package com.espertech.esper.epl.join.plan;
import com.espertech.esper.collection.InterchangeablePair;
import com.espertech.esper.epl.spec.OuterJoinDesc;
import com.espertech.esper.type.OuterJoinType;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
public class InnerJoinGraph {
private final int numStreams;
private final boolean isAllInnerJoin;
private final Set<InterchangeablePair<Integer, Integer>> innerJoins;
public InnerJoinGraph(int numStreams, Set<InterchangeablePair<Integer, Integer>> innerJoins) {
this.numStreams = numStreams;
this.isAllInnerJoin = false;
this.innerJoins = innerJoins;
}
public InnerJoinGraph(int numStreams, boolean isAllInnerJoin) {
this.numStreams = numStreams;
this.isAllInnerJoin = isAllInnerJoin;
this.innerJoins = null;
}
public boolean isAllInnerJoin() {
return isAllInnerJoin;
}
public boolean isEmpty() {
if (isAllInnerJoin) {
return false;
}
return innerJoins.isEmpty();
}
public boolean hasInnerJoin(int toStream) {
if (isAllInnerJoin) {
return true;
}
boolean hasInnerJoin = false;
for (InterchangeablePair<Integer, Integer> pair : innerJoins)
{
if (pair.getFirst() == toStream)
{
hasInnerJoin = true;
}
if (pair.getSecond() == toStream)
{
hasInnerJoin = true;
}
}
return hasInnerJoin;
}
public static InnerJoinGraph graphInnerJoins(int numStreams, List<OuterJoinDesc> outerJoinDescList)
{
if ((outerJoinDescList.size() + 1) != numStreams)
{
throw new IllegalArgumentException("Number of outer join descriptors and number of streams not matching up");
}
Set<InterchangeablePair<Integer, Integer>> graph = new HashSet<InterchangeablePair<Integer, Integer>>();
boolean allInnerJoin = true;
for (int i = 0; i < outerJoinDescList.size(); i++)
{
OuterJoinDesc desc = outerJoinDescList.get(i);
int streamMax = i + 1; // the outer join must references streams less then streamMax
// Check outer join
int streamOne = desc.getLeftNode().getStreamId();
int streamTwo = desc.getRightNode().getStreamId();
if ((streamOne > streamMax) || (streamTwo > streamMax) ||
(streamOne == streamTwo))
{
throw new IllegalArgumentException("Outer join descriptors reference future streams, or same streams");
}
if (desc.getOuterJoinType() == OuterJoinType.INNER)
{
graph.add(new InterchangeablePair<Integer, Integer>(streamOne, streamTwo));
}
else {
allInnerJoin = false;
}
}
if (allInnerJoin) {
return new InnerJoinGraph(numStreams, true);
}
return new InnerJoinGraph(numStreams, graph);
}
public void addRequiredStreams(int streamNum, Set<Integer> requiredStreams, Set<Integer> completedStreams) {
if (isAllInnerJoin) {
for (int i = 0; i < numStreams; i++) {
if (!completedStreams.contains(i)) {
requiredStreams.add(i);
}
}
return;
}
for (InterchangeablePair<Integer, Integer> pair : innerJoins)
{
if (pair.getFirst() == streamNum)
{
if (!completedStreams.contains(pair.getSecond()))
{
requiredStreams.add(pair.getSecond());
}
}
if (pair.getSecond() == streamNum)
{
if (!completedStreams.contains(pair.getFirst()))
{
requiredStreams.add(pair.getFirst());
}
}
}
}
}