Added new ReferenceMap class.
PR:9571 Obtained from: Submitted by: Reviewed by: git-svn-id: https://svn.apache.org/repos/asf/jakarta/commons/proper/collections/trunk@130760 13f79535-47bb-0310-9956-ffa450edef68
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pjack
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package org.apache.commons.collections;
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import java.io.IOException;
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import java.io.ObjectInputStream;
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import java.io.ObjectOutputStream;
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import java.io.Serializable;
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import java.lang.ref.Reference;
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import java.lang.ref.ReferenceQueue;
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import java.lang.ref.SoftReference;
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import java.lang.ref.WeakReference;
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import java.util.AbstractCollection;
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import java.util.AbstractMap;
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import java.util.AbstractSet;
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import java.util.ArrayList;
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import java.util.Arrays;
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import java.util.Collection;
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import java.util.Collections;
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import java.util.ConcurrentModificationException;
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import java.util.Iterator;
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import java.util.Map;
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import java.util.NoSuchElementException;
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import java.util.Set;
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/**
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* Hashtable-based {@link Map} implementation that allows
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* mappings to be removed by the garbage collector.<P>
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*
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* When you construct a <Code>ReferenceMap</Code>, you can
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* specify what kind of references are used to store the
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* map's keys and values. If non-hard references are
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* used, then the garbage collector can remove mappings
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* if a key or value becomes unreachable, or if the
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* JVM's memory is running low. For information on how
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* the different reference types behave, see
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* {@link Reference}.<P>
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*
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* Different types of references can be specified for keys
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* and values. The keys can be configured to be weak but
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* the values hard, in which case this class will behave
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* like a {@link java.util.WeakHashMap}. However, you
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* can also specify hard keys and weak values, or any other
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* combination. The default constructor uses hard keys
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* and soft values, providing a memory-sensitive cache.<P>
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*
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* The algorithms used are basically the same as those
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* in {@link java.util.HashMap}. In particular, you
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* can specify a load factor and capacity to suit your
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* needs. All optional {@link Map} operations are
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* supported.<P>
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*
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* However, this {@link Map} implementation does <I>not</I>
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* allow null elements. Attempting to add a null key or
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* or a null value to the map will raise a
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* <Code>NullPointerException</Code>.<P>
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*
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* As usual, this implementation is not synchronized. You
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* can use {@link java.util.Collections#synchronizedMap} to
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* provide synchronized access to a <Code>ReferenceMap</Code>.
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*
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* @author Paul Jack
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* @see java.lang.ref.Reference
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*/
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public class ReferenceMap extends AbstractMap implements Serializable {
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/**
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* Constant indicating that hard references should be used.
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*/
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final public static int HARD = 0;
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/**
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* Constant indiciating that soft references should be used.
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*/
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final public static int SOFT = 1;
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/**
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* Constant indicating that weak references should be used.
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*/
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final public static int WEAK = 2;
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// --- serialized instance variables:
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/**
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* The reference type for keys. Must be HARD, SOFT, WEAK.
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* Note: I originally marked this field as final, but then this class
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* didn't compile under JDK1.2.2.
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* @serial
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*/
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private int keyType;
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/**
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* The reference type for values. Must be HARD, SOFT, WEAK.
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* Note: I originally marked this field as final, but then this class
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* didn't compile under JDK1.2.2.
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* @serial
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*/
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private int valueType;
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/**
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* The threshold variable is calculated by multiplying
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* table.length and loadFactor.
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* Note: I originally marked this field as final, but then this class
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* didn't compile under JDK1.2.2.
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* @serial
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*/
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private float loadFactor;
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// -- Non-serialized instance variables
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/**
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* ReferenceQueue used to eliminate stale mappings.
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* @see #purge
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*/
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private transient ReferenceQueue queue = new ReferenceQueue();
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/**
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* The hash table. Its length is always a power of two.
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*/
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private transient Entry[] table;
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/**
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* Number of mappings in this map.
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*/
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private transient int size;
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/**
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* When size reaches threshold, the map is resized.
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* @see resize
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*/
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private transient int threshold;
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/**
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* Number of times this map has been modified.
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*/
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private transient volatile int modCount;
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/**
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* Cached key set. May be null if key set is never accessed.
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*/
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private transient Set keySet;
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/**
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* Cached entry set. May be null if entry set is never accessed.
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*/
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private transient Set entrySet;
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/**
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* Cached values. May be null if values() is never accessed.
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*/
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private transient Collection values;
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/**
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* Constructs a new <Code>ReferenceMap</Code> that will
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* use hard references to keys and soft references to values.
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*/
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public ReferenceMap() {
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this(HARD, SOFT);
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}
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/**
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* Constructs a new <Code>ReferenceMap</Code> that will
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* use the specified types of references.
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*
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* @param keyType the type of reference to use for keys;
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* must be {@link #HARD}, {@link #SOFT}, {@link WEAK}
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* @param valueType the type of reference to use for values;
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* must be {@link #HARD}, {@link #SOFT}, {@link WEAK}
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*/
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public ReferenceMap(int keyType, int valueType) {
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this(keyType, valueType, 16, 0.75f);
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}
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/**
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* Constructs a new <Code>ReferenceMap</Code> with the
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* specified reference types, load factor and initial
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* capacity.
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*
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* @param keyType the type of reference to use for keys;
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* must be {@link #HARD}, {@link #SOFT}, {@link WEAK}
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* @param valueType the type of reference to use for values;
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* must be {@link #HARD}, {@link #SOFT}, {@link WEAK}
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* @param capacity the initial capacity for the map
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* @param loadFactor the load factor for the map
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*/
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public ReferenceMap(int keyType, int valueType, int capacity, float loadFactor) {
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super();
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verify("keyType", keyType);
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verify("valueType", valueType);
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if (capacity <= 0) {
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throw new IllegalArgumentException("capacity must be positive");
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}
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if ((loadFactor <= 0.0f) || (loadFactor >= 1.0f)) {
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throw new IllegalArgumentException("Load factor must be greater than 0 and less than 1.");
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}
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this.keyType = keyType;
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this.valueType = valueType;
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int v = 1;
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while (v < capacity) v *= 2;
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this.table = new Entry[v];
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this.loadFactor = loadFactor;
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this.threshold = (int)(v * loadFactor);
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}
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// used by constructor
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private static void verify(String name, int type) {
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if ((type < HARD) || (type > WEAK)) {
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throw new IllegalArgumentException(name +
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" must be HARD, SOFT, WEAK.");
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}
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}
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/**
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* Writes this object to the given output stream.
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*
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* @param out the output stream to write to
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* @throws IOException if the stream raises it
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*/
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private void writeObject(ObjectOutputStream out) throws IOException {
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out.defaultWriteObject();
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out.writeInt(table.length);
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// Have to use null-terminated list because size might shrink
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// during iteration
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for (Iterator iter = entrySet().iterator(); iter.hasNext();) {
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Map.Entry entry = (Map.Entry)iter.next();
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out.writeObject(entry.getKey());
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out.writeObject(entry.getValue());
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}
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out.writeObject(null);
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}
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/**
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* Reads the contents of this object from the given input stream.
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*
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* @param inp the input stream to read from
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* @throws IOException if the stream raises it
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* @throws ClassNotFoundException if the stream raises it
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*/
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private void readObject(ObjectInputStream inp) throws IOException, ClassNotFoundException {
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inp.defaultReadObject();
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table = new Entry[inp.readInt()];
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threshold = (int)(table.length * loadFactor);
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queue = new ReferenceQueue();
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Object key = inp.readObject();
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while (key != null) {
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Object value = inp.readObject();
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put(key, value);
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key = inp.readObject();
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}
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}
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/**
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* Constructs a reference of the given type to the given
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* referent. The reference is registered with the queue
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* for later purging.
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*
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* @param type HARD, SOFT or WEAK
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* @param referent the object to refer to
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* @param hash the hash code of the <I>key</I> of the mapping;
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* this number might be different from referent.hashCode() if
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* the referent represents a value and not a key
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*/
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private Object toReference(int type, Object referent, int hash) {
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switch (type) {
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case HARD: return referent;
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case SOFT: return new SoftRef(hash, referent, queue);
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case WEAK: return new WeakRef(hash, referent, queue);
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default: throw new Error();
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}
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}
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/**
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* Returns the entry associated with the given key.
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*
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* @param key the key of the entry to look up
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* @return the entry associated with that key, or null
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* if the key is not in this map
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*/
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private Entry getEntry(Object key) {
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if (key == null) return null;
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int hash = key.hashCode();
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int index = indexFor(hash);
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for (Entry entry = table[index]; entry != null; entry = entry.next) {
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if ((entry.hash == hash) && key.equals(entry.getKey())) {
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return entry;
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}
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}
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return null;
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}
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/**
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* Converts the given hash code into an index into the
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* hash table.
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*/
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private int indexFor(int hash) {
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// mix the bits to avoid bucket collisions...
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hash += ~(hash << 15);
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hash ^= (hash >>> 10);
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hash += (hash << 3);
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hash ^= (hash >>> 6);
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hash += ~(hash << 11);
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hash ^= (hash >>> 16);
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return hash & (table.length - 1);
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}
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/**
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* Resizes this hash table by doubling its capacity.
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* This is an expensive operation, as entries must
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* be copied from the old smaller table to the new
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* bigger table.
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*/
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private void resize() {
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Entry[] old = table;
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table = new Entry[old.length * 2];
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for (int i = 0; i < old.length; i++) {
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Entry next = old[i];
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while (next != null) {
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Entry entry = next;
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next = next.next;
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int index = indexFor(entry.hash);
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entry.next = table[index];
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table[index] = entry;
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}
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old[i] = null;
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}
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threshold = (int)(table.length * loadFactor);
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}
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/**
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* Purges stale mappings from this map.<P>
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*
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* Ordinarily, stale mappings are only removed during
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* a write operation; typically a write operation will
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* occur often enough that you'll never need to manually
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* invoke this method.<P>
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*
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* Note that this method is not synchronized! Special
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* care must be taken if, for instance, you want stale
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* mappings to be removed on a periodic basis by some
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* background thread.
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*/
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private void purge() {
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Reference ref = queue.poll();
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while (ref != null) {
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purge(ref);
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ref = queue.poll();
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}
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}
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private void purge(Reference ref) {
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// The hashCode of the reference is the hashCode of the
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// mapping key, even if the reference refers to the
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// mapping value...
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int hash = ref.hashCode();
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int index = indexFor(hash);
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Entry previous = null;
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Entry entry = table[index];
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while (entry != null) {
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if (entry.purge(ref)) {
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if (previous == null) table[index] = entry.next;
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else previous.next = entry.next;
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this.size--;
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return;
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}
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previous = entry;
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entry = entry.next;
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}
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}
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/**
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* Returns the size of this map.
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*
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* @return the size of this map
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*/
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public int size() {
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purge();
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return size;
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}
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/**
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* Returns <Code>true</Code> if this map is empty.
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*
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* @return <Code>true</Code> if this map is empty
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*/
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public boolean isEmpty() {
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purge();
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return size == 0;
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}
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/**
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* Returns <Code>true</Code> if this map contains the given key.
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*
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* @return true if the given key is in this map
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*/
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public boolean containsKey(Object key) {
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purge();
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Entry entry = getEntry(key);
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if (entry == null) return false;
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return entry.getValue() != null;
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}
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/**
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* Returns the value associated with the given key, if any.
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*
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* @return the value associated with the given key, or <Code>null</Code>
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* if the key maps to no value
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*/
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public Object get(Object key) {
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purge();
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Entry entry = getEntry(key);
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if (entry == null) return null;
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return entry.getValue();
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}
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/**
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* Associates the given key with the given value.<P>
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* Neither the key nor the value may be null.
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*
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* @param key the key of the mapping
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* @param value the value of the mapping
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* @return the last value associated with that key, or
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* null if no value was associated with the key
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* @throws NullPointerException if either the key or value
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* is null
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*/
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public Object put(Object key, Object value) {
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if (key == null) throw new NullPointerException("null keys not allowed");
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if (value == null) throw new NullPointerException("null values not allowed");
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purge();
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if (size + 1 > threshold) resize();
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int hash = key.hashCode();
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int index = indexFor(hash);
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Entry entry = table[index];
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while (entry != null) {
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if ((hash == entry.hash) && key.equals(entry.getKey())) {
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Object result = entry.getValue();
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entry.setValue(value);
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return result;
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}
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entry = entry.next;
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}
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this.size++;
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modCount++;
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key = toReference(keyType, key, hash);
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value = toReference(valueType, value, hash);
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table[index] = new Entry(key, hash, value, table[index]);
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return null;
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}
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/**
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* Removes the key and its associated value from this map.
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*
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* @param key the key to remove
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* @return the value associated with that key, or null if
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* the key was not in the map
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*/
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public Object remove(Object key) {
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if (key == null) return null;
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purge();
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int hash = key.hashCode();
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int index = indexFor(hash);
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Entry previous = null;
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Entry entry = table[index];
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while (entry != null) {
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if ((hash == entry.hash) && key.equals(entry.getKey())) {
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if (previous == null) table[index] = entry.next;
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else previous.next = entry.next;
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this.size--;
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modCount++;
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return entry.getValue();
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}
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previous = entry;
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entry = entry.next;
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}
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return null;
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}
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/**
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* Clears this map.
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*/
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public void clear() {
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Arrays.fill(table, null);
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size = 0;
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while (queue.poll() != null); // drain the queue
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}
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/**
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* Returns a set view of this map's entries.
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*
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* @return a set view of this map's entries
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*/
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public Set entrySet() {
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if (entrySet != null) return entrySet;
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entrySet = new AbstractSet() {
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public int size() {
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return ReferenceMap.this.size();
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}
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||||
|
||||
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 key.equals(getKey()) && value.equals(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;
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
}
|
||||
|
|
@ -1,7 +1,7 @@
|
|||
/*
|
||||
* $Header: /home/jerenkrantz/tmp/commons/commons-convert/cvs/home/cvs/jakarta-commons//collections/src/test/org/apache/commons/collections/TestAll.java,v 1.30 2002/07/09 16:48:56 rwaldhoff Exp $
|
||||
* $Revision: 1.30 $
|
||||
* $Date: 2002/07/09 16:48:56 $
|
||||
* $Header: /home/jerenkrantz/tmp/commons/commons-convert/cvs/home/cvs/jakarta-commons//collections/src/test/org/apache/commons/collections/TestAll.java,v 1.31 2002/08/12 18:13:09 pjack Exp $
|
||||
* $Revision: 1.31 $
|
||||
* $Date: 2002/08/12 18:13:09 $
|
||||
*
|
||||
* ====================================================================
|
||||
*
|
||||
|
|
@ -67,7 +67,7 @@ import junit.framework.*;
|
|||
/**
|
||||
* Entry point for all Collections tests.
|
||||
* @author Rodney Waldhoff
|
||||
* @version $Id: TestAll.java,v 1.30 2002/07/09 16:48:56 rwaldhoff Exp $
|
||||
* @version $Id: TestAll.java,v 1.31 2002/08/12 18:13:09 pjack Exp $
|
||||
*/
|
||||
public class TestAll extends TestCase {
|
||||
public TestAll(String testName) {
|
||||
|
|
@ -111,6 +111,7 @@ public class TestAll extends TestCase {
|
|||
suite.addTest(TestTreeBag.suite());
|
||||
suite.addTest(TestUnboundedFifoBuffer.suite());
|
||||
suite.addTest(TestUniqueFilterIterator.suite());
|
||||
suite.addTest(TestReferenceMap.suite());
|
||||
suite.addTest(org.apache.commons.collections.primitives.TestAll.suite());
|
||||
return suite;
|
||||
}
|
||||
|
|
|
|||
|
|
@ -0,0 +1,207 @@
|
|||
/*
|
||||
* $Header: /home/jerenkrantz/tmp/commons/commons-convert/cvs/home/cvs/jakarta-commons//collections/src/test/org/apache/commons/collections/TestReferenceMap.java,v 1.1 2002/08/12 18:13:09 pjack Exp $
|
||||
* $Revision: 1.1 $
|
||||
* $Date: 2002/08/12 18:13:09 $
|
||||
*
|
||||
* ====================================================================
|
||||
*
|
||||
* 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/>.
|
||||
*
|
||||
*/
|
||||
|
||||
package org.apache.commons.collections;
|
||||
|
||||
import junit.framework.Test;
|
||||
import junit.framework.TestCase;
|
||||
import junit.framework.TestSuite;
|
||||
import java.lang.ref.Reference;
|
||||
import java.lang.ref.WeakReference;
|
||||
import java.lang.ref.ReferenceQueue;
|
||||
import java.util.ArrayList;
|
||||
import java.util.Iterator;
|
||||
import java.util.Map;
|
||||
import java.util.HashMap;
|
||||
import java.util.Random;
|
||||
|
||||
|
||||
/**
|
||||
* Tests for ReferenceMap.
|
||||
*
|
||||
* @author Paul Jack
|
||||
* @version $Id: TestReferenceMap.java,v 1.1 2002/08/12 18:13:09 pjack Exp $
|
||||
*/
|
||||
public class TestReferenceMap extends TestMap {
|
||||
|
||||
|
||||
private static Random random = new Random();
|
||||
|
||||
|
||||
private Object[] hardKeys;
|
||||
private Object[] hardValues;
|
||||
private HashMap refs = new HashMap();
|
||||
|
||||
|
||||
public TestReferenceMap(String testName) {
|
||||
super(testName);
|
||||
}
|
||||
|
||||
public static Test suite() {
|
||||
return BulkTest.makeSuite(TestReferenceMap.class);
|
||||
}
|
||||
|
||||
public static void main(String args[]) {
|
||||
String[] testCaseName = { TestReferenceMap.class.getName() };
|
||||
junit.textui.TestRunner.main(testCaseName);
|
||||
}
|
||||
|
||||
public Map makeEmptyMap() {
|
||||
ReferenceMap map = new ReferenceMap(ReferenceMap.WEAK, ReferenceMap.WEAK);
|
||||
return map;
|
||||
}
|
||||
|
||||
public boolean useNullKey() {
|
||||
return false;
|
||||
}
|
||||
|
||||
public boolean useNullValue() {
|
||||
return false;
|
||||
}
|
||||
|
||||
|
||||
/*
|
||||
// Unfortunately, these tests all rely on System.gc(), which is
|
||||
// not reliable across platforms. Not sure how to code the tests
|
||||
// without using System.gc() though...
|
||||
// They all passed on my platform though. :)
|
||||
|
||||
public void testPurge() {
|
||||
ReferenceMap map = new ReferenceMap(ReferenceMap.WEAK, ReferenceMap.WEAK);
|
||||
Object[] hard = new Object[10];
|
||||
for (int i = 0; i < hard.length; i++) {
|
||||
hard[i] = new Object();
|
||||
map.put(hard[i], new Object());
|
||||
}
|
||||
System.gc();
|
||||
assertTrue("map should be empty after purge of weak values", map.isEmpty());
|
||||
|
||||
for (int i = 0; i < hard.length; i++) {
|
||||
map.put(new Object(), hard[i]);
|
||||
}
|
||||
System.gc();
|
||||
assertTrue("map should be empty after purge of weak keys", map.isEmpty());
|
||||
|
||||
for (int i = 0; i < hard.length; i++) {
|
||||
map.put(new Object(), hard[i]);
|
||||
map.put(hard[i], new Object());
|
||||
}
|
||||
|
||||
System.gc();
|
||||
assertTrue("map should be empty after purge of weak keys and values", map.isEmpty());
|
||||
}
|
||||
|
||||
|
||||
public void testGetAfterGC() {
|
||||
ReferenceMap map = new ReferenceMap(ReferenceMap.WEAK, ReferenceMap.WEAK);
|
||||
for (int i = 0; i < 10; i++) {
|
||||
map.put(new Integer(i), new Integer(i));
|
||||
}
|
||||
|
||||
System.gc();
|
||||
for (int i = 0; i < 10; i++) {
|
||||
Integer I = new Integer(i);
|
||||
assertTrue("map.containsKey should return false for GC'd element", !map.containsKey(I));
|
||||
assertTrue("map.get should return null for GC'd element", map.get(I) == null);
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
public void testEntrySetIteratorAfterGC() {
|
||||
ReferenceMap map = new ReferenceMap(ReferenceMap.WEAK, ReferenceMap.WEAK);
|
||||
Object[] hard = new Object[10];
|
||||
for (int i = 0; i < 10; i++) {
|
||||
hard[i] = new Integer(10 + i);
|
||||
map.put(new Integer(i), new Integer(i));
|
||||
map.put(hard[i], hard[i]);
|
||||
}
|
||||
|
||||
System.gc();
|
||||
Iterator iterator = map.entrySet().iterator();
|
||||
while (iterator.hasNext()) {
|
||||
Map.Entry entry = (Map.Entry)iterator.next();
|
||||
Integer key = (Integer)entry.getKey();
|
||||
Integer value = (Integer)entry.getValue();
|
||||
assertTrue("iterator should skip GC'd keys", key.intValue() >= 10);
|
||||
assertTrue("iterator should skip GC'd values", value.intValue() >= 10);
|
||||
}
|
||||
|
||||
}
|
||||
*/
|
||||
|
||||
|
||||
/*
|
||||
// Uncomment to create test files in /data/test
|
||||
public void testCreateTestFiles() throws Exception {
|
||||
ReferenceMap m = (ReferenceMap)makeEmptyMap();
|
||||
writeExternalFormToDisk(m, getCanonicalEmptyCollectionName(m));
|
||||
m = (ReferenceMap)makeFullMap();
|
||||
writeExternalFormToDisk(m, getCanonicalFullCollectionName(m));
|
||||
}
|
||||
*/
|
||||
|
||||
|
||||
public int getCompatibilityVersion() {
|
||||
return 2; // actually 2.1, but can't represent that as an int
|
||||
}
|
||||
|
||||
|
||||
}
|
||||
Loading…
Reference in New Issue