001package votorola.g.logging; // Copyright 2007, Michael Allan.  Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Votorola Software"), to deal in the Votorola Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicence, and/or sell copies of the Votorola Software, and to permit persons to whom the Votorola Software is furnished to do so, subject to the following conditions: The preceding copyright notice and this permission notice shall be included in all copies or substantial portions of the Votorola Software. THE VOTOROLA SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE VOTOROLA SOFTWARE OR THE USE OR OTHER DEALINGS IN THE VOTOROLA SOFTWARE.
002
003import java.util.logging.*;
004import votorola.g.lang.*;
005
006
007/** A level switch to prevent repeat messages in a loop.
008  * If reusing the switch, be sure to query it on every pass
009  * so that null throwables will clear the repeat memory.
010  */
011public final @ThreadRestricted class LevelSwitchR
012{
013
014
015 // /** Clears the state of this switch.
016 //   */
017 // public void clear() { throwableLast = null; }
018
019
020
021    /** Returns the switched logging level for the specified throwable.
022      * ThrowableX.{@linkplain ThrowableX#isSimilar(Throwable,Throwable) isSimilar}
023      * is used for comparing throwables.
024      *
025      *     @return Level.ALL if the throwable is a repeat; otherwise baseLevel
026      */
027    public Level level( final Throwable throwable, final Level baseLevel )
028    {
029        final Level level;
030        if( ThrowableX.isSimilar( throwable, throwableLast )) level = Level.ALL;
031        else level = baseLevel;
032
033        throwableLast = throwable;
034        return level;
035    }
036
037
038
039//// P r i v a t e ///////////////////////////////////////////////////////////////////////
040
041
042    private Throwable throwableLast;
043
044
045
046}