Run multiple session save requests in parallel.

src/session/download_storer.h

@@ -0,0 +1,44 @@
+#ifndef RTORRENT_SESSION_DOWNLOAD_STORER_H
+#define RTORRENT_SESSION_DOWNLOAD_STORER_H
+
+#include <memory>
+#include <sstream>
+#include <string>
+#include <torrent/common.h>
+
+namespace core {
+class Download;
+}
+
+namespace utils {
+  class Directory;
+}
+
+namespace session {
+
+class DownloadStorer {
+public:
+  DownloadStorer(core::Download* download);
+
+  core::Download*     download() const { return m_download; }
+
+  void                build_streams(bool skip_static);
+  std::string         build_path(const std::string& session_path);
+
+  auto                torrent_stream()    { return std::move(m_torrent_stream); }
+  auto                rtorrent_stream()   { return std::move(m_rtorrent_stream); }
+  auto                libtorrent_stream() { return std::move(m_libtorrent_stream); }
+
+  static utils::Directory get_formated_entries(const std::string& session_path);
+
+private:
+  core::Download*     m_download;
+
+  std::unique_ptr<std::stringstream> m_torrent_stream;
+  std::unique_ptr<std::stringstream> m_rtorrent_stream;
+  std::unique_ptr<std::stringstream> m_libtorrent_stream;
+};
+
+} // namespace session
+
+#endif // RTORRENT_SESSION_DOWNLOAD_STORER_H