Switched from sync transcoder to async transcoder

src/libs/auth/impl/PasswordService.cpp

@@ -82,7 +82,7 @@ checkUserPassword(Database::Session& session, const std::string& loginName, cons
 		case Database::User::AuthMode::Internal:
 		{
 			LMS_LOG(AUTH, DEBUG) << "Checking internal password for user '" << loginName << "'";
-			const Wt::Auth::BCryptHashFunction hashFunc {6}; // TODO parametrize this
+			const Wt::Auth::BCryptHashFunction hashFunc {7}; // TODO parametrize this
 			return hashFunc.verify(password, passwordHash.salt, passwordHash.hash);
 		}
 

src/libs/av/CMakeLists.txt

@@ -1,9 +1,9 @@
 
 add_library(lmsav SHARED
-	impl/AvInfo.cpp
+	impl/AudioFile.cpp
-	impl/AvTranscoder.cpp
+	impl/Transcoder.cpp
-	impl/AvTranscodeResourceHandler.cpp
+	impl/TranscodeResourceHandler.cpp
-	impl/AvTypes.cpp
+	impl/Types.cpp
 	)
 
 target_include_directories(lmsav INTERFACE

src/libs/av/impl/AudioFile.cpp

@@ -17,7 +17,7 @@
  * along with LMS.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include "av/AvInfo.hpp"
+#include "AudioFile.hpp"
 
 extern "C"
 {
@@ -44,20 +44,28 @@ static std::string averror_to_string(int error)
 		return "Unknown error";
 }
 
-MediaFileException::MediaFileException(int avError)
+class AudioFileException : public Av::Exception
-: AvException {"MediaFileException: " + averror_to_string(avError)}
 {
+	public:
+		AudioFileException(int avError)
+			: Av::Exception {"AudioFileException: " + averror_to_string(avError)}
+		{}
+};
+
+std::unique_ptr<IAudioFile>
+parseAudioFile(const std::filesystem::path& p)
+{
+	return std::make_unique<AudioFile>(p);
 }
 
-
+AudioFile::AudioFile(const std::filesystem::path& p)
-MediaFile::MediaFile(const std::filesystem::path& p)
 : _p {p}
 {
-	int error = avformat_open_input(&_context, _p.string().c_str(), nullptr, nullptr);
+	int error {avformat_open_input(&_context, _p.string().c_str(), nullptr, nullptr)};
 	if (error < 0)
 	{
 		LMS_LOG(AV, ERROR) << "Cannot open " << _p.string() << ": " << averror_to_string(error);
-		throw MediaFileException(error);
+		throw AudioFileException {error};
 	}
 
 	error = avformat_find_stream_info(_context, nullptr);
@@ -65,32 +73,32 @@ MediaFile::MediaFile(const std::filesystem::path& p)
 	{
 		LMS_LOG(AV, ERROR) << "Cannot find stream information on " << _p.string() << ": " << averror_to_string(error);
 		avformat_close_input(&_context);
-		throw MediaFileException(error);
+		throw AudioFileException {error};
 	}
 }
 
-MediaFile::~MediaFile()
+AudioFile::~AudioFile()
 {
 	avformat_close_input(&_context);
 }
 
-std::string
+const std::filesystem::path&
-MediaFile::getFormatName() const
+AudioFile::getPath() const
 {
-	return _context->iformat->name;
+	return _p;
 }
 
 std::chrono::milliseconds
-MediaFile::getDuration() const
+AudioFile::getDuration() const
 {
 	if (_context->duration == AV_NOPTS_VALUE)
-		return std::chrono::milliseconds(0); // TODO estimate
+		return std::chrono::milliseconds {0}; // TODO estimate
 
-	return std::chrono::milliseconds(_context->duration / AV_TIME_BASE * 1000);
+	return std::chrono::milliseconds {_context->duration / AV_TIME_BASE * 1000};
 }
 
 void
-getMetaDataFromDictionnary(AVDictionary* dictionnary, std::map<std::string, std::string>& res)
+getMetaDataFromDictionnary(AVDictionary* dictionnary, AudioFile::MetadataMap& res)
 {
 	if (!dictionnary)
 		return;
@@ -102,10 +110,10 @@ getMetaDataFromDictionnary(AVDictionary* dictionnary, std::map<std::string, std:
 	}
 }
 
-std::map<std::string, std::string>
+AudioFile::MetadataMap
-MediaFile::getMetaData(void)
+AudioFile::getMetaData() const
 {
-	std::map<std::string, std::string> res;
+	MetadataMap res;
 
 	getMetaDataFromDictionnary(_context->metadata, res);
 
@@ -113,7 +121,7 @@ MediaFile::getMetaData(void)
 	// If we did not find tags, search metadata in streams
 	if (res.empty())
 	{
-		for (std::size_t i = 0; i < _context->nb_streams; ++i)
+		for (std::size_t i {}; i < _context->nb_streams; ++i)
 		{
 			getMetaDataFromDictionnary(_context->streams[i]->metadata, res);
 
@@ -126,7 +134,7 @@ MediaFile::getMetaData(void)
 }
 
 std::vector<StreamInfo>
-MediaFile::getStreamInfo() const
+AudioFile::getStreamInfo() const
 {
 	std::vector<StreamInfo> res;
 
@@ -154,7 +162,7 @@ MediaFile::getStreamInfo() const
 }
 
 std::optional<std::size_t>
-MediaFile::getBestStream() const
+AudioFile::getBestStream() const
 {
 	int res = av_find_best_stream(_context,
 		AVMEDIA_TYPE_AUDIO,
@@ -170,7 +178,7 @@ MediaFile::getBestStream() const
 }
 
 bool
-MediaFile::hasAttachedPictures(void) const
+AudioFile::hasAttachedPictures(void) const
 {
 	for (std::size_t i = 0; i < _context->nb_streams; ++i)
 	{
@@ -182,9 +190,9 @@ MediaFile::hasAttachedPictures(void) const
 }
 
 void
-MediaFile::visitAttachedPictures(std::function<void(const Picture&)> func) const
+AudioFile::visitAttachedPictures(std::function<void(const Picture&)> func) const
 {
-	static const std::map<int, std::string> codecMimeMap =
+	static const std::unordered_map<int, std::string> codecMimeMap =
 	{
 		{ AV_CODEC_ID_BMP, "image/x-bmp" },
 		{ AV_CODEC_ID_GIF, "image/gif" },
@@ -230,7 +238,7 @@ MediaFile::visitAttachedPictures(std::function<void(const Picture&)> func) const
 	}
 }
 
-std::optional<MediaFileFormat>
+std::optional<AudioFileFormat>
 guessMediaFileFormat(const std::filesystem::path& file)
 {
 	AVOutputFormat* format {av_guess_format(NULL,file.string().c_str(),NULL)};
@@ -252,7 +260,7 @@ guessMediaFileFormat(const std::filesystem::path& file)
 	else if (mimeTypes.size() > 1)
 		LMS_LOG(AV, INFO) << "File '" << file.string() << "' reported several mime types: '" << format->mime_type << "'";
 
-	MediaFileFormat res;
+	AudioFileFormat res;
 	res.format = formats.front();
 	res.mimeType = mimeTypes.empty() ? "application/octet-stream" : mimeTypes.front();
 

src/libs/av/impl/AudioFile.hpp

@@ -0,0 +1,57 @@
+/*
+ * Copyright (C) 2020 Emeric Poupon
+ *
+ * This file is part of LMS.
+ *
+ * LMS 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.
+ *
+ * LMS 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 LMS.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/* This file contains some classes in order to get info from file using the libavconv */
+
+#pragma once
+
+#include "av/IAudioFile.hpp"
+
+struct AVFormatContext;
+
+namespace Av
+{
+
+	class AudioFile final : public IAudioFile
+	{
+		public:
+			AudioFile(const std::filesystem::path& p);
+			~AudioFile();
+
+			AudioFile(const AudioFile&) = delete;
+			AudioFile(AudioFile&&) = delete;
+			AudioFile& operator=(const AudioFile&) = delete;
+			AudioFile& operator=(AudioFile&&) = delete;
+
+			const std::filesystem::path&		getPath() const override;
+			std::chrono::milliseconds			getDuration() const override;
+			MetadataMap							getMetaData() const override;
+			std::vector<StreamInfo>				getStreamInfo() const override;
+			std::optional<std::size_t>			getBestStream() const override;
+			bool								hasAttachedPictures() const override;
+			void								visitAttachedPictures(std::function<void(const Picture&)> func) const override;
+
+		private:
+
+			const std::filesystem::path	_p;
+			AVFormatContext* _context {};
+	};
+
+} // namespace Av
+

src/libs/av/impl/TranscodeResourceHandler.cpp

@@ -17,7 +17,7 @@
  * along with LMS.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include "AvTranscodeResourceHandler.hpp"
+#include "TranscodeResourceHandler.hpp"
 
 namespace Av
 {
@@ -36,24 +36,32 @@ namespace Av
 		_transcoder.start();
 	}
 
-	void
+	Wt::Http::ResponseContinuation*
 	TranscodeResourceHandler::processRequest(const Wt::Http::Request& /*request*/, Wt::Http::Response& response)
 	{
 		response.setMimeType(_transcoder.getOutputMimeType());
 
-		if (!_transcoder.isComplete())
+		if (_nbBytesReady > 0)
 		{
-			std::vector<unsigned char> buffer;
+			response.out().write(reinterpret_cast<const char *>(&_buffer[0]), _nbBytesReady);
-
+			_nbBytesReady = 0;
-			_transcoder.process(buffer, _chunkSize);
-			response.out().write(reinterpret_cast<const char *>(&buffer[0]), buffer.size());
-		}
 		}
 
-	bool
+		if (!_transcoder.finished())
-	TranscodeResourceHandler::isFinished() const
 		{
-		return _transcoder.isComplete();
+			Wt::Http::ResponseContinuation *continuation {response.createContinuation()};
+			continuation->waitForMoreData();
+			_transcoder.asyncRead(_buffer.data(), _buffer.size(), [=](std::size_t nbBytesRead)
+			{
+				assert(_nbBytesReady == 0);
+				_nbBytesReady = nbBytesRead;
+				continuation->haveMoreData();
+			});
+
+			return continuation;
+		}
+
+		return {};
 	}
 }
 

src/libs/av/impl/TranscodeResourceHandler.hpp

@@ -19,9 +19,12 @@
 
 #pragma once
 
+#include <array>
 #include <filesystem>
-#include "av/AvTranscoder.hpp"
+
+#include "av/TranscodeParameters.hpp"
 #include "utils/IResourceHandler.hpp"
+#include "Transcoder.hpp"
 
 namespace Av
 {
@@ -33,10 +36,11 @@ namespace Av
 
 		private:
 
-			void processRequest(const Wt::Http::Request& request, Wt::Http::Response& reponse) override;
+			Wt::Http::ResponseContinuation* processRequest(const Wt::Http::Request& request, Wt::Http::Response& reponse) override;
-			bool isFinished() const override;
 
-			static constexpr std::size_t _chunkSize {262144};
+			static constexpr std::size_t _chunkSize {32768};
+			std::array<std::byte, _chunkSize> _buffer;
+			std::size_t _nbBytesReady {};
 			const std::filesystem::path _trackPath;
 			Transcoder _transcoder;
 	};

src/libs/av/impl/Transcoder.cpp

@@ -17,12 +17,12 @@
  * along with LMS.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include "av/AvTranscoder.hpp"
+#include "Transcoder.hpp"
 
 #include <atomic>
-#include <mutex>
+#include <iomanip>
 
-#include "av/AvInfo.hpp"
+#include "utils/IChildProcessManager.hpp"
 #include "utils/IConfig.hpp"
 #include "utils/Path.hpp"
 #include "utils/Logger.hpp"
@@ -40,39 +40,41 @@ Transcoder::init()
 {
 	ffmpegPath = Service<IConfig>::get()->getPath("ffmpeg-file", "/usr/bin/ffmpeg");
 	if (!std::filesystem::exists(ffmpegPath))
-		throw LmsException {"File '" + ffmpegPath.string() + "' does not exist!"};
+		throw Exception {"File '" + ffmpegPath.string() + "' does not exist!"};
 }
 
 Transcoder::Transcoder(const std::filesystem::path& filePath, const TranscodeParameters& parameters)
-: _filePath {filePath},
+:  _id {globalId++}
-  _parameters {parameters},
+, _filePath {filePath}
-  _id {globalId++}
+, _parameters {parameters}
 {
 
 }
 
+Transcoder::~Transcoder() = default;
+
 bool
 Transcoder::start()
 {
+	if (ffmpegPath.empty())
+		init();
+
 	try
 	{
 		if (!std::filesystem::exists(_filePath))
 		{
 			LOG(ERROR) << "File '" << _filePath << "' does not exist!";
-			_isComplete = true;
 			return false;
 		}
 		else if (!std::filesystem::is_regular_file( _filePath) )
 		{
 			LOG(ERROR) << "File '" << _filePath << "' is not regular!";
-			_isComplete = true;
 			return false;
 		}
 	}
 	catch (const std::filesystem::filesystem_error& e)
 	{
 		LOG(ERROR) << "File error on '" << _filePath.string() << "': " << e.what();
-		_isComplete = true;
 		return false;
 	}
 
@@ -82,17 +84,21 @@ Transcoder::start()
 
 	args.emplace_back(ffmpegPath.string());
 
-	// Make sure we do not produce anything in the stderr output
+	// Make sure:
+	// - we do not produce anything in the stderr output
+	// - we do not rely on input
 	// in order not to block the whole forked process
 	args.emplace_back("-loglevel");
 	args.emplace_back("quiet");
 	args.emplace_back("-nostdin");
 
 	// input Offset
-	if (_parameters.offset)
 	{
 		args.emplace_back("-ss");
-		args.emplace_back(std::to_string((*_parameters.offset).count()));
+
+		std::ostringstream oss;
+		oss << std::fixed << std::showpoint << std::setprecision(3) << (_parameters.offset.count() / float {1000});
+		args.emplace_back(oss.str());
 	}
 
 	// Input file
@@ -120,6 +126,7 @@ Transcoder::start()
 	args.emplace_back("-b:a");
 	args.emplace_back(std::to_string(_parameters.bitrate));
 
+
 	// Codecs and formats
 	switch (_parameters.format)
 	{
@@ -157,7 +164,6 @@ Transcoder::start()
 			break;
 
 		default:
-			_isComplete = true;
 			return false;
 	}
 
@@ -169,84 +175,56 @@ Transcoder::start()
 	for (const std::string& arg : args)
 		LOG(DEBUG) << "Arg = '" << arg << "'";
 
-	// make sure only one thread is executing this part of code
-	{
-		static std::mutex transcoderMutex;
-
-		std::lock_guard<std::mutex> lock {transcoderMutex};
-
-		_child = std::make_shared<redi::ipstream>();
-
 	// Caution: stdin must have been closed before
-		_child->open(ffmpegPath.string(), args);
+	try
-		if (!_child->is_open())
 	{
-			LOG(DEBUG) << "Exec failed!";
+		_childProcess = Service<IChildProcessManager>::get()->spawnChildProcess(ffmpegPath, args);
-			_isComplete = true;
+	}
+	catch (ChildProcessException& exception)
+	{
+		LOG(ERROR) << "Cannot execute '" << ffmpegPath << "': " << exception.what();
 		return false;
 	}
 
-		if (_child->out().eof())
-		{
-			LOG(DEBUG) << "Early end of file!";
-			_isComplete = true;
-			return false;
-		}
-
-	}
-	LOG(DEBUG) << "Stream opened!";
-
 	return true;
 }
 
 void
-Transcoder::process(std::vector<unsigned char>& output, std::size_t maxSize)
+Transcoder::asyncWaitForData(WaitCallback cb)
 {
-	if (!_child || _isComplete)
+	assert(_childProcess);
-		return;
 
-	output.resize(maxSize);
+	LOG(DEBUG) << "Want to wait for data";
 
-	//Read on the output stream
+	_childProcess->asyncWaitForData([cb = std::move(cb)]
-	_child->out().read(reinterpret_cast<char*>(&output[0]), maxSize);
-	output.resize(_child->out().gcount());
-
-	if (_child->out().fail())
 	{
-		LOG(DEBUG) << "Stdout FAILED";
+		cb();
-		_isComplete = true;
+	});
 }
 
-	if (_child->out().eof())
+void
+Transcoder::asyncRead(std::byte* buffer, std::size_t bufferSize, ReadCallback readCallback)
 {
-		LOG(DEBUG) << "Stdout EOF!";
+	assert(_childProcess);
-		_isComplete = true;
+
+	return _childProcess->asyncRead(buffer, bufferSize, [readCallback {std::move(readCallback)}](IChildProcess::ReadResult /*res*/, std::size_t nbBytesRead)
+	{
+		readCallback(nbBytesRead);
+	});
 }
 
-	if (_isComplete)
+std::size_t
+Transcoder::readSome(std::byte* buffer, std::size_t bufferSize)
 {
-		LOG(DEBUG) << "Transcode complete!";
+	assert(_childProcess);
-		_child->clear();
+
-		_child.reset();
+	return _childProcess->readSome(buffer, bufferSize);
 }
 
-	_total += output.size();
+bool
-
+Transcoder::finished() const
-	LOG(DEBUG) << "nb bytes = " << output.size() << ", total = " << _total;
-}
-
-Transcoder::~Transcoder()
 {
-	LOG(DEBUG) << ", ~Transcoder called! Total produced bytes = " << _total;
+	return _childProcess->finished();
-
-	if (_child)
-	{
-		LOG(DEBUG) << "Child still here!";
-		_child->rdbuf()->kill(SIGKILL);
-		LOG(DEBUG) << "Closing...";
-		_child->rdbuf()->close();
-		LOG(DEBUG) << "Closing DONE";
-	}
 }
 
 } // namespace Transcode

src/libs/av/impl/Transcoder.hpp

@@ -0,0 +1,72 @@
+/*
+ * Copyright (C) 2015 Emeric Poupon
+ *
+ * This file is part of LMS.
+ *
+ * LMS 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.
+ *
+ * LMS 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 LMS.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include <filesystem>
+#include <functional>
+
+#include "av/TranscodeParameters.hpp"
+#include "av/Types.hpp"
+
+class IChildProcess;
+
+namespace Av
+{
+	class Transcoder
+	{
+		public:
+			Transcoder(const std::filesystem::path& file, const TranscodeParameters& parameters);
+			~Transcoder();
+
+			Transcoder(const Transcoder&) = delete;
+			Transcoder& operator=(const Transcoder&) = delete;
+			Transcoder(Transcoder&&) = delete;
+			Transcoder& operator=(Transcoder&&) = delete;
+
+			bool			start();
+
+			using WaitCallback = std::function<void()>;
+			void			asyncWaitForData(WaitCallback cb);
+
+			// non blocking calls
+			using ReadCallback = std::function<void(std::size_t nbReadBytes)>;
+			void			asyncRead(std::byte* buffer, std::size_t bufferSize, ReadCallback);
+			std::size_t		readSome(std::byte* buffer, std::size_t bufferSize);
+
+			const std::string&	getOutputMimeType() const { return _outputMimeType; }
+			const TranscodeParameters& getParameters() const { return _parameters; }
+
+			bool			finished() const;
+
+		private:
+			static void init();
+
+			const std::size_t		_id {};
+			const std::filesystem::path	_filePath;
+			const TranscodeParameters	_parameters;
+
+			std::unique_ptr<IChildProcess>	_childProcess;
+
+			bool			_finished {};
+			std::string		_outputMimeType;
+	};
+
+} // namespace Av
+

src/libs/av/impl/Types.cpp

@@ -17,11 +17,13 @@
  * along with LMS.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include "av/AvTypes.hpp"
+#include "av/Types.hpp"
 
-namespace Av {
+namespace Av
+{
 
-const char* formatToMimetype(Format format)
+	std::string_view
+	formatToMimetype(Format format)
 	{
 		switch (format)
 		{
@@ -32,7 +34,7 @@ const char* formatToMimetype(Format format)
 			case Format::WEBM_VORBIS:	return "audio/webm";
 		}
 
-	throw AvException {"Invalid encoding"};
+		throw Exception {"Invalid encoding"};
 	}
 
 }

src/libs/av/include/av/AvInfo.hpp

@@ -1,99 +0,0 @@
-/*
- * Copyright (C) 2015 Emeric Poupon
- *
- * This file is part of LMS.
- *
- * LMS 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.
- *
- * LMS 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 LMS.  If not, see <http://www.gnu.org/licenses/>.
- */
-
-/* This file contains some classes in order to get info from file using the libavconv */
-
-#pragma once
-
-#include <chrono>
-#include <filesystem>
-#include <functional>
-#include <map>
-#include <optional>
-#include <string>
-#include <vector>
-
-#include "AvTypes.hpp"
-
-struct AVFormatContext;
-
-namespace Av
-{
-
-void AvInit();
-
-struct Picture
-{
-	std::string mimeType;
-	const std::byte* data {};
-	std::size_t dataSize;
-};
-
-struct StreamInfo
-{
-	size_t		id;
-	std::size_t     bitrate;
-};
-
-class MediaFileException : public AvException
-{
-	public:
-		MediaFileException(int avError);
-};
-
-class MediaFile
-{
-	public:
-		MediaFile(const std::filesystem::path& p);
-		~MediaFile();
-
-		MediaFile(const MediaFile&) = delete;
-		MediaFile& operator=(const MediaFile&) = delete;
-		MediaFile(MediaFile&&) = delete;
-		MediaFile& operator=(MediaFile&&) = delete;
-
-		std::string		getFormatName() const;
-
-		const std::filesystem::path&		getPath() const {return _p;};
-
-		std::chrono::milliseconds		getDuration() const;
-		std::map<std::string, std::string>	getMetaData(void);
-
-		std::vector<StreamInfo>	getStreamInfo() const;
-		std::optional<std::size_t>	getBestStream() const; // none if failure/unknown
-		bool			hasAttachedPictures(void) const;
-		void			visitAttachedPictures(std::function<void(const Picture&)> func) const;
-
-	private:
-
-		const std::filesystem::path	_p;
-		AVFormatContext* _context {};
-};
-
-
-struct MediaFileFormat
-{
-	std::string mimeType;
-	std::string format;
-};
-
-std::optional<MediaFileFormat> guessMediaFileFormat(const std::filesystem::path& file);
-
-} // namespace Av
-

src/libs/av/include/av/AvTranscoder.hpp

@@ -1,76 +0,0 @@
-/*
- * Copyright (C) 2015 Emeric Poupon
- *
- * This file is part of LMS.
- *
- * LMS 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.
- *
- * LMS 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 LMS.  If not, see <http://www.gnu.org/licenses/>.
- */
-
-#pragma once
-
-#include <chrono>
-#include <filesystem>
-#include <optional>
-
-#include <pstreams/pstream.h>
-
-#include "AvTypes.hpp"
-
-namespace Av {
-
-
-
-struct TranscodeParameters
-{
-	Format					format;
-	std::size_t				bitrate {128000};
-	std::optional<std::size_t>		stream; // Id of the stream to be transcoded (auto detect by default)
-	std::optional<std::chrono::seconds>	offset;
-	bool 					stripMetadata {true};
-};
-
-class Transcoder
-{
-	public:
-		static void init();
-
-		Transcoder(const std::filesystem::path& file, const TranscodeParameters& parameters);
-		~Transcoder();
-
-		Transcoder(const Transcoder&) = delete;
-		Transcoder& operator=(const Transcoder&) = delete;
-		Transcoder(Transcoder&&) = delete;
-		Transcoder& operator=(Transcoder&&) = delete;
-
-		bool			start();
-		const std::string&	getOutputMimeType() const { return _outputMimeType; }
-		void			process(std::vector<unsigned char>& output, std::size_t maxSize);
-		bool			isComplete(void) const { return _isComplete; }
-
-		const TranscodeParameters& getParameters() const { return _parameters; }
-
-	private:
-		const std::filesystem::path	_filePath;
-		const TranscodeParameters	_parameters;
-
-		std::shared_ptr<redi::ipstream>	_child;
-
-		bool			_isComplete {};
-		std::size_t		_total {};
-		const std::size_t	_id {};
-		std::string		_outputMimeType;
-};
-
-} // namespace Av
-

src/libs/av/include/av/IAudioFile.hpp

@@ -0,0 +1,76 @@
+/*
+ * Copyright (C) 2015 Emeric Poupon
+ *
+ * This file is part of LMS.
+ *
+ * LMS 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.
+ *
+ * LMS 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 LMS.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/* This file contains some classes in order to get info from file using the libavconv */
+
+#pragma once
+
+#include <chrono>
+#include <filesystem>
+#include <functional>
+#include <unordered_map>
+#include <optional>
+#include <string>
+#include <vector>
+
+#include "Types.hpp"
+
+namespace Av
+{
+	struct Picture
+	{
+		std::string			mimeType;
+		const std::byte*	data {};
+		std::size_t			dataSize;
+	};
+
+	struct StreamInfo
+	{
+		size_t			id;
+		std::size_t     bitrate;
+	};
+
+	class IAudioFile
+	{
+		public:
+			virtual ~IAudioFile() = default;
+
+			using MetadataMap = std::unordered_map<std::string, std::string>;
+
+			virtual const std::filesystem::path& getPath() const = 0;
+			virtual std::chrono::milliseconds	getDuration() const = 0;
+			virtual MetadataMap					getMetaData() const = 0;
+			virtual std::vector<StreamInfo>		getStreamInfo() const = 0;
+			virtual std::optional<std::size_t>	getBestStream() const = 0; // none if failure/unknown
+			virtual bool 						hasAttachedPictures() const = 0;
+			virtual void 						visitAttachedPictures(std::function<void(const Picture&)> func) const = 0;
+	};
+
+	std::unique_ptr<IAudioFile> parseAudioFile(const std::filesystem::path& p);
+
+	struct AudioFileFormat
+	{
+		std::string mimeType;
+		std::string format;
+	};
+
+	std::optional<AudioFileFormat> guessAudioFileFormat(const std::filesystem::path& file);
+
+} // namespace Av
+

src/libs/av/include/av/TranscodeParameters.hpp

@@ -0,0 +1,39 @@
+/*
+ * Copyright (C) 2015 Emeric Poupon
+ *
+ * This file is part of LMS.
+ *
+ * LMS 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.
+ *
+ * LMS 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 LMS.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include <chrono>
+#include <optional>
+
+#include "Types.hpp"
+
+namespace Av {
+
+struct TranscodeParameters
+{
+	Format						format;
+	std::size_t					bitrate {128000};
+	std::optional<std::size_t>	stream; // Id of the stream to be transcoded (auto detect by default)
+	std::chrono::milliseconds	offset {0};
+	bool 						stripMetadata {true};
+};
+
+} // namespace Av
+

src/libs/av/include/av/TranscodeResourceHandlerCreator.hpp

@@ -29,6 +29,5 @@ namespace Av
 	struct TranscodeParameters;
 
 	std::unique_ptr<IResourceHandler> createTranscodeResourceHandler(const std::filesystem::path& trackPath, const TranscodeParameters& parameters);
-
 }
 

src/libs/av/include/av/Types.hpp

@@ -19,21 +19,21 @@
 
 #pragma once
 
-#include <string>
+#include <string_view>
 
 #include "utils/Exception.hpp"
 
 namespace Av {
 
-class AvException : public LmsException
+	class Exception : public LmsException
 	{
 		public:
-		AvException(const std::string& msg) : LmsException(msg) {}
+			using LmsException::LmsException;
 	};
 
 	enum class Format
 	{
-	// Values are important and must not be changed
+		// Values are important and must not be changed (stored in the UI's localstorage)
 		MP3				= 0,
 		OGG_OPUS		= 1,
 		MATROSKA_OPUS	= 2,
@@ -41,7 +41,6 @@ enum class Format
 		WEBM_VORBIS		= 4,
 	};
 
-const char* formatToMimetype(Format encoding);
+	std::string_view formatToMimetype(Format format);
-
 }
 

src/libs/cover/impl/CoverArtGrabber.cpp

@@ -19,7 +19,7 @@
 
 #include "CoverArtGrabber.hpp"
 
-#include "av/AvInfo.hpp"
+#include "av/IAudioFile.hpp"
 
 #include "database/Release.hpp"
 #include "database/Session.hpp"
@@ -125,7 +125,7 @@ Grabber::Grabber(const std::filesystem::path& execPath,
 }
 
 std::unique_ptr<IEncodedImage>
-Grabber::getFromAvMediaFile(const Av::MediaFile& input, ImageSize width) const
+Grabber::getFromAvMediaFile(const Av::IAudioFile& input, ImageSize width) const
 {
 	std::unique_ptr<IEncodedImage> image;
 
@@ -303,10 +303,9 @@ Grabber::getFromTrack(const std::filesystem::path& p, ImageSize width) const
 
 	try
 	{
-		const Av::MediaFile input {p};
+		image = getFromAvMediaFile(*Av::parseAudioFile(p), width);
-		image = getFromAvMediaFile(input, width);
 	}
-	catch (Av::AvException& e)
+	catch (Av::Exception& e)
 	{
 		LMS_LOG(COVER, ERROR) << "Cannot get covers from track " << p.string() << ": " << e.what();
 	}

src/libs/cover/impl/CoverArtGrabber.hpp

@@ -39,7 +39,7 @@ namespace Database
 
 namespace Av
 {
-	class MediaFile;
+	class IAudioFile;
 }
 
 namespace CoverArt
@@ -106,7 +106,7 @@ namespace CoverArt
 			void							flushCache() override;
 
 			std::shared_ptr<IEncodedImage>	getFromTrack(Database::Session& dbSession, Database::IdType trackId, ImageSize width, bool allowReleaseFallback);
-			std::unique_ptr<IEncodedImage>	getFromAvMediaFile(const Av::MediaFile& input, ImageSize width) const;
+			std::unique_ptr<IEncodedImage>	getFromAvMediaFile(const Av::IAudioFile& input, ImageSize width) const;
 			std::unique_ptr<IEncodedImage>	getFromCoverFile(const std::filesystem::path& p, ImageSize width) const;
 
 			std::unique_ptr<IEncodedImage>	getFromTrack(const std::filesystem::path& path, ImageSize width) const;

src/libs/metadata/impl/AvFormatParser.cpp

@@ -22,7 +22,7 @@
 #include <algorithm>
 #include <iostream>
 
-#include "av/AvInfo.hpp"
+#include "av/IAudioFile.hpp"
 #include "utils/Logger.hpp"
 #include "utils/String.hpp"
 
@@ -30,11 +30,9 @@
 namespace MetaData
 {
 
-using MetadataMap = std::map<std::string, std::string>;
-
 template <typename T>
 std::optional<T>
-findFirstValueOfAs(const MetadataMap& metadataMap, std::initializer_list<std::string> tags)
+findFirstValueOfAs(const Av::IAudioFile::MetadataMap& metadataMap, std::initializer_list<std::string> tags)
 {
 	auto it = std::find_first_of(std::cbegin(metadataMap), std::cend(metadataMap), std::cbegin(tags), std::cend(tags), [](const auto& it, const auto& str) { return it.first == str; });
 	if (it == std::cend(metadataMap))
@@ -45,7 +43,7 @@ findFirstValueOfAs(const MetadataMap& metadataMap, std::initializer_list<std::st
 
 template <>
 std::optional<std::vector<UUID>>
-findFirstValueOfAs(const MetadataMap& metadataMap, std::initializer_list<std::string> tags)
+findFirstValueOfAs(const Av::IAudioFile::MetadataMap& metadataMap, std::initializer_list<std::string> tags)
 {
 	std::optional<std::string> str {findFirstValueOfAs<std::string>(metadataMap, tags)};
 	if (!str)
@@ -69,7 +67,7 @@ findFirstValueOfAs(const MetadataMap& metadataMap, std::initializer_list<std::st
 
 static
 std::optional<Album>
-getAlbum(const MetadataMap& metadataMap)
+getAlbum(const Av::IAudioFile::MetadataMap& metadataMap)
 {
 	std::optional<Album> res;
 
@@ -84,7 +82,7 @@ getAlbum(const MetadataMap& metadataMap)
 
 static
 std::vector<Artist>
-getAlbumArtists(const MetadataMap& metadataMap)
+getAlbumArtists(const Av::IAudioFile::MetadataMap& metadataMap)
 {
 	std::vector<Artist> res;
 
@@ -99,7 +97,7 @@ getAlbumArtists(const MetadataMap& metadataMap)
 
 static
 std::vector<Artist>
-getArtists(const MetadataMap& metadataMap)
+getArtists(const Av::IAudioFile::MetadataMap& metadataMap)
 {
 	std::vector<Artist> artists;
 
@@ -133,31 +131,28 @@ AvFormatParser::parse(const std::filesystem::path& p, bool debug)
 
 	try
 	{
-		Av::MediaFile mediaFile {p};
+		const auto mediaFile {Av::parseAudioFile(p)};
 
 		// Stream info
 		{
 			std::vector<AudioStream> audioStreams;
 
-			for (auto stream : mediaFile.getStreamInfo())
+			for (auto stream : mediaFile->getStreamInfo())
 			{
 				MetaData::AudioStream audioStream {static_cast<unsigned>(stream.bitrate)};
 				track.audioStreams.emplace_back(audioStream);
 			}
 		}
 
-		track.duration = mediaFile.getDuration();
+		track.duration = mediaFile->getDuration();
-		track.hasCover = mediaFile.hasAttachedPictures();
+		track.hasCover = mediaFile->hasAttachedPictures();
 
 		MetaData::Clusters clusters;
 
-		const std::map<std::string, std::string> metadataMap {mediaFile.getMetaData()};
+		const Av::IAudioFile::MetadataMap metadataMap {mediaFile->getMetaData()};
 
-		for (const auto& metadata : metadataMap)
+		for (const auto& [tag, value] : metadataMap)
 		{
-			const std::string& tag {metadata.first};
-			const std::string& value {metadata.second};
-
 			if (debug)
 				std::cout << "TAG = " << tag << ", VAL = " << value << std::endl;
 
@@ -231,7 +226,7 @@ AvFormatParser::parse(const std::filesystem::path& p, bool debug)
 		track.album = getAlbum(metadataMap);
 		track.albumArtists = getAlbumArtists(metadataMap);
 	}
-	catch(Av::MediaFileException& e)
+	catch(Av::Exception& e)
 	{
 		return std::nullopt;
 	}

src/libs/subsonic/impl/Stream.cpp

@@ -19,9 +19,9 @@
 
 #include "Stream.hpp"
 
-#include "av/AvTranscoder.hpp"
+#include "av/TranscodeParameters.hpp"
-#include "av/AvTranscodeResourceHandlerCreator.hpp"
+#include "av/TranscodeResourceHandlerCreator.hpp"
-#include "av/AvTypes.hpp"
+#include "av/Types.hpp"
 #include "database/Session.hpp"
 #include "database/Track.hpp"
 #include "database/User.hpp"
@@ -113,7 +113,7 @@ handleDownload(RequestContext& context, const Wt::Http::Request& request, Wt::Ht
 {
 	std::shared_ptr<IResourceHandler> resourceHandler;
 
-	Wt::Http::ResponseContinuation *continuation = request.continuation();
+	Wt::Http::ResponseContinuation* continuation {request.continuation()};
 	if (!continuation)
 	{
 		// Mandatory params
@@ -137,13 +137,10 @@ handleDownload(RequestContext& context, const Wt::Http::Request& request, Wt::Ht
 		resourceHandler = Wt::cpp17::any_cast<std::shared_ptr<IResourceHandler>>(continuation->data());
 	}
 
-	resourceHandler->processRequest(request, response);
+	continuation = resourceHandler->processRequest(request, response);
-	if (!resourceHandler->isFinished())
+	if (continuation)
-	{
-		Wt::Http::ResponseContinuation *continuation = response.createContinuation();
 		continuation->setData(resourceHandler);
 }
-}
 
 void
 handleStream(RequestContext& context, const Wt::Http::Request& request, Wt::Http::Response& response)
@@ -164,13 +161,10 @@ handleStream(RequestContext& context, const Wt::Http::Request& request, Wt::Http
 		resourceHandler = Wt::cpp17::any_cast<std::shared_ptr<IResourceHandler>>(continuation->data());
 	}
 
-	resourceHandler->processRequest(request, response);
+	continuation = resourceHandler->processRequest(request, response);
-	if (!resourceHandler->isFinished())
+	if (continuation)
-	{
-		Wt::Http::ResponseContinuation *continuation = response.createContinuation();
 		continuation->setData(resourceHandler);
 }
-}
 
 }
 

src/libs/utils/CMakeLists.txt

@@ -1,5 +1,7 @@
 
 add_library(lmsutils SHARED
+	impl/ChildProcess.cpp
+	impl/ChildProcessManager.cpp
 	impl/Config.cpp
 	impl/FileResourceHandler.cpp
 	impl/Logger.cpp

src/libs/utils/impl/ChildProcess.cpp

@@ -0,0 +1,201 @@
+#include "ChildProcess.hpp"
+
+#include <cstring>
+#include <cerrno>
+#include <fcntl.h>
+#include <stdexcept>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <signal.h>
+#include <unistd.h>
+
+#include <algorithm>
+#include <iostream>
+#include <mutex>
+
+#include <boost/asio/read.hpp>
+#include <boost/asio/buffer.hpp>
+
+#include "utils/Exception.hpp"
+#include "utils/Logger.hpp"
+
+namespace
+{
+	class SystemException : public ChildProcessException
+	{
+		public:
+			SystemException(int err, const std::string& errMsg)
+				: ChildProcessException {errMsg + ": " + strerror(err)}
+			{}
+	};
+}
+
+ChildProcess::ChildProcess(boost::asio::io_context& ioContext, const std::filesystem::path& path, const Args& args)
+: _ioContext {ioContext}
+, _childStdout {_ioContext}
+
+{
+	// make sure only one thread is executing this part of code
+	static std::mutex mutex;
+	std::unique_lock<std::mutex> lock {mutex};
+
+	int pipe[2];
+
+	int res {pipe2(pipe, O_NONBLOCK | O_CLOEXEC)};
+	if (res < 0)
+		throw SystemException {errno, "pipe2 failed!"};
+
+	{
+		const std::size_t pipeSize {65536*8};
+
+		if (fcntl(pipe[0], F_SETPIPE_SZ, pipeSize) == -1)
+			throw SystemException {errno, "fcntl failed!"};
+
+		if (fcntl(pipe[1], F_SETPIPE_SZ, pipeSize) == -1)
+			throw SystemException {errno, "fcntl failed!"};
+	}
+
+	res = fork();
+	if (res == -1)
+		throw SystemException {errno, "fork failed!"};
+
+	if (res == 0) // CHILD
+	{
+		close(pipe[0]);
+		close(STDIN_FILENO);
+		close(STDERR_FILENO);
+
+		// Replace stdout with pipe write
+		if (dup2(pipe[1], STDOUT_FILENO) == -1)
+			exit(-1);
+
+		std::vector<const char*> execArgs;
+		std::transform(std::cbegin(args), std::cend(args), std::back_inserter(execArgs), [](const std::string& arg) { return arg.c_str(); });
+		execArgs.push_back(nullptr);
+
+		res = execv(path.string().c_str(), (char *const*)&execArgs[0]);
+		if (res == -1)
+			exit(-1);
+	}
+	else // PARENT
+	{
+		close(pipe[1]);
+		_childStdout.assign(pipe[0]);
+		_childPID = res;
+	}
+}
+
+ChildProcess::~ChildProcess()
+{
+	if (!_waited)
+	{
+		close(_childStdout.native_handle());
+		kill();
+		wait(true);
+	}
+}
+
+void
+ChildProcess::drain()
+{
+	char buf[128];
+
+	while (boost::asio::read(_childStdout, boost::asio::buffer(buf)) > 0)
+		LMS_LOG(CHILDPROCESS, DEBUG) << "drained some bytes" << std::endl;
+}
+
+void
+ChildProcess::kill()
+{
+	::kill(_childPID, SIGKILL);
+}
+
+bool
+ChildProcess::wait(bool block)
+{
+	int wstatus {};
+
+	pid_t pid {waitpid(_childPID, &wstatus, block ? 0 : WNOHANG)};
+
+	if (pid == -1)
+		throw SystemException {errno, "waitpid failed!"};
+	else if (pid == 0)
+		return false;
+
+	if (WIFEXITED(wstatus))
+		_exitCode = WEXITSTATUS(wstatus);
+
+	_waited = true;
+	return true;
+}
+
+
+void
+ChildProcess::asyncRead(std::byte* data, std::size_t bufferSize, ReadCallback callback) 
+{
+	LMS_LOG(CHILDPROCESS, DEBUG) << "ASYNC READ";
+
+	boost::asio::async_read(_childStdout, boost::asio::buffer(data, bufferSize),
+		[this, callback {std::move(callback)}](const boost::system::error_code& error, std::size_t bytesTransferred)
+		{
+			LMS_LOG(CHILDPROCESS, DEBUG) << "ASYNC READ CB - error = '" << error.message() << "', bytesTransferred = " << bytesTransferred;
+
+			if (error)
+			{
+				{
+					boost::system::error_code closeError;
+					_childStdout.close(closeError);
+				}
+
+				if (error == boost::asio::error::operation_aborted)
+				{
+					return;
+				}
+				if (error == boost::asio::error::eof)
+				{
+					callback(ReadResult::EndOfFile, bytesTransferred);
+					return;
+				}
+				else
+				{
+					callback(ReadResult::Error, bytesTransferred);
+					return;
+				}
+			}
+
+			callback(ReadResult::Success, bytesTransferred);
+		});
+}
+
+void
+ChildProcess::asyncWaitForData(WaitCallback cb)
+{
+	LMS_LOG(CHILDPROCESS, DEBUG) << "Async wait requested";
+
+	_childStdout.async_wait(boost::asio::posix::stream_descriptor::wait_read,
+			[cb {std::move(cb)}](const boost::system::error_code& ec)
+	{
+		LMS_LOG(CHILDPROCESS, DEBUG) << "Wait CB, error = " << ec.message();
+		if (!ec)
+			cb();
+	});
+}
+
+std::size_t
+ChildProcess::readSome(std::byte* data, std::size_t bufferSize)
+{
+	boost::system::error_code ec;
+	const std::size_t res {_childStdout.read_some(boost::asio::buffer(data, bufferSize), ec)};
+	LMS_LOG(CHILDPROCESS, DEBUG) << "read some " << res << " bytes, ec = " << ec.message();
+	if (ec)
+		_childStdout.close(ec);
+
+	return res;
+}
+
+bool
+ChildProcess::finished()
+{
+	return !_childStdout.is_open();
+}
+

src/libs/utils/impl/ChildProcess.hpp

@@ -0,0 +1,37 @@
+#pragma once
+
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <filesystem>
+
+#include <boost/asio/io_context.hpp>
+#include <boost/asio/posix/stream_descriptor.hpp>
+
+#include "utils/IChildProcess.hpp"
+
+
+class ChildProcess : public IChildProcess
+{
+	public:
+		~ChildProcess();
+		ChildProcess(boost::asio::io_context& ioContext, const std::filesystem::path& path, const Args& args);
+
+	private:
+		void		asyncRead(std::byte* data, std::size_t bufferSize, ReadCallback callback) override;
+		void		asyncWaitForData(WaitCallback cb) override;
+		std::size_t	readSome(std::byte* data, std::size_t bufferSize) override;
+		bool		finished() override;
+
+		void	kill();
+		void	drain();
+		bool	wait(bool block); // return true if waited
+
+		using FileDescriptor = boost::asio::posix::stream_descriptor;
+
+		boost::asio::io_context&	_ioContext;
+		FileDescriptor				_childStdout;
+		::pid_t						_childPID {};
+		bool						_waited {};
+		std::optional<int>			_exitCode;
+};

src/libs/utils/impl/ChildProcessManager.cpp

@@ -0,0 +1,54 @@
+
+#include "ChildProcessManager.hpp"
+
+#include "utils/Logger.hpp"
+
+#include "ChildProcess.hpp"
+
+
+std::unique_ptr<IChildProcessManager>
+createChildProcessManager()
+{
+	return std::make_unique<ChildProcessManager>();
+}
+
+ChildProcessManager::ChildProcessManager()
+: _work {boost::asio::make_work_guard(_ioContext)}
+{
+	start();
+}
+
+ChildProcessManager::~ChildProcessManager()
+{
+	stop();
+}
+
+void
+ChildProcessManager::start()
+{
+	LMS_LOG(CHILDPROCESS, INFO) << "Starting child process manager...";
+
+	_thread = std::make_unique<std::thread>([&]()
+	{
+		_ioContext.run();
+	});
+
+	LMS_LOG(CHILDPROCESS, INFO) << "Child process manager started!";
+}
+
+void
+ChildProcessManager::stop()
+{
+	LMS_LOG(CHILDPROCESS, INFO) << "Stopping child process manager";
+	_work.reset();
+	_thread->join();
+	LMS_LOG(CHILDPROCESS, INFO) << "Stopped child process manager";
+}
+
+std::unique_ptr<IChildProcess>
+ChildProcessManager::spawnChildProcess(const std::filesystem::path& path, const IChildProcess::Args& args)
+{
+	return std::make_unique<ChildProcess>(_ioContext, path, args);
+}
+
+

src/libs/utils/impl/ChildProcessManager.hpp

@@ -0,0 +1,34 @@
+#pragma once
+
+#include <memory>
+#include <thread>
+
+#include <boost/asio/io_context.hpp>
+#include <boost/asio/executor_work_guard.hpp>
+
+#include "utils/IChildProcessManager.hpp"
+
+class ChildProcessManager : public IChildProcessManager
+{
+	public:
+
+		ChildProcessManager();
+		~ChildProcessManager();
+
+		ChildProcessManager(const ChildProcessManager&) = delete;
+		ChildProcessManager(ChildProcessManager&&) = delete;
+		ChildProcessManager& operator=(const ChildProcessManager&) = delete;
+		ChildProcessManager& operator=(ChildProcessManager&&) = delete;
+
+	private:
+		std::unique_ptr<IChildProcess> spawnChildProcess(const std::filesystem::path& path, const IChildProcess::Args& args) override;
+
+		void start();
+		void stop();
+
+		boost::asio::io_context	_ioContext;
+		std::unique_ptr<std::thread> _thread;
+		boost::asio::executor_work_guard<boost::asio::io_context::executor_type> _work;
+};
+
+

src/libs/utils/impl/FileResourceHandler.cpp

@@ -36,7 +36,7 @@ FileResourceHandler::FileResourceHandler(const std::filesystem::path& path)
 }
 
 
-void
+Wt::Http::ResponseContinuation*
 FileResourceHandler::processRequest(const Wt::Http::Request& request, Wt::Http::Response& response)
 {
 	::uint64_t startByte {_offset};
@@ -49,7 +49,7 @@ FileResourceHandler::processRequest(const Wt::Http::Request& request, Wt::Http::
 			LMS_LOG(UTILS, ERROR) << "Cannot open file stream for '" << _path.string() << "'";
 			response.setStatus(404);
 			_isFinished = true;
-			return;
+			return {};
 		}
 		else
 		{
@@ -72,7 +72,7 @@ FileResourceHandler::processRequest(const Wt::Http::Request& request, Wt::Http::
 
 			LMS_LOG(UTILS, DEBUG) << "Range not satisfiable";
 			_isFinished = true;
-			return;
+			return {};
 		}
 
 		if (ranges.size() == 1)
@@ -102,7 +102,7 @@ FileResourceHandler::processRequest(const Wt::Http::Request& request, Wt::Http::
 	{
 		LMS_LOG(UTILS, ERROR) << "Cannot reopen file stream for '" << _path.string() << "'";
 		_isFinished = true;
-		return;
+		return {};
 	}
 
 	ifs.seekg(static_cast<std::istream::pos_type>(startByte));
@@ -123,20 +123,16 @@ FileResourceHandler::processRequest(const Wt::Http::Request& request, Wt::Http::
 	if (ifs.good() && actualPieceSize < restSize)
 	{
 		_offset = startByte + actualPieceSize;
-
 		LMS_LOG(UTILS, DEBUG) << "Job not complete! Next chunk offset = " << _offset;
+
+		return response.createContinuation();
 	}
-	else
+
-	{
 	_isFinished = true;
 	LMS_LOG(UTILS, DEBUG) << "Job complete!";
-	}
-}
 
-bool
+	return {};
-FileResourceHandler::isFinished() const
-{
-	return _isFinished;
 }
 
 
+

src/libs/utils/impl/FileResourceHandler.hpp

@@ -29,10 +29,9 @@ class FileResourceHandler final : public IResourceHandler
 
 	private:
 
-		void processRequest(const Wt::Http::Request& request, Wt::Http::Response& response) override;
+		Wt::Http::ResponseContinuation* processRequest(const Wt::Http::Request& request, Wt::Http::Response& response) override;
-		bool isFinished() const override;
 
-		static constexpr std::size_t _chunkSize {262144};
+		static constexpr std::size_t _chunkSize {65536};
 
 		std::filesystem::path	_path;
 		::uint64_t		_beyondLastByte {};

src/libs/utils/impl/Logger.cpp

@@ -26,6 +26,7 @@ const char* getModuleName(Module mod)
 		case Module::API_SUBSONIC:	return "API_SUBSONIC";
 		case Module::AUTH:			return "AUTH";
 		case Module::AV:			return "AV";
+		case Module::CHILDPROCESS:	return "CHILDPROC";
 		case Module::COVER:			return "COVER";
 		case Module::DB:			return "DB";
 		case Module::DBUPDATER:		return "DB UPDATER";

src/libs/utils/include/utils/IChildProcess.hpp

@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) 2020 Emeric Poupon
+ *
+ * This file is part of LMS.
+ *
+ * LMS 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.
+ *
+ * LMS 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 LMS.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#pragma once
+
+#include <cstddef>
+#include <functional>
+#include <string>
+#include <vector>
+
+#include "utils/Exception.hpp"
+
+class ChildProcessException : public LmsException
+{
+	public:
+		using LmsException::LmsException;
+};
+
+class IChildProcess
+{
+	public:
+		using Args = std::vector<std::string>;
+
+		virtual ~IChildProcess() = default;
+
+		enum class ReadResult
+		{
+			Success,
+			Error,
+			EndOfFile,
+		};
+
+		using ReadCallback = std::function<void(ReadResult, std::size_t)>;
+		virtual void		asyncRead(std::byte* data, std::size_t bufferSize, ReadCallback callback) = 0;
+
+		using WaitCallback = std::function<void(void)>;
+		virtual void		asyncWaitForData(WaitCallback cb) = 0;
+		virtual std::size_t	readSome(std::byte* data, std::size_t bufferSize) = 0;
+		virtual bool		finished() = 0;
+};
+

src/libs/utils/include/utils/IChildProcessManager.hpp

@@ -0,0 +1,40 @@
+/*
+ * Copyright (C) 2020 Emeric Poupon
+ *
+ * This file is part of LMS.
+ *
+ * LMS 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.
+ *
+ * LMS 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 LMS.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#pragma once
+
+#include <filesystem>
+#include <memory>
+#pragma once
+
+#include <filesystem>
+#include <memory>
+
+#include "IChildProcess.hpp"
+
+class IChildProcessManager
+{
+	public:
+		virtual ~IChildProcessManager() = default;
+
+		virtual std::unique_ptr<IChildProcess> spawnChildProcess(const std::filesystem::path& path, const IChildProcess::Args& args) = 0;
+};
+
+std::unique_ptr<IChildProcessManager> createChildProcessManager();
+
+

src/libs/utils/include/utils/IResourceHandler.hpp

@@ -28,7 +28,6 @@ class IResourceHandler
 	public:
 		virtual ~IResourceHandler() = default;
 
-		virtual void processRequest(const Wt::Http::Request& request, Wt::Http::Response& response) = 0;
+		[[nodiscard]] virtual Wt::Http::ResponseContinuation* processRequest(const Wt::Http::Request& request, Wt::Http::Response& response) = 0;
-		virtual bool isFinished() const = 0;
 };
 

src/libs/utils/include/utils/Logger.hpp

@@ -38,6 +38,7 @@ enum class Module
 	API_SUBSONIC,
 	AUTH,
 	AV,
+	CHILDPROCESS,
 	COVER,
 	DB,
 	DBUPDATER,

src/lms/main.cpp

@@ -26,8 +26,6 @@
 
 #include "auth/IAuthTokenService.hpp"
 #include "auth/IPasswordService.hpp"
-#include "av/AvInfo.hpp"
-#include "av/AvTranscoder.hpp"
 #include "cover/ICoverArtGrabber.hpp"
 #include "database/Db.hpp"
 #include "database/Session.hpp"
@@ -35,6 +33,7 @@
 #include "recommendation/IEngine.hpp"
 #include "subsonic/SubsonicResource.hpp"
 #include "ui/LmsApplication.hpp"
+#include "utils/IChildProcessManager.hpp"
 #include "utils/IConfig.hpp"
 #include "utils/Service.hpp"
 #include "utils/WtLogger.hpp"
@@ -203,9 +202,6 @@ int main(int argc, char* argv[])
 		Wt::WServer server {argv[0]};
 		server.setServerConfiguration(wtServerArgs.size(), const_cast<char**>(&wtArgv[0]));
 
-		// lib init
-		Av::Transcoder::init();
-
 		// Initializing a connection pool to the database that will be shared along services
 		Database::Db database {config->getPath("working-dir") / "lms.db"};
 		{
@@ -217,6 +213,7 @@ int main(int argc, char* argv[])
 		UserInterface::LmsApplicationGroupContainer appGroups;
 
 		// Service initialization order is important
+		Service<IChildProcessManager> childProcessManagerService {createChildProcessManager()};
 		Service<Auth::IAuthTokenService> authTokenService {Auth::createAuthTokenService(config->getULong("login-throttler-max-entriees", 10000))};
 		Service<Auth::IPasswordService> passwordService {Auth::createPasswordService(config->getULong("login-throttler-max-entriees", 10000))};
 		Service<CoverArt::IGrabber> coverArtService {CoverArt::createGrabber(argv[0],

src/lms/ui/resource/AudioFileResource.cpp

@@ -22,7 +22,7 @@
 #include <fstream>
 #include <Wt/Http/Response.h>
 
-#include "av/AvInfo.hpp"
+#include "av/IAudioFile.hpp"
 #include "database/Session.hpp"
 #include "database/Track.hpp"
 #include "utils/FileResourceHandlerCreator.hpp"
@@ -101,14 +101,10 @@ AudioFileResource::handleRequest(const Wt::Http::Request& request,
 		fileResourceHandler = Wt::cpp17::any_cast<std::shared_ptr<IResourceHandler>>(request.continuation()->data());
 	}
 
-	fileResourceHandler->processRequest(request, response);
+	auto* continuation {fileResourceHandler->processRequest(request, response)};
-
+	if (continuation)
-	if (!fileResourceHandler->isFinished())
-	{
-		auto* continuation {response.createContinuation()};
 		continuation->setData(fileResourceHandler);
 }
-}
 
 
 } // namespace UserInterface

src/lms/ui/resource/AudioTranscodeResource.cpp

@@ -19,9 +19,12 @@
 
 #include "AudioTranscodeResource.hpp"
 
+#include <optional>
 #include <Wt/Http/Response.h>
 
-#include "av/AvTranscoder.hpp"
+#include "av/TranscodeParameters.hpp"
+#include "av/TranscodeResourceHandlerCreator.hpp"
+#include "av/Types.hpp"
 #include "database/Session.hpp"
 #include "database/Track.hpp"
 #include "database/User.hpp"
@@ -66,13 +69,6 @@ namespace StringUtils
 	}
 }
 
-namespace UserInterface {
-
-AudioTranscodeResource:: ~AudioTranscodeResource()
-{
-	beingDeleted();
-}
-
 static
 std::optional<Av::Format>
 AudioFormatToAvFormat(Database::AudioFormat format)
@@ -91,6 +87,14 @@ AudioFormatToAvFormat(Database::AudioFormat format)
 	return std::nullopt;
 }
 
+
+namespace UserInterface {
+
+AudioTranscodeResource:: ~AudioTranscodeResource()
+{
+	beingDeleted();
+}
+
 std::string
 AudioTranscodeResource::getUrl(Database::IdType trackId) const
 {
@@ -115,22 +119,17 @@ readParameterAs(const Wt::Http::Request& request, const std::string& parameterNa
 	return res;
 }
 
-void
+struct TranscodeParameters
-AudioTranscodeResource::handleRequest(const Wt::Http::Request& request,
-		Wt::Http::Response& response)
 {
-	std::shared_ptr<Av::Transcoder> transcoder;
+	std::filesystem::path file;
+	Av::TranscodeParameters transcodeParameters;
+};
 
-	// First, see if this request is for a continuation
+static
-	Wt::Http::ResponseContinuation *continuation = request.continuation();
+std::optional<TranscodeParameters>
-	if (continuation)
+readTranscodeParameters(const Wt::Http::Request& request)
 {
-		LOG(DEBUG) << "Continuation! " << continuation ;
+	TranscodeParameters parameters;
-		transcoder = Wt::cpp17::any_cast<std::shared_ptr<Av::Transcoder>>(continuation->data());
-	}
-	else
-	{
-		LOG(DEBUG) << "First request: creating transcoder";
 
 	// mandatory parameters
 	auto trackId {readParameterAs<Database::IdType>(request, "trackid")};
@@ -138,14 +137,14 @@ AudioTranscodeResource::handleRequest(const Wt::Http::Request& request,
 	auto bitrate {readParameterAs<Database::Bitrate>(request, "bitrate")};
 
 	if (!trackId || !format || !bitrate)
-			return;
+		return std::nullopt;
 
-		auto avFormat {AudioFormatToAvFormat(*format)};
+	const std::optional<Av::Format> avFormat {AudioFormatToAvFormat(*format)};
 	if (!avFormat)
-			return;
+		return std::nullopt;
 
 	// optional parameter
-		auto offset {readParameterAs<std::size_t>(request, "offset")};
+	std::size_t offset {readParameterAs<std::size_t>(request, "offset").value_or(0)};
 
 	std::filesystem::path trackPath;
 	{
@@ -155,62 +154,50 @@ AudioTranscodeResource::handleRequest(const Wt::Http::Request& request,
 		if (!track)
 		{
 			LOG(ERROR) << "Missing track";
-				return;
+			return std::nullopt;
 		}
 
-			trackPath = track->getPath();
+		parameters.file = track->getPath();
 
 		if (Database::User::audioTranscodeAllowedBitrates.find(*bitrate) == std::cend(Database::User::audioTranscodeAllowedBitrates))
 		{
 			LOG(ERROR) << "Bitrate '" << *bitrate << "' is not allowed";
-				return;
+			return std::nullopt;
 		}
 	}
 
-		Av::TranscodeParameters parameters {};
+	parameters.transcodeParameters.stripMetadata = true;
-		parameters.stripMetadata = true;
+	parameters.transcodeParameters.format = *avFormat;
-		parameters.format = *avFormat;
+	parameters.transcodeParameters.bitrate = *bitrate;
-		parameters.bitrate = *bitrate;
+	parameters.transcodeParameters.offset = std::chrono::seconds {offset};
-		parameters.offset = std::chrono::seconds {offset ? *offset : 0};
 
-		transcoder = std::make_shared<Av::Transcoder>(trackPath, parameters);
+	return parameters;
-		if (!transcoder->start())
+}
+
+void
+AudioTranscodeResource::handleRequest(const Wt::Http::Request& request,
+		Wt::Http::Response& response)
 {
-			LOG(ERROR) << "Cannot start transcoder";
+	std::shared_ptr<IResourceHandler> resourceHandler;
-			return;
-		}
 
-		LOG(DEBUG) << "Transcoder started";
+	Wt::Http::ResponseContinuation* continuation {request.continuation()};
-
+	if (!continuation)
-		std::string mimeType {transcoder->getOutputMimeType()};
-		response.setMimeType(mimeType);
-		LOG(DEBUG) << "Mime type set to '" << mimeType << "'";
-
-	}
-
-	if (!transcoder->isComplete())
 	{
-		std::vector<unsigned char> data;
+		const std::optional<TranscodeParameters>& parameters {readTranscodeParameters(request)};
-		data.reserve(_chunkSize);
+		if (parameters)
-
+			resourceHandler = Av::createTranscodeResourceHandler(parameters->file, parameters->transcodeParameters);
-		transcoder->process(data, _chunkSize);
-
-		response.out().write(reinterpret_cast<char*>(&data[0]), data.size());
-		LOG(DEBUG) << "Written " << data.size() << " bytes! complete = " << (transcoder->isComplete() ? "true" : "false");
-
-		if (!response.out())
-		{
-			LOG(ERROR) << "Write failed!";
-		}
-	}
-
-	if (!transcoder->isComplete() && response.out())
-	{
-		continuation = response.createContinuation();
-		continuation->setData(transcoder);
 	}
 	else
-		LOG(DEBUG) << "No more data!";
+	{
+		resourceHandler = Wt::cpp17::any_cast<std::shared_ptr<IResourceHandler>>(continuation->data());
+	}
+
+	if (resourceHandler)
+	{
+		continuation = resourceHandler->processRequest(request, response);
+		if (continuation)
+			continuation->setData(resourceHandler);
+	}
 }
 
 } // namespace UserInterface