Package org.apache.cassandra.io.util

Class LimitingRebufferer

java.lang.Object

org.apache.cassandra.io.util.LimitingRebufferer

All Implemented Interfaces:

java.lang.AutoCloseable, ReaderFileProxy, Rebufferer, Rebufferer.BufferHolder

public class LimitingRebufferer
extends java.lang.Object
implements Rebufferer, Rebufferer.BufferHolder

Rebufferer wrapper that applies rate limiting. Instantiated once per RandomAccessReader, thread-unsafe. The instances reuse themselves as the BufferHolder to avoid having to return a new object for each rebuffer call.

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.cassandra.io.util.Rebufferer

Rebufferer.BufferHolder

Field Summary

Fields inherited from interface org.apache.cassandra.io.util.Rebufferer

EMPTY

Constructor Summary

Constructors

Constructor	Description
LimitingRebufferer(Rebufferer wrapped, com.google.common.util.concurrent.RateLimiter limiter, int limitQuant)

Method Summary

Modifier and Type	Method	Description
java.nio.ByteBuffer	buffer()	Returns a useable buffer (i.e.
ChannelProxy	channel()
void	close()
void	closeReader()	Called when a reader is closed.
long	fileLength()
double	getCrcCheckChance()	Needed for tests.
long	offset()	Position in the file of the start of the buffer.
Rebufferer.BufferHolder	rebuffer(long position)	Rebuffer (move on or seek to) a given position, and return a buffer that can be used there.
void	release()	To be called when this buffer is no longer in use.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

LimitingRebufferer

public LimitingRebufferer(Rebufferer wrapped,
                          com.google.common.util.concurrent.RateLimiter limiter,
                          int limitQuant)

Method Detail

rebuffer

public Rebufferer.BufferHolder rebuffer(long position)

Description copied from interface: Rebufferer

Rebuffer (move on or seek to) a given position, and return a buffer that can be used there. The only guarantee about the size of the returned data is that unless rebuffering at the end of the file, the buffer will not be empty and will contain the requested position, i.e. offset <= position < offset + bh.buffer().limit(), but the buffer will not be positioned there.

Specified by:

rebuffer in interface Rebufferer

channel

public ChannelProxy channel()

Specified by:

channel in interface ReaderFileProxy

fileLength

public long fileLength()

Specified by:

fileLength in interface ReaderFileProxy

getCrcCheckChance

public double getCrcCheckChance()

Description copied from interface: ReaderFileProxy

Needed for tests. Returns the table's CRC check chance, which is only set for compressed tables.

Specified by:

getCrcCheckChance in interface ReaderFileProxy

close

public void close()

Specified by:

close in interface java.lang.AutoCloseable

Specified by:

close in interface ReaderFileProxy

closeReader

public void closeReader()

Description copied from interface: Rebufferer

Called when a reader is closed. Should clean up reader-specific data.

Specified by:

closeReader in interface Rebufferer

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

buffer

public java.nio.ByteBuffer buffer()

Description copied from interface: Rebufferer.BufferHolder

Returns a useable buffer (i.e. one whose position and limit can be freely modified). Its limit will be set to the size of the available data in the buffer. The buffer must be treated as read-only.

Specified by:

buffer in interface Rebufferer.BufferHolder

offset

public long offset()

Description copied from interface: Rebufferer.BufferHolder

Position in the file of the start of the buffer.

Specified by:

offset in interface Rebufferer.BufferHolder

release

public void release()

Description copied from interface: Rebufferer.BufferHolder

To be called when this buffer is no longer in use. Must be called for all BufferHolders, or ChunkCache will not be able to free blocks.

Specified by:

release in interface Rebufferer.BufferHolder