| /* |
| * 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.iotdb.db.queryengine.plan.planner.plan.node.process; |
| |
| import org.apache.iotdb.db.queryengine.plan.planner.plan.node.PlanNode; |
| import org.apache.iotdb.db.queryengine.plan.planner.plan.node.PlanNodeId; |
| import org.apache.iotdb.db.queryengine.plan.planner.plan.node.PlanNodeType; |
| import org.apache.iotdb.db.queryengine.plan.planner.plan.node.PlanVisitor; |
| import org.apache.iotdb.db.queryengine.plan.planner.plan.parameter.OrderByParameter; |
| |
| import org.apache.tsfile.utils.ReadWriteIOUtils; |
| |
| import java.io.DataOutputStream; |
| import java.io.IOException; |
| import java.nio.ByteBuffer; |
| import java.util.ArrayList; |
| import java.util.List; |
| import java.util.Objects; |
| |
| /** TopNode is optimized for `order by time|expression limit N align by device` query. */ |
| public class TopKNode extends MultiChildProcessNode { |
| |
| // when LIMIT value is less this value, can use TopKNode |
| public static final int LIMIT_VALUE_USE_TOP_K = 1000000; |
| |
| private final int topValue; |
| |
| private final OrderByParameter mergeOrderParameter; |
| |
| private final List<String> outputColumns; |
| |
| public TopKNode( |
| PlanNodeId id, |
| int topValue, |
| OrderByParameter mergeOrderParameter, |
| List<String> outputColumns) { |
| super(id); |
| this.topValue = topValue; |
| this.mergeOrderParameter = mergeOrderParameter; |
| this.outputColumns = outputColumns; |
| } |
| |
| public TopKNode( |
| PlanNodeId id, |
| int topValue, |
| List<PlanNode> children, |
| OrderByParameter mergeOrderParameter, |
| List<String> outputColumns) { |
| super(id, children); |
| this.topValue = topValue; |
| this.mergeOrderParameter = mergeOrderParameter; |
| this.outputColumns = outputColumns; |
| } |
| |
| public OrderByParameter getMergeOrderParameter() { |
| return mergeOrderParameter; |
| } |
| |
| @Override |
| public PlanNodeType getType() { |
| return PlanNodeType.TOP_K; |
| } |
| |
| @Override |
| public PlanNode clone() { |
| return new TopKNode(getPlanNodeId(), getTopValue(), getMergeOrderParameter(), outputColumns); |
| } |
| |
| @Override |
| public PlanNode createSubNode(int subNodeId, int startIndex, int endIndex) { |
| return new TopKNode( |
| new PlanNodeId(String.format("%s-%s", getPlanNodeId(), subNodeId)), |
| getTopValue(), |
| new ArrayList<>(children.subList(startIndex, endIndex)), |
| getMergeOrderParameter(), |
| outputColumns); |
| } |
| |
| @Override |
| public List<String> getOutputColumnNames() { |
| return outputColumns; |
| } |
| |
| @Override |
| public <R, C> R accept(PlanVisitor<R, C> visitor, C context) { |
| return visitor.visitTopK(this, context); |
| } |
| |
| @Override |
| protected void serializeAttributes(ByteBuffer byteBuffer) { |
| PlanNodeType.TOP_K.serialize(byteBuffer); |
| ReadWriteIOUtils.write(topValue, byteBuffer); |
| mergeOrderParameter.serializeAttributes(byteBuffer); |
| ReadWriteIOUtils.write(outputColumns.size(), byteBuffer); |
| for (String column : outputColumns) { |
| ReadWriteIOUtils.write(column, byteBuffer); |
| } |
| } |
| |
| @Override |
| protected void serializeAttributes(DataOutputStream stream) throws IOException { |
| PlanNodeType.TOP_K.serialize(stream); |
| ReadWriteIOUtils.write(topValue, stream); |
| mergeOrderParameter.serializeAttributes(stream); |
| ReadWriteIOUtils.write(outputColumns.size(), stream); |
| for (String column : outputColumns) { |
| ReadWriteIOUtils.write(column, stream); |
| } |
| } |
| |
| public static TopKNode deserialize(ByteBuffer byteBuffer) { |
| int topValue = ReadWriteIOUtils.readInt(byteBuffer); |
| OrderByParameter orderByParameter = OrderByParameter.deserialize(byteBuffer); |
| int columnSize = ReadWriteIOUtils.readInt(byteBuffer); |
| List<String> outputColumns = new ArrayList<>(); |
| while (columnSize > 0) { |
| outputColumns.add(ReadWriteIOUtils.readString(byteBuffer)); |
| columnSize--; |
| } |
| PlanNodeId planNodeId = PlanNodeId.deserialize(byteBuffer); |
| return new TopKNode(planNodeId, topValue, orderByParameter, outputColumns); |
| } |
| |
| @Override |
| public boolean equals(Object o) { |
| if (this == o) { |
| return true; |
| } |
| if (o == null || getClass() != o.getClass()) { |
| return false; |
| } |
| if (!super.equals(o)) { |
| return false; |
| } |
| TopKNode that = (TopKNode) o; |
| return topValue == that.getTopValue() |
| && Objects.equals(mergeOrderParameter, that.getMergeOrderParameter()); |
| } |
| |
| @Override |
| public int hashCode() { |
| return Objects.hash(super.hashCode(), topValue, mergeOrderParameter); |
| } |
| |
| @Override |
| public String toString() { |
| return String.format("TopK-%s", this.getPlanNodeId()); |
| } |
| |
| public int getTopValue() { |
| return this.topValue; |
| } |
| } |