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mirror of https://git.teknik.io/Teknikode/Teknik.git synced 2023-08-02 14:16:22 +02:00
Teknik/Utilities/StringHelper.cs

116 lines
4.3 KiB
C#

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace Teknik.Utilities
{
public static class StringHelper
{
public static string RandomString(int length)
{
return RandomString(length, "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789");
}
public static string RandomString(int length, string allowedChars)
{
const int byteSize = 0x100;
var allowedCharSet = new HashSet<char>(allowedChars).ToArray();
if (byteSize < allowedCharSet.Length) throw new ArgumentException(String.Format("allowedChars may contain no more than {0} characters.", byteSize));
// Guid.NewGuid and System.Random are not particularly random. By using a
// cryptographically-secure random number generator, the caller is always
// protected, regardless of use.
using (var rng = new System.Security.Cryptography.RNGCryptoServiceProvider())
{
var result = new StringBuilder();
var buf = new byte[128];
while (result.Length < length)
{
rng.GetBytes(buf);
for (var i = 0; i < buf.Length && result.Length < length; ++i)
{
// Divide the byte into allowedCharSet-sized groups. If the
// random value falls into the last group and the last group is
// too small to choose from the entire allowedCharSet, ignore
// the value in order to avoid biasing the result.
var outOfRangeStart = byteSize - (byteSize % allowedCharSet.Length);
if (outOfRangeStart <= buf[i]) continue;
result.Append(allowedCharSet[buf[i] % allowedCharSet.Length]);
}
}
return result.ToString();
}
}
public static string GetBytesReadable(long i)
{
// Get absolute value
long absolute_i = (i < 0 ? -i : i);
// Determine the suffix and readable value
string suffix;
double readable;
if (absolute_i >= 0x1000000000000000) // Exabyte
{
suffix = "EB";
readable = (i >> 50);
}
else if (absolute_i >= 0x4000000000000) // Petabyte
{
suffix = "PB";
readable = (i >> 40);
}
else if (absolute_i >= 0x10000000000) // Terabyte
{
suffix = "TB";
readable = (i >> 30);
}
else if (absolute_i >= 0x40000000) // Gigabyte
{
suffix = "GB";
readable = (i >> 20);
}
else if (absolute_i >= 0x100000) // Megabyte
{
suffix = "MB";
readable = (i >> 10);
}
else if (absolute_i >= 0x400) // Kilobyte
{
suffix = "KB";
readable = i;
}
else
{
return i.ToString("0 B"); // Byte
}
// Divide by 1024 to get fractional value
readable = (readable / 1024);
// Return formatted number with suffix
return readable.ToString("0.### ") + suffix;
}
public static KeyValuePair<string, string> ParseBasicAuthHeader(string value)
{
return ParseBasicAuthHeader(value, Encoding.UTF8);
}
public static KeyValuePair<string, string> ParseBasicAuthHeader(string value, Encoding encoding)
{
KeyValuePair<string, string> result = new KeyValuePair<string, string>();
if (!string.IsNullOrEmpty(value))
{
byte[] rawVal = Convert.FromBase64String(value);
string stringVal = encoding.GetString(rawVal);
string[] parts = stringVal.Split(new char[] { ':' }, StringSplitOptions.RemoveEmptyEntries);
if (parts.Length > 1)
{
result = new KeyValuePair<string, string>(parts[0], parts[1]);
}
}
return result;
}
}
}