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boost::iostreams::copy - sink - ENOSPC (No space left on device) error handling

Open codemedic opened this issue 7 years ago • 0 comments

Copying the issue reported on legacy Trac system https://svn.boost.org/trac10/ticket/9478

Platform: GCC 7 on Linux with boost v1.66 (originally reported on older version; confirmed by re-testing) In the code fragment below, is there a way to handle ENOSPC?

#include <fstream>
#include <iostream>
#include <boost/iostreams/filtering_streambuf.hpp>
#include <boost/iostreams/copy.hpp>
#include <boost/iostreams/filter/bzip2.hpp>

// open input file stream of the bzip2 file
std::ifstream ifs("file.bz2");

// open output stream to the "full" device
// full device is a "utility-device" to check how applications handle ENOSPC
// more details in "man full"
std::ofstream ofs("/dev/full");

// Setup the iostreams filter
boost::iostreams::filtering_streambuf<boost::iostreams::output> filters;
filters.push(boost::iostreams::bzip2_decompressor());
filters.push(ofs);

// "run" the filter
boost::iostreams::copy(ifs, filters);

If I do strace of the compiled binary, the code seem to infinitely call writev() with the same data and returns ENOSPC error.

writev(4, [{NULL, 0}, {"DATA DATA "..., 4096}], 2) = -1 ENOSPC (No space left on device)

How can this error be handled or made thrown as an error from boost::iostreams::copy()

Is it possible to set appropriate exceptions() on the ofstream object? I tried ofs.exceptions(std::ios::badbit | std::ios::failbit) but it didn't make any difference.

More detailed discussion on SO: ​http://stackoverflow.com/q/20414577/83005

A shorter code to reproduce the issue.

#include <boost/iostreams/filtering_streambuf.hpp>
#include <boost/iostreams/copy.hpp>
#include <boost/iostreams/device/file.hpp>

int main()
{
    using namespace boost::iostreams;
    file_sink   ofs("/dev/full");
    file_source ifs("/dev/zero");

    filtering_streambuf<output> filters(ofs);
    copy(ifs, filters);
}

codemedic avatar Mar 12 '18 18:03 codemedic