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
  18#include SHA1_HEADER
  19#include <zlib.h>
  20
  21#if ZLIB_VERNUM < 0x1200
  22#define deflateBound(c,s)  ((s) + (((s) + 7) >> 3) + (((s) + 63) >> 6) + 11)
  23#endif
  24
  25#ifdef DT_UNKNOWN
  26#define DTYPE(de)       ((de)->d_type)
  27#else
  28#define DT_UNKNOWN      0
  29#define DT_DIR          1
  30#define DT_REG          2
  31#define DT_LNK          3
  32#define DTYPE(de)       DT_UNKNOWN
  33#endif
  34
  35#ifdef __GNUC__
  36#define NORETURN __attribute__((__noreturn__))
  37#else
  38#define NORETURN
  39#endif
  40
  41/*
  42 * Environment variables transition.
  43 * We accept older names for now but warn.
  44 */
  45extern char *gitenv_bc(const char *);
  46#define gitenv(e) (getenv(e) ? : gitenv_bc(e))
  47
  48/*
  49 * Basic data structures for the directory cache
  50 */
  51
  52#define CACHE_SIGNATURE 0x44495243      /* "DIRC" */
  53struct cache_header {
  54        unsigned int hdr_signature;
  55        unsigned int hdr_version;
  56        unsigned int hdr_entries;
  57};
  58
  59/*
  60 * The "cache_time" is just the low 32 bits of the
  61 * time. It doesn't matter if it overflows - we only
  62 * check it for equality in the 32 bits we save.
  63 */
  64struct cache_time {
  65        unsigned int sec;
  66        unsigned int nsec;
  67};
  68
  69/*
  70 * dev/ino/uid/gid/size are also just tracked to the low 32 bits
  71 * Again - this is just a (very strong in practice) heuristic that
  72 * the inode hasn't changed.
  73 *
  74 * We save the fields in big-endian order to allow using the
  75 * index file over NFS transparently.
  76 */
  77struct cache_entry {
  78        struct cache_time ce_ctime;
  79        struct cache_time ce_mtime;
  80        unsigned int ce_dev;
  81        unsigned int ce_ino;
  82        unsigned int ce_mode;
  83        unsigned int ce_uid;
  84        unsigned int ce_gid;
  85        unsigned int ce_size;
  86        unsigned char sha1[20];
  87        unsigned short ce_flags;
  88        char name[0];
  89};
  90
  91#define CE_NAMEMASK  (0x0fff)
  92#define CE_STAGEMASK (0x3000)
  93#define CE_UPDATE    (0x4000)
  94#define CE_STAGESHIFT 12
  95
  96#define create_ce_flags(len, stage) htons((len) | ((stage) << CE_STAGESHIFT))
  97#define ce_namelen(ce) (CE_NAMEMASK & ntohs((ce)->ce_flags))
  98#define ce_size(ce) cache_entry_size(ce_namelen(ce))
  99#define ce_stage(ce) ((CE_STAGEMASK & ntohs((ce)->ce_flags)) >> CE_STAGESHIFT)
 100
 101#define ce_permissions(mode) (((mode) & 0100) ? 0755 : 0644)
 102static inline unsigned int create_ce_mode(unsigned int mode)
 103{
 104        if (S_ISLNK(mode))
 105                return htonl(S_IFLNK);
 106        return htonl(S_IFREG | ce_permissions(mode));
 107}
 108
 109#define cache_entry_size(len) ((offsetof(struct cache_entry,name) + (len) + 8) & ~7)
 110
 111extern struct cache_entry **active_cache;
 112extern unsigned int active_nr, active_alloc, active_cache_changed;
 113
 114#define GIT_DIR_ENVIRONMENT "GIT_DIR"
 115#define DEFAULT_GIT_DIR_ENVIRONMENT ".git"
 116#define DB_ENVIRONMENT "GIT_OBJECT_DIRECTORY"
 117#define INDEX_ENVIRONMENT "GIT_INDEX_FILE"
 118
 119extern char *get_object_directory(void);
 120extern char *get_index_file(void);
 121
 122#define ALTERNATE_DB_ENVIRONMENT "GIT_ALTERNATE_OBJECT_DIRECTORIES"
 123
 124#define alloc_nr(x) (((x)+16)*3/2)
 125
 126/* Initialize and use the cache information */
 127extern int read_cache(void);
 128extern int write_cache(int newfd, struct cache_entry **cache, int entries);
 129extern int cache_name_pos(const char *name, int namelen);
 130#define ADD_CACHE_OK_TO_ADD 1           /* Ok to add */
 131#define ADD_CACHE_OK_TO_REPLACE 2       /* Ok to replace file/directory */
 132extern int add_cache_entry(struct cache_entry *ce, int option);
 133extern int remove_cache_entry_at(int pos);
 134extern int remove_file_from_cache(char *path);
 135extern int ce_same_name(struct cache_entry *a, struct cache_entry *b);
 136extern int ce_match_stat(struct cache_entry *ce, struct stat *st);
 137extern int index_fd(unsigned char *sha1, int fd, struct stat *st);
 138extern void fill_stat_cache_info(struct cache_entry *ce, struct stat *st);
 139
 140struct cache_file {
 141        struct cache_file *next;
 142        char lockfile[PATH_MAX];
 143};
 144extern int hold_index_file_for_update(struct cache_file *, const char *path);
 145extern int commit_index_file(struct cache_file *);
 146extern void rollback_index_file(struct cache_file *);
 147
 148#define MTIME_CHANGED   0x0001
 149#define CTIME_CHANGED   0x0002
 150#define OWNER_CHANGED   0x0004
 151#define MODE_CHANGED    0x0008
 152#define INODE_CHANGED   0x0010
 153#define DATA_CHANGED    0x0020
 154#define TYPE_CHANGED    0x0040
 155
 156/* Return a statically allocated filename matching the sha1 signature */
 157extern char *sha1_file_name(const unsigned char *sha1);
 158
 159/* Read and unpack a sha1 file into memory, write memory to a sha1 file */
 160extern void * map_sha1_file(const unsigned char *sha1, unsigned long *size);
 161extern int unpack_sha1_header(z_stream *stream, void *map, unsigned long mapsize, void *buffer, unsigned long size);
 162extern int parse_sha1_header(char *hdr, char *type, unsigned long *sizep);
 163extern int sha1_delta_base(const unsigned char *, unsigned char *);
 164extern int sha1_file_size(const unsigned char *, unsigned long *);
 165extern void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size);
 166extern void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size);
 167extern int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *return_sha1);
 168
 169extern int check_sha1_signature(unsigned char *sha1, void *buf, unsigned long size, const char *type);
 170
 171/* Read a tree into the cache */
 172extern int read_tree(void *buffer, unsigned long size, int stage);
 173
 174extern int write_sha1_from_fd(const unsigned char *sha1, int fd);
 175
 176extern int has_sha1_file(const unsigned char *sha1);
 177
 178/* Convert to/from hex/sha1 representation */
 179extern int get_sha1(const char *str, unsigned char *sha1);
 180extern int get_sha1_hex(const char *hex, unsigned char *sha1);
 181extern char *sha1_to_hex(const unsigned char *sha1);    /* static buffer result! */
 182
 183/* General helper functions */
 184extern void usage(const char *err) NORETURN;
 185extern void die(const char *err, ...) NORETURN;
 186extern int error(const char *err, ...);
 187
 188extern int base_name_compare(const char *name1, int len1, int mode1, const char *name2, int len2, int mode2);
 189extern int cache_name_compare(const char *name1, int len1, const char *name2, int len2);
 190
 191extern void *read_object_with_reference(const unsigned char *sha1,
 192                                        const char *required_type,
 193                                        unsigned long *size,
 194                                        unsigned char *sha1_ret);
 195
 196const char *show_date(unsigned long time, int timezone);
 197void parse_date(char *date, char *buf, int bufsize);
 198void datestamp(char *buf, int bufsize);
 199
 200static inline void *xmalloc(size_t size)
 201{
 202        void *ret = malloc(size);
 203        if (!ret)
 204                die("Out of memory, malloc failed");
 205        return ret;
 206}
 207
 208static inline void *xrealloc(void *ptr, size_t size)
 209{
 210        void *ret = realloc(ptr, size);
 211        if (!ret)
 212                die("Out of memory, realloc failed");
 213        return ret;
 214}
 215
 216static inline void *xcalloc(size_t nmemb, size_t size)
 217{
 218        void *ret = calloc(nmemb, size);
 219        if (!ret)
 220                die("Out of memory, calloc failed");
 221        return ret;
 222}
 223
 224struct checkout {
 225        const char *base_dir;
 226        int base_dir_len;
 227        unsigned force:1,
 228                 quiet:1,
 229                 not_new:1,
 230                 refresh_cache:1;
 231};
 232
 233extern int checkout_entry(struct cache_entry *ce, struct checkout *state);
 234
 235#endif /* CACHE_H */