/// <summary>
/// To help ensure hashcode uniqueness, a carefully selected random number multiplier
/// is used within the calculation. Goodrich and Tamassia's Data Structures and
/// Algorithms in Java asserts that 31, 33, 37, 39 and 41 will produce the fewest number
/// of collissions. See http://computinglife.wordpress.com/2008/11/20/why-do-hash-functions-use-prime-numbers/
/// for more information.
/// </summary>
public override int GetHashCode()
{
if (cachedHashcode.HasValue)
{
return(cachedHashcode.Value);
}
if (IsTransient())
{
//this.cachedHashcode = base.GetHashCode();
return(TransientId.GetHashCode()); //don't cache because this won't stay transient forever
}
else
{
unchecked
{
// It's possible for two objects to return the same hash code based on
// identically valued properties, even if they're of two different types,
// so we include the object's type in the hash calculation
var hashCode = GetType().GetHashCode();
cachedHashcode = (hashCode * HashMultiplier) ^ Id.GetHashCode();
}
}
return(cachedHashcode.Value);
}
public override bool Equals(object obj)
{
var compareTo = obj as AuditEntityConfiguration;
if (ReferenceEquals(this, compareTo))
{
return(true);
}
if (compareTo == null || !GetType().Equals(compareTo.GetTypeUnproxied()))
{
return(false);
}
if (HasSameNonDefaultIdAs(compareTo))
{
return(true);
}
// Since the Ids aren't the same, both of them must be transient to
// compare domain signatures; because if one is transient and the
// other is a persisted entity, then they cannot be the same object.
return(IsTransient() && compareTo.IsTransient() && (base.Equals(compareTo) || TransientId.Equals(compareTo.TransientId)));
}