Andrew's git - gitweb.git/blob

b8e3d9bfacfb0fa924accd705bac18238c138eb8
   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 * This port has been properly assigned for git use by IANA:
  55 * git (Assigned-9418) [I06-050728-0001].
  56 *
  57 *      git  9418/tcp   git pack transfer service
  58 *      git  9418/udp   git pack transfer service
  59 *
  60 * with Linus Torvalds <torvalds@osdl.org> as the point of
  61 * contact. September 2005.
  62 *
  63 * See http://www.iana.org/assignments/port-numbers
  64 */
  65#define DEFAULT_GIT_PORT 9418
  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_git_dir(void);
 140extern char *get_object_directory(void);
 141extern char *get_refs_directory(void);
 142extern char *get_index_file(void);
 143extern char *get_graft_file(void);
 144
 145#define ALTERNATE_DB_ENVIRONMENT "GIT_ALTERNATE_OBJECT_DIRECTORIES"
 146
 147extern const char **get_pathspec(const char *prefix, const char **pathspec);
 148extern const char *setup_git_directory(void);
 149extern const char *prefix_path(const char *prefix, int len, const char *path);
 150
 151#define alloc_nr(x) (((x)+16)*3/2)
 152
 153/* Initialize and use the cache information */
 154extern int read_cache(void);
 155extern int write_cache(int newfd, struct cache_entry **cache, int entries);
 156extern int cache_name_pos(const char *name, int namelen);
 157#define ADD_CACHE_OK_TO_ADD 1           /* Ok to add */
 158#define ADD_CACHE_OK_TO_REPLACE 2       /* Ok to replace file/directory */
 159#define ADD_CACHE_SKIP_DFCHECK 4        /* Ok to skip DF conflict checks */
 160extern int add_cache_entry(struct cache_entry *ce, int option);
 161extern int remove_cache_entry_at(int pos);
 162extern int remove_file_from_cache(const char *path);
 163extern int ce_same_name(struct cache_entry *a, struct cache_entry *b);
 164extern int ce_match_stat(struct cache_entry *ce, struct stat *st);
 165extern int ce_modified(struct cache_entry *ce, struct stat *st);
 166extern int ce_path_match(const struct cache_entry *ce, const char **pathspec);
 167extern int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object, const char *type);
 168extern void fill_stat_cache_info(struct cache_entry *ce, struct stat *st);
 169
 170struct cache_file {
 171        struct cache_file *next;
 172        char lockfile[PATH_MAX];
 173};
 174extern int hold_index_file_for_update(struct cache_file *, const char *path);
 175extern int commit_index_file(struct cache_file *);
 176extern void rollback_index_file(struct cache_file *);
 177
 178#define MTIME_CHANGED   0x0001
 179#define CTIME_CHANGED   0x0002
 180#define OWNER_CHANGED   0x0004
 181#define MODE_CHANGED    0x0008
 182#define INODE_CHANGED   0x0010
 183#define DATA_CHANGED    0x0020
 184#define TYPE_CHANGED    0x0040
 185
 186/* Return a statically allocated filename matching the sha1 signature */
 187extern char *mkpath(const char *fmt, ...) __attribute__((format (printf, 1, 2)));
 188extern char *git_path(const char *fmt, ...) __attribute__((format (printf, 1, 2)));
 189extern char *sha1_file_name(const unsigned char *sha1);
 190extern char *sha1_pack_name(const unsigned char *sha1);
 191extern char *sha1_pack_index_name(const unsigned char *sha1);
 192extern const unsigned char null_sha1[20];
 193
 194int git_mkstemp(char *path, size_t n, const char *template);
 195
 196int safe_create_leading_directories(char *path);
 197char *safe_strncpy(char *, const char *, size_t);
 198
 199/* Read and unpack a sha1 file into memory, write memory to a sha1 file */
 200extern int unpack_sha1_header(z_stream *stream, void *map, unsigned long mapsize, void *buffer, unsigned long size);
 201extern int parse_sha1_header(char *hdr, char *type, unsigned long *sizep);
 202extern int sha1_object_info(const unsigned char *, char *, unsigned long *);
 203extern void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size);
 204extern void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size);
 205extern int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *return_sha1);
 206extern char *write_sha1_file_prepare(void *buf,
 207                                     unsigned long len,
 208                                     const char *type,
 209                                     unsigned char *sha1,
 210                                     unsigned char *hdr,
 211                                     int *hdrlen);
 212
 213extern int check_sha1_signature(const unsigned char *sha1, void *buf, unsigned long size, const char *type);
 214
 215/* Read a tree into the cache */
 216extern int read_tree(void *buffer, unsigned long size, int stage, const char **paths);
 217
 218extern int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
 219                              size_t bufsize, size_t *bufposn);
 220extern int write_sha1_to_fd(int fd, const unsigned char *sha1);
 221
 222extern int has_sha1_pack(const unsigned char *sha1);
 223extern int has_sha1_file(const unsigned char *sha1);
 224
 225extern int has_pack_file(const unsigned char *sha1);
 226extern int has_pack_index(const unsigned char *sha1);
 227
 228/* Convert to/from hex/sha1 representation */
 229extern int get_sha1(const char *str, unsigned char *sha1);
 230extern int get_sha1_hex(const char *hex, unsigned char *sha1);
 231extern char *sha1_to_hex(const unsigned char *sha1);    /* static buffer result! */
 232
 233/* General helper functions */
 234extern void usage(const char *err) NORETURN;
 235extern void die(const char *err, ...) NORETURN __attribute__((format (printf, 1, 2)));
 236extern int error(const char *err, ...) __attribute__((format (printf, 1, 2)));
 237
 238extern int base_name_compare(const char *name1, int len1, int mode1, const char *name2, int len2, int mode2);
 239extern int cache_name_compare(const char *name1, int len1, const char *name2, int len2);
 240
 241extern void *read_object_with_reference(const unsigned char *sha1,
 242                                        const char *required_type,
 243                                        unsigned long *size,
 244                                        unsigned char *sha1_ret);
 245
 246const char *show_date(unsigned long time, int timezone);
 247int parse_date(const char *date, char *buf, int bufsize);
 248void datestamp(char *buf, int bufsize);
 249
 250extern int setup_ident(void);
 251extern char *get_ident(const char *name, const char *email, const char *date_str);
 252extern char *git_author_info(void);
 253extern char *git_committer_info(void);
 254
 255static inline void *xmalloc(size_t size)
 256{
 257        void *ret = malloc(size);
 258        if (!ret)
 259                die("Out of memory, malloc failed");
 260        return ret;
 261}
 262
 263static inline void *xrealloc(void *ptr, size_t size)
 264{
 265        void *ret = realloc(ptr, size);
 266        if (!ret)
 267                die("Out of memory, realloc failed");
 268        return ret;
 269}
 270
 271static inline void *xcalloc(size_t nmemb, size_t size)
 272{
 273        void *ret = calloc(nmemb, size);
 274        if (!ret)
 275                die("Out of memory, calloc failed");
 276        return ret;
 277}
 278
 279struct checkout {
 280        const char *base_dir;
 281        int base_dir_len;
 282        unsigned force:1,
 283                 quiet:1,
 284                 not_new:1,
 285                 refresh_cache:1;
 286};
 287
 288extern int checkout_entry(struct cache_entry *ce, struct checkout *state);
 289
 290extern struct alternate_object_database {
 291        struct alternate_object_database *next;
 292        char *name;
 293        char base[0]; /* more */
 294} *alt_odb_list;
 295extern void prepare_alt_odb(void);
 296
 297extern struct packed_git {
 298        struct packed_git *next;
 299        unsigned long index_size;
 300        unsigned long pack_size;
 301        unsigned int *index_base;
 302        void *pack_base;
 303        unsigned int pack_last_used;
 304        unsigned int pack_use_cnt;
 305        unsigned char sha1[20];
 306        char pack_name[0]; /* something like ".git/objects/pack/xxxxx.pack" */
 307} *packed_git;
 308
 309struct pack_entry {
 310        unsigned int offset;
 311        unsigned char sha1[20];
 312        struct packed_git *p;
 313};
 314
 315struct ref {
 316        struct ref *next;
 317        unsigned char old_sha1[20];
 318        unsigned char new_sha1[20];
 319        unsigned char force;
 320        struct ref *peer_ref; /* when renaming */
 321        char name[0];
 322};
 323
 324extern int git_connect(int fd[2], char *url, const char *prog);
 325extern int finish_connect(pid_t pid);
 326extern int path_match(const char *path, int nr, char **match);
 327extern int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail,
 328                      int nr_refspec, char **refspec, int all);
 329extern int get_ack(int fd, unsigned char *result_sha1);
 330extern struct ref **get_remote_heads(int in, struct ref **list, int nr_match, char **match);
 331
 332extern struct packed_git *parse_pack_index(unsigned char *sha1);
 333extern struct packed_git *parse_pack_index_file(const unsigned char *sha1,
 334                                                char *idx_path);
 335
 336extern void prepare_packed_git(void);
 337extern void install_packed_git(struct packed_git *pack);
 338
 339extern struct packed_git *find_sha1_pack(const unsigned char *sha1, 
 340                                         struct packed_git *packs);
 341
 342extern int use_packed_git(struct packed_git *);
 343extern void unuse_packed_git(struct packed_git *);
 344extern struct packed_git *add_packed_git(char *, int);
 345extern int num_packed_objects(const struct packed_git *p);
 346extern int nth_packed_object_sha1(const struct packed_git *, int, unsigned char*);
 347extern int find_pack_entry_one(const unsigned char *, struct pack_entry *, struct packed_git *);
 348extern void *unpack_entry_gently(struct pack_entry *, char *, unsigned long *);
 349extern void packed_object_info_detail(struct pack_entry *, char *, unsigned long *, unsigned long *, int *, unsigned char *);
 350
 351/* Dumb servers support */
 352extern int update_server_info(int);
 353
 354#endif /* CACHE_H */