mORMot Open Source

Arnaud, I prepare very simple example (dpr with 65 lines), please check this code and callstack readed from OnBeforeException event level:

https://pastebin.com/8CXhiSgS

I get this result (first part is result od event, second part is standard SynLog catching exsception log):

--- mormotLogOnBeforeException -------- begin --------
Exception class: Exception
line #0:  onBeforeExceptionTest.InsideProc (38)
--- mormotLogOnBeforeException --------- end ----------
20200623 16272444 EXC   Exception ("test exception from inside procedure") [] at
 54cc89 onBeforeExceptionTest.InsideProc (38)  stack trace API 54cc89 onBeforeEx
ceptionTest.InsideProc (38) 54ccec onBeforeExceptionTest.OutsideProc (43) 54ccf8
 onBeforeExceptionTest.VeryOutsideProc (48) 54ce24 onBeforeExceptionTest.Main (5
8)

Why in OnBeforeException (where I use new introduced TSynMapFile.FindStackTrace() method) I can't get full stack?

Thanks Arnaud!

I still have a problem with the callstack, with the OnBeforeException event (from TSynLogFamily), it is almost empty, there is only a line calling the exception. The problem is probably not in the callstack extraction itself, because the EStackCount value of the aExceptionContext object is zero.

See:

Are you suggesting that I should read and parse the whole log to get a potential exception? Really?

I need to catch an exception, decode the call stack and send it somewhere... what you're recommending is a lot of over-the-top ideas.
I want SynLog (or other part of mormot) to let me convert the callstack (from OnBeforeException level) to thong with its internal tricks.
So, I just want Arnaud to refactor the code a bit and give external access to callstack conversion (using a private TSynMapFile instance)

I don't want to avoid TSynMapFile, I want to avoid having to duplicate code with SynLog (and problems with two TSynMapFile instances!). I just want the SynLog module to have a public function to read the callstack. This function could be used by TSynLog and external code (as I need it now).

Besides, TSynMapFile class should have one global instance (it is currently private).

A good solution would be to add a static class function to the TSynMapFile class, eg.:

class function TSynMapFile.GetCallStackAsStr(const CallStack: PPtrUInt) : TStrings;

or global function in a module, like this:

function GetCallStackAsStr(const CallStack: PPtrUInt) : TStrings;

This functionality would GREATLY extend the usability of SynLog! Even without a rest of mORMot!

Sometimes I have an impression that it is rather the mORMot that sponsors Delphi and it is Delphi that is mORMot powered ;-)

I debug source, in SynCRTSock.pas method RetrieveHeaders() fill RemoteIP param as ermpty string when IP = localhost:

Is this the intended change or should it return '127.0.0.1' or '::1'?

Maybe uncompressed size is coded in first bytes of file? Try this.

@ab, yes, for record serialization enums can be serialized as string, but please consider adding options to the server/service configuration so that the parameters of the enumerated type (including complex types such as records or arrays) are serialized to a string

Thanks for replies...
I don't think that the transfer of parameters of the enumerated type is noticeably slower, although it is to be tested.
But I personally see three advantages of this enumeration type encoding:
- makes debugging services easier
- makes it easier to connect foreign clients to the server (in other languages, e.g. JS)
- eliminates the problem of extending the type in the future by new values (then e.g. ftTable = 5 soon becomes ftTable = 10 and all client code needs to be corrected)

@Vitaly for enumerated types, see Spring4D and TEnum type :-)

Ehhh, I forgot that TDynArray is just a wrapper! Thx!

Thanks, this link works properly, previous not.

Yes, I'm also waiting for the official repo.
Arnaud, please review and merge these changes.

I create simple example apps based od Example 31 from mORMot demos.
See screencast how the second close the connection does not result in an OnWebSocketsClosed event on client side:

https://youtu.be/ugrVsqb-998

client source: https://pastebin.com/4teDqTJG
server source: https://pastebin.com/QKLFUKZF

I got the next problem.

If after unexpected closing the websocket connection I will resume this connection again (start websocket from client side) then next connection break (simulated by TCPView -> Close connection) no longer triggers the OnWebSocketsClosed event.

Correct the order of these lines:

  finally
   ffactory.free; //first
   ffactory := nil; //second
  end;   

It partially works, but there are further problems.
On the server side, I assign the OnClientDisconnected event:

procedure TWSLogServer.StartRemoteLogService();
begin
  [...]
  fHTTPServer := TSQLHttpServer.Create(IntToStr(fHTTPPort), [fRestServer], '+', useBidirSocket);
  fWSServer := fHTTPServer.WebSocketsEnable(fRestServer, cWebSocketEncryptionKey);
  fWSServer.Settings.OnClientDisconnected := OnClientDisconnected;   <========== event assigned
end;

When I release the server, I want to release the event, so I execute the code:

procedure TWSLogServer.StopRemoteLogService();
begin
  if Assigned(fHTTPServer) then
  begin
    fWSServer.Settings.OnClientDisconnected := nil;  <======== event released, but only on TWebSocketServer class side!
    FreeAndNil(fHTTPServer);
    FreeAndNil(fRestServer);
  end;
end;

However, the event is still called!

Code review and debugging led me to the conclusion that there is an error in the settings, because they are saved in the record:

  /// parameters to be used for WebSockets process
  TWebSocketProcessSettings = record
 [...]

And in working classes there are separate instances of those records that have copies of settings data, so that changing Settings in the TWebSocketServer  class instance does not affect the TWebSocketProcess class instance.

  TWebSocketServer = class(THttpServer)
  protected
    fSettings: TWebSocketProcessSettings;  <==== first settings
    
  TWebSocketProcess = class(TSynPersistent)
  protected
    fSettings: TWebSocketProcessSettings;  <===== next settings

How do I release a OnClientDisconnected event from a TWebSocketProcess?

Maybe worth change TWebSocketProcessSettings  from record to class?

In the code that I showed in the example, there are two events:

procedure TLogClientWebsockets.OnClientDisconnected(sender: TObject);
begin
  //   disconnect event handling is never called!!
end;

procedure TLogClientWebsockets.OnWebSocketsClosed(sender: TObject);
begin
  //   disconnect event handling is never called!!
end;

None of these events is called, so I ask what I am doing wrong or how to do it correctly?