/*
  Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.

  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation; version 2 of the License.

  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 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
*/

#include "compression_zlib_writer.h"

using namespace Mysql::Tools::Dump;

void Compression_zlib_writer::process_buffer(bool flush_stream)
{
  do
  {
    m_compression_context.avail_out= Compression_zlib_writer::buffer_size;
    m_compression_context.next_out= (Bytef*)&m_buffer[0];

    int res= deflate(&m_compression_context,
      flush_stream ? Z_FINISH : Z_NO_FLUSH);

    if (res == Z_STREAM_ERROR)
    {
      this->pass_message(Mysql::Tools::Base::Message_data(
        0, "zlib compression failed",
        Mysql::Tools::Base::Message_type_error));
    }

    this->append_output(std::string(&m_buffer[0],
      Compression_zlib_writer::buffer_size - m_compression_context.avail_out));
  }
  while (m_compression_context.avail_in > 0);
}

void Compression_zlib_writer::append(const std::string& data_to_append)
{
  my_boost::mutex::scoped_lock lock(m_zlib_mutex);
  m_compression_context.avail_in= data_to_append.size();
  m_compression_context.next_in= (Bytef*)data_to_append.c_str();
  this->process_buffer(false);
}

Compression_zlib_writer::~Compression_zlib_writer()
{
  my_boost::mutex::scoped_lock lock(m_zlib_mutex);
  this->process_buffer(true);
  deflateEnd(&m_compression_context);
}

Compression_zlib_writer::Compression_zlib_writer(
  Mysql::I_callable<bool, const Mysql::Tools::Base::Message_data&>*
    message_handler, Simple_id_generator* object_id_generator,
    uint compression_level)
  : Abstract_output_writer_wrapper(message_handler, object_id_generator)
{
  memset(&m_compression_context, 0, sizeof(m_compression_context));
  m_buffer.resize(Compression_zlib_writer::buffer_size);
  int ret = deflateInit(&m_compression_context, compression_level);
  if (ret != Z_OK)
  {
    this->pass_message(Mysql::Tools::Base::Message_data(
      0, "zlib compression initialization failed",
      Mysql::Tools::Base::Message_type_error));
  }
}