/*
* Copyright 2009 Red Hat, Inc.
*
* Red Hat 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.jboss.netty.util.internal;
import java.util.ArrayList;
import java.util.List;
import java.util.regex.Pattern;
import org.jboss.netty.util.DebugUtil;
import org.jboss.netty.util.ThreadRenamingRunnable;
/**
* Simplifies an exception stack trace by removing unnecessary
* {@link StackTraceElement}s. Please note that the stack trace simplification
* is disabled if {@linkplain DebugUtil debug mode} is turned on.
*
* @author <a href="http://www.jboss.org/netty/">The Netty Project</a>
* @author <a href="http://gleamynode.net/">Trustin Lee</a>
*
* @version $Rev: 2080 $, $Date: 2010-01-26 18:04:19 +0900 (Tue, 26 Jan 2010) $
*
*/
public class StackTraceSimplifier {
private static final boolean SIMPLIFY_STACK_TRACE = !DebugUtil.isDebugEnabled();
private static final Pattern EXCLUDED_STACK_TRACE =
Pattern.compile(
"^org\\.jboss\\.netty\\." +
"(util\\.(ThreadRenamingRunnable|internal\\.DeadLockProofWorker)" +
"|channel\\.(SimpleChannel(Upstream|Downstream)?Handler|(Default|Static)ChannelPipeline.*))(\\$.*)?$");
/**
* Removes unnecessary {@link StackTraceElement}s from the specified
* exception. {@link ThreadRenamingRunnable}, {@link SimpleChannelHandler},
* {@link DefaultChannelPipeline}, and {@link StaticChannelPipeline}
* will be dropped from the trace.
*/
public static void simplify(Throwable e) {
if (!SIMPLIFY_STACK_TRACE) {
return;
}
if (e.getCause() != null) {
simplify(e.getCause());
}
StackTraceElement[] trace = e.getStackTrace();
if (trace == null || trace.length == 0) {
return;
}
// Perhaps Netty bug. Let us not strip things out.
if (EXCLUDED_STACK_TRACE.matcher(trace[0].getClassName()).matches()) {
return;
}
List<StackTraceElement> simpleTrace =
new ArrayList<StackTraceElement>(trace.length);
simpleTrace.add(trace[0]);
// Remove unnecessary stack trace elements.
for (int i = 1; i < trace.length; i ++) {
if (EXCLUDED_STACK_TRACE.matcher(trace[i].getClassName()).matches()) {
continue;
}
simpleTrace.add(trace[i]);
}
e.setStackTrace(
simpleTrace.toArray(new StackTraceElement[simpleTrace.size()]));
}
}