/// <summary>
/// Commits changes stored in the Delta object.
/// </summary>
/// <remarks>
/// The Delta object is added to the History, and a new
/// one is allocated.
/// </remarks>
/// <returns>Commited Delta object</returns>
public DataDelta Commit()
{
if (Delta.PCWritten)
{
_pc = Delta.PC;
}
if (Delta.SPWritten)
{
_sp = Delta.SP;
}
foreach (DataDelta.WrittenLocation location in Delta.WrittenLocations.Values)
{
_memory[location.Address] = location.Value;
}
if (HistorySize > 0)
{
if (HistorySize == _history.Count)
{
_history.RemoveAt(0);
}
_history.Add(_delta);
}
DataDelta result = _delta;
_delta = new DataDelta();
return(result);
}
/// <summary>
/// Clears the Data object.
/// </summary>
/// <remarks>
/// Contents of the memory, registers and the currect Delta object is
/// cleared.
/// </remarks>
public void Clear()
{
_memory = new ushort[Size];
_pc = 0;
_sp = (ushort)(Size - 1);
_history.Clear();
_delta = new DataDelta();
}
/// <summary>
/// Uncommits the last DataDelta object from history. (Currect Delta is discarded.)
/// </summary>
/// <remarks>
/// Assuming that Commit() is called after every instruction, calling Uncommit() and
/// Rollback() after that undoes last executed instruction.
///
/// Uncommit fails if the History is empty.
/// </remarks>
/// <returns>A value indicating whether Uncommit was successful.</returns>
public bool Uncommit()
{
if (History.Count > 0)
{
_delta = History[History.Count - 1];
History.RemoveAt(History.Count - 1);
if (Delta.PCWritten)
{
_pc = Delta.OldPC;
}
if (Delta.SPWritten)
{
_sp = Delta.OldSP;
}
foreach (DataDelta.WrittenLocation location in Delta.WrittenLocations.Values)
{
_memory[location.Address] = location.OldValue;
}
return(true);
}
return(false);
}
/// <summary>
/// Uncommits the last DataDelta object from history. (Currect Delta is discarded.)
/// </summary>
/// <remarks>
/// Assuming that Commit() is called after every instruction, calling Uncommit() and
/// Rollback() after that undoes last executed instruction.
///
/// Uncommit fails if the History is empty.
/// </remarks>
/// <returns>A value indicating whether Uncommit was successful.</returns>
public bool Uncommit()
{
if (History.Count > 0)
{
_delta = History[History.Count - 1];
History.RemoveAt(History.Count - 1);
if (Delta.PCWritten) _pc = Delta.OldPC;
if (Delta.SPWritten) _sp = Delta.OldSP;
foreach (DataDelta.WrittenLocation location in Delta.WrittenLocations.Values)
{
_memory[location.Address] = location.OldValue;
}
return true;
}
return false;
}
/// <summary>
/// Discards the Delta object.
/// </summary>
public void Rollback()
{
_delta = new DataDelta();
}
/// <summary>
/// Commits changes stored in the Delta object.
/// </summary>
/// <remarks>
/// The Delta object is added to the History, and a new
/// one is allocated.
/// </remarks>
/// <returns>Commited Delta object</returns>
public DataDelta Commit()
{
if (Delta.PCWritten) _pc = Delta.PC;
if (Delta.SPWritten) _sp = Delta.SP;
foreach (DataDelta.WrittenLocation location in Delta.WrittenLocations.Values)
{
_memory[location.Address] = location.Value;
}
if (HistorySize > 0)
{
if (HistorySize == _history.Count)
_history.RemoveAt(0);
_history.Add(_delta);
}
DataDelta result = _delta;
_delta = new DataDelta();
return result;
}
/// <summary>
/// Clears the Data object.
/// </summary>
/// <remarks>
/// Contents of the memory, registers and the currect Delta object is
/// cleared.
/// </remarks>
public void Clear()
{
_memory = new ushort[Size];
_pc = 0;
_sp = (ushort)(Size - 1);
_history.Clear();
_delta = new DataDelta();
}
/// <summary>
/// Discards the Delta object.
/// </summary>
public void Rollback()
{
_delta = new DataDelta();
}
/// <summary>
/// Sets the NextDelta and the corresponding PC.
/// </summary>
/// <remarks>
/// This method should be used when stepping back to avoid
/// reexecuting the undone instruction in CalculateNextDelta.
/// </remarks>
/// <param name="nextDelta">The Delta of the next instruction</param>
/// <param name="pc">The address of the instruction</param>
public void SetNextDelta(DataDelta nextDelta, ushort pc)
{
_nextDelta = nextDelta;
_nextDeltaPC = pc;
}