testkit/src/main/java/org/apache/calcite/test/schemata/orderstream/InfiniteOrdersTable.java

/*
 * 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.test.schemata.orderstream;

import org.apache.calcite.DataContext;
import org.apache.calcite.linq4j.Enumerable;
import org.apache.calcite.linq4j.Linq4j;
import org.apache.calcite.schema.StreamableTable;
import org.apache.calcite.schema.Table;

import org.checkerframework.checker.nullness.qual.Nullable;

import java.util.Iterator;

/**
 * Table representing an infinitely larger ORDERS stream.
 */
public class InfiniteOrdersTable extends BaseOrderStreamTable
    implements StreamableTable {
  public Enumerable<@Nullable Object[]> scan(DataContext root) {
    return Linq4j.asEnumerable(() -> new Iterator<Object[]>() {
      private final String[] items = {"paint", "paper", "brush"};
      private int counter = 0;

      public boolean hasNext() {
        return true;
      }

      public Object[] next() {
        final int index = counter++;
        return new Object[]{
            System.currentTimeMillis(), index, items[index % items.length], 10};
      }

      public void remove() {
        throw new UnsupportedOperationException();
      }
    });
  }

  public Table stream() {
    return this;
  }
}