Package org.apache.solr.store.blockcache

Class BlockCache

java.lang.Object

org.apache.solr.store.blockcache.BlockCache

public class BlockCache
extends Object

WARNING: This API is experimental and might change in incompatible ways in the next release.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	BlockCache.OnRelease

Field Summary

Fields

Modifier and Type	Field	Description
static int	_128M
static int	_32K

Constructor Summary

Constructors

Constructor	Description
BlockCache(Metrics metrics, boolean directAllocation, long totalMemory)
BlockCache(Metrics metrics, boolean directAllocation, long totalMemory, int slabSize)
BlockCache(Metrics metrics, boolean directAllocation, long totalMemory, int slabSize, int blockSize)

Method Summary

Modifier and Type	Method	Description
boolean	fetch(BlockCacheKey blockCacheKey, byte[] buffer)
boolean	fetch(BlockCacheKey blockCacheKey, byte[] buffer, int blockOffset, int off, int length)
int	getSize()	returns the number of elements in the cache
void	release(BlockCacheKey key)
boolean	store(BlockCacheKey blockCacheKey, int blockOffset, byte[] data, int offset, int length)	This is only best-effort...

Methods inherited from class java.lang.Object

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

Field Detail

_128M

public static final int _128M

See Also:

Constant Field Values

_32K

public static final int _32K

See Also:

Constant Field Values

Constructor Detail

BlockCache

public BlockCache(Metrics metrics,
                  boolean directAllocation,
                  long totalMemory)

BlockCache

public BlockCache(Metrics metrics,
                  boolean directAllocation,
                  long totalMemory,
                  int slabSize)

BlockCache

public BlockCache(Metrics metrics,
                  boolean directAllocation,
                  long totalMemory,
                  int slabSize,
                  int blockSize)

Method Detail

release

public void release(BlockCacheKey key)

store

public boolean store(BlockCacheKey blockCacheKey,
                     int blockOffset,
                     byte[] data,
                     int offset,
                     int length)

This is only best-effort... it's possible for false to be returned, meaning the block was not able to be cached. NOTE: blocks may not currently be updated (false will be returned if the block is already cached) The blockCacheKey is cloned before it is inserted into the map, so it may be reused by clients if desired.

Parameters:

blockCacheKey - the key for the block

blockOffset - the offset within the block

data - source data to write to the block

offset - offset within the source data array

length - the number of bytes to write.

Returns:

true if the block was cached/updated

fetch

public boolean fetch(BlockCacheKey blockCacheKey,
                     byte[] buffer,
                     int blockOffset,
                     int off,
                     int length)

Parameters:

blockCacheKey - the key for the block

buffer - the target buffer for the read result

blockOffset - offset within the block

off - offset within the target buffer

length - the number of bytes to read

Returns:

true if the block was cached and the bytes were read

fetch

public boolean fetch(BlockCacheKey blockCacheKey,
                     byte[] buffer)

getSize

public int getSize()

returns the number of elements in the cache