mapnik/src/mapped_memory_cache.cpp
2011-11-18 09:39:57 +00:00

88 lines
2.6 KiB
C++

/*****************************************************************************
*
* This file is part of Mapnik (c++ mapping toolkit)
*
* Copyright (C) 2011 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
*
*****************************************************************************/
//$Id$
// mapnik
#include <mapnik/mapped_memory_cache.hpp>
// boost
#include <boost/assert.hpp>
#include <boost/interprocess/file_mapping.hpp>
#include <boost/filesystem/operations.hpp>
namespace mapnik
{
boost::unordered_map<std::string, mapped_region_ptr> mapped_memory_cache::cache_;
bool mapped_memory_cache::insert (std::string const& uri, mapped_region_ptr mem)
{
#ifdef MAPNIK_THREADSAFE
mutex::scoped_lock lock(mutex_);
#endif
return cache_.insert(std::make_pair(uri,mem)).second;
}
boost::optional<mapped_region_ptr> mapped_memory_cache::find(std::string const& uri, bool update_cache)
{
#ifdef MAPNIK_THREADSAFE
mutex::scoped_lock lock(mutex_);
#endif
typedef boost::unordered_map<std::string, mapped_region_ptr>::const_iterator iterator_type;
boost::optional<mapped_region_ptr> result;
iterator_type itr = cache_.find(uri);
if (itr != cache_.end())
{
result.reset(itr->second);
return result;
}
boost::filesystem::path path(uri);
if (exists(path))
{
try
{
file_mapping mapping(uri.c_str(),read_only);
mapped_region_ptr region(new mapped_region(mapping,read_only));
result.reset(region);
if (update_cache)
{
cache_.insert(std::make_pair(uri,*result));
}
return result;
}
catch (...)
{
std::cerr << "Exception caught while loading mapping memory file: " << uri << std::endl;
}
}
/*else
{
std::cerr << "### WARNING Memory region does not exist file: " << uri << std::endl;
}*/
return result;
}
}