/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF 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.apache.tomcat.util.log;
import org.apache.juli.logging.Log;
/**
* This helper class assists with the logging associated with invalid input
* data. A developer may want all instances of invalid input data logged to
* assist with debugging whereas in production it is likely to be desirable not
* to log anything for invalid data. The following settings may be used:
* <ul>
* <li>NOTHING: Log nothing.</li>
* <li>DEBUG_ALL: Log all problems at DEBUG log level.</li>
* <li>INFO_THEN_DEBUG: Log first problem at INFO log level and any further
* issues in the following TBD (configurable) seconds at DEBUG level</li>
* <li>INFO_ALL: Log all problems at INFO log level.</li>
* </ul>
* By default, INFO_THEN_DEBUG is used with a suppression time of 24 hours.
*
* NOTE: This class is not completely thread-safe. When using INFO_THEN_DEBUG it
* is possible that several INFO messages will be logged before dropping to
* DEBUG.
*/
public class UserDataHelper {
private final Log log;
private final Config config;
// A value of 0 is equivalent to using INFO_ALL
// A negative value will trigger infinite suppression
// The value is milliseconds
private final long suppressionTime;
private volatile long lastInfoTime = 0;
public UserDataHelper(Log log) {
this.log = log;
Config tempConfig;
String configString = System.getProperty(
"org.apache.juli.logging.UserDataHelper.CONFIG");
if (configString ==
null) {
tempConfig = Config.INFO_THEN_DEBUG;
}
else {
try {
tempConfig = Config.valueOf(configString);
}
catch (IllegalArgumentException iae) {
// Ignore - use default
tempConfig = Config.INFO_THEN_DEBUG;
}
}
// Default suppression time of 1 day.
suppressionTime = Integer.getInteger(
"org.apache.juli.logging.UserDataHelper.SUPPRESSION_TIME",
60 * 60 * 24).intValue() * 1000L;
if (suppressionTime == 0) {
tempConfig = Config.INFO_ALL;
}
config = tempConfig;
}
/**
* Returns log mode for the next log message, or <code>null</code> if the
* message should not be logged.
*
* <p>
* If <code>INFO_THEN_DEBUG</code> configuration option is enabled, this
* method might change internal state of this object.
*
* @return Log mode, or <code>null</code>
*/
public Mode getNextMode() {
if (Config.NONE == config) {
return null;
}
else if (Config.DEBUG_ALL == config) {
return log.isDebugEnabled() ? Mode.DEBUG :
null;
}
else if (Config.INFO_THEN_DEBUG == config) {
if (logAtInfo()) {
return log.isInfoEnabled() ? Mode.INFO_THEN_DEBUG :
null;
}
else {
return log.isDebugEnabled() ? Mode.DEBUG :
null;
}
}
else if (Config.INFO_ALL == config) {
return log.isInfoEnabled() ? Mode.INFO :
null;
}
// Should never happen
return null;
}
/*
* Not completely thread-safe but good enough for this use case. I couldn't
* see a simple enough way to make it completely thread-safe that was not
* likely to compromise performance.
*/
private boolean logAtInfo() {
if (suppressionTime < 0 && lastInfoTime > 0) {
return false;
}
long now = System.currentTimeMillis();
if (lastInfoTime + suppressionTime > now) {
return false;
}
lastInfoTime = now;
return true;
}
private enum Config {
NONE,
DEBUG_ALL,
INFO_THEN_DEBUG,
INFO_ALL
}
/**
* Log mode for the next log message.
*/
public enum Mode {
DEBUG,
INFO_THEN_DEBUG,
INFO
}
}
