1 files changed, 136 insertions, 0 deletions
diff --git a/trunk/infrastructure/rhino1_7R1/src/org/mozilla/javascript/LazilyLoadedCtor.java b/trunk/infrastructure/rhino1_7R1/src/org/mozilla/javascript/LazilyLoadedCtor.java
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@@ -0,0 +1,136 @@
+/* -*- Mode: java; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ *
+ * ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (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.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is Rhino code, released
+ * May 6, 1999.
+ *
+ * The Initial Developer of the Original Code is
+ * Netscape Communications Corporation.
+ * Portions created by the Initial Developer are Copyright (C) 1997-2000
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *   Norris Boyd
+ *   Igor Bukanov
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * the GNU General Public License Version 2 or later (the "GPL"), in which
+ * case the provisions of the GPL are applicable instead of those above. If
+ * you wish to allow use of your version of this file only under the terms of
+ * the GPL and not to allow others to use your version of this file under the
+ * MPL, indicate your decision by deleting the provisions above and replacing
+ * them with the notice and other provisions required by the GPL. If you do
+ * not delete the provisions above, a recipient may use your version of this
+ * file under either the MPL or the GPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+package org.mozilla.javascript;
+
+import java.lang.reflect.*;
+
+/**
+ * Avoid loading classes unless they are used.
+ *
+ * <p> This improves startup time and average memory usage.
+ */
+public final class LazilyLoadedCtor implements java.io.Serializable {
+	private static final long serialVersionUID = 1L;
+	
+    private static final int STATE_BEFORE_INIT = 0;
+    private static final int STATE_INITIALIZING = 1;
+    private static final int STATE_WITH_VALUE = 2;
+
+    private final ScriptableObject scope;
+    private final String propertyName;
+    private final String className;
+    private final boolean sealed;
+    private Object initializedValue;
+    private int state;
+
+    public LazilyLoadedCtor(ScriptableObject scope, String propertyName,
+                            String className, boolean sealed)
+    {
+
+        this.scope = scope;
+        this.propertyName = propertyName;
+        this.className = className;
+        this.sealed = sealed;
+        this.state = STATE_BEFORE_INIT;
+
+        scope.addLazilyInitializedValue(propertyName, 0, this,
+                                        ScriptableObject.DONTENUM);
+    }
+
+    void init()
+    {
+        synchronized (this) {
+            if (state == STATE_INITIALIZING)
+                throw new IllegalStateException(
+                    "Recursive initialization for "+propertyName);
+            if (state == STATE_BEFORE_INIT) {
+                state = STATE_INITIALIZING;
+                // Set value now to have something to set in finally block if
+                // buildValue throws.
+                Object value = Scriptable.NOT_FOUND;
+                try {
+                    value = buildValue();
+                } finally {
+                    initializedValue = value;
+                    state = STATE_WITH_VALUE;
+                }
+            }
+        }
+    }
+
+    Object getValue()
+    {
+        if (state != STATE_WITH_VALUE)
+            throw new IllegalStateException(propertyName);
+        return initializedValue;
+    }
+
+    private Object buildValue()
+    {
+        Class cl = Kit.classOrNull(className);
+        if (cl != null) {
+            try {
+                Object value = ScriptableObject.buildClassCtor(scope, cl,
+                                                               sealed, false);
+                if (value != null) {
+                    return value;
+                }
+                else {
+                    // cl has own static initializer which is expected
+                    // to set the property on its own.
+                    value = scope.get(propertyName, scope);
+                    if (value != Scriptable.NOT_FOUND)
+                        return value;
+                }
+            } catch (InvocationTargetException ex) {
+                Throwable target = ex.getTargetException();
+                if (target instanceof RuntimeException) {
+                    throw (RuntimeException)target;
+                }
+            } catch (RhinoException ex) {
+            } catch (InstantiationException ex) {
+            } catch (IllegalAccessException ex) {
+            } catch (SecurityException ex) {
+            }
+        }
+        return Scriptable.NOT_FOUND;
+    }
+
+}