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

Class SegmentedLruPolicy

java.lang.Object

com.github.benmanes.caffeine.cache.simulator.policy.linked.SegmentedLruPolicy

All Implemented Interfaces:

Policy, Policy.KeyOnlyPolicy

public final class SegmentedLruPolicy
extends Object
implements Policy.KeyOnlyPolicy

"Segmented LRU is based on the observation that objects with at least two accesses are much more popular than those with only one access during a short interval. In Segmented LRU, cache space is partitioned into two segments: probationary segment and protected segment.

New objects (with only one access) are first faulted into the probationary segment, whereas objects with two or more accesses are kept in the protected segment. When a probationary object gets one more reference, it will change to the protected segment. When the whole cache space becomes full, the least recently used object in the probationary segment will first be replaced. The protected segment is finite in size. When it gets full, the overflowed will be re-cached in probationary segment. Since objects in protected segment have to go a longer way before being evicted, popular object or an object with more accesses tends to be kept in cache for longer time." from LRU-SP: A Size-Adjusted and Popularity-Aware LRU Replacement Algorithm for Web Caching

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
SegmentedLruPolicy(Admission admission, Config config)

Method Summary

Modifier and Type	Method and Description
static Set<Policy>	policies(Config config) Returns all variations of this policy based on the configuration parameters.
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

finished, name

Constructor Detail

SegmentedLruPolicy

public SegmentedLruPolicy(Admission admission,
                          Config config)

Method Detail

policies

public static Set<Policy> policies(Config config)

Returns all variations of this policy based on the configuration parameters.

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