| /** |
| * 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.mapreduce.lib.input; |
| |
| import java.io.IOException; |
| import java.io.InputStream; |
| |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.apache.hadoop.classification.InterfaceStability; |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.fs.FSDataInputStream; |
| import org.apache.hadoop.io.Text; |
| |
| /** |
| * SplitLineReader for uncompressed files. |
| * This class can split the file correctly even if the delimiter is multi-bytes. |
| */ |
| @InterfaceAudience.Private |
| @InterfaceStability.Unstable |
| public class UncompressedSplitLineReader extends SplitLineReader { |
| private boolean needAdditionalRecord = false; |
| private long splitLength; |
| /** Total bytes read from the input stream. */ |
| private long totalBytesRead = 0; |
| private boolean finished = false; |
| private boolean usingCRLF; |
| |
| public UncompressedSplitLineReader(FSDataInputStream in, Configuration conf, |
| byte[] recordDelimiterBytes, long splitLength) throws IOException { |
| super(in, conf, recordDelimiterBytes); |
| this.splitLength = splitLength; |
| usingCRLF = (recordDelimiterBytes == null); |
| } |
| |
| @Override |
| protected int fillBuffer(InputStream in, byte[] buffer, boolean inDelimiter) |
| throws IOException { |
| int maxBytesToRead = buffer.length; |
| if (totalBytesRead < splitLength) { |
| long bytesLeftInSplit = splitLength - totalBytesRead; |
| |
| if (bytesLeftInSplit < maxBytesToRead) { |
| maxBytesToRead = (int)bytesLeftInSplit; |
| } |
| } |
| int bytesRead = in.read(buffer, 0, maxBytesToRead); |
| |
| // If the split ended in the middle of a record delimiter then we need |
| // to read one additional record, as the consumer of the next split will |
| // not recognize the partial delimiter as a record. |
| // However if using the default delimiter and the next character is a |
| // linefeed then next split will treat it as a delimiter all by itself |
| // and the additional record read should not be performed. |
| if (totalBytesRead == splitLength && inDelimiter && bytesRead > 0) { |
| if (usingCRLF) { |
| needAdditionalRecord = (buffer[0] != '\n'); |
| } else { |
| needAdditionalRecord = true; |
| } |
| } |
| if (bytesRead > 0) { |
| totalBytesRead += bytesRead; |
| } |
| return bytesRead; |
| } |
| |
| @Override |
| public int readLine(Text str, int maxLineLength, int maxBytesToConsume) |
| throws IOException { |
| int bytesRead = 0; |
| if (!finished) { |
| // only allow at most one more record to be read after the stream |
| // reports the split ended |
| if (totalBytesRead > splitLength) { |
| finished = true; |
| } |
| |
| bytesRead = super.readLine(str, maxLineLength, maxBytesToConsume); |
| } |
| return bytesRead; |
| } |
| |
| @Override |
| public boolean needAdditionalRecordAfterSplit() { |
| return !finished && needAdditionalRecord; |
| } |
| |
| @Override |
| protected void unsetNeedAdditionalRecordAfterSplit() { |
| needAdditionalRecord = false; |
| } |
| } |