Andrew's git - gitweb.git/blob

041ec0b2b0a7faa341b4c65fe9a939abcbf1a3c1
   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 <sys/mman.h>
  14#include <sys/param.h>
  15#include <netinet/in.h>
  16
  17#include SHA1_HEADER
  18#include <zlib.h>
  19
  20#if ZLIB_VERNUM < 0x1200
  21#define deflateBound(c,s)  ((s) + (((s) + 7) >> 3) + (((s) + 63) >> 6) + 11)
  22#endif
  23
  24#ifdef DT_UNKNOWN
  25#define DTYPE(de)       ((de)->d_type)
  26#else
  27#define DT_UNKNOWN      0
  28#define DT_DIR          1
  29#define DT_REG          2
  30#define DT_LNK          3
  31#define DTYPE(de)       DT_UNKNOWN
  32#endif
  33
  34/*
  35 * Environment variables transition.
  36 * We accept older names for now but warn.
  37 */
  38extern char *gitenv_bc(const char *);
  39#define gitenv(e) (getenv(e) ? : gitenv_bc(e))
  40
  41/*
  42 * Basic data structures for the directory cache
  43 */
  44
  45#define CACHE_SIGNATURE 0x44495243      /* "DIRC" */
  46struct cache_header {
  47        unsigned int hdr_signature;
  48        unsigned int hdr_version;
  49        unsigned int hdr_entries;
  50};
  51
  52/*
  53 * The "cache_time" is just the low 32 bits of the
  54 * time. It doesn't matter if it overflows - we only
  55 * check it for equality in the 32 bits we save.
  56 */
  57struct cache_time {
  58        unsigned int sec;
  59        unsigned int nsec;
  60};
  61
  62/*
  63 * dev/ino/uid/gid/size are also just tracked to the low 32 bits
  64 * Again - this is just a (very strong in practice) heuristic that
  65 * the inode hasn't changed.
  66 *
  67 * We save the fields in big-endian order to allow using the
  68 * index file over NFS transparently.
  69 */
  70struct cache_entry {
  71        struct cache_time ce_ctime;
  72        struct cache_time ce_mtime;
  73        unsigned int ce_dev;
  74        unsigned int ce_ino;
  75        unsigned int ce_mode;
  76        unsigned int ce_uid;
  77        unsigned int ce_gid;
  78        unsigned int ce_size;
  79        unsigned char sha1[20];
  80        unsigned short ce_flags;
  81        char name[0];
  82};
  83
  84#define CE_NAMEMASK  (0x0fff)
  85#define CE_STAGEMASK (0x3000)
  86#define CE_STAGESHIFT 12
  87
  88#define create_ce_flags(len, stage) htons((len) | ((stage) << CE_STAGESHIFT))
  89#define ce_namelen(ce) (CE_NAMEMASK & ntohs((ce)->ce_flags))
  90#define ce_size(ce) cache_entry_size(ce_namelen(ce))
  91#define ce_stage(ce) ((CE_STAGEMASK & ntohs((ce)->ce_flags)) >> CE_STAGESHIFT)
  92
  93#define ce_permissions(mode) (((mode) & 0100) ? 0755 : 0644)
  94static inline unsigned int create_ce_mode(unsigned int mode)
  95{
  96        if (S_ISLNK(mode))
  97                return htonl(S_IFLNK);
  98        return htonl(S_IFREG | ce_permissions(mode));
  99}
 100
 101#define cache_entry_size(len) ((offsetof(struct cache_entry,name) + (len) + 8) & ~7)
 102
 103extern struct cache_entry **active_cache;
 104extern unsigned int active_nr, active_alloc, active_cache_changed;
 105
 106#define GIT_DIR_ENVIRONMENT "GIT_DIR"
 107#define DEFAULT_GIT_DIR_ENVIRONMENT ".git"
 108#define DB_ENVIRONMENT "GIT_OBJECT_DIRECTORY"
 109#define INDEX_ENVIRONMENT "GIT_INDEX_FILE"
 110
 111extern char *get_object_directory(void);
 112extern char *get_index_file(void);
 113
 114#define ALTERNATE_DB_ENVIRONMENT "GIT_ALTERNATE_OBJECT_DIRECTORIES"
 115
 116#define alloc_nr(x) (((x)+16)*3/2)
 117
 118/* Initialize and use the cache information */
 119extern int read_cache(void);
 120extern int write_cache(int newfd, struct cache_entry **cache, int entries);
 121extern int cache_name_pos(const char *name, int namelen);
 122#define ADD_CACHE_OK_TO_ADD 1           /* Ok to add */
 123#define ADD_CACHE_OK_TO_REPLACE 2       /* Ok to replace file/directory */
 124extern int add_cache_entry(struct cache_entry *ce, int option);
 125extern int remove_cache_entry_at(int pos);
 126extern int remove_file_from_cache(char *path);
 127extern int ce_same_name(struct cache_entry *a, struct cache_entry *b);
 128extern int ce_match_stat(struct cache_entry *ce, struct stat *st);
 129extern int index_fd(unsigned char *sha1, int fd, struct stat *st);
 130
 131#define MTIME_CHANGED   0x0001
 132#define CTIME_CHANGED   0x0002
 133#define OWNER_CHANGED   0x0004
 134#define MODE_CHANGED    0x0008
 135#define INODE_CHANGED   0x0010
 136#define DATA_CHANGED    0x0020
 137#define TYPE_CHANGED    0x0040
 138
 139/* Return a statically allocated filename matching the sha1 signature */
 140extern char *sha1_file_name(const unsigned char *sha1);
 141
 142/* Read and unpack a sha1 file into memory, write memory to a sha1 file */
 143extern void * map_sha1_file(const unsigned char *sha1, unsigned long *size);
 144extern void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size);
 145extern void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size);
 146extern int write_sha1_file(char *buf, unsigned long len, const char *type, unsigned char *return_sha1);
 147
 148extern int check_sha1_signature(unsigned char *sha1, void *buf, unsigned long size, const char *type);
 149
 150/* Read a tree into the cache */
 151extern int read_tree(void *buffer, unsigned long size, int stage);
 152
 153extern int write_sha1_from_fd(const unsigned char *sha1, int fd);
 154
 155extern int has_sha1_file(const unsigned char *sha1);
 156
 157/* Convert to/from hex/sha1 representation */
 158extern int get_sha1(const char *str, unsigned char *sha1);
 159extern int get_sha1_hex(const char *hex, unsigned char *sha1);
 160extern char *sha1_to_hex(const unsigned char *sha1);    /* static buffer result! */
 161
 162/* General helper functions */
 163extern void usage(const char *err);
 164extern void die(const char *err, ...);
 165extern int error(const char *err, ...);
 166
 167extern int cache_name_compare(const char *name1, int len1, const char *name2, int len2);
 168
 169extern void *read_object_with_reference(const unsigned char *sha1,
 170                                        const unsigned char *required_type,
 171                                        unsigned long *size,
 172                                        unsigned char *sha1_ret);
 173
 174const char *show_date(unsigned long time, int timezone);
 175void parse_date(char *date, char *buf, int bufsize);
 176void datestamp(char *buf, int bufsize);
 177
 178static inline void *xmalloc(size_t size)
 179{
 180        void *ret = malloc(size);
 181        if (!ret)
 182                die("Out of memory, malloc failed");
 183        return ret;
 184}
 185
 186static inline void *xrealloc(void *ptr, size_t size)
 187{
 188        void *ret = realloc(ptr, size);
 189        if (!ret)
 190                die("Out of memory, realloc failed");
 191        return ret;
 192}
 193
 194static inline void *xcalloc(size_t nmemb, size_t size)
 195{
 196        void *ret = calloc(nmemb, size);
 197        if (!ret)
 198                die("Out of memory, calloc failed");
 199        return ret;
 200}
 201
 202#endif /* CACHE_H */