| /** |
| * 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.crunch.io.hbase; |
| |
| import org.apache.crunch.io.FileReaderFactory; |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.fs.FileSystem; |
| import org.apache.hadoop.fs.Path; |
| import org.apache.hadoop.hbase.KeyValue; |
| import org.apache.hadoop.hbase.io.hfile.CacheConfig; |
| import org.apache.hadoop.hbase.io.hfile.HFile; |
| import org.apache.hadoop.hbase.io.hfile.HFileScanner; |
| |
| import java.io.IOException; |
| import java.util.Iterator; |
| |
| public class HFileReaderFactory implements FileReaderFactory<KeyValue> { |
| |
| public static final String HFILE_SCANNER_CACHE_BLOCKS = "crunch.hfile.scanner.cache.blocks"; |
| public static final String HFILE_SCANNER_PREAD = "crunch.hfile.scanner.pread"; |
| |
| @Override |
| public Iterator<KeyValue> read(FileSystem fs, Path path) { |
| Configuration conf = fs.getConf(); |
| CacheConfig cacheConfig = new CacheConfig(conf); |
| try { |
| HFile.Reader hfr = HFile.createReader(fs, path, cacheConfig, conf); |
| HFileScanner scanner = hfr.getScanner( |
| conf.getBoolean(HFILE_SCANNER_CACHE_BLOCKS, false), |
| conf.getBoolean(HFILE_SCANNER_PREAD, false)); |
| scanner.seekTo(); |
| return new HFileIterator(scanner); |
| } catch (IOException e) { |
| throw new RuntimeException(e); |
| } |
| } |
| |
| private static class HFileIterator implements Iterator<KeyValue> { |
| |
| private final HFileScanner scanner; |
| private KeyValue curr; |
| |
| public HFileIterator(HFileScanner scanner) { |
| this.scanner = scanner; |
| this.curr = scanner.getKeyValue(); |
| } |
| |
| @Override |
| public boolean hasNext() { |
| return curr != null; |
| } |
| |
| @Override |
| public KeyValue next() { |
| KeyValue ret = curr; |
| try { |
| if (scanner.next()) { |
| curr = scanner.getKeyValue(); |
| } else { |
| curr = null; |
| } |
| } catch (IOException e) { |
| throw new RuntimeException(e); |
| } |
| return ret; |
| } |
| |
| @Override |
| public void remove() { |
| throw new UnsupportedOperationException("HFileIterator is read-only"); |
| } |
| } |
| } |