org.apache.beam.examples.complete.game

Class StatefulTeamScore.UpdateTeamScoreFn

java.lang.Object

org.apache.beam.sdk.transforms.DoFn<org.apache.beam.sdk.values.KV<java.lang.String,org.apache.beam.examples.complete.game.UserScore.GameActionInfo>,org.apache.beam.sdk.values.KV<java.lang.String,java.lang.Integer>>

org.apache.beam.examples.complete.game.StatefulTeamScore.UpdateTeamScoreFn

All Implemented Interfaces:

java.io.Serializable, org.apache.beam.sdk.transforms.display.HasDisplayData

Enclosing class:

StatefulTeamScore

public static class StatefulTeamScore.UpdateTeamScoreFn
extends org.apache.beam.sdk.transforms.DoFn<org.apache.beam.sdk.values.KV<java.lang.String,org.apache.beam.examples.complete.game.UserScore.GameActionInfo>,org.apache.beam.sdk.values.KV<java.lang.String,java.lang.Integer>>

Tracks each team's score separately in a single state cell and outputs the score every time it passes a new multiple of a threshold.

We use stateful DoFn because:

• State is key-partitioned. Therefore, the score is calculated per team.
• Stateful DoFn can determine when to output based on the state. This only allows outputting when a team's score passes a given threshold.

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.beam.sdk.transforms.DoFn

org.apache.beam.sdk.transforms.DoFn.AlwaysFetched, org.apache.beam.sdk.transforms.DoFn.BoundedPerElement, org.apache.beam.sdk.transforms.DoFn.BundleFinalizer, org.apache.beam.sdk.transforms.DoFn.Element, org.apache.beam.sdk.transforms.DoFn.FieldAccess, org.apache.beam.sdk.transforms.DoFn.FinishBundle, org.apache.beam.sdk.transforms.DoFn.FinishBundleContext, org.apache.beam.sdk.transforms.DoFn.GetInitialRestriction, org.apache.beam.sdk.transforms.DoFn.GetInitialWatermarkEstimatorState, org.apache.beam.sdk.transforms.DoFn.GetRestrictionCoder, org.apache.beam.sdk.transforms.DoFn.GetSize, org.apache.beam.sdk.transforms.DoFn.GetWatermarkEstimatorStateCoder, org.apache.beam.sdk.transforms.DoFn.Key, org.apache.beam.sdk.transforms.DoFn.MultiOutputReceiver, org.apache.beam.sdk.transforms.DoFn.NewTracker, org.apache.beam.sdk.transforms.DoFn.NewWatermarkEstimator, org.apache.beam.sdk.transforms.DoFn.OnTimer, org.apache.beam.sdk.transforms.DoFn.OnTimerContext, org.apache.beam.sdk.transforms.DoFn.OnTimerFamily, org.apache.beam.sdk.transforms.DoFn.OnWindowExpiration, org.apache.beam.sdk.transforms.DoFn.OnWindowExpirationContext, org.apache.beam.sdk.transforms.DoFn.OutputReceiver<T>, org.apache.beam.sdk.transforms.DoFn.ProcessContext, org.apache.beam.sdk.transforms.DoFn.ProcessContinuation, org.apache.beam.sdk.transforms.DoFn.ProcessElement, org.apache.beam.sdk.transforms.DoFn.RequiresStableInput, org.apache.beam.sdk.transforms.DoFn.RequiresTimeSortedInput, org.apache.beam.sdk.transforms.DoFn.Restriction, org.apache.beam.sdk.transforms.DoFn.Setup, org.apache.beam.sdk.transforms.DoFn.SideInput, org.apache.beam.sdk.transforms.DoFn.SplitRestriction, org.apache.beam.sdk.transforms.DoFn.StartBundle, org.apache.beam.sdk.transforms.DoFn.StartBundleContext, org.apache.beam.sdk.transforms.DoFn.StateId, org.apache.beam.sdk.transforms.DoFn.Teardown, org.apache.beam.sdk.transforms.DoFn.TimerFamily, org.apache.beam.sdk.transforms.DoFn.TimerId, org.apache.beam.sdk.transforms.DoFn.Timestamp, org.apache.beam.sdk.transforms.DoFn.TruncateRestriction, org.apache.beam.sdk.transforms.DoFn.UnboundedPerElement, org.apache.beam.sdk.transforms.DoFn.WatermarkEstimatorState, org.apache.beam.sdk.transforms.DoFn.WindowedContext

Constructor Summary

Constructors

Constructor and Description
UpdateTeamScoreFn(int thresholdScore)

Method Summary

Modifier and Type	Method and Description
void	processElement(org.apache.beam.sdk.transforms.DoFn.ProcessContext c, org.apache.beam.sdk.state.ValueState<java.lang.Integer> totalScore) To use a state cell, annotate a parameter with DoFn.StateId that matches the state declaration.

Methods inherited from class org.apache.beam.sdk.transforms.DoFn

getAllowedTimestampSkew, getInputTypeDescriptor, getOutputTypeDescriptor, populateDisplayData, prepareForProcessing

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

UpdateTeamScoreFn

public UpdateTeamScoreFn(int thresholdScore)

Method Detail

processElement

@DoFn.ProcessElement
public void processElement(org.apache.beam.sdk.transforms.DoFn.ProcessContext c,
                                                @DoFn.StateId(value="totalScore")
                                                org.apache.beam.sdk.state.ValueState<java.lang.Integer> totalScore)

To use a state cell, annotate a parameter with DoFn.StateId that matches the state declaration. The type of the parameter should match the StateSpec type.