com.google.cloud.dataflow.sdk.transforms.windowing

Interface Trigger.TriggerContext<W extends BoundedWindow>

Type Parameters:

W - BoundedWindow subclass used to represent the windows used by this TriggerContext

Enclosing class:

Trigger<W extends BoundedWindow>

public static interface Trigger.TriggerContext<W extends BoundedWindow>

Information accessible to all of the callbacks that are executed on a trigger.

Method Summary

Methods

Modifier and Type	Method and Description
Instant	currentProcessingTime() Returns the current processing time.
void	deleteTimer(W window, Trigger.TimeDomain timeDomain) Removes the timer set in this trigger context for the given window and timeDomain.
Trigger.TriggerContext<W>	forChild(int childIndex) Create a TriggerContext for executing a given sub-trigger.
<T> java.util.Map<W,T>	lookup(CodedTupleTag<T> tag, java.lang.Iterable<W> windows) Lookup the value stored for a given tag in a bunch of windows.
<T> T	lookup(CodedTupleTag<T> tag, W window) Lookup the value stored for the given tag and window.
<T> void	remove(CodedTupleTag<T> tag, W window) Removes the keyed state associated with the given tag and window.
void	setTimer(W window, Instant timestamp, Trigger.TimeDomain timeDomain) Sets a timer to fire when the watermark or processing time is beyond the given timestamp.
<T> void	store(CodedTupleTag<T> tag, W window, T value) Updates the value stored in keyed state for the given tag and window.

Method Detail

setTimer

void setTimer(W window,
            Instant timestamp,
            Trigger.TimeDomain timeDomain)
              throws java.io.IOException

Sets a timer to fire when the watermark or processing time is beyond the given timestamp. Timers are not gauranteed to fire immediately, but will be delivered at some time afterwards.

Each trigger can have a single timer in per timeDomain and window. If the trigger has already set a timer for a given domain and window, then setting overwrites it.

Parameters:

window - the window the timer is being set for.

timestamp - the time at which the trigger’s Trigger.onTimer(com.google.cloud.dataflow.sdk.transforms.windowing.Trigger.TriggerContext<W>, com.google.cloud.dataflow.sdk.transforms.windowing.Trigger.OnTimerEvent<W>) callback should execute

timeDomain - the domain that the timestamp applies to

Throws:

java.io.IOException

deleteTimer

void deleteTimer(W window,
               Trigger.TimeDomain timeDomain)
                 throws java.io.IOException

Removes the timer set in this trigger context for the given window and timeDomain.

Throws:

java.io.IOException

currentProcessingTime

Instant currentProcessingTime()

Returns the current processing time.

store

<T> void store(CodedTupleTag<T> tag,
             W window,
             T value)
           throws java.io.IOException

Updates the value stored in keyed state for the given tag and window.

Throws:

java.io.IOException

remove

<T> void remove(CodedTupleTag<T> tag,
              W window)
            throws java.io.IOException

Removes the keyed state associated with the given tag and window.

Throws:

java.io.IOException

lookup

<T> T lookup(CodedTupleTag<T> tag,
           W window)
         throws java.io.IOException

Lookup the value stored for the given tag and window.

Throws:

java.io.IOException

lookup

<T> java.util.Map<W,T> lookup(CodedTupleTag<T> tag,
                            java.lang.Iterable<W> windows)
                                                throws java.io.IOException

Lookup the value stored for a given tag in a bunch of windows.

Throws:

java.io.IOException

forChild

Trigger.TriggerContext<W> forChild(int childIndex)

Create a TriggerContext for executing a given sub-trigger.