org.yamcs.algo.ReverseBinaryDecoder Maven / Gradle / Ivy
package org.yamcs.algo;
import org.yamcs.algorithms.AlgorithmExecutionContext;
import org.yamcs.mdb.AbstractDataDecoder;
import org.yamcs.mdb.ContainerProcessingContext;
import org.yamcs.parameter.Value;
import org.yamcs.utils.BitBuffer;
import org.yamcs.utils.ValueUtility;
import org.yamcs.xtce.BinaryDataEncoding;
import org.yamcs.xtce.CustomAlgorithm;
import org.yamcs.xtce.DataEncoding;
/**
* A custom data decoder that returns a binary value that has all the bytes reversed from the encoded binary.
*
* This is intended to be used with a custom transformation for the {@link BinaryDataEncoding} of a binary parameter.
*
* The implementation assumes a fixed-size encoding.
*/
public class ReverseBinaryDecoder extends AbstractDataDecoder {
public ReverseBinaryDecoder(CustomAlgorithm alg, AlgorithmExecutionContext ctx) {
// Constructor required
}
@Override
public Value extractRaw(DataEncoding de, ContainerProcessingContext pcontext, BitBuffer buffer) {
var sizeInBits = de.getSizeInBits();
if (sizeInBits < 0) {
throw new IllegalArgumentException("Cannot decode binary parameter. Size is not fixed");
}
if (sizeInBits % 8 != 0) {
throw new IllegalArgumentException("Cannot decode binary parameter. Bit size should be multiple of 8");
}
var sizeInBytes = sizeInBits / 8;
if (sizeInBytes > buffer.remainingBytes()) {
throw new IndexOutOfBoundsException("Cannot decode binary parameter of size " + sizeInBytes
+ ". Remaining in the buffer: " + buffer.remainingBytes());
}
var bytes = new byte[sizeInBytes];
buffer.getByteArray(bytes);
// Reverse in-place
for (int i = 0; i < bytes.length / 2; i++) {
var temp = bytes[i];
bytes[i] = bytes[bytes.length - i - 1];
bytes[bytes.length - i - 1] = temp;
}
return ValueUtility.getBinaryValue(bytes);
}
}