org.eclipse.linuxtools.lttng2.control.ui/src/org/eclipse/linuxtools/internal/lttng2/control/ui/views/logging/ControlCommandLogger.java

   1 /**********************************************************************
   2  * Copyright (c) 2012, 2013 Ericsson
   3  *
   4  * All rights reserved. This program and the accompanying materials are
   5  * made available under the terms of the Eclipse Public License v1.0 which
   6  * accompanies this distribution, and is available at
   7  * http://www.eclipse.org/legal/epl-v10.html
   8  *
   9  * Contributors:
  10  *   Bernd Hufmann - Initial API and implementation
  11  **********************************************************************/
  12 package org.eclipse.linuxtools.internal.lttng2.control.ui.views.logging;
  13
  14 import java.io.BufferedWriter;
  15 import java.io.FileWriter;
  16 import java.io.IOException;
  17
  18 import org.eclipse.linuxtools.internal.lttng2.control.ui.Activator;
  19
  20 /**
  21  * <p>
  22  * Class to log control commands.
  23  * </p>
  24  *
  25  * @author Bernd Hufmann
  26  */
  27 final public class ControlCommandLogger {
  28
  29     // ------------------------------------------------------------------------
  30     // Attributes
  31     // ------------------------------------------------------------------------
  32     /**
  33      * The bufferd writer reference
  34      */
  35     private static BufferedWriter fTraceLog = null;
  36
  37     // ------------------------------------------------------------------------
  38     // Constructor
  39     // ------------------------------------------------------------------------
  40     private ControlCommandLogger() {
  41     }
  42
  43     // ------------------------------------------------------------------------
  44     // Operations
  45     // ------------------------------------------------------------------------
  46     /**
  47      * Initializes the logger class and opens the log file with the given parameter.
  48      * @param filename - file name of logger output
  49      * @param append - true to open log file in append mode else false (overwrite)
  50      */
  51     public static void init(String filename, boolean append) {
  52         if (fTraceLog != null) {
  53             close();
  54         }
  55         fTraceLog = openLogFile(filename, append);
  56     }
  57
  58     /**
  59      * Closes the log file if open.
  60      */
  61     public static void close() {
  62         if (fTraceLog == null) {
  63             return;
  64         }
  65
  66         try {
  67             fTraceLog.close();
  68             fTraceLog = null;
  69         } catch (IOException e) {
  70             Activator.getDefault().logWarning("Can't close log file of the trace control", e); //$NON-NLS-1$
  71         }
  72     }
  73
  74     /**
  75      * Logs a message to the log file.
  76      * @param msg - message (e.g. command or command result) to log
  77      */
  78     @SuppressWarnings("nls")
  79     public static void log(String msg) {
  80         long currentTime = System.currentTimeMillis();
  81         StringBuilder message = new StringBuilder("[");
  82         message.append(currentTime / 1000);
  83         message.append(".");
  84         message.append(String.format("%1$03d", currentTime % 1000));
  85         message.append("] ");
  86         message.append(msg);
  87         if (fTraceLog != null) {
  88             try {
  89                 fTraceLog.write(message.toString());
  90                 fTraceLog.newLine();
  91                 fTraceLog.flush();
  92             } catch (IOException e) {
  93                 Activator.getDefault().logError("Can't log message in log file of the tracer control", e); //$NON-NLS-1$
  94             }
  95         }
  96     }
  97
  98     // ------------------------------------------------------------------------
  99     // Helper methods
 100     // ------------------------------------------------------------------------
 101     /**
 102      * Opens the trace log file with given name in the workspace root directory
 103      * @param filename - file name of logger output
 104      * @param append - true to open log file in append mode else false (overwrite)
 105      * @return the buffer writer class or null if not successful
 106      */
 107     private static BufferedWriter openLogFile(String filename, boolean append) {
 108         BufferedWriter outfile = null;
 109         try {
 110             outfile = new BufferedWriter(new FileWriter(filename, append));
 111         } catch (IOException e) {
 112             Activator.getDefault().logError("Can't open log file for logging of tracer control commands: " + filename, e); //$NON-NLS-1$
 113         }
 114         return outfile;
 115     }
 116 }
 117