Andrew's git - gitweb.git/blob

   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 */
  57extern 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" */
  65struct 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 */
  76struct 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 */
  89struct 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)
 114static 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
 123extern struct cache_entry **active_cache;
 124extern 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#define GRAFT_ENVIRONMENT "GIT_GRAFT_FILE"
 131
 132extern char *get_object_directory(void);
 133extern char *get_refs_directory(void);
 134extern char *get_index_file(void);
 135extern char *get_graft_file(void);
 136
 137#define ALTERNATE_DB_ENVIRONMENT "GIT_ALTERNATE_OBJECT_DIRECTORIES"
 138
 139#define alloc_nr(x) (((x)+16)*3/2)
 140
 141/* Initialize and use the cache information */
 142extern int read_cache(void);
 143extern int write_cache(int newfd, struct cache_entry **cache, int entries);
 144extern 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 */
 148extern int add_cache_entry(struct cache_entry *ce, int option);
 149extern int remove_cache_entry_at(int pos);
 150extern int remove_file_from_cache(char *path);
 151extern int ce_same_name(struct cache_entry *a, struct cache_entry *b);
 152extern int ce_match_stat(struct cache_entry *ce, struct stat *st);
 153extern int ce_path_match(const struct cache_entry *ce, const char **pathspec);
 154extern int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object, const char *type);
 155extern void fill_stat_cache_info(struct cache_entry *ce, struct stat *st);
 156
 157struct cache_file {
 158        struct cache_file *next;
 159        char lockfile[PATH_MAX];
 160};
 161extern int hold_index_file_for_update(struct cache_file *, const char *path);
 162extern int commit_index_file(struct cache_file *);
 163extern 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 */
 174extern char *mkpath(const char *fmt, ...);
 175extern char *git_path(const char *fmt, ...);
 176extern char *sha1_file_name(const unsigned char *sha1);
 177extern char *sha1_pack_name(const unsigned char *sha1);
 178extern char *sha1_pack_index_name(const unsigned char *sha1);
 179
 180int git_mkstemp(char *path, size_t n, const char *template);
 181
 182int safe_create_leading_directories(char *path);
 183char *safe_strncpy(char *, const char *, size_t);
 184
 185/* Read and unpack a sha1 file into memory, write memory to a sha1 file */
 186extern int unpack_sha1_header(z_stream *stream, void *map, unsigned long mapsize, void *buffer, unsigned long size);
 187extern int parse_sha1_header(char *hdr, char *type, unsigned long *sizep);
 188extern int sha1_object_info(const unsigned char *, char *, unsigned long *);
 189extern void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size);
 190extern void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size);
 191extern int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *return_sha1);
 192extern 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
 199extern int check_sha1_signature(const unsigned char *sha1, void *buf, unsigned long size, const char *type);
 200
 201/* Read a tree into the cache */
 202extern int read_tree(void *buffer, unsigned long size, int stage, const char **paths);
 203
 204extern int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
 205                              size_t bufsize, size_t *bufposn);
 206extern int write_sha1_to_fd(int fd, const unsigned char *sha1);
 207
 208extern int has_sha1_pack(const unsigned char *sha1);
 209extern int has_sha1_file(const unsigned char *sha1);
 210
 211extern int has_pack_file(const unsigned char *sha1);
 212extern int has_pack_index(const unsigned char *sha1);
 213
 214/* Convert to/from hex/sha1 representation */
 215extern int get_sha1(const char *str, unsigned char *sha1);
 216extern int get_sha1_hex(const char *hex, unsigned char *sha1);
 217extern char *sha1_to_hex(const unsigned char *sha1);    /* static buffer result! */
 218
 219/* General helper functions */
 220extern void usage(const char *err) NORETURN;
 221extern void die(const char *err, ...) NORETURN;
 222extern int error(const char *err, ...);
 223
 224extern int base_name_compare(const char *name1, int len1, int mode1, const char *name2, int len2, int mode2);
 225extern int cache_name_compare(const char *name1, int len1, const char *name2, int len2);
 226
 227extern void *read_object_with_reference(const unsigned char *sha1,
 228                                        const char *required_type,
 229                                        unsigned long *size,
 230                                        unsigned char *sha1_ret);
 231
 232const char *show_date(unsigned long time, int timezone);
 233void parse_date(const char *date, char *buf, int bufsize);
 234void datestamp(char *buf, int bufsize);
 235
 236extern int setup_ident(void);
 237extern char *get_ident(const char *name, const char *email, const char *date_str);
 238extern char *git_author_info(void);
 239extern char *git_committer_info(void);
 240
 241static 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
 249static 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
 257static 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
 265struct 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
 274extern int checkout_entry(struct cache_entry *ce, struct checkout *state);
 275
 276extern struct alternate_object_database {
 277        char *base;
 278        char *name;
 279} *alt_odb;
 280extern void prepare_alt_odb(void);
 281
 282extern struct packed_git {
 283        struct packed_git *next;
 284        unsigned long index_size;
 285        unsigned long pack_size;
 286        unsigned int *index_base;
 287        void *pack_base;
 288        unsigned int pack_last_used;
 289        unsigned int pack_use_cnt;
 290        unsigned char sha1[20];
 291        char pack_name[0]; /* something like ".git/objects/pack/xxxxx.pack" */
 292} *packed_git;
 293
 294struct pack_entry {
 295        unsigned int offset;
 296        unsigned char sha1[20];
 297        struct packed_git *p;
 298};
 299
 300struct ref {
 301        struct ref *next;
 302        unsigned char old_sha1[20];
 303        unsigned char new_sha1[20];
 304        struct ref *peer_ref; /* when renaming */
 305        char name[0];
 306};
 307
 308extern int git_connect(int fd[2], char *url, const char *prog);
 309extern int finish_connect(pid_t pid);
 310extern int path_match(const char *path, int nr, char **match);
 311extern int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail,
 312                      int nr_refspec, char **refspec, int all);
 313extern int get_ack(int fd, unsigned char *result_sha1);
 314extern struct ref **get_remote_heads(int in, struct ref **list, int nr_match, char **match);
 315
 316extern struct packed_git *parse_pack_index(unsigned char *sha1);
 317
 318extern void prepare_packed_git(void);
 319extern void install_packed_git(struct packed_git *pack);
 320
 321extern struct packed_git *find_sha1_pack(const unsigned char *sha1, 
 322                                         struct packed_git *packs);
 323
 324extern int use_packed_git(struct packed_git *);
 325extern void unuse_packed_git(struct packed_git *);
 326extern struct packed_git *add_packed_git(char *, int);
 327extern int num_packed_objects(const struct packed_git *p);
 328extern int nth_packed_object_sha1(const struct packed_git *, int, unsigned char*);
 329extern int find_pack_entry_one(const unsigned char *, struct pack_entry *, struct packed_git *);
 330extern void *unpack_entry_gently(struct pack_entry *, char *, unsigned long *);
 331extern void packed_object_info_detail(struct pack_entry *, char *, unsigned long *, unsigned long *, int *, unsigned char *);
 332
 333/* Dumb servers support */
 334extern int update_server_info(int);
 335
 336#endif /* CACHE_H */