final ErrorCollector collector = new ErrorCollectorImpl();
final List<TransferPair> transfers = Lists.newArrayList();
final ClassGenerator<Projector> cg = CodeGenerator.getRoot(Projector.TEMPLATE_DEFINITION, context.getFunctionRegistry());
IntOpenHashSet transferFieldIds = new IntOpenHashSet();
boolean isAnyWildcard = false;
ClassifierResult result = new ClassifierResult();
boolean classify = isClassificationNeeded(exprs);
for (int i = 0; i < exprs.size(); i++) {
final NamedExpression namedExpression = exprs.get(i);
result.clear();
if (classify && namedExpression.getExpr() instanceof SchemaPath) {
classifyExpr(namedExpression, incoming, result);
if (result.isStar) {
isAnyWildcard = true;
Integer value = result.prefixMap.get(result.prefix);
if (value != null && value.intValue() == 1) {
int k = 0;
for (VectorWrapper<?> wrapper : incoming) {
ValueVector vvIn = wrapper.getValueVector();
SchemaPath originalPath = vvIn.getField().getPath();
if (k > result.outputNames.size()-1) {
assert false;
}
String name = result.outputNames.get(k++); // get the renamed column names
if (name == EMPTY_STRING) {
continue;
}
FieldReference ref = new FieldReference(name);
ValueVector vvOut = container.addOrGet(MaterializedField.create(ref, vvIn.getField().getType()));
TransferPair tp = vvIn.makeTransferPair(vvOut);
transfers.add(tp);
}
} else if (value != null && value.intValue() > 1) { // subsequent wildcards should do a copy of incoming valuevectors
int k = 0;
for (VectorWrapper<?> wrapper : incoming) {
ValueVector vvIn = wrapper.getValueVector();
SchemaPath originalPath = vvIn.getField().getPath();
if (k > result.outputNames.size()-1) {
assert false;
}
String name = result.outputNames.get(k++); // get the renamed column names
if (name == EMPTY_STRING) {
continue;
}
final LogicalExpression expr = ExpressionTreeMaterializer.materialize(originalPath, incoming, collector, context.getFunctionRegistry() );
if (collector.hasErrors()) {
throw new SchemaChangeException(String.format("Failure while trying to materialize incoming schema. Errors:\n %s.", collector.toErrorString()));
}
MaterializedField outputField = MaterializedField.create(name, expr.getMajorType());
ValueVector vv = container.addOrGet(outputField);
allocationVectors.add(vv);
TypedFieldId fid = container.getValueVectorId(outputField.getPath());
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);
}
}
continue;
}
}
String outputName = getRef(namedExpression).getRootSegment().getPath();
if (result != null && result.outputNames != null && result.outputNames.size() > 0) {
for (int j = 0; j < result.outputNames.size(); j++) {
if (!result.outputNames.get(j).equals(EMPTY_STRING)) {
outputName = result.outputNames.get(j);
break;
}
}
}
final LogicalExpression 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()));
}
// add value vector to transfer if direct reference and this is allowed, otherwise, add to evaluation stack.
if (expr instanceof ValueVectorReadExpression && incoming.getSchema().getSelectionVectorMode() == SelectionVectorMode.NONE
&& !((ValueVectorReadExpression) expr).hasReadPath()
&& !isAnyWildcard
&& !transferFieldIds.contains(((ValueVectorReadExpression) expr).getFieldId().getFieldIds()[0])) {
ValueVectorReadExpression vectorRead = (ValueVectorReadExpression) expr;
TypedFieldId id = vectorRead.getFieldId();
ValueVector vvIn = incoming.getValueAccessorById(id.getIntermediateClass(), id.getFieldIds()).getValueVector();
Preconditions.checkNotNull(incoming);
FieldReference ref = getRef(namedExpression);
ValueVector vvOut = container.addOrGet(MaterializedField.create(ref, vectorRead.getMajorType()));
TransferPair tp = vvIn.makeTransferPair(vvOut);
transfers.add(tp);
transferFieldIds.add(vectorRead.getFieldId().getFieldIds()[0]);
logger.debug("Added transfer for project expression.");
} else 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.