content: /*
   * Copyright (c) 2015, 2020, Oracle and/or its affiliates.
   *
   * This program is free software; you can redistribute it and/or modify it under
   * the terms of the GNU General Public License, version 2.0, as published by the
   * Free Software Foundation.
   *
   * This program is also distributed with certain software (including but not
   * limited to OpenSSL) that is licensed under separate terms, as designated in a
   * particular file or component or in included license documentation. The
   * authors of MySQL hereby grant you an additional permission to link the
   * program and your derivative works with the separately licensed software that
   * they have included with MySQL.
   *
   * Without limiting anything contained in the foregoing, this file, which is
   * part of MySQL Connector/J, is also subject to the Universal FOSS Exception,
   * version 1.0, a copy of which can be found at
   * http://oss.oracle.com/licenses/universal-foss-exception.
   *
   * This program is distributed in the hope that it will be useful, but WITHOUT
   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
   * FOR A PARTICULAR PURPOSE. See the GNU General Public License, version 2.0,
   * for more details.
   *
   * You should have received a copy of the GNU General Public License along with
   * this program; if not, write to the Free Software Foundation, Inc.,
   * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA
   */
  
  package com.mysql.cj.xdevapi;
  
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.Iterator;
  import java.util.List;
  import java.util.NoSuchElementException;
  import java.util.function.Supplier;
  
  import com.mysql.cj.exceptions.WrongArgumentException;
  import com.mysql.cj.protocol.ProtocolEntity;
  import com.mysql.cj.protocol.ProtocolEntityFactory;
  import com.mysql.cj.protocol.ResultStreamer;
  import com.mysql.cj.protocol.x.StatementExecuteOk;
  import com.mysql.cj.protocol.x.XMessage;
  import com.mysql.cj.result.BufferedRowList;
  import com.mysql.cj.result.Row;
  import com.mysql.cj.result.RowList;
  
  /**
   * Base class for data set results.
   * 
   * @param <T>
   *            Result entry type
   */
  public abstract class AbstractDataResult<T> implements ResultStreamer, Iterator<T>, Result {
  
      protected int position = -1;
      protected int count = -1;
      protected RowList rows;
      protected Supplier<ProtocolEntity> completer;
      protected StatementExecuteOk ok;
      protected ProtocolEntityFactory<T, XMessage> rowToData;
      /** List of all elements. <code>null</code> until requested via {@link #fetchAll()}. */
      protected List<T> all;
  
      /**
       * Constructor.
       * 
       * @param rows
       *            {@link RowList} object
       * @param completer
       *            Supplier for StatementExecuteOk object
       * @param rowToData
       *            {@link ProtocolEntityFactory}
       */
      public AbstractDataResult(RowList rows, Supplier<ProtocolEntity> completer, ProtocolEntityFactory<T, XMessage> rowToData) {
          this.rows = rows;
          this.completer = completer;
          this.rowToData = rowToData;
      }
  
      public T next() {
          if (this.all != null) {
              throw new WrongArgumentException("Cannot iterate after fetchAll()");
          }
  
          Row r = this.rows.next();
          if (r == null) {
              throw new NoSuchElementException();
          }
          this.position++;
          return this.rowToData.createFromProtocolEntity(r);
      }
  
      /**
       * Create a list of all elements in the result forcing internal buffering.
       * 
       * @return list of result elements
       */
      public List<T> fetchAll() {
          if (this.position > -1) {
              throw new WrongArgumentException("Cannot fetchAll() after starting iteration");
          }
  
          if (this.all == null) {
              this.all = new ArrayList<>((int) count());
              this.rows.forEachRemaining(r -> this.all.add(this.rowToData.createFromProtocolEntity(r)));
              this.all = Collections.unmodifiableList(this.all);
          }
          return this.all;
      }
  
      /**
       * Return the number of items in this result. Forces internal buffering of the entire result.
       * 
       * @return number of elements in result
       */
      public long count() {
          finishStreaming();
          return this.count;
      }
  
      public boolean hasNext() {
          return this.rows.hasNext();
      }
  
      /**
       * Get StatementExecuteOk object finalizing the result transfer. Forces internal buffering of the entire result.
       * 
       * @return StatementExecuteOk object
       */
      public StatementExecuteOk getStatementExecuteOk() {
          finishStreaming();
          return this.ok;
      }
  
      @Override
      public void finishStreaming() {
          if (this.ok == null) {
              BufferedRowList remainingRows = new BufferedRowList(this.rows);
              this.count = 1 + this.position + remainingRows.size();
              this.rows = remainingRows;
              this.ok = (StatementExecuteOk) this.completer.get();
          }
      }
  
      @Override
      public long getAffectedItemsCount() {
          return getStatementExecuteOk().getAffectedItemsCount();
      }
  
      @Override
      public int getWarningsCount() {
          return getStatementExecuteOk().getWarningsCount();
      }
  
      @Override
      public Iterator<Warning> getWarnings() {
          return getStatementExecuteOk().getWarnings();
      }
  }
  