Java tutorial
/* * 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.phoenix.hbase.index.builder; import java.io.IOException; import java.lang.reflect.Constructor; import java.util.Collection; import java.util.List; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.hbase.KeyValue; import org.apache.hadoop.hbase.client.Increment; import org.apache.hadoop.hbase.client.Mutation; import org.apache.hadoop.hbase.coprocessor.RegionCoprocessorEnvironment; import org.apache.hadoop.hbase.regionserver.MiniBatchOperationInProgress; import org.apache.hadoop.hbase.util.Pair; import org.apache.phoenix.coprocessor.BaseScannerRegionObserver.ReplayWrite; import org.apache.phoenix.hbase.index.covered.IndexCodec; import org.apache.phoenix.hbase.index.covered.IndexMetaData; import org.apache.phoenix.hbase.index.covered.NonTxIndexBuilder; /** * Basic implementation of the {@link IndexBuilder} that doesn't do any actual work of indexing. * <p> * You should extend this class, rather than implementing IndexBuilder directly to maintain compatability going forward. * <p> * Generally, you should consider using one of the implemented IndexBuilders (e.g {@link NonTxIndexBuilder}) as there is * a lot of work required to keep an index table up-to-date. */ public abstract class BaseIndexBuilder implements IndexBuilder { public static final String CODEC_CLASS_NAME_KEY = "org.apache.hadoop.hbase.index.codec.class"; private static final Log LOG = LogFactory.getLog(BaseIndexBuilder.class); protected boolean stopped; protected RegionCoprocessorEnvironment env; protected IndexCodec codec; @Override public void extendBaseIndexBuilderInstead() { } @Override public void setup(RegionCoprocessorEnvironment env) throws IOException { this.env = env; // setup the phoenix codec. Generally, this will just be in standard one, but abstracting here // so we can use it later when generalizing covered indexes Configuration conf = env.getConfiguration(); Class<? extends IndexCodec> codecClass = conf.getClass(CODEC_CLASS_NAME_KEY, null, IndexCodec.class); try { Constructor<? extends IndexCodec> meth = codecClass.getDeclaredConstructor(new Class[0]); meth.setAccessible(true); this.codec = meth.newInstance(); this.codec.initialize(env); } catch (IOException e) { throw e; } catch (Exception e) { throw new IOException(e); } } @Override public void batchStarted(MiniBatchOperationInProgress<Mutation> miniBatchOp, IndexMetaData context) throws IOException { // noop } @Override public IndexMetaData getIndexMetaData(MiniBatchOperationInProgress<Mutation> miniBatchOp) throws IOException { return IndexMetaData.NULL_INDEX_META_DATA; } @Override public void batchCompleted(MiniBatchOperationInProgress<Mutation> miniBatchOp) { // noop } /** * By default, we always attempt to index the mutation. Commonly this can be slow (because the framework spends the * time to do the indexing, only to realize that you don't need it) or not ideal (if you want to turn on/off * indexing on a table without completely reloading it). * * @throws IOException */ @Override public boolean isEnabled(Mutation m) throws IOException { // ask the codec to see if we should even attempt indexing return this.codec.isEnabled(m); } @Override public boolean isAtomicOp(Mutation m) throws IOException { return false; } @Override public List<Mutation> executeAtomicOp(Increment inc) throws IOException { return null; } /** * Exposed for testing! * * @param codec * codec to use for this instance of the builder */ public void setIndexCodecForTesting(IndexCodec codec) { this.codec = codec; } @Override public Collection<Pair<Mutation, byte[]>> getIndexUpdateForFilteredRows(Collection<KeyValue> filtered, IndexMetaData context) throws IOException { throw new UnsupportedOperationException(); } @Override public void stop(String why) { LOG.debug("Stopping because: " + why); this.stopped = true; } @Override public boolean isStopped() { return this.stopped; } @Override public ReplayWrite getReplayWrite(Mutation m) { return null; } }