}
expr = ExpressionTreeMaterializer.materialize(namedExpression.getExpr(), incoming, collector, context.getFunctionRegistry(), true);
final MaterializedField outputField = MaterializedField.create(outputName, expr.getMajorType());
if (collector.hasErrors()) {
throw new SchemaChangeException(String.format("Failure while trying to materialize incoming schema. Errors:\n %s.", collector.toErrorString()));
}
if (expr instanceof DrillFuncHolderExpr &&
((DrillFuncHolderExpr) expr).isComplexWriterFuncHolder()) {
// Need to process ComplexWriter function evaluation.
// Lazy initialization of the list of complex writers, if not done yet.
if (complexWriters == null) {
complexWriters = Lists.newArrayList();
}
// The reference name will be passed to ComplexWriter, used as the name of the output vector from the writer.
((DrillComplexWriterFuncHolder) ((DrillFuncHolderExpr) expr).getHolder()).setReference(namedExpression.getRef());
cg.addExpr(expr);
} else{
// need to do evaluation.
ValueVector vector = TypeHelper.getNewVector(outputField, oContext.getAllocator());
allocationVectors.add(vector);
TypedFieldId fid = container.add(vector);
ValueVectorWriteExpression write = new ValueVectorWriteExpression(fid, expr, true);
HoldingContainer hc = cg.addExpr(write);
cg.getEvalBlock()._if(hc.getValue().eq(JExpr.lit(0)))._then()._return(JExpr.FALSE);
logger.debug("Added eval for project expression.");
}
}
cg.rotateBlock();
cg.getEvalBlock()._return(JExpr.TRUE);
container.buildSchema(SelectionVectorMode.NONE);
try {
this.flattener = context.getImplementationClass(cg.getCodeGenerator());
flattener.setup(context, incoming, this, transfers);
} catch (ClassTransformationException | IOException e) {
throw new SchemaChangeException("Failure while attempting to load generated class", e);
}
return true;
}