001: /*
002: * Copyright (c) 2002-2008 Gargoyle Software Inc. All rights reserved.
003: *
004: * Redistribution and use in source and binary forms, with or without
005: * modification, are permitted provided that the following conditions are met:
006: *
007: * 1. Redistributions of source code must retain the above copyright notice,
008: * this list of conditions and the following disclaimer.
009: * 2. Redistributions in binary form must reproduce the above copyright notice,
010: * this list of conditions and the following disclaimer in the documentation
011: * and/or other materials provided with the distribution.
012: * 3. The end-user documentation included with the redistribution, if any, must
013: * include the following acknowledgment:
014: *
015: * "This product includes software developed by Gargoyle Software Inc.
016: * (http://www.GargoyleSoftware.com/)."
017: *
018: * Alternately, this acknowledgment may appear in the software itself, if
019: * and wherever such third-party acknowledgments normally appear.
020: * 4. The name "Gargoyle Software" must not be used to endorse or promote
021: * products derived from this software without prior written permission.
022: * For written permission, please contact info@GargoyleSoftware.com.
023: * 5. Products derived from this software may not be called "HtmlUnit", nor may
024: * "HtmlUnit" appear in their name, without prior written permission of
025: * Gargoyle Software Inc.
026: *
027: * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES,
028: * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
029: * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL GARGOYLE
030: * SOFTWARE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
031: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
032: * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
033: * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
034: * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
035: * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
036: * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
037: */
038: package com.gargoylesoftware.htmlunit.javascript;
039:
040: import org.apache.commons.logging.Log;
041: import org.mozilla.javascript.Callable;
042: import org.mozilla.javascript.Context;
043: import org.mozilla.javascript.ContextFactory;
044: import org.mozilla.javascript.ScriptRuntime;
045: import org.mozilla.javascript.Scriptable;
046:
047: import com.gargoylesoftware.htmlunit.Assert;
048: import com.gargoylesoftware.htmlunit.javascript.regexp.HtmlUnitRegExpProxy;
049:
050: /**
051: * ContextFactory that supports termination of scripts if they exceed a timeout. Based on example from
052: * <a href="http://www.mozilla.org/rhino/apidocs/org/mozilla/javascript/ContextFactory.html">ContextFactory</a>.
053: *
054: * @version $Revision: 2132 $
055: * @author Andre Soereng
056: */
057: public class HtmlUnitContextFactory extends ContextFactory {
058:
059: private final Log log_;
060: private static final int INSTRUCTION_COUNT_THRESHOLD = 10000;
061: private static long Timeout_ = 0;
062: private static boolean DebuggerEnabled_;
063:
064: /**
065: * Create a new instance of HtmlUnitContextFactory
066: *
067: * @param log the log that the error reporter should use
068: */
069: public HtmlUnitContextFactory(final Log log) {
070: Assert.notNull("log", log);
071: log_ = log;
072: }
073:
074: /**
075: * Set the number of milliseconds a script is allowed to execute before
076: * being terminated. A value of 0 or less means no timeout.
077: *
078: * @param timeout the timeout value
079: */
080: public static void setTimeout(final long timeout) {
081: Timeout_ = timeout;
082: }
083:
084: /**
085: * Returns the number of milliseconds a script is allowed to execute before
086: * being terminated. A value of 0 or less means no timeout.
087: *
088: * @return the timeout value. Default value is 0.
089: */
090: public static long getTimeout() {
091: return Timeout_;
092: }
093:
094: /**
095: * Enables or disables the debugger, which logs stack entries and exceptions. Enabling the
096: * debugger may be useful if HtmlUnit is having trouble with JavaScript, especially if you are
097: * using some of the more advanced libraries like Dojo, Prototype or jQuery.
098: *
099: * @param enabled whether or not the debugger should be enabled
100: * @see DebuggerImpl
101: * @see DebugFrameImpl
102: */
103: public static void setDebuggerEnabled(final boolean enabled) {
104: DebuggerEnabled_ = enabled;
105: }
106:
107: /**
108: * Returns <tt>true</tt> if the debugger is enabled, <tt>false</tt> otherwise.
109: *
110: * @return <tt>true</tt> if the debugger is enabled, <tt>false</tt> otherwise
111: * @see DebuggerImpl
112: * @see DebugFrameImpl
113: */
114: public static boolean getDebuggerEnabled() {
115: return DebuggerEnabled_;
116: }
117:
118: // Custom Context to store execution time.
119: private static class TimeoutContext extends Context {
120: private long startTime_;
121:
122: public void startClock() {
123: startTime_ = System.currentTimeMillis();
124: }
125:
126: public void terminateScriptIfNecessary() {
127: if (Timeout_ > 0) {
128: final long currentTime = System.currentTimeMillis();
129: if (currentTime - startTime_ > Timeout_) {
130: // Terminate script by throwing an Error instance to ensure that the
131: // script will never get control back through catch or finally.
132: throw new TimeoutError(Timeout_, currentTime
133: - startTime_);
134: }
135: }
136: }
137: }
138:
139: /**
140: * {@inheritDoc}
141: */
142: protected Context makeContext() {
143: final TimeoutContext cx = new TimeoutContext();
144:
145: // Use pure interpreter mode to get observeInstructionCount() callbacks.
146: cx.setOptimizationLevel(-1);
147:
148: // Set threshold on how often we want to receive the callbacks
149: cx.setInstructionObserverThreshold(INSTRUCTION_COUNT_THRESHOLD);
150:
151: cx.setErrorReporter(new StrictErrorReporter(log_));
152: cx.setWrapFactory(new HtmlUnitWrapFactory());
153:
154: if (DebuggerEnabled_) {
155: cx.setDebugger(new DebuggerImpl(), null);
156: }
157:
158: // register custom RegExp processing
159: ScriptRuntime.setRegExpProxy(cx, new HtmlUnitRegExpProxy(
160: ScriptRuntime.getRegExpProxy(cx)));
161:
162: return cx;
163: }
164:
165: /**
166: * Run-time calls this when instruction counting is enabled and the counter
167: * reaches limit set by setInstructionObserverThreshold(). A script can be
168: * terminated by throwing an Error instance here.
169: *
170: * @param cx the context calling us
171: * @param instructionCount amount of script instruction executed since last call to observeInstructionCount
172: */
173: protected void observeInstructionCount(final Context cx,
174: final int instructionCount) {
175: final TimeoutContext tcx = (TimeoutContext) cx;
176: tcx.terminateScriptIfNecessary();
177: }
178:
179: /**
180: * {@inheritDoc}
181: */
182: protected Object doTopCall(final Callable callable,
183: final Context cx, final Scriptable scope,
184: final Scriptable this Obj, final Object[] args) {
185:
186: final TimeoutContext tcx = (TimeoutContext) cx;
187: tcx.startClock();
188: return super .doTopCall(callable, cx, scope, this Obj, args);
189: }
190:
191: /**
192: * {@inheritDoc}
193: */
194: protected boolean hasFeature(final Context cx,
195: final int featureIndex) {
196: if (Context.FEATURE_RESERVED_KEYWORD_AS_IDENTIFIER == featureIndex) {
197: return true;
198: } else {
199: return super.hasFeature(cx, featureIndex);
200: }
201: }
202: }
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