org.apache.tools.ant.property.LocalPropertyStack Maven / Gradle / Ivy
/*
* 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.tools.ant.property;
import java.util.LinkedList;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import org.apache.tools.ant.PropertyHelper;
/**
* A stack of local property maps.
* There is a map for each scope (target, sequential, macro).
* @since Ant 1.8.0
*/
public class LocalPropertyStack {
private final LinkedList> stack = new LinkedList>();
private final Object LOCK = new Object();
// --------------------------------------------------
//
// Local property adding and scoping
//
// --------------------------------------------------
/**
* Add a local property.
* @param property the name of the local property.
*/
public void addLocal(String property) {
synchronized (LOCK) {
Map map = stack.peek();
if (map != null) {
map.put(property, NullReturn.NULL);
}
}
}
/**
* Enter the local scope.
*/
public void enterScope() {
synchronized (LOCK) {
stack.addFirst(new ConcurrentHashMap());
}
}
/**
* Exit the local scope.
*/
public void exitScope() {
synchronized (LOCK) {
stack.removeFirst().clear();
}
}
// --------------------------------------------------
//
// Copy - used in parallel to make a new stack
//
// --------------------------------------------------
/**
* Copy the stack for a parallel thread.
* @return a copy.
*/
public LocalPropertyStack copy() {
synchronized (LOCK) {
LocalPropertyStack ret = new LocalPropertyStack();
ret.stack.addAll(stack);
return ret;
}
}
// --------------------------------------------------
//
// PropertyHelper delegate methods
//
// --------------------------------------------------
/**
* Evaluate a property.
* @param property the property's String "identifier".
* @param helper the invoking PropertyHelper.
* @return Object value.
*/
public Object evaluate(String property, PropertyHelper helper) {
synchronized (LOCK) {
for (Map map : stack) {
Object ret = map.get(property);
if (ret != null) {
return ret;
}
}
}
return null;
}
/**
* Set a *new" property.
* @param property the property's String "identifier".
* @param value the value to set.
* @param propertyHelper the invoking PropertyHelper.
* @return true if this entity 'owns' the property.
*/
public boolean setNew(
String property, Object value, PropertyHelper propertyHelper) {
Map map = getMapForProperty(property);
if (map == null) {
return false;
}
Object currValue = map.get(property);
if (currValue == NullReturn.NULL) {
map.put(property, value);
}
return true;
}
/**
* Set a property.
* @param property the property's String "identifier".
* @param value the value to set.
* @param propertyHelper the invoking PropertyHelper.
* @return true if this entity 'owns' the property.
*/
public boolean set(String property, Object value, PropertyHelper propertyHelper) {
Map map = getMapForProperty(property);
if (map == null) {
return false;
}
map.put(property, value);
return true;
}
private Map getMapForProperty(String property) {
synchronized (LOCK) {
for (Map map : stack) {
if (map.get(property) != null) {
return map;
}
}
}
return null;
}
}