| /* |
| * 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.record; |
| |
| import org.apache.drill.exec.exception.OutOfMemoryException; |
| import org.apache.drill.exec.exception.SchemaChangeException; |
| import org.apache.drill.exec.ops.FragmentContext; |
| import org.apache.drill.exec.physical.base.PhysicalOperator; |
| import org.apache.drill.exec.record.BatchSchema.SelectionVectorMode; |
| import org.apache.drill.exec.vector.SchemaChangeCallBack; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| /** |
| * The base class for operators that have a single input. The concrete implementations provide the |
| * input by implementing the getIncoming() method |
| * Known implementations: AbstractSingleRecordBatch and AbstractTableFunctionRecordBatch. |
| * @see org.apache.drill.exec.record.AbstractRecordBatch |
| * @see org.apache.drill.exec.record.AbstractSingleRecordBatch |
| * @see org.apache.drill.exec.record.AbstractTableFunctionRecordBatch |
| * @param <T> |
| */ |
| public abstract class AbstractUnaryRecordBatch<T extends PhysicalOperator> extends AbstractRecordBatch<T> { |
| private static final Logger logger = LoggerFactory.getLogger(new Object() {}.getClass().getEnclosingClass()); |
| |
| protected SchemaChangeCallBack callBack = new SchemaChangeCallBack(); |
| private IterOutcome lastKnownOutcome; |
| |
| public AbstractUnaryRecordBatch(T popConfig, FragmentContext context) throws OutOfMemoryException { |
| super(popConfig, context, false); |
| } |
| |
| protected abstract RecordBatch getIncoming(); |
| |
| @Override |
| protected void killIncoming(boolean sendUpstream) { |
| final RecordBatch incoming = getIncoming(); |
| incoming.kill(sendUpstream); |
| } |
| |
| @Override |
| public IterOutcome innerNext() { |
| final RecordBatch incoming = getIncoming(); |
| // Short circuit if record batch has already sent all data and is done |
| if (state == BatchState.DONE) { |
| return IterOutcome.NONE; |
| } |
| |
| IterOutcome upstream = next(incoming); |
| if (state != BatchState.FIRST && upstream == IterOutcome.OK && incoming.getRecordCount() == 0) { |
| do { |
| incoming.getContainer().zeroVectors(); |
| } while ((upstream = next(incoming)) == IterOutcome.OK && incoming.getRecordCount() == 0); |
| } |
| if (state == BatchState.FIRST) { |
| if (upstream == IterOutcome.OK) { |
| upstream = IterOutcome.OK_NEW_SCHEMA; |
| } else if (upstream == IterOutcome.EMIT) { |
| throw new IllegalStateException("Received first batch with unexpected EMIT IterOutcome"); |
| } |
| } |
| |
| // update the last outcome seen |
| lastKnownOutcome = upstream; |
| switch (upstream) { |
| case NONE: |
| if (state == BatchState.FIRST) { |
| return handleNullInput(); |
| } |
| return upstream; |
| case NOT_YET: |
| case STOP: |
| if (state == BatchState.FIRST) { |
| container.buildSchema(SelectionVectorMode.NONE); |
| } |
| return upstream; |
| case OK_NEW_SCHEMA: |
| if (state == BatchState.FIRST) { |
| state = BatchState.NOT_FIRST; |
| } |
| try { |
| stats.startSetup(); |
| if (!setupNewSchema()) { |
| upstream = IterOutcome.OK; |
| } |
| } catch (SchemaChangeException ex) { |
| kill(false); |
| logger.error("Failure during query", ex); |
| context.getExecutorState().fail(ex); |
| return IterOutcome.STOP; |
| } finally { |
| stats.stopSetup(); |
| } |
| // fall through. |
| case OK: |
| case EMIT: |
| assert state != BatchState.FIRST : "First batch should be OK_NEW_SCHEMA"; |
| container.zeroVectors(); |
| IterOutcome out = doWork(); |
| |
| // since doWork method does not know if there is a new schema, it will always return IterOutcome.OK if it was successful. |
| // But if upstream is IterOutcome.OK_NEW_SCHEMA, we should return that |
| if (out != IterOutcome.OK) { |
| upstream = out; |
| } |
| |
| // Check if schema has changed |
| if (callBack.getSchemaChangedAndReset()) { |
| return IterOutcome.OK_NEW_SCHEMA; |
| } |
| |
| return upstream; // change if upstream changed, otherwise normal. |
| default: |
| throw new UnsupportedOperationException(); |
| } |
| } |
| |
| protected abstract boolean setupNewSchema() throws SchemaChangeException; |
| protected abstract IterOutcome doWork(); |
| |
| /** |
| * Default behavior to handle NULL input (aka FAST NONE): incoming return NONE |
| * before return a OK_NEW_SCHEMA: This could happen when the underneath Scan |
| * operators do not produce any batch with schema. |
| * <p> |
| * Notice that NULL input is different from input with an empty batch. In the |
| * later case, input provides at least a batch, thought it's empty. |
| * </p> |
| * <p> |
| * This behavior could be override in each individual operator, if the |
| * operator's semantics is to inject a batch with schema. |
| * </p> |
| * |
| * @return IterOutcome.NONE. |
| */ |
| protected IterOutcome handleNullInput() { |
| container.buildSchema(SelectionVectorMode.NONE); |
| container.setRecordCount(0); |
| return IterOutcome.NONE; |
| } |
| |
| protected IterOutcome getLastKnownOutcome() { |
| return lastKnownOutcome; |
| } |
| |
| /** |
| * Set's the outcome received with current input batch in processing |
| * @param outcome |
| */ |
| protected void setLastKnownOutcome(IterOutcome outcome) { |
| lastKnownOutcome = outcome; |
| } |
| } |