mysql5/mysql-5.7.27/client/dump/compression_zlib_writer.cc

76 lines
2.5 KiB
C++

/*
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));
}
}