mORMot Open Source

So do you have a plan to fix it?

A sample JSON response I got while debugging this issue:

[{"DocId":2078946242580065800,"DocDate":"2015-09-15","EventType":"e_po","ProductNr":"000020"}]

note 1: the DocId value is long...
note 2: I'm using the latest version from github.

Update: SQLite has already the json1 extension and it's expected to be integrated into the core once it's stabilized: https://www.sqlite.org/draft/json1.html

Obviously can be very useful for people who need very flexible, even nested database schema.

I think you can do that with mORMot, but I maybe a queue like this http://zeromq.org/ fits your needs more?

You are so fast! Thanks ab!

Thanks to the help by the author of OTL Primoz, problem's fixed for approach A, OtlTaskControl.CreateTask needs the .Unobserved modifier!

Well, after some more testing, it turned out the problem has nothing to do with TSQLHttpClient (because I replaced the http client connection with Sleep(5000) to rule it out), but there seems to be some incompatibility between OmniThreadLibrary (latest github SVN) and mORMot (I'm using the latest version about 1 day ago).

My server is configured like this:

  FDbSvr := TDbServer.Create(FDataModel, GetDbFileName, False);
  SetupServerLogging;
  FDBSvr.PublishAllServices;

  (*
    WAL might increase the risk of data losses!
    http://liferea.blogspot.jp/2012/03/morpheus-suggested-in-comment-to-check.html
    http://www.sqlabs.com/sqlitedoctor_details.php
    http://stackoverflow.com/a/20970876/133516
  *)
  FDbSvr.DB.WALMode := False;
  FDbSvr.DB.Synchronous := smFull;//ensure max data stability!

  FHttpSvr := TSQLHttpServer.Create(IntToStr(gServerPort), [FDbSvr], '+', HTTP_DEFAULT_MODE);
  FHttpSvr.AccessControlAllowOrigin := '*'; // allow cross-site AJAX queries;

and I have an interface-based service on the server side, with default configuration:

  /// this is the main interface exposed by the server
  TServerApi = class(TInterfacedObject, IServerApi)
  public
    function StartCommonDataDownload(aManualCall: Boolean): Boolean;
  end;

And in this StartCommonDataDownload() method, a thread will be started, like this:

/// approach A, the method will not return until 5 seconds are passed
function TServerApi.StartCommonDataDownload(aManualCall: Boolean): Boolean;
begin
  OtlTaskControl.CreateTask(
    procedure (const task: IOmniTask)
    begin
        Sleep(5000);
    end
  ).Run;
end;

/// approach B, the method will not return until 5 seconds are passed
function TServerApi.StartCommonDataDownload(aManualCall: Boolean): Boolean;
begin
    TThread.Queue(nil, procedure
      begin
        Sleep(5000);
      end
    );
end;

  /// approach C, works!
  Parallel.Async(procedure
  begin
      Sleep(5000);
  end);

Only approach C worked. Does it have anything to do with the way the TSQLHttpServer is running in? I run it with administrator and I guess it runs in the http.sys mode? (update: : tried useBidirSocket just now, same problem...) I also noticed the OmniThreadLibrary 's communication sub-system also is not working inside an interfaced service method...

Thanks for any help.

I Arnaud,

I haven't been updated my mORMot source for a while, I see the newly added OnEngineAddComputeID event for TSQLRestStorageExternal - looks like it's for **external** DB only. Is there already a similar event for customizing the record ID value for new records on the server side?

Great software is about passion, which you have on your open source projects! And I'm really glad to see the progress you have made to support FPC/Lazarus in the past years for mORMot!

@ab, in addtion to updating json properties, we'll also need  the ability to add property values.

I think you can investigate the recently added JSON support in postgresql, in order to plan a better support for mORMot.

HI Arnaud, before I read through the document you pointed out and the new blog post you just written (I guess it's a reaction of this forum post), I'd like to say that you are awesome, you are so fast!

How did your database corrupt?

I wish you have done this before I started using mORMot

Arnaud,

I mean something like this: http://www.generatedata.com/

Hi Arnaud,

I'm using the latest rev. committed today, when being accessed on the server side, ServiceContext.Request is always nil. Any comments? Thanks.

Hi,

That showcase thread doesn't necessarily represents the mORMot adoption status by the  Delphi community.

The Delphi community is a small one when compared to mainstream languages such as Java and C#, that being said, you might be able to have a feel by looking at:
- The stars of the github repository (https://github.com/synopse/mORMot);
- How active this forum is.
- How active the development of the project (check the commits of the above-mentioned github repository).

In my case, I did a quick check, my Samatra PDF Reader seems render all pages, but no bookmarks.

I must say I am really not good at this kind of thing, what I actually mean is that as opposed using pure random numbers for PKs, the timestamp+random PKs increase over time - in other worlds, a new record in most cases will have a greater  ID value than the old ones.

@alpinistbb, yes, there is no true random number generation without resorting to some kind of physical devices, and I guess that's out of the scope of the topic.

So my latest method is a time sortable 64bit UUID generation: http://synopse.info/forum/viewtopic.php?id=2522

Arnaud,

Thanks for your comment. Yes, we discussed about it here earlier, but I'm worried about the "office offset" approach that the users might input wrong Ids and it'll won't be detected until data syncing is under way. At the end, it's the program that has to handle it. We want to avoid this.

re. timestamp-based Id's generation, I'm not sure if the chance of collision is lower, all after all, we'll still have to combine it with random numbers.

I also have found this simple node.js algorithm for generating low-collision UUID: https://github.com/recurly/node-druuid its worth looking at, but I'm not sure how to port it to Pascal...