Duration.java
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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 org.apache.cassandra.cql3.functions.types;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import com.google.common.base.Objects;
import static com.google.common.base.Preconditions.checkArgument;
/**
* Represents a duration. A duration stores separately months, days, and seconds due to the fact
* that the number of days in a month varies, and a day can have 23 or 25 hours if a daylight saving
* is involved.
*/
public final class Duration
{
private static final long NANOS_PER_MICRO = 1000L;
private static final long NANOS_PER_MILLI = 1000 * NANOS_PER_MICRO;
private static final long NANOS_PER_SECOND = 1000 * NANOS_PER_MILLI;
private static final long NANOS_PER_MINUTE = 60 * NANOS_PER_SECOND;
private static final long NANOS_PER_HOUR = 60 * NANOS_PER_MINUTE;
private static final int DAYS_PER_WEEK = 7;
private static final int MONTHS_PER_YEAR = 12;
/**
* The Regexp used to parse the duration provided as String.
*/
private static final Pattern STANDARD_PATTERN =
Pattern.compile(
"\\G(\\d+)(y|Y|mo|MO|mO|Mo|w|W|d|D|h|H|s|S|ms|MS|mS|Ms|us|US|uS|Us|µs|µS|ns|NS|nS|Ns|m|M)");
/**
* The Regexp used to parse the duration when provided in the ISO 8601 format with designators.
*/
private static final Pattern ISO8601_PATTERN =
Pattern.compile("P((\\d+)Y)?((\\d+)M)?((\\d+)D)?(T((\\d+)H)?((\\d+)M)?((\\d+)S)?)?");
/**
* The Regexp used to parse the duration when provided in the ISO 8601 format with designators.
*/
private static final Pattern ISO8601_WEEK_PATTERN = Pattern.compile("P(\\d+)W");
/**
* The Regexp used to parse the duration when provided in the ISO 8601 alternative format.
*/
private static final Pattern ISO8601_ALTERNATIVE_PATTERN =
Pattern.compile("P(\\d{4})-(\\d{2})-(\\d{2})T(\\d{2}):(\\d{2}):(\\d{2})");
/**
* The number of months.
*/
private final int months;
/**
* The number of days.
*/
private final int days;
/**
* The number of nanoseconds.
*/
private final long nanoseconds;
private Duration(int months, int days, long nanoseconds)
{
// Makes sure that all the values are negative if one of them is
if ((months < 0 || days < 0 || nanoseconds < 0)
&& ((months > 0 || days > 0 || nanoseconds > 0)))
{
throw new IllegalArgumentException(
String.format(
"All values must be either negative or positive, got %d months, %d days, %d nanoseconds",
months, days, nanoseconds));
}
this.months = months;
this.days = days;
this.nanoseconds = nanoseconds;
}
/**
* Creates a duration with the given number of months, days and nanoseconds.
*
* <p>A duration can be negative. In this case, all the non zero values must be negative.
*
* @param months the number of months
* @param days the number of days
* @param nanoseconds the number of nanoseconds
* @throws IllegalArgumentException if the values are not all negative or all positive
*/
public static Duration newInstance(int months, int days, long nanoseconds)
{
return new Duration(months, days, nanoseconds);
}
/**
* Converts a <code>String</code> into a duration.
*
* <p>The accepted formats are:
*
* <ul>
* <li>multiple digits followed by a time unit like: 12h30m where the time unit can be:
* <ul>
* <li>{@code y}: years
* <li>{@code m}: months
* <li>{@code w}: weeks
* <li>{@code d}: days
* <li>{@code h}: hours
* <li>{@code m}: minutes
* <li>{@code s}: seconds
* <li>{@code ms}: milliseconds
* <li>{@code us} or {@code µs}: microseconds
* <li>{@code ns}: nanoseconds
* </ul>
* <li>ISO 8601 format: P[n]Y[n]M[n]DT[n]H[n]M[n]S or P[n]W
* <li>ISO 8601 alternative format: P[YYYY]-[MM]-[DD]T[hh]:[mm]:[ss]
* </ul>
*
* @param input the <code>String</code> to convert
* @return a {@link Duration}
*/
public static Duration from(String input)
{
boolean isNegative = input.startsWith("-");
String source = isNegative ? input.substring(1) : input;
if (source.startsWith("P"))
{
if (source.endsWith("W")) return parseIso8601WeekFormat(isNegative, source);
if (source.contains("-")) return parseIso8601AlternativeFormat(isNegative, source);
return parseIso8601Format(isNegative, source);
}
return parseStandardFormat(isNegative, source);
}
private static Duration parseIso8601Format(boolean isNegative, String source)
{
Matcher matcher = ISO8601_PATTERN.matcher(source);
if (!matcher.matches())
throw new IllegalArgumentException(
String.format("Unable to convert '%s' to a duration", source));
Builder builder = new Builder(isNegative);
if (matcher.group(1) != null) builder.addYears(groupAsLong(matcher, 2));
if (matcher.group(3) != null) builder.addMonths(groupAsLong(matcher, 4));
if (matcher.group(5) != null) builder.addDays(groupAsLong(matcher, 6));
// Checks if the String contains time information
if (matcher.group(7) != null)
{
if (matcher.group(8) != null) builder.addHours(groupAsLong(matcher, 9));
if (matcher.group(10) != null) builder.addMinutes(groupAsLong(matcher, 11));
if (matcher.group(12) != null) builder.addSeconds(groupAsLong(matcher, 13));
}
return builder.build();
}
private static Duration parseIso8601AlternativeFormat(boolean isNegative, String source)
{
Matcher matcher = ISO8601_ALTERNATIVE_PATTERN.matcher(source);
if (!matcher.matches())
throw new IllegalArgumentException(
String.format("Unable to convert '%s' to a duration", source));
return new Builder(isNegative)
.addYears(groupAsLong(matcher, 1))
.addMonths(groupAsLong(matcher, 2))
.addDays(groupAsLong(matcher, 3))
.addHours(groupAsLong(matcher, 4))
.addMinutes(groupAsLong(matcher, 5))
.addSeconds(groupAsLong(matcher, 6))
.build();
}
private static Duration parseIso8601WeekFormat(boolean isNegative, String source)
{
Matcher matcher = ISO8601_WEEK_PATTERN.matcher(source);
if (!matcher.matches())
throw new IllegalArgumentException(
String.format("Unable to convert '%s' to a duration", source));
return new Builder(isNegative).addWeeks(groupAsLong(matcher, 1)).build();
}
private static Duration parseStandardFormat(boolean isNegative, String source)
{
Matcher matcher = STANDARD_PATTERN.matcher(source);
if (!matcher.find())
throw new IllegalArgumentException(
String.format("Unable to convert '%s' to a duration", source));
Builder builder = new Builder(isNegative);
boolean done;
do
{
long number = groupAsLong(matcher, 1);
String symbol = matcher.group(2);
add(builder, number, symbol);
done = matcher.end() == source.length();
} while (matcher.find());
if (!done)
throw new IllegalArgumentException(
String.format("Unable to convert '%s' to a duration", source));
return builder.build();
}
private static long groupAsLong(Matcher matcher, int group)
{
return Long.parseLong(matcher.group(group));
}
private static Builder add(Builder builder, long number, String symbol)
{
String s = symbol.toLowerCase();
if (s.equals("y"))
{
return builder.addYears(number);
}
else if (s.equals("mo"))
{
return builder.addMonths(number);
}
else if (s.equals("w"))
{
return builder.addWeeks(number);
}
else if (s.equals("d"))
{
return builder.addDays(number);
}
else if (s.equals("h"))
{
return builder.addHours(number);
}
else if (s.equals("m"))
{
return builder.addMinutes(number);
}
else if (s.equals("s"))
{
return builder.addSeconds(number);
}
else if (s.equals("ms"))
{
return builder.addMillis(number);
}
else if (s.equals("us") || s.equals("µs"))
{
return builder.addMicros(number);
}
else if (s.equals("ns"))
{
return builder.addNanos(number);
}
throw new IllegalArgumentException(String.format("Unknown duration symbol '%s'", symbol));
}
/**
* Appends the result of the division to the specified builder if the dividend is not zero.
*
* @param builder the builder to append to
* @param dividend the dividend
* @param divisor the divisor
* @param unit the time unit to append after the result of the division
* @return the remainder of the division
*/
private static long append(StringBuilder builder, long dividend, long divisor, String unit)
{
if (dividend == 0 || dividend < divisor) return dividend;
builder.append(dividend / divisor).append(unit);
return dividend % divisor;
}
/**
* Returns the number of months in this duration.
*
* @return the number of months in this duration.
*/
public int getMonths()
{
return months;
}
/**
* Returns the number of days in this duration.
*
* @return the number of days in this duration.
*/
public int getDays()
{
return days;
}
/**
* Returns the number of nanoseconds in this duration.
*
* @return the number of months in this duration.
*/
public long getNanoseconds()
{
return nanoseconds;
}
@Override
public int hashCode()
{
return Objects.hashCode(days, months, nanoseconds);
}
@Override
public boolean equals(Object obj)
{
if (!(obj instanceof Duration)) return false;
Duration other = (Duration) obj;
return days == other.days && months == other.months && nanoseconds == other.nanoseconds;
}
@Override
public String toString()
{
StringBuilder builder = new StringBuilder();
if (months < 0 || days < 0 || nanoseconds < 0) builder.append('-');
long remainder = append(builder, Math.abs(months), MONTHS_PER_YEAR, "y");
append(builder, remainder, 1, "mo");
append(builder, Math.abs(days), 1, "d");
if (nanoseconds != 0)
{
remainder = append(builder, Math.abs(nanoseconds), NANOS_PER_HOUR, "h");
remainder = append(builder, remainder, NANOS_PER_MINUTE, "m");
remainder = append(builder, remainder, NANOS_PER_SECOND, "s");
remainder = append(builder, remainder, NANOS_PER_MILLI, "ms");
remainder = append(builder, remainder, NANOS_PER_MICRO, "us");
append(builder, remainder, 1, "ns");
}
return builder.toString();
}
private static class Builder
{
/**
* {@code true} if the duration is a negative one, {@code false} otherwise.
*/
private final boolean isNegative;
/**
* The number of months.
*/
private int months;
/**
* The number of days.
*/
private int days;
/**
* The number of nanoseconds.
*/
private long nanoseconds;
/**
* We need to make sure that the values for each units are provided in order.
*/
private int currentUnitIndex;
public Builder(boolean isNegative)
{
this.isNegative = isNegative;
}
/**
* Adds the specified amount of years.
*
* @param numberOfYears the number of years to add.
* @return this {@code Builder}
*/
public Builder addYears(long numberOfYears)
{
validateOrder(1);
validateMonths(numberOfYears, MONTHS_PER_YEAR);
months += numberOfYears * MONTHS_PER_YEAR;
return this;
}
/**
* Adds the specified amount of months.
*
* @param numberOfMonths the number of months to add.
* @return this {@code Builder}
*/
public Builder addMonths(long numberOfMonths)
{
validateOrder(2);
validateMonths(numberOfMonths, 1);
months += numberOfMonths;
return this;
}
/**
* Adds the specified amount of weeks.
*
* @param numberOfWeeks the number of weeks to add.
* @return this {@code Builder}
*/
public Builder addWeeks(long numberOfWeeks)
{
validateOrder(3);
validateDays(numberOfWeeks, DAYS_PER_WEEK);
days += numberOfWeeks * DAYS_PER_WEEK;
return this;
}
/**
* Adds the specified amount of days.
*
* @param numberOfDays the number of days to add.
* @return this {@code Builder}
*/
public Builder addDays(long numberOfDays)
{
validateOrder(4);
validateDays(numberOfDays, 1);
days += numberOfDays;
return this;
}
/**
* Adds the specified amount of hours.
*
* @param numberOfHours the number of hours to add.
* @return this {@code Builder}
*/
public Builder addHours(long numberOfHours)
{
validateOrder(5);
validateNanos(numberOfHours, NANOS_PER_HOUR);
nanoseconds += numberOfHours * NANOS_PER_HOUR;
return this;
}
/**
* Adds the specified amount of minutes.
*
* @param numberOfMinutes the number of minutes to add.
* @return this {@code Builder}
*/
public Builder addMinutes(long numberOfMinutes)
{
validateOrder(6);
validateNanos(numberOfMinutes, NANOS_PER_MINUTE);
nanoseconds += numberOfMinutes * NANOS_PER_MINUTE;
return this;
}
/**
* Adds the specified amount of seconds.
*
* @param numberOfSeconds the number of seconds to add.
* @return this {@code Builder}
*/
public Builder addSeconds(long numberOfSeconds)
{
validateOrder(7);
validateNanos(numberOfSeconds, NANOS_PER_SECOND);
nanoseconds += numberOfSeconds * NANOS_PER_SECOND;
return this;
}
/**
* Adds the specified amount of milliseconds.
*
* @param numberOfMillis the number of milliseconds to add.
* @return this {@code Builder}
*/
public Builder addMillis(long numberOfMillis)
{
validateOrder(8);
validateNanos(numberOfMillis, NANOS_PER_MILLI);
nanoseconds += numberOfMillis * NANOS_PER_MILLI;
return this;
}
/**
* Adds the specified amount of microseconds.
*
* @param numberOfMicros the number of microseconds to add.
* @return this {@code Builder}
*/
public Builder addMicros(long numberOfMicros)
{
validateOrder(9);
validateNanos(numberOfMicros, NANOS_PER_MICRO);
nanoseconds += numberOfMicros * NANOS_PER_MICRO;
return this;
}
/**
* Adds the specified amount of nanoseconds.
*
* @param numberOfNanos the number of nanoseconds to add.
* @return this {@code Builder}
*/
public Builder addNanos(long numberOfNanos)
{
validateOrder(10);
validateNanos(numberOfNanos, 1);
nanoseconds += numberOfNanos;
return this;
}
/**
* Validates that the total number of months can be stored.
*
* @param units the number of units that need to be added
* @param monthsPerUnit the number of days per unit
*/
private void validateMonths(long units, int monthsPerUnit)
{
validate(units, (Integer.MAX_VALUE - months) / monthsPerUnit, "months");
}
/**
* Validates that the total number of days can be stored.
*
* @param units the number of units that need to be added
* @param daysPerUnit the number of days per unit
*/
private void validateDays(long units, int daysPerUnit)
{
validate(units, (Integer.MAX_VALUE - days) / daysPerUnit, "days");
}
/**
* Validates that the total number of nanoseconds can be stored.
*
* @param units the number of units that need to be added
* @param nanosPerUnit the number of nanoseconds per unit
*/
private void validateNanos(long units, long nanosPerUnit)
{
validate(units, (Long.MAX_VALUE - nanoseconds) / nanosPerUnit, "nanoseconds");
}
/**
* Validates that the specified amount is less than the limit.
*
* @param units the number of units to check
* @param limit the limit on the number of units
* @param unitName the unit name
*/
private void validate(long units, long limit, String unitName)
{
checkArgument(
units <= limit,
"Invalid duration. The total number of %s must be less or equal to %s",
unitName,
Integer.MAX_VALUE);
}
/**
* Validates that the duration values are added in the proper order.
*
* @param unitIndex the unit index (e.g. years=1, months=2, ...)
*/
private void validateOrder(int unitIndex)
{
if (unitIndex == currentUnitIndex)
throw new IllegalArgumentException(
String.format(
"Invalid duration. The %s are specified multiple times", getUnitName(unitIndex)));
if (unitIndex <= currentUnitIndex)
throw new IllegalArgumentException(
String.format(
"Invalid duration. The %s should be after %s",
getUnitName(currentUnitIndex), getUnitName(unitIndex)));
currentUnitIndex = unitIndex;
}
/**
* Returns the name of the unit corresponding to the specified index.
*
* @param unitIndex the unit index
* @return the name of the unit corresponding to the specified index.
*/
private String getUnitName(int unitIndex)
{
switch (unitIndex)
{
case 1:
return "years";
case 2:
return "months";
case 3:
return "weeks";
case 4:
return "days";
case 5:
return "hours";
case 6:
return "minutes";
case 7:
return "seconds";
case 8:
return "milliseconds";
case 9:
return "microseconds";
case 10:
return "nanoseconds";
default:
throw new AssertionError("unknown unit index: " + unitIndex);
}
}
public Duration build()
{
return isNegative
? new Duration(-months, -days, -nanoseconds)
: new Duration(months, days, nanoseconds);
}
}
}