Jump to content

Arnaud Bouchez

Members
  • Content Count

    215
  • Joined

  • Last visited

  • Days Won

    10

Arnaud Bouchez last won the day on November 9

Arnaud Bouchez had the most liked content!

Community Reputation

225 Excellent

4 Followers

Recent Profile Visitors

The recent visitors block is disabled and is not being shown to other users.

  1. Arnaud Bouchez

    auto-generated REST APIs?

    This is not TMS DB Remote for sure. But a request like GET /tms/xdata/Customer?$filter=Country/Name eq 'USA'&$orderby=Name&$top=10 seems very close to a SQL SELECT. Security seems pretty basic: is there something more than the CRUD permissions of https://download.tmssoftware.com/business/xdata/doc/web/entity_sets_permissions.html ? I guess the https://download.tmssoftware.com/business/xdata/doc/web/onentityget_event.html callback seems a bit manual to handle. Even if the client is authenticated, how to you go deeper into the authorization? For instance, if you have a DB with all customers for all salers, how to prevent one saler to get the customers of other salers from the same table? So not any arbitrary SQL statement could be executed, for sure. But the client side is still deciding what it queries, unless the server is bloated with authorization code. What I would like to emphase is that it may be a 3-tier physical architecture, but it is still a 2-tier logical Architecture. The logic is still in the client. A much cleaner n-Tier architecture would be to create a real business layer (logical 3-tier) - or even better an application layer (logicial 4-tier as in DDD), and expose only safe and efficient REST endpoints to the clients. Then the server will query the data, and expose it as DTOs to the clients, depending on each bounded context (business layer) or each use-case (app layer). The client side is still much too tied to the underlying database. In a clean SOA architecture, you don't start from the database, but from the client use-cases.
  2. Some hints about performance on REAL bottlenecks: It covers, among others, the tip of a sub-function if you have some temporary managed variables (like string). The associated code, proving the slide assumptions, is available at https://synopse.info/files/slides/EKON22_2_High_Performance_Pascal_Code_On_Servers.zip Worth I look to understand how it works in practice. But remember: "Premature Optimization if the Root of All Evil !" (DK)
  3. Arnaud Bouchez

    auto-generated REST APIs?

    It is clearly a wrong good idea. I don't see the benefit in respect to executing the SQL and return some JSON - which is a bad idea per se. I just answered on SO why direct exposition of the database to a REST/HTTP/JSON client is not a good idea. https://stackoverflow.com/a/64936643/458259 It is still a 2-Tier architecture, from the logical point of view. Of course, it is a 3-Tier architecture from the physical point of view, but what matters is the logical point of view, and adding a physical layer is not a benefit here.
  4. Arnaud Bouchez

    Speed of Graphics32

    Did you try with FMX? Then you can switch the rendering engine behind it.
  5. Arnaud Bouchez

    Speed of Graphics32

    Do you speak about Direct 2D 1.1 or Direct 2D 1.0? 😉 At least with GDI (GDI+) or Graphics32 we have consistent performance.
  6. Arnaud Bouchez

    Speed of Graphics32

    @FPiette Direct2D is no silver bullet either. It has been reported to be slower than GDI, due to wrongly implemented drivers, and is somewhat deprecated/unoptimized/unused. @Mike James Don't forget about GDI+ which is part of Windows, and has good performance, with nice features like Alpha channel and good antialiaising. Which kind of drawing do you need?
  7. Arnaud Bouchez

    NERO5 chess engine

    So many "goto" in the source code. 🙂
  8. I had a similar problem decades ago with a French payment processor called "Yaskifo". Small startup which offered best prices at that time. But with wrong management of their internal costs, and which were sued by French banks at that time... Yaskifo owned me thousands of Euros, which I never saw back... Once their company was bankrupted, all customers could just weep. I don't know anything about FastSpring, but in doubt, my advice would be to switch to a bigger and safer alternative - at least joined to some well known bank or company. Even if their fee is higher.
  9. Arnaud Bouchez

    Threads on dual-Xeon system

    You would need two memory managers, one per CPU socket.... Which is not possible with the Delphi RTL yet. You may try to use a per-thread memory manager, not FastMM4, which uses a per-thread arena for small blocks. There are some around for Delphi - just google for it.
  10. Arnaud Bouchez

    Feature Request for String Paste As

    Some tools - like cnpack IIRC - allow to format the text into source code string after being pasted.
  11. Not possible, as François wrote, and also not useful. What would be the purpose of adding new properties at runtime? How to you access them? If what you expect is to make public something private, then you can trick the class by inheriting it locally, publishing the properties, then hard-casting to your type. If what you expect is to add some fields to an existing class, it is not possible because the class instance size if hardcoded during compilation. If what you expect is to have some additional information linked to an existing class, maintain a dictionary/map with the instances, and create a co-object associated with the main object lifetime, in which you put the needed data. If what you expect is to have some additional information linked to an existing class (as a variation to the previous item), inherit from this class or even better nest this class into a main owner class/TComponenet, which will have your expected behavior.
  12. @David Heffernan , come out of @Stefan Glienke body! Now both Delphi reference guys have enabled their internal Technical English Compiler (tm) in paranoid mode! 😄
  13. Exactly. This is one of the reasons why enabling extended RTTI did increase the exe size by a big margin, and why I usually disable it unless I know I will actually need it.
  14. Arnaud Bouchez

    Compile code on the fly...?

    They just rewrite a regexp-like engine, which are usually using byte codes. Note that when a regexp uses JIT, it is faster, but not in all cases. For pascal source code of a very fast regexp engine, check https://github.com/BeRo1985/flre - you will see it is complex to make such things fast! But to be fair, my guess is that Everything as a tool is fast not because its pattern search is fast, but because all the file names are already cached in memory. So it doesn't have to call the Windows API to get all the file names. The real bottleneck is not the search itself, but the OS API calls. Byte-code search in the list may result in the search being a bit faster, but for only a few percent. So this performance statement is more like a marketing statement - not false, but not the real performance trick. As another reference code, perhaps easier to read than FLRE, check our Open Source TMatch object in https://github.com/synopse/mORMot2/blob/master/src/core/mormot.core.search.pas It is very fast e.g. to find e.g. '*.pas' or 'toto*.pas' or '*inside*'. When I mean fast, it is fast (using algorithms like Holub and Durian (2005) SBNDM2 algorithm). And if you want to see some code about an expression search engine, using an AST and some kind of byte codes, check the TExprParserMatch class in the same unit.
  15. Nice to read. But I am not sure indeed where it should be used in practice.
×