org.apache.hadoop.io.erasurecode.rawcoder.RSRawEncoder Maven / Gradle / Ivy
/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.hadoop.io.erasurecode.rawcoder;
import org.apache.hadoop.HadoopIllegalArgumentException;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.io.erasurecode.ErasureCoderOptions;
import org.apache.hadoop.io.erasurecode.rawcoder.util.DumpUtil;
import org.apache.hadoop.io.erasurecode.rawcoder.util.RSUtil;
/**
* A raw erasure encoder in RS code scheme in pure Java in case native one
* isn't available in some environment. Please always use native implementations
* when possible. This new Java coder is about 5X faster than the one originated
* from HDFS-RAID, and also compatible with the native/ISA-L coder.
*/
@InterfaceAudience.Private
public class RSRawEncoder extends RawErasureEncoder {
// relevant to schema and won't change during encode calls.
private byte[] encodeMatrix;
/**
* Array of input tables generated from coding coefficients previously.
* Must be of size 32*k*rows
*/
private byte[] gfTables;
public RSRawEncoder(ErasureCoderOptions coderOptions) {
super(coderOptions);
if (getNumAllUnits() >= RSUtil.GF.getFieldSize()) {
throw new HadoopIllegalArgumentException(
"Invalid numDataUnits and numParityUnits");
}
encodeMatrix = new byte[getNumAllUnits() * getNumDataUnits()];
RSUtil.genCauchyMatrix(encodeMatrix, getNumAllUnits(), getNumDataUnits());
if (allowVerboseDump()) {
DumpUtil.dumpMatrix(encodeMatrix, getNumDataUnits(), getNumAllUnits());
}
gfTables = new byte[getNumAllUnits() * getNumDataUnits() * 32];
RSUtil.initTables(getNumDataUnits(), getNumParityUnits(), encodeMatrix,
getNumDataUnits() * getNumDataUnits(), gfTables);
if (allowVerboseDump()) {
System.out.println(DumpUtil.bytesToHex(gfTables, -1));
}
}
@Override
protected void doEncode(ByteBufferEncodingState encodingState) {
CoderUtil.resetOutputBuffers(encodingState.outputs,
encodingState.encodeLength);
RSUtil.encodeData(gfTables, encodingState.inputs, encodingState.outputs);
}
@Override
protected void doEncode(ByteArrayEncodingState encodingState) {
CoderUtil.resetOutputBuffers(encodingState.outputs,
encodingState.outputOffsets,
encodingState.encodeLength);
RSUtil.encodeData(gfTables, encodingState.encodeLength,
encodingState.inputs,
encodingState.inputOffsets, encodingState.outputs,
encodingState.outputOffsets);
}
}