1 /*
   2  * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package jdk.jfr.internal;
  27 
  28 import java.util.function.Supplier;
  29 
  30 /**
  31  * JFR logger
  32  *
  33  */
  34 
  35 public final class Logger {
  36 
  37     private final static int MAX_SIZE = 10000;
  38     static {
  39         // This will try to initialize the JVM logging system
  40         JVMSupport.tryToInitializeJVM();
  41     }
  42 
  43 
  44     public static void log(LogTag logTag, LogLevel logLevel, String message) {
  45         if (shouldLog(logTag, logLevel)) {
  46             logInternal(logTag, logLevel, message);
  47         }
  48     }
  49 
  50     public static void log(LogTag logTag, LogLevel logLevel, Supplier<String> messageSupplier) {
  51         if (shouldLog(logTag, logLevel)) {
  52             logInternal(logTag, logLevel, messageSupplier.get());
  53         }
  54     }
  55 
  56     private static void logInternal(LogTag logTag, LogLevel logLevel, String message) {
  57         if (message == null || message.length() < MAX_SIZE) {
  58             JVM.log(logTag.id, logLevel.level, message);
  59         } else {
  60             JVM.log(logTag.id, logLevel.level, message.substring(0, MAX_SIZE));
  61         }
  62     }
  63 
  64     public static boolean shouldLog(LogTag tag, LogLevel level) {
  65         // Logging level is not initialized because of lack of Xlog support in jdk8,
  66         // so this method returns true directly now.
  67         return true; // TODO: level.level >= tag.tagSetLevel;
  68     }
  69 }