Java tutorial
/* * Copyright (C) 2014 Indeed Inc. * * Licensed 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 com.indeed.imhotep.iql; import com.google.common.collect.Lists; import com.indeed.imhotep.api.ImhotepOutOfMemoryException; import com.indeed.imhotep.ez.EZImhotepSession; import com.indeed.imhotep.ez.GroupKey; import com.indeed.imhotep.ez.StatReference; import org.apache.log4j.Logger; import java.util.Collections; import java.util.Iterator; import java.util.List; import java.util.Map; /** * @author jplaisance */ public abstract class Grouping { private static final Logger log = Logger.getLogger(Grouping.class); public abstract Map<Integer, GroupKey> regroup(EZImhotepSession session, Map<Integer, GroupKey> groupKeys) throws ImhotepOutOfMemoryException; public Iterator<GroupStats> getGroupStats(EZImhotepSession session, Map<Integer, GroupKey> groupKeys, List<StatReference> statRefs, long timeoutTS) throws ImhotepOutOfMemoryException { if (groupKeys.isEmpty()) { // we don't have any parent groups probably because all docs were filtered out return Collections.<GroupStats>emptyList().iterator(); } groupKeys = regroup(session, groupKeys); final int statCount = statRefs.size(); final double[][] statGroupValues = new double[statCount][]; for (int i = 0; i < statCount; i++) { statGroupValues[i] = statRefs.get(i).getGroupStats(); } final int groupCount = statGroupValues[0].length; final List<GroupStats> ret = Lists.newArrayListWithCapacity(groupCount); for (int group = 1; group < groupCount; group++) { final double[] groupStats = new double[statCount]; for (int statNum = 0; statNum < groupStats.length; statNum++) { groupStats[statNum] = statGroupValues[statNum][group]; } ret.add(new GroupStats(groupKeys.get(group), groupStats)); } final double[] emptyGroupStats = new double[statCount]; for (int group = groupCount; group < groupKeys.size() + 1; group++) { ret.add(new GroupStats(groupKeys.get(group), emptyGroupStats)); } return ret.iterator(); } }