FrdPolicy (simulator 3.1.5 API)

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 Description

FrdPolicy(Config config)

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	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
name

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

- 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