boost::shared_ptr<file> file_pool::open_file(void* st, fs::path const& p, file::open_mode m)
{
assert(st != 0);
assert(p.is_complete());
assert(m == file::in || m == (file::in | file::out));
boost::mutex::scoped_lock l(m_mutex);
typedef nth_index<file_set, 0>::type path_view;
path_view& pt = get<0>(m_files);
path_view::iterator i = pt.find(p);
if (i != pt.end())
{
lru_file_entry e = *i;
e.last_use = time_now();
if (e.key != st)
{
// this means that another instance of the storage
// is using the exact same file.
throw file_error("torrent uses the same file as another torrent "
"(" + p.string() + ")");
}
e.key = st;
if ((e.mode & m) != m)
{
// close the file before we open it with
// the new read/write privilages
i->file_ptr.reset();
assert(e.file_ptr.unique());
e.file_ptr.reset();
e.file_ptr.reset(new file(p, m));
e.mode = m;
}
pt.replace(i, e);
return e.file_ptr;
}
// the file is not in our cache
if ((int)m_files.size() >= m_size)
{
// the file cache is at its maximum size, close
// the least recently used (lru) file from it
typedef nth_index<file_set, 1>::type lru_view;
lru_view& lt = get<1>(m_files);
lru_view::iterator i = lt.begin();
// the first entry in this view is the least recently used
assert(lt.size() == 1 || (i->last_use <= boost::next(i)->last_use));
lt.erase(i);
}
lru_file_entry e(boost::shared_ptr<file>(new file(p, m)));
e.mode = m;
e.key = st;
e.file_path = p;
pt.insert(e);
return e.file_ptr;
}
boost::shared_ptr<file> file_pool::open_file(void* st, fs::path const& p
, file::open_mode m, error_code& ec)
{
TORRENT_ASSERT(st != 0);
TORRENT_ASSERT(p.is_complete());
TORRENT_ASSERT(m == file::in || m == (file::in | file::out));
boost::mutex::scoped_lock l(m_mutex);
typedef nth_index<file_set, 0>::type path_view;
path_view& pt = get<0>(m_files);
path_view::iterator i = pt.find(p);
if (i != pt.end())
{
lru_file_entry e = *i;
e.last_use = time_now();
if (e.key != st && (e.mode != file::in
|| m != file::in))
{
// this means that another instance of the storage
// is using the exact same file.
#if BOOST_VERSION >= 103500
ec = error_code(errors::file_collision, libtorrent_category);
#endif
return boost::shared_ptr<file>();
}
e.key = st;
if ((e.mode & m) != m)
{
// close the file before we open it with
// the new read/write privilages
i->file_ptr.reset();
TORRENT_ASSERT(e.file_ptr.unique());
e.file_ptr->close();
if (!e.file_ptr->open(p, m, ec))
{
m_files.erase(i);
return boost::shared_ptr<file>();
}
TORRENT_ASSERT(e.file_ptr->is_open());
e.mode = m;
}
pt.replace(i, e);
return e.file_ptr;
}
// the file is not in our cache
if ((int)m_files.size() >= m_size)
{
// the file cache is at its maximum size, close
// the least recently used (lru) file from it
typedef nth_index<file_set, 1>::type lru_view;
lru_view& lt = get<1>(m_files);
lru_view::iterator i = lt.begin();
// the first entry in this view is the least recently used
TORRENT_ASSERT(lt.size() == 1 || (i->last_use <= boost::next(i)->last_use));
lt.erase(i);
}
lru_file_entry e;
e.file_ptr.reset(new (std::nothrow)file);
if (!e.file_ptr)
{
ec = error_code(ENOMEM, get_posix_category());
return e.file_ptr;
}
if (!e.file_ptr->open(p, m, ec))
return boost::shared_ptr<file>();
e.mode = m;
e.key = st;
e.file_path = p;
pt.insert(e);
TORRENT_ASSERT(e.file_ptr->is_open());
return e.file_ptr;
}