multithreading

CHANGELOG.md

@@ -0,0 +1,8 @@
+# Changelog
+
+## MLC 1.0.1 (July 21, 2023)
+### Added multithreaded encoding
+### Only the first artist vorbis tag is left in the id3 tags
+
+## MLC 1.0.0 (July 19, 2023)
+### Initial release, only core functionality

CMakeLists.txt

@@ -1,7 +1,7 @@
 cmake_minimum_required(VERSION 3.0)
 project(
     mlc
-    VERSION 0.0.1
+    VERSION 1.0.1
     DESCRIPTION "Media Library Compiler: rips your media library to a lossy compilation"
     LANGUAGES CXX
 )
@@ -22,6 +22,7 @@ add_executable(mlc
     decoded.cpp
     flactomp3.cpp
     collection.cpp
+    taskmanager.cpp
 )
 
 target_link_libraries(mlc

collection.cpp

@@ -1,22 +1,24 @@
 #include "collection.h"
 
+#include "taskmanager.h"
+
 namespace fs = std::filesystem;
 
 static const std::string flac(".flac");
 
-Collection::Collection(const std::string& path) :
+Collection::Collection(const std::string& path, TaskManager* tm) :
     path(fs::canonical(path)),
     countMusical(0),
     counted(false),
-    convertedSoFar(0)
+    taskManager(tm)
 {
 }
 
-Collection::Collection(const std::filesystem::path& path):
+Collection::Collection(const std::filesystem::path& path, TaskManager* tm):
     path(fs::canonical(path)),
     countMusical(0),
     counted(false),
-    convertedSoFar(0)
+    taskManager(tm)
 {
 }
 
@@ -60,12 +62,11 @@ uint32_t Collection::countMusicFiles() const {
     return countMusical;
 }
 
-void Collection::convert(const std::string& outPath, std::function<void()> progress) {
+void Collection::convert(const std::string& outPath) {
-    convertedSoFar = 0;
+    if (taskManager == nullptr)
+        throw 6;
+
     fs::path out = fs::absolute(outPath);
-    if (progress == nullptr) {
-        progress = std::bind(&Collection::prg, this);
-    }
 
     fs::create_directories(out);
     out = fs::canonical(outPath);
@@ -76,22 +77,18 @@ void Collection::convert(const std::string& outPath, std::function<void()> progr
                 fs::path dstPath = out / sourcePath.filename();
                 if (isMusic(sourcePath)) {
                     dstPath.replace_extension(".mp3");
-                    FLACtoMP3 convertor;
+                    taskManager->queueJob(sourcePath, dstPath);
-                    convertor.setInputFile(sourcePath);
-                    convertor.setOutputFile(dstPath);
-                    convertor.run();
-                    progress();
                 } else {
-                    fs::copy_file(sourcePath, dstPath);
+                    fs::copy_file(sourcePath, dstPath, fs::copy_options::overwrite_existing);
                 }
                 //std::cout << sourcePath << " => " << dstPath << std::endl;
             }   break;
             case fs::file_type::directory: {
                 fs::path sourcePath = entry.path();
-                Collection collection(sourcePath);
+                Collection collection(sourcePath, taskManager);
                 fs::path::iterator itr = sourcePath.end();
                 --itr;
-                collection.convert(std::string(out / *itr), progress);
+                collection.convert(std::string(out / *itr));
             }   break;
             default:
                 break;
@@ -103,7 +100,3 @@ bool Collection::isMusic(const std::filesystem::path& path) {
     return path.extension() == flac;    //I know, it's primitive yet, but it's the fastest
 }
 
-void Collection::prg() const {
-    std::cout << "\r" << ++convertedSoFar << "/" << countMusicFiles() << std::flush;
-}
-

collection.h

@@ -3,28 +3,28 @@
 #include <string>
 #include <iostream>
 #include <filesystem>
-#include <functional>
 
 #include "flactomp3.h"
 
+class TaskManager;
+
 class Collection {
 public:
-    Collection(const std::string& path);
+    Collection(const std::string& path, TaskManager* tm = nullptr);
-    Collection(const std::filesystem::path& path);
+    Collection(const std::filesystem::path& path, TaskManager* tm = nullptr);
     ~Collection();
 
     void list() const;
     uint32_t countMusicFiles() const;
-    void convert(const std::string& outPath, std::function<void()> progress = nullptr);
+    void convert(const std::string& outPath);
 
 private:
     static bool isMusic(const std::filesystem::path& path);
-    void prg() const;
 
 private:
     std::filesystem::path path;
     mutable uint32_t countMusical;
     mutable bool counted;
-    mutable uint32_t convertedSoFar;
+    TaskManager* taskManager;
 };
 

flactomp3.cpp

@@ -173,13 +173,17 @@ void FLACtoMP3::processInfo(const FLAC__StreamMetadata_StreamInfo& info) {
 }
 
 void FLACtoMP3::processTags(const FLAC__StreamMetadata_VorbisComment& tags) {
-    for (FLAC__uint32 i = 0; i < tags.num_comments; ++i) {
+    bool artistSet = false;                                                         //in vorbis comment there could be more then 1 artist tag
-        const FLAC__StreamMetadata_VorbisComment_Entry& entry = tags.comments[i];
+    for (FLAC__uint32 i = 0; i < tags.num_comments; ++i) {                          //usualy it's about guested and fetured artists
+        const FLAC__StreamMetadata_VorbisComment_Entry& entry = tags.comments[i];   //gonna keep only the first one for now
         std::string_view comm((const char*)entry.entry);
         if (comm.find(title) == 0) {
             id3tag_set_title(encoder, comm.substr(title.size()).data());
         } else if (comm.find(artist) == 0) {
-            id3tag_set_artist(encoder, comm.substr(artist.size()).data());
+            if (!artistSet) {
+                id3tag_set_artist(encoder, comm.substr(artist.size()).data());
+                artistSet = true;
+            }
         } else if (comm.find(album) == 0) {
             id3tag_set_album(encoder, comm.substr(album.size()).data());
         } else if (comm.find(comment) == 0) {

main.cpp

@@ -1,29 +1,43 @@
 #include <iostream>
 #include <string>
+#include <chrono>
+#include <unistd.h>
 
 #include "FLAC/stream_decoder.h"
 #include <lame/lame.h>
 
 #include "help.h"
-#include "flactomp3.h"
+#include "collection.h"
+#include "taskmanager.h"
 
 int main(int argc, char **argv) {
-    if (argc < 2) {
+    if (argc < 3) {
         std::cout << "Insufficient amount of arguments, launch with \"--help\" argument to see usage" << std::endl;
         return 1;
     }
 
     const std::string firstArgument(argv[1]);
+    const std::string secondArgument(argv[2]);
 
     if (firstArgument == "--help") {
         printHelp();
         return 0;
     }
 
-    FLACtoMP3 pipe;
+    TaskManager taskManager;
-    pipe.setInputFile(firstArgument);
+    taskManager.start();
-    pipe.setOutputFile("out.mp3");
+
-    pipe.run();
+    std::chrono::time_point start = std::chrono::system_clock::now();
+    Collection collection(firstArgument, &taskManager);
+    collection.convert(secondArgument);
+
+    taskManager.printProgress();
+    taskManager.wait();
+    std::chrono::time_point end = std::chrono::system_clock::now();
+    std::chrono::duration<double> seconds = end - start;
+    std::cout << std::endl << "took " << seconds.count() << std::endl;
+
+    taskManager.stop();
 
     return 0;
 }

taskmanager.cpp

@@ -0,0 +1,108 @@
+#include "taskmanager.h"
+
+#include "flactomp3.h"
+
+TaskManager::TaskManager():
+    busyThreads(0),
+    maxTasks(0),
+    completeTasks(0),
+    terminate(false),
+    queueMutex(),
+    busyMutex(),
+    loopConditional(),
+    waitConditional(),
+    threads(),
+    jobs(),
+    boundLoopCondition(std::bind(&TaskManager::loopCondition, this)),
+    boundWaitCondition(std::bind(&TaskManager::waitCondition, this))
+{
+}
+
+TaskManager::~TaskManager() {
+}
+
+void TaskManager::queueJob(const std::string& source, const std::string& destination) {
+    {
+        std::unique_lock<std::mutex> lock(queueMutex);
+        jobs.emplace(source, destination);
+    }
+    ++maxTasks;
+    loopConditional.notify_one();
+    waitConditional.notify_all();
+}
+
+bool TaskManager::busy() const {
+    bool result;
+    {
+        std::unique_lock<std::mutex> lock(queueMutex);
+        result = !jobs.empty();
+    }
+
+    return result;
+}
+
+void TaskManager::start() {
+    const uint32_t num_threads = std::thread::hardware_concurrency();
+    for (uint32_t ii = 0; ii < num_threads; ++ii)
+        threads.emplace_back(std::thread(&TaskManager::loop, this));
+}
+
+void TaskManager::loop() {
+    while (true) {
+        std::pair<std::string, std::string> pair;
+        {
+            std::unique_lock<std::mutex> lock(queueMutex);
+            loopConditional.wait(lock, boundLoopCondition);
+            if (terminate)
+                return;
+
+            pair = jobs.front();
+            ++busyThreads;
+            waitConditional.notify_all();
+            jobs.pop();
+        }
+
+        job(pair.first, pair.second);
+        ++completeTasks;
+        printProgress();
+        --busyThreads;
+        waitConditional.notify_all();
+    }
+}
+
+bool TaskManager::loopCondition() const {
+    return !jobs.empty() || terminate;
+}
+
+bool TaskManager::waitCondition() const {
+    return busyThreads == 0 && !busy();
+}
+
+void TaskManager::stop() {
+    {
+        std::unique_lock<std::mutex> lock(queueMutex);
+        terminate = true;
+    }
+
+    loopConditional.notify_all();
+    for (std::thread& thread : threads)
+        thread.join();
+
+    threads.clear();
+}
+
+void TaskManager::wait() {
+    std::unique_lock<std::mutex> lock(busyMutex);
+    waitConditional.wait(lock, boundWaitCondition);
+}
+
+bool TaskManager::job(const std::string& source, const std::string& destination) {
+    FLACtoMP3 convertor;
+    convertor.setInputFile(source);
+    convertor.setOutputFile(destination);
+    return convertor.run();
+}
+
+void TaskManager::printProgress() const {
+    std::cout << "\r" << completeTasks << "/" << maxTasks << std::flush;
+}

taskmanager.h

@@ -0,0 +1,45 @@
+#pragma once
+
+#include <mutex>
+#include <condition_variable>
+#include <thread>
+#include <functional>
+#include <vector>
+#include <queue>
+#include <string>
+#include <atomic>
+
+class TaskManager {
+public:
+    TaskManager();
+    ~TaskManager();
+
+    void start();
+    void queueJob(const std::string& source, const std::string& destination);
+    void stop();
+    bool busy() const;
+    void wait();
+    void printProgress() const;
+
+private:
+    void loop();
+    bool loopCondition() const;
+    bool waitCondition() const;
+    static bool job(const std::string& source, const std::string& destination);
+
+private:
+    std::atomic<uint32_t> busyThreads;
+    std::atomic<uint32_t> maxTasks;
+    std::atomic<uint32_t> completeTasks;
+    bool terminate;
+    mutable std::mutex queueMutex;
+    std::mutex busyMutex;
+    std::condition_variable loopConditional;
+    std::condition_variable waitConditional;
+    std::vector<std::thread> threads;
+    std::queue<std::pair<std::string, std::string>> jobs;
+    std::function<bool()> boundLoopCondition;
+    std::function<bool()> boundWaitCondition;
+
+};
+