com.hazelcast.org.apache.calcite.adapter.clone.ListTable Maven / Gradle / Ivy
/*
* 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 com.hazelcast.org.apache.calcite.adapter.clone;
import com.hazelcast.org.apache.calcite.adapter.java.AbstractQueryableTable;
import com.hazelcast.org.apache.calcite.linq4j.AbstractQueryable;
import com.hazelcast.org.apache.calcite.linq4j.Enumerator;
import com.hazelcast.org.apache.calcite.linq4j.Linq4j;
import com.hazelcast.org.apache.calcite.linq4j.QueryProvider;
import com.hazelcast.org.apache.calcite.linq4j.Queryable;
import com.hazelcast.org.apache.calcite.linq4j.tree.Expression;
import com.hazelcast.org.apache.calcite.rel.type.RelDataType;
import com.hazelcast.org.apache.calcite.rel.type.RelDataTypeFactory;
import com.hazelcast.org.apache.calcite.rel.type.RelProtoDataType;
import com.hazelcast.org.apache.calcite.schema.SchemaPlus;
import com.hazelcast.org.apache.calcite.schema.Statistic;
import com.hazelcast.org.apache.calcite.schema.Statistics;
import com.hazelcast.com.google.common.collect.ImmutableList;
import java.lang.reflect.Type;
import java.util.Iterator;
import java.util.List;
/**
* Implementation of table that reads rows from a read-only list and returns
* an enumerator of rows. Each row is object (if there is just one column) or
* an object array (if there are multiple columns).
*/
class ListTable extends AbstractQueryableTable {
private final RelProtoDataType protoRowType;
private final Expression expression;
private final List list;
/** Creates a ListTable. */
ListTable(
Type elementType,
RelProtoDataType protoRowType,
Expression expression,
List list) {
super(elementType);
this.protoRowType = protoRowType;
this.expression = expression;
this.list = list;
}
public RelDataType getRowType(RelDataTypeFactory typeFactory) {
return protoRowType.apply(typeFactory);
}
public Statistic getStatistic() {
return Statistics.of(list.size(), ImmutableList.of());
}
public Queryable asQueryable(final QueryProvider queryProvider,
SchemaPlus schema, String tableName) {
return new AbstractQueryable() {
public Type getElementType() {
return elementType;
}
public Expression getExpression() {
return expression;
}
public QueryProvider getProvider() {
return queryProvider;
}
public Iterator iterator() {
//noinspection unchecked
return list.iterator();
}
public Enumerator enumerator() {
//noinspection unchecked
return Linq4j.enumerator(list);
}
};
}
}