Introduce InternalIterator

Author: nikic

Zend/zend_interfaces.c

@@ -29,6 +29,9 @@ ZEND_API zend_class_entry *zend_ce_arrayaccess;
 ZEND_API zend_class_entry *zend_ce_serializable;
 ZEND_API zend_class_entry *zend_ce_countable;
 ZEND_API zend_class_entry *zend_ce_stringable;
+ZEND_API zend_class_entry *zend_ce_internal_iterator;
+
+static zend_object_handlers zend_internal_iterator_handlers;
 
 /* {{{ zend_call_method
  Only returns the returned zval if retval_ptr != NULL */
@@ -287,20 +290,16 @@ ZEND_API zend_object_iterator *zend_user_it_get_new_iterator(zend_class_entry *c
 /* {{{ zend_implement_traversable */
 static int zend_implement_traversable(zend_class_entry *interface, zend_class_entry *class_type)
 {
-	/* check that class_type is traversable at c-level or implements at least one of 'aggregate' and 'Iterator' */
-	uint32_t i;
-
-	if (class_type->get_iterator || (class_type->parent && class_type->parent->get_iterator)) {
-		return SUCCESS;
-	}
 	/* Abstract class can implement Traversable only, in which case the extending class must
 	 * implement Iterator or IteratorAggregate. */
 	if (class_type->ce_flags & ZEND_ACC_EXPLICIT_ABSTRACT_CLASS) {
 		return SUCCESS;
 	}
+
+	/* Check that class_type implements at least one of 'IteratorAggregate' or 'Iterator' */
 	if (class_type->num_interfaces) {
 		ZEND_ASSERT(class_type->ce_flags & ZEND_ACC_RESOLVED_INTERFACES);
-		for (i = 0; i < class_type->num_interfaces; i++) {
+		for (uint32_t i = 0; i < class_type->num_interfaces; i++) {
 			if (class_type->interfaces[i] == zend_ce_aggregate || class_type->interfaces[i] == zend_ce_iterator) {
 				return SUCCESS;
 			}
@@ -484,9 +483,169 @@ static int zend_implement_serializable(zend_class_entry *interface, zend_class_e
 }
 /* }}}*/
 
+typedef struct {
+	zend_object std;
+	zend_object_iterator *iter;
+	zend_bool rewind_called;
+} zend_internal_iterator;
+
+static zend_object *zend_internal_iterator_create(zend_class_entry *ce) {
+	zend_internal_iterator *intern = emalloc(sizeof(zend_internal_iterator));
+	zend_object_std_init(&intern->std, ce);
+	intern->std.handlers = &zend_internal_iterator_handlers;
+	intern->iter = NULL;
+	intern->rewind_called = 0;
+	return &intern->std;
+}
+
+ZEND_API int zend_create_internal_iterator_zval(zval *return_value, zval *obj) {
+	zend_class_entry *scope = EG(current_execute_data)->func->common.scope;
+	ZEND_ASSERT(scope->get_iterator != zend_user_it_get_new_iterator);
+	zend_object_iterator *iter = scope->get_iterator(Z_OBJCE_P(obj), obj, /* by_ref */ 0);
+	if (!iter) {
+		return FAILURE;
+	}
+
+	zend_internal_iterator *intern =
+		(zend_internal_iterator *) zend_internal_iterator_create(zend_ce_internal_iterator);
+	intern->iter = iter;
+	ZVAL_OBJ(return_value, &intern->std);
+	return SUCCESS;
+}
+
+static void zend_internal_iterator_free(zend_object *obj) {
+	zend_internal_iterator *intern = (zend_internal_iterator *) obj;
+	if (intern->iter) {
+		zend_iterator_dtor(intern->iter);
+	}
+	zend_object_std_dtor(&intern->std);
+}
+
+static zend_internal_iterator *zend_internal_iterator_fetch(zval *This) {
+	zend_internal_iterator *intern = (zend_internal_iterator *) Z_OBJ_P(This);
+	if (!intern->iter) {
+		zend_throw_error(NULL, "The InternalIterator object has not been properly initialized");
+		return NULL;
+	}
+	return intern;
+}
+
+/* Many iterators will not behave correctly if rewind() is not called, make sure it happens. */
+static int zend_internal_iterator_ensure_rewound(zend_internal_iterator *intern) {
+	if (!intern->rewind_called) {
+		zend_object_iterator *iter = intern->iter;
+		intern->rewind_called = 1;
+		if (iter->funcs->rewind) {
+			iter->funcs->rewind(iter);
+			if (UNEXPECTED(EG(exception))) {
+				return FAILURE;
+			}
+		}
+	}
+	return SUCCESS;
+}
+
+
+ZEND_METHOD(InternalIterator, __construct) {
+	zend_throw_error(NULL, "Cannot manually construct InternalIterator");
+}
+
+ZEND_METHOD(InternalIterator, current) {
+	ZEND_PARSE_PARAMETERS_NONE();
+
+	zend_internal_iterator *intern = zend_internal_iterator_fetch(ZEND_THIS);
+	if (!intern) {
+		RETURN_THROWS();
+	}
+
+	if (zend_internal_iterator_ensure_rewound(intern) == FAILURE) {
+		RETURN_THROWS();
+	}
+
+	zval *data = intern->iter->funcs->get_current_data(intern->iter);
+	if (data) {
+		ZVAL_COPY_DEREF(return_value, data);
+	}
+}
+
+ZEND_METHOD(InternalIterator, key) {
+	ZEND_PARSE_PARAMETERS_NONE();
+
+	zend_internal_iterator *intern = zend_internal_iterator_fetch(ZEND_THIS);
+	if (!intern) {
+		RETURN_THROWS();
+	}
+
+	if (zend_internal_iterator_ensure_rewound(intern) == FAILURE) {
+		RETURN_THROWS();
+	}
+
+	if (intern->iter->funcs->get_current_key) {
+		intern->iter->funcs->get_current_key(intern->iter, return_value);
+	} else {
+		RETURN_LONG(intern->iter->index);
+	}
+}
+
+ZEND_METHOD(InternalIterator, next) {
+	ZEND_PARSE_PARAMETERS_NONE();
+
+	zend_internal_iterator *intern = zend_internal_iterator_fetch(ZEND_THIS);
+	if (!intern) {
+		RETURN_THROWS();
+	}
+
+	if (zend_internal_iterator_ensure_rewound(intern) == FAILURE) {
+		RETURN_THROWS();
+	}
+
+	intern->iter->funcs->move_forward(intern->iter);
+	intern->iter->index++;
+}
+
+ZEND_METHOD(InternalIterator, valid) {
+	ZEND_PARSE_PARAMETERS_NONE();
+
+	zend_internal_iterator *intern = zend_internal_iterator_fetch(ZEND_THIS);
+	if (!intern) {
+		RETURN_THROWS();
+	}
+
+	if (zend_internal_iterator_ensure_rewound(intern) == FAILURE) {
+		RETURN_THROWS();
+	}
+
+	RETURN_BOOL(intern->iter->funcs->valid(intern->iter) == SUCCESS);
+}
+
+ZEND_METHOD(InternalIterator, rewind) {
+	ZEND_PARSE_PARAMETERS_NONE();
+
+	zend_internal_iterator *intern = zend_internal_iterator_fetch(ZEND_THIS);
+	if (!intern) {
+		RETURN_THROWS();
+	}
+
+	if (!intern->iter->funcs->rewind) {
+		/* Allow calling rewind() if no iteration has happened yet,
+		 * even if the iterator does not support rewinding. */
+		if (intern->iter->index != 0) {
+			zend_throw_error(NULL, "Iterator does not support rewinding");
+			RETURN_THROWS();
+		}
+		intern->iter->index = 0;
+		return;
+	}
+
+	intern->iter->funcs->rewind(intern->iter);
+	intern->iter->index = 0;
+}
+
 /* {{{ zend_register_interfaces */
 ZEND_API void zend_register_interfaces(void)
 {
+	zend_class_entry ce;
+
 	REGISTER_MAGIC_INTERFACE(traversable, Traversable);
 
 	REGISTER_MAGIC_INTERFACE(aggregate, IteratorAggregate);
@@ -497,7 +656,6 @@ ZEND_API void zend_register_interfaces(void)
 
 	REGISTER_MAGIC_INTERFACE(serializable, Serializable);
 
-	zend_class_entry ce;
 	INIT_CLASS_ENTRY(ce, "ArrayAccess", class_ArrayAccess_methods);
 	zend_ce_arrayaccess = zend_register_internal_interface(&ce);
 
@@ -506,5 +664,17 @@ ZEND_API void zend_register_interfaces(void)
 
 	INIT_CLASS_ENTRY(ce, "Stringable", class_Stringable_methods);
 	zend_ce_stringable = zend_register_internal_interface(&ce);
+
+	INIT_CLASS_ENTRY(ce, "InternalIterator", class_InternalIterator_methods);
+	zend_ce_internal_iterator = zend_register_internal_class(&ce);
+	zend_class_implements(zend_ce_internal_iterator, 1, zend_ce_iterator);
+	zend_ce_internal_iterator->ce_flags |= ZEND_ACC_FINAL;
+	zend_ce_internal_iterator->create_object = zend_internal_iterator_create;
+	zend_ce_internal_iterator->serialize = zend_class_serialize_deny;
+	zend_ce_internal_iterator->unserialize = zend_class_unserialize_deny;
+
+	memcpy(&zend_internal_iterator_handlers, zend_get_std_object_handlers(),
+		sizeof(zend_object_handlers));
+	zend_internal_iterator_handlers.free_obj = zend_internal_iterator_free;
 }
 /* }}} */

Zend/zend_interfaces.h

@@ -78,6 +78,8 @@ ZEND_API int zend_user_unserialize(zval *object, zend_class_entry *ce, const uns
 ZEND_API int zend_class_serialize_deny(zval *object, unsigned char **buffer, size_t *buf_len, zend_serialize_data *data);
 ZEND_API int zend_class_unserialize_deny(zval *object, zend_class_entry *ce, const unsigned char *buf, size_t buf_len, zend_unserialize_data *data);
 
+ZEND_API int zend_create_internal_iterator_zval(zval *return_value, zval *obj);
+
 END_EXTERN_C()
 
 #endif /* ZEND_INTERFACES_H */

Zend/zend_interfaces.stub.php

@@ -63,3 +63,20 @@ interface Stringable
 {
     public function __toString(): string;
 }
+
+final class InternalIterator implements Iterator
+{
+    private function __construct();
+
+    /** @return mixed */
+    public function current();
+
+    /** @return mixed */
+    public function key();
+
+    public function next(): void;
+
+    public function valid(): bool;
+
+    public function rewind(): void;
+}

Zend/zend_interfaces_arginfo.h

@@ -37,7 +37,27 @@ ZEND_END_ARG_INFO()
 ZEND_BEGIN_ARG_WITH_RETURN_TYPE_INFO_EX(arginfo_class_Stringable___toString, 0, 0, IS_STRING, 0)
 ZEND_END_ARG_INFO()
 
+#define arginfo_class_InternalIterator___construct arginfo_class_IteratorAggregate_getIterator
 
+#define arginfo_class_InternalIterator_current arginfo_class_IteratorAggregate_getIterator
+
+#define arginfo_class_InternalIterator_key arginfo_class_IteratorAggregate_getIterator
+
+ZEND_BEGIN_ARG_WITH_RETURN_TYPE_INFO_EX(arginfo_class_InternalIterator_next, 0, 0, IS_VOID, 0)
+ZEND_END_ARG_INFO()
+
+ZEND_BEGIN_ARG_WITH_RETURN_TYPE_INFO_EX(arginfo_class_InternalIterator_valid, 0, 0, _IS_BOOL, 0)
+ZEND_END_ARG_INFO()
+
+#define arginfo_class_InternalIterator_rewind arginfo_class_InternalIterator_next
+
+
+ZEND_METHOD(InternalIterator, __construct);
+ZEND_METHOD(InternalIterator, current);
+ZEND_METHOD(InternalIterator, key);
+ZEND_METHOD(InternalIterator, next);
+ZEND_METHOD(InternalIterator, valid);
+ZEND_METHOD(InternalIterator, rewind);
 
 
 static const zend_function_entry class_Traversable_methods[] = {
@@ -87,3 +107,14 @@ static const zend_function_entry class_Stringable_methods[] = {
 	ZEND_ABSTRACT_ME_WITH_FLAGS(Stringable, __toString, arginfo_class_Stringable___toString, ZEND_ACC_PUBLIC|ZEND_ACC_ABSTRACT)
 	ZEND_FE_END
 };
+
+
+static const zend_function_entry class_InternalIterator_methods[] = {
+	ZEND_ME(InternalIterator, __construct, arginfo_class_InternalIterator___construct, ZEND_ACC_PRIVATE)
+	ZEND_ME(InternalIterator, current, arginfo_class_InternalIterator_current, ZEND_ACC_PUBLIC)
+	ZEND_ME(InternalIterator, key, arginfo_class_InternalIterator_key, ZEND_ACC_PUBLIC)
+	ZEND_ME(InternalIterator, next, arginfo_class_InternalIterator_next, ZEND_ACC_PUBLIC)
+	ZEND_ME(InternalIterator, valid, arginfo_class_InternalIterator_valid, ZEND_ACC_PUBLIC)
+	ZEND_ME(InternalIterator, rewind, arginfo_class_InternalIterator_rewind, ZEND_ACC_PUBLIC)
+	ZEND_FE_END
+};

Zend/zend_weakrefs.c

@@ -613,6 +613,15 @@ ZEND_METHOD(WeakMap, count)
 	RETURN_LONG(count);
 }
 
+ZEND_METHOD(WeakMap, getIterator)
+{
+	if (zend_parse_parameters_none() == FAILURE) {
+		return;
+	}
+
+	zend_create_internal_iterator_zval(return_value, ZEND_THIS);
+}
+
 void zend_register_weakref_ce(void) /* {{{ */
 {
 	zend_class_entry ce;
@@ -638,17 +647,16 @@ void zend_register_weakref_ce(void) /* {{{ */
 
 	INIT_CLASS_ENTRY(ce, "WeakMap", class_WeakMap_methods);
 	zend_ce_weakmap = zend_register_internal_class(&ce);
+	zend_class_implements(
+		zend_ce_weakmap, 3, zend_ce_arrayaccess, zend_ce_countable, zend_ce_aggregate);
+
 	zend_ce_weakmap->ce_flags |= ZEND_ACC_FINAL;
 
 	zend_ce_weakmap->create_object = zend_weakmap_create_object;
 	zend_ce_weakmap->get_iterator = zend_weakmap_get_iterator;
 	zend_ce_weakmap->serialize = zend_class_serialize_deny;
 	zend_ce_weakmap->unserialize = zend_class_unserialize_deny;
 
-	/* Must happen after get_iterator is assigned. */
-	zend_class_implements(
-		zend_ce_weakmap, 3, zend_ce_arrayaccess, zend_ce_countable, zend_ce_traversable);
-
 	memcpy(&zend_weakmap_handlers, zend_get_std_object_handlers(), sizeof(zend_object_handlers));
 	zend_weakmap_handlers.offset = XtOffsetOf(zend_weakmap, std);
 	zend_weakmap_handlers.free_obj = zend_weakmap_free_obj;

Zend/zend_weakrefs.stub.php

@@ -11,7 +11,7 @@ public static function create(): WeakReference {}
     public function get(): ?object {}
 }
 
-final class WeakMap implements ArrayAccess, Countable, Traversable
+final class WeakMap implements ArrayAccess, Countable, IteratorAggregate
 {
     /**
      * @param object $object
@@ -32,4 +32,6 @@ public function offsetExists($object): bool {}
     public function offsetUnset($object): void {}
 
     public function count(): int {}
+
+    public function getIterator(): Iterator {}
 }

Zend/zend_weakrefs_arginfo.h

@@ -29,6 +29,9 @@ ZEND_END_ARG_INFO()
 ZEND_BEGIN_ARG_WITH_RETURN_TYPE_INFO_EX(arginfo_class_WeakMap_count, 0, 0, IS_LONG, 0)
 ZEND_END_ARG_INFO()
 
+ZEND_BEGIN_ARG_WITH_RETURN_OBJ_INFO_EX(arginfo_class_WeakMap_getIterator, 0, 0, Iterator, 0)
+ZEND_END_ARG_INFO()
+
 
 ZEND_METHOD(WeakReference, __construct);
 ZEND_METHOD(WeakReference, create);
@@ -38,6 +41,7 @@ ZEND_METHOD(WeakMap, offsetSet);
 ZEND_METHOD(WeakMap, offsetExists);
 ZEND_METHOD(WeakMap, offsetUnset);
 ZEND_METHOD(WeakMap, count);
+ZEND_METHOD(WeakMap, getIterator);
 
 
 static const zend_function_entry class_WeakReference_methods[] = {
@@ -54,5 +58,6 @@ static const zend_function_entry class_WeakMap_methods[] = {
 	ZEND_ME(WeakMap, offsetExists, arginfo_class_WeakMap_offsetExists, ZEND_ACC_PUBLIC)
 	ZEND_ME(WeakMap, offsetUnset, arginfo_class_WeakMap_offsetUnset, ZEND_ACC_PUBLIC)
 	ZEND_ME(WeakMap, count, arginfo_class_WeakMap_count, ZEND_ACC_PUBLIC)
+	ZEND_ME(WeakMap, getIterator, arginfo_class_WeakMap_getIterator, ZEND_ACC_PUBLIC)
 	ZEND_FE_END
 };