| /** |
| * 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.tajo.engine.planner.physical; |
| |
| import org.apache.tajo.catalog.Column; |
| import org.apache.tajo.plan.function.FunctionContext; |
| import org.apache.tajo.plan.logical.GroupbyNode; |
| import org.apache.tajo.storage.Tuple; |
| import org.apache.tajo.storage.VTuple; |
| import org.apache.tajo.worker.TaskAttemptContext; |
| |
| import java.io.IOException; |
| |
| /** |
| * This is the sort-based aggregation operator. |
| * |
| * <h3>Implementation</h3> |
| * Sort Aggregation has two states while running. |
| * |
| * <h4>Aggregate state</h4> |
| * If lastkey is null or lastkey is equivalent to the current key, sort aggregation is changed to this state. |
| * In this state, this operator aggregates measure values via aggregation functions. |
| * |
| * <h4>Finalize state</h4> |
| * If currentKey is different from the last key, it computes final aggregation results, and then |
| * it makes an output tuple. |
| */ |
| public class SortAggregateExec extends AggregationExec { |
| private final int groupingKeyIds[]; |
| private Tuple lastKey = null; |
| private final Tuple currentKey; |
| private final Tuple outTuple; |
| private boolean finished = false; |
| private FunctionContext contexts[]; |
| |
| public SortAggregateExec(TaskAttemptContext context, GroupbyNode plan, PhysicalExec child) throws IOException { |
| super(context, plan, child); |
| contexts = new FunctionContext[plan.getAggFunctions() == null ? 0 : plan.getAggFunctions().length]; |
| |
| final Column [] keyColumns = plan.getGroupingColumns(); |
| groupingKeyIds = new int[groupingKeyNum]; |
| Column col; |
| for (int idx = 0; idx < plan.getGroupingColumns().length; idx++) { |
| col = keyColumns[idx]; |
| if (col.hasQualifier()) { |
| groupingKeyIds[idx] = inSchema.getColumnId(col.getQualifiedName()); |
| } else { |
| groupingKeyIds[idx] = inSchema.getColumnIdByName(col.getSimpleName()); |
| } |
| } |
| currentKey = new VTuple(groupingKeyNum); |
| outTuple = new VTuple(outSchema.size()); |
| } |
| |
| @Override |
| public Tuple next() throws IOException { |
| Tuple tuple = null; |
| |
| while(!context.isStopped() && (tuple = child.next()) != null) { |
| // get a key tuple |
| for(int i = 0; i < groupingKeyIds.length; i++) { |
| currentKey.put(i, tuple.asDatum(groupingKeyIds[i])); |
| } |
| |
| /** Aggregation State */ |
| if (lastKey == null || lastKey.equals(currentKey)) { |
| if (lastKey == null) { |
| for(int i = 0; i < aggFunctionsNum; i++) { |
| contexts[i] = aggFunctions[i].newContext(); |
| |
| // Merge when aggregator doesn't receive NullDatum |
| if (!(groupingKeyNum == 0 && aggFunctionsNum == tuple.size() |
| && tuple.isBlankOrNull(i))) { |
| aggFunctions[i].merge(contexts[i], tuple); |
| } |
| } |
| lastKey = new VTuple(currentKey.getValues()); |
| } else { |
| // aggregate |
| for (int i = 0; i < aggFunctionsNum; i++) { |
| aggFunctions[i].merge(contexts[i], tuple); |
| } |
| } |
| |
| } else { /** Finalization State */ |
| // finalize aggregate and return |
| int tupleIdx = 0; |
| |
| for(; tupleIdx < groupingKeyNum; tupleIdx++) { |
| outTuple.put(tupleIdx, lastKey.asDatum(tupleIdx)); |
| } |
| for(int aggFuncIdx = 0; aggFuncIdx < aggFunctionsNum; tupleIdx++, aggFuncIdx++) { |
| outTuple.put(tupleIdx, aggFunctions[aggFuncIdx].terminate(contexts[aggFuncIdx])); |
| } |
| |
| for(int evalIdx = 0; evalIdx < aggFunctionsNum; evalIdx++) { |
| contexts[evalIdx] = aggFunctions[evalIdx].newContext(); |
| aggFunctions[evalIdx].merge(contexts[evalIdx], tuple); |
| } |
| |
| lastKey.put(currentKey.getValues()); |
| return outTuple; |
| } |
| } // while loop |
| |
| if (tuple == null && lastKey == null) { |
| finished = true; |
| return null; |
| } |
| if (!finished) { |
| int tupleIdx = 0; |
| for(; tupleIdx < groupingKeyNum; tupleIdx++) { |
| outTuple.put(tupleIdx, lastKey.asDatum(tupleIdx)); |
| } |
| for(int aggFuncIdx = 0; aggFuncIdx < aggFunctionsNum; tupleIdx++, aggFuncIdx++) { |
| outTuple.put(tupleIdx, aggFunctions[aggFuncIdx].terminate(contexts[aggFuncIdx])); |
| } |
| finished = true; |
| return outTuple; |
| } |
| return null; |
| } |
| |
| @Override |
| public void rescan() throws IOException { |
| super.rescan(); |
| |
| lastKey = null; |
| finished = false; |
| } |
| } |