osrm-backend/src/engine/datafacade/mmap_memory_allocator.cpp
2018-10-26 23:53:59 -07:00

73 lines
2.6 KiB
C++

#include "engine/datafacade/mmap_memory_allocator.hpp"
#include "storage/block.hpp"
#include "storage/io.hpp"
#include "storage/serialization.hpp"
#include "storage/storage.hpp"
#include "util/log.hpp"
#include "util/mmap_file.hpp"
#include <boost/assert.hpp>
namespace osrm
{
namespace engine
{
namespace datafacade
{
MMapMemoryAllocator::MMapMemoryAllocator(const storage::StorageConfig &config)
{
storage::Storage storage(config);
std::vector<storage::SharedDataIndex::AllocatedRegion> allocated_regions;
{
std::unique_ptr<storage::BaseDataLayout> fake_layout =
std::make_unique<storage::TarDataLayout>();
// Convert the boost::filesystem::path object into a plain string
// that's stored as a member of this allocator object
rtree_filename = storage.PopulateLayoutWithRTree(*fake_layout);
// Now, we add one more AllocatedRegion, with it's start address as the start
// of the rtree_filename string we've saved. In the fake_layout, we've
// stated that the data is at offset 0, which is where the string starts
// at it's own memory address.
// The syntax &(rtree_filename[0]) gets the memory address of the first char.
// We can't use the convenient `.data()` or `.c_str()` methods, because
// prior to C++17 (which we're not using), those return a `const char *`,
// which isn't compatible with the `char *` that AllocatedRegion expects
// for it's memory_ptr
allocated_regions.push_back({&(rtree_filename[0]), std::move(fake_layout)});
}
auto files = storage.GetStaticFiles();
auto updatable_files = storage.GetUpdatableFiles();
files.insert(files.end(), updatable_files.begin(), updatable_files.end());
for (const auto &file : files)
{
if (boost::filesystem::exists(file.second))
{
std::unique_ptr<storage::BaseDataLayout> layout =
std::make_unique<storage::TarDataLayout>();
boost::iostreams::mapped_file mapped_memory_file;
util::mmapFile<char>(file.second, mapped_memory_file);
mapped_memory_files.push_back(std::move(mapped_memory_file));
storage::populateLayoutFromFile(file.second, *layout);
allocated_regions.push_back({mapped_memory_file.data(), std::move(layout)});
}
}
index = storage::SharedDataIndex{std::move(allocated_regions)};
}
MMapMemoryAllocator::~MMapMemoryAllocator() {}
const storage::SharedDataIndex &MMapMemoryAllocator::GetIndex() { return index; }
} // namespace datafacade
} // namespace engine
} // namespace osrm