groovyx.gpars.dataflow.stream
[Java] Class StreamCore

java.lang.Object
  groovyx.gpars.dataflow.stream.StreamCore

All Implemented Interfaces:

FList

public abstract class StreamCore

Represents a common base for publish-subscribe deterministic channels.

Parameters:

- Type for values to pass through the channels

Authors:

Johannes Link, Vaclav Pech

first

protected final DataflowVariable first

rest

protected final java.util.concurrent.atomic.AtomicReference rest

wheneverBoundListeners

protected final java.util.Collection wheneverBoundListeners

A collection of listeners who need to be informed each time the stream is bound to a value

StreamCore

protected StreamCore(DataflowVariable first)

Creates an empty stream

Parameters:

first - The variable to store as the head of the stream

StreamCore

protected StreamCore(DataflowVariable first, groovy.lang.Closure toBeApplied)

Creates a stream while applying the supplied initialization closure to it

Parameters:

first - The variable to store as the head of the stream

toBeApplied - The closure to use for initialization

StreamCore

@SuppressWarnings({"AssignmentToCollectionOrArrayFieldFromParameter"})
protected StreamCore(DataflowVariable first, java.util.Collection wheneverBoundListeners, java.util.Collection updateListeners)

addUpdateListener

final void addUpdateListener(DataflowChannelListener updateListener)

addUpdateListeners

private void addUpdateListeners(java.util.Collection updateListeners)

appendingString

@Override
public java.lang.String appendingString()

apply

public final StreamCore apply(groovy.lang.Closure closure)

Calls the supplied closure with the stream as a parameter

Parameters:

closure - The closure to call

Returns:

This instance of DataflowStream

bind

private void bind(java.lang.Object value)

createNewStream

protected StreamCore createNewStream()

A factory method to create new instances of the correct class when needed

Returns:

An instance of the appropriate sub-class

decrementParties

public void decrementParties()

Decreases the number of parties required to perform the data exchange

eos

public static java.lang.Object eos()

equals

@Override
public boolean equals(java.lang.Object obj)

eval

private static java.lang.Object eval(java.lang.Object valueOrDataflowVariable)

filter

@Override
public final FList filter(groovy.lang.Closure filterClosure)

Builds a filtered stream using the supplied filter closure

Parameters:

filterClosure - The closure to decide on inclusion of elements

Returns:

The first item of the filtered stream

filter

private void filter(StreamCore rest, groovy.lang.Closure filterClosure, StreamCore result)

generate

public final StreamCore generate(java.lang.Object seed, groovy.lang.Closure generator, groovy.lang.Closure condition)

Populates the stream with generated values

Parameters:

seed - The initial element to evaluate and add as the first value of the stream

generator - A closure generating stream elements from the previous values

condition - A closure indicating whether the generation should continue based on the last generated value

Returns:

This stream

generateNext

private void generateNext(java.lang.Object value, StreamCore stream, groovy.lang.Closure generator, groovy.lang.Closure condition)

getFirst

@Override
public final java.lang.Object getFirst()

Retrieved the first element in the stream, blocking until a value is available

Returns:

The first item in the stream

getFirstDFV

final DataflowVariable getFirstDFV()

getRest

@Override
public FList getRest()

Retrieves a DataflowStream representing the rest of this Stream after removing the first element

Returns:

The remaining stream elements

hashCode

@Override
public int hashCode()

hookWheneverBoundListeners

private DataflowExpression hookWheneverBoundListeners(DataflowExpression expr)

Hooks the registered when bound handlers to the supplied dataflow expression

Parameters:

expr - The expression to hook all the when bound listeners to

Returns:

The supplied expression handler to allow method chaining

incrementParties

public void incrementParties()

Increases the number of parties required to perform the data exchange

isEmpty

@Override
public final boolean isEmpty()

Indicates, whether the first element in the stream is an eos

iterator

@Override
public final java.util.Iterator iterator()

Builds an iterator to iterate over the stream

Returns:

A new FListIterator instance

leftShift

public final StreamCore leftShift(DataflowReadChannel ref)

Adds a dataflow variable value to the stream, once the value is available

Parameters:

ref - The DataflowVariable to check for value

Returns:

The rest of the stream

leftShift

public final StreamCore leftShift(java.lang.Object value)

Adds a value to the stream

Parameters:

value - The value to add

Returns:

The rest of the stream

map

@Override
public final FList map(groovy.lang.Closure mapClosure)

Builds a modified stream using the supplied map closure

Parameters:

mapClosure - The closure to transform elements

Returns:

The first item of the transformed stream

map

private void map(FList rest, groovy.lang.Closure mapClosure, StreamCore result)

reduce

@Override
public final java.lang.Object reduce(groovy.lang.Closure reduceClosure)

Reduces all elements in the stream using the supplied closure

Parameters:

reduceClosure - The closure to reduce elements of the stream gradually into an accumulator. The accumulator is seeded with the first stream element.

Returns:

The result of reduction of the whole stream

reduce

@Override
public final java.lang.Object reduce(java.lang.Object seed, groovy.lang.Closure reduceClosure)

Reduces all elements in the stream using the supplied closure

Parameters:

reduceClosure - The closure to reduce elements of the stream gradually into an accumulator.

seed - The value to initialize the accumulator with.

Returns:

The result of reduction of the whole stream

reduce

private java.lang.Object reduce(java.lang.Object current, FList rest, groovy.lang.Closure reduceClosure)

wheneverBound

public final void wheneverBound(groovy.lang.Closure closure)

wheneverBound

public final void wheneverBound(MessageStream stream)

Copyright © 2008–2012 Václav Pech. All Rights Reserved.