Don't generate real random UUIDs while loading libraries

Fixes https://gitlab.com/kicad/code/kicad/-/issues/7921

common/footprint_info.cpp

@@ -174,6 +174,9 @@ void FOOTPRINT_ASYNC_LOADER::SetList( FOOTPRINT_LIST* aList )
 void FOOTPRINT_ASYNC_LOADER::Start( FP_LIB_TABLE* aTable, wxString const* aNickname,
                                     unsigned aNThreads )
 {
+    // Disable KIID generation: not needed for library parts; sometimes very slow
+    KIID::CreateNilUuids( true );
+
     // Capture the FP_LIB_TABLE into m_last_table. Formatting it as a string instead of storing the
     // raw data avoids having to pull in the FP-specific parts.
     STRING_FORMATTER sof;
@@ -204,4 +207,6 @@ void FOOTPRINT_ASYNC_LOADER::Abort()
         m_list->stopWorkers();
         m_list = nullptr;
     }
+
+    KIID::CreateNilUuids( false );
 }

common/kiid.cpp

@@ -47,6 +47,9 @@ static boost::uuids::nil_generator    nilGenerator;
 // Global nil reference
 KIID niluuid( 0 );
 
+// When true, always create nil uuids for performance, when valid ones aren't needed
+static bool createNilUuids = false;
+
 
 // For static initialization
 KIID& NilUuid()
@@ -65,6 +68,9 @@ KIID::KIID()
     {
 #endif
 
+        if( createNilUuids )
+            m_uuid = nilGenerator();
+        else
             m_uuid = randomGenerator();
 
 #if BOOST_VERSION >= 106700
@@ -232,6 +238,12 @@ void KIID::ConvertTimestampToUuid()
 }
 
 
+void KIID::CreateNilUuids( bool aNil )
+{
+    createNilUuids = aNil;
+}
+
+
 KIID_PATH::KIID_PATH( const wxString& aString )
 {
     for( const wxString& pathStep : wxSplit( aString, '/' ) )

eeschema/symbol_tree_model_adapter.cpp

@@ -65,6 +65,9 @@ void SYMBOL_TREE_MODEL_ADAPTER::AddLibraries( const std::vector<wxString>& aNick
                                        aNicknames.size(), aParent );
     }
 
+    // Disable KIID generation: not needed for library parts; sometimes very slow
+    KIID::CreateNilUuids( true );
+
     unsigned int ii = 0;
 
     for( const auto& nickname : aNicknames )
@@ -80,6 +83,8 @@ void SYMBOL_TREE_MODEL_ADAPTER::AddLibraries( const std::vector<wxString>& aNick
         ii++;
     }
 
+    KIID::CreateNilUuids( false );
+
     m_tree.AssignIntrinsicRanks();
 
     if( prg )

include/kiid.h

@@ -61,6 +61,8 @@ public:
 
     static bool SniffTest( const wxString& aCandidate );
 
+    static void CreateNilUuids( bool aNil = true );
+
     /**
      * Change an existing time stamp based UUID into a true UUID.
      *