diff options
Diffstat (limited to 'path.c')
| -rw-r--r-- | path.c | 277 |
1 files changed, 247 insertions, 30 deletions
@@ -91,54 +91,271 @@ static void replace_dir(struct strbuf *buf, int len, const char *newdir) buf->buf[newlen] = '/'; } -static const char *common_list[] = { - "/branches", "/hooks", "/info", "!/logs", "/lost-found", - "/objects", "/refs", "/remotes", "/worktrees", "/rr-cache", "/svn", - "config", "!gc.pid", "packed-refs", "shallow", - NULL +struct common_dir { + /* Not considered garbage for report_linked_checkout_garbage */ + unsigned ignore_garbage:1; + unsigned is_dir:1; + /* Not common even though its parent is */ + unsigned exclude:1; + const char *dirname; }; -static void update_common_dir(struct strbuf *buf, int git_dir_len) +static struct common_dir common_list[] = { + { 0, 1, 0, "branches" }, + { 0, 1, 0, "hooks" }, + { 0, 1, 0, "info" }, + { 0, 0, 1, "info/sparse-checkout" }, + { 1, 1, 0, "logs" }, + { 1, 1, 1, "logs/HEAD" }, + { 0, 1, 1, "logs/refs/bisect" }, + { 0, 1, 0, "lost-found" }, + { 0, 1, 0, "objects" }, + { 0, 1, 0, "refs" }, + { 0, 1, 1, "refs/bisect" }, + { 0, 1, 0, "remotes" }, + { 0, 1, 0, "worktrees" }, + { 0, 1, 0, "rr-cache" }, + { 0, 1, 0, "svn" }, + { 0, 0, 0, "config" }, + { 1, 0, 0, "gc.pid" }, + { 0, 0, 0, "packed-refs" }, + { 0, 0, 0, "shallow" }, + { 0, 0, 0, NULL } +}; + +/* + * A compressed trie. A trie node consists of zero or more characters that + * are common to all elements with this prefix, optionally followed by some + * children. If value is not NULL, the trie node is a terminal node. + * + * For example, consider the following set of strings: + * abc + * def + * definite + * definition + * + * The trie would look look like: + * root: len = 0, children a and d non-NULL, value = NULL. + * a: len = 2, contents = bc, value = (data for "abc") + * d: len = 2, contents = ef, children i non-NULL, value = (data for "def") + * i: len = 3, contents = nit, children e and i non-NULL, value = NULL + * e: len = 0, children all NULL, value = (data for "definite") + * i: len = 2, contents = on, children all NULL, + * value = (data for "definition") + */ +struct trie { + struct trie *children[256]; + int len; + char *contents; + void *value; +}; + +static struct trie *make_trie_node(const char *key, void *value) { - char *base = buf->buf + git_dir_len; - const char **p; - - if (is_dir_file(base, "logs", "HEAD") || - is_dir_file(base, "info", "sparse-checkout")) - return; /* keep this in $GIT_DIR */ - for (p = common_list; *p; p++) { - const char *path = *p; - int is_dir = 0; - if (*path == '!') - path++; - if (*path == '/') { - path++; - is_dir = 1; + struct trie *new_node = xcalloc(1, sizeof(*new_node)); + new_node->len = strlen(key); + if (new_node->len) { + new_node->contents = xmalloc(new_node->len); + memcpy(new_node->contents, key, new_node->len); + } + new_node->value = value; + return new_node; +} + +/* + * Add a key/value pair to a trie. The key is assumed to be \0-terminated. + * If there was an existing value for this key, return it. + */ +static void *add_to_trie(struct trie *root, const char *key, void *value) +{ + struct trie *child; + void *old; + int i; + + if (!*key) { + /* we have reached the end of the key */ + old = root->value; + root->value = value; + return old; + } + + for (i = 0; i < root->len; i++) { + if (root->contents[i] == key[i]) + continue; + + /* + * Split this node: child will contain this node's + * existing children. + */ + child = malloc(sizeof(*child)); + memcpy(child->children, root->children, sizeof(root->children)); + + child->len = root->len - i - 1; + if (child->len) { + child->contents = xstrndup(root->contents + i + 1, + child->len); } - if (is_dir && dir_prefix(base, path)) { - replace_dir(buf, git_dir_len, get_git_common_dir()); - return; + child->value = root->value; + root->value = NULL; + root->len = i; + + memset(root->children, 0, sizeof(root->children)); + root->children[(unsigned char)root->contents[i]] = child; + + /* This is the newly-added child. */ + root->children[(unsigned char)key[i]] = + make_trie_node(key + i + 1, value); + return NULL; + } + + /* We have matched the entire compressed section */ + if (key[i]) { + child = root->children[(unsigned char)key[root->len]]; + if (child) { + return add_to_trie(child, key + root->len + 1, value); + } else { + child = make_trie_node(key + root->len + 1, value); + root->children[(unsigned char)key[root->len]] = child; + return NULL; } - if (!is_dir && !strcmp(base, path)) { - replace_dir(buf, git_dir_len, get_git_common_dir()); - return; + } + + old = root->value; + root->value = value; + return old; +} + +typedef int (*match_fn)(const char *unmatched, void *data, void *baton); + +/* + * Search a trie for some key. Find the longest /-or-\0-terminated + * prefix of the key for which the trie contains a value. Call fn + * with the unmatched portion of the key and the found value, and + * return its return value. If there is no such prefix, return -1. + * + * The key is partially normalized: consecutive slashes are skipped. + * + * For example, consider the trie containing only [refs, + * refs/worktree] (both with values). + * + * | key | unmatched | val from node | return value | + * |-----------------|------------|---------------|--------------| + * | a | not called | n/a | -1 | + * | refs | \0 | refs | as per fn | + * | refs/ | / | refs | as per fn | + * | refs/w | /w | refs | as per fn | + * | refs/worktree | \0 | refs/worktree | as per fn | + * | refs/worktree/ | / | refs/worktree | as per fn | + * | refs/worktree/a | /a | refs/worktree | as per fn | + * |-----------------|------------|---------------|--------------| + * + */ +static int trie_find(struct trie *root, const char *key, match_fn fn, + void *baton) +{ + int i; + int result; + struct trie *child; + + if (!*key) { + /* we have reached the end of the key */ + if (root->value && !root->len) + return fn(key, root->value, baton); + else + return -1; + } + + for (i = 0; i < root->len; i++) { + /* Partial path normalization: skip consecutive slashes. */ + if (key[i] == '/' && key[i+1] == '/') { + key++; + continue; } + if (root->contents[i] != key[i]) + return -1; } + + /* Matched the entire compressed section */ + key += i; + if (!*key) + /* End of key */ + return fn(key, root->value, baton); + + /* Partial path normalization: skip consecutive slashes */ + while (key[0] == '/' && key[1] == '/') + key++; + + child = root->children[(unsigned char)*key]; + if (child) + result = trie_find(child, key + 1, fn, baton); + else + result = -1; + + if (result >= 0 || (*key != '/' && *key != 0)) + return result; + if (root->value) + return fn(key, root->value, baton); + else + return -1; +} + +static struct trie common_trie; +static int common_trie_done_setup; + +static void init_common_trie(void) +{ + struct common_dir *p; + + if (common_trie_done_setup) + return; + + for (p = common_list; p->dirname; p++) + add_to_trie(&common_trie, p->dirname, p); + + common_trie_done_setup = 1; +} + +/* + * Helper function for update_common_dir: returns 1 if the dir + * prefix is common. + */ +static int check_common(const char *unmatched, void *value, void *baton) +{ + struct common_dir *dir = value; + + if (!dir) + return 0; + + if (dir->is_dir && (unmatched[0] == 0 || unmatched[0] == '/')) + return !dir->exclude; + + if (!dir->is_dir && unmatched[0] == 0) + return !dir->exclude; + + return 0; +} + +static void update_common_dir(struct strbuf *buf, int git_dir_len) +{ + char *base = buf->buf + git_dir_len; + init_common_trie(); + if (trie_find(&common_trie, base, check_common, NULL) > 0) + replace_dir(buf, git_dir_len, get_git_common_dir()); } void report_linked_checkout_garbage(void) { struct strbuf sb = STRBUF_INIT; - const char **p; + const struct common_dir *p; int len; if (!git_common_dir_env) return; strbuf_addf(&sb, "%s/", get_git_dir()); len = sb.len; - for (p = common_list; *p; p++) { - const char *path = *p; - if (*path == '!') + for (p = common_list; p->dirname; p++) { + const char *path = p->dirname; + if (p->ignore_garbage) continue; strbuf_setlen(&sb, len); strbuf_addstr(&sb, path); |