org.jlab.coda.emu.support.data

Class ByteBufferItem

java.lang.Object

org.jlab.coda.emu.support.data.ByteBufferItem

public class ByteBufferItem
extends java.lang.Object

This class is used in conjunction with the ByteBufferSupply class to provide a very fast supply of ByteBuffer objects for reuse. Objects of this class are used to populate the ring buffer in ByteBufferSupply. Uses the Disruptor software package.

Author:

timmer (4/14/14)

Field Summary

Fields

Modifier and Type	Field and Description
int	myIndex Auxiliary integer storage.

Constructor Summary

Constructors

Constructor and Description
ByteBufferItem(java.nio.ByteBuffer templateBuf, boolean orderedRelease, int myId) Constructor used to initially fill each ByteBufferItem of a ByteBufferSupply with a copy of a template buffer.
ByteBufferItem(int bufferSize, java.nio.ByteOrder order, boolean direct, boolean orderedRelease, int myId) Constructor.
ByteBufferItem(int bufferSize, java.nio.ByteOrder order, boolean direct, boolean orderedRelease, int myId, java.lang.Object auxObject, int auxIndex) Constructor.

Method Summary

Modifier and Type	Method and Description
void	addUsers(int additionalUsers) If a reference to this ByteBufferItem is copied, then it is necessary to increase the number of users.
(package private) boolean	decrementCounter() Called by buffer user by way of ByteBufferSupply.release(ByteBufferItem) if no longer using it so it may be reused later.
void	ensureCapacity(int capacity) Make sure the buffer is the size needed.
boolean	equals(java.nio.ByteBuffer buf)
java.nio.ByteBuffer	getBuffer() Get the contained ByteBuffer.
java.nio.ByteBuffer	getBufferAsIs() Get the contained ByteBuffer without any modifications.
int	getBufferSize() Get the size in bytes of the contained ByteBuffer.
long	getConsumerSequence() Get the sequence of this item for consumer.
boolean	getForce() Get the flag used to suggest a forced write to a consumer.
int	getMyId() Get the unique id of this object.
java.lang.Object	getMyObject() Get the auxiliary object.
long	getProducerSequence() Get the sequence of this item for producer.
boolean	getUserBoolean() Get the user boolean.
int	getUserInt() Get the user integer.
int	getUsers() Get the number of users of this buffer.
boolean	isDirect() Is this a direct buffer or not?
boolean	isFromConsumerGet() Was this item obtained through a call to consumerGet()?
void	reset() Method to reset this item each time it is retrieved from the supply.
void	setBuffer(java.nio.ByteBuffer buf) Set the contained ByteBuffer.
void	setConsumerSequence(long sequence) Set the sequence of this item for consumer.
void	setForce(boolean force) Set the flag used to suggest a forced write to a consumer.
void	setFromConsumerGet(boolean fromConsumerGet) Set whether this item was obtained through a call to consumerGet().
void	setMyObject(java.lang.Object obj) Set the auxiliary object.
void	setProducerSequence(long sequence) Set the sequence of this item for producer.
void	setUserBoolean(boolean bool) Set user boolean.
void	setUserInt(int i) Set the user integer.
void	setUsers(int users) Set the number of users of this buffer.

Methods inherited from class java.lang.Object

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

Field Detail

myIndex

public int myIndex

Auxiliary integer storage. Used to store pool ID.

Constructor Detail

ByteBufferItem

ByteBufferItem(int bufferSize,
               java.nio.ByteOrder order,
               boolean direct,
               boolean orderedRelease,
               int myId)

Constructor.

Parameters:

bufferSize - size in bytes of ByteBuffer to construct.

order - byte order of ByteBuffer to construct.

direct - is the buffer direct (in memory not managed by JVM) or not.

orderedRelease - if true, release ByteBufferItems in same order as acquired.

myId - unique id of this object.

ByteBufferItem

ByteBufferItem(int bufferSize,
               java.nio.ByteOrder order,
               boolean direct,
               boolean orderedRelease,
               int myId,
               java.lang.Object auxObject,
               int auxIndex)

Constructor.

Parameters:

bufferSize - size in bytes of ByteBuffer to construct.

order - byte order of ByteBuffer to construct.

direct - is the buffer direct (in memory not managed by JVM) or not.

orderedRelease - if true, release ByteBufferItems in same order as acquired.

myId - unique id of this object.

auxObject - auxiliary object to store.

auxIndex - auxiliary integer to store.

ByteBufferItem

ByteBufferItem(java.nio.ByteBuffer templateBuf,
               boolean orderedRelease,
               int myId)

Constructor used to initially fill each ByteBufferItem of a ByteBufferSupply with a copy of a template buffer.

Parameters:

templateBuf - this item's buffer is a copy this of template ByteBuffer.

orderedRelease - if true, release ByteBufferItems in same order as acquired.

myId - unique id of this object.

Method Detail

reset

public void reset()

Method to reset this item each time it is retrieved from the supply.

equals

public boolean equals(java.nio.ByteBuffer buf)

getMyId

public int getMyId()

Get the unique id of this object.

Returns:

unique id of this object.

getMyObject

public java.lang.Object getMyObject()

Get the auxiliary object.

Returns:

auxiliary object.

setMyObject

public void setMyObject(java.lang.Object obj)

Set the auxiliary object.

Parameters:

obj - auxiliary object.

isDirect

public boolean isDirect()

Is this a direct buffer or not?

Returns:

true if direct buffer, else false.

getForce

public boolean getForce()

Get the flag used to suggest a forced write to a consumer.

Returns:

flag used to suggest a forced write to a consumer.

setForce

public void setForce(boolean force)

Set the flag used to suggest a forced write to a consumer.

Parameters:

force - flag used to suggest a forced write to a consumer.

isFromConsumerGet

public boolean isFromConsumerGet()

Was this item obtained through a call to consumerGet()?

Returns:

true only if item obtained through a call to consumerGet().

setFromConsumerGet

public void setFromConsumerGet(boolean fromConsumerGet)

Set whether this item was obtained through a call to consumerGet().

Parameters:

fromConsumerGet - true only if item obtained through a call to consumerGet().

getUserInt

public int getUserInt()

Get the user integer. User int gets reset to 0 each time supply.get() is called.

Returns:

user integer.

setUserInt

public void setUserInt(int i)

Set the user integer.

Parameters:

i - user integer.

getUserBoolean

public boolean getUserBoolean()

Get the user boolean. User boolean gets reset to false each time supply.get() is called.

Returns:

user boolean.

setUserBoolean

public void setUserBoolean(boolean bool)

Set user boolean.

Parameters:

bool - user boolean.

getProducerSequence

public long getProducerSequence()

Get the sequence of this item for producer.

Returns:

sequence of this item for producer.

setProducerSequence

public void setProducerSequence(long sequence)

Set the sequence of this item for producer.

Parameters:

sequence - sequence of this item for producer.

getConsumerSequence

public long getConsumerSequence()

Get the sequence of this item for consumer.

Returns:

sequence of this item for consumer.

setConsumerSequence

public void setConsumerSequence(long sequence)

Set the sequence of this item for consumer.

Parameters:

sequence - sequence of this item for consumer.

getBufferSize

public int getBufferSize()

Get the size in bytes of the contained ByteBuffer.

Returns:

size in bytes of the contained ByteBuffer.

setBuffer

public void setBuffer(java.nio.ByteBuffer buf)

Set the contained ByteBuffer. This method is dangerous -- definitely not thread safe!

Parameters:

buf - contained ByteBuffer.

getBuffer

public java.nio.ByteBuffer getBuffer()

Get the contained ByteBuffer. Position is set to 0.

Returns:

contained ByteBuffer.

getBufferAsIs

public java.nio.ByteBuffer getBufferAsIs()

Get the contained ByteBuffer without any modifications.

Returns:

contained ByteBuffer without any modifications.

ensureCapacity

public void ensureCapacity(int capacity)

Make sure the buffer is the size needed.

Parameters:

capacity - minimum necessary size of buffer in bytes.

setUsers

public void setUsers(int users)

Set the number of users of this buffer. If multiple users of the buffer exist, keep track of all until last one is finished.

Parameters:

users - number of buffer users

getUsers

public int getUsers()

Get the number of users of this buffer.

Returns:

number of users of this buffer.

decrementCounter

boolean decrementCounter()

Called by buffer user by way of ByteBufferSupply.release(ByteBufferItem) if no longer using it so it may be reused later.

Returns:

true if no one using buffer now, else false.

addUsers

public void addUsers(int additionalUsers)

If a reference to this ByteBufferItem is copied, then it is necessary to increase the number of users. Although this method is not safe to call in general, it is safe, for example, if a RingItem is copied in the ER BEFORE it is copied again onto multiple output channels' rings and then released. Currently this is only used in just such a situation - in the ER when a ring item must be copied and placed on all extra output channels. In this case, there is always at least one existing user.

Parameters:

additionalUsers - number of users to add