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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  import java.text.DecimalFormat;
    28
    29  /**
    30   *
    31   * A collection of utility methods.
    32   *
    33   * @author Ceki G&uuml;lc&uuml;
    34   *
    35   */
    36  class Util {
    37
    38      static final long NANOS_IN_ONE_MICROSECOND = 1000;
    39      static final long NANOS_IN_ONE_MILLISECOND = NANOS_IN_ONE_MICROSECOND * 1000;
    40      static final long NANOS_IN_ONE_SECOND = NANOS_IN_ONE_MILLISECOND * 1000;
    41      private static final DecimalFormat DECIMAL_FORMAT = new DecimalFormat("0.000");
    42
    43      static DurationUnit selectDurationUnitForDisplay(StopWatch sw) {
    44          return selectDurationUnitForDisplay(sw.elapsedTime());
    45      }
    46
    47      static DurationUnit selectDurationUnitForDisplay(long durationInNanos) {
    48          if (durationInNanos < 10 * NANOS_IN_ONE_MICROSECOND) {
    49              return DurationUnit.NANOSECOND;
    50          } else if (durationInNanos < 10 * NANOS_IN_ONE_MILLISECOND) {
    51              return DurationUnit.MICROSECOND;
    52          } else if (durationInNanos < 10 * NANOS_IN_ONE_SECOND) {
    53              return DurationUnit.MILLISSECOND;
    54          } else {
    55              return DurationUnit.SECOND;
    56          }
    57      }
    58
    59      static public double convertToMicros(long nanos) {
    60          return (double) nanos / NANOS_IN_ONE_MICROSECOND;
    61      }
    62
    63      static public double convertToMillis(long nanos) {
    64          return (double) nanos / NANOS_IN_ONE_MILLISECOND;
    65      }
    66
    67      static public double convertToSeconds(long nanos) {
    68          return ((double) nanos / NANOS_IN_ONE_SECOND);
    69      }
    70
    71      static String durationInDurationUnitsAsStr(StringBuilder buf, StopWatch sw) {
    72          DurationUnit du = selectDurationUnitForDisplay(sw);
    73          return durationInDurationUnitsAsStr(sw.elapsedTime(), du);
    74      }
    75
    76      static String durationInDurationUnitsAsStr(long nanos, DurationUnit durationUnit) {
    77          StringBuilder buf = new StringBuilder();
    78          switch (durationUnit) {
    79          case NANOSECOND:
    80              buf.append(nanos);
    81              break;
    82          case MICROSECOND:
    83              double micros = convertToMicros(nanos);
    84              buf.append(DECIMAL_FORMAT.format(micros));
    85              break;
    86          case MILLISSECOND:
    87              double millis = convertToMillis(nanos);
    88              buf.append(DECIMAL_FORMAT.format(millis));
    89              break;
    90          case SECOND:
    91              double seconds = convertToSeconds(nanos);
    92              buf.append(DECIMAL_FORMAT.format(seconds));
    93              break;
    94          }
    95          return buf.toString();
    96      }
    97
    98      static void appendDurationUnitAsStr(StringBuilder buf, DurationUnit durationUnit) {
    99          switch (durationUnit) {
    100         case NANOSECOND:
    101             buf.append("nanoseconds.");
    102             break;
    103         case MICROSECOND:
    104             buf.append("microseconds.");
    105             break;
    106         case MILLISSECOND:
    107             buf.append("milliseconds.");
    108             break;
    109         case SECOND:
    110             buf.append(" seconds.");
    111             break;
    112         }
    113     }
    114 }