com.thimbleware.jmemcached.storage.bytebuffer
Class ByteBufferBlockStore

java.lang.Object
  com.thimbleware.jmemcached.storage.bytebuffer.ByteBufferBlockStore

Direct Known Subclasses:

MemoryMappedBlockStore

public class ByteBufferBlockStore
extends java.lang.Object

Memory mapped block storage mechanism with a free-list maintained by TreeMap Allows memory for storage to be mapped outside of the VM's main memory, and outside the purvey of the GC. Should offer O(Log(N)) search and free of blocks.

Nested Class Summary

static class	ByteBufferBlockStore.BadAllocationException Exception thrown on inability to allocate a new block
static class	ByteBufferBlockStore.ByteBufferBlockStoreFactory

Field Summary

protected org.jboss.netty.buffer.ChannelBuffer

storageBuffer

Constructor Summary

protected

ByteBufferBlockStore(int blockSizeBytes) Constructor used only be subclasses, allowing them to provide their own buffer.

Method Summary

Region	alloc(int desiredSize, org.jboss.netty.buffer.ChannelBuffer data) Allocate a region in the block storage
void	clear()
void	close() Close the store, destroying all data and closing the backing file
void	free(Region region)
protected void	freeResources()
org.jboss.netty.buffer.ChannelBuffer	get(Region region)
int	getBlockSizeBytes()
static BlockStoreFactory	getFactory()
long	getFreeBytes()
long	getStoreSizeBytes()
protected void	initialize(int storeSizeBytes)
static long	roundUp(long size, long blockSize) Rounds up a requested size to the nearest block width.

Methods inherited from class java.lang.Object

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

Field Detail

storageBuffer

protected org.jboss.netty.buffer.ChannelBuffer storageBuffer

Constructor Detail

ByteBufferBlockStore

protected ByteBufferBlockStore(int blockSizeBytes)

Constructor used only be subclasses, allowing them to provide their own buffer.

Method Detail

getFactory

public static BlockStoreFactory getFactory()

initialize

protected void initialize(int storeSizeBytes)

roundUp

public static long roundUp(long size,
                           long blockSize)

Rounds up a requested size to the nearest block width.

Parameters:

size - the requested size

blockSize - the block size to use

Returns:

the actual mount to use

close

public void close()
           throws java.io.IOException

Close the store, destroying all data and closing the backing file

Throws:

java.io.IOException - thrown on failure to close file

freeResources

protected void freeResources()
                      throws java.io.IOException

Throws:

java.io.IOException

alloc

public Region alloc(int desiredSize,
                    org.jboss.netty.buffer.ChannelBuffer data)

Allocate a region in the block storage

Parameters:

desiredSize - size (in bytes) desired for the region

data - initial data to place in it

Returns:

the region descriptor

get

public org.jboss.netty.buffer.ChannelBuffer get(Region region)

free

public void free(Region region)

clear

public void clear()

getStoreSizeBytes

public long getStoreSizeBytes()

getBlockSizeBytes

public int getBlockSizeBytes()

getFreeBytes

public long getFreeBytes()