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_refs_directory(void);
 121extern char *get_index_file(void);
 122
 123#define ALTERNATE_DB_ENVIRONMENT "GIT_ALTERNATE_OBJECT_DIRECTORIES"
 124
 125#define alloc_nr(x) (((x)+16)*3/2)
 126
 127/* Initialize and use the cache information */
 128extern int read_cache(void);
 129extern int write_cache(int newfd, struct cache_entry **cache, int entries);
 130extern int cache_name_pos(const char *name, int namelen);
 131#define ADD_CACHE_OK_TO_ADD 1           /* Ok to add */
 132#define ADD_CACHE_OK_TO_REPLACE 2       /* Ok to replace file/directory */
 133extern int add_cache_entry(struct cache_entry *ce, int option);
 134extern int remove_cache_entry_at(int pos);
 135extern int remove_file_from_cache(char *path);
 136extern int ce_same_name(struct cache_entry *a, struct cache_entry *b);
 137extern int ce_match_stat(struct cache_entry *ce, struct stat *st);
 138extern int index_fd(unsigned char *sha1, int fd, struct stat *st);
 139extern void fill_stat_cache_info(struct cache_entry *ce, struct stat *st);
 140
 141struct cache_file {
 142        struct cache_file *next;
 143        char lockfile[PATH_MAX];
 144};
 145extern int hold_index_file_for_update(struct cache_file *, const char *path);
 146extern int commit_index_file(struct cache_file *);
 147extern void rollback_index_file(struct cache_file *);
 148
 149#define MTIME_CHANGED   0x0001
 150#define CTIME_CHANGED   0x0002
 151#define OWNER_CHANGED   0x0004
 152#define MODE_CHANGED    0x0008
 153#define INODE_CHANGED   0x0010
 154#define DATA_CHANGED    0x0020
 155#define TYPE_CHANGED    0x0040
 156
 157/* Return a statically allocated filename matching the sha1 signature */
 158extern char *sha1_file_name(const unsigned char *sha1);
 159
 160/* Read and unpack a sha1 file into memory, write memory to a sha1 file */
 161extern void * map_sha1_file(const unsigned char *sha1, unsigned long *size);
 162extern int unpack_sha1_header(z_stream *stream, void *map, unsigned long mapsize, void *buffer, unsigned long size);
 163extern int parse_sha1_header(char *hdr, char *type, unsigned long *sizep);
 164extern int sha1_delta_base(const unsigned char *, unsigned char *);
 165extern int sha1_file_size(const unsigned char *, unsigned long *);
 166extern void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size);
 167extern void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size);
 168extern int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *return_sha1);
 169
 170extern int check_sha1_signature(const unsigned char *sha1, void *buf, unsigned long size, const char *type);
 171
 172/* Read a tree into the cache */
 173extern int read_tree(void *buffer, unsigned long size, int stage);
 174
 175extern int write_sha1_from_fd(const unsigned char *sha1, int fd);
 176
 177extern int has_sha1_file(const unsigned char *sha1);
 178
 179/* Convert to/from hex/sha1 representation */
 180extern int get_sha1(const char *str, unsigned char *sha1);
 181extern int get_sha1_hex(const char *hex, unsigned char *sha1);
 182extern char *sha1_to_hex(const unsigned char *sha1);    /* static buffer result! */
 183
 184/* General helper functions */
 185extern void usage(const char *err) NORETURN;
 186extern void die(const char *err, ...) NORETURN;
 187extern int error(const char *err, ...);
 188
 189extern int base_name_compare(const char *name1, int len1, int mode1, const char *name2, int len2, int mode2);
 190extern int cache_name_compare(const char *name1, int len1, const char *name2, int len2);
 191
 192extern void *read_object_with_reference(const unsigned char *sha1,
 193                                        const char *required_type,
 194                                        unsigned long *size,
 195                                        unsigned char *sha1_ret);
 196
 197const char *show_date(unsigned long time, int timezone);
 198void parse_date(char *date, char *buf, int bufsize);
 199void datestamp(char *buf, int bufsize);
 200
 201static inline void *xmalloc(size_t size)
 202{
 203        void *ret = malloc(size);
 204        if (!ret)
 205                die("Out of memory, malloc failed");
 206        return ret;
 207}
 208
 209static inline void *xrealloc(void *ptr, size_t size)
 210{
 211        void *ret = realloc(ptr, size);
 212        if (!ret)
 213                die("Out of memory, realloc failed");
 214        return ret;
 215}
 216
 217static inline void *xcalloc(size_t nmemb, size_t size)
 218{
 219        void *ret = calloc(nmemb, size);
 220        if (!ret)
 221                die("Out of memory, calloc failed");
 222        return ret;
 223}
 224
 225struct checkout {
 226        const char *base_dir;
 227        int base_dir_len;
 228        unsigned force:1,
 229                 quiet:1,
 230                 not_new:1,
 231                 refresh_cache:1;
 232};
 233
 234extern int checkout_entry(struct cache_entry *ce, struct checkout *state);
 235
 236#endif /* CACHE_H */