edu.nps.moves.dis.VariableDatum Maven / Gradle / Ivy
package edu.nps.moves.dis;
import java.util.*;
import java.io.*;
import java.nio.charset.Charset;
/**
* Section 5.2.32. Variable Datum Record
*
* Copyright (c) 2008-2016, MOVES Institute, Naval Postgraduate School. All
* rights reserved. This work is licensed under the BSD open source license,
* available at https://www.movesinstitute.org/licenses/bsd.html
*
* @author DMcG
*/
public class VariableDatum extends Object implements Serializable {
/**
* ID of the variable datum
*/
protected long variableDatumID;
/**
* length of the variable datums, in bits. Note that this is not
* programmatically tied to the size of the variableData. The variable data
* field may be 64 bits long but only 16 bits of it could actually be used.
*/
protected long variableDatumLength;
/**
* The data payload
*/
private byte[] payload = EMPTY;
/**
* The padding required to 64 bit boundary
*/
private byte[] padding = EMPTY;
private static final byte[] EMPTY = new byte[0];
/**
* Constructor
*/
public VariableDatum() {
}
// additional constructors + payload setting
public VariableDatum(long id, double d) {
this.variableDatumID = id;
setPayload(d);
}
public VariableDatum(long id, long l) {
this.variableDatumID = id;
setPayload(l);
}
public VariableDatum(long id, String s) {
this.variableDatumID = id;
setPayload(s);
}
public VariableDatum(long id, byte[] payload) {
this.variableDatumID = id;
setPayload(payload);
}
public int getMarshalledSize() {
int marshalSize = 0;
marshalSize = marshalSize + 4; // variableDatumID
marshalSize = marshalSize + 4; // variableDatumLength
marshalSize = marshalSize + payload.length; // payload length
marshalSize = marshalSize + padding.length; // padding
return marshalSize;
}
public void setVariableDatumID(long pVariableDatumID) {
variableDatumID = pVariableDatumID;
}
public long getVariableDatumID() {
return variableDatumID;
}
/**
* Return length of the variable datum, in bytes. Does not account for
* padding
*/
public long getVariableDatumLength() {
return (long) variableDatumLength; // * Byte.SIZE;
}
/**
* Note that setting this value will not change the marshalled value. The
* list whose length this describes is used for that purpose. The
* getvariableDatumLength method will also be based on the actual list
* length rather than this value. The method is simply here for java bean
* completeness.
*/
public void setVariableDatumLength(long pVariableDatumLength) {
variableDatumLength = pVariableDatumLength;
}
public void setVariableData(byte[] pVariableData) {
setPayload(pVariableData);
}
public byte[] getVariableData() {
return getPayload();
}
public double getPayloadAsDouble() {
return Double.longBitsToDouble(getPayloadAsLong());
}
public long getPayloadAsLong() {
return (((long) payload[0] << 56)
+ ((long) (payload[1] & 255) << 48)
+ ((long) (payload[2] & 255) << 40)
+ ((long) (payload[3] & 255) << 32)
+ ((long) (payload[4] & 255) << 24)
+ ((payload[5] & 255) << 16)
+ ((payload[6] & 255) << 8)
+ (payload[7] & 255));
}
public String getPayloadAsString() {
return new String(payload);
}
public byte[] getPayload() {
return payload;
}
/**
* Sets the payload as a double
*
* @param d
* @return True if valid, False otherwise
*/
public final boolean setPayload(double d) {
return setPayload(Double.doubleToRawLongBits(d));
}
/**
* Sets the payload as a long
*
* @param l
* @return True if valid, False otherwise
*/
public final boolean setPayload(long l) {
byte[] bytes = new byte[8];
bytes[0] = (byte) (l >>> 56);
bytes[1] = (byte) (l >>> 48);
bytes[2] = (byte) (l >>> 40);
bytes[3] = (byte) (l >>> 32);
bytes[4] = (byte) (l >>> 24);
bytes[5] = (byte) (l >>> 16);
bytes[6] = (byte) (l >>> 8);
bytes[7] = (byte) (l);
return setPayload(bytes);
}
/**
* Sets the payload as a String
*
* @param s
* @return True if valid, False otherwise
*/
public final boolean setPayload(String s) {
if (s != null) {
return setPayload(s.getBytes(Charset.forName("US-ASCII")));
} else {
return false;
}
}
/**
* Sets the payload
*
* @param payload
* @return True if valid, False otherwise
*/
public final boolean setPayload(byte[] payload) {
if (payload != null) {
return setPayload(payload, payload.length * 8);
} else {
return false;
}
}
/**
* Sets the payload
*
* @param payload
* @param lengthBits
* @return True if valid, False otherwise
*/
public final boolean setPayload(byte[] payload, long lengthBits) {
if (payload != null) {
int payloadBits = payload.length * 8;
if (lengthBits >= 0 && lengthBits <= payloadBits && lengthBits > payloadBits - 8) {
this.payload = payload;
this.variableDatumLength = lengthBits;
padding = createPadding(payload.length);
return true;
}
}
return false;
}
/**
* Creates a byte array of padding based on the input
*
* @param payloadBytes
* @return The proper padding array
*/
private static byte[] createPadding(int payloadBytes) {
int mod = payloadBytes % 8;
if (mod != 0) {
return new byte[8 - mod];
} else {
return EMPTY;
}
}
/**
* Packs a Pdu into the ByteBuffer.
*
* @throws java.nio.BufferOverflowException if buff is too small
* @throws java.nio.ReadOnlyBufferException if buff is read only
* @see java.nio.ByteBuffer
* @param buff The ByteBuffer at the position to begin writing
* @since ??
*/
public void marshal(java.nio.ByteBuffer buff) {
buff.putInt((int) variableDatumID);
buff.putInt((int) getVariableDatumLength());
buff.put(payload);
buff.put(padding);
} // end of marshal method
/**
* Unpacks a Pdu from the underlying data.
*
* @throws java.nio.BufferUnderflowException if buff is too small
* @see java.nio.ByteBuffer
* @param buff The ByteBuffer at the position to begin reading
* @since ??
*/
public void unmarshal(java.nio.ByteBuffer buff) {
variableDatumID = buff.getInt();
variableDatumLength = buff.getInt();
int payloadBytes = (int) (variableDatumLength / 8);
if (variableDatumLength % 8 > 0) {
payloadBytes++;
}
payload = new byte[payloadBytes];
buff.get(payload);
padding = createPadding(payloadBytes);
buff.get(padding);
} // end of unmarshal method
/*
* The equals method doesn't always work--mostly it works only on classes that consist only of primitives. Be careful.
*/
@Override
public boolean equals(Object obj) {
if (this == obj) {
return true;
}
if (obj == null) {
return false;
}
if (getClass() != obj.getClass()) {
return false;
}
return equalsImpl(obj);
}
/**
* Compare all fields that contribute to the state, ignoring transient and
* static fields, for this and the supplied object
*
* @param obj the object to compare to
* @return true if the objects are equal, false otherwise.
*/
public boolean equalsImpl(Object obj) {
boolean ivarsEqual = true;
if (!(obj instanceof VariableDatum)) {
return false;
}
final VariableDatum rhs = (VariableDatum) obj;
if (!(variableDatumID == rhs.variableDatumID)) {
ivarsEqual = false;
}
if (!(variableDatumLength == rhs.variableDatumLength)) {
ivarsEqual = false;
}
if (!(Arrays.equals(payload, rhs.payload))) {
ivarsEqual = false;
}
if (!(Arrays.equals(padding, rhs.padding))) {
ivarsEqual = false;
}
return ivarsEqual;
}
} // end of class
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