Performance: Search libraries on system once per app instance and net type group. Cache these in TConnectionParameters.FLibraries. OLE DB providers take some time to collect.

source/connections.pas

@@ -11,7 +11,7 @@ interface
 uses
   Windows, SysUtils, Classes, Controls, Forms, Dialogs, StdCtrls, ExtCtrls, ComCtrls,
   VirtualTrees, Menus, Graphics, Generics.Collections, ActiveX, extra_controls, Messages,
-  dbconnection, gnugettext, SynRegExpr, System.Types, System.IOUtils, Vcl.GraphUtil, ADODB;
+  dbconnection, gnugettext, SynRegExpr, System.Types, Vcl.GraphUtil, ADODB;
 
 type
   Tconnform = class(TExtForm)
@@ -190,7 +190,6 @@ type
     procedure WMNCLBUTTONDOWN(var Msg: TWMNCLButtonDown) ; message WM_NCLBUTTONDOWN;
     procedure WMNCLBUTTONUP(var Msg: TWMNCLButtonUp) ; message WM_NCLBUTTONUP;
     procedure RefreshBackgroundColors;
-    procedure RefreshLibraries(Sess: TConnectionParameters);
   public
     { Public declarations }
   end;
@@ -855,7 +854,7 @@ begin
     RefreshBackgroundColors;
     ColorBoxBackgroundColor.Selected := Sess.SessionColor;
     editDatabases.Text := Sess.AllDatabasesStr;
-    RefreshLibraries(Sess^);
+    comboLibrary.Items := Sess.GetLibraries;
     comboLibrary.ItemIndex := comboLibrary.Items.IndexOf(Sess.LibraryOrProvider);
     if (comboLibrary.ItemIndex = -1) and (comboLibrary.Items.Count > 0) then begin
       comboLibrary.ItemIndex := 0;
@@ -897,45 +896,6 @@ begin
 end;
 
 
-procedure Tconnform.RefreshLibraries(Sess: TConnectionParameters);
-var
-  rx: TRegExpr;
-  Libs: TStringDynArray;
-  LibPath, LibFile: String;
-  Providers: TStringList;
-  Provider: String;
-begin
-  // Detect existing dll files in app folder
-  comboLibrary.Clear;
-
-  rx := TRegExpr.Create;
-  rx.ModifierI := True;
-  case Sess.NetTypeGroup of
-    ngMySQL: rx.Expression := '^lib(mysql|mariadb).*\.dll$';
-    ngMSSQL: rx.Expression := '^(MSOLEDBSQL|SQLOLEDB)$';
-    ngPgSQL: rx.Expression := '^libpq.*\.dll$';
-  end;
-
-  if Sess.NetTypeGroup in [ngMySQL, ngPgSQL] then begin
-    Libs := TDirectory.GetFiles(ExtractFilePath(ParamStr(0)), '*.dll');
-    for LibPath in Libs do begin
-      LibFile := ExtractFileName(LibPath);
-      if rx.Exec(LibFile) then begin
-        comboLibrary.Items.Add(LibFile);
-      end;
-    end;
-  end else begin
-    Providers := TStringList.Create;
-    GetProviderNames(Providers);
-    for Provider in Providers do begin
-      if rx.Exec(Provider) then begin
-        comboLibrary.Items.Add(Provider);
-      end;
-    end;
-  end;
-end;
-
-
 procedure Tconnform.TimerStatisticsTimer(Sender: TObject);
 var
   LastConnect, Created, DummyDate: TDateTime;

source/dbconnection.pas

@@ -5,7 +5,7 @@ interface
 uses
   Classes, SysUtils, windows, dbstructures, SynRegExpr, Generics.Collections, Generics.Defaults,
   DateUtils, Types, Math, Dialogs, ADODB, DB, DBCommon, ComObj, Graphics, ExtCtrls, StrUtils,
-  gnugettext, AnsiStrings, Controls, Forms;
+  gnugettext, AnsiStrings, Controls, Forms, System.IOUtils;
 
 
 type
@@ -202,6 +202,7 @@ type
     ntMSSQL_NamedPipe, ntMSSQL_TCPIP, ntMSSQL_SPX, ntMSSQL_VINES, ntMSSQL_RPC,
     ntPgSQL_TCPIP, ntPgSQL_SSHtunnel);
   TNetTypeGroup = (ngMySQL, ngMSSQL, ngPgSQL);
+  TNetGroupLibs = TDictionary<TNetTypeGroup, TStringList>;
 
   TConnectionParameters = class(TObject)
     strict private
@@ -214,6 +215,7 @@ type
       FWindowsAuth, FWantSSL, FIsFolder, FCleartextPluginEnabled: Boolean;
       FSessionColor: TColor;
       FLastConnect: TDateTime;
+      class var FLibraries: TNetGroupLibs;
       function GetImageIndex: Integer;
       function GetSessionName: String;
     public
@@ -236,6 +238,7 @@ type
       function IsAzure: Boolean;
       function IsMemSQL: Boolean;
       property ImageIndex: Integer read GetImageIndex;
+      function GetLibraries: TStringList;
       function DefaultLibrary: String;
       function DefaultPort: Integer;
       function DefaultUsername: String;
@@ -1458,6 +1461,53 @@ begin
 end;
 
 
+function TConnectionParameters.GetLibraries: TStringList;
+var
+  rx: TRegExpr;
+  Dlls: TStringDynArray;
+  DllPath, DllFile: String;
+  FoundLibs, Providers: TStringList;
+  Provider: String;
+begin
+  if not Assigned(FLibraries) then begin
+    FLibraries := TNetGroupLibs.Create;
+  end;
+
+  if not FLibraries.ContainsKey(NetTypeGroup) then begin
+    FoundLibs := TStringList.Create;
+    rx := TRegExpr.Create;
+    rx.ModifierI := True;
+    case NetTypeGroup of
+      ngMySQL: rx.Expression := '^lib(mysql|mariadb).*\.dll$';
+      ngMSSQL: rx.Expression := '^(MSOLEDBSQL|SQLOLEDB)$';
+      ngPgSQL: rx.Expression := '^libpq.*\.dll$';
+    end;
+    if NetTypeGroup in [ngMySQL, ngPgSQL] then begin
+      Dlls := TDirectory.GetFiles(ExtractFilePath(ParamStr(0)), '*.dll');
+      for DllPath in Dlls do begin
+        DllFile := ExtractFileName(DllPath);
+        if rx.Exec(DllFile) then begin
+          FoundLibs.Add(DllFile);
+        end;
+      end;
+      SetLength(Dlls, 0);
+    end else begin
+      Providers := TStringList.Create;
+      GetProviderNames(Providers);
+      for Provider in Providers do begin
+        if rx.Exec(Provider) then begin
+          FoundLibs.Add(Provider);
+        end;
+      end;
+      Providers.Free;
+    end;
+    rx.Free;
+    FLibraries.Add(NetTypeGroup, FoundLibs);
+  end;
+  FLibraries.TryGetValue(NetTypeGroup, Result);
+end;
+
+
 function TConnectionParameters.GetSessionName: String;
 var
   LastBackSlash: Integer;