com.yahoo.bullet.windowing

Class Scheme

java.lang.Object

com.yahoo.bullet.windowing.Scheme

All Implemented Interfaces:

Closable, Monoidal

Direct Known Subclasses:

Basic

public abstract class Scheme
extends Object
implements Monoidal

This represents the common parent for all windowing schemes. This wraps the Strategy since it needs to control when the aggregation strategy resets its result etc. Windowing schemes generally accept data even if they are Closable.isClosed() or isClosedForPartition(). It is up to the user to make sure data is emitted and the window is reset and feed it data accordingly.

Field Summary

Fields

Modifier and Type	Field and Description
protected Strategy	aggregation
protected Map<String,String>	metadataKeys
protected Window	window

Constructor Summary

Constructors

Constructor and Description
Scheme(Strategy aggregation, Window window, BulletConfig config) Creates an instance of this windowing scheme with the provided Strategy, Window and BulletConfig.

Method Summary

Modifier and Type	Method and Description
Meta	getMetadata() Return any Meta for this windowing scheme and the Strategy.
protected abstract Map<String,Object>	getMetadata(Map<String,String> metadataKeys) Return any metadata for the windowing scheme with the given configured names for the metadata concepts.
abstract boolean	isClosedForPartition() Returns true if this window is closed when operating in partition mode.
abstract void	resetForPartition() Resets the window when operating in partition mode.
abstract void	start() Readies the window for querying.

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.yahoo.bullet.common.Monoidal

combine, consume, getData, getRecords, getResult, merge, reset

Methods inherited from interface com.yahoo.bullet.common.Closable

isClosed

Field Detail

aggregation

protected Strategy aggregation

window

protected Window window

metadataKeys

protected Map<String,String> metadataKeys

Constructor Detail

Scheme

public Scheme(Strategy aggregation,
              Window window,
              BulletConfig config)

Creates an instance of this windowing scheme with the provided Strategy, Window and BulletConfig.

Parameters:

aggregation - The non-null initialized aggregation strategy that this window will operate.

window - The initialized, configured window to use.

config - The validated config to use.

Method Detail

getMetadata

protected abstract Map<String,Object> getMetadata(Map<String,String> metadataKeys)

Return any metadata for the windowing scheme with the given configured names for the metadata concepts.

Parameters:

metadataKeys - The mapping of metadata concepts to their names to get metadata for.

Returns:

A Map of strings to objects of the metadata.

isClosedForPartition

public abstract boolean isClosedForPartition()

Returns true if this window is closed when operating in partition mode. If this window has been consuming slices of the data (partitions) instead of the full data, this can be used to determine whether the window could or needs to emit data to maintain the windowing invariant.

Returns:

A boolean whether this window is considered closed if it were consuming a slice of the data.

resetForPartition

public abstract void resetForPartition()

Resets the window when operating in partition mode. If this window has been consuming slices of data (partitions) instead of the full data, you should use this method to reset the window to maintain the windowing invariant.

start

public abstract void start()

Readies the window for querying. This is called in Querier.restart().

getMetadata

public Meta getMetadata()

Return any Meta for this windowing scheme and the Strategy.

Specified by:

getMetadata in interface Monoidal

Returns:

A non-null Meta object.