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 */
25package org.slf4j.profiler;
26
27import java.text.DecimalFormat;
28
29/**
30 *
31 * A collection of utility methods.
32 *
33 * @author Ceki Gülcü
34 *
35 */
36class 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}
115