private static void SwapByteOrder(byte[] guid)
{
DeterministicGuidGenerator.SwapBytes(guid, 0, 3);
DeterministicGuidGenerator.SwapBytes(guid, 1, 2);
DeterministicGuidGenerator.SwapBytes(guid, 4, 5);
DeterministicGuidGenerator.SwapBytes(guid, 6, 7);
}
/// <summary>Creates a deterministic GUID.</summary>
/// <param name="source">A source to generate the GUID from.</param>
/// <returns>A deterministically generated GUID.</returns>
public Guid Create(byte[] source)
{
byte[] hash;
using (SHA1 shA1 = SHA1.Create())
{
shA1.TransformBlock(this._namespaceBytes, 0, this._namespaceBytes.Length, (byte[])null, 0);
shA1.TransformFinalBlock(source, 0, source.Length);
hash = shA1.Hash;
}
byte[] numArray = new byte[16];
Array.Copy((Array)hash, 0, (Array)numArray, 0, 16);
numArray[6] = (byte)((int)numArray[6] & 15 | 80);
numArray[8] = (byte)((int)numArray[8] & 63 | 128);
DeterministicGuidGenerator.SwapByteOrder(numArray);
return(new Guid(numArray));
}
/// <summary>
/// Initializes a new instance of <see cref="T:SqlStreamStore.Infrastructure.DeterministicGuidGenerator" />
/// </summary>
/// <param name="guidNameSpace">
/// A namespace that ensures that the GUID generated with this instance
/// do not collided with other generators. Your application should define
/// it's namespace as a constant.
/// </param>
public DeterministicGuidGenerator(Guid guidNameSpace)
{
this._namespaceBytes = guidNameSpace.ToByteArray();
DeterministicGuidGenerator.SwapByteOrder(this._namespaceBytes);
}