org.apache.calcite.chinook.PreferredGenresTableFactory.java Source code

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Here is the source code for org.apache.calcite.chinook.PreferredGenresTableFactory.java

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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 org.apache.calcite.chinook;

import org.apache.calcite.adapter.java.AbstractQueryableTable;
import org.apache.calcite.linq4j.Linq4j;
import org.apache.calcite.linq4j.QueryProvider;
import org.apache.calcite.linq4j.Queryable;
import org.apache.calcite.rel.type.RelDataType;
import org.apache.calcite.rel.type.RelDataTypeFactory;
import org.apache.calcite.schema.SchemaPlus;
import org.apache.calcite.schema.TableFactory;
import org.apache.calcite.sql.type.SqlTypeName;

import com.google.common.collect.ContiguousSet;
import com.google.common.collect.DiscreteDomain;
import com.google.common.collect.Range;

import java.util.Map;

/**
 * Factory for the table of genres preferred by the current user.
 */
public class PreferredGenresTableFactory implements TableFactory<AbstractQueryableTable> {
    private static final Integer[] SPECIFIC_USER_PREFERRED_GENRES = { 1, 2, 7, 9, 15 };
    private static final int FIRST_ID = 1;
    private static final int LAST_ID = 25;

    @Override
    public AbstractQueryableTable create(SchemaPlus schema, String name, Map<String, Object> operand,
            RelDataType rowType) {
        return new AbstractQueryableTable(Integer.class) {
            @Override
            public RelDataType getRowType(RelDataTypeFactory typeFactory) {
                return typeFactory.builder().add("ID", SqlTypeName.INTEGER).build();
            }

            @Override
            public Queryable<Integer> asQueryable(QueryProvider qp, SchemaPlus sp, String string) {
                return fetchPreferredGenres();
            }
        };
    }

    private Queryable<Integer> fetchPreferredGenres() {
        if (EnvironmentFairy.getUser() == EnvironmentFairy.User.SPECIFIC_USER) {
            return Linq4j.asEnumerable(SPECIFIC_USER_PREFERRED_GENRES).asQueryable();
        } else {
            final ContiguousSet<Integer> set = ContiguousSet.create(Range.closed(FIRST_ID, LAST_ID),
                    DiscreteDomain.integers());
            return Linq4j.asEnumerable(set).asQueryable();
        }
    }
}

// End PreferredGenresTableFactory.java