/// <summary>
/// Init for
/// </summary>
/// <param name="stream">Stream</param>
internal void InitFor(FuzzingStream stream, int index)
{
var s = new Step
{
// Max changes
MaxChanges = MaxChanges == null ? 1 : Math.Max(1, (int)MaxChanges.Get())
};
if (FuzzPercentType == EFuzzingPercentType.PeerStream)
{
// Fill indexes
var length = stream.Length;
var changes = Math.Min(s.MaxChanges, (long)(length * (FuzzPercent == null ? 100D : FuzzPercent.Get()) / 100.0));
while (changes > s.FuzzIndex.Count)
{
long value;
do
{
value = RandomHelper.GetRandom(0, length);
}while (s.FuzzIndex.Contains(value) || ValidOffset?.ItsValid(value) == false);
s.FuzzIndex.Add(value);
}
s.FuzzIndex.Sort();
}
stream.Variables[index] = s;
}
/// <summary>
/// Get next mutation change (if happend)
/// </summary>
/// <param name="stream">Stream</param>
/// <param name="offset">Offset</param>
/// <param name="index">Index</param>
public MutationalChange Get(FuzzingStream stream, long offset, int index)
{
if (ValidOffset?.ItsValid(offset) == false)
{
return(null);
}
switch (FuzzPercentType)
{
case EFuzzingPercentType.PeerByte:
{
// Check Max changes
if (MaxChanges != null &&
stream.Log.Length >= MaxChanges.Get())
{
return(null);
}
// Check Percent
if (FuzzPercent != null)
{
var value = FuzzPercent.Get();
if (!RandomHelper.IsRandomPercentOk(value))
{
return(null);
}
}
// Get Item
return(Changes.Get());
}
case EFuzzingPercentType.PeerStream:
{
// Check Max changes
var s = (Step)stream.Variables[index];
if (stream.Log.Length >= s.MaxChanges)
{
return(null);
}
if (!s.FuzzIndex.Contains(offset))
{
return(null);
}
// Get Item
return(Changes.Get());
}
default:
{
throw new ArgumentException(nameof(FuzzPercentType));
}
}
}