OSGi 8.1.0 · org.osgi.util.pushstream.ThresholdPushbackPolicy

Provides a configurable PushbackPolicy implementation that returns zero back pressure until the buffer fills beyond the supplied threshold. Once the threshold is reached back pressure is returned based on the supplied parameters.

The starting level of the back pressure once the threshold is exceeded is defined using the initial parameter. Additional back pressure is applied for each queued item over the threshold. The amount of this additional back pressure is defined by the increment parameter.

The following common use cases are supported:

The increment size can be zero, returning the initial value as a fixed back pressure after the threshold is exceeded.
The initial value can be zero, returning a linearly increasing back pressure from zero once the threshold is exceeded

Modifier and Type	Field and Description
private final long	increment
private final long	initial
private final int	threshold

Access	Constructor and Description
private	ThresholdPushbackPolicy(int the queue size limit after which back pressure will be applied threshold, long the initial back pressure which defines the floor after the threshold is exceeded initial, long the increments in which the pressure increases. increment)

Method Summary

Modifier and Type	Method and Description
public static <T, U extends BlockingQueue<PushEvent<? extends T>>> ThresholdPushbackPolicy<T, U>	Returns: a new `ThresholdPushbackPolicy` createIncrementalThresholdPushbackPolicy(int the queue size limit after which back pressure will be applied threshold, long the increments in which the pressure increases increment) A simple configuration, where the increment size is used as the initial back pressure.
public static <T, U extends BlockingQueue<PushEvent<? extends T>>> ThresholdPushbackPolicy<T, U>	Returns: a new `ThresholdPushbackPolicy` createSimpleThresholdPushbackPolicy(int the queue size limit after which back pressure will be applied threshold) A simple configuration with an initial back pressure of one and and increase increment size of one.
public static <T, U extends BlockingQueue<PushEvent<? extends T>>> ThresholdPushbackPolicy<T, U>	Returns: a new `ThresholdPushbackPolicy` createThresholdPushbackPolicy(int the queue size limit after which back pressure will be applied threshold, long the initial back pressure which defines the floor after the threshold is exceeded initial, long the increments in which the pressure increases. increment) Provides a `ThresholdPushbackPolicy` with an individual configuration for all possible parameters.
public long	pushback(U queue) Implements org.osgi.util.pushstream.PushbackPolicy.pushback. Given the current state of the queue, determine the level of back pressure that should be applied

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

increment	back to summary
private final long increment

initial	back to summary
private final long initial

threshold	back to summary
private final int threshold

Constructor Detail

ThresholdPushbackPolicy	back to summary
private ThresholdPushbackPolicy(int threshold, long initial, long increment) Parameters threshold:int the queue size limit after which back pressure will be applied initial:long the initial back pressure which defines the floor after the threshold is exceeded increment:long the increments in which the pressure increases. Exceptions IllegalArgumentException: if any of the given values is lower then zero

ThresholdPushbackPolicy

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private ThresholdPushbackPolicy(int threshold, long initial, long increment)

Parameters

threshold:int: the queue size limit after which back pressure will be applied
initial:long: the initial back pressure which defines the floor after the threshold is exceeded
increment:long: the increments in which the pressure increases.

Exceptions

IllegalArgumentException:: if any of the given values is lower then zero

Method Detail

createIncrementalThresholdPushbackPolicy back to summary

createIncrementalThresholdPushbackPolicy	back to summary
public static <T, U extends BlockingQueue<PushEvent<? extends T>>> ThresholdPushbackPolicy<T, U> createIncrementalThresholdPushbackPolicy(int threshold, long increment) A simple configuration, where the increment size is used as the initial back pressure. Parameters threshold:int the queue size limit after which back pressure will be applied increment:long the increments in which the pressure increases Returns:ThresholdPushbackPolicy<T, U> a new `ThresholdPushbackPolicy` Exceptions IllegalArgumentException: if any of the given values is lower then zero See Also `createThresholdPushbackPolicy(int threshold, long initial, long increment)`

public static <T, U extends BlockingQueue<PushEvent<? extends T>>> ThresholdPushbackPolicy<T, U> createIncrementalThresholdPushbackPolicy(int threshold, long increment)

A simple configuration, where the increment size is used as the initial back pressure.

Parameters

threshold:int: the queue size limit after which back pressure will be applied
increment:long: the increments in which the pressure increases

Returns:ThresholdPushbackPolicy<T, U>

a new ThresholdPushbackPolicy

Exceptions

IllegalArgumentException:: if any of the given values is lower then zero

createSimpleThresholdPushbackPolicy back to summary

createSimpleThresholdPushbackPolicy	back to summary
public static <T, U extends BlockingQueue<PushEvent<? extends T>>> ThresholdPushbackPolicy<T, U> createSimpleThresholdPushbackPolicy(int threshold) A simple configuration with an initial back pressure of one and and increase increment size of one. Parameters threshold:int the queue size limit after which back pressure will be applied Returns:ThresholdPushbackPolicy<T, U> a new `ThresholdPushbackPolicy` Exceptions IllegalArgumentException: if any of the given values is lower then zero See Also `createThresholdPushbackPolicy(int threshold, long initial, long increment)`

public static <T, U extends BlockingQueue<PushEvent<? extends T>>> ThresholdPushbackPolicy<T, U> createSimpleThresholdPushbackPolicy(int threshold)

A simple configuration with an initial back pressure of one and and increase increment size of one.

Parameters

threshold:int: the queue size limit after which back pressure will be applied

Returns:ThresholdPushbackPolicy<T, U>

a new ThresholdPushbackPolicy

Exceptions

IllegalArgumentException:: if any of the given values is lower then zero

createThresholdPushbackPolicy back to summary

createThresholdPushbackPolicy	back to summary
public static <T, U extends BlockingQueue<PushEvent<? extends T>>> ThresholdPushbackPolicy<T, U> createThresholdPushbackPolicy(int threshold, long initial, long increment) Provides a `ThresholdPushbackPolicy` with an individual configuration for all possible parameters. Parameters threshold:int the queue size limit after which back pressure will be applied initial:long the initial back pressure which defines the floor after the threshold is exceeded increment:long the increments in which the pressure increases. Returns:ThresholdPushbackPolicy<T, U> a new `ThresholdPushbackPolicy` Exceptions IllegalArgumentException: if any of the given values is lower then zero

public static <T, U extends BlockingQueue<PushEvent<? extends T>>> ThresholdPushbackPolicy<T, U> createThresholdPushbackPolicy(int threshold, long initial, long increment)

Provides a ThresholdPushbackPolicy with an individual configuration for all possible parameters.

Parameters

threshold:int: the queue size limit after which back pressure will be applied
initial:long: the initial back pressure which defines the floor after the threshold is exceeded
increment:long: the increments in which the pressure increases.

Returns:ThresholdPushbackPolicy<T, U>

a new ThresholdPushbackPolicy

Exceptions

IllegalArgumentException:: if any of the given values is lower then zero

pushback	back to summary
public long pushback(U queue) throws Exception Implements org.osgi.util.pushstream.PushbackPolicy.pushback. Doc from org.osgi.util.pushstream.PushbackPolicy.pushback. Given the current state of the queue, determine the level of back pressure that should be applied Returns:long a back pressure value in nanoseconds Annotations @Override

pushback

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public long pushback(U queue) throws Exception

Implements org.osgi.util.pushstream.PushbackPolicy.pushback.

Doc from org.osgi.util.pushstream.PushbackPolicy.pushback.

Given the current state of the queue, determine the level of back pressure that should be applied

Returns:long

a back pressure value in nanoseconds

Annotations

@Override

public final Class ThresholdPushbackPolicy<T, U extends BlockingQueue<PushEvent<? extends T>>>

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