Reduce memory consumption by using lazy initialization.

Speed things up a little by using unsynchronized collections.
PR: 21296


git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@274758 13f79535-47bb-0310-9956-ffa450edef68

src/main/org/apache/tools/ant/RuntimeConfigurable.java

@@ -54,11 +54,16 @@
 
 package org.apache.tools.ant;
 
+import java.io.Serializable;
+import java.util.ArrayList;
+import java.util.Collections;
 import java.util.Enumeration;
-import java.util.Locale;
-import java.util.Vector;
+import java.util.HashMap;
 import java.util.Hashtable;
-import java.io.Serializable;
+import java.util.List;
+import java.util.Locale;
+import java.util.Map;
+import java.util.NoSuchElementException;
 
 import org.xml.sax.AttributeList;
 import org.xml.sax.helpers.AttributeListImpl;
@@ -76,7 +81,7 @@ public class RuntimeConfigurable implements Serializable {
     private String elementTag = null;
     
     /** List of child element wrappers. */
-    private Vector children = new Vector();
+    private List/*<RuntimeConfigurable>*/ children = null;
     
     /** The element to configure. It is only used during
      * maybeConfigure.
@@ -94,14 +99,15 @@ public class RuntimeConfigurable implements Serializable {
      *  exact order. The following code is copied from AttributeImpl.
      *  We could also just use SAX2 Attributes and convert to SAX1 ( DOM
      *  attribute Nodes can also be stored in SAX2 Attributges )
+     *  XXX under JDK 1.4 you can just use a LinkedHashMap for this purpose -jglick
      */
-    private Vector attributeNames = new Vector();
+    private List/*<String>*/ attributeNames = null;
     
     /** Map of attribute names to values */
-    private Hashtable attributeMap = new Hashtable();
+    private Map/*<String,String>*/ attributeMap = null;
 
     /** Text appearing within the element. */
-    private StringBuffer characters = new StringBuffer();
+    private StringBuffer characters = null;
     
     /** Indicates if the wrapped object has been configured */
     private boolean proxyConfigured = false;
@@ -164,7 +170,11 @@ public class RuntimeConfigurable implements Serializable {
      * @param value the attribute's value.
      */
     public void setAttribute(String name, String value) {
-        attributeNames.addElement(name);
+        if (attributeNames == null) {
+            attributeNames = new ArrayList();
+            attributeMap = new HashMap();
+        }
+        attributeNames.add(name);
         attributeMap.put(name, value);
     }
 
@@ -173,7 +183,12 @@ public class RuntimeConfigurable implements Serializable {
      * @return Attribute name to attribute value map
      */
     public Hashtable getAttributeMap() {
-        return attributeMap;
+        // Nobody calls this method, maybe it could just be deleted?
+        if (attributeMap != null) {
+            return new Hashtable(attributeMap);
+        } else {
+            return new Hashtable(1);
+        }
     }
 
     /**
@@ -194,7 +209,10 @@ public class RuntimeConfigurable implements Serializable {
      *              Must not be <code>null</code>.
      */
     public void addChild(RuntimeConfigurable child) {
-        children.addElement(child);
+        if (children == null) {
+            children = new ArrayList();
+        }
+        children.add(child);
     }
 
     /**
@@ -206,7 +224,7 @@ public class RuntimeConfigurable implements Serializable {
      *         list.
      */
     RuntimeConfigurable getChild(int index) {
-        return (RuntimeConfigurable) children.elementAt(index);
+        return (RuntimeConfigurable) children.get(index);
     }
 
     /**
@@ -215,7 +233,21 @@ public class RuntimeConfigurable implements Serializable {
      * @since Ant 1.5.1
      */
     Enumeration getChildren() {
-        return children.elements();
+        if (children != null) {
+            return Collections.enumeration(children);
+        } else {
+            return new EmptyEnumeration();
+        }
+    }
+    
+    static final class EmptyEnumeration implements Enumeration {
+        public EmptyEnumeration() {}
+        public boolean hasMoreElements() {
+            return false;
+        }
+        public Object nextElement() throws NoSuchElementException {
+            throw new NoSuchElementException();
+        }
     }
 
     /**
@@ -225,7 +257,14 @@ public class RuntimeConfigurable implements Serializable {
      *        Should not be <code>null</code>.
      */
     public void addText(String data) {
-        characters.append(data);
+        if (data.length() == 0) {
+            return;
+        }
+        if (characters != null) {
+            characters.append(data);
+        } else {
+            characters = new StringBuffer(data);
+        }
     }
 
     /**
@@ -238,7 +277,13 @@ public class RuntimeConfigurable implements Serializable {
      *
      */
     public void addText(char[] buf, int start, int count) {
-        addText(new String(buf, start, count));
+        if (count == 0) {
+            return;
+        }
+        if (characters == null) {
+            characters = new StringBuffer(count);
+        }
+        characters.append(buf, start, count);
     }
 
     /** Get the text content of this element. Various text chunks are
@@ -248,7 +293,11 @@ public class RuntimeConfigurable implements Serializable {
      * @return the text content of this element.
      */
     public StringBuffer getText() {
-        return characters;
+        if (characters != null) {
+            return characters;
+        } else {
+            return new StringBuffer(0);
+        }
     }
 
     /**
@@ -317,8 +366,9 @@ public class RuntimeConfigurable implements Serializable {
         IntrospectionHelper ih =
             IntrospectionHelper.getHelper(p, target.getClass());
 
+        if (attributeNames != null) {
         for (int i = 0; i < attributeNames.size(); i++) {
-            String name = (String) attributeNames.elementAt(i);
+            String name = (String) attributeNames.get(i);
             String value = (String) attributeMap.get(name);
 
             // reflect these into the target
@@ -334,12 +384,13 @@ public class RuntimeConfigurable implements Serializable {
             }
         }
         id = (String) attributeMap.get("id");
+        }
 
-        if (characters.length() != 0) {
+        if (characters != null) {
             ProjectHelper.addText(p, wrappedObject, characters.substring(0));
         }
 
-        Enumeration enum = children.elements();
+        Enumeration enum = getChildren();
         while (enum.hasMoreElements()) {
             RuntimeConfigurable child
                     = (RuntimeConfigurable) enum.nextElement();

src/main/org/apache/tools/ant/Target.java

@@ -1,7 +1,7 @@
 /*
  * The Apache Software License, Version 1.1
  *
- * Copyright (c) 2000-2002 The Apache Software Foundation.  All rights
+ * Copyright (c) 2000-2003 The Apache Software Foundation.  All rights
  * reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -54,9 +54,12 @@
 
 package org.apache.tools.ant;
 
+import java.util.ArrayList;
+import java.util.Collections;
 import java.util.Enumeration;
+import java.util.Iterator;
+import java.util.List;
 import java.util.StringTokenizer;
-import java.util.Vector;
 
 /**
  * Class to implement a target object with required parameters.
@@ -72,9 +75,9 @@ public class Target implements TaskContainer {
     /** The "unless" condition to test on execution. */
     private String unlessCondition = "";
     /** List of targets this target is dependent on. */
-    private Vector dependencies = new Vector(2);
+    private List/*<String>*/ dependencies = null;
     /** Children of this target (tasks and data types). */
-    private Vector children = new Vector(5);
+    private List/*<Task|RuntimeConfigurable>*/ children = new ArrayList(5);
     /** Project this target belongs to. */
     private Project project;
     /** Description of this target, if any. */
@@ -166,7 +169,7 @@ public class Target implements TaskContainer {
      * @param task The task to be added. Must not be <code>null</code>.
      */
     public void addTask(Task task) {
-        children.addElement(task);
+        children.add(task);
     }
 
     /**
@@ -176,7 +179,7 @@ public class Target implements TaskContainer {
      *          Must not be <code>null</code>.
      */
     public void addDataType(RuntimeConfigurable r) {
-        children.addElement(r);
+        children.add(r);
     }
 
     /** 
@@ -185,18 +188,16 @@ public class Target implements TaskContainer {
      * @return an array of the tasks currently within this target
      */
     public Task[] getTasks() {
-        Vector tasks = new Vector(children.size());
-        Enumeration enum = children.elements();
-        while (enum.hasMoreElements()) {
-            Object o = enum.nextElement();
+        List tasks = new ArrayList(children.size());
+        Iterator it = children.iterator();
+        while (it.hasNext()) {
+            Object o = it.next();
             if (o instanceof Task) {
-                tasks.addElement(o);
+                tasks.add(o);
             }
         }
         
-        Task[] retval = new Task[tasks.size()];
-        tasks.copyInto(retval);
-        return retval;
+        return (Task[])tasks.toArray(new Task[tasks.size()]);
     }
 
     /**
@@ -206,7 +207,10 @@ public class Target implements TaskContainer {
      *                   Must not be <code>null</code>.
      */
     public void addDependency(String dependency) {
-        dependencies.addElement(dependency);
+        if (dependencies == null) {
+            dependencies = new ArrayList(2);
+        }
+        dependencies.add(dependency);
     }
 
     /**
@@ -215,7 +219,11 @@ public class Target implements TaskContainer {
      * @return an enumeration of the dependencies of this target
      */
     public Enumeration getDependencies() {
-        return dependencies.elements();
+        if (dependencies != null) {
+            return Collections.enumeration(dependencies);
+        } else {
+            return new RuntimeConfigurable.EmptyEnumeration();
+        }
     }
 
     /**
@@ -301,9 +309,9 @@ public class Target implements TaskContainer {
      */
     public void execute() throws BuildException {
         if (testIfCondition() && testUnlessCondition()) {
-            Enumeration enum = children.elements();
-            while (enum.hasMoreElements()) {
-                Object o = enum.nextElement();
+            Iterator it = children.iterator();
+            while (it.hasNext()) {
+                Object o = it.next();
                 if (o instanceof Task) {
                     Task task = (Task) o;
                     task.perform();
@@ -352,7 +360,7 @@ public class Target implements TaskContainer {
     void replaceChild(Task el, RuntimeConfigurable o) {
         int index;
         while ((index = children.indexOf(el)) >= 0) {
-            children.setElementAt(o, index);
+            children.set(index, o);
         }
     }
 
@@ -367,7 +375,7 @@ public class Target implements TaskContainer {
     void replaceChild(Task el, Task o) {
         int index;
         while ((index = children.indexOf(el)) >= 0) {
-            children.setElementAt(o, index);
+            children.set(index, o);
         }
     }
 

src/main/org/apache/tools/ant/UnknownElement.java

@@ -54,8 +54,10 @@
 
 package org.apache.tools.ant;
 
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.List;
 import java.util.Locale;
-import java.util.Vector;
 import java.io.IOException;
 
 /**
@@ -87,7 +89,7 @@ public class UnknownElement extends Task {
     /**
      * List of child elements (UnknownElements).
      */
-    private Vector children = new Vector();
+    private List/*<UnknownElement>*/ children = null;
 
     /**
      * Creates an UnknownElement for the given element name.
@@ -281,7 +283,10 @@ public class UnknownElement extends Task {
      * @param child The child element to add. Must not be <code>null</code>.
      */
     public void addChild(UnknownElement child) {
-        children.addElement(child);
+        if (children == null) {
+            children = new ArrayList();
+        }
+        children.add(child);
     }
 
     /**
@@ -307,9 +312,11 @@ public class UnknownElement extends Task {
         Class parentClass = parent.getClass();
         IntrospectionHelper ih = IntrospectionHelper.getHelper(parentClass);
 
-        for (int i = 0;  i < children.size(); i++) {
+        if (children != null) {
+        Iterator it = children.iterator();
+        for (int i = 0; it.hasNext(); i++) {
             RuntimeConfigurable childWrapper = parentWrapper.getChild(i);
-            UnknownElement child = (UnknownElement) children.elementAt(i);
+            UnknownElement child = (UnknownElement) it.next();
             
             // backwards compatibility - element names of nested
             // elements have been all lower-case in Ant, except for
@@ -327,6 +334,7 @@ public class UnknownElement extends Task {
                 }
             }
         }
+        }
     }
 
     /**