@JsonCreator
public Project(@JsonProperty("projections") NamedExpression[] selections) {
this.selections = selections;
if (selections == null || selections.length == 0)
throw new ExpressionParsingException(
"Project did not provide any projection selections. At least one projection must be provided.");
for (int i = 0; i < selections.length; i++) {
PathSegment segment = selections[i].getRef().getRootSegment();
CharSequence path = segment.getNameSegment().getPath();
if (!segment.isNamed() || !path.equals("output"))
throw new ExpressionParsingException(
String.format(
"Outputs for projections always have to start with named path of output. First segment was named '%s' or was named [%s]",
path, segment.isNamed()));
}
}
// This function assumes that the fields in the schema parameter are in the same order as the
// fields in the columns parameter. The
// columns parameter may have fields that are not present in the schema, though.
public DrillParquetGroupConverter(
OutputMutator mutator,
MapWriter mapWriter,
GroupType schema,
Collection<SchemaPath> columns,
OptionManager options) {
this.mapWriter = mapWriter;
this.mutator = mutator;
converters = Lists.newArrayList();
this.options = options;
Iterator<SchemaPath> colIterator = columns.iterator();
for (Type type : schema.getFields()) {
Repetition rep = type.getRepetition();
boolean isPrimitive = type.isPrimitive();
// Match the name of the field in the schema definition to the name of the field in the query.
String name = null;
SchemaPath col = null;
PathSegment colPath = null;
PathSegment colNextChild = null;
while (colIterator.hasNext()) {
col = colIterator.next();
colPath = col.getRootSegment();
colNextChild = colPath.getChild();
if (colPath != null
&& colPath.isNamed()
&& (!colPath.getNameSegment().getPath().equals("*"))) {
name = colPath.getNameSegment().getPath();
// We may have a field that does not exist in the schema
if (!name.equalsIgnoreCase(type.getName())) {
continue;
}
}
break;
}
if (name == null) {
name = type.getName();
}
if (!isPrimitive) {
Collection<SchemaPath> c = new ArrayList<SchemaPath>();
while (colNextChild != null) {
if (colNextChild.isNamed()) {
break;
}
colNextChild = colNextChild.getChild();
}
if (colNextChild != null) {
SchemaPath s = new SchemaPath(colNextChild.getNameSegment());
c.add(s);
}
if (rep != Repetition.REPEATED) {
DrillParquetGroupConverter converter =
new DrillParquetGroupConverter(
mutator, mapWriter.map(name), type.asGroupType(), c, options);
converters.add(converter);
} else {
DrillParquetGroupConverter converter =
new DrillParquetGroupConverter(
mutator, mapWriter.list(name).map(), type.asGroupType(), c, options);
converters.add(converter);
}
} else {
PrimitiveConverter converter = getConverterForType(name, type.asPrimitiveType());
converters.add(converter);
}
}
}