Andrew's git / gitweb.git / cache.h
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cache.hon commit rebase: one safety net, one bugfix and one optimization. (7f4bd5d)
   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#ifndef NO_MMAP
  15#include <sys/mman.h>
  16#endif
  17#include <sys/param.h>
  18#include <netinet/in.h>
  19#include <sys/types.h>
  20#include <dirent.h>
  21
  22#include SHA1_HEADER
  23#include <zlib.h>
  24
  25#if ZLIB_VERNUM < 0x1200
  26#define deflateBound(c,s)  ((s) + (((s) + 7) >> 3) + (((s) + 63) >> 6) + 11)
  27#endif
  28
  29#ifdef DT_UNKNOWN
  30#define DTYPE(de)       ((de)->d_type)
  31#else
  32#define DT_UNKNOWN      0
  33#define DT_DIR          1
  34#define DT_REG          2
  35#define DT_LNK          3
  36#define DTYPE(de)       DT_UNKNOWN
  37#endif
  38
  39#ifdef __GNUC__
  40#define NORETURN __attribute__((__noreturn__))
  41#else
  42#define NORETURN
  43#ifndef __attribute__
  44#define __attribute__(x)
  45#endif
  46#endif
  47
  48/*
  49 * Intensive research over the course of many years has shown that
  50 * port 9418 is totally unused by anything else. Or
  51 *
  52 *      Your search - "port 9418" - did not match any documents.
  53 *
  54 * as www.google.com puts it.
  55 *
  56 * This port has been properly assigned for git use by IANA:
  57 * git (Assigned-9418) [I06-050728-0001].
  58 *
  59 *      git  9418/tcp   git pack transfer service
  60 *      git  9418/udp   git pack transfer service
  61 *
  62 * with Linus Torvalds <torvalds@osdl.org> as the point of
  63 * contact. September 2005.
  64 *
  65 * See http://www.iana.org/assignments/port-numbers
  66 */
  67#define DEFAULT_GIT_PORT 9418
  68
  69/*
  70 * Basic data structures for the directory cache
  71 */
  72
  73#define CACHE_SIGNATURE 0x44495243      /* "DIRC" */
  74struct cache_header {
  75        unsigned int hdr_signature;
  76        unsigned int hdr_version;
  77        unsigned int hdr_entries;
  78};
  79
  80/*
  81 * The "cache_time" is just the low 32 bits of the
  82 * time. It doesn't matter if it overflows - we only
  83 * check it for equality in the 32 bits we save.
  84 */
  85struct cache_time {
  86        unsigned int sec;
  87        unsigned int nsec;
  88};
  89
  90/*
  91 * dev/ino/uid/gid/size are also just tracked to the low 32 bits
  92 * Again - this is just a (very strong in practice) heuristic that
  93 * the inode hasn't changed.
  94 *
  95 * We save the fields in big-endian order to allow using the
  96 * index file over NFS transparently.
  97 */
  98struct cache_entry {
  99        struct cache_time ce_ctime;
 100        struct cache_time ce_mtime;
 101        unsigned int ce_dev;
 102        unsigned int ce_ino;
 103        unsigned int ce_mode;
 104        unsigned int ce_uid;
 105        unsigned int ce_gid;
 106        unsigned int ce_size;
 107        unsigned char sha1[20];
 108        unsigned short ce_flags;
 109        char name[0];
 110};
 111
 112#define CE_NAMEMASK  (0x0fff)
 113#define CE_STAGEMASK (0x3000)
 114#define CE_UPDATE    (0x4000)
 115#define CE_STAGESHIFT 12
 116
 117#define create_ce_flags(len, stage) htons((len) | ((stage) << CE_STAGESHIFT))
 118#define ce_namelen(ce) (CE_NAMEMASK & ntohs((ce)->ce_flags))
 119#define ce_size(ce) cache_entry_size(ce_namelen(ce))
 120#define ce_stage(ce) ((CE_STAGEMASK & ntohs((ce)->ce_flags)) >> CE_STAGESHIFT)
 121
 122#define ce_permissions(mode) (((mode) & 0100) ? 0755 : 0644)
 123static inline unsigned int create_ce_mode(unsigned int mode)
 124{
 125        if (S_ISLNK(mode))
 126                return htonl(S_IFLNK);
 127        return htonl(S_IFREG | ce_permissions(mode));
 128}
 129
 130#define cache_entry_size(len) ((offsetof(struct cache_entry,name) + (len) + 8) & ~7)
 131
 132extern struct cache_entry **active_cache;
 133extern unsigned int active_nr, active_alloc, active_cache_changed;
 134
 135#define GIT_DIR_ENVIRONMENT "GIT_DIR"
 136#define DEFAULT_GIT_DIR_ENVIRONMENT ".git"
 137#define DB_ENVIRONMENT "GIT_OBJECT_DIRECTORY"
 138#define INDEX_ENVIRONMENT "GIT_INDEX_FILE"
 139#define GRAFT_ENVIRONMENT "GIT_GRAFT_FILE"
 140
 141extern char *get_git_dir(void);
 142extern char *get_object_directory(void);
 143extern char *get_refs_directory(void);
 144extern char *get_index_file(void);
 145extern char *get_graft_file(void);
 146
 147#define ALTERNATE_DB_ENVIRONMENT "GIT_ALTERNATE_OBJECT_DIRECTORIES"
 148
 149extern const char **get_pathspec(const char *prefix, const char **pathspec);
 150extern const char *setup_git_directory(void);
 151extern const char *prefix_path(const char *prefix, int len, const char *path);
 152
 153#define alloc_nr(x) (((x)+16)*3/2)
 154
 155/* Initialize and use the cache information */
 156extern int read_cache(void);
 157extern int write_cache(int newfd, struct cache_entry **cache, int entries);
 158extern int cache_name_pos(const char *name, int namelen);
 159#define ADD_CACHE_OK_TO_ADD 1           /* Ok to add */
 160#define ADD_CACHE_OK_TO_REPLACE 2       /* Ok to replace file/directory */
 161#define ADD_CACHE_SKIP_DFCHECK 4        /* Ok to skip DF conflict checks */
 162extern int add_cache_entry(struct cache_entry *ce, int option);
 163extern int remove_cache_entry_at(int pos);
 164extern int remove_file_from_cache(const char *path);
 165extern int ce_same_name(struct cache_entry *a, struct cache_entry *b);
 166extern int ce_match_stat(struct cache_entry *ce, struct stat *st);
 167extern int ce_modified(struct cache_entry *ce, struct stat *st);
 168extern int ce_path_match(const struct cache_entry *ce, const char **pathspec);
 169extern int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object, const char *type);
 170extern int index_path(unsigned char *sha1, const char *path, struct stat *st, int write_object);
 171extern void fill_stat_cache_info(struct cache_entry *ce, struct stat *st);
 172
 173struct cache_file {
 174        struct cache_file *next;
 175        char lockfile[PATH_MAX];
 176};
 177extern int hold_index_file_for_update(struct cache_file *, const char *path);
 178extern int commit_index_file(struct cache_file *);
 179extern void rollback_index_file(struct cache_file *);
 180
 181extern int trust_executable_bit;
 182extern int only_use_symrefs;
 183extern int diff_rename_limit_default;
 184
 185#define GIT_REPO_VERSION 0
 186extern int repository_format_version;
 187extern int check_repository_format(void);
 188
 189#define MTIME_CHANGED   0x0001
 190#define CTIME_CHANGED   0x0002
 191#define OWNER_CHANGED   0x0004
 192#define MODE_CHANGED    0x0008
 193#define INODE_CHANGED   0x0010
 194#define DATA_CHANGED    0x0020
 195#define TYPE_CHANGED    0x0040
 196
 197/* Return a statically allocated filename matching the sha1 signature */
 198extern char *mkpath(const char *fmt, ...) __attribute__((format (printf, 1, 2)));
 199extern char *git_path(const char *fmt, ...) __attribute__((format (printf, 1, 2)));
 200extern char *sha1_file_name(const unsigned char *sha1);
 201extern char *sha1_pack_name(const unsigned char *sha1);
 202extern char *sha1_pack_index_name(const unsigned char *sha1);
 203extern const char *find_unique_abbrev(const unsigned char *sha1, int);
 204extern const unsigned char null_sha1[20];
 205
 206int git_mkstemp(char *path, size_t n, const char *template);
 207
 208int safe_create_leading_directories(char *path);
 209char *safe_strncpy(char *, const char *, size_t);
 210char *enter_repo(char *path, int strict);
 211
 212/* Read and unpack a sha1 file into memory, write memory to a sha1 file */
 213extern int unpack_sha1_header(z_stream *stream, void *map, unsigned long mapsize, void *buffer, unsigned long size);
 214extern int parse_sha1_header(char *hdr, char *type, unsigned long *sizep);
 215extern int sha1_object_info(const unsigned char *, char *, unsigned long *);
 216extern void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size);
 217extern void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size);
 218extern int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *return_sha1);
 219extern char *write_sha1_file_prepare(void *buf,
 220                                     unsigned long len,
 221                                     const char *type,
 222                                     unsigned char *sha1,
 223                                     unsigned char *hdr,
 224                                     int *hdrlen);
 225
 226extern int check_sha1_signature(const unsigned char *sha1, void *buf, unsigned long size, const char *type);
 227
 228/* Read a tree into the cache */
 229extern int read_tree(void *buffer, unsigned long size, int stage, const char **paths);
 230
 231extern int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
 232                              size_t bufsize, size_t *bufposn);
 233extern int write_sha1_to_fd(int fd, const unsigned char *sha1);
 234extern int move_temp_to_file(const char *tmpfile, char *filename);
 235
 236extern int has_sha1_pack(const unsigned char *sha1);
 237extern int has_sha1_file(const unsigned char *sha1);
 238
 239extern int has_pack_file(const unsigned char *sha1);
 240extern int has_pack_index(const unsigned char *sha1);
 241
 242/* Convert to/from hex/sha1 representation */
 243extern int get_sha1(const char *str, unsigned char *sha1);
 244extern int get_sha1_hex(const char *hex, unsigned char *sha1);
 245extern char *sha1_to_hex(const unsigned char *sha1);    /* static buffer result! */
 246extern int read_ref(const char *filename, unsigned char *sha1);
 247extern const char *resolve_ref(const char *path, unsigned char *sha1, int);
 248extern int create_symref(const char *git_HEAD, const char *refs_heads_master);
 249extern int validate_symref(const char *git_HEAD);
 250
 251/* General helper functions */
 252extern void usage(const char *err) NORETURN;
 253extern void die(const char *err, ...) NORETURN __attribute__((format (printf, 1, 2)));
 254extern int error(const char *err, ...) __attribute__((format (printf, 1, 2)));
 255
 256extern int base_name_compare(const char *name1, int len1, int mode1, const char *name2, int len2, int mode2);
 257extern int cache_name_compare(const char *name1, int len1, const char *name2, int len2);
 258
 259extern void *read_object_with_reference(const unsigned char *sha1,
 260                                        const char *required_type,
 261                                        unsigned long *size,
 262                                        unsigned char *sha1_ret);
 263
 264const char *show_date(unsigned long time, int timezone);
 265int parse_date(const char *date, char *buf, int bufsize);
 266void datestamp(char *buf, int bufsize);
 267unsigned long approxidate(const char *);
 268
 269extern int setup_ident(void);
 270extern const char *git_author_info(void);
 271extern const char *git_committer_info(void);
 272
 273static inline void *xmalloc(size_t size)
 274{
 275        void *ret = malloc(size);
 276        if (!ret)
 277                die("Out of memory, malloc failed");
 278        return ret;
 279}
 280
 281static inline void *xrealloc(void *ptr, size_t size)
 282{
 283        void *ret = realloc(ptr, size);
 284        if (!ret)
 285                die("Out of memory, realloc failed");
 286        return ret;
 287}
 288
 289static inline void *xcalloc(size_t nmemb, size_t size)
 290{
 291        void *ret = calloc(nmemb, size);
 292        if (!ret)
 293                die("Out of memory, calloc failed");
 294        return ret;
 295}
 296
 297struct checkout {
 298        const char *base_dir;
 299        int base_dir_len;
 300        unsigned force:1,
 301                 quiet:1,
 302                 not_new:1,
 303                 refresh_cache:1;
 304};
 305
 306extern int checkout_entry(struct cache_entry *ce, struct checkout *state);
 307
 308extern struct alternate_object_database {
 309        struct alternate_object_database *next;
 310        char *name;
 311        char base[0]; /* more */
 312} *alt_odb_list;
 313extern void prepare_alt_odb(void);
 314
 315extern struct packed_git {
 316        struct packed_git *next;
 317        unsigned long index_size;
 318        unsigned long pack_size;
 319        unsigned int *index_base;
 320        void *pack_base;
 321        unsigned int pack_last_used;
 322        unsigned int pack_use_cnt;
 323        int pack_local;
 324        unsigned char sha1[20];
 325        char pack_name[0]; /* something like ".git/objects/pack/xxxxx.pack" */
 326} *packed_git;
 327
 328struct pack_entry {
 329        unsigned int offset;
 330        unsigned char sha1[20];
 331        struct packed_git *p;
 332};
 333
 334struct ref {
 335        struct ref *next;
 336        unsigned char old_sha1[20];
 337        unsigned char new_sha1[20];
 338        unsigned char force;
 339        struct ref *peer_ref; /* when renaming */
 340        char name[0];
 341};
 342
 343extern int git_connect(int fd[2], char *url, const char *prog);
 344extern int finish_connect(pid_t pid);
 345extern int path_match(const char *path, int nr, char **match);
 346extern int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail,
 347                      int nr_refspec, char **refspec, int all);
 348extern int get_ack(int fd, unsigned char *result_sha1);
 349extern struct ref **get_remote_heads(int in, struct ref **list, int nr_match, char **match, int ignore_funny);
 350extern int server_supports(const char *feature);
 351
 352extern struct packed_git *parse_pack_index(unsigned char *sha1);
 353extern struct packed_git *parse_pack_index_file(const unsigned char *sha1,
 354                                                char *idx_path);
 355
 356extern void prepare_packed_git(void);
 357extern void install_packed_git(struct packed_git *pack);
 358
 359extern struct packed_git *find_sha1_pack(const unsigned char *sha1, 
 360                                         struct packed_git *packs);
 361
 362extern int use_packed_git(struct packed_git *);
 363extern void unuse_packed_git(struct packed_git *);
 364extern struct packed_git *add_packed_git(char *, int, int);
 365extern int num_packed_objects(const struct packed_git *p);
 366extern int nth_packed_object_sha1(const struct packed_git *, int, unsigned char*);
 367extern int find_pack_entry_one(const unsigned char *, struct pack_entry *, struct packed_git *);
 368extern void *unpack_entry_gently(struct pack_entry *, char *, unsigned long *);
 369extern void packed_object_info_detail(struct pack_entry *, char *, unsigned long *, unsigned long *, int *, unsigned char *);
 370
 371/* Dumb servers support */
 372extern int update_server_info(int);
 373
 374#ifdef NO_MMAP
 375
 376#ifndef PROT_READ
 377#define PROT_READ 1
 378#define PROT_WRITE 2
 379#define MAP_PRIVATE 1
 380#define MAP_FAILED ((void*)-1)
 381#endif
 382
 383extern void *gitfakemmap(void *start, size_t length, int prot , int flags, int fd, off_t offset);
 384extern int gitfakemunmap(void *start, size_t length);
 385
 386#endif
 387
 388typedef int (*config_fn_t)(const char *, const char *);
 389extern int git_default_config(const char *, const char *);
 390extern int git_config_from_file(config_fn_t fn, const char *);
 391extern int git_config(config_fn_t fn);
 392extern int git_config_int(const char *, const char *);
 393extern int git_config_bool(const char *, const char *);
 394extern int git_config_set(const char *, const char *);
 395extern int git_config_set_multivar(const char *, const char *, const char *, int);
 396extern int check_repository_format_version(const char *var, const char *value);
 397
 398#define MAX_GITNAME (1000)
 399extern char git_default_email[MAX_GITNAME];
 400extern char git_default_name[MAX_GITNAME];
 401
 402#define MAX_ENCODING_LENGTH 64
 403extern char git_commit_encoding[MAX_ENCODING_LENGTH];
 404
 405/* Sane ctype - no locale, and works with signed chars */
 406#undef isspace
 407#undef isdigit
 408#undef isalpha
 409#undef isalnum
 410#undef tolower
 411#undef toupper
 412extern unsigned char sane_ctype[256];
 413#define GIT_SPACE 0x01
 414#define GIT_DIGIT 0x02
 415#define GIT_ALPHA 0x04
 416#define sane_istest(x,mask) ((sane_ctype[(unsigned char)(x)] & (mask)) != 0)
 417#define isspace(x) sane_istest(x,GIT_SPACE)
 418#define isdigit(x) sane_istest(x,GIT_DIGIT)
 419#define isalpha(x) sane_istest(x,GIT_ALPHA)
 420#define isalnum(x) sane_istest(x,GIT_ALPHA | GIT_DIGIT)
 421#define tolower(x) sane_case((unsigned char)(x), 0x20)
 422#define toupper(x) sane_case((unsigned char)(x), 0)
 423
 424static inline int sane_case(int x, int high)
 425{
 426        if (sane_istest(x, GIT_ALPHA))
 427                x = (x & ~0x20) | high;
 428        return x;
 429}
 430
 431extern int copy_fd(int ifd, int ofd);
 432#endif /* CACHE_H */