/**
* Copyright 2008 Google Inc.
*
* Licensed 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.waveprotocol.wave.common.logging;
import org.waveprotocol.wave.common.logging.AbstractLogger.Level;
/**
* Base class for log entry sinks.
*
*/
public abstract class LogSink {
/**
* Outputs a log entry to this sink.
*
* @param level the level to log at
* @param message the message to log
*/
public abstract void log(Level level, String message);
/**
* All implementations of this method which are intended to run in the
* browser must buffer output before writing in order to avoid slowing
* down the UI. For these cases, messages must not be stringified until
* they are to be written.
*
* @param level the level to log at
* @param messages list of messages to (potentially lazily) stringify and
* concatenate
*
* NOTE: This method should not have a default implementation which does
* any stringification, because if a LogSink implementation were to
* neglect to override this method, and were used in the browser, there
* may be significant performance implications.
*/
public abstract void lazyLog(Level level, Object... messages);
/**
* Lazily logs a message and a throwable. This implementation XML-escapes
* the label, and the message from the throwable, and prints the stack trace as
* HTML. Sinks which are not intended to output HTML should override this method.
*
* @param level the level to log at
* @param label a label to log
* @param t the throwable to log
*
* NOTE: This method should not have a default implementation which does
* any stringification, because if a LogSink implementation were to
* neglect to override this method, and were used in the browser, there
* may be significant performance implications.
*/
public void lazyLog(Level level, String label, final Throwable t) {
lazyLog(level, label, ": ", new Object() {
@Override
public String toString() {
return LogUtils.xmlEscape(t.toString()) + "<br/>" + LogUtils.printStackTraceAsHtml(t);
}
});
}
}