com.neeve.util

Class UtlConcurrentRingBuffer<T>

java.lang.Object

com.neeve.util.UtlConcurrentRingBuffer<T>

public final class UtlConcurrentRingBuffer<T>
extends Object

Class implementing a concurrent bounded ring buffer

This class implements a ring buffer of a specific size with the following semantics - write will block if no space is available and read will return null if nothing to read.

Threading:

This class is safe for single thread write and single thread read. It is not safe for concurrent writes and concurrent reads.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	UtlConcurrentRingBuffer.ItemFactory<T> The interface of the item creation factory.

Method Summary

Modifier and Type	Method and Description
static <T> UtlConcurrentRingBuffer<T>	create(int size, UtlConcurrentRingBuffer.ItemFactory<T> factory) Create a ring buffer.
T	get(long slot) Get the item at the specified slot.
boolean	hasSpace()
long	head()
int	length() Get number of items in buffer
long	nextRead() Get the read slot i.e. the slot at the head of the buffer
long	nextWrite() Get the write slot i.e. the slot at the tail of the buffer The calling thread will block in case the buffer is full until a slot frees us
long	numFulls() Get the number of times the buffer was full during a write attempt
void	read(long slot) Advance the read slot
int	size() Get buffer capacity
long	tail()
void	write(long slot) Advance the write slot

Methods inherited from class java.lang.Object

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

Method Detail

create

public static <T> UtlConcurrentRingBuffer<T> create(int size,
                                                    UtlConcurrentRingBuffer.ItemFactory<T> factory)

Create a ring buffer.

Parameters:

size - The size of the buffer to create

factory - The item factory

Returns:

Returns the created ring buffer

Threading:

This method is safe for concurrent access by multiple threads

hasSpace

public final boolean hasSpace()

head

public final long head()

tail

public final long tail()

size

public final int size()

Get buffer capacity

length

public final int length()

Get number of items in buffer

get

public final T get(long slot)

Get the item at the specified slot.

Parameters:

slot - The slot returned by #next

Throws:

IllegalArgumentException - if the supplied slot does not match what is returned by #next

nextWrite

public final long nextWrite()

Get the write slot i.e. the slot at the tail of the buffer

The calling thread will block in case the buffer is full until a slot frees us

Returns:

The slot for the next write operation

write

public final void write(long slot)

Advance the write slot

Parameters:

slot - The slot returned by nextWrite().

Throws:

IllegalArgumentException - if the supplied slot does not match what is returned by nextWrite()

nextRead

public final long nextRead()

Get the read slot i.e. the slot at the head of the buffer

Returns:

The slot for the next read operation or -1 if no item to read

read

public final void read(long slot)

Advance the read slot

Parameters:

slot - The slot returned by nextRead().

Throws:

IllegalArgumentException - if the supplied slot does not match what is returned by nextRead()

numFulls

public final long numFulls()

Get the number of times the buffer was full during a write attempt