read_file.hpp

Go to the documentation of this file.

#ifndef SILICIUM_READ_FILE_HPP
#define SILICIUM_READ_FILE_HPP

#include <silicium/error_or.hpp>
#include <silicium/memory_range.hpp>
#include <silicium/native_file_descriptor.hpp>

namespace Si
{
    inline error_or<std::size_t> read(native_file_descriptor file, mutable_memory_range destination)
    {
#ifdef _WIN32
        DWORD read_bytes = 0;
        DWORD const reading = static_cast<DWORD>(std::min<size_t>(destination.size(), std::numeric_limits<DWORD>::max()));
        if (!ReadFile(file, destination.begin(), reading, &read_bytes, nullptr))
        {
            DWORD error = GetLastError();
            if (error == ERROR_BROKEN_PIPE)
            {
                //end of pipe
                return static_cast<std::size_t>(0);
            }
            return boost::system::error_code(error, boost::system::system_category());
        }
#else
        ssize_t const read_bytes = ::read(file, destination.begin(), destination.size());
        if (read_bytes < 0)
        {
            return get_last_error();
        }
#endif
        if (read_bytes == 0)
        {
            //end of file
            return static_cast<std::size_t>(0);
        }
        return static_cast<std::size_t>(read_bytes);
    }
}

#endif