/* -*- 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) 1997-1999 * the Initial Developer. All Rights Reserved. * * Contributor(s): * Igor Bukanov, igor@fastmail.fm * * 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.io.IOException; import java.io.InputStream; import java.io.Reader; import java.lang.reflect.Method; import java.util.Map; /** * Collection of utilities */ public class Kit { /** * Reflection of Throwable.initCause(Throwable) from JDK 1.4 * or nul if it is not available. */ private static Method Throwable_initCause = null; static { // Are we running on a JDK 1.4 or later system? try { Class ThrowableClass = Kit.classOrNull("java.lang.Throwable"); Class[] signature = { ThrowableClass }; Throwable_initCause = ThrowableClass.getMethod("initCause", signature); } catch (Exception ex) { // Assume any exceptions means the method does not exist. } } public static Class classOrNull(String className) { try { return Class.forName(className); } catch (ClassNotFoundException ex) { } catch (SecurityException ex) { } catch (LinkageError ex) { } catch (IllegalArgumentException e) { // Can be thrown if name has characters that a class name // can not contain } return null; } /** * Attempt to load the class of the given name. Note that the type parameter * isn't checked. */ public static Class classOrNull(ClassLoader loader, String className) { try { return loader.loadClass(className); } catch (ClassNotFoundException ex) { } catch (SecurityException ex) { } catch (LinkageError ex) { } catch (IllegalArgumentException e) { // Can be thrown if name has characters that a class name // can not contain } return null; } static Object newInstanceOrNull(Class cl) { try { return cl.newInstance(); } catch (SecurityException x) { } catch (LinkageError ex) { } catch (InstantiationException x) { } catch (IllegalAccessException x) { } return null; } /** * Check that testClass is accessible from the given loader. */ static boolean testIfCanLoadRhinoClasses(ClassLoader loader) { Class testClass = ScriptRuntime.ContextFactoryClass; Class x = Kit.classOrNull(loader, testClass.getName()); if (x != testClass) { // The check covers the case when x == null => // loader does not know about testClass or the case // when x != null && x != testClass => // loader loads a class unrelated to testClass return false; } return true; } /** * If initCause methods exists in Throwable, call * ex.initCause(cause) or otherwise do nothing. * @return The ex argument. */ public static RuntimeException initCause(RuntimeException ex, Throwable cause) { if (Throwable_initCause != null) { Object[] args = { cause }; try { Throwable_initCause.invoke(ex, args); } catch (Exception e) { // Ignore any exceptions } } return ex; } /** * If character c is a hexadecimal digit, return * accumulator * 16 plus corresponding * number. Otherise return -1. */ public static int xDigitToInt(int c, int accumulator) { check: { // Use 0..9 < A..Z < a..z if (c <= '9') { c -= '0'; if (0 <= c) { break check; } } else if (c <= 'F') { if ('A' <= c) { c -= ('A' - 10); break check; } } else if (c <= 'f') { if ('a' <= c) { c -= ('a' - 10); break check; } } return -1; } return (accumulator << 4) | c; } /** * Add listener to bag of listeners. * The function does not modify bag and return a new collection * containing listener and all listeners from bag. * Bag without listeners always represented as the null value. *

* Usage example: *

     *     private volatile Object changeListeners;
     *
     *     public void addMyListener(PropertyChangeListener l)
     *     {
     *         synchronized (this) {
     *             changeListeners = Kit.addListener(changeListeners, l);
     *         }
     *     }
     *
     *     public void removeTextListener(PropertyChangeListener l)
     *     {
     *         synchronized (this) {
     *             changeListeners = Kit.removeListener(changeListeners, l);
     *         }
     *     }
     *
     *     public void fireChangeEvent(Object oldValue, Object newValue)
     *     {
     *     // Get immune local copy
     *         Object listeners = changeListeners;
     *         if (listeners != null) {
     *             PropertyChangeEvent e = new PropertyChangeEvent(
     *                 this, "someProperty" oldValue, newValue);
     *             for (int i = 0; ; ++i) {
     *                 Object l = Kit.getListener(listeners, i);
     *                 if (l == null)
     *                     break;
     *                 ((PropertyChangeListener)l).propertyChange(e);
     *             }
     *         }
     *     }
     * 
* * @param listener Listener to add to bag * @param bag Current collection of listeners. * @return A new bag containing all listeners from bag and * listener. * @see #removeListener(Object bag, Object listener) * @see #getListener(Object bag, int index) */ public static Object addListener(Object bag, Object listener) { if (listener == null) throw new IllegalArgumentException(); if (listener instanceof Object[]) throw new IllegalArgumentException(); if (bag == null) { bag = listener; } else if (!(bag instanceof Object[])) { bag = new Object[] { bag, listener }; } else { Object[] array = (Object[])bag; int L = array.length; // bag has at least 2 elements if it is array if (L < 2) throw new IllegalArgumentException(); Object[] tmp = new Object[L + 1]; System.arraycopy(array, 0, tmp, 0, L); tmp[L] = listener; bag = tmp; } return bag; } /** * Remove listener from bag of listeners. * The function does not modify bag and return a new collection * containing all listeners from bag except listener. * If bag does not contain listener, the function returns * bag. *

* For usage example, see {@link #addListener(Object bag, Object listener)}. * * @param listener Listener to remove from bag * @param bag Current collection of listeners. * @return A new bag containing all listeners from bag except * listener. * @see #addListener(Object bag, Object listener) * @see #getListener(Object bag, int index) */ public static Object removeListener(Object bag, Object listener) { if (listener == null) throw new IllegalArgumentException(); if (listener instanceof Object[]) throw new IllegalArgumentException(); if (bag == listener) { bag = null; } else if (bag instanceof Object[]) { Object[] array = (Object[])bag; int L = array.length; // bag has at least 2 elements if it is array if (L < 2) throw new IllegalArgumentException(); if (L == 2) { if (array[1] == listener) { bag = array[0]; } else if (array[0] == listener) { bag = array[1]; } } else { int i = L; do { --i; if (array[i] == listener) { Object[] tmp = new Object[L - 1]; System.arraycopy(array, 0, tmp, 0, i); System.arraycopy(array, i + 1, tmp, i, L - (i + 1)); bag = tmp; break; } } while (i != 0); } } return bag; } /** * Get listener at index position in bag or null if * index equals to number of listeners in bag. *

* For usage example, see {@link #addListener(Object bag, Object listener)}. * * @param bag Current collection of listeners. * @param index Index of the listener to access. * @return Listener at the given index or null. * @see #addListener(Object bag, Object listener) * @see #removeListener(Object bag, Object listener) */ public static Object getListener(Object bag, int index) { if (index == 0) { if (bag == null) return null; if (!(bag instanceof Object[])) return bag; Object[] array = (Object[])bag; // bag has at least 2 elements if it is array if (array.length < 2) throw new IllegalArgumentException(); return array[0]; } else if (index == 1) { if (!(bag instanceof Object[])) { if (bag == null) throw new IllegalArgumentException(); return null; } Object[] array = (Object[])bag; // the array access will check for index on its own return array[1]; } else { // bag has to array Object[] array = (Object[])bag; int L = array.length; if (L < 2) throw new IllegalArgumentException(); if (index == L) return null; return array[index]; } } static Object initHash(Map h, Object key, Object initialValue) { synchronized (h) { Object current = h.get(key); if (current == null) { h.put(key, initialValue); } else { initialValue = current; } } return initialValue; } private final static class ComplexKey { private Object key1; private Object key2; private int hash; ComplexKey(Object key1, Object key2) { this.key1 = key1; this.key2 = key2; } @Override public boolean equals(Object anotherObj) { if (!(anotherObj instanceof ComplexKey)) return false; ComplexKey another = (ComplexKey)anotherObj; return key1.equals(another.key1) && key2.equals(another.key2); } @Override public int hashCode() { if (hash == 0) { hash = key1.hashCode() ^ key2.hashCode(); } return hash; } } public static Object makeHashKeyFromPair(Object key1, Object key2) { if (key1 == null) throw new IllegalArgumentException(); if (key2 == null) throw new IllegalArgumentException(); return new ComplexKey(key1, key2); } public static String readReader(Reader r) throws IOException { char[] buffer = new char[512]; int cursor = 0; for (;;) { int n = r.read(buffer, cursor, buffer.length - cursor); if (n < 0) { break; } cursor += n; if (cursor == buffer.length) { char[] tmp = new char[buffer.length * 2]; System.arraycopy(buffer, 0, tmp, 0, cursor); buffer = tmp; } } return new String(buffer, 0, cursor); } public static byte[] readStream(InputStream is, int initialBufferCapacity) throws IOException { if (initialBufferCapacity <= 0) { throw new IllegalArgumentException( "Bad initialBufferCapacity: "+initialBufferCapacity); } byte[] buffer = new byte[initialBufferCapacity]; int cursor = 0; for (;;) { int n = is.read(buffer, cursor, buffer.length - cursor); if (n < 0) { break; } cursor += n; if (cursor == buffer.length) { byte[] tmp = new byte[buffer.length * 2]; System.arraycopy(buffer, 0, tmp, 0, cursor); buffer = tmp; } } if (cursor != buffer.length) { byte[] tmp = new byte[cursor]; System.arraycopy(buffer, 0, tmp, 0, cursor); buffer = tmp; } return buffer; } /** * Throws RuntimeException to indicate failed assertion. * The function never returns and its return type is RuntimeException * only to be able to write throw Kit.codeBug() if plain * Kit.codeBug() triggers unreachable code error. */ public static RuntimeException codeBug() throws RuntimeException { RuntimeException ex = new IllegalStateException("FAILED ASSERTION"); // Print stack trace ASAP ex.printStackTrace(System.err); throw ex; } }