#region Copyright notice and license
// Protocol Buffers - Google's data interchange format
// Copyright 2015 Google Inc. All rights reserved.
// https://developers.google.com/protocol-buffers/
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#endregion
using System;
namespace Google.Protobuf.WellKnownTypes
{
public partial class Timestamp
{
private static readonly DateTime UnixEpoch = new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc);
// Constants determined programmatically, but then hard-coded so they can be constant expressions.
private const long BclSecondsAtUnixEpoch = 62135596800;
internal const long UnixSecondsAtBclMaxValue = 253402300799;
internal const long UnixSecondsAtBclMinValue = -BclSecondsAtUnixEpoch;
internal const int MaxNanos = Duration.NanosecondsPerSecond - 1;
private bool IsNormalized =>
Nanos >= 0 &&
Nanos <= MaxNanos &&
Seconds >= UnixSecondsAtBclMinValue &&
Seconds <= UnixSecondsAtBclMaxValue;
/// <summary>
/// Returns the difference between one <see cref="Timestamp"/> and another, as a <see cref="Duration"/>.
/// </summary>
/// <param name="lhs">The timestamp to subtract from. Must not be null.</param>
/// <param name="rhs">The timestamp to subtract. Must not be null.</param>
/// <returns>The difference between the two specified timestamps.</returns>
public static Duration operator -(Timestamp lhs, Timestamp rhs)
{
Preconditions.CheckNotNull(lhs, "lhs");
Preconditions.CheckNotNull(rhs, "rhs");
checked
{
return Duration.Normalize(lhs.Seconds - rhs.Seconds, lhs.Nanos - rhs.Nanos);
}
}
/// <summary>
/// Adds a <see cref="Duration"/> to a <see cref="Timestamp"/>, to obtain another <c>Timestamp</c>.
/// </summary>
/// <param name="lhs">The timestamp to add the duration to. Must not be null.</param>
/// <param name="rhs">The duration to add. Must not be null.</param>
/// <returns>The result of adding the duration to the timestamp.</returns>
public static Timestamp operator +(Timestamp lhs, Duration rhs)
{
Preconditions.CheckNotNull(lhs, "lhs");
Preconditions.CheckNotNull(rhs, "rhs");
checked
{
return Normalize(lhs.Seconds + rhs.Seconds, lhs.Nanos + rhs.Nanos);
}
}
/// <summary>
/// Subtracts a <see cref="Duration"/> from a <see cref="Timestamp"/>, to obtain another <c>Timestamp</c>.
/// </summary>
/// <param name="lhs">The timestamp to subtract the duration from. Must not be null.</param>
/// <param name="rhs">The duration to subtract.</param>
/// <returns>The result of subtracting the duration from the timestamp.</returns>
public static Timestamp operator -(Timestamp lhs, Duration rhs)
{
Preconditions.CheckNotNull(lhs, "lhs");
Preconditions.CheckNotNull(rhs, "rhs");
checked
{
return Normalize(lhs.Seconds - rhs.Seconds, lhs.Nanos - rhs.Nanos);
}
}
/// <summary>
/// Converts this timestamp into a <see cref="DateTime"/>.
/// </summary>
/// <remarks>
/// The resulting <c>DateTime</c> will always have a <c>Kind</c> of <c>Utc</c>.
/// If the timestamp is not a precise number of ticks, it will be truncated towards the start
/// of time. For example, a timestamp with a <see cref="Nanos"/> value of 99 will result in a
/// <see cref="DateTime"/> value precisely on a second.
/// </remarks>
/// <returns>This timestamp as a <c>DateTime</c>.</returns>
/// <exception cref="InvalidOperationException">The timestamp contains invalid values; either it is
/// incorrectly normalized or is outside the valid range.</exception>
public DateTime ToDateTime()
{
if (!IsNormalized)
{
throw new InvalidOperationException(@"Timestamp contains invalid values: Seconds={Seconds}; Nanos={Nanos}");
}
return UnixEpoch.AddSeconds(Seconds).AddTicks(Nanos / Duration.NanosecondsPerTick);
}
/// <summary>
/// Converts this timestamp into a <see cref="DateTimeOffset"/>.
/// </summary>
/// <remarks>
/// The resulting <c>DateTimeOffset</c> will always have an <c>Offset</c> of zero.
/// If the timestamp is not a precise number of ticks, it will be truncated towards the start
/// of time. For example, a timestamp with a <see cref="Nanos"/> value of 99 will result in a
/// <see cref="DateTimeOffset"/> value precisely on a second.
/// </remarks>
/// <returns>This timestamp as a <c>DateTimeOffset</c>.</returns>
/// <exception cref="InvalidOperationException">The timestamp contains invalid values; either it is
/// incorrectly normalized or is outside the valid range.</exception>
public DateTimeOffset ToDateTimeOffset()
{
return new DateTimeOffset(ToDateTime(), TimeSpan.Zero);
}
/// <summary>
/// Converts the specified <see cref="DateTime"/> to a <see cref="Timestamp"/>.
/// </summary>
/// <param name="dateTime"></param>
/// <exception cref="ArgumentException">The <c>Kind</c> of <paramref name="dateTime"/> is not <c>DateTimeKind.Utc</c>.</exception>
/// <returns>The converted timestamp.</returns>
public static Timestamp FromDateTime(DateTime dateTime)
{
if (dateTime.Kind != DateTimeKind.Utc)
{
throw new ArgumentException("Conversion from DateTime to Timestamp requires the DateTime kind to be Utc", "dateTime");
}
// Do the arithmetic using DateTime.Ticks, which is always non-negative, making things simpler.
long secondsSinceBclEpoch = dateTime.Ticks / TimeSpan.TicksPerSecond;
int nanoseconds = (int) (dateTime.Ticks % TimeSpan.TicksPerSecond) * Duration.NanosecondsPerTick;
return new Timestamp { Seconds = secondsSinceBclEpoch - BclSecondsAtUnixEpoch, Nanos = nanoseconds };
}
/// <summary>
/// Converts the given <see cref="DateTimeOffset"/> to a <see cref="Timestamp"/>
/// </summary>
/// <remarks>The offset is taken into consideration when converting the value (so the same instant in time
/// is represented) but is not a separate part of the resulting value. In other words, there is no
/// roundtrip operation to retrieve the original <c>DateTimeOffset</c>.</remarks>
/// <param name="dateTimeOffset">The date and time (with UTC offset) to convert to a timestamp.</param>
/// <returns>The converted timestamp.</returns>
public static Timestamp FromDateTimeOffset(DateTimeOffset dateTimeOffset)
{
// We don't need to worry about this having negative ticks: DateTimeOffset is constrained to handle
// values whose *UTC* value is in the range of DateTime.
return FromDateTime(dateTimeOffset.UtcDateTime);
}
internal static Timestamp Normalize(long seconds, int nanoseconds)
{
int extraSeconds = nanoseconds / Duration.NanosecondsPerSecond;
seconds += extraSeconds;
nanoseconds -= extraSeconds * Duration.NanosecondsPerSecond;
if (nanoseconds < 0)
{
nanoseconds += Duration.NanosecondsPerSecond;
seconds--;
}
return new Timestamp { Seconds = seconds, Nanos = nanoseconds };
}
}
}
