private static QueryPlanNode BuildPlanNode(
int numStreams,
int streamNo,
string[] streamNames,
QueryGraph queryGraph,
OuterInnerDirectionalGraph outerInnerGraph,
OuterJoinDesc[] outerJoinDescList,
InnerJoinGraph innerJoinGraph,
QueryPlanIndex[] indexSpecs,
EventType[] typesPerStream,
bool[] ishistorical,
DependencyGraph dependencyGraph,
HistoricalStreamIndexList[] historicalStreamIndexLists,
ExprEvaluatorContext exprEvaluatorContext,
TableMetadata[] tablesPerStream)
{
// For each stream build an array of substreams, considering required streams (inner joins) first
// The order is relevant therefore preserving order via a LinkedHashMap.
var substreamsPerStream = new LinkedHashMap <int, int[]>();
var requiredPerStream = new bool[numStreams];
// Recursive populating the required (outer) and optional (inner) relationships
// of this stream and the substream
ISet <int> completedStreams = new HashSet <int>();
// keep track of tree path as only those stream events are always available to historical streams
var streamCallStack = new Stack <int>();
streamCallStack.Push(streamNo);
// For all inner-joins, the algorithm is slightly different
if (innerJoinGraph.IsAllInnerJoin)
{
requiredPerStream.Fill(true);
RecursiveBuildInnerJoin(streamNo, streamCallStack, queryGraph, completedStreams, substreamsPerStream, dependencyGraph);
// compute a best chain to see if all streams are handled and add the remaining
var bestChain = NStreamQueryPlanBuilder.ComputeBestPath(streamNo, queryGraph, dependencyGraph);
AddNotYetNavigated(streamNo, numStreams, substreamsPerStream, bestChain);
}
else
{
RecursiveBuild(streamNo, streamCallStack, queryGraph, outerInnerGraph, innerJoinGraph, completedStreams, substreamsPerStream, requiredPerStream, dependencyGraph);
}
// verify the substreamsPerStream, all streams must exists and be linked
VerifyJoinedPerStream(streamNo, substreamsPerStream);
// build list of instructions for lookup
var lookupInstructions = BuildLookupInstructions(streamNo, substreamsPerStream, requiredPerStream,
streamNames, queryGraph, indexSpecs, typesPerStream, outerJoinDescList, ishistorical, historicalStreamIndexLists, exprEvaluatorContext, tablesPerStream);
// build strategy tree for putting the result back together
var assemblyTopNodeFactory = AssemblyStrategyTreeBuilder.Build(streamNo, substreamsPerStream, requiredPerStream);
var assemblyInstructionFactories = BaseAssemblyNodeFactory.GetDescendentNodesBottomUp(assemblyTopNodeFactory);
return(new LookupInstructionQueryPlanNode(streamNo, streamNames[streamNo], numStreams, requiredPerStream,
lookupInstructions, assemblyInstructionFactories));
}
public void TestComputeBestPath()
{
NStreamQueryPlanBuilder.BestChainResult bestChain = NStreamQueryPlanBuilder.ComputeBestPath(
0, _queryGraph, _dependencyGraph);
Assert.AreEqual(3, bestChain.Depth);
Assert.IsTrue(Collections.AreEqual(bestChain.Chain, new int[] { 2, 4, 3, 1 }));
bestChain = NStreamQueryPlanBuilder.ComputeBestPath(3, _queryGraph, _dependencyGraph);
Assert.AreEqual(4, bestChain.Depth);
Assert.IsTrue(Collections.AreEqual(bestChain.Chain, new int[] { 4, 2, 0, 1 }));
// try a stream that is not connected in any way
_queryGraph = new QueryGraph(6, null, false);
bestChain = NStreamQueryPlanBuilder.ComputeBestPath(5, _queryGraph, _dependencyGraph);
Log.Debug(".testComputeBestPath bestChain=" + bestChain);
Assert.AreEqual(0, bestChain.Depth);
Assert.IsTrue(Collections.AreEqual(bestChain.Chain, new int[] { 0, 1, 2, 3, 4 }));
}
