bsnes/ananke/nall/stream/mmap.hpp

43 lines
1.1 KiB
C++

#ifndef NALL_STREAM_MMAP_HPP
#define NALL_STREAM_MMAP_HPP
#include <nall/filemap.hpp>
namespace nall {
struct mmapstream : stream {
using stream::read;
using stream::write;
bool seekable() const { return true; }
bool readable() const { return true; }
bool writable() const { return pwritable; }
bool randomaccess() const { return true; }
unsigned size() const { return pmmap.size(); }
unsigned offset() const { return poffset; }
void seek(unsigned offset) const { poffset = offset; }
uint8_t read() const { return pdata[poffset++]; }
void write(uint8_t data) const { pdata[poffset++] = data; }
uint8_t read(unsigned offset) const { return pdata[offset]; }
void write(unsigned offset, uint8_t data) const { pdata[offset] = data; }
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;
}
private:
mutable filemap pmmap;
mutable uint8_t *pdata;
mutable unsigned pwritable, poffset;
};
}
#endif