[CLOSED] Improvement of TFPCustomImage.FindHandlerFromExtension
lazarus / 64-FPC development

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lagprogramming · 2023-07-07 12:27

packages/fcl-image/src/fpimage.inc has the following function:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i class
function TFPCustomImage.FindHandlerFromExtension(extension: String  ):
TIHData;var s : string;    r : integer;begin  if extension='' then   
Exit(nil);  extension := lowercase (extension);  if (extension <> '')
and (extension[1] = '.') then    delete (extension,1,1);  with
ImageHandlers do    begin      r := count-1;      s := dumchar  +
extension + dumchar;      while (r >= 0) do        begin        Result
:= GetData(r);        if (pos(s, dumchar+Result.Fextension+dumchar) <>
0) then          Exit;        dec (r);        end;    end;  Result :=
nil;end;The patch at the end of the message changes the above code to
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i class
function TFPCustomImage.FindHandlerFromExtension(extension: String  ):
TIHData;var s : string;    r : integer;begin  if extension <> '' then 
  begin    extension := lowercase (extension);    if extension[1] =
'.' then      delete (extension,1,1);    with ImageHandlers do     
begin        r := count-1;        s := dumchar  + extension +
dumchar;        while (r >= 0) do          begin          Result :=
GetData(r);          if (pos(s, dumchar+Result.Fextension+dumchar) <>
0) then            Exit;          dec (r);          end;      end;   
end;  Result := nil;end;

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i begin  if
extension='' then    Exit(nil);  //CODE  Result := nil;end;is changed
to
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i begin  if
extension<>'' then    begin    //CODE    end;  Result := nil;end;and
after that
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i if
(extension <> '') and (extension[1] = '.') thenis replaced with
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i if
extension[1] = '.' then
The modified pascal code avoids duplicate nil assignments to
function's result and also avoids the duplicate check for a nil(empty)
extension variable. Obviously, the compiler produces better code for
the modified pascal sources than for the original.
I've tried to keep the original code formatting style, here is the
patch.
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i diff --git
a/packages/fcl-image/src/fpimage.inc b/packages/fcl-
image/src/fpimage.incindex 531c4ec219..b4fb9dac24 100644---
a/packages/fcl-image/src/fpimage.inc+++ b/packages/fcl-
image/src/fpimage.inc@@ -274,22 +274,23 @@ class function
TFPCustomImage.FindHandlerFromExtension(extension: String var s :
string;     r : integer; begin-  if extension='' then-    Exit(nil);-
 extension := lowercase (extension);-  if (extension <> '') and
(extension[1] = '.') then-    delete (extension,1,1);-  with
ImageHandlers do+  if extension <> '' then     begin-      r :=
count-1;-      s := dumchar  + extension + dumchar;-      while (r >=
0) do-        begin-        Result := GetData(r);-        if (pos(s,
dumchar+Result.Fextension+dumchar) <> 0) then-          Exit;-      
 dec (r);-        end;+    extension := lowercase (extension);+    if
extension[1] = '.' then+      delete (extension,1,1);+    with
ImageHandlers do+      begin+        r := count-1;+        s :=
dumchar  + extension + dumchar;+        while (r >= 0) do+        
 begin+          Result := GetData(r);+          if (pos(s,
dumchar+Result.Fextension+dumchar) <> 0) then+            Exit;+     
   dec (r);+          end;+      end;     end;   Result := nil; end;