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#define XERR
#include "mmapbuf.ih"
// 'mode' defines the access permissions of the file when it's creaed.
// by default rw-r--r-- (0644) and is passed to MmapBuf via the [IO]mapbuf
// derived class
void MmapBuf::setFileSize(mode_t mode)
{
// ios::
// in the file must exist
// out recreates unless also in
// ate start initially at the end. Needs in to prevent rewriting
// trunc truncates, with in|out reading also OK
// app when writing always reposition to the end
if (d_openMode & ios::app)
d_openMode |= ios::out;
if ( // create the file if
(d_openMode & ios::trunc) // truncate or
or // out-mode w/o in-mode
((d_openMode & ios::out) and (d_openMode & ios::in) == 0)
)
{
if (creat(d_fname.c_str(), mode) == -1)
failure("can't create " + d_fname);
d_fileSize = 0;
return;
}
Stat stat{ d_fname }; // obtain the file's info
if (not stat)
failure("can't stat " + d_fname);
d_fileSize = stat.size();
}
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