LRUCache (IBM FHIR Server)

java.lang.Object
- java.util.AbstractMap<K,V>
- - java.util.HashMap<K,V>
  - - java.util.LinkedHashMap<K,V>
    - - com.ibm.fhir.persistence.jdbc.cache.LRUCache<K,V>

All Implemented Interfaces:

Serializable, Cloneable, Map<K,V>
```
public class LRUCache<K,V>
extends LinkedHashMap<K,V>
```
An LRU implementation which limits the maximum number of entries and ejects older entries. Null values are not permitted in this implementation.

See Also:

Serialized Form

Nested Class Summary
- Nested classes/interfaces inherited from class java.util.AbstractMap
  AbstractMap.SimpleEntry<K extends Object,V extends Object>, AbstractMap.SimpleImmutableEntry<K extends Object,V extends Object>

Constructor Summary

Constructors
Constructor Description

LRUCache(int maxSize)
Public constructor

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`LinkedHashMap<K,V>`	`newUpdateMap()`	Create a new instance of a LinkedHashMap which can be used for collecting updates to apply to the cache.
`protected boolean`	`removeEldestEntry(Map.Entry<K,V> eldest)`
`void`	`update(LinkedHashMap<K,V> updates)`	Update this LRU with the updates in the given LinkedHashMap, which we use because we apply the updates in a specific order (as defined by the entrySet of the updates parameter).
`void`	`update(List<K> updates)`	Update the LRU by processing each of the keys in the updates parameter

Methods inherited from class java.util.LinkedHashMap
clear, containsValue, entrySet, forEach, get, getOrDefault, keySet, replaceAll, values

Methods inherited from class java.util.HashMap
clone, compute, computeIfAbsent, computeIfPresent, containsKey, isEmpty, merge, put, putAll, putIfAbsent, remove, remove, replace, replace, size

Methods inherited from class java.util.AbstractMap
equals, hashCode, toString

Methods inherited from class java.lang.Object
getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Map
compute, computeIfAbsent, computeIfPresent, containsKey, equals, hashCode, isEmpty, merge, put, putAll, putIfAbsent, remove, remove, replace, replace, size

- Constructor Detail
  - LRUCache
```
public LRUCache(int maxSize)
```
    Public constructor
    
    Parameters:
    
    maxSize -
- Method Detail
  - removeEldestEntry
```
protected boolean removeEldestEntry(Map.Entry<K,V> eldest)
```
    Overrides:
    
    removeEldestEntry in class LinkedHashMap<K,V>
  - update
```
public void update(LinkedHashMap<K,V> updates)
```
    Update this LRU with the updates in the given LinkedHashMap, which we use because we apply the updates in a specific order (as defined by the entrySet of the updates parameter).
    
    Parameters:
    
    updates -
  - update
```
public void update(List<K> updates)
```
    Update the LRU by processing each of the keys in the updates parameter
    
    Parameters:
    
    updates -
  - newUpdateMap
```
public LinkedHashMap<K,V> newUpdateMap()
```
    Create a new instance of a LinkedHashMap which can be used for collecting updates to apply to the cache.
    
    Returns:
    
    a new empty instance of a LinkedHashMap