bsnes/nall/stream/mmap.hpp

42 lines
1.1 KiB
C++

#pragma once
#include <nall/filemap.hpp>
namespace nall {
struct mmapstream : stream {
using stream::read;
using stream::write;
mmapstream(const string& filename) {
pmmap.open(filename, filemap::mode::readwrite);
pwritable = pmmap.open();
if(!pwritable) pmmap.open(filename, filemap::mode::read);
pdata = pmmap.data();
poffset = 0;
}
auto seekable() const -> bool { return true; }
auto readable() const -> bool { return true; }
auto writable() const -> bool { return pwritable; }
auto randomaccess() const -> bool { return true; }
auto size() const -> uint { return pmmap.size(); }
auto offset() const -> uint { return poffset; }
auto seek(unsigned offset) const -> void { poffset = offset; }
auto read() const -> uint8 { return pdata[poffset++]; }
auto write(uint8 data) const -> void { pdata[poffset++] = data; }
auto read(uint offset) const -> uint8 { return pdata[offset]; }
auto write(uint offset, uint8 data) const -> void { pdata[offset] = data; }
private:
mutable filemap pmmap;
mutable uint8* pdata = nullptr;
mutable uint poffset = 0;
mutable bool pwritable = false;
};
}