initial commit, 4.5 stable

core/variant/callable.h

@@ -0,0 +1,215 @@
+/**************************************************************************/
+/*  callable.h                                                            */
+/**************************************************************************/
+/*                         This file is part of:                          */
+/*                             GODOT ENGINE                               */
+/*                        https://godotengine.org                         */
+/**************************************************************************/
+/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
+/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
+/*                                                                        */
+/* Permission is hereby granted, free of charge, to any person obtaining  */
+/* a copy of this software and associated documentation files (the        */
+/* "Software"), to deal in the Software without restriction, including    */
+/* without limitation the rights to use, copy, modify, merge, publish,    */
+/* distribute, sublicense, and/or sell copies of the Software, and to     */
+/* permit persons to whom the Software is furnished to do so, subject to  */
+/* the following conditions:                                              */
+/*                                                                        */
+/* The above copyright notice and this permission notice shall be         */
+/* included in all copies or substantial portions of the Software.        */
+/*                                                                        */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,        */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF     */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. */
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY   */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,   */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE      */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                 */
+/**************************************************************************/
+
+#pragma once
+
+#include "core/object/object_id.h"
+#include "core/string/string_name.h"
+
+class Object;
+class Variant;
+class CallableCustom;
+
+// This is an abstraction of things that can be called.
+// It is used for signals and other cases where efficient calling of functions
+// is required. It is designed for the standard case (object and method)
+// but can be optimized or customized.
+
+// Enforce 16 bytes with `alignas` to avoid arch-specific alignment issues on x86 vs armv7.
+
+class Callable {
+	alignas(8) StringName method;
+	union {
+		uint64_t object = 0;
+		CallableCustom *custom;
+	};
+
+public:
+	struct CallError {
+		enum Error {
+			CALL_OK,
+			CALL_ERROR_INVALID_METHOD,
+			CALL_ERROR_INVALID_ARGUMENT, // expected is variant type
+			CALL_ERROR_TOO_MANY_ARGUMENTS, // expected is number of arguments
+			CALL_ERROR_TOO_FEW_ARGUMENTS, // expected is number of arguments
+			CALL_ERROR_INSTANCE_IS_NULL,
+			CALL_ERROR_METHOD_NOT_CONST,
+		};
+		Error error = Error::CALL_OK;
+		int argument = 0;
+		int expected = 0;
+	};
+
+	template <typename... VarArgs>
+	Variant call(VarArgs... p_args) const;
+	void callp(const Variant **p_arguments, int p_argcount, Variant &r_return_value, CallError &r_call_error) const;
+	void call_deferredp(const Variant **p_arguments, int p_argcount) const;
+	Variant callv(const Array &p_arguments) const;
+
+	template <typename... VarArgs>
+	void call_deferred(VarArgs... p_args) const {
+		Variant args[sizeof...(p_args) + 1] = { p_args..., 0 }; // +1 makes sure zero sized arrays are also supported.
+		const Variant *argptrs[sizeof...(p_args) + 1];
+		for (uint32_t i = 0; i < sizeof...(p_args); i++) {
+			argptrs[i] = &args[i];
+		}
+		return call_deferredp(sizeof...(p_args) == 0 ? nullptr : (const Variant **)argptrs, sizeof...(p_args));
+	}
+
+	Error rpcp(int p_id, const Variant **p_arguments, int p_argcount, CallError &r_call_error) const;
+
+	_FORCE_INLINE_ bool is_null() const {
+		return method == StringName() && object == 0;
+	}
+	_FORCE_INLINE_ bool is_custom() const {
+		return method == StringName() && custom != nullptr;
+	}
+	_FORCE_INLINE_ bool is_standard() const {
+		return method != StringName();
+	}
+	bool is_valid() const;
+
+	template <typename... VarArgs>
+	Callable bind(VarArgs... p_args) const;
+	Callable bindv(const Array &p_arguments);
+
+	Callable bindp(const Variant **p_arguments, int p_argcount) const;
+	Callable unbind(int p_argcount) const;
+
+	Object *get_object() const;
+	ObjectID get_object_id() const;
+	StringName get_method() const;
+	CallableCustom *get_custom() const;
+	int get_argument_count(bool *r_is_valid = nullptr) const;
+	int get_bound_arguments_count() const;
+	void get_bound_arguments_ref(Vector<Variant> &r_arguments) const; // Internal engine use, the exposed one is below.
+	Array get_bound_arguments() const;
+	int get_unbound_arguments_count() const;
+
+	uint32_t hash() const;
+
+	const Callable *get_base_comparator() const; //used for bind/unbind to do less precise comparisons (ignoring binds) in signal connect/disconnect
+
+	bool operator==(const Callable &p_callable) const;
+	bool operator!=(const Callable &p_callable) const;
+	bool operator<(const Callable &p_callable) const;
+
+	void operator=(const Callable &p_callable);
+
+	explicit operator String() const;
+
+	static Callable create(const Variant &p_variant, const StringName &p_method);
+
+	Callable(const Object *p_object, const StringName &p_method);
+	Callable(ObjectID p_object, const StringName &p_method);
+	Callable(CallableCustom *p_custom);
+	Callable(const Callable &p_callable);
+	Callable() {}
+	~Callable();
+};
+
+// Zero-constructing Callable initializes method and object to 0 (and thus empty).
+template <>
+struct is_zero_constructible<Callable> : std::true_type {};
+
+class CallableCustom {
+	friend class Callable;
+	SafeRefCount ref_count;
+	bool referenced = false;
+
+public:
+	typedef bool (*CompareEqualFunc)(const CallableCustom *p_a, const CallableCustom *p_b);
+	typedef bool (*CompareLessFunc)(const CallableCustom *p_a, const CallableCustom *p_b);
+
+	//for every type that inherits, these must always be the same for this type
+	virtual uint32_t hash() const = 0;
+	virtual String get_as_text() const = 0;
+	virtual CompareEqualFunc get_compare_equal_func() const = 0;
+	virtual CompareLessFunc get_compare_less_func() const = 0;
+	virtual bool is_valid() const;
+	virtual StringName get_method() const;
+	virtual ObjectID get_object() const = 0;
+	virtual void call(const Variant **p_arguments, int p_argcount, Variant &r_return_value, Callable::CallError &r_call_error) const = 0;
+	virtual Error rpc(int p_peer_id, const Variant **p_arguments, int p_argcount, Callable::CallError &r_call_error) const;
+	virtual const Callable *get_base_comparator() const;
+	virtual int get_argument_count(bool &r_is_valid) const;
+	virtual int get_bound_arguments_count() const;
+	virtual void get_bound_arguments(Vector<Variant> &r_arguments) const;
+	virtual int get_unbound_arguments_count() const;
+
+	CallableCustom();
+	virtual ~CallableCustom() {}
+};
+
+// This is just a proxy object to object signals, its only
+// allocated on demand by/for scripting languages so it can
+// be put inside a Variant, but it is not
+// used by the engine itself.
+
+// Enforce 16 bytes with `alignas` to avoid arch-specific alignment issues on x86 vs armv7.
+class Signal {
+	alignas(8) StringName name;
+	ObjectID object;
+
+public:
+	_FORCE_INLINE_ bool is_null() const {
+		return object.is_null() && name == StringName();
+	}
+	Object *get_object() const;
+	ObjectID get_object_id() const;
+	StringName get_name() const;
+
+	bool operator==(const Signal &p_signal) const;
+	bool operator!=(const Signal &p_signal) const;
+	bool operator<(const Signal &p_signal) const;
+
+	explicit operator String() const;
+
+	Error emit(const Variant **p_arguments, int p_argcount) const;
+	Error connect(const Callable &p_callable, uint32_t p_flags = 0);
+	void disconnect(const Callable &p_callable);
+	bool is_connected(const Callable &p_callable) const;
+	bool has_connections() const;
+
+	Array get_connections() const;
+	Signal(const Object *p_object, const StringName &p_name);
+	Signal(ObjectID p_object, const StringName &p_name);
+	Signal() {}
+};
+
+// Zero-constructing Signal initializes name and object to 0 (and thus empty).
+template <>
+struct is_zero_constructible<Signal> : std::true_type {};
+
+struct CallableComparator {
+	const Callable &func;
+
+	bool operator()(const Variant &p_l, const Variant &p_r) const;
+};