package net.i2p.data.i2np; /* * free (adj.): unencumbered; not under the control of others * Written by jrandom in 2003 and released into the public domain * with no warranty of any kind, either expressed or implied. * It probably won't make your computer catch on fire, or eat * your children, but it might. Use at your own risk. * */ import java.io.IOException; import net.i2p.I2PAppContext; import net.i2p.data.DataHelper; import net.i2p.util.Log; /** * Defines a message containing arbitrary bytes of data * * @author jrandom */ public class DataMessage extends I2NPMessageImpl { private final static Log _log = new Log(DataMessage.class); public final static int MESSAGE_TYPE = 20; private byte _data[]; private static final int MAX_SIZE = 64*1024; public DataMessage(I2PAppContext context) { super(context); _data = null; } public byte[] getData() { verifyUnwritten(); return _data; } public void setData(byte[] data) { verifyUnwritten(); _data = data; } public int getSize() { verifyUnwritten(); return _data.length; } public void readMessage(byte data[], int offset, int dataSize, int type) throws I2NPMessageException, IOException { if (type != MESSAGE_TYPE) throw new I2NPMessageException("Message type is incorrect for this message"); int curIndex = offset; long size = DataHelper.fromLong(data, curIndex, 4); curIndex += 4; if (size > 64*1024) throw new I2NPMessageException("wtf, size=" + size); _data = new byte[(int)size]; System.arraycopy(data, curIndex, _data, 0, (int)size); } /** calculate the message body's length (not including the header and footer */ protected int calculateWrittenLength() { if (_data == null) return 4; else return 4 + _data.length; } /** write the message body to the output array, starting at the given index */ protected int writeMessageBody(byte out[], int curIndex) { verifyUnwritten(); if (_data == null) { out[curIndex++] = 0x0; out[curIndex++] = 0x0; out[curIndex++] = 0x0; out[curIndex++] = 0x0; } else { byte len[] = DataHelper.toLong(4, _data.length); System.arraycopy(len, 0, out, curIndex, 4); curIndex += 4; System.arraycopy(_data, 0, out, curIndex, _data.length); curIndex += _data.length; } return curIndex; } protected void written() { super.written(); _data = null; } public int getType() { return MESSAGE_TYPE; } public int hashCode() { return DataHelper.hashCode(getData()); } public boolean equals(Object object) { if ( (object != null) && (object instanceof DataMessage) ) { DataMessage msg = (DataMessage)object; return DataHelper.eq(getData(),msg.getData()); } else { return false; } } public String toString() { StringBuffer buf = new StringBuffer(); buf.append("[DataMessage: "); buf.append("\n\tData: ").append(DataHelper.toString(getData(), 64)); buf.append("]"); return buf.toString(); } }