/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to you under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package net.hydromatic.optiq.impl.interpreter;
import net.hydromatic.linq4j.Enumerable;
import net.hydromatic.linq4j.Enumerator;
import net.hydromatic.linq4j.Queryable;
import net.hydromatic.linq4j.function.Function1;
import net.hydromatic.optiq.DataContext;
import net.hydromatic.optiq.QueryableTable;
import net.hydromatic.optiq.SchemaPlus;
import net.hydromatic.optiq.Schemas;
import org.eigenbase.rel.TableAccessRelBase;
import org.eigenbase.util.Util;
import com.google.common.collect.ImmutableList;
import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import java.lang.reflect.Type;
import java.util.List;
/**
* Interpreter node that implements a
* {@link org.eigenbase.rel.TableAccessRelBase}.
*/
public class ScanNode implements Node {
private final Sink sink;
private final TableAccessRelBase rel;
private final DataContext root;
public ScanNode(Interpreter interpreter, TableAccessRelBase rel) {
this.rel = rel;
this.sink = interpreter.sink(rel);
this.root = interpreter.getDataContext();
}
public void run() throws InterruptedException {
final Enumerable<Row> iterable = iterable();
final Enumerator<Row> enumerator = iterable.enumerator();
while (enumerator.moveNext()) {
sink.send(enumerator.current());
}
enumerator.close();
sink.end();
}
private Enumerable<Row> iterable() {
//noinspection unchecked
Enumerable<Row> iterable = rel.getTable().unwrap(Enumerable.class);
if (iterable != null) {
return iterable;
}
final QueryableTable queryableTable =
rel.getTable().unwrap(QueryableTable.class);
if (queryableTable != null) {
final Type elementType = queryableTable.getElementType();
SchemaPlus schema = root.getRootSchema();
for (String name : Util.skipLast(rel.getTable().getQualifiedName())) {
schema = schema.getSubSchema(name);
}
if (elementType instanceof Class) {
//noinspection unchecked
final Queryable<Object> queryable = Schemas.queryable(root,
(Class) elementType, rel.getTable().getQualifiedName());
ImmutableList.Builder<Field> fieldBuilder = ImmutableList.builder();
Class type = (Class) elementType;
for (Field field : type.getFields()) {
if (Modifier.isPublic(field.getModifiers())
&& !Modifier.isStatic(field.getModifiers())) {
fieldBuilder.add(field);
}
}
final List<Field> fields = fieldBuilder.build();
return queryable.select(
new Function1<Object, Row>() {
public Row apply(Object o) {
final Object[] values = new Object[fields.size()];
for (int i = 0; i < fields.size(); i++) {
Field field = fields.get(i);
try {
values[i] = field.get(o);
} catch (IllegalAccessException e) {
throw new RuntimeException(e);
}
}
return new Row(values);
}
});
} else {
return Schemas.queryable(root, Row.class,
rel.getTable().getQualifiedName());
}
}
throw new AssertionError("cannot convert table " + rel.getTable()
+ " to iterable");
}
}
// End ScanNode.java