/** Deduces the names and types of a table's columns by reading the first line of a CSV file. */
static RelDataType deduceRowType(
JavaTypeFactory typeFactory, File file, List<CsvFieldType> fieldTypes) {
final List<RelDataType> types = new ArrayList<RelDataType>();
final List<String> names = new ArrayList<String>();
CSVReader reader = null;
try {
reader = openCsv(file);
final String[] strings = reader.readNext();
for (String string : strings) {
final String name;
final CsvFieldType fieldType;
final int colon = string.indexOf(':');
if (colon >= 0) {
name = string.substring(0, colon);
String typeString = string.substring(colon + 1);
fieldType = CsvFieldType.of(typeString);
if (fieldType == null) {
System.out.println(
"WARNING: Found unknown type: "
+ typeString
+ " in file: "
+ file.getAbsolutePath()
+ " for column: "
+ name
+ ". Will assume the type of column is string");
}
} else {
name = string;
fieldType = null;
}
final RelDataType type;
if (fieldType == null) {
type = typeFactory.createJavaType(String.class);
} else {
type = fieldType.toType(typeFactory);
}
names.add(name);
types.add(type);
if (fieldTypes != null) {
fieldTypes.add(fieldType);
}
}
} catch (IOException e) {
// ignore
} finally {
if (reader != null) {
try {
reader.close();
} catch (IOException e) {
// ignore
}
}
}
if (names.isEmpty()) {
names.add("line");
types.add(typeFactory.createJavaType(String.class));
}
return typeFactory.createStructType(Pair.zip(names, types));
}
private static List<Integer> nullableArgs(List<Integer> list0, List<RelDataType> types) {
final List<Integer> list = new ArrayList<Integer>();
for (Pair<Integer, RelDataType> pair : Pair.zip(list0, types)) {
if (pair.right.isNullable()) {
list.add(pair.left);
}
}
return list;
}
/**
* Catch-all implementation for {@link BuiltInMetadata.Size#averageRowSize()}, invoked using
* reflection.
*
* @see org.apache.calcite.rel.metadata.RelMetadataQuery#getAverageRowSize
*/
public Double averageRowSize(RelNode rel, RelMetadataQuery mq) {
final List<Double> averageColumnSizes = mq.getAverageColumnSizes(rel);
if (averageColumnSizes == null) {
return null;
}
Double d = 0d;
final List<RelDataTypeField> fields = rel.getRowType().getFieldList();
for (Pair<Double, RelDataTypeField> p : Pair.zip(averageColumnSizes, fields)) {
if (p.left == null) {
d += averageFieldValueSize(p.right);
} else {
d += p.left;
}
}
return d;
}