asmuts 02/05/13 11:36:33
Modified: src/java/org/apache/jcs/engine/memory/lru
LRUMemoryCache.java
Log:
Added locking on getArray
This will probably need a better locking strategy
Revision Changes Path
1.7 +107 -100
jakarta-turbine-jcs/src/java/org/apache/jcs/engine/memory/lru/LRUMemoryCache.java
Index: LRUMemoryCache.java
===================================================================
RCS file:
/home/cvs/jakarta-turbine-jcs/src/java/org/apache/jcs/engine/memory/lru/LRUMemoryCache.java,v
retrieving revision 1.6
retrieving revision 1.7
diff -u -r1.6 -r1.7
--- LRUMemoryCache.java 13 May 2002 16:25:42 -0000 1.6
+++ LRUMemoryCache.java 13 May 2002 18:36:33 -0000 1.7
@@ -20,19 +20,20 @@
import org.apache.jcs.engine.memory.shrinking.ShrinkerThread;
/**
- * A fast reference management system. The least recently used items move to the
- * end of the list and get spooled to disk if the cache hub is configured to use
- * a disk cache. Most of the cache bottelnecks ar ein IO. There are no io
- * bottlenecks here, it's all about processing power. Even though there are only
- * a few adjustments necessary to maintain the double linked list, we might want
- * to find a more efficient memory manager for large cache regions. The
- * LRUMemoryCache is most efficeint when the first element is selected. The
- * smaller teh region, the better the chance that this will be the case. < .04
- * ms per put, p3 866, 1/10 of that per get
+ * A fast reference management system. The least recently used items move to
+ * the end of the list and get spooled to disk if the cache hub is configured
+ * to use a disk cache. Most of the cache bottelnecks ar ein IO. There are no
+ * io bottlenecks here, it's all about processing power. Even though there are
+ * only a few adjustments necessary to maintain the double linked list, we
+ * might want to find a more efficient memory manager for large cache regions.
+ * The LRUMemoryCache is most efficeint when the first element is selected. The
+ * smaller teh region, the better the chance that this will be the case. < .04
+ * ms per put, p3 866, 1/10 of that per get
*
- * @author <a href="mailto:[EMAIL PROTECTED]";>Aaron Smuts</a>
- * @author <a href="mailto:[EMAIL PROTECTED]";>James Taylor</a>
- * @version $Id: LRUMemoryCache.java,v 1.6 2002/05/13 16:25:42 asmuts Exp $
+ *@author <a href="mailto:[EMAIL PROTECTED]";>Aaron Smuts</a>
+ *@author <a href="mailto:[EMAIL PROTECTED]";>James Taylor</a>
+ *@created May 13, 2002
+ *@version $Id: LRUMemoryCache.java,v 1.7 2002/05/13 18:36:33 asmuts Exp $
*/
public class LRUMemoryCache implements MemoryCache, Serializable
{
@@ -41,7 +42,9 @@
String cacheName;
- /** Map where items are stored by key */
+ /**
+ * Map where items are stored by key
+ */
protected Map map = new Hashtable();
// LRU double linked list head/tail nodes
@@ -51,17 +54,17 @@
private int max;
/**
- * Region Elemental Attributes
+ * Region Elemental Attributes
*/
public IElementAttributes attr;
/**
- * Cache Attributes
+ * Cache Attributes
*/
public ICompositeCacheAttributes cattr;
/**
- * The cache this store is associated with
+ * The cache this store is associated with
*/
Cache cache;
@@ -72,12 +75,12 @@
private int chunkSize = 2;
/**
- * The background memory shrinker
+ * The background memory shrinker
*/
private ShrinkerThread shrinker;
/**
- * Constructor for the LRUMemoryCache object
+ * Constructor for the LRUMemoryCache object
*/
public LRUMemoryCache()
{
@@ -85,9 +88,9 @@
}
/**
- * For post reflection creation initialization
+ * For post reflection creation initialization
*
- * @param hub
+ *@param hub
*/
public synchronized void initialize( Cache hub )
{
@@ -109,10 +112,10 @@
}
/**
- * Puts an item to the cache.
+ * Puts an item to the cache.
*
- * @param ce
- * @exception IOException
+ *@param ce Description of the Parameter
+ *@exception IOException
*/
public void update( ICacheElement ce )
throws IOException
@@ -150,8 +153,8 @@
if ( log.isDebugEnabled() )
{
log.debug( "About to spool to disk cache, map size: " + size
- + ", max objects: " + this.cattr.getMaxObjects()
- + ", items to spool: " + chunkSizeCorrected );
+ + ", max objects: " + this.cattr.getMaxObjects()
+ + ", items to spool: " + chunkSizeCorrected );
}
// The spool will put them in a disk event queue, so there is no
@@ -174,19 +177,19 @@
if ( log.isDebugEnabled() )
{
- log.debug( "After spool map size: " + size );
+ log.debug( "After spool map size: " + size );
}
}
}
/**
- * Get an item from the cache without affecting its last access
- * time or position.
+ * Get an item from the cache without affecting its last access time or
+ * position.
*
- * @return Element mathinh key if found, or null
- * @param key Identifies item to find
- * @exception IOException
+ *@param key Identifies item to find
+ *@return Element mathinh key if found, or null
+ *@exception IOException
*/
public ICacheElement getQuiet( Serializable key )
throws IOException
@@ -197,21 +200,21 @@
try
{
- me = ( MemoryElementDescriptor ) map.get( key );
- if ( me != null )
- {
- if ( log.isDebugEnabled() )
- {
- log.debug( cacheName + ": LRUMemoryCache quiet hit for " + key );
- }
-
- ce = me.ce;
-
- }
- else
- {
- log.debug( cacheName + ": LRUMemoryCache quiet miss for " + key );
- }
+ me = ( MemoryElementDescriptor ) map.get( key );
+ if ( me != null )
+ {
+ if ( log.isDebugEnabled() )
+ {
+ log.debug( cacheName + ": LRUMemoryCache quiet hit for " + key
);
+ }
+
+ ce = me.ce;
+
+ }
+ else
+ {
+ log.debug( cacheName + ": LRUMemoryCache quiet miss for " + key );
+ }
}
catch ( Exception e )
@@ -220,16 +223,14 @@
}
return ce;
-
-
}
/**
- * Get an item from the cache
+ * Get an item from the cache
*
- * @return Element mathinh key if found, or null
- * @param key Identifies item to find
- * @exception IOException
+ *@param key Identifies item to find
+ *@return Element mathinh key if found, or null
+ *@exception IOException
*/
public ICacheElement get( Serializable key )
throws IOException
@@ -272,11 +273,11 @@
}
/**
- * Removes an item from the cache.
+ * Removes an item from the cache.
*
- * @return
- * @param key
- * @exception IOException
+ *@param key
+ *@return
+ *@exception IOException
*/
public boolean remove( Serializable key )
throws IOException
@@ -290,12 +291,12 @@
// handle partial removal
if ( key instanceof String && ( ( String ) key )
- .endsWith( CacheConstants.NAME_COMPONENT_DELIMITER ) )
+ .endsWith( CacheConstants.NAME_COMPONENT_DELIMITER ) )
{
// remove all keys of the same name hierarchy.
synchronized ( map )
{
- for ( Iterator itr = map.entrySet().iterator(); itr.hasNext(); )
+ for ( Iterator itr = map.entrySet().iterator(); itr.hasNext(); )
{
Map.Entry entry = ( Map.Entry ) itr.next();
Object k = entry.getKey();
@@ -330,9 +331,9 @@
}
/**
- * Removes all cached items from the cache.
+ * Removes all cached items from the cache.
*
- * @exception IOException
+ *@exception IOException
*/
public void removeAll()
throws IOException
@@ -341,19 +342,17 @@
}
/**
- * Prepares for shutdown.
+ * Prepares for shutdown.
*
- * @exception IOException
+ *@exception IOException
*/
public void dispose()
- throws IOException
- {
- }
+ throws IOException { }
/**
- * Returns the current cache size.
+ * Returns the current cache size.
*
- * @return The size value
+ *@return The size value
*/
public int getSize()
{
@@ -361,9 +360,9 @@
}
/**
- * Returns the cache status.
+ * Returns the cache status.
*
- * @return The status value
+ *@return The status value
*/
public int getStatus()
{
@@ -371,9 +370,9 @@
}
/**
- * Returns the cache name.
+ * Returns the cache name.
*
- * @return The cacheName value
+ *@return The cacheName value
*/
public String getCacheName()
{
@@ -381,9 +380,9 @@
}
/**
- * Gets the iterator attribute of the LRUMemoryCache object
+ * Gets the iterator attribute of the LRUMemoryCache object
*
- * @return The iterator value
+ *@return The iterator value
*/
public Iterator getIterator()
{
@@ -392,28 +391,27 @@
/**
- * Get an Array of the keys for all elements in the memory cache
+ * Get an Array of the keys for all elements in the memory cache
*
- * @return An Object[]
+ *@return An Object[]
*/
public Object[] getKeyArray()
{
- // may need to lock to map here?
- return map.keySet().toArray();
+ // need a better locking strategy here.
+ synchronized ( this )
+ {
+ // may need to lock to map here?
+ return map.keySet().toArray();
+ }
}
/**
- * Puts an item to the cache.
+ * Puts an item to the cache.
*
- * @param me
- * @exception IOException
+ *@param ce Description of the Parameter
+ *@exception IOException
*/
-// public void waterfal( MemoryElementDescriptor me )
-// throws IOException
-// {
-// this.cache.spoolToDisk( me.ce );
-// }
public void waterfal( ICacheElement ce )
throws IOException
{
@@ -421,11 +419,10 @@
}
-
/**
- * Returns the CacheAttributes.
+ * Returns the CacheAttributes.
*
- * @return The CacheAttributes value
+ *@return The CacheAttributes value
*/
public ICompositeCacheAttributes getCacheAttributes()
{
@@ -433,9 +430,9 @@
}
/**
- * Sets the CacheAttributes.
+ * Sets the CacheAttributes.
*
- * @param cattr The new CacheAttributes value
+ *@param cattr The new CacheAttributes value
*/
public void setCacheAttributes( ICompositeCacheAttributes cattr )
{
@@ -445,7 +442,9 @@
// --------------------------- internal mehods (linked list implementation)
/**
- * Removes the specified node from the link list.
+ * Removes the specified node from the link list.
+ *
+ *@param me Description of the Parameter
*/
private synchronized void removeNode( MemoryElementDescriptor me )
{
@@ -493,7 +492,9 @@
}
/**
- * Adds a new node to the end of the link list. Currently not used.
+ * Adds a new node to the end of the link list. Currently not used.
+ *
+ *@param ce The feature to be added to the Last
*/
private void addLast( CacheElement ce )
{
@@ -514,7 +515,9 @@
}
/**
- * Adds a new node to the start of the link list.
+ * Adds a new node to the start of the link list.
+ *
+ *@param ce The feature to be added to the First
*/
private synchronized void addFirst( ICacheElement ce )
{
@@ -536,7 +539,9 @@
}
/**
- * Moves an existing node to the start of the link list.
+ * Moves an existing node to the start of the link list.
+ *
+ *@param ce Description of the Parameter
*/
public void makeFirst( ICacheElement ce )
{
@@ -544,7 +549,9 @@
}
/**
- * Moves an existing node to the start of the link list.
+ * Moves an existing node to the start of the link list.
+ *
+ *@param me Description of the Parameter
*/
public synchronized void makeFirst( MemoryElementDescriptor me )
{
@@ -583,24 +590,24 @@
// ---------------------------------------------------------- debug methods
/**
- * Dump the cache map for debugging.
+ * Dump the cache map for debugging.
*/
public void dumpMap()
{
log.debug( "dumpingMap" );
- for ( Iterator itr = map.entrySet().iterator(); itr.hasNext(); )
+ for ( Iterator itr = map.entrySet().iterator(); itr.hasNext(); )
{
//for ( Iterator itr = memCache.getIterator(); itr.hasNext();) {
Map.Entry e = ( Map.Entry ) itr.next();
MemoryElementDescriptor me =
( MemoryElementDescriptor ) e.getValue();
log.debug( "dumpMap> key=" + e.getKey()
- + ", val=" + me.ce.getVal() );
+ + ", val=" + me.ce.getVal() );
}
}
/**
- * Dump the cache entries from first to list for debugging.
+ * Dump the cache entries from first to list for debugging.
*/
public void dumpCacheEntries()
{
@@ -608,7 +615,7 @@
for ( MemoryElementDescriptor me = first; me != null; me = me.next )
{
log.debug( "dumpCacheEntries> key="
- + me.ce.getKey() + ", val=" + me.ce.getVal() );
+ + me.ce.getKey() + ", val=" + me.ce.getVal() );
}
}
}
--
To unsubscribe, e-mail: <mailto:[EMAIL PROTECTED]>
For additional commands, e-mail: <mailto:[EMAIL PROTECTED]>
