AbstractQueryCache (OpenJPA Parent POM 3.1.2 API)

java.lang.Object
- org.apache.openjpa.lib.util.concurrent.AbstractConcurrentEventManager
- - org.apache.openjpa.datacache.AbstractQueryCache

All Implemented Interfaces:

Serializable, QueryCache, TypesChangedListener, Configurable, Closeable, EventManager

Direct Known Subclasses:

ConcurrentQueryCache
```
public abstract class AbstractQueryCache
extends AbstractConcurrentEventManager
implements QueryCache, Configurable
```
Abstract QueryCache implementation that provides various statistics, logging, and timeout functionality common across cache implementations.

Author:

Patrick Linskey, Abe White

See Also:

Serialized Form

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`static class`	`AbstractQueryCache.Default<T>` A default implementation of query statistics for the Query result cache.
`static class`	`AbstractQueryCache.EvictPolicy`

Field Summary

Fields
Modifier and Type	Field and Description
`protected OpenJPAConfiguration`	`conf` The configuration set by the system.
`protected ConcurrentHashMap<String,Long>`	`entityTimestampMap`
`AbstractQueryCache.EvictPolicy`	`evictPolicy`
`protected Log`	`log` The log to use.

Fields inherited from class org.apache.openjpa.lib.util.concurrent.AbstractConcurrentEventManager
_listeners

Constructor Summary

Constructors
Constructor and Description

AbstractQueryCache()

Constructors
Constructor and Description
`AbstractQueryCache()`

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`addTypesChangedListener(TypesChangedListener listen)` Add a new types event listener to this cache.
`void`	`afterCommit(RemoteCommitEvent event)` This method is part of the `RemoteCommitListener` interface.
`void`	`clear()` Remove all data from this cache.
`protected abstract void`	`clearInternal()` Clear the cache.
`void`	`close()` Free the resources used by this cache.
`protected void`	`close(boolean clear)`
`int`	`count()`
`void`	`endConfiguration()` Invoked upon completion of bean property configuration for this object.
`protected void`	`fireEvent(Object event, Object listener)` Implement this method to fire the given event to the given listener.
`QueryResult`	`get(QueryKey key)` Return a list of oids for the given query key.
`List<Long>`	`getAllEntityTimestamp(List<String> keyList)` Returns a list of timestamps in the form of Long objects which are the last updated time stamps for the given entities in the keylist.
`boolean`	`getEnableStatistics()`
`AbstractQueryCache.EvictPolicy`	`getEvictPolicy()` Returns the evictionPolicy for QueryCache
`protected abstract QueryResult`	`getInternal(QueryKey qk)` Return the list for the given key.
`String`	`getName()`
`QueryStatistics<QueryKey>`	`getStatistics()` Gets the simple statistics for query results.
`void`	`initialize(DataCacheManager manager)` Initialize any resources associated with the given `DataCacheManager`.
`boolean`	`isClosed()`
`protected abstract Collection`	`keySet()` Return a threadsafe view of the keys in this cache.
`protected Collection`	`newListenerCollection()` Individual query results will be registered as types changed listeners.
`void`	`onTypesChanged(TypesChangedEvent ev)` Notification that instances of persistent types have changed.
`boolean`	`pin(QueryKey key)` Pin the value stored under `qk` into the cache.
`protected abstract boolean`	`pinInternal(QueryKey qk)` Pin an object to the cache.
`QueryResult`	`put(QueryKey qk, QueryResult oids)` Set the list of OIDs for the given query key.
`protected abstract QueryResult`	`putInternal(QueryKey qk, QueryResult oids)` Add the given result to the cache, returning the old result under the given key.
`QueryResult`	`remove(QueryKey key)` Remove the value stored under the given query key.
`protected void`	`removeAllInternal(Collection qks)` Remove all results under the given keys from the cache.
`protected abstract QueryResult`	`removeInternal(QueryKey qk)` Remove the result under the given key from the cache.
`boolean`	`removeTypesChangedListener(TypesChangedListener listen)` Remove an types event listener from this cache.
`void`	`setConfiguration(Configuration conf)` Invoked prior to setting bean properties.
`void`	`setEnableStatistics(boolean enable)`
`void`	`setEvictPolicy(String evictPolicy)` Sets the eviction policy for the query cache
`void`	`setName(String n)`
`void`	`startConfiguration()` Invoked before bean property configuration is begun on this object.
`boolean`	`unpin(QueryKey key)` Unpin the value stored under `key` into the cache.
`protected abstract boolean`	`unpinInternal(QueryKey qk)` Unpin an object from the cache.
`protected void`	`updateEntityTimestamp(Map<String,Long> timestampMap)` Updates the entity timestamp map with the current time in milliseconds

Methods inherited from class org.apache.openjpa.lib.util.concurrent.AbstractConcurrentEventManager
addListener, fireEvent, getListeners, hasListener, hasListeners, isFailFast, removeListener, setFailFast

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

Methods inherited from interface org.apache.openjpa.datacache.QueryCache
writeLock, writeUnlock

- Field Detail
  - conf
```
protected OpenJPAConfiguration conf
```
    The configuration set by the system.
  - log
```
protected Log log
```
    The log to use.
  - entityTimestampMap
```
protected ConcurrentHashMap<String,Long> entityTimestampMap
```
  - evictPolicy
```
public AbstractQueryCache.EvictPolicy evictPolicy
```
- Constructor Detail
  - AbstractQueryCache
```
public AbstractQueryCache()
```
- Method Detail
  - setEnableStatistics
```
public void setEnableStatistics(boolean enable)
```
  - getEnableStatistics
```
public boolean getEnableStatistics()
```
  - getStatistics
```
public QueryStatistics<QueryKey> getStatistics()
```
    Description copied from interface: QueryCache
    
    Gets the simple statistics for query results. If the statistics gathering is disabled, an empty statistics is returned.
    
    Specified by:
    
    getStatistics in interface QueryCache
  - initialize
```
public void initialize(DataCacheManager manager)
```
    Description copied from interface: QueryCache
    
    Initialize any resources associated with the given DataCacheManager.
    
    Specified by:
    
    initialize in interface QueryCache
  - onTypesChanged
```
public void onTypesChanged(TypesChangedEvent ev)
```
    Description copied from interface: TypesChangedListener
    
    Notification that instances of persistent types have changed.
    
    Specified by:
    
    onTypesChanged in interface TypesChangedListener
  - get
```
public QueryResult get(QueryKey key)
```
    Description copied from interface: QueryCache
    
    Return a list of oids for the given query key. This is an unmodifiable list.
    
    Specified by:
    
    get in interface QueryCache
    
    Returns:
    
    The query results matching the given key, or null if none
  - put
```
public QueryResult put(QueryKey qk,
                       QueryResult oids)
```
    Description copied from interface: QueryCache
    
    Set the list of OIDs for the given query key. A reference to the given list will be stored in the query cache, so the list should not be modified after invoking this method.
    
    Specified by:
    
    put in interface QueryCache
    
    Returns:
    
    The previously cached value, or null if the key was not previously cached. See Map.put(K, V) for more information.
  - remove
```
public QueryResult remove(QueryKey key)
```
    Description copied from interface: QueryCache
    
    Remove the value stored under the given query key. This method is typically not invoked directly from outside the QueryCache class. Instead, the cache should be updated by implementing RemoteCommitListener, which will result in all queries that may be invalid being dropped.
    
    Specified by:
    
    remove in interface QueryCache
    
    Returns:
    
    The previously cached value, or null if the key was not previously cached. See Map.remove(java.lang.Object) for more information.
  - pin
```
public boolean pin(QueryKey key)
```
    Description copied from interface: QueryCache
    
    Pin the value stored under qk into the cache. This method guarantees that qk's value will not be expired if the cache exceeds its capacity. It causes this data to be ignored when determining whether or not the cache is full, effectively increasing the total amount of data stored in the cache. This method does not affect the behavior of QueryCache.remove(org.apache.openjpa.datacache.QueryKey) or TypesChangedListener.onTypesChanged(org.apache.openjpa.datacache.TypesChangedEvent).
    
    Specified by:
    
    pin in interface QueryCache
    
    Returns:
    
    true if key's value was pinned into the cache; false if the key is not in the cache.
  - unpin
```
public boolean unpin(QueryKey key)
```
    Description copied from interface: QueryCache
    
    Unpin the value stored under key into the cache. This method reverses a previous invocation of QueryCache.pin(org.apache.openjpa.datacache.QueryKey). This method does not remove anything from the cache; it merely makes key's value a candidate for flushing from the cache.
    
    Specified by:
    
    unpin in interface QueryCache
    
    Returns:
    
    true if key's value was unpinned from the cache; false if the key is not in the cache.
  - clear
```
public void clear()
```
    Description copied from interface: QueryCache
    
    Remove all data from this cache.
    
    Specified by:
    
    clear in interface QueryCache
  - close
```
public void close()
```
    Description copied from interface: QueryCache
    
    Free the resources used by this cache.
    
    Specified by:
    
    close in interface QueryCache
    
    Specified by:
    
    close in interface Closeable
  - close
```
protected void close(boolean clear)
```
  - isClosed
```
public boolean isClosed()
```
  - addTypesChangedListener
```
public void addTypesChangedListener(TypesChangedListener listen)
```
    Description copied from interface: QueryCache
    
    Add a new types event listener to this cache.
    
    Specified by:
    
    addTypesChangedListener in interface QueryCache
  - removeTypesChangedListener
```
public boolean removeTypesChangedListener(TypesChangedListener listen)
```
    Description copied from interface: QueryCache
    
    Remove an types event listener from this cache.
    
    Specified by:
    
    removeTypesChangedListener in interface QueryCache
  - afterCommit
```
public void afterCommit(RemoteCommitEvent event)
```
    This method is part of the RemoteCommitListener interface. If your cache subclass relies on OpenJPA for clustering support, make it implement RemoteCommitListener. This method will take care of invalidating entries from remote commits, by delegating to onTypesChanged(org.apache.openjpa.datacache.TypesChangedEvent).
  - keySet
```
protected abstract Collection keySet()
```
    Return a threadsafe view of the keys in this cache. This collection must be iterable without risk of concurrent modification exceptions. It does not have to implement contains() efficiently or use set semantics.
  - getInternal
```
protected abstract QueryResult getInternal(QueryKey qk)
```
    Return the list for the given key.
  - putInternal
```
protected abstract QueryResult putInternal(QueryKey qk,
                                           QueryResult oids)
```
    Add the given result to the cache, returning the old result under the given key.
  - removeInternal
```
protected abstract QueryResult removeInternal(QueryKey qk)
```
    Remove the result under the given key from the cache.
  - removeAllInternal
```
protected void removeAllInternal(Collection qks)
```
    Remove all results under the given keys from the cache.
  - clearInternal
```
protected abstract void clearInternal()
```
    Clear the cache.
  - pinInternal
```
protected abstract boolean pinInternal(QueryKey qk)
```
    Pin an object to the cache.
  - unpinInternal
```
protected abstract boolean unpinInternal(QueryKey qk)
```
    Unpin an object from the cache.
  - setConfiguration
```
public void setConfiguration(Configuration conf)
```
    Description copied from interface: Configurable
    
    Invoked prior to setting bean properties.
    
    Specified by:
    
    setConfiguration in interface Configurable
  - startConfiguration
```
public void startConfiguration()
```
    Description copied from interface: Configurable
    
    Invoked before bean property configuration is begun on this object.
    
    Specified by:
    
    startConfiguration in interface Configurable
  - endConfiguration
```
public void endConfiguration()
```
    Description copied from interface: Configurable
    
    Invoked upon completion of bean property configuration for this object.
    
    Specified by:
    
    endConfiguration in interface Configurable
  - fireEvent
```
protected void fireEvent(Object event,
                         Object listener)
```
    Description copied from class: AbstractConcurrentEventManager
    
    Implement this method to fire the given event to the given listener.
    
    Specified by:
    
    fireEvent in class AbstractConcurrentEventManager
  - newListenerCollection
```
protected Collection newListenerCollection()
```
    Individual query results will be registered as types changed listeners. We want such query results to be gc'd once the only reference is held by the list of expiration listeners.
    
    Overrides:
    
    newListenerCollection in class AbstractConcurrentEventManager
  - setEvictPolicy
```
public void setEvictPolicy(String evictPolicy)
```
    Sets the eviction policy for the query cache
    
    Parameters:
    
    evictPolicy - -- String value that specifies the eviction policy
  - getEvictPolicy
```
public AbstractQueryCache.EvictPolicy getEvictPolicy()
```
    Returns the evictionPolicy for QueryCache
    
    Returns:
    
    -- returns a String value of evictPolicy attribute
  - updateEntityTimestamp
```
protected void updateEntityTimestamp(Map<String,Long> timestampMap)
```
    Updates the entity timestamp map with the current time in milliseconds
    
    Parameters:
    
    timestampMap - -- a map that contains entityname and its last updated timestamp
  - getAllEntityTimestamp
```
public List<Long> getAllEntityTimestamp(List<String> keyList)
```
    Returns a list of timestamps in the form of Long objects which are the last updated time stamps for the given entities in the keylist.
    
    Parameters:
    
    keyList - -- List of entity names
    
    Returns:
    
    -- Returns a list that has the timestamp for the given entities
  - setName
```
public void setName(String n)
```
  - getName
```
public String getName()
```
  - count
```
public int count()
```

Class AbstractQueryCache

Nested Class Summary

Field Summary

Fields inherited from class org.apache.openjpa.lib.util.concurrent.AbstractConcurrentEventManager

Constructor Summary

Method Summary

Methods inherited from class org.apache.openjpa.lib.util.concurrent.AbstractConcurrentEventManager

Methods inherited from class java.lang.Object

Methods inherited from interface org.apache.openjpa.datacache.QueryCache

Field Detail

conf

log

entityTimestampMap

evictPolicy

Constructor Detail

AbstractQueryCache

Method Detail

setEnableStatistics

getEnableStatistics

getStatistics

initialize

onTypesChanged

get

put

remove

pin

unpin

clear

close

close

isClosed

addTypesChangedListener

removeTypesChangedListener

afterCommit

keySet

getInternal

putInternal

removeInternal

removeAllInternal

clearInternal

pinInternal

unpinInternal

setConfiguration

startConfiguration

endConfiguration

fireEvent

newListenerCollection

setEvictPolicy

getEvictPolicy

updateEntityTimestamp

getAllEntityTimestamp

setName

getName

count