Radarr/NzbDrone.Common/HashUtil.cs

68 lines
1.9 KiB
C#

using System;
using System.Security.Cryptography;
using System.Text;
using System.Threading;
namespace NzbDrone.Common
{
public static class HashUtil
{
//This should never be changed. very bad things will happen!
private static readonly DateTime Epoch = new DateTime(2010, 1, 1);
private static readonly object _lock = new object();
public static string CalculateCrc(string input)
{
uint mCrc = 0xffffffff;
byte[] bytes = Encoding.UTF8.GetBytes(input);
foreach (byte myByte in bytes)
{
mCrc ^= ((uint)(myByte) << 24);
for (var i = 0; i < 8; i++)
{
if ((Convert.ToUInt32(mCrc) & 0x80000000) == 0x80000000)
{
mCrc = (mCrc << 1) ^ 0x04C11DB7;
}
else
{
mCrc <<= 1;
}
}
}
return String.Format("{0:x8}", mCrc);
}
public static string GenerateCommandId()
{
return GenerateId("c");
}
private static string GenerateId(string prefix)
{
lock (_lock)
{
Thread.Sleep(1);
var tick = (DateTime.Now - Epoch).Ticks;
return prefix + "." + ToBase(tick);
}
}
private static string ToBase(long input)
{
const string BASE_CHARS = "0123456789abcdefghijklmnopqrstuvwxyz";
int targetBase = BASE_CHARS.Length;
var result = new StringBuilder();
do
{
result.Append(BASE_CHARS[(int)(input % targetBase)]);
input /= targetBase;
} while (input > 0);
return result.ToString();
}
}
}