SequenceFileInputFormat.java
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上传日期:2018-01-08
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- /**
- * 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.util.List;
- import org.apache.hadoop.fs.FileStatus;
- import org.apache.hadoop.fs.FileSystem;
- import org.apache.hadoop.fs.Path;
- import org.apache.hadoop.io.SequenceFile;
- import org.apache.hadoop.io.MapFile;
- import org.apache.hadoop.mapreduce.InputFormat;
- import org.apache.hadoop.mapreduce.InputSplit;
- import org.apache.hadoop.mapreduce.JobContext;
- import org.apache.hadoop.mapreduce.RecordReader;
- import org.apache.hadoop.mapreduce.TaskAttemptContext;
- /** An {@link InputFormat} for {@link SequenceFile}s. */
- public class SequenceFileInputFormat<K, V> extends FileInputFormat<K, V> {
- @Override
- public RecordReader<K, V> createRecordReader(InputSplit split,
- TaskAttemptContext context
- ) throws IOException {
- return new SequenceFileRecordReader<K,V>();
- }
- @Override
- protected long getFormatMinSplitSize() {
- return SequenceFile.SYNC_INTERVAL;
- }
- @Override
- protected List<FileStatus> listStatus(JobContext job
- )throws IOException {
- List<FileStatus> files = super.listStatus(job);
- int len = files.size();
- for(int i=0; i < len; ++i) {
- FileStatus file = files.get(i);
- if (file.isDir()) { // it's a MapFile
- Path p = file.getPath();
- FileSystem fs = p.getFileSystem(job.getConfiguration());
- // use the data file
- files.set(i, fs.getFileStatus(new Path(p, MapFile.DATA_FILE_NAME)));
- }
- }
- return files;
- }
- }