/// <summary>
/// Returns the current value of <typeparamref name="T"/> stored by the <see cref="ValueHistory{T}"/> object.
/// </summary>
/// <param name="storage">The storage object that holds the value of <typeparamref name="T"/>.</param>
/// <returns>The value of <typeparamref name="T"/> stored by the <paramref name="storage"/> object.</returns>
/// <exception cref="ArgumentNullException">
/// Thrown if <paramref name="storage"/> is <see langword="null" />.
/// </exception>
public static T FromStorage(ValueHistory <T> storage)
{
{
Lokad.Enforce.Argument(() => storage);
}
return(storage.Current);
}
public void RollBackPastFirstValue()
{
var storage = new ValueHistory <int>();
int maximumValue = 10;
for (int i = 1; i < maximumValue; i++)
{
storage.Current = i;
storage.StoreCurrent(new TimeMarker((ulong)(i + 1)));
}
storage.RollBackTo(new TimeMarker(0));
int storedValue = storage;
Assert.AreEqual(0, storedValue);
}
public void RollForwardPastLastValue()
{
var storage = new ValueHistory <int>();
int maximumValue = 10;
for (int i = 0; i < maximumValue; i++)
{
storage.Current = i;
storage.StoreCurrent(new TimeMarker((ulong)(i + 1)));
}
storage.RollBackTo(new TimeMarker(5));
storage.RollForwardTo(new TimeMarker((ulong)(maximumValue + 1)));
int storedValue = storage;
Assert.AreEqual(maximumValue - 1, storedValue);
}
public void RollBackToPreviousValue()
{
var storage = new ValueHistory <int>();
int maximumValue = 10;
for (int i = 0; i < maximumValue; i++)
{
storage.Current = i;
storage.StoreCurrent(new TimeMarker((ulong)(i + 1)));
}
for (int i = maximumValue; i > 0; i--)
{
storage.RollBackTo(new TimeMarker((ulong)i));
int storedValue = storage;
Assert.AreEqual(i - 1, storedValue);
}
}
public void RollBackToStartWithNoValues()
{
var storage = new ValueHistory <int>();
Assert.DoesNotThrow(() => storage.RollBackToStart());
}