Exheredludis/paludis/util/safe_ifstream.cc
Wouter van Kesteren 82a9e92b64 throw() -> noexcept
Change-Id: I461abfda8b7297c1bd04f1090f8d58fa96364616
Reviewed-on: https://galileo.mailstation.de/gerrit/1892
Reviewed-by: Saleem Abdulrasool <compnerd@compnerd.org>
Reviewed-by: Kylie McClain <somasis@exherbo.org>
2015-08-21 17:19:40 +02:00

136 lines
3.8 KiB
C++

/* vim: set sw=4 sts=4 et foldmethod=syntax : */
/*
* Copyright (c) 2009, 2010 Ciaran McCreesh
*
* This file is part of the Paludis package manager. Paludis is free software;
* you can redistribute it and/or modify it under the terms of the GNU General
* Public License version 2, as published by the Free Software Foundation.
*
* Paludis is distributed in the hope that it will be useful, but WITHOUT ANY
* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc., 59 Temple
* Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <paludis/util/safe_ifstream.hh>
#include <paludis/util/stringify.hh>
#include <unistd.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <fcntl.h>
#include <string.h>
#include <cstring>
#include <errno.h>
using namespace paludis;
SafeIFStreamBuf::SafeIFStreamBuf(const int f) :
fd(f)
{
setg(buffer + lookbehind_size, buffer + lookbehind_size, buffer + lookbehind_size);
underflow();
}
SafeIFStreamBuf::int_type
SafeIFStreamBuf::underflow()
{
if (gptr() < egptr())
return traits_type::to_int_type(*gptr());
int n_putback = gptr() - eback();
if (n_putback > lookbehind_size)
n_putback = lookbehind_size;
std::memmove(buffer + (lookbehind_size - n_putback), gptr() - n_putback, n_putback);
int n_read(read(fd, buffer + lookbehind_size, buffer_size - lookbehind_size));
if (-1 == n_read)
throw SafeIFStreamError("Error reading from fd " + stringify(fd) + ": " + strerror(errno));
else if (0 == n_read)
return traits_type::eof();
setg(buffer + (lookbehind_size - n_putback), buffer + lookbehind_size, buffer + lookbehind_size + n_read);
return traits_type::to_int_type(*gptr());
}
SafeIFStreamBuf::pos_type
SafeIFStreamBuf::seekoff(off_type off, std::ios_base::seekdir dir, std::ios_base::openmode)
{
off_t result;
if (dir == std::ios_base::beg)
result = lseek(fd, off, SEEK_SET);
else if (dir == std::ios_base::cur)
result = lseek(fd, off, SEEK_CUR);
else if (dir == std::ios_base::end)
result = lseek(fd, off, SEEK_END);
else
throw SafeIFStreamError("Got bad std::ios_base::seekdir");
if (-1 == result)
throw SafeIFStreamError("Error seeking to offset with fd " + stringify(fd) + ": " + strerror(errno));
setg(buffer + lookbehind_size, buffer + lookbehind_size, buffer + lookbehind_size);
return result;
}
SafeIFStreamBuf::pos_type
SafeIFStreamBuf::seekpos(pos_type p, std::ios_base::openmode)
{
off_t result(lseek(fd, p, SEEK_SET));
if (-1 == result)
throw SafeIFStreamError("Error seeking with fd " + stringify(fd) + ": " + strerror(errno));
setg(buffer + lookbehind_size, buffer + lookbehind_size, buffer + lookbehind_size);
return p;
}
SafeIFStreamBase::SafeIFStreamBase(const int f) :
buf(f)
{
}
SafeIFStream::SafeIFStream(const int f) :
SafeIFStreamBase(f),
std::istream(&buf),
_close(false)
{
}
namespace
{
int open_path(const FSPath & e)
{
Context context("When opening '" + stringify(e) + "' for read:");
int result(open(stringify(e).c_str(), O_RDONLY | O_CLOEXEC));
if (-1 == result)
throw SafeIFStreamError("Could not open '" + stringify(e) + "': " + strerror(errno));
return result;
}
}
SafeIFStream::SafeIFStream(const FSPath & e) :
SafeIFStreamBase(open_path(e)),
std::istream(&buf),
_close(true)
{
}
SafeIFStream::~SafeIFStream()
{
if (_close)
::close(buf.fd);
}
SafeIFStreamError::SafeIFStreamError(const std::string & s) noexcept :
Exception(s)
{
}