/// <summary>
/// Shift given shiftedBlock behind target, if possible
/// </summary>
/// <param name="shiftedBlock"></param>
/// <param name="target"></param>
/// <param name="view"></param>
private bool shiftBehind(ExecutedBlock shiftedBlock, ExecutedBlock target, ExecutionView view)
{
//cumulative list of blocks that has to be shifted
//It has reverse ordering of transformations that will be generated
var shiftedBlocks = new List <ExecutedBlock>();
shiftedBlocks.Add(shiftedBlock);
var borderInstances = new HashSet <Instance>();
borderInstances.UnionWith(view.AffectedInstances(shiftedBlock));
//find all colliding blocks, so we can move them with shifted block if possible
var currentBlock = shiftedBlock;
while (currentBlock != target)
{
currentBlock = view.NextBlock(currentBlock);
if (!canCross(currentBlock, borderInstances, view))
{
//this block cannot be crossed
borderInstances.UnionWith(view.AffectedInstances(currentBlock));
shiftedBlocks.Add(currentBlock);
}
}
//shifting is not possible, due to collisions between blocks
if (!canCross(target, borderInstances, view))
{
return(false);
}
shiftedBlocks.Reverse();
foreach (var block in shiftedBlocks)
{
view.ShiftBehind(block, target);
}
return(true);
}
private void initializeScopes(ExecutionView view, ExecutedBlock earliestStart)
{
var current = earliestStart;
//initialize active scope index
var activeScopes = new Dictionary <Instance, Dictionary <VariableName, ExecutedBlock> >();
foreach (var instance in _monitoredInstances)
{
if (instance.CreationBlock == null)
{
//earliest start cannot be determined - we have to traverse from begining
current = view.EntryBlock;
}
activeScopes.Add(instance, new Dictionary <VariableName, ExecutedBlock>());
}
//search block for scopes
ExecutedBlock lastBlock = null;
while (current != null)
{
foreach (var instance in _monitoredInstances)
{
var scopeStarts = view.ScopeStarts(current, instance);
var scopeEnds = view.ScopeEnds(current, instance);
//activate new scope starts
var scopesIndex = activeScopes[instance];
foreach (var variable in scopeStarts)
{
scopesIndex[variable] = current;
}
foreach (var variable in scopeEnds)
{
ExecutedBlock scopeStart;
if (!scopesIndex.TryGetValue(variable, out scopeStart))
{
//there is no matching start
continue;
}
scopesIndex.Remove(variable);
if (scopeStart == current)
{
//empty scope
continue;
}
var scope = new InstanceScope(variable, instance, scopeStart, current);
_scopes.Add(instance, scope);
}
}
lastBlock = current;
current = view.NextBlock(current);
}
//handle non-closed scopes
foreach (var instance in _monitoredInstances)
{
//activate new scope starts
var scopesIndex = activeScopes[instance];
foreach (var scopePair in scopesIndex)
{
var scope = new InstanceScope(scopePair.Key, instance, scopePair.Value, lastBlock);
//empty scope is allowed here, because it is not closed
_scopes.Add(instance, scope);
}
}
}