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 * Environment variables transition.
  45 * We accept older names for now but warn.
  46 */
  47extern char *gitenv_bc(const char *);
  48#define gitenv(e) (getenv(e) ? : gitenv_bc(e))
  49
  50/*
  51 * Basic data structures for the directory cache
  52 */
  53
  54#define CACHE_SIGNATURE 0x44495243      /* "DIRC" */
  55struct cache_header {
  56        unsigned int hdr_signature;
  57        unsigned int hdr_version;
  58        unsigned int hdr_entries;
  59};
  60
  61/*
  62 * The "cache_time" is just the low 32 bits of the
  63 * time. It doesn't matter if it overflows - we only
  64 * check it for equality in the 32 bits we save.
  65 */
  66struct cache_time {
  67        unsigned int sec;
  68        unsigned int nsec;
  69};
  70
  71/*
  72 * dev/ino/uid/gid/size are also just tracked to the low 32 bits
  73 * Again - this is just a (very strong in practice) heuristic that
  74 * the inode hasn't changed.
  75 *
  76 * We save the fields in big-endian order to allow using the
  77 * index file over NFS transparently.
  78 */
  79struct cache_entry {
  80        struct cache_time ce_ctime;
  81        struct cache_time ce_mtime;
  82        unsigned int ce_dev;
  83        unsigned int ce_ino;
  84        unsigned int ce_mode;
  85        unsigned int ce_uid;
  86        unsigned int ce_gid;
  87        unsigned int ce_size;
  88        unsigned char sha1[20];
  89        unsigned short ce_flags;
  90        char name[0];
  91};
  92
  93#define CE_NAMEMASK  (0x0fff)
  94#define CE_STAGEMASK (0x3000)
  95#define CE_UPDATE    (0x4000)
  96#define CE_STAGESHIFT 12
  97
  98#define create_ce_flags(len, stage) htons((len) | ((stage) << CE_STAGESHIFT))
  99#define ce_namelen(ce) (CE_NAMEMASK & ntohs((ce)->ce_flags))
 100#define ce_size(ce) cache_entry_size(ce_namelen(ce))
 101#define ce_stage(ce) ((CE_STAGEMASK & ntohs((ce)->ce_flags)) >> CE_STAGESHIFT)
 102
 103#define ce_permissions(mode) (((mode) & 0100) ? 0755 : 0644)
 104static inline unsigned int create_ce_mode(unsigned int mode)
 105{
 106        if (S_ISLNK(mode))
 107                return htonl(S_IFLNK);
 108        return htonl(S_IFREG | ce_permissions(mode));
 109}
 110
 111#define cache_entry_size(len) ((offsetof(struct cache_entry,name) + (len) + 8) & ~7)
 112
 113extern struct cache_entry **active_cache;
 114extern unsigned int active_nr, active_alloc, active_cache_changed;
 115
 116#define GIT_DIR_ENVIRONMENT "GIT_DIR"
 117#define DEFAULT_GIT_DIR_ENVIRONMENT ".git"
 118#define DB_ENVIRONMENT "GIT_OBJECT_DIRECTORY"
 119#define INDEX_ENVIRONMENT "GIT_INDEX_FILE"
 120
 121extern char *get_object_directory(void);
 122extern char *get_refs_directory(void);
 123extern char *get_index_file(void);
 124
 125#define ALTERNATE_DB_ENVIRONMENT "GIT_ALTERNATE_OBJECT_DIRECTORIES"
 126
 127#define alloc_nr(x) (((x)+16)*3/2)
 128
 129/* Initialize and use the cache information */
 130extern int read_cache(void);
 131extern int write_cache(int newfd, struct cache_entry **cache, int entries);
 132extern int cache_name_pos(const char *name, int namelen);
 133#define ADD_CACHE_OK_TO_ADD 1           /* Ok to add */
 134#define ADD_CACHE_OK_TO_REPLACE 2       /* Ok to replace file/directory */
 135#define ADD_CACHE_SKIP_DFCHECK 4        /* Ok to skip DF conflict checks */
 136extern int add_cache_entry(struct cache_entry *ce, int option);
 137extern int remove_cache_entry_at(int pos);
 138extern int remove_file_from_cache(char *path);
 139extern int ce_same_name(struct cache_entry *a, struct cache_entry *b);
 140extern int ce_match_stat(struct cache_entry *ce, struct stat *st);
 141extern int index_fd(unsigned char *sha1, int fd, struct stat *st);
 142extern void fill_stat_cache_info(struct cache_entry *ce, struct stat *st);
 143
 144struct cache_file {
 145        struct cache_file *next;
 146        char lockfile[PATH_MAX];
 147};
 148extern int hold_index_file_for_update(struct cache_file *, const char *path);
 149extern int commit_index_file(struct cache_file *);
 150extern void rollback_index_file(struct cache_file *);
 151
 152#define MTIME_CHANGED   0x0001
 153#define CTIME_CHANGED   0x0002
 154#define OWNER_CHANGED   0x0004
 155#define MODE_CHANGED    0x0008
 156#define INODE_CHANGED   0x0010
 157#define DATA_CHANGED    0x0020
 158#define TYPE_CHANGED    0x0040
 159
 160/* Return a statically allocated filename matching the sha1 signature */
 161extern char *sha1_file_name(const unsigned char *sha1);
 162
 163/* Read and unpack a sha1 file into memory, write memory to a sha1 file */
 164extern void * map_sha1_file(const unsigned char *sha1, unsigned long *size);
 165extern int unpack_sha1_header(z_stream *stream, void *map, unsigned long mapsize, void *buffer, unsigned long size);
 166extern int parse_sha1_header(char *hdr, char *type, unsigned long *sizep);
 167extern int sha1_object_info(const unsigned char *, char *, unsigned long *);
 168extern void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size);
 169extern void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size);
 170extern int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *return_sha1);
 171
 172extern int check_sha1_signature(const unsigned char *sha1, void *buf, unsigned long size, const char *type);
 173
 174/* Read a tree into the cache */
 175extern int read_tree(void *buffer, unsigned long size, int stage);
 176
 177extern int write_sha1_from_fd(const unsigned char *sha1, int fd);
 178
 179extern int has_sha1_file(const unsigned char *sha1);
 180
 181/* Convert to/from hex/sha1 representation */
 182extern int get_sha1(const char *str, unsigned char *sha1);
 183extern int get_sha1_hex(const char *hex, unsigned char *sha1);
 184extern char *sha1_to_hex(const unsigned char *sha1);    /* static buffer result! */
 185
 186/* General helper functions */
 187extern void usage(const char *err) NORETURN;
 188extern void die(const char *err, ...) NORETURN;
 189extern int error(const char *err, ...);
 190
 191extern int base_name_compare(const char *name1, int len1, int mode1, const char *name2, int len2, int mode2);
 192extern int cache_name_compare(const char *name1, int len1, const char *name2, int len2);
 193
 194extern void *read_object_with_reference(const unsigned char *sha1,
 195                                        const char *required_type,
 196                                        unsigned long *size,
 197                                        unsigned char *sha1_ret);
 198
 199const char *show_date(unsigned long time, int timezone);
 200void parse_date(char *date, char *buf, int bufsize);
 201void datestamp(char *buf, int bufsize);
 202
 203static inline void *xmalloc(size_t size)
 204{
 205        void *ret = malloc(size);
 206        if (!ret)
 207                die("Out of memory, malloc failed");
 208        return ret;
 209}
 210
 211static inline void *xrealloc(void *ptr, size_t size)
 212{
 213        void *ret = realloc(ptr, size);
 214        if (!ret)
 215                die("Out of memory, realloc failed");
 216        return ret;
 217}
 218
 219static inline void *xcalloc(size_t nmemb, size_t size)
 220{
 221        void *ret = calloc(nmemb, size);
 222        if (!ret)
 223                die("Out of memory, calloc failed");
 224        return ret;
 225}
 226
 227struct checkout {
 228        const char *base_dir;
 229        int base_dir_len;
 230        unsigned force:1,
 231                 quiet:1,
 232                 not_new:1,
 233                 refresh_cache:1;
 234};
 235
 236extern int checkout_entry(struct cache_entry *ce, struct checkout *state);
 237
 238extern struct alternate_object_database {
 239        char *base;
 240        char *name;
 241} *alt_odb;
 242extern void prepare_alt_odb(void);
 243
 244extern struct packed_git {
 245        struct packed_git *next;
 246        unsigned long index_size;
 247        unsigned long pack_size;
 248        unsigned int *index_base;
 249        void *pack_base;
 250        unsigned int pack_last_used;
 251        unsigned int pack_use_cnt;
 252        char pack_name[0]; /* something like ".git/objects/pack/xxxxx.pack" */
 253} *packed_git;
 254extern void prepare_packed_git(void);
 255extern int use_packed_git(struct packed_git *);
 256extern void unuse_packed_git(struct packed_git *);
 257extern struct packed_git *add_packed_git(char *, int);
 258extern int num_packed_objects(const struct packed_git *p);
 259extern int nth_packed_object_sha1(const struct packed_git *, int, unsigned char*);
 260
 261#endif /* CACHE_H */