support for resuming magnet links

libtransmission/magnet-metainfo.cc

@@ -178,9 +178,15 @@ std::string tr_magnet_metainfo::magnet() const
     return s;
 }
 
+std::string tr_magnet_metainfo::magnetLink() const
+{
+    return magnet_link_;
+}
+
 bool tr_magnet_metainfo::parseMagnet(std::string_view magnet_link, tr_error** error)
 {
     magnet_link = tr_strvStrip(magnet_link);
+    this->setMagnetLink(magnet_link);
 
     if (auto const hash = parseHash(magnet_link); hash)
     {

libtransmission/magnet-metainfo.h

@@ -22,11 +22,14 @@ class tr_magnet_metainfo
     bool parseMagnet(std::string_view magnet_link, tr_error** error = nullptr);
 
     std::string magnet() const;
+
+    std::string magnetLink() const;
 
     auto const& infoHash() const
     {
         return info_hash_;
     }
+
     auto const& name() const
     {
         return name_;
@@ -61,11 +64,17 @@ class tr_magnet_metainfo
     {
         name_ = name;
     }
+
+    void setMagnetLink(std::string_view magnet_link)
+    {
+        magnet_link_ = magnet_link;
+    }
 
 protected:
     tr_announce_list announce_list_;
     std::vector<std::string> webseed_urls_;
     tr_sha1_digest_t info_hash_;
     std::string info_hash_str_;
     std::string name_;
+    std::string magnet_link_;
 };

libtransmission/session.cc

@@ -2041,13 +2041,25 @@ static void sessionLoadTorrents(void* vdata)
         char const* name = nullptr;
         while ((name = tr_sys_dir_read_name(odir, nullptr)) != nullptr)
         {
-            if (!tr_strvEndsWith(name, ".torrent"sv))
+            if (!tr_strvEndsWith(name, ".torrent"sv) && !tr_strvEndsWith(name, ".magnet"sv))
             {
                 continue;
             }
 
             tr_buildBuf(path, dirname_sv, "/", name);
-            tr_ctorSetMetainfoFromFile(data->ctor, path, nullptr);
+
+            // is a magnet link?
+            if (!tr_ctorSetMetainfoFromFile(data->ctor, path, nullptr))
+            {
+                auto buf = std::vector<char>{};
+                if (!tr_loadFile(buf, path))
+                {
+                    continue;
+                }
+                auto const magnet_link = std::string{ std::data(buf), std::size(buf) };
+                tr_ctorSetMetainfoFromMagnetLink(data->ctor, magnet_link.c_str(), nullptr);
+            }
+
             if (tr_torrent* const tor = tr_torrentNew(data->ctor, nullptr); tor != nullptr)
             {
                 torrents.push_back(tor);

libtransmission/torrent-ctor.cc

@@ -127,6 +127,21 @@ bool tr_ctorSaveContents(tr_ctor const* ctor, std::string const& filename, tr_er
     return tr_saveFile(filename, { std::data(ctor->contents), std::size(ctor->contents) }, error);
 }
 
+bool tr_ctorSaveMagnetContents(tr_torrent* tor, std::string const& filename, tr_error** error)
+{
+    TR_ASSERT(tor != nullptr);
+    TR_ASSERT(!std::empty(filename));
+
+    if (std::empty(tor->metainfo_.magnetLink()))
+    {
+        tr_error_set(error, EINVAL, "torrent has no magnetlink to save"sv);
+        return false;
+    }
+
+    std::string magnet_link = tor->metainfo_.magnetLink();
+    return tr_saveFile(filename, std::string_view{ magnet_link }, error);
+}
+
 /***
 ****
 ***/

libtransmission/torrent-magnet.cc

@@ -277,6 +277,10 @@ static bool useNewMetainfo(tr_torrent* tor, tr_incomplete_metadata const* m, tr_
     {
         return false;
     }
+
+    // remove .magnet file
+    auto const magnetFilename = tor->magnetFile();
+    tr_sys_path_remove(magnetFilename.c_str(), nullptr);
 
     // tor should keep this metainfo
     tor->setMetainfo(metainfo);

libtransmission/torrent-metainfo.h

@@ -138,6 +138,11 @@ struct tr_torrent_metainfo : public tr_magnet_metainfo
     {
         return makeFilename(torrent_dir, name(), infoHashString(), BasenameFormat::Hash, ".torrent");
     }
+
+    [[nodiscard]] std::string magnetFile(std::string_view torrent_dir) const
+    {
+        return makeFilename(torrent_dir, name(), infoHashString(), BasenameFormat::Hash, ".magnet");
+    }
 
     [[nodiscard]] std::string resumeFile(std::string_view resume_dir) const
     {

libtransmission/torrent.cc

@@ -767,17 +767,35 @@ static void torrentInit(tr_torrent* tor, tr_ctor const* ctor)
 
     tr_sessionAddTorrent(session, tor);
 
-    // if we don't have a local .torrent file already, assume the torrent is new
-    auto const filename = tor->torrentFile();
+    // if we don't have a local .torrent or .magent file already, assume the torrent is new
+    auto filename = tor->torrentFile();
+
+    // is a magnet link
+    if (!tor->hasMetadata()) {
+        filename = tor->magnetFile();
+    }
+
     bool const is_new_torrent = !tr_sys_path_exists(filename.c_str(), nullptr);
     if (is_new_torrent)
     {
         tr_error* error = nullptr;
-        if (!tr_ctorSaveContents(ctor, filename, &error))
+        if (tor->hasMetadata()) {
+            if (!tr_ctorSaveContents(ctor, filename, &error))
+            {
+                tor->setLocalError(
+                    tr_strvJoin("Unable to save torrent file: ", error->message, " ("sv, std::to_string(error->code), ")"sv));
+            }
+        }
+        else
         {
-            tor->setLocalError(
-                tr_strvJoin("Unable to save torrent file: ", error->message, " ("sv, std::to_string(error->code), ")"sv));
+            // magnet link
+            if (!tr_ctorSaveMagnetContents(tor, filename, &error))
+            {
+                tor->setLocalError(
+                    tr_strvJoin("Unable to save magnet file: ", error->message, " ("sv, std::to_string(error->code), ")"sv));
+            }
         }
+
         tr_error_clear(&error);
     }
 
@@ -1566,6 +1584,7 @@ static void closeTorrent(void* vtor)
     if (tor->isDeleting)
     {
         tr_torrent_metainfo::removeFile(tor->session->torrent_dir, tor->name(), tor->infoHashString(), ".torrent"sv);
+        tr_torrent_metainfo::removeFile(tor->session->resume_dir, tor->name(), tor->infoHashString(), ".magnet"sv);
         tr_torrent_metainfo::removeFile(tor->session->resume_dir, tor->name(), tor->infoHashString(), ".resume"sv);
     }
 

libtransmission/torrent.h

@@ -53,6 +53,8 @@ void tr_ctorInitTorrentWanted(tr_ctor const* ctor, tr_torrent* tor);
 
 bool tr_ctorSaveContents(tr_ctor const* ctor, std::string const& filename, tr_error** error);
 
+bool tr_ctorSaveMagnetContents(tr_torrent* tor, std::string const& filename, tr_error** error);
+
 std::string_view tr_ctorGetContents(tr_ctor const* ctor);
 
 tr_session* tr_ctorGetSession(tr_ctor const* ctor);
@@ -462,6 +464,11 @@ struct tr_torrent : public tr_completion::torrent_view
     {
         return metainfo_.torrentFile(this->session->torrent_dir);
     }
+
+    [[nodiscard]] auto resumeFile() const
+    {
+        return metainfo_.resumeFile(this->session->resume_dir);
+    }
 
     [[nodiscard]] auto resumeFile() const
     {
@@ -763,4 +770,5 @@ tr_peer_id_t const& tr_torrentGetPeerId(tr_torrent* tor);
 tr_torrent_metainfo&& tr_ctorStealMetainfo(tr_ctor* ctor);
 
 bool tr_ctorSetMetainfoFromFile(tr_ctor* ctor, std::string const& filename, tr_error** error);
+bool tr_ctorSetMetainfoFromMagnetLink(tr_ctor* ctor, std::string const& filename, tr_error** error);
 void tr_ctorSetLabels(tr_ctor* ctor, tr_labels_t&& labels);