com.hazelcast.shaded.org.apache.calcite.linq4j.BaseQueryable Maven / Gradle / Ivy
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* 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.shaded.org.apache.calcite.linq4j;
import com.hazelcast.shaded.org.apache.calcite.linq4j.tree.Expression;
import com.hazelcast.shaded.org.checkerframework.checker.nullness.qual.Nullable;
import java.lang.reflect.Type;
import java.util.Iterator;
/**
* Skeleton implementation of {@link Queryable}.
*
* The default implementation of {@link #enumerator()} calls the provider's
* {@link QueryProvider#executeQuery(Queryable)} method, but the derived class
* can override.
*
* @param Element type
*/
public abstract class BaseQueryable
extends AbstractQueryable {
protected final QueryProvider provider;
protected final Type elementType;
protected final @Nullable Expression expression;
protected BaseQueryable(QueryProvider provider, Type elementType,
@Nullable Expression expression) {
this.provider = provider;
this.elementType = elementType;
this.expression = expression;
}
@Override public QueryProvider getProvider() {
return provider;
}
@Override public Type getElementType() {
return elementType;
}
@Override public @Nullable Expression getExpression() {
return expression;
}
@Override public Iterator iterator() {
return Linq4j.enumeratorIterator(enumerator());
}
@Override public Enumerator enumerator() {
return provider.executeQuery(this);
}
}