mapnik/src/mapped_memory_cache.cpp
2014-11-20 15:25:50 +01:00

99 lines
2.9 KiB
C++

/*****************************************************************************
*
* This file is part of Mapnik (c++ mapping toolkit)
*
* Copyright (C) 2014 Artem Pavlenko
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
*****************************************************************************/
#if defined(SHAPE_MEMORY_MAPPED_FILE)
// mapnik
#include <mapnik/debug.hpp>
#include <mapnik/util/fs.hpp>
#include <mapnik/mapped_memory_cache.hpp>
// boost
#include <boost/assert.hpp>
#include <boost/interprocess/mapped_region.hpp>
#include <boost/interprocess/file_mapping.hpp>
namespace mapnik
{
void mapped_memory_cache::clear()
{
#ifdef MAPNIK_THREADSAFE
mapnik::scoped_lock lock(mutex_);
#endif
return cache_.clear();
}
bool mapped_memory_cache::insert(std::string const& uri, mapped_region_ptr mem)
{
#ifdef MAPNIK_THREADSAFE
mapnik::scoped_lock lock(mutex_);
#endif
return cache_.emplace(uri,mem).second;
}
boost::optional<mapped_region_ptr> mapped_memory_cache::find(std::string const& uri, bool update_cache)
{
#ifdef MAPNIK_THREADSAFE
mapnik::scoped_lock lock(mutex_);
#endif
using iterator_type = std::unordered_map<std::string, mapped_region_ptr>::const_iterator;
boost::optional<mapped_region_ptr> result;
iterator_type itr = cache_.find(uri);
if (itr != cache_.end())
{
result.reset(itr->second);
return result;
}
if (mapnik::util::exists(uri))
{
try
{
boost::interprocess::file_mapping mapping(uri.c_str(),boost::interprocess::read_only);
mapped_region_ptr region(std::make_shared<boost::interprocess::mapped_region>(mapping,boost::interprocess::read_only));
result.reset(region);
if (update_cache)
{
cache_.emplace(uri,*result);
}
return result;
}
catch (std::exception const& ex)
{
MAPNIK_LOG_ERROR(mapped_memory_cache)
<< "Error loading mapped memory file: '"
<< uri << "' (" << ex.what() << ")";
}
}
/*
else
{
MAPNIK_LOG_WARN(mapped_memory_cache) << "Memory region does not exist file: " << uri;
}
*/
return result;
}
}
#endif