Package org.apache.jackrabbit.oak.segment.spi.persistence.persistentcache

Class DelegatingPersistentCache

java.lang.Object

org.apache.jackrabbit.oak.segment.spi.persistence.persistentcache.DelegatingPersistentCache

All Implemented Interfaces:

PersistentCache

Direct Known Subclasses:

SegmentPreloader

public abstract class DelegatingPersistentCache
extends Object
implements PersistentCache

Simple abstract implementation of a delegating PersistentCache that can be used as a base class for PersistentCache decorators.

Constructor Summary

Constructors

Constructor	Description
DelegatingPersistentCache()

Method Summary

Modifier and Type	Method	Description
void	cleanUp()	Purges the cache entries according to the implementation policy (e.g.
boolean	containsSegment(long msb, long lsb)	Check if the segment exists in the cache.
protected abstract PersistentCache	delegate()
@Nullable Buffer	readSegment(long msb, long lsb, @NotNull Callable<Buffer> loader)	Reads the segment from cache.
void	writeSegment(long msb, long lsb, Buffer buffer)	Writes the segment to the cache.

Methods inherited from class java.lang.Object

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

Constructor Detail

DelegatingPersistentCache

public DelegatingPersistentCache()

Method Detail

delegate

protected abstract PersistentCache delegate()

readSegment

@Nullable
public @Nullable Buffer readSegment(long msb,
                                    long lsb,
                                    @NotNull
                                    @NotNull Callable<Buffer> loader)

Description copied from interface: PersistentCache

Reads the segment from cache.

Specified by:

readSegment in interface PersistentCache

Parameters:

msb - the most significant bits of the identifier of the segment

lsb - the least significant bits of the identifier of the segment

loader - in case of cache miss, with loader.call() missing element will be retrieved

Returns:

byte buffer containing the segment data or null if the segment doesn't exist

containsSegment

public boolean containsSegment(long msb,
                               long lsb)

Description copied from interface: PersistentCache

Check if the segment exists in the cache.

Specified by:

containsSegment in interface PersistentCache

Parameters:

msb - the most significant bits of the identifier of the segment

lsb - the least significant bits of the identifier of the segment

Returns:

true if the segment exists

writeSegment

public void writeSegment(long msb,
                         long lsb,
                         Buffer buffer)

Description copied from interface: PersistentCache

Writes the segment to the cache.

Specified by:

writeSegment in interface PersistentCache

Parameters:

msb - the most significant bits of the identifier of the segment

lsb - the least significant bits of the identifier of the segment

buffer - the byte buffer containing the segment data

cleanUp

public void cleanUp()

Description copied from interface: PersistentCache

Purges the cache entries according to the implementation policy (e.g. maximum cache size, maximum number of entries, etc.)

Specified by:

cleanUp in interface PersistentCache