core/src/main/java/org/apache/calcite/jdbc/CalciteStatement.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.jdbc;

import org.apache.calcite.avatica.AvaticaStatement;
import org.apache.calcite.avatica.Meta;
import org.apache.calcite.avatica.NoSuchStatementException;
import org.apache.calcite.linq4j.Queryable;
import org.apache.calcite.server.CalciteServerStatement;

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

import java.sql.SQLException;

/**
 * Implementation of {@link java.sql.Statement}
 * for the Calcite engine.
 */
public abstract class CalciteStatement extends AvaticaStatement {
  /**
   * Creates a CalciteStatement.
   *
   * @param connection Connection
   * @param h Statement handle
   * @param resultSetType Result set type
   * @param resultSetConcurrency Result set concurrency
   * @param resultSetHoldability Result set holdability
   */
  CalciteStatement(CalciteConnectionImpl connection, Meta.@Nullable StatementHandle h,
      int resultSetType, int resultSetConcurrency, int resultSetHoldability) {
    super(connection, h, resultSetType, resultSetConcurrency,
        resultSetHoldability);
  }

  // implement Statement

  @Override public <T> T unwrap(Class<T> iface) throws SQLException {
    if (iface == CalciteServerStatement.class) {
      final CalciteServerStatement statement;
      try {
        statement = getConnection().server.getStatement(handle);
      } catch (NoSuchStatementException e) {
        throw new AssertionError("invalid statement", e);
      }
      return iface.cast(statement);
    }
    return super.unwrap(iface);
  }

  @Override public CalciteConnectionImpl getConnection() {
    return (CalciteConnectionImpl) connection;
  }

  protected <T> CalcitePrepare.CalciteSignature<T> prepare(
      Queryable<T> queryable) {
    final CalciteConnectionImpl calciteConnection = getConnection();
    final CalcitePrepare prepare = calciteConnection.prepareFactory.apply();
    final CalciteServerStatement serverStatement;
    try {
      serverStatement = calciteConnection.server.getStatement(handle);
    } catch (NoSuchStatementException e) {
      throw new AssertionError("invalid statement", e);
    }
    final CalcitePrepare.Context prepareContext =
        serverStatement.createPrepareContext();
    return prepare.prepareQueryable(prepareContext, queryable);
  }

  @Override protected void close_() {
    if (!closed) {
      ((CalciteConnectionImpl) connection).server.removeStatement(handle);
      super.close_();
    }
  }
}