com.proofpoint.units.Duration.java Source code

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Here is the source code for com.proofpoint.units.Duration.java

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/*
 * Copyright 2010 Proofpoint, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.proofpoint.units;

import com.fasterxml.jackson.annotation.JsonCreator;
import com.fasterxml.jackson.annotation.JsonValue;
import com.google.common.base.Preconditions;
import com.google.common.primitives.Doubles;

import java.util.Locale;
import java.util.concurrent.TimeUnit;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import static java.util.concurrent.TimeUnit.DAYS;
import static java.util.concurrent.TimeUnit.HOURS;
import static java.util.concurrent.TimeUnit.MICROSECONDS;
import static java.util.concurrent.TimeUnit.MILLISECONDS;
import static java.util.concurrent.TimeUnit.MINUTES;
import static java.util.concurrent.TimeUnit.NANOSECONDS;
import static java.util.concurrent.TimeUnit.SECONDS;

public final class Duration implements Comparable<Duration> {
    private static final Pattern PATTERN = Pattern.compile("^\\s*(\\d+(?:\\.\\d+)?)\\s*([a-zA-Z]+)\\s*$");

    public static Duration nanosSince(long start) {
        long end = System.nanoTime();

        long value = end - start;
        double millis = value * millisPerTimeUnit(NANOSECONDS);
        return new Duration(millis, MILLISECONDS).convertToMostSuccinctTimeUnit();
    }

    private final double value;
    private final TimeUnit unit;

    public Duration(double value, TimeUnit unit) {
        Preconditions.checkArgument(!Double.isInfinite(value), "value is infinite");
        Preconditions.checkArgument(!Double.isNaN(value), "value is not a number");
        Preconditions.checkArgument(value >= 0, "value is negative");
        Preconditions.checkNotNull(unit, "unit is null");

        this.value = value;
        this.unit = unit;
    }

    public long toMillis() {
        return roundTo(MILLISECONDS);
    }

    public double getValue() {
        return value;
    }

    public TimeUnit getUnit() {
        return unit;
    }

    public double getValue(TimeUnit timeUnit) {
        Preconditions.checkNotNull(timeUnit, "timeUnit is null");
        return value * (millisPerTimeUnit(this.unit) * 1.0 / millisPerTimeUnit(timeUnit));
    }

    public long roundTo(TimeUnit timeUnit) {
        Preconditions.checkNotNull(timeUnit, "timeUnit is null");
        double rounded = Math.floor(getValue(timeUnit) + 0.5d);
        Preconditions.checkArgument(rounded <= Long.MAX_VALUE,
                "size is too large to be represented in requested unit as a long");
        return (long) rounded;
    }

    public Duration convertToMostSuccinctTimeUnit() {
        TimeUnit unitToUse = NANOSECONDS;
        for (TimeUnit unitToTest : TimeUnit.values()) {
            // since time units are powers of ten, we can get rounding errors here, so fuzzy match
            if (getValue(unitToTest) > 0.9999) {
                unitToUse = unitToTest;
            } else {
                break;
            }
        }
        return new Duration(getValue(unitToUse), unitToUse);
    }

    @JsonValue
    @Override
    public String toString() {
        return toString(unit);
    }

    public String toString(TimeUnit timeUnit) {
        Preconditions.checkNotNull(timeUnit, "timeUnit is null");
        double magnitude = getValue(timeUnit);
        String timeUnitAbbreviation = timeUnitToString(timeUnit);
        return String.format(Locale.ENGLISH, "%.2f%s", magnitude, timeUnitAbbreviation);
    }

    @JsonCreator
    public static Duration valueOf(String duration) throws IllegalArgumentException {
        Preconditions.checkNotNull(duration, "duration is null");
        Preconditions.checkArgument(!duration.isEmpty(), "duration is empty");

        Matcher matcher = PATTERN.matcher(duration);
        if (!matcher.matches()) {
            throw new IllegalArgumentException("duration is not a valid data duration string: " + duration);
        }

        double value = Double.parseDouble(matcher.group(1));
        String unitString = matcher.group(2);

        TimeUnit timeUnit = valueOfTimeUnit(unitString);
        return new Duration(value, timeUnit);
    }

    @Override
    public int compareTo(Duration o) {
        return Double.compare(getValue(MILLISECONDS), o.getValue(MILLISECONDS));
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) {
            return true;
        }
        if (o == null || getClass() != o.getClass()) {
            return false;
        }

        Duration duration = (Duration) o;

        return compareTo(duration) == 0;
    }

    @Override
    public int hashCode() {
        double value = getValue(MILLISECONDS);
        return Doubles.hashCode(value);
    }

    public static TimeUnit valueOfTimeUnit(String timeUnitString) {
        Preconditions.checkNotNull(timeUnitString, "timeUnitString is null");
        switch (timeUnitString) {
        case "ns":
            return NANOSECONDS;
        case "us":
            return MICROSECONDS;
        case "ms":
            return MILLISECONDS;
        case "s":
            return SECONDS;
        case "m":
            return MINUTES;
        case "h":
            return HOURS;
        case "d":
            return DAYS;
        default:
            throw new IllegalArgumentException("Unknown time unit: " + timeUnitString);
        }
    }

    public static String timeUnitToString(TimeUnit timeUnit) {
        Preconditions.checkNotNull(timeUnit, "timeUnit is null");
        switch (timeUnit) {
        case NANOSECONDS:
            return "ns";
        case MICROSECONDS:
            return "us";
        case MILLISECONDS:
            return "ms";
        case SECONDS:
            return "s";
        case MINUTES:
            return "m";
        case HOURS:
            return "h";
        case DAYS:
            return "d";
        default:
            throw new IllegalArgumentException("Unsupported time unit " + timeUnit);
        }
    }

    private static double millisPerTimeUnit(TimeUnit timeUnit) {
        switch (timeUnit) {
        case NANOSECONDS:
            return 1.0 / 1000000.0;
        case MICROSECONDS:
            return 1.0 / 1000.0;
        case MILLISECONDS:
            return 1;
        case SECONDS:
            return 1000;
        case MINUTES:
            return 1000 * 60;
        case HOURS:
            return 1000 * 60 * 60;
        case DAYS:
            return 1000 * 60 * 60 * 24;
        default:
            throw new IllegalArgumentException("Unsupported time unit " + timeUnit);
        }
    }
}