cache.hon commit revision.c: explain what tree_difference does (0a4ba7f)
   1#ifndef CACHE_H
   2#define CACHE_H
   3
   4#include "git-compat-util.h"
   5
   6#include SHA1_HEADER
   7#include <zlib.h>
   8
   9#if ZLIB_VERNUM < 0x1200
  10#define deflateBound(c,s)  ((s) + (((s) + 7) >> 3) + (((s) + 63) >> 6) + 11)
  11#endif
  12
  13#if defined(DT_UNKNOWN) && !defined(NO_D_TYPE_IN_DIRENT)
  14#define DTYPE(de)       ((de)->d_type)
  15#else
  16#undef DT_UNKNOWN
  17#undef DT_DIR
  18#undef DT_REG
  19#undef DT_LNK
  20#define DT_UNKNOWN      0
  21#define DT_DIR          1
  22#define DT_REG          2
  23#define DT_LNK          3
  24#define DTYPE(de)       DT_UNKNOWN
  25#endif
  26
  27/*
  28 * Intensive research over the course of many years has shown that
  29 * port 9418 is totally unused by anything else. Or
  30 *
  31 *      Your search - "port 9418" - did not match any documents.
  32 *
  33 * as www.google.com puts it.
  34 *
  35 * This port has been properly assigned for git use by IANA:
  36 * git (Assigned-9418) [I06-050728-0001].
  37 *
  38 *      git  9418/tcp   git pack transfer service
  39 *      git  9418/udp   git pack transfer service
  40 *
  41 * with Linus Torvalds <torvalds@osdl.org> as the point of
  42 * contact. September 2005.
  43 *
  44 * See http://www.iana.org/assignments/port-numbers
  45 */
  46#define DEFAULT_GIT_PORT 9418
  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[FLEX_ARRAY]; /* more */
  89};
  90
  91#define CE_NAMEMASK  (0x0fff)
  92#define CE_STAGEMASK (0x3000)
  93#define CE_UPDATE    (0x4000)
  94#define CE_VALID     (0x8000)
  95#define CE_STAGESHIFT 12
  96
  97#define create_ce_flags(len, stage) htons((len) | ((stage) << CE_STAGESHIFT))
  98#define ce_namelen(ce) (CE_NAMEMASK & ntohs((ce)->ce_flags))
  99#define ce_size(ce) cache_entry_size(ce_namelen(ce))
 100#define ce_stage(ce) ((CE_STAGEMASK & ntohs((ce)->ce_flags)) >> CE_STAGESHIFT)
 101
 102#define ce_permissions(mode) (((mode) & 0100) ? 0755 : 0644)
 103static inline unsigned int create_ce_mode(unsigned int mode)
 104{
 105        if (S_ISLNK(mode))
 106                return htonl(S_IFLNK);
 107        return htonl(S_IFREG | ce_permissions(mode));
 108}
 109static inline unsigned int ce_mode_from_stat(struct cache_entry *ce, unsigned int mode)
 110{
 111        extern int trust_executable_bit, has_symlinks;
 112        if (!has_symlinks && S_ISREG(mode) &&
 113            ce && S_ISLNK(ntohl(ce->ce_mode)))
 114                return ce->ce_mode;
 115        if (!trust_executable_bit && S_ISREG(mode)) {
 116                if (ce && S_ISREG(ntohl(ce->ce_mode)))
 117                        return ce->ce_mode;
 118                return create_ce_mode(0666);
 119        }
 120        return create_ce_mode(mode);
 121}
 122#define canon_mode(mode) \
 123        (S_ISREG(mode) ? (S_IFREG | ce_permissions(mode)) : \
 124        S_ISLNK(mode) ? S_IFLNK : S_IFDIR)
 125
 126#define cache_entry_size(len) ((offsetof(struct cache_entry,name) + (len) + 8) & ~7)
 127
 128extern struct cache_entry **active_cache;
 129extern unsigned int active_nr, active_alloc, active_cache_changed;
 130extern struct cache_tree *active_cache_tree;
 131extern int cache_errno;
 132
 133enum object_type {
 134        OBJ_BAD = -1,
 135        OBJ_NONE = 0,
 136        OBJ_COMMIT = 1,
 137        OBJ_TREE = 2,
 138        OBJ_BLOB = 3,
 139        OBJ_TAG = 4,
 140        /* 5 for future expansion */
 141        OBJ_OFS_DELTA = 6,
 142        OBJ_REF_DELTA = 7,
 143        OBJ_MAX,
 144};
 145
 146#define GIT_DIR_ENVIRONMENT "GIT_DIR"
 147#define DEFAULT_GIT_DIR_ENVIRONMENT ".git"
 148#define DB_ENVIRONMENT "GIT_OBJECT_DIRECTORY"
 149#define INDEX_ENVIRONMENT "GIT_INDEX_FILE"
 150#define GRAFT_ENVIRONMENT "GIT_GRAFT_FILE"
 151#define TEMPLATE_DIR_ENVIRONMENT "GIT_TEMPLATE_DIR"
 152#define CONFIG_ENVIRONMENT "GIT_CONFIG"
 153#define CONFIG_LOCAL_ENVIRONMENT "GIT_CONFIG_LOCAL"
 154#define EXEC_PATH_ENVIRONMENT "GIT_EXEC_PATH"
 155
 156extern int is_bare_repository_cfg;
 157extern int is_bare_repository(void);
 158extern int is_inside_git_dir(void);
 159extern const char *get_git_dir(void);
 160extern char *get_object_directory(void);
 161extern char *get_refs_directory(void);
 162extern char *get_index_file(void);
 163extern char *get_graft_file(void);
 164
 165#define ALTERNATE_DB_ENVIRONMENT "GIT_ALTERNATE_OBJECT_DIRECTORIES"
 166
 167extern const char **get_pathspec(const char *prefix, const char **pathspec);
 168extern const char *setup_git_directory_gently(int *);
 169extern const char *setup_git_directory(void);
 170extern const char *prefix_path(const char *prefix, int len, const char *path);
 171extern const char *prefix_filename(const char *prefix, int len, const char *path);
 172extern void verify_filename(const char *prefix, const char *name);
 173extern void verify_non_filename(const char *prefix, const char *name);
 174
 175#define alloc_nr(x) (((x)+16)*3/2)
 176
 177/* Initialize and use the cache information */
 178extern int read_cache(void);
 179extern int read_cache_from(const char *path);
 180extern int write_cache(int newfd, struct cache_entry **cache, int entries);
 181extern int discard_cache(void);
 182extern int verify_path(const char *path);
 183extern int cache_name_pos(const char *name, int namelen);
 184#define ADD_CACHE_OK_TO_ADD 1           /* Ok to add */
 185#define ADD_CACHE_OK_TO_REPLACE 2       /* Ok to replace file/directory */
 186#define ADD_CACHE_SKIP_DFCHECK 4        /* Ok to skip DF conflict checks */
 187extern int add_cache_entry(struct cache_entry *ce, int option);
 188extern struct cache_entry *refresh_cache_entry(struct cache_entry *ce, int really);
 189extern int remove_cache_entry_at(int pos);
 190extern int remove_file_from_cache(const char *path);
 191extern int add_file_to_index(const char *path, int verbose);
 192extern int ce_same_name(struct cache_entry *a, struct cache_entry *b);
 193extern int ce_match_stat(struct cache_entry *ce, struct stat *st, int);
 194extern int ce_modified(struct cache_entry *ce, struct stat *st, int);
 195extern int ce_path_match(const struct cache_entry *ce, const char **pathspec);
 196extern int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object, enum object_type type, const char *path);
 197extern int read_pipe(int fd, char** return_buf, unsigned long* return_size);
 198extern int index_pipe(unsigned char *sha1, int fd, const char *type, int write_object);
 199extern int index_path(unsigned char *sha1, const char *path, struct stat *st, int write_object);
 200extern void fill_stat_cache_info(struct cache_entry *ce, struct stat *st);
 201
 202#define REFRESH_REALLY          0x0001  /* ignore_valid */
 203#define REFRESH_UNMERGED        0x0002  /* allow unmerged */
 204#define REFRESH_QUIET           0x0004  /* be quiet about it */
 205#define REFRESH_IGNORE_MISSING  0x0008  /* ignore non-existent */
 206extern int refresh_cache(unsigned int flags);
 207
 208struct lock_file {
 209        struct lock_file *next;
 210        char on_list;
 211        char filename[PATH_MAX];
 212};
 213extern int hold_lock_file_for_update(struct lock_file *, const char *path, int);
 214extern int commit_lock_file(struct lock_file *);
 215extern void rollback_lock_file(struct lock_file *);
 216extern int delete_ref(const char *, unsigned char *sha1);
 217
 218/* Environment bits from configuration mechanism */
 219extern int use_legacy_headers;
 220extern int trust_executable_bit;
 221extern int has_symlinks;
 222extern int assume_unchanged;
 223extern int prefer_symlink_refs;
 224extern int log_all_ref_updates;
 225extern int warn_ambiguous_refs;
 226extern int shared_repository;
 227extern const char *apply_default_whitespace;
 228extern int zlib_compression_level;
 229extern size_t packed_git_window_size;
 230extern size_t packed_git_limit;
 231extern int auto_crlf;
 232
 233#define GIT_REPO_VERSION 0
 234extern int repository_format_version;
 235extern int check_repository_format(void);
 236
 237#define MTIME_CHANGED   0x0001
 238#define CTIME_CHANGED   0x0002
 239#define OWNER_CHANGED   0x0004
 240#define MODE_CHANGED    0x0008
 241#define INODE_CHANGED   0x0010
 242#define DATA_CHANGED    0x0020
 243#define TYPE_CHANGED    0x0040
 244
 245/* Return a statically allocated filename matching the sha1 signature */
 246extern char *mkpath(const char *fmt, ...) __attribute__((format (printf, 1, 2)));
 247extern char *git_path(const char *fmt, ...) __attribute__((format (printf, 1, 2)));
 248extern char *sha1_file_name(const unsigned char *sha1);
 249extern char *sha1_pack_name(const unsigned char *sha1);
 250extern char *sha1_pack_index_name(const unsigned char *sha1);
 251extern const char *find_unique_abbrev(const unsigned char *sha1, int);
 252extern const unsigned char null_sha1[20];
 253static inline int is_null_sha1(const unsigned char *sha1)
 254{
 255        return !memcmp(sha1, null_sha1, 20);
 256}
 257static inline int hashcmp(const unsigned char *sha1, const unsigned char *sha2)
 258{
 259        return memcmp(sha1, sha2, 20);
 260}
 261static inline void hashcpy(unsigned char *sha_dst, const unsigned char *sha_src)
 262{
 263        memcpy(sha_dst, sha_src, 20);
 264}
 265static inline void hashclr(unsigned char *hash)
 266{
 267        memset(hash, 0, 20);
 268}
 269
 270int git_mkstemp(char *path, size_t n, const char *template);
 271
 272enum sharedrepo {
 273        PERM_UMASK = 0,
 274        PERM_GROUP,
 275        PERM_EVERYBODY
 276};
 277int git_config_perm(const char *var, const char *value);
 278int adjust_shared_perm(const char *path);
 279int safe_create_leading_directories(char *path);
 280char *enter_repo(char *path, int strict);
 281
 282/* Read and unpack a sha1 file into memory, write memory to a sha1 file */
 283extern int sha1_object_info(const unsigned char *, unsigned long *);
 284extern void * read_sha1_file(const unsigned char *sha1, enum object_type *type, unsigned long *size);
 285extern int hash_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *sha1);
 286extern int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *return_sha1);
 287extern int pretend_sha1_file(void *, unsigned long, enum object_type, unsigned char *);
 288
 289extern int check_sha1_signature(const unsigned char *sha1, void *buf, unsigned long size, const char *type);
 290
 291extern int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
 292                              size_t bufsize, size_t *bufposn);
 293extern int write_sha1_to_fd(int fd, const unsigned char *sha1);
 294extern int move_temp_to_file(const char *tmpfile, const char *filename);
 295
 296extern int has_sha1_pack(const unsigned char *sha1, const char **ignore);
 297extern int has_sha1_file(const unsigned char *sha1);
 298extern void *map_sha1_file(const unsigned char *sha1, unsigned long *);
 299extern int legacy_loose_object(unsigned char *);
 300
 301extern int has_pack_file(const unsigned char *sha1);
 302extern int has_pack_index(const unsigned char *sha1);
 303
 304extern signed char hexval_table[256];
 305static inline unsigned int hexval(unsigned int c)
 306{
 307        return hexval_table[c];
 308}
 309
 310/* Convert to/from hex/sha1 representation */
 311#define MINIMUM_ABBREV 4
 312#define DEFAULT_ABBREV 7
 313
 314extern int get_sha1(const char *str, unsigned char *sha1);
 315extern int get_sha1_hex(const char *hex, unsigned char *sha1);
 316extern char *sha1_to_hex(const unsigned char *sha1);    /* static buffer result! */
 317extern int read_ref(const char *filename, unsigned char *sha1);
 318extern const char *resolve_ref(const char *path, unsigned char *sha1, int, int *);
 319extern int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref);
 320extern int dwim_log(const char *str, int len, unsigned char *sha1, char **ref);
 321
 322extern int create_symref(const char *ref, const char *refs_heads_master, const char *logmsg);
 323extern int validate_headref(const char *ref);
 324
 325extern int base_name_compare(const char *name1, int len1, int mode1, const char *name2, int len2, int mode2);
 326extern int cache_name_compare(const char *name1, int len1, const char *name2, int len2);
 327
 328extern void *read_object_with_reference(const unsigned char *sha1,
 329                                        const char *required_type,
 330                                        unsigned long *size,
 331                                        unsigned char *sha1_ret);
 332
 333enum date_mode { DATE_NORMAL = 0, DATE_RELATIVE, DATE_SHORT };
 334const char *show_date(unsigned long time, int timezone, enum date_mode mode);
 335const char *show_rfc2822_date(unsigned long time, int timezone);
 336int parse_date(const char *date, char *buf, int bufsize);
 337void datestamp(char *buf, int bufsize);
 338unsigned long approxidate(const char *);
 339
 340extern const char *git_author_info(int);
 341extern const char *git_committer_info(int);
 342extern const char *fmt_ident(const char *name, const char *email, const char *date_str, int);
 343
 344struct checkout {
 345        const char *base_dir;
 346        int base_dir_len;
 347        unsigned force:1,
 348                 quiet:1,
 349                 not_new:1,
 350                 refresh_cache:1;
 351};
 352
 353extern int checkout_entry(struct cache_entry *ce, struct checkout *state, char *topath);
 354
 355extern struct alternate_object_database {
 356        struct alternate_object_database *next;
 357        char *name;
 358        char base[FLEX_ARRAY]; /* more */
 359} *alt_odb_list;
 360extern void prepare_alt_odb(void);
 361
 362struct pack_window {
 363        struct pack_window *next;
 364        unsigned char *base;
 365        off_t offset;
 366        size_t len;
 367        unsigned int last_used;
 368        unsigned int inuse_cnt;
 369};
 370
 371extern struct packed_git {
 372        struct packed_git *next;
 373        struct pack_window *windows;
 374        uint32_t *index_base;
 375        time_t mtime;
 376        off_t index_size;
 377        off_t pack_size;
 378        int pack_fd;
 379        int pack_local;
 380        unsigned char sha1[20];
 381        /* something like ".git/objects/pack/xxxxx.pack" */
 382        char pack_name[FLEX_ARRAY]; /* more */
 383} *packed_git;
 384
 385struct pack_entry {
 386        off_t offset;
 387        unsigned char sha1[20];
 388        struct packed_git *p;
 389};
 390
 391struct ref {
 392        struct ref *next;
 393        unsigned char old_sha1[20];
 394        unsigned char new_sha1[20];
 395        unsigned char force;
 396        struct ref *peer_ref; /* when renaming */
 397        char name[FLEX_ARRAY]; /* more */
 398};
 399
 400#define REF_NORMAL      (1u << 0)
 401#define REF_HEADS       (1u << 1)
 402#define REF_TAGS        (1u << 2)
 403
 404extern pid_t git_connect(int fd[2], char *url, const char *prog);
 405extern int finish_connect(pid_t pid);
 406extern int path_match(const char *path, int nr, char **match);
 407extern int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail,
 408                      int nr_refspec, char **refspec, int all);
 409extern int get_ack(int fd, unsigned char *result_sha1);
 410extern struct ref **get_remote_heads(int in, struct ref **list, int nr_match, char **match, unsigned int flags);
 411extern int server_supports(const char *feature);
 412
 413extern struct packed_git *parse_pack_index(unsigned char *sha1);
 414extern struct packed_git *parse_pack_index_file(const unsigned char *sha1,
 415                                                char *idx_path);
 416
 417extern void prepare_packed_git(void);
 418extern void reprepare_packed_git(void);
 419extern void install_packed_git(struct packed_git *pack);
 420
 421extern struct packed_git *find_sha1_pack(const unsigned char *sha1, 
 422                                         struct packed_git *packs);
 423
 424extern void pack_report(void);
 425extern unsigned char* use_pack(struct packed_git *, struct pack_window **, off_t, unsigned int *);
 426extern void unuse_pack(struct pack_window **);
 427extern struct packed_git *add_packed_git(char *, int, int);
 428extern uint32_t num_packed_objects(const struct packed_git *p);
 429extern int nth_packed_object_sha1(const struct packed_git *, uint32_t, unsigned char*);
 430extern off_t find_pack_entry_one(const unsigned char *, struct packed_git *);
 431extern void *unpack_entry(struct packed_git *, off_t, enum object_type *, unsigned long *);
 432extern unsigned long unpack_object_header_gently(const unsigned char *buf, unsigned long len, enum object_type *type, unsigned long *sizep);
 433extern const char *packed_object_info_detail(struct packed_git *, off_t, unsigned long *, unsigned long *, unsigned int *, unsigned char *);
 434
 435/* Dumb servers support */
 436extern int update_server_info(int);
 437
 438typedef int (*config_fn_t)(const char *, const char *);
 439extern int git_default_config(const char *, const char *);
 440extern int git_config_from_file(config_fn_t fn, const char *);
 441extern int git_config(config_fn_t fn);
 442extern int git_config_int(const char *, const char *);
 443extern int git_config_bool(const char *, const char *);
 444extern int git_config_set(const char *, const char *);
 445extern int git_config_set_multivar(const char *, const char *, const char *, int);
 446extern int git_config_rename_section(const char *, const char *);
 447extern int check_repository_format_version(const char *var, const char *value);
 448
 449#define MAX_GITNAME (1000)
 450extern char git_default_email[MAX_GITNAME];
 451extern char git_default_name[MAX_GITNAME];
 452
 453extern char *git_commit_encoding;
 454extern const char *git_log_output_encoding;
 455
 456extern int copy_fd(int ifd, int ofd);
 457extern int read_in_full(int fd, void *buf, size_t count);
 458extern int write_in_full(int fd, const void *buf, size_t count);
 459extern void write_or_die(int fd, const void *buf, size_t count);
 460extern int write_or_whine(int fd, const void *buf, size_t count, const char *msg);
 461extern int write_or_whine_pipe(int fd, const void *buf, size_t count, const char *msg);
 462
 463/* pager.c */
 464extern void setup_pager(void);
 465extern int pager_in_use;
 466extern int pager_use_color;
 467
 468/* base85 */
 469int decode_85(char *dst, char *line, int linelen);
 470void encode_85(char *buf, unsigned char *data, int bytes);
 471
 472/* alloc.c */
 473struct blob;
 474struct tree;
 475struct commit;
 476struct tag;
 477extern struct blob *alloc_blob_node(void);
 478extern struct tree *alloc_tree_node(void);
 479extern struct commit *alloc_commit_node(void);
 480extern struct tag *alloc_tag_node(void);
 481extern void alloc_report(void);
 482
 483/* trace.c */
 484extern int nfasprintf(char **str, const char *fmt, ...);
 485extern int nfvasprintf(char **str, const char *fmt, va_list va);
 486extern void trace_printf(const char *format, ...);
 487extern void trace_argv_printf(const char **argv, int count, const char *format, ...);
 488
 489/* convert.c */
 490extern int convert_to_git(const char *path, char **bufp, unsigned long *sizep);
 491extern int convert_to_working_tree(const char *path, char **bufp, unsigned long *sizep);
 492
 493#endif /* CACHE_H */