#include "internal.h"

mmap·Reader
mmap·open(byte *filename)
{
    int    err;
    void  *buf;
    io·Buffer io;
    sys·Info info;
    mmap·Reader rdr = {0};

    if(io·open(filename, sys·ORead, &io)){
        errorf("failed to open %s", filename);
        goto done;
    }

    if(sys·infofd(io.fd, &info)){
        errorf("file stat: error code %d", err);
        goto done;
    }

    if(sys·mmap(nil, info.size, sys·ProtRead, sys·MapShared, io.fd, 0, &buf)){
        errorf("mmap: failed");
        goto done;
    }
    // NOTE: posix systems require that reference kept to mmap file after fd is closed
    rdr = (mmap·Reader){.len=info.size, .b=buf};
done:
    io·close((io·Header*)&io);
    return rdr;
}

int
mmap·close(mmap·Reader rdr)
{
    sys·munmap(rdr.b, rdr.len);
    return 0;
}