refactor: turn StreamerMode into a singleton(-like thing) (#5216)

src/singletons/StreamerMode.cpp

@@ -0,0 +1,245 @@
+#include "singletons/StreamerMode.hpp"
+
+#include "Application.hpp"
+#include "common/Literals.hpp"
+#include "common/QLogging.hpp"
+#include "providers/twitch/TwitchIrcServer.hpp"
+#include "singletons/Settings.hpp"
+#include "util/PostToThread.hpp"
+
+#include <QAbstractEventDispatcher>
+#include <QDebug>
+#include <QProcess>
+#include <QThread>
+#include <QTimer>
+
+#ifdef Q_OS_WIN
+// clang-format off
+#    include <Windows.h>
+#    include <VersionHelpers.h>
+#    include <WtsApi32.h>
+// clang-format on
+#endif
+
+#include <atomic>
+
+namespace {
+
+using namespace chatterino;
+using namespace literals;
+
+/// Number of timeouts to skip if nothing called `isEnabled` in the meantime.
+constexpr uint8_t SKIPPED_TIMEOUTS = 5;
+
+const QStringList &broadcastingBinaries()
+{
+#ifdef USEWINSDK
+    static QStringList bins = {
+        u"obs.exe"_s,         u"obs64.exe"_s,        u"PRISMLiveStudio.exe"_s,
+        u"XSplit.Core.exe"_s, u"TwitchStudio.exe"_s, u"vMix64.exe"_s,
+    };
+#else
+    static QStringList bins = {
+        u"obs"_s,
+        u"Twitch Studio"_s,
+        u"Streamlabs Desktop"_s,
+    };
+#endif
+    return bins;
+}
+
+bool isBroadcasterSoftwareActive()
+{
+#if defined(Q_OS_LINUX) || defined(Q_OS_MACOS)
+    QProcess p;
+    p.start("pgrep", {"-x", broadcastingBinaries().join("|")},
+            QIODevice::NotOpen);
+
+    if (p.waitForFinished(1000) && p.exitStatus() == QProcess::NormalExit)
+    {
+        return (p.exitCode() == 0);
+    }
+
+    // Fallback to false and showing a warning
+
+    static bool shouldShowWarning = true;
+    if (shouldShowWarning)
+    {
+        shouldShowWarning = false;
+
+        postToThread([] {
+            getApp()->twitch->addGlobalSystemMessage(
+                "Streamer Mode is set to Automatic, but pgrep is missing. "
+                "Install it to fix the issue or set Streamer Mode to "
+                "Enabled or Disabled in the Settings.");
+        });
+    }
+
+    qCWarning(chatterinoStreamerMode) << "pgrep execution timed out!";
+    return false;
+#elif defined(Q_OS_WIN)
+    if (!IsWindowsVistaOrGreater())
+    {
+        return false;
+    }
+
+    WTS_PROCESS_INFO *pProcessInfo = nullptr;
+    DWORD dwProcCount = 0;
+
+    if (WTSEnumerateProcesses(WTS_CURRENT_SERVER_HANDLE, 0, 1, &pProcessInfo,
+                              &dwProcCount))
+    {
+        //Go through all processes retrieved
+        for (DWORD i = 0; i < dwProcCount; i++)
+        {
+            QStringView processName(pProcessInfo[i].pProcessName);
+
+            if (broadcastingBinaries().contains(processName))
+            {
+                WTSFreeMemory(pProcessInfo);
+                return true;
+            }
+        }
+    }
+
+    if (pProcessInfo)
+    {
+        WTSFreeMemory(pProcessInfo);
+    }
+
+#else
+#    warning Unsupported OS: Broadcasting software can't be detected
+#endif
+    return false;
+}
+
+}  // namespace
+
+namespace chatterino {
+
+using namespace std::chrono_literals;
+
+class StreamerModePrivate
+{
+public:
+    StreamerModePrivate(StreamerMode *parent_);
+
+    [[nodiscard]] bool isEnabled() const;
+
+private:
+    void settingChanged(StreamerModeSetting value);
+    void setEnabled(bool enabled);
+
+    void check();
+
+    StreamerMode *parent_;
+    pajlada::Signals::SignalHolder settingConnections_;
+
+    QTimer timer_;
+    QThread thread_;
+
+    std::atomic<bool> enabled_ = false;
+    mutable std::atomic<uint8_t> timeouts_ = 0;
+    StreamerModeSetting currentSetting_ = StreamerModeSetting::Disabled;
+};
+
+StreamerMode::StreamerMode()
+    : private_(new StreamerModePrivate(this))
+{
+}
+
+StreamerMode::~StreamerMode() = default;
+
+void StreamerMode::updated(bool enabled)
+{
+    this->changed(enabled);
+}
+
+bool StreamerMode::isEnabled() const
+{
+    return this->private_->isEnabled();
+}
+
+StreamerModePrivate::StreamerModePrivate(StreamerMode *parent)
+    : parent_(parent)
+{
+    this->thread_.start();
+    this->timer_.moveToThread(&this->thread_);
+    QObject::connect(&this->timer_, &QTimer::timeout, [this] {
+        auto timeouts =
+            this->timeouts_.fetch_add(1, std::memory_order::relaxed);
+        if (timeouts < SKIPPED_TIMEOUTS)
+        {
+            return;
+        }
+        this->timeouts_.store(0, std::memory_order::relaxed);
+        this->check();
+    });
+
+    getSettings()->enableStreamerMode.connect(
+        [this](auto value) {
+            QMetaObject::invokeMethod(this->thread_.eventDispatcher(), [this,
+                                                                        value] {
+                this->settingChanged(static_cast<StreamerModeSetting>(value));
+            });
+        },
+        this->settingConnections_);
+}
+
+bool StreamerModePrivate::isEnabled() const
+{
+    this->timeouts_.store(SKIPPED_TIMEOUTS, std::memory_order::relaxed);
+    return this->enabled_.load(std::memory_order::relaxed);
+}
+
+void StreamerModePrivate::setEnabled(bool enabled)
+{
+    if (enabled == this->enabled_.load(std::memory_order::relaxed))
+    {
+        return;
+    }
+
+    this->enabled_.store(enabled, std::memory_order::relaxed);
+    this->parent_->updated(enabled);
+}
+
+void StreamerModePrivate::settingChanged(StreamerModeSetting value)
+{
+    if (value == this->currentSetting_)
+    {
+        return;
+    }
+    this->currentSetting_ = value;
+
+    switch (this->currentSetting_)
+    {
+        case StreamerModeSetting::Disabled: {
+            this->setEnabled(false);
+            this->timer_.stop();
+        }
+        break;
+        case StreamerModeSetting::Enabled: {
+            this->setEnabled(true);
+            this->timer_.stop();
+        }
+        break;
+        case StreamerModeSetting::DetectStreamingSoftware: {
+            if (!this->timer_.isActive())
+            {
+                this->timer_.start(20s);
+                this->check();
+            }
+        }
+        break;
+        default:
+            assert(false && "Unexpected setting");
+            break;
+    }
+}
+
+void StreamerModePrivate::check()
+{
+    this->setEnabled(isBroadcasterSoftwareActive());
+}
+
+}  // namespace chatterino