Package org.apache.jackrabbit.oak.segment

Class RecordCache<K>

java.lang.Object

org.apache.jackrabbit.oak.segment.RecordCache<K>

Type Parameters:

K -

All Implemented Interfaces:

Cache<K,RecordId>

public abstract class RecordCache<K>
extends Object
implements Cache<K,RecordId>

Partial mapping of keys of type K to values of type RecordId. This is typically used for de-duplicating values that have already been persisted and thus already have a RecordId.

Constructor Summary

Constructors

Constructor	Description
RecordCache()

Method Summary

Modifier and Type	Method	Description
abstract long	estimateCurrentWeight()
static <T> @NotNull Supplier<RecordCache<T>>	factory(int size)
static <T> @NotNull Supplier<RecordCache<T>>	factory(int size, @NotNull org.apache.jackrabbit.guava.common.cache.Weigher<T,RecordId> weigher)
abstract @NotNull org.apache.jackrabbit.guava.common.cache.CacheStats	getStats()
static <T> @NotNull RecordCache<T>	newRecordCache(int size)	Factory method for creating RecordCache instances.
void	put(K key, @NotNull RecordId value, byte cost)	Add a mapping from key to value with a given cost.
abstract long	size()

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.jackrabbit.oak.segment.Cache

get, put

Constructor Detail

RecordCache

public RecordCache()

Method Detail

size

public abstract long size()

Returns:

number of mappings

estimateCurrentWeight

public abstract long estimateCurrentWeight()

put

public void put(@NotNull
                K key,
                @NotNull
                @NotNull RecordId value,
                byte cost)

Description copied from interface: Cache

Add a mapping from key to value with a given cost.

Specified by:

put in interface Cache<K,RecordId>

getStats

@NotNull
public abstract @NotNull org.apache.jackrabbit.guava.common.cache.CacheStats getStats()

Returns:

access statistics for this cache

newRecordCache

@NotNull
public static <T> @NotNull RecordCache<T> newRecordCache(int size)

Factory method for creating RecordCache instances. The returned instances are all thread safe. They implement a simple LRU behaviour where the least recently accessed mapping would be replaced when inserting a new mapping would exceed size.

Returns:

A new RecordCache instance of the given size.

factory

@NotNull
public static <T> @NotNull Supplier<RecordCache<T>> factory(int size,
                                                            @NotNull
                                                            @NotNull org.apache.jackrabbit.guava.common.cache.Weigher<T,RecordId> weigher)

Parameters:

size - size of the cache

weigher - Needed to provide an estimation of the cache weight in memory

Returns:

A factory returning RecordCache instances of the given size when invoked.

See Also:

newRecordCache(int)

factory

@NotNull
public static <T> @NotNull Supplier<RecordCache<T>> factory(int size)

Parameters:

size - size of the cache

Returns:

A factory returning RecordCache instances of the given size when invoked.

See Also:

newRecordCache(int)