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jellyfin/MediaBrowser.Server.Mono/Security/BitConverterLE.cs

240 lines
5.7 KiB

//
// Mono.Security.BitConverterLE.cs
// Like System.BitConverter but always little endian
//
// Author:
// Bernie Solomon
//
//
// 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.
//
using System;
namespace MediaBrowser.Server.Mono.Security
{
internal sealed class BitConverterLE
{
private BitConverterLE ()
{
}
unsafe private static byte[] GetUShortBytes (byte *bytes)
{
if (BitConverter.IsLittleEndian)
return new byte [] { bytes [0], bytes [1] };
else
return new byte [] { bytes [1], bytes [0] };
}
unsafe private static byte[] GetUIntBytes (byte *bytes)
{
if (BitConverter.IsLittleEndian)
return new byte [] { bytes [0], bytes [1], bytes [2], bytes [3] };
else
return new byte [] { bytes [3], bytes [2], bytes [1], bytes [0] };
}
unsafe private static byte[] GetULongBytes (byte *bytes)
{
if (BitConverter.IsLittleEndian)
return new byte [] { bytes [0], bytes [1], bytes [2], bytes [3],
bytes [4], bytes [5], bytes [6], bytes [7] };
else
return new byte [] { bytes [7], bytes [6], bytes [5], bytes [4],
bytes [3], bytes [2], bytes [1], bytes [0] };
}
unsafe internal static byte[] GetBytes (bool value)
{
return new byte [] { value ? (byte)1 : (byte)0 };
}
unsafe internal static byte[] GetBytes (char value)
{
return GetUShortBytes ((byte *) &value);
}
unsafe internal static byte[] GetBytes (short value)
{
return GetUShortBytes ((byte *) &value);
}
unsafe internal static byte[] GetBytes (int value)
{
return GetUIntBytes ((byte *) &value);
}
unsafe internal static byte[] GetBytes (long value)
{
return GetULongBytes ((byte *) &value);
}
unsafe internal static byte[] GetBytes (ushort value)
{
return GetUShortBytes ((byte *) &value);
}
unsafe internal static byte[] GetBytes (uint value)
{
return GetUIntBytes ((byte *) &value);
}
unsafe internal static byte[] GetBytes (ulong value)
{
return GetULongBytes ((byte *) &value);
}
unsafe internal static byte[] GetBytes (float value)
{
return GetUIntBytes ((byte *) &value);
}
unsafe internal static byte[] GetBytes (double value)
{
return GetULongBytes ((byte *) &value);
}
unsafe private static void UShortFromBytes (byte *dst, byte[] src, int startIndex)
{
if (BitConverter.IsLittleEndian) {
dst [0] = src [startIndex];
dst [1] = src [startIndex + 1];
} else {
dst [0] = src [startIndex + 1];
dst [1] = src [startIndex];
}
}
unsafe private static void UIntFromBytes (byte *dst, byte[] src, int startIndex)
{
if (BitConverter.IsLittleEndian) {
dst [0] = src [startIndex];
dst [1] = src [startIndex + 1];
dst [2] = src [startIndex + 2];
dst [3] = src [startIndex + 3];
} else {
dst [0] = src [startIndex + 3];
dst [1] = src [startIndex + 2];
dst [2] = src [startIndex + 1];
dst [3] = src [startIndex];
}
}
unsafe private static void ULongFromBytes (byte *dst, byte[] src, int startIndex)
{
if (BitConverter.IsLittleEndian) {
for (int i = 0; i < 8; ++i)
dst [i] = src [startIndex + i];
} else {
for (int i = 0; i < 8; ++i)
dst [i] = src [startIndex + (7 - i)];
}
}
unsafe internal static bool ToBoolean (byte[] value, int startIndex)
{
return value [startIndex] != 0;
}
unsafe internal static char ToChar (byte[] value, int startIndex)
{
char ret;
UShortFromBytes ((byte *) &ret, value, startIndex);
return ret;
}
unsafe internal static short ToInt16 (byte[] value, int startIndex)
{
short ret;
UShortFromBytes ((byte *) &ret, value, startIndex);
return ret;
}
unsafe internal static int ToInt32 (byte[] value, int startIndex)
{
int ret;
UIntFromBytes ((byte *) &ret, value, startIndex);
return ret;
}
unsafe internal static long ToInt64 (byte[] value, int startIndex)
{
long ret;
ULongFromBytes ((byte *) &ret, value, startIndex);
return ret;
}
unsafe internal static ushort ToUInt16 (byte[] value, int startIndex)
{
ushort ret;
UShortFromBytes ((byte *) &ret, value, startIndex);
return ret;
}
unsafe internal static uint ToUInt32 (byte[] value, int startIndex)
{
uint ret;
UIntFromBytes ((byte *) &ret, value, startIndex);
return ret;
}
unsafe internal static ulong ToUInt64 (byte[] value, int startIndex)
{
ulong ret;
ULongFromBytes ((byte *) &ret, value, startIndex);
return ret;
}
unsafe internal static float ToSingle (byte[] value, int startIndex)
{
float ret;
UIntFromBytes ((byte *) &ret, value, startIndex);
return ret;
}
unsafe internal static double ToDouble (byte[] value, int startIndex)
{
double ret;
ULongFromBytes ((byte *) &ret, value, startIndex);
return ret;
}
}
}