/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.openjpa.util;
import java.io.InputStream;
import java.io.ObjectStreamException;
import java.util.AbstractSet;
import java.util.Collection;
import java.util.Map;
import java.util.Iterator;
import java.util.Set;
/**
* Utility methods used by map proxies.
*
* @author Abe White
*/
public class ProxyMaps
extends Proxies {
/**
* Call before invoking {@link Map#clear} on super.
*/
public static void beforeClear(ProxyMap map) {
dirty(map, true);
Map.Entry entry;
for (Iterator itr = map.entrySet().iterator(); itr.hasNext();) {
entry = (Map.Entry) itr.next();
removed(map, entry.getKey(), true);
removed(map, entry.getValue(), false);
}
}
/**
* Override for {@link Map#keySet}.
*/
public static Set keySet(ProxyMap map) {
ProxyEntrySet entries = (ProxyEntrySet) map.entrySet();
entries.setView(ProxyEntrySet.VIEW_KEYS);
return entries;
}
/**
* Override for {@link Map#values}.
*/
public static Collection values(ProxyMap map) {
ProxyEntrySet entries = (ProxyEntrySet) map.entrySet();
entries.setView(ProxyEntrySet.VIEW_VALUES);
return entries;
}
/**
* Wrap the given entry set in a proxy.
*/
public static Set afterEntrySet(ProxyMap map, Set entries) {
return new ProxyEntrySetImpl(map, entries);
}
/**
* Call before invoking {@link Map#get} on super.
*/
public static boolean beforeGet(ProxyMap map, Object key) {
assertAllowedType(key, map.getKeyType());
// Java 8 solution/workaround due to containsKey() calling get!=null, which could cause infinite loop
return map.keySet().contains(key);
}
/**
* Call after invoking {@link Map#get} on super.
* The potential change is tracked when the get method is called. This change
* will not translated to an update statement if the retrieved value
* is not dirty.
*
* @param ret the return value from the super's method
* @param before the return value from {@link #beforeGet}
* @return the value to return from {@link Map#get}
*/
public static Object afterGet(ProxyMap map, Object key,
Object ret, boolean before) {
if (before) {
if (map.getChangeTracker() != null)
((MapChangeTracker) map.getChangeTracker()).changed(key, ret,
ret);
}
return ret;
}
/**
* Call before invoking {@link Map#put} on super.
*/
public static boolean beforePut(ProxyMap map, Object key, Object value) {
assertAllowedType(key, map.getKeyType());
assertAllowedType(value, map.getValueType());
dirty(map, false);
return map.containsKey(key);
}
/**
* Call after invoking {@link Map#put} on super.
*
* @param ret the return value from the super's method
* @param before the return value from {@link #beforePut}
* @return the value to return from {@link Map#put}
*/
public static Object afterPut(ProxyMap map, Object key, Object value,
Object ret, boolean before) {
if (before) {
if (map.getChangeTracker() != null)
((MapChangeTracker) map.getChangeTracker()).changed(key, ret,
value);
removed(map, ret, false);
} else if (map.getChangeTracker() != null)
((MapChangeTracker) map.getChangeTracker()).added(key, value);
return ret;
}
/**
* Call before invoking {@link Properties#setProperty} on super.
*/
public static boolean beforeSetProperty(ProxyMap map, String key,
String value) {
return beforePut(map, key, value);
}
/**
* Call after invoking {@link Properties#setProperty} on super.
*
* @param ret the return value from the super's method
* @param before the return value from {@link #beforeSetProperty}
* @return the value to return from {@link Properties#setProperty}
*/
public static Object afterSetProperty(ProxyMap map, String key,
String value, Object ret, boolean before) {
return afterPut(map, key, value, ret, before);
}
/**
* Call before invoking {@link Properties#load} on super.
*/
public static void beforeLoad(ProxyMap map, InputStream in) {
dirty(map, true);
}
/**
* Call before invoking {@link Properties#loadXML} on super.
*/
public static void beforeLoadFromXML(ProxyMap map, InputStream in) {
dirty(map, true);
}
/**
* Overload for {@link Map#putAll}.
*/
public static void putAll(ProxyMap map, Map values) {
Map.Entry entry;
for (Iterator itr = values.entrySet().iterator(); itr.hasNext();) {
entry = (Map.Entry) itr.next();
map.put(entry.getKey(), entry.getValue());
}
}
/**
* Call before invoking {@link Map#remove} on super.
*/
public static boolean beforeRemove(ProxyMap map, Object key) {
dirty(map, false);
return map.containsKey(key);
}
/**
* Call after invoking {@link Map#remove} on super.
*
* @param ret the return value from the super's method
* @param before the return value from {@link #beforeRemove}
* @return the value to return from {@link Map#remove}
*/
public static Object afterRemove(ProxyMap map, Object key, Object ret,
boolean before) {
if (before) {
if (map.getChangeTracker() != null)
((MapChangeTracker) map.getChangeTracker()).removed(key, ret);
removed(map, key, true);
removed(map, ret, false);
}
return ret;
}
/**
* Marker interface for a proxy entry set.
*/
public static interface ProxyEntrySet
extends Set {
public static final int VIEW_KEYS = 0;
public static final int VIEW_VALUES = 1;
public static final int VIEW_ENTRIES = 2;
/**
* Set what entry view this set exposes.
*/
public void setView(int view);
}
/**
* Dirtying proxy for map entry set.
*/
private static class ProxyEntrySetImpl
extends AbstractSet
implements ProxyEntrySet {
private final ProxyMap _map;
private final Set _entries;
private int _view = VIEW_ENTRIES;
/**
* Supply owning map and delegate entry set on construction.
*/
public ProxyEntrySetImpl(ProxyMap map, Set entries) {
_map = map;
_entries = entries;
}
/**
* View mode.
*/
public int getView() {
return _view;
}
/**
* View mode.
*/
public void setView(int view) {
_view = view;
}
public int size() {
return _entries.size();
}
public boolean remove(Object o) {
if (_view != VIEW_KEYS)
throw new UnsupportedOperationException();
if (!_map.containsKey(o))
return false;
_map.remove(o);
return true;
}
public Iterator iterator() {
final Iterator itr = _entries.iterator();
return new Iterator() {
private Map.Entry _last = null;
public boolean hasNext() {
return itr.hasNext();
}
public Object next() {
_last = (Map.Entry) itr.next();
switch (_view) {
case VIEW_KEYS:
return _last.getKey();
case VIEW_VALUES:
return _last.getValue();
default:
return _last;
}
}
public void remove() {
dirty(_map, false);
itr.remove();
if (_map.getChangeTracker() != null)
((MapChangeTracker) _map.getChangeTracker()).
removed(_last.getKey(), _last.getValue());
Proxies.removed(_map, _last.getKey(), true);
Proxies.removed(_map, _last.getValue(), false);
}
};
}
protected Object writeReplace()
throws ObjectStreamException {
switch (_view) {
case VIEW_KEYS:
return ((Map) _map).keySet();
case VIEW_VALUES:
return ((Map) _map).values();
default:
return ((Map) _map).entrySet();
}
}
}
}