diff options
Diffstat (limited to 'third_party/git/cache-tree.c')
| -rw-r--r-- | third_party/git/cache-tree.c | 808 |
1 files changed, 808 insertions, 0 deletions
diff --git a/third_party/git/cache-tree.c b/third_party/git/cache-tree.c new file mode 100644 index 0000000000..706ffcf188 --- /dev/null +++ b/third_party/git/cache-tree.c @@ -0,0 +1,808 @@ +#include "cache.h" +#include "lockfile.h" +#include "tree.h" +#include "tree-walk.h" +#include "cache-tree.h" +#include "object-store.h" +#include "replace-object.h" + +#ifndef DEBUG_CACHE_TREE +#define DEBUG_CACHE_TREE 0 +#endif + +struct cache_tree *cache_tree(void) +{ + struct cache_tree *it = xcalloc(1, sizeof(struct cache_tree)); + it->entry_count = -1; + return it; +} + +void cache_tree_free(struct cache_tree **it_p) +{ + int i; + struct cache_tree *it = *it_p; + + if (!it) + return; + for (i = 0; i < it->subtree_nr; i++) + if (it->down[i]) { + cache_tree_free(&it->down[i]->cache_tree); + free(it->down[i]); + } + free(it->down); + free(it); + *it_p = NULL; +} + +static int subtree_name_cmp(const char *one, int onelen, + const char *two, int twolen) +{ + if (onelen < twolen) + return -1; + if (twolen < onelen) + return 1; + return memcmp(one, two, onelen); +} + +static int subtree_pos(struct cache_tree *it, const char *path, int pathlen) +{ + struct cache_tree_sub **down = it->down; + int lo, hi; + lo = 0; + hi = it->subtree_nr; + while (lo < hi) { + int mi = lo + (hi - lo) / 2; + struct cache_tree_sub *mdl = down[mi]; + int cmp = subtree_name_cmp(path, pathlen, + mdl->name, mdl->namelen); + if (!cmp) + return mi; + if (cmp < 0) + hi = mi; + else + lo = mi + 1; + } + return -lo-1; +} + +static struct cache_tree_sub *find_subtree(struct cache_tree *it, + const char *path, + int pathlen, + int create) +{ + struct cache_tree_sub *down; + int pos = subtree_pos(it, path, pathlen); + if (0 <= pos) + return it->down[pos]; + if (!create) + return NULL; + + pos = -pos-1; + ALLOC_GROW(it->down, it->subtree_nr + 1, it->subtree_alloc); + it->subtree_nr++; + + FLEX_ALLOC_MEM(down, name, path, pathlen); + down->cache_tree = NULL; + down->namelen = pathlen; + + if (pos < it->subtree_nr) + MOVE_ARRAY(it->down + pos + 1, it->down + pos, + it->subtree_nr - pos - 1); + it->down[pos] = down; + return down; +} + +struct cache_tree_sub *cache_tree_sub(struct cache_tree *it, const char *path) +{ + int pathlen = strlen(path); + return find_subtree(it, path, pathlen, 1); +} + +static int do_invalidate_path(struct cache_tree *it, const char *path) +{ + /* a/b/c + * ==> invalidate self + * ==> find "a", have it invalidate "b/c" + * a + * ==> invalidate self + * ==> if "a" exists as a subtree, remove it. + */ + const char *slash; + int namelen; + struct cache_tree_sub *down; + +#if DEBUG_CACHE_TREE + fprintf(stderr, "cache-tree invalidate <%s>\n", path); +#endif + + if (!it) + return 0; + slash = strchrnul(path, '/'); + namelen = slash - path; + it->entry_count = -1; + if (!*slash) { + int pos; + pos = subtree_pos(it, path, namelen); + if (0 <= pos) { + cache_tree_free(&it->down[pos]->cache_tree); + free(it->down[pos]); + /* 0 1 2 3 4 5 + * ^ ^subtree_nr = 6 + * pos + * move 4 and 5 up one place (2 entries) + * 2 = 6 - 3 - 1 = subtree_nr - pos - 1 + */ + MOVE_ARRAY(it->down + pos, it->down + pos + 1, + it->subtree_nr - pos - 1); + it->subtree_nr--; + } + return 1; + } + down = find_subtree(it, path, namelen, 0); + if (down) + do_invalidate_path(down->cache_tree, slash + 1); + return 1; +} + +void cache_tree_invalidate_path(struct index_state *istate, const char *path) +{ + if (do_invalidate_path(istate->cache_tree, path)) + istate->cache_changed |= CACHE_TREE_CHANGED; +} + +static int verify_cache(struct cache_entry **cache, + int entries, int flags) +{ + int i, funny; + int silent = flags & WRITE_TREE_SILENT; + + /* Verify that the tree is merged */ + funny = 0; + for (i = 0; i < entries; i++) { + const struct cache_entry *ce = cache[i]; + if (ce_stage(ce)) { + if (silent) + return -1; + if (10 < ++funny) { + fprintf(stderr, "...\n"); + break; + } + fprintf(stderr, "%s: unmerged (%s)\n", + ce->name, oid_to_hex(&ce->oid)); + } + } + if (funny) + return -1; + + /* Also verify that the cache does not have path and path/file + * at the same time. At this point we know the cache has only + * stage 0 entries. + */ + funny = 0; + for (i = 0; i < entries - 1; i++) { + /* path/file always comes after path because of the way + * the cache is sorted. Also path can appear only once, + * which means conflicting one would immediately follow. + */ + const char *this_name = cache[i]->name; + const char *next_name = cache[i+1]->name; + int this_len = strlen(this_name); + if (this_len < strlen(next_name) && + strncmp(this_name, next_name, this_len) == 0 && + next_name[this_len] == '/') { + if (10 < ++funny) { + fprintf(stderr, "...\n"); + break; + } + fprintf(stderr, "You have both %s and %s\n", + this_name, next_name); + } + } + if (funny) + return -1; + return 0; +} + +static void discard_unused_subtrees(struct cache_tree *it) +{ + struct cache_tree_sub **down = it->down; + int nr = it->subtree_nr; + int dst, src; + for (dst = src = 0; src < nr; src++) { + struct cache_tree_sub *s = down[src]; + if (s->used) + down[dst++] = s; + else { + cache_tree_free(&s->cache_tree); + free(s); + it->subtree_nr--; + } + } +} + +int cache_tree_fully_valid(struct cache_tree *it) +{ + int i; + if (!it) + return 0; + if (it->entry_count < 0 || !has_object_file(&it->oid)) + return 0; + for (i = 0; i < it->subtree_nr; i++) { + if (!cache_tree_fully_valid(it->down[i]->cache_tree)) + return 0; + } + return 1; +} + +static int update_one(struct cache_tree *it, + struct cache_entry **cache, + int entries, + const char *base, + int baselen, + int *skip_count, + int flags) +{ + struct strbuf buffer; + int missing_ok = flags & WRITE_TREE_MISSING_OK; + int dryrun = flags & WRITE_TREE_DRY_RUN; + int repair = flags & WRITE_TREE_REPAIR; + int to_invalidate = 0; + int i; + + assert(!(dryrun && repair)); + + *skip_count = 0; + + if (0 <= it->entry_count && has_object_file(&it->oid)) + return it->entry_count; + + /* + * We first scan for subtrees and update them; we start by + * marking existing subtrees -- the ones that are unmarked + * should not be in the result. + */ + for (i = 0; i < it->subtree_nr; i++) + it->down[i]->used = 0; + + /* + * Find the subtrees and update them. + */ + i = 0; + while (i < entries) { + const struct cache_entry *ce = cache[i]; + struct cache_tree_sub *sub; + const char *path, *slash; + int pathlen, sublen, subcnt, subskip; + + path = ce->name; + pathlen = ce_namelen(ce); + if (pathlen <= baselen || memcmp(base, path, baselen)) + break; /* at the end of this level */ + + slash = strchr(path + baselen, '/'); + if (!slash) { + i++; + continue; + } + /* + * a/bbb/c (base = a/, slash = /c) + * ==> + * path+baselen = bbb/c, sublen = 3 + */ + sublen = slash - (path + baselen); + sub = find_subtree(it, path + baselen, sublen, 1); + if (!sub->cache_tree) + sub->cache_tree = cache_tree(); + subcnt = update_one(sub->cache_tree, + cache + i, entries - i, + path, + baselen + sublen + 1, + &subskip, + flags); + if (subcnt < 0) + return subcnt; + if (!subcnt) + die("index cache-tree records empty sub-tree"); + i += subcnt; + sub->count = subcnt; /* to be used in the next loop */ + *skip_count += subskip; + sub->used = 1; + } + + discard_unused_subtrees(it); + + /* + * Then write out the tree object for this level. + */ + strbuf_init(&buffer, 8192); + + i = 0; + while (i < entries) { + const struct cache_entry *ce = cache[i]; + struct cache_tree_sub *sub = NULL; + const char *path, *slash; + int pathlen, entlen; + const struct object_id *oid; + unsigned mode; + int expected_missing = 0; + int contains_ita = 0; + int ce_missing_ok; + + path = ce->name; + pathlen = ce_namelen(ce); + if (pathlen <= baselen || memcmp(base, path, baselen)) + break; /* at the end of this level */ + + slash = strchr(path + baselen, '/'); + if (slash) { + entlen = slash - (path + baselen); + sub = find_subtree(it, path + baselen, entlen, 0); + if (!sub) + die("cache-tree.c: '%.*s' in '%s' not found", + entlen, path + baselen, path); + i += sub->count; + oid = &sub->cache_tree->oid; + mode = S_IFDIR; + contains_ita = sub->cache_tree->entry_count < 0; + if (contains_ita) { + to_invalidate = 1; + expected_missing = 1; + } + } + else { + oid = &ce->oid; + mode = ce->ce_mode; + entlen = pathlen - baselen; + i++; + } + + ce_missing_ok = mode == S_IFGITLINK || missing_ok || + (repository_format_partial_clone && + ce_skip_worktree(ce)); + if (is_null_oid(oid) || + (!ce_missing_ok && !has_object_file(oid))) { + strbuf_release(&buffer); + if (expected_missing) + return -1; + return error("invalid object %06o %s for '%.*s'", + mode, oid_to_hex(oid), entlen+baselen, path); + } + + /* + * CE_REMOVE entries are removed before the index is + * written to disk. Skip them to remain consistent + * with the future on-disk index. + */ + if (ce->ce_flags & CE_REMOVE) { + *skip_count = *skip_count + 1; + continue; + } + + /* + * CE_INTENT_TO_ADD entries exist on on-disk index but + * they are not part of generated trees. Invalidate up + * to root to force cache-tree users to read elsewhere. + */ + if (!sub && ce_intent_to_add(ce)) { + to_invalidate = 1; + continue; + } + + /* + * "sub" can be an empty tree if all subentries are i-t-a. + */ + if (contains_ita && is_empty_tree_oid(oid)) + continue; + + strbuf_grow(&buffer, entlen + 100); + strbuf_addf(&buffer, "%o %.*s%c", mode, entlen, path + baselen, '\0'); + strbuf_add(&buffer, oid->hash, the_hash_algo->rawsz); + +#if DEBUG_CACHE_TREE + fprintf(stderr, "cache-tree update-one %o %.*s\n", + mode, entlen, path + baselen); +#endif + } + + if (repair) { + struct object_id oid; + hash_object_file(buffer.buf, buffer.len, tree_type, &oid); + if (has_object_file(&oid)) + oidcpy(&it->oid, &oid); + else + to_invalidate = 1; + } else if (dryrun) { + hash_object_file(buffer.buf, buffer.len, tree_type, &it->oid); + } else if (write_object_file(buffer.buf, buffer.len, tree_type, + &it->oid)) { + strbuf_release(&buffer); + return -1; + } + + strbuf_release(&buffer); + it->entry_count = to_invalidate ? -1 : i - *skip_count; +#if DEBUG_CACHE_TREE + fprintf(stderr, "cache-tree update-one (%d ent, %d subtree) %s\n", + it->entry_count, it->subtree_nr, + oid_to_hex(&it->oid)); +#endif + return i; +} + +int cache_tree_update(struct index_state *istate, int flags) +{ + struct cache_tree *it = istate->cache_tree; + struct cache_entry **cache = istate->cache; + int entries = istate->cache_nr; + int skip, i = verify_cache(cache, entries, flags); + + if (i) + return i; + trace_performance_enter(); + i = update_one(it, cache, entries, "", 0, &skip, flags); + trace_performance_leave("cache_tree_update"); + if (i < 0) + return i; + istate->cache_changed |= CACHE_TREE_CHANGED; + return 0; +} + +static void write_one(struct strbuf *buffer, struct cache_tree *it, + const char *path, int pathlen) +{ + int i; + + /* One "cache-tree" entry consists of the following: + * path (NUL terminated) + * entry_count, subtree_nr ("%d %d\n") + * tree-sha1 (missing if invalid) + * subtree_nr "cache-tree" entries for subtrees. + */ + strbuf_grow(buffer, pathlen + 100); + strbuf_add(buffer, path, pathlen); + strbuf_addf(buffer, "%c%d %d\n", 0, it->entry_count, it->subtree_nr); + +#if DEBUG_CACHE_TREE + if (0 <= it->entry_count) + fprintf(stderr, "cache-tree <%.*s> (%d ent, %d subtree) %s\n", + pathlen, path, it->entry_count, it->subtree_nr, + oid_to_hex(&it->oid)); + else + fprintf(stderr, "cache-tree <%.*s> (%d subtree) invalid\n", + pathlen, path, it->subtree_nr); +#endif + + if (0 <= it->entry_count) { + strbuf_add(buffer, it->oid.hash, the_hash_algo->rawsz); + } + for (i = 0; i < it->subtree_nr; i++) { + struct cache_tree_sub *down = it->down[i]; + if (i) { + struct cache_tree_sub *prev = it->down[i-1]; + if (subtree_name_cmp(down->name, down->namelen, + prev->name, prev->namelen) <= 0) + die("fatal - unsorted cache subtree"); + } + write_one(buffer, down->cache_tree, down->name, down->namelen); + } +} + +void cache_tree_write(struct strbuf *sb, struct cache_tree *root) +{ + write_one(sb, root, "", 0); +} + +static struct cache_tree *read_one(const char **buffer, unsigned long *size_p) +{ + const char *buf = *buffer; + unsigned long size = *size_p; + const char *cp; + char *ep; + struct cache_tree *it; + int i, subtree_nr; + const unsigned rawsz = the_hash_algo->rawsz; + + it = NULL; + /* skip name, but make sure name exists */ + while (size && *buf) { + size--; + buf++; + } + if (!size) + goto free_return; + buf++; size--; + it = cache_tree(); + + cp = buf; + it->entry_count = strtol(cp, &ep, 10); + if (cp == ep) + goto free_return; + cp = ep; + subtree_nr = strtol(cp, &ep, 10); + if (cp == ep) + goto free_return; + while (size && *buf && *buf != '\n') { + size--; + buf++; + } + if (!size) + goto free_return; + buf++; size--; + if (0 <= it->entry_count) { + if (size < rawsz) + goto free_return; + oidread(&it->oid, (const unsigned char *)buf); + buf += rawsz; + size -= rawsz; + } + +#if DEBUG_CACHE_TREE + if (0 <= it->entry_count) + fprintf(stderr, "cache-tree <%s> (%d ent, %d subtree) %s\n", + *buffer, it->entry_count, subtree_nr, + oid_to_hex(&it->oid)); + else + fprintf(stderr, "cache-tree <%s> (%d subtrees) invalid\n", + *buffer, subtree_nr); +#endif + + /* + * Just a heuristic -- we do not add directories that often but + * we do not want to have to extend it immediately when we do, + * hence +2. + */ + it->subtree_alloc = subtree_nr + 2; + it->down = xcalloc(it->subtree_alloc, sizeof(struct cache_tree_sub *)); + for (i = 0; i < subtree_nr; i++) { + /* read each subtree */ + struct cache_tree *sub; + struct cache_tree_sub *subtree; + const char *name = buf; + + sub = read_one(&buf, &size); + if (!sub) + goto free_return; + subtree = cache_tree_sub(it, name); + subtree->cache_tree = sub; + } + if (subtree_nr != it->subtree_nr) + die("cache-tree: internal error"); + *buffer = buf; + *size_p = size; + return it; + + free_return: + cache_tree_free(&it); + return NULL; +} + +struct cache_tree *cache_tree_read(const char *buffer, unsigned long size) +{ + if (buffer[0]) + return NULL; /* not the whole tree */ + return read_one(&buffer, &size); +} + +static struct cache_tree *cache_tree_find(struct cache_tree *it, const char *path) +{ + if (!it) + return NULL; + while (*path) { + const char *slash; + struct cache_tree_sub *sub; + + slash = strchrnul(path, '/'); + /* + * Between path and slash is the name of the subtree + * to look for. + */ + sub = find_subtree(it, path, slash - path, 0); + if (!sub) + return NULL; + it = sub->cache_tree; + + path = slash; + while (*path == '/') + path++; + } + return it; +} + +int write_index_as_tree(struct object_id *oid, struct index_state *index_state, const char *index_path, int flags, const char *prefix) +{ + int entries, was_valid; + struct lock_file lock_file = LOCK_INIT; + int ret = 0; + + hold_lock_file_for_update(&lock_file, index_path, LOCK_DIE_ON_ERROR); + + entries = read_index_from(index_state, index_path, get_git_dir()); + if (entries < 0) { + ret = WRITE_TREE_UNREADABLE_INDEX; + goto out; + } + if (flags & WRITE_TREE_IGNORE_CACHE_TREE) + cache_tree_free(&index_state->cache_tree); + + if (!index_state->cache_tree) + index_state->cache_tree = cache_tree(); + + was_valid = cache_tree_fully_valid(index_state->cache_tree); + if (!was_valid) { + if (cache_tree_update(index_state, flags) < 0) { + ret = WRITE_TREE_UNMERGED_INDEX; + goto out; + } + write_locked_index(index_state, &lock_file, COMMIT_LOCK); + /* Not being able to write is fine -- we are only interested + * in updating the cache-tree part, and if the next caller + * ends up using the old index with unupdated cache-tree part + * it misses the work we did here, but that is just a + * performance penalty and not a big deal. + */ + } + + if (prefix) { + struct cache_tree *subtree; + subtree = cache_tree_find(index_state->cache_tree, prefix); + if (!subtree) { + ret = WRITE_TREE_PREFIX_ERROR; + goto out; + } + oidcpy(oid, &subtree->oid); + } + else + oidcpy(oid, &index_state->cache_tree->oid); + +out: + rollback_lock_file(&lock_file); + return ret; +} + +static void prime_cache_tree_rec(struct repository *r, + struct cache_tree *it, + struct tree *tree) +{ + struct tree_desc desc; + struct name_entry entry; + int cnt; + + oidcpy(&it->oid, &tree->object.oid); + init_tree_desc(&desc, tree->buffer, tree->size); + cnt = 0; + while (tree_entry(&desc, &entry)) { + if (!S_ISDIR(entry.mode)) + cnt++; + else { + struct cache_tree_sub *sub; + struct tree *subtree = lookup_tree(r, &entry.oid); + if (!subtree->object.parsed) + parse_tree(subtree); + sub = cache_tree_sub(it, entry.path); + sub->cache_tree = cache_tree(); + prime_cache_tree_rec(r, sub->cache_tree, subtree); + cnt += sub->cache_tree->entry_count; + } + } + it->entry_count = cnt; +} + +void prime_cache_tree(struct repository *r, + struct index_state *istate, + struct tree *tree) +{ + cache_tree_free(&istate->cache_tree); + istate->cache_tree = cache_tree(); + prime_cache_tree_rec(r, istate->cache_tree, tree); + istate->cache_changed |= CACHE_TREE_CHANGED; +} + +/* + * find the cache_tree that corresponds to the current level without + * exploding the full path into textual form. The root of the + * cache tree is given as "root", and our current level is "info". + * (1) When at root level, info->prev is NULL, so it is "root" itself. + * (2) Otherwise, find the cache_tree that corresponds to one level + * above us, and find ourselves in there. + */ +static struct cache_tree *find_cache_tree_from_traversal(struct cache_tree *root, + struct traverse_info *info) +{ + struct cache_tree *our_parent; + + if (!info->prev) + return root; + our_parent = find_cache_tree_from_traversal(root, info->prev); + return cache_tree_find(our_parent, info->name.path); +} + +int cache_tree_matches_traversal(struct cache_tree *root, + struct name_entry *ent, + struct traverse_info *info) +{ + struct cache_tree *it; + + it = find_cache_tree_from_traversal(root, info); + it = cache_tree_find(it, ent->path); + if (it && it->entry_count > 0 && oideq(&ent->oid, &it->oid)) + return it->entry_count; + return 0; +} + +static void verify_one(struct repository *r, + struct index_state *istate, + struct cache_tree *it, + struct strbuf *path) +{ + int i, pos, len = path->len; + struct strbuf tree_buf = STRBUF_INIT; + struct object_id new_oid; + + for (i = 0; i < it->subtree_nr; i++) { + strbuf_addf(path, "%s/", it->down[i]->name); + verify_one(r, istate, it->down[i]->cache_tree, path); + strbuf_setlen(path, len); + } + + if (it->entry_count < 0 || + /* no verification on tests (t7003) that replace trees */ + lookup_replace_object(r, &it->oid) != &it->oid) + return; + + if (path->len) { + pos = index_name_pos(istate, path->buf, path->len); + pos = -pos - 1; + } else { + pos = 0; + } + + i = 0; + while (i < it->entry_count) { + struct cache_entry *ce = istate->cache[pos + i]; + const char *slash; + struct cache_tree_sub *sub = NULL; + const struct object_id *oid; + const char *name; + unsigned mode; + int entlen; + + if (ce->ce_flags & (CE_STAGEMASK | CE_INTENT_TO_ADD | CE_REMOVE)) + BUG("%s with flags 0x%x should not be in cache-tree", + ce->name, ce->ce_flags); + name = ce->name + path->len; + slash = strchr(name, '/'); + if (slash) { + entlen = slash - name; + sub = find_subtree(it, ce->name + path->len, entlen, 0); + if (!sub || sub->cache_tree->entry_count < 0) + BUG("bad subtree '%.*s'", entlen, name); + oid = &sub->cache_tree->oid; + mode = S_IFDIR; + i += sub->cache_tree->entry_count; + } else { + oid = &ce->oid; + mode = ce->ce_mode; + entlen = ce_namelen(ce) - path->len; + i++; + } + strbuf_addf(&tree_buf, "%o %.*s%c", mode, entlen, name, '\0'); + strbuf_add(&tree_buf, oid->hash, the_hash_algo->rawsz); + } + hash_object_file(tree_buf.buf, tree_buf.len, tree_type, &new_oid); + if (!oideq(&new_oid, &it->oid)) + BUG("cache-tree for path %.*s does not match. " + "Expected %s got %s", len, path->buf, + oid_to_hex(&new_oid), oid_to_hex(&it->oid)); + strbuf_setlen(path, len); + strbuf_release(&tree_buf); +} + +void cache_tree_verify(struct repository *r, struct index_state *istate) +{ + struct strbuf path = STRBUF_INIT; + + if (!istate->cache_tree) + return; + verify_one(r, istate, istate->cache_tree, &path); + strbuf_release(&path); +} |