Qt: Asynchronous loading of covers

common/vsprops/QtCompile.props

@@ -32,7 +32,7 @@
     </ClCompile>
     <Link>
       <AdditionalLibraryDirectories>$(QtLibDir);%(AdditionalLibraryDirectories)</AdditionalLibraryDirectories>
-      <AdditionalDependencies>Qt6Core$(QtLibSuffix).lib;Qt6Gui$(QtLibSuffix).lib;Qt6Widgets$(QtLibSuffix).lib;Qt6Network$(QtLibSuffix).lib;%(AdditionalDependencies)</AdditionalDependencies>
+      <AdditionalDependencies>Qt6Core$(QtLibSuffix).lib;Qt6Gui$(QtLibSuffix).lib;Qt6Widgets$(QtLibSuffix).lib;Qt6Network$(QtLibSuffix).lib;Qt6Concurrent$(QtLibSuffix).lib;%(AdditionalDependencies)</AdditionalDependencies>
     </Link>
   </ItemDefinitionGroup>
 
@@ -118,7 +118,7 @@
 
   <!--Copy the needed dlls-->
   <ItemGroup>
-    <QtLibNames Include="Qt6Core$(QtLibSuffix);Qt6Gui$(QtLibSuffix);Qt6Widgets$(QtLibSuffix);Qt6Network$(QtLibSuffix);Qt6Svg$(QtLibSuffix)" />
+    <QtLibNames Include="Qt6Core$(QtLibSuffix);Qt6Gui$(QtLibSuffix);Qt6Widgets$(QtLibSuffix);Qt6Network$(QtLibSuffix);Qt6Svg$(QtLibSuffix);Qt6Concurrent$(QtLibSuffix)" />
     <QtDlls Include="@(QtLibNames -> '$(QtBinDir)%(Identity).dll')" />
     <!--Filter plugins to copy based on the observation that all debug versions end in "d"-->
     <QtAllPlugins Include="$(QtPluginsDir)**\*$(QtLibSuffix).dll" />

pcsx2-qt/GameList/GameListModel.cpp

@@ -24,6 +24,9 @@
 #include "fmt/format.h"
 #include <QtCore/QDate>
 #include <QtCore/QDateTime>
+#include <QtCore/QFuture>
+#include <QtCore/QFutureWatcher>
+#include <QtConcurrent/QtConcurrent>
 #include <QtGui/QGuiApplication>
 #include <QtGui/QIcon>
 #include <QtGui/QPainter>
@@ -34,6 +37,7 @@ static constexpr std::array<const char*, GameListModel::Column_Count> s_column_n
 static constexpr int COVER_ART_WIDTH = 350;
 static constexpr int COVER_ART_HEIGHT = 512;
 static constexpr int COVER_ART_SPACING = 32;
+static constexpr int MIN_COVER_CACHE_SIZE = 256;
 
 static int DPRScale(int size, float dpr)
 {
@@ -125,31 +129,111 @@ const char* GameListModel::getColumnName(Column col)
 
 GameListModel::GameListModel(QObject* parent /* = nullptr */)
 	: QAbstractTableModel(parent)
+	, m_cover_pixmap_cache(MIN_COVER_CACHE_SIZE)
 {
 	loadCommonImages();
 	setColumnDisplayNames();
 }
 GameListModel::~GameListModel() = default;
 
+void GameListModel::refreshImages()
+{
+	loadCommonImages();
+	refresh();
+}
+
 void GameListModel::setCoverScale(float scale)
 {
 	if (m_cover_scale == scale)
 		return;
 
-	m_cover_pixmap_cache.clear();
+	m_cover_pixmap_cache.Clear();
 	m_cover_scale = scale;
+	m_cover_scale_counter.fetch_add(1, std::memory_order_release);
+	m_loading_pixmap = QPixmap(getCoverArtWidth(), getCoverArtHeight());
+	m_loading_pixmap.fill(QColor(0, 0, 0, 0));
 }
 
 void GameListModel::refreshCovers()
 {
-	m_cover_pixmap_cache.clear();
+	m_cover_pixmap_cache.Clear();
 	refresh();
 }
 
-void GameListModel::refreshImages()
+void GameListModel::updateCacheSize(int width, int height)
 {
-	loadCommonImages();
-	refresh();
+	// This is a bit conversative, since it doesn't consider padding, but better to be over than under.
+	const int cover_width = getCoverArtWidth();
+	const int cover_height = getCoverArtHeight();
+	const int num_columns = ((width + (cover_width - 1)) / cover_width);
+	const int num_rows = ((height + (cover_height - 1)) / cover_height);
+	m_cover_pixmap_cache.SetMaxCapacity(static_cast<int>(std::max(num_columns * num_rows, MIN_COVER_CACHE_SIZE)));
+}
+
+void GameListModel::loadOrGenerateCover(const GameList::Entry* ge)
+{
+	// Why this counter: Every time we change the cover scale, we increment the counter variable. This way if the scale is changed
+	// while there's outstanding jobs, the old jobs won't proceed (at the wrong size), or get added into the grid.
+	const u32 counter = m_cover_scale_counter.load(std::memory_order_acquire);
+
+	QFuture<QPixmap> future = QtConcurrent::run([this, path = ge->path, title = ge->title, serial = ge->serial, counter]()->QPixmap {
+		QPixmap image;
+		if (m_cover_scale_counter.load(std::memory_order_acquire) == counter)
+		{
+			const std::string cover_path(GameList::GetCoverImagePath(path, serial, title));
+			if (!cover_path.empty())
+			{
+				const float dpr = qApp->devicePixelRatio();
+				image = QPixmap(QString::fromStdString(cover_path));
+				if (!image.isNull())
+				{
+					image.setDevicePixelRatio(dpr);
+					resizeAndPadPixmap(&image, getCoverArtWidth(), getCoverArtHeight(), dpr);
+				}
+			}
+		}
+
+		if (image.isNull())
+			image = createPlaceholderImage(m_placeholder_pixmap, getCoverArtWidth(), getCoverArtHeight(), m_cover_scale, title);
+
+		if (m_cover_scale_counter.load(std::memory_order_acquire) != counter)
+			image = {};
+
+		return image;
+	});
+
+	// Context must be 'this' so we run on the UI thread.
+	future.then(this, [this, path = ge->path, counter](QPixmap pm) {
+		if (m_cover_scale_counter.load(std::memory_order_acquire) != counter)
+			return;
+
+		m_cover_pixmap_cache.Insert(std::move(path), std::move(pm));
+		invalidateCoverForPath(path);
+	});
+}
+
+void GameListModel::invalidateCoverForPath(const std::string& path)
+{
+	// This isn't ideal, but not sure how else we can get the row, when it might change while scanning...
+	auto lock = GameList::GetLock();
+	const u32 count = GameList::GetEntryCount();
+	std::optional<u32> row;
+	for (u32 i = 0; i < count; i++)
+	{
+		if (GameList::GetEntryByIndex(i)->path == path)
+		{
+			row = i;
+			break;
+		}
+	}
+	if (!row.has_value())
+	{
+		// Game removed?
+		return;
+	}
+
+	const QModelIndex mi(index(static_cast<int>(row.value()), Column_Cover));
+	emit dataChanged(mi, mi, {Qt::DecorationRole});
 }
 
 int GameListModel::getCoverArtWidth() const
@@ -289,31 +373,14 @@ QVariant GameListModel::data(const QModelIndex& index, int role) const
 
 				case Column_Cover:
 				{
-					auto it = m_cover_pixmap_cache.find(ge->path);
-					if (it != m_cover_pixmap_cache.end())
-						return it->second;
+					QPixmap* pm = m_cover_pixmap_cache.Lookup(ge->path);
+					if (pm)
+						return *pm;
 
-					QPixmap image;
-					std::string path = GameList::GetCoverImagePathForEntry(ge);
-					if (!path.empty())
-					{
-						const float dpr = qApp->devicePixelRatio();
-						image = QPixmap(QString::fromStdString(path));
-						if (!image.isNull())
-						{
-							image.setDevicePixelRatio(dpr);
-							resizeAndPadPixmap(&image, getCoverArtWidth(), getCoverArtHeight(), dpr);
-						}
-					}
-
-					if (image.isNull())
-					{
-						image = createPlaceholderImage(m_placeholder_pixmap, getCoverArtWidth(), getCoverArtHeight(), m_cover_scale,
-							ge->title);
-					}
-
-					m_cover_pixmap_cache.emplace(ge->path, image);
-					return image;
+					// We insert the placeholder into the cache, so that we don't repeatedly
+					// queue loading jobs for this game.
+					const_cast<GameListModel*>(this)->loadOrGenerateCover(ge);
+					return *m_cover_pixmap_cache.Insert(ge->path, m_loading_pixmap);
 				}
 				break;
 
@@ -478,6 +545,7 @@ void GameListModel::loadCommonImages()
 		m_compatibility_pixmaps[i].load(QStringLiteral("%1/icons/star-%2.png").arg(base_path).arg(i - 1));
 
 	m_placeholder_pixmap.load(QStringLiteral("%1/cover-placeholder.png").arg(base_path));
+	setCoverScale(1.0f);
 }
 
 void GameListModel::setColumnDisplayNames()

pcsx2-qt/GameList/GameListModel.h

@@ -15,9 +15,11 @@
 
 #pragma once
 #include "pcsx2/Frontend/GameList.h"
+#include "common/LRUCache.h"
 #include <QtCore/QAbstractTableModel>
 #include <QtGui/QPixmap>
 #include <algorithm>
+#include <atomic>
 #include <array>
 #include <optional>
 #include <unordered_map>
@@ -59,6 +61,7 @@ public:
 	__fi const QString& getColumnDisplayName(int column) { return m_column_display_names[column]; }
 
 	void refresh();
+	void refreshImages();
 
 	bool titlesLessThan(int left_row, int right_row) const;
 
@@ -73,20 +76,24 @@ public:
 	int getCoverArtHeight() const;
 	int getCoverArtSpacing() const;
 	void refreshCovers();
-	void refreshImages();
+	void updateCacheSize(int width, int height);
 
 private:
 	void loadCommonImages();
 	void setColumnDisplayNames();
+	void loadOrGenerateCover(const GameList::Entry* ge);
+	void invalidateCoverForPath(const std::string& path);
 
-	float m_cover_scale = 1.0f;
+	float m_cover_scale = 0.0f;
+	std::atomic<u32> m_cover_scale_counter{0};
 	bool m_show_titles_for_covers = false;
 
 	std::array<QString, Column_Count> m_column_display_names;
 	std::array<QPixmap, static_cast<u32>(GameList::EntryType::Count)> m_type_pixmaps;
 	std::array<QPixmap, static_cast<u32>(GameList::Region::Count)> m_region_pixmaps;
 	QPixmap m_placeholder_pixmap;
+	QPixmap m_loading_pixmap;
 
 	std::array<QPixmap, static_cast<int>(GameList::CompatibilityRatingCount)> m_compatibility_pixmaps;
-	mutable std::unordered_map<std::string, QPixmap> m_cover_pixmap_cache;
+	mutable LRUCache<std::string, QPixmap> m_cover_pixmap_cache;
 };

pcsx2-qt/GameList/GameListWidget.cpp

@@ -111,6 +111,7 @@ void GameListWidget::initialize()
 	m_model = new GameListModel(this);
 	m_model->setCoverScale(Host::GetBaseFloatSettingValue("UI", "GameListCoverArtScale", 0.45f));
 	m_model->setShowCoverTitles(Host::GetBaseBoolSettingValue("UI", "GameListShowCoverTitles", true));
+	m_model->updateCacheSize(width(), height());
 
 	m_sort_model = new GameListSortModel(m_model);
 	m_sort_model->setSourceModel(m_model);
@@ -348,10 +349,9 @@ void GameListWidget::listZoom(float delta)
 	const float new_scale = std::clamp(m_model->getCoverScale() + delta, MIN_SCALE, MAX_SCALE);
 	QtHost::SetBaseFloatSettingValue("UI", "GameListCoverArtScale", new_scale);
 	m_model->setCoverScale(new_scale);
+	m_model->updateCacheSize(width(), height());
 	updateListFont();
 	updateToolbar();
-
-	m_model->refresh();
 }
 
 void GameListWidget::gridZoomIn()
@@ -370,10 +370,9 @@ void GameListWidget::gridIntScale(int int_scale)
 
 	QtHost::SetBaseFloatSettingValue("UI", "GameListCoverArtScale", new_scale);
 	m_model->setCoverScale(new_scale);
+	m_model->updateCacheSize(width(), height());
 	updateListFont();
 	updateToolbar();
-
-	m_model->refresh();
 }
 
 void GameListWidget::refreshGridCovers()
@@ -460,6 +459,7 @@ void GameListWidget::resizeEvent(QResizeEvent* event)
 {
 	QWidget::resizeEvent(event);
 	resizeTableViewColumnsToFit();
+	m_model->updateCacheSize(width(), height());
 }
 
 void GameListWidget::resizeTableViewColumnsToFit()