com.avaje.ebeaninternal.server.lib.sql

Class PstmtCache

java.lang.Object

java.util.AbstractMap<K,V>

java.util.HashMap<K,V>

java.util.LinkedHashMap<String,ExtendedPreparedStatement>

com.avaje.ebeaninternal.server.lib.sql.PstmtCache

All Implemented Interfaces:

Serializable, Cloneable, Map<String,ExtendedPreparedStatement>

public class PstmtCache
extends LinkedHashMap<String,ExtendedPreparedStatement>

A LRU based cache for PreparedStatements.

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class java.util.AbstractMap

AbstractMap.SimpleEntry<K,V>, AbstractMap.SimpleImmutableEntry<K,V>

Field Summary

Fields

Modifier and Type	Field and Description
protected String	cacheName The name of the cache, for tracing purposes.

Constructor Summary

Constructors

Constructor and Description
PstmtCache(String cacheName, int maxCacheSize)

Method Summary

Methods

Modifier and Type	Method and Description
ExtendedPreparedStatement	get(Object key) additionally maintains hit and miss statistics.
String	getDescription() Return a summary description of this cache.
int	getHitCounter() The total number of hits against this cache.
int	getHitRatio() Gets the hit ratio.
int	getMaxSize() returns the current maximum size of the cache.
int	getMissCounter() The total number of misses against this cache.
int	getPutCounter() The total number of puts against this cache.
ExtendedPreparedStatement	put(String key, ExtendedPreparedStatement value) additionally maintains put counter statistics.
ExtendedPreparedStatement	remove(Object key) additionally maintains hit and miss statistics.
protected boolean	removeEldestEntry(Map.Entry<String,ExtendedPreparedStatement> eldest) will check to see if we need to remove entries and if so call the cacheCleanup.cleanupEldestLRUCacheEntry() if one has been set.
boolean	returnStatement(ExtendedPreparedStatement pstmt) Try to add the returning statement to the cache.

Methods inherited from class java.util.LinkedHashMap

clear, containsValue

Methods inherited from class java.util.HashMap

clone, containsKey, entrySet, isEmpty, keySet, putAll, size, values

Methods inherited from class java.util.AbstractMap

equals, hashCode, toString

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Map

containsKey, entrySet, equals, hashCode, isEmpty, keySet, putAll, size, values

Field Detail

cacheName

protected final String cacheName

The name of the cache, for tracing purposes.

Constructor Detail

PstmtCache

public PstmtCache(String cacheName,
          int maxCacheSize)

Method Detail

getDescription

public String getDescription()

Return a summary description of this cache.

getMaxSize

public int getMaxSize()

returns the current maximum size of the cache.

getHitRatio

public int getHitRatio()

Gets the hit ratio. A number between 0 and 100 indicating the number of hits to misses. A number approaching 100 is desirable.

getHitCounter

public int getHitCounter()

The total number of hits against this cache.

getMissCounter

public int getMissCounter()

The total number of misses against this cache.

getPutCounter

public int getPutCounter()

The total number of puts against this cache.

returnStatement

public boolean returnStatement(ExtendedPreparedStatement pstmt)

Try to add the returning statement to the cache. If there is already a matching ExtendedPreparedStatement in the cache return false else add the statement to the cache and return true.

get

public ExtendedPreparedStatement get(Object key)

additionally maintains hit and miss statistics.

Specified by:

get in interface Map<String,ExtendedPreparedStatement>

Overrides:

get in class LinkedHashMap<String,ExtendedPreparedStatement>

remove

public ExtendedPreparedStatement remove(Object key)

additionally maintains hit and miss statistics.

Specified by:

remove in interface Map<String,ExtendedPreparedStatement>

Overrides:

remove in class HashMap<String,ExtendedPreparedStatement>

put

public ExtendedPreparedStatement put(String key,
                            ExtendedPreparedStatement value)

additionally maintains put counter statistics.

Specified by:

put in interface Map<String,ExtendedPreparedStatement>

Overrides:

put in class HashMap<String,ExtendedPreparedStatement>

removeEldestEntry

protected boolean removeEldestEntry(Map.Entry<String,ExtendedPreparedStatement> eldest)

will check to see if we need to remove entries and if so call the cacheCleanup.cleanupEldestLRUCacheEntry() if one has been set.

Overrides:

removeEldestEntry in class LinkedHashMap<String,ExtendedPreparedStatement>