Reactive streams and aggregate reads and writes

[Douglas Surber]

How about something like this for Blob?

Douglas

 /**
   * Return an Operation the result of which will publish the bytes of this
   * Blob in order from the position at the time the Operation is completed.
   * Subsequent Operations on this Blob <em>will | will not<\em> change the 
   * sequence of bytes published.
   * 
   * Any bytes between the position and the limit when the call to onNext
   * returns will not be between the position and the limit in the ByteBuffer
   * passed to the next call. The ByteBuffer passed to calls to
   * Subscriber.onNext are valid only for the duration of the call. After a call
   * to onNext returns, using the ByteBuffer passed to that call may yield
   * unexpected results.
   *
   * @param chunkSize the maximum size of the ByteBuffer the Publisher
   * will pass in a call to Subscriber.onNext.
   * @return
   */
  public Operation<Flow.Publisher<ByteBuffer>> publisherOperation(int chunkSize);
  
  /**
   * Return an Operation the result of which is a Subscriber which will insert
   * the bytes published to it into this Blob at the position at the time the
   * Operation is completed. Subsequent Operations on this Blob will not change 
   * the position at which subsequent published bytes are inserted.
   *
   * @param chunkSize the maximum size of ByteBuffer the Subscriber
   * expects to receive in a call to onNext. The Subscriber may throw
   * IllegalArgumentException if a ByteBuffer is larger though it is not 
   * required to.
   * @return a Subscriber to the bytes of this Blob
   */
  public Operation<Flow.Subscriber<ByteBuffer>> subscriberOperation(int chunkSize);
  
  /**
   * Return the default chunk size for this Blob. This is the default maximum size of
   * the ByteBuffer passed to Subscriber.onNext.
   * 
   * @return the default chunk size
   */
  public int defaultChunkSize();
  
  /**
   * Convenience method that create a Publisher of the bytes of this Blob.
   * 
   * @return a Publisher of the bytes of this Blob
   */
  public default CompletionStage<Flow.Publisher<ByteBuffer>> publisher() {
    return publisherOperation(defaultChunkSize()).submit().getCompletionStage();
  }
  
  /**
   * Convenience method that create a Subscriber for bytes in this Blob.
   * 
   * @return a Subscriber for inserting  bytes into this Blob.
   */
  public default CompletionStage<Flow.Subscriber<ByteBuffer>> subscriber() {
    return subscriberOperation(defaultChunkSize()).submit().getCompletionStage();
  }