Java tutorial
/** * Copyright 2009 The Apache Software Foundation 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.hbase.regionserver.tableindexed; import java.util.SortedMap; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.hadoop.hbase.KeyValue; import org.apache.hadoop.hbase.client.Put; import org.apache.hadoop.hbase.client.tableindexed.IndexSpecification; import org.apache.hadoop.hbase.client.tableindexed.IndexedTable; import org.apache.hadoop.hbase.util.Bytes; /** * Singleton class for index maintence logic. */ public class IndexMaintenanceUtils { private static final Log LOG = LogFactory.getLog(IndexMaintenanceUtils.class); public static Put createIndexUpdate(final IndexSpecification indexSpec, final byte[] row, final SortedMap<byte[], byte[]> columnValues) { byte[] indexRow = indexSpec.getKeyGenerator().createIndexKey(row, columnValues); Put update = new Put(indexRow); update.add(IndexedTable.INDEX_COL_FAMILY, IndexedTable.INDEX_BASE_ROW, row); for (byte[] col : indexSpec.getIndexedColumns()) { byte[] val = columnValues.get(col); if (val == null) { throw new RuntimeException("Unexpected missing column value. [" + Bytes.toString(col) + "]"); } byte[][] colSeperated = KeyValue.parseColumn(col); update.add(colSeperated[0], colSeperated[1], val); } for (byte[] col : indexSpec.getAdditionalColumns()) { byte[] val = columnValues.get(col); if (val != null) { byte[][] colSeperated = KeyValue.parseColumn(col); update.add(colSeperated[0], colSeperated[1], val); } } return update; } /** * Ask if this update does apply to the index. * * @param indexSpec * @param columnValues * @return true if possibly apply. */ public static boolean doesApplyToIndex(final IndexSpecification indexSpec, final SortedMap<byte[], byte[]> columnValues) { for (byte[] neededCol : indexSpec.getIndexedColumns()) { if (!columnValues.containsKey(neededCol)) { LOG.debug("Index [" + indexSpec.getIndexId() + "] can't be updated because [" + Bytes.toString(neededCol) + "] is missing"); return false; } } return true; } }