seojangho commented on a change in pull request #31: [NEMO-97] Refactor TaskExecutor and fix a sideinput bug URL: https://github.com/apache/incubator-nemo/pull/31#discussion_r195328777
########## File path: runtime/executor/src/main/java/edu/snu/nemo/runtime/executor/task/ParentTaskDataFetcher.java ########## @@ -0,0 +1,137 @@ +/* + * Copyright (C) 2018 Seoul National University + * + * Licensed 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 edu.snu.nemo.runtime.executor.task; + +import edu.snu.nemo.common.exception.BlockFetchException; +import edu.snu.nemo.common.ir.vertex.IRVertex; +import edu.snu.nemo.runtime.executor.data.DataUtil; +import edu.snu.nemo.runtime.executor.datatransfer.InputReader; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import java.io.IOException; +import java.util.List; +import java.util.Map; +import java.util.concurrent.CompletableFuture; +import java.util.concurrent.LinkedBlockingQueue; + +/** + * Fetches data from parent tasks. + */ +class ParentTaskDataFetcher extends DataFetcher { + private static final Logger LOG = LoggerFactory.getLogger(ParentTaskDataFetcher.class.getName()); + + private final InputReader readersForParentTask; + private final LinkedBlockingQueue<DataUtil.IteratorWithNumBytes> dataQueue; + + // Non-finals (lazy fetching) + private boolean hasFetchStarted; + private int expectedNumOfIterators; + private DataUtil.IteratorWithNumBytes currentIterator; + private int currentIteratorIndex; + private boolean noElementAtAll = true; + + ParentTaskDataFetcher(final IRVertex dataSource, + final InputReader readerForParentTask, + final VertexHarness child, + final Map<String, Object> metricMap, + final boolean isFromSideInput, + final boolean isToSideInput) { + super(dataSource, child, metricMap, isFromSideInput, isToSideInput); + this.readersForParentTask = readerForParentTask; + this.hasFetchStarted = false; + this.dataQueue = new LinkedBlockingQueue<>(); + } + + private void handleMetric(final DataUtil.IteratorWithNumBytes iterator) { + long serBytes = 0; + long encodedBytes = 0; + try { + serBytes += iterator.getNumSerializedBytes(); + } catch (final DataUtil.IteratorWithNumBytes.NumBytesNotSupportedException e) { + serBytes = -1; + } catch (final IllegalStateException e) { + LOG.error("Failed to get the number of bytes of serialized data - the data is not ready yet ", e); + } + try { + encodedBytes += iterator.getNumEncodedBytes(); + } catch (final DataUtil.IteratorWithNumBytes.NumBytesNotSupportedException e) { + encodedBytes = -1; + } catch (final IllegalStateException e) { + LOG.error("Failed to get the number of bytes of encoded data - the data is not ready yet ", e); + } + if (serBytes != encodedBytes) { + getMetricMap().put("ReadBytes(raw)", serBytes); + } + getMetricMap().put("ReadBytes", encodedBytes); + } + + private void fetchInBackground() { + final List<CompletableFuture<DataUtil.IteratorWithNumBytes>> futures = readersForParentTask.read(); + this.expectedNumOfIterators = futures.size(); + + futures.forEach(compFuture -> compFuture.whenComplete((iterator, exception) -> { Review comment: Actually `fetchInBackground` method can block, since `compFuture` may be already completed. How about adding method-level comments about it? ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org With regards, Apache Git Services
