message_pack.h

/*************************************************************************/
/*  message_pack.h                                                       */
/*************************************************************************/
/*                       This file is part of:                           */
/*                           GODOT ENGINE                                */
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/* Copyright (c) 2007-2022 Juan Linietsky, Ariel Manzur.                 */
/* Copyright (c) 2014-2022 Godot Engine contributors (cf. AUTHORS.md).   */
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#ifndef MESSAGE_PACK_H
#define MESSAGE_PACK_H

#include "core/object/ref_counted.h"
#include "core/string/ustring.h"
#include "core/templates/rb_map.h"
#include "core/templates/vector.h"
#include "core/variant/array.h"
#include "core/variant/dictionary.h"
#include "core/variant/typed_array.h"

#include "mpack/mpack.h"

// Limit the depth of recursive functions
#define _RECURSION_MAX_DEPTH 32
// Default maximum message size in bytes: 8MB
#define _MSG_MAX_SIZE (1 << 23)
// Default maximum node size
#define _NODE_MAX_SIZE (1 << 20)
// String length limit: 1MB
#define _STR_MAX_SIZE (1 << 20)
// Binary data size limit in bytes: 1MB
#define _BIN_MAX_SIZE (1 << 20)

class MessagePack : public Object {
	GDCLASS(MessagePack, Object);

#if MPACK_EXTENSIONS
	HashMap<int8_t, Callable> ext_decoder;
#endif

	Variant data;
	String err_msg;
	mpack_tree_t tree;
	bool started = false;

	PackedByteArray stream_data;
	int stream_head;
	int stream_tail;

	static Error _got_error_or_not(mpack_error_t p_err, String &r_err_str);
	Variant _parse_node_recursive(mpack_node_t p_node, int p_depth);

	static size_t _read_stream(mpack_tree_t *p_tree, char *r_buffer, size_t p_count);

	static Variant _read_recursive(mpack_reader_t &p_reader, int p_depth);
	static void _write_recursive(mpack_writer_t &p_writer, Variant p_val, int p_depth);

	typedef size_t (*Callback)(mpack_tree_t *p_tree, char *r_buffer, size_t p_count);

protected:
	static void _bind_methods();

public:
	static Array decode(const PackedByteArray &p_msg_buf);
	static Array encode(const Variant &p_val);

	void start_stream_with_reader(const Callback p_reader, void *context, int p_msgs_max = _MSG_MAX_SIZE);
	Error try_parse_stream();

	void start_stream(int p_msgs_max = _MSG_MAX_SIZE);
	Error update_stream(const PackedByteArray &p_data, int p_from = 0, int p_to = INT_MAX);

#if MPACK_EXTENSIONS
	void register_extension_type(int8_t p_ext_type, const Callable &p_decoder);
#endif

	inline Variant get_data() const { return data; }
	inline int get_current_stream_length() const { return tree.data_length; }
	inline String get_error_message() const { return err_msg; }

	MessagePack();
	~MessagePack();
};

#endif // MESSAGE_PACK_H