@Override
public ParseContext transform(ParseContext pctx) throws SemanticException {
pGraphContext = pctx;
Map<Rule, NodeProcessor> opRules = new LinkedHashMap<Rule, NodeProcessor>();
opRules.put(
new RuleRegExp(
"R1",
"("
+ FilterOperator.getOperatorName()
+ "%"
+ ReduceSinkOperator.getOperatorName()
+ "%"
+ JoinOperator.getOperatorName()
+ "%)"),
new JoinTransitive());
// The dispatcher fires the processor corresponding to the closest matching
// rule and passes the context along
TransitiveContext context = new TransitiveContext();
Dispatcher disp = new DefaultRuleDispatcher(null, opRules, context);
GraphWalker ogw = new LevelOrderWalker(disp, 2);
// Create a list of topop nodes
List<Node> topNodes = new ArrayList<Node>();
topNodes.addAll(pGraphContext.getTopOps().values());
ogw.startWalking(topNodes, null);
Map<ReduceSinkOperator, List<ExprNodeDesc>> newFilters = context.getNewfilters();
// insert new filter between RS and parent of RS
for (Map.Entry<ReduceSinkOperator, List<ExprNodeDesc>> entry : newFilters.entrySet()) {
ReduceSinkOperator reducer = entry.getKey();
Operator<?> parent = reducer.getParentOperators().get(0);
List<ExprNodeDesc> exprs = entry.getValue();
if (parent instanceof FilterOperator) {
exprs = ExprNodeDescUtils.split(((FilterOperator) parent).getConf().getPredicate(), exprs);
ExprNodeDesc merged = ExprNodeDescUtils.mergePredicates(exprs);
((FilterOperator) parent).getConf().setPredicate(merged);
} else {
ExprNodeDesc merged = ExprNodeDescUtils.mergePredicates(exprs);
RowSchema parentRS = parent.getSchema();
Operator<FilterDesc> newFilter = createFilter(reducer, parent, parentRS, merged);
}
}
return pGraphContext;
}
