| /** |
| * 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.coder; |
| |
| import org.apache.hadoop.io.erasurecode.CodecUtil; |
| import org.apache.hadoop.io.erasurecode.ECBlock; |
| import org.apache.hadoop.io.erasurecode.ECBlockGroup; |
| import org.apache.hadoop.io.erasurecode.ECSchema; |
| import org.apache.hadoop.io.erasurecode.rawcoder.RawErasureDecoder; |
| |
| /** |
| * Reed-Solomon erasure decoder that decodes a block group. |
| * |
| * It implements {@link ErasureCoder}. |
| */ |
| public class RSErasureDecoder extends AbstractErasureDecoder { |
| private RawErasureDecoder rsRawDecoder; |
| |
| public RSErasureDecoder(int numDataUnits, int numParityUnits) { |
| super(numDataUnits, numParityUnits); |
| } |
| |
| public RSErasureDecoder(ECSchema schema) { |
| super(schema); |
| } |
| |
| @Override |
| protected ErasureCodingStep prepareDecodingStep(final ECBlockGroup blockGroup) { |
| |
| ECBlock[] inputBlocks = getInputBlocks(blockGroup); |
| ECBlock[] outputBlocks = getOutputBlocks(blockGroup); |
| |
| RawErasureDecoder rawDecoder = checkCreateRSRawDecoder(); |
| return new ErasureDecodingStep(inputBlocks, |
| getErasedIndexes(inputBlocks), outputBlocks, rawDecoder); |
| } |
| |
| private RawErasureDecoder checkCreateRSRawDecoder() { |
| if (rsRawDecoder == null) { |
| rsRawDecoder = CodecUtil.createRSRawDecoder(getConf(), |
| getNumDataUnits(), getNumParityUnits()); |
| } |
| return rsRawDecoder; |
| } |
| |
| @Override |
| public void release() { |
| if (rsRawDecoder != null) { |
| rsRawDecoder.release(); |
| } |
| } |
| } |