PacketBase.cpp

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00001 /*
00002 
00003 Copyright (C) 2006-2007 by Peter Dimov.
00004 
00005 This file is part of Calitko (http://www.calitko.org).
00006 
00007 Calitko is free software; you can redistribute it and/or modify
00008 it under the terms of the GNU General Public License as published by
00009 the Free Software Foundation; either version 2 of the License, or
00010 (at your option) any later version.
00011 
00012 Calitko is distributed in the hope that it will be useful,
00013 but WITHOUT ANY WARRANTY; without even the implied warranty of
00014 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00015 GNU General Public License for more details.
00016 
00017 You should have received a copy of the GNU General Public License
00018 along with Calitko; if not, write to the Free Software
00019 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
00020 
00021 */
00022 
00023 #include "Qt.h"
00024 #include "PacketBase.h"
00025 #include "Imports.cpp"
00026 
00028 QString PacketBase::protocol() const
00029 {
00030     return "BitTorrent";
00031 }
00032 
00034 
00043 
00044 
00053 PacketBase::PacketBase (Data *dd, PacketType packetType)
00054     : GenericsPacketBase (dd)
00055 {
00056     Q_SD (Data);
00057     d->packetType       = packetType;
00058 }
00059 
00061 
00077 bool PacketBase::readHeader (const QByteArray &rawHeader)
00078 {
00079     Q_SD (Data);
00080     BinaryReader reader (rawHeader, BinaryReader::BigEndian);
00081     qint32 bytesLeft = reader.readInt32();
00082     QByteArray payload = rawPayload();
00083     Q_ASSERT (payload.length() == bytesLeft);
00084     if (bytesLeft > 0) {
00085         PacketType packetType = static_cast <PacketType> (payload.at(0));
00086         // packetType read here must match the value passed to the ctor:
00087         Q_ASSERT (packetType == d->packetType);
00088     } else {
00089         // Keepalives have no payload:
00090         d->packetType = KeepalivePacket;
00091     }
00092     return reader.hasReadAll() && !reader.hasReadPastEnd();
00093 }
00094 
00096 
00101 QByteArray PacketBase::writeHeader() const
00102 {
00103     Q_SD (const Data);
00104     QByteArray rawHeader (4, 0);
00105     BinaryWriter writer (&rawHeader, BinaryWriter::BigEndian);
00106     quint32 payloadLength = this->payloadLength();
00107     Q_ASSERT ((d->packetType == KeepalivePacket && payloadLength == 0)
00108               || (d->packetType != KeepalivePacket && payloadLength > 0));
00109     writer.writeUInt32 (payloadLength);
00110     Q_ASSERT (4 == writer.bytesWritten());
00111     return rawHeader;
00112 }
00113 
00115 
00129 bool PacketBase::readPayload (const QByteArray &rawPayload)
00130 {
00131     BinaryReader reader (rawPayload, BinaryReader::BigEndian);
00132     if (packetType() != KeepalivePacket)
00133         reader.readByte(); // Eat the PacketType marker from payload.
00134     readPayload (reader);
00135     return reader.hasReadAll() && !reader.hasReadPastEnd();
00136 }
00137 
00149 
00150 
00158 QByteArray PacketBase::writePayload() const
00159 {
00160     BinaryWriter writer (BinaryWriter::BigEndian);
00161     if (packetType() != KeepalivePacket)
00162         writer.writeByte (static_cast <uchar> (packetType()));
00163     writePayload (writer);
00164     Q_ASSERT (writer.hasWrittenAll() && !writer.hasWrittenPastEnd());
00165     return writer.buffer();
00166 }
00167