108 lines
2.1 KiB
Java
108 lines
2.1 KiB
Java
package biz.nellemann.jperf;
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import java.io.IOException;
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import java.nio.ByteBuffer;
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import org.slf4j.Logger;
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import org.slf4j.LoggerFactory;
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/**
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*
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* A datagram consists of
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*
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* <-------------------- HEADER 32 bytes --------------> <---------- DATA -------->
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* int-4bytes int-4bytes long-8bytes long-8bytes
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* TYPE SIZE SEQUENCE TIMESTAMP
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*
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*/
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public class Datagram {
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final Logger log = LoggerFactory.getLogger(Datagram.class);
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private final int HEADER_LENGTH = 24;
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private final int type;
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private final int length;
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private final long sequence;
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private final long timestamp;
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private final byte[] data;
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/**
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* Create new empty datagram
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* @param type
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* @param lenght
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* @param sequence
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*/
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public Datagram(int type, int lenght, long sequence) {
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this.type = type;
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this.length = lenght;
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this.sequence = sequence;
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this.timestamp = System.currentTimeMillis();
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this.data = new byte[lenght - HEADER_LENGTH];
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}
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/**
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* Assemble datagram from payload
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* @param payload
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*/
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public Datagram(byte[] payload) {
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log.info("Datagram() 1");
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ByteBuffer buffer = ByteBuffer.wrap(payload);
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// Order is importent when assembling header fields like this
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type = buffer.getInt();
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length = buffer.getInt();
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sequence = buffer.getLong();
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timestamp = buffer.getLong();
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log.info("Datagram() 2 ");
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log.info("Datagram() 3 ");
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data = new byte[length - HEADER_LENGTH];
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buffer.get(data);
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log.info("Datagram() 4");
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}
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public int getLength() {
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return length;
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}
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public byte[] getPayload() throws IOException {
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ByteBuffer buffer = ByteBuffer.allocate(length);
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// Order is important
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buffer.putInt(type);
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buffer.putInt(length);
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buffer.putLong(sequence);
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buffer.putLong(timestamp);
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buffer.put(data);
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return buffer.array();
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}
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public int getType() {
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return type;
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}
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public long getSequence() {
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return sequence;
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}
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}
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