Simple implementation of Ringbuffer, exposing lock-free get*(..) and put*(..) methods. More...

Inheritance diagram for org.jau.util.LFRingbuffer< T >:

Collaboration diagram for org.jau.util.LFRingbuffer< T >:

Public Member Functions

final String toString ()

Returns a short string representation incl. More...

final void dump (final PrintStream stream, final String prefix)

Debug functionality - Dumps the contents of the internal array. More...

LFRingbuffer (final T[] copyFrom) throws IllegalArgumentException

Create a full ring buffer instance w/ the given array's net capacity and content. More...

LFRingbuffer (final Class<? extends T[]> arrayType, final int capacity)

Create an empty ring buffer instance w/ the given net capacity. More...

final int capacity ()

Returns the net capacity of this ring buffer. More...

final void clear ()

Resets the read and write position according to an empty ring buffer and set all ring buffer slots to null. More...

final void resetFull (final T[] copyFrom) throws IllegalArgumentException

Resets the read and write position according to a full ring buffer and fill all slots w/ elements of array copyFrom. More...

final int size ()

Returns the number of elements in this ring buffer. More...

final int getFreeSlots ()

Returns the number of free slots available to put. More...

final boolean isEmpty ()

Returns true if this ring buffer is empty, otherwise false. More...

final boolean isFull ()

Returns true if this ring buffer is full, otherwise false. More...

final T get ()

Dequeues the oldest enqueued element if available, otherwise null.The returned ring buffer slot will be set to null to release the reference and move ownership to the caller. Method is non blocking and returns immediately;.

Returns: the oldest put element if available, otherwise null.

More...

final T getBlocking () throws InterruptedException

Dequeues the oldest enqueued element.The returned ring buffer slot will be set to null to release the reference and move ownership to the caller. Methods blocks until an element becomes available via put.

Returns: the oldest put element

Exceptions

InterruptedException

More...

final T peek ()

Peeks the next element at the read position w/o modifying pointer, nor blocking. More...

final T peekBlocking () throws InterruptedException

Peeks the next element at the read position w/o modifying pointer, but w/ blocking. More...

final boolean put (final T e)

Enqueues the given element.Returns true if successful, otherwise false in case buffer is full. Method is non blocking and returns immediately;. More...

final void putBlocking (final T e) throws InterruptedException

Enqueues the given element.Method blocks until a free slot becomes available via get.

Exceptions

InterruptedException

More...

final boolean putSame (final boolean blocking) throws InterruptedException

Enqueues the same element at it's write position, if not full.Returns true if successful, otherwise false in case buffer is full. If blocking is true, method blocks until a free slot becomes available via get.

Parameters

blocking if true, wait until a free slot becomes available via get.

Exceptions

InterruptedException

More...

final void waitForFreeSlots (final int count) throws InterruptedException

Blocks until at least count free slots become available. More...

final void growEmptyBuffer (final T[] newElements) throws IllegalStateException, IllegalArgumentException

Grows an empty ring buffer, increasing it's capacity about the amount. More...

final void growFullBuffer (final int growAmount) throws IllegalStateException, IllegalArgumentException

Grows a full ring buffer, increasing it's capacity about the amount. More...

String toString ()

Returns a short string representation incl. More...

void dump (PrintStream stream, String prefix)

Debug functionality - Dumps the contents of the internal array. More...

int capacity ()

Returns the net capacity of this ring buffer. More...

void clear ()

Resets the read and write position according to an empty ring buffer and set all ring buffer slots to null. More...

void resetFull (T[] copyFrom) throws IllegalArgumentException

Resets the read and write position according to a full ring buffer and fill all slots w/ elements of array copyFrom. More...

int size ()

Returns the number of elements in this ring buffer. More...

int getFreeSlots ()

Returns the number of free slots available to put. More...

boolean isEmpty ()

Returns true if this ring buffer is empty, otherwise false. More...

boolean isFull ()

Returns true if this ring buffer is full, otherwise false. More...

T get ()

Dequeues the oldest enqueued element if available, otherwise null. More...

T getBlocking () throws InterruptedException

Dequeues the oldest enqueued element. More...

T peek ()

Peeks the next element at the read position w/o modifying pointer, nor blocking. More...

T peekBlocking () throws InterruptedException

Peeks the next element at the read position w/o modifying pointer, but w/ blocking. More...

boolean put (T e)

Enqueues the given element. More...

void putBlocking (T e) throws InterruptedException

Enqueues the given element. More...

boolean putSame (boolean blocking) throws InterruptedException

Enqueues the same element at it's write position, if not full. More...

void waitForFreeSlots (int count) throws InterruptedException

Blocks until at least count free slots become available. More...

void growEmptyBuffer (T[] newElements) throws IllegalStateException, IllegalArgumentException

Grows an empty ring buffer, increasing it's capacity about the amount. More...

void growFullBuffer (int amount) throws IllegalStateException, IllegalArgumentException

Grows a full ring buffer, increasing it's capacity about the amount. More...

Detailed Description

Simple implementation of Ringbuffer, exposing lock-free get*(..) and put*(..) methods.

Implementation utilizes the Always Keep One Slot Open, hence implementation maintains an internal array of capacity plus one!

Implementation is thread safe if:

get*(..) operations are performed from one thread only.
put*(..) operations are performed from one thread only.
get*(..) and put*(..) thread may be the same.

Following methods utilize global synchronization:

User needs to synchronize above methods w/ the lock-free w/ get*(..) and put*(..) methods, e.g. by controlling their threads before invoking the above.

Characteristics:

Read position points to the last read element.
Write position points to the last written element.

Empty	writePos == readPos	size == 0
Full	writePos == readPos - 1	size == capacity

Definition at line 71 of file LFRingbuffer.java.

Constructor & Destructor Documentation

◆ LFRingbuffer() [1/2]

org.jau.util.LFRingbuffer< T >.LFRingbuffer ( final T[] copyFrom ) throws IllegalArgumentException

Create a full ring buffer instance w/ the given array's net capacity and content.

Example for a 10 element Integer array:

 Integer[] source = new Integer[10];
 // fill source with content ..
 Ringbuffer<Integer> rb = new LFRingbuffer<Integer>(source);

isFull() returns true on the newly created full ring buffer.

Implementation will allocate an internal array with size of array copyFrom plus one, and copy all elements from array copyFrom into the internal array.

Parameters

copyFrom mandatory source array determining ring buffer's net capacity() and initial content.

Exceptions

IllegalArgumentException if copyFrom is null

Definition at line 117 of file LFRingbuffer.java.

◆ LFRingbuffer() [2/2]

org.jau.util.LFRingbuffer< T >.LFRingbuffer	(	final Class<? extends T[]>	arrayType,
		final int	capacity
	)

Create an empty ring buffer instance w/ the given net capacity.

Example for a 10 element Integer array:

 Ringbuffer<Integer> rb = new LFRingbuffer<Integer>(10, Integer[].class);

isEmpty() returns true on the newly created empty ring buffer.

Implementation will allocate an internal array of size capacity plus one.

Parameters

arrayType	the array type of the created empty internal array.
capacity	the initial net capacity of the ring buffer

Definition at line 140 of file LFRingbuffer.java.

Here is the call graph for this function:

Member Function Documentation

◆ capacity()

final int org.jau.util.LFRingbuffer< T >.capacity ( )

Returns the net capacity of this ring buffer.

final void org.jau.util.LFRingbuffer< T >.dump	(	final PrintStream	stream,
		final String	prefix
	)

IllegalStateException	if buffer is not empty
IllegalArgumentException	if newElements is null

IllegalStateException	if buffer is not full
IllegalArgumentException	if amount is < 0

IllegalArgumentException	if `copyFrom` is `null`.
IllegalArgumentException	if `copyFrom`'s length is different from `capacity()`.

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ LFRingbuffer() [1/2]

◆ LFRingbuffer() [2/2]

Member Function Documentation

◆ capacity()

◆ clear()

◆ dump()

◆ get()

◆ getBlocking()

◆ getFreeSlots()

◆ growEmptyBuffer()

◆ growFullBuffer()

◆ isEmpty()

◆ isFull()

◆ peek()

◆ peekBlocking()

◆ put()

◆ putBlocking()

◆ putSame()

◆ resetFull()

◆ size()

◆ toString()

◆ waitForFreeSlots()