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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.adapter.file;

import org.apache.calcite.DataContext;
import org.apache.calcite.adapter.java.JavaTypeFactory;
import org.apache.calcite.linq4j.AbstractEnumerable;
import org.apache.calcite.linq4j.Enumerable;
import org.apache.calcite.linq4j.Enumerator;
import org.apache.calcite.linq4j.QueryProvider;
import org.apache.calcite.linq4j.Queryable;
import org.apache.calcite.linq4j.tree.Expression;
import org.apache.calcite.plan.RelOptTable;
import org.apache.calcite.rel.RelNode;
import org.apache.calcite.rel.type.RelProtoDataType;
import org.apache.calcite.schema.QueryableTable;
import org.apache.calcite.schema.SchemaPlus;
import org.apache.calcite.schema.Schemas;
import org.apache.calcite.schema.TranslatableTable;
import org.apache.calcite.util.ImmutableIntList;
import org.apache.calcite.util.Source;

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

import java.lang.reflect.Type;
import java.util.concurrent.atomic.AtomicBoolean;

/**
 * Table based on a CSV file.
 *
 * 

Copied from {@code CsvTranslatableTable} in demo CSV adapter, * with more advanced features. */ public class CsvTranslatableTable extends CsvTable implements QueryableTable, TranslatableTable { /** Creates a CsvTable. */ CsvTranslatableTable(Source source, @Nullable RelProtoDataType protoRowType) { super(source, protoRowType); } @Override public String toString() { return "CsvTranslatableTable"; } /** Returns an enumerable over a given projection of the fields. */ @SuppressWarnings("unused") // called from generated code public Enumerable project(final DataContext root, final int[] fields) { final AtomicBoolean cancelFlag = DataContext.Variable.CANCEL_FLAG.get(root); return new AbstractEnumerable() { @Override public Enumerator enumerator() { JavaTypeFactory typeFactory = root.getTypeFactory(); return new CsvEnumerator<>(source, cancelFlag, getFieldTypes(typeFactory), ImmutableIntList.of(fields)); } }; } @Override public Expression getExpression(SchemaPlus schema, String tableName, Class clazz) { return Schemas.tableExpression(schema, getElementType(), tableName, clazz); } @Override public Type getElementType() { return Object[].class; } @Override public Queryable asQueryable(QueryProvider queryProvider, SchemaPlus schema, String tableName) { throw new UnsupportedOperationException(); } @Override public RelNode toRel( RelOptTable.ToRelContext context, RelOptTable relOptTable) { // Request all fields. final int fieldCount = relOptTable.getRowType().getFieldCount(); final int[] fields = CsvEnumerator.identityList(fieldCount); return new CsvTableScan(context.getCluster(), relOptTable, this, fields); } }