Package com.illumon.iris.db.util.caching.redesign

Class DataBufferHolder

java.lang.Object

com.illumon.iris.db.util.caching.redesign.DataBufferHolder

public final class DataBufferHolder
extends Object

Holder for ByteBuffers pooled in the DataBufferPool and associated views. Manages visibility for readers, transaction buffering for writers, and other state associated with a given data buffer.

Method Summary

Modifier and Type	Method	Description
final void	clear()	Clear any state, in order to allow for re-use.
final void	clearPending()	Clear the pending view, if there is one.
final ByteBuffer	getCurrent()	Get the current visible view for readers.
final void	promotePending()	Promote the pending view, if non-null, to the current view.
final ByteBuffer	readOnlyView()	Get a new view of the held buffer as if with ByteBuffer.asReadOnlyBuffer(), always with limit and position 0.
final void	setCurrent(ByteBuffer current)	Set the current visible view for readers.
final void	setPending(ByteBuffer pending)	Set the pending view for incomplete transactions still being written.
final ByteBuffer	writableView()	Get a new view of the held buffer as if with ByteBuffer.duplicate(), always with limit and position 0.

Methods inherited from class java.lang.Object

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

Method Details

getCurrent

public final ByteBuffer getCurrent()

Get the current visible view for readers. Must not be mutated.

Returns:

The current visible view

setCurrent

public final void setCurrent(@NotNull
 ByteBuffer current)

Set the current visible view for readers.

The input buffer must have been created with writableView() and must not be mutated further by application code after it is passed to this method.

Parameters:

current - The new current visible view

writableView

public final ByteBuffer writableView()

Get a new view of the held buffer as if with ByteBuffer.duplicate(), always with limit and position 0.

Returns:

The new view, which belongs to the caller to mutate until given back with setCurrent(ByteBuffer) or setPending(ByteBuffer).

readOnlyView

public final ByteBuffer readOnlyView()

Get a new view of the held buffer as if with ByteBuffer.asReadOnlyBuffer(), always with limit and position 0.

Returns:

The new view, which belongs to the caller to mutate

setPending

public final void setPending(@NotNull
 ByteBuffer pending)

Set the pending view for incomplete transactions still being written.

The input buffer must have been created with writableView() and must not be mutated further by application code after it is passed to this method.

Parameters:

pending - The new pending view

promotePending

public final void promotePending()

Promote the pending view, if non-null, to the current view. Clear the pending view.

clearPending

public final void clearPending()

Clear the pending view, if there is one.

clear

public final void clear()

Clear any state, in order to allow for re-use.