User: simone
Date: 00/12/12 01:53:34
Modified: src/main/org/jboss/util LRUCachePolicy.java
Log:
Removed unnecessary synchronization.
Added toString implementation for debug.
Corrected 2 major bugs, related to methods demote and remove.
Revision Changes Path
1.6 +32 -23 jboss/src/main/org/jboss/util/LRUCachePolicy.java
Index: LRUCachePolicy.java
===================================================================
RCS file: /products/cvs/ejboss/jboss/src/main/org/jboss/util/LRUCachePolicy.java,v
retrieving revision 1.5
retrieving revision 1.6
diff -u -r1.5 -r1.6
--- LRUCachePolicy.java 2000/12/07 15:45:20 1.5
+++ LRUCachePolicy.java 2000/12/12 09:53:34 1.6
@@ -12,7 +12,7 @@
* Implementation of a Least Recently Used cache policy.
*
* @author Simone Bordet ([EMAIL PROTECTED])
- * @version $Revision: 1.5 $
+ * @version $Revision: 1.6 $
*/
public class LRUCachePolicy
implements CachePolicy
@@ -102,10 +102,6 @@
*/
public void destroy()
{
- m_map = null;
- m_list = null;
- m_minCapacity = 0;
- m_maxCapacity = 0;
}
public Object get(Object key)
@@ -148,24 +144,23 @@
{
if (o == null) {throw new IllegalArgumentException("Cannot insert a
null object in the cache");}
if (key == null) {throw new IllegalArgumentException("Cannot insert an
object in the cache with null key");}
-
Object obj = m_map.get(key);
if (obj == null)
{
- synchronized (m_list)
- {
- m_list.demote();
- LRUCacheEntry entry = createCacheEntry(key, o);
- m_list.promote(entry);
- m_map.put(key, entry);
- }
+ m_list.demote();
+ LRUCacheEntry entry = createCacheEntry(key, o);
+ m_list.promote(entry);
+ m_map.put(key, entry);
}
- else {throw new IllegalStateException("Attempt to put in the cache an
object that is already there");}
+ else
+ {
+ throw new IllegalStateException("Attempt to put in the cache
an object that is already there");
+ }
}
public void remove(Object key)
{
if (key == null) {throw new IllegalArgumentException("Removing an
object using a null key");}
-
+
Object value = m_map.get(key);
if (value != null)
{
@@ -199,7 +194,7 @@
*/
protected void ageOut(LRUCacheEntry entry)
{
- remove(entry);
+ remove(entry.m_key);
}
/**
* Callback method called when a cache miss happens.
@@ -254,7 +249,7 @@
* @see #demote
* @throws IllegalStateException if this method is called with a full
cache
*/
- protected synchronized void promote(LRUCacheEntry entry)
+ protected void promote(LRUCacheEntry entry)
{
if (entry == null) {throw new IllegalArgumentException("Trying
to promote a null object");}
if (m_capacity < 1) {throw new IllegalStateException("Can't
work with capacity < 1");}
@@ -322,11 +317,11 @@
* If the cache is not full, does nothing.
* @see #promote
*/
- protected synchronized void demote()
+ protected void demote()
{
if (m_capacity < 1) {throw new IllegalStateException("Can't
work with capacity < 1");}
- if (m_count > m_capacity) {throw new
IllegalStateException("Cache list entries number (" + m_count + ") > than the maximum
allowed (" + m_capacity + ")");}
- if (m_count == m_capacity)
+ if (m_count > m_maxCapacity) {throw new
IllegalStateException("Cache list entries number (" + m_count + ") > than the maximum
allowed (" + m_maxCapacity + ")");}
+ if (m_count == m_maxCapacity)
{
LRUCacheEntry entry = m_tail;
@@ -338,7 +333,7 @@
/**
* Removes from the cache list the specified entry.
*/
- protected synchronized void remove(LRUCacheEntry entry)
+ protected void remove(LRUCacheEntry entry)
{
if (entry == null) {throw new IllegalArgumentException("Cannot
remove a null entry from the cache");}
if (m_count < 1) {throw new IllegalStateException("Trying to
remove an entry from an empty cache");}
@@ -372,6 +367,16 @@
}
--m_count;
}
+ public String toString()
+ {
+ String s = Integer.toHexString(super.hashCode());
+ s += " size: " + m_count;
+ for (LRUCacheEntry entry = m_head; entry != null; entry =
entry.m_next)
+ {
+ s += "\n" + entry;
+ }
+ return s;
+ }
}
/**
@@ -380,9 +385,9 @@
protected class LRUCacheEntry
{
/** Reference to the next cell in the list */
- protected LRUCacheEntry m_next;
+ public LRUCacheEntry m_next;
/** Reference to the previous cell in the list */
- protected LRUCacheEntry m_prev;
+ public LRUCacheEntry m_prev;
/** The key used to retrieve the cached object */
public Object m_key;
/** The cached object */
@@ -400,6 +405,10 @@
m_next = null;
m_prev = null;
m_time = 0; // Set when inserted in the list.
+ }
+ public String toString()
+ {
+ return "key: " + m_key + ", object: " +
Integer.toHexString(m_object.hashCode()) + ", entry: " +
Integer.toHexString(super.hashCode());
}
}
}
