godot/core/io/packet_peer.cpp

/*************************************************************************/
/*  packet_peer.cpp                                                      */
/*************************************************************************/
/*                       This file is part of:                           */
/*                           GODOT ENGINE                                */
/*                    http://www.godotengine.org                         */
/*************************************************************************/
/* Copyright (c) 2007-2016 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.                */
/*************************************************************************/
#include "packet_peer.h"

#include "io/marshalls.h"
#include "globals.h"
/* helpers / binders */



PacketPeer::PacketPeer() {

	last_get_error=OK;
}

Error PacketPeer::get_packet_buffer(DVector<uint8_t> &r_buffer) const {

	const uint8_t *buffer;
	int buffer_size;
	Error err = get_packet(&buffer,buffer_size);
	if (err)
		return err;

	r_buffer.resize(buffer_size);
	if (buffer_size==0)
		return OK;

	DVector<uint8_t>::Write w = r_buffer.write();
	for(int i=0;i<buffer_size;i++)
		w[i]=buffer[i];

	return OK;

}

Error PacketPeer::put_packet_buffer(const DVector<uint8_t> &p_buffer) {

	int len = p_buffer.size();
	if (len==0)
		return OK;

	DVector<uint8_t>::Read r = p_buffer.read();
	return put_packet(&r[0],len);

}

Error PacketPeer::get_var(Variant &r_variant) const {

	const uint8_t *buffer;
	int buffer_size;
	Error err = get_packet(&buffer,buffer_size);
	if (err)
		return err;

	return decode_variant(r_variant,buffer,buffer_size);

}

Error PacketPeer::put_var(const Variant& p_packet) {

	int len;
	Error err = encode_variant(p_packet,NULL,len); // compute len first
	if (err)
		return err;

	if (len==0)
		return OK;

	uint8_t  *buf = (uint8_t*)alloca(len);
	ERR_FAIL_COND_V(!buf,ERR_OUT_OF_MEMORY);
	err = encode_variant(p_packet,buf,len);
	ERR_FAIL_COND_V(err, err);

	return put_packet(buf, len);

}

Variant PacketPeer::_bnd_get_var() const {
	Variant var;
	get_var(var);

	return var;
};

Error PacketPeer::_put_packet(const DVector<uint8_t> &p_buffer)  {
	return put_packet_buffer(p_buffer);
}
DVector<uint8_t> PacketPeer::_get_packet() const {

	DVector<uint8_t> raw;
	last_get_error=get_packet_buffer(raw);
	return raw;
}

Error PacketPeer::_get_packet_error() const {

	return last_get_error;
}


void PacketPeer::_bind_methods() {

	ObjectTypeDB::bind_method(_MD("get_var"),&PacketPeer::_bnd_get_var);
	ObjectTypeDB::bind_method(_MD("put_var", "var:Variant"),&PacketPeer::put_var);
	ObjectTypeDB::bind_method(_MD("get_packet"),&PacketPeer::_get_packet);
	ObjectTypeDB::bind_method(_MD("put_packet:Error", "buffer"),&PacketPeer::_put_packet);
	ObjectTypeDB::bind_method(_MD("get_packet_error:Error"),&PacketPeer::_get_packet_error);
	ObjectTypeDB::bind_method(_MD("get_available_packet_count"),&PacketPeer::get_available_packet_count);
};

/***************/


void PacketPeerStream::_set_stream_peer(REF p_peer) {

	ERR_FAIL_COND(p_peer.is_null());
	set_stream_peer(p_peer);
}

void PacketPeerStream::_bind_methods() {

	ObjectTypeDB::bind_method(_MD("set_stream_peer","peer:StreamPeer"),&PacketPeerStream::_set_stream_peer);
}

Error PacketPeerStream::_poll_buffer() const {

	ERR_FAIL_COND_V(peer.is_null(),ERR_UNCONFIGURED);

	int read = 0;
	Error err = peer->get_partial_data(&temp_buffer[0], ring_buffer.space_left(), read);
	if (err)
		return err;
	if (read==0)
		return OK;

	int w = ring_buffer.write(&temp_buffer[0],read);
	ERR_FAIL_COND_V(w!=read,ERR_BUG);

	return OK;
}

int PacketPeerStream::get_available_packet_count() const {

	_poll_buffer();

	uint32_t remaining = ring_buffer.data_left();

	int ofs=0;
	int count=0;

	while(remaining>=4) {

		uint8_t lbuf[4];
		ring_buffer.copy(lbuf,ofs,4);
		uint32_t len = decode_uint32(lbuf);
		remaining-=4;
		ofs+=4;		
		if (len>remaining)
			break;
		remaining-=len;		
		ofs+=len;
		count++;
	}

	return count;
}

Error PacketPeerStream::get_packet(const uint8_t **r_buffer,int &r_buffer_size) const {

	ERR_FAIL_COND_V(peer.is_null(),ERR_UNCONFIGURED);
	_poll_buffer();

	int remaining = ring_buffer.data_left();
	ERR_FAIL_COND_V(remaining<4,ERR_UNAVAILABLE);
	uint8_t lbuf[4];
	ring_buffer.copy(lbuf,0,4);
	remaining-=4;
	uint32_t len = decode_uint32(lbuf);	
	ERR_FAIL_COND_V(remaining<(int)len,ERR_UNAVAILABLE);

	ring_buffer.read(lbuf,4); //get rid of first 4 bytes
	ring_buffer.read(&temp_buffer[0],len); // read packet

	*r_buffer=&temp_buffer[0];
	r_buffer_size=len;
	return OK;

}

Error PacketPeerStream::put_packet(const uint8_t *p_buffer,int p_buffer_size) {

	ERR_FAIL_COND_V(peer.is_null(),ERR_UNCONFIGURED);
	Error err = _poll_buffer(); //won't hurt to poll here too

	if (err)
		return err;

	if (p_buffer_size==0)
		return OK;

	ERR_FAIL_COND_V( p_buffer_size<0, ERR_INVALID_PARAMETER);
	ERR_FAIL_COND_V( p_buffer_size+4 > temp_buffer.size(), ERR_INVALID_PARAMETER );

	encode_uint32(p_buffer_size,&temp_buffer[0]);
	uint8_t *dst=&temp_buffer[4];
	for(int i=0;i<p_buffer_size;i++)
		dst[i]=p_buffer[i];

	return peer->put_data(&temp_buffer[0],p_buffer_size+4);
}

int PacketPeerStream::get_max_packet_size() const {


	return temp_buffer.size();
}

void PacketPeerStream::set_stream_peer(const Ref<StreamPeer> &p_peer) {

	ERR_FAIL_COND(p_peer.is_null());

	if (p_peer.ptr() != peer.ptr()) {
		ring_buffer.advance_read(ring_buffer.data_left()); // reset the ring buffer
	};

	peer=p_peer;
}

void PacketPeerStream::set_input_buffer_max_size(int p_max_size) {

	//warning may lose packets
	ERR_EXPLAIN("Buffer in use, resizing would cause loss of data");
	ERR_FAIL_COND(ring_buffer.data_left());
	ring_buffer.resize(nearest_shift(p_max_size+4));
	temp_buffer.resize(nearest_power_of_2(p_max_size+4));

}

PacketPeerStream::PacketPeerStream() {


	int rbsize=GLOBAL_DEF( "core/packet_stream_peer_max_buffer_po2",(16));

	ring_buffer.resize(rbsize);
	temp_buffer.resize(1<<rbsize);


}