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 void preload_index(struct index_state *index,
 322                    const struct pathspec *pathspec,
 323                    unsigned int refresh_flags);
 324 int do_read_index(struct index_state *istate, const char *path,
 325                   int must_exist); /* for testting only! */
 326 int read_index_from(struct index_state *, const char *path,
 327                     const char *gitdir);
 328 int is_index_unborn(struct index_state *);
 329
 330 void ensure_full_index(struct index_state *istate);
 331
 332 /* For use with `write_locked_index()`. */
 333 #define COMMIT_LOCK             (1 << 0)
 334 #define SKIP_IF_UNCHANGED       (1 << 1)
 335
 336 /*
 337  * Write the index while holding an already-taken lock. Close the lock,
 338  * and if `COMMIT_LOCK` is given, commit it.
 339  *
 340  * Unless a split index is in use, write the index into the lockfile.
 341  *
 342  * With a split index, write the shared index to a temporary file,
 343  * adjust its permissions and rename it into place, then write the
 344  * split index to the lockfile. If the temporary file for the shared
 345  * index cannot be created, fall back to the behavior described in
 346  * the previous paragraph.
 347  *
 348  * With `COMMIT_LOCK`, the lock is always committed or rolled back.
 349  * Without it, the lock is closed, but neither committed nor rolled
 350  * back.
 351  *
 352  * If `SKIP_IF_UNCHANGED` is given and the index is unchanged, nothing
 353  * is written (and the lock is rolled back if `COMMIT_LOCK` is given).
 354  */
 355 int write_locked_index(struct index_state *, struct lock_file *lock, unsigned flags);
 356
 357 void discard_index(struct index_state *);
 358 void move_index_extensions(struct index_state *dst, struct index_state *src);
 359 int unmerged_index(const struct index_state *);
 360
 361 /**
 362  * Returns 1 if istate differs from tree, 0 otherwise.  If tree is NULL,
 363  * compares istate to HEAD.  If tree is NULL and on an unborn branch,
 364  * returns 1 if there are entries in istate, 0 otherwise.  If an strbuf is
 365  * provided, the space-separated list of files that differ will be appended
 366  * to it.
 367  */
 368 int repo_index_has_changes(struct repository *repo,
 369                            struct tree *tree,
 370                            struct strbuf *sb);
 371
 372 int verify_path(const char *path, unsigned mode);
 373 int strcmp_offset(const char *s1, const char *s2, size_t *first_change);
 374
 375 /*
 376  * Searches for an entry defined by name and namelen in the given index.
 377  * If the return value is positive (including 0) it is the position of an
 378  * exact match. If the return value is negative, the negated value minus 1
 379  * is the position where the entry would be inserted.
 380  * Example: The current index consists of these files and its stages:
 381  *
 382  *   b#0, d#0, f#1, f#3
 383  *
 384  * index_name_pos(&index, "a", 1) -> -1
 385  * index_name_pos(&index, "b", 1) ->  0
 386  * index_name_pos(&index, "c", 1) -> -2
 387  * index_name_pos(&index, "d", 1) ->  1
 388  * index_name_pos(&index, "e", 1) -> -3
 389  * index_name_pos(&index, "f", 1) -> -3
 390  * index_name_pos(&index, "g", 1) -> -5
 391  */
 392 int index_name_pos(struct index_state *, const char *name, int namelen);
 393
 394 /*
 395  * Like index_name_pos, returns the position of an entry of the given name in
 396  * the index if one exists, otherwise returns a negative value where the negated
 397  * value minus 1 is the position where the index entry would be inserted. Unlike
 398  * index_name_pos, however, a sparse index is not expanded to find an entry
 399  * inside a sparse directory.
 400  */
 401 int index_name_pos_sparse(struct index_state *, const char *name, int namelen);
 402
 403 /*
 404  * Determines whether an entry with the given name exists within the
 405  * given index. The return value is 1 if an exact match is found, otherwise
 406  * it is 0. Note that, unlike index_name_pos, this function does not expand
 407  * the index if it is sparse. If an item exists within the full index but it
 408  * is contained within a sparse directory (and not in the sparse index), 0 is
 409  * returned.
 410  */
 411 int index_entry_exists(struct index_state *, const char *name, int namelen);
 412
 413 /*
 414  * Some functions return the negative complement of an insert position when a
 415  * precise match was not found but a position was found where the entry would
 416  * need to be inserted. This helper protects that logic from any integer
 417  * underflow.
 418  */
 419 static inline int index_pos_to_insert_pos(uintmax_t pos)
 420 {
 421         if (pos > INT_MAX)
 422                 die("overflow: -1 - %"PRIuMAX, pos);
 423         return -1 - (int)pos;
 424 }
 425
 426 #define ADD_CACHE_OK_TO_ADD 1           /* Ok to add */
 427 #define ADD_CACHE_OK_TO_REPLACE 2       /* Ok to replace file/directory */
 428 #define ADD_CACHE_SKIP_DFCHECK 4        /* Ok to skip DF conflict checks */
 429 #define ADD_CACHE_JUST_APPEND 8         /* Append only */
 430 #define ADD_CACHE_NEW_ONLY 16           /* Do not replace existing ones */
 431 #define ADD_CACHE_KEEP_CACHE_TREE 32    /* Do not invalidate cache-tree */
 432 #define ADD_CACHE_RENORMALIZE 64        /* Pass along HASH_RENORMALIZE */
 433 int add_index_entry(struct index_state *, struct cache_entry *ce, int option);
 434 void rename_index_entry_at(struct index_state *, int pos, const char *new_name);
 435
 436 /* Remove entry, return true if there are more entries to go. */
 437 int remove_index_entry_at(struct index_state *, int pos);
 438
 439 void remove_marked_cache_entries(struct index_state *istate, int invalidate);
 440 int remove_file_from_index(struct index_state *, const char *path);
 441 #define ADD_CACHE_VERBOSE 1
 442 #define ADD_CACHE_PRETEND 2
 443 #define ADD_CACHE_IGNORE_ERRORS 4
 444 #define ADD_CACHE_IGNORE_REMOVAL 8
 445 #define ADD_CACHE_INTENT 16
 446 /*
 447  * These two are used to add the contents of the file at path
 448  * to the index, marking the working tree up-to-date by storing
 449  * the cached stat info in the resulting cache entry.  A caller
 450  * that has already run lstat(2) on the path can call
 451  * add_to_index(), and all others can call add_file_to_index();
 452  * the latter will do necessary lstat(2) internally before
 453  * calling the former.
 454  */
 455 int add_to_index(struct index_state *, const char *path, struct stat *, int flags);
 456 int add_file_to_index(struct index_state *, const char *path, int flags);
 457
 458 int chmod_index_entry(struct index_state *, struct cache_entry *ce, char flip);
 459 int ce_same_name(const struct cache_entry *a, const struct cache_entry *b);
 460 void set_object_name_for_intent_to_add_entry(struct cache_entry *ce);
 461 int index_name_is_other(struct index_state *, const char *, int);
 462 void *read_blob_data_from_index(struct index_state *, const char *, unsigned long *);
 463
 464 /* do stat comparison even if CE_VALID is true */
 465 #define CE_MATCH_IGNORE_VALID           01
 466 /* do not check the contents but report dirty on racily-clean entries */
 467 #define CE_MATCH_RACY_IS_DIRTY          02
 468 /* do stat comparison even if CE_SKIP_WORKTREE is true */
 469 #define CE_MATCH_IGNORE_SKIP_WORKTREE   04
 470 /* ignore non-existent files during stat update  */
 471 #define CE_MATCH_IGNORE_MISSING         0x08
 472 /* enable stat refresh */
 473 #define CE_MATCH_REFRESH                0x10
 474 /* don't refresh_fsmonitor state or do stat comparison even if CE_FSMONITOR_VALID is true */
 475 #define CE_MATCH_IGNORE_FSMONITOR 0X20
 476 int is_racy_timestamp(const struct index_state *istate,
 477                       const struct cache_entry *ce);
 478 int has_racy_timestamp(struct index_state *istate);
 479 int ie_match_stat(struct index_state *, const struct cache_entry *, struct stat *, unsigned int);
 480 int ie_modified(struct index_state *, const struct cache_entry *, struct stat *, unsigned int);
 481
 482 int match_stat_data_racy(const struct index_state *istate,
 483                          const struct stat_data *sd, struct stat *st);
 484
 485 void fill_stat_cache_info(struct index_state *istate, struct cache_entry *ce, struct stat *st);
 486
 487 #define REFRESH_REALLY                   (1 << 0) /* ignore_valid */
 488 #define REFRESH_UNMERGED                 (1 << 1) /* allow unmerged */
 489 #define REFRESH_QUIET                    (1 << 2) /* be quiet about it */
 490 #define REFRESH_IGNORE_MISSING           (1 << 3) /* ignore non-existent */
 491 #define REFRESH_IGNORE_SUBMODULES        (1 << 4) /* ignore submodules */
 492 #define REFRESH_IN_PORCELAIN             (1 << 5) /* user friendly output, not "needs update" */
 493 #define REFRESH_PROGRESS                 (1 << 6) /* show progress bar if stderr is tty */
 494 #define REFRESH_IGNORE_SKIP_WORKTREE     (1 << 7) /* ignore skip_worktree entries */
 495 int refresh_index(struct index_state *, unsigned int flags, const struct pathspec *pathspec, char *seen, const char *header_msg);
 496 /*
 497  * Refresh the index and write it to disk.
 498  *
 499  * 'refresh_flags' is passed directly to 'refresh_index()', while
 500  * 'COMMIT_LOCK | write_flags' is passed to 'write_locked_index()', so
 501  * the lockfile is always either committed or rolled back.
 502  *
 503  * If 'gentle' is passed, errors locking the index are ignored.
 504  *
 505  * Return 1 if refreshing the index returns an error, -1 if writing
 506  * the index to disk fails, 0 on success.
 507  *
 508  * Note that if refreshing the index returns an error, we still write
 509  * out the index (unless locking fails).
 510  */
 511 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);
 512
 513 struct cache_entry *refresh_cache_entry(struct index_state *, struct cache_entry *, unsigned int);
 514
 515 void set_alternate_index_output(const char *);
 516
 517 extern int verify_index_checksum;
 518 extern int verify_ce_order;
 519
 520 int cmp_cache_name_compare(const void *a_, const void *b_);
 521
 522 /* add */
 523 /*
 524  * return 0 if success, 1 - if addition of a file failed and
 525  * ADD_FILES_IGNORE_ERRORS was specified in flags
 526  */
 527 int add_files_to_cache(struct repository *repo, const char *prefix,
 528                        const struct pathspec *pathspec, int include_sparse,
 529                        int flags);
 530
 531 /* diff.c */
 532 extern int diff_auto_refresh_index;
 533
 534 /* ls-files */
 535 void overlay_tree_on_index(struct index_state *istate,
 536                            const char *tree_name, const char *prefix);
 537
 538 /* merge.c */
 539 struct commit_list;
 540 int try_merge_command(struct repository *r,
 541                 const char *strategy, size_t xopts_nr,
 542                 const char **xopts, struct commit_list *common,
 543                 const char *head_arg, struct commit_list *remotes);
 544 int checkout_fast_forward(struct repository *r,
 545                           const struct object_id *from,
 546                           const struct object_id *to,
 547                           int overwrite_ignore);
 548
 549 #endif /* CACHE_H */