| /* |
| * 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.drill.exec.physical.impl; |
| |
| import org.apache.drill.exec.proto.ExecProtos.FragmentHandle; |
| |
| /** |
| * Node which is the last processing node in a query plan. FragmentTerminals |
| * include Exchange output nodes and storage nodes. They are there driving force |
| * behind the completion of a query. |
| * </p> |
| * Assumes that all implementations of {@link RootExec} assume that all their |
| * methods are called by the same thread. |
| */ |
| public interface RootExec extends AutoCloseable { |
| |
| /** |
| * Do the next batch of work. |
| * |
| * @return Whether or not additional batches of work are necessary. False |
| * means that this fragment is done. |
| */ |
| boolean next(); |
| |
| /** |
| * Inform sender that receiving fragment is finished and doesn't need any more |
| * data. This can be called multiple times (once for each downstream |
| * receiver). If all receivers are finished then a subsequent call to |
| * {@link #next()} will return false. |
| * |
| * @param handle |
| * The handle pointing to the downstream receiver that does not need |
| * anymore data. |
| */ |
| void receivingFragmentFinished(FragmentHandle handle); |
| |
| /** |
| * Dump failed batches' state preceded by its parent's state to logs. Invoked |
| * when there is a failure during fragment execution. |
| * |
| * @param t the exception thrown by an operator and which therefore |
| * records, in its stack trace, which operators were active on the stack |
| */ |
| void dumpBatches(Throwable t); |
| } |