The external tagreader mostly works now:

* Make TagReaderClient a singleton until it's easier to pass dependencies around
 * Add a WaitForSignal() that uses a local event loop to wait for a signal to be emitted
 * Add a WaitForFinished() to _MessageReplyBase that blocks using a semaphore
 * Add blocking versions of all TagReaderClient methods
 * Use the TagReaderClient everywhere that Song::InitFromFile and friends were used before

ext/clementine-tagreader/main.cpp

@@ -17,6 +17,7 @@
 
 #include "tagreaderworker.h"
 #include "core/encoding.h"
+#include "core/logging.h"
 
 #include <QCoreApplication>
 #include <QLocalSocket>
@@ -35,6 +36,9 @@ int main(int argc, char** argv) {
     return 1;
   }
 
+  logging::Init();
+  qLog(Info) << "TagReader worker connecting to" << args[1];
+
   // Detect technically invalid usage of non-ASCII in ID3v1 tags.
   UniversalEncodingHandler handler;
   TagLib::ID3v1::Tag::setStringHandler(&handler);

ext/clementine-tagreader/tagreaderworker.cpp

@@ -18,6 +18,7 @@
 #include "fmpsparser.h"
 #include "tagreaderworker.h"
 #include "core/encoding.h"
+#include "core/logging.h"
 #include "core/timeconstants.h"
 
 #include <QDateTime>
@@ -90,6 +91,7 @@ TagLib::String QStringToTaglibString(const QString& s) {
 
 TagReaderWorker::TagReaderWorker(QIODevice* socket, QObject* parent)
   : AbstractMessageHandler<pb::tagreader::Message>(socket, parent),
+    factory_(new TagLibFileRefFactory),
     kEmbeddedCover("(embedded)")
 {
 }
@@ -122,6 +124,8 @@ void TagReaderWorker::ReadFile(const QString& filename,
   const QByteArray url(QUrl::fromLocalFile(filename).toEncoded());
   const QFileInfo info(filename);
 
+  qLog(Debug) << "Reading tags from" << filename;
+
   song->set_basefilename(DataCommaSizeFromQString(info.fileName()));
   song->set_url(url.constData(), url.size());
   song->set_filesize(info.size());
@@ -402,6 +406,8 @@ bool TagReaderWorker::SaveFile(const QString& filename,
   if (filename.isNull())
     return false;
 
+  qLog(Debug) << "Saving tags to" << filename;
+
   scoped_ptr<TagLib::FileRef> fileref(factory_->GetFileRef(filename));
 
   if (!fileref || fileref->isNull()) // The file probably doesn't exist
@@ -475,6 +481,8 @@ void TagReaderWorker::SetTextFrame(const char* id, const std::string& value,
 }
 
 bool TagReaderWorker::IsMediaFile(const QString& filename) const {
+  qLog(Debug) << "Checking for valid file" << filename;
+
   scoped_ptr<TagLib::FileRef> fileref(factory_->GetFileRef(filename));
   return !fileref->isNull() && fileref->tag();
 }
@@ -483,6 +491,8 @@ QByteArray TagReaderWorker::LoadEmbeddedArt(const QString& filename) const {
   if (filename.isEmpty())
     return QByteArray();
 
+  qLog(Debug) << "Loading art from" << filename;
+
 #ifdef Q_OS_WIN32
   TagLib::FileRef ref(filename.toStdWString().c_str());
 #else

ext/libclementine-common/CMakeLists.txt

@@ -8,6 +8,7 @@ set(SOURCES
   core/encoding.cpp
   core/logging.cpp
   core/messagehandler.cpp
+  core/waitforsignal.cpp
   core/workerpool.cpp
 )
 

ext/libclementine-common/core/messagehandler.cpp

@@ -95,13 +95,21 @@ void _MessageHandlerBase::WriteMessage(const QByteArray& data) {
 _MessageReplyBase::_MessageReplyBase(int id, QObject* parent)
   : QObject(parent),
     id_(id),
-    finished_(false)
+    finished_(false),
+    success_(false)
 {
 }
 
+bool _MessageReplyBase::WaitForFinished() {
+  semaphore_.acquire();
+  return success_;
+}
+
 void _MessageReplyBase::Abort() {
   Q_ASSERT(!finished_);
   finished_ = true;
+  success_ = false;
 
-  emit Finished(false);
+  emit Finished(success_);
+  semaphore_.release();
 }

ext/libclementine-common/core/messagehandler.h

@@ -27,6 +27,7 @@
 #include <QMutex>
 #include <QMutexLocker>
 #include <QObject>
+#include <QSemaphore>
 #include <QThread>
 
 class QAbstractSocket;
@@ -46,10 +47,16 @@ class _MessageReplyBase : public QObject {
   Q_OBJECT
 
 public:
-  _MessageReplyBase(int id, QObject* parent);
+  _MessageReplyBase(int id, QObject* parent = 0);
 
   int id() const { return id_; }
   bool is_finished() const { return finished_; }
+  bool is_successful() const { return success_; }
+
+  // Waits for the reply to finish by waiting on a semaphore.  Never call this
+  // from the MessageHandler's thread or it will block forever.
+  // Returns true if the call was successful.
+  bool WaitForFinished();
 
   void Abort();
 
@@ -59,6 +66,9 @@ signals:
 protected:
   int id_;
   bool finished_;
+  bool success_;
+
+  QSemaphore semaphore_;
 };
 
 
@@ -67,7 +77,7 @@ protected:
 template <typename MessageType>
 class MessageReply : public _MessageReplyBase {
 public:
-  MessageReply(int id, QObject* parent);
+  MessageReply(int id, QObject* parent = 0);
 
   const MessageType& message() const { return message_; }
 
@@ -219,7 +229,7 @@ AbstractMessageHandler<MessageType>::NewReply(
     QMutexLocker l(&mutex_);
 
     const int id = next_id_ ++;
-    reply = new ReplyType(id, this);
+    reply = new ReplyType(id);
     pending_replies_[id] = reply;
   }
 
@@ -260,8 +270,10 @@ void MessageReply<MessageType>::SetReply(const MessageType& message) {
 
   message_.MergeFrom(message);
   finished_ = true;
+  success_ = true;
 
-  emit Finished(true);
+  emit Finished(success_);
+  semaphore_.release();
 }
 
 #endif // MESSAGEHANDLER_H

ext/libclementine-common/core/waitforsignal.cpp

@@ -0,0 +1,26 @@
+/* This file is part of Clementine.
+   Copyright 2011, David Sansome <me@davidsansome.com>
+
+   Clementine is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   Clementine 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 Clementine.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "waitforsignal.h"
+
+#include <QEventLoop>
+
+void WaitForSignal(QObject* sender, const char* signal) {
+  QEventLoop loop;
+  QObject::connect(sender, signal, &loop, SLOT(quit()));
+  loop.exec();
+}

ext/libclementine-common/core/waitforsignal.h

@@ -0,0 +1,25 @@
+/* This file is part of Clementine.
+   Copyright 2011, David Sansome <me@davidsansome.com>
+
+   Clementine is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   Clementine 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 Clementine.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef WAITFORSIGNAL_H
+#define WAITFORSIGNAL_H
+
+class QObject;
+
+void WaitForSignal(QObject* sender, const char* signal);
+
+#endif // WAITFORSIGNAL_H

ext/libclementine-common/core/workerpool.h

@@ -21,11 +21,14 @@
 #include <QCoreApplication>
 #include <QFile>
 #include <QLocalServer>
+#include <QLocalSocket>
 #include <QObject>
 #include <QProcess>
 #include <QThread>
 
 #include "core/closure.h"
+#include "core/logging.h"
+#include "core/waitforsignal.h"
 
 
 // Base class containing signals and slots - required because moc doesn't do
@@ -46,6 +49,7 @@ signals:
   void WorkerConnected();
 
 protected slots:
+  virtual void DoStart() {}
   virtual void NewConnection() {}
   virtual void ProcessError(QProcess::ProcessError) {}
 };
@@ -83,6 +87,7 @@ public:
   HandlerType* NextHandler();
 
 protected:
+  void DoStart();
   void NewConnection();
   void ProcessError(QProcess::ProcessError error);
 
@@ -99,15 +104,17 @@ private:
 
   template <typename T>
   Worker* FindWorker(T Worker::*member, T value) {
-    foreach (Worker& worker, workers_) {
-      if (worker.*member == value) {
-        return &worker;
+    for (typename QList<Worker>::iterator it = workers_.begin() ;
+         it != workers_.end() ; ++it) {
+      if ((*it).*member == value) {
+        return &(*it);
       }
     }
     return NULL;
   }
 
-  void DeleteQObjectPointerLater(QObject** p) {
+  template <typename T>
+  void DeleteQObjectPointerLater(T** p) {
     if (*p) {
       (*p)->deleteLater();
       *p = NULL;
@@ -157,7 +164,13 @@ void WorkerPool<HandlerType>::SetExecutableName(const QString& executable_name)
 
 template <typename HandlerType>
 void WorkerPool<HandlerType>::Start() {
+  metaObject()->invokeMethod(this, "DoStart");
+}
+
+template <typename HandlerType>
+void WorkerPool<HandlerType>::DoStart() {
   Q_ASSERT(workers_.isEmpty());
+  Q_ASSERT(!executable_name_.isEmpty());
 
   // Find the executable if we can, default to searching $PATH
   executable_path_ = executable_name_;
@@ -200,7 +213,7 @@ void WorkerPool<HandlerType>::StartOneWorker(Worker* worker) {
 
   // Create a server, find an unused name and start listening
   forever {
-    const int unique_number = qrand() ^ reinterpret_cast<int>(this);
+    const int unique_number = qrand() ^ ((int)(quint64(this) & 0xFFFFFFFF));
     const QString name = QString("%1_%2").arg(local_server_name_).arg(unique_number);
 
     if (worker->local_server_->listen(name)) {
@@ -208,10 +221,13 @@ void WorkerPool<HandlerType>::StartOneWorker(Worker* worker) {
     }
   }
 
+  qLog(Debug) << "Starting worker" << executable_path_
+              << worker->local_server_->fullServerName();
+
   // Start the process
   worker->process_->setProcessChannelMode(QProcess::ForwardedChannels);
   worker->process_->start(executable_path_,
-                          QStringList() << worker->socket_server_->fullServerName());
+                          QStringList() << worker->local_server_->fullServerName());
 }
 
 template <typename HandlerType>
@@ -223,11 +239,14 @@ void WorkerPool<HandlerType>::NewConnection() {
   if (!worker)
     return;
 
+  qLog(Debug) << "Worker connected to" << server->fullServerName();
+
   // Accept the connection.
   QLocalSocket* socket = server->nextPendingConnection();
 
   // We only ever accept one connection per worker, so destroy the server now.
-  server->deleteLater();
+  socket->setParent(this);
+  worker->local_server_->deleteLater();
   worker->local_server_ = NULL;
 
   // Create the handler.
@@ -250,11 +269,13 @@ void WorkerPool<HandlerType>::ProcessError(QProcess::ProcessError error) {
     // Failed to start errors are bad - it usually means the worker isn't
     // installed.  Don't restart the process, but tell our owner, who will
     // probably want to do something fatal.
+    qLog(Error) << "Worker failed to start";
     emit WorkerFailedToStart();
     break;
 
   default:
     // On any other error we just restart the process.
+    qLog(Debug) << "Worker failed with error" << error << "- restarting";
     StartOneWorker(worker);
     break;
   }
@@ -262,15 +283,19 @@ void WorkerPool<HandlerType>::ProcessError(QProcess::ProcessError error) {
 
 template <typename HandlerType>
 HandlerType* WorkerPool<HandlerType>::NextHandler() {
-  for (int i=0 ; i<workers_.count() ; ++i) {
-    const int worker_index = (next_worker_ + i) % workers_.count();
+  forever {
+    for (int i=0 ; i<workers_.count() ; ++i) {
+      const int worker_index = (next_worker_ + i) % workers_.count();
 
-    if (workers_[worker_index].handler_) {
-      next_worker_ = (worker_index + 1) % workers_.count();
-      return workers_[worker_index].handler_;
+      if (workers_[worker_index].handler_) {
+        next_worker_ = (worker_index + 1) % workers_.count();
+        return workers_[worker_index].handler_;
+      }
     }
+
+    // No workers were connected, wait for one.
+    WaitForSignal(this, SIGNAL(WorkerConnected()));
   }
-  return NULL;
 }
 
 #endif // WORKERPOOL_H

src/CMakeLists.txt

@@ -702,6 +702,9 @@ optional_source(HAVE_SPOTIFY
     internet/spotifyserver.h
     internet/spotifyservice.h
     internet/spotifysettingspage.h
+  INCLUDE_DIRECTORIES
+    ${CMAKE_SOURCE_DIR}/ext/libclementine-spotifyblob
+    ${CMAKE_BINARY_DIR}/ext/libclementine-spotifyblob
 )
 
 optional_source(HAVE_QCA INCLUDE_DIRECTORIES ${QCA_INCLUDE_DIRS})
@@ -961,6 +964,7 @@ target_link_libraries(clementine_lib
   libclementine-tagreader
   echoprint
   sha2
+  ${TAGLIB_LIBRARIES}
   ${ECHONEST_LIBRARIES}
   ${GOBJECT_LIBRARIES}
   ${GLIB_LIBRARIES}

src/core/organise.cpp

@@ -19,6 +19,7 @@
 #include "organise.h"
 #include "taskmanager.h"
 #include "core/logging.h"
+#include "core/tagreaderclient.h"
 
 #include <QDir>
 #include <QFileInfo>
@@ -137,7 +138,7 @@ void Organise::ProcessSomeFiles() {
 
     // Read metadata from the file
     Song song;
-    song.InitFromFile(task.filename_, -1);
+    TagReaderClient::Instance()->ReadFileBlocking(task.filename_, &song);
     if (!song.is_valid())
       continue;
 

src/core/song.h

@@ -208,8 +208,6 @@ class Song {
 
   // Setters
   bool IsEditable() const;
-  bool Save() const;
-  QFuture<bool> BackgroundSave() const;
 
   void set_id(int id);
   void set_valid(bool v);

src/core/songloader.cpp

@@ -19,13 +19,14 @@
 #include "songloader.h"
 #include "core/logging.h"
 #include "core/song.h"
+#include "core/tagreaderclient.h"
 #include "core/timeconstants.h"
+#include "internet/fixlastfm.h"
 #include "library/librarybackend.h"
 #include "library/sqlrow.h"
 #include "playlistparsers/parserbase.h"
 #include "playlistparsers/cueparser.h"
 #include "playlistparsers/playlistparser.h"
-#include "internet/fixlastfm.h"
 
 #include <QBuffer>
 #include <QDirIterator>
@@ -286,7 +287,7 @@ SongLoader::Result SongLoader::LoadLocal(const QString& filename, bool block,
     // it's a normal media file
     } else {
       Song song;
-      song.InitFromFile(filename, -1);
+      TagReaderClient::Instance()->ReadFileBlocking(filename, &song);
 
       song_list << song;
 
@@ -316,7 +317,7 @@ void SongLoader::EffectiveSongsLoad() {
     } else {
       // it's a normal media file
       QString filename = song.url().toLocalFile();
-      song.InitFromFile(filename, -1);
+      TagReaderClient::Instance()->ReadFileBlocking(filename, &song);
     }
   }
 }

src/core/tagreaderclient.cpp

@@ -24,11 +24,15 @@
 
 
 const char* TagReaderClient::kWorkerExecutableName = "clementine-tagreader";
+TagReaderClient* TagReaderClient::sInstance = NULL;
 
 TagReaderClient::TagReaderClient(QObject* parent)
   : QObject(parent),
     worker_pool_(new WorkerPool<HandlerType>(this))
 {
+  sInstance = this;
+
+  worker_pool_->SetExecutableName(kWorkerExecutableName);
 }
 
 void TagReaderClient::Start() {
@@ -41,7 +45,7 @@ TagReaderReply* TagReaderClient::ReadFile(const QString& filename) {
 
   req->set_filename(DataCommaSizeFromQString(filename));
 
-  return handler_->SendMessageWithReply(&message);
+  return worker_pool_->NextHandler()->SendMessageWithReply(&message);
 }
 
 TagReaderReply* TagReaderClient::SaveFile(const QString& filename, const Song& metadata) {
@@ -51,7 +55,7 @@ TagReaderReply* TagReaderClient::SaveFile(const QString& filename, const Song& m
   req->set_filename(DataCommaSizeFromQString(filename));
   metadata.ToProtobuf(req->mutable_metadata());
 
-  return handler_->SendMessageWithReply(&message);
+  return worker_pool_->NextHandler()->SendMessageWithReply(&message);
 }
 
 TagReaderReply* TagReaderClient::IsMediaFile(const QString& filename) {
@@ -60,7 +64,7 @@ TagReaderReply* TagReaderClient::IsMediaFile(const QString& filename) {
 
   req->set_filename(DataCommaSizeFromQString(filename));
 
-  return handler_->SendMessageWithReply(&message);
+  return worker_pool_->NextHandler()->SendMessageWithReply(&message);
 }
 
 TagReaderReply* TagReaderClient::LoadEmbeddedArt(const QString& filename) {
@@ -69,5 +73,59 @@ TagReaderReply* TagReaderClient::LoadEmbeddedArt(const QString& filename) {
 
   req->set_filename(DataCommaSizeFromQString(filename));
 
-  return handler_->SendMessageWithReply(&message);
+  return worker_pool_->NextHandler()->SendMessageWithReply(&message);
+}
+
+void TagReaderClient::ReadFileBlocking(const QString& filename, Song* song) {
+  Q_ASSERT(QThread::currentThread() != thread());
+
+  TagReaderReply* reply = ReadFile(filename);
+  if (reply->WaitForFinished()) {
+    song->InitFromProtobuf(reply->message().read_file_response().metadata());
+  }
+  reply->deleteLater();
+}
+
+bool TagReaderClient::SaveFileBlocking(const QString& filename, const Song& metadata) {
+  Q_ASSERT(QThread::currentThread() != thread());
+
+  bool ret = false;
+
+  TagReaderReply* reply = SaveFile(filename, metadata);
+  if (reply->WaitForFinished()) {
+    ret = reply->message().save_file_response().success();
+  }
+  reply->deleteLater();
+
+  return ret;
+}
+
+bool TagReaderClient::IsMediaFileBlocking(const QString& filename) {
+  Q_ASSERT(QThread::currentThread() != thread());
+
+  bool ret = false;
+
+  TagReaderReply* reply = IsMediaFile(filename);
+  if (reply->WaitForFinished()) {
+    ret = reply->message().is_media_file_response().success();
+  }
+  reply->deleteLater();
+
+  return ret;
+}
+
+QImage TagReaderClient::LoadEmbeddedArtBlocking(const QString& filename) {
+  Q_ASSERT(QThread::currentThread() != thread());
+
+  QImage ret;
+
+  TagReaderReply* reply = LoadEmbeddedArt(filename);
+  if (reply->WaitForFinished()) {
+    const std::string& data_str =
+        reply->message().load_embedded_art_response().data();
+    ret.loadFromData(QByteArray(data_str.data(), data_str.size()));
+  }
+  reply->deleteLater();
+
+  return ret;
 }

src/core/tagreaderclient.h

@@ -46,10 +46,20 @@ public:
   ReplyType* IsMediaFile(const QString& filename);
   ReplyType* LoadEmbeddedArt(const QString& filename);
 
-private:
-  void SendOrQueue(const pb::tagreader::Message& message);
+  // Convenience functions that call the above functions and wait for a
+  // response.  These block the calling thread with a semaphore, and must NOT
+  // be called from the TagReaderClient's thread.
+  void ReadFileBlocking(const QString& filename, Song* song);
+  bool SaveFileBlocking(const QString& filename, const Song& metadata);
+  bool IsMediaFileBlocking(const QString& filename);
+  QImage LoadEmbeddedArtBlocking(const QString& filename);
+
+  // TODO: Make this not a singleton
+  static TagReaderClient* Instance() { return sInstance; }
 
 private:
+  static TagReaderClient* sInstance;
+
   WorkerPool<HandlerType>* worker_pool_;
   QList<pb::tagreader::Message> message_queue_;
 };

src/covers/albumcoverloader.cpp

@@ -19,6 +19,7 @@
 #include "config.h"
 #include "core/logging.h"
 #include "core/network.h"
+#include "core/tagreaderclient.h"
 #include "core/utilities.h"
 #include "internet/internetmodel.h"
 
@@ -137,7 +138,9 @@ AlbumCoverLoader::TryLoadResult AlbumCoverLoader::TryLoadImage(
     return TryLoadResult(false, true, default_);
 
   if (filename == Song::kEmbeddedCover && !task.song_filename.isEmpty()) {
-    QImage taglib_image = Song::LoadEmbeddedArt(task.song_filename);
+    const QImage taglib_image =
+        TagReaderClient::Instance()->LoadEmbeddedArtBlocking(task.song_filename);
+
     if (!taglib_image.isNull())
       return TryLoadResult(false, true, ScaleAndPad(taglib_image));
   }
@@ -263,7 +266,8 @@ QPixmap AlbumCoverLoader::TryLoadPixmap(const QString& automatic,
     ret.load(manual);
   if (ret.isNull()) {
     if (automatic == Song::kEmbeddedCover && !filename.isNull())
-      ret = QPixmap::fromImage(Song::LoadEmbeddedArt(filename));
+      ret = QPixmap::fromImage(
+            TagReaderClient::Instance()->LoadEmbeddedArtBlocking(filename));
     else if (!automatic.isEmpty())
       ret.load(automatic);
   }

src/globalsearch/spotifysearchprovider.cpp

@@ -15,13 +15,13 @@
    along with Clementine.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+#include "spotifymessagehandler.h"
 #include "spotifysearchprovider.h"
 #include "core/logging.h"
 #include "internet/internetmodel.h"
 #include "internet/spotifyserver.h"
 #include "internet/spotifyservice.h"
 #include "playlist/songmimedata.h"
-#include "spotifyblob/common/spotifymessagehandler.h"
 
 SpotifySearchProvider::SpotifySearchProvider(QObject* parent)
   : SearchProvider(parent),

src/internet/spotifyserver.cpp

@@ -19,8 +19,8 @@
 #include "core/closure.h"
 #include "core/logging.h"
 
-#include "spotifyblob/common/spotifymessages.pb.h"
-#include "spotifyblob/common/spotifymessagehandler.h"
+#include "spotifymessages.pb.h"
+#include "spotifymessagehandler.h"
 
 #include <QTcpServer>
 #include <QTcpSocket>

src/internet/spotifyservice.cpp

@@ -1,6 +1,8 @@
+#include "blobversion.h"
 #include "config.h"
 #include "internetmodel.h"
 #include "spotifyblobdownloader.h"
+#include "spotifymessagehandler.h"
 #include "spotifyserver.h"
 #include "spotifyservice.h"
 #include "spotifysearchplaylisttype.h"
@@ -15,8 +17,6 @@
 #include "playlist/playlist.h"
 #include "playlist/playlistcontainer.h"
 #include "playlist/playlistmanager.h"
-#include "spotifyblob/common/blobversion.h"
-#include "spotifyblob/common/spotifymessagehandler.h"
 #include "widgets/didyoumean.h"
 #include "ui/iconloader.h"
 

src/library/library.h

@@ -34,7 +34,7 @@ class Library : public QObject {
   Q_OBJECT
 
  public:
-  Library(BackgroundThread<Database>* db_thread, TaskManager* task_manager_,
+  Library(BackgroundThread<Database>* db_thread, TaskManager* task_manager,
           QObject* parent);
 
   static const char* kSongsTable;

src/library/libraryplaylistitem.cpp

@@ -16,6 +16,7 @@
 */
 
 #include "libraryplaylistitem.h"
+#include "core/tagreaderclient.h"
 
 #include <QSettings>
 
@@ -36,7 +37,7 @@ QUrl LibraryPlaylistItem::Url() const {
 }
 
 void LibraryPlaylistItem::Reload() {
-  song_.InitFromFile(song_.url().toLocalFile(), song_.directory_id());
+  TagReaderClient::Instance()->ReadFileBlocking(song_.url().toLocalFile(), &song_);
 }
 
 bool LibraryPlaylistItem::InitFromQuery(const SqlRow& query) {

src/library/librarywatcher.cpp

@@ -18,6 +18,7 @@
 #include "librarywatcher.h"
 #include "librarybackend.h"
 #include "core/logging.h"
+#include "core/tagreaderclient.h"
 #include "core/taskmanager.h"
 #include "playlistparsers/cueparser.h"
 
@@ -451,7 +452,8 @@ void LibraryWatcher::UpdateNonCueAssociatedSong(const QString& file, const Song&
   }
 
   Song song_on_disk;
-  song_on_disk.InitFromFile(file, t->dir());
+  song_on_disk.set_directory_id(t->dir());
+  TagReaderClient::Instance()->ReadFileBlocking(file, &song_on_disk);
 
   if(song_on_disk.is_valid()) {
     PreserveUserSetData(file, image, matching_song, &song_on_disk, t);
@@ -476,8 +478,10 @@ SongList LibraryWatcher::ScanNewFile(const QString& file, const QString& path,
     // media files. Playlist parser for CUEs considers every entry in sheet
     // valid and we don't want invalid media getting into library!
     foreach(const Song& cue_song, cue_parser_->Load(&cue, matching_cue, path)) {
-      if(cue_song.url().toLocalFile() == file && cue_song.HasProperMediaFile()) {
-        song_list << cue_song;
+      if (cue_song.url().toLocalFile() == file) {
+        if (TagReaderClient::Instance()->IsMediaFileBlocking(file)) {
+          song_list << cue_song;
+        }
       }
     }
 
@@ -488,7 +492,7 @@ SongList LibraryWatcher::ScanNewFile(const QString& file, const QString& path,
   // it's a normal media file
   } else {
     Song song;
-    song.InitFromFile(file, -1);
+    TagReaderClient::Instance()->ReadFileBlocking(file, &song);
 
     if (song.is_valid()) {
       song_list << song;

src/main.cpp

@@ -369,6 +369,14 @@ int main(int argc, char *argv[]) {
   CoverProviders cover_providers;
   cover_providers.AddProvider(new AmazonCoverProvider);
 
+  // Create the tag loader on another thread.
+  TagReaderClient tag_reader_client;
+
+  QThread tag_reader_thread;
+  tag_reader_thread.start();
+  tag_reader_client.moveToThread(&tag_reader_thread);
+  tag_reader_client.Start();
+
   // Create some key objects
   scoped_ptr<BackgroundThread<Database> > database(
       new BackgroundThreadImplementation<Database, Database>(NULL));
@@ -408,9 +416,6 @@ int main(int argc, char *argv[]) {
   GlobalSearchService global_search_service(&global_search);
 #endif
 
-  // Tag reader client
-  TagReaderClient tag_reader_client;
-
   // Window
   MainWindow w(
       database.get(),
@@ -422,8 +427,7 @@ int main(int argc, char *argv[]) {
       &osd,
       &art_loader,
       &cover_providers,
-      &global_search,
-      &tag_reader_client);
+      &global_search);
 #ifdef HAVE_DBUS
   QObject::connect(&mpris, SIGNAL(RaiseMainWindow()), &w, SLOT(Raise()));
 #endif

src/playlist/playlist.cpp

@@ -25,8 +25,10 @@
 #include "songloaderinserter.h"
 #include "songmimedata.h"
 #include "songplaylistitem.h"
+#include "core/closure.h"
 #include "core/logging.h"
 #include "core/modelfuturewatcher.h"
+#include "core/tagreaderclient.h"
 #include "core/timeconstants.h"
 #include "internet/jamendoplaylistitem.h"
 #include "internet/jamendoservice.h"
@@ -321,24 +323,25 @@ bool Playlist::setData(const QModelIndex &index, const QVariant &value, int) {
     library_->AddOrUpdateSongs(SongList() << song);
     emit EditingFinished(index);
   } else {
-    QFuture<bool> future = song.BackgroundSave();
-    ModelFutureWatcher<bool>* watcher = new ModelFutureWatcher<bool>(index, this);
-    watcher->setFuture(future);
-    connect(watcher, SIGNAL(finished()), SLOT(SongSaveComplete()));
+    TagReaderReply* reply = TagReaderClient::Instance()->SaveFile(
+          song.url().toLocalFile(), song);
+
+    NewClosure(reply, SIGNAL(Finished(bool)),
+               this, SLOT(SongSaveComplete(TagReaderReply*,QPersistentModelIndex)),
+               reply, QPersistentModelIndex(index));
   }
   return true;
 }
 
-void Playlist::SongSaveComplete() {
-  ModelFutureWatcher<bool>* watcher = static_cast<ModelFutureWatcher<bool>*>(sender());
-  watcher->deleteLater();
-  const QPersistentModelIndex& index = watcher->index();
-  if (index.isValid()) {
+void Playlist::SongSaveComplete(TagReaderReply* reply, const QPersistentModelIndex& index) {
+  if (reply->is_successful() && index.isValid()) {
     QFuture<void> future = item_at(index.row())->BackgroundReload();
     ModelFutureWatcher<void>* watcher = new ModelFutureWatcher<void>(index, this);
     watcher->setFuture(future);
     connect(watcher, SIGNAL(finished()), SLOT(ItemReloadComplete()));
   }
+
+  reply->deleteLater();
 }
 
 void Playlist::ItemReloadComplete() {

src/playlist/playlist.h

@@ -25,6 +25,7 @@
 
 #include "playlistitem.h"
 #include "playlistsequence.h"
+#include "core/tagreaderclient.h"
 #include "core/song.h"
 #include "smartplaylists/generator_fwd.h"
 
@@ -328,7 +329,7 @@ class Playlist : public QAbstractListModel {
   void TracksDequeued();
   void TracksEnqueued(const QModelIndex&, int begin, int end);
   void QueueLayoutChanged();
-  void SongSaveComplete();
+  void SongSaveComplete(TagReaderReply* reply, const QPersistentModelIndex& index);
   void ItemReloadComplete();
   void ItemsLoaded();
   void SongInsertVetoListenerDestroyed();

src/playlist/songplaylistitem.cpp

@@ -17,6 +17,7 @@
 
 #include "playlistbackend.h"
 #include "songplaylistitem.h"
+#include "core/tagreaderclient.h"
 
 #include "library/sqlrow.h"
 
@@ -40,8 +41,6 @@ bool SongPlaylistItem::InitFromQuery(const SqlRow& query) {
 
   if (type() == "Stream") {
     song_.set_filetype(Song::Type_Stream);
-  } else {
-    song_.set_directory_id(-1);
   }
 
   return true;
@@ -54,11 +53,8 @@ QUrl SongPlaylistItem::Url() const {
 void SongPlaylistItem::Reload() {
   if (song_.url().scheme() != "file")
     return;
-  QString old_filename = song_.url().toLocalFile();
-  int old_directory_id = song_.directory_id();
 
-  song_ = Song();
-  song_.InitFromFile(old_filename, old_directory_id);
+  TagReaderClient::Instance()->ReadFileBlocking(song_.url().toLocalFile(), &song_);
 }
 
 Song SongPlaylistItem::Metadata() const {

src/playlistparsers/parserbase.cpp

@@ -16,6 +16,7 @@
 */
 
 #include "parserbase.h"
+#include "core/tagreaderclient.h"
 #include "library/librarybackend.h"
 #include "library/libraryquery.h"
 #include "library/sqlrow.h"
@@ -74,7 +75,7 @@ void ParserBase::LoadSong(const QString& filename_or_url, qint64 beginning,
   if (library_song.is_valid()) {
     *song = library_song;
   } else {
-    song->InitFromFile(filename, -1);
+    TagReaderClient::Instance()->ReadFileBlocking(filename, song);
   }
 }
 

src/ui/edittagdialog.cpp

@@ -20,6 +20,7 @@
 #include "trackselectiondialog.h"
 #include "ui_edittagdialog.h"
 #include "core/logging.h"
+#include "core/tagreaderclient.h"
 #include "core/utilities.h"
 #include "covers/albumcoverloader.h"
 #include "covers/coverproviders.h"
@@ -195,7 +196,7 @@ QList<EditTagDialog::Data> EditTagDialog::LoadData(const SongList& songs) const
     if (song.IsEditable()) {
       // Try reloading the tags from file
       Song copy(song);
-      copy.InitFromFile(copy.url().toLocalFile(), copy.directory_id());
+      TagReaderClient::Instance()->ReadFileBlocking(copy.url().toLocalFile(), &copy);
 
       if (copy.is_valid())
         ret << Data(copy);
@@ -607,7 +608,8 @@ void EditTagDialog::SaveData(const QList<Data>& data) {
     if (ref.current_.IsMetadataEqual(ref.original_))
       continue;
 
-    if (!ref.current_.Save()) {
+    if (!TagReaderClient::Instance()->SaveFileBlocking(
+          ref.current_.url().toLocalFile(), ref.current_)) {
       emit Error(tr("An error occurred writing metadata to '%1'").arg(ref.current_.url().toLocalFile()));
     }
   }

src/ui/mainwindow.cpp

@@ -161,7 +161,6 @@ MainWindow::MainWindow(
     ArtLoader* art_loader,
     CoverProviders* cover_providers,
     GlobalSearch* global_search,
-    TagReader* tag_reader_client,
     QWidget* parent)
   : QMainWindow(parent),
     ui_(new Ui_MainWindow),
@@ -178,7 +177,6 @@ MainWindow::MainWindow(
     library_(NULL),
     global_shortcuts_(new GlobalShortcuts(this)),
     global_search_(global_search),
-    tag_reader_client_(tag_reader_client),
     remote_(NULL),
     devices_(NULL),
     library_view_(new LibraryViewContainer(this)),
@@ -1499,21 +1497,24 @@ void MainWindow::RenumberTracks() {
 
     if (song.IsEditable()) {
       song.set_track(track);
-      QFuture<bool> future = song.BackgroundSave();
-      ModelFutureWatcher<bool>* watcher = new ModelFutureWatcher<bool>(source_index, this);
-      watcher->setFuture(future);
-      connect(watcher, SIGNAL(finished()), SLOT(SongSaveComplete()));
+
+      TagReaderReply* reply =
+          TagReaderClient::Instance()->SaveFile(song.url().toLocalFile(), song);
+
+      NewClosure(reply, SIGNAL(Finished(bool)),
+                 this, SLOT(SongSaveComplete(TagReaderReply*,QPersistentModelIndex)),
+                 reply, QPersistentModelIndex(source_index));
     }
     track++;
   }
 }
 
-void MainWindow::SongSaveComplete() {
-  ModelFutureWatcher<bool>* watcher = static_cast<ModelFutureWatcher<bool>*>(sender());
-  watcher->deleteLater();
-  if (watcher->index().isValid()) {
-    playlists_->current()->ReloadItems(QList<int>() << watcher->index().row());
+void MainWindow::SongSaveComplete(TagReaderReply* reply,
+                                  const QPersistentModelIndex& index) {
+  if (reply->is_successful() && index.isValid()) {
+    playlists_->current()->ReloadItems(QList<int>() << index.row());
   }
+  reply->deleteLater();
 }
 
 void MainWindow::SelectionSetValue() {
@@ -1531,10 +1532,12 @@ void MainWindow::SelectionSetValue() {
     Song song = playlists_->current()->item_at(row)->Metadata();
 
     if (Playlist::set_column_value(song, column, column_value)) {
-      QFuture<bool> future = song.BackgroundSave();
-      ModelFutureWatcher<bool>* watcher = new ModelFutureWatcher<bool>(source_index, this);
-      watcher->setFuture(future);
-      connect(watcher, SIGNAL(finished()), SLOT(SongSaveComplete()));
+      TagReaderReply* reply =
+          TagReaderClient::Instance()->SaveFile(song.url().toLocalFile(), song);
+
+      NewClosure(reply, SIGNAL(Finished(bool)),
+                 this, SLOT(SongSaveComplete(TagReaderReply*,QPersistentModelIndex)),
+                 reply, QPersistentModelIndex(source_index));
     }
   }
 }

src/ui/mainwindow.h

@@ -26,6 +26,7 @@
 
 #include "config.h"
 #include "core/mac_startup.h"
+#include "core/tagreaderclient.h"
 #include "engines/engine_fwd.h"
 #include "library/librarymodel.h"
 #include "playlist/playlistitem.h"
@@ -68,7 +69,6 @@ class SongInfoBase;
 class SongInfoView;
 class SystemTrayIcon;
 class TagFetcher;
-class TagReaderClient;
 class TaskManager;
 class TrackSelectionDialog;
 class TranscodeDialog;
@@ -93,7 +93,6 @@ class MainWindow : public QMainWindow, public PlatformInterface {
              ArtLoader* art_loader,
              CoverProviders* cover_providers,
              GlobalSearch* global_search,
-             TagReaderClient* tag_reader_client,
              QWidget *parent = 0);
   ~MainWindow();
 
@@ -222,7 +221,8 @@ class MainWindow : public QMainWindow, public PlatformInterface {
 
   void NowPlayingWidgetPositionChanged(bool above_status_bar);
 
-  void SongSaveComplete();
+  void SongSaveComplete(TagReaderReply* reply,
+                        const QPersistentModelIndex& index);
 
   void ShowCoverManager();
 #ifdef HAVE_LIBLASTFM
@@ -281,7 +281,6 @@ class MainWindow : public QMainWindow, public PlatformInterface {
   Library* library_;
   GlobalShortcuts* global_shortcuts_;
   GlobalSearch* global_search_;
-  TagReaderClient* tag_reader_client_;
   Remote* remote_;
 
   DeviceManager* devices_;

src/ui/organisedialog.cpp

@@ -21,6 +21,7 @@
 #include "ui_organisedialog.h"
 #include "core/musicstorage.h"
 #include "core/organise.h"
+#include "core/tagreaderclient.h"
 
 #include <QDir>
 #include <QFileInfo>
@@ -172,7 +173,8 @@ void OrganiseDialog::LoadPreviewSongs(const QString& filename) {
   }
 
   Song song;
-  song.InitFromFile(filename, -1);
+  TagReaderClient::Instance()->ReadFileBlocking(filename, &song);
+
   if (song.is_valid())
     preview_songs_ << song;
 }

src/ui/trackselectiondialog.cpp

@@ -18,6 +18,7 @@
 #include "iconloader.h"
 #include "trackselectiondialog.h"
 #include "ui_trackselectiondialog.h"
+#include "core/tagreaderclient.h"
 
 #include <QFileInfo>
 #include <QFutureWatcher>
@@ -241,7 +242,7 @@ void TrackSelectionDialog::SaveData(const QList<Data>& data) {
     copy.set_album(new_metadata.album());
     copy.set_track(new_metadata.track());
 
-    copy.Save();
+    TagReaderClient::Instance()->SaveFileBlocking(copy.url().toLocalFile(), copy);
   }
 }