com.github.benmanes.caffeine.cache.simulator.policy.irr

Class FrdPolicy

java.lang.Object

com.github.benmanes.caffeine.cache.simulator.policy.irr.FrdPolicy

All Implemented Interfaces:

Policy, Policy.KeyOnlyPolicy

public final class FrdPolicy
extends Object
implements Policy.KeyOnlyPolicy

Filtering-based Buffer Cache (FRD) algorithm. This algorithm organizes blocks by their reuse distance and partitions the cache into a filter and main space. The filter employs the LRU policy and accumulates new arrivals. The main space also employs LRU and holds history entries (filter and non-resident) and promoted resident entries. A resident entry is promoted when a miss occurs on a non-resident node, meaning that is has been used after having been evicted by the filter or main cache partitions.

While the authors describe the filter entry and its history entry as distinct, thereby requiring two hash tables, this implementation merges them. Thus, during the main space's pruning operation an entry also in the filter space is treated as a history node, pruned, and remains in the hash table. This simplification should have no effect on the algorithm or its performance.

The algorithm is explained by the authors in FRD: A Filtering based Buffer Cache Algorithm that Considers both Frequency and Reuse Distance.

Nested Class Summary

Nested classes/interfaces inherited from interface com.github.benmanes.caffeine.cache.simulator.policy.Policy

Policy.Characteristic, Policy.KeyOnlyPolicy, Policy.PolicySpec

Constructor Summary

Constructors

Constructor and Description
FrdPolicy(Config config)

Method Summary

Modifier and Type	Method and Description
void	finished() Indicates that the recording has completed.
void	record(long key)
PolicyStats	stats() Returns the cache efficiency statistics.

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.github.benmanes.caffeine.cache.simulator.policy.Policy.KeyOnlyPolicy

record

Methods inherited from interface com.github.benmanes.caffeine.cache.simulator.policy.Policy

name

Constructor Detail

FrdPolicy

public FrdPolicy(Config config)

Method Detail

record

public void record(long key)

Specified by:

record in interface Policy.KeyOnlyPolicy

stats

public PolicyStats stats()

Description copied from interface: Policy

Returns the cache efficiency statistics.

Specified by:

stats in interface Policy

finished

public void finished()

Description copied from interface: Policy

Indicates that the recording has completed.

Specified by:

finished in interface Policy