private static void AddNotYetNavigated(
int streamNo,
int numStreams,
LinkedHashMap <int, int[]> substreamsPerStream,
NStreamQueryPlanBuilder.BestChainResult bestChain)
{
// sum up all substreams (the query plan for each stream: nested iteration or cardinal)
ISet <int> streams = new HashSet <int>();
streams.Add(streamNo);
RecursiveAdd(streamNo, streamNo, substreamsPerStream, streams, false);
// we are done, all have navigated
if (streams.Count == numStreams)
{
return;
}
var previous = streamNo;
foreach (var stream in bestChain.Chain)
{
if (streams.Contains(stream))
{
previous = stream;
continue;
}
// add node as a nested join to the previous stream
var substreams = substreamsPerStream.Get(previous);
if (substreams == null)
{
substreams = new int[0];
}
var added = CollectionUtil.AddValue(substreams, stream);
substreamsPerStream.Put(previous, added);
if (!substreamsPerStream.ContainsKey(stream))
{
substreamsPerStream.Put(stream, new int[0]);
}
previous = stream;
}
}
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 }));
}
