CacheMap (OpenJPA Parent POM 3.1.0 API)

java.lang.Object
- org.apache.openjpa.util.CacheMap

All Implemented Interfaces:

Map
```
public class CacheMap
extends Object
implements Map
```
Fixed-size map that has ability to pin/unpin entries and move overflow to a backing soft map.

Author:

Patrick Linskey, Abe White

Nested Class Summary
- Nested classes/interfaces inherited from interface java.util.Map
  Map.Entry<K,V>

Field Summary

Fields
Modifier and Type	Field and Description
`protected SizedMap`	`cacheMap` The map for non-expired and non-pinned references.
`protected Map`	`pinnedMap` The set of objects pinned into the cache.
`protected SizedMap`	`softMap` The map for expired references.

Constructor Summary

Constructors
Constructor and Description
`CacheMap()` Create a non-LRU (and therefore highly concurrent) cache map with a size of 1000.
`CacheMap(boolean lru)` Create a cache map with a size of 1000.
`CacheMap(boolean lru, int max)` Create a cache map with the given properties.
`CacheMap(boolean lru, int max, int size, float load)` Deprecated. use `CacheMap(boolean, int, int, float, int)` instead.
`CacheMap(boolean lru, int max, int size, float load, int concurrencyLevel)` Create a cache map with the given properties.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`protected void`	`cacheMapOverflowRemoved(Object key, Object value)` Called from `SizedMap.overflowRemoved(java.lang.Object, java.lang.Object)` in the cache map.
`void`	`clear()` Removes pinned objects as well as unpinned ones.
`boolean`	`containsKey(Object key)`
`boolean`	`containsValue(Object val)`
`protected void`	`entryAdded(Object key, Object value)` Invoked when an entry is added to the cache.
`protected void`	`entryRemoved(Object key, Object value, boolean expired)` Invoked when a key-value pair is evicted from this data structure.
`Set`	`entrySet()`
`Object`	`get(Object key)`
`int`	`getCacheSize()` The maximum number of hard references to maintain, or -1 for no limit.
`Set`	`getPinnedKeys()` The keys pinned into the map.
`int`	`getSoftReferenceSize()` The maximum number of soft references to maintain, or -1 for no limit.
`boolean`	`isEmpty()`
`boolean`	`isLRU()` Whether this cache map uses LRU eviction.
`Set`	`keySet()`
`boolean`	`pin(Object key)` Locks the given key and its value into the map.
`protected Object`	`put(Map map, Object key, Object value)` Put the given entry into the given map.
`Object`	`put(Object key, Object value)`
`void`	`putAll(Map map)`
`void`	`putAll(Map map, boolean replaceExisting)`
`void`	`readLock()` Acquire read lock.
`void`	`readUnlock()` Release read lock.
`protected Object`	`remove(Map map, Object key)` Remove the given key from the given map.
`Object`	`remove(Object key)` If `key` is pinned into the cache, the pin is cleared and the object is removed.
`void`	`setCacheSize(int size)` The maximum number of hard references to maintain, or -1 for no limit.
`void`	`setSoftReferenceSize(int size)` The maximum number of soft references to maintain, or -1 for no limit.
`int`	`size()`
`protected void`	`softMapOverflowRemoved(Object key, Object value)` Called from `SizedMap.overflowRemoved(java.lang.Object, java.lang.Object)` in the soft map.
`protected void`	`softMapValueExpired(Object key)` Called when a value expires from the soft map.
`String`	`toString()`
`boolean`	`unpin(Object key)` Undo a pinning.
`Collection`	`values()`
`void`	`writeLock()` Acquire write lock.
`void`	`writeUnlock()` Release write lock.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Map
compute, computeIfAbsent, computeIfPresent, equals, forEach, getOrDefault, hashCode, merge, putIfAbsent, remove, replace, replace, replaceAll

- Field Detail
  - cacheMap
```
protected final SizedMap cacheMap
```
    The map for non-expired and non-pinned references.
  - softMap
```
protected final SizedMap softMap
```
    The map for expired references.
  - pinnedMap
```
protected final Map pinnedMap
```
    The set of objects pinned into the cache.
- Constructor Detail
  - CacheMap
```
public CacheMap()
```
    Create a non-LRU (and therefore highly concurrent) cache map with a size of 1000.
  - CacheMap
```
public CacheMap(boolean lru)
```
    Create a cache map with a size of 1000.
    
    Parameters:
    
    lru - if true, create a LRU cache map otherwise a non-LRU map will be created.
  - CacheMap
```
public CacheMap(boolean lru,
                int max)
```
    Create a cache map with the given properties.
  - CacheMap
```
@Deprecated
public CacheMap(boolean lru,
                            int max,
                            int size,
                            float load)
```
    Deprecated. use CacheMap(boolean, int, int, float, int) instead.
  - CacheMap
```
public CacheMap(boolean lru,
                int max,
                int size,
                float load,
                int concurrencyLevel)
```
    Create a cache map with the given properties.
    
    Since:
    
    1.1.0
- Method Detail
  - cacheMapOverflowRemoved
```
protected void cacheMapOverflowRemoved(Object key,
                                       Object value)
```
    Called from SizedMap.overflowRemoved(java.lang.Object, java.lang.Object) in the cache map.
  - softMapOverflowRemoved
```
protected void softMapOverflowRemoved(Object key,
                                      Object value)
```
    Called from SizedMap.overflowRemoved(java.lang.Object, java.lang.Object) in the soft map.
  - softMapValueExpired
```
protected void softMapValueExpired(Object key)
```
    Called when a value expires from the soft map.
  - put
```
protected Object put(Map map,
                     Object key,
                     Object value)
```
    Put the given entry into the given map. Allows subclasses to take additional actions.
  - remove
```
protected Object remove(Map map,
                        Object key)
```
    Remove the given key from the given map. Allows subclasses to take additional actions.
  - readLock
```
public void readLock()
```
    Acquire read lock.
  - readUnlock
```
public void readUnlock()
```
    Release read lock.
  - writeLock
```
public void writeLock()
```
    Acquire write lock.
  - writeUnlock
```
public void writeUnlock()
```
    Release write lock.
  - isLRU
```
public boolean isLRU()
```
    Whether this cache map uses LRU eviction.
  - setCacheSize
```
public void setCacheSize(int size)
```
    The maximum number of hard references to maintain, or -1 for no limit.
  - getCacheSize
```
public int getCacheSize()
```
    The maximum number of hard references to maintain, or -1 for no limit.
  - setSoftReferenceSize
```
public void setSoftReferenceSize(int size)
```
    The maximum number of soft references to maintain, or -1 for no limit.
  - getSoftReferenceSize
```
public int getSoftReferenceSize()
```
    The maximum number of soft references to maintain, or -1 for no limit.
  - getPinnedKeys
```
public Set getPinnedKeys()
```
    The keys pinned into the map.
  - pin
```
public boolean pin(Object key)
```
    Locks the given key and its value into the map. Objects pinned into the map are not counted towards the maximum cache size, and are never evicted implicitly. You may pin keys for which no value is in the map.
    
    Returns:
    
    true if the givne key's value was pinned; false if no value for the given key is cached
  - unpin
```
public boolean unpin(Object key)
```
    Undo a pinning.
  - entryRemoved
```
protected void entryRemoved(Object key,
                            Object value,
                            boolean expired)
```
    Invoked when a key-value pair is evicted from this data structure. This is invoked with expired set to true when an object is dropped because of space requirements or through garbage collection of soft references. It is invoked with expired set to false when an object is explicitly removed via the remove(java.util.Map, java.lang.Object) or clear() methods. This may be invoked more than once for a given entry.
    
    Parameters:
    
    value - may be null if the value was a soft reference that has been GCd
    
    Since:
    
    0.2.5.0
  - entryAdded
```
protected void entryAdded(Object key,
                          Object value)
```
    Invoked when an entry is added to the cache. This may be invoked more than once for an entry.
  - get
```
public Object get(Object key)
```
    Specified by:
    
    get in interface Map
  - put
```
public Object put(Object key,
                  Object value)
```
    Specified by:
    
    put in interface Map
  - putAll
```
public void putAll(Map map)
```
    Specified by:
    
    putAll in interface Map
  - putAll
```
public void putAll(Map map,
                   boolean replaceExisting)
```
  - remove
```
public Object remove(Object key)
```
    If key is pinned into the cache, the pin is cleared and the object is removed.
    
    Specified by:
    
    remove in interface Map
  - clear
```
public void clear()
```
    Removes pinned objects as well as unpinned ones.
    
    Specified by:
    
    clear in interface Map
  - size
```
public int size()
```
    Specified by:
    
    size in interface Map
  - isEmpty
```
public boolean isEmpty()
```
    Specified by:
    
    isEmpty in interface Map
  - containsKey
```
public boolean containsKey(Object key)
```
    Specified by:
    
    containsKey in interface Map
  - containsValue
```
public boolean containsValue(Object val)
```
    Specified by:
    
    containsValue in interface Map
  - keySet
```
public Set keySet()
```
    Specified by:
    
    keySet in interface Map
  - values
```
public Collection values()
```
    Specified by:
    
    values in interface Map
  - entrySet
```
public Set entrySet()
```
    Specified by:
    
    entrySet in interface Map
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object

Class CacheMap

Nested Class Summary

Nested classes/interfaces inherited from interface java.util.Map

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Methods inherited from interface java.util.Map

Field Detail

cacheMap

softMap

pinnedMap

Constructor Detail

CacheMap

CacheMap

CacheMap

CacheMap

CacheMap

Method Detail

cacheMapOverflowRemoved

softMapOverflowRemoved

softMapValueExpired

put

remove

readLock

readUnlock

writeLock

writeUnlock

isLRU

setCacheSize

getCacheSize

setSoftReferenceSize

getSoftReferenceSize

getPinnedKeys

pin

unpin

entryRemoved

entryAdded

get

put

putAll

putAll

remove

clear

size

isEmpty

containsKey

containsValue

keySet

values

entrySet

toString