a61b2d3f0d79b0f56992e0343803811f5265d716
   1#ifndef CACHE_H
   2#define CACHE_H
   3
   4#include "git-compat-util.h"
   5#include "strbuf.h"
   6#include "hashmap.h"
   7#include "list.h"
   8#include "advice.h"
   9#include "gettext.h"
  10#include "convert.h"
  11#include "trace.h"
  12#include "string-list.h"
  13#include "pack-revindex.h"
  14#include "hash.h"
  15#include "path.h"
  16#include "sha1-array.h"
  17#include "repository.h"
  18
  19#include <zlib.h>
  20typedef struct git_zstream {
  21        z_stream z;
  22        unsigned long avail_in;
  23        unsigned long avail_out;
  24        unsigned long total_in;
  25        unsigned long total_out;
  26        unsigned char *next_in;
  27        unsigned char *next_out;
  28} git_zstream;
  29
  30void git_inflate_init(git_zstream *);
  31void git_inflate_init_gzip_only(git_zstream *);
  32void git_inflate_end(git_zstream *);
  33int git_inflate(git_zstream *, int flush);
  34
  35void git_deflate_init(git_zstream *, int level);
  36void git_deflate_init_gzip(git_zstream *, int level);
  37void git_deflate_init_raw(git_zstream *, int level);
  38void git_deflate_end(git_zstream *);
  39int git_deflate_abort(git_zstream *);
  40int git_deflate_end_gently(git_zstream *);
  41int git_deflate(git_zstream *, int flush);
  42unsigned long git_deflate_bound(git_zstream *, unsigned long);
  43
  44/* The length in bytes and in hex digits of an object name (SHA-1 value). */
  45#define GIT_SHA1_RAWSZ 20
  46#define GIT_SHA1_HEXSZ (2 * GIT_SHA1_RAWSZ)
  47
  48/* The length in byte and in hex digits of the largest possible hash value. */
  49#define GIT_MAX_RAWSZ GIT_SHA1_RAWSZ
  50#define GIT_MAX_HEXSZ GIT_SHA1_HEXSZ
  51
  52struct object_id {
  53        unsigned char hash[GIT_MAX_RAWSZ];
  54};
  55
  56#define the_hash_algo the_repository->hash_algo
  57
  58#if defined(DT_UNKNOWN) && !defined(NO_D_TYPE_IN_DIRENT)
  59#define DTYPE(de)       ((de)->d_type)
  60#else
  61#undef DT_UNKNOWN
  62#undef DT_DIR
  63#undef DT_REG
  64#undef DT_LNK
  65#define DT_UNKNOWN      0
  66#define DT_DIR          1
  67#define DT_REG          2
  68#define DT_LNK          3
  69#define DTYPE(de)       DT_UNKNOWN
  70#endif
  71
  72/* unknown mode (impossible combination S_IFIFO|S_IFCHR) */
  73#define S_IFINVALID     0030000
  74
  75/*
  76 * A "directory link" is a link to another git directory.
  77 *
  78 * The value 0160000 is not normally a valid mode, and
  79 * also just happens to be S_IFDIR + S_IFLNK
  80 */
  81#define S_IFGITLINK     0160000
  82#define S_ISGITLINK(m)  (((m) & S_IFMT) == S_IFGITLINK)
  83
  84/*
  85 * Some mode bits are also used internally for computations.
  86 *
  87 * They *must* not overlap with any valid modes, and they *must* not be emitted
  88 * to outside world - i.e. appear on disk or network. In other words, it's just
  89 * temporary fields, which we internally use, but they have to stay in-house.
  90 *
  91 * ( such approach is valid, as standard S_IF* fits into 16 bits, and in Git
  92 *   codebase mode is `unsigned int` which is assumed to be at least 32 bits )
  93 */
  94
  95/* used internally in tree-diff */
  96#define S_DIFFTREE_IFXMIN_NEQ   0x80000000
  97
  98
  99/*
 100 * Intensive research over the course of many years has shown that
 101 * port 9418 is totally unused by anything else. Or
 102 *
 103 *      Your search - "port 9418" - did not match any documents.
 104 *
 105 * as www.google.com puts it.
 106 *
 107 * This port has been properly assigned for git use by IANA:
 108 * git (Assigned-9418) [I06-050728-0001].
 109 *
 110 *      git  9418/tcp   git pack transfer service
 111 *      git  9418/udp   git pack transfer service
 112 *
 113 * with Linus Torvalds <torvalds@osdl.org> as the point of
 114 * contact. September 2005.
 115 *
 116 * See http://www.iana.org/assignments/port-numbers
 117 */
 118#define DEFAULT_GIT_PORT 9418
 119
 120/*
 121 * Basic data structures for the directory cache
 122 */
 123
 124#define CACHE_SIGNATURE 0x44495243      /* "DIRC" */
 125struct cache_header {
 126        uint32_t hdr_signature;
 127        uint32_t hdr_version;
 128        uint32_t hdr_entries;
 129};
 130
 131#define INDEX_FORMAT_LB 2
 132#define INDEX_FORMAT_UB 4
 133
 134/*
 135 * The "cache_time" is just the low 32 bits of the
 136 * time. It doesn't matter if it overflows - we only
 137 * check it for equality in the 32 bits we save.
 138 */
 139struct cache_time {
 140        uint32_t sec;
 141        uint32_t nsec;
 142};
 143
 144struct stat_data {
 145        struct cache_time sd_ctime;
 146        struct cache_time sd_mtime;
 147        unsigned int sd_dev;
 148        unsigned int sd_ino;
 149        unsigned int sd_uid;
 150        unsigned int sd_gid;
 151        unsigned int sd_size;
 152};
 153
 154struct cache_entry {
 155        struct hashmap_entry ent;
 156        struct stat_data ce_stat_data;
 157        unsigned int ce_mode;
 158        unsigned int ce_flags;
 159        unsigned int ce_namelen;
 160        unsigned int index;     /* for link extension */
 161        struct object_id oid;
 162        char name[FLEX_ARRAY]; /* more */
 163};
 164
 165#define CE_STAGEMASK (0x3000)
 166#define CE_EXTENDED  (0x4000)
 167#define CE_VALID     (0x8000)
 168#define CE_STAGESHIFT 12
 169
 170/*
 171 * Range 0xFFFF0FFF in ce_flags is divided into
 172 * two parts: in-memory flags and on-disk ones.
 173 * Flags in CE_EXTENDED_FLAGS will get saved on-disk
 174 * if you want to save a new flag, add it in
 175 * CE_EXTENDED_FLAGS
 176 *
 177 * In-memory only flags
 178 */
 179#define CE_UPDATE            (1 << 16)
 180#define CE_REMOVE            (1 << 17)
 181#define CE_UPTODATE          (1 << 18)
 182#define CE_ADDED             (1 << 19)
 183
 184#define CE_HASHED            (1 << 20)
 185#define CE_FSMONITOR_VALID   (1 << 21)
 186#define CE_WT_REMOVE         (1 << 22) /* remove in work directory */
 187#define CE_CONFLICTED        (1 << 23)
 188
 189#define CE_UNPACKED          (1 << 24)
 190#define CE_NEW_SKIP_WORKTREE (1 << 25)
 191
 192/* used to temporarily mark paths matched by pathspecs */
 193#define CE_MATCHED           (1 << 26)
 194
 195#define CE_UPDATE_IN_BASE    (1 << 27)
 196#define CE_STRIP_NAME        (1 << 28)
 197
 198/*
 199 * Extended on-disk flags
 200 */
 201#define CE_INTENT_TO_ADD     (1 << 29)
 202#define CE_SKIP_WORKTREE     (1 << 30)
 203/* CE_EXTENDED2 is for future extension */
 204#define CE_EXTENDED2         (1U << 31)
 205
 206#define CE_EXTENDED_FLAGS (CE_INTENT_TO_ADD | CE_SKIP_WORKTREE)
 207
 208/*
 209 * Safeguard to avoid saving wrong flags:
 210 *  - CE_EXTENDED2 won't get saved until its semantic is known
 211 *  - Bits in 0x0000FFFF have been saved in ce_flags already
 212 *  - Bits in 0x003F0000 are currently in-memory flags
 213 */
 214#if CE_EXTENDED_FLAGS & 0x803FFFFF
 215#error "CE_EXTENDED_FLAGS out of range"
 216#endif
 217
 218/* Forward structure decls */
 219struct pathspec;
 220struct child_process;
 221
 222/*
 223 * Copy the sha1 and stat state of a cache entry from one to
 224 * another. But we never change the name, or the hash state!
 225 */
 226static inline void copy_cache_entry(struct cache_entry *dst,
 227                                    const struct cache_entry *src)
 228{
 229        unsigned int state = dst->ce_flags & CE_HASHED;
 230
 231        /* Don't copy hash chain and name */
 232        memcpy(&dst->ce_stat_data, &src->ce_stat_data,
 233                        offsetof(struct cache_entry, name) -
 234                        offsetof(struct cache_entry, ce_stat_data));
 235
 236        /* Restore the hash state */
 237        dst->ce_flags = (dst->ce_flags & ~CE_HASHED) | state;
 238}
 239
 240static inline unsigned create_ce_flags(unsigned stage)
 241{
 242        return (stage << CE_STAGESHIFT);
 243}
 244
 245#define ce_namelen(ce) ((ce)->ce_namelen)
 246#define ce_size(ce) cache_entry_size(ce_namelen(ce))
 247#define ce_stage(ce) ((CE_STAGEMASK & (ce)->ce_flags) >> CE_STAGESHIFT)
 248#define ce_uptodate(ce) ((ce)->ce_flags & CE_UPTODATE)
 249#define ce_skip_worktree(ce) ((ce)->ce_flags & CE_SKIP_WORKTREE)
 250#define ce_mark_uptodate(ce) ((ce)->ce_flags |= CE_UPTODATE)
 251#define ce_intent_to_add(ce) ((ce)->ce_flags & CE_INTENT_TO_ADD)
 252
 253#define ce_permissions(mode) (((mode) & 0100) ? 0755 : 0644)
 254static inline unsigned int create_ce_mode(unsigned int mode)
 255{
 256        if (S_ISLNK(mode))
 257                return S_IFLNK;
 258        if (S_ISDIR(mode) || S_ISGITLINK(mode))
 259                return S_IFGITLINK;
 260        return S_IFREG | ce_permissions(mode);
 261}
 262static inline unsigned int ce_mode_from_stat(const struct cache_entry *ce,
 263                                             unsigned int mode)
 264{
 265        extern int trust_executable_bit, has_symlinks;
 266        if (!has_symlinks && S_ISREG(mode) &&
 267            ce && S_ISLNK(ce->ce_mode))
 268                return ce->ce_mode;
 269        if (!trust_executable_bit && S_ISREG(mode)) {
 270                if (ce && S_ISREG(ce->ce_mode))
 271                        return ce->ce_mode;
 272                return create_ce_mode(0666);
 273        }
 274        return create_ce_mode(mode);
 275}
 276static inline int ce_to_dtype(const struct cache_entry *ce)
 277{
 278        unsigned ce_mode = ntohl(ce->ce_mode);
 279        if (S_ISREG(ce_mode))
 280                return DT_REG;
 281        else if (S_ISDIR(ce_mode) || S_ISGITLINK(ce_mode))
 282                return DT_DIR;
 283        else if (S_ISLNK(ce_mode))
 284                return DT_LNK;
 285        else
 286                return DT_UNKNOWN;
 287}
 288static inline unsigned int canon_mode(unsigned int mode)
 289{
 290        if (S_ISREG(mode))
 291                return S_IFREG | ce_permissions(mode);
 292        if (S_ISLNK(mode))
 293                return S_IFLNK;
 294        if (S_ISDIR(mode))
 295                return S_IFDIR;
 296        return S_IFGITLINK;
 297}
 298
 299#define cache_entry_size(len) (offsetof(struct cache_entry,name) + (len) + 1)
 300
 301#define SOMETHING_CHANGED       (1 << 0) /* unclassified changes go here */
 302#define CE_ENTRY_CHANGED        (1 << 1)
 303#define CE_ENTRY_REMOVED        (1 << 2)
 304#define CE_ENTRY_ADDED          (1 << 3)
 305#define RESOLVE_UNDO_CHANGED    (1 << 4)
 306#define CACHE_TREE_CHANGED      (1 << 5)
 307#define SPLIT_INDEX_ORDERED     (1 << 6)
 308#define UNTRACKED_CHANGED       (1 << 7)
 309#define FSMONITOR_CHANGED       (1 << 8)
 310
 311struct split_index;
 312struct untracked_cache;
 313
 314struct index_state {
 315        struct cache_entry **cache;
 316        unsigned int version;
 317        unsigned int cache_nr, cache_alloc, cache_changed;
 318        struct string_list *resolve_undo;
 319        struct cache_tree *cache_tree;
 320        struct split_index *split_index;
 321        struct cache_time timestamp;
 322        unsigned name_hash_initialized : 1,
 323                 initialized : 1,
 324                 drop_cache_tree : 1;
 325        struct hashmap name_hash;
 326        struct hashmap dir_hash;
 327        unsigned char sha1[20];
 328        struct untracked_cache *untracked;
 329        uint64_t fsmonitor_last_update;
 330        struct ewah_bitmap *fsmonitor_dirty;
 331};
 332
 333extern struct index_state the_index;
 334
 335/* Name hashing */
 336extern int test_lazy_init_name_hash(struct index_state *istate, int try_threaded);
 337extern void add_name_hash(struct index_state *istate, struct cache_entry *ce);
 338extern void remove_name_hash(struct index_state *istate, struct cache_entry *ce);
 339extern void free_name_hash(struct index_state *istate);
 340
 341
 342#ifndef NO_THE_INDEX_COMPATIBILITY_MACROS
 343#define active_cache (the_index.cache)
 344#define active_nr (the_index.cache_nr)
 345#define active_alloc (the_index.cache_alloc)
 346#define active_cache_changed (the_index.cache_changed)
 347#define active_cache_tree (the_index.cache_tree)
 348
 349#define read_cache() read_index(&the_index)
 350#define read_cache_from(path) read_index_from(&the_index, (path), (get_git_dir()))
 351#define read_cache_preload(pathspec) read_index_preload(&the_index, (pathspec))
 352#define is_cache_unborn() is_index_unborn(&the_index)
 353#define read_cache_unmerged() read_index_unmerged(&the_index)
 354#define discard_cache() discard_index(&the_index)
 355#define unmerged_cache() unmerged_index(&the_index)
 356#define cache_name_pos(name, namelen) index_name_pos(&the_index,(name),(namelen))
 357#define add_cache_entry(ce, option) add_index_entry(&the_index, (ce), (option))
 358#define rename_cache_entry_at(pos, new_name) rename_index_entry_at(&the_index, (pos), (new_name))
 359#define remove_cache_entry_at(pos) remove_index_entry_at(&the_index, (pos))
 360#define remove_file_from_cache(path) remove_file_from_index(&the_index, (path))
 361#define add_to_cache(path, st, flags) add_to_index(&the_index, (path), (st), (flags))
 362#define add_file_to_cache(path, flags) add_file_to_index(&the_index, (path), (flags))
 363#define chmod_cache_entry(ce, flip) chmod_index_entry(&the_index, (ce), (flip))
 364#define refresh_cache(flags) refresh_index(&the_index, (flags), NULL, NULL, NULL)
 365#define ce_match_stat(ce, st, options) ie_match_stat(&the_index, (ce), (st), (options))
 366#define ce_modified(ce, st, options) ie_modified(&the_index, (ce), (st), (options))
 367#define cache_dir_exists(name, namelen) index_dir_exists(&the_index, (name), (namelen))
 368#define cache_file_exists(name, namelen, igncase) index_file_exists(&the_index, (name), (namelen), (igncase))
 369#define cache_name_is_other(name, namelen) index_name_is_other(&the_index, (name), (namelen))
 370#define resolve_undo_clear() resolve_undo_clear_index(&the_index)
 371#define unmerge_cache_entry_at(at) unmerge_index_entry_at(&the_index, at)
 372#define unmerge_cache(pathspec) unmerge_index(&the_index, pathspec)
 373#define read_blob_data_from_cache(path, sz) read_blob_data_from_index(&the_index, (path), (sz))
 374#endif
 375
 376enum object_type {
 377        OBJ_BAD = -1,
 378        OBJ_NONE = 0,
 379        OBJ_COMMIT = 1,
 380        OBJ_TREE = 2,
 381        OBJ_BLOB = 3,
 382        OBJ_TAG = 4,
 383        /* 5 for future expansion */
 384        OBJ_OFS_DELTA = 6,
 385        OBJ_REF_DELTA = 7,
 386        OBJ_ANY,
 387        OBJ_MAX
 388};
 389
 390static inline enum object_type object_type(unsigned int mode)
 391{
 392        return S_ISDIR(mode) ? OBJ_TREE :
 393                S_ISGITLINK(mode) ? OBJ_COMMIT :
 394                OBJ_BLOB;
 395}
 396
 397/* Double-check local_repo_env below if you add to this list. */
 398#define GIT_DIR_ENVIRONMENT "GIT_DIR"
 399#define GIT_COMMON_DIR_ENVIRONMENT "GIT_COMMON_DIR"
 400#define GIT_NAMESPACE_ENVIRONMENT "GIT_NAMESPACE"
 401#define GIT_WORK_TREE_ENVIRONMENT "GIT_WORK_TREE"
 402#define GIT_PREFIX_ENVIRONMENT "GIT_PREFIX"
 403#define GIT_SUPER_PREFIX_ENVIRONMENT "GIT_INTERNAL_SUPER_PREFIX"
 404#define DEFAULT_GIT_DIR_ENVIRONMENT ".git"
 405#define DB_ENVIRONMENT "GIT_OBJECT_DIRECTORY"
 406#define INDEX_ENVIRONMENT "GIT_INDEX_FILE"
 407#define GRAFT_ENVIRONMENT "GIT_GRAFT_FILE"
 408#define GIT_SHALLOW_FILE_ENVIRONMENT "GIT_SHALLOW_FILE"
 409#define TEMPLATE_DIR_ENVIRONMENT "GIT_TEMPLATE_DIR"
 410#define CONFIG_ENVIRONMENT "GIT_CONFIG"
 411#define CONFIG_DATA_ENVIRONMENT "GIT_CONFIG_PARAMETERS"
 412#define EXEC_PATH_ENVIRONMENT "GIT_EXEC_PATH"
 413#define CEILING_DIRECTORIES_ENVIRONMENT "GIT_CEILING_DIRECTORIES"
 414#define NO_REPLACE_OBJECTS_ENVIRONMENT "GIT_NO_REPLACE_OBJECTS"
 415#define GIT_REPLACE_REF_BASE_ENVIRONMENT "GIT_REPLACE_REF_BASE"
 416#define GITATTRIBUTES_FILE ".gitattributes"
 417#define INFOATTRIBUTES_FILE "info/attributes"
 418#define ATTRIBUTE_MACRO_PREFIX "[attr]"
 419#define GITMODULES_FILE ".gitmodules"
 420#define GIT_NOTES_REF_ENVIRONMENT "GIT_NOTES_REF"
 421#define GIT_NOTES_DEFAULT_REF "refs/notes/commits"
 422#define GIT_NOTES_DISPLAY_REF_ENVIRONMENT "GIT_NOTES_DISPLAY_REF"
 423#define GIT_NOTES_REWRITE_REF_ENVIRONMENT "GIT_NOTES_REWRITE_REF"
 424#define GIT_NOTES_REWRITE_MODE_ENVIRONMENT "GIT_NOTES_REWRITE_MODE"
 425#define GIT_LITERAL_PATHSPECS_ENVIRONMENT "GIT_LITERAL_PATHSPECS"
 426#define GIT_GLOB_PATHSPECS_ENVIRONMENT "GIT_GLOB_PATHSPECS"
 427#define GIT_NOGLOB_PATHSPECS_ENVIRONMENT "GIT_NOGLOB_PATHSPECS"
 428#define GIT_ICASE_PATHSPECS_ENVIRONMENT "GIT_ICASE_PATHSPECS"
 429#define GIT_QUARANTINE_ENVIRONMENT "GIT_QUARANTINE_PATH"
 430#define GIT_OPTIONAL_LOCKS_ENVIRONMENT "GIT_OPTIONAL_LOCKS"
 431
 432/*
 433 * Environment variable used in handshaking the wire protocol.
 434 * Contains a colon ':' separated list of keys with optional values
 435 * 'key[=value]'.  Presence of unknown keys and values must be
 436 * ignored.
 437 */
 438#define GIT_PROTOCOL_ENVIRONMENT "GIT_PROTOCOL"
 439/* HTTP header used to handshake the wire protocol */
 440#define GIT_PROTOCOL_HEADER "Git-Protocol"
 441
 442/*
 443 * This environment variable is expected to contain a boolean indicating
 444 * whether we should or should not treat:
 445 *
 446 *   GIT_DIR=foo.git git ...
 447 *
 448 * as if GIT_WORK_TREE=. was given. It's not expected that users will make use
 449 * of this, but we use it internally to communicate to sub-processes that we
 450 * are in a bare repo. If not set, defaults to true.
 451 */
 452#define GIT_IMPLICIT_WORK_TREE_ENVIRONMENT "GIT_IMPLICIT_WORK_TREE"
 453
 454/*
 455 * Repository-local GIT_* environment variables; these will be cleared
 456 * when git spawns a sub-process that runs inside another repository.
 457 * The array is NULL-terminated, which makes it easy to pass in the "env"
 458 * parameter of a run-command invocation, or to do a simple walk.
 459 */
 460extern const char * const local_repo_env[];
 461
 462extern void setup_git_env(void);
 463
 464/*
 465 * Returns true iff we have a configured git repository (either via
 466 * setup_git_directory, or in the environment via $GIT_DIR).
 467 */
 468int have_git_dir(void);
 469
 470extern int is_bare_repository_cfg;
 471extern int is_bare_repository(void);
 472extern int is_inside_git_dir(void);
 473extern char *git_work_tree_cfg;
 474extern int is_inside_work_tree(void);
 475extern const char *get_git_dir(void);
 476extern const char *get_git_common_dir(void);
 477extern char *get_object_directory(void);
 478extern char *get_index_file(void);
 479extern char *get_graft_file(void);
 480extern int set_git_dir(const char *path);
 481extern int get_common_dir_noenv(struct strbuf *sb, const char *gitdir);
 482extern int get_common_dir(struct strbuf *sb, const char *gitdir);
 483extern const char *get_git_namespace(void);
 484extern const char *strip_namespace(const char *namespaced_ref);
 485extern const char *get_super_prefix(void);
 486extern const char *get_git_work_tree(void);
 487
 488/*
 489 * Return true if the given path is a git directory; note that this _just_
 490 * looks at the directory itself. If you want to know whether "foo/.git"
 491 * is a repository, you must feed that path, not just "foo".
 492 */
 493extern int is_git_directory(const char *path);
 494
 495/*
 496 * Return 1 if the given path is the root of a git repository or
 497 * submodule, else 0. Will not return 1 for bare repositories with the
 498 * exception of creating a bare repository in "foo/.git" and calling
 499 * is_git_repository("foo").
 500 *
 501 * If we run into read errors, we err on the side of saying "yes, it is",
 502 * as we usually consider sub-repos precious, and would prefer to err on the
 503 * side of not disrupting or deleting them.
 504 */
 505extern int is_nonbare_repository_dir(struct strbuf *path);
 506
 507#define READ_GITFILE_ERR_STAT_FAILED 1
 508#define READ_GITFILE_ERR_NOT_A_FILE 2
 509#define READ_GITFILE_ERR_OPEN_FAILED 3
 510#define READ_GITFILE_ERR_READ_FAILED 4
 511#define READ_GITFILE_ERR_INVALID_FORMAT 5
 512#define READ_GITFILE_ERR_NO_PATH 6
 513#define READ_GITFILE_ERR_NOT_A_REPO 7
 514#define READ_GITFILE_ERR_TOO_LARGE 8
 515extern void read_gitfile_error_die(int error_code, const char *path, const char *dir);
 516extern const char *read_gitfile_gently(const char *path, int *return_error_code);
 517#define read_gitfile(path) read_gitfile_gently((path), NULL)
 518extern const char *resolve_gitdir_gently(const char *suspect, int *return_error_code);
 519#define resolve_gitdir(path) resolve_gitdir_gently((path), NULL)
 520
 521extern void set_git_work_tree(const char *tree);
 522
 523#define ALTERNATE_DB_ENVIRONMENT "GIT_ALTERNATE_OBJECT_DIRECTORIES"
 524
 525extern void setup_work_tree(void);
 526/*
 527 * Find the commondir and gitdir of the repository that contains the current
 528 * working directory, without changing the working directory or other global
 529 * state. The result is appended to commondir and gitdir.  If the discovered
 530 * gitdir does not correspond to a worktree, then 'commondir' and 'gitdir' will
 531 * both have the same result appended to the buffer.  The return value is
 532 * either 0 upon success and non-zero if no repository was found.
 533 */
 534extern int discover_git_directory(struct strbuf *commondir,
 535                                  struct strbuf *gitdir);
 536extern const char *setup_git_directory_gently(int *);
 537extern const char *setup_git_directory(void);
 538extern char *prefix_path(const char *prefix, int len, const char *path);
 539extern char *prefix_path_gently(const char *prefix, int len, int *remaining, const char *path);
 540
 541/*
 542 * Concatenate "prefix" (if len is non-zero) and "path", with no
 543 * connecting characters (so "prefix" should end with a "/").
 544 * Unlike prefix_path, this should be used if the named file does
 545 * not have to interact with index entry; i.e. name of a random file
 546 * on the filesystem.
 547 *
 548 * The return value is always a newly allocated string (even if the
 549 * prefix was empty).
 550 */
 551extern char *prefix_filename(const char *prefix, const char *path);
 552
 553extern int check_filename(const char *prefix, const char *name);
 554extern void verify_filename(const char *prefix,
 555                            const char *name,
 556                            int diagnose_misspelt_rev);
 557extern void verify_non_filename(const char *prefix, const char *name);
 558extern int path_inside_repo(const char *prefix, const char *path);
 559
 560#define INIT_DB_QUIET 0x0001
 561#define INIT_DB_EXIST_OK 0x0002
 562
 563extern int init_db(const char *git_dir, const char *real_git_dir,
 564                   const char *template_dir, unsigned int flags);
 565
 566extern void sanitize_stdfds(void);
 567extern int daemonize(void);
 568
 569#define alloc_nr(x) (((x)+16)*3/2)
 570
 571/*
 572 * Realloc the buffer pointed at by variable 'x' so that it can hold
 573 * at least 'nr' entries; the number of entries currently allocated
 574 * is 'alloc', using the standard growing factor alloc_nr() macro.
 575 *
 576 * DO NOT USE any expression with side-effect for 'x', 'nr', or 'alloc'.
 577 */
 578#define ALLOC_GROW(x, nr, alloc) \
 579        do { \
 580                if ((nr) > alloc) { \
 581                        if (alloc_nr(alloc) < (nr)) \
 582                                alloc = (nr); \
 583                        else \
 584                                alloc = alloc_nr(alloc); \
 585                        REALLOC_ARRAY(x, alloc); \
 586                } \
 587        } while (0)
 588
 589/* Initialize and use the cache information */
 590struct lock_file;
 591extern int read_index(struct index_state *);
 592extern int read_index_preload(struct index_state *, const struct pathspec *pathspec);
 593extern int do_read_index(struct index_state *istate, const char *path,
 594                         int must_exist); /* for testting only! */
 595extern int read_index_from(struct index_state *, const char *path,
 596                           const char *gitdir);
 597extern int is_index_unborn(struct index_state *);
 598extern int read_index_unmerged(struct index_state *);
 599
 600/* For use with `write_locked_index()`. */
 601#define COMMIT_LOCK             (1 << 0)
 602#define SKIP_IF_UNCHANGED       (1 << 1)
 603
 604/*
 605 * Write the index while holding an already-taken lock. Close the lock,
 606 * and if `COMMIT_LOCK` is given, commit it.
 607 *
 608 * Unless a split index is in use, write the index into the lockfile.
 609 *
 610 * With a split index, write the shared index to a temporary file,
 611 * adjust its permissions and rename it into place, then write the
 612 * split index to the lockfile. If the temporary file for the shared
 613 * index cannot be created, fall back to the behavior described in
 614 * the previous paragraph.
 615 *
 616 * With `COMMIT_LOCK`, the lock is always committed or rolled back.
 617 * Without it, the lock is closed, but neither committed nor rolled
 618 * back.
 619 *
 620 * If `SKIP_IF_UNCHANGED` is given and the index is unchanged, nothing
 621 * is written (and the lock is rolled back if `COMMIT_LOCK` is given).
 622 */
 623extern int write_locked_index(struct index_state *, struct lock_file *lock, unsigned flags);
 624
 625extern int discard_index(struct index_state *);
 626extern void move_index_extensions(struct index_state *dst, struct index_state *src);
 627extern int unmerged_index(const struct index_state *);
 628
 629/**
 630 * Returns 1 if the index differs from HEAD, 0 otherwise. When on an unborn
 631 * branch, returns 1 if there are entries in the index, 0 otherwise. If an
 632 * strbuf is provided, the space-separated list of files that differ will be
 633 * appended to it.
 634 */
 635extern int index_has_changes(struct strbuf *sb);
 636
 637extern int verify_path(const char *path);
 638extern int strcmp_offset(const char *s1, const char *s2, size_t *first_change);
 639extern int index_dir_exists(struct index_state *istate, const char *name, int namelen);
 640extern void adjust_dirname_case(struct index_state *istate, char *name);
 641extern struct cache_entry *index_file_exists(struct index_state *istate, const char *name, int namelen, int igncase);
 642
 643/*
 644 * Searches for an entry defined by name and namelen in the given index.
 645 * If the return value is positive (including 0) it is the position of an
 646 * exact match. If the return value is negative, the negated value minus 1
 647 * is the position where the entry would be inserted.
 648 * Example: The current index consists of these files and its stages:
 649 *
 650 *   b#0, d#0, f#1, f#3
 651 *
 652 * index_name_pos(&index, "a", 1) -> -1
 653 * index_name_pos(&index, "b", 1) ->  0
 654 * index_name_pos(&index, "c", 1) -> -2
 655 * index_name_pos(&index, "d", 1) ->  1
 656 * index_name_pos(&index, "e", 1) -> -3
 657 * index_name_pos(&index, "f", 1) -> -3
 658 * index_name_pos(&index, "g", 1) -> -5
 659 */
 660extern int index_name_pos(const struct index_state *, const char *name, int namelen);
 661
 662#define ADD_CACHE_OK_TO_ADD 1           /* Ok to add */
 663#define ADD_CACHE_OK_TO_REPLACE 2       /* Ok to replace file/directory */
 664#define ADD_CACHE_SKIP_DFCHECK 4        /* Ok to skip DF conflict checks */
 665#define ADD_CACHE_JUST_APPEND 8         /* Append only; tree.c::read_tree() */
 666#define ADD_CACHE_NEW_ONLY 16           /* Do not replace existing ones */
 667#define ADD_CACHE_KEEP_CACHE_TREE 32    /* Do not invalidate cache-tree */
 668extern int add_index_entry(struct index_state *, struct cache_entry *ce, int option);
 669extern void rename_index_entry_at(struct index_state *, int pos, const char *new_name);
 670
 671/* Remove entry, return true if there are more entries to go. */
 672extern int remove_index_entry_at(struct index_state *, int pos);
 673
 674extern void remove_marked_cache_entries(struct index_state *istate);
 675extern int remove_file_from_index(struct index_state *, const char *path);
 676#define ADD_CACHE_VERBOSE 1
 677#define ADD_CACHE_PRETEND 2
 678#define ADD_CACHE_IGNORE_ERRORS 4
 679#define ADD_CACHE_IGNORE_REMOVAL 8
 680#define ADD_CACHE_INTENT 16
 681/*
 682 * These two are used to add the contents of the file at path
 683 * to the index, marking the working tree up-to-date by storing
 684 * the cached stat info in the resulting cache entry.  A caller
 685 * that has already run lstat(2) on the path can call
 686 * add_to_index(), and all others can call add_file_to_index();
 687 * the latter will do necessary lstat(2) internally before
 688 * calling the former.
 689 */
 690extern int add_to_index(struct index_state *, const char *path, struct stat *, int flags);
 691extern int add_file_to_index(struct index_state *, const char *path, int flags);
 692
 693extern struct cache_entry *make_cache_entry(unsigned int mode, const unsigned char *sha1, const char *path, int stage, unsigned int refresh_options);
 694extern int chmod_index_entry(struct index_state *, struct cache_entry *ce, char flip);
 695extern int ce_same_name(const struct cache_entry *a, const struct cache_entry *b);
 696extern void set_object_name_for_intent_to_add_entry(struct cache_entry *ce);
 697extern int index_name_is_other(const struct index_state *, const char *, int);
 698extern void *read_blob_data_from_index(const struct index_state *, const char *, unsigned long *);
 699
 700/* do stat comparison even if CE_VALID is true */
 701#define CE_MATCH_IGNORE_VALID           01
 702/* do not check the contents but report dirty on racily-clean entries */
 703#define CE_MATCH_RACY_IS_DIRTY          02
 704/* do stat comparison even if CE_SKIP_WORKTREE is true */
 705#define CE_MATCH_IGNORE_SKIP_WORKTREE   04
 706/* ignore non-existent files during stat update  */
 707#define CE_MATCH_IGNORE_MISSING         0x08
 708/* enable stat refresh */
 709#define CE_MATCH_REFRESH                0x10
 710/* don't refresh_fsmonitor state or do stat comparison even if CE_FSMONITOR_VALID is true */
 711#define CE_MATCH_IGNORE_FSMONITOR 0X20
 712extern int ie_match_stat(struct index_state *, const struct cache_entry *, struct stat *, unsigned int);
 713extern int ie_modified(struct index_state *, const struct cache_entry *, struct stat *, unsigned int);
 714
 715#define HASH_WRITE_OBJECT 1
 716#define HASH_FORMAT_CHECK 2
 717#define HASH_RENORMALIZE  4
 718extern int index_fd(struct object_id *oid, int fd, struct stat *st, enum object_type type, const char *path, unsigned flags);
 719extern int index_path(struct object_id *oid, const char *path, struct stat *st, unsigned flags);
 720
 721/*
 722 * Record to sd the data from st that we use to check whether a file
 723 * might have changed.
 724 */
 725extern void fill_stat_data(struct stat_data *sd, struct stat *st);
 726
 727/*
 728 * Return 0 if st is consistent with a file not having been changed
 729 * since sd was filled.  If there are differences, return a
 730 * combination of MTIME_CHANGED, CTIME_CHANGED, OWNER_CHANGED,
 731 * INODE_CHANGED, and DATA_CHANGED.
 732 */
 733extern int match_stat_data(const struct stat_data *sd, struct stat *st);
 734extern int match_stat_data_racy(const struct index_state *istate,
 735                                const struct stat_data *sd, struct stat *st);
 736
 737extern void fill_stat_cache_info(struct cache_entry *ce, struct stat *st);
 738
 739#define REFRESH_REALLY          0x0001  /* ignore_valid */
 740#define REFRESH_UNMERGED        0x0002  /* allow unmerged */
 741#define REFRESH_QUIET           0x0004  /* be quiet about it */
 742#define REFRESH_IGNORE_MISSING  0x0008  /* ignore non-existent */
 743#define REFRESH_IGNORE_SUBMODULES       0x0010  /* ignore submodules */
 744#define REFRESH_IN_PORCELAIN    0x0020  /* user friendly output, not "needs update" */
 745extern int refresh_index(struct index_state *, unsigned int flags, const struct pathspec *pathspec, char *seen, const char *header_msg);
 746extern struct cache_entry *refresh_cache_entry(struct cache_entry *, unsigned int);
 747
 748/*
 749 * Opportunistically update the index but do not complain if we can't.
 750 * The lockfile is always committed or rolled back.
 751 */
 752extern void update_index_if_able(struct index_state *, struct lock_file *);
 753
 754extern int hold_locked_index(struct lock_file *, int);
 755extern void set_alternate_index_output(const char *);
 756
 757extern int verify_index_checksum;
 758extern int verify_ce_order;
 759
 760/* Environment bits from configuration mechanism */
 761extern int trust_executable_bit;
 762extern int trust_ctime;
 763extern int check_stat;
 764extern int quote_path_fully;
 765extern int has_symlinks;
 766extern int minimum_abbrev, default_abbrev;
 767extern int ignore_case;
 768extern int assume_unchanged;
 769extern int prefer_symlink_refs;
 770extern int warn_ambiguous_refs;
 771extern int warn_on_object_refname_ambiguity;
 772extern const char *apply_default_whitespace;
 773extern const char *apply_default_ignorewhitespace;
 774extern const char *git_attributes_file;
 775extern const char *git_hooks_path;
 776extern int zlib_compression_level;
 777extern int core_compression_level;
 778extern int pack_compression_level;
 779extern size_t packed_git_window_size;
 780extern size_t packed_git_limit;
 781extern size_t delta_base_cache_limit;
 782extern unsigned long big_file_threshold;
 783extern unsigned long pack_size_limit_cfg;
 784
 785/*
 786 * Accessors for the core.sharedrepository config which lazy-load the value
 787 * from the config (if not already set). The "reset" function can be
 788 * used to unset "set" or cached value, meaning that the value will be loaded
 789 * fresh from the config file on the next call to get_shared_repository().
 790 */
 791void set_shared_repository(int value);
 792int get_shared_repository(void);
 793void reset_shared_repository(void);
 794
 795/*
 796 * Do replace refs need to be checked this run?  This variable is
 797 * initialized to true unless --no-replace-object is used or
 798 * $GIT_NO_REPLACE_OBJECTS is set, but is set to false by some
 799 * commands that do not want replace references to be active.  As an
 800 * optimization it is also set to false if replace references have
 801 * been sought but there were none.
 802 */
 803extern int check_replace_refs;
 804extern char *git_replace_ref_base;
 805
 806extern int fsync_object_files;
 807extern int core_preload_index;
 808extern int core_apply_sparse_checkout;
 809extern int precomposed_unicode;
 810extern int protect_hfs;
 811extern int protect_ntfs;
 812extern const char *core_fsmonitor;
 813
 814/*
 815 * Include broken refs in all ref iterations, which will
 816 * generally choke dangerous operations rather than letting
 817 * them silently proceed without taking the broken ref into
 818 * account.
 819 */
 820extern int ref_paranoia;
 821
 822/*
 823 * Returns the boolean value of $GIT_OPTIONAL_LOCKS (or the default value).
 824 */
 825int use_optional_locks(void);
 826
 827/*
 828 * The character that begins a commented line in user-editable file
 829 * that is subject to stripspace.
 830 */
 831extern char comment_line_char;
 832extern int auto_comment_line_char;
 833
 834/* Windows only */
 835enum hide_dotfiles_type {
 836        HIDE_DOTFILES_FALSE = 0,
 837        HIDE_DOTFILES_TRUE,
 838        HIDE_DOTFILES_DOTGITONLY
 839};
 840extern enum hide_dotfiles_type hide_dotfiles;
 841
 842enum log_refs_config {
 843        LOG_REFS_UNSET = -1,
 844        LOG_REFS_NONE = 0,
 845        LOG_REFS_NORMAL,
 846        LOG_REFS_ALWAYS
 847};
 848extern enum log_refs_config log_all_ref_updates;
 849
 850enum branch_track {
 851        BRANCH_TRACK_UNSPECIFIED = -1,
 852        BRANCH_TRACK_NEVER = 0,
 853        BRANCH_TRACK_REMOTE,
 854        BRANCH_TRACK_ALWAYS,
 855        BRANCH_TRACK_EXPLICIT,
 856        BRANCH_TRACK_OVERRIDE
 857};
 858
 859enum rebase_setup_type {
 860        AUTOREBASE_NEVER = 0,
 861        AUTOREBASE_LOCAL,
 862        AUTOREBASE_REMOTE,
 863        AUTOREBASE_ALWAYS
 864};
 865
 866enum push_default_type {
 867        PUSH_DEFAULT_NOTHING = 0,
 868        PUSH_DEFAULT_MATCHING,
 869        PUSH_DEFAULT_SIMPLE,
 870        PUSH_DEFAULT_UPSTREAM,
 871        PUSH_DEFAULT_CURRENT,
 872        PUSH_DEFAULT_UNSPECIFIED
 873};
 874
 875extern enum branch_track git_branch_track;
 876extern enum rebase_setup_type autorebase;
 877extern enum push_default_type push_default;
 878
 879enum object_creation_mode {
 880        OBJECT_CREATION_USES_HARDLINKS = 0,
 881        OBJECT_CREATION_USES_RENAMES = 1
 882};
 883
 884extern enum object_creation_mode object_creation_mode;
 885
 886extern char *notes_ref_name;
 887
 888extern int grafts_replace_parents;
 889
 890/*
 891 * GIT_REPO_VERSION is the version we write by default. The
 892 * _READ variant is the highest number we know how to
 893 * handle.
 894 */
 895#define GIT_REPO_VERSION 0
 896#define GIT_REPO_VERSION_READ 1
 897extern int repository_format_precious_objects;
 898extern char *repository_format_partial_clone;
 899extern const char *core_partial_clone_filter_default;
 900
 901struct repository_format {
 902        int version;
 903        int precious_objects;
 904        char *partial_clone; /* value of extensions.partialclone */
 905        int is_bare;
 906        int hash_algo;
 907        char *work_tree;
 908        struct string_list unknown_extensions;
 909};
 910
 911/*
 912 * Read the repository format characteristics from the config file "path" into
 913 * "format" struct. Returns the numeric version. On error, -1 is returned,
 914 * format->version is set to -1, and all other fields in the struct are
 915 * undefined.
 916 */
 917int read_repository_format(struct repository_format *format, const char *path);
 918
 919/*
 920 * Verify that the repository described by repository_format is something we
 921 * can read. If it is, return 0. Otherwise, return -1, and "err" will describe
 922 * any errors encountered.
 923 */
 924int verify_repository_format(const struct repository_format *format,
 925                             struct strbuf *err);
 926
 927/*
 928 * Check the repository format version in the path found in get_git_dir(),
 929 * and die if it is a version we don't understand. Generally one would
 930 * set_git_dir() before calling this, and use it only for "are we in a valid
 931 * repo?".
 932 */
 933extern void check_repository_format(void);
 934
 935#define MTIME_CHANGED   0x0001
 936#define CTIME_CHANGED   0x0002
 937#define OWNER_CHANGED   0x0004
 938#define MODE_CHANGED    0x0008
 939#define INODE_CHANGED   0x0010
 940#define DATA_CHANGED    0x0020
 941#define TYPE_CHANGED    0x0040
 942
 943/*
 944 * Put in `buf` the name of the file in the local object database that
 945 * would be used to store a loose object with the specified sha1.
 946 */
 947extern void sha1_file_name(struct strbuf *buf, const unsigned char *sha1);
 948
 949/*
 950 * Return an abbreviated sha1 unique within this repository's object database.
 951 * The result will be at least `len` characters long, and will be NUL
 952 * terminated.
 953 *
 954 * The non-`_r` version returns a static buffer which remains valid until 4
 955 * more calls to find_unique_abbrev are made.
 956 *
 957 * The `_r` variant writes to a buffer supplied by the caller, which must be at
 958 * least `GIT_SHA1_HEXSZ + 1` bytes. The return value is the number of bytes
 959 * written (excluding the NUL terminator).
 960 *
 961 * Note that while this version avoids the static buffer, it is not fully
 962 * reentrant, as it calls into other non-reentrant git code.
 963 */
 964extern const char *find_unique_abbrev(const unsigned char *sha1, int len);
 965extern int find_unique_abbrev_r(char *hex, const unsigned char *sha1, int len);
 966
 967extern const unsigned char null_sha1[GIT_MAX_RAWSZ];
 968extern const struct object_id null_oid;
 969
 970static inline int hashcmp(const unsigned char *sha1, const unsigned char *sha2)
 971{
 972        return memcmp(sha1, sha2, GIT_SHA1_RAWSZ);
 973}
 974
 975static inline int oidcmp(const struct object_id *oid1, const struct object_id *oid2)
 976{
 977        return hashcmp(oid1->hash, oid2->hash);
 978}
 979
 980static inline int is_null_sha1(const unsigned char *sha1)
 981{
 982        return !hashcmp(sha1, null_sha1);
 983}
 984
 985static inline int is_null_oid(const struct object_id *oid)
 986{
 987        return !hashcmp(oid->hash, null_sha1);
 988}
 989
 990static inline void hashcpy(unsigned char *sha_dst, const unsigned char *sha_src)
 991{
 992        memcpy(sha_dst, sha_src, GIT_SHA1_RAWSZ);
 993}
 994
 995static inline void oidcpy(struct object_id *dst, const struct object_id *src)
 996{
 997        hashcpy(dst->hash, src->hash);
 998}
 999
1000static inline struct object_id *oiddup(const struct object_id *src)
1001{
1002        struct object_id *dst = xmalloc(sizeof(struct object_id));
1003        oidcpy(dst, src);
1004        return dst;
1005}
1006
1007static inline void hashclr(unsigned char *hash)
1008{
1009        memset(hash, 0, GIT_SHA1_RAWSZ);
1010}
1011
1012static inline void oidclr(struct object_id *oid)
1013{
1014        memset(oid->hash, 0, GIT_MAX_RAWSZ);
1015}
1016
1017
1018#define EMPTY_TREE_SHA1_HEX \
1019        "4b825dc642cb6eb9a060e54bf8d69288fbee4904"
1020#define EMPTY_TREE_SHA1_BIN_LITERAL \
1021         "\x4b\x82\x5d\xc6\x42\xcb\x6e\xb9\xa0\x60" \
1022         "\xe5\x4b\xf8\xd6\x92\x88\xfb\xee\x49\x04"
1023extern const struct object_id empty_tree_oid;
1024#define EMPTY_TREE_SHA1_BIN (empty_tree_oid.hash)
1025
1026#define EMPTY_BLOB_SHA1_HEX \
1027        "e69de29bb2d1d6434b8b29ae775ad8c2e48c5391"
1028#define EMPTY_BLOB_SHA1_BIN_LITERAL \
1029        "\xe6\x9d\xe2\x9b\xb2\xd1\xd6\x43\x4b\x8b" \
1030        "\x29\xae\x77\x5a\xd8\xc2\xe4\x8c\x53\x91"
1031extern const struct object_id empty_blob_oid;
1032
1033static inline int is_empty_blob_sha1(const unsigned char *sha1)
1034{
1035        return !hashcmp(sha1, the_hash_algo->empty_blob->hash);
1036}
1037
1038static inline int is_empty_blob_oid(const struct object_id *oid)
1039{
1040        return !oidcmp(oid, the_hash_algo->empty_blob);
1041}
1042
1043static inline int is_empty_tree_sha1(const unsigned char *sha1)
1044{
1045        return !hashcmp(sha1, the_hash_algo->empty_tree->hash);
1046}
1047
1048static inline int is_empty_tree_oid(const struct object_id *oid)
1049{
1050        return !oidcmp(oid, the_hash_algo->empty_tree);
1051}
1052
1053/* set default permissions by passing mode arguments to open(2) */
1054int git_mkstemps_mode(char *pattern, int suffix_len, int mode);
1055int git_mkstemp_mode(char *pattern, int mode);
1056
1057/*
1058 * NOTE NOTE NOTE!!
1059 *
1060 * PERM_UMASK, OLD_PERM_GROUP and OLD_PERM_EVERYBODY enumerations must
1061 * not be changed. Old repositories have core.sharedrepository written in
1062 * numeric format, and therefore these values are preserved for compatibility
1063 * reasons.
1064 */
1065enum sharedrepo {
1066        PERM_UMASK          = 0,
1067        OLD_PERM_GROUP      = 1,
1068        OLD_PERM_EVERYBODY  = 2,
1069        PERM_GROUP          = 0660,
1070        PERM_EVERYBODY      = 0664
1071};
1072int git_config_perm(const char *var, const char *value);
1073int adjust_shared_perm(const char *path);
1074
1075/*
1076 * Create the directory containing the named path, using care to be
1077 * somewhat safe against races. Return one of the scld_error values to
1078 * indicate success/failure. On error, set errno to describe the
1079 * problem.
1080 *
1081 * SCLD_VANISHED indicates that one of the ancestor directories of the
1082 * path existed at one point during the function call and then
1083 * suddenly vanished, probably because another process pruned the
1084 * directory while we were working.  To be robust against this kind of
1085 * race, callers might want to try invoking the function again when it
1086 * returns SCLD_VANISHED.
1087 *
1088 * safe_create_leading_directories() temporarily changes path while it
1089 * is working but restores it before returning.
1090 * safe_create_leading_directories_const() doesn't modify path, even
1091 * temporarily.
1092 */
1093enum scld_error {
1094        SCLD_OK = 0,
1095        SCLD_FAILED = -1,
1096        SCLD_PERMS = -2,
1097        SCLD_EXISTS = -3,
1098        SCLD_VANISHED = -4
1099};
1100enum scld_error safe_create_leading_directories(char *path);
1101enum scld_error safe_create_leading_directories_const(const char *path);
1102
1103/*
1104 * Callback function for raceproof_create_file(). This function is
1105 * expected to do something that makes dirname(path) permanent despite
1106 * the fact that other processes might be cleaning up empty
1107 * directories at the same time. Usually it will create a file named
1108 * path, but alternatively it could create another file in that
1109 * directory, or even chdir() into that directory. The function should
1110 * return 0 if the action was completed successfully. On error, it
1111 * should return a nonzero result and set errno.
1112 * raceproof_create_file() treats two errno values specially:
1113 *
1114 * - ENOENT -- dirname(path) does not exist. In this case,
1115 *             raceproof_create_file() tries creating dirname(path)
1116 *             (and any parent directories, if necessary) and calls
1117 *             the function again.
1118 *
1119 * - EISDIR -- the file already exists and is a directory. In this
1120 *             case, raceproof_create_file() removes the directory if
1121 *             it is empty (and recursively any empty directories that
1122 *             it contains) and calls the function again.
1123 *
1124 * Any other errno causes raceproof_create_file() to fail with the
1125 * callback's return value and errno.
1126 *
1127 * Obviously, this function should be OK with being called again if it
1128 * fails with ENOENT or EISDIR. In other scenarios it will not be
1129 * called again.
1130 */
1131typedef int create_file_fn(const char *path, void *cb);
1132
1133/*
1134 * Create a file in dirname(path) by calling fn, creating leading
1135 * directories if necessary. Retry a few times in case we are racing
1136 * with another process that is trying to clean up the directory that
1137 * contains path. See the documentation for create_file_fn for more
1138 * details.
1139 *
1140 * Return the value and set the errno that resulted from the most
1141 * recent call of fn. fn is always called at least once, and will be
1142 * called more than once if it returns ENOENT or EISDIR.
1143 */
1144int raceproof_create_file(const char *path, create_file_fn fn, void *cb);
1145
1146int mkdir_in_gitdir(const char *path);
1147extern char *expand_user_path(const char *path, int real_home);
1148const char *enter_repo(const char *path, int strict);
1149static inline int is_absolute_path(const char *path)
1150{
1151        return is_dir_sep(path[0]) || has_dos_drive_prefix(path);
1152}
1153int is_directory(const char *);
1154char *strbuf_realpath(struct strbuf *resolved, const char *path,
1155                      int die_on_error);
1156const char *real_path(const char *path);
1157const char *real_path_if_valid(const char *path);
1158char *real_pathdup(const char *path, int die_on_error);
1159const char *absolute_path(const char *path);
1160char *absolute_pathdup(const char *path);
1161const char *remove_leading_path(const char *in, const char *prefix);
1162const char *relative_path(const char *in, const char *prefix, struct strbuf *sb);
1163int normalize_path_copy_len(char *dst, const char *src, int *prefix_len);
1164int normalize_path_copy(char *dst, const char *src);
1165int longest_ancestor_length(const char *path, struct string_list *prefixes);
1166char *strip_path_suffix(const char *path, const char *suffix);
1167int daemon_avoid_alias(const char *path);
1168extern int is_ntfs_dotgit(const char *name);
1169
1170/*
1171 * Returns true iff "str" could be confused as a command-line option when
1172 * passed to a sub-program like "ssh". Note that this has nothing to do with
1173 * shell-quoting, which should be handled separately; we're assuming here that
1174 * the string makes it verbatim to the sub-program.
1175 */
1176int looks_like_command_line_option(const char *str);
1177
1178/**
1179 * Return a newly allocated string with the evaluation of
1180 * "$XDG_CONFIG_HOME/git/$filename" if $XDG_CONFIG_HOME is non-empty, otherwise
1181 * "$HOME/.config/git/$filename". Return NULL upon error.
1182 */
1183extern char *xdg_config_home(const char *filename);
1184
1185/**
1186 * Return a newly allocated string with the evaluation of
1187 * "$XDG_CACHE_HOME/git/$filename" if $XDG_CACHE_HOME is non-empty, otherwise
1188 * "$HOME/.cache/git/$filename". Return NULL upon error.
1189 */
1190extern char *xdg_cache_home(const char *filename);
1191
1192extern void *read_sha1_file_extended(const unsigned char *sha1,
1193                                     enum object_type *type,
1194                                     unsigned long *size, int lookup_replace);
1195static inline void *read_sha1_file(const unsigned char *sha1, enum object_type *type, unsigned long *size)
1196{
1197        return read_sha1_file_extended(sha1, type, size, 1);
1198}
1199
1200/*
1201 * This internal function is only declared here for the benefit of
1202 * lookup_replace_object().  Please do not call it directly.
1203 */
1204extern const unsigned char *do_lookup_replace_object(const unsigned char *sha1);
1205
1206/*
1207 * If object sha1 should be replaced, return the replacement object's
1208 * name (replaced recursively, if necessary).  The return value is
1209 * either sha1 or a pointer to a permanently-allocated value.  When
1210 * object replacement is suppressed, always return sha1.
1211 */
1212static inline const unsigned char *lookup_replace_object(const unsigned char *sha1)
1213{
1214        if (!check_replace_refs)
1215                return sha1;
1216        return do_lookup_replace_object(sha1);
1217}
1218
1219/* Read and unpack a sha1 file into memory, write memory to a sha1 file */
1220extern int sha1_object_info(const unsigned char *, unsigned long *);
1221
1222extern int hash_object_file(const void *buf, unsigned long len,
1223                            const char *type, struct object_id *oid);
1224
1225extern int write_object_file(const void *buf, unsigned long len,
1226                             const char *type, struct object_id *oid);
1227
1228extern int hash_object_file_literally(const void *buf, unsigned long len,
1229                                      const char *type, struct object_id *oid,
1230                                      unsigned flags);
1231
1232extern int pretend_object_file(void *, unsigned long, enum object_type,
1233                               struct object_id *oid);
1234
1235extern int force_object_loose(const struct object_id *oid, time_t mtime);
1236
1237extern int git_open_cloexec(const char *name, int flags);
1238#define git_open(name) git_open_cloexec(name, O_RDONLY)
1239extern void *map_sha1_file(const unsigned char *sha1, unsigned long *size);
1240extern int unpack_sha1_header(git_zstream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz);
1241extern int parse_sha1_header(const char *hdr, unsigned long *sizep);
1242
1243extern int check_sha1_signature(const unsigned char *sha1, void *buf, unsigned long size, const char *type);
1244
1245extern int finalize_object_file(const char *tmpfile, const char *filename);
1246
1247/*
1248 * Open the loose object at path, check its sha1, and return the contents,
1249 * type, and size. If the object is a blob, then "contents" may return NULL,
1250 * to allow streaming of large blobs.
1251 *
1252 * Returns 0 on success, negative on error (details may be written to stderr).
1253 */
1254int read_loose_object(const char *path,
1255                      const unsigned char *expected_sha1,
1256                      enum object_type *type,
1257                      unsigned long *size,
1258                      void **contents);
1259
1260/*
1261 * Convenience for sha1_object_info_extended() with a NULL struct
1262 * object_info. OBJECT_INFO_SKIP_CACHED is automatically set; pass
1263 * nonzero flags to also set other flags.
1264 */
1265extern int has_sha1_file_with_flags(const unsigned char *sha1, int flags);
1266static inline int has_sha1_file(const unsigned char *sha1)
1267{
1268        return has_sha1_file_with_flags(sha1, 0);
1269}
1270
1271/* Same as the above, except for struct object_id. */
1272extern int has_object_file(const struct object_id *oid);
1273extern int has_object_file_with_flags(const struct object_id *oid, int flags);
1274
1275/*
1276 * Return true iff an alternate object database has a loose object
1277 * with the specified name.  This function does not respect replace
1278 * references.
1279 */
1280extern int has_loose_object_nonlocal(const unsigned char *sha1);
1281
1282extern void assert_sha1_type(const unsigned char *sha1, enum object_type expect);
1283
1284/* Helper to check and "touch" a file */
1285extern int check_and_freshen_file(const char *fn, int freshen);
1286
1287extern const signed char hexval_table[256];
1288static inline unsigned int hexval(unsigned char c)
1289{
1290        return hexval_table[c];
1291}
1292
1293/*
1294 * Convert two consecutive hexadecimal digits into a char.  Return a
1295 * negative value on error.  Don't run over the end of short strings.
1296 */
1297static inline int hex2chr(const char *s)
1298{
1299        unsigned int val = hexval(s[0]);
1300        return (val & ~0xf) ? val : (val << 4) | hexval(s[1]);
1301}
1302
1303/* Convert to/from hex/sha1 representation */
1304#define MINIMUM_ABBREV minimum_abbrev
1305#define DEFAULT_ABBREV default_abbrev
1306
1307/* used when the code does not know or care what the default abbrev is */
1308#define FALLBACK_DEFAULT_ABBREV 7
1309
1310struct object_context {
1311        unsigned char tree[20];
1312        unsigned mode;
1313        /*
1314         * symlink_path is only used by get_tree_entry_follow_symlinks,
1315         * and only for symlinks that point outside the repository.
1316         */
1317        struct strbuf symlink_path;
1318        /*
1319         * If GET_OID_RECORD_PATH is set, this will record path (if any)
1320         * found when resolving the name. The caller is responsible for
1321         * releasing the memory.
1322         */
1323        char *path;
1324};
1325
1326#define GET_OID_QUIETLY           01
1327#define GET_OID_COMMIT            02
1328#define GET_OID_COMMITTISH        04
1329#define GET_OID_TREE             010
1330#define GET_OID_TREEISH          020
1331#define GET_OID_BLOB             040
1332#define GET_OID_FOLLOW_SYMLINKS 0100
1333#define GET_OID_RECORD_PATH     0200
1334#define GET_OID_ONLY_TO_DIE    04000
1335
1336#define GET_OID_DISAMBIGUATORS \
1337        (GET_OID_COMMIT | GET_OID_COMMITTISH | \
1338        GET_OID_TREE | GET_OID_TREEISH | \
1339        GET_OID_BLOB)
1340
1341extern int get_oid(const char *str, struct object_id *oid);
1342extern int get_oid_commit(const char *str, struct object_id *oid);
1343extern int get_oid_committish(const char *str, struct object_id *oid);
1344extern int get_oid_tree(const char *str, struct object_id *oid);
1345extern int get_oid_treeish(const char *str, struct object_id *oid);
1346extern int get_oid_blob(const char *str, struct object_id *oid);
1347extern void maybe_die_on_misspelt_object_name(const char *name, const char *prefix);
1348extern int get_oid_with_context(const char *str, unsigned flags, struct object_id *oid, struct object_context *oc);
1349
1350
1351typedef int each_abbrev_fn(const struct object_id *oid, void *);
1352extern int for_each_abbrev(const char *prefix, each_abbrev_fn, void *);
1353
1354extern int set_disambiguate_hint_config(const char *var, const char *value);
1355
1356/*
1357 * Try to read a SHA1 in hexadecimal format from the 40 characters
1358 * starting at hex.  Write the 20-byte result to sha1 in binary form.
1359 * Return 0 on success.  Reading stops if a NUL is encountered in the
1360 * input, so it is safe to pass this function an arbitrary
1361 * null-terminated string.
1362 */
1363extern int get_sha1_hex(const char *hex, unsigned char *sha1);
1364extern int get_oid_hex(const char *hex, struct object_id *sha1);
1365
1366/*
1367 * Read `len` pairs of hexadecimal digits from `hex` and write the
1368 * values to `binary` as `len` bytes. Return 0 on success, or -1 if
1369 * the input does not consist of hex digits).
1370 */
1371extern int hex_to_bytes(unsigned char *binary, const char *hex, size_t len);
1372
1373/*
1374 * Convert a binary sha1 to its hex equivalent. The `_r` variant is reentrant,
1375 * and writes the NUL-terminated output to the buffer `out`, which must be at
1376 * least `GIT_SHA1_HEXSZ + 1` bytes, and returns a pointer to out for
1377 * convenience.
1378 *
1379 * The non-`_r` variant returns a static buffer, but uses a ring of 4
1380 * buffers, making it safe to make multiple calls for a single statement, like:
1381 *
1382 *   printf("%s -> %s", sha1_to_hex(one), sha1_to_hex(two));
1383 */
1384extern char *sha1_to_hex_r(char *out, const unsigned char *sha1);
1385extern char *oid_to_hex_r(char *out, const struct object_id *oid);
1386extern char *sha1_to_hex(const unsigned char *sha1);    /* static buffer result! */
1387extern char *oid_to_hex(const struct object_id *oid);   /* same static buffer as sha1_to_hex */
1388
1389/*
1390 * Parse a 40-character hexadecimal object ID starting from hex, updating the
1391 * pointer specified by end when parsing stops.  The resulting object ID is
1392 * stored in oid.  Returns 0 on success.  Parsing will stop on the first NUL or
1393 * other invalid character.  end is only updated on success; otherwise, it is
1394 * unmodified.
1395 */
1396extern int parse_oid_hex(const char *hex, struct object_id *oid, const char **end);
1397
1398/*
1399 * This reads short-hand syntax that not only evaluates to a commit
1400 * object name, but also can act as if the end user spelled the name
1401 * of the branch from the command line.
1402 *
1403 * - "@{-N}" finds the name of the Nth previous branch we were on, and
1404 *   places the name of the branch in the given buf and returns the
1405 *   number of characters parsed if successful.
1406 *
1407 * - "<branch>@{upstream}" finds the name of the other ref that
1408 *   <branch> is configured to merge with (missing <branch> defaults
1409 *   to the current branch), and places the name of the branch in the
1410 *   given buf and returns the number of characters parsed if
1411 *   successful.
1412 *
1413 * If the input is not of the accepted format, it returns a negative
1414 * number to signal an error.
1415 *
1416 * If the input was ok but there are not N branch switches in the
1417 * reflog, it returns 0.
1418 *
1419 * If "allowed" is non-zero, it is a treated as a bitfield of allowable
1420 * expansions: local branches ("refs/heads/"), remote branches
1421 * ("refs/remotes/"), or "HEAD". If no "allowed" bits are set, any expansion is
1422 * allowed, even ones to refs outside of those namespaces.
1423 */
1424#define INTERPRET_BRANCH_LOCAL (1<<0)
1425#define INTERPRET_BRANCH_REMOTE (1<<1)
1426#define INTERPRET_BRANCH_HEAD (1<<2)
1427extern int interpret_branch_name(const char *str, int len, struct strbuf *,
1428                                 unsigned allowed);
1429extern int get_oid_mb(const char *str, struct object_id *oid);
1430
1431extern int validate_headref(const char *ref);
1432
1433extern int base_name_compare(const char *name1, int len1, int mode1, const char *name2, int len2, int mode2);
1434extern int df_name_compare(const char *name1, int len1, int mode1, const char *name2, int len2, int mode2);
1435extern int name_compare(const char *name1, size_t len1, const char *name2, size_t len2);
1436extern int cache_name_stage_compare(const char *name1, int len1, int stage1, const char *name2, int len2, int stage2);
1437
1438extern void *read_object_with_reference(const unsigned char *sha1,
1439                                        const char *required_type,
1440                                        unsigned long *size,
1441                                        unsigned char *sha1_ret);
1442
1443extern struct object *peel_to_type(const char *name, int namelen,
1444                                   struct object *o, enum object_type);
1445
1446struct date_mode {
1447        enum date_mode_type {
1448                DATE_NORMAL = 0,
1449                DATE_RELATIVE,
1450                DATE_SHORT,
1451                DATE_ISO8601,
1452                DATE_ISO8601_STRICT,
1453                DATE_RFC2822,
1454                DATE_STRFTIME,
1455                DATE_RAW,
1456                DATE_UNIX
1457        } type;
1458        const char *strftime_fmt;
1459        int local;
1460};
1461
1462/*
1463 * Convenience helper for passing a constant type, like:
1464 *
1465 *   show_date(t, tz, DATE_MODE(NORMAL));
1466 */
1467#define DATE_MODE(t) date_mode_from_type(DATE_##t)
1468struct date_mode *date_mode_from_type(enum date_mode_type type);
1469
1470const char *show_date(timestamp_t time, int timezone, const struct date_mode *mode);
1471void show_date_relative(timestamp_t time, int tz, const struct timeval *now,
1472                        struct strbuf *timebuf);
1473int parse_date(const char *date, struct strbuf *out);
1474int parse_date_basic(const char *date, timestamp_t *timestamp, int *offset);
1475int parse_expiry_date(const char *date, timestamp_t *timestamp);
1476void datestamp(struct strbuf *out);
1477#define approxidate(s) approxidate_careful((s), NULL)
1478timestamp_t approxidate_careful(const char *, int *);
1479timestamp_t approxidate_relative(const char *date, const struct timeval *now);
1480void parse_date_format(const char *format, struct date_mode *mode);
1481int date_overflows(timestamp_t date);
1482
1483#define IDENT_STRICT           1
1484#define IDENT_NO_DATE          2
1485#define IDENT_NO_NAME          4
1486extern const char *git_author_info(int);
1487extern const char *git_committer_info(int);
1488extern const char *fmt_ident(const char *name, const char *email, const char *date_str, int);
1489extern const char *fmt_name(const char *name, const char *email);
1490extern const char *ident_default_name(void);
1491extern const char *ident_default_email(void);
1492extern const char *git_editor(void);
1493extern const char *git_pager(int stdout_is_tty);
1494extern int is_terminal_dumb(void);
1495extern int git_ident_config(const char *, const char *, void *);
1496extern void reset_ident_date(void);
1497
1498struct ident_split {
1499        const char *name_begin;
1500        const char *name_end;
1501        const char *mail_begin;
1502        const char *mail_end;
1503        const char *date_begin;
1504        const char *date_end;
1505        const char *tz_begin;
1506        const char *tz_end;
1507};
1508/*
1509 * Signals an success with 0, but time part of the result may be NULL
1510 * if the input lacks timestamp and zone
1511 */
1512extern int split_ident_line(struct ident_split *, const char *, int);
1513
1514/*
1515 * Like show_date, but pull the timestamp and tz parameters from
1516 * the ident_split. It will also sanity-check the values and produce
1517 * a well-known sentinel date if they appear bogus.
1518 */
1519const char *show_ident_date(const struct ident_split *id,
1520                            const struct date_mode *mode);
1521
1522/*
1523 * Compare split idents for equality or strict ordering. Note that we
1524 * compare only the ident part of the line, ignoring any timestamp.
1525 *
1526 * Because there are two fields, we must choose one as the primary key; we
1527 * currently arbitrarily pick the email.
1528 */
1529extern int ident_cmp(const struct ident_split *, const struct ident_split *);
1530
1531struct checkout {
1532        struct index_state *istate;
1533        const char *base_dir;
1534        int base_dir_len;
1535        struct delayed_checkout *delayed_checkout;
1536        unsigned force:1,
1537                 quiet:1,
1538                 not_new:1,
1539                 refresh_cache:1;
1540};
1541#define CHECKOUT_INIT { NULL, "" }
1542
1543#define TEMPORARY_FILENAME_LENGTH 25
1544extern int checkout_entry(struct cache_entry *ce, const struct checkout *state, char *topath);
1545extern void enable_delayed_checkout(struct checkout *state);
1546extern int finish_delayed_checkout(struct checkout *state);
1547
1548struct cache_def {
1549        struct strbuf path;
1550        int flags;
1551        int track_flags;
1552        int prefix_len_stat_func;
1553};
1554#define CACHE_DEF_INIT { STRBUF_INIT, 0, 0, 0 }
1555static inline void cache_def_clear(struct cache_def *cache)
1556{
1557        strbuf_release(&cache->path);
1558}
1559
1560extern int has_symlink_leading_path(const char *name, int len);
1561extern int threaded_has_symlink_leading_path(struct cache_def *, const char *, int);
1562extern int check_leading_path(const char *name, int len);
1563extern int has_dirs_only_path(const char *name, int len, int prefix_len);
1564extern void schedule_dir_for_removal(const char *name, int len);
1565extern void remove_scheduled_dirs(void);
1566
1567extern struct alternate_object_database {
1568        struct alternate_object_database *next;
1569
1570        /* see alt_scratch_buf() */
1571        struct strbuf scratch;
1572        size_t base_len;
1573
1574        /*
1575         * Used to store the results of readdir(3) calls when searching
1576         * for unique abbreviated hashes.  This cache is never
1577         * invalidated, thus it's racy and not necessarily accurate.
1578         * That's fine for its purpose; don't use it for tasks requiring
1579         * greater accuracy!
1580         */
1581        char loose_objects_subdir_seen[256];
1582        struct oid_array loose_objects_cache;
1583
1584        char path[FLEX_ARRAY];
1585} *alt_odb_list;
1586extern void prepare_alt_odb(void);
1587extern char *compute_alternate_path(const char *path, struct strbuf *err);
1588typedef int alt_odb_fn(struct alternate_object_database *, void *);
1589extern int foreach_alt_odb(alt_odb_fn, void*);
1590
1591/*
1592 * Allocate a "struct alternate_object_database" but do _not_ actually
1593 * add it to the list of alternates.
1594 */
1595struct alternate_object_database *alloc_alt_odb(const char *dir);
1596
1597/*
1598 * Add the directory to the on-disk alternates file; the new entry will also
1599 * take effect in the current process.
1600 */
1601extern void add_to_alternates_file(const char *dir);
1602
1603/*
1604 * Add the directory to the in-memory list of alternates (along with any
1605 * recursive alternates it points to), but do not modify the on-disk alternates
1606 * file.
1607 */
1608extern void add_to_alternates_memory(const char *dir);
1609
1610/*
1611 * Returns a scratch strbuf pre-filled with the alternate object directory,
1612 * including a trailing slash, which can be used to access paths in the
1613 * alternate. Always use this over direct access to alt->scratch, as it
1614 * cleans up any previous use of the scratch buffer.
1615 */
1616extern struct strbuf *alt_scratch_buf(struct alternate_object_database *alt);
1617
1618struct pack_window {
1619        struct pack_window *next;
1620        unsigned char *base;
1621        off_t offset;
1622        size_t len;
1623        unsigned int last_used;
1624        unsigned int inuse_cnt;
1625};
1626
1627extern struct packed_git {
1628        struct packed_git *next;
1629        struct list_head mru;
1630        struct pack_window *windows;
1631        off_t pack_size;
1632        const void *index_data;
1633        size_t index_size;
1634        uint32_t num_objects;
1635        uint32_t num_bad_objects;
1636        unsigned char *bad_object_sha1;
1637        int index_version;
1638        time_t mtime;
1639        int pack_fd;
1640        unsigned pack_local:1,
1641                 pack_keep:1,
1642                 freshened:1,
1643                 do_not_close:1,
1644                 pack_promisor:1;
1645        unsigned char sha1[20];
1646        struct revindex_entry *revindex;
1647        /* something like ".git/objects/pack/xxxxx.pack" */
1648        char pack_name[FLEX_ARRAY]; /* more */
1649} *packed_git;
1650
1651/*
1652 * A most-recently-used ordered version of the packed_git list.
1653 */
1654extern struct list_head packed_git_mru;
1655
1656struct pack_entry {
1657        off_t offset;
1658        unsigned char sha1[20];
1659        struct packed_git *p;
1660};
1661
1662/*
1663 * Create a temporary file rooted in the object database directory, or
1664 * die on failure. The filename is taken from "pattern", which should have the
1665 * usual "XXXXXX" trailer, and the resulting filename is written into the
1666 * "template" buffer. Returns the open descriptor.
1667 */
1668extern int odb_mkstemp(struct strbuf *temp_filename, const char *pattern);
1669
1670/*
1671 * Create a pack .keep file named "name" (which should generally be the output
1672 * of odb_pack_name). Returns a file descriptor opened for writing, or -1 on
1673 * error.
1674 */
1675extern int odb_pack_keep(const char *name);
1676
1677/*
1678 * Iterate over the files in the loose-object parts of the object
1679 * directory "path", triggering the following callbacks:
1680 *
1681 *  - loose_object is called for each loose object we find.
1682 *
1683 *  - loose_cruft is called for any files that do not appear to be
1684 *    loose objects. Note that we only look in the loose object
1685 *    directories "objects/[0-9a-f]{2}/", so we will not report
1686 *    "objects/foobar" as cruft.
1687 *
1688 *  - loose_subdir is called for each top-level hashed subdirectory
1689 *    of the object directory (e.g., "$OBJDIR/f0"). It is called
1690 *    after the objects in the directory are processed.
1691 *
1692 * Any callback that is NULL will be ignored. Callbacks returning non-zero
1693 * will end the iteration.
1694 *
1695 * In the "buf" variant, "path" is a strbuf which will also be used as a
1696 * scratch buffer, but restored to its original contents before
1697 * the function returns.
1698 */
1699typedef int each_loose_object_fn(const struct object_id *oid,
1700                                 const char *path,
1701                                 void *data);
1702typedef int each_loose_cruft_fn(const char *basename,
1703                                const char *path,
1704                                void *data);
1705typedef int each_loose_subdir_fn(unsigned int nr,
1706                                 const char *path,
1707                                 void *data);
1708int for_each_file_in_obj_subdir(unsigned int subdir_nr,
1709                                struct strbuf *path,
1710                                each_loose_object_fn obj_cb,
1711                                each_loose_cruft_fn cruft_cb,
1712                                each_loose_subdir_fn subdir_cb,
1713                                void *data);
1714int for_each_loose_file_in_objdir(const char *path,
1715                                  each_loose_object_fn obj_cb,
1716                                  each_loose_cruft_fn cruft_cb,
1717                                  each_loose_subdir_fn subdir_cb,
1718                                  void *data);
1719int for_each_loose_file_in_objdir_buf(struct strbuf *path,
1720                                      each_loose_object_fn obj_cb,
1721                                      each_loose_cruft_fn cruft_cb,
1722                                      each_loose_subdir_fn subdir_cb,
1723                                      void *data);
1724
1725/*
1726 * Iterate over loose objects in both the local
1727 * repository and any alternates repositories (unless the
1728 * LOCAL_ONLY flag is set).
1729 */
1730#define FOR_EACH_OBJECT_LOCAL_ONLY 0x1
1731extern int for_each_loose_object(each_loose_object_fn, void *, unsigned flags);
1732
1733struct object_info {
1734        /* Request */
1735        enum object_type *typep;
1736        unsigned long *sizep;
1737        off_t *disk_sizep;
1738        unsigned char *delta_base_sha1;
1739        struct strbuf *type_name;
1740        void **contentp;
1741
1742        /* Response */
1743        enum {
1744                OI_CACHED,
1745                OI_LOOSE,
1746                OI_PACKED,
1747                OI_DBCACHED
1748        } whence;
1749        union {
1750                /*
1751                 * struct {
1752                 *      ... Nothing to expose in this case
1753                 * } cached;
1754                 * struct {
1755                 *      ... Nothing to expose in this case
1756                 * } loose;
1757                 */
1758                struct {
1759                        struct packed_git *pack;
1760                        off_t offset;
1761                        unsigned int is_delta;
1762                } packed;
1763        } u;
1764};
1765
1766/*
1767 * Initializer for a "struct object_info" that wants no items. You may
1768 * also memset() the memory to all-zeroes.
1769 */
1770#define OBJECT_INFO_INIT {NULL}
1771
1772/* Invoke lookup_replace_object() on the given hash */
1773#define OBJECT_INFO_LOOKUP_REPLACE 1
1774/* Allow reading from a loose object file of unknown/bogus type */
1775#define OBJECT_INFO_ALLOW_UNKNOWN_TYPE 2
1776/* Do not check cached storage */
1777#define OBJECT_INFO_SKIP_CACHED 4
1778/* Do not retry packed storage after checking packed and loose storage */
1779#define OBJECT_INFO_QUICK 8
1780extern int sha1_object_info_extended(const unsigned char *, struct object_info *, unsigned flags);
1781
1782/*
1783 * Set this to 0 to prevent sha1_object_info_extended() from fetching missing
1784 * blobs. This has a difference only if extensions.partialClone is set.
1785 *
1786 * Its default value is 1.
1787 */
1788extern int fetch_if_missing;
1789
1790/* Dumb servers support */
1791extern int update_server_info(int);
1792
1793extern const char *get_log_output_encoding(void);
1794extern const char *get_commit_output_encoding(void);
1795
1796/*
1797 * This is a hack for test programs like test-dump-untracked-cache to
1798 * ensure that they do not modify the untracked cache when reading it.
1799 * Do not use it otherwise!
1800 */
1801extern int ignore_untracked_cache_config;
1802
1803extern int committer_ident_sufficiently_given(void);
1804extern int author_ident_sufficiently_given(void);
1805
1806extern const char *git_commit_encoding;
1807extern const char *git_log_output_encoding;
1808extern const char *git_mailmap_file;
1809extern const char *git_mailmap_blob;
1810
1811/* IO helper functions */
1812extern void maybe_flush_or_die(FILE *, const char *);
1813__attribute__((format (printf, 2, 3)))
1814extern void fprintf_or_die(FILE *, const char *fmt, ...);
1815
1816#define COPY_READ_ERROR (-2)
1817#define COPY_WRITE_ERROR (-3)
1818extern int copy_fd(int ifd, int ofd);
1819extern int copy_file(const char *dst, const char *src, int mode);
1820extern int copy_file_with_time(const char *dst, const char *src, int mode);
1821
1822extern void write_or_die(int fd, const void *buf, size_t count);
1823extern void fsync_or_die(int fd, const char *);
1824
1825extern ssize_t read_in_full(int fd, void *buf, size_t count);
1826extern ssize_t write_in_full(int fd, const void *buf, size_t count);
1827extern ssize_t pread_in_full(int fd, void *buf, size_t count, off_t offset);
1828
1829static inline ssize_t write_str_in_full(int fd, const char *str)
1830{
1831        return write_in_full(fd, str, strlen(str));
1832}
1833
1834/**
1835 * Open (and truncate) the file at path, write the contents of buf to it,
1836 * and close it. Dies if any errors are encountered.
1837 */
1838extern void write_file_buf(const char *path, const char *buf, size_t len);
1839
1840/**
1841 * Like write_file_buf(), but format the contents into a buffer first.
1842 * Additionally, write_file() will append a newline if one is not already
1843 * present, making it convenient to write text files:
1844 *
1845 *   write_file(path, "counter: %d", ctr);
1846 */
1847__attribute__((format (printf, 2, 3)))
1848extern void write_file(const char *path, const char *fmt, ...);
1849
1850/* pager.c */
1851extern void setup_pager(void);
1852extern int pager_in_use(void);
1853extern int pager_use_color;
1854extern int term_columns(void);
1855extern int decimal_width(uintmax_t);
1856extern int check_pager_config(const char *cmd);
1857extern void prepare_pager_args(struct child_process *, const char *pager);
1858
1859extern const char *editor_program;
1860extern const char *askpass_program;
1861extern const char *excludes_file;
1862
1863/* base85 */
1864int decode_85(char *dst, const char *line, int linelen);
1865void encode_85(char *buf, const unsigned char *data, int bytes);
1866
1867/* alloc.c */
1868extern void *alloc_blob_node(void);
1869extern void *alloc_tree_node(void);
1870extern void *alloc_commit_node(void);
1871extern void *alloc_tag_node(void);
1872extern void *alloc_object_node(void);
1873extern void alloc_report(void);
1874extern unsigned int alloc_commit_index(void);
1875
1876/* pkt-line.c */
1877void packet_trace_identity(const char *prog);
1878
1879/* add */
1880/*
1881 * return 0 if success, 1 - if addition of a file failed and
1882 * ADD_FILES_IGNORE_ERRORS was specified in flags
1883 */
1884int add_files_to_cache(const char *prefix, const struct pathspec *pathspec, int flags);
1885
1886/* diff.c */
1887extern int diff_auto_refresh_index;
1888
1889/* match-trees.c */
1890void shift_tree(const struct object_id *, const struct object_id *, struct object_id *, int);
1891void shift_tree_by(const struct object_id *, const struct object_id *, struct object_id *, const char *);
1892
1893/*
1894 * whitespace rules.
1895 * used by both diff and apply
1896 * last two digits are tab width
1897 */
1898#define WS_BLANK_AT_EOL         0100
1899#define WS_SPACE_BEFORE_TAB     0200
1900#define WS_INDENT_WITH_NON_TAB  0400
1901#define WS_CR_AT_EOL           01000
1902#define WS_BLANK_AT_EOF        02000
1903#define WS_TAB_IN_INDENT       04000
1904#define WS_TRAILING_SPACE      (WS_BLANK_AT_EOL|WS_BLANK_AT_EOF)
1905#define WS_DEFAULT_RULE (WS_TRAILING_SPACE|WS_SPACE_BEFORE_TAB|8)
1906#define WS_TAB_WIDTH_MASK        077
1907/* All WS_* -- when extended, adapt diff.c emit_symbol */
1908#define WS_RULE_MASK           07777
1909extern unsigned whitespace_rule_cfg;
1910extern unsigned whitespace_rule(const char *);
1911extern unsigned parse_whitespace_rule(const char *);
1912extern unsigned ws_check(const char *line, int len, unsigned ws_rule);
1913extern void ws_check_emit(const char *line, int len, unsigned ws_rule, FILE *stream, const char *set, const char *reset, const char *ws);
1914extern char *whitespace_error_string(unsigned ws);
1915extern void ws_fix_copy(struct strbuf *, const char *, int, unsigned, int *);
1916extern int ws_blank_line(const char *line, int len, unsigned ws_rule);
1917#define ws_tab_width(rule)     ((rule) & WS_TAB_WIDTH_MASK)
1918
1919/* ls-files */
1920void overlay_tree_on_index(struct index_state *istate,
1921                           const char *tree_name, const char *prefix);
1922
1923char *alias_lookup(const char *alias);
1924int split_cmdline(char *cmdline, const char ***argv);
1925/* Takes a negative value returned by split_cmdline */
1926const char *split_cmdline_strerror(int cmdline_errno);
1927
1928/* setup.c */
1929struct startup_info {
1930        int have_repository;
1931        const char *prefix;
1932};
1933extern struct startup_info *startup_info;
1934
1935/* merge.c */
1936struct commit_list;
1937int try_merge_command(const char *strategy, size_t xopts_nr,
1938                const char **xopts, struct commit_list *common,
1939                const char *head_arg, struct commit_list *remotes);
1940int checkout_fast_forward(const struct object_id *from,
1941                          const struct object_id *to,
1942                          int overwrite_ignore);
1943
1944
1945int sane_execvp(const char *file, char *const argv[]);
1946
1947/*
1948 * A struct to encapsulate the concept of whether a file has changed
1949 * since we last checked it. This uses criteria similar to those used
1950 * for the index.
1951 */
1952struct stat_validity {
1953        struct stat_data *sd;
1954};
1955
1956void stat_validity_clear(struct stat_validity *sv);
1957
1958/*
1959 * Returns 1 if the path is a regular file (or a symlink to a regular
1960 * file) and matches the saved stat_validity, 0 otherwise.  A missing
1961 * or inaccessible file is considered a match if the struct was just
1962 * initialized, or if the previous update found an inaccessible file.
1963 */
1964int stat_validity_check(struct stat_validity *sv, const char *path);
1965
1966/*
1967 * Update the stat_validity from a file opened at descriptor fd. If
1968 * the file is missing, inaccessible, or not a regular file, then
1969 * future calls to stat_validity_check will match iff one of those
1970 * conditions continues to be true.
1971 */
1972void stat_validity_update(struct stat_validity *sv, int fd);
1973
1974int versioncmp(const char *s1, const char *s2);
1975void sleep_millisec(int millisec);
1976
1977/*
1978 * Create a directory and (if share is nonzero) adjust its permissions
1979 * according to the shared_repository setting. Only use this for
1980 * directories under $GIT_DIR.  Don't use it for working tree
1981 * directories.
1982 */
1983void safe_create_dir(const char *dir, int share);
1984
1985/*
1986 * Should we print an ellipsis after an abbreviated SHA-1 value
1987 * when doing diff-raw output or indicating a detached HEAD?
1988 */
1989extern int print_sha1_ellipsis(void);
1990
1991#endif /* CACHE_H */