private void buildSelectListEvaluators() throws SemanticException, HiveException {
resultExprInfo = new ResultExprInfo();
resultExprInfo.resultExprEvals = new ArrayList<ExprNodeEvaluator>();
resultExprInfo.resultExprNames = new ArrayList<String>();
resultExprInfo.resultExprNodes = new ArrayList<ExprNodeDesc>();
// result
ArrayList<ObjectInspector> selectListExprOIs = new ArrayList<ObjectInspector>();
int i = 0;
for (WindowExpressionSpec expr : selectSpec) {
String selectColName = expr.getAlias();
ASTNode selectColumnNode = expr.getExpression();
ExprNodeDesc selectColumnExprNode =
ResultExpressionParser.buildExprNode(selectColumnNode, selectListInputTypeCheckCtx);
ExprNodeEvaluator selectColumnExprEval = ExprNodeEvaluatorFactory.get(selectColumnExprNode);
ObjectInspector selectColumnOI = null;
selectColumnOI = selectColumnExprEval.initialize(selectListInputOI);
selectColName = getColumnName(selectColName, selectColumnExprNode, i);
resultExprInfo.resultExprEvals.add(selectColumnExprEval);
selectListExprOIs.add(selectColumnOI);
resultExprInfo.resultExprNodes.add(selectColumnExprNode);
resultExprInfo.resultExprNames.add(selectColName);
i++;
}
resultExprInfo.resultOI =
ObjectInspectorFactory.getStandardStructObjectInspector(
resultExprInfo.resultExprNames, selectListExprOIs);
}
/**
*
*
* <ul>
* <li>check structure of Arguments:
* <ol>
* <li>First arg should be a String
* <li>then there should be an even number of Arguments: String, expression; expression
* should be Convertible to Boolean.
* <li>finally there should be a String.
* </ol>
* <li>convert pattern into a NNode chain.
* <li>convert symbol args into a Symbol Map.
* <li>parse selectList into SelectList struct. The inputOI used to translate these
* expressions should be based on the columns in the Input, the 'path.attr'
* </ul>
*/
@Override
public void setupOutputOI() throws SemanticException {
MatchPath evaluator = (MatchPath) getEvaluator();
PartitionedTableFunctionDef tDef = evaluator.getTableDef();
List<PTFExpressionDef> args = tDef.getArgs();
int argsNum = args == null ? 0 : args.size();
if (argsNum < 4) {
throwErrorWithSignature("at least 4 arguments required");
}
validateAndSetupPatternStr(evaluator, args);
validateAndSetupSymbolInfo(evaluator, args, argsNum);
validateAndSetupResultExprStr(evaluator, args, argsNum);
setupSymbolFunctionChain(evaluator);
/*
* setup OI for input to resultExpr select list
*/
RowResolver selectListInputRR = MatchPath.createSelectListRR(evaluator, tDef.getInput());
/*
* parse ResultExpr Str and setup OI.
*/
ResultExpressionParser resultExprParser =
new ResultExpressionParser(evaluator.resultExprStr, selectListInputRR);
try {
resultExprParser.translate();
} catch (HiveException he) {
throw new SemanticException(he);
}
evaluator.resultExprInfo = resultExprParser.getResultExprInfo();
StructObjectInspector OI = evaluator.resultExprInfo.resultOI;
setOutputOI(OI);
}
