/// <summary>
/// Recursively assembles interpretation plan from scheduled search plan, beginning at index 0.
/// Decides which specialized build procedure is to be called.
/// The specialized build procedure then calls this procedure again,
/// in order to process the next search plan operation at the following index.
/// The insertionPoint is the lastly built operation;
/// the next operation built is inserted into the next link of it,
/// then it becomes the current insertionPoint.
/// </summary>
private void BuildInterpretationPlan(InterpretationPlan insertionPoint, int index)
{
if (index >= ssp.Operations.Length)
{ // end of scheduled search plan reached, stop recursive iteration
buildMatchComplete(insertionPoint);
return;
}
SearchOperation op = ssp.Operations[index];
// for current scheduled search plan operation
// insert corresponding interpretation plan operations into interpretation plan
switch (op.Type)
{
case SearchOperationType.Lookup:
if(((SearchPlanNode)op.Element).NodeType == PlanNodeType.Node)
buildLookup(insertionPoint, index, (SearchPlanNodeNode)op.Element);
else
buildLookup(insertionPoint, index, (SearchPlanEdgeNode)op.Element);
break;
case SearchOperationType.ImplicitSource:
buildImplicit(insertionPoint, index,
(SearchPlanEdgeNode)op.SourceSPNode,
(SearchPlanNodeNode)op.Element,
ImplicitNodeType.Source);
break;
case SearchOperationType.ImplicitTarget:
buildImplicit(insertionPoint, index,
(SearchPlanEdgeNode)op.SourceSPNode,
(SearchPlanNodeNode)op.Element,
ImplicitNodeType.Target);
break;
case SearchOperationType.Implicit:
buildImplicit(insertionPoint, index,
(SearchPlanEdgeNode)op.SourceSPNode,
(SearchPlanNodeNode)op.Element,
ImplicitNodeType.SourceOrTarget);
break;
case SearchOperationType.Incoming:
buildIncident(insertionPoint, index,
(SearchPlanNodeNode)op.SourceSPNode,
(SearchPlanEdgeNode)op.Element,
IncidentEdgeType.Incoming);
break;
case SearchOperationType.Outgoing:
buildIncident(insertionPoint, index,
(SearchPlanNodeNode)op.SourceSPNode,
(SearchPlanEdgeNode)op.Element,
IncidentEdgeType.Outgoing);
break;
case SearchOperationType.Incident:
buildIncident(insertionPoint, index,
(SearchPlanNodeNode)op.SourceSPNode,
(SearchPlanEdgeNode)op.Element,
IncidentEdgeType.IncomingOrOutgoing);
break;
case SearchOperationType.Condition:
buildCondition(insertionPoint, index,
(PatternCondition)op.Element);
break;
default:
throw new Exception("Unknown or unsupported search operation");
}
}
/// <summary>
/// Decides which check connectedness operations are needed for the given edge of fixed direction
/// and inserts them into the interpretation plan
/// receives insertion point, returns new insertion point
/// </summary>
private InterpretationPlan decideOnAndInsertCheckConnectednessOfEdgeFixedDirection(
InterpretationPlan insertionPoint,
SearchPlanEdgeNode edge,
CheckCandidateForConnectednessType connectednessType)
{
Debug.Assert(connectednessType == CheckCandidateForConnectednessType.Source || connectednessType == CheckCandidateForConnectednessType.Target);
// check whether source/target-nodes of the candidate edge
// are the same as the already found nodes to which the edge must be incident
// don't need to, if that node is not matched by now (signaled by visited)
SearchPlanNodeNode nodeRequiringCheck =
connectednessType == CheckCandidateForConnectednessType.Source ?
edge.PatternEdgeSource : edge.PatternEdgeTarget;
if (nodeRequiringCheck.Visited)
{
if(connectednessType == CheckCandidateForConnectednessType.Source)
{
insertionPoint.next = new InterpretationPlanCheckConnectednessSource(
nodeRequiringCheck.nodeMatcher, edge.edgeMatcher);
insertionPoint = insertionPoint.next;
}
else //if(connectednessType == CheckCandidateForConnectednessType.Target)
{
insertionPoint.next = new InterpretationPlanCheckConnectednessTarget(
nodeRequiringCheck.nodeMatcher, edge.edgeMatcher);
insertionPoint = insertionPoint.next;
}
}
return insertionPoint;
}
/// <summary>
/// Decides which check connectedness operations are needed for the given edge in both directions
/// and inserts them into the interpretation plan
/// receives insertion point, returns new insertion point
/// </summary>
private InterpretationPlan decideOnAndInsertCheckConnectednessOfEdgeBothDirections(
InterpretationPlan insertionPoint,
SearchPlanEdgeNode edge,
bool edgeDeterminationContainsFirstNodeLoop)
{
// check whether source/target-nodes of the candidate edge
// are the same as the already found nodes to which the edge must be incident
if (!edgeDeterminationContainsFirstNodeLoop && currentEdgeConnectsToFirstIncidentNode(edge))
{
SearchPlanNodeNode nodeRequiringFirstNodeLoop = edge.PatternEdgeSource != null ?
edge.PatternEdgeSource : edge.PatternEdgeTarget;
// due to currentEdgeConnectsToFirstIncidentNode: at least on incident node available
if (edge.PatternEdgeSource == edge.PatternEdgeTarget)
{
// reflexive edge without direction iteration as we don't want 2 matches
insertionPoint.next = new InterpretationPlanCheckConnectednessSource(
nodeRequiringFirstNodeLoop.nodeMatcher, edge.edgeMatcher); // might be Target as well
insertionPoint = insertionPoint.next;
}
else
{
edge.directionVariable = new InterpretationPlanBothDirections();
insertionPoint.next = edge.directionVariable;
insertionPoint = insertionPoint.next;
insertionPoint.next = new InterpretationPlanCheckConnectednessSourceOrTarget(
nodeRequiringFirstNodeLoop.nodeMatcher, edge.edgeMatcher, edge.directionVariable);
insertionPoint = insertionPoint.next;
}
}
if (currentEdgeConnectsToSecondIncidentNode(edge))
{
// due to currentEdgeConnectsToSecondIncidentNode: both incident node available
insertionPoint.next = new InterpretationPlanCheckConnectednessTheOther(
edge.PatternEdgeTarget.nodeMatcher, edge.edgeMatcher, edge.PatternEdgeSource.nodeMatcher);
insertionPoint = insertionPoint.next;
}
return insertionPoint;
}
/// <summary>
/// Decides which check connectedness operations are needed for the given edge determined by lookup
/// and inserts them into the interpretation plan
/// receives insertion point, returns new insertion point
/// </summary>
private InterpretationPlan decideOnAndInsertCheckConnectednessOfEdgeFromLookup(
InterpretationPlan insertionPoint,
SearchPlanEdgeNode edge)
{
if (((PatternEdge)edge.PatternElement).fixedDirection)
{
// don't need to check if the edge is not required by the pattern to be incident to some given node
if (edge.PatternEdgeSource != null)
{
insertionPoint = decideOnAndInsertCheckConnectednessOfEdgeFixedDirection(insertionPoint,
edge, CheckCandidateForConnectednessType.Source);
}
if (edge.PatternEdgeTarget != null)
{
insertionPoint = decideOnAndInsertCheckConnectednessOfEdgeFixedDirection(insertionPoint,
edge, CheckCandidateForConnectednessType.Target);
}
}
else
{
insertionPoint = decideOnAndInsertCheckConnectednessOfEdgeBothDirections(insertionPoint,
edge, false);
}
return insertionPoint;
}
/// <summary>
/// Decides which check connectedness operations are needed for the given edge determined from incident node
/// and inserts them into the interpretation plan
/// receives insertion point, returns new insertions point
/// </summary>
private InterpretationPlan decideOnAndInsertCheckConnectednessOfIncidentEdgeFromNode(
InterpretationPlan insertionPoint,
SearchPlanEdgeNode edge,
SearchPlanNodeNode originatingNode,
bool edgeIncomingAtOriginatingNode)
{
if (((PatternEdge)edge.PatternElement).fixedDirection)
{
// don't need to check if the edge is not required by the pattern to be incident to some given node
// or if the edge was taken from the given originating node
if (edge.PatternEdgeSource != null)
{
if (!(!edgeIncomingAtOriginatingNode
&& edge.PatternEdgeSource == originatingNode))
{
insertionPoint = decideOnAndInsertCheckConnectednessOfEdgeFixedDirection(insertionPoint,
edge, CheckCandidateForConnectednessType.Source);
}
}
if (edge.PatternEdgeTarget != null)
{
if (!(edgeIncomingAtOriginatingNode
&& edge.PatternEdgeTarget == originatingNode))
{
insertionPoint = decideOnAndInsertCheckConnectednessOfEdgeFixedDirection(insertionPoint,
edge, CheckCandidateForConnectednessType.Target);
}
}
}
else
{
insertionPoint = decideOnAndInsertCheckConnectednessOfEdgeBothDirections(insertionPoint,
edge, true);
}
return insertionPoint;
}
/// <summary>
/// Decides which check connectedness operations are needed for the given node and edge of fixed direction
/// and inserts them into the interpretation plan
/// receives insertion point, returns new insertion point
/// </summary>
private InterpretationPlan decideOnAndInsertCheckConnectednessOfNodeFixedDirection(
InterpretationPlan insertionPoint,
SearchPlanNodeNode currentNode,
SearchPlanEdgeNode edge,
CheckCandidateForConnectednessType connectednessType)
{
Debug.Assert(connectednessType == CheckCandidateForConnectednessType.Source || connectednessType == CheckCandidateForConnectednessType.Target);
// check whether the pattern edges which must be incident to the candidate node (according to the pattern)
// are really incident to it
// only if edge is already matched by now (signaled by visited)
if (edge.Visited)
{
if(connectednessType == CheckCandidateForConnectednessType.Source)
{
insertionPoint.next = new InterpretationPlanCheckConnectednessSource(
currentNode.nodeMatcher, edge.edgeMatcher);
insertionPoint = insertionPoint.next;
}
else //if(connectednessType == CheckCandidateForConnectednessType.Target)
{
insertionPoint.next = new InterpretationPlanCheckConnectednessTarget(
currentNode.nodeMatcher, edge.edgeMatcher);
insertionPoint = insertionPoint.next;
}
}
return insertionPoint;
}
/// <summary>
/// Decides which check connectedness operations are needed for the given node and edge in both directions
/// and inserts them into the interpretation plan
/// receives insertion point, returns new insertion point
/// </summary>
private InterpretationPlan decideOnAndInsertCheckConnectednessOfNodeBothDirections(
InterpretationPlan insertionPoint,
SearchPlanNodeNode currentNode,
SearchPlanEdgeNode edge)
{
Debug.Assert(edge.PatternEdgeSource != edge.PatternEdgeTarget);
// check whether the pattern edges which must be incident to the candidate node (according to the pattern)
// are really incident to it
if (currentNodeIsFirstIncidentNodeOfEdge(currentNode, edge))
{
edge.directionVariable = new InterpretationPlanBothDirections();
insertionPoint.next = edge.directionVariable;
insertionPoint = insertionPoint.next;
insertionPoint.next = new InterpretationPlanCheckConnectednessSourceOrTarget(
currentNode.nodeMatcher, edge.edgeMatcher, edge.directionVariable);
insertionPoint = insertionPoint.next;
}
if (currentNodeIsSecondIncidentNodeOfEdge(currentNode, edge))
{
insertionPoint.next = new InterpretationPlanCheckConnectednessTheOther(
currentNode.nodeMatcher, edge.edgeMatcher,
edge.PatternEdgeSource == currentNode ? edge.PatternEdgeTarget.nodeMatcher : edge.PatternEdgeSource.nodeMatcher);
insertionPoint = insertionPoint.next;
}
return insertionPoint;
}
/// <summary>
/// Decides which check connectedness operations are needed for the given node just determined by lookup
/// and inserts them into the interpretation plan
/// receives insertion point, returns new insertion point
/// </summary>
private InterpretationPlan decideOnAndInsertCheckConnectednessOfNodeFromLookup(
InterpretationPlan insertionPoint,
SearchPlanNodeNode node)
{
// check for edges required by the pattern to be incident to the given node
foreach (SearchPlanEdgeNode edge in node.OutgoingPatternEdges)
{
if (((PatternEdge)edge.PatternElement).fixedDirection
|| edge.PatternEdgeSource == edge.PatternEdgeTarget)
{
insertionPoint = decideOnAndInsertCheckConnectednessOfNodeFixedDirection(insertionPoint,
node, edge, CheckCandidateForConnectednessType.Source);
}
else
{
insertionPoint = decideOnAndInsertCheckConnectednessOfNodeBothDirections(insertionPoint,
node, edge);
}
}
foreach (SearchPlanEdgeNode edge in node.IncomingPatternEdges)
{
if (((PatternEdge)edge.PatternElement).fixedDirection
|| edge.PatternEdgeSource == edge.PatternEdgeTarget)
{
insertionPoint = decideOnAndInsertCheckConnectednessOfNodeFixedDirection(insertionPoint,
node, edge, CheckCandidateForConnectednessType.Target);
}
else
{
insertionPoint = decideOnAndInsertCheckConnectednessOfNodeBothDirections(insertionPoint,
node, edge);
}
}
return insertionPoint;
}
/// <summary>
/// Decides which check connectedness operations are needed for the given node just drawn from edge
/// and inserts them into the interpretation plan
/// receives insertion point, returns new insertion point
/// </summary>
private InterpretationPlan decideOnAndInsertCheckConnectednessOfImplicitNodeFromEdge(
InterpretationPlan insertionPoint,
SearchPlanNodeNode node,
SearchPlanEdgeNode originatingEdge,
SearchPlanNodeNode otherNodeOfOriginatingEdge)
{
// check for edges required by the pattern to be incident to the given node
// only if the node was not taken from the given originating edge
// with the exception of reflexive edges, as these won't get checked thereafter
foreach (SearchPlanEdgeNode edge in node.OutgoingPatternEdges)
{
if (((PatternEdge)edge.PatternElement).fixedDirection
|| edge.PatternEdgeSource == edge.PatternEdgeTarget)
{
if (edge != originatingEdge || node == otherNodeOfOriginatingEdge)
{
insertionPoint = decideOnAndInsertCheckConnectednessOfNodeFixedDirection(insertionPoint,
node, edge, CheckCandidateForConnectednessType.Source);
}
}
else
{
if (edge != originatingEdge || node == otherNodeOfOriginatingEdge)
{
insertionPoint = decideOnAndInsertCheckConnectednessOfNodeBothDirections(insertionPoint,
node, edge);
}
}
}
foreach (SearchPlanEdgeNode edge in node.IncomingPatternEdges)
{
if (((PatternEdge)edge.PatternElement).fixedDirection
|| edge.PatternEdgeSource == edge.PatternEdgeTarget)
{
if (edge != originatingEdge || node == otherNodeOfOriginatingEdge)
{
insertionPoint = decideOnAndInsertCheckConnectednessOfNodeFixedDirection(insertionPoint,
node, edge, CheckCandidateForConnectednessType.Target);
}
}
else
{
if (edge != originatingEdge || node == otherNodeOfOriginatingEdge)
{
insertionPoint = decideOnAndInsertCheckConnectednessOfNodeBothDirections(insertionPoint,
node, edge);
}
}
}
return insertionPoint;
}
///////////////////////////////////////////////////////////////////////////////////
/// <summary>
/// Inserts code to get an implicit node from an edge
/// receives insertion point, returns new insertion point
/// </summary>
private InterpretationPlan insertImplicitNodeFromEdge(
InterpretationPlan insertionPoint,
SearchPlanEdgeNode edge,
SearchPlanNodeNode currentNode,
ImplicitNodeType nodeType)
{
int targetType = currentNode.PatternElement.TypeID;
if (nodeType == ImplicitNodeType.Source)
{
currentNode.nodeMatcher = new InterpretationPlanImplicitSource(targetType, edge.edgeMatcher,
currentNode);
}
else if(nodeType == ImplicitNodeType.Target)
{
currentNode.nodeMatcher = new InterpretationPlanImplicitTarget(targetType, edge.edgeMatcher,
currentNode);
}
else
{
Debug.Assert(nodeType != ImplicitNodeType.TheOther);
if (currentNodeIsSecondIncidentNodeOfEdge(currentNode, edge))
{
currentNode.nodeMatcher = new InterpretationPlanImplicitTheOther(targetType, edge.edgeMatcher,
edge.PatternEdgeSource == currentNode ? edge.PatternEdgeTarget.nodeMatcher : edge.PatternEdgeSource.nodeMatcher,
currentNode);
}
else // edge connects to first incident node
{
if (edge.PatternEdgeSource == edge.PatternEdgeTarget)
{
// reflexive edge without direction iteration as we don't want 2 matches
currentNode.nodeMatcher = new InterpretationPlanImplicitSource(targetType, edge.edgeMatcher,
currentNode);
}
else
{
edge.directionVariable = new InterpretationPlanBothDirections();
insertionPoint.next = edge.directionVariable;
insertionPoint = insertionPoint.next;
currentNode.nodeMatcher = new InterpretationPlanImplicitSourceOrTarget(targetType, edge.edgeMatcher,
edge.directionVariable, currentNode);
}
}
}
currentNode.nodeMatcher.prev = insertionPoint;
insertionPoint.next = currentNode.nodeMatcher;
insertionPoint = insertionPoint.next;
return insertionPoint;
}
/// <summary>
/// Inserts code to get an incident edge from some node
/// receives insertion point, returns new insertion point
/// </summary>
private InterpretationPlan insertIncidentEdgeFromNode(
InterpretationPlan insertionPoint,
SearchPlanNodeNode node,
SearchPlanEdgeNode currentEdge,
IncidentEdgeType incidentType)
{
int targetType = currentEdge.PatternElement.TypeID;
if (incidentType == IncidentEdgeType.Incoming)
{
currentEdge.edgeMatcher = new InterpretationPlanIncoming(targetType, node.nodeMatcher,
currentEdge);
}
else if(incidentType == IncidentEdgeType.Outgoing)
{
currentEdge.edgeMatcher = new InterpretationPlanOutgoing(targetType, node.nodeMatcher,
currentEdge);
}
else // IncidentEdgeType.IncomingOrOutgoing
{
if (currentEdge.PatternEdgeSource == currentEdge.PatternEdgeTarget)
{
// reflexive edge without direction iteration as we don't want 2 matches
currentEdge.edgeMatcher = new InterpretationPlanIncoming(targetType, node.nodeMatcher,
currentEdge);
}
else
{
currentEdge.directionVariable = new InterpretationPlanBothDirections();
insertionPoint.next = currentEdge.directionVariable;
insertionPoint = insertionPoint.next;
currentEdge.edgeMatcher = new InterpretationPlanIncomingOrOutgoing(targetType, node.nodeMatcher,
currentEdge.directionVariable, currentEdge);
}
}
currentEdge.edgeMatcher.prev = insertionPoint;
insertionPoint.next = currentEdge.edgeMatcher;
insertionPoint = insertionPoint.next;
return insertionPoint;
}
/// <summary>
/// The closing matching completed interpretation plan operation is added at the insertion point
/// </summary>
private void buildMatchComplete(InterpretationPlan insertionPoint)
{
insertionPoint.next = new InterpretationPlanMatchComplete(
ssp.PatternGraph.nodesPlusInlined.Length,
ssp.PatternGraph.edgesPlusInlined.Length);
insertionPoint.next.prev = insertionPoint;
}
/// <summary>
/// Interpretation plan operations implementing the
/// CheckCondition search plan operation
/// are created and inserted into the interpretation plan at the insertion point
/// </summary>
private void buildCondition(
InterpretationPlan insertionPoint, int index,
PatternCondition condition)
{
// check condition
expression.AreAttributesEqual aae = (expression.AreAttributesEqual)condition.ConditionExpression;
foreach(SearchPlanNode spn in spg.Nodes)
{
if(spn.PatternElement == aae.thisInPattern)
{
InterpretationPlanCheckCondition checkCondition;
if(spn is SearchPlanNodeNode)
{
SearchPlanNodeNode nodeNode = (SearchPlanNodeNode)spn;
checkCondition = new InterpretationPlanCheckCondition(
aae, nodeNode.nodeMatcher, Array.IndexOf(aae.thisInPattern.pointOfDefinition.nodes, aae.thisInPattern));
}
else
{
SearchPlanEdgeNode edgeNode = (SearchPlanEdgeNode)spn;
checkCondition = new InterpretationPlanCheckCondition(
aae, edgeNode.edgeMatcher, Array.IndexOf(aae.thisInPattern.pointOfDefinition.edges, aae.thisInPattern));
}
checkCondition.prev = insertionPoint;
insertionPoint.next = checkCondition;
insertionPoint = insertionPoint.next;
// continue with next operation
BuildInterpretationPlan(insertionPoint, index + 1);
return;
}
}
throw new Exception("Internal error constructing interpretation plan!");
}
/// <summary>
/// Interpretation plan operations implementing the
/// Extend Incoming|Outgoing|IncomingOrOutgoing search plan operation
/// are created and inserted into the interpretation plan at the insertion point
/// </summary>
private void buildIncident(
InterpretationPlan insertionPoint, int index,
SearchPlanNodeNode source,
SearchPlanEdgeNode target,
IncidentEdgeType edgeType)
{
// get candidate = iterate available incident edges
insertionPoint = insertIncidentEdgeFromNode(insertionPoint,
source, target, edgeType);
// check connectedness of candidate
insertionPoint = decideOnAndInsertCheckConnectednessOfIncidentEdgeFromNode(insertionPoint,
target, source, edgeType==IncidentEdgeType.Incoming);
// continue with next operation
target.Visited = true;
BuildInterpretationPlan(insertionPoint, index + 1);
target.Visited = false;
}
/// <summary>
/// Interpretation plan operations implementing the
/// Implicit Source|Target|SourceOrTarget search plan operation
/// are created and inserted into the interpretation plan at the insertion point
/// </summary>
private void buildImplicit(
InterpretationPlan insertionPoint, int index,
SearchPlanEdgeNode source,
SearchPlanNodeNode target,
ImplicitNodeType nodeType)
{
// get candidate = demanded node from edge
insertionPoint = insertImplicitNodeFromEdge(insertionPoint,
source, target, nodeType);
// check connectedness of candidate
SearchPlanNodeNode otherNodeOfOriginatingEdge = null;
if (nodeType == ImplicitNodeType.Source) otherNodeOfOriginatingEdge = source.PatternEdgeTarget;
if (nodeType == ImplicitNodeType.Target) otherNodeOfOriginatingEdge = source.PatternEdgeSource;
if (source.PatternEdgeTarget == source.PatternEdgeSource) // reflexive sign needed in unfixed direction case, too
otherNodeOfOriginatingEdge = source.PatternEdgeSource;
insertionPoint = decideOnAndInsertCheckConnectednessOfImplicitNodeFromEdge(insertionPoint,
target, source, otherNodeOfOriginatingEdge);
// continue with next operation
target.Visited = true;
BuildInterpretationPlan(insertionPoint, index + 1);
target.Visited = false;
}
/// <summary>
/// Interpretation plan operations implementing the
/// Lookup edge search plan operation
/// are created and inserted into the interpretation plan at the insertion point
/// </summary>
private void buildLookup(
InterpretationPlan insertionPoint, int index,
SearchPlanEdgeNode target)
{
// get candidate = iterate available edges
target.edgeMatcher = new InterpretationPlanLookupEdge(target.PatternElement.TypeID, target);
target.edgeMatcher.prev = insertionPoint;
insertionPoint.next = target.edgeMatcher;
insertionPoint = insertionPoint.next;
// check connectedness of candidate
insertionPoint = decideOnAndInsertCheckConnectednessOfEdgeFromLookup(insertionPoint,
target);
// continue with next operation
target.Visited = true;
BuildInterpretationPlan(insertionPoint, index + 1);
target.Visited = false;
}
