private CorrelationVector(string baseVector, int extension, CorrelationVectorVersion version, bool immutable)
{
this.BaseVector = baseVector;
this.extension = extension;
this.Version = version;
this.immutable = immutable || CorrelationVector.IsOversized(baseVector, extension, version);
}
/// <summary>
/// Helper method to run method based on version.
/// </summary>
/// <param name="correlationVector">String representation of your cV</param>
/// <param name="v">Correlation Vector version.</param>
/// <param name="functions">The parameters for each cV version. Versions are in order from V1, V2, V3, etc.</param>
/// <returns>cV based on cV version.</returns>
private static CorrelationVector RunStaticMethod(string correlationVector, CorrelationVectorVersion v, params Func <string, CorrelationVector>[] functions)
{
if ((int)v < functions.Length)
{
return(functions[(int)v](correlationVector));
}
else
{
throw new ArgumentException("No function indicated for this version");
}
}
private static bool IsOversized(string baseVector, int extension, CorrelationVectorVersion version)
{
if (!string.IsNullOrEmpty(baseVector))
{
int size = baseVector.Length + 1 +
(extension > 0 ? (int)Math.Log10(extension) : 0) + 1;
return((version == CorrelationVectorVersion.V1 &&
size > CorrelationVector.MaxVectorLength) ||
(version == CorrelationVectorVersion.V2 &&
size > CorrelationVector.MaxVectorLengthV2));
}
return(false);
}
public static CorrelationVector Spin(string correlationVector, SpinParameters parameters)
{
CorrelationVectorVersion version = InferVersion(correlationVector);
switch (version)
{
case CorrelationVectorVersion.V1:
return(CorrelationVectorV1.Spin(correlationVector, parameters));
case CorrelationVectorVersion.V2:
return(CorrelationVectorV2.Spin(correlationVector, parameters));
default:
return(null);
}
}
private static string GetUniqueValue(CorrelationVectorVersion version)
{
if (CorrelationVectorVersion.V1 == version)
{
byte[] bytes = Guid.NewGuid().ToByteArray();
return(Convert.ToBase64String(bytes, 0, 12));
}
else if (CorrelationVectorVersion.V2 == version)
{
return(Guid.NewGuid().GetBaseFromGuid());
}
else
{
throw new ArgumentException(string.Format(CultureInfo.CurrentCulture, "Unsupported correlation vector version: {0}", version));
}
}
/// <summary>
/// Creates a new correlation vector by applying the Spin operator to an existing value.
/// This should be done at the entry point of an operation.
/// </summary>
/// <param name="correlationVector">
/// Taken from the message header indicated by <see cref="HeaderName"/>.
/// </param>
/// <param name="parameters">
/// The parameters to use when applying the Spin operator.
/// </param>
/// <returns>A new correlation vector extended from the current vector.</returns>
public static CorrelationVector Spin(string correlationVector, SpinParameters parameters)
{
if (CorrelationVector.IsImmutable(correlationVector))
{
return(CorrelationVector.Parse(correlationVector));
}
CorrelationVectorVersion version = CorrelationVector.InferVersion(
correlationVector, CorrelationVector.ValidateCorrelationVectorDuringCreation);
if (CorrelationVector.ValidateCorrelationVectorDuringCreation)
{
CorrelationVector.Validate(correlationVector, version);
}
byte[] entropy = new byte[parameters.EntropyBytes];
rng.NextBytes(entropy);
ulong value = (ulong)(DateTime.UtcNow.Ticks >> parameters.TicksBitsToDrop);
for (int i = 0; i < parameters.EntropyBytes; i++)
{
value = (value << 8) | Convert.ToUInt64(entropy[i]);
}
// Generate a bitmask and mask the lower TotalBits in the value.
// The mask is generated by (1 << TotalBits) - 1. We need to handle the edge case
// when shifting 64 bits, as it wraps around.
value &= (parameters.TotalBits == 64 ? 0 : (ulong)1 << parameters.TotalBits) - 1;
string s = unchecked ((uint)value).ToString();
if (parameters.TotalBits > 32)
{
s = string.Concat((value >> 32).ToString(), ".", s);
}
string baseVector = string.Concat(correlationVector, ".", s);
if (CorrelationVector.IsOversized(baseVector, 0, version))
{
return(CorrelationVector.Parse(correlationVector + CorrelationVector.TerminationSign));
}
return(new CorrelationVector(baseVector, 0, version, false));
}
private static void Validate(string correlationVector, CorrelationVectorVersion version)
{
byte maxVectorLength;
byte baseLength;
if (CorrelationVectorVersion.V1 == version)
{
maxVectorLength = CorrelationVector.MaxVectorLength;
baseLength = CorrelationVector.BaseLength;
}
else if (CorrelationVectorVersion.V2 == version)
{
maxVectorLength = CorrelationVector.MaxVectorLengthV2;
baseLength = CorrelationVector.BaseLengthV2;
}
else
{
throw new ArgumentException(string.Format(CultureInfo.CurrentCulture, "Unsupported correlation vector version: {0}", version));
}
if (string.IsNullOrWhiteSpace(correlationVector) || correlationVector.Length > maxVectorLength)
{
throw new ArgumentException(string.Format(CultureInfo.InvariantCulture,
"The {0} correlation vector can not be null or bigger than {1} characters", version, maxVectorLength));
}
string[] parts = correlationVector.Split('.');
if (parts.Length < 2 || parts[0].Length != baseLength)
{
throw new ArgumentException(string.Format(CultureInfo.InvariantCulture, "Invalid correlation vector {0}. Invalid base value {1}", correlationVector, parts[0]));
}
for (int i = 1; i < parts.Length; i++)
{
int result;
if (int.TryParse(parts[i], out result) == false || result < 0)
{
throw new ArgumentException(string.Format(CultureInfo.InvariantCulture, "Invalid correlation vector {0}. Invalid extension value {1}", correlationVector, parts[i]));
}
}
}
/// <summary>
/// Creates a new correlation vector by extending an existing value. This should be
/// done at the entry point of an operation.
/// </summary>
/// <param name="correlationVector">
/// Taken from the message header indicated by <see cref="HeaderName"/>.
/// </param>
/// <returns>A new correlation vector extended from the current vector.</returns>
public static CorrelationVector Extend(string correlationVector)
{
if (CorrelationVector.IsImmutable(correlationVector))
{
return(CorrelationVector.Parse(correlationVector));
}
CorrelationVectorVersion version = CorrelationVector.InferVersion(
correlationVector, CorrelationVector.ValidateCorrelationVectorDuringCreation);
if (CorrelationVector.ValidateCorrelationVectorDuringCreation)
{
CorrelationVector.Validate(correlationVector, version);
}
if (CorrelationVector.IsOversized(correlationVector, 0, version))
{
return(CorrelationVector.Parse(correlationVector + CorrelationVector.TerminationSign));
}
return(new CorrelationVector(correlationVector, 0, version, false));
}
/// <summary>
/// Converts a string representation of a Correlation Vector into this class.
/// </summary>
/// <param name="correlationVector">String representation</param>
/// <returns>The Correlation Vector based on its version.</returns>
public static CorrelationVector Parse(string correlationVector)
{
CorrelationVectorVersion version = InferVersion(correlationVector);
return(RunStaticMethod(correlationVector, version, CorrelationVectorV1.Parse, CorrelationVectorV2.Parse));
}
public static CorrelationVector Extend(string correlationVector)
{
CorrelationVectorVersion version = InferVersion(correlationVector);
return(RunStaticMethod(correlationVector, version, CorrelationVectorV1.Extend, CorrelationVectorV2.Extend));
}
/// <summary>
/// Initializes a new instance of the <see cref="CorrelationVector"/> class of the
/// given implemenation version. This should only be called when no correlation
/// vector was found in the message header.
/// </summary>
/// <param name="version">The correlation vector implemenation version.</param>
public CorrelationVector(CorrelationVectorVersion version)
: this(CorrelationVector.GetUniqueValue(version), 0, version, false)
{
}
