From f9d4b757264b300c9a8a731ffc7f2f854ff32569 Mon Sep 17 00:00:00 2001
From: Mike Williams <mike@mikebwilliams.com>
Date: Sat, 17 Jun 2023 12:56:00 -0400
Subject: [PATCH] Symbol Fields Table: performance optimizations

Fixes: https://gitlab.com/kicad/code/kicad/-/issues/14972
---
 .../dialogs/dialog_symbol_fields_table.cpp    | 10 ++++++++-
 eeschema/fields_data_model.cpp                | 22 +++++++++++++++++++
 eeschema/fields_data_model.h                  |  8 ++++++-
 eeschema/sch_reference_list.h                 |  1 +
 4 files changed, 39 insertions(+), 2 deletions(-)

diff --git a/eeschema/dialogs/dialog_symbol_fields_table.cpp b/eeschema/dialogs/dialog_symbol_fields_table.cpp
index 0b2411b7c9..7ba97d905c 100644
--- a/eeschema/dialogs/dialog_symbol_fields_table.cpp
+++ b/eeschema/dialogs/dialog_symbol_fields_table.cpp
@@ -1509,6 +1509,10 @@ void DIALOG_SYMBOL_FIELDS_TABLE::onBomPresetChanged( wxCommandEvent& aEvent )
 
 void DIALOG_SYMBOL_FIELDS_TABLE::doApplyBomPreset( const BOM_PRESET& aPreset )
 {
+    // Disable rebuilds while we're applying the preset otherwise we'll be
+    // rebuilding the model constantly while firing off wx events
+    m_dataModel->DisableRebuilds();
+
     // Basically, we apply the BOM preset to the data model and then
     // update our UI to reflect resulting the data model state, not the preset.
     m_dataModel->ApplyBomPreset( aPreset );
@@ -1580,6 +1584,7 @@ void DIALOG_SYMBOL_FIELDS_TABLE::doApplyBomPreset( const BOM_PRESET& aPreset )
 
     // This will rebuild all rows and columns in the model such that the order
     // and labels are right, then we refresh the shown grid data to match
+    m_dataModel->EnableRebuilds();
     m_dataModel->RebuildRows();
     m_grid->ForceRefresh();
 }
@@ -1900,7 +1905,10 @@ void DIALOG_SYMBOL_FIELDS_TABLE::doApplyBomFmtPreset( const BOM_FMT_PRESET& aPre
     m_checkKeepTabs->SetValue( aPreset.keepTabs );
     m_checkKeepLineBreaks->SetValue( aPreset.keepLineBreaks );
 
-    PreviewRefresh();
+
+    // Refresh the preview if that's the current page
+    if( m_nbPages->GetSelection() == 1 )
+        PreviewRefresh();
 }
 
 
diff --git a/eeschema/fields_data_model.cpp b/eeschema/fields_data_model.cpp
index 1331e0eb56..6091a2a959 100644
--- a/eeschema/fields_data_model.cpp
+++ b/eeschema/fields_data_model.cpp
@@ -350,8 +350,23 @@ bool FIELDS_EDITOR_GRID_DATA_MODEL::groupMatch( const SCH_REFERENCE& lhRef,
 }
 
 
+void FIELDS_EDITOR_GRID_DATA_MODEL::EnableRebuilds()
+{
+    m_rebuildsEnabled = true;
+}
+
+
+void FIELDS_EDITOR_GRID_DATA_MODEL::DisableRebuilds()
+{
+    m_rebuildsEnabled = false;
+}
+
+
 void FIELDS_EDITOR_GRID_DATA_MODEL::RebuildRows()
 {
+    if( !m_rebuildsEnabled )
+        return;
+
     if( GetView() )
     {
         // Commit any pending in-place edits before the row gets moved out from under
@@ -379,6 +394,13 @@ void FIELDS_EDITOR_GRID_DATA_MODEL::RebuildRows()
 
         bool matchFound = false;
 
+        // Performance optimization for ungrouped case to skip the N^2 for loop
+        if( !m_groupingEnabled && !ref.IsMultiUnit() )
+        {
+            m_rows.emplace_back( DATA_MODEL_ROW( ref, GROUP_SINGLETON ) );
+            continue;
+        }
+
         // See if we already have a row which this symbol fits into
         for( DATA_MODEL_ROW& row : m_rows )
         {
diff --git a/eeschema/fields_data_model.h b/eeschema/fields_data_model.h
index c8fe052a71..b8b765b090 100644
--- a/eeschema/fields_data_model.h
+++ b/eeschema/fields_data_model.h
@@ -53,7 +53,7 @@ public:
     FIELDS_EDITOR_GRID_DATA_MODEL( SCH_REFERENCE_LIST& aSymbolsList ) :
             m_symbolsList( aSymbolsList ), m_edited( false ), m_sortColumn( 0 ),
             m_sortAscending( false ), m_groupingEnabled( false ), m_excludeDNP( false ),
-            m_includeExcluded( false )
+            m_includeExcluded( false ), m_rebuildsEnabled( true )
     {
         m_symbolsList.SplitReferences();
     }
@@ -131,7 +131,12 @@ public:
     int  GetSortCol() { return m_sortColumn; }
     bool GetSortAsc() { return m_sortAscending; }
 
+    // These are used to disable the RebuildRows functionality while we're generating
+    // lots of events in the UI, e.g. applying a BOM preset, that would thrash the grid.
+    void EnableRebuilds();
+    void DisableRebuilds();
     void RebuildRows();
+
     void ExpandRow( int aRow );
     void CollapseRow( int aRow );
     void ExpandCollapseRow( int aRow );
@@ -204,6 +209,7 @@ protected:
     bool               m_groupingEnabled;
     bool               m_excludeDNP;
     bool               m_includeExcluded;
+    bool               m_rebuildsEnabled;
 
     std::vector<DATA_MODEL_COL> m_cols;
     std::vector<DATA_MODEL_ROW> m_rows;
diff --git a/eeschema/sch_reference_list.h b/eeschema/sch_reference_list.h
index 93c3c6889e..8bd49e06c7 100644
--- a/eeschema/sch_reference_list.h
+++ b/eeschema/sch_reference_list.h
@@ -100,6 +100,7 @@ public:
 
     int GetUnit() const                        { return m_unit; }
     void SetUnit( int aUnit )                  { m_unit = aUnit; }
+    bool IsMultiUnit() const                   { return GetLibPart()->GetUnitCount() > 1; }
 
     const wxString GetValue() const            { return m_value; }
     void SetValue( const wxString& aValue )    { m_value = aValue; }