private HoldingContainer generateEval(ClassGenerator<?> g, HoldingContainer[] inputVariables, JVar[] workspaceJVars) {
HoldingContainer out = g.declare(returnType);
JCodeModel m = g.getModel();
JBlock sub = new JBlock(true, true);
// initialize DeferredObject's. For an optional type, assign the value holder only if it is not null
for(int i=0; i<argTypes.length; i++) {
if (inputVariables[i].isOptional()) {
JBlock conditionalBlock = new JBlock(false, false);
JConditional jc = conditionalBlock._if(inputVariables[i].getIsSet().ne(JExpr.lit(0)));
jc._then().assign(workspaceJVars[3].component(JExpr.lit(i)), workspaceJVars[2].component(JExpr.lit(i)));
jc._then().assign(JExpr.ref(workspaceJVars[3].component(JExpr.lit(i)), "valueHolder"), inputVariables[i].getHolder());
jc._else().assign(workspaceJVars[3].component(JExpr.lit(i)), JExpr._null());
sub.add(conditionalBlock);
} else {
sub.assign(workspaceJVars[3].component(JExpr.lit(i)), workspaceJVars[2].component(JExpr.lit(i)));
sub.assign(JExpr.ref(workspaceJVars[3].component(JExpr.lit(i)), "valueHolder"), inputVariables[i].getHolder());
}
}
// declare generic object for storing return value from GenericUDF.evaluate
JVar retVal = sub.decl(m._ref(Object.class), "ret");
// create try..catch block to call the GenericUDF instance with given input
JTryBlock udfEvalTry = sub._try();
udfEvalTry.body().assign(retVal,
workspaceJVars[1].invoke("evaluate").arg(workspaceJVars[3]));
JCatchBlock udfEvalCatch = udfEvalTry._catch(m.directClass(Exception.class.getCanonicalName()));
JVar exVar = udfEvalCatch.param("ex");
udfEvalCatch.body()
._throw(JExpr._new(m.directClass(RuntimeException.class.getCanonicalName()))
.arg(JExpr.lit(String.format("GenericUDF.evaluate method failed"))).arg(exVar));
// get the ValueHolder from retVal and return ObjectInspector
sub.add(ObjectInspectorHelper.getDrillObject(m, returnOI, workspaceJVars[0], workspaceJVars[4], retVal));
sub.assign(out.getHolder(), workspaceJVars[4]);
// now add it to the doEval block in Generated class
JBlock setup = g.getBlock(ClassGenerator.BlockType.EVAL);
setup.directStatement(String.format("/** start %s for function %s **/ ",
ClassGenerator.BlockType.EVAL.name(), genericUdfClazz.getName() + (!isGenericUDF ? "("+udfName+")" : "")));
setup.add(sub);
setup.directStatement(String.format("/** end %s for function %s **/ ",
ClassGenerator.BlockType.EVAL.name(), genericUdfClazz.getName() + (!isGenericUDF ? "("+udfName+")" : "")));
return out;
}