read-cache.con commit Merge branch 'pw/add-p-single' (60f8b89)
   1/*
   2 * GIT - The information manager from hell
   3 *
   4 * Copyright (C) Linus Torvalds, 2005
   5 */
   6#define NO_THE_INDEX_COMPATIBILITY_MACROS
   7#include "cache.h"
   8#include "config.h"
   9#include "tempfile.h"
  10#include "lockfile.h"
  11#include "cache-tree.h"
  12#include "refs.h"
  13#include "dir.h"
  14#include "tree.h"
  15#include "commit.h"
  16#include "blob.h"
  17#include "resolve-undo.h"
  18#include "strbuf.h"
  19#include "varint.h"
  20#include "split-index.h"
  21#include "utf8.h"
  22#include "fsmonitor.h"
  23
  24/* Mask for the name length in ce_flags in the on-disk index */
  25
  26#define CE_NAMEMASK  (0x0fff)
  27
  28/* Index extensions.
  29 *
  30 * The first letter should be 'A'..'Z' for extensions that are not
  31 * necessary for a correct operation (i.e. optimization data).
  32 * When new extensions are added that _needs_ to be understood in
  33 * order to correctly interpret the index file, pick character that
  34 * is outside the range, to cause the reader to abort.
  35 */
  36
  37#define CACHE_EXT(s) ( (s[0]<<24)|(s[1]<<16)|(s[2]<<8)|(s[3]) )
  38#define CACHE_EXT_TREE 0x54524545       /* "TREE" */
  39#define CACHE_EXT_RESOLVE_UNDO 0x52455543 /* "REUC" */
  40#define CACHE_EXT_LINK 0x6c696e6b         /* "link" */
  41#define CACHE_EXT_UNTRACKED 0x554E5452    /* "UNTR" */
  42#define CACHE_EXT_FSMONITOR 0x46534D4E    /* "FSMN" */
  43
  44/* changes that can be kept in $GIT_DIR/index (basically all extensions) */
  45#define EXTMASK (RESOLVE_UNDO_CHANGED | CACHE_TREE_CHANGED | \
  46                 CE_ENTRY_ADDED | CE_ENTRY_REMOVED | CE_ENTRY_CHANGED | \
  47                 SPLIT_INDEX_ORDERED | UNTRACKED_CHANGED | FSMONITOR_CHANGED)
  48
  49struct index_state the_index;
  50static const char *alternate_index_output;
  51
  52static void set_index_entry(struct index_state *istate, int nr, struct cache_entry *ce)
  53{
  54        istate->cache[nr] = ce;
  55        add_name_hash(istate, ce);
  56}
  57
  58static void replace_index_entry(struct index_state *istate, int nr, struct cache_entry *ce)
  59{
  60        struct cache_entry *old = istate->cache[nr];
  61
  62        replace_index_entry_in_base(istate, old, ce);
  63        remove_name_hash(istate, old);
  64        free(old);
  65        set_index_entry(istate, nr, ce);
  66        ce->ce_flags |= CE_UPDATE_IN_BASE;
  67        mark_fsmonitor_invalid(istate, ce);
  68        istate->cache_changed |= CE_ENTRY_CHANGED;
  69}
  70
  71void rename_index_entry_at(struct index_state *istate, int nr, const char *new_name)
  72{
  73        struct cache_entry *old = istate->cache[nr], *new;
  74        int namelen = strlen(new_name);
  75
  76        new = xmalloc(cache_entry_size(namelen));
  77        copy_cache_entry(new, old);
  78        new->ce_flags &= ~CE_HASHED;
  79        new->ce_namelen = namelen;
  80        new->index = 0;
  81        memcpy(new->name, new_name, namelen + 1);
  82
  83        cache_tree_invalidate_path(istate, old->name);
  84        untracked_cache_remove_from_index(istate, old->name);
  85        remove_index_entry_at(istate, nr);
  86        add_index_entry(istate, new, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
  87}
  88
  89void fill_stat_data(struct stat_data *sd, struct stat *st)
  90{
  91        sd->sd_ctime.sec = (unsigned int)st->st_ctime;
  92        sd->sd_mtime.sec = (unsigned int)st->st_mtime;
  93        sd->sd_ctime.nsec = ST_CTIME_NSEC(*st);
  94        sd->sd_mtime.nsec = ST_MTIME_NSEC(*st);
  95        sd->sd_dev = st->st_dev;
  96        sd->sd_ino = st->st_ino;
  97        sd->sd_uid = st->st_uid;
  98        sd->sd_gid = st->st_gid;
  99        sd->sd_size = st->st_size;
 100}
 101
 102int match_stat_data(const struct stat_data *sd, struct stat *st)
 103{
 104        int changed = 0;
 105
 106        if (sd->sd_mtime.sec != (unsigned int)st->st_mtime)
 107                changed |= MTIME_CHANGED;
 108        if (trust_ctime && check_stat &&
 109            sd->sd_ctime.sec != (unsigned int)st->st_ctime)
 110                changed |= CTIME_CHANGED;
 111
 112#ifdef USE_NSEC
 113        if (check_stat && sd->sd_mtime.nsec != ST_MTIME_NSEC(*st))
 114                changed |= MTIME_CHANGED;
 115        if (trust_ctime && check_stat &&
 116            sd->sd_ctime.nsec != ST_CTIME_NSEC(*st))
 117                changed |= CTIME_CHANGED;
 118#endif
 119
 120        if (check_stat) {
 121                if (sd->sd_uid != (unsigned int) st->st_uid ||
 122                        sd->sd_gid != (unsigned int) st->st_gid)
 123                        changed |= OWNER_CHANGED;
 124                if (sd->sd_ino != (unsigned int) st->st_ino)
 125                        changed |= INODE_CHANGED;
 126        }
 127
 128#ifdef USE_STDEV
 129        /*
 130         * st_dev breaks on network filesystems where different
 131         * clients will have different views of what "device"
 132         * the filesystem is on
 133         */
 134        if (check_stat && sd->sd_dev != (unsigned int) st->st_dev)
 135                        changed |= INODE_CHANGED;
 136#endif
 137
 138        if (sd->sd_size != (unsigned int) st->st_size)
 139                changed |= DATA_CHANGED;
 140
 141        return changed;
 142}
 143
 144/*
 145 * This only updates the "non-critical" parts of the directory
 146 * cache, ie the parts that aren't tracked by GIT, and only used
 147 * to validate the cache.
 148 */
 149void fill_stat_cache_info(struct cache_entry *ce, struct stat *st)
 150{
 151        fill_stat_data(&ce->ce_stat_data, st);
 152
 153        if (assume_unchanged)
 154                ce->ce_flags |= CE_VALID;
 155
 156        if (S_ISREG(st->st_mode)) {
 157                ce_mark_uptodate(ce);
 158                mark_fsmonitor_valid(ce);
 159        }
 160}
 161
 162static int ce_compare_data(const struct cache_entry *ce, struct stat *st)
 163{
 164        int match = -1;
 165        int fd = git_open_cloexec(ce->name, O_RDONLY);
 166
 167        if (fd >= 0) {
 168                struct object_id oid;
 169                if (!index_fd(&oid, fd, st, OBJ_BLOB, ce->name, 0))
 170                        match = oidcmp(&oid, &ce->oid);
 171                /* index_fd() closed the file descriptor already */
 172        }
 173        return match;
 174}
 175
 176static int ce_compare_link(const struct cache_entry *ce, size_t expected_size)
 177{
 178        int match = -1;
 179        void *buffer;
 180        unsigned long size;
 181        enum object_type type;
 182        struct strbuf sb = STRBUF_INIT;
 183
 184        if (strbuf_readlink(&sb, ce->name, expected_size))
 185                return -1;
 186
 187        buffer = read_sha1_file(ce->oid.hash, &type, &size);
 188        if (buffer) {
 189                if (size == sb.len)
 190                        match = memcmp(buffer, sb.buf, size);
 191                free(buffer);
 192        }
 193        strbuf_release(&sb);
 194        return match;
 195}
 196
 197static int ce_compare_gitlink(const struct cache_entry *ce)
 198{
 199        struct object_id oid;
 200
 201        /*
 202         * We don't actually require that the .git directory
 203         * under GITLINK directory be a valid git directory. It
 204         * might even be missing (in case nobody populated that
 205         * sub-project).
 206         *
 207         * If so, we consider it always to match.
 208         */
 209        if (resolve_gitlink_ref(ce->name, "HEAD", &oid) < 0)
 210                return 0;
 211        return oidcmp(&oid, &ce->oid);
 212}
 213
 214static int ce_modified_check_fs(const struct cache_entry *ce, struct stat *st)
 215{
 216        switch (st->st_mode & S_IFMT) {
 217        case S_IFREG:
 218                if (ce_compare_data(ce, st))
 219                        return DATA_CHANGED;
 220                break;
 221        case S_IFLNK:
 222                if (ce_compare_link(ce, xsize_t(st->st_size)))
 223                        return DATA_CHANGED;
 224                break;
 225        case S_IFDIR:
 226                if (S_ISGITLINK(ce->ce_mode))
 227                        return ce_compare_gitlink(ce) ? DATA_CHANGED : 0;
 228                /* else fallthrough */
 229        default:
 230                return TYPE_CHANGED;
 231        }
 232        return 0;
 233}
 234
 235static int ce_match_stat_basic(const struct cache_entry *ce, struct stat *st)
 236{
 237        unsigned int changed = 0;
 238
 239        if (ce->ce_flags & CE_REMOVE)
 240                return MODE_CHANGED | DATA_CHANGED | TYPE_CHANGED;
 241
 242        switch (ce->ce_mode & S_IFMT) {
 243        case S_IFREG:
 244                changed |= !S_ISREG(st->st_mode) ? TYPE_CHANGED : 0;
 245                /* We consider only the owner x bit to be relevant for
 246                 * "mode changes"
 247                 */
 248                if (trust_executable_bit &&
 249                    (0100 & (ce->ce_mode ^ st->st_mode)))
 250                        changed |= MODE_CHANGED;
 251                break;
 252        case S_IFLNK:
 253                if (!S_ISLNK(st->st_mode) &&
 254                    (has_symlinks || !S_ISREG(st->st_mode)))
 255                        changed |= TYPE_CHANGED;
 256                break;
 257        case S_IFGITLINK:
 258                /* We ignore most of the st_xxx fields for gitlinks */
 259                if (!S_ISDIR(st->st_mode))
 260                        changed |= TYPE_CHANGED;
 261                else if (ce_compare_gitlink(ce))
 262                        changed |= DATA_CHANGED;
 263                return changed;
 264        default:
 265                die("internal error: ce_mode is %o", ce->ce_mode);
 266        }
 267
 268        changed |= match_stat_data(&ce->ce_stat_data, st);
 269
 270        /* Racily smudged entry? */
 271        if (!ce->ce_stat_data.sd_size) {
 272                if (!is_empty_blob_sha1(ce->oid.hash))
 273                        changed |= DATA_CHANGED;
 274        }
 275
 276        return changed;
 277}
 278
 279static int is_racy_stat(const struct index_state *istate,
 280                        const struct stat_data *sd)
 281{
 282        return (istate->timestamp.sec &&
 283#ifdef USE_NSEC
 284                 /* nanosecond timestamped files can also be racy! */
 285                (istate->timestamp.sec < sd->sd_mtime.sec ||
 286                 (istate->timestamp.sec == sd->sd_mtime.sec &&
 287                  istate->timestamp.nsec <= sd->sd_mtime.nsec))
 288#else
 289                istate->timestamp.sec <= sd->sd_mtime.sec
 290#endif
 291                );
 292}
 293
 294static int is_racy_timestamp(const struct index_state *istate,
 295                             const struct cache_entry *ce)
 296{
 297        return (!S_ISGITLINK(ce->ce_mode) &&
 298                is_racy_stat(istate, &ce->ce_stat_data));
 299}
 300
 301int match_stat_data_racy(const struct index_state *istate,
 302                         const struct stat_data *sd, struct stat *st)
 303{
 304        if (is_racy_stat(istate, sd))
 305                return MTIME_CHANGED;
 306        return match_stat_data(sd, st);
 307}
 308
 309int ie_match_stat(struct index_state *istate,
 310                  const struct cache_entry *ce, struct stat *st,
 311                  unsigned int options)
 312{
 313        unsigned int changed;
 314        int ignore_valid = options & CE_MATCH_IGNORE_VALID;
 315        int ignore_skip_worktree = options & CE_MATCH_IGNORE_SKIP_WORKTREE;
 316        int assume_racy_is_modified = options & CE_MATCH_RACY_IS_DIRTY;
 317        int ignore_fsmonitor = options & CE_MATCH_IGNORE_FSMONITOR;
 318
 319        if (!ignore_fsmonitor)
 320                refresh_fsmonitor(istate);
 321        /*
 322         * If it's marked as always valid in the index, it's
 323         * valid whatever the checked-out copy says.
 324         *
 325         * skip-worktree has the same effect with higher precedence
 326         */
 327        if (!ignore_skip_worktree && ce_skip_worktree(ce))
 328                return 0;
 329        if (!ignore_valid && (ce->ce_flags & CE_VALID))
 330                return 0;
 331        if (!ignore_fsmonitor && (ce->ce_flags & CE_FSMONITOR_VALID))
 332                return 0;
 333
 334        /*
 335         * Intent-to-add entries have not been added, so the index entry
 336         * by definition never matches what is in the work tree until it
 337         * actually gets added.
 338         */
 339        if (ce_intent_to_add(ce))
 340                return DATA_CHANGED | TYPE_CHANGED | MODE_CHANGED;
 341
 342        changed = ce_match_stat_basic(ce, st);
 343
 344        /*
 345         * Within 1 second of this sequence:
 346         *      echo xyzzy >file && git-update-index --add file
 347         * running this command:
 348         *      echo frotz >file
 349         * would give a falsely clean cache entry.  The mtime and
 350         * length match the cache, and other stat fields do not change.
 351         *
 352         * We could detect this at update-index time (the cache entry
 353         * being registered/updated records the same time as "now")
 354         * and delay the return from git-update-index, but that would
 355         * effectively mean we can make at most one commit per second,
 356         * which is not acceptable.  Instead, we check cache entries
 357         * whose mtime are the same as the index file timestamp more
 358         * carefully than others.
 359         */
 360        if (!changed && is_racy_timestamp(istate, ce)) {
 361                if (assume_racy_is_modified)
 362                        changed |= DATA_CHANGED;
 363                else
 364                        changed |= ce_modified_check_fs(ce, st);
 365        }
 366
 367        return changed;
 368}
 369
 370int ie_modified(struct index_state *istate,
 371                const struct cache_entry *ce,
 372                struct stat *st, unsigned int options)
 373{
 374        int changed, changed_fs;
 375
 376        changed = ie_match_stat(istate, ce, st, options);
 377        if (!changed)
 378                return 0;
 379        /*
 380         * If the mode or type has changed, there's no point in trying
 381         * to refresh the entry - it's not going to match
 382         */
 383        if (changed & (MODE_CHANGED | TYPE_CHANGED))
 384                return changed;
 385
 386        /*
 387         * Immediately after read-tree or update-index --cacheinfo,
 388         * the length field is zero, as we have never even read the
 389         * lstat(2) information once, and we cannot trust DATA_CHANGED
 390         * returned by ie_match_stat() which in turn was returned by
 391         * ce_match_stat_basic() to signal that the filesize of the
 392         * blob changed.  We have to actually go to the filesystem to
 393         * see if the contents match, and if so, should answer "unchanged".
 394         *
 395         * The logic does not apply to gitlinks, as ce_match_stat_basic()
 396         * already has checked the actual HEAD from the filesystem in the
 397         * subproject.  If ie_match_stat() already said it is different,
 398         * then we know it is.
 399         */
 400        if ((changed & DATA_CHANGED) &&
 401            (S_ISGITLINK(ce->ce_mode) || ce->ce_stat_data.sd_size != 0))
 402                return changed;
 403
 404        changed_fs = ce_modified_check_fs(ce, st);
 405        if (changed_fs)
 406                return changed | changed_fs;
 407        return 0;
 408}
 409
 410int base_name_compare(const char *name1, int len1, int mode1,
 411                      const char *name2, int len2, int mode2)
 412{
 413        unsigned char c1, c2;
 414        int len = len1 < len2 ? len1 : len2;
 415        int cmp;
 416
 417        cmp = memcmp(name1, name2, len);
 418        if (cmp)
 419                return cmp;
 420        c1 = name1[len];
 421        c2 = name2[len];
 422        if (!c1 && S_ISDIR(mode1))
 423                c1 = '/';
 424        if (!c2 && S_ISDIR(mode2))
 425                c2 = '/';
 426        return (c1 < c2) ? -1 : (c1 > c2) ? 1 : 0;
 427}
 428
 429/*
 430 * df_name_compare() is identical to base_name_compare(), except it
 431 * compares conflicting directory/file entries as equal. Note that
 432 * while a directory name compares as equal to a regular file, they
 433 * then individually compare _differently_ to a filename that has
 434 * a dot after the basename (because '\0' < '.' < '/').
 435 *
 436 * This is used by routines that want to traverse the git namespace
 437 * but then handle conflicting entries together when possible.
 438 */
 439int df_name_compare(const char *name1, int len1, int mode1,
 440                    const char *name2, int len2, int mode2)
 441{
 442        int len = len1 < len2 ? len1 : len2, cmp;
 443        unsigned char c1, c2;
 444
 445        cmp = memcmp(name1, name2, len);
 446        if (cmp)
 447                return cmp;
 448        /* Directories and files compare equal (same length, same name) */
 449        if (len1 == len2)
 450                return 0;
 451        c1 = name1[len];
 452        if (!c1 && S_ISDIR(mode1))
 453                c1 = '/';
 454        c2 = name2[len];
 455        if (!c2 && S_ISDIR(mode2))
 456                c2 = '/';
 457        if (c1 == '/' && !c2)
 458                return 0;
 459        if (c2 == '/' && !c1)
 460                return 0;
 461        return c1 - c2;
 462}
 463
 464int name_compare(const char *name1, size_t len1, const char *name2, size_t len2)
 465{
 466        size_t min_len = (len1 < len2) ? len1 : len2;
 467        int cmp = memcmp(name1, name2, min_len);
 468        if (cmp)
 469                return cmp;
 470        if (len1 < len2)
 471                return -1;
 472        if (len1 > len2)
 473                return 1;
 474        return 0;
 475}
 476
 477int cache_name_stage_compare(const char *name1, int len1, int stage1, const char *name2, int len2, int stage2)
 478{
 479        int cmp;
 480
 481        cmp = name_compare(name1, len1, name2, len2);
 482        if (cmp)
 483                return cmp;
 484
 485        if (stage1 < stage2)
 486                return -1;
 487        if (stage1 > stage2)
 488                return 1;
 489        return 0;
 490}
 491
 492static int index_name_stage_pos(const struct index_state *istate, const char *name, int namelen, int stage)
 493{
 494        int first, last;
 495
 496        first = 0;
 497        last = istate->cache_nr;
 498        while (last > first) {
 499                int next = (last + first) >> 1;
 500                struct cache_entry *ce = istate->cache[next];
 501                int cmp = cache_name_stage_compare(name, namelen, stage, ce->name, ce_namelen(ce), ce_stage(ce));
 502                if (!cmp)
 503                        return next;
 504                if (cmp < 0) {
 505                        last = next;
 506                        continue;
 507                }
 508                first = next+1;
 509        }
 510        return -first-1;
 511}
 512
 513int index_name_pos(const struct index_state *istate, const char *name, int namelen)
 514{
 515        return index_name_stage_pos(istate, name, namelen, 0);
 516}
 517
 518int remove_index_entry_at(struct index_state *istate, int pos)
 519{
 520        struct cache_entry *ce = istate->cache[pos];
 521
 522        record_resolve_undo(istate, ce);
 523        remove_name_hash(istate, ce);
 524        save_or_free_index_entry(istate, ce);
 525        istate->cache_changed |= CE_ENTRY_REMOVED;
 526        istate->cache_nr--;
 527        if (pos >= istate->cache_nr)
 528                return 0;
 529        MOVE_ARRAY(istate->cache + pos, istate->cache + pos + 1,
 530                   istate->cache_nr - pos);
 531        return 1;
 532}
 533
 534/*
 535 * Remove all cache entries marked for removal, that is where
 536 * CE_REMOVE is set in ce_flags.  This is much more effective than
 537 * calling remove_index_entry_at() for each entry to be removed.
 538 */
 539void remove_marked_cache_entries(struct index_state *istate)
 540{
 541        struct cache_entry **ce_array = istate->cache;
 542        unsigned int i, j;
 543
 544        for (i = j = 0; i < istate->cache_nr; i++) {
 545                if (ce_array[i]->ce_flags & CE_REMOVE) {
 546                        remove_name_hash(istate, ce_array[i]);
 547                        save_or_free_index_entry(istate, ce_array[i]);
 548                }
 549                else
 550                        ce_array[j++] = ce_array[i];
 551        }
 552        if (j == istate->cache_nr)
 553                return;
 554        istate->cache_changed |= CE_ENTRY_REMOVED;
 555        istate->cache_nr = j;
 556}
 557
 558int remove_file_from_index(struct index_state *istate, const char *path)
 559{
 560        int pos = index_name_pos(istate, path, strlen(path));
 561        if (pos < 0)
 562                pos = -pos-1;
 563        cache_tree_invalidate_path(istate, path);
 564        untracked_cache_remove_from_index(istate, path);
 565        while (pos < istate->cache_nr && !strcmp(istate->cache[pos]->name, path))
 566                remove_index_entry_at(istate, pos);
 567        return 0;
 568}
 569
 570static int compare_name(struct cache_entry *ce, const char *path, int namelen)
 571{
 572        return namelen != ce_namelen(ce) || memcmp(path, ce->name, namelen);
 573}
 574
 575static int index_name_pos_also_unmerged(struct index_state *istate,
 576        const char *path, int namelen)
 577{
 578        int pos = index_name_pos(istate, path, namelen);
 579        struct cache_entry *ce;
 580
 581        if (pos >= 0)
 582                return pos;
 583
 584        /* maybe unmerged? */
 585        pos = -1 - pos;
 586        if (pos >= istate->cache_nr ||
 587                        compare_name((ce = istate->cache[pos]), path, namelen))
 588                return -1;
 589
 590        /* order of preference: stage 2, 1, 3 */
 591        if (ce_stage(ce) == 1 && pos + 1 < istate->cache_nr &&
 592                        ce_stage((ce = istate->cache[pos + 1])) == 2 &&
 593                        !compare_name(ce, path, namelen))
 594                pos++;
 595        return pos;
 596}
 597
 598static int different_name(struct cache_entry *ce, struct cache_entry *alias)
 599{
 600        int len = ce_namelen(ce);
 601        return ce_namelen(alias) != len || memcmp(ce->name, alias->name, len);
 602}
 603
 604/*
 605 * If we add a filename that aliases in the cache, we will use the
 606 * name that we already have - but we don't want to update the same
 607 * alias twice, because that implies that there were actually two
 608 * different files with aliasing names!
 609 *
 610 * So we use the CE_ADDED flag to verify that the alias was an old
 611 * one before we accept it as
 612 */
 613static struct cache_entry *create_alias_ce(struct index_state *istate,
 614                                           struct cache_entry *ce,
 615                                           struct cache_entry *alias)
 616{
 617        int len;
 618        struct cache_entry *new;
 619
 620        if (alias->ce_flags & CE_ADDED)
 621                die("Will not add file alias '%s' ('%s' already exists in index)", ce->name, alias->name);
 622
 623        /* Ok, create the new entry using the name of the existing alias */
 624        len = ce_namelen(alias);
 625        new = xcalloc(1, cache_entry_size(len));
 626        memcpy(new->name, alias->name, len);
 627        copy_cache_entry(new, ce);
 628        save_or_free_index_entry(istate, ce);
 629        return new;
 630}
 631
 632void set_object_name_for_intent_to_add_entry(struct cache_entry *ce)
 633{
 634        struct object_id oid;
 635        if (write_object_file("", 0, blob_type, &oid))
 636                die("cannot create an empty blob in the object database");
 637        oidcpy(&ce->oid, &oid);
 638}
 639
 640int add_to_index(struct index_state *istate, const char *path, struct stat *st, int flags)
 641{
 642        int size, namelen, was_same;
 643        mode_t st_mode = st->st_mode;
 644        struct cache_entry *ce, *alias = NULL;
 645        unsigned ce_option = CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE|CE_MATCH_RACY_IS_DIRTY;
 646        int verbose = flags & (ADD_CACHE_VERBOSE | ADD_CACHE_PRETEND);
 647        int pretend = flags & ADD_CACHE_PRETEND;
 648        int intent_only = flags & ADD_CACHE_INTENT;
 649        int add_option = (ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE|
 650                          (intent_only ? ADD_CACHE_NEW_ONLY : 0));
 651        int newflags = HASH_WRITE_OBJECT;
 652
 653        if (flags & HASH_RENORMALIZE)
 654                newflags |= HASH_RENORMALIZE;
 655
 656        if (!S_ISREG(st_mode) && !S_ISLNK(st_mode) && !S_ISDIR(st_mode))
 657                return error("%s: can only add regular files, symbolic links or git-directories", path);
 658
 659        namelen = strlen(path);
 660        if (S_ISDIR(st_mode)) {
 661                while (namelen && path[namelen-1] == '/')
 662                        namelen--;
 663        }
 664        size = cache_entry_size(namelen);
 665        ce = xcalloc(1, size);
 666        memcpy(ce->name, path, namelen);
 667        ce->ce_namelen = namelen;
 668        if (!intent_only)
 669                fill_stat_cache_info(ce, st);
 670        else
 671                ce->ce_flags |= CE_INTENT_TO_ADD;
 672
 673
 674        if (trust_executable_bit && has_symlinks) {
 675                ce->ce_mode = create_ce_mode(st_mode);
 676        } else {
 677                /* If there is an existing entry, pick the mode bits and type
 678                 * from it, otherwise assume unexecutable regular file.
 679                 */
 680                struct cache_entry *ent;
 681                int pos = index_name_pos_also_unmerged(istate, path, namelen);
 682
 683                ent = (0 <= pos) ? istate->cache[pos] : NULL;
 684                ce->ce_mode = ce_mode_from_stat(ent, st_mode);
 685        }
 686
 687        /* When core.ignorecase=true, determine if a directory of the same name but differing
 688         * case already exists within the Git repository.  If it does, ensure the directory
 689         * case of the file being added to the repository matches (is folded into) the existing
 690         * entry's directory case.
 691         */
 692        if (ignore_case) {
 693                adjust_dirname_case(istate, ce->name);
 694        }
 695        if (!(flags & HASH_RENORMALIZE)) {
 696                alias = index_file_exists(istate, ce->name,
 697                                          ce_namelen(ce), ignore_case);
 698                if (alias &&
 699                    !ce_stage(alias) &&
 700                    !ie_match_stat(istate, alias, st, ce_option)) {
 701                        /* Nothing changed, really */
 702                        if (!S_ISGITLINK(alias->ce_mode))
 703                                ce_mark_uptodate(alias);
 704                        alias->ce_flags |= CE_ADDED;
 705
 706                        free(ce);
 707                        return 0;
 708                }
 709        }
 710        if (!intent_only) {
 711                if (index_path(&ce->oid, path, st, newflags)) {
 712                        free(ce);
 713                        return error("unable to index file %s", path);
 714                }
 715        } else
 716                set_object_name_for_intent_to_add_entry(ce);
 717
 718        if (ignore_case && alias && different_name(ce, alias))
 719                ce = create_alias_ce(istate, ce, alias);
 720        ce->ce_flags |= CE_ADDED;
 721
 722        /* It was suspected to be racily clean, but it turns out to be Ok */
 723        was_same = (alias &&
 724                    !ce_stage(alias) &&
 725                    !oidcmp(&alias->oid, &ce->oid) &&
 726                    ce->ce_mode == alias->ce_mode);
 727
 728        if (pretend)
 729                free(ce);
 730        else if (add_index_entry(istate, ce, add_option)) {
 731                free(ce);
 732                return error("unable to add %s to index", path);
 733        }
 734        if (verbose && !was_same)
 735                printf("add '%s'\n", path);
 736        return 0;
 737}
 738
 739int add_file_to_index(struct index_state *istate, const char *path, int flags)
 740{
 741        struct stat st;
 742        if (lstat(path, &st))
 743                die_errno("unable to stat '%s'", path);
 744        return add_to_index(istate, path, &st, flags);
 745}
 746
 747struct cache_entry *make_cache_entry(unsigned int mode,
 748                const unsigned char *sha1, const char *path, int stage,
 749                unsigned int refresh_options)
 750{
 751        int size, len;
 752        struct cache_entry *ce, *ret;
 753
 754        if (!verify_path(path)) {
 755                error("Invalid path '%s'", path);
 756                return NULL;
 757        }
 758
 759        len = strlen(path);
 760        size = cache_entry_size(len);
 761        ce = xcalloc(1, size);
 762
 763        hashcpy(ce->oid.hash, sha1);
 764        memcpy(ce->name, path, len);
 765        ce->ce_flags = create_ce_flags(stage);
 766        ce->ce_namelen = len;
 767        ce->ce_mode = create_ce_mode(mode);
 768
 769        ret = refresh_cache_entry(ce, refresh_options);
 770        if (ret != ce)
 771                free(ce);
 772        return ret;
 773}
 774
 775/*
 776 * Chmod an index entry with either +x or -x.
 777 *
 778 * Returns -1 if the chmod for the particular cache entry failed (if it's
 779 * not a regular file), -2 if an invalid flip argument is passed in, 0
 780 * otherwise.
 781 */
 782int chmod_index_entry(struct index_state *istate, struct cache_entry *ce,
 783                      char flip)
 784{
 785        if (!S_ISREG(ce->ce_mode))
 786                return -1;
 787        switch (flip) {
 788        case '+':
 789                ce->ce_mode |= 0111;
 790                break;
 791        case '-':
 792                ce->ce_mode &= ~0111;
 793                break;
 794        default:
 795                return -2;
 796        }
 797        cache_tree_invalidate_path(istate, ce->name);
 798        ce->ce_flags |= CE_UPDATE_IN_BASE;
 799        mark_fsmonitor_invalid(istate, ce);
 800        istate->cache_changed |= CE_ENTRY_CHANGED;
 801
 802        return 0;
 803}
 804
 805int ce_same_name(const struct cache_entry *a, const struct cache_entry *b)
 806{
 807        int len = ce_namelen(a);
 808        return ce_namelen(b) == len && !memcmp(a->name, b->name, len);
 809}
 810
 811/*
 812 * We fundamentally don't like some paths: we don't want
 813 * dot or dot-dot anywhere, and for obvious reasons don't
 814 * want to recurse into ".git" either.
 815 *
 816 * Also, we don't want double slashes or slashes at the
 817 * end that can make pathnames ambiguous.
 818 */
 819static int verify_dotfile(const char *rest)
 820{
 821        /*
 822         * The first character was '.', but that
 823         * has already been discarded, we now test
 824         * the rest.
 825         */
 826
 827        /* "." is not allowed */
 828        if (*rest == '\0' || is_dir_sep(*rest))
 829                return 0;
 830
 831        switch (*rest) {
 832        /*
 833         * ".git" followed by  NUL or slash is bad. This
 834         * shares the path end test with the ".." case.
 835         */
 836        case 'g':
 837        case 'G':
 838                if (rest[1] != 'i' && rest[1] != 'I')
 839                        break;
 840                if (rest[2] != 't' && rest[2] != 'T')
 841                        break;
 842                rest += 2;
 843        /* fallthrough */
 844        case '.':
 845                if (rest[1] == '\0' || is_dir_sep(rest[1]))
 846                        return 0;
 847        }
 848        return 1;
 849}
 850
 851int verify_path(const char *path)
 852{
 853        char c;
 854
 855        if (has_dos_drive_prefix(path))
 856                return 0;
 857
 858        goto inside;
 859        for (;;) {
 860                if (!c)
 861                        return 1;
 862                if (is_dir_sep(c)) {
 863inside:
 864                        if (protect_hfs && is_hfs_dotgit(path))
 865                                return 0;
 866                        if (protect_ntfs && is_ntfs_dotgit(path))
 867                                return 0;
 868                        c = *path++;
 869                        if ((c == '.' && !verify_dotfile(path)) ||
 870                            is_dir_sep(c) || c == '\0')
 871                                return 0;
 872                }
 873                c = *path++;
 874        }
 875}
 876
 877/*
 878 * Do we have another file that has the beginning components being a
 879 * proper superset of the name we're trying to add?
 880 */
 881static int has_file_name(struct index_state *istate,
 882                         const struct cache_entry *ce, int pos, int ok_to_replace)
 883{
 884        int retval = 0;
 885        int len = ce_namelen(ce);
 886        int stage = ce_stage(ce);
 887        const char *name = ce->name;
 888
 889        while (pos < istate->cache_nr) {
 890                struct cache_entry *p = istate->cache[pos++];
 891
 892                if (len >= ce_namelen(p))
 893                        break;
 894                if (memcmp(name, p->name, len))
 895                        break;
 896                if (ce_stage(p) != stage)
 897                        continue;
 898                if (p->name[len] != '/')
 899                        continue;
 900                if (p->ce_flags & CE_REMOVE)
 901                        continue;
 902                retval = -1;
 903                if (!ok_to_replace)
 904                        break;
 905                remove_index_entry_at(istate, --pos);
 906        }
 907        return retval;
 908}
 909
 910
 911/*
 912 * Like strcmp(), but also return the offset of the first change.
 913 * If strings are equal, return the length.
 914 */
 915int strcmp_offset(const char *s1, const char *s2, size_t *first_change)
 916{
 917        size_t k;
 918
 919        if (!first_change)
 920                return strcmp(s1, s2);
 921
 922        for (k = 0; s1[k] == s2[k]; k++)
 923                if (s1[k] == '\0')
 924                        break;
 925
 926        *first_change = k;
 927        return (unsigned char)s1[k] - (unsigned char)s2[k];
 928}
 929
 930/*
 931 * Do we have another file with a pathname that is a proper
 932 * subset of the name we're trying to add?
 933 *
 934 * That is, is there another file in the index with a path
 935 * that matches a sub-directory in the given entry?
 936 */
 937static int has_dir_name(struct index_state *istate,
 938                        const struct cache_entry *ce, int pos, int ok_to_replace)
 939{
 940        int retval = 0;
 941        int stage = ce_stage(ce);
 942        const char *name = ce->name;
 943        const char *slash = name + ce_namelen(ce);
 944        size_t len_eq_last;
 945        int cmp_last = 0;
 946
 947        /*
 948         * We are frequently called during an iteration on a sorted
 949         * list of pathnames and while building a new index.  Therefore,
 950         * there is a high probability that this entry will eventually
 951         * be appended to the index, rather than inserted in the middle.
 952         * If we can confirm that, we can avoid binary searches on the
 953         * components of the pathname.
 954         *
 955         * Compare the entry's full path with the last path in the index.
 956         */
 957        if (istate->cache_nr > 0) {
 958                cmp_last = strcmp_offset(name,
 959                        istate->cache[istate->cache_nr - 1]->name,
 960                        &len_eq_last);
 961                if (cmp_last > 0) {
 962                        if (len_eq_last == 0) {
 963                                /*
 964                                 * The entry sorts AFTER the last one in the
 965                                 * index and their paths have no common prefix,
 966                                 * so there cannot be a F/D conflict.
 967                                 */
 968                                return retval;
 969                        } else {
 970                                /*
 971                                 * The entry sorts AFTER the last one in the
 972                                 * index, but has a common prefix.  Fall through
 973                                 * to the loop below to disect the entry's path
 974                                 * and see where the difference is.
 975                                 */
 976                        }
 977                } else if (cmp_last == 0) {
 978                        /*
 979                         * The entry exactly matches the last one in the
 980                         * index, but because of multiple stage and CE_REMOVE
 981                         * items, we fall through and let the regular search
 982                         * code handle it.
 983                         */
 984                }
 985        }
 986
 987        for (;;) {
 988                size_t len;
 989
 990                for (;;) {
 991                        if (*--slash == '/')
 992                                break;
 993                        if (slash <= ce->name)
 994                                return retval;
 995                }
 996                len = slash - name;
 997
 998                if (cmp_last > 0) {
 999                        /*
1000                         * (len + 1) is a directory boundary (including
1001                         * the trailing slash).  And since the loop is
1002                         * decrementing "slash", the first iteration is
1003                         * the longest directory prefix; subsequent
1004                         * iterations consider parent directories.
1005                         */
1006
1007                        if (len + 1 <= len_eq_last) {
1008                                /*
1009                                 * The directory prefix (including the trailing
1010                                 * slash) also appears as a prefix in the last
1011                                 * entry, so the remainder cannot collide (because
1012                                 * strcmp said the whole path was greater).
1013                                 *
1014                                 * EQ: last: xxx/A
1015                                 *     this: xxx/B
1016                                 *
1017                                 * LT: last: xxx/file_A
1018                                 *     this: xxx/file_B
1019                                 */
1020                                return retval;
1021                        }
1022
1023                        if (len > len_eq_last) {
1024                                /*
1025                                 * This part of the directory prefix (excluding
1026                                 * the trailing slash) is longer than the known
1027                                 * equal portions, so this sub-directory cannot
1028                                 * collide with a file.
1029                                 *
1030                                 * GT: last: xxxA
1031                                 *     this: xxxB/file
1032                                 */
1033                                return retval;
1034                        }
1035
1036                        if (istate->cache_nr > 0 &&
1037                                ce_namelen(istate->cache[istate->cache_nr - 1]) > len) {
1038                                /*
1039                                 * The directory prefix lines up with part of
1040                                 * a longer file or directory name, but sorts
1041                                 * after it, so this sub-directory cannot
1042                                 * collide with a file.
1043                                 *
1044                                 * last: xxx/yy-file (because '-' sorts before '/')
1045                                 * this: xxx/yy/abc
1046                                 */
1047                                return retval;
1048                        }
1049
1050                        /*
1051                         * This is a possible collision. Fall through and
1052                         * let the regular search code handle it.
1053                         *
1054                         * last: xxx
1055                         * this: xxx/file
1056                         */
1057                }
1058
1059                pos = index_name_stage_pos(istate, name, len, stage);
1060                if (pos >= 0) {
1061                        /*
1062                         * Found one, but not so fast.  This could
1063                         * be a marker that says "I was here, but
1064                         * I am being removed".  Such an entry is
1065                         * not a part of the resulting tree, and
1066                         * it is Ok to have a directory at the same
1067                         * path.
1068                         */
1069                        if (!(istate->cache[pos]->ce_flags & CE_REMOVE)) {
1070                                retval = -1;
1071                                if (!ok_to_replace)
1072                                        break;
1073                                remove_index_entry_at(istate, pos);
1074                                continue;
1075                        }
1076                }
1077                else
1078                        pos = -pos-1;
1079
1080                /*
1081                 * Trivial optimization: if we find an entry that
1082                 * already matches the sub-directory, then we know
1083                 * we're ok, and we can exit.
1084                 */
1085                while (pos < istate->cache_nr) {
1086                        struct cache_entry *p = istate->cache[pos];
1087                        if ((ce_namelen(p) <= len) ||
1088                            (p->name[len] != '/') ||
1089                            memcmp(p->name, name, len))
1090                                break; /* not our subdirectory */
1091                        if (ce_stage(p) == stage && !(p->ce_flags & CE_REMOVE))
1092                                /*
1093                                 * p is at the same stage as our entry, and
1094                                 * is a subdirectory of what we are looking
1095                                 * at, so we cannot have conflicts at our
1096                                 * level or anything shorter.
1097                                 */
1098                                return retval;
1099                        pos++;
1100                }
1101        }
1102        return retval;
1103}
1104
1105/* We may be in a situation where we already have path/file and path
1106 * is being added, or we already have path and path/file is being
1107 * added.  Either one would result in a nonsense tree that has path
1108 * twice when git-write-tree tries to write it out.  Prevent it.
1109 *
1110 * If ok-to-replace is specified, we remove the conflicting entries
1111 * from the cache so the caller should recompute the insert position.
1112 * When this happens, we return non-zero.
1113 */
1114static int check_file_directory_conflict(struct index_state *istate,
1115                                         const struct cache_entry *ce,
1116                                         int pos, int ok_to_replace)
1117{
1118        int retval;
1119
1120        /*
1121         * When ce is an "I am going away" entry, we allow it to be added
1122         */
1123        if (ce->ce_flags & CE_REMOVE)
1124                return 0;
1125
1126        /*
1127         * We check if the path is a sub-path of a subsequent pathname
1128         * first, since removing those will not change the position
1129         * in the array.
1130         */
1131        retval = has_file_name(istate, ce, pos, ok_to_replace);
1132
1133        /*
1134         * Then check if the path might have a clashing sub-directory
1135         * before it.
1136         */
1137        return retval + has_dir_name(istate, ce, pos, ok_to_replace);
1138}
1139
1140static int add_index_entry_with_check(struct index_state *istate, struct cache_entry *ce, int option)
1141{
1142        int pos;
1143        int ok_to_add = option & ADD_CACHE_OK_TO_ADD;
1144        int ok_to_replace = option & ADD_CACHE_OK_TO_REPLACE;
1145        int skip_df_check = option & ADD_CACHE_SKIP_DFCHECK;
1146        int new_only = option & ADD_CACHE_NEW_ONLY;
1147
1148        if (!(option & ADD_CACHE_KEEP_CACHE_TREE))
1149                cache_tree_invalidate_path(istate, ce->name);
1150
1151        /*
1152         * If this entry's path sorts after the last entry in the index,
1153         * we can avoid searching for it.
1154         */
1155        if (istate->cache_nr > 0 &&
1156                strcmp(ce->name, istate->cache[istate->cache_nr - 1]->name) > 0)
1157                pos = -istate->cache_nr - 1;
1158        else
1159                pos = index_name_stage_pos(istate, ce->name, ce_namelen(ce), ce_stage(ce));
1160
1161        /* existing match? Just replace it. */
1162        if (pos >= 0) {
1163                if (!new_only)
1164                        replace_index_entry(istate, pos, ce);
1165                return 0;
1166        }
1167        pos = -pos-1;
1168
1169        if (!(option & ADD_CACHE_KEEP_CACHE_TREE))
1170                untracked_cache_add_to_index(istate, ce->name);
1171
1172        /*
1173         * Inserting a merged entry ("stage 0") into the index
1174         * will always replace all non-merged entries..
1175         */
1176        if (pos < istate->cache_nr && ce_stage(ce) == 0) {
1177                while (ce_same_name(istate->cache[pos], ce)) {
1178                        ok_to_add = 1;
1179                        if (!remove_index_entry_at(istate, pos))
1180                                break;
1181                }
1182        }
1183
1184        if (!ok_to_add)
1185                return -1;
1186        if (!verify_path(ce->name))
1187                return error("Invalid path '%s'", ce->name);
1188
1189        if (!skip_df_check &&
1190            check_file_directory_conflict(istate, ce, pos, ok_to_replace)) {
1191                if (!ok_to_replace)
1192                        return error("'%s' appears as both a file and as a directory",
1193                                     ce->name);
1194                pos = index_name_stage_pos(istate, ce->name, ce_namelen(ce), ce_stage(ce));
1195                pos = -pos-1;
1196        }
1197        return pos + 1;
1198}
1199
1200int add_index_entry(struct index_state *istate, struct cache_entry *ce, int option)
1201{
1202        int pos;
1203
1204        if (option & ADD_CACHE_JUST_APPEND)
1205                pos = istate->cache_nr;
1206        else {
1207                int ret;
1208                ret = add_index_entry_with_check(istate, ce, option);
1209                if (ret <= 0)
1210                        return ret;
1211                pos = ret - 1;
1212        }
1213
1214        /* Make sure the array is big enough .. */
1215        ALLOC_GROW(istate->cache, istate->cache_nr + 1, istate->cache_alloc);
1216
1217        /* Add it in.. */
1218        istate->cache_nr++;
1219        if (istate->cache_nr > pos + 1)
1220                MOVE_ARRAY(istate->cache + pos + 1, istate->cache + pos,
1221                           istate->cache_nr - pos - 1);
1222        set_index_entry(istate, pos, ce);
1223        istate->cache_changed |= CE_ENTRY_ADDED;
1224        return 0;
1225}
1226
1227/*
1228 * "refresh" does not calculate a new sha1 file or bring the
1229 * cache up-to-date for mode/content changes. But what it
1230 * _does_ do is to "re-match" the stat information of a file
1231 * with the cache, so that you can refresh the cache for a
1232 * file that hasn't been changed but where the stat entry is
1233 * out of date.
1234 *
1235 * For example, you'd want to do this after doing a "git-read-tree",
1236 * to link up the stat cache details with the proper files.
1237 */
1238static struct cache_entry *refresh_cache_ent(struct index_state *istate,
1239                                             struct cache_entry *ce,
1240                                             unsigned int options, int *err,
1241                                             int *changed_ret)
1242{
1243        struct stat st;
1244        struct cache_entry *updated;
1245        int changed, size;
1246        int refresh = options & CE_MATCH_REFRESH;
1247        int ignore_valid = options & CE_MATCH_IGNORE_VALID;
1248        int ignore_skip_worktree = options & CE_MATCH_IGNORE_SKIP_WORKTREE;
1249        int ignore_missing = options & CE_MATCH_IGNORE_MISSING;
1250        int ignore_fsmonitor = options & CE_MATCH_IGNORE_FSMONITOR;
1251
1252        if (!refresh || ce_uptodate(ce))
1253                return ce;
1254
1255        if (!ignore_fsmonitor)
1256                refresh_fsmonitor(istate);
1257        /*
1258         * CE_VALID or CE_SKIP_WORKTREE means the user promised us
1259         * that the change to the work tree does not matter and told
1260         * us not to worry.
1261         */
1262        if (!ignore_skip_worktree && ce_skip_worktree(ce)) {
1263                ce_mark_uptodate(ce);
1264                return ce;
1265        }
1266        if (!ignore_valid && (ce->ce_flags & CE_VALID)) {
1267                ce_mark_uptodate(ce);
1268                return ce;
1269        }
1270        if (!ignore_fsmonitor && (ce->ce_flags & CE_FSMONITOR_VALID)) {
1271                ce_mark_uptodate(ce);
1272                return ce;
1273        }
1274
1275        if (has_symlink_leading_path(ce->name, ce_namelen(ce))) {
1276                if (ignore_missing)
1277                        return ce;
1278                if (err)
1279                        *err = ENOENT;
1280                return NULL;
1281        }
1282
1283        if (lstat(ce->name, &st) < 0) {
1284                if (ignore_missing && errno == ENOENT)
1285                        return ce;
1286                if (err)
1287                        *err = errno;
1288                return NULL;
1289        }
1290
1291        changed = ie_match_stat(istate, ce, &st, options);
1292        if (changed_ret)
1293                *changed_ret = changed;
1294        if (!changed) {
1295                /*
1296                 * The path is unchanged.  If we were told to ignore
1297                 * valid bit, then we did the actual stat check and
1298                 * found that the entry is unmodified.  If the entry
1299                 * is not marked VALID, this is the place to mark it
1300                 * valid again, under "assume unchanged" mode.
1301                 */
1302                if (ignore_valid && assume_unchanged &&
1303                    !(ce->ce_flags & CE_VALID))
1304                        ; /* mark this one VALID again */
1305                else {
1306                        /*
1307                         * We do not mark the index itself "modified"
1308                         * because CE_UPTODATE flag is in-core only;
1309                         * we are not going to write this change out.
1310                         */
1311                        if (!S_ISGITLINK(ce->ce_mode)) {
1312                                ce_mark_uptodate(ce);
1313                                mark_fsmonitor_valid(ce);
1314                        }
1315                        return ce;
1316                }
1317        }
1318
1319        if (ie_modified(istate, ce, &st, options)) {
1320                if (err)
1321                        *err = EINVAL;
1322                return NULL;
1323        }
1324
1325        size = ce_size(ce);
1326        updated = xmalloc(size);
1327        memcpy(updated, ce, size);
1328        fill_stat_cache_info(updated, &st);
1329        /*
1330         * If ignore_valid is not set, we should leave CE_VALID bit
1331         * alone.  Otherwise, paths marked with --no-assume-unchanged
1332         * (i.e. things to be edited) will reacquire CE_VALID bit
1333         * automatically, which is not really what we want.
1334         */
1335        if (!ignore_valid && assume_unchanged &&
1336            !(ce->ce_flags & CE_VALID))
1337                updated->ce_flags &= ~CE_VALID;
1338
1339        /* istate->cache_changed is updated in the caller */
1340        return updated;
1341}
1342
1343static void show_file(const char * fmt, const char * name, int in_porcelain,
1344                      int * first, const char *header_msg)
1345{
1346        if (in_porcelain && *first && header_msg) {
1347                printf("%s\n", header_msg);
1348                *first = 0;
1349        }
1350        printf(fmt, name);
1351}
1352
1353int refresh_index(struct index_state *istate, unsigned int flags,
1354                  const struct pathspec *pathspec,
1355                  char *seen, const char *header_msg)
1356{
1357        int i;
1358        int has_errors = 0;
1359        int really = (flags & REFRESH_REALLY) != 0;
1360        int allow_unmerged = (flags & REFRESH_UNMERGED) != 0;
1361        int quiet = (flags & REFRESH_QUIET) != 0;
1362        int not_new = (flags & REFRESH_IGNORE_MISSING) != 0;
1363        int ignore_submodules = (flags & REFRESH_IGNORE_SUBMODULES) != 0;
1364        int first = 1;
1365        int in_porcelain = (flags & REFRESH_IN_PORCELAIN);
1366        unsigned int options = (CE_MATCH_REFRESH |
1367                                (really ? CE_MATCH_IGNORE_VALID : 0) |
1368                                (not_new ? CE_MATCH_IGNORE_MISSING : 0));
1369        const char *modified_fmt;
1370        const char *deleted_fmt;
1371        const char *typechange_fmt;
1372        const char *added_fmt;
1373        const char *unmerged_fmt;
1374        uint64_t start = getnanotime();
1375
1376        modified_fmt = (in_porcelain ? "M\t%s\n" : "%s: needs update\n");
1377        deleted_fmt = (in_porcelain ? "D\t%s\n" : "%s: needs update\n");
1378        typechange_fmt = (in_porcelain ? "T\t%s\n" : "%s needs update\n");
1379        added_fmt = (in_porcelain ? "A\t%s\n" : "%s needs update\n");
1380        unmerged_fmt = (in_porcelain ? "U\t%s\n" : "%s: needs merge\n");
1381        for (i = 0; i < istate->cache_nr; i++) {
1382                struct cache_entry *ce, *new;
1383                int cache_errno = 0;
1384                int changed = 0;
1385                int filtered = 0;
1386
1387                ce = istate->cache[i];
1388                if (ignore_submodules && S_ISGITLINK(ce->ce_mode))
1389                        continue;
1390
1391                if (pathspec && !ce_path_match(ce, pathspec, seen))
1392                        filtered = 1;
1393
1394                if (ce_stage(ce)) {
1395                        while ((i < istate->cache_nr) &&
1396                               ! strcmp(istate->cache[i]->name, ce->name))
1397                                i++;
1398                        i--;
1399                        if (allow_unmerged)
1400                                continue;
1401                        if (!filtered)
1402                                show_file(unmerged_fmt, ce->name, in_porcelain,
1403                                          &first, header_msg);
1404                        has_errors = 1;
1405                        continue;
1406                }
1407
1408                if (filtered)
1409                        continue;
1410
1411                new = refresh_cache_ent(istate, ce, options, &cache_errno, &changed);
1412                if (new == ce)
1413                        continue;
1414                if (!new) {
1415                        const char *fmt;
1416
1417                        if (really && cache_errno == EINVAL) {
1418                                /* If we are doing --really-refresh that
1419                                 * means the index is not valid anymore.
1420                                 */
1421                                ce->ce_flags &= ~CE_VALID;
1422                                ce->ce_flags |= CE_UPDATE_IN_BASE;
1423                                mark_fsmonitor_invalid(istate, ce);
1424                                istate->cache_changed |= CE_ENTRY_CHANGED;
1425                        }
1426                        if (quiet)
1427                                continue;
1428
1429                        if (cache_errno == ENOENT)
1430                                fmt = deleted_fmt;
1431                        else if (ce_intent_to_add(ce))
1432                                fmt = added_fmt; /* must be before other checks */
1433                        else if (changed & TYPE_CHANGED)
1434                                fmt = typechange_fmt;
1435                        else
1436                                fmt = modified_fmt;
1437                        show_file(fmt,
1438                                  ce->name, in_porcelain, &first, header_msg);
1439                        has_errors = 1;
1440                        continue;
1441                }
1442
1443                replace_index_entry(istate, i, new);
1444        }
1445        trace_performance_since(start, "refresh index");
1446        return has_errors;
1447}
1448
1449struct cache_entry *refresh_cache_entry(struct cache_entry *ce,
1450                                               unsigned int options)
1451{
1452        return refresh_cache_ent(&the_index, ce, options, NULL, NULL);
1453}
1454
1455
1456/*****************************************************************
1457 * Index File I/O
1458 *****************************************************************/
1459
1460#define INDEX_FORMAT_DEFAULT 3
1461
1462static unsigned int get_index_format_default(void)
1463{
1464        char *envversion = getenv("GIT_INDEX_VERSION");
1465        char *endp;
1466        int value;
1467        unsigned int version = INDEX_FORMAT_DEFAULT;
1468
1469        if (!envversion) {
1470                if (!git_config_get_int("index.version", &value))
1471                        version = value;
1472                if (version < INDEX_FORMAT_LB || INDEX_FORMAT_UB < version) {
1473                        warning(_("index.version set, but the value is invalid.\n"
1474                                  "Using version %i"), INDEX_FORMAT_DEFAULT);
1475                        return INDEX_FORMAT_DEFAULT;
1476                }
1477                return version;
1478        }
1479
1480        version = strtoul(envversion, &endp, 10);
1481        if (*endp ||
1482            version < INDEX_FORMAT_LB || INDEX_FORMAT_UB < version) {
1483                warning(_("GIT_INDEX_VERSION set, but the value is invalid.\n"
1484                          "Using version %i"), INDEX_FORMAT_DEFAULT);
1485                version = INDEX_FORMAT_DEFAULT;
1486        }
1487        return version;
1488}
1489
1490/*
1491 * dev/ino/uid/gid/size are also just tracked to the low 32 bits
1492 * Again - this is just a (very strong in practice) heuristic that
1493 * the inode hasn't changed.
1494 *
1495 * We save the fields in big-endian order to allow using the
1496 * index file over NFS transparently.
1497 */
1498struct ondisk_cache_entry {
1499        struct cache_time ctime;
1500        struct cache_time mtime;
1501        uint32_t dev;
1502        uint32_t ino;
1503        uint32_t mode;
1504        uint32_t uid;
1505        uint32_t gid;
1506        uint32_t size;
1507        unsigned char sha1[20];
1508        uint16_t flags;
1509        char name[FLEX_ARRAY]; /* more */
1510};
1511
1512/*
1513 * This struct is used when CE_EXTENDED bit is 1
1514 * The struct must match ondisk_cache_entry exactly from
1515 * ctime till flags
1516 */
1517struct ondisk_cache_entry_extended {
1518        struct cache_time ctime;
1519        struct cache_time mtime;
1520        uint32_t dev;
1521        uint32_t ino;
1522        uint32_t mode;
1523        uint32_t uid;
1524        uint32_t gid;
1525        uint32_t size;
1526        unsigned char sha1[20];
1527        uint16_t flags;
1528        uint16_t flags2;
1529        char name[FLEX_ARRAY]; /* more */
1530};
1531
1532/* These are only used for v3 or lower */
1533#define align_padding_size(size, len) ((size + (len) + 8) & ~7) - (size + len)
1534#define align_flex_name(STRUCT,len) ((offsetof(struct STRUCT,name) + (len) + 8) & ~7)
1535#define ondisk_cache_entry_size(len) align_flex_name(ondisk_cache_entry,len)
1536#define ondisk_cache_entry_extended_size(len) align_flex_name(ondisk_cache_entry_extended,len)
1537#define ondisk_ce_size(ce) (((ce)->ce_flags & CE_EXTENDED) ? \
1538                            ondisk_cache_entry_extended_size(ce_namelen(ce)) : \
1539                            ondisk_cache_entry_size(ce_namelen(ce)))
1540
1541/* Allow fsck to force verification of the index checksum. */
1542int verify_index_checksum;
1543
1544/* Allow fsck to force verification of the cache entry order. */
1545int verify_ce_order;
1546
1547static int verify_hdr(struct cache_header *hdr, unsigned long size)
1548{
1549        git_hash_ctx c;
1550        unsigned char hash[GIT_MAX_RAWSZ];
1551        int hdr_version;
1552
1553        if (hdr->hdr_signature != htonl(CACHE_SIGNATURE))
1554                return error("bad signature");
1555        hdr_version = ntohl(hdr->hdr_version);
1556        if (hdr_version < INDEX_FORMAT_LB || INDEX_FORMAT_UB < hdr_version)
1557                return error("bad index version %d", hdr_version);
1558
1559        if (!verify_index_checksum)
1560                return 0;
1561
1562        the_hash_algo->init_fn(&c);
1563        the_hash_algo->update_fn(&c, hdr, size - the_hash_algo->rawsz);
1564        the_hash_algo->final_fn(hash, &c);
1565        if (hashcmp(hash, (unsigned char *)hdr + size - the_hash_algo->rawsz))
1566                return error("bad index file sha1 signature");
1567        return 0;
1568}
1569
1570static int read_index_extension(struct index_state *istate,
1571                                const char *ext, void *data, unsigned long sz)
1572{
1573        switch (CACHE_EXT(ext)) {
1574        case CACHE_EXT_TREE:
1575                istate->cache_tree = cache_tree_read(data, sz);
1576                break;
1577        case CACHE_EXT_RESOLVE_UNDO:
1578                istate->resolve_undo = resolve_undo_read(data, sz);
1579                break;
1580        case CACHE_EXT_LINK:
1581                if (read_link_extension(istate, data, sz))
1582                        return -1;
1583                break;
1584        case CACHE_EXT_UNTRACKED:
1585                istate->untracked = read_untracked_extension(data, sz);
1586                break;
1587        case CACHE_EXT_FSMONITOR:
1588                read_fsmonitor_extension(istate, data, sz);
1589                break;
1590        default:
1591                if (*ext < 'A' || 'Z' < *ext)
1592                        return error("index uses %.4s extension, which we do not understand",
1593                                     ext);
1594                fprintf(stderr, "ignoring %.4s extension\n", ext);
1595                break;
1596        }
1597        return 0;
1598}
1599
1600int hold_locked_index(struct lock_file *lk, int lock_flags)
1601{
1602        return hold_lock_file_for_update(lk, get_index_file(), lock_flags);
1603}
1604
1605int read_index(struct index_state *istate)
1606{
1607        return read_index_from(istate, get_index_file(), get_git_dir());
1608}
1609
1610static struct cache_entry *cache_entry_from_ondisk(struct ondisk_cache_entry *ondisk,
1611                                                   unsigned int flags,
1612                                                   const char *name,
1613                                                   size_t len)
1614{
1615        struct cache_entry *ce = xmalloc(cache_entry_size(len));
1616
1617        ce->ce_stat_data.sd_ctime.sec = get_be32(&ondisk->ctime.sec);
1618        ce->ce_stat_data.sd_mtime.sec = get_be32(&ondisk->mtime.sec);
1619        ce->ce_stat_data.sd_ctime.nsec = get_be32(&ondisk->ctime.nsec);
1620        ce->ce_stat_data.sd_mtime.nsec = get_be32(&ondisk->mtime.nsec);
1621        ce->ce_stat_data.sd_dev   = get_be32(&ondisk->dev);
1622        ce->ce_stat_data.sd_ino   = get_be32(&ondisk->ino);
1623        ce->ce_mode  = get_be32(&ondisk->mode);
1624        ce->ce_stat_data.sd_uid   = get_be32(&ondisk->uid);
1625        ce->ce_stat_data.sd_gid   = get_be32(&ondisk->gid);
1626        ce->ce_stat_data.sd_size  = get_be32(&ondisk->size);
1627        ce->ce_flags = flags & ~CE_NAMEMASK;
1628        ce->ce_namelen = len;
1629        ce->index = 0;
1630        hashcpy(ce->oid.hash, ondisk->sha1);
1631        memcpy(ce->name, name, len);
1632        ce->name[len] = '\0';
1633        return ce;
1634}
1635
1636/*
1637 * Adjacent cache entries tend to share the leading paths, so it makes
1638 * sense to only store the differences in later entries.  In the v4
1639 * on-disk format of the index, each on-disk cache entry stores the
1640 * number of bytes to be stripped from the end of the previous name,
1641 * and the bytes to append to the result, to come up with its name.
1642 */
1643static unsigned long expand_name_field(struct strbuf *name, const char *cp_)
1644{
1645        const unsigned char *ep, *cp = (const unsigned char *)cp_;
1646        size_t len = decode_varint(&cp);
1647
1648        if (name->len < len)
1649                die("malformed name field in the index");
1650        strbuf_remove(name, name->len - len, len);
1651        for (ep = cp; *ep; ep++)
1652                ; /* find the end */
1653        strbuf_add(name, cp, ep - cp);
1654        return (const char *)ep + 1 - cp_;
1655}
1656
1657static struct cache_entry *create_from_disk(struct ondisk_cache_entry *ondisk,
1658                                            unsigned long *ent_size,
1659                                            struct strbuf *previous_name)
1660{
1661        struct cache_entry *ce;
1662        size_t len;
1663        const char *name;
1664        unsigned int flags;
1665
1666        /* On-disk flags are just 16 bits */
1667        flags = get_be16(&ondisk->flags);
1668        len = flags & CE_NAMEMASK;
1669
1670        if (flags & CE_EXTENDED) {
1671                struct ondisk_cache_entry_extended *ondisk2;
1672                int extended_flags;
1673                ondisk2 = (struct ondisk_cache_entry_extended *)ondisk;
1674                extended_flags = get_be16(&ondisk2->flags2) << 16;
1675                /* We do not yet understand any bit out of CE_EXTENDED_FLAGS */
1676                if (extended_flags & ~CE_EXTENDED_FLAGS)
1677                        die("Unknown index entry format %08x", extended_flags);
1678                flags |= extended_flags;
1679                name = ondisk2->name;
1680        }
1681        else
1682                name = ondisk->name;
1683
1684        if (!previous_name) {
1685                /* v3 and earlier */
1686                if (len == CE_NAMEMASK)
1687                        len = strlen(name);
1688                ce = cache_entry_from_ondisk(ondisk, flags, name, len);
1689
1690                *ent_size = ondisk_ce_size(ce);
1691        } else {
1692                unsigned long consumed;
1693                consumed = expand_name_field(previous_name, name);
1694                ce = cache_entry_from_ondisk(ondisk, flags,
1695                                             previous_name->buf,
1696                                             previous_name->len);
1697
1698                *ent_size = (name - ((char *)ondisk)) + consumed;
1699        }
1700        return ce;
1701}
1702
1703static void check_ce_order(struct index_state *istate)
1704{
1705        unsigned int i;
1706
1707        if (!verify_ce_order)
1708                return;
1709
1710        for (i = 1; i < istate->cache_nr; i++) {
1711                struct cache_entry *ce = istate->cache[i - 1];
1712                struct cache_entry *next_ce = istate->cache[i];
1713                int name_compare = strcmp(ce->name, next_ce->name);
1714
1715                if (0 < name_compare)
1716                        die("unordered stage entries in index");
1717                if (!name_compare) {
1718                        if (!ce_stage(ce))
1719                                die("multiple stage entries for merged file '%s'",
1720                                    ce->name);
1721                        if (ce_stage(ce) > ce_stage(next_ce))
1722                                die("unordered stage entries for '%s'",
1723                                    ce->name);
1724                }
1725        }
1726}
1727
1728static void tweak_untracked_cache(struct index_state *istate)
1729{
1730        switch (git_config_get_untracked_cache()) {
1731        case -1: /* keep: do nothing */
1732                break;
1733        case 0: /* false */
1734                remove_untracked_cache(istate);
1735                break;
1736        case 1: /* true */
1737                add_untracked_cache(istate);
1738                break;
1739        default: /* unknown value: do nothing */
1740                break;
1741        }
1742}
1743
1744static void tweak_split_index(struct index_state *istate)
1745{
1746        switch (git_config_get_split_index()) {
1747        case -1: /* unset: do nothing */
1748                break;
1749        case 0: /* false */
1750                remove_split_index(istate);
1751                break;
1752        case 1: /* true */
1753                add_split_index(istate);
1754                break;
1755        default: /* unknown value: do nothing */
1756                break;
1757        }
1758}
1759
1760static void post_read_index_from(struct index_state *istate)
1761{
1762        check_ce_order(istate);
1763        tweak_untracked_cache(istate);
1764        tweak_split_index(istate);
1765        tweak_fsmonitor(istate);
1766}
1767
1768/* remember to discard_cache() before reading a different cache! */
1769int do_read_index(struct index_state *istate, const char *path, int must_exist)
1770{
1771        int fd, i;
1772        struct stat st;
1773        unsigned long src_offset;
1774        struct cache_header *hdr;
1775        void *mmap;
1776        size_t mmap_size;
1777        struct strbuf previous_name_buf = STRBUF_INIT, *previous_name;
1778
1779        if (istate->initialized)
1780                return istate->cache_nr;
1781
1782        istate->timestamp.sec = 0;
1783        istate->timestamp.nsec = 0;
1784        fd = open(path, O_RDONLY);
1785        if (fd < 0) {
1786                if (!must_exist && errno == ENOENT)
1787                        return 0;
1788                die_errno("%s: index file open failed", path);
1789        }
1790
1791        if (fstat(fd, &st))
1792                die_errno("cannot stat the open index");
1793
1794        mmap_size = xsize_t(st.st_size);
1795        if (mmap_size < sizeof(struct cache_header) + the_hash_algo->rawsz)
1796                die("index file smaller than expected");
1797
1798        mmap = xmmap(NULL, mmap_size, PROT_READ, MAP_PRIVATE, fd, 0);
1799        if (mmap == MAP_FAILED)
1800                die_errno("unable to map index file");
1801        close(fd);
1802
1803        hdr = mmap;
1804        if (verify_hdr(hdr, mmap_size) < 0)
1805                goto unmap;
1806
1807        hashcpy(istate->sha1, (const unsigned char *)hdr + mmap_size - the_hash_algo->rawsz);
1808        istate->version = ntohl(hdr->hdr_version);
1809        istate->cache_nr = ntohl(hdr->hdr_entries);
1810        istate->cache_alloc = alloc_nr(istate->cache_nr);
1811        istate->cache = xcalloc(istate->cache_alloc, sizeof(*istate->cache));
1812        istate->initialized = 1;
1813
1814        if (istate->version == 4)
1815                previous_name = &previous_name_buf;
1816        else
1817                previous_name = NULL;
1818
1819        src_offset = sizeof(*hdr);
1820        for (i = 0; i < istate->cache_nr; i++) {
1821                struct ondisk_cache_entry *disk_ce;
1822                struct cache_entry *ce;
1823                unsigned long consumed;
1824
1825                disk_ce = (struct ondisk_cache_entry *)((char *)mmap + src_offset);
1826                ce = create_from_disk(disk_ce, &consumed, previous_name);
1827                set_index_entry(istate, i, ce);
1828
1829                src_offset += consumed;
1830        }
1831        strbuf_release(&previous_name_buf);
1832        istate->timestamp.sec = st.st_mtime;
1833        istate->timestamp.nsec = ST_MTIME_NSEC(st);
1834
1835        while (src_offset <= mmap_size - the_hash_algo->rawsz - 8) {
1836                /* After an array of active_nr index entries,
1837                 * there can be arbitrary number of extended
1838                 * sections, each of which is prefixed with
1839                 * extension name (4-byte) and section length
1840                 * in 4-byte network byte order.
1841                 */
1842                uint32_t extsize;
1843                memcpy(&extsize, (char *)mmap + src_offset + 4, 4);
1844                extsize = ntohl(extsize);
1845                if (read_index_extension(istate,
1846                                         (const char *) mmap + src_offset,
1847                                         (char *) mmap + src_offset + 8,
1848                                         extsize) < 0)
1849                        goto unmap;
1850                src_offset += 8;
1851                src_offset += extsize;
1852        }
1853        munmap(mmap, mmap_size);
1854        return istate->cache_nr;
1855
1856unmap:
1857        munmap(mmap, mmap_size);
1858        die("index file corrupt");
1859}
1860
1861/*
1862 * Signal that the shared index is used by updating its mtime.
1863 *
1864 * This way, shared index can be removed if they have not been used
1865 * for some time.
1866 */
1867static void freshen_shared_index(const char *shared_index, int warn)
1868{
1869        if (!check_and_freshen_file(shared_index, 1) && warn)
1870                warning("could not freshen shared index '%s'", shared_index);
1871}
1872
1873int read_index_from(struct index_state *istate, const char *path,
1874                    const char *gitdir)
1875{
1876        uint64_t start = getnanotime();
1877        struct split_index *split_index;
1878        int ret;
1879        char *base_sha1_hex;
1880        char *base_path;
1881
1882        /* istate->initialized covers both .git/index and .git/sharedindex.xxx */
1883        if (istate->initialized)
1884                return istate->cache_nr;
1885
1886        ret = do_read_index(istate, path, 0);
1887        trace_performance_since(start, "read cache %s", path);
1888
1889        split_index = istate->split_index;
1890        if (!split_index || is_null_sha1(split_index->base_sha1)) {
1891                post_read_index_from(istate);
1892                return ret;
1893        }
1894
1895        if (split_index->base)
1896                discard_index(split_index->base);
1897        else
1898                split_index->base = xcalloc(1, sizeof(*split_index->base));
1899
1900        base_sha1_hex = sha1_to_hex(split_index->base_sha1);
1901        base_path = xstrfmt("%s/sharedindex.%s", gitdir, base_sha1_hex);
1902        ret = do_read_index(split_index->base, base_path, 1);
1903        if (hashcmp(split_index->base_sha1, split_index->base->sha1))
1904                die("broken index, expect %s in %s, got %s",
1905                    base_sha1_hex, base_path,
1906                    sha1_to_hex(split_index->base->sha1));
1907
1908        freshen_shared_index(base_path, 0);
1909        merge_base_index(istate);
1910        post_read_index_from(istate);
1911        trace_performance_since(start, "read cache %s", base_path);
1912        free(base_path);
1913        return ret;
1914}
1915
1916int is_index_unborn(struct index_state *istate)
1917{
1918        return (!istate->cache_nr && !istate->timestamp.sec);
1919}
1920
1921int discard_index(struct index_state *istate)
1922{
1923        int i;
1924
1925        for (i = 0; i < istate->cache_nr; i++) {
1926                if (istate->cache[i]->index &&
1927                    istate->split_index &&
1928                    istate->split_index->base &&
1929                    istate->cache[i]->index <= istate->split_index->base->cache_nr &&
1930                    istate->cache[i] == istate->split_index->base->cache[istate->cache[i]->index - 1])
1931                        continue;
1932                free(istate->cache[i]);
1933        }
1934        resolve_undo_clear_index(istate);
1935        istate->cache_nr = 0;
1936        istate->cache_changed = 0;
1937        istate->timestamp.sec = 0;
1938        istate->timestamp.nsec = 0;
1939        free_name_hash(istate);
1940        cache_tree_free(&(istate->cache_tree));
1941        istate->initialized = 0;
1942        FREE_AND_NULL(istate->cache);
1943        istate->cache_alloc = 0;
1944        discard_split_index(istate);
1945        free_untracked_cache(istate->untracked);
1946        istate->untracked = NULL;
1947        return 0;
1948}
1949
1950int unmerged_index(const struct index_state *istate)
1951{
1952        int i;
1953        for (i = 0; i < istate->cache_nr; i++) {
1954                if (ce_stage(istate->cache[i]))
1955                        return 1;
1956        }
1957        return 0;
1958}
1959
1960#define WRITE_BUFFER_SIZE 8192
1961static unsigned char write_buffer[WRITE_BUFFER_SIZE];
1962static unsigned long write_buffer_len;
1963
1964static int ce_write_flush(git_hash_ctx *context, int fd)
1965{
1966        unsigned int buffered = write_buffer_len;
1967        if (buffered) {
1968                the_hash_algo->update_fn(context, write_buffer, buffered);
1969                if (write_in_full(fd, write_buffer, buffered) < 0)
1970                        return -1;
1971                write_buffer_len = 0;
1972        }
1973        return 0;
1974}
1975
1976static int ce_write(git_hash_ctx *context, int fd, void *data, unsigned int len)
1977{
1978        while (len) {
1979                unsigned int buffered = write_buffer_len;
1980                unsigned int partial = WRITE_BUFFER_SIZE - buffered;
1981                if (partial > len)
1982                        partial = len;
1983                memcpy(write_buffer + buffered, data, partial);
1984                buffered += partial;
1985                if (buffered == WRITE_BUFFER_SIZE) {
1986                        write_buffer_len = buffered;
1987                        if (ce_write_flush(context, fd))
1988                                return -1;
1989                        buffered = 0;
1990                }
1991                write_buffer_len = buffered;
1992                len -= partial;
1993                data = (char *) data + partial;
1994        }
1995        return 0;
1996}
1997
1998static int write_index_ext_header(git_hash_ctx *context, int fd,
1999                                  unsigned int ext, unsigned int sz)
2000{
2001        ext = htonl(ext);
2002        sz = htonl(sz);
2003        return ((ce_write(context, fd, &ext, 4) < 0) ||
2004                (ce_write(context, fd, &sz, 4) < 0)) ? -1 : 0;
2005}
2006
2007static int ce_flush(git_hash_ctx *context, int fd, unsigned char *hash)
2008{
2009        unsigned int left = write_buffer_len;
2010
2011        if (left) {
2012                write_buffer_len = 0;
2013                the_hash_algo->update_fn(context, write_buffer, left);
2014        }
2015
2016        /* Flush first if not enough space for hash signature */
2017        if (left + the_hash_algo->rawsz > WRITE_BUFFER_SIZE) {
2018                if (write_in_full(fd, write_buffer, left) < 0)
2019                        return -1;
2020                left = 0;
2021        }
2022
2023        /* Append the hash signature at the end */
2024        the_hash_algo->final_fn(write_buffer + left, context);
2025        hashcpy(hash, write_buffer + left);
2026        left += the_hash_algo->rawsz;
2027        return (write_in_full(fd, write_buffer, left) < 0) ? -1 : 0;
2028}
2029
2030static void ce_smudge_racily_clean_entry(struct cache_entry *ce)
2031{
2032        /*
2033         * The only thing we care about in this function is to smudge the
2034         * falsely clean entry due to touch-update-touch race, so we leave
2035         * everything else as they are.  We are called for entries whose
2036         * ce_stat_data.sd_mtime match the index file mtime.
2037         *
2038         * Note that this actually does not do much for gitlinks, for
2039         * which ce_match_stat_basic() always goes to the actual
2040         * contents.  The caller checks with is_racy_timestamp() which
2041         * always says "no" for gitlinks, so we are not called for them ;-)
2042         */
2043        struct stat st;
2044
2045        if (lstat(ce->name, &st) < 0)
2046                return;
2047        if (ce_match_stat_basic(ce, &st))
2048                return;
2049        if (ce_modified_check_fs(ce, &st)) {
2050                /* This is "racily clean"; smudge it.  Note that this
2051                 * is a tricky code.  At first glance, it may appear
2052                 * that it can break with this sequence:
2053                 *
2054                 * $ echo xyzzy >frotz
2055                 * $ git-update-index --add frotz
2056                 * $ : >frotz
2057                 * $ sleep 3
2058                 * $ echo filfre >nitfol
2059                 * $ git-update-index --add nitfol
2060                 *
2061                 * but it does not.  When the second update-index runs,
2062                 * it notices that the entry "frotz" has the same timestamp
2063                 * as index, and if we were to smudge it by resetting its
2064                 * size to zero here, then the object name recorded
2065                 * in index is the 6-byte file but the cached stat information
2066                 * becomes zero --- which would then match what we would
2067                 * obtain from the filesystem next time we stat("frotz").
2068                 *
2069                 * However, the second update-index, before calling
2070                 * this function, notices that the cached size is 6
2071                 * bytes and what is on the filesystem is an empty
2072                 * file, and never calls us, so the cached size information
2073                 * for "frotz" stays 6 which does not match the filesystem.
2074                 */
2075                ce->ce_stat_data.sd_size = 0;
2076        }
2077}
2078
2079/* Copy miscellaneous fields but not the name */
2080static void copy_cache_entry_to_ondisk(struct ondisk_cache_entry *ondisk,
2081                                       struct cache_entry *ce)
2082{
2083        short flags;
2084
2085        ondisk->ctime.sec = htonl(ce->ce_stat_data.sd_ctime.sec);
2086        ondisk->mtime.sec = htonl(ce->ce_stat_data.sd_mtime.sec);
2087        ondisk->ctime.nsec = htonl(ce->ce_stat_data.sd_ctime.nsec);
2088        ondisk->mtime.nsec = htonl(ce->ce_stat_data.sd_mtime.nsec);
2089        ondisk->dev  = htonl(ce->ce_stat_data.sd_dev);
2090        ondisk->ino  = htonl(ce->ce_stat_data.sd_ino);
2091        ondisk->mode = htonl(ce->ce_mode);
2092        ondisk->uid  = htonl(ce->ce_stat_data.sd_uid);
2093        ondisk->gid  = htonl(ce->ce_stat_data.sd_gid);
2094        ondisk->size = htonl(ce->ce_stat_data.sd_size);
2095        hashcpy(ondisk->sha1, ce->oid.hash);
2096
2097        flags = ce->ce_flags & ~CE_NAMEMASK;
2098        flags |= (ce_namelen(ce) >= CE_NAMEMASK ? CE_NAMEMASK : ce_namelen(ce));
2099        ondisk->flags = htons(flags);
2100        if (ce->ce_flags & CE_EXTENDED) {
2101                struct ondisk_cache_entry_extended *ondisk2;
2102                ondisk2 = (struct ondisk_cache_entry_extended *)ondisk;
2103                ondisk2->flags2 = htons((ce->ce_flags & CE_EXTENDED_FLAGS) >> 16);
2104        }
2105}
2106
2107static int ce_write_entry(git_hash_ctx *c, int fd, struct cache_entry *ce,
2108                          struct strbuf *previous_name, struct ondisk_cache_entry *ondisk)
2109{
2110        int size;
2111        int saved_namelen = saved_namelen; /* compiler workaround */
2112        int result;
2113        static unsigned char padding[8] = { 0x00 };
2114
2115        if (ce->ce_flags & CE_STRIP_NAME) {
2116                saved_namelen = ce_namelen(ce);
2117                ce->ce_namelen = 0;
2118        }
2119
2120        if (ce->ce_flags & CE_EXTENDED)
2121                size = offsetof(struct ondisk_cache_entry_extended, name);
2122        else
2123                size = offsetof(struct ondisk_cache_entry, name);
2124
2125        if (!previous_name) {
2126                int len = ce_namelen(ce);
2127                copy_cache_entry_to_ondisk(ondisk, ce);
2128                result = ce_write(c, fd, ondisk, size);
2129                if (!result)
2130                        result = ce_write(c, fd, ce->name, len);
2131                if (!result)
2132                        result = ce_write(c, fd, padding, align_padding_size(size, len));
2133        } else {
2134                int common, to_remove, prefix_size;
2135                unsigned char to_remove_vi[16];
2136                for (common = 0;
2137                     (ce->name[common] &&
2138                      common < previous_name->len &&
2139                      ce->name[common] == previous_name->buf[common]);
2140                     common++)
2141                        ; /* still matching */
2142                to_remove = previous_name->len - common;
2143                prefix_size = encode_varint(to_remove, to_remove_vi);
2144
2145                copy_cache_entry_to_ondisk(ondisk, ce);
2146                result = ce_write(c, fd, ondisk, size);
2147                if (!result)
2148                        result = ce_write(c, fd, to_remove_vi, prefix_size);
2149                if (!result)
2150                        result = ce_write(c, fd, ce->name + common, ce_namelen(ce) - common);
2151                if (!result)
2152                        result = ce_write(c, fd, padding, 1);
2153
2154                strbuf_splice(previous_name, common, to_remove,
2155                              ce->name + common, ce_namelen(ce) - common);
2156        }
2157        if (ce->ce_flags & CE_STRIP_NAME) {
2158                ce->ce_namelen = saved_namelen;
2159                ce->ce_flags &= ~CE_STRIP_NAME;
2160        }
2161
2162        return result;
2163}
2164
2165/*
2166 * This function verifies if index_state has the correct sha1 of the
2167 * index file.  Don't die if we have any other failure, just return 0.
2168 */
2169static int verify_index_from(const struct index_state *istate, const char *path)
2170{
2171        int fd;
2172        ssize_t n;
2173        struct stat st;
2174        unsigned char hash[GIT_MAX_RAWSZ];
2175
2176        if (!istate->initialized)
2177                return 0;
2178
2179        fd = open(path, O_RDONLY);
2180        if (fd < 0)
2181                return 0;
2182
2183        if (fstat(fd, &st))
2184                goto out;
2185
2186        if (st.st_size < sizeof(struct cache_header) + the_hash_algo->rawsz)
2187                goto out;
2188
2189        n = pread_in_full(fd, hash, the_hash_algo->rawsz, st.st_size - the_hash_algo->rawsz);
2190        if (n != the_hash_algo->rawsz)
2191                goto out;
2192
2193        if (hashcmp(istate->sha1, hash))
2194                goto out;
2195
2196        close(fd);
2197        return 1;
2198
2199out:
2200        close(fd);
2201        return 0;
2202}
2203
2204static int verify_index(const struct index_state *istate)
2205{
2206        return verify_index_from(istate, get_index_file());
2207}
2208
2209static int has_racy_timestamp(struct index_state *istate)
2210{
2211        int entries = istate->cache_nr;
2212        int i;
2213
2214        for (i = 0; i < entries; i++) {
2215                struct cache_entry *ce = istate->cache[i];
2216                if (is_racy_timestamp(istate, ce))
2217                        return 1;
2218        }
2219        return 0;
2220}
2221
2222void update_index_if_able(struct index_state *istate, struct lock_file *lockfile)
2223{
2224        if ((istate->cache_changed || has_racy_timestamp(istate)) &&
2225            verify_index(istate))
2226                write_locked_index(istate, lockfile, COMMIT_LOCK);
2227        else
2228                rollback_lock_file(lockfile);
2229}
2230
2231/*
2232 * On success, `tempfile` is closed. If it is the temporary file
2233 * of a `struct lock_file`, we will therefore effectively perform
2234 * a 'close_lock_file_gently()`. Since that is an implementation
2235 * detail of lockfiles, callers of `do_write_index()` should not
2236 * rely on it.
2237 */
2238static int do_write_index(struct index_state *istate, struct tempfile *tempfile,
2239                          int strip_extensions)
2240{
2241        uint64_t start = getnanotime();
2242        int newfd = tempfile->fd;
2243        git_hash_ctx c;
2244        struct cache_header hdr;
2245        int i, err = 0, removed, extended, hdr_version;
2246        struct cache_entry **cache = istate->cache;
2247        int entries = istate->cache_nr;
2248        struct stat st;
2249        struct ondisk_cache_entry_extended ondisk;
2250        struct strbuf previous_name_buf = STRBUF_INIT, *previous_name;
2251        int drop_cache_tree = istate->drop_cache_tree;
2252
2253        for (i = removed = extended = 0; i < entries; i++) {
2254                if (cache[i]->ce_flags & CE_REMOVE)
2255                        removed++;
2256
2257                /* reduce extended entries if possible */
2258                cache[i]->ce_flags &= ~CE_EXTENDED;
2259                if (cache[i]->ce_flags & CE_EXTENDED_FLAGS) {
2260                        extended++;
2261                        cache[i]->ce_flags |= CE_EXTENDED;
2262                }
2263        }
2264
2265        if (!istate->version) {
2266                istate->version = get_index_format_default();
2267                if (getenv("GIT_TEST_SPLIT_INDEX"))
2268                        init_split_index(istate);
2269        }
2270
2271        /* demote version 3 to version 2 when the latter suffices */
2272        if (istate->version == 3 || istate->version == 2)
2273                istate->version = extended ? 3 : 2;
2274
2275        hdr_version = istate->version;
2276
2277        hdr.hdr_signature = htonl(CACHE_SIGNATURE);
2278        hdr.hdr_version = htonl(hdr_version);
2279        hdr.hdr_entries = htonl(entries - removed);
2280
2281        the_hash_algo->init_fn(&c);
2282        if (ce_write(&c, newfd, &hdr, sizeof(hdr)) < 0)
2283                return -1;
2284
2285        previous_name = (hdr_version == 4) ? &previous_name_buf : NULL;
2286
2287        for (i = 0; i < entries; i++) {
2288                struct cache_entry *ce = cache[i];
2289                if (ce->ce_flags & CE_REMOVE)
2290                        continue;
2291                if (!ce_uptodate(ce) && is_racy_timestamp(istate, ce))
2292                        ce_smudge_racily_clean_entry(ce);
2293                if (is_null_oid(&ce->oid)) {
2294                        static const char msg[] = "cache entry has null sha1: %s";
2295                        static int allow = -1;
2296
2297                        if (allow < 0)
2298                                allow = git_env_bool("GIT_ALLOW_NULL_SHA1", 0);
2299                        if (allow)
2300                                warning(msg, ce->name);
2301                        else
2302                                err = error(msg, ce->name);
2303
2304                        drop_cache_tree = 1;
2305                }
2306                if (ce_write_entry(&c, newfd, ce, previous_name, (struct ondisk_cache_entry *)&ondisk) < 0)
2307                        err = -1;
2308
2309                if (err)
2310                        break;
2311        }
2312        strbuf_release(&previous_name_buf);
2313
2314        if (err)
2315                return err;
2316
2317        /* Write extension data here */
2318        if (!strip_extensions && istate->split_index) {
2319                struct strbuf sb = STRBUF_INIT;
2320
2321                err = write_link_extension(&sb, istate) < 0 ||
2322                        write_index_ext_header(&c, newfd, CACHE_EXT_LINK,
2323                                               sb.len) < 0 ||
2324                        ce_write(&c, newfd, sb.buf, sb.len) < 0;
2325                strbuf_release(&sb);
2326                if (err)
2327                        return -1;
2328        }
2329        if (!strip_extensions && !drop_cache_tree && istate->cache_tree) {
2330                struct strbuf sb = STRBUF_INIT;
2331
2332                cache_tree_write(&sb, istate->cache_tree);
2333                err = write_index_ext_header(&c, newfd, CACHE_EXT_TREE, sb.len) < 0
2334                        || ce_write(&c, newfd, sb.buf, sb.len) < 0;
2335                strbuf_release(&sb);
2336                if (err)
2337                        return -1;
2338        }
2339        if (!strip_extensions && istate->resolve_undo) {
2340                struct strbuf sb = STRBUF_INIT;
2341
2342                resolve_undo_write(&sb, istate->resolve_undo);
2343                err = write_index_ext_header(&c, newfd, CACHE_EXT_RESOLVE_UNDO,
2344                                             sb.len) < 0
2345                        || ce_write(&c, newfd, sb.buf, sb.len) < 0;
2346                strbuf_release(&sb);
2347                if (err)
2348                        return -1;
2349        }
2350        if (!strip_extensions && istate->untracked) {
2351                struct strbuf sb = STRBUF_INIT;
2352
2353                write_untracked_extension(&sb, istate->untracked);
2354                err = write_index_ext_header(&c, newfd, CACHE_EXT_UNTRACKED,
2355                                             sb.len) < 0 ||
2356                        ce_write(&c, newfd, sb.buf, sb.len) < 0;
2357                strbuf_release(&sb);
2358                if (err)
2359                        return -1;
2360        }
2361        if (!strip_extensions && istate->fsmonitor_last_update) {
2362                struct strbuf sb = STRBUF_INIT;
2363
2364                write_fsmonitor_extension(&sb, istate);
2365                err = write_index_ext_header(&c, newfd, CACHE_EXT_FSMONITOR, sb.len) < 0
2366                        || ce_write(&c, newfd, sb.buf, sb.len) < 0;
2367                strbuf_release(&sb);
2368                if (err)
2369                        return -1;
2370        }
2371
2372        if (ce_flush(&c, newfd, istate->sha1))
2373                return -1;
2374        if (close_tempfile_gently(tempfile)) {
2375                error(_("could not close '%s'"), tempfile->filename.buf);
2376                return -1;
2377        }
2378        if (stat(tempfile->filename.buf, &st))
2379                return -1;
2380        istate->timestamp.sec = (unsigned int)st.st_mtime;
2381        istate->timestamp.nsec = ST_MTIME_NSEC(st);
2382        trace_performance_since(start, "write index, changed mask = %x", istate->cache_changed);
2383        return 0;
2384}
2385
2386void set_alternate_index_output(const char *name)
2387{
2388        alternate_index_output = name;
2389}
2390
2391static int commit_locked_index(struct lock_file *lk)
2392{
2393        if (alternate_index_output)
2394                return commit_lock_file_to(lk, alternate_index_output);
2395        else
2396                return commit_lock_file(lk);
2397}
2398
2399static int do_write_locked_index(struct index_state *istate, struct lock_file *lock,
2400                                 unsigned flags)
2401{
2402        int ret = do_write_index(istate, lock->tempfile, 0);
2403        if (ret)
2404                return ret;
2405        if (flags & COMMIT_LOCK)
2406                return commit_locked_index(lock);
2407        return close_lock_file_gently(lock);
2408}
2409
2410static int write_split_index(struct index_state *istate,
2411                             struct lock_file *lock,
2412                             unsigned flags)
2413{
2414        int ret;
2415        prepare_to_write_split_index(istate);
2416        ret = do_write_locked_index(istate, lock, flags);
2417        finish_writing_split_index(istate);
2418        return ret;
2419}
2420
2421static const char *shared_index_expire = "2.weeks.ago";
2422
2423static unsigned long get_shared_index_expire_date(void)
2424{
2425        static unsigned long shared_index_expire_date;
2426        static int shared_index_expire_date_prepared;
2427
2428        if (!shared_index_expire_date_prepared) {
2429                git_config_get_expiry("splitindex.sharedindexexpire",
2430                                      &shared_index_expire);
2431                shared_index_expire_date = approxidate(shared_index_expire);
2432                shared_index_expire_date_prepared = 1;
2433        }
2434
2435        return shared_index_expire_date;
2436}
2437
2438static int should_delete_shared_index(const char *shared_index_path)
2439{
2440        struct stat st;
2441        unsigned long expiration;
2442
2443        /* Check timestamp */
2444        expiration = get_shared_index_expire_date();
2445        if (!expiration)
2446                return 0;
2447        if (stat(shared_index_path, &st))
2448                return error_errno(_("could not stat '%s'"), shared_index_path);
2449        if (st.st_mtime > expiration)
2450                return 0;
2451
2452        return 1;
2453}
2454
2455static int clean_shared_index_files(const char *current_hex)
2456{
2457        struct dirent *de;
2458        DIR *dir = opendir(get_git_dir());
2459
2460        if (!dir)
2461                return error_errno(_("unable to open git dir: %s"), get_git_dir());
2462
2463        while ((de = readdir(dir)) != NULL) {
2464                const char *sha1_hex;
2465                const char *shared_index_path;
2466                if (!skip_prefix(de->d_name, "sharedindex.", &sha1_hex))
2467                        continue;
2468                if (!strcmp(sha1_hex, current_hex))
2469                        continue;
2470                shared_index_path = git_path("%s", de->d_name);
2471                if (should_delete_shared_index(shared_index_path) > 0 &&
2472                    unlink(shared_index_path))
2473                        warning_errno(_("unable to unlink: %s"), shared_index_path);
2474        }
2475        closedir(dir);
2476
2477        return 0;
2478}
2479
2480static int write_shared_index(struct index_state *istate,
2481                              struct tempfile **temp)
2482{
2483        struct split_index *si = istate->split_index;
2484        int ret;
2485
2486        move_cache_to_base_index(istate);
2487        ret = do_write_index(si->base, *temp, 1);
2488        if (ret)
2489                return ret;
2490        ret = adjust_shared_perm(get_tempfile_path(*temp));
2491        if (ret) {
2492                error("cannot fix permission bits on %s", get_tempfile_path(*temp));
2493                return ret;
2494        }
2495        ret = rename_tempfile(temp,
2496                              git_path("sharedindex.%s", sha1_to_hex(si->base->sha1)));
2497        if (!ret) {
2498                hashcpy(si->base_sha1, si->base->sha1);
2499                clean_shared_index_files(sha1_to_hex(si->base->sha1));
2500        }
2501
2502        return ret;
2503}
2504
2505static const int default_max_percent_split_change = 20;
2506
2507static int too_many_not_shared_entries(struct index_state *istate)
2508{
2509        int i, not_shared = 0;
2510        int max_split = git_config_get_max_percent_split_change();
2511
2512        switch (max_split) {
2513        case -1:
2514                /* not or badly configured: use the default value */
2515                max_split = default_max_percent_split_change;
2516                break;
2517        case 0:
2518                return 1; /* 0% means always write a new shared index */
2519        case 100:
2520                return 0; /* 100% means never write a new shared index */
2521        default:
2522                break; /* just use the configured value */
2523        }
2524
2525        /* Count not shared entries */
2526        for (i = 0; i < istate->cache_nr; i++) {
2527                struct cache_entry *ce = istate->cache[i];
2528                if (!ce->index)
2529                        not_shared++;
2530        }
2531
2532        return (int64_t)istate->cache_nr * max_split < (int64_t)not_shared * 100;
2533}
2534
2535int write_locked_index(struct index_state *istate, struct lock_file *lock,
2536                       unsigned flags)
2537{
2538        int new_shared_index, ret;
2539        struct split_index *si = istate->split_index;
2540
2541        if (istate->fsmonitor_last_update)
2542                fill_fsmonitor_bitmap(istate);
2543
2544        if (!si || alternate_index_output ||
2545            (istate->cache_changed & ~EXTMASK)) {
2546                if (si)
2547                        hashclr(si->base_sha1);
2548                ret = do_write_locked_index(istate, lock, flags);
2549                goto out;
2550        }
2551
2552        if (getenv("GIT_TEST_SPLIT_INDEX")) {
2553                int v = si->base_sha1[0];
2554                if ((v & 15) < 6)
2555                        istate->cache_changed |= SPLIT_INDEX_ORDERED;
2556        }
2557        if (too_many_not_shared_entries(istate))
2558                istate->cache_changed |= SPLIT_INDEX_ORDERED;
2559
2560        new_shared_index = istate->cache_changed & SPLIT_INDEX_ORDERED;
2561
2562        if (new_shared_index) {
2563                struct tempfile *temp;
2564                int saved_errno;
2565
2566                temp = mks_tempfile(git_path("sharedindex_XXXXXX"));
2567                if (!temp) {
2568                        hashclr(si->base_sha1);
2569                        ret = do_write_locked_index(istate, lock, flags);
2570                        goto out;
2571                }
2572                ret = write_shared_index(istate, &temp);
2573
2574                saved_errno = errno;
2575                if (is_tempfile_active(temp))
2576                        delete_tempfile(&temp);
2577                errno = saved_errno;
2578
2579                if (ret)
2580                        goto out;
2581        }
2582
2583        ret = write_split_index(istate, lock, flags);
2584
2585        /* Freshen the shared index only if the split-index was written */
2586        if (!ret && !new_shared_index) {
2587                const char *shared_index = git_path("sharedindex.%s",
2588                                                    sha1_to_hex(si->base_sha1));
2589                freshen_shared_index(shared_index, 1);
2590        }
2591
2592out:
2593        if (flags & COMMIT_LOCK)
2594                rollback_lock_file(lock);
2595        return ret;
2596}
2597
2598/*
2599 * Read the index file that is potentially unmerged into given
2600 * index_state, dropping any unmerged entries.  Returns true if
2601 * the index is unmerged.  Callers who want to refuse to work
2602 * from an unmerged state can call this and check its return value,
2603 * instead of calling read_cache().
2604 */
2605int read_index_unmerged(struct index_state *istate)
2606{
2607        int i;
2608        int unmerged = 0;
2609
2610        read_index(istate);
2611        for (i = 0; i < istate->cache_nr; i++) {
2612                struct cache_entry *ce = istate->cache[i];
2613                struct cache_entry *new_ce;
2614                int size, len;
2615
2616                if (!ce_stage(ce))
2617                        continue;
2618                unmerged = 1;
2619                len = ce_namelen(ce);
2620                size = cache_entry_size(len);
2621                new_ce = xcalloc(1, size);
2622                memcpy(new_ce->name, ce->name, len);
2623                new_ce->ce_flags = create_ce_flags(0) | CE_CONFLICTED;
2624                new_ce->ce_namelen = len;
2625                new_ce->ce_mode = ce->ce_mode;
2626                if (add_index_entry(istate, new_ce, 0))
2627                        return error("%s: cannot drop to stage #0",
2628                                     new_ce->name);
2629        }
2630        return unmerged;
2631}
2632
2633/*
2634 * Returns 1 if the path is an "other" path with respect to
2635 * the index; that is, the path is not mentioned in the index at all,
2636 * either as a file, a directory with some files in the index,
2637 * or as an unmerged entry.
2638 *
2639 * We helpfully remove a trailing "/" from directories so that
2640 * the output of read_directory can be used as-is.
2641 */
2642int index_name_is_other(const struct index_state *istate, const char *name,
2643                int namelen)
2644{
2645        int pos;
2646        if (namelen && name[namelen - 1] == '/')
2647                namelen--;
2648        pos = index_name_pos(istate, name, namelen);
2649        if (0 <= pos)
2650                return 0;       /* exact match */
2651        pos = -pos - 1;
2652        if (pos < istate->cache_nr) {
2653                struct cache_entry *ce = istate->cache[pos];
2654                if (ce_namelen(ce) == namelen &&
2655                    !memcmp(ce->name, name, namelen))
2656                        return 0; /* Yup, this one exists unmerged */
2657        }
2658        return 1;
2659}
2660
2661void *read_blob_data_from_index(const struct index_state *istate,
2662                                const char *path, unsigned long *size)
2663{
2664        int pos, len;
2665        unsigned long sz;
2666        enum object_type type;
2667        void *data;
2668
2669        len = strlen(path);
2670        pos = index_name_pos(istate, path, len);
2671        if (pos < 0) {
2672                /*
2673                 * We might be in the middle of a merge, in which
2674                 * case we would read stage #2 (ours).
2675                 */
2676                int i;
2677                for (i = -pos - 1;
2678                     (pos < 0 && i < istate->cache_nr &&
2679                      !strcmp(istate->cache[i]->name, path));
2680                     i++)
2681                        if (ce_stage(istate->cache[i]) == 2)
2682                                pos = i;
2683        }
2684        if (pos < 0)
2685                return NULL;
2686        data = read_sha1_file(istate->cache[pos]->oid.hash, &type, &sz);
2687        if (!data || type != OBJ_BLOB) {
2688                free(data);
2689                return NULL;
2690        }
2691        if (size)
2692                *size = sz;
2693        return data;
2694}
2695
2696void stat_validity_clear(struct stat_validity *sv)
2697{
2698        FREE_AND_NULL(sv->sd);
2699}
2700
2701int stat_validity_check(struct stat_validity *sv, const char *path)
2702{
2703        struct stat st;
2704
2705        if (stat(path, &st) < 0)
2706                return sv->sd == NULL;
2707        if (!sv->sd)
2708                return 0;
2709        return S_ISREG(st.st_mode) && !match_stat_data(sv->sd, &st);
2710}
2711
2712void stat_validity_update(struct stat_validity *sv, int fd)
2713{
2714        struct stat st;
2715
2716        if (fstat(fd, &st) < 0 || !S_ISREG(st.st_mode))
2717                stat_validity_clear(sv);
2718        else {
2719                if (!sv->sd)
2720                        sv->sd = xcalloc(1, sizeof(struct stat_data));
2721                fill_stat_data(sv->sd, &st);
2722        }
2723}
2724
2725void move_index_extensions(struct index_state *dst, struct index_state *src)
2726{
2727        dst->untracked = src->untracked;
2728        src->untracked = NULL;
2729}