Qt: Eliminate heap allocations in GameListSortModel

More of an issue since the filter is now checking multiple fields.

src/common/string_util.h

@@ -29,6 +29,16 @@
 
 namespace StringUtil {
 
+/// Returns the given character in uppercase.
+ALWAYS_INLINE static char ToLower(char ch)
+{
+  return ch + ((static_cast<u8>(ch) >= 'A' && static_cast<u8>(ch) <= 'Z') ? ('a' - 'A') : 0);
+}
+ALWAYS_INLINE static char ToUpper(char ch)
+{
+  return ch - ((static_cast<u8>(ch) >= 'a' && static_cast<u8>(ch) <= 'z') ? ('a' - 'A') : 0);
+}
+
 /// Checks if a wildcard matches a search string.
 bool WildcardMatch(const char* subject, const char* mask, bool case_sensitive = true);
 
@@ -81,6 +91,11 @@ static inline int CompareNoCase(std::string_view s1, std::string_view s2)
   const int compare_res = (compare_len > 0) ? Strncasecmp(s1.data(), s2.data(), compare_len) : 0;
   return (compare_len != 0) ? compare_res : ((s1_len < s2_len) ? -1 : ((s1_len > s2_len) ? 1 : 0));
 }
+static inline bool ContainsNoCase(std::string_view s1, std::string_view s2)
+{
+  return (std::search(s1.begin(), s1.end(), s2.begin(), s2.end(),
+                      [](char lhs, char rhs) { return (ToLower(lhs) == ToLower(rhs)); }) != s1.end());
+}
 
 /// Wrapper around std::from_chars
 template<typename T, std::enable_if_t<std::is_integral<T>::value, bool> = true>
@@ -234,7 +249,7 @@ inline std::string ToChars(bool value, int base)
 }
 
 /// Returns true if the given character is whitespace.
-static inline bool IsWhitespace(char ch)
+ALWAYS_INLINE static bool IsWhitespace(char ch)
 {
   return ((ch >= 0x09 && ch <= 0x0D) || // horizontal tab, line feed, vertical tab, form feed, carriage return
           ch == 0x20);                  // space

src/duckstation-qt/gamelistwidget.cpp

@@ -30,6 +30,7 @@
 #include <QtWidgets/QMenu>
 #include <QtWidgets/QScrollBar>
 #include <QtWidgets/QStyledItemDelegate>
+#include <algorithm>
 
 static constexpr float MIN_SCALE = 0.1f;
 static constexpr float MAX_SCALE = 2.0f;
@@ -938,9 +939,10 @@ public:
     m_filter_region = region;
     invalidateRowsFilter();
   }
-  void setFilterName(const QString& name)
+  void setFilterName(std::string name)
   {
-    m_filter_name = name;
+    m_filter_name = std::move(name);
+    std::transform(m_filter_name.begin(), m_filter_name.end(), m_filter_name.begin(), StringUtil::ToLower);
     invalidateRowsFilter();
   }
 
@@ -970,11 +972,15 @@ public:
     if (m_filter_region != DiscRegion::Count && entry->region != m_filter_region)
       return false;
 
-    if (!m_filter_name.isEmpty() &&
+    if (!m_filter_name.empty())
-          !QString::fromStdString(entry->path).contains(m_filter_name, Qt::CaseInsensitive) &&
+    {
-          !QString::fromStdString(entry->serial).contains(m_filter_name, Qt::CaseInsensitive) &&
+      if (!((!entry->IsDiscSet() && !entry->path.empty() && StringUtil::ContainsNoCase(entry->path, m_filter_name)) ||
-          !QString::fromStdString(entry->title).contains(m_filter_name, Qt::CaseInsensitive))
+            (!entry->serial.empty() && StringUtil::ContainsNoCase(entry->serial, m_filter_name)) ||
+            (!entry->title.empty() && StringUtil::ContainsNoCase(entry->title, m_filter_name))))
+      {
         return false;
+      }
+    }
 
     return QSortFilterProxyModel::filterAcceptsRow(source_row, source_parent);
   }
@@ -988,7 +994,7 @@ private:
   GameListModel* m_model;
   GameList::EntryType m_filter_type = GameList::EntryType::MaxCount;
   DiscRegion m_filter_region = DiscRegion::Count;
-  QString m_filter_name;
+  std::string m_filter_name;
   bool m_merge_disc_sets = true;
 };
 
@@ -1155,7 +1161,7 @@ void GameListWidget::initialize()
     m_sort_model->setFilterRegion((index == 0) ? DiscRegion::Count : static_cast<DiscRegion>(index - 1));
   });
   connect(m_ui.searchText, &QLineEdit::textChanged, this,
-          [this](const QString& text) { m_sort_model->setFilterName(text); });
+          [this](const QString& text) { m_sort_model->setFilterName(text.toStdString()); });
   connect(m_ui.searchText, &QLineEdit::returnPressed, this, &GameListWidget::onSearchReturnPressed);
 
   GameListCenterIconStyleDelegate* center_icon_delegate = new GameListCenterIconStyleDelegate(this);