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    1   /**
    2    * Copyright (c) 2004-2011 QOS.ch
    3    * All rights reserved.
    4    *
    5    * Permission is hereby granted, free  of charge, to any person obtaining
    6    * a  copy  of this  software  and  associated  documentation files  (the
    7    * "Software"), to  deal in  the Software without  restriction, including
    8    * without limitation  the rights to  use, copy, modify,  merge, publish,
    9    * distribute,  sublicense, and/or sell  copies of  the Software,  and to
    10   * permit persons to whom the Software  is furnished to do so, subject to
    11   * the following conditions:
    12   *
    13   * The  above  copyright  notice  and  this permission  notice  shall  be
    14   * included in all copies or substantial portions of the Software.
    15   *
    16   * THE  SOFTWARE IS  PROVIDED  "AS  IS", WITHOUT  WARRANTY  OF ANY  KIND,
    17   * EXPRESS OR  IMPLIED, INCLUDING  BUT NOT LIMITED  TO THE  WARRANTIES OF
    18   * MERCHANTABILITY,    FITNESS    FOR    A   PARTICULAR    PURPOSE    AND
    19   * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
    20   * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
    21   * OF CONTRACT, TORT OR OTHERWISE,  ARISING FROM, OUT OF OR IN CONNECTION
    22   * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
    23   *
    24   */
    25  package org.slf4j.profiler;
    26
    27  /**
    28   * A very basic {@link TimeInstrument} which can be started and stopped
    29   * once and only once.
    30   *
    31   * @author Ceki G&uuml;lc&uuml;
    32   *
    33   */
    34  public class StopWatch implements TimeInstrument {
    35
    36      private String name;
    37      private long startTime;
    38      private long stopTime;
    39      TimeInstrumentStatus status;
    40
    41      public StopWatch(String name) {
    42          start(name);
    43      }
    44
    45      StopWatch(StopWatch original) {
    46          this.name = original.name;
    47          this.startTime = original.startTime;
    48          this.stopTime = original.stopTime;
    49          this.status = original.status;
    50      }
    51
    52      public void start(String name) {
    53          this.name = name;
    54          startTime = System.nanoTime();
    55          status = TimeInstrumentStatus.STARTED;
    56      }
    57
    58      public String getName() {
    59          return name;
    60      }
    61
    62      public TimeInstrument stop() {
    63          if (status == TimeInstrumentStatus.STOPPED) {
    64              return this;
    65          }
    66          return stop(System.nanoTime());
    67      }
    68
    69      public StopWatch stop(long stopTime) {
    70          this.status = TimeInstrumentStatus.STOPPED;
    71          this.stopTime = stopTime;
    72          return this;
    73      }
    74
    75      @Override
    76      public String toString() {
    77          StringBuilder buf = new StringBuilder();
    78          buf.append("StopWatch [");
    79          buf.append(name);
    80          buf.append("] ");
    81
    82          switch (status) {
    83          case STARTED:
    84              buf.append("STARTED");
    85              break;
    86          case STOPPED:
    87              buf.append("elapsed time: ");
    88              buf.append(Util.durationInDurationUnitsAsStr(elapsedTime(), DurationUnit.MICROSECOND));
    89              break;
    90          default:
    91              throw new IllegalStateException("Status " + status + " is not expected");
    92          }
    93          return buf.toString();
    94      }
    95
    96      public final long elapsedTime() {
    97          if (status == TimeInstrumentStatus.STARTED) {
    98              return 0;
    99          } else {
    100             return stopTime - startTime;
    101         }
    102     }
    103
    104     public TimeInstrumentStatus getStatus() {
    105         return status;
    106     }
    107
    108     public void print() {
    109         System.out.println(toString());
    110     }
    111
    112     public void log() {
    113         throw new UnsupportedOperationException("A stopwatch instance does not know how to log");
    114     }
    115
    116 }