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_STAGESHIFT 12
  88
  89#define create_ce_flags(len, stage) htons((len) | ((stage) << CE_STAGESHIFT))
  90#define ce_namelen(ce) (CE_NAMEMASK & ntohs((ce)->ce_flags))
  91#define ce_size(ce) cache_entry_size(ce_namelen(ce))
  92#define ce_stage(ce) ((CE_STAGEMASK & ntohs((ce)->ce_flags)) >> CE_STAGESHIFT)
  93
  94#define ce_permissions(mode) (((mode) & 0100) ? 0755 : 0644)
  95static inline unsigned int create_ce_mode(unsigned int mode)
  96{
  97        if (S_ISLNK(mode))
  98                return htonl(S_IFLNK);
  99        return htonl(S_IFREG | ce_permissions(mode));
 100}
 101
 102#define cache_entry_size(len) ((offsetof(struct cache_entry,name) + (len) + 8) & ~7)
 103
 104extern struct cache_entry **active_cache;
 105extern unsigned int active_nr, active_alloc, active_cache_changed;
 106
 107#define GIT_DIR_ENVIRONMENT "GIT_DIR"
 108#define DEFAULT_GIT_DIR_ENVIRONMENT ".git"
 109#define DB_ENVIRONMENT "GIT_OBJECT_DIRECTORY"
 110#define INDEX_ENVIRONMENT "GIT_INDEX_FILE"
 111
 112extern char *get_object_directory(void);
 113extern char *get_index_file(void);
 114
 115#define ALTERNATE_DB_ENVIRONMENT "GIT_ALTERNATE_OBJECT_DIRECTORIES"
 116
 117#define alloc_nr(x) (((x)+16)*3/2)
 118
 119/* Initialize and use the cache information */
 120extern int read_cache(void);
 121extern int write_cache(int newfd, struct cache_entry **cache, int entries);
 122extern int cache_name_pos(const char *name, int namelen);
 123#define ADD_CACHE_OK_TO_ADD 1           /* Ok to add */
 124#define ADD_CACHE_OK_TO_REPLACE 2       /* Ok to replace file/directory */
 125extern int add_cache_entry(struct cache_entry *ce, int option);
 126extern int remove_cache_entry_at(int pos);
 127extern int remove_file_from_cache(char *path);
 128extern int ce_same_name(struct cache_entry *a, struct cache_entry *b);
 129extern int ce_match_stat(struct cache_entry *ce, struct stat *st);
 130extern int index_fd(unsigned char *sha1, int fd, struct stat *st);
 131extern void fill_stat_cache_info(struct cache_entry *ce, struct stat *st);
 132
 133struct cache_file {
 134        struct cache_file *next;
 135        char lockfile[PATH_MAX];
 136};
 137extern int hold_index_file_for_update(struct cache_file *, const char *path);
 138extern int commit_index_file(struct cache_file *);
 139extern void rollback_index_file(struct cache_file *);
 140
 141#define MTIME_CHANGED   0x0001
 142#define CTIME_CHANGED   0x0002
 143#define OWNER_CHANGED   0x0004
 144#define MODE_CHANGED    0x0008
 145#define INODE_CHANGED   0x0010
 146#define DATA_CHANGED    0x0020
 147#define TYPE_CHANGED    0x0040
 148
 149/* Return a statically allocated filename matching the sha1 signature */
 150extern char *sha1_file_name(const unsigned char *sha1);
 151
 152/* Read and unpack a sha1 file into memory, write memory to a sha1 file */
 153extern void * map_sha1_file(const unsigned char *sha1, unsigned long *size);
 154extern void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size);
 155extern void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size);
 156extern int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *return_sha1);
 157
 158extern int check_sha1_signature(unsigned char *sha1, void *buf, unsigned long size, const char *type);
 159
 160/* Read a tree into the cache */
 161extern int read_tree(void *buffer, unsigned long size, int stage);
 162
 163extern int write_sha1_from_fd(const unsigned char *sha1, int fd);
 164
 165extern int has_sha1_file(const unsigned char *sha1);
 166
 167/* Convert to/from hex/sha1 representation */
 168extern int get_sha1(const char *str, unsigned char *sha1);
 169extern int get_sha1_hex(const char *hex, unsigned char *sha1);
 170extern char *sha1_to_hex(const unsigned char *sha1);    /* static buffer result! */
 171
 172/* General helper functions */
 173extern void usage(const char *err);
 174extern void die(const char *err, ...);
 175extern int error(const char *err, ...);
 176
 177extern int base_name_compare(const char *name1, int len1, int mode1, const char *name2, int len2, int mode2);
 178extern int cache_name_compare(const char *name1, int len1, const char *name2, int len2);
 179
 180extern void *read_object_with_reference(const unsigned char *sha1,
 181                                        const char *required_type,
 182                                        unsigned long *size,
 183                                        unsigned char *sha1_ret);
 184
 185const char *show_date(unsigned long time, int timezone);
 186void parse_date(char *date, char *buf, int bufsize);
 187void datestamp(char *buf, int bufsize);
 188
 189static inline void *xmalloc(size_t size)
 190{
 191        void *ret = malloc(size);
 192        if (!ret)
 193                die("Out of memory, malloc failed");
 194        return ret;
 195}
 196
 197static inline void *xrealloc(void *ptr, size_t size)
 198{
 199        void *ret = realloc(ptr, size);
 200        if (!ret)
 201                die("Out of memory, realloc failed");
 202        return ret;
 203}
 204
 205static inline void *xcalloc(size_t nmemb, size_t size)
 206{
 207        void *ret = calloc(nmemb, size);
 208        if (!ret)
 209                die("Out of memory, calloc failed");
 210        return ret;
 211}
 212
 213#endif /* CACHE_H */