Package org.apache.storm.windowing
Interface Window<T>
- Type Parameters:
T
- the type of event that this window contains. E.g.Tuple
- All Known Subinterfaces:
TupleWindow
- All Known Implementing Classes:
TupleWindowImpl
,TupleWindowIterImpl
public interface Window<T>
A view of events in a sliding window.
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Method Summary
Modifier and TypeMethodDescriptionget()
Gets the list of events in the window.If processing based on event time, returns the window end time based on watermark otherwise returns the window end time based on processing time.Get the list of events expired from the window since the last time the window was generated.getIter()
Returns an iterator over the events in the window.getNew()
Get the list of newly added events in the window since the last time the window was generated.Returns the window start timestamp.
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Method Details
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get
Gets the list of events in the window.Note: If the number of tuples in windows is huge, invoking
get
would load all the tuples into memory and may throw an OOM exception. Use windowing with persistence (BaseStatefulWindowedBolt.withPersistence()
) andgetIter()
to retrieve an iterator over the events in the window.- Returns:
- the list of events in the window.
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getIter
Returns an iterator over the events in the window.Note: This is only supported when using windowing with persistence
BaseStatefulWindowedBolt.withPersistence()
.- Returns:
- an
Iterator
over the events in the current window. - Throws:
UnsupportedOperationException
- if not usingBaseStatefulWindowedBolt.withPersistence()
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getNew
Get the list of newly added events in the window since the last time the window was generated.Note: This is not supported when using windowing with persistence (
BaseStatefulWindowedBolt.withPersistence()
).- Returns:
- the list of newly added events in the window.
- Throws:
UnsupportedOperationException
- if usingBaseStatefulWindowedBolt.withPersistence()
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getExpired
Get the list of events expired from the window since the last time the window was generated.Note: This is not supported when using windowing with persistence (
BaseStatefulWindowedBolt.withPersistence()
).- Returns:
- the list of events expired from the window.
- Throws:
UnsupportedOperationException
- if usingBaseStatefulWindowedBolt.withPersistence()
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getEndTimestamp
Long getEndTimestamp()If processing based on event time, returns the window end time based on watermark otherwise returns the window end time based on processing time.- Returns:
- the window end timestamp
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getStartTimestamp
Long getStartTimestamp()Returns the window start timestamp. Will return null if the window length is not based on time duration.- Returns:
- the window start timestamp or null if the window length is not time based
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