/* * GIT - The information manager from hell * * Copyright (C) Linus Torvalds, 2005 */ #include "cache.h" #include "config.h" #include "diff.h" #include "diffcore.h" #include "tempfile.h" #include "lockfile.h" #include "cache-tree.h" #include "refs.h" #include "dir.h" #include "object-store.h" #include "tree.h" #include "commit.h" #include "blob.h" #include "resolve-undo.h" #include "run-command.h" #include "strbuf.h" #include "varint.h" #include "split-index.h" #include "utf8.h" #include "fsmonitor.h" #include "thread-utils.h" #include "progress.h" /* Mask for the name length in ce_flags in the on-disk index */ #define CE_NAMEMASK (0x0fff) /* Index extensions. * * The first letter should be 'A'..'Z' for extensions that are not * necessary for a correct operation (i.e. optimization data). * When new extensions are added that _needs_ to be understood in * order to correctly interpret the index file, pick character that * is outside the range, to cause the reader to abort. */ #define CACHE_EXT(s) ( (s[0]<<24)|(s[1]<<16)|(s[2]<<8)|(s[3]) ) #define CACHE_EXT_TREE 0x54524545 /* "TREE" */ #define CACHE_EXT_RESOLVE_UNDO 0x52455543 /* "REUC" */ #define CACHE_EXT_LINK 0x6c696e6b /* "link" */ #define CACHE_EXT_UNTRACKED 0x554E5452 /* "UNTR" */ #define CACHE_EXT_FSMONITOR 0x46534D4E /* "FSMN" */ #define CACHE_EXT_ENDOFINDEXENTRIES 0x454F4945 /* "EOIE" */ #define CACHE_EXT_INDEXENTRYOFFSETTABLE 0x49454F54 /* "IEOT" */ /* changes that can be kept in $GIT_DIR/index (basically all extensions) */ #define EXTMASK (RESOLVE_UNDO_CHANGED | CACHE_TREE_CHANGED | \ CE_ENTRY_ADDED | CE_ENTRY_REMOVED | CE_ENTRY_CHANGED | \ SPLIT_INDEX_ORDERED | UNTRACKED_CHANGED | FSMONITOR_CHANGED) /* * This is an estimate of the pathname length in the index. We use * this for V4 index files to guess the un-deltafied size of the index * in memory because of pathname deltafication. This is not required * for V2/V3 index formats because their pathnames are not compressed. * If the initial amount of memory set aside is not sufficient, the * mem pool will allocate extra memory. */ #define CACHE_ENTRY_PATH_LENGTH 80 static inline struct cache_entry *mem_pool__ce_alloc(struct mem_pool *mem_pool, size_t len) { struct cache_entry *ce; ce = mem_pool_alloc(mem_pool, cache_entry_size(len)); ce->mem_pool_allocated = 1; return ce; } static inline struct cache_entry *mem_pool__ce_calloc(struct mem_pool *mem_pool, size_t len) { struct cache_entry * ce; ce = mem_pool_calloc(mem_pool, 1, cache_entry_size(len)); ce->mem_pool_allocated = 1; return ce; } static struct mem_pool *find_mem_pool(struct index_state *istate) { struct mem_pool **pool_ptr; if (istate->split_index && istate->split_index->base) pool_ptr = &istate->split_index->base->ce_mem_pool; else pool_ptr = &istate->ce_mem_pool; if (!*pool_ptr) { *pool_ptr = xmalloc(sizeof(**pool_ptr)); mem_pool_init(*pool_ptr, 0); } return *pool_ptr; } static const char *alternate_index_output; static void set_index_entry(struct index_state *istate, int nr, struct cache_entry *ce) { istate->cache[nr] = ce; add_name_hash(istate, ce); } static void replace_index_entry(struct index_state *istate, int nr, struct cache_entry *ce) { struct cache_entry *old = istate->cache[nr]; replace_index_entry_in_base(istate, old, ce); remove_name_hash(istate, old); discard_cache_entry(old); ce->ce_flags &= ~CE_HASHED; set_index_entry(istate, nr, ce); ce->ce_flags |= CE_UPDATE_IN_BASE; mark_fsmonitor_invalid(istate, ce); istate->cache_changed |= CE_ENTRY_CHANGED; } void rename_index_entry_at(struct index_state *istate, int nr, const char *new_name) { struct cache_entry *old_entry = istate->cache[nr], *new_entry; int namelen = strlen(new_name); new_entry = make_empty_cache_entry(istate, namelen); copy_cache_entry(new_entry, old_entry); new_entry->ce_flags &= ~CE_HASHED; new_entry->ce_namelen = namelen; new_entry->index = 0; memcpy(new_entry->name, new_name, namelen + 1); cache_tree_invalidate_path(istate, old_entry->name); untracked_cache_remove_from_index(istate, old_entry->name); remove_index_entry_at(istate, nr); add_index_entry(istate, new_entry, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE); } void fill_stat_data(struct stat_data *sd, struct stat *st) { sd->sd_ctime.sec = (unsigned int)st->st_ctime; sd->sd_mtime.sec = (unsigned int)st->st_mtime; sd->sd_ctime.nsec = ST_CTIME_NSEC(*st); sd->sd_mtime.nsec = ST_MTIME_NSEC(*st); sd->sd_dev = st->st_dev; sd->sd_ino = st->st_ino; sd->sd_uid = st->st_uid; sd->sd_gid = st->st_gid; sd->sd_size = st->st_size; } int match_stat_data(const struct stat_data *sd, struct stat *st) { int changed = 0; if (sd->sd_mtime.sec != (unsigned int)st->st_mtime) changed |= MTIME_CHANGED; if (trust_ctime && check_stat && sd->sd_ctime.sec != (unsigned int)st->st_ctime) changed |= CTIME_CHANGED; #ifdef USE_NSEC if (check_stat && sd->sd_mtime.nsec != ST_MTIME_NSEC(*st)) changed |= MTIME_CHANGED; if (trust_ctime && check_stat && sd->sd_ctime.nsec != ST_CTIME_NSEC(*st)) changed |= CTIME_CHANGED; #endif if (check_stat) { if (sd->sd_uid != (unsigned int) st->st_uid || sd->sd_gid != (unsigned int) st->st_gid) changed |= OWNER_CHANGED; if (sd->sd_ino != (unsigned int) st->st_ino) changed |= INODE_CHANGED; } #ifdef USE_STDEV /* * st_dev breaks on network filesystems where different * clients will have different views of what "device" * the filesystem is on */ if (check_stat && sd->sd_dev != (unsigned int) st->st_dev) changed |= INODE_CHANGED; #endif if (sd->sd_size != (unsigned int) st->st_size) changed |= DATA_CHANGED; return changed; } /* * This only updates the "non-critical" parts of the directory * cache, ie the parts that aren't tracked by GIT, and only used * to validate the cache. */ void fill_stat_cache_info(struct index_state *istate, struct cache_entry *ce, struct stat *st) { fill_stat_data(&ce->ce_stat_data, st); if (assume_unchanged) ce->ce_flags |= CE_VALID; if (S_ISREG(st->st_mode)) { ce_mark_uptodate(ce); mark_fsmonitor_valid(istate, ce); } } static int ce_compare_data(struct index_state *istate, const struct cache_entry *ce, struct stat *st) { int match = -1; int fd = git_open_cloexec(ce->name, O_RDONLY); if (fd >= 0) { struct object_id oid; if (!index_fd(istate, &oid, fd, st, OBJ_BLOB, ce->name, 0)) match = !oideq(&oid, &ce->oid); /* index_fd() closed the file descriptor already */ } return match; } static int ce_compare_link(const struct cache_entry *ce, size_t expected_size) { int match = -1; void *buffer; unsigned long size; enum object_type type; struct strbuf sb = STRBUF_INIT; if (strbuf_readlink(&sb, ce->name, expected_size)) return -1; buffer = read_object_file(&ce->oid, &type, &size); if (buffer) { if (size == sb.len) match = memcmp(buffer, sb.buf, size); free(buffer); } strbuf_release(&sb); return match; } static int ce_compare_gitlink(const struct cache_entry *ce) { struct object_id oid; /* * We don't actually require that the .git directory * under GITLINK directory be a valid git directory. It * might even be missing (in case nobody populated that * sub-project). * * If so, we consider it always to match. */ if (resolve_gitlink_ref(ce->name, "HEAD", &oid) < 0) return 0; return !oideq(&oid, &ce->oid); } static int ce_modified_check_fs(struct index_state *istate, const struct cache_entry *ce, struct stat *st) { switch (st->st_mode & S_IFMT) { case S_IFREG: if (ce_compare_data(istate, ce, st)) return DATA_CHANGED; break; case S_IFLNK: if (ce_compare_link(ce, xsize_t(st->st_size))) return DATA_CHANGED; break; case S_IFDIR: if (S_ISGITLINK(ce->ce_mode)) return ce_compare_gitlink(ce) ? DATA_CHANGED : 0; /* else fallthrough */ default: return TYPE_CHANGED; } return 0; } static int ce_match_stat_basic(const struct cache_entry *ce, struct stat *st) { unsigned int changed = 0; if (ce->ce_flags & CE_REMOVE) return MODE_CHANGED | DATA_CHANGED | TYPE_CHANGED; switch (ce->ce_mode & S_IFMT) { case S_IFREG: changed |= !S_ISREG(st->st_mode) ? TYPE_CHANGED : 0; /* We consider only the owner x bit to be relevant for * "mode changes" */ if (trust_executable_bit && (0100 & (ce->ce_mode ^ st->st_mode))) changed |= MODE_CHANGED; break; case S_IFLNK: if (!S_ISLNK(st->st_mode) && (has_symlinks || !S_ISREG(st->st_mode))) changed |= TYPE_CHANGED; break; case S_IFGITLINK: /* We ignore most of the st_xxx fields for gitlinks */ if (!S_ISDIR(st->st_mode)) changed |= TYPE_CHANGED; else if (ce_compare_gitlink(ce)) changed |= DATA_CHANGED; return changed; default: BUG("unsupported ce_mode: %o", ce->ce_mode); } changed |= match_stat_data(&ce->ce_stat_data, st); /* Racily smudged entry? */ if (!ce->ce_stat_data.sd_size) { if (!is_empty_blob_sha1(ce->oid.hash)) changed |= DATA_CHANGED; } return changed; } static int is_racy_stat(const struct index_state *istate, const struct stat_data *sd) { return (istate->timestamp.sec && #ifdef USE_NSEC /* nanosecond timestamped files can also be racy! */ (istate->timestamp.sec < sd->sd_mtime.sec || (istate->timestamp.sec == sd->sd_mtime.sec && istate->timestamp.nsec <= sd->sd_mtime.nsec)) #else istate->timestamp.sec <= sd->sd_mtime.sec #endif ); } int is_racy_timestamp(const struct index_state *istate, const struct cache_entry *ce) { return (!S_ISGITLINK(ce->ce_mode) && is_racy_stat(istate, &ce->ce_stat_data)); } int match_stat_data_racy(const struct index_state *istate, const struct stat_data *sd, struct stat *st) { if (is_racy_stat(istate, sd)) return MTIME_CHANGED; return match_stat_data(sd, st); } int ie_match_stat(struct index_state *istate, const struct cache_entry *ce, struct stat *st, unsigned int options) { unsigned int changed; int ignore_valid = options & CE_MATCH_IGNORE_VALID; int ignore_skip_worktree = options & CE_MATCH_IGNORE_SKIP_WORKTREE; int assume_racy_is_modified = options & CE_MATCH_RACY_IS_DIRTY; int ignore_fsmonitor = options & CE_MATCH_IGNORE_FSMONITOR; if (!ignore_fsmonitor) refresh_fsmonitor(istate); /* * If it's marked as always valid in the index, it's * valid whatever the checked-out copy says. * * skip-worktree has the same effect with higher precedence */ if (!ignore_skip_worktree && ce_skip_worktree(ce)) return 0; if (!ignore_valid && (ce->ce_flags & CE_VALID)) return 0; if (!ignore_fsmonitor && (ce->ce_flags & CE_FSMONITOR_VALID)) return 0; /* * Intent-to-add entries have not been added, so the index entry * by definition never matches what is in the work tree until it * actually gets added. */ if (ce_intent_to_add(ce)) return DATA_CHANGED | TYPE_CHANGED | MODE_CHANGED; changed = ce_match_stat_basic(ce, st); /* * Within 1 second of this sequence: * echo xyzzy >file && git-update-index --add file * running this command: * echo frotz >file * would give a falsely clean cache entry. The mtime and * length match the cache, and other stat fields do not change. * * We could detect this at update-index time (the cache entry * being registered/updated records the same time as "now") * and delay the return from git-update-index, but that would * effectively mean we can make at most one commit per second, * which is not acceptable. Instead, we check cache entries * whose mtime are the same as the index file timestamp more * carefully than others. */ if (!changed && is_racy_timestamp(istate, ce)) { if (assume_racy_is_modified) changed |= DATA_CHANGED; else changed |= ce_modified_check_fs(istate, ce, st); } return changed; } int ie_modified(struct index_state *istate, const struct cache_entry *ce, struct stat *st, unsigned int options) { int changed, changed_fs; changed = ie_match_stat(istate, ce, st, options); if (!changed) return 0; /* * If the mode or type has changed, there's no point in trying * to refresh the entry - it's not going to match */ if (changed & (MODE_CHANGED | TYPE_CHANGED)) return changed; /* * Immediately after read-tree or update-index --cacheinfo, * the length field is zero, as we have never even read the * lstat(2) information once, and we cannot trust DATA_CHANGED * returned by ie_match_stat() which in turn was returned by * ce_match_stat_basic() to signal that the filesize of the * blob changed. We have to actually go to the filesystem to * see if the contents match, and if so, should answer "unchanged". * * The logic does not apply to gitlinks, as ce_match_stat_basic() * already has checked the actual HEAD from the filesystem in the * subproject. If ie_match_stat() already said it is different, * then we know it is. */ if ((changed & DATA_CHANGED) && (S_ISGITLINK(ce->ce_mode) || ce->ce_stat_data.sd_size != 0)) return changed; changed_fs = ce_modified_check_fs(istate, ce, st); if (changed_fs) return changed | changed_fs; return 0; } int base_name_compare(const char *name1, int len1, int mode1, const char *name2, int len2, int mode2) { unsigned char c1, c2; int len = len1 < len2 ? len1 : len2; int cmp; cmp = memcmp(name1, name2, len); if (cmp) return cmp; c1 = name1[len]; c2 = name2[len]; if (!c1 && S_ISDIR(mode1)) c1 = '/'; if (!c2 && S_ISDIR(mode2)) c2 = '/'; return (c1 < c2) ? -1 : (c1 > c2) ? 1 : 0; } /* * df_name_compare() is identical to base_name_compare(), except it * compares conflicting directory/file entries as equal. Note that * while a directory name compares as equal to a regular file, they * then individually compare _differently_ to a filename that has * a dot after the basename (because '\0' < '.' < '/'). * * This is used by routines that want to traverse the git namespace * but then handle conflicting entries together when possible. */ int df_name_compare(const char *name1, int len1, int mode1, const char *name2, int len2, int mode2) { int len = len1 < len2 ? len1 : len2, cmp; unsigned char c1, c2; cmp = memcmp(name1, name2, len); if (cmp) return cmp; /* Directories and files compare equal (same length, same name) */ if (len1 == len2) return 0; c1 = name1[len]; if (!c1 && S_ISDIR(mode1)) c1 = '/'; c2 = name2[len]; if (!c2 && S_ISDIR(mode2)) c2 = '/'; if (c1 == '/' && !c2) return 0; if (c2 == '/' && !c1) return 0; return c1 - c2; } int name_compare(const char *name1, size_t len1, const char *name2, size_t len2) { size_t min_len = (len1 < len2) ? len1 : len2; int cmp = memcmp(name1, name2, min_len); if (cmp) return cmp; if (len1 < len2) return -1; if (len1 > len2) return 1; return 0; } int cache_name_stage_compare(const char *name1, int len1, int stage1, const char *name2, int len2, int stage2) { int cmp; cmp = name_compare(name1, len1, name2, len2); if (cmp) return cmp; if (stage1 < stage2) return -1; if (stage1 > stage2) return 1; return 0; } static int index_name_stage_pos(const struct index_state *istate, const char *name, int namelen, int stage) { int first, last; first = 0; last = istate->cache_nr; while (last > first) { int next = first + ((last - first) >> 1); struct cache_entry *ce = istate->cache[next]; int cmp = cache_name_stage_compare(name, namelen, stage, ce->name, ce_namelen(ce), ce_stage(ce)); if (!cmp) return next; if (cmp < 0) { last = next; continue; } first = next+1; } return -first-1; } int index_name_pos(const struct index_state *istate, const char *name, int namelen) { return index_name_stage_pos(istate, name, namelen, 0); } int remove_index_entry_at(struct index_state *istate, int pos) { struct cache_entry *ce = istate->cache[pos]; record_resolve_undo(istate, ce); remove_name_hash(istate, ce); save_or_free_index_entry(istate, ce); istate->cache_changed |= CE_ENTRY_REMOVED; istate->cache_nr--; if (pos >= istate->cache_nr) return 0; MOVE_ARRAY(istate->cache + pos, istate->cache + pos + 1, istate->cache_nr - pos); return 1; } /* * Remove all cache entries marked for removal, that is where * CE_REMOVE is set in ce_flags. This is much more effective than * calling remove_index_entry_at() for each entry to be removed. */ void remove_marked_cache_entries(struct index_state *istate, int invalidate) { struct cache_entry **ce_array = istate->cache; unsigned int i, j; for (i = j = 0; i < istate->cache_nr; i++) { if (ce_array[i]->ce_flags & CE_REMOVE) { if (invalidate) { cache_tree_invalidate_path(istate, ce_array[i]->name); untracked_cache_remove_from_index(istate, ce_array[i]->name); } remove_name_hash(istate, ce_array[i]); save_or_free_index_entry(istate, ce_array[i]); } else ce_array[j++] = ce_array[i]; } if (j == istate->cache_nr) return; istate->cache_changed |= CE_ENTRY_REMOVED; istate->cache_nr = j; } int remove_file_from_index(struct index_state *istate, const char *path) { int pos = index_name_pos(istate, path, strlen(path)); if (pos < 0) pos = -pos-1; cache_tree_invalidate_path(istate, path); untracked_cache_remove_from_index(istate, path); while (pos < istate->cache_nr && !strcmp(istate->cache[pos]->name, path)) remove_index_entry_at(istate, pos); return 0; } static int compare_name(struct cache_entry *ce, const char *path, int namelen) { return namelen != ce_namelen(ce) || memcmp(path, ce->name, namelen); } static int index_name_pos_also_unmerged(struct index_state *istate, const char *path, int namelen) { int pos = index_name_pos(istate, path, namelen); struct cache_entry *ce; if (pos >= 0) return pos; /* maybe unmerged? */ pos = -1 - pos; if (pos >= istate->cache_nr || compare_name((ce = istate->cache[pos]), path, namelen)) return -1; /* order of preference: stage 2, 1, 3 */ if (ce_stage(ce) == 1 && pos + 1 < istate->cache_nr && ce_stage((ce = istate->cache[pos + 1])) == 2 && !compare_name(ce, path, namelen)) pos++; return pos; } static int different_name(struct cache_entry *ce, struct cache_entry *alias) { int len = ce_namelen(ce); return ce_namelen(alias) != len || memcmp(ce->name, alias->name, len); } /* * If we add a filename that aliases in the cache, we will use the * name that we already have - but we don't want to update the same * alias twice, because that implies that there were actually two * different files with aliasing names! * * So we use the CE_ADDED flag to verify that the alias was an old * one before we accept it as */ static struct cache_entry *create_alias_ce(struct index_state *istate, struct cache_entry *ce, struct cache_entry *alias) { int len; struct cache_entry *new_entry; if (alias->ce_flags & CE_ADDED) die(_("will not add file alias '%s' ('%s' already exists in index)"), ce->name, alias->name); /* Ok, create the new entry using the name of the existing alias */ len = ce_namelen(alias); new_entry = make_empty_cache_entry(istate, len); memcpy(new_entry->name, alias->name, len); copy_cache_entry(new_entry, ce); save_or_free_index_entry(istate, ce); return new_entry; } void set_object_name_for_intent_to_add_entry(struct cache_entry *ce) { struct object_id oid; if (write_object_file("", 0, blob_type, &oid)) die(_("cannot create an empty blob in the object database")); oidcpy(&ce->oid, &oid); } int add_to_index(struct index_state *istate, const char *path, struct stat *st, int flags) { int namelen, was_same; mode_t st_mode = st->st_mode; struct cache_entry *ce, *alias = NULL; unsigned ce_option = CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE|CE_MATCH_RACY_IS_DIRTY; int verbose = flags & (ADD_CACHE_VERBOSE | ADD_CACHE_PRETEND); int pretend = flags & ADD_CACHE_PRETEND; int intent_only = flags & ADD_CACHE_INTENT; int add_option = (ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE| (intent_only ? ADD_CACHE_NEW_ONLY : 0)); int hash_flags = HASH_WRITE_OBJECT; struct object_id oid; if (flags & ADD_CACHE_RENORMALIZE) hash_flags |= HASH_RENORMALIZE; if (!S_ISREG(st_mode) && !S_ISLNK(st_mode) && !S_ISDIR(st_mode)) return error(_("%s: can only add regular files, symbolic links or git-directories"), path); namelen = strlen(path); if (S_ISDIR(st_mode)) { if (resolve_gitlink_ref(path, "HEAD", &oid) < 0) return error(_("'%s' does not have a commit checked out"), path); while (namelen && path[namelen-1] == '/') namelen--; } ce = make_empty_cache_entry(istate, namelen); memcpy(ce->name, path, namelen); ce->ce_namelen = namelen; if (!intent_only) fill_stat_cache_info(istate, ce, st); else ce->ce_flags |= CE_INTENT_TO_ADD; if (trust_executable_bit && has_symlinks) { ce->ce_mode = create_ce_mode(st_mode); } else { /* If there is an existing entry, pick the mode bits and type * from it, otherwise assume unexecutable regular file. */ struct cache_entry *ent; int pos = index_name_pos_also_unmerged(istate, path, namelen); ent = (0 <= pos) ? istate->cache[pos] : NULL; ce->ce_mode = ce_mode_from_stat(ent, st_mode); } /* When core.ignorecase=true, determine if a directory of the same name but differing * case already exists within the Git repository. If it does, ensure the directory * case of the file being added to the repository matches (is folded into) the existing * entry's directory case. */ if (ignore_case) { adjust_dirname_case(istate, ce->name); } if (!(flags & ADD_CACHE_RENORMALIZE)) { alias = index_file_exists(istate, ce->name, ce_namelen(ce), ignore_case); if (alias && !ce_stage(alias) && !ie_match_stat(istate, alias, st, ce_option)) { /* Nothing changed, really */ if (!S_ISGITLINK(alias->ce_mode)) ce_mark_uptodate(alias); alias->ce_flags |= CE_ADDED; discard_cache_entry(ce); return 0; } } if (!intent_only) { if (index_path(istate, &ce->oid, path, st, hash_flags)) { discard_cache_entry(ce); return error(_("unable to index file '%s'"), path); } } else set_object_name_for_intent_to_add_entry(ce); if (ignore_case && alias && different_name(ce, alias)) ce = create_alias_ce(istate, ce, alias); ce->ce_flags |= CE_ADDED; /* It was suspected to be racily clean, but it turns out to be Ok */ was_same = (alias && !ce_stage(alias) && oideq(&alias->oid, &ce->oid) && ce->ce_mode == alias->ce_mode); if (pretend) discard_cache_entry(ce); else if (add_index_entry(istate, ce, add_option)) { discard_cache_entry(ce); return error(_("unable to add '%s' to index"), path); } if (verbose && !was_same) printf("add '%s'\n", path); return 0; } int add_file_to_index(struct index_state *istate, const char *path, int flags) { struct stat st; if (lstat(path, &st)) die_errno(_("unable to stat '%s'"), path); return add_to_index(istate, path, &st, flags); } struct cache_entry *make_empty_cache_entry(struct index_state *istate, size_t len) { return mem_pool__ce_calloc(find_mem_pool(istate), len); } struct cache_entry *make_empty_transient_cache_entry(size_t len) { return xcalloc(1, cache_entry_size(len)); } struct cache_entry *make_cache_entry(struct index_state *istate, unsigned int mode, const struct object_id *oid, const char *path, int stage, unsigned int refresh_options) { struct cache_entry *ce, *ret; int len; if (!verify_path(path, mode)) { error(_("invalid path '%s'"), path); return NULL; } len = strlen(path); ce = make_empty_cache_entry(istate, len); oidcpy(&ce->oid, oid); memcpy(ce->name, path, len); ce->ce_flags = create_ce_flags(stage); ce->ce_namelen = len; ce->ce_mode = create_ce_mode(mode); ret = refresh_cache_entry(istate, ce, refresh_options); if (ret != ce) discard_cache_entry(ce); return ret; } struct cache_entry *make_transient_cache_entry(unsigned int mode, const struct object_id *oid, const char *path, int stage) { struct cache_entry *ce; int len; if (!verify_path(path, mode)) { error(_("invalid path '%s'"), path); return NULL; } len = strlen(path); ce = make_empty_transient_cache_entry(len); oidcpy(&ce->oid, oid); memcpy(ce->name, path, len); ce->ce_flags = create_ce_flags(stage); ce->ce_namelen = len; ce->ce_mode = create_ce_mode(mode); return ce; } /* * Chmod an index entry with either +x or -x. * * Returns -1 if the chmod for the particular cache entry failed (if it's * not a regular file), -2 if an invalid flip argument is passed in, 0 * otherwise. */ int chmod_index_entry(struct index_state *istate, struct cache_entry *ce, char flip) { if (!S_ISREG(ce->ce_mode)) return -1; switch (flip) { case '+': ce->ce_mode |= 0111; break; case '-': ce->ce_mode &= ~0111; break; default: return -2; } cache_tree_invalidate_path(istate, ce->name); ce->ce_flags |= CE_UPDATE_IN_BASE; mark_fsmonitor_invalid(istate, ce); istate->cache_changed |= CE_ENTRY_CHANGED; return 0; } int ce_same_name(const struct cache_entry *a, const struct cache_entry *b) { int len = ce_namelen(a); return ce_namelen(b) == len && !memcmp(a->name, b->name, len); } /* * We fundamentally don't like some paths: we don't want * dot or dot-dot anywhere, and for obvious reasons don't * want to recurse into ".git" either. * * Also, we don't want double slashes or slashes at the * end that can make pathnames ambiguous. */ static int verify_dotfile(const char *rest, unsigned mode) { /* * The first character was '.', but that * has already been discarded, we now test * the rest. */ /* "." is not allowed */ if (*rest == '\0' || is_dir_sep(*rest)) return 0; switch (*rest) { /* * ".git" followed by NUL or slash is bad. Note that we match * case-insensitively here, even if ignore_case is not set. * This outlaws ".GIT" everywhere out of an abundance of caution, * since there's really no good reason to allow it. * * Once we've seen ".git", we can also find ".gitmodules", etc (also * case-insensitively). */ case 'g': case 'G': if (rest[1] != 'i' && rest[1] != 'I') break; if (rest[2] != 't' && rest[2] != 'T') break; if (rest[3] == '\0' || is_dir_sep(rest[3])) return 0; if (S_ISLNK(mode)) { rest += 3; if (skip_iprefix(rest, "modules", &rest) && (*rest == '\0' || is_dir_sep(*rest))) return 0; } break; case '.': if (rest[1] == '\0' || is_dir_sep(rest[1])) return 0; } return 1; } int verify_path(const char *path, unsigned mode) { char c = 0; if (has_dos_drive_prefix(path)) return 0; if (!is_valid_path(path)) return 0; goto inside; for (;;) { if (!c) return 1; if (is_dir_sep(c)) { inside: if (protect_hfs) { if (is_hfs_dotgit(path)) return 0; if (S_ISLNK(mode)) { if (is_hfs_dotgitmodules(path)) return 0; } } if (protect_ntfs) { #ifdef GIT_WINDOWS_NATIVE if (c == '\\') return 0; #endif if (is_ntfs_dotgit(path)) return 0; if (S_ISLNK(mode)) { if (is_ntfs_dotgitmodules(path)) return 0; } } c = *path++; if ((c == '.' && !verify_dotfile(path, mode)) || is_dir_sep(c) || c == '\0') return 0; } else if (c == '\\' && protect_ntfs) { if (is_ntfs_dotgit(path)) return 0; if (S_ISLNK(mode)) { if (is_ntfs_dotgitmodules(path)) return 0; } } c = *path++; } } /* * Do we have another file that has the beginning components being a * proper superset of the name we're trying to add? */ static int has_file_name(struct index_state *istate, const struct cache_entry *ce, int pos, int ok_to_replace) { int retval = 0; int len = ce_namelen(ce); int stage = ce_stage(ce); const char *name = ce->name; while (pos < istate->cache_nr) { struct cache_entry *p = istate->cache[pos++]; if (len >= ce_namelen(p)) break; if (memcmp(name, p->name, len)) break; if (ce_stage(p) != stage) continue; if (p->name[len] != '/') continue; if (p->ce_flags & CE_REMOVE) continue; retval = -1; if (!ok_to_replace) break; remove_index_entry_at(istate, --pos); } return retval; } /* * Like strcmp(), but also return the offset of the first change. * If strings are equal, return the length. */ int strcmp_offset(const char *s1, const char *s2, size_t *first_change) { size_t k; if (!first_change) return strcmp(s1, s2); for (k = 0; s1[k] == s2[k]; k++) if (s1[k] == '\0') break; *first_change = k; return (unsigned char)s1[k] - (unsigned char)s2[k]; } /* * Do we have another file with a pathname that is a proper * subset of the name we're trying to add? * * That is, is there another file in the index with a path * that matches a sub-directory in the given entry? */ static int has_dir_name(struct index_state *istate, const struct cache_entry *ce, int pos, int ok_to_replace) { int retval = 0; int stage = ce_stage(ce); const char *name = ce->name; const char *slash = name + ce_namelen(ce); size_t len_eq_last; int cmp_last = 0; /* * We are frequently called during an iteration on a sorted * list of pathnames and while building a new index. Therefore, * there is a high probability that this entry will eventually * be appended to the index, rather than inserted in the middle. * If we can confirm that, we can avoid binary searches on the * components of the pathname. * * Compare the entry's full path with the last path in the index. */ if (istate->cache_nr > 0) { cmp_last = strcmp_offset(name, istate->cache[istate->cache_nr - 1]->name, &len_eq_last); if (cmp_last > 0) { if (len_eq_last == 0) { /* * The entry sorts AFTER the last one in the * index and their paths have no common prefix, * so there cannot be a F/D conflict. */ return retval; } else { /* * The entry sorts AFTER the last one in the * index, but has a common prefix. Fall through * to the loop below to disect the entry's path * and see where the difference is. */ } } else if (cmp_last == 0) { /* * The entry exactly matches the last one in the * index, but because of multiple stage and CE_REMOVE * items, we fall through and let the regular search * code handle it. */ } } for (;;) { size_t len; for (;;) { if (*--slash == '/') break; if (slash <= ce->name) return retval; } len = slash - name; if (cmp_last > 0) { /* * (len + 1) is a directory boundary (including * the trailing slash). And since the loop is * decrementing "slash", the first iteration is * the longest directory prefix; subsequent * iterations consider parent directories. */ if (len + 1 <= len_eq_last) { /* * The directory prefix (including the trailing * slash) also appears as a prefix in the last * entry, so the remainder cannot collide (because * strcmp said the whole path was greater). * * EQ: last: xxx/A * this: xxx/B * * LT: last: xxx/file_A * this: xxx/file_B */ return retval; } if (len > len_eq_last) { /* * This part of the directory prefix (excluding * the trailing slash) is longer than the known * equal portions, so this sub-directory cannot * collide with a file. * * GT: last: xxxA * this: xxxB/file */ return retval; } /* * This is a possible collision. Fall through and * let the regular search code handle it. * * last: xxx * this: xxx/file */ } pos = index_name_stage_pos(istate, name, len, stage); if (pos >= 0) { /* * Found one, but not so fast. This could * be a marker that says "I was here, but * I am being removed". Such an entry is * not a part of the resulting tree, and * it is Ok to have a directory at the same * path. */ if (!(istate->cache[pos]->ce_flags & CE_REMOVE)) { retval = -1; if (!ok_to_replace) break; remove_index_entry_at(istate, pos); continue; } } else pos = -pos-1; /* * Trivial optimization: if we find an entry that * already matches the sub-directory, then we know * we're ok, and we can exit. */ while (pos < istate->cache_nr) { struct cache_entry *p = istate->cache[pos]; if ((ce_namelen(p) <= len) || (p->name[len] != '/') || memcmp(p->name, name, len)) break; /* not our subdirectory */ if (ce_stage(p) == stage && !(p->ce_flags & CE_REMOVE)) /* * p is at the same stage as our entry, and * is a subdirectory of what we are looking * at, so we cannot have conflicts at our * level or anything shorter. */ return retval; pos++; } } return retval; } /* We may be in a situation where we already have path/file and path * is being added, or we already have path and path/file is being * added. Either one would result in a nonsense tree that has path * twice when git-write-tree tries to write it out. Prevent it. * * If ok-to-replace is specified, we remove the conflicting entries * from the cache so the caller should recompute the insert position. * When this happens, we return non-zero. */ static int check_file_directory_conflict(struct index_state *istate, const struct cache_entry *ce, int pos, int ok_to_replace) { int retval; /* * When ce is an "I am going away" entry, we allow it to be added */ if (ce->ce_flags & CE_REMOVE) return 0; /* * We check if the path is a sub-path of a subsequent pathname * first, since removing those will not change the position * in the array. */ retval = has_file_name(istate, ce, pos, ok_to_replace); /* * Then check if the path might have a clashing sub-directory * before it. */ return retval + has_dir_name(istate, ce, pos, ok_to_replace); } static int add_index_entry_with_check(struct index_state *istate, struct cache_entry *ce, int option) { int pos; int ok_to_add = option & ADD_CACHE_OK_TO_ADD; int ok_to_replace = option & ADD_CACHE_OK_TO_REPLACE; int skip_df_check = option & ADD_CACHE_SKIP_DFCHECK; int new_only = option & ADD_CACHE_NEW_ONLY; if (!(option & ADD_CACHE_KEEP_CACHE_TREE)) cache_tree_invalidate_path(istate, ce->name); /* * If this entry's path sorts after the last entry in the index, * we can avoid searching for it. */ if (istate->cache_nr > 0 && strcmp(ce->name, istate->cache[istate->cache_nr - 1]->name) > 0) pos = index_pos_to_insert_pos(istate->cache_nr); else pos = index_name_stage_pos(istate, ce->name, ce_namelen(ce), ce_stage(ce)); /* existing match? Just replace it. */ if (pos >= 0) { if (!new_only) replace_index_entry(istate, pos, ce); return 0; } pos = -pos-1; if (!(option & ADD_CACHE_KEEP_CACHE_TREE)) untracked_cache_add_to_index(istate, ce->name); /* * Inserting a merged entry ("stage 0") into the index * will always replace all non-merged entries.. */ if (pos < istate->cache_nr && ce_stage(ce) == 0) { while (ce_same_name(istate->cache[pos], ce)) { ok_to_add = 1; if (!remove_index_entry_at(istate, pos)) break; } } if (!ok_to_add) return -1; if (!verify_path(ce->name, ce->ce_mode)) return error(_("invalid path '%s'"), ce->name); if (!skip_df_check && check_file_directory_conflict(istate, ce, pos, ok_to_replace)) { if (!ok_to_replace) return error(_("'%s' appears as both a file and as a directory"), ce->name); pos = index_name_stage_pos(istate, ce->name, ce_namelen(ce), ce_stage(ce)); pos = -pos-1; } return pos + 1; } int add_index_entry(struct index_state *istate, struct cache_entry *ce, int option) { int pos; if (option & ADD_CACHE_JUST_APPEND) pos = istate->cache_nr; else { int ret; ret = add_index_entry_with_check(istate, ce, option); if (ret <= 0) return ret; pos = ret - 1; } /* Make sure the array is big enough .. */ ALLOC_GROW(istate->cache, istate->cache_nr + 1, istate->cache_alloc); /* Add it in.. */ istate->cache_nr++; if (istate->cache_nr > pos + 1) MOVE_ARRAY(istate->cache + pos + 1, istate->cache + pos, istate->cache_nr - pos - 1); set_index_entry(istate, pos, ce); istate->cache_changed |= CE_ENTRY_ADDED; return 0; } /* * "refresh" does not calculate a new sha1 file or bring the * cache up-to-date for mode/content changes. But what it * _does_ do is to "re-match" the stat information of a file * with the cache, so that you can refresh the cache for a * file that hasn't been changed but where the stat entry is * out of date. * * For example, you'd want to do this after doing a "git-read-tree", * to link up the stat cache details with the proper files. */ static struct cache_entry *refresh_cache_ent(struct index_state *istate, struct cache_entry *ce, unsigned int options, int *err, int *changed_ret) { struct stat st; struct cache_entry *updated; int changed; int refresh = options & CE_MATCH_REFRESH; int ignore_valid = options & CE_MATCH_IGNORE_VALID; int ignore_skip_worktree = options & CE_MATCH_IGNORE_SKIP_WORKTREE; int ignore_missing = options & CE_MATCH_IGNORE_MISSING; int ignore_fsmonitor = options & CE_MATCH_IGNORE_FSMONITOR; if (!refresh || ce_uptodate(ce)) return ce; if (!ignore_fsmonitor) refresh_fsmonitor(istate); /* * CE_VALID or CE_SKIP_WORKTREE means the user promised us * that the change to the work tree does not matter and told * us not to worry. */ if (!ignore_skip_worktree && ce_skip_worktree(ce)) { ce_mark_uptodate(ce); return ce; } if (!ignore_valid && (ce->ce_flags & CE_VALID)) { ce_mark_uptodate(ce); return ce; } if (!ignore_fsmonitor && (ce->ce_flags & CE_FSMONITOR_VALID)) { ce_mark_uptodate(ce); return ce; } if (has_symlink_leading_path(ce->name, ce_namelen(ce))) { if (ignore_missing) return ce; if (err) *err = ENOENT; return NULL; } if (lstat(ce->name, &st) < 0) { if (ignore_missing && errno == ENOENT) return ce; if (err) *err = errno; return NULL; } changed = ie_match_stat(istate, ce, &st, options); if (changed_ret) *changed_ret = changed; if (!changed) { /* * The path is unchanged. If we were told to ignore * valid bit, then we did the actual stat check and * found that the entry is unmodified. If the entry * is not marked VALID, this is the place to mark it * valid again, under "assume unchanged" mode. */ if (ignore_valid && assume_unchanged && !(ce->ce_flags & CE_VALID)) ; /* mark this one VALID again */ else { /* * We do not mark the index itself "modified" * because CE_UPTODATE flag is in-core only; * we are not going to write this change out. */ if (!S_ISGITLINK(ce->ce_mode)) { ce_mark_uptodate(ce); mark_fsmonitor_valid(istate, ce); } return ce; } } if (ie_modified(istate, ce, &st, options)) { if (err) *err = EINVAL; return NULL; } updated = make_empty_cache_entry(istate, ce_namelen(ce)); copy_cache_entry(updated, ce); memcpy(updated->name, ce->name, ce->ce_namelen + 1); fill_stat_cache_info(istate, updated, &st); /* * If ignore_valid is not set, we should leave CE_VALID bit * alone. Otherwise, paths marked with --no-assume-unchanged * (i.e. things to be edited) will reacquire CE_VALID bit * automatically, which is not really what we want. */ if (!ignore_valid && assume_unchanged && !(ce->ce_flags & CE_VALID)) updated->ce_flags &= ~CE_VALID; /* istate->cache_changed is updated in the caller */ return updated; } static void show_file(const char * fmt, const char * name, int in_porcelain, int * first, const char *header_msg) { if (in_porcelain && *first && header_msg) { printf("%s\n", header_msg); *first = 0; } printf(fmt, name); } int repo_refresh_and_write_index(struct repository *repo, unsigned int refresh_flags, unsigned int write_flags, int gentle, const struct pathspec *pathspec, char *seen, const char *header_msg) { struct lock_file lock_file = LOCK_INIT; int fd, ret = 0; fd = repo_hold_locked_index(repo, &lock_file, 0); if (!gentle && fd < 0) return -1; if (refresh_index(repo->index, refresh_flags, pathspec, seen, header_msg)) ret = 1; if (0 <= fd && write_locked_index(repo->index, &lock_file, COMMIT_LOCK | write_flags)) ret = -1; return ret; } int refresh_index(struct index_state *istate, unsigned int flags, const struct pathspec *pathspec, char *seen, const char *header_msg) { int i; int has_errors = 0; int really = (flags & REFRESH_REALLY) != 0; int allow_unmerged = (flags & REFRESH_UNMERGED) != 0; int quiet = (flags & REFRESH_QUIET) != 0; int not_new = (flags & REFRESH_IGNORE_MISSING) != 0; int ignore_submodules = (flags & REFRESH_IGNORE_SUBMODULES) != 0; int first = 1; int in_porcelain = (flags & REFRESH_IN_PORCELAIN); unsigned int options = (CE_MATCH_REFRESH | (really ? CE_MATCH_IGNORE_VALID : 0) | (not_new ? CE_MATCH_IGNORE_MISSING : 0)); const char *modified_fmt; const char *deleted_fmt; const char *typechange_fmt; const char *added_fmt; const char *unmerged_fmt; struct progress *progress = NULL; if (flags & REFRESH_PROGRESS && isatty(2)) progress = start_delayed_progress(_("Refresh index"), istate->cache_nr); trace_performance_enter(); modified_fmt = in_porcelain ? "M\t%s\n" : "%s: needs update\n"; deleted_fmt = in_porcelain ? "D\t%s\n" : "%s: needs update\n"; typechange_fmt = in_porcelain ? "T\t%s\n" : "%s: needs update\n"; added_fmt = in_porcelain ? "A\t%s\n" : "%s: needs update\n"; unmerged_fmt = in_porcelain ? "U\t%s\n" : "%s: needs merge\n"; /* * Use the multi-threaded preload_index() to refresh most of the * cache entries quickly then in the single threaded loop below, * we only have to do the special cases that are left. */ preload_index(istate, pathspec, 0); for (i = 0; i < istate->cache_nr; i++) { struct cache_entry *ce, *new_entry; int cache_errno = 0; int changed = 0; int filtered = 0; ce = istate->cache[i]; if (ignore_submodules && S_ISGITLINK(ce->ce_mode)) continue; if (pathspec && !ce_path_match(istate, ce, pathspec, seen)) filtered = 1; if (ce_stage(ce)) { while ((i < istate->cache_nr) && ! strcmp(istate->cache[i]->name, ce->name)) i++; i--; if (allow_unmerged) continue; if (!filtered) show_file(unmerged_fmt, ce->name, in_porcelain, &first, header_msg); has_errors = 1; continue; } if (filtered) continue; new_entry = refresh_cache_ent(istate, ce, options, &cache_errno, &changed); if (new_entry == ce) continue; if (progress) display_progress(progress, i); if (!new_entry) { const char *fmt; if (really && cache_errno == EINVAL) { /* If we are doing --really-refresh that * means the index is not valid anymore. */ ce->ce_flags &= ~CE_VALID; ce->ce_flags |= CE_UPDATE_IN_BASE; mark_fsmonitor_invalid(istate, ce); istate->cache_changed |= CE_ENTRY_CHANGED; } if (quiet) continue; if (cache_errno == ENOENT) fmt = deleted_fmt; else if (ce_intent_to_add(ce)) fmt = added_fmt; /* must be before other checks */ else if (changed & TYPE_CHANGED) fmt = typechange_fmt; else fmt = modified_fmt; show_file(fmt, ce->name, in_porcelain, &first, header_msg); has_errors = 1; continue; } replace_index_entry(istate, i, new_entry); } if (progress) { display_progress(progress, istate->cache_nr); stop_progress(&progress); } trace_performance_leave("refresh index"); return has_errors; } struct cache_entry *refresh_cache_entry(struct index_state *istate, struct cache_entry *ce, unsigned int options) { return refresh_cache_ent(istate, ce, options, NULL, NULL); } /***************************************************************** * Index File I/O *****************************************************************/ #define INDEX_FORMAT_DEFAULT 3 static unsigned int get_index_format_default(struct repository *r) { char *envversion = getenv("GIT_INDEX_VERSION"); char *endp; unsigned int version = INDEX_FORMAT_DEFAULT; if (!envversion) { prepare_repo_settings(r); if (r->settings.index_version >= 0) version = r->settings.index_version; if (version < INDEX_FORMAT_LB || INDEX_FORMAT_UB < version) { warning(_("index.version set, but the value is invalid.\n" "Using version %i"), INDEX_FORMAT_DEFAULT); return INDEX_FORMAT_DEFAULT; } return version; } version = strtoul(envversion, &endp, 10); if (*endp || version < INDEX_FORMAT_LB || INDEX_FORMAT_UB < version) { warning(_("GIT_INDEX_VERSION set, but the value is invalid.\n" "Using version %i"), INDEX_FORMAT_DEFAULT); version = INDEX_FORMAT_DEFAULT; } return version; } /* * dev/ino/uid/gid/size are also just tracked to the low 32 bits * Again - this is just a (very strong in practice) heuristic that * the inode hasn't changed. * * We save the fields in big-endian order to allow using the * index file over NFS transparently. */ struct ondisk_cache_entry { struct cache_time ctime; struct cache_time mtime; uint32_t dev; uint32_t ino; uint32_t mode; uint32_t uid; uint32_t gid; uint32_t size; /* * unsigned char hash[hashsz]; * uint16_t flags; * if (flags & CE_EXTENDED) * uint16_t flags2; */ unsigned char data[GIT_MAX_RAWSZ + 2 * sizeof(uint16_t)]; char name[FLEX_ARRAY]; }; /* These are only used for v3 or lower */ #define align_padding_size(size, len) ((size + (len) + 8) & ~7) - (size + len) #define align_flex_name(STRUCT,len) ((offsetof(struct STRUCT,data) + (len) + 8) & ~7) #define ondisk_cache_entry_size(len) align_flex_name(ondisk_cache_entry,len) #define ondisk_data_size(flags, len) (the_hash_algo->rawsz + \ ((flags & CE_EXTENDED) ? 2 : 1) * sizeof(uint16_t) + len) #define ondisk_data_size_max(len) (ondisk_data_size(CE_EXTENDED, len)) #define ondisk_ce_size(ce) (ondisk_cache_entry_size(ondisk_data_size((ce)->ce_flags, ce_namelen(ce)))) /* Allow fsck to force verification of the index checksum. */ int verify_index_checksum; /* Allow fsck to force verification of the cache entry order. */ int verify_ce_order; static int verify_hdr(const struct cache_header *hdr, unsigned long size) { git_hash_ctx c; unsigned char hash[GIT_MAX_RAWSZ]; int hdr_version; if (hdr->hdr_signature != htonl(CACHE_SIGNATURE)) return error(_("bad signature 0x%08x"), hdr->hdr_signature); hdr_version = ntohl(hdr->hdr_version); if (hdr_version < INDEX_FORMAT_LB || INDEX_FORMAT_UB < hdr_version) return error(_("bad index version %d"), hdr_version); if (!verify_index_checksum) return 0; the_hash_algo->init_fn(&c); the_hash_algo->update_fn(&c, hdr, size - the_hash_algo->rawsz); the_hash_algo->final_fn(hash, &c); if (!hasheq(hash, (unsigned char *)hdr + size - the_hash_algo->rawsz)) return error(_("bad index file sha1 signature")); return 0; } static int read_index_extension(struct index_state *istate, const char *ext, const char *data, unsigned long sz) { switch (CACHE_EXT(ext)) { case CACHE_EXT_TREE: istate->cache_tree = cache_tree_read(data, sz); break; case CACHE_EXT_RESOLVE_UNDO: istate->resolve_undo = resolve_undo_read(data, sz); break; case CACHE_EXT_LINK: if (read_link_extension(istate, data, sz)) return -1; break; case CACHE_EXT_UNTRACKED: istate->untracked = read_untracked_extension(data, sz); break; case CACHE_EXT_FSMONITOR: read_fsmonitor_extension(istate, data, sz); break; case CACHE_EXT_ENDOFINDEXENTRIES: case CACHE_EXT_INDEXENTRYOFFSETTABLE: /* already handled in do_read_index() */ break; default: if (*ext < 'A' || 'Z' < *ext) return error(_("index uses %.4s extension, which we do not understand"), ext); fprintf_ln(stderr, _("ignoring %.4s extension"), ext); break; } return 0; } static struct cache_entry *create_from_disk(struct mem_pool *ce_mem_pool, unsigned int version, struct ondisk_cache_entry *ondisk, unsigned long *ent_size, const struct cache_entry *previous_ce) { struct cache_entry *ce; size_t len; const char *name; const unsigned hashsz = the_hash_algo->rawsz; const uint16_t *flagsp = (const uint16_t *)(ondisk->data + hashsz); unsigned int flags; size_t copy_len = 0; /* * Adjacent cache entries tend to share the leading paths, so it makes * sense to only store the differences in later entries. In the v4 * on-disk format of the index, each on-disk cache entry stores the * number of bytes to be stripped from the end of the previous name, * and the bytes to append to the result, to come up with its name. */ int expand_name_field = version == 4; /* On-disk flags are just 16 bits */ flags = get_be16(flagsp); len = flags & CE_NAMEMASK; if (flags & CE_EXTENDED) { int extended_flags; extended_flags = get_be16(flagsp + 1) << 16; /* We do not yet understand any bit out of CE_EXTENDED_FLAGS */ if (extended_flags & ~CE_EXTENDED_FLAGS) die(_("unknown index entry format 0x%08x"), extended_flags); flags |= extended_flags; name = (const char *)(flagsp + 2); } else name = (const char *)(flagsp + 1); if (expand_name_field) { const unsigned char *cp = (const unsigned char *)name; size_t strip_len, previous_len; /* If we're at the beginning of a block, ignore the previous name */ strip_len = decode_varint(&cp); if (previous_ce) { previous_len = previous_ce->ce_namelen; if (previous_len < strip_len) die(_("malformed name field in the index, near path '%s'"), previous_ce->name); copy_len = previous_len - strip_len; } name = (const char *)cp; } if (len == CE_NAMEMASK) { len = strlen(name); if (expand_name_field) len += copy_len; } ce = mem_pool__ce_alloc(ce_mem_pool, len); ce->ce_stat_data.sd_ctime.sec = get_be32(&ondisk->ctime.sec); ce->ce_stat_data.sd_mtime.sec = get_be32(&ondisk->mtime.sec); ce->ce_stat_data.sd_ctime.nsec = get_be32(&ondisk->ctime.nsec); ce->ce_stat_data.sd_mtime.nsec = get_be32(&ondisk->mtime.nsec); ce->ce_stat_data.sd_dev = get_be32(&ondisk->dev); ce->ce_stat_data.sd_ino = get_be32(&ondisk->ino); ce->ce_mode = get_be32(&ondisk->mode); ce->ce_stat_data.sd_uid = get_be32(&ondisk->uid); ce->ce_stat_data.sd_gid = get_be32(&ondisk->gid); ce->ce_stat_data.sd_size = get_be32(&ondisk->size); ce->ce_flags = flags & ~CE_NAMEMASK; ce->ce_namelen = len; ce->index = 0; hashcpy(ce->oid.hash, ondisk->data); memcpy(ce->name, name, len); ce->name[len] = '\0'; if (expand_name_field) { if (copy_len) memcpy(ce->name, previous_ce->name, copy_len); memcpy(ce->name + copy_len, name, len + 1 - copy_len); *ent_size = (name - ((char *)ondisk)) + len + 1 - copy_len; } else { memcpy(ce->name, name, len + 1); *ent_size = ondisk_ce_size(ce); } return ce; } static void check_ce_order(struct index_state *istate) { unsigned int i; if (!verify_ce_order) return; for (i = 1; i < istate->cache_nr; i++) { struct cache_entry *ce = istate->cache[i - 1]; struct cache_entry *next_ce = istate->cache[i]; int name_compare = strcmp(ce->name, next_ce->name); if (0 < name_compare) die(_("unordered stage entries in index")); if (!name_compare) { if (!ce_stage(ce)) die(_("multiple stage entries for merged file '%s'"), ce->name); if (ce_stage(ce) > ce_stage(next_ce)) die(_("unordered stage entries for '%s'"), ce->name); } } } static void tweak_untracked_cache(struct index_state *istate) { struct repository *r = the_repository; prepare_repo_settings(r); if (r->settings.core_untracked_cache == UNTRACKED_CACHE_REMOVE) { remove_untracked_cache(istate); return; } if (r->settings.core_untracked_cache == UNTRACKED_CACHE_WRITE) add_untracked_cache(istate); } static void tweak_split_index(struct index_state *istate) { switch (git_config_get_split_index()) { case -1: /* unset: do nothing */ break; case 0: /* false */ remove_split_index(istate); break; case 1: /* true */ add_split_index(istate); break; default: /* unknown value: do nothing */ break; } } static void post_read_index_from(struct index_state *istate) { check_ce_order(istate); tweak_untracked_cache(istate); tweak_split_index(istate); tweak_fsmonitor(istate); } static size_t estimate_cache_size_from_compressed(unsigned int entries) { return entries * (sizeof(struct cache_entry) + CACHE_ENTRY_PATH_LENGTH); } static size_t estimate_cache_size(size_t ondisk_size, unsigned int entries) { long per_entry = sizeof(struct cache_entry) - sizeof(struct ondisk_cache_entry); /* * Account for potential alignment differences. */ per_entry += align_padding_size(per_entry, 0); return ondisk_size + entries * per_entry; } struct index_entry_offset { /* starting byte offset into index file, count of index entries in this block */ int offset, nr; }; struct index_entry_offset_table { int nr; struct index_entry_offset entries[FLEX_ARRAY]; }; static struct index_entry_offset_table *read_ieot_extension(const char *mmap, size_t mmap_size, size_t offset); static void write_ieot_extension(struct strbuf *sb, struct index_entry_offset_table *ieot); static size_t read_eoie_extension(const char *mmap, size_t mmap_size); static void write_eoie_extension(struct strbuf *sb, git_hash_ctx *eoie_context, size_t offset); struct load_index_extensions { pthread_t pthread; struct index_state *istate; const char *mmap; size_t mmap_size; unsigned long src_offset; }; static void *load_index_extensions(void *_data) { struct load_index_extensions *p = _data; unsigned long src_offset = p->src_offset; while (src_offset <= p->mmap_size - the_hash_algo->rawsz - 8) { /* After an array of active_nr index entries, * there can be arbitrary number of extended * sections, each of which is prefixed with * extension name (4-byte) and section length * in 4-byte network byte order. */ uint32_t extsize = get_be32(p->mmap + src_offset + 4); if (read_index_extension(p->istate, p->mmap + src_offset, p->mmap + src_offset + 8, extsize) < 0) { munmap((void *)p->mmap, p->mmap_size); die(_("index file corrupt")); } src_offset += 8; src_offset += extsize; } return NULL; } /* * A helper function that will load the specified range of cache entries * from the memory mapped file and add them to the given index. */ static unsigned long load_cache_entry_block(struct index_state *istate, struct mem_pool *ce_mem_pool, int offset, int nr, const char *mmap, unsigned long start_offset, const struct cache_entry *previous_ce) { int i; unsigned long src_offset = start_offset; for (i = offset; i < offset + nr; i++) { struct ondisk_cache_entry *disk_ce; struct cache_entry *ce; unsigned long consumed; disk_ce = (struct ondisk_cache_entry *)(mmap + src_offset); ce = create_from_disk(ce_mem_pool, istate->version, disk_ce, &consumed, previous_ce); set_index_entry(istate, i, ce); src_offset += consumed; previous_ce = ce; } return src_offset - start_offset; } static unsigned long load_all_cache_entries(struct index_state *istate, const char *mmap, size_t mmap_size, unsigned long src_offset) { unsigned long consumed; istate->ce_mem_pool = xmalloc(sizeof(*istate->ce_mem_pool)); if (istate->version == 4) { mem_pool_init(istate->ce_mem_pool, estimate_cache_size_from_compressed(istate->cache_nr)); } else { mem_pool_init(istate->ce_mem_pool, estimate_cache_size(mmap_size, istate->cache_nr)); } consumed = load_cache_entry_block(istate, istate->ce_mem_pool, 0, istate->cache_nr, mmap, src_offset, NULL); return consumed; } /* * Mostly randomly chosen maximum thread counts: we * cap the parallelism to online_cpus() threads, and we want * to have at least 10000 cache entries per thread for it to * be worth starting a thread. */ #define THREAD_COST (10000) struct load_cache_entries_thread_data { pthread_t pthread; struct index_state *istate; struct mem_pool *ce_mem_pool; int offset; const char *mmap; struct index_entry_offset_table *ieot; int ieot_start; /* starting index into the ieot array */ int ieot_blocks; /* count of ieot entries to process */ unsigned long consumed; /* return # of bytes in index file processed */ }; /* * A thread proc to run the load_cache_entries() computation * across multiple background threads. */ static void *load_cache_entries_thread(void *_data) { struct load_cache_entries_thread_data *p = _data; int i; /* iterate across all ieot blocks assigned to this thread */ for (i = p->ieot_start; i < p->ieot_start + p->ieot_blocks; i++) { p->consumed += load_cache_entry_block(p->istate, p->ce_mem_pool, p->offset, p->ieot->entries[i].nr, p->mmap, p->ieot->entries[i].offset, NULL); p->offset += p->ieot->entries[i].nr; } return NULL; } static unsigned long load_cache_entries_threaded(struct index_state *istate, const char *mmap, size_t mmap_size, int nr_threads, struct index_entry_offset_table *ieot) { int i, offset, ieot_blocks, ieot_start, err; struct load_cache_entries_thread_data *data; unsigned long consumed = 0; /* a little sanity checking */ if (istate->name_hash_initialized) BUG("the name hash isn't thread safe"); istate->ce_mem_pool = xmalloc(sizeof(*istate->ce_mem_pool)); mem_pool_init(istate->ce_mem_pool, 0); /* ensure we have no more threads than we have blocks to process */ if (nr_threads > ieot->nr) nr_threads = ieot->nr; data = xcalloc(nr_threads, sizeof(*data)); offset = ieot_start = 0; ieot_blocks = DIV_ROUND_UP(ieot->nr, nr_threads); for (i = 0; i < nr_threads; i++) { struct load_cache_entries_thread_data *p = &data[i]; int nr, j; if (ieot_start + ieot_blocks > ieot->nr) ieot_blocks = ieot->nr - ieot_start; p->istate = istate; p->offset = offset; p->mmap = mmap; p->ieot = ieot; p->ieot_start = ieot_start; p->ieot_blocks = ieot_blocks; /* create a mem_pool for each thread */ nr = 0; for (j = p->ieot_start; j < p->ieot_start + p->ieot_blocks; j++) nr += p->ieot->entries[j].nr; p->ce_mem_pool = xmalloc(sizeof(*istate->ce_mem_pool)); if (istate->version == 4) { mem_pool_init(p->ce_mem_pool, estimate_cache_size_from_compressed(nr)); } else { mem_pool_init(p->ce_mem_pool, estimate_cache_size(mmap_size, nr)); } err = pthread_create(&p->pthread, NULL, load_cache_entries_thread, p); if (err) die(_("unable to create load_cache_entries thread: %s"), strerror(err)); /* increment by the number of cache entries in the ieot block being processed */ for (j = 0; j < ieot_blocks; j++) offset += ieot->entries[ieot_start + j].nr; ieot_start += ieot_blocks; } for (i = 0; i < nr_threads; i++) { struct load_cache_entries_thread_data *p = &data[i]; err = pthread_join(p->pthread, NULL); if (err) die(_("unable to join load_cache_entries thread: %s"), strerror(err)); mem_pool_combine(istate->ce_mem_pool, p->ce_mem_pool); consumed += p->consumed; } free(data); return consumed; } /* remember to discard_cache() before reading a different cache! */ int do_read_index(struct index_state *istate, const char *path, int must_exist) { int fd; struct stat st; unsigned long src_offset; const struct cache_header *hdr; const char *mmap; size_t mmap_size; struct load_index_extensions p; size_t extension_offset = 0; int nr_threads, cpus; struct index_entry_offset_table *ieot = NULL; if (istate->initialized) return istate->cache_nr; istate->timestamp.sec = 0; istate->timestamp.nsec = 0; fd = open(path, O_RDONLY); if (fd < 0) { if (!must_exist && errno == ENOENT) return 0; die_errno(_("%s: index file open failed"), path); } if (fstat(fd, &st)) die_errno(_("%s: cannot stat the open index"), path); mmap_size = xsize_t(st.st_size); if (mmap_size < sizeof(struct cache_header) + the_hash_algo->rawsz) die(_("%s: index file smaller than expected"), path); mmap = xmmap_gently(NULL, mmap_size, PROT_READ, MAP_PRIVATE, fd, 0); if (mmap == MAP_FAILED) die_errno(_("%s: unable to map index file"), path); close(fd); hdr = (const struct cache_header *)mmap; if (verify_hdr(hdr, mmap_size) < 0) goto unmap; hashcpy(istate->oid.hash, (const unsigned char *)hdr + mmap_size - the_hash_algo->rawsz); istate->version = ntohl(hdr->hdr_version); istate->cache_nr = ntohl(hdr->hdr_entries); istate->cache_alloc = alloc_nr(istate->cache_nr); istate->cache = xcalloc(istate->cache_alloc, sizeof(*istate->cache)); istate->initialized = 1; p.istate = istate; p.mmap = mmap; p.mmap_size = mmap_size; src_offset = sizeof(*hdr); if (git_config_get_index_threads(&nr_threads)) nr_threads = 1; /* TODO: does creating more threads than cores help? */ if (!nr_threads) { nr_threads = istate->cache_nr / THREAD_COST; cpus = online_cpus(); if (nr_threads > cpus) nr_threads = cpus; } if (!HAVE_THREADS) nr_threads = 1; if (nr_threads > 1) { extension_offset = read_eoie_extension(mmap, mmap_size); if (extension_offset) { int err; p.src_offset = extension_offset; err = pthread_create(&p.pthread, NULL, load_index_extensions, &p); if (err) die(_("unable to create load_index_extensions thread: %s"), strerror(err)); nr_threads--; } } /* * Locate and read the index entry offset table so that we can use it * to multi-thread the reading of the cache entries. */ if (extension_offset && nr_threads > 1) ieot = read_ieot_extension(mmap, mmap_size, extension_offset); if (ieot) { src_offset += load_cache_entries_threaded(istate, mmap, mmap_size, nr_threads, ieot); free(ieot); } else { src_offset += load_all_cache_entries(istate, mmap, mmap_size, src_offset); } istate->timestamp.sec = st.st_mtime; istate->timestamp.nsec = ST_MTIME_NSEC(st); /* if we created a thread, join it otherwise load the extensions on the primary thread */ if (extension_offset) { int ret = pthread_join(p.pthread, NULL); if (ret) die(_("unable to join load_index_extensions thread: %s"), strerror(ret)); } else { p.src_offset = src_offset; load_index_extensions(&p); } munmap((void *)mmap, mmap_size); /* * TODO trace2: replace "the_repository" with the actual repo instance * that is associated with the given "istate". */ trace2_data_intmax("index", the_repository, "read/version", istate->version); trace2_data_intmax("index", the_repository, "read/cache_nr", istate->cache_nr); return istate->cache_nr; unmap: munmap((void *)mmap, mmap_size); die(_("index file corrupt")); } /* * Signal that the shared index is used by updating its mtime. * * This way, shared index can be removed if they have not been used * for some time. */ static void freshen_shared_index(const char *shared_index, int warn) { if (!check_and_freshen_file(shared_index, 1) && warn) warning(_("could not freshen shared index '%s'"), shared_index); } int read_index_from(struct index_state *istate, const char *path, const char *gitdir) { struct split_index *split_index; int ret; char *base_oid_hex; char *base_path; /* istate->initialized covers both .git/index and .git/sharedindex.xxx */ if (istate->initialized) return istate->cache_nr; /* * TODO trace2: replace "the_repository" with the actual repo instance * that is associated with the given "istate". */ trace2_region_enter_printf("index", "do_read_index", the_repository, "%s", path); trace_performance_enter(); ret = do_read_index(istate, path, 0); trace_performance_leave("read cache %s", path); trace2_region_leave_printf("index", "do_read_index", the_repository, "%s", path); split_index = istate->split_index; if (!split_index || is_null_oid(&split_index->base_oid)) { post_read_index_from(istate); return ret; } trace_performance_enter(); if (split_index->base) discard_index(split_index->base); else split_index->base = xcalloc(1, sizeof(*split_index->base)); base_oid_hex = oid_to_hex(&split_index->base_oid); base_path = xstrfmt("%s/sharedindex.%s", gitdir, base_oid_hex); trace2_region_enter_printf("index", "shared/do_read_index", the_repository, "%s", base_path); ret = do_read_index(split_index->base, base_path, 1); trace2_region_leave_printf("index", "shared/do_read_index", the_repository, "%s", base_path); if (!oideq(&split_index->base_oid, &split_index->base->oid)) die(_("broken index, expect %s in %s, got %s"), base_oid_hex, base_path, oid_to_hex(&split_index->base->oid)); freshen_shared_index(base_path, 0); merge_base_index(istate); post_read_index_from(istate); trace_performance_leave("read cache %s", base_path); free(base_path); return ret; } int is_index_unborn(struct index_state *istate) { return (!istate->cache_nr && !istate->timestamp.sec); } int discard_index(struct index_state *istate) { /* * Cache entries in istate->cache[] should have been allocated * from the memory pool associated with this index, or from an * associated split_index. There is no need to free individual * cache entries. validate_cache_entries can detect when this * assertion does not hold. */ validate_cache_entries(istate); resolve_undo_clear_index(istate); istate->cache_nr = 0; istate->cache_changed = 0; istate->timestamp.sec = 0; istate->timestamp.nsec = 0; free_name_hash(istate); cache_tree_free(&(istate->cache_tree)); istate->initialized = 0; istate->fsmonitor_has_run_once = 0; FREE_AND_NULL(istate->fsmonitor_last_update); FREE_AND_NULL(istate->cache); istate->cache_alloc = 0; discard_split_index(istate); free_untracked_cache(istate->untracked); istate->untracked = NULL; if (istate->ce_mem_pool) { mem_pool_discard(istate->ce_mem_pool, should_validate_cache_entries()); FREE_AND_NULL(istate->ce_mem_pool); } return 0; } /* * Validate the cache entries of this index. * All cache entries associated with this index * should have been allocated by the memory pool * associated with this index, or by a referenced * split index. */ void validate_cache_entries(const struct index_state *istate) { int i; if (!should_validate_cache_entries() ||!istate || !istate->initialized) return; for (i = 0; i < istate->cache_nr; i++) { if (!istate) { BUG("cache entry is not allocated from expected memory pool"); } else if (!istate->ce_mem_pool || !mem_pool_contains(istate->ce_mem_pool, istate->cache[i])) { if (!istate->split_index || !istate->split_index->base || !istate->split_index->base->ce_mem_pool || !mem_pool_contains(istate->split_index->base->ce_mem_pool, istate->cache[i])) { BUG("cache entry is not allocated from expected memory pool"); } } } if (istate->split_index) validate_cache_entries(istate->split_index->base); } int unmerged_index(const struct index_state *istate) { int i; for (i = 0; i < istate->cache_nr; i++) { if (ce_stage(istate->cache[i])) return 1; } return 0; } int repo_index_has_changes(struct repository *repo, struct tree *tree, struct strbuf *sb) { struct index_state *istate = repo->index; struct object_id cmp; int i; if (tree) cmp = tree->object.oid; if (tree || !get_oid_tree("HEAD", &cmp)) { struct diff_options opt; repo_diff_setup(repo, &opt); opt.flags.exit_with_status = 1; if (!sb) opt.flags.quick = 1; do_diff_cache(&cmp, &opt); diffcore_std(&opt); for (i = 0; sb && i < diff_queued_diff.nr; i++) { if (i) strbuf_addch(sb, ' '); strbuf_addstr(sb, diff_queued_diff.queue[i]->two->path); } diff_flush(&opt); return opt.flags.has_changes != 0; } else { for (i = 0; sb && i < istate->cache_nr; i++) { if (i) strbuf_addch(sb, ' '); strbuf_addstr(sb, istate->cache[i]->name); } return !!istate->cache_nr; } } #define WRITE_BUFFER_SIZE 8192 static unsigned char write_buffer[WRITE_BUFFER_SIZE]; static unsigned long write_buffer_len; static int ce_write_flush(git_hash_ctx *context, int fd) { unsigned int buffered = write_buffer_len; if (buffered) { the_hash_algo->update_fn(context, write_buffer, buffered); if (write_in_full(fd, write_buffer, buffered) < 0) return -1; write_buffer_len = 0; } return 0; } static int ce_write(git_hash_ctx *context, int fd, void *data, unsigned int len) { while (len) { unsigned int buffered = write_buffer_len; unsigned int partial = WRITE_BUFFER_SIZE - buffered; if (partial > len) partial = len; memcpy(write_buffer + buffered, data, partial); buffered += partial; if (buffered == WRITE_BUFFER_SIZE) { write_buffer_len = buffered; if (ce_write_flush(context, fd)) return -1; buffered = 0; } write_buffer_len = buffered; len -= partial; data = (char *) data + partial; } return 0; } static int write_index_ext_header(git_hash_ctx *context, git_hash_ctx *eoie_context, int fd, unsigned int ext, unsigned int sz) { ext = htonl(ext); sz = htonl(sz); if (eoie_context) { the_hash_algo->update_fn(eoie_context, &ext, 4); the_hash_algo->update_fn(eoie_context, &sz, 4); } return ((ce_write(context, fd, &ext, 4) < 0) || (ce_write(context, fd, &sz, 4) < 0)) ? -1 : 0; } static int ce_flush(git_hash_ctx *context, int fd, unsigned char *hash) { unsigned int left = write_buffer_len; if (left) { write_buffer_len = 0; the_hash_algo->update_fn(context, write_buffer, left); } /* Flush first if not enough space for hash signature */ if (left + the_hash_algo->rawsz > WRITE_BUFFER_SIZE) { if (write_in_full(fd, write_buffer, left) < 0) return -1; left = 0; } /* Append the hash signature at the end */ the_hash_algo->final_fn(write_buffer + left, context); hashcpy(hash, write_buffer + left); left += the_hash_algo->rawsz; return (write_in_full(fd, write_buffer, left) < 0) ? -1 : 0; } static void ce_smudge_racily_clean_entry(struct index_state *istate, struct cache_entry *ce) { /* * The only thing we care about in this function is to smudge the * falsely clean entry due to touch-update-touch race, so we leave * everything else as they are. We are called for entries whose * ce_stat_data.sd_mtime match the index file mtime. * * Note that this actually does not do much for gitlinks, for * which ce_match_stat_basic() always goes to the actual * contents. The caller checks with is_racy_timestamp() which * always says "no" for gitlinks, so we are not called for them ;-) */ struct stat st; if (lstat(ce->name, &st) < 0) return; if (ce_match_stat_basic(ce, &st)) return; if (ce_modified_check_fs(istate, ce, &st)) { /* This is "racily clean"; smudge it. Note that this * is a tricky code. At first glance, it may appear * that it can break with this sequence: * * $ echo xyzzy >frotz * $ git-update-index --add frotz * $ : >frotz * $ sleep 3 * $ echo filfre >nitfol * $ git-update-index --add nitfol * * but it does not. When the second update-index runs, * it notices that the entry "frotz" has the same timestamp * as index, and if we were to smudge it by resetting its * size to zero here, then the object name recorded * in index is the 6-byte file but the cached stat information * becomes zero --- which would then match what we would * obtain from the filesystem next time we stat("frotz"). * * However, the second update-index, before calling * this function, notices that the cached size is 6 * bytes and what is on the filesystem is an empty * file, and never calls us, so the cached size information * for "frotz" stays 6 which does not match the filesystem. */ ce->ce_stat_data.sd_size = 0; } } /* Copy miscellaneous fields but not the name */ static void copy_cache_entry_to_ondisk(struct ondisk_cache_entry *ondisk, struct cache_entry *ce) { short flags; const unsigned hashsz = the_hash_algo->rawsz; uint16_t *flagsp = (uint16_t *)(ondisk->data + hashsz); ondisk->ctime.sec = htonl(ce->ce_stat_data.sd_ctime.sec); ondisk->mtime.sec = htonl(ce->ce_stat_data.sd_mtime.sec); ondisk->ctime.nsec = htonl(ce->ce_stat_data.sd_ctime.nsec); ondisk->mtime.nsec = htonl(ce->ce_stat_data.sd_mtime.nsec); ondisk->dev = htonl(ce->ce_stat_data.sd_dev); ondisk->ino = htonl(ce->ce_stat_data.sd_ino); ondisk->mode = htonl(ce->ce_mode); ondisk->uid = htonl(ce->ce_stat_data.sd_uid); ondisk->gid = htonl(ce->ce_stat_data.sd_gid); ondisk->size = htonl(ce->ce_stat_data.sd_size); hashcpy(ondisk->data, ce->oid.hash); flags = ce->ce_flags & ~CE_NAMEMASK; flags |= (ce_namelen(ce) >= CE_NAMEMASK ? CE_NAMEMASK : ce_namelen(ce)); flagsp[0] = htons(flags); if (ce->ce_flags & CE_EXTENDED) { flagsp[1] = htons((ce->ce_flags & CE_EXTENDED_FLAGS) >> 16); } } static int ce_write_entry(git_hash_ctx *c, int fd, struct cache_entry *ce, struct strbuf *previous_name, struct ondisk_cache_entry *ondisk) { int size; int result; unsigned int saved_namelen; int stripped_name = 0; static unsigned char padding[8] = { 0x00 }; if (ce->ce_flags & CE_STRIP_NAME) { saved_namelen = ce_namelen(ce); ce->ce_namelen = 0; stripped_name = 1; } size = offsetof(struct ondisk_cache_entry,data) + ondisk_data_size(ce->ce_flags, 0); if (!previous_name) { int len = ce_namelen(ce); copy_cache_entry_to_ondisk(ondisk, ce); result = ce_write(c, fd, ondisk, size); if (!result) result = ce_write(c, fd, ce->name, len); if (!result) result = ce_write(c, fd, padding, align_padding_size(size, len)); } else { int common, to_remove, prefix_size; unsigned char to_remove_vi[16]; for (common = 0; (ce->name[common] && common < previous_name->len && ce->name[common] == previous_name->buf[common]); common++) ; /* still matching */ to_remove = previous_name->len - common; prefix_size = encode_varint(to_remove, to_remove_vi); copy_cache_entry_to_ondisk(ondisk, ce); result = ce_write(c, fd, ondisk, size); if (!result) result = ce_write(c, fd, to_remove_vi, prefix_size); if (!result) result = ce_write(c, fd, ce->name + common, ce_namelen(ce) - common); if (!result) result = ce_write(c, fd, padding, 1); strbuf_splice(previous_name, common, to_remove, ce->name + common, ce_namelen(ce) - common); } if (stripped_name) { ce->ce_namelen = saved_namelen; ce->ce_flags &= ~CE_STRIP_NAME; } return result; } /* * This function verifies if index_state has the correct sha1 of the * index file. Don't die if we have any other failure, just return 0. */ static int verify_index_from(const struct index_state *istate, const char *path) { int fd; ssize_t n; struct stat st; unsigned char hash[GIT_MAX_RAWSZ]; if (!istate->initialized) return 0; fd = open(path, O_RDONLY); if (fd < 0) return 0; if (fstat(fd, &st)) goto out; if (st.st_size < sizeof(struct cache_header) + the_hash_algo->rawsz) goto out; n = pread_in_full(fd, hash, the_hash_algo->rawsz, st.st_size - the_hash_algo->rawsz); if (n != the_hash_algo->rawsz) goto out; if (!hasheq(istate->oid.hash, hash)) goto out; close(fd); return 1; out: close(fd); return 0; } static int repo_verify_index(struct repository *repo) { return verify_index_from(repo->index, repo->index_file); } static int has_racy_timestamp(struct index_state *istate) { int entries = istate->cache_nr; int i; for (i = 0; i < entries; i++) { struct cache_entry *ce = istate->cache[i]; if (is_racy_timestamp(istate, ce)) return 1; } return 0; } void repo_update_index_if_able(struct repository *repo, struct lock_file *lockfile) { if ((repo->index->cache_changed || has_racy_timestamp(repo->index)) && repo_verify_index(repo)) write_locked_index(repo->index, lockfile, COMMIT_LOCK); else rollback_lock_file(lockfile); } static int record_eoie(void) { int val; if (!git_config_get_bool("index.recordendofindexentries", &val)) return val; /* * As a convenience, the end of index entries extension * used for threading is written by default if the user * explicitly requested threaded index reads. */ return !git_config_get_index_threads(&val) && val != 1; } static int record_ieot(void) { int val; if (!git_config_get_bool("index.recordoffsettable", &val)) return val; /* * As a convenience, the offset table used for threading is * written by default if the user explicitly requested * threaded index reads. */ return !git_config_get_index_threads(&val) && val != 1; } /* * On success, `tempfile` is closed. If it is the temporary file * of a `struct lock_file`, we will therefore effectively perform * a 'close_lock_file_gently()`. Since that is an implementation * detail of lockfiles, callers of `do_write_index()` should not * rely on it. */ static int do_write_index(struct index_state *istate, struct tempfile *tempfile, int strip_extensions) { uint64_t start = getnanotime(); int newfd = tempfile->fd; git_hash_ctx c, eoie_c; struct cache_header hdr; int i, err = 0, removed, extended, hdr_version; struct cache_entry **cache = istate->cache; int entries = istate->cache_nr; struct stat st; struct ondisk_cache_entry ondisk; struct strbuf previous_name_buf = STRBUF_INIT, *previous_name; int drop_cache_tree = istate->drop_cache_tree; off_t offset; int ieot_entries = 1; struct index_entry_offset_table *ieot = NULL; int nr, nr_threads; for (i = removed = extended = 0; i < entries; i++) { if (cache[i]->ce_flags & CE_REMOVE) removed++; /* reduce extended entries if possible */ cache[i]->ce_flags &= ~CE_EXTENDED; if (cache[i]->ce_flags & CE_EXTENDED_FLAGS) { extended++; cache[i]->ce_flags |= CE_EXTENDED; } } if (!istate->version) { istate->version = get_index_format_default(the_repository); if (git_env_bool("GIT_TEST_SPLIT_INDEX", 0)) init_split_index(istate); } /* demote version 3 to version 2 when the latter suffices */ if (istate->version == 3 || istate->version == 2) istate->version = extended ? 3 : 2; hdr_version = istate->version; hdr.hdr_signature = htonl(CACHE_SIGNATURE); hdr.hdr_version = htonl(hdr_version); hdr.hdr_entries = htonl(entries - removed); the_hash_algo->init_fn(&c); if (ce_write(&c, newfd, &hdr, sizeof(hdr)) < 0) return -1; if (!HAVE_THREADS || git_config_get_index_threads(&nr_threads)) nr_threads = 1; if (nr_threads != 1 && record_ieot()) { int ieot_blocks, cpus; /* * ensure default number of ieot blocks maps evenly to the * default number of threads that will process them leaving * room for the thread to load the index extensions. */ if (!nr_threads) { ieot_blocks = istate->cache_nr / THREAD_COST; cpus = online_cpus(); if (ieot_blocks > cpus - 1) ieot_blocks = cpus - 1; } else { ieot_blocks = nr_threads; if (ieot_blocks > istate->cache_nr) ieot_blocks = istate->cache_nr; } /* * no reason to write out the IEOT extension if we don't * have enough blocks to utilize multi-threading */ if (ieot_blocks > 1) { ieot = xcalloc(1, sizeof(struct index_entry_offset_table) + (ieot_blocks * sizeof(struct index_entry_offset))); ieot_entries = DIV_ROUND_UP(entries, ieot_blocks); } } offset = lseek(newfd, 0, SEEK_CUR); if (offset < 0) { free(ieot); return -1; } offset += write_buffer_len; nr = 0; previous_name = (hdr_version == 4) ? &previous_name_buf : NULL; for (i = 0; i < entries; i++) { struct cache_entry *ce = cache[i]; if (ce->ce_flags & CE_REMOVE) continue; if (!ce_uptodate(ce) && is_racy_timestamp(istate, ce)) ce_smudge_racily_clean_entry(istate, ce); if (is_null_oid(&ce->oid)) { static const char msg[] = "cache entry has null sha1: %s"; static int allow = -1; if (allow < 0) allow = git_env_bool("GIT_ALLOW_NULL_SHA1", 0); if (allow) warning(msg, ce->name); else err = error(msg, ce->name); drop_cache_tree = 1; } if (ieot && i && (i % ieot_entries == 0)) { ieot->entries[ieot->nr].nr = nr; ieot->entries[ieot->nr].offset = offset; ieot->nr++; /* * If we have a V4 index, set the first byte to an invalid * character to ensure there is nothing common with the previous * entry */ if (previous_name) previous_name->buf[0] = 0; nr = 0; offset = lseek(newfd, 0, SEEK_CUR); if (offset < 0) { free(ieot); return -1; } offset += write_buffer_len; } if (ce_write_entry(&c, newfd, ce, previous_name, (struct ondisk_cache_entry *)&ondisk) < 0) err = -1; if (err) break; nr++; } if (ieot && nr) { ieot->entries[ieot->nr].nr = nr; ieot->entries[ieot->nr].offset = offset; ieot->nr++; } strbuf_release(&previous_name_buf); if (err) { free(ieot); return err; } /* Write extension data here */ offset = lseek(newfd, 0, SEEK_CUR); if (offset < 0) { free(ieot); return -1; } offset += write_buffer_len; the_hash_algo->init_fn(&eoie_c); /* * Lets write out CACHE_EXT_INDEXENTRYOFFSETTABLE first so that we * can minimize the number of extensions we have to scan through to * find it during load. Write it out regardless of the * strip_extensions parameter as we need it when loading the shared * index. */ if (ieot) { struct strbuf sb = STRBUF_INIT; write_ieot_extension(&sb, ieot); err = write_index_ext_header(&c, &eoie_c, newfd, CACHE_EXT_INDEXENTRYOFFSETTABLE, sb.len) < 0 || ce_write(&c, newfd, sb.buf, sb.len) < 0; strbuf_release(&sb); free(ieot); if (err) return -1; } if (!strip_extensions && istate->split_index && !is_null_oid(&istate->split_index->base_oid)) { struct strbuf sb = STRBUF_INIT; err = write_link_extension(&sb, istate) < 0 || write_index_ext_header(&c, &eoie_c, newfd, CACHE_EXT_LINK, sb.len) < 0 || ce_write(&c, newfd, sb.buf, sb.len) < 0; strbuf_release(&sb); if (err) return -1; } if (!strip_extensions && !drop_cache_tree && istate->cache_tree) { struct strbuf sb = STRBUF_INIT; cache_tree_write(&sb, istate->cache_tree); err = write_index_ext_header(&c, &eoie_c, newfd, CACHE_EXT_TREE, sb.len) < 0 || ce_write(&c, newfd, sb.buf, sb.len) < 0; strbuf_release(&sb); if (err) return -1; } if (!strip_extensions && istate->resolve_undo) { struct strbuf sb = STRBUF_INIT; resolve_undo_write(&sb, istate->resolve_undo); err = write_index_ext_header(&c, &eoie_c, newfd, CACHE_EXT_RESOLVE_UNDO, sb.len) < 0 || ce_write(&c, newfd, sb.buf, sb.len) < 0; strbuf_release(&sb); if (err) return -1; } if (!strip_extensions && istate->untracked) { struct strbuf sb = STRBUF_INIT; write_untracked_extension(&sb, istate->untracked); err = write_index_ext_header(&c, &eoie_c, newfd, CACHE_EXT_UNTRACKED, sb.len) < 0 || ce_write(&c, newfd, sb.buf, sb.len) < 0; strbuf_release(&sb); if (err) return -1; } if (!strip_extensions && istate->fsmonitor_last_update) { struct strbuf sb = STRBUF_INIT; write_fsmonitor_extension(&sb, istate); err = write_index_ext_header(&c, &eoie_c, newfd, CACHE_EXT_FSMONITOR, sb.len) < 0 || ce_write(&c, newfd, sb.buf, sb.len) < 0; strbuf_release(&sb); if (err) return -1; } /* * CACHE_EXT_ENDOFINDEXENTRIES must be written as the last entry before the SHA1 * so that it can be found and processed before all the index entries are * read. Write it out regardless of the strip_extensions parameter as we need it * when loading the shared index. */ if (offset && record_eoie()) { struct strbuf sb = STRBUF_INIT; write_eoie_extension(&sb, &eoie_c, offset); err = write_index_ext_header(&c, NULL, newfd, CACHE_EXT_ENDOFINDEXENTRIES, sb.len) < 0 || ce_write(&c, newfd, sb.buf, sb.len) < 0; strbuf_release(&sb); if (err) return -1; } if (ce_flush(&c, newfd, istate->oid.hash)) return -1; if (close_tempfile_gently(tempfile)) { error(_("could not close '%s'"), get_tempfile_path(tempfile)); return -1; } if (stat(get_tempfile_path(tempfile), &st)) return -1; istate->timestamp.sec = (unsigned int)st.st_mtime; istate->timestamp.nsec = ST_MTIME_NSEC(st); trace_performance_since(start, "write index, changed mask = %x", istate->cache_changed); /* * TODO trace2: replace "the_repository" with the actual repo instance * that is associated with the given "istate". */ trace2_data_intmax("index", the_repository, "write/version", istate->version); trace2_data_intmax("index", the_repository, "write/cache_nr", istate->cache_nr); return 0; } void set_alternate_index_output(const char *name) { alternate_index_output = name; } static int commit_locked_index(struct lock_file *lk) { if (alternate_index_output) return commit_lock_file_to(lk, alternate_index_output); else return commit_lock_file(lk); } static int do_write_locked_index(struct index_state *istate, struct lock_file *lock, unsigned flags) { int ret; /* * TODO trace2: replace "the_repository" with the actual repo instance * that is associated with the given "istate". */ trace2_region_enter_printf("index", "do_write_index", the_repository, "%s", get_lock_file_path(lock)); ret = do_write_index(istate, lock->tempfile, 0); trace2_region_leave_printf("index", "do_write_index", the_repository, "%s", get_lock_file_path(lock)); if (ret) return ret; if (flags & COMMIT_LOCK) ret = commit_locked_index(lock); else ret = close_lock_file_gently(lock); run_hook_le(NULL, "post-index-change", istate->updated_workdir ? "1" : "0", istate->updated_skipworktree ? "1" : "0", NULL); istate->updated_workdir = 0; istate->updated_skipworktree = 0; return ret; } static int write_split_index(struct index_state *istate, struct lock_file *lock, unsigned flags) { int ret; prepare_to_write_split_index(istate); ret = do_write_locked_index(istate, lock, flags); finish_writing_split_index(istate); return ret; } static const char *shared_index_expire = "2.weeks.ago"; static unsigned long get_shared_index_expire_date(void) { static unsigned long shared_index_expire_date; static int shared_index_expire_date_prepared; if (!shared_index_expire_date_prepared) { git_config_get_expiry("splitindex.sharedindexexpire", &shared_index_expire); shared_index_expire_date = approxidate(shared_index_expire); shared_index_expire_date_prepared = 1; } return shared_index_expire_date; } static int should_delete_shared_index(const char *shared_index_path) { struct stat st; unsigned long expiration; /* Check timestamp */ expiration = get_shared_index_expire_date(); if (!expiration) return 0; if (stat(shared_index_path, &st)) return error_errno(_("could not stat '%s'"), shared_index_path); if (st.st_mtime > expiration) return 0; return 1; } static int clean_shared_index_files(const char *current_hex) { struct dirent *de; DIR *dir = opendir(get_git_dir()); if (!dir) return error_errno(_("unable to open git dir: %s"), get_git_dir()); while ((de = readdir(dir)) != NULL) { const char *sha1_hex; const char *shared_index_path; if (!skip_prefix(de->d_name, "sharedindex.", &sha1_hex)) continue; if (!strcmp(sha1_hex, current_hex)) continue; shared_index_path = git_path("%s", de->d_name); if (should_delete_shared_index(shared_index_path) > 0 && unlink(shared_index_path)) warning_errno(_("unable to unlink: %s"), shared_index_path); } closedir(dir); return 0; } static int write_shared_index(struct index_state *istate, struct tempfile **temp) { struct split_index *si = istate->split_index; int ret; move_cache_to_base_index(istate); trace2_region_enter_printf("index", "shared/do_write_index", the_repository, "%s", get_tempfile_path(*temp)); ret = do_write_index(si->base, *temp, 1); trace2_region_leave_printf("index", "shared/do_write_index", the_repository, "%s", get_tempfile_path(*temp)); if (ret) return ret; ret = adjust_shared_perm(get_tempfile_path(*temp)); if (ret) { error(_("cannot fix permission bits on '%s'"), get_tempfile_path(*temp)); return ret; } ret = rename_tempfile(temp, git_path("sharedindex.%s", oid_to_hex(&si->base->oid))); if (!ret) { oidcpy(&si->base_oid, &si->base->oid); clean_shared_index_files(oid_to_hex(&si->base->oid)); } return ret; } static const int default_max_percent_split_change = 20; static int too_many_not_shared_entries(struct index_state *istate) { int i, not_shared = 0; int max_split = git_config_get_max_percent_split_change(); switch (max_split) { case -1: /* not or badly configured: use the default value */ max_split = default_max_percent_split_change; break; case 0: return 1; /* 0% means always write a new shared index */ case 100: return 0; /* 100% means never write a new shared index */ default: break; /* just use the configured value */ } /* Count not shared entries */ for (i = 0; i < istate->cache_nr; i++) { struct cache_entry *ce = istate->cache[i]; if (!ce->index) not_shared++; } return (int64_t)istate->cache_nr * max_split < (int64_t)not_shared * 100; } int write_locked_index(struct index_state *istate, struct lock_file *lock, unsigned flags) { int new_shared_index, ret; struct split_index *si = istate->split_index; if (git_env_bool("GIT_TEST_CHECK_CACHE_TREE", 0)) cache_tree_verify(the_repository, istate); if ((flags & SKIP_IF_UNCHANGED) && !istate->cache_changed) { if (flags & COMMIT_LOCK) rollback_lock_file(lock); return 0; } if (istate->fsmonitor_last_update) fill_fsmonitor_bitmap(istate); if (!si || alternate_index_output || (istate->cache_changed & ~EXTMASK)) { if (si) oidclr(&si->base_oid); ret = do_write_locked_index(istate, lock, flags); goto out; } if (git_env_bool("GIT_TEST_SPLIT_INDEX", 0)) { int v = si->base_oid.hash[0]; if ((v & 15) < 6) istate->cache_changed |= SPLIT_INDEX_ORDERED; } if (too_many_not_shared_entries(istate)) istate->cache_changed |= SPLIT_INDEX_ORDERED; new_shared_index = istate->cache_changed & SPLIT_INDEX_ORDERED; if (new_shared_index) { struct tempfile *temp; int saved_errno; /* Same initial permissions as the main .git/index file */ temp = mks_tempfile_sm(git_path("sharedindex_XXXXXX"), 0, 0666); if (!temp) { oidclr(&si->base_oid); ret = do_write_locked_index(istate, lock, flags); goto out; } ret = write_shared_index(istate, &temp); saved_errno = errno; if (is_tempfile_active(temp)) delete_tempfile(&temp); errno = saved_errno; if (ret) goto out; } ret = write_split_index(istate, lock, flags); /* Freshen the shared index only if the split-index was written */ if (!ret && !new_shared_index && !is_null_oid(&si->base_oid)) { const char *shared_index = git_path("sharedindex.%s", oid_to_hex(&si->base_oid)); freshen_shared_index(shared_index, 1); } out: if (flags & COMMIT_LOCK) rollback_lock_file(lock); return ret; } /* * Read the index file that is potentially unmerged into given * index_state, dropping any unmerged entries to stage #0 (potentially * resulting in a path appearing as both a file and a directory in the * index; the caller is responsible to clear out the extra entries * before writing the index to a tree). Returns true if the index is * unmerged. Callers who want to refuse to work from an unmerged * state can call this and check its return value, instead of calling * read_cache(). */ int repo_read_index_unmerged(struct repository *repo) { struct index_state *istate; int i; int unmerged = 0; repo_read_index(repo); istate = repo->index; for (i = 0; i < istate->cache_nr; i++) { struct cache_entry *ce = istate->cache[i]; struct cache_entry *new_ce; int len; if (!ce_stage(ce)) continue; unmerged = 1; len = ce_namelen(ce); new_ce = make_empty_cache_entry(istate, len); memcpy(new_ce->name, ce->name, len); new_ce->ce_flags = create_ce_flags(0) | CE_CONFLICTED; new_ce->ce_namelen = len; new_ce->ce_mode = ce->ce_mode; if (add_index_entry(istate, new_ce, ADD_CACHE_SKIP_DFCHECK)) return error(_("%s: cannot drop to stage #0"), new_ce->name); } return unmerged; } /* * Returns 1 if the path is an "other" path with respect to * the index; that is, the path is not mentioned in the index at all, * either as a file, a directory with some files in the index, * or as an unmerged entry. * * We helpfully remove a trailing "/" from directories so that * the output of read_directory can be used as-is. */ int index_name_is_other(const struct index_state *istate, const char *name, int namelen) { int pos; if (namelen && name[namelen - 1] == '/') namelen--; pos = index_name_pos(istate, name, namelen); if (0 <= pos) return 0; /* exact match */ pos = -pos - 1; if (pos < istate->cache_nr) { struct cache_entry *ce = istate->cache[pos]; if (ce_namelen(ce) == namelen && !memcmp(ce->name, name, namelen)) return 0; /* Yup, this one exists unmerged */ } return 1; } void *read_blob_data_from_index(const struct index_state *istate, const char *path, unsigned long *size) { int pos, len; unsigned long sz; enum object_type type; void *data; len = strlen(path); pos = index_name_pos(istate, path, len); if (pos < 0) { /* * We might be in the middle of a merge, in which * case we would read stage #2 (ours). */ int i; for (i = -pos - 1; (pos < 0 && i < istate->cache_nr && !strcmp(istate->cache[i]->name, path)); i++) if (ce_stage(istate->cache[i]) == 2) pos = i; } if (pos < 0) return NULL; data = read_object_file(&istate->cache[pos]->oid, &type, &sz); if (!data || type != OBJ_BLOB) { free(data); return NULL; } if (size) *size = sz; return data; } void stat_validity_clear(struct stat_validity *sv) { FREE_AND_NULL(sv->sd); } int stat_validity_check(struct stat_validity *sv, const char *path) { struct stat st; if (stat(path, &st) < 0) return sv->sd == NULL; if (!sv->sd) return 0; return S_ISREG(st.st_mode) && !match_stat_data(sv->sd, &st); } void stat_validity_update(struct stat_validity *sv, int fd) { struct stat st; if (fstat(fd, &st) < 0 || !S_ISREG(st.st_mode)) stat_validity_clear(sv); else { if (!sv->sd) sv->sd = xcalloc(1, sizeof(struct stat_data)); fill_stat_data(sv->sd, &st); } } void move_index_extensions(struct index_state *dst, struct index_state *src) { dst->untracked = src->untracked; src->untracked = NULL; dst->cache_tree = src->cache_tree; src->cache_tree = NULL; } struct cache_entry *dup_cache_entry(const struct cache_entry *ce, struct index_state *istate) { unsigned int size = ce_size(ce); int mem_pool_allocated; struct cache_entry *new_entry = make_empty_cache_entry(istate, ce_namelen(ce)); mem_pool_allocated = new_entry->mem_pool_allocated; memcpy(new_entry, ce, size); new_entry->mem_pool_allocated = mem_pool_allocated; return new_entry; } void discard_cache_entry(struct cache_entry *ce) { if (ce && should_validate_cache_entries()) memset(ce, 0xCD, cache_entry_size(ce->ce_namelen)); if (ce && ce->mem_pool_allocated) return; free(ce); } int should_validate_cache_entries(void) { static int validate_index_cache_entries = -1; if (validate_index_cache_entries < 0) { if (getenv("GIT_TEST_VALIDATE_INDEX_CACHE_ENTRIES")) validate_index_cache_entries = 1; else validate_index_cache_entries = 0; } return validate_index_cache_entries; } #define EOIE_SIZE (4 + GIT_SHA1_RAWSZ) /* <4-byte offset> + <20-byte hash> */ #define EOIE_SIZE_WITH_HEADER (4 + 4 + EOIE_SIZE) /* <4-byte signature> + <4-byte length> + EOIE_SIZE */ static size_t read_eoie_extension(const char *mmap, size_t mmap_size) { /* * The end of index entries (EOIE) extension is guaranteed to be last * so that it can be found by scanning backwards from the EOF. * * "EOIE" * <4-byte length> * <4-byte offset> * <20-byte hash> */ const char *index, *eoie; uint32_t extsize; size_t offset, src_offset; unsigned char hash[GIT_MAX_RAWSZ]; git_hash_ctx c; /* ensure we have an index big enough to contain an EOIE extension */ if (mmap_size < sizeof(struct cache_header) + EOIE_SIZE_WITH_HEADER + the_hash_algo->rawsz) return 0; /* validate the extension signature */ index = eoie = mmap + mmap_size - EOIE_SIZE_WITH_HEADER - the_hash_algo->rawsz; if (CACHE_EXT(index) != CACHE_EXT_ENDOFINDEXENTRIES) return 0; index += sizeof(uint32_t); /* validate the extension size */ extsize = get_be32(index); if (extsize != EOIE_SIZE) return 0; index += sizeof(uint32_t); /* * Validate the offset we're going to look for the first extension * signature is after the index header and before the eoie extension. */ offset = get_be32(index); if (mmap + offset < mmap + sizeof(struct cache_header)) return 0; if (mmap + offset >= eoie) return 0; index += sizeof(uint32_t); /* * The hash is computed over extension types and their sizes (but not * their contents). E.g. if we have "TREE" extension that is N-bytes * long, "REUC" extension that is M-bytes long, followed by "EOIE", * then the hash would be: * * SHA-1("TREE" + + * "REUC" + ) */ src_offset = offset; the_hash_algo->init_fn(&c); while (src_offset < mmap_size - the_hash_algo->rawsz - EOIE_SIZE_WITH_HEADER) { /* After an array of active_nr index entries, * there can be arbitrary number of extended * sections, each of which is prefixed with * extension name (4-byte) and section length * in 4-byte network byte order. */ uint32_t extsize; memcpy(&extsize, mmap + src_offset + 4, 4); extsize = ntohl(extsize); /* verify the extension size isn't so large it will wrap around */ if (src_offset + 8 + extsize < src_offset) return 0; the_hash_algo->update_fn(&c, mmap + src_offset, 8); src_offset += 8; src_offset += extsize; } the_hash_algo->final_fn(hash, &c); if (!hasheq(hash, (const unsigned char *)index)) return 0; /* Validate that the extension offsets returned us back to the eoie extension. */ if (src_offset != mmap_size - the_hash_algo->rawsz - EOIE_SIZE_WITH_HEADER) return 0; return offset; } static void write_eoie_extension(struct strbuf *sb, git_hash_ctx *eoie_context, size_t offset) { uint32_t buffer; unsigned char hash[GIT_MAX_RAWSZ]; /* offset */ put_be32(&buffer, offset); strbuf_add(sb, &buffer, sizeof(uint32_t)); /* hash */ the_hash_algo->final_fn(hash, eoie_context); strbuf_add(sb, hash, the_hash_algo->rawsz); } #define IEOT_VERSION (1) static struct index_entry_offset_table *read_ieot_extension(const char *mmap, size_t mmap_size, size_t offset) { const char *index = NULL; uint32_t extsize, ext_version; struct index_entry_offset_table *ieot; int i, nr; /* find the IEOT extension */ if (!offset) return NULL; while (offset <= mmap_size - the_hash_algo->rawsz - 8) { extsize = get_be32(mmap + offset + 4); if (CACHE_EXT((mmap + offset)) == CACHE_EXT_INDEXENTRYOFFSETTABLE) { index = mmap + offset + 4 + 4; break; } offset += 8; offset += extsize; } if (!index) return NULL; /* validate the version is IEOT_VERSION */ ext_version = get_be32(index); if (ext_version != IEOT_VERSION) { error("invalid IEOT version %d", ext_version); return NULL; } index += sizeof(uint32_t); /* extension size - version bytes / bytes per entry */ nr = (extsize - sizeof(uint32_t)) / (sizeof(uint32_t) + sizeof(uint32_t)); if (!nr) { error("invalid number of IEOT entries %d", nr); return NULL; } ieot = xmalloc(sizeof(struct index_entry_offset_table) + (nr * sizeof(struct index_entry_offset))); ieot->nr = nr; for (i = 0; i < nr; i++) { ieot->entries[i].offset = get_be32(index); index += sizeof(uint32_t); ieot->entries[i].nr = get_be32(index); index += sizeof(uint32_t); } return ieot; } static void write_ieot_extension(struct strbuf *sb, struct index_entry_offset_table *ieot) { uint32_t buffer; int i; /* version */ put_be32(&buffer, IEOT_VERSION); strbuf_add(sb, &buffer, sizeof(uint32_t)); /* ieot */ for (i = 0; i < ieot->nr; i++) { /* offset */ put_be32(&buffer, ieot->entries[i].offset); strbuf_add(sb, &buffer, sizeof(uint32_t)); /* count */ put_be32(&buffer, ieot->entries[i].nr); strbuf_add(sb, &buffer, sizeof(uint32_t)); } }