content: /*
   * Copyright 2014-2025 Real Logic Limited.
   *
   * Licensed 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
   *
   * https://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.agrona.concurrent;
  
  import org.agrona.MutableDirectBuffer;
  
  /**
   * Callback interface for processing of messages that are read from a buffer.
   */
  @FunctionalInterface
  public interface ControlledMessageHandler
  {
      /**
       * Action to be taken on return from {@link #onMessage(int, MutableDirectBuffer, int, int)}.
       */
      enum Action
      {
          /**
           * Abort the current read operation and do not advance the position for this message.
           */
          ABORT,
  
          /**
           * Break from the current read operation and commit the position as of the end of the current message
           * being handled.
           */
          BREAK,
  
          /**
           * Continue processing but commit the position as of the end of the current message so that
           * flow control is applied to this point.
           */
          COMMIT,
  
          /**
           * Continue processing until limit or no messages with position commit at end of read as the in
           * {@link #onMessage(int, MutableDirectBuffer, int, int)}.
           */
          CONTINUE,
      }
  
      /**
       * Called for the processing of each message read from a buffer in turn.
       *
       * @param msgTypeId type of the encoded message.
       * @param buffer    containing the encoded message.
       * @param index     at which the encoded message begins.
       * @param length    in bytes of the encoded message.
       * @return {@link Action} to be taken to control how the read progresses.
       */
      Action onMessage(int msgTypeId, MutableDirectBuffer buffer, int index, int length);
  }
  