/**
* Analye EQUALS (=) node.
*
* @param equalsNode - node to analyze
* @param queryGraph - store relationships between stream properties
*/
protected static void analyzeEqualsNode(
ExprEqualsNode equalsNode, QueryGraph queryGraph, boolean isOuterJoin) {
if ((equalsNode.getChildNodes()[0] instanceof ExprIdentNode)
&& (equalsNode.getChildNodes()[1] instanceof ExprIdentNode)) {
ExprIdentNode identNodeLeft = (ExprIdentNode) equalsNode.getChildNodes()[0];
ExprIdentNode identNodeRight = (ExprIdentNode) equalsNode.getChildNodes()[1];
if (identNodeLeft.getStreamId() != identNodeRight.getStreamId()) {
queryGraph.addStrictEquals(
identNodeLeft.getStreamId(),
identNodeLeft.getResolvedPropertyName(),
identNodeLeft,
identNodeRight.getStreamId(),
identNodeRight.getResolvedPropertyName(),
identNodeRight);
}
return;
}
if (isOuterJoin) { // outerjoins don't use constants or one-way expression-derived information
// to evaluate join
return;
}
// handle constant-compare or transformation case
int indexedStream = -1;
String indexedProp = null;
ExprNode exprNodeNoIdent = null;
if (equalsNode.getChildNodes()[0] instanceof ExprIdentNode) {
ExprIdentNode identNode = (ExprIdentNode) equalsNode.getChildNodes()[0];
indexedStream = identNode.getStreamId();
indexedProp = identNode.getResolvedPropertyName();
exprNodeNoIdent = equalsNode.getChildNodes()[1];
} else if (equalsNode.getChildNodes()[1] instanceof ExprIdentNode) {
ExprIdentNode identNode = (ExprIdentNode) equalsNode.getChildNodes()[1];
indexedStream = identNode.getStreamId();
indexedProp = identNode.getResolvedPropertyName();
exprNodeNoIdent = equalsNode.getChildNodes()[0];
}
if (indexedStream == -1) {
return; // require property of right/left side of equals
}
EligibilityDesc eligibility = EligibilityUtil.verifyInputStream(exprNodeNoIdent, indexedStream);
if (!eligibility.getEligibility().isEligible()) {
return;
}
if (eligibility.getEligibility() == Eligibility.REQUIRE_NONE) {
queryGraph.addUnkeyedExpression(indexedStream, indexedProp, exprNodeNoIdent);
} else {
queryGraph.addKeyedExpression(
indexedStream, indexedProp, eligibility.getStreamNum(), exprNodeNoIdent);
}
}
/**
* Analyzes filter expression to build query graph model.
*
* @param topNode - filter top node
* @param queryGraph - model containing relationships between streams, to be written to
*/
public static void analyze(ExprNode topNode, QueryGraph queryGraph, boolean isOuterJoin) {
// Analyze relationships between streams. Relationships are properties in AND and EQUALS nodes
// of joins.
if (topNode instanceof ExprEqualsNode) {
ExprEqualsNode equalsNode = (ExprEqualsNode) topNode;
if (!equalsNode.isNotEquals()) {
analyzeEqualsNode(equalsNode, queryGraph, isOuterJoin);
}
} else if (topNode instanceof ExprAndNode) {
ExprAndNode andNode = (ExprAndNode) topNode;
analyzeAndNode(andNode, queryGraph, isOuterJoin);
} else if (topNode instanceof ExprBetweenNode) {
ExprBetweenNode betweenNode = (ExprBetweenNode) topNode;
analyzeBetweenNode(betweenNode, queryGraph);
} else if (topNode instanceof ExprRelationalOpNode) {
ExprRelationalOpNode relNode = (ExprRelationalOpNode) topNode;
analyzeRelationalOpNode(relNode, queryGraph);
} else if (topNode instanceof ExprDotNode && !isOuterJoin) {
ExprDotNode dotNode = (ExprDotNode) topNode;
analyzeDotNode(dotNode, queryGraph);
}
}