OpenSpace/modules/sync/torrentclient.h

/*****************************************************************************************
 *                                                                                       *
 * OpenSpace                                                                             *
 *                                                                                       *
 * Copyright (c) 2014-2018                                                               *
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 * or substantial portions of the Software.                                              *
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#ifndef __OPENSPACE_MODULE_SYNC___TORRENTCLIENT___H__
#define __OPENSPACE_MODULE_SYNC___TORRENTCLIENT___H__

#include <ghoul/misc/exception.h>

#include <functional>

namespace openspace {

struct TorrentError : public ghoul::RuntimeError {
    /**
    * Creates the SpecificationError exception instance.
    * \param result The offending TestResult that is passed on
    * \param component The component that initiated the specification test
    * \pre \p result%'s TestResult::success must be \c false
    */
    TorrentError(std::string component);
};

class TorrentClientBase {
public:
    struct TorrentProgress {
        bool finished = false;
        bool nTotalBytesKnown = false;
        size_t nTotalBytes = 0;
        size_t nDownloadedBytes = 0;
    };

    virtual ~TorrentClientBase() = default;

    using TorrentProgressCallback = std::function<void(TorrentProgress)>;

    using TorrentId = int32_t;

    virtual void initialize() = 0;
    virtual TorrentId addTorrentFile(std::string torrentFile,
        std::string destination,
        TorrentProgressCallback cb) = 0;

    virtual TorrentId addMagnetLink(std::string magnetLink,
        std::string destination,
        TorrentProgressCallback cb) = 0;

    virtual void removeTorrent(TorrentId id) = 0;
    virtual void pollAlerts() = 0;
};

} // namespace openspace

#ifdef SYNC_USE_LIBTORRENT

#include <atomic>
#include <string>
#include <memory>
#include <thread>
#include <mutex>
#include <unordered_map>

#include "libtorrent/torrent_handle.hpp"

namespace libtorrent { class session; }

namespace openspace {

class TorrentClient : public TorrentClientBase {
public:
    TorrentClient();
    virtual ~TorrentClient();

    void initialize() override;
    TorrentId addTorrentFile(std::string torrentFile,
        std::string destination,
        TorrentProgressCallback cb) override;

    TorrentId addMagnetLink(std::string magnetLink,
        std::string destination,
        TorrentProgressCallback cb) override;

    void removeTorrent(TorrentId id) override;
    void pollAlerts() override;

private:
    struct Torrent {
        TorrentId id;
        libtorrent::torrent_handle handle;
        TorrentProgressCallback callback;
    };

    void notify(TorrentId id);

    std::unordered_map<TorrentId, Torrent> _torrents;
    std::unique_ptr<libtorrent::session> _session;
    std::thread _torrentThread;
    std::mutex _mutex;
    std::atomic_bool _keepRunning;
};

} // namespace openspace

#else // SYNC_USE_LIBTORRENT

namespace openspace {

class TorrentClient : public TorrentClientBase {
public:
    TorrentClient();
    virtual ~TorrentClient();

    void initialize() override;
    TorrentId addTorrentFile(std::string torrentFile,
        std::string destination,
        TorrentProgressCallback cb) override;

    TorrentId addMagnetLink(std::string magnetLink,
        std::string destination,
        TorrentProgressCallback cb) override;

    void removeTorrent(TorrentId id) override;
    void pollAlerts() override;
};

} // namespace openspace

#endif // SYNC_USE_LIBTORRENT

#endif // __OPENSPACE_MODULE_SYNC___TORRENTCLIENT___H__