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#include <sys/types.h>
  18#include <dirent.h>
  19
  20#include SHA1_HEADER
  21#include <zlib.h>
  22
  23#if ZLIB_VERNUM < 0x1200
  24#define deflateBound(c,s)  ((s) + (((s) + 7) >> 3) + (((s) + 63) >> 6) + 11)
  25#endif
  26
  27#ifdef DT_UNKNOWN
  28#define DTYPE(de)       ((de)->d_type)
  29#else
  30#define DT_UNKNOWN      0
  31#define DT_DIR          1
  32#define DT_REG          2
  33#define DT_LNK          3
  34#define DTYPE(de)       DT_UNKNOWN
  35#endif
  36
  37#ifdef __GNUC__
  38#define NORETURN __attribute__((__noreturn__))
  39#else
  40#define NORETURN
  41#ifndef __attribute__
  42#define __attribute__(x)
  43#endif
  44#endif
  45
  46/*
  47 * Intensive research over the course of many years has shown that
  48 * port 9418 is totally unused by anything else. Or
  49 *
  50 *      Your search - "port 9418" - did not match any documents.
  51 *
  52 * as www.google.com puts it.
  53 */
  54#define DEFAULT_GIT_PORT 9418
  55
  56/*
  57 * Environment variables transition.
  58 * We accept older names for now but warn.
  59 */
  60extern char *gitenv_bc(const char *);
  61#ifdef __GNUC__
  62#define gitenv(e) (getenv(e) ? : gitenv_bc(e))
  63#else
  64#define gitenv(e) (getenv(e) ? getenv(e) : gitenv_bc(e))
  65#endif
  66
  67/*
  68 * Basic data structures for the directory cache
  69 */
  70
  71#define CACHE_SIGNATURE 0x44495243      /* "DIRC" */
  72struct cache_header {
  73        unsigned int hdr_signature;
  74        unsigned int hdr_version;
  75        unsigned int hdr_entries;
  76};
  77
  78/*
  79 * The "cache_time" is just the low 32 bits of the
  80 * time. It doesn't matter if it overflows - we only
  81 * check it for equality in the 32 bits we save.
  82 */
  83struct cache_time {
  84        unsigned int sec;
  85        unsigned int nsec;
  86};
  87
  88/*
  89 * dev/ino/uid/gid/size are also just tracked to the low 32 bits
  90 * Again - this is just a (very strong in practice) heuristic that
  91 * the inode hasn't changed.
  92 *
  93 * We save the fields in big-endian order to allow using the
  94 * index file over NFS transparently.
  95 */
  96struct cache_entry {
  97        struct cache_time ce_ctime;
  98        struct cache_time ce_mtime;
  99        unsigned int ce_dev;
 100        unsigned int ce_ino;
 101        unsigned int ce_mode;
 102        unsigned int ce_uid;
 103        unsigned int ce_gid;
 104        unsigned int ce_size;
 105        unsigned char sha1[20];
 106        unsigned short ce_flags;
 107        char name[0];
 108};
 109
 110#define CE_NAMEMASK  (0x0fff)
 111#define CE_STAGEMASK (0x3000)
 112#define CE_UPDATE    (0x4000)
 113#define CE_STAGESHIFT 12
 114
 115#define create_ce_flags(len, stage) htons((len) | ((stage) << CE_STAGESHIFT))
 116#define ce_namelen(ce) (CE_NAMEMASK & ntohs((ce)->ce_flags))
 117#define ce_size(ce) cache_entry_size(ce_namelen(ce))
 118#define ce_stage(ce) ((CE_STAGEMASK & ntohs((ce)->ce_flags)) >> CE_STAGESHIFT)
 119
 120#define ce_permissions(mode) (((mode) & 0100) ? 0755 : 0644)
 121static inline unsigned int create_ce_mode(unsigned int mode)
 122{
 123        if (S_ISLNK(mode))
 124                return htonl(S_IFLNK);
 125        return htonl(S_IFREG | ce_permissions(mode));
 126}
 127
 128#define cache_entry_size(len) ((offsetof(struct cache_entry,name) + (len) + 8) & ~7)
 129
 130extern struct cache_entry **active_cache;
 131extern unsigned int active_nr, active_alloc, active_cache_changed;
 132
 133#define GIT_DIR_ENVIRONMENT "GIT_DIR"
 134#define DEFAULT_GIT_DIR_ENVIRONMENT ".git"
 135#define DB_ENVIRONMENT "GIT_OBJECT_DIRECTORY"
 136#define INDEX_ENVIRONMENT "GIT_INDEX_FILE"
 137#define GRAFT_ENVIRONMENT "GIT_GRAFT_FILE"
 138
 139extern char *get_object_directory(void);
 140extern char *get_refs_directory(void);
 141extern char *get_index_file(void);
 142extern char *get_graft_file(void);
 143
 144#define ALTERNATE_DB_ENVIRONMENT "GIT_ALTERNATE_OBJECT_DIRECTORIES"
 145
 146extern const char **get_pathspec(const char *prefix, char **pathspec);
 147extern const char *setup_git_directory(void);
 148extern char *prefix_path(const char *prefix, int len, char *path);
 149
 150#define alloc_nr(x) (((x)+16)*3/2)
 151
 152/* Initialize and use the cache information */
 153extern int read_cache(void);
 154extern int write_cache(int newfd, struct cache_entry **cache, int entries);
 155extern int cache_name_pos(const char *name, int namelen);
 156#define ADD_CACHE_OK_TO_ADD 1           /* Ok to add */
 157#define ADD_CACHE_OK_TO_REPLACE 2       /* Ok to replace file/directory */
 158#define ADD_CACHE_SKIP_DFCHECK 4        /* Ok to skip DF conflict checks */
 159extern int add_cache_entry(struct cache_entry *ce, int option);
 160extern int remove_cache_entry_at(int pos);
 161extern int remove_file_from_cache(char *path);
 162extern int ce_same_name(struct cache_entry *a, struct cache_entry *b);
 163extern int ce_match_stat(struct cache_entry *ce, struct stat *st);
 164extern int ce_path_match(const struct cache_entry *ce, const char **pathspec);
 165extern int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object, const char *type);
 166extern void fill_stat_cache_info(struct cache_entry *ce, struct stat *st);
 167
 168struct cache_file {
 169        struct cache_file *next;
 170        char lockfile[PATH_MAX];
 171};
 172extern int hold_index_file_for_update(struct cache_file *, const char *path);
 173extern int commit_index_file(struct cache_file *);
 174extern void rollback_index_file(struct cache_file *);
 175
 176#define MTIME_CHANGED   0x0001
 177#define CTIME_CHANGED   0x0002
 178#define OWNER_CHANGED   0x0004
 179#define MODE_CHANGED    0x0008
 180#define INODE_CHANGED   0x0010
 181#define DATA_CHANGED    0x0020
 182#define TYPE_CHANGED    0x0040
 183
 184/* Return a statically allocated filename matching the sha1 signature */
 185extern char *mkpath(const char *fmt, ...) __attribute__((format (printf, 1, 2)));
 186extern char *git_path(const char *fmt, ...) __attribute__((format (printf, 1, 2)));
 187extern char *sha1_file_name(const unsigned char *sha1);
 188extern char *sha1_pack_name(const unsigned char *sha1);
 189extern char *sha1_pack_index_name(const unsigned char *sha1);
 190
 191int git_mkstemp(char *path, size_t n, const char *template);
 192
 193int safe_create_leading_directories(char *path);
 194char *safe_strncpy(char *, const char *, size_t);
 195
 196/* Read and unpack a sha1 file into memory, write memory to a sha1 file */
 197extern int unpack_sha1_header(z_stream *stream, void *map, unsigned long mapsize, void *buffer, unsigned long size);
 198extern int parse_sha1_header(char *hdr, char *type, unsigned long *sizep);
 199extern int sha1_object_info(const unsigned char *, char *, unsigned long *);
 200extern void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size);
 201extern void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size);
 202extern int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *return_sha1);
 203extern char *write_sha1_file_prepare(void *buf,
 204                                     unsigned long len,
 205                                     const char *type,
 206                                     unsigned char *sha1,
 207                                     unsigned char *hdr,
 208                                     int *hdrlen);
 209
 210extern int check_sha1_signature(const unsigned char *sha1, void *buf, unsigned long size, const char *type);
 211
 212/* Read a tree into the cache */
 213extern int read_tree(void *buffer, unsigned long size, int stage, const char **paths);
 214
 215extern int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
 216                              size_t bufsize, size_t *bufposn);
 217extern int write_sha1_to_fd(int fd, const unsigned char *sha1);
 218
 219extern int has_sha1_pack(const unsigned char *sha1);
 220extern int has_sha1_file(const unsigned char *sha1);
 221
 222extern int has_pack_file(const unsigned char *sha1);
 223extern int has_pack_index(const unsigned char *sha1);
 224
 225/* Convert to/from hex/sha1 representation */
 226extern int get_sha1(const char *str, unsigned char *sha1);
 227extern int get_sha1_hex(const char *hex, unsigned char *sha1);
 228extern char *sha1_to_hex(const unsigned char *sha1);    /* static buffer result! */
 229
 230/* General helper functions */
 231extern void usage(const char *err) NORETURN;
 232extern void die(const char *err, ...) NORETURN __attribute__((format (printf, 1, 2)));
 233extern int error(const char *err, ...) __attribute__((format (printf, 1, 2)));
 234
 235extern int base_name_compare(const char *name1, int len1, int mode1, const char *name2, int len2, int mode2);
 236extern int cache_name_compare(const char *name1, int len1, const char *name2, int len2);
 237
 238extern void *read_object_with_reference(const unsigned char *sha1,
 239                                        const char *required_type,
 240                                        unsigned long *size,
 241                                        unsigned char *sha1_ret);
 242
 243const char *show_date(unsigned long time, int timezone);
 244void parse_date(const char *date, char *buf, int bufsize);
 245void datestamp(char *buf, int bufsize);
 246
 247extern int setup_ident(void);
 248extern char *get_ident(const char *name, const char *email, const char *date_str);
 249extern char *git_author_info(void);
 250extern char *git_committer_info(void);
 251
 252static inline void *xmalloc(size_t size)
 253{
 254        void *ret = malloc(size);
 255        if (!ret)
 256                die("Out of memory, malloc failed");
 257        return ret;
 258}
 259
 260static inline void *xrealloc(void *ptr, size_t size)
 261{
 262        void *ret = realloc(ptr, size);
 263        if (!ret)
 264                die("Out of memory, realloc failed");
 265        return ret;
 266}
 267
 268static inline void *xcalloc(size_t nmemb, size_t size)
 269{
 270        void *ret = calloc(nmemb, size);
 271        if (!ret)
 272                die("Out of memory, calloc failed");
 273        return ret;
 274}
 275
 276struct checkout {
 277        const char *base_dir;
 278        int base_dir_len;
 279        unsigned force:1,
 280                 quiet:1,
 281                 not_new:1,
 282                 refresh_cache:1;
 283};
 284
 285extern int checkout_entry(struct cache_entry *ce, struct checkout *state);
 286
 287extern struct alternate_object_database {
 288        struct alternate_object_database *next;
 289        char *name;
 290        char base[0]; /* more */
 291} *alt_odb_list;
 292extern void prepare_alt_odb(void);
 293
 294extern struct packed_git {
 295        struct packed_git *next;
 296        unsigned long index_size;
 297        unsigned long pack_size;
 298        unsigned int *index_base;
 299        void *pack_base;
 300        unsigned int pack_last_used;
 301        unsigned int pack_use_cnt;
 302        unsigned char sha1[20];
 303        char pack_name[0]; /* something like ".git/objects/pack/xxxxx.pack" */
 304} *packed_git;
 305
 306struct pack_entry {
 307        unsigned int offset;
 308        unsigned char sha1[20];
 309        struct packed_git *p;
 310};
 311
 312struct ref {
 313        struct ref *next;
 314        unsigned char old_sha1[20];
 315        unsigned char new_sha1[20];
 316        unsigned char force;
 317        struct ref *peer_ref; /* when renaming */
 318        char name[0];
 319};
 320
 321extern int git_connect(int fd[2], char *url, const char *prog);
 322extern int finish_connect(pid_t pid);
 323extern int path_match(const char *path, int nr, char **match);
 324extern int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail,
 325                      int nr_refspec, char **refspec, int all);
 326extern int get_ack(int fd, unsigned char *result_sha1);
 327extern struct ref **get_remote_heads(int in, struct ref **list, int nr_match, char **match);
 328
 329extern struct packed_git *parse_pack_index(unsigned char *sha1);
 330extern struct packed_git *parse_pack_index_file(const unsigned char *sha1,
 331                                                char *idx_path);
 332
 333extern void prepare_packed_git(void);
 334extern void install_packed_git(struct packed_git *pack);
 335
 336extern struct packed_git *find_sha1_pack(const unsigned char *sha1, 
 337                                         struct packed_git *packs);
 338
 339extern int use_packed_git(struct packed_git *);
 340extern void unuse_packed_git(struct packed_git *);
 341extern struct packed_git *add_packed_git(char *, int);
 342extern int num_packed_objects(const struct packed_git *p);
 343extern int nth_packed_object_sha1(const struct packed_git *, int, unsigned char*);
 344extern int find_pack_entry_one(const unsigned char *, struct pack_entry *, struct packed_git *);
 345extern void *unpack_entry_gently(struct pack_entry *, char *, unsigned long *);
 346extern void packed_object_info_detail(struct pack_entry *, char *, unsigned long *, unsigned long *, int *, unsigned char *);
 347
 348/* Dumb servers support */
 349extern int update_server_info(int);
 350
 351#endif /* CACHE_H */