Merge branch 'ps/refname-avail-check-optim'

The code paths to check whether a refname X is available (by seeing
if another ref X/Y exists, etc.) have been optimized.

* ps/refname-avail-check-optim:
  refs: reuse iterators when determining refname availability
  refs/iterator: implement seeking for files iterators
  refs/iterator: implement seeking for packed-ref iterators
  refs/iterator: implement seeking for ref-cache iterators
  refs/iterator: implement seeking for reftable iterators
  refs/iterator: implement seeking for merged iterators
  refs/iterator: provide infrastructure to re-seek iterators
  refs/iterator: separate lifecycle from iteration
  refs: stop re-verifying common prefixes for availability
  refs/files: batch refname availability checks for initial transactions
  refs/files: batch refname availability checks for normal transactions
  refs/reftable: batch refname availability checks
  refs: introduce function to batch refname availability checks
  builtin/update-ref: skip ambiguity checks when parsing object IDs
  object-name: allow skipping ambiguity checks in `get_oid()` family
  object-name: introduce `repo_get_oid_with_flags()`

Author: gitster

builtin/clone.c

@@ -342,6 +342,8 @@ static void copy_or_link_directory(struct strbuf *src, struct strbuf *dest,
 		strbuf_setlen(src, src_len);
 		die(_("failed to iterate over '%s'"), src->buf);
 	}
+
+	dir_iterator_free(iter);
 }
 
 static void clone_local(const char *src_repo, const char *dest_repo)

builtin/update-ref.c

@@ -179,7 +179,8 @@ static int parse_next_oid(const char **next, const char *end,
 		(*next)++;
 		*next = parse_arg(*next, &arg);
 		if (arg.len) {
-			if (repo_get_oid(the_repository, arg.buf, oid))
+			if (repo_get_oid_with_flags(the_repository, arg.buf, oid,
+						    GET_OID_SKIP_AMBIGUITY_CHECK))
 				goto invalid;
 		} else {
 			/* Without -z, an empty value means all zeros: */
@@ -197,7 +198,8 @@ static int parse_next_oid(const char **next, const char *end,
 		*next += arg.len;
 
 		if (arg.len) {
-			if (repo_get_oid(the_repository, arg.buf, oid))
+			if (repo_get_oid_with_flags(the_repository, arg.buf, oid,
+						    GET_OID_SKIP_AMBIGUITY_CHECK))
 				goto invalid;
 		} else if (flags & PARSE_SHA1_ALLOW_EMPTY) {
 			/* With -z, treat an empty value as all zeros: */
@@ -299,7 +301,8 @@ static void parse_cmd_symref_update(struct ref_transaction *transaction,
 			die("symref-update %s: expected old value", refname);
 
 		if (!strcmp(old_arg, "oid")) {
-			if (repo_get_oid(the_repository, old_target, &old_oid))
+			if (repo_get_oid_with_flags(the_repository, old_target, &old_oid,
+						    GET_OID_SKIP_AMBIGUITY_CHECK))
 				die("symref-update %s: invalid oid: %s", refname, old_target);
 
 			have_old_oid = 1;
@@ -772,7 +775,8 @@ int cmd_update_ref(int argc,
 		refname = argv[0];
 		value = argv[1];
 		oldval = argv[2];
-		if (repo_get_oid(the_repository, value, &oid))
+		if (repo_get_oid_with_flags(the_repository, value, &oid,
+					    GET_OID_SKIP_AMBIGUITY_CHECK))
 			die("%s: not a valid SHA1", value);
 	}
 
@@ -783,7 +787,8 @@ int cmd_update_ref(int argc,
 			 * must not already exist:
 			 */
 			oidclr(&oldoid, the_repository->hash_algo);
-		else if (repo_get_oid(the_repository, oldval, &oldoid))
+		else if (repo_get_oid_with_flags(the_repository, oldval, &oldoid,
+						 GET_OID_SKIP_AMBIGUITY_CHECK))
 			die("%s: not a valid old SHA1", oldval);
 	}
 

dir-iterator.c

@@ -193,9 +193,9 @@ int dir_iterator_advance(struct dir_iterator *dir_iterator)
 
 	if (S_ISDIR(iter->base.st.st_mode) && push_level(iter)) {
 		if (errno != ENOENT && iter->flags & DIR_ITERATOR_PEDANTIC)
-			goto error_out;
+			return ITER_ERROR;
 		if (iter->levels_nr == 0)
-			goto error_out;
+			return ITER_ERROR;
 	}
 
 	/* Loop until we find an entry that we can give back to the caller. */
@@ -211,19 +211,19 @@ int dir_iterator_advance(struct dir_iterator *dir_iterator)
 			int ret = next_directory_entry(level->dir, iter->base.path.buf, &de);
 			if (ret < 0) {
 				if (iter->flags & DIR_ITERATOR_PEDANTIC)
-					goto error_out;
+					return ITER_ERROR;
 				continue;
 			} else if (ret > 0) {
 				if (pop_level(iter) == 0)
-					return dir_iterator_abort(dir_iterator);
+					return ITER_DONE;
 				continue;
 			}
 
 			name = de->d_name;
 		} else {
 			if (level->entries_idx >= level->entries.nr) {
 				if (pop_level(iter) == 0)
-					return dir_iterator_abort(dir_iterator);
+					return ITER_DONE;
 				continue;
 			}
 
@@ -232,22 +232,21 @@ int dir_iterator_advance(struct dir_iterator *dir_iterator)
 
 		if (prepare_next_entry_data(iter, name)) {
 			if (errno != ENOENT && iter->flags & DIR_ITERATOR_PEDANTIC)
-				goto error_out;
+				return ITER_ERROR;
 			continue;
 		}
 
 		return ITER_OK;
 	}
-
-error_out:
-	dir_iterator_abort(dir_iterator);
-	return ITER_ERROR;
 }
 
-int dir_iterator_abort(struct dir_iterator *dir_iterator)
+void dir_iterator_free(struct dir_iterator *dir_iterator)
 {
 	struct dir_iterator_int *iter = (struct dir_iterator_int *)dir_iterator;
 
+	if (!iter)
+		return;
+
 	for (; iter->levels_nr; iter->levels_nr--) {
 		struct dir_iterator_level *level =
 			&iter->levels[iter->levels_nr - 1];
@@ -266,7 +265,6 @@ int dir_iterator_abort(struct dir_iterator *dir_iterator)
 	free(iter->levels);
 	strbuf_release(&iter->base.path);
 	free(iter);
-	return ITER_DONE;
 }
 
 struct dir_iterator *dir_iterator_begin(const char *path, unsigned int flags)
@@ -301,7 +299,7 @@ struct dir_iterator *dir_iterator_begin(const char *path, unsigned int flags)
 	return dir_iterator;
 
 error_out:
-	dir_iterator_abort(dir_iterator);
+	dir_iterator_free(dir_iterator);
 	errno = saved_errno;
 	return NULL;
 }

dir-iterator.h

@@ -28,7 +28,7 @@
  *
  *     while ((ok = dir_iterator_advance(iter)) == ITER_OK) {
  *             if (want_to_stop_iteration()) {
- *                     ok = dir_iterator_abort(iter);
+ *                     ok = ITER_DONE;
  *                     break;
  *             }
  *
@@ -39,6 +39,7 @@
  *
  *     if (ok != ITER_DONE)
  *             handle_error();
+ *     dir_iterator_free(iter);
  *
  * Callers are allowed to modify iter->path while they are working,
  * but they must restore it to its original contents before calling
@@ -107,11 +108,7 @@ struct dir_iterator *dir_iterator_begin(const char *path, unsigned int flags);
  */
 int dir_iterator_advance(struct dir_iterator *iterator);
 
-/*
- * End the iteration before it has been exhausted. Free the
- * dir_iterator and any associated resources and return ITER_DONE. On
- * error, free the dir_iterator and return ITER_ERROR.
- */
-int dir_iterator_abort(struct dir_iterator *iterator);
+/* Free the dir_iterator and any associated resources. */
+void dir_iterator_free(struct dir_iterator *iterator);
 
 #endif

hash.h

@@ -193,17 +193,18 @@ struct object_id {
 	int algo;	/* XXX requires 4-byte alignment */
 };
 
-#define GET_OID_QUIETLY           01
-#define GET_OID_COMMIT            02
-#define GET_OID_COMMITTISH        04
-#define GET_OID_TREE             010
-#define GET_OID_TREEISH          020
-#define GET_OID_BLOB             040
-#define GET_OID_FOLLOW_SYMLINKS 0100
-#define GET_OID_RECORD_PATH     0200
-#define GET_OID_ONLY_TO_DIE    04000
-#define GET_OID_REQUIRE_PATH  010000
-#define GET_OID_HASH_ANY      020000
+#define GET_OID_QUIETLY                  01
+#define GET_OID_COMMIT                   02
+#define GET_OID_COMMITTISH               04
+#define GET_OID_TREE                    010
+#define GET_OID_TREEISH                 020
+#define GET_OID_BLOB                    040
+#define GET_OID_FOLLOW_SYMLINKS        0100
+#define GET_OID_RECORD_PATH            0200
+#define GET_OID_ONLY_TO_DIE           04000
+#define GET_OID_REQUIRE_PATH         010000
+#define GET_OID_HASH_ANY             020000
+#define GET_OID_SKIP_AMBIGUITY_CHECK 040000
 
 #define GET_OID_DISAMBIGUATORS \
 	(GET_OID_COMMIT | GET_OID_COMMITTISH | \

iterator.h

@@ -12,7 +12,7 @@
 #define ITER_OK 0
 
 /*
- * The iterator is exhausted and has been freed.
+ * The iterator is exhausted.
  */
 #define ITER_DONE -1
 

object-name.c

@@ -961,7 +961,9 @@ static int get_oid_basic(struct repository *r, const char *str, int len,
 	int fatal = !(flags & GET_OID_QUIETLY);
 
 	if (len == r->hash_algo->hexsz && !get_oid_hex(str, oid)) {
-		if (repo_settings_get_warn_ambiguous_refs(r) && warn_on_object_refname_ambiguity) {
+		if (!(flags & GET_OID_SKIP_AMBIGUITY_CHECK) &&
+		    repo_settings_get_warn_ambiguous_refs(r) &&
+		    warn_on_object_refname_ambiguity) {
 			refs_found = repo_dwim_ref(r, str, len, &tmp_oid, &real_ref, 0);
 			if (refs_found > 0) {
 				warning(warn_msg, len, str);
@@ -1794,18 +1796,20 @@ void object_context_release(struct object_context *ctx)
 	strbuf_release(&ctx->symlink_path);
 }
 
-/*
- * This is like "get_oid_basic()", except it allows "object ID expressions",
- * notably "xyz^" for "parent of xyz"
- */
-int repo_get_oid(struct repository *r, const char *name, struct object_id *oid)
+int repo_get_oid_with_flags(struct repository *r, const char *name,
+			    struct object_id *oid, unsigned flags)
 {
 	struct object_context unused;
-	int ret = get_oid_with_context(r, name, 0, oid, &unused);
+	int ret = get_oid_with_context(r, name, flags, oid, &unused);
 	object_context_release(&unused);
 	return ret;
 }
 
+int repo_get_oid(struct repository *r, const char *name, struct object_id *oid)
+{
+	return repo_get_oid_with_flags(r, name, oid, 0);
+}
+
 /*
  * This returns a non-zero value if the string (built using printf
  * format and the given arguments) is not a valid object.

object-name.h

@@ -51,6 +51,12 @@ void strbuf_repo_add_unique_abbrev(struct strbuf *sb, struct repository *repo,
 void strbuf_add_unique_abbrev(struct strbuf *sb, const struct object_id *oid,
 			      int abbrev_len);
 
+/*
+ * This is like "get_oid_basic()", except it allows "object ID expressions",
+ * notably "xyz^" for "parent of xyz". Accepts GET_OID_* flags.
+ */
+int repo_get_oid_with_flags(struct repository *r, const char *str,
+			    struct object_id *oid, unsigned flags);
 int repo_get_oid(struct repository *r, const char *str, struct object_id *oid);
 __attribute__((format (printf, 2, 3)))
 int get_oidf(struct object_id *oid, const char *fmt, ...);