Add new PacketBuffer class for buffered peers

modules/websocket/packet_buffer.h

@@ -0,0 +1,122 @@
+/*************************************************************************/
+/*  packet_buffer.h                                                      */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2018 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2018 Godot Engine contributors (cf. AUTHORS.md)    */
+/*                                                                       */
+/* 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.                */
+/*************************************************************************/
+
+#ifndef PACKET_BUFFER_H
+#define PACKET_BUFFER_H
+
+#include "core/os/copymem.h"
+#include "core/ring_buffer.h"
+
+template <class T>
+class PacketBuffer {
+
+private:
+	typedef struct {
+		uint32_t size;
+		T info;
+	} _Packet;
+
+	RingBuffer<_Packet> _packets;
+	RingBuffer<uint8_t> _payload;
+
+public:
+	Error write_packet(const uint8_t *p_payload, uint32_t p_size, const T *p_info) {
+#ifdef TOOLS_ENABLED
+		// Verbose buffer warnings
+		if (p_payload && _payload.space_left() < p_size) {
+			ERR_PRINT("Buffer payload full! Dropping data.");
+			ERR_FAIL_V(ERR_OUT_OF_MEMORY);
+		}
+		if (p_info && _packets.space_left() < 1) {
+			ERR_PRINT("Too many packets in queue! Dropping data.");
+			ERR_FAIL_V(ERR_OUT_OF_MEMORY);
+		}
+#else
+		ERR_FAIL_COND_V(p_payload && _payload.space_left() < p_size, ERR_OUT_OF_MEMORY);
+		ERR_FAIL_COND_V(p_info && _packets.space_left() < 1, ERR_OUT_OF_MEMORY);
+#endif
+
+		// If p_info is NULL, only the payload is written
+		if (p_info) {
+			_Packet p;
+			p.size = p_size;
+			copymem(&p.info, p_info, sizeof(T));
+			_packets.write(p);
+		}
+
+		// If p_payload is NULL, only the packet information is written.
+		if (p_payload) {
+			_payload.write((const uint8_t *)p_payload, p_size);
+		}
+
+		return OK;
+	}
+
+	Error read_packet(uint8_t *r_payload, int p_bytes, T *r_info, int &r_read) {
+		ERR_FAIL_COND_V(_packets.data_left() < 1, ERR_UNAVAILABLE);
+		_Packet p;
+		_packets.read(&p, 1);
+		ERR_FAIL_COND_V(_payload.data_left() < p.size, ERR_BUG);
+		ERR_FAIL_COND_V(p_bytes < p.size, ERR_OUT_OF_MEMORY);
+
+		r_read = p.size;
+		copymem(r_info, &p.info, sizeof(T));
+		_payload.read(r_payload, p.size);
+		return OK;
+	}
+
+	void discard_payload(int p_size) {
+		_packets.decrease_write(p_size);
+	}
+
+	void resize(int p_pkt_shift, int p_buf_shift) {
+		_packets.resize(p_pkt_shift);
+		_payload.resize(p_buf_shift);
+	}
+
+	int packets_left() const {
+		return _packets.data_left();
+	}
+
+	void clear() {
+		_payload.resize(0);
+		_packets.resize(0);
+	}
+
+	PacketBuffer() {
+		clear();
+	}
+
+	~PacketBuffer() {
+		clear();
+	}
+};
+
+#endif // PACKET_BUFFER_H