content: /*
   * Copyright (c) 2012, 2016, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.  Oracle designates this
   * particular file as subject to the "Classpath" exception as provided
   * by Oracle in the LICENSE file that accompanied this code.
   *
   * This code is distributed in the hope that it will be useful, but WITHOUT
   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
   * version 2 for more details (a copy is included in the LICENSE file that
   * accompanied this code).
   *
   * You should have received a copy of the GNU General Public License version
   * 2 along with this work; if not, write to the Free Software Foundation,
   * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
   * or visit www.oracle.com if you need additional information or have any
   * questions.
   */
  
  package openjdk.tools.sjavac;
  
  import java.io.PrintWriter;
  import java.io.StringWriter;
  import java.io.Writer;
  import java.util.Locale;
  
  /**
   * Utility class only for sjavac logging.
   *
   * Logging in sjavac has special requirements when running in server/client
   * mode. Most of the log messages is generated server-side, but the server
   * is typically spawned by the client in the background, so the user usually
   * does not see the server stdout/stderr. For this reason log messages needs
   * to relayed back to the client that performed the request that generated the
   * log message. To support this use case this class maintains a per-thread log
   * instance so that each connected client can have its own instance that
   * relays messages back to the requesting client.
   *
   * On the client-side (or when running sjavac without server-mode) there will
   * typically just be one Log instance.
   *
   *  <p><b>This is NOT part of any supported API.
   *  If you write code that depends on this, you do so at your own risk.
   *  This code and its internal interfaces are subject to change or
   *  deletion without notice.</b>
   */
  public class Log {
  
      public enum Level {
          ERROR,
          WARN,
          INFO,
          DEBUG,
          TRACE;
      }
  
      private static Log stdOutErr = new Log(new PrintWriter(System.out), new PrintWriter(System.err));
      private static ThreadLocal<Log> loggers = new ThreadLocal<>();
  
      protected PrintWriter err; // Used for error and warning messages
      protected PrintWriter out; // Used for other messages
      protected Level level = Level.INFO;
  
      public Log(Writer out, Writer err) {
          this.out = out == null ? null : new PrintWriter(out, true);
          this.err = err == null ? null : new PrintWriter(err, true);
      }
  
      public static void setLogForCurrentThread(Log log) {
          loggers.set(log);
      }
  
      public static void setLogLevel(String l) {
          setLogLevel(Level.valueOf(l.toUpperCase(Locale.US)));
      }
  
      public static void setLogLevel(Level l) {
          get().level = l;
      }
  
      static public void trace(String msg) {
          log(Level.TRACE, msg);
      }
  
      static public void debug(String msg) {
          log(Level.DEBUG, msg);
      }
  
      static public void info(String msg) {
          log(Level.INFO, msg);
      }
  
      static public void warn(String msg) {
          log(Level.WARN, msg);
      }
  
      static public void error(String msg) {
          log(Level.ERROR, msg);
      }
  
      static public void error(Throwable t) {
          log(Level.ERROR, t);
      }
  
      static public void log(Level l, String msg) {
          get().printLogMsg(l, msg);
      }
  
      public static void debug(Throwable t) {
          log(Level.DEBUG, t);
      }
  
      public static void log(Level l, Throwable t) {
          StringWriter sw = new StringWriter();
          t.printStackTrace(new PrintWriter(sw, true));
          log(l, sw.toString());
      }
  
      static public boolean isDebugging() {
          return get().isLevelLogged(Level.DEBUG);
      }
  
      protected boolean isLevelLogged(Level l) {
          return l.ordinal() <= level.ordinal();
      }
  
      public static Log get() {
          Log log = loggers.get();
          return log != null ? log : stdOutErr;
      }
  
      protected void printLogMsg(Level msgLevel, String msg) {
          if (isLevelLogged(msgLevel)) {
              PrintWriter pw = msgLevel.ordinal() <= Level.WARN.ordinal() ? err : out;
              pw.println(msg);
          }
      }
  }
  