GameDatabase: Store strings as views

Saves duplicating everything in memory, and a ton of heap allocations.

src/common/ryml_helpers.h

@@ -41,6 +41,20 @@
   return true;
 }
 
+[[maybe_unused]] static bool GetStringFromObject(const ryml::ConstNodeRef& object, std::string_view key,
+                                                 std::string_view* dest)
+{
+  const ryml::ConstNodeRef member = object.find_child(to_csubstr(key));
+  if (!member.valid())
+  {
+    *dest = std::string_view();
+    return false;
+  }
+
+  *dest = to_stringview(member.val());
+  return true;
+}
+
 template<typename T>
 [[maybe_unused]] static bool GetUIntFromObject(const ryml::ConstNodeRef& object, std::string_view key, T* dest)
 {

src/core/fullscreen_ui.cpp

@@ -6418,12 +6418,13 @@ void FullscreenUI::DrawGameList(const ImVec2& heading_size)
       if (selected_entry->dbentry && !selected_entry->dbentry->developer.empty())
       {
         text_width =
-          ImGui::CalcTextSize(selected_entry->dbentry->developer.c_str(),
+          ImGui::CalcTextSize(selected_entry->dbentry->developer.data(),
-                              selected_entry->dbentry->developer.c_str() + selected_entry->dbentry->developer.length(),
+                              selected_entry->dbentry->developer.data() + selected_entry->dbentry->developer.length(),
                               false, work_width)
             .x;
         ImGui::SetCursorPosX((work_width - text_width) / 2.0f);
-        ImGui::TextWrapped("%s", selected_entry->dbentry->developer.c_str());
+        ImGui::TextWrapped("%.*s", static_cast<int>(selected_entry->dbentry->developer.size()),
+                           selected_entry->dbentry->developer.data());
       }
 
       // code
@@ -6452,7 +6453,10 @@ void FullscreenUI::DrawGameList(const ImVec2& heading_size)
 
       // genre
       if (selected_entry->dbentry && !selected_entry->dbentry->genre.empty())
-        ImGui::Text(FSUI_CSTR("Genre: %s"), selected_entry->dbentry->genre.c_str());
+      {
+        ImGui::Text(FSUI_CSTR("Genre: %.*s"), static_cast<int>(selected_entry->dbentry->genre.size()),
+                    selected_entry->dbentry->genre.data());
+      }
 
       // release date
       ImGui::Text(FSUI_CSTR("Release Date: %s"), selected_entry->GetReleaseDateString().c_str());

src/core/game_database.cpp

@@ -147,6 +147,7 @@ static constexpr const char* DISCDB_YAML_FILENAME = "discdb.yaml";
 static bool s_loaded = false;
 static bool s_track_hashes_loaded = false;
 
+static DynamicHeapArray<u8> s_db_data; // we take strings from the data, so store a copy
 static std::vector<GameDatabase::Entry> s_entries;
 static PreferUnorderedStringMap<u32> s_code_lookup;
 
@@ -167,8 +168,15 @@ void GameDatabase::EnsureLoaded()
     s_entries = {};
     s_code_lookup = {};
 
-    LoadGameDBYaml();
+    if (LoadGameDBYaml())
-    SaveToCache();
+    {
+      SaveToCache();
+    }
+    else
+    {
+      s_entries = {};
+      s_code_lookup = {};
+    }
   }
 
   INFO_LOG("Database load of {} entries took {:.0f}ms.", s_entries.size(), timer.GetTimeMilliseconds());
@@ -848,14 +856,15 @@ static std::string GetCacheFile()
 
 bool GameDatabase::LoadFromCache()
 {
-  auto fp = FileSystem::OpenManagedCFile(GetCacheFile().c_str(), "rb");
+  Error error;
-  if (!fp)
+  std::optional<DynamicHeapArray<u8>> db_data = FileSystem::ReadBinaryFile(GetCacheFile().c_str(), &error);
+  if (!db_data.has_value())
   {
-    DEV_LOG("Cache does not exist, loading full database.");
+    DEV_LOG("Failed to read cache, loading full database: {}", error.GetDescription());
     return false;
   }
 
-  BinaryFileReader reader(fp.get());
+  BinarySpanReader reader(db_data->cspan());
   const u64 gamedb_ts = Host::GetResourceFileTimestamp("gamedb.yaml", false).value_or(0);
 
   u32 signature, version, num_entries, num_codes;
@@ -950,6 +959,7 @@ bool GameDatabase::LoadFromCache()
     s_code_lookup.emplace(std::move(code), index);
   }
 
+  s_db_data = std::move(db_data.value());
   return true;
 }
 
@@ -1051,7 +1061,7 @@ void GameDatabase::SetRymlCallbacks()
 
 bool GameDatabase::LoadGameDBYaml()
 {
-  const std::optional<std::string> gamedb_data = Host::ReadResourceFileToString(GAMEDB_YAML_FILENAME, false);
+  std::optional<DynamicHeapArray<u8>> gamedb_data = Host::ReadResourceFile(GAMEDB_YAML_FILENAME, false);
   if (!gamedb_data.has_value())
   {
     ERROR_LOG("Failed to read game database");
@@ -1060,7 +1070,8 @@ bool GameDatabase::LoadGameDBYaml()
 
   SetRymlCallbacks();
 
-  const ryml::Tree tree = ryml::parse_in_arena(to_csubstr(GAMEDB_YAML_FILENAME), to_csubstr(gamedb_data.value()));
+  const ryml::Tree tree = ryml::parse_in_place(
+    to_csubstr(GAMEDB_YAML_FILENAME), c4::substr(reinterpret_cast<char*>(gamedb_data->data()), gamedb_data->size()));
   const ryml::ConstNodeRef root = tree.rootref();
   s_entries.reserve(root.num_children());
 
@@ -1108,7 +1119,14 @@ bool GameDatabase::LoadGameDBYaml()
       ERROR_LOG("Failed to insert code {}", code);
   }
 
-  return !s_entries.empty();
+  if (s_entries.empty())
+  {
+    ERROR_LOG("Game database is empty.");
+    return false;
+  }
+
+  s_db_data = std::move(gamedb_data.value());
+  return true;
 }
 
 bool GameDatabase::ParseYamlEntry(Entry* entry, const ryml::ConstNodeRef& value)

src/core/game_database.h

@@ -92,14 +92,13 @@ enum class Language : u8
 
 struct Entry
 {
-  // TODO: Make string_view.
+  std::string_view serial;
-  std::string serial;
+  std::string_view title;
-  std::string title;
+  std::string_view genre;
-  std::string genre;
+  std::string_view developer;
-  std::string developer;
+  std::string_view publisher;
-  std::string publisher;
+  std::string_view compatibility_version_tested;
-  std::string compatibility_version_tested;
+  std::string_view compatibility_comments;
-  std::string compatibility_comments;
   u64 release_date;
   u8 min_players;
   u8 max_players;

src/duckstation-qt/gamelistmodel.cpp

@@ -415,24 +415,22 @@ QVariant GameListModel::data(const QModelIndex& index, int role, const GameList:
       switch (index.column())
       {
         case Column_Serial:
-          return QString::fromStdString(ge->serial);
+          return QtUtils::StringViewToQString(ge->serial);
 
         case Column_Title:
-          return QString::fromStdString(ge->title);
+          return QtUtils::StringViewToQString(ge->title);
 
         case Column_FileTitle:
           return QtUtils::StringViewToQString(Path::GetFileTitle(ge->path));
 
         case Column_Developer:
-          return (ge->dbentry && !ge->dbentry->developer.empty()) ? QString::fromStdString(ge->dbentry->developer) :
+          return ge->dbentry ? QtUtils::StringViewToQString(ge->dbentry->developer) : QString();
-                                                                    QString();
 
         case Column_Publisher:
-          return (ge->dbentry && !ge->dbentry->publisher.empty()) ? QString::fromStdString(ge->dbentry->publisher) :
+          return ge->dbentry ? QtUtils::StringViewToQString(ge->dbentry->publisher) : QString();
-                                                                    QString();
 
         case Column_Genre:
-          return (ge->dbentry && !ge->dbentry->genre.empty()) ? QString::fromStdString(ge->dbentry->genre) : QString();
+          return ge->dbentry ? QtUtils::StringViewToQString(ge->dbentry->genre) : QString();
 
         case Column_Year:
         {
@@ -505,15 +503,13 @@ QVariant GameListModel::data(const QModelIndex& index, int role, const GameList:
           return QtUtils::StringViewToQString(Path::GetFileTitle(ge->path));
 
         case Column_Developer:
-          return (ge->dbentry && !ge->dbentry->developer.empty()) ? QString::fromStdString(ge->dbentry->developer) :
+          return ge->dbentry ? QtUtils::StringViewToQString(ge->dbentry->developer) : QString();
-                                                                    QString();
 
         case Column_Publisher:
-          return (ge->dbentry && !ge->dbentry->publisher.empty()) ? QString::fromStdString(ge->dbentry->publisher) :
+          return ge->dbentry ? QtUtils::StringViewToQString(ge->dbentry->publisher) : QString();
-                                                                    QString();
 
         case Column_Genre:
-          return (ge->dbentry && !ge->dbentry->genre.empty()) ? QString::fromStdString(ge->dbentry->genre) : QString();
+          return ge->dbentry ? QtUtils::StringViewToQString(ge->dbentry->genre) : QString();
 
         case Column_Year:
           return ge->dbentry ? QDateTime::fromSecsSinceEpoch(static_cast<qint64>(ge->dbentry->release_date), Qt::UTC)

src/duckstation-qt/gamesummarywidget.cpp

@@ -83,17 +83,17 @@ void GameSummaryWidget::populateUi(const std::string& path, const std::string& s
 
   if (entry)
   {
-    m_ui.title->setText(QString::fromStdString(entry->title));
+    m_ui.title->setText(QtUtils::StringViewToQString(entry->title));
     m_ui.compatibility->setCurrentIndex(static_cast<int>(entry->compatibility));
-    m_ui.genre->setText(entry->genre.empty() ? tr("Unknown") : QString::fromStdString(entry->genre));
+    m_ui.genre->setText(entry->genre.empty() ? tr("Unknown") : QtUtils::StringViewToQString(entry->genre));
     if (!entry->developer.empty() && !entry->publisher.empty() && entry->developer != entry->publisher)
       m_ui.developer->setText(tr("%1 (Published by %2)")
-                                .arg(QString::fromStdString(entry->developer))
+                                .arg(QtUtils::StringViewToQString(entry->developer))
-                                .arg(QString::fromStdString(entry->publisher)));
+                                .arg(QtUtils::StringViewToQString(entry->publisher)));
     else if (!entry->developer.empty())
-      m_ui.developer->setText(QString::fromStdString(entry->developer));
+      m_ui.developer->setText(QtUtils::StringViewToQString(entry->developer));
     else if (!entry->publisher.empty())
-      m_ui.developer->setText(tr("Published by %1").arg(QString::fromStdString(entry->publisher)));
+      m_ui.developer->setText(tr("Published by %1").arg(QtUtils::StringViewToQString(entry->publisher)));
     else
       m_ui.developer->setText(tr("Unknown"));
 

src/duckstation-qt/settingswindow.cpp

@@ -46,7 +46,7 @@ SettingsWindow::SettingsWindow() : QWidget()
   connectUi();
 }
 
-SettingsWindow::SettingsWindow(const std::string& path, const std::string& serial, DiscRegion region,
+SettingsWindow::SettingsWindow(const std::string& path, std::string serial, DiscRegion region,
                                const GameDatabase::Entry* entry, std::unique_ptr<INISettingsInterface> sif)
   : QWidget(), m_sif(std::move(sif)), m_database_entry(entry)
 {
@@ -656,7 +656,7 @@ void SettingsWindow::openGamePropertiesDialog(const std::string& path, const std
     }
   }
 
-  const std::string& real_serial = dentry ? dentry->serial : serial;
+  std::string real_serial = dentry ? std::string(dentry->serial) : std::move(serial);
   std::string ini_filename = System::GetGameSettingsPath(real_serial);
 
   // check for an existing dialog with this crc
@@ -677,7 +677,7 @@ void SettingsWindow::openGamePropertiesDialog(const std::string& path, const std
   if (FileSystem::FileExists(sif->GetFileName().c_str()))
     sif->Load();
 
-  SettingsWindow* dialog = new SettingsWindow(path, real_serial, region, dentry, std::move(sif));
+  SettingsWindow* dialog = new SettingsWindow(path, std::string(real_serial), region, dentry, std::move(sif));
   dialog->show();
 }
 

src/duckstation-qt/settingswindow.h

@@ -41,8 +41,8 @@ class SettingsWindow final : public QWidget
 
 public:
   SettingsWindow();
-  SettingsWindow(const std::string& path, const std::string& serial, DiscRegion region,
+  SettingsWindow(const std::string& path, std::string serial, DiscRegion region, const GameDatabase::Entry* entry,
-                 const GameDatabase::Entry* entry, std::unique_ptr<INISettingsInterface> sif);
+                 std::unique_ptr<INISettingsInterface> sif);
   ~SettingsWindow();
 
   static void openGamePropertiesDialog(const std::string& path, const std::string& title, const std::string& serial,