cache.h

   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 "pathspec.h"
   8 #include "object.h"
   9 #include "statinfo.h"
  10
  11 /*
  12  * Basic data structures for the directory cache
  13  */
  14
  15 #define CACHE_SIGNATURE 0x44495243      /* "DIRC" */
  16 struct cache_header {
  17         uint32_t hdr_signature;
  18         uint32_t hdr_version;
  19         uint32_t hdr_entries;
  20 };
  21
  22 #define INDEX_FORMAT_LB 2
  23 #define INDEX_FORMAT_UB 4
  24
  25 struct cache_entry {
  26         struct hashmap_entry ent;
  27         struct stat_data ce_stat_data;
  28         unsigned int ce_mode;
  29         unsigned int ce_flags;
  30         unsigned int mem_pool_allocated;
  31         unsigned int ce_namelen;
  32         unsigned int index;     /* for link extension */
  33         struct object_id oid;
  34         char name[FLEX_ARRAY]; /* more */
  35 };
  36
  37 #define CE_STAGEMASK (0x3000)
  38 #define CE_EXTENDED  (0x4000)
  39 #define CE_VALID     (0x8000)
  40 #define CE_STAGESHIFT 12
  41
  42 /*
  43  * Range 0xFFFF0FFF in ce_flags is divided into
  44  * two parts: in-memory flags and on-disk ones.
  45  * Flags in CE_EXTENDED_FLAGS will get saved on-disk
  46  * if you want to save a new flag, add it in
  47  * CE_EXTENDED_FLAGS
  48  *
  49  * In-memory only flags
  50  */
  51 #define CE_UPDATE            (1 << 16)
  52 #define CE_REMOVE            (1 << 17)
  53 #define CE_UPTODATE          (1 << 18)
  54 #define CE_ADDED             (1 << 19)
  55
  56 #define CE_HASHED            (1 << 20)
  57 #define CE_FSMONITOR_VALID   (1 << 21)
  58 #define CE_WT_REMOVE         (1 << 22) /* remove in work directory */
  59 #define CE_CONFLICTED        (1 << 23)
  60
  61 #define CE_UNPACKED          (1 << 24)
  62 #define CE_NEW_SKIP_WORKTREE (1 << 25)
  63
  64 /* used to temporarily mark paths matched by pathspecs */
  65 #define CE_MATCHED           (1 << 26)
  66
  67 #define CE_UPDATE_IN_BASE    (1 << 27)
  68 #define CE_STRIP_NAME        (1 << 28)
  69
  70 /*
  71  * Extended on-disk flags
  72  */
  73 #define CE_INTENT_TO_ADD     (1 << 29)
  74 #define CE_SKIP_WORKTREE     (1 << 30)
  75 /* CE_EXTENDED2 is for future extension */
  76 #define CE_EXTENDED2         (1U << 31)
  77
  78 #define CE_EXTENDED_FLAGS (CE_INTENT_TO_ADD | CE_SKIP_WORKTREE)
  79
  80 /*
  81  * Safeguard to avoid saving wrong flags:
  82  *  - CE_EXTENDED2 won't get saved until its semantic is known
  83  *  - Bits in 0x0000FFFF have been saved in ce_flags already
  84  *  - Bits in 0x003F0000 are currently in-memory flags
  85  */
  86 #if CE_EXTENDED_FLAGS & 0x803FFFFF
  87 #error "CE_EXTENDED_FLAGS out of range"
  88 #endif
  89
  90 /* Forward structure decls */
  91 struct pathspec;
  92 struct tree;
  93
  94 /*
  95  * Copy the sha1 and stat state of a cache entry from one to
  96  * another. But we never change the name, or the hash state!
  97  */
  98 static inline void copy_cache_entry(struct cache_entry *dst,
  99                                     const struct cache_entry *src)
 100 {
 101         unsigned int state = dst->ce_flags & CE_HASHED;
 102         int mem_pool_allocated = dst->mem_pool_allocated;
 103
 104         /* Don't copy hash chain and name */
 105         memcpy(&dst->ce_stat_data, &src->ce_stat_data,
 106                         offsetof(struct cache_entry, name) -
 107                         offsetof(struct cache_entry, ce_stat_data));
 108
 109         /* Restore the hash state */
 110         dst->ce_flags = (dst->ce_flags & ~CE_HASHED) | state;
 111
 112         /* Restore the mem_pool_allocated flag */
 113         dst->mem_pool_allocated = mem_pool_allocated;
 114 }
 115
 116 static inline unsigned create_ce_flags(unsigned stage)
 117 {
 118         return (stage << CE_STAGESHIFT);
 119 }
 120
 121 #define ce_namelen(ce) ((ce)->ce_namelen)
 122 #define ce_size(ce) cache_entry_size(ce_namelen(ce))
 123 #define ce_stage(ce) ((CE_STAGEMASK & (ce)->ce_flags) >> CE_STAGESHIFT)
 124 #define ce_uptodate(ce) ((ce)->ce_flags & CE_UPTODATE)
 125 #define ce_skip_worktree(ce) ((ce)->ce_flags & CE_SKIP_WORKTREE)
 126 #define ce_mark_uptodate(ce) ((ce)->ce_flags |= CE_UPTODATE)
 127 #define ce_intent_to_add(ce) ((ce)->ce_flags & CE_INTENT_TO_ADD)
 128
 129 static inline unsigned int ce_mode_from_stat(const struct cache_entry *ce,
 130                                              unsigned int mode)
 131 {
 132         extern int trust_executable_bit, has_symlinks;
 133         if (!has_symlinks && S_ISREG(mode) &&
 134             ce && S_ISLNK(ce->ce_mode))
 135                 return ce->ce_mode;
 136         if (!trust_executable_bit && S_ISREG(mode)) {
 137                 if (ce && S_ISREG(ce->ce_mode))
 138                         return ce->ce_mode;
 139                 return create_ce_mode(0666);
 140         }
 141         return create_ce_mode(mode);
 142 }
 143 static inline int ce_to_dtype(const struct cache_entry *ce)
 144 {
 145         unsigned ce_mode = ntohl(ce->ce_mode);
 146         if (S_ISREG(ce_mode))
 147                 return DT_REG;
 148         else if (S_ISDIR(ce_mode) || S_ISGITLINK(ce_mode))
 149                 return DT_DIR;
 150         else if (S_ISLNK(ce_mode))
 151                 return DT_LNK;
 152         else
 153                 return DT_UNKNOWN;
 154 }
 155
 156 static inline int ce_path_match(struct index_state *istate,
 157                                 const struct cache_entry *ce,
 158                                 const struct pathspec *pathspec,
 159                                 char *seen)
 160 {
 161         return match_pathspec(istate, pathspec, ce->name, ce_namelen(ce), 0, seen,
 162                               S_ISDIR(ce->ce_mode) || S_ISGITLINK(ce->ce_mode));
 163 }
 164
 165 #define cache_entry_size(len) (offsetof(struct cache_entry,name) + (len) + 1)
 166
 167 #define SOMETHING_CHANGED       (1 << 0) /* unclassified changes go here */
 168 #define CE_ENTRY_CHANGED        (1 << 1)
 169 #define CE_ENTRY_REMOVED        (1 << 2)
 170 #define CE_ENTRY_ADDED          (1 << 3)
 171 #define RESOLVE_UNDO_CHANGED    (1 << 4)
 172 #define CACHE_TREE_CHANGED      (1 << 5)
 173 #define SPLIT_INDEX_ORDERED     (1 << 6)
 174 #define UNTRACKED_CHANGED       (1 << 7)
 175 #define FSMONITOR_CHANGED       (1 << 8)
 176
 177 struct split_index;
 178 struct untracked_cache;
 179 struct progress;
 180 struct pattern_list;
 181
 182 enum sparse_index_mode {
 183         /*
 184          * There are no sparse directories in the index at all.
 185          *
 186          * Repositories that don't use cone-mode sparse-checkout will
 187          * always have their indexes in this mode.
 188          */
 189         INDEX_EXPANDED = 0,
 190
 191         /*
 192          * The index has already been collapsed to sparse directories
 193          * whereever possible.
 194          */
 195         INDEX_COLLAPSED,
 196
 197         /*
 198          * The sparse directories that exist are outside the
 199          * sparse-checkout boundary, but it is possible that some file
 200          * entries could collapse to sparse directory entries.
 201          */
 202         INDEX_PARTIALLY_SPARSE,
 203 };
 204
 205 struct index_state {
 206         struct cache_entry **cache;
 207         unsigned int version;
 208         unsigned int cache_nr, cache_alloc, cache_changed;
 209         struct string_list *resolve_undo;
 210         struct cache_tree *cache_tree;
 211         struct split_index *split_index;
 212         struct cache_time timestamp;
 213         unsigned name_hash_initialized : 1,
 214                  initialized : 1,
 215                  drop_cache_tree : 1,
 216                  updated_workdir : 1,
 217                  updated_skipworktree : 1,
 218                  fsmonitor_has_run_once : 1;
 219         enum sparse_index_mode sparse_index;
 220         struct hashmap name_hash;
 221         struct hashmap dir_hash;
 222         struct object_id oid;
 223         struct untracked_cache *untracked;
 224         char *fsmonitor_last_update;
 225         struct ewah_bitmap *fsmonitor_dirty;
 226         struct mem_pool *ce_mem_pool;
 227         struct progress *progress;
 228         struct repository *repo;
 229         struct pattern_list *sparse_checkout_patterns;
 230 };
 231
 232 /**
 233  * A "struct index_state istate" must be initialized with
 234  * INDEX_STATE_INIT or the corresponding index_state_init().
 235  *
 236  * If the variable won't be used again, use release_index() to free()
 237  * its resources. If it needs to be used again use discard_index(),
 238  * which does the same thing, but will use use index_state_init() at
 239  * the end. The discard_index() will use its own "istate->repo" as the
 240  * "r" argument to index_state_init() in that case.
 241  */
 242 #define INDEX_STATE_INIT(r) { \
 243         .repo = (r), \
 244 }
 245 void index_state_init(struct index_state *istate, struct repository *r);
 246 void release_index(struct index_state *istate);
 247
 248 /* Cache entry creation and cleanup */
 249
 250 /*
 251  * Create cache_entry intended for use in the specified index. Caller
 252  * is responsible for discarding the cache_entry with
 253  * `discard_cache_entry`.
 254  */
 255 struct cache_entry *make_cache_entry(struct index_state *istate,
 256                                      unsigned int mode,
 257                                      const struct object_id *oid,
 258                                      const char *path,
 259                                      int stage,
 260                                      unsigned int refresh_options);
 261
 262 struct cache_entry *make_empty_cache_entry(struct index_state *istate,
 263                                            size_t name_len);
 264
 265 /*
 266  * Create a cache_entry that is not intended to be added to an index. If
 267  * `ce_mem_pool` is not NULL, the entry is allocated within the given memory
 268  * pool. Caller is responsible for discarding "loose" entries with
 269  * `discard_cache_entry()` and the memory pool with
 270  * `mem_pool_discard(ce_mem_pool, should_validate_cache_entries())`.
 271  */
 272 struct cache_entry *make_transient_cache_entry(unsigned int mode,
 273                                                const struct object_id *oid,
 274                                                const char *path,
 275                                                int stage,
 276                                                struct mem_pool *ce_mem_pool);
 277
 278 struct cache_entry *make_empty_transient_cache_entry(size_t len,
 279                                                      struct mem_pool *ce_mem_pool);
 280
 281 /*
 282  * Discard cache entry.
 283  */
 284 void discard_cache_entry(struct cache_entry *ce);
 285
 286 /*
 287  * Check configuration if we should perform extra validation on cache
 288  * entries.
 289  */
 290 int should_validate_cache_entries(void);
 291
 292 /*
 293  * Duplicate a cache_entry. Allocate memory for the new entry from a
 294  * memory_pool. Takes into account cache_entry fields that are meant
 295  * for managing the underlying memory allocation of the cache_entry.
 296  */
 297 struct cache_entry *dup_cache_entry(const struct cache_entry *ce, struct index_state *istate);
 298
 299 /*
 300  * Validate the cache entries in the index.  This is an internal
 301  * consistency check that the cache_entry structs are allocated from
 302  * the expected memory pool.
 303  */
 304 void validate_cache_entries(const struct index_state *istate);
 305
 306 /*
 307  * Bulk prefetch all missing cache entries that are not GITLINKs and that match
 308  * the given predicate. This function should only be called if
 309  * repo_has_promisor_remote() returns true.
 310  */
 311 typedef int (*must_prefetch_predicate)(const struct cache_entry *);
 312 void prefetch_cache_entries(const struct index_state *istate,
 313                             must_prefetch_predicate must_prefetch);
 314
 315 #ifdef USE_THE_INDEX_VARIABLE
 316 extern struct index_state the_index;
 317 #endif
 318
 319 /* Initialize and use the cache information */
 320 struct lock_file;
 321 int do_read_index(struct index_state *istate, const char *path,
 322                   int must_exist); /* for testting only! */
 323 int read_index_from(struct index_state *, const char *path,
 324                     const char *gitdir);
 325 int is_index_unborn(struct index_state *);
 326
 327 /* For use with `write_locked_index()`. */
 328 #define COMMIT_LOCK             (1 << 0)
 329 #define SKIP_IF_UNCHANGED       (1 << 1)
 330
 331 /*
 332  * Write the index while holding an already-taken lock. Close the lock,
 333  * and if `COMMIT_LOCK` is given, commit it.
 334  *
 335  * Unless a split index is in use, write the index into the lockfile.
 336  *
 337  * With a split index, write the shared index to a temporary file,
 338  * adjust its permissions and rename it into place, then write the
 339  * split index to the lockfile. If the temporary file for the shared
 340  * index cannot be created, fall back to the behavior described in
 341  * the previous paragraph.
 342  *
 343  * With `COMMIT_LOCK`, the lock is always committed or rolled back.
 344  * Without it, the lock is closed, but neither committed nor rolled
 345  * back.
 346  *
 347  * If `SKIP_IF_UNCHANGED` is given and the index is unchanged, nothing
 348  * is written (and the lock is rolled back if `COMMIT_LOCK` is given).
 349  */
 350 int write_locked_index(struct index_state *, struct lock_file *lock, unsigned flags);
 351
 352 void discard_index(struct index_state *);
 353 void move_index_extensions(struct index_state *dst, struct index_state *src);
 354 int unmerged_index(const struct index_state *);
 355
 356 /**
 357  * Returns 1 if istate differs from tree, 0 otherwise.  If tree is NULL,
 358  * compares istate to HEAD.  If tree is NULL and on an unborn branch,
 359  * returns 1 if there are entries in istate, 0 otherwise.  If an strbuf is
 360  * provided, the space-separated list of files that differ will be appended
 361  * to it.
 362  */
 363 int repo_index_has_changes(struct repository *repo,
 364                            struct tree *tree,
 365                            struct strbuf *sb);
 366
 367 int verify_path(const char *path, unsigned mode);
 368 int strcmp_offset(const char *s1, const char *s2, size_t *first_change);
 369
 370 /*
 371  * Searches for an entry defined by name and namelen in the given index.
 372  * If the return value is positive (including 0) it is the position of an
 373  * exact match. If the return value is negative, the negated value minus 1
 374  * is the position where the entry would be inserted.
 375  * Example: The current index consists of these files and its stages:
 376  *
 377  *   b#0, d#0, f#1, f#3
 378  *
 379  * index_name_pos(&index, "a", 1) -> -1
 380  * index_name_pos(&index, "b", 1) ->  0
 381  * index_name_pos(&index, "c", 1) -> -2
 382  * index_name_pos(&index, "d", 1) ->  1
 383  * index_name_pos(&index, "e", 1) -> -3
 384  * index_name_pos(&index, "f", 1) -> -3
 385  * index_name_pos(&index, "g", 1) -> -5
 386  */
 387 int index_name_pos(struct index_state *, const char *name, int namelen);
 388
 389 /*
 390  * Like index_name_pos, returns the position of an entry of the given name in
 391  * the index if one exists, otherwise returns a negative value where the negated
 392  * value minus 1 is the position where the index entry would be inserted. Unlike
 393  * index_name_pos, however, a sparse index is not expanded to find an entry
 394  * inside a sparse directory.
 395  */
 396 int index_name_pos_sparse(struct index_state *, const char *name, int namelen);
 397
 398 /*
 399  * Determines whether an entry with the given name exists within the
 400  * given index. The return value is 1 if an exact match is found, otherwise
 401  * it is 0. Note that, unlike index_name_pos, this function does not expand
 402  * the index if it is sparse. If an item exists within the full index but it
 403  * is contained within a sparse directory (and not in the sparse index), 0 is
 404  * returned.
 405  */
 406 int index_entry_exists(struct index_state *, const char *name, int namelen);
 407
 408 /*
 409  * Some functions return the negative complement of an insert position when a
 410  * precise match was not found but a position was found where the entry would
 411  * need to be inserted. This helper protects that logic from any integer
 412  * underflow.
 413  */
 414 static inline int index_pos_to_insert_pos(uintmax_t pos)
 415 {
 416         if (pos > INT_MAX)
 417                 die("overflow: -1 - %"PRIuMAX, pos);
 418         return -1 - (int)pos;
 419 }
 420
 421 #define ADD_CACHE_OK_TO_ADD 1           /* Ok to add */
 422 #define ADD_CACHE_OK_TO_REPLACE 2       /* Ok to replace file/directory */
 423 #define ADD_CACHE_SKIP_DFCHECK 4        /* Ok to skip DF conflict checks */
 424 #define ADD_CACHE_JUST_APPEND 8         /* Append only */
 425 #define ADD_CACHE_NEW_ONLY 16           /* Do not replace existing ones */
 426 #define ADD_CACHE_KEEP_CACHE_TREE 32    /* Do not invalidate cache-tree */
 427 #define ADD_CACHE_RENORMALIZE 64        /* Pass along HASH_RENORMALIZE */
 428 int add_index_entry(struct index_state *, struct cache_entry *ce, int option);
 429 void rename_index_entry_at(struct index_state *, int pos, const char *new_name);
 430
 431 /* Remove entry, return true if there are more entries to go. */
 432 int remove_index_entry_at(struct index_state *, int pos);
 433
 434 void remove_marked_cache_entries(struct index_state *istate, int invalidate);
 435 int remove_file_from_index(struct index_state *, const char *path);
 436 #define ADD_CACHE_VERBOSE 1
 437 #define ADD_CACHE_PRETEND 2
 438 #define ADD_CACHE_IGNORE_ERRORS 4
 439 #define ADD_CACHE_IGNORE_REMOVAL 8
 440 #define ADD_CACHE_INTENT 16
 441 /*
 442  * These two are used to add the contents of the file at path
 443  * to the index, marking the working tree up-to-date by storing
 444  * the cached stat info in the resulting cache entry.  A caller
 445  * that has already run lstat(2) on the path can call
 446  * add_to_index(), and all others can call add_file_to_index();
 447  * the latter will do necessary lstat(2) internally before
 448  * calling the former.
 449  */
 450 int add_to_index(struct index_state *, const char *path, struct stat *, int flags);
 451 int add_file_to_index(struct index_state *, const char *path, int flags);
 452
 453 int chmod_index_entry(struct index_state *, struct cache_entry *ce, char flip);
 454 int ce_same_name(const struct cache_entry *a, const struct cache_entry *b);
 455 void set_object_name_for_intent_to_add_entry(struct cache_entry *ce);
 456 int index_name_is_other(struct index_state *, const char *, int);
 457 void *read_blob_data_from_index(struct index_state *, const char *, unsigned long *);
 458
 459 /* do stat comparison even if CE_VALID is true */
 460 #define CE_MATCH_IGNORE_VALID           01
 461 /* do not check the contents but report dirty on racily-clean entries */
 462 #define CE_MATCH_RACY_IS_DIRTY          02
 463 /* do stat comparison even if CE_SKIP_WORKTREE is true */
 464 #define CE_MATCH_IGNORE_SKIP_WORKTREE   04
 465 /* ignore non-existent files during stat update  */
 466 #define CE_MATCH_IGNORE_MISSING         0x08
 467 /* enable stat refresh */
 468 #define CE_MATCH_REFRESH                0x10
 469 /* don't refresh_fsmonitor state or do stat comparison even if CE_FSMONITOR_VALID is true */
 470 #define CE_MATCH_IGNORE_FSMONITOR 0X20
 471 int is_racy_timestamp(const struct index_state *istate,
 472                       const struct cache_entry *ce);
 473 int has_racy_timestamp(struct index_state *istate);
 474 int ie_match_stat(struct index_state *, const struct cache_entry *, struct stat *, unsigned int);
 475 int ie_modified(struct index_state *, const struct cache_entry *, struct stat *, unsigned int);
 476
 477 int match_stat_data_racy(const struct index_state *istate,
 478                          const struct stat_data *sd, struct stat *st);
 479
 480 void fill_stat_cache_info(struct index_state *istate, struct cache_entry *ce, struct stat *st);
 481
 482 #define REFRESH_REALLY                   (1 << 0) /* ignore_valid */
 483 #define REFRESH_UNMERGED                 (1 << 1) /* allow unmerged */
 484 #define REFRESH_QUIET                    (1 << 2) /* be quiet about it */
 485 #define REFRESH_IGNORE_MISSING           (1 << 3) /* ignore non-existent */
 486 #define REFRESH_IGNORE_SUBMODULES        (1 << 4) /* ignore submodules */
 487 #define REFRESH_IN_PORCELAIN             (1 << 5) /* user friendly output, not "needs update" */
 488 #define REFRESH_PROGRESS                 (1 << 6) /* show progress bar if stderr is tty */
 489 #define REFRESH_IGNORE_SKIP_WORKTREE     (1 << 7) /* ignore skip_worktree entries */
 490 int refresh_index(struct index_state *, unsigned int flags, const struct pathspec *pathspec, char *seen, const char *header_msg);
 491 /*
 492  * Refresh the index and write it to disk.
 493  *
 494  * 'refresh_flags' is passed directly to 'refresh_index()', while
 495  * 'COMMIT_LOCK | write_flags' is passed to 'write_locked_index()', so
 496  * the lockfile is always either committed or rolled back.
 497  *
 498  * If 'gentle' is passed, errors locking the index are ignored.
 499  *
 500  * Return 1 if refreshing the index returns an error, -1 if writing
 501  * the index to disk fails, 0 on success.
 502  *
 503  * Note that if refreshing the index returns an error, we still write
 504  * out the index (unless locking fails).
 505  */
 506 int repo_refresh_and_write_index(struct repository*, unsigned int refresh_flags, unsigned int write_flags, int gentle, const struct pathspec *, char *seen, const char *header_msg);
 507
 508 struct cache_entry *refresh_cache_entry(struct index_state *, struct cache_entry *, unsigned int);
 509
 510 void set_alternate_index_output(const char *);
 511
 512 extern int verify_index_checksum;
 513 extern int verify_ce_order;
 514
 515 int cmp_cache_name_compare(const void *a_, const void *b_);
 516
 517 /* add */
 518 /*
 519  * return 0 if success, 1 - if addition of a file failed and
 520  * ADD_FILES_IGNORE_ERRORS was specified in flags
 521  */
 522 int add_files_to_cache(struct repository *repo, const char *prefix,
 523                        const struct pathspec *pathspec, int include_sparse,
 524                        int flags);
 525
 526 /* ls-files */
 527 void overlay_tree_on_index(struct index_state *istate,
 528                            const char *tree_name, const char *prefix);
 529
 530 /* merge.c */
 531 struct commit_list;
 532 int try_merge_command(struct repository *r,
 533                 const char *strategy, size_t xopts_nr,
 534                 const char **xopts, struct commit_list *common,
 535                 const char *head_arg, struct commit_list *remotes);
 536 int checkout_fast_forward(struct repository *r,
 537                           const struct object_id *from,
 538                           const struct object_id *to,
 539                           int overwrite_ignore);
 540
 541 #endif /* CACHE_H */