Added comments in mergesort algorithm

.gitignore

@@ -1,3 +1,3 @@
-cmake-build-*
+.out
 .idea
 task1/dataset.dat

CMakeLists.txt

@@ -1,21 +1,28 @@
-cmake_minimum_required(VERSION 3.0)
+cmake_minimum_required(VERSION 3.25)
 project(aca-tasks)
 
+# Set C++ standard
 set(CMAKE_CXX_STANDARD 20)
-set(CMAKE_INCLUDE_CURRENT_DIR ON)
 
+# Set install directory
 set(CMAKE_INSTALL_PREFIX ${CMAKE_BINARY_DIR}/installed)
 
+# Set compiler flags for optimization on Release build
 if (${CMAKE_BUILD_TYPE} STREQUAL "Release")
+    # Compiler options
     add_compile_options(
             -Wall
             -Wpedantic
             -O3
-            -g3
-    )
+            -g3)
+
+    # Defines for some libraries
     add_compile_definitions(
             NDEBUG)
 endif ()
 
+# Include general purpose libraries to build
 add_subdirectory(third-party/fmt)
+
+# Include CMakeLists files from subdirs for specific tasks
 add_subdirectory(task1)

CMakePresets.json

@@ -0,0 +1,20 @@
+{
+  "version": 6,
+  "cmakeMinimumRequired": {
+    "major": 3,
+    "minor": 25,
+    "patch": 0
+  },
+  "configurePresets": [
+    {
+      "name": "task1@release",
+      "displayName": "Task1 Release build",
+      "description": "Builds the targets of task1 as release",
+      "generator": "Ninja",
+      "binaryDir": "${sourceDir}/.out/task1-release",
+      "cacheVariables": {
+        "CMAKE_BUILD_TYPE": "Release"
+      }
+    }
+  ]
+}

task1/CMakeLists.txt

@@ -1,29 +1,56 @@
-find_package(Python3 COMPONENTS Interpreter REQUIRED)
+# Find packages necessary for this application
+find_package(Qt6 COMPONENTS Core REQUIRED)
 find_package(fmt)
 
+# Search for python to generate the test dataset
+find_package(Python3 COMPONENTS Interpreter REQUIRED)
+
+# Generate random dataset
 add_custom_command(OUTPUT ${CMAKE_CURRENT_SOURCE_DIR}/dataset.dat
         DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/dataset-gen.py
         COMMAND ${Python3_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/dataset-gen.py
         WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
         COMMENT "Generating random dataset")
+# Copy random dataset to binary dir
 add_custom_command(OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/dataset.dat
         DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/dataset.dat
         COMMAND ${CMAKE_COMMAND} -E copy_if_different ${CMAKE_CURRENT_SOURCE_DIR}/dataset.dat ${CMAKE_CURRENT_BINARY_DIR}/dataset.dat
         COMMENT "Copying dataset")
 
-add_custom_target(task1_7_dataset
+add_custom_target(task1-dataset
         DEPENDS
         ${CMAKE_CURRENT_SOURCE_DIR}/dataset.dat
         ${CMAKE_CURRENT_BINARY_DIR}/dataset.dat)
 
-add_executable(task1_7 main.cpp
-        mergesort_mt.h)
 
-target_link_libraries(task1_7 PRIVATE
+# Add task1 automated target (Automatically loads generated dataset
+add_executable(task1-auto)
+add_dependencies(task1-auto task1-dataset)
+target_sources(task1-auto PRIVATE
+        src/task1-auto.cpp)
+target_include_directories(task1-auto PRIVATE
+        ${CMAKE_CURRENT_SOURCE_DIR}/include)
+target_link_libraries(task1-auto PRIVATE
         fmt::fmt)
 
+# Add task1 target with an C++ written random data generator
+add_executable(task1-randgen)
+target_sources(task1-randgen PRIVATE
+        src/task1-randgen.cpp)
+target_link_libraries(task1-randgen PRIVATE
+        Qt6::Core)
 
-install(TARGETS task1_7 DESTINATION bin)
-install(IMPORTED_RUNTIME_ARTIFACTS task1_7 DESTINATION bin)
+# Add task1 target with an C++ written QT-based mergesort
+add_executable(task1-sorter)
+target_sources(task1-sorter PRIVATE
+        src/task1-sorter.cpp)
+target_include_directories(task1-sorter PRIVATE
+${CMAKE_CURRENT_SOURCE_DIR}/include)
+target_link_libraries(task1-sorter PRIVATE
+        Qt6::Core)
 
-add_dependencies(task1_7 task1_7_dataset)
+# Define install options
+install(TARGETS task1-auto DESTINATION bin)
+install(TARGETS task1-randgen DESTINATION bin)
+install(IMPORTED_RUNTIME_ARTIFACTS task1-auto DESTINATION lib)
+install(IMPORTED_RUNTIME_ARTIFACTS task1-randgen DESTINATION lib)

task1/include/mergesort_mt.h

@@ -4,22 +4,30 @@
 #include <mutex>
 #include <functional>
 
+// General purpose mergesorter with multi threading support by Robin Dietzel <robin.dietzel@iem.thm.de>
 template<typename T>
 class MergeSorterMT {
 
 public:
     template<typename C>
     MergeSorterMT(C cmp, int max_depth) : cmp(cmp), max_depth(max_depth) {
+        // Assert that cmp is a function that returns bool and takes two arguments of type T
         static_assert(std::is_same<std::invoke_result_t<C, T, T>, bool>(), "C must be a function that returns a bool");
     }
 
+    // Start sorting process
     auto sort(std::vector<T> &data) -> void {
+        // Create span: like a 'view' on the vector -> no unnecessary copies are made when subdividing sorting problem
         std::span<T> sortable(data);
         split(sortable, 0, max_depth);
     }
 
 private:
+    // Merge function that merges left & right span into the output span
+    // No exclusive access on output is necessary (e.g. via mutex) because all parallel threads work on different parts of output
     auto merge(std::span<T> &output, std::span<T> left, std::span<T> right) -> void {
+        // Create buffer, here we need a temporary container where we copy values to, because left and right are a view on parts
+        // of output
         std::vector<T> buf;
         buf.reserve(left.size() + right.size());
 
@@ -27,6 +35,7 @@ private:
         auto r = right.begin();
         auto o = buf.begin();
 
+        // Insert from pre sorted half's
         while (l < left.end() && r < right.end()) {
             if (cmp(*l, *r)) {
                 buf.insert(o, *l);
@@ -37,52 +46,72 @@ private:
             }
             o++;
         }
+
+        // Fill up with rest of left values
         while (l < left.end()) {
             buf.insert(o, *l);
             o++;
             l++;
         }
+
+        // Fill up with rest of right values
         while (r < right.end()) {
             buf.insert(o, *r);
             o++;
             r++;
         }
 
+        // Completely move buffer to output
+        // IMPORTANT: left and right are still a view on the splitted output, that is now sorted
         std::move(buf.begin(), buf.end(), output.begin());
     }
 
+    // Splitup function
     auto split(std::span<T> &data, int depth, const int &mdepth) -> void {
+
         if (std::distance(data.begin(), data.end()) <= 1) {
+            // Quit if only one element 'insortable'
             return;
         } else if (std::distance(data.begin(), data.end()) == 2) {
+            // Swap two values dependant on size for small speedup (no call to further split must be made)
             if(cmp(data[1], data[0])) {
                 std::swap(data[0], data[1]);
                 return;
             }
         }
 
+        // Determine mid of data
         auto mid = data.begin();
         std::advance(mid, std::distance(data.begin(), data.end()) / 2);
 
+        // Generate left and right view on data (no copies are made here)
         std::span<T> left(data.begin(), mid);
         std::span<T> right(mid, data.end());
 
         if (depth < mdepth) {
+            // Create recursive split functions if maximum depth not reached
             std::thread left_thread([&]() { split(left, depth + 1, mdepth); });
             std::thread right_thread([&]() { split(right, depth + 1, mdepth); });
 
+            // Both threads must join before we could further work on the data viewed
+            // by left and right (recursively sorted by the both calls)
             left_thread.join();
             right_thread.join();
         } else {
+            // Do normal recursion in a single thread if maximum depth is reached
             split(left, depth + 1, mdepth);
             split(right, depth + 1, mdepth);
         }
 
+        // Merge left and right together before returning
         merge(data, left, right);
+        return;
     }
 
 
 private:
+    // Templated comparator function
     std::function<bool(T, T)> cmp;
+    // Maximum depth
     const int max_depth;
 };

task1/mergesort.h

@@ -1,379 +0,0 @@
-#pragma once
-
-#include <vector>
-#include <algorithm>
-#include <thread>
-#include <mutex>
-#include <future>
-#include <ranges>
-#include <span>
-
-namespace algo {
-
-    class MergeSort_v1 {
-    private:
-        template<typename Iterator, typename Comparator>
-        static auto
-        merge(Iterator start, Iterator middle, Iterator end, Comparator cmp, Iterator output_start) -> void {
-            Iterator start_m = start;
-            Iterator begin = output_start;
-            Iterator start2 = middle + 1;
-
-            //merge from input until one half completes
-            while (start <= middle && start2 <= end) {
-                if (cmp(*start, *start2)) {
-                    *output_start = *start;
-                    start++;
-                } else {
-                    *output_start = *start2;
-                    start2++;
-                }
-                output_start++;
-            }
-
-            //try to finish first half
-            while (start <= middle) {
-                *output_start = *start;
-                start++;
-                output_start++;
-            }
-
-            while (start2 <= end) {
-                *output_start = *start2;
-                start2++;
-                output_start++;
-            }
-
-            const auto size = std::distance(start_m, end);
-            for (auto i = 0; i <= size; i++, start_m++, begin++) {
-                *start_m = *begin;
-            }
-
-        }
-
-        template<typename Container, typename Iterator, typename Comparator>
-        static auto
-        ms_split(Container &output_vec, Iterator start, Iterator end, Comparator cmp, Iterator output_start) -> void {
-            Iterator mid = start;
-            Iterator begin = output_start;
-
-            if (std::distance(start, end) < 1) {
-                return;
-            } else {
-                //move mid iterator litterally to the mid
-                std::advance(mid, std::distance(start, end) / 2);
-                //sort the first half within an recursion
-                ms_split(output_vec, start, mid, cmp, output_start);
-
-                //move output iterator
-                std::advance(output_start, std::distance(start, mid + 1));
-                //sort the second half within a recursion
-                ms_split(output_vec, mid + 1, end, cmp, output_start);
-
-                //merge everything together starting from the complete beginning
-                merge(start, mid, end, cmp, begin);
-            }
-        }
-
-    public:
-        template<typename Iterator, typename Comparator>
-        static auto sort(Iterator start, Iterator end, Comparator cmp) -> void {
-            using valtype = typename std::iterator_traits<Iterator>::value_type;
-            std::vector<valtype> temporary_dataset(std::distance(start, end));
-            ms_split(temporary_dataset, start, end - 1, cmp, temporary_dataset.begin());
-        }
-    };
-
-    class MergeSort_v2 {
-    private:
-
-        template<typename Container, typename Comparator>
-        static auto
-        mt_merge(Container left, Container right, Comparator cmp) -> Container {
-            //using Iterator = typename std::iterator_traits<Container>::value_type;
-
-            Container output;
-
-            auto lefti = left.begin();
-            auto righti = right.begin();
-
-            while (lefti < left.end() && righti < right.end()) {
-                if (cmp(*lefti, *righti)) {
-                    output.emplace_back(std::move(*lefti));
-                    lefti++;
-                } else {
-                    output.emplace_back(std::move(*righti));
-                    righti++;
-                }
-            }
-
-            while (lefti < left.end()) {
-                output.emplace_back(std::move(*lefti));
-                lefti++;
-            }
-            while (righti < right.end()) {
-                output.emplace_back(std::move(*righti));
-                righti++;
-            }
-
-            return output;
-        }
-
-        template<typename Iterator, typename Comparator>
-        static auto
-        merge(Iterator start, Iterator middle, Iterator end, Comparator cmp, Iterator output_start,
-              std::recursive_mutex &dataset_guard) -> void {
-            Iterator start_m = start;
-            Iterator begin = output_start;
-            Iterator start2 = middle + 1;
-
-            //merge from input until one half completes
-            while (start <= middle && start2 <= end) {
-                if (cmp(*start, *start2)) {
-                    *output_start = *start;
-                    start++;
-                } else {
-                    *output_start = *start2;
-                    start2++;
-                }
-                output_start++;
-            }
-
-            //try to finish first half
-            while (start <= middle) {
-                *output_start = *start;
-                start++;
-                output_start++;
-            }
-
-            while (start2 <= end) {
-                *output_start = *start2;
-                start2++;
-                output_start++;
-            }
-
-            dataset_guard.lock();
-            const auto size = std::distance(start_m, end);
-            for (auto i = 0; i <= size; i++, start_m++, begin++) {
-                *start_m = *begin;
-            }
-            dataset_guard.unlock();
-
-        }
-
-        template<typename Container, typename Iterator, typename Comparator>
-        static auto mt_split(Container &output_vec, Iterator start, Iterator end, Comparator cmp, Iterator output_start,
-                             int &nthreads, std::recursive_mutex &dataset_guard, std::mutex &depth_guard) -> void {
-            Iterator mid = start;
-            Iterator to_start = output_start;
-
-            if (std::distance(start, end) < 1) {
-                return;
-
-            }
-
-            bool rem_threads;
-            {
-                std::lock_guard guard(depth_guard); //RAII guard
-                rem_threads = nthreads > 1;
-            }
-
-            if (rem_threads) {
-                {
-                    std::lock_guard guard(depth_guard); //RAII guard
-                    nthreads -= 2;
-                }
-
-                std::advance(mid, std::distance(start, end) / 2);
-                std::thread t1([&]() {
-                    mt_split(output_vec, start, mid, cmp, output_start, nthreads, dataset_guard, depth_guard);
-                });
-
-                std::advance(output_start, std::distance(start, mid + 1));
-                std::thread t2([&]() {
-                    mt_split(output_vec, mid + 1, end, cmp, output_start, nthreads, dataset_guard, depth_guard);
-                });
-
-
-                //merge everything together starting from the complete beginning
-                t1.join();
-                t2.join();
-                std::vector<int> left;
-                left.assign(start, mid);
-                std::vector<int> right;
-                right.assign(mid + 1, end);
-
-                mt_merge(left, right, cmp);
-            } else {
-                //move mid iterator litterally to the mid
-                std::advance(mid, std::distance(start, end) / 2);
-                //sort the first half within an recursion
-                mt_split(output_vec, start, mid, cmp, output_start, nthreads, dataset_guard, depth_guard);
-
-                //move output iterator
-                std::advance(output_start, std::distance(start, mid + 1));
-                //sort the second half within a recursion
-                mt_split(output_vec, mid + 1, end, cmp, output_start, nthreads, dataset_guard, depth_guard);
-
-                std::vector<int> left;
-                left.assign(start, mid);
-                std::vector<int> right;
-                right.assign(mid + 1, end);
-
-                mt_merge(left, right, cmp);
-            }
-        }
-
-        template<typename Container, typename Iterator, typename Comparator>
-        static auto ms_split(Container &output_vec, Iterator start, Iterator end, Comparator cmp, Iterator output_start,
-                             int &nthreads, std::recursive_mutex &dataset_guard, std::mutex &depth_guard) -> void {
-            Iterator mid = start;
-            Iterator begin = output_start;
-
-            if (std::distance(start, end) < 1) {
-                //Quit on smalles list size (one element is always sorted)
-                return;
-            } else {
-                if (nthreads > 1) {
-                    depth_guard.lock();
-                    nthreads -= 2;
-                    depth_guard.unlock();
-                    //move mid iterator litterally to the mid
-                    std::advance(mid, std::distance(start, end) / 2);
-                    //sort the first half within an recursion
-
-                    std::thread t1([&]() {
-                        ms_split(output_vec, start, mid, cmp, output_start, nthreads, dataset_guard, depth_guard);
-                    });
-
-                    //move output iteratoroutput_vec, start, mid, cmp, output_start
-                    std::advance(output_start, std::distance(start, mid + 1));
-                    //sort the second half within a recursion
-                    std::thread t2([&]() {
-                        ms_split(output_vec, mid + 1, end, cmp, output_start, nthreads, dataset_guard, depth_guard);
-                    });
-
-
-                    //merge everything together starting from the complete beginning
-                    t1.join();
-                    t2.join();
-                    merge(start, mid, end, cmp, begin, dataset_guard);
-                } else {
-                    //move mid iterator litterally to the mid
-                    std::advance(mid, std::distance(start, end) / 2);
-                    //sort the first half within an recursion
-                    ms_split(output_vec, start, mid, cmp, output_start, nthreads, dataset_guard, depth_guard);
-
-                    //move output iterator
-                    std::advance(output_start, std::distance(start, mid + 1));
-                    //sort the second half within a recursion
-                    ms_split(output_vec, mid + 1, end, cmp, output_start, nthreads, dataset_guard, depth_guard);
-
-                    //merge everything together starting from the complete beginning
-                    merge(start, mid, end, cmp, begin, dataset_guard);
-                }
-            }
-        }
-
-    public:
-        template<typename Iterator, typename Comparator>
-        static auto sort(Iterator start, Iterator end, Comparator cmp, int nthreads) -> void {
-            using valtype = typename std::iterator_traits<Iterator>::value_type;
-            std::vector<valtype> temporary_dataset(std::distance(start, end));
-            std::recursive_mutex dataset_guard;
-            std::mutex depth_guard;
-
-            mt_split(temporary_dataset, start, end - 1, cmp, temporary_dataset.begin(), nthreads, dataset_guard,
-                     depth_guard);
-        }
-    };
-
-    class MergeSort_mt {
-
-        template<typename T, typename Comparator>
-        static auto
-        merge(std::vector<T> left, std::vector<T> right,
-              Comparator cmp, std::mutex &mut) -> std::vector<T> {
-
-            std::vector<T> output;
-            output.reserve(left.size() + right.size());
-
-            auto l = left.begin();
-            auto r = right.begin();
-
-            auto o = output.begin();
-
-            while (l < left.end() && r < right.end()) {
-                if (cmp(*l, *r)) {
-                    output.insert(o, *l);
-                    l++;
-                } else {
-                    output.insert(o, *r);
-                    r++;
-                }
-                o++;
-            }
-            while (l < left.end()) {
-                output.insert(o, *l);
-                o++;
-                l++;
-            }
-            while (r < right.end()) {
-                output.insert(o, *r);
-                o++;
-                r++;
-            }
-        return output;
-        }
-
-        template<typename T, typename Comparator>
-        static auto split(std::vector<T> data, Comparator cmp, int depth, int &max_depth,
-                          std::mutex &mut) -> std::vector<T>{
-
-            if (data.size() <= 1) {
-                return data;
-            } else if (data.size() == 2) {
-                if(cmp(data[0], data[1])) {
-                    return std::vector<T> {data[0], data[1]};
-                } else {
-                    return std::vector<T> {data[1], data[0]};
-                }
-            }
-
-            std::vector<T> output;
-            output.reserve(data.size());
-
-            auto mid = data.begin();
-            std::advance(mid, std::distance(data.begin(), data.end()) / 2);
-
-
-            std::vector<T> left(data.begin(), mid);
-            std::vector<T> right(mid, data.end());
-
-            if (depth < max_depth) {
-                std::thread left_thread([&]() { left = split(left, cmp, depth + 1, max_depth, mut); });
-                std::thread right_thread([&]() { right = split(right, cmp, depth + 1, max_depth, mut); });
-
-                left_thread.join();
-                right_thread.join();
-            } else {
-                left = split(left, cmp, depth + 1, max_depth, mut);
-                right = split(right, cmp, depth + 1, max_depth, mut);
-            }
-
-            return merge(left, right, cmp, mut);
-        }
-
-    public:
-        template<typename T, typename Comparator>
-        static auto
-        sort(std::vector<T> &data, Comparator cmp, int max_depth = 0) -> void {
-            std::mutex local_result_lock;
-            std::vector<T> output;
-            output.reserve(data.size());
-
-            output = split(data, cmp, 0, max_depth, local_result_lock);
-            data.assign(output.begin(), output.end());
-        }
-    };
-}

task1/src/task1-auto.cpp

@@ -1,11 +1,11 @@
-#include <fmt/format.h>
+#include "fmt/format.h"
 #include <vector>
 #include <fstream>
 #include <string>
 #include <chrono>
 #include <cmath>
 
-#include <mergesort_mt.h>
+#include "mergesort_mt.h"
 
 /*
 Create a simple sorting application that uses the mergesort algorithm to sort a
@@ -32,7 +32,6 @@ auto parse_file(std::ifstream &stream, std::vector<T> &vec) -> void {
         convbuf = static_cast<T>(std::stoul(buf));
         vec.emplace_back(std::move(convbuf));
     }
-
 }
 
 auto main(int argc, char *argv[]) -> int {

task1/src/task1-randgen.cpp

@@ -0,0 +1,64 @@
+#include <QRandomGenerator>
+#include <QCommandLineParser>
+#include <QCoreApplication>
+#include <QFile>
+#include <QFileInfo>
+
+#include <cmath>
+#include <ranges>
+
+
+auto main(int argc, char *argv[]) -> int{
+    QCoreApplication app(argc, argv);
+    QCoreApplication::setApplicationName("Random dataset generator");
+    QCoreApplication::setApplicationVersion("1.0");
+
+    QCommandLineParser parser;
+    parser.setApplicationDescription("Generates random dataset files for mergesort algorithm testing");
+    parser.addHelpOption();
+    parser.addVersionOption();
+    parser.addPositionalArgument("destination", "Filename of where to place the generated data");
+    parser.addPositionalArgument("num_values", "The power of 10 for the number of values to generate");
+    parser.process(app);
+
+    const QStringList args = parser.positionalArguments();
+
+    if (args.length() != 2) {
+        parser.showHelp(-1);
+    }
+
+    const QString dest = args.at(0);
+    bool convOK;
+    const int pow_value = args.at(1).toInt(&convOK);
+    if (!convOK) {
+        parser.showHelp(-1);
+    }
+
+    const int num_values = std::pow(10, pow_value);
+
+    QTextStream print(stdout);
+
+    print << "Writing " << num_values << " values into " << dest << Qt::endl;
+
+    QFile file(dest);
+    if (!file.open(QIODevice::WriteOnly | QIODevice::Text)) {
+        print << "Error opening file: " << file.errorString() << Qt::endl;
+        app.exit(-1);
+        return app.exec();
+    }
+
+    QTextStream out(&file);
+    for (int i: std::views::iota(0, num_values)) {
+        out << QString::number(QRandomGenerator::global()->generate()) << '\n';
+    }
+    file.flush();
+
+    QFileInfo finfo(file);
+    print << "Wrote " << num_values << " to " << dest << " with resulting size of " << (finfo.size() / 1000000) << " mb"
+          << Qt::endl;
+    file.close();
+
+
+    app.exit(0);
+    return 0;
+}

task1/src/task1-sorter.cpp

@@ -0,0 +1,123 @@
+#include <QRandomGenerator>
+#include <QCommandLineParser>
+#include <QCoreApplication>
+#include <QFile>
+#include <QFileInfo>
+
+#include <cmath>
+#include <thread>
+#include <ranges>
+#include <chrono>
+
+#include <mergesort_mt.h>
+
+auto main(int argc, char *argv[]) -> int {
+    QCoreApplication app(argc, argv);
+    QCoreApplication::setApplicationName("Multi purpose mergesort application");
+    QCoreApplication::setApplicationVersion("1.0.42");
+    QTextStream print(stdout);
+
+
+    QCommandLineParser parser;
+    parser.setApplicationDescription(
+            "Used to run either sequential or parallel mergesort on a texfile containing ascii encoded int32s");
+    parser.addHelpOption();
+    parser.addVersionOption();
+
+    QCommandLineOption sequential("S", "Run sequential sort on dataset");
+    QCommandLineOption parallel("P", "Run parallel sort on dataset");
+    QCommandLineOption nthreads(QStringList() << "d" << "depth", "Recursion depth of parallel part", "nthreads");
+    QCommandLineOption output(QStringList() << "o", "output", "File to write the sorted dataset to");
+
+    parser.addOption(sequential);
+    parser.addOption(parallel);
+    parser.addOption(nthreads);
+    parser.addOption(output);
+
+    parser.addPositionalArgument("dataset", "Filename where to load the data from");
+    parser.process(app);
+
+    const QStringList args = parser.positionalArguments();
+
+    if (args.length() != 1) {
+        parser.showHelp(-1);
+    }
+
+    const QString source = args.at(0);
+    QFile input(source);
+    if (!input.open(QIODevice::ReadOnly | QIODevice::Text)) {
+        print << "Could not open file " << source << " for reading" << Qt::endl;
+        print << input.errorString();
+        app.exit(-1);
+        return app.exec();
+    }
+
+    std::vector<int32_t> dataset;
+
+    QTextStream stream(&input);
+    while (!stream.atEnd()) {
+        QString line = stream.readLine();
+        bool ok;
+        int parsed_value = line.toUInt(&ok);
+        if (!ok) {
+            print << "Error converting value: " << line << Qt::endl;
+        } else {
+            dataset.push_back(std::move(parsed_value));
+        }
+    }
+
+    print << "Read " << dataset.size() << " values from " << source << Qt::endl;
+
+    const int threads = std::thread::hardware_concurrency();
+    int max_depth = std::sqrt(threads);
+
+    print << "Hardware concurrency of " << threads << " detected" << Qt::endl;
+
+    if (parser.isSet(nthreads)) {
+        bool ok;
+        max_depth = parser.value(nthreads).toInt(&ok);
+        if (!ok) {
+            parser.showHelp(-1);
+        }
+        print << "Overwriting maximum parallelized recursion depth with " << max_depth << Qt::endl;
+    } else {
+        print << "Assuming default parallelized recursion depth via sqrt(nthreads) of " << max_depth << Qt::endl;
+    }
+
+    if (parser.isSet(sequential)) {
+        auto buf = dataset;
+        auto t1 = std::chrono::high_resolution_clock::now();
+        MergeSorterMT<int32_t> sorter(
+                [](int32_t a, int32_t b) {
+                    return (a > b);
+                }, 0);
+        sorter.sort(buf);
+        auto t2 = std::chrono::high_resolution_clock::now();
+        auto diff = t2 - t1;
+
+        print << "=> Duration for sequential sort: " << std::chrono::duration_cast<std::chrono::milliseconds>(diff).count() << " ms" << Qt::endl;
+    }
+
+    if (parser.isSet(parallel)) {
+        auto buf = dataset;
+        auto t1 = std::chrono::high_resolution_clock::now();
+        MergeSorterMT<int32_t> sorter(
+                [](int32_t a, int32_t b) {
+                    return (a > b);
+                }, max_depth);
+        sorter.sort(buf);
+        auto t2 = std::chrono::high_resolution_clock::now();
+        auto diff = t2 - t1;
+
+        print << "=> Duration for parallel sort: " << std::chrono::duration_cast<std::chrono::milliseconds>(diff).count() << " ms" << Qt::endl;
+    }
+
+    if(parser.isSet(output)) {
+        print << "Sooory, not yet implemented :( you might do it yourself!" << Qt::endl;
+        app.exit(-1);
+        return app.exec();
+    }
+
+    app.exit(0);
+    return 0;
+}