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Posted to ojb-dev@db.apache.org by ar...@apache.org on 2004/01/27 20:42:46 UTC
cvs commit: db-ojb/src/test/org/apache/ojb/broker AllTests.java
arminw 2004/01/27 11:42:46
Modified: src/java/org/apache/ojb/broker/metadata/fieldaccess
AnonymousPersistentField.java
src/test/org/apache/ojb/broker AllTests.java
Added: src/java/org/apache/ojb/broker/util ReferenceMap.java
src/test/org/apache/ojb/broker/metadata
ReferenceMapTest.java
Log:
patch by Andy Malakov
- new attempt to fix object identity problem in conjunction
of anonymous keys (persistence capable objects used as key in weak
HashMap can cause problems when user override hashcode/equals methods)
- add new Map implementation supports identity weak Map
- add test case for ReferenceMap
Revision Changes Path
1.10 +21 -10 db-ojb/src/java/org/apache/ojb/broker/metadata/fieldaccess/AnonymousPersistentField.java
Index: AnonymousPersistentField.java
===================================================================
RCS file: /home/cvs/db-ojb/src/java/org/apache/ojb/broker/metadata/fieldaccess/AnonymousPersistentField.java,v
retrieving revision 1.9
retrieving revision 1.10
diff -u -r1.9 -r1.10
--- AnonymousPersistentField.java 24 Jan 2004 19:09:24 -0000 1.9
+++ AnonymousPersistentField.java 27 Jan 2004 19:42:45 -0000 1.10
@@ -55,9 +55,11 @@
*/
import java.util.Map;
-import java.util.WeakHashMap;
import org.apache.ojb.broker.metadata.MetadataException;
+import org.apache.ojb.broker.util.ReferenceMap;
+
+//import org.apache.commons.collections.ReferenceMap;
/**
* This class handle an anonymous persistent fiels for 1-1 association,
@@ -69,6 +71,8 @@
{
private static final long serialVersionUID = 3989863424358352941L;
+ private static final String NULL_VALUE = "ojbNullValue";
+
private transient Map fkCache;
private String fieldname;
@@ -88,8 +92,7 @@
}
/*
- TODO: Use WeakIdentityHashMap instead WeakHashMap to hold anonymous field values
-
+ Use WeakIdentityHashMap instead WeakHashMap to hold anonymous field values
Here is an snip of the mail from Andy Malakov:
I found that usage of database identity in Java produces quite interesting problem in OJB:
@@ -113,19 +116,27 @@
3)
If Full GC happens after that moment it will dispose fcCache entry if the FIRST reference becomes
soft-referenced only.
- */
- protected void putToFieldCache(Object key, Object value)
+*/
+ protected void putToFieldCache(Object key, Object value)
{
- if(fkCache == null)
+ if (key != null)
{
- fkCache = new WeakHashMap();
+ if (fkCache == null)
+ {
+ fkCache = new ReferenceMap (ReferenceMap.WEAK, ReferenceMap.HARD, 10, 0.75f, true);
+ // fkCache = new WeakHashMap();
+ }
+ // thus we can't put 'null' as value, we use a replacement
+ if(value == null) value = NULL_VALUE;
+ fkCache.put(key, value);
}
- fkCache.put(key, value);
}
protected Object getFromFieldCache(Object key)
{
- return fkCache != null ? fkCache.get(key) : null;
+ Object obj = (key != null && fkCache != null) ? fkCache.get(key) : null;
+ if(obj == NULL_VALUE) obj = null;
+ return obj;
}
/**
1.1 db-ojb/src/java/org/apache/ojb/broker/util/ReferenceMap.java
Index: ReferenceMap.java
===================================================================
package org.apache.ojb.broker.util;
/* ====================================================================
*
* The Apache Software License, Version 1.1
*
* Copyright (c) 1999-2001 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution, if
* any, must include the following acknowlegement:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowlegement may appear in the software itself,
* if and wherever such third-party acknowlegements normally appear.
*
* 4. The names "The Jakarta Project", "Commons", and "Apache Software
* Foundation" must not be used to endorse or promote products derived
* from this software without prior written permission. For written
* permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache"
* nor may "Apache" appear in their names without prior written
* permission of the Apache Group.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*
*/
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.lang.ref.Reference;
import java.lang.ref.ReferenceQueue;
import java.lang.ref.SoftReference;
import java.lang.ref.WeakReference;
import java.util.AbstractCollection;
import java.util.AbstractMap;
import java.util.AbstractSet;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.ConcurrentModificationException;
import java.util.Iterator;
import java.util.Map;
import java.util.NoSuchElementException;
import java.util.Set;
/**
* <p>
* Modified version of {@link org.apache.commons.collections.ReferenceMap}, using
* object identity for key comparison (). This class
* simply extended {@link org.apache.commons.collections.ReferenceMap} with an extra field
* "useSystemIdentity" which is initialized in constructor and is used every time we
* want to compare (or hash) keys or values.
* </p>
* <p>
* Javadoc of ReferenceMap starts here:
* <br/>
* Hashtable-based {@link java.util.Map} implementation that allows
* mappings to be removed by the garbage collector.
* </p>
* <P>
* When you construct a <Code>ReferenceMap</Code>, you can
* specify what kind of references are used to store the
* map's keys and values. If non-hard references are
* used, then the garbage collector can remove mappings
* if a key or value becomes unreachable, or if the
* JVM's memory is running low. For information on how
* the different reference types behave, see
* {@link java.lang.ref.Reference}.<P>
*
* Different types of references can be specified for keys
* and values. The keys can be configured to be weak but
* the values hard, in which case this class will behave
* like a <A HREF="http://java.sun.com/j2se/1.4/docs/api/java/util/WeakHashMap.html">
* <Code>WeakHashMap</Code></A>. However, you
* can also specify hard keys and weak values, or any other
* combination. The default constructor uses hard keys
* and soft values, providing a memory-sensitive cache.<P>
*
* The algorithms used are basically the same as those
* in {@link java.util.HashMap}. In particular, you
* can specify a load factor and capacity to suit your
* needs. All optional {@link java.util.Map} operations are
* supported.<P>
*
* However, this {@link java.util.Map} implementation does <I>not</I>
* allow null elements. Attempting to add a null key or
* or a null value to the map will raise a
* <Code>NullPointerException</Code>.<P>
*
* As usual, this implementation is not synchronized. You
* can use {@link java.util.Collections#synchronizedMap} to
* provide synchronized access to a <Code>ReferenceMap</Code>.
*
* @author Andy Malakov
* @version $Id: ReferenceMap.java,v 1.1 2004/01/27 19:42:46 arminw Exp $
*/
public class ReferenceMap extends AbstractMap
{
/**
* For serialization.
*/
final private static long serialVersionUID = -3370601314380922368L;
/**
* Constant indicating that hard references should be used.
*/
final public static int HARD = 0;
/**
* Constant indiciating that soft references should be used.
*/
final public static int SOFT = 1;
/**
* Constant indicating that weak references should be used.
*/
final public static int WEAK = 2;
// --- serialized instance variables:
/**
* The reference type for keys. Must be HARD, SOFT, WEAK.
* Note: I originally marked this field as final, but then this class
* didn't compile under JDK1.2.2.
* @serial
*/
private final int keyType;
/**
* The reference type for values. Must be HARD, SOFT, WEAK.
* Note: I originally marked this field as final, but then this class
* didn't compile under JDK1.2.2.
* @serial
*/
private final int valueType;
/**
* The threshold variable is calculated by multiplying
* table.length and loadFactor.
* Note: I originally marked this field as final, but then this class
* didn't compile under JDK1.2.2.
* @serial
*/
private final float loadFactor;
// -- Non-serialized instance variables
/**
* ReferenceQueue used to eliminate stale mappings.
* @see #purge
*/
private transient ReferenceQueue queue = new ReferenceQueue();
/**
* The hash table. Its length is always a power of two.
*/
private transient Entry[] table;
/**
* Number of mappings in this map.
*/
private transient int size;
/**
* When size reaches threshold, the map is resized.
* @see #resize
*/
private transient int threshold;
/**
* Number of times this map has been modified.
*/
private transient volatile int modCount;
/**
* Cached key set. May be null if key set is never accessed.
*/
private transient Set keySet;
/**
* Cached entry set. May be null if entry set is never accessed.
*/
private transient Set entrySet;
/**
* Cached values. May be null if values() is never accessed.
*/
private transient Collection values;
private final boolean useSystemIdentity;
/**
* Constructs a new <Code>ReferenceMap</Code> that will
* use hard references to keys and soft references to values.
*/
public ReferenceMap()
{
this(HARD, SOFT);
}
/**
* Constructs a new <Code>ReferenceMap</Code> that will
* use the specified types of references.
*
* @param keyType the type of reference to use for keys;
* must be {@link #HARD}, {@link #SOFT}, {@link #WEAK}
* @param valueType the type of reference to use for values;
* must be {@link #HARD}, {@link #SOFT}, {@link #WEAK}
*/
public ReferenceMap(int keyType, int valueType)
{
this(keyType, valueType, 16, 0.75f, false);
}
/**
* Constructs a new <Code>ReferenceMap</Code> with the
* specified reference types, load factor and initial
* capacity.
*
* @param keyType the type of reference to use for keys;
* must be {@link #HARD}, {@link #SOFT}, {@link #WEAK}
* @param valueType the type of reference to use for values;
* must be {@link #HARD}, {@link #SOFT}, {@link #WEAK}
* @param capacity the initial capacity for the map
* @param loadFactor the load factor for the map
* @param useSystemIdentity if true System.identityHashCode() and comparision operator (==) will be used
* in place of Object.hashCode and Object.equals (Please read {@link java.util.WeakHashMap}
* java doc for more information).
*/
public ReferenceMap(int keyType, int valueType, int capacity, float loadFactor, boolean useSystemIdentity)
{
super();
verify("keyType", keyType);
verify("valueType", valueType);
this.useSystemIdentity = useSystemIdentity;
if (capacity <= 0)
{
throw new IllegalArgumentException("capacity must be positive");
}
if ((loadFactor <= 0.0f) || (loadFactor >= 1.0f))
{
throw new IllegalArgumentException("Load factor must be greater than 0 and less than 1.");
}
this.keyType = keyType;
this.valueType = valueType;
int v = 1;
while (v < capacity) v *= 2;
this.table = new Entry[v];
this.loadFactor = loadFactor;
this.threshold = (int) (v * loadFactor);
}
// used by constructor
private static void verify(String name, int type)
{
if ((type < HARD) || (type > WEAK))
{
throw new IllegalArgumentException(name +
" must be HARD, SOFT, WEAK.");
}
}
/**
* Writes this object to the given output stream.
*
* @param out the output stream to write to
* @throws java.io.IOException if the stream raises it
*/
private void writeObject(ObjectOutputStream out) throws IOException
{
out.defaultWriteObject();
out.writeInt(table.length);
// Have to use null-terminated list because size might shrink
// during iteration
for (Iterator iter = entrySet().iterator(); iter.hasNext();)
{
Map.Entry entry = (Map.Entry) iter.next();
out.writeObject(entry.getKey());
out.writeObject(entry.getValue());
}
out.writeObject(null);
}
/**
* Reads the contents of this object from the given input stream.
*
* @param inp the input stream to read from
* @throws java.io.IOException if the stream raises it
* @throws java.lang.ClassNotFoundException if the stream raises it
*/
private void readObject(ObjectInputStream inp) throws IOException, ClassNotFoundException
{
inp.defaultReadObject();
table = new Entry[inp.readInt()];
threshold = (int) (table.length * loadFactor);
queue = new ReferenceQueue();
Object key = inp.readObject();
while (key != null)
{
Object value = inp.readObject();
put(key, value);
key = inp.readObject();
}
}
/**
* Constructs a reference of the given type to the given
* referent. The reference is registered with the queue
* for later purging.
*
* @param type HARD, SOFT or WEAK
* @param referent the object to refer to
* @param hash the hash code of the <I>key</I> of the mapping;
* this number might be different from referent.hashCode() if
* the referent represents a value and not a key
*/
private Object toReference(int type, Object referent, int hash)
{
switch (type)
{
case HARD:
return referent;
case SOFT:
return new SoftRef(hash, referent, queue);
case WEAK:
return new WeakRef(hash, referent, queue);
default:
throw new Error();
}
}
/**
* Returns the entry associated with the given key.
*
* @param key the key of the entry to look up
* @return the entry associated with that key, or null
* if the key is not in this map
*/
private Entry getEntry(Object key)
{
if (key == null) return null;
int hash = hashCode(key);
int index = indexFor(hash);
for (Entry entry = table[index]; entry != null; entry = entry.next)
{
if ((entry.hash == hash) && equals(key, entry.getKey()))
{
return entry;
}
}
return null;
}
/**
* Converts the given hash code into an index into the
* hash table.
*/
private int indexFor(int hash)
{
// mix the bits to avoid bucket collisions...
hash += ~(hash << 15);
hash ^= (hash >>> 10);
hash += (hash << 3);
hash ^= (hash >>> 6);
hash += ~(hash << 11);
hash ^= (hash >>> 16);
return hash & (table.length - 1);
}
/**
* Resizes this hash table by doubling its capacity.
* This is an expensive operation, as entries must
* be copied from the old smaller table to the new
* bigger table.
*/
private void resize()
{
Entry[] old = table;
table = new Entry[old.length * 2];
for (int i = 0; i < old.length; i++)
{
Entry next = old[i];
while (next != null)
{
Entry entry = next;
next = next.next;
int index = indexFor(entry.hash);
entry.next = table[index];
table[index] = entry;
}
old[i] = null;
}
threshold = (int) (table.length * loadFactor);
}
/**
* Purges stale mappings from this map.<P>
*
* Ordinarily, stale mappings are only removed during
* a write operation; typically a write operation will
* occur often enough that you'll never need to manually
* invoke this method.<P>
*
* Note that this method is not synchronized! Special
* care must be taken if, for instance, you want stale
* mappings to be removed on a periodic basis by some
* background thread.
*/
private void purge()
{
Reference ref = queue.poll();
while (ref != null)
{
purge(ref);
ref = queue.poll();
}
}
private void purge(Reference ref)
{
// The hashCode of the reference is the hashCode of the
// mapping key, even if the reference refers to the
// mapping value...
int hash = ref.hashCode(); // note: hashCode() is referined
int index = indexFor(hash);
Entry previous = null;
Entry entry = table[index];
while (entry != null)
{
if (entry.purge(ref))
{
if (previous == null)
table[index] = entry.next;
else
previous.next = entry.next;
this.size--;
return;
}
previous = entry;
entry = entry.next;
}
}
/**
* Returns the size of this map.
*
* @return the size of this map
*/
public int size()
{
purge();
return size;
}
/**
* Returns <Code>true</Code> if this map is empty.
*
* @return <Code>true</Code> if this map is empty
*/
public boolean isEmpty()
{
purge();
return size == 0;
}
/**
* Returns <Code>true</Code> if this map contains the given key.
*
* @return true if the given key is in this map
*/
public boolean containsKey(Object key)
{
purge();
Entry entry = getEntry(key);
if (entry == null) return false;
return entry.getValue() != null;
}
/**
* Returns the value associated with the given key, if any.
*
* @return the value associated with the given key, or <Code>null</Code>
* if the key maps to no value
*/
public Object get(Object key)
{
purge();
Entry entry = getEntry(key);
if (entry == null) return null;
return entry.getValue();
}
/**
* Associates the given key with the given value.<P>
* Neither the key nor the value may be null.
*
* @param key the key of the mapping
* @param value the value of the mapping
* @return the last value associated with that key, or
* null if no value was associated with the key
* @throws java.lang.NullPointerException if either the key or value
* is null
*/
public Object put(Object key, Object value)
{
if (key == null) throw new NullPointerException("null keys not allowed");
if (value == null) throw new NullPointerException("null values not allowed");
purge();
if (size + 1 > threshold) resize();
int hash = hashCode(key);
int index = indexFor(hash);
Entry entry = table[index];
while (entry != null)
{
if ((hash == entry.hash) && equals(key, entry.getKey()))
{
Object result = entry.getValue();
entry.setValue(value);
return result;
}
entry = entry.next;
}
this.size++;
modCount++;
key = toReference(keyType, key, hash);
value = toReference(valueType, value, hash);
table[index] = new Entry(key, hash, value, table[index]);
return null;
}
/**
* Removes the key and its associated value from this map.
*
* @param key the key to remove
* @return the value associated with that key, or null if
* the key was not in the map
*/
public Object remove(Object key)
{
if (key == null) return null;
purge();
int hash = hashCode(key);
int index = indexFor(hash);
Entry previous = null;
Entry entry = table[index];
while (entry != null)
{
if ((hash == entry.hash) && equals(key, entry.getKey()))
{
if (previous == null)
table[index] = entry.next;
else
previous.next = entry.next;
this.size--;
modCount++;
return entry.getValue();
}
previous = entry;
entry = entry.next;
}
return null;
}
/**
* Clears this map.
*/
public void clear()
{
Arrays.fill(table, null);
size = 0;
while (queue.poll() != null) ; // drain the queue
}
/**
* Returns a set view of this map's entries.
*
* @return a set view of this map's entries
*/
public Set entrySet()
{
if (entrySet != null) return entrySet;
entrySet = new AbstractSet()
{
public int size()
{
return ReferenceMap.this.size();
}
public void clear()
{
ReferenceMap.this.clear();
}
public boolean contains(Object o)
{
if (o == null) return false;
if (!(o instanceof Map.Entry)) return false;
Map.Entry e = (Map.Entry) o;
Entry e2 = getEntry(e.getKey());
return (e2 != null) && e.equals(e2);
}
public boolean remove(Object o)
{
boolean r = contains(o);
if (r)
{
Map.Entry e = (Map.Entry) o;
ReferenceMap.this.remove(e.getKey());
}
return r;
}
public Iterator iterator()
{
return new EntryIterator();
}
public Object[] toArray()
{
return toArray(new Object[0]);
}
public Object[] toArray(Object[] arr)
{
ArrayList list = new ArrayList();
Iterator iterator = iterator();
while (iterator.hasNext())
{
Entry e = (Entry) iterator.next();
list.add(new DefaultMapEntry(e.getKey(), e.getValue()));
}
return list.toArray(arr);
}
};
return entrySet;
}
/**
* Returns a set view of this map's keys.
*
* @return a set view of this map's keys
*/
public Set keySet()
{
if (keySet != null) return keySet;
keySet = new AbstractSet()
{
public int size()
{
return size;
}
public Iterator iterator()
{
return new KeyIterator();
}
public boolean contains(Object o)
{
return containsKey(o);
}
public boolean remove(Object o)
{
Object r = ReferenceMap.this.remove(o);
return r != null;
}
public void clear()
{
ReferenceMap.this.clear();
}
};
return keySet;
}
/**
* Returns a collection view of this map's values.
*
* @return a collection view of this map's values.
*/
public Collection values()
{
if (values != null) return values;
values = new AbstractCollection()
{
public int size()
{
return size;
}
public void clear()
{
ReferenceMap.this.clear();
}
public Iterator iterator()
{
return new ValueIterator();
}
};
return values;
}
// If getKey() or getValue() returns null, it means
// the mapping is stale and should be removed.
private class Entry implements Map.Entry
{
Object key;
Object value;
int hash;
Entry next;
public Entry(Object key, int hash, Object value, Entry next)
{
this.key = key;
this.hash = hash;
this.value = value;
this.next = next;
}
public Object getKey()
{
return (keyType > HARD) ? ((Reference) key).get() : key;
}
public Object getValue()
{
return (valueType > HARD) ? ((Reference) value).get() : value;
}
public Object setValue(Object object)
{
Object old = getValue();
if (valueType > HARD) ((Reference) value).clear();
value = toReference(valueType, object, hash);
return old;
}
public boolean equals(Object o)
{
if (o == null) return false;
if (o == this) return true;
if (!(o instanceof Map.Entry)) return false;
Map.Entry entry = (Map.Entry) o;
Object key = entry.getKey();
Object value = entry.getValue();
if ((key == null) || (value == null)) return false;
return ReferenceMap.this.equals(key, getKey()) &&
ReferenceMap.this.equals(value, getValue());
}
public int hashCode()
{
Object v = getValue();
return hash ^ ((v == null) ? 0 : v.hashCode());
}
public String toString()
{
return getKey() + "=" + getValue();
}
boolean purge(Reference ref)
{
boolean r = (keyType > HARD) && (key == ref);
r = r || ((valueType > HARD) && (value == ref));
if (r)
{
if (keyType > HARD) ((Reference) key).clear();
if (valueType > HARD) ((Reference) value).clear();
}
return r;
}
}
private class EntryIterator implements Iterator
{
// These fields keep track of where we are in the table.
int index;
Entry entry;
Entry previous;
// These Object fields provide hard references to the
// current and next entry; this assures that if hasNext()
// returns true, next() will actually return a valid element.
Object nextKey, nextValue;
Object currentKey, currentValue;
int expectedModCount;
public EntryIterator()
{
index = (size() != 0 ? table.length : 0);
// have to do this here! size() invocation above
// may have altered the modCount.
expectedModCount = modCount;
}
public boolean hasNext()
{
checkMod();
while (nextNull())
{
Entry e = entry;
int i = index;
while ((e == null) && (i > 0))
{
i--;
e = table[i];
}
entry = e;
index = i;
if (e == null)
{
currentKey = null;
currentValue = null;
return false;
}
nextKey = e.getKey();
nextValue = e.getValue();
if (nextNull()) entry = entry.next;
}
return true;
}
private void checkMod()
{
if (modCount != expectedModCount)
{
throw new ConcurrentModificationException();
}
}
private boolean nextNull()
{
return (nextKey == null) || (nextValue == null);
}
protected Entry nextEntry()
{
checkMod();
if (nextNull() && !hasNext()) throw new NoSuchElementException();
previous = entry;
entry = entry.next;
currentKey = nextKey;
currentValue = nextValue;
nextKey = null;
nextValue = null;
return previous;
}
public Object next()
{
return nextEntry();
}
public void remove()
{
checkMod();
if (previous == null) throw new IllegalStateException();
ReferenceMap.this.remove(currentKey);
previous = null;
currentKey = null;
currentValue = null;
expectedModCount = modCount;
}
}
private class ValueIterator extends EntryIterator
{
public Object next()
{
return nextEntry().getValue();
}
}
private class KeyIterator extends EntryIterator
{
public Object next()
{
return nextEntry().getKey();
}
}
// These two classes store the hashCode of the key of
// of the mapping, so that after they're dequeued a quick
// lookup of the bucket in the table can occur.
private static class SoftRef extends SoftReference
{
private int hash;
public SoftRef(int hash, Object r, ReferenceQueue q)
{
super(r, q);
this.hash = hash;
}
public int hashCode()
{
return hash;
}
}
private static class WeakRef extends WeakReference
{
private int hash;
public WeakRef(int hash, Object r, ReferenceQueue q)
{
super(r, q);
this.hash = hash;
}
public int hashCode()
{
return hash;
}
}
private int hashCode(Object obj)
{
return useSystemIdentity ? System.identityHashCode(obj) : obj.hashCode(); // null keys|values are not supported
}
private boolean equals(Object obj1, Object obj2)
{
return (obj1 == obj2) ||
(!useSystemIdentity && obj1.equals(obj2)); // null keys|values are not supported
}
//***********************************************
// inner class
//***********************************************
/** A default implementation of {@link java.util.Map.Entry}
*
* @since 1.0
* @author <a href="mailto:jstrachan@apache.org">James Strachan</a>
* @author <a href="mailto:mas@apache.org">Michael A. Smith</a>
*/
public class DefaultMapEntry implements Map.Entry {
private Object key;
private Object value;
/**
* Constructs a new <Code>DefaultMapEntry</Code> with a null key
* and null value.
*/
public DefaultMapEntry() {
}
/**
* Constructs a new <Code>DefaultMapEntry</Code> with the given
* key and given value.
*
* @param key the key for the entry, may be null
* @param value the value for the entyr, may be null
*/
public DefaultMapEntry(Object key, Object value) {
this.key = key;
this.value = value;
}
/**
* Implemented per API documentation of
* {@link java.util.Map.Entry#equals(java.lang.Object)}
**/
public boolean equals(Object o) {
if( o == null ) return false;
if( o == this ) return true;
if ( ! (o instanceof Map.Entry ) )
return false;
Map.Entry e2 = (Map.Entry)o;
return ((getKey() == null ?
e2.getKey() == null : getKey().equals(e2.getKey())) &&
(getValue() == null ?
e2.getValue() == null : getValue().equals(e2.getValue())));
}
/**
* Implemented per API documentation of
* {@link java.util.Map.Entry#hashCode()}
**/
public int hashCode() {
return ( ( getKey() == null ? 0 : getKey().hashCode() ) ^
( getValue() == null ? 0 : getValue().hashCode() ) );
}
// Map.Entry interface
//-------------------------------------------------------------------------
/**
* Returns the key.
*
* @return the key
*/
public Object getKey() {
return key;
}
/**
* Returns the value.
*
* @return the value
*/
public Object getValue() {
return value;
}
// Properties
//-------------------------------------------------------------------------
/**
* Sets the key. This method does not modify any map.
*
* @param key the new key
*/
public void setKey(Object key) {
this.key = key;
}
/** Note that this method only sets the local reference inside this object and
* does not modify the original Map.
*
* @return the old value of the value
* @param value the new value
*/
public Object setValue(Object value) {
Object answer = this.value;
this.value = value;
return answer;
}
}
}
1.1 db-ojb/src/test/org/apache/ojb/broker/metadata/ReferenceMapTest.java
Index: ReferenceMapTest.java
===================================================================
package org.apache.ojb.broker.metadata;
import junit.framework.TestCase;
import org.apache.ojb.broker.util.ReferenceMap;
public class ReferenceMapTest extends TestCase
{
private ReferenceMap referenceMap = null;
public ReferenceMapTest(String name)
{
super(name);
}
public static void main(String[] args)
{
String[] arr = {ReferenceMapTest.class.getName()};
junit.textui.TestRunner.main(arr);
}
protected void setUp()
throws Exception
{
super.setUp();
/*
todo: verify the constructors
*/
referenceMap = new ReferenceMap(ReferenceMap.WEAK, ReferenceMap.HARD, 10, 0.75f, true);
}
protected void tearDown()
throws Exception
{
referenceMap = null;
super.tearDown();
}
public void testWeakIdentityMap()
{
String key1 = new String("abc");
String key2 = new String("abc");
String value1 = new String("abc");
String value2 = new String("abc");
assertNotSame("different references", key1, key2);
assertEquals("identical strings", key1, key2);
referenceMap.put(key1, "nonsence");
assertEquals("size", 1, referenceMap.size());
//if we put the same value size will remain the same
referenceMap.put(key1, value1);
assertEquals("size", 1, referenceMap.size());
//if we put equal value size will increase
referenceMap.put(key2, value2);
assertEquals("size", 2, referenceMap.size());
// test containsKey
assertTrue("ref1 is there", referenceMap.containsKey(key1));
assertTrue("ref2 is there", referenceMap.containsKey(key2));
// test remove
assertSame("key1=>value1", value1, referenceMap.remove(key1));
assertEquals("size", 1, referenceMap.size());
referenceMap.put(key1, value1); // put it back
assertEquals("size", 2, referenceMap.size());
key2 = ""; // will weaken ref2 key in referenceMap
gc();
assertEquals("GC didn't release weak references", 1, referenceMap.size());
assertFalse("ref2 is not there", referenceMap.containsKey(key2));
assertTrue("ref1 is there", referenceMap.containsKey(key1));
if (key1.length() < 0) // lets do something with ref1 to avoid GC
fail(key1); // never
// check NULL
//referenceMap.put(key1, null);
}
public static void gc()
{
try
{
// trigger GC
byte[][] tooLarge = new byte[1000000000][1000000000];
fail("you have too much RAM");
}
catch (OutOfMemoryError ex)
{
System.gc(); // ignore
}
}
}
1.38 +2 -0 db-ojb/src/test/org/apache/ojb/broker/AllTests.java
Index: AllTests.java
===================================================================
RCS file: /home/cvs/db-ojb/src/test/org/apache/ojb/broker/AllTests.java,v
retrieving revision 1.37
retrieving revision 1.38
diff -u -r1.37 -r1.38
--- AllTests.java 9 Dec 2003 13:46:46 -0000 1.37
+++ AllTests.java 27 Jan 2004 19:42:46 -0000 1.38
@@ -8,6 +8,7 @@
import org.apache.ojb.broker.metadata.RepositoryElementsTest;
import org.apache.ojb.broker.metadata.MetadataMultithreadedTest;
import org.apache.ojb.broker.metadata.ReadonlyTest;
+import org.apache.ojb.broker.metadata.ReferenceMapTest;
import org.apache.ojb.broker.sequence.SequenceManagerTest;
import org.apache.ojb.broker.sequence.NativeIdentifierTest;
import org.apache.ojb.broker.sequence.SMMultiThreadedTest;
@@ -84,6 +85,7 @@
suite.addTestSuite(MtoNTest.class);
suite.addTestSuite(NestedFieldsTest.class);
suite.addTestSuite(ReadonlyTest.class);
+ suite.addTestSuite(ReferenceMapTest.class);
return suite;
}
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