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