Java tutorial
/* * Licensed to Metamarkets Group Inc. (Metamarkets) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. Metamarkets 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 io.druid.indexing.appenderator; import com.google.common.base.Function; import com.google.common.collect.Iterables; import com.google.common.collect.Maps; import com.google.common.collect.Sets; import io.druid.common.utils.JodaUtils; import io.druid.indexing.common.actions.SegmentListUsedAction; import io.druid.indexing.common.actions.TaskActionClient; import io.druid.segment.realtime.appenderator.SegmentIdentifier; import io.druid.segment.realtime.appenderator.UsedSegmentChecker; import io.druid.timeline.DataSegment; import org.joda.time.Interval; import java.io.IOException; import java.util.List; import java.util.Map; import java.util.Set; public class ActionBasedUsedSegmentChecker implements UsedSegmentChecker { private final TaskActionClient taskActionClient; public ActionBasedUsedSegmentChecker(TaskActionClient taskActionClient) { this.taskActionClient = taskActionClient; } @Override public Set<DataSegment> findUsedSegments(Set<SegmentIdentifier> identifiers) throws IOException { // Group by dataSource final Map<String, Set<SegmentIdentifier>> identifiersByDataSource = Maps.newTreeMap(); for (SegmentIdentifier identifier : identifiers) { if (!identifiersByDataSource.containsKey(identifier.getDataSource())) { identifiersByDataSource.put(identifier.getDataSource(), Sets.<SegmentIdentifier>newHashSet()); } identifiersByDataSource.get(identifier.getDataSource()).add(identifier); } final Set<DataSegment> retVal = Sets.newHashSet(); for (Map.Entry<String, Set<SegmentIdentifier>> entry : identifiersByDataSource.entrySet()) { final List<Interval> intervals = JodaUtils.condenseIntervals( Iterables.transform(entry.getValue(), new Function<SegmentIdentifier, Interval>() { @Override public Interval apply(SegmentIdentifier input) { return input.getInterval(); } })); final List<DataSegment> usedSegmentsForIntervals = taskActionClient .submit(new SegmentListUsedAction(entry.getKey(), null, intervals)); for (DataSegment segment : usedSegmentsForIntervals) { if (identifiers.contains(SegmentIdentifier.fromDataSegment(segment))) { retVal.add(segment); } } } return retVal; } }