touchida commented on a change in pull request #2585: URL: https://github.com/apache/hadoop/pull/2585#discussion_r598355454
########## File path: hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/erasurecode/rawcoder/DecodingValidator.java ########## @@ -0,0 +1,189 @@ +/** + * 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.classification.InterfaceAudience; +import org.apache.hadoop.thirdparty.com.google.common.annotations.VisibleForTesting; +import org.apache.hadoop.io.erasurecode.ECChunk; + +import java.io.IOException; +import java.nio.ByteBuffer; + +/** + * A utility class to validate decoding. + */ +@InterfaceAudience.Private +public class DecodingValidator { + + private final RawErasureDecoder decoder; + private ByteBuffer buffer; + private int[] newValidIndexes; + private int newErasedIndex; + + public DecodingValidator(RawErasureDecoder decoder) { + this.decoder = decoder; + } + + /** + * Validate outputs decoded from inputs, by decoding an input back from + * the outputs and comparing it with the original one. + * + * For instance, in RS (6, 3), let (d0, d1, d2, d3, d4, d5) be sources + * and (p0, p1, p2) be parities, and assume + * inputs = [d0, null (d1), d2, d3, d4, d5, null (p0), p1, null (p2)]; + * erasedIndexes = [1, 6]; + * outputs = [d1, p1]. + * Then + * 1. Create new inputs, erasedIndexes and outputs for validation so that + * the inputs could contain the decoded outputs, and decode them: + * newInputs = [d1, d2, d3, d4, d5, p1] + * newErasedIndexes = [0] + * newOutputs = [d0'] + * 2. Compare d0 and d0'. The comparison will fail with high probability + * when the initial outputs are wrong. + * + * Note that the input buffers' positions must be the ones where data are + * read: If the input buffers have been processed by a decoder, the buffers' + * positions must be reset before being passed into this method. + * + * This method does not change outputs and erasedIndexes. + * + * @param inputs input buffers used for decoding. The buffers' position + * are moved to the end after this method. + * @param erasedIndexes indexes of erased units used for decoding + * @param outputs decoded output buffers, which are ready to be read after + * the call + * @throws IOException + */ + public void validate(ByteBuffer[] inputs, int[] erasedIndexes, + ByteBuffer[] outputs) throws IOException { + markBuffers(outputs); + + try { + ByteBuffer validInput = CoderUtil.findFirstValidInput(inputs); + boolean isDirect = validInput.isDirect(); + int capacity = validInput.capacity(); + int remaining = validInput.remaining(); + + // Init buffer + if (buffer == null) { + buffer = allocateBuffer(isDirect, capacity); + } else if (buffer.isDirect() != isDirect + || buffer.capacity() < remaining) { + buffer = allocateBuffer(isDirect, capacity); + } Review comment: @aajisaka Fixed at e13b28f. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: common-issues-unsubscr...@hadoop.apache.org For additional commands, e-mail: common-issues-h...@hadoop.apache.org
