/*

 * Copyright (c)  2017, 2018, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code 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 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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 * questions.

 */

package jdk.incubator.sql2;

import java.nio.channels.AsynchronousByteChannel;

import java.util.concurrent.CompletionStage;

/**

 * A reference to a BINARY LARGE OBJECT in the attached database.

 *

 */

public interface SqlBlob extends AutoCloseable {

  /**

   * Return an {@link Operation} that will release the temporary resources

   *

   * @return an {@link Operation} that will release the temporary resources

   */

  public Operation<Void> closeOperation();

  @Override

  public default void close() {

    this.closeOperation().submit();

  }

  /**

   * The position is 1-based. Position 0 is immediately before the first byte in

   *

   * Position is between 0 and length + 1.

   *

   * @throws IllegalStateException if the {@link Session} that created this

   */

  public Operation<Long> getPositionOperation();

  /**

   *

   * Position is between 0 and length + 1.

   *

   * ISSUE: Should position be 1-based as SQL seems to do or 0-based as Java

   * does?

   *

   * @throws IllegalStateException if the {@link Session} that created this

   */

  public default CompletionStage<Long> getPosition() {

    return getPositionOperation().submit().getCompletionStage();

  }

  /**

   *

   * @throws IllegalStateException if the {@link Session} that created this

   */

  public Operation<Long> lengthOperation();

  /**

   *

   * @throws IllegalStateException if the {@link Session} that created this

   */

  public default CompletionStage<Long> length() {

    return lengthOperation().submit().getCompletionStage();

  }

  /**

   *

   * @param offset a non-negative number

   * @throws IllegalArgumentException if {@code offset} is less than 0

   * @throws IllegalStateException if the {@link Session} that created this

   */

  public Operation<Long> setPositionOperation(long offset);

  /**

   * past the last byte.

   *

   * @param offset the 1-based position to set

   * @throws IllegalArgumentException if offset is less than 0

   * @throws IllegalStateException if the {@link Session} that created this

   */

  public default SqlBlob setPosition(long offset) {

    setPositionOperation(offset).submit();

    return this;

  }

  /**

   * Return a {@link Operation} to set the position to the beginning of the next

   * occurrence of the target after the position. If there is no such occurrence

   * set the position to 0.

   *

   * containing the byte sequence to search for

   * @return a {@link Operation} that locates {@code target} in this

   * @throws IllegalArgumentException if {@code target} was created by some

   * other {@link Session}

   * @throws IllegalStateException if the {@link Session} that created this

   */

  public Operation<Long> locateOperation(SqlBlob target);

  /**

   * Set the position to the beginning of the next occurrence of the target

   * after the position. If there is no such occurrence set the position to 0.

   *

   * @param target the byte sequence to search for

   * @throws IllegalArgumentException if {@code target} was created by some

   * other {@link Session}

   * @throws IllegalStateException if the {@link Session} that created this

   */

  public default SqlBlob locate(SqlBlob target) {

    locateOperation(target).submit();

    return this;

  }

  /**

   * Return an {@link Operation} to set the position to the beginning of the

   * next occurrence of the target after the position. If there is no such

   * occurrence set the position to 0.

   *

   * @param target the byte sequence to search for. Not {@code null}. Captured.

   * @return a {@link Operation} that locates {@code target} in this

   * @throws IllegalStateException if the {@link Session} that created this

   */

  public Operation<Long> locateOperation(byte[] target);

  /**

   * Set the position to the beginning of the next occurrence of the target

   * after the position. If there is no such occurrence set the position to 0.

   *

   * @param target the byte sequence to search for

   * @throws IllegalStateException if the {@link Session} that created this

   */

  public default SqlBlob locate(byte[] target) {

    locateOperation(target).submit();

    return this;

  }

  /**

   * after {@link trim()} the length is N - 1. The position is still N. This

   * will fail if position is 0.

   *

   * @throws IllegalStateException if the {@link Session} that created this

   */

  public Operation<Long> trimOperation();

  /**

   * N - 1. The position is still N. This will fail if position is 0.

   *

   * @return this SqlBlob

   * @throws IllegalStateException if the {@link Session} that created this

   */

  public default SqlBlob trim() {

    trimOperation().submit();

    return this;

  }

  /**

   * Return a {@link java.nio.channels.Channel} that can be used to read bytes from the

   * {@link java.nio.channels.Channel} advances the position.

   *

   * Each call to a read method that fetches bytes from the server creates and

   * submits a virtual {@link Operation} to fetch those bytes. This virtual

   * {@link Operation} is executed in sequence with other {@link Operation}s and

   * may be skipped if an error occurs.

   *

   * @return a read-only byte {@link java.nio.channels.Channel} beginning at the position.

   * @throws IllegalStateException if the {@link Session} that created this

 SqlBlob is closed.

   */

  public AsynchronousByteChannel getReadChannel();

  /**

   * Return a {@link java.nio.channels.Channel} that can be used to write bytes

   * {@link java.nio.channels.Channel} advances the position.

   *

   * Each call to a write method that flushes bytes to the server creates and

   * submits a virtual {@link Operation} to flush those bytes. This virtual

   * {@link Operation} is executed in sequence with other {@link Operation}s and

   * may be skipped if an error occurs.

   *

   * ISSUE: Can the app read bytes from a write

   * {@link java.nio.channels.Channel}? If so then maybe remove

   * {@link getReadChannel} and add a read-only flag to this method, renamed

   * {@code getChannel}.

   *

   * @return a writable byte {@link java.nio.channels.Channel} beginning at the

   * position.

   * @throws IllegalStateException if the {@link Session} that created this

   */

  public AsynchronousByteChannel getWriteChannel();

}