| /* |
| * 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.execution.operator; |
| |
| import com.google.common.util.concurrent.ListenableFuture; |
| import org.apache.tsfile.read.common.block.TsBlock; |
| |
| import static com.google.common.util.concurrent.Futures.immediateVoidFuture; |
| |
| public interface Operator extends AutoCloseable { |
| |
| ListenableFuture<?> NOT_BLOCKED = immediateVoidFuture(); |
| |
| OperatorContext getOperatorContext(); |
| |
| /** |
| * Returns a future that will be completed when the operator becomes unblocked. If the operator is |
| * not blocked, this method should return {@code NOT_BLOCKED}. |
| */ |
| @SuppressWarnings("squid:S1452") |
| default ListenableFuture<?> isBlocked() { |
| return NOT_BLOCKED; |
| } |
| |
| default TsBlock nextWithTimer() throws Exception { |
| OperatorContext context = getOperatorContext(); |
| long startTime = System.nanoTime(); |
| TsBlock output = null; |
| try { |
| output = next(); |
| } finally { |
| context.recordExecutionTime(System.nanoTime() - startTime); |
| if (output != null) { |
| context.addOutputRows(output.getPositionCount()); |
| } |
| context.recordNextCalled(); |
| } |
| return output; |
| } |
| |
| /** |
| * Gets next tsBlock from this operator. If no data is currently available, return null. |
| * |
| * @throws Exception Error happened while fetching next batch |
| */ |
| @SuppressWarnings("squid:S112") |
| TsBlock next() throws Exception; |
| |
| default boolean hasNextWithTimer() throws Exception { |
| OperatorContext context = getOperatorContext(); |
| long startTime = System.nanoTime(); |
| |
| try { |
| return hasNext(); |
| } finally { |
| context.recordExecutionTime(System.nanoTime() - startTime); |
| context.recordHasNextCalled(); |
| } |
| } |
| |
| default long calculateMaxPeekMemoryWithCounter() { |
| long maxPeekMemory = calculateMaxPeekMemory(); |
| getOperatorContext().setEstimatedMemorySize(maxPeekMemory); |
| return maxPeekMemory; |
| } |
| |
| /** |
| * return true if the operator has more data, otherwise false. |
| * |
| * @throws Exception Error happened while judging whether there exists next batch |
| */ |
| @SuppressWarnings("squid:S112") |
| boolean hasNext() throws Exception; |
| |
| /** |
| * The close method cleans up the resources occupied by this Operator. This method will always be |
| * called before releasing the Operator reference. |
| * |
| * <p><b>Note:</b> If this Operator has child Operators, please ensure that child operators are |
| * also closed. |
| * |
| * @throws Exception An exception occurred during the close operation. |
| */ |
| @Override |
| void close() throws Exception; |
| |
| /** |
| * Is this operator completely finished processing and no more output TsBlock will be produced. |
| * |
| * @throws Exception Error happened while judging whether operator is finished |
| */ |
| @SuppressWarnings("squid:S112") |
| boolean isFinished() throws Exception; |
| |
| /** |
| * We should also consider the memory used by its children operator, so the calculation logic may |
| * be like: long estimatedOfCurrentOperator = XXXXX; return max(estimatedOfCurrentOperator, |
| * child1.calculateMaxPeekMemory(), child2.calculateMaxPeekMemory(), ....). |
| * |
| * <p>Each operator's MaxPeekMemory should also take retained size of each child operator into |
| * account. |
| * |
| * @return estimated max memory footprint that the Operator Tree(rooted from this operator) will |
| * use while doing its own read processing |
| */ |
| long calculateMaxPeekMemory(); |
| |
| /** return estimated max memory footprint for returned TsBlock when calling operator.next(). */ |
| long calculateMaxReturnSize(); |
| |
| /** |
| * return each operator's retained size(including all its children's retained size) after calling |
| * its next() method. |
| */ |
| long calculateRetainedSizeAfterCallingNext(); |
| } |