public virtual IGraphQueryStep Visit(IGraphQueryStep root)
{
_token.ThrowIfCancellationRequested();
switch (root)
{
case QueryQueryStep qqs:
return(VisitQueryQueryStep(qqs));
case EdgeQueryStep eqs:
return(VisitEdgeQueryStep(eqs));
case CollectionDestinationQueryStep cdqs:
return(VisitCollectionDestinationQueryStep(cdqs));
case IntersectionQueryStep <Except> iqse:
return(VisitIntersectionQueryStepExcept(iqse));
case IntersectionQueryStep <Union> iqsu:
return(VisitIntersectionQueryStepUnion(iqsu));
case IntersectionQueryStep <Intersection> iqsi:
return(VisitIntersectionQueryStepIntersection(iqsi));
case RecursionQueryStep rqs:
return(VisitRecursionQueryStep(rqs));
default:
throw new NotSupportedException($"Unexpected type {root.GetType().Name} for QueryPlanRewriter.Visit");
}
}
public bool GetNext(out Match match)
{
_token.ThrowIfCancellationRequested();
if (_index >= _results.Count)
{
match = default;
return(false);
}
match = _results[_index++];
return(true);
}
public void Complete(List <Match> output, Dictionary <long, List <Match> > intersection, HashSet <Match> state, OperationCancelToken token)
{
foreach (var kvp in intersection)
{
foreach (var item in kvp.Value)
{
token.ThrowIfCancellationRequested();
if (state.Contains(item) == false)
{
output.Add(item);
}
}
}
}
private void IntersectExpressions()
{
_token.ThrowIfCancellationRequested();
_index = 0;
if (_returnEmptyIfRightEmpty && _right.IsEmpty())
{
return;
}
_tempIntersect.Clear();
var operation = new TOp();
operation.Set(_left, _right);
var operationState = new HashSet <Match>();
if (_intersectedAliases.Count == 0 && !operation.ShouldContinueWhenNoIntersection)
{
return; // no matching aliases, so we need to stop when the operation is intersection
}
while (_left.GetNext(out var leftMatch))
{
_token.ThrowIfCancellationRequested();
long key = GetMatchHashKey(_intersectedAliases, leftMatch);
if (_tempIntersect.TryGetValue(key, out var matches) == false)
{
_tempIntersect[key] = matches = new List <Match>(); // TODO: pool these
}
matches.Add(leftMatch);
}
while (_right.GetNext(out var rightMatch))
{
_token.ThrowIfCancellationRequested();
long key = GetMatchHashKey(_intersectedAliases, rightMatch);
if (_tempIntersect.TryGetValue(key, out var matchesFromLeft) == false)
{
if (operation.ShouldContinueWhenNoIntersection)
{
operationState.Add(rightMatch);
}
continue; // nothing matched, can skip
}
for (int i = 0; i < matchesFromLeft.Count; i++)
{
_token.ThrowIfCancellationRequested();
var leftMatch = matchesFromLeft[i];
var allIntersectionsMatch = true;
for (int j = 0; j < _intersectedAliases.Count; j++)
{
var intersect = _intersectedAliases[j];
if (!leftMatch.TryGetAliasId(intersect, out var x) ||
!rightMatch.TryGetAliasId(intersect, out var y) ||
x != y)
{
allIntersectionsMatch = false;
break;
}
}
operation.Op(_results, leftMatch, rightMatch, allIntersectionsMatch, operationState);
}
}
operation.Complete(_results, _tempIntersect, operationState, _token);
}
