| // © 2016 and later: Unicode, Inc. and others. |
| // License & terms of use: http://www.unicode.org/copyright.html#License |
| /* |
| ********************************************************************************* |
| * Copyright (C) 2004-2016, International Business Machines Corporation and * |
| * others. All Rights Reserved. * |
| ********************************************************************************* |
| * |
| */ |
| |
| package com.ibm.icu.util; |
| |
| import com.ibm.icu.math.BigDecimal; |
| |
| /** |
| * There are quite a few different conventions for binary datetime, depending on different |
| * platforms and protocols. Some of these have severe drawbacks. For example, people using |
| * Unix time (seconds since Jan 1, 1970, usually in a 32-bit integer) |
| * think that they are safe until near the year 2038. |
| * But cases can and do arise where arithmetic manipulations causes serious problems. Consider |
| * the computation of the average of two datetimes, for example: if one calculates them with |
| * <code>averageTime = (time1 + time2)/2</code>, there will be overflow even with dates |
| * beginning in 2004. Moreover, even if these problems don't occur, there is the issue of |
| * conversion back and forth between different systems. |
| * |
| * <p>Binary datetimes differ in a number of ways: the datatype, the unit, |
| * and the epoch (origin). We refer to these as time scales. |
| * |
| * <p>ICU implements a universal time scale that is similar to the |
| * .NET framework's System.DateTime. The universal time scale is a |
| * 64-bit integer that holds ticks since midnight, January 1st, 0001. |
| * (One tick is 100 nanoseconds.) |
| * Negative values are supported. This has enough range to guarantee that |
| * calculations involving dates around the present are safe. |
| * |
| * <p>The universal time scale always measures time according to the |
| * proleptic Gregorian calendar. That is, the Gregorian calendar's |
| * leap year rules are used for all times, even before 1582 when it was |
| * introduced. (This is different from the default ICU calendar which |
| * switches from the Julian to the Gregorian calendar in 1582. |
| * See GregorianCalendar.setGregorianChange() and ucal_setGregorianChange().) |
| * |
| * ICU provides conversion functions to and from all other major time |
| * scales, allowing datetimes in any time scale to be converted to the |
| * universal time scale, safely manipulated, and converted back to any other |
| * datetime time scale. |
| * |
| * <p>For more details and background, see the |
| * <a href="http://www.icu-project.org/userguide/universalTimeScale.html">Universal Time Scale</a> |
| * chapter in the ICU User Guide. |
| * |
| * @stable ICU 3.2 |
| */ |
| |
| public final class UniversalTimeScale |
| { |
| /** |
| * Used in the JDK. Data is a <code>long</code>. Value |
| * is milliseconds since January 1, 1970. |
| * |
| * @stable ICU 3.2 |
| */ |
| public static final int JAVA_TIME = 0; |
| |
| /** |
| * Used in Unix systems. Data is an <code>int</code> or a <code>long</code>. Value |
| * is seconds since January 1, 1970. |
| * |
| * @stable ICU 3.2 |
| */ |
| public static final int UNIX_TIME = 1; |
| |
| /** |
| * Used in the ICU4C. Data is a <code>double</code>. Value |
| * is milliseconds since January 1, 1970. |
| * |
| * @stable ICU 3.2 |
| */ |
| public static final int ICU4C_TIME = 2; |
| |
| /** |
| * Used in Windows for file times. Data is a <code>long</code>. Value |
| * is ticks (1 tick == 100 nanoseconds) since January 1, 1601. |
| * |
| * @stable ICU 3.2 |
| */ |
| public static final int WINDOWS_FILE_TIME = 3; |
| |
| /** |
| * Used in the .NET framework's <code>System.DateTime</code> structure. |
| * Data is a <code>long</code>. Value is ticks (1 tick == 100 nanoseconds) since January 1, 0001. |
| * |
| * @stable ICU 3.2 |
| */ |
| public static final int DOTNET_DATE_TIME = 4; |
| |
| /** |
| * Used in older Macintosh systems. Data is an <code>int</code>. Value |
| * is seconds since January 1, 1904. |
| * |
| * @stable ICU 3.2 |
| */ |
| public static final int MAC_OLD_TIME = 5; |
| |
| /** |
| * Used in the JDK. Data is a <code>double</code>. Value |
| * is milliseconds since January 1, 2001. |
| * |
| * @stable ICU 3.2 |
| */ |
| public static final int MAC_TIME = 6; |
| |
| /** |
| * Used in Excel. Data is a <code>?unknown?</code>. Value |
| * is days since December 31, 1899. |
| * |
| * @stable ICU 3.2 |
| */ |
| public static final int EXCEL_TIME = 7; |
| |
| /** |
| * Used in DB2. Data is a <code>?unknown?</code>. Value |
| * is days since December 31, 1899. |
| * |
| * @stable ICU 3.2 |
| */ |
| public static final int DB2_TIME = 8; |
| |
| /** |
| * Data is a <code>long</code>. Value is microseconds since January 1, 1970. |
| * Similar to Unix time (linear value from 1970) and struct timeval |
| * (microseconds resolution). |
| * |
| * @stable ICU 3.8 |
| */ |
| public static final int UNIX_MICROSECONDS_TIME = 9; |
| |
| /** |
| * This is the first unused time scale value. |
| * |
| * @deprecated ICU 59 |
| */ |
| @Deprecated |
| public static final int MAX_SCALE = 10; |
| |
| /** |
| * The constant used to select the units value |
| * for a time scale. |
| * |
| * |
| * @stable ICU 3.2 |
| */ |
| public static final int UNITS_VALUE = 0; |
| |
| /** |
| * The constant used to select the epoch offset value |
| * for a time scale. |
| * |
| * @see #getTimeScaleValue |
| * |
| * @stable ICU 3.2 |
| */ |
| public static final int EPOCH_OFFSET_VALUE = 1; |
| |
| /** |
| * The constant used to select the minimum from value |
| * for a time scale. |
| * |
| * @see #getTimeScaleValue |
| * |
| * @stable ICU 3.2 |
| */ |
| public static final int FROM_MIN_VALUE = 2; |
| |
| /** |
| * The constant used to select the maximum from value |
| * for a time scale. |
| * |
| * @see #getTimeScaleValue |
| * |
| * @stable ICU 3.2 |
| */ |
| public static final int FROM_MAX_VALUE = 3; |
| |
| /** |
| * The constant used to select the minimum to value |
| * for a time scale. |
| * |
| * @see #getTimeScaleValue |
| * |
| * @stable ICU 3.2 |
| */ |
| public static final int TO_MIN_VALUE = 4; |
| |
| /** |
| * The constant used to select the maximum to value |
| * for a time scale. |
| * |
| * @see #getTimeScaleValue |
| * |
| * @stable ICU 3.2 |
| */ |
| public static final int TO_MAX_VALUE = 5; |
| |
| /** |
| * The constant used to select the epoch plus one value |
| * for a time scale. |
| * |
| * NOTE: This is an internal value. DO NOT USE IT. May not |
| * actually be equal to the epoch offset value plus one. |
| * |
| * @see #getTimeScaleValue |
| * |
| * @stable ICU 3.2 |
| */ |
| public static final int EPOCH_OFFSET_PLUS_1_VALUE = 6; |
| |
| /** |
| * The constant used to select the epoch offset minus one value |
| * for a time scale. |
| * |
| * NOTE: This is an internal value. DO NOT USE IT. May not |
| * actually be equal to the epoch offset value minus one. |
| * |
| * @see #getTimeScaleValue |
| * |
| * @internal |
| * @deprecated This API is ICU internal only. |
| */ |
| @Deprecated |
| public static final int EPOCH_OFFSET_MINUS_1_VALUE = 7; |
| |
| /** |
| * The constant used to select the units round value |
| * for a time scale. |
| * |
| * NOTE: This is an internal value. DO NOT USE IT. |
| * |
| * @see #getTimeScaleValue |
| * |
| * @internal |
| * @deprecated This API is ICU internal only. |
| */ |
| @Deprecated |
| public static final int UNITS_ROUND_VALUE = 8; |
| |
| /** |
| * The constant used to select the minimum safe rounding value |
| * for a time scale. |
| * |
| * NOTE: This is an internal value. DO NOT USE IT. |
| * |
| * @see #getTimeScaleValue |
| * |
| * @internal |
| * @deprecated This API is ICU internal only. |
| */ |
| @Deprecated |
| public static final int MIN_ROUND_VALUE = 9; |
| |
| /** |
| * The constant used to select the maximum safe rounding value |
| * for a time scale. |
| * |
| * NOTE: This is an internal value. DO NOT USE IT. |
| * |
| * @see #getTimeScaleValue |
| * |
| * @internal |
| * @deprecated This API is ICU internal only. |
| */ |
| @Deprecated |
| public static final int MAX_ROUND_VALUE = 10; |
| |
| /** |
| * The number of time scale values. |
| * |
| * NOTE: This is an internal value. DO NOT USE IT. |
| * |
| * @see #getTimeScaleValue |
| * |
| * @internal |
| * @deprecated This API is ICU internal only. |
| */ |
| @Deprecated |
| public static final int MAX_SCALE_VALUE = 11; |
| |
| private static final long ticks = 1; |
| private static final long microseconds = ticks * 10; |
| private static final long milliseconds = microseconds * 1000; |
| private static final long seconds = milliseconds * 1000; |
| private static final long minutes = seconds * 60; |
| private static final long hours = minutes * 60; |
| private static final long days = hours * 24; |
| |
| /** |
| * This class holds the data that describes a particular |
| * time scale. |
| */ |
| private static final class TimeScaleData |
| { |
| TimeScaleData(long theUnits, long theEpochOffset, |
| long theToMin, long theToMax, |
| long theFromMin, long theFromMax) |
| { |
| units = theUnits; |
| unitsRound = theUnits / 2; |
| |
| minRound = Long.MIN_VALUE + unitsRound; |
| maxRound = Long.MAX_VALUE - unitsRound; |
| |
| epochOffset = theEpochOffset / theUnits; |
| |
| if (theUnits == 1) { |
| epochOffsetP1 = epochOffsetM1 = epochOffset; |
| } else { |
| epochOffsetP1 = epochOffset + 1; |
| epochOffsetM1 = epochOffset - 1; |
| } |
| |
| toMin = theToMin; |
| toMax = theToMax; |
| |
| fromMin = theFromMin; |
| fromMax = theFromMax; |
| } |
| |
| long units; |
| long epochOffset; |
| long fromMin; |
| long fromMax; |
| long toMin; |
| long toMax; |
| |
| long epochOffsetP1; |
| long epochOffsetM1; |
| long unitsRound; |
| long minRound; |
| long maxRound; |
| } |
| |
| private static final TimeScaleData[] timeScaleTable = { |
| new TimeScaleData(milliseconds, 621355968000000000L, -9223372036854774999L, 9223372036854774999L, -984472800485477L, 860201606885477L), // JAVA_TIME |
| new TimeScaleData(seconds, 621355968000000000L, -9223372036854775808L, 9223372036854775807L, -984472800485L, 860201606885L), // UNIX_TIME |
| new TimeScaleData(milliseconds, 621355968000000000L, -9223372036854774999L, 9223372036854774999L, -984472800485477L, 860201606885477L), // ICU4C_TIME |
| new TimeScaleData(ticks, 504911232000000000L, -8718460804854775808L, 9223372036854775807L, -9223372036854775808L, 8718460804854775807L), // WINDOWS_FILE_TIME |
| new TimeScaleData(ticks, 000000000000000000L, -9223372036854775808L, 9223372036854775807L, -9223372036854775808L, 9223372036854775807L), // DOTNET_DATE_TIME |
| new TimeScaleData(seconds, 600527520000000000L, -9223372036854775808L, 9223372036854775807L, -982389955685L, 862284451685L), // MAC_OLD_TIME |
| new TimeScaleData(seconds, 631139040000000000L, -9223372036854775808L, 9223372036854775807L, -985451107685L, 859223299685L), // MAC_TIME |
| new TimeScaleData(days, 599265216000000000L, -9223372036854775808L, 9223372036854775807L, -11368793L, 9981605L), // EXCEL_TIME |
| new TimeScaleData(days, 599265216000000000L, -9223372036854775808L, 9223372036854775807L, -11368793L, 9981605L), // DB2_TIME |
| new TimeScaleData(microseconds, 621355968000000000L, -9223372036854775804L, 9223372036854775804L, -984472800485477580L, 860201606885477580L) // UNIX_MICROSECONDS_TIME |
| }; |
| |
| |
| /* |
| * Prevent construction of this class. |
| */ |
| ///CLOVER:OFF |
| private UniversalTimeScale() |
| { |
| // nothing to do |
| } |
| ///CLOVER:ON |
| |
| /** |
| * Convert a <code>long</code> datetime from the given time scale to the universal time scale. |
| * |
| * @param otherTime The <code>long</code> datetime |
| * @param timeScale The time scale to convert from |
| * |
| * @return The datetime converted to the universal time scale |
| * |
| * @stable ICU 3.2 |
| */ |
| public static long from(long otherTime, int timeScale) |
| { |
| TimeScaleData data = fromRangeCheck(otherTime, timeScale); |
| |
| return (otherTime + data.epochOffset) * data.units; |
| } |
| |
| /** |
| * Convert a <code>double</code> datetime from the given time scale to the universal time scale. |
| * All calculations are done using <code>BigDecimal</code> to guarantee that the value |
| * does not go out of range. |
| * |
| * @param otherTime The <code>double</code> datetime |
| * @param timeScale The time scale to convert from |
| * |
| * @return The datetime converted to the universal time scale |
| * |
| * @stable ICU 3.2 |
| */ |
| public static BigDecimal bigDecimalFrom(double otherTime, int timeScale) |
| { |
| TimeScaleData data = getTimeScaleData(timeScale); |
| BigDecimal other = new BigDecimal(String.valueOf(otherTime)); |
| BigDecimal units = new BigDecimal(data.units); |
| BigDecimal epochOffset = new BigDecimal(data.epochOffset); |
| |
| return other.add(epochOffset).multiply(units); |
| } |
| |
| /** |
| * Convert a <code>long</code> datetime from the given time scale to the universal time scale. |
| * All calculations are done using <code>BigDecimal</code> to guarantee that the value |
| * does not go out of range. |
| * |
| * @param otherTime The <code>long</code> datetime |
| * @param timeScale The time scale to convert from |
| * |
| * @return The datetime converted to the universal time scale |
| * |
| * @stable ICU 3.2 |
| */ |
| public static BigDecimal bigDecimalFrom(long otherTime, int timeScale) |
| { |
| TimeScaleData data = getTimeScaleData(timeScale); |
| BigDecimal other = new BigDecimal(otherTime); |
| BigDecimal units = new BigDecimal(data.units); |
| BigDecimal epochOffset = new BigDecimal(data.epochOffset); |
| |
| return other.add(epochOffset).multiply(units); |
| } |
| |
| /** |
| * Convert a <code>BigDecimal</code> datetime from the given time scale to the universal time scale. |
| * All calculations are done using <code>BigDecimal</code> to guarantee that the value |
| * does not go out of range. |
| * |
| * @param otherTime The <code>BigDecimal</code> datetime |
| * @param timeScale The time scale to convert from |
| * |
| * @return The datetime converted to the universal time scale |
| * |
| * @stable ICU 3.2 |
| */ |
| public static BigDecimal bigDecimalFrom(BigDecimal otherTime, int timeScale) |
| { |
| TimeScaleData data = getTimeScaleData(timeScale); |
| |
| BigDecimal units = new BigDecimal(data.units); |
| BigDecimal epochOffset = new BigDecimal(data.epochOffset); |
| |
| return otherTime.add(epochOffset).multiply(units); |
| } |
| |
| /** |
| * Convert a datetime from the universal time scale stored as a <code>BigDecimal</code> to a |
| * <code>long</code> in the given time scale. |
| * |
| * Since this calculation requires a divide, we must round. The straight forward |
| * way to round by adding half of the divisor will push the sum out of range for values |
| * within have the divisor of the limits of the precision of a <code>long</code>. To get around this, we do |
| * the rounding like this: |
| * |
| * <p><code> |
| * (universalTime - units + units/2) / units + 1 |
| * </code> |
| * |
| * <p> |
| * (i.e. we subtract units first to guarantee that we'll still be in range when we |
| * add <code>units/2</code>. We then need to add one to the quotent to make up for the extra subtraction. |
| * This simplifies to: |
| * |
| * <p><code> |
| * (universalTime - units/2) / units - 1 |
| * </code> |
| * |
| * <p> |
| * For negative values to round away from zero, we need to flip the signs: |
| * |
| * <p><code> |
| * (universalTime + units/2) / units + 1 |
| * </code> |
| * |
| * <p> |
| * Since we also need to subtract the epochOffset, we fold the <code>+/- 1</code> |
| * into the offset value. (i.e. <code>epochOffsetP1</code>, <code>epochOffsetM1</code>.) |
| * |
| * @param universalTime The datetime in the universal time scale |
| * @param timeScale The time scale to convert to |
| * |
| * @return The datetime converted to the given time scale |
| * |
| * @stable ICU 3.2 |
| */ |
| public static long toLong(long universalTime, int timeScale) |
| { |
| TimeScaleData data = toRangeCheck(universalTime, timeScale); |
| |
| if (universalTime < 0) { |
| if (universalTime < data.minRound) { |
| return (universalTime + data.unitsRound) / data.units - data.epochOffsetP1; |
| } |
| |
| return (universalTime - data.unitsRound) / data.units - data.epochOffset; |
| } |
| |
| if (universalTime > data.maxRound) { |
| return (universalTime - data.unitsRound) / data.units - data.epochOffsetM1; |
| } |
| |
| return (universalTime + data.unitsRound) / data.units - data.epochOffset; |
| } |
| |
| /** |
| * Convert a datetime from the universal time scale to a <code>BigDecimal</code> in the given time scale. |
| * |
| * @param universalTime The datetime in the universal time scale |
| * @param timeScale The time scale to convert to |
| * |
| * @return The datetime converted to the given time scale |
| * |
| * @stable ICU 3.2 |
| */ |
| public static BigDecimal toBigDecimal(long universalTime, int timeScale) |
| { |
| TimeScaleData data = getTimeScaleData(timeScale); |
| BigDecimal universal = new BigDecimal(universalTime); |
| BigDecimal units = new BigDecimal(data.units); |
| BigDecimal epochOffset = new BigDecimal(data.epochOffset); |
| |
| return universal.divide(units, BigDecimal.ROUND_HALF_UP).subtract(epochOffset); |
| } |
| |
| /** |
| * Convert a datetime from the universal time scale to a <code>BigDecimal</code> in the given time scale. |
| * |
| * @param universalTime The datetime in the universal time scale |
| * @param timeScale The time scale to convert to |
| * |
| * @return The datetime converted to the given time scale |
| * |
| * @stable ICU 3.2 |
| */ |
| public static BigDecimal toBigDecimal(BigDecimal universalTime, int timeScale) |
| { |
| TimeScaleData data = getTimeScaleData(timeScale); |
| BigDecimal units = new BigDecimal(data.units); |
| BigDecimal epochOffset = new BigDecimal(data.epochOffset); |
| |
| return universalTime.divide(units, BigDecimal.ROUND_HALF_UP).subtract(epochOffset); |
| } |
| |
| /** |
| * Return the <code>TimeScaleData</code> object for the given time |
| * scale. |
| * |
| * @param scale - the time scale |
| * @return the <code>TimeScaleData</code> object for the given time scale |
| */ |
| private static TimeScaleData getTimeScaleData(int scale) |
| { |
| if (scale < 0 || scale >= MAX_SCALE) { |
| throw new IllegalArgumentException("scale out of range: " + scale); |
| } |
| |
| return timeScaleTable[scale]; |
| } |
| |
| /** |
| * Get a value associated with a particular time scale. |
| * |
| * @param scale - the time scale |
| * @param value - a constant representing the value to get |
| * |
| * @return - the value. |
| * |
| * @stable ICU 3.2 |
| */ |
| public static long getTimeScaleValue(int scale, int value) |
| { |
| TimeScaleData data = getTimeScaleData(scale); |
| |
| switch (value) |
| { |
| case UNITS_VALUE: |
| return data.units; |
| |
| case EPOCH_OFFSET_VALUE: |
| return data.epochOffset; |
| |
| case FROM_MIN_VALUE: |
| return data.fromMin; |
| |
| case FROM_MAX_VALUE: |
| return data.fromMax; |
| |
| case TO_MIN_VALUE: |
| return data.toMin; |
| |
| case TO_MAX_VALUE: |
| return data.toMax; |
| |
| case EPOCH_OFFSET_PLUS_1_VALUE: |
| return data.epochOffsetP1; |
| |
| case EPOCH_OFFSET_MINUS_1_VALUE: |
| return data.epochOffsetM1; |
| |
| case UNITS_ROUND_VALUE: |
| return data.unitsRound; |
| |
| case MIN_ROUND_VALUE: |
| return data.minRound; |
| |
| case MAX_ROUND_VALUE: |
| return data.maxRound; |
| |
| default: |
| throw new IllegalArgumentException("value out of range: " + value); |
| } |
| } |
| |
| private static TimeScaleData toRangeCheck(long universalTime, int scale) |
| { |
| TimeScaleData data = getTimeScaleData(scale); |
| |
| if (universalTime >= data.toMin && universalTime <= data.toMax) { |
| return data; |
| } |
| |
| throw new IllegalArgumentException("universalTime out of range:" + universalTime); |
| } |
| |
| private static TimeScaleData fromRangeCheck(long otherTime, int scale) |
| { |
| TimeScaleData data = getTimeScaleData(scale); |
| |
| if (otherTime >= data.fromMin && otherTime <= data.fromMax) { |
| return data; |
| } |
| |
| throw new IllegalArgumentException("otherTime out of range:" + otherTime); |
| } |
| |
| /** |
| * Convert a time in the Universal Time Scale into another time |
| * scale. The division used to do the conversion rounds down. |
| * |
| * NOTE: This is an internal routine used by the tool that |
| * generates the to and from limits. Use it at your own risk. |
| * |
| * @param universalTime the time in the Universal Time scale |
| * @param timeScale the time scale to convert to |
| * @return the time in the given time scale |
| * |
| * @internal |
| * @deprecated This API is ICU internal only. |
| */ |
| @Deprecated |
| public static BigDecimal toBigDecimalTrunc(BigDecimal universalTime, int timeScale) |
| { |
| TimeScaleData data = getTimeScaleData(timeScale); |
| BigDecimal units = new BigDecimal(data.units); |
| BigDecimal epochOffset = new BigDecimal(data.epochOffset); |
| |
| return universalTime.divide(units, BigDecimal.ROUND_DOWN).subtract(epochOffset); |
| } |
| } |