@Override
public ParseContext transform(ParseContext pctx) throws SemanticException {
pGraphContext = pctx;
// create a the context for walking operators
OpWalkerInfo opWalkerInfo = new OpWalkerInfo(pGraphContext);
Map<Rule, NodeProcessor> opRules = new LinkedHashMap<Rule, NodeProcessor>();
opRules.put(
new RuleRegExp("R1", FilterOperator.getOperatorName() + "%"),
OpProcFactory.getFilterProc());
opRules.put(
new RuleRegExp("R2", PTFOperator.getOperatorName() + "%"), OpProcFactory.getPTFProc());
opRules.put(
new RuleRegExp("R3", CommonJoinOperator.getOperatorName() + "%"),
OpProcFactory.getJoinProc());
opRules.put(
new RuleRegExp("R4", TableScanOperator.getOperatorName() + "%"), OpProcFactory.getTSProc());
opRules.put(
new RuleRegExp("R5", ScriptOperator.getOperatorName() + "%"), OpProcFactory.getSCRProc());
opRules.put(
new RuleRegExp("R6", LimitOperator.getOperatorName() + "%"), OpProcFactory.getLIMProc());
opRules.put(
new RuleRegExp("R7", UDTFOperator.getOperatorName() + "%"), OpProcFactory.getUDTFProc());
opRules.put(
new RuleRegExp("R8", LateralViewForwardOperator.getOperatorName() + "%"),
OpProcFactory.getLVFProc());
opRules.put(
new RuleRegExp("R9", LateralViewJoinOperator.getOperatorName() + "%"),
OpProcFactory.getLVJProc());
opRules.put(
new RuleRegExp("R10", ReduceSinkOperator.getOperatorName() + "%"),
OpProcFactory.getRSProc());
// The dispatcher fires the processor corresponding to the closest matching
// rule and passes the context along
Dispatcher disp =
new DefaultRuleDispatcher(OpProcFactory.getDefaultProc(), opRules, opWalkerInfo);
GraphWalker ogw = new DefaultGraphWalker(disp);
// Create a list of topop nodes
ArrayList<Node> topNodes = new ArrayList<Node>();
topNodes.addAll(pGraphContext.getTopOps().values());
ogw.startWalking(topNodes, null);
if (LOG.isDebugEnabled()) {
LOG.debug("After PPD:\n" + Operator.toString(pctx.getTopOps().values()));
}
return pGraphContext;
}
@Override
public Object process(Node nd, Stack<Node> stack, NodeProcessorCtx ctx, Object... nodeOutputs)
throws SemanticException {
LateralViewJoinOperator op = (LateralViewJoinOperator) nd;
ColumnPrunerProcCtx cppCtx = (ColumnPrunerProcCtx) ctx;
List<String> cols = cppCtx.genColLists(op);
if (cols == null) {
return null;
}
Map<String, ExprNodeDesc> colExprMap = op.getColumnExprMap();
// As columns go down the DAG, the LVJ will transform internal column
// names from something like 'key' to '_col0'. Because of this, we need
// to undo this transformation using the column expression map as the
// column names propagate up the DAG.
// this is SEL(*) cols + UDTF cols
List<String> outputCols = op.getConf().getOutputInternalColNames();
// cause we cannot prune columns from UDTF branch currently, extract
// columns from SEL(*) branch only and append all columns from UDTF branch to it
int numSelColumns = op.getConf().getNumSelColumns();
List<String> colsAfterReplacement = new ArrayList<String>();
ArrayList<String> newColNames = new ArrayList<String>();
for (String col : cols) {
int index = outputCols.indexOf(col);
// colExprMap.size() == size of cols from SEL(*) branch
if (index >= 0 && index < numSelColumns) {
ExprNodeDesc transformed = colExprMap.get(col);
Utilities.mergeUniqElems(colsAfterReplacement, transformed.getCols());
newColNames.add(col);
}
}
// update number of columns from sel(*)
op.getConf().setNumSelColumns(newColNames.size());
// add all UDTF columns
// following SEL will do CP for columns from UDTF, not adding SEL in here
newColNames.addAll(outputCols.subList(numSelColumns, outputCols.size()));
op.getConf().setOutputInternalColNames(newColNames);
pruneOperator(ctx, op, newColNames);
cppCtx.getPrunedColLists().put(op, colsAfterReplacement);
return null;
}
