
 154 struct cache_file {
 155         struct cache_file *next;
 156         char lockfile[PATH_MAX];
 157 };
 158 extern int hold_index_file_for_update(struct cache_file *, const char *path);
 159 extern int commit_index_file(struct cache_file *);
 160 extern void rollback_index_file(struct cache_file *);
 161
 162 #define MTIME_CHANGED   0x0001
 163 #define CTIME_CHANGED   0x0002
 164 #define OWNER_CHANGED   0x0004
 165 #define MODE_CHANGED    0x0008
 166 #define INODE_CHANGED   0x0010
 167 #define DATA_CHANGED    0x0020
 168 #define TYPE_CHANGED    0x0040
 169
 170 /* Return a statically allocated filename matching the sha1 signature */
 171 extern char *mkpath(const char *fmt, ...);
 172 extern char *git_path(const char *fmt, ...);
 173 extern char *sha1_file_name(const unsigned char *sha1);
 174
 175 int safe_create_leading_directories(char *path);
 176
 177 /* Read and unpack a sha1 file into memory, write memory to a sha1 file */
 178 extern int unpack_sha1_header(z_stream *stream, void *map, unsigned long mapsize, void *buffer, unsigned long size);
 179 extern int parse_sha1_header(char *hdr, char *type, unsigned long *sizep);
 180 extern int sha1_object_info(const unsigned char *, char *, unsigned long *);
 181 extern void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size);
 182 extern void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size);
 183 extern int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *return_sha1);
 184 extern char *write_sha1_file_prepare(void *buf,
 185                                      unsigned long len,
 186                                      const char *type,
 187                                      unsigned char *sha1,
 188                                      unsigned char *hdr,
 189                                      int *hdrlen);
 190
 191 extern int check_sha1_signature(const unsigned char *sha1, void *buf, unsigned long size, const char *type);
 192
 193 /* Read a tree into the cache */
 194 extern int read_tree(void *buffer, unsigned long size, int stage);
 195
 196 extern int write_sha1_from_fd(const unsigned char *sha1, int fd);
 197 extern int write_sha1_to_fd(int fd, const unsigned char *sha1);
 198
 199 extern int has_sha1_pack(const unsigned char *sha1);
 200 extern int has_sha1_file(const unsigned char *sha1);
 201
 202 /* Convert to/from hex/sha1 representation */
 203 extern int get_sha1(const char *str, unsigned char *sha1);
 204 extern int get_sha1_hex(const char *hex, unsigned char *sha1);
 205 extern char *sha1_to_hex(const unsigned char *sha1);    /* static buffer result! */
 206
 207 /* General helper functions */
 208 extern void usage(const char *err) NORETURN;
 209 extern void die(const char *err, ...) NORETURN;
 210 extern int error(const char *err, ...);
 211
 212 extern int base_name_compare(const char *name1, int len1, int mode1, const char *name2, int len2, int mode2);
 213 extern int cache_name_compare(const char *name1, int len1, const char *name2, int len2);
 214
 215 extern void *read_object_with_reference(const unsigned char *sha1,
 216                                         const char *required_type,
 217                                         unsigned long *size,
 218                                         unsigned char *sha1_ret);
 219
 220 const char *show_date(unsigned long time, int timezone);
 221 void parse_date(const char *date, char *buf, int bufsize);
 222 void datestamp(char *buf, int bufsize);
 223
 224 extern int setup_ident(void);
 225 extern char *get_ident(const char *name, const char *email, const char *date_str);
 226
 227 static inline void *xmalloc(size_t size)
 228 {
 229         void *ret = malloc(size);
 230         if (!ret)
 231                 die("Out of memory, malloc failed");
 232         return ret;
 233 }
 234
 235 static inline void *xrealloc(void *ptr, size_t size)
 236 {
 237         void *ret = realloc(ptr, size);
 238         if (!ret)
 239                 die("Out of memory, realloc failed");
 240         return ret;
 241 }
 242
 243 static inline void *xcalloc(size_t nmemb, size_t size)
 244 {
 245         void *ret = calloc(nmemb, size);
 246         if (!ret)
 247                 die("Out of memory, calloc failed");
 248         return ret;
 249 }
 250
 251 struct checkout {
 252         const char *base_dir;
 253         int base_dir_len;
 254         unsigned force:1,
 255                  quiet:1,
 256                  not_new:1,
 257                  refresh_cache:1;
 258 };
 259
 260 extern int checkout_entry(struct cache_entry *ce, struct checkout *state);
 261
 262 extern struct alternate_object_database {
 263         char *base;
 264         char *name;
 265 } *alt_odb;
 266 extern void prepare_alt_odb(void);
 267
 268 extern struct packed_git {
 269         struct packed_git *next;
 270         unsigned long index_size;
 271         unsigned long pack_size;
 272         unsigned int *index_base;
 273         void *pack_base;
 274         unsigned int pack_last_used;
 275         unsigned int pack_use_cnt;
 276         char pack_name[0]; /* something like ".git/objects/pack/xxxxx.pack" */
 277 } *packed_git;
 278
 279 struct pack_entry {
 280         unsigned int offset;
 281         unsigned char sha1[20];
 282         struct packed_git *p;
 283 };
 284
 285 extern int git_connect(int fd[2], char *url, const char *prog);
 286 extern int finish_connect(pid_t pid);
 287 extern int path_match(const char *path, int nr, char **match);
 288 extern int get_ack(int fd, unsigned char *result_sha1);
 289
 290 extern void prepare_packed_git(void);
 291 extern int use_packed_git(struct packed_git *);
 292 extern void unuse_packed_git(struct packed_git *);
 293 extern struct packed_git *add_packed_git(char *, int);
 294 extern int num_packed_objects(const struct packed_git *p);
 295 extern int nth_packed_object_sha1(const struct packed_git *, int, unsigned char*);
 296 extern int find_pack_entry_one(const unsigned char *, struct pack_entry *, struct packed_git *);
 297 extern void *unpack_entry_gently(struct pack_entry *, char *, unsigned long *);
 298 extern void packed_object_info_detail(struct pack_entry *, char *, unsigned long *, unsigned long *, int *, unsigned char *);
 299
 300 #endif /* CACHE_H */