csharp-sdk-upm/Libs/Newtonsoft.Json/Utilities/DateTimeParser.cs

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2021-03-29 14:54:12 +08:00
#region License
// Copyright (c) 2007 James Newton-King
//
// Permission is hereby granted, free of charge, to any person
// obtaining a copy of this software and associated documentation
// files (the "Software"), to deal in the Software without
// restriction, including without limitation the rights to use,
// copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following
// conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
// OTHER DEALINGS IN THE SOFTWARE.
#endregion
using System;
namespace LC.Newtonsoft.Json.Utilities
{
internal enum ParserTimeZone
{
Unspecified = 0,
Utc = 1,
LocalWestOfUtc = 2,
LocalEastOfUtc = 3
}
internal struct DateTimeParser
{
static DateTimeParser()
{
Power10 = new[] { -1, 10, 100, 1000, 10000, 100000, 1000000 };
Lzyyyy = "yyyy".Length;
Lzyyyy_ = "yyyy-".Length;
Lzyyyy_MM = "yyyy-MM".Length;
Lzyyyy_MM_ = "yyyy-MM-".Length;
Lzyyyy_MM_dd = "yyyy-MM-dd".Length;
Lzyyyy_MM_ddT = "yyyy-MM-ddT".Length;
LzHH = "HH".Length;
LzHH_ = "HH:".Length;
LzHH_mm = "HH:mm".Length;
LzHH_mm_ = "HH:mm:".Length;
LzHH_mm_ss = "HH:mm:ss".Length;
Lz_ = "-".Length;
Lz_zz = "-zz".Length;
}
public int Year;
public int Month;
public int Day;
public int Hour;
public int Minute;
public int Second;
public int Fraction;
public int ZoneHour;
public int ZoneMinute;
public ParserTimeZone Zone;
private char[] _text;
private int _end;
private static readonly int[] Power10;
private static readonly int Lzyyyy;
private static readonly int Lzyyyy_;
private static readonly int Lzyyyy_MM;
private static readonly int Lzyyyy_MM_;
private static readonly int Lzyyyy_MM_dd;
private static readonly int Lzyyyy_MM_ddT;
private static readonly int LzHH;
private static readonly int LzHH_;
private static readonly int LzHH_mm;
private static readonly int LzHH_mm_;
private static readonly int LzHH_mm_ss;
private static readonly int Lz_;
private static readonly int Lz_zz;
private const short MaxFractionDigits = 7;
public bool Parse(char[] text, int startIndex, int length)
{
_text = text;
_end = startIndex + length;
if (ParseDate(startIndex) && ParseChar(Lzyyyy_MM_dd + startIndex, 'T') && ParseTimeAndZoneAndWhitespace(Lzyyyy_MM_ddT + startIndex))
{
return true;
}
return false;
}
private bool ParseDate(int start)
{
return (Parse4Digit(start, out Year)
&& 1 <= Year
&& ParseChar(start + Lzyyyy, '-')
&& Parse2Digit(start + Lzyyyy_, out Month)
&& 1 <= Month
&& Month <= 12
&& ParseChar(start + Lzyyyy_MM, '-')
&& Parse2Digit(start + Lzyyyy_MM_, out Day)
&& 1 <= Day
&& Day <= DateTime.DaysInMonth(Year, Month));
}
private bool ParseTimeAndZoneAndWhitespace(int start)
{
return (ParseTime(ref start) && ParseZone(start));
}
private bool ParseTime(ref int start)
{
if (!(Parse2Digit(start, out Hour)
&& Hour <= 24
&& ParseChar(start + LzHH, ':')
&& Parse2Digit(start + LzHH_, out Minute)
&& Minute < 60
&& ParseChar(start + LzHH_mm, ':')
&& Parse2Digit(start + LzHH_mm_, out Second)
&& Second < 60
&& (Hour != 24 || (Minute == 0 && Second == 0)))) // hour can be 24 if minute/second is zero)
{
return false;
}
start += LzHH_mm_ss;
if (ParseChar(start, '.'))
{
Fraction = 0;
int numberOfDigits = 0;
while (++start < _end && numberOfDigits < MaxFractionDigits)
{
int digit = _text[start] - '0';
if (digit < 0 || digit > 9)
{
break;
}
Fraction = (Fraction * 10) + digit;
numberOfDigits++;
}
if (numberOfDigits < MaxFractionDigits)
{
if (numberOfDigits == 0)
{
return false;
}
Fraction *= Power10[MaxFractionDigits - numberOfDigits];
}
if (Hour == 24 && Fraction != 0)
{
return false;
}
}
return true;
}
private bool ParseZone(int start)
{
if (start < _end)
{
char ch = _text[start];
if (ch == 'Z' || ch == 'z')
{
Zone = ParserTimeZone.Utc;
start++;
}
else
{
if (start + 2 < _end
&& Parse2Digit(start + Lz_, out ZoneHour)
&& ZoneHour <= 99)
{
switch (ch)
{
case '-':
Zone = ParserTimeZone.LocalWestOfUtc;
start += Lz_zz;
break;
case '+':
Zone = ParserTimeZone.LocalEastOfUtc;
start += Lz_zz;
break;
}
}
if (start < _end)
{
if (ParseChar(start, ':'))
{
start += 1;
if (start + 1 < _end
&& Parse2Digit(start, out ZoneMinute)
&& ZoneMinute <= 99)
{
start += 2;
}
}
else
{
if (start + 1 < _end
&& Parse2Digit(start, out ZoneMinute)
&& ZoneMinute <= 99)
{
start += 2;
}
}
}
}
}
return (start == _end);
}
private bool Parse4Digit(int start, out int num)
{
if (start + 3 < _end)
{
int digit1 = _text[start] - '0';
int digit2 = _text[start + 1] - '0';
int digit3 = _text[start + 2] - '0';
int digit4 = _text[start + 3] - '0';
if (0 <= digit1 && digit1 < 10
&& 0 <= digit2 && digit2 < 10
&& 0 <= digit3 && digit3 < 10
&& 0 <= digit4 && digit4 < 10)
{
num = (((((digit1 * 10) + digit2) * 10) + digit3) * 10) + digit4;
return true;
}
}
num = 0;
return false;
}
private bool Parse2Digit(int start, out int num)
{
if (start + 1 < _end)
{
int digit1 = _text[start] - '0';
int digit2 = _text[start + 1] - '0';
if (0 <= digit1 && digit1 < 10
&& 0 <= digit2 && digit2 < 10)
{
num = (digit1 * 10) + digit2;
return true;
}
}
num = 0;
return false;
}
private bool ParseChar(int start, char ch)
{
return (start < _end && _text[start] == ch);
}
}
}