/** @file

  A brief file description

  @section license License

  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.
 */

#include "proxy/http3/Http3StreamDataVIOAdaptor.h"
#include "iocore/eventsystem/VIO.h"

Http3StreamDataVIOAdaptor::Http3StreamDataVIOAdaptor(VIO *sink) : _sink_vio(sink), _buffer(new_MIOBuffer(BUFFER_SIZE_INDEX_4K))
{
  this->_reader = this->_buffer->alloc_reader();
}

Http3StreamDataVIOAdaptor::~Http3StreamDataVIOAdaptor()
{
  this->_buffer->dealloc_reader(this->_reader);
  free_MIOBuffer(this->_buffer);
}

std::vector<Http3FrameType> const &
Http3StreamDataVIOAdaptor::interests()
{
  static std::vector<Http3FrameType> const types = {Http3FrameType::DATA};
  return types;
}

Http3ErrorUPtr
Http3StreamDataVIOAdaptor::handle_frame(std::shared_ptr<const Http3Frame> frame, Http3StreamType /* s_type */)
{
  ink_assert(frame->type() == Http3FrameType::DATA);
  const Http3DataFrame *dframe = dynamic_cast<const Http3DataFrame *>(frame.get());

  // The frame's reader is bounded to this frame by size_limit, but the default
  // length for MIOBuffer::write is INT64_MAX, which walks the raw block chain
  // and copies whatever follows the frame in the stream read buffer. Pass
  // read_avail(), which honours size_limit, to bound the copy to the payload.
  IOBufferReader *reader  = dframe->data();
  int64_t         written = this->_buffer->write(reader, reader->read_avail());

  this->_total_data_length += written;

  return Http3ErrorUPtr(nullptr);
}

void
Http3StreamDataVIOAdaptor::finalize()
{
  if (this->_finalized) {
    return;
  }

  SCOPED_MUTEX_LOCK(lock, this->_sink_vio->mutex, this_ethread());
  MIOBuffer *writer    = this->_sink_vio->get_writer();
  int64_t    delivered = writer->write(this->_reader, this->_reader->read_avail());
  this->_reader->consume(delivered);
  this->_sink_vio->ndone  += delivered;
  this->_sink_vio->nbytes  = this->_sink_vio->ndone;
  this->_finalized         = true;
}

bool
Http3StreamDataVIOAdaptor::has_data() const
{
  return this->_total_data_length > 0;
}