| /* |
| * 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.beam.runners.core; |
| |
| import static org.apache.beam.vendor.guava.v20_0.com.google.common.base.Preconditions.checkState; |
| |
| import org.apache.beam.sdk.state.ReadableState; |
| import org.apache.beam.sdk.state.ValueState; |
| import org.apache.beam.sdk.transforms.windowing.AfterWatermark; |
| import org.apache.beam.sdk.transforms.windowing.PaneInfo; |
| import org.apache.beam.sdk.transforms.windowing.PaneInfo.PaneInfoCoder; |
| import org.apache.beam.sdk.transforms.windowing.PaneInfo.Timing; |
| import org.apache.beam.sdk.util.WindowTracing; |
| import org.apache.beam.vendor.guava.v20_0.com.google.common.annotations.VisibleForTesting; |
| import org.joda.time.Instant; |
| |
| /** |
| * Determine the timing and other properties of a new pane for a given computation, key and window. |
| * Incorporates any previous pane, whether the pane has been produced because an on-time {@link |
| * AfterWatermark} trigger firing, and the relation between the element's timestamp and the current |
| * output watermark. |
| */ |
| public class PaneInfoTracker { |
| private TimerInternals timerInternals; |
| |
| public PaneInfoTracker(TimerInternals timerInternals) { |
| this.timerInternals = timerInternals; |
| } |
| |
| @VisibleForTesting |
| static final StateTag<ValueState<PaneInfo>> PANE_INFO_TAG = |
| StateTags.makeSystemTagInternal(StateTags.value("pane", PaneInfoCoder.INSTANCE)); |
| |
| public void clear(StateAccessor<?> state) { |
| state.access(PANE_INFO_TAG).clear(); |
| } |
| |
| public void prefetchPaneInfo(ReduceFn<?, ?, ?, ?>.Context context) { |
| context.state().access(PaneInfoTracker.PANE_INFO_TAG).readLater(); |
| } |
| |
| /** |
| * Return a ({@link ReadableState} for) the pane info appropriate for {@code context}. The pane |
| * info includes the timing for the pane, who's calculation is quite subtle. |
| * |
| * @param isFinal should be {@code true} only if the triggering machinery can guarantee no further |
| * firings for the |
| */ |
| public ReadableState<PaneInfo> getNextPaneInfo( |
| ReduceFn<?, ?, ?, ?>.Context context, final boolean isFinal) { |
| final Object key = context.key(); |
| final ReadableState<PaneInfo> previousPaneFuture = |
| context.state().access(PaneInfoTracker.PANE_INFO_TAG); |
| final Instant windowMaxTimestamp = context.window().maxTimestamp(); |
| |
| return new ReadableState<PaneInfo>() { |
| @Override |
| public ReadableState<PaneInfo> readLater() { |
| previousPaneFuture.readLater(); |
| return this; |
| } |
| |
| @Override |
| public PaneInfo read() { |
| PaneInfo previousPane = previousPaneFuture.read(); |
| return describePane(key, windowMaxTimestamp, previousPane, isFinal); |
| } |
| }; |
| } |
| |
| public void storeCurrentPaneInfo(ReduceFn<?, ?, ?, ?>.Context context, PaneInfo currentPane) { |
| context.state().access(PANE_INFO_TAG).write(currentPane); |
| } |
| |
| private <W> PaneInfo describePane( |
| Object key, Instant windowMaxTimestamp, PaneInfo previousPane, boolean isFinal) { |
| boolean isFirst = previousPane == null; |
| Timing previousTiming = isFirst ? null : previousPane.getTiming(); |
| long index = isFirst ? 0 : previousPane.getIndex() + 1; |
| long nonSpeculativeIndex = isFirst ? 0 : previousPane.getNonSpeculativeIndex() + 1; |
| Instant outputWM = timerInternals.currentOutputWatermarkTime(); |
| Instant inputWM = timerInternals.currentInputWatermarkTime(); |
| |
| // True if it is not possible to assign the element representing this pane a timestamp |
| // which will make an ON_TIME pane for any following computation. |
| // Ie true if the element's latest possible timestamp is before the current output watermark. |
| boolean isLateForOutput = outputWM != null && windowMaxTimestamp.isBefore(outputWM); |
| |
| // True if all emitted panes (if any) were EARLY panes. |
| // Once the ON_TIME pane has fired, all following panes must be considered LATE even |
| // if the output watermark is behind the end of the window. |
| boolean onlyEarlyPanesSoFar = previousTiming == null || previousTiming == Timing.EARLY; |
| |
| // True is the input watermark hasn't passed the window's max timestamp. |
| boolean isEarlyForInput = !inputWM.isAfter(windowMaxTimestamp); |
| |
| Timing timing; |
| if (isLateForOutput || !onlyEarlyPanesSoFar) { |
| // The output watermark has already passed the end of this window, or we have already |
| // emitted a non-EARLY pane. Irrespective of how this pane was triggered we must |
| // consider this pane LATE. |
| timing = Timing.LATE; |
| } else if (isEarlyForInput) { |
| // This is an EARLY firing. |
| timing = Timing.EARLY; |
| nonSpeculativeIndex = -1; |
| } else { |
| // This is the unique ON_TIME firing for the window. |
| timing = Timing.ON_TIME; |
| } |
| |
| WindowTracing.debug( |
| "describePane: {} pane (prev was {}) for key:{}; windowMaxTimestamp:{}; " |
| + "inputWatermark:{}; outputWatermark:{}; isLateForOutput:{}", |
| timing, |
| previousTiming, |
| key, |
| windowMaxTimestamp, |
| inputWM, |
| outputWM, |
| isLateForOutput); |
| |
| if (previousPane != null) { |
| // Timing transitions should follow EARLY* ON_TIME? LATE* |
| switch (previousTiming) { |
| case EARLY: |
| checkState( |
| timing == Timing.EARLY || timing == Timing.ON_TIME || timing == Timing.LATE, |
| "EARLY cannot transition to %s", |
| timing); |
| break; |
| case ON_TIME: |
| checkState(timing == Timing.LATE, "ON_TIME cannot transition to %s", timing); |
| break; |
| case LATE: |
| checkState(timing == Timing.LATE, "LATE cannot transtion to %s", timing); |
| break; |
| case UNKNOWN: |
| break; |
| } |
| checkState(!previousPane.isLast(), "Last pane was not last after all."); |
| } |
| |
| return PaneInfo.createPane(isFirst, isFinal, timing, index, nonSpeculativeIndex); |
| } |
| } |