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Clément

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Everything posted by Clément

  1. IsInRangeEx is using Cardinals as parameters. The ideia is to use the unsigned type. In the example Cardinal( 5 - 10 ) = 4294967291 as expected. IsInRangeEx will not accept negative numbers... Using in extreme cases like: IsInRangeEx(cardinal(-2),Cardinal(-3),Cardinal(-1)) will also work. IsInRangeEx2 will work with negative numbers. I cannot see the overflows 😞
  2. I love these topics. Under 64 bits: Math.InRange: 859 IsInRange: 858 If: 860 IsInRangeEx: 858 IsInRangeEx2: 858 Under 32bits: Math.InRange: 1288 IsInRange: 906 If: 906 IsInRangeEx: 858 IsInRangeEx2: 858 The code for IsInRangeEx and isInRangeEx2: function IsInRangeEx(const AValue, AMin, AMax: Cardinal): Boolean; inline; begin Result := (AValue - AMin) <= (aMax - aMin); end; function IsInRangeEx2(const AValue, AMin, AMax: Integer): Boolean; inline; begin Result := ((AValue-AMax)*(aValue-AMin) <= 0); end;
  3. Clément

    Transforming Data (Pivot ?)

    DxPivotGrid should give you the expected results. It's a matter of setting accordingly the rows , columns and values. The trick is to transform the "Operational data" to "Pivotable data". Having "true" in pivot table is not meaningfull.. but display 75% Oil Ok will indicate something is wrong and your user will figure out what's ( or where it's) wrong by drilling down.
  4. Clément

    I will be less active for a few weeks

    I'm glad you're back! Still no vaccine for me. I'm too young . I hope by Aug or Sept I'll get my double dose.
  5. Hi , I'm using 10.4.2 and it works as expected Althought it's not selecting the first option, apparently it selects the closest match, in this case, the cursor remains over "Load" til I type "e" then it moves to "loaded" Are you using some IDE plugin? (I'm using Delphi as it came in the world! ) Clément
  6. Clément

    Min & Max

    deleted
  7. Why can't you use MD5? A TObjectDictionary< String, TDataset > where "String" is MD5( _Your_SQL_String_With_All_Parameters_evaluated ) and TDataset the structure for the result. The Dictionary should be created with OwnValues parameter, this way the TDataset instances will be freed when the dictionary is destroyed.
  8. Clément

    I will be less active for a few weeks

    Stay safe and I wish you a full recovery!
  9. Clément

    Delphi 10.4.2 first impressions

    After using the IDE (10.4.2) for a few days, I wouldn't be fair to say it's just more stable. All the features I'm using are working, including Debug! Most debugging problem are solved, mostly 64bits. If you have a problem LSP you can still deactivacte it. The new LSP features are working fine for me, but it might help if one deactivate it. For instance you can disable error insight: And disable LSP: Even without those items, the IDE still has enough features to justify the migration. You can call me a dreamer ( or incorrigible optimist ), but if Emb can keep that same quality ration from 10.4 ->10.4.2, it's very likely to have a good 10.5 version. 10.4.2 is a clear improvement over 10.4.x (Error insight level at "Warnings and Above") By hovering the mouse over the yellow line, the IDE shows the warning. Cool eh?
  10. Clément

    Delphi 10.4.2 first impressions

    I'm impressed! I used the migration tool to update from 10.4.1 to 10.4.2. Downloaded the WebInstall. Everything went well. The IDE opened and as expected only Getit Packages were out. Getit package got better! I manage to install my packages without any glitches. ( VCL Styles, ICS, SynEdit and JCL is also there ). I don't understand why some VCL Styles were only available to some IDEs (older). Shouldn't they be available to all? I understand VCL Styles should be part of delphi from the version it is released upwards. When opening a large project a status screen the unit being loaded! It also shows when you open a unit/frame/form. Cool! There's a nice progress bar on the project manager window footer. It shows code insight working! Cool! The compiler screen has more info too! I haven't tested debugging yet, but I have high hope with viewing generics and of course a more stable debugging experience (Win32/Win64) I haven't noticed any faster compilation. My projects are not suitable for such tests. All of them compiles in a few seconds. I still prefer the Dark theme. I haven't noticed any flicking in the IDE and there's clearing a lot more going on. There's absolutely no doubt the IDE improved a LOT. In 10.4.1 when typing [CTRL+SPACE] to call the form methods nothing was shown. You had to type method declarations / parameters.. Very annoying. They fixed it in 10.4.2! Cool! We can click "Inherited" Cool! Can wait to start debugging my projects!
  11. Clément

    Delphi is 26 years old - Marco's blog

    Also started with Turbo Pascal , Turbo C, Paradox et al. ... since then always learning something new everyday
  12. I use a profiler and I try to avoid wasting memory allocation. I've seen code searching for POST,PUT,GET,DELETE in a string spread all over the place. Why does one need to search so much? Parse and search once. Use enumerated types. There's a plethora of ready to use structures. Sometimes too KISSy is not KISS but simply S.
  13. Actually I guess is the other way around! The more expert I get the more refactoring I do! As @Lars Fosdal said, cryptic code, WTF was I thinking code, Code that could benefit from modern RTL code if there's no performance penalty. For example: For lPair in SomeObjectList is slower than for i:= 0 to SomeobjectList.count-1. So I won't refactor it. Depending where the code is placed, I will use one form or the other. Replacing TStringList (used as dictionary) with a TDictionary/TDictionaryObject makes a huge diference!
  14. Hi, I'm using D10.4.1. Recently I switch to FastMM4 from github ( 4.992 ) to track down some (unexpected) leaks. With the embedded version of FastMM4 those leaks were not reported. I manage to find all of them.. But when I close the application the below exception is raised.. I thought it was memory leak related , but even after removing all leaks, it continues to "kind of" show. I google that address to see if has a meaningful magical number but I found nothing. No matter for how long I use the application, or what screens are opened/closed. Always the same address. If I close the main form without opening any other forms, the program exits normally. if I either open one form, or all the application's forms , the below exception is raised: --------------------------- Debugger Exception Notification --------------------------- Project Project007.exe raised exception class $C0000005 with message 'access violation at 0x02099099: read of address 0x74be973f'. --------------------------- Break Continue Help --------------------------- If I press the "Break button" then this is shown: The call stack: The call stack first line points to "FastMM_FullDebugMode.dll" which is in the same path as the executable. I'm using the precompiled version 32 bits. The "Build configuration" is set to DEBUG. If I run "With Debug" (F9) the error is raised. If I run "Without Debug" (CTRL+SHFT + F9) no error is raised. There's no memory leak no matter what version of FastMM4 runs. FastMM4 is set to report as follows: If I uncheck RawStackTraces the exceptions no longer is raised. Can I gracefully ignore "RawStackTraces" and leave it unchecked, or there's a bomb in my code?! TIA
  15. Anyway thanks for your help. I will do some more tracking to be sure I'm not messing TdxAlphaColors in any way. But I'm using their skins and all of their components. So it might well be some acceptable exception. I will check with their support. Thanks a lot for your help!
  16. I managed to get the typeinfo. The addess in my code has changed, but all the others are the same. The $692BB8 became $6AC4D8. This is what I came up with: Is this correct? I installed the trial version of EurekaLog, activated it, set all the trace raw stack options and nothing happens. No report is produced or dialog displayed. If I force an exception in my application it does kick in. Even the exception raised by FastMM4's RawStackTrace option is no longer raised. Since there's a lot of options to set up, I will have to play a little more with it. As soon as I deactivate EL, the exception raises back again iif FastMM4's RawStacktrace is set.
  17. First of all let me thank you very much for such great explanation! Once I unselected "AlwaysAllocateTopDown" the address changes every time, but it still a high address access violation at 0x02089099: read of address 0x755f973f'. access violation at 0x02099099: read of address 0x755f973f'. access violation at 0x020d9099: read of address 0x755f973f'. So far I manage to pass by all finalization sections. The RTL code that executes the finalizations is a while loop with a decreasing counter and in my case the count start at 732 and the error is raise when that counter reaches 196. At that point all my finalizations passed ( they ended by 650). When entering the correct point (entry 196) I can just follow up a few "Tobject.Free" methods and the exception is raised. No qualified named to help me locate the code. I'm using "debug dcus" and almost all my debug settings are on. That's what I was afraid of. And of course that bomb will only explode at customer's
  18. Hi, I'm experimenting some interface design and came up with the following: I would like to query a BaseClass instance if it supports a given interface, without freeing the class! As the example below, my great grand child class can support an interface, but I don't want to include the class definition ( great grand child class ) in the Base class.. So, by defining interfaces, I can write exactly what I want: TMyFrame = Class( TBaseFrame, {SupportedInterfaces}) In the code below procedure TForm22.Button1Click(Sender: TObject); begin if Supports( fBaseFrameClass, ISupportTask ) then (fBaseFrame as ISupportTask).CheckTask; end; No matter what overload Support method I call, fBaseFrame is freed once the method exits. Is there a way to know if my class instance supports an interface and call the corresponding method without messing ref counting and free the class instance prematurely? unit frm.main; interface uses Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics, Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls; type ISupportTask = Interface ['{3F785F20-7C44-4163-B55C-5EA267C7204E}'] function CheckTask : Boolean; end; ISupportList = Interface ['{9B7D95E1-DA96-475A-9A1C-910CAF99E5F5}'] function ListCount : Integer; End; ISupportItem = Interface ['{ACADFA2F-3500-4ACB-8049-F49FAC38EFB2}'] function SaveItem : Boolean; End; TBaseFrame = Class( TInterfacedObject ) protected fDummy : Boolean; End; TBaseFrameClass = Class of TBaseFrame; TMyFrame = Class( TBaseFrame, ISupportTask, ISupportList, ISupportItem ) public function CheckTask : Boolean; function ListCount : Integer; function SaveItem : Boolean; destructor Destroy; override; End; TForm22 = class(TForm) Button1: TButton; procedure Button1Click(Sender: TObject); procedure FormCreate(Sender: TObject); procedure FormDestroy(Sender: TObject); private { Private declarations } fBaseFrameClass : TBaseFrameClass; fBaseFrame : TBaseFrame; public { Public declarations } end; var Form22: TForm22; implementation {$R *.dfm} procedure TForm22.Button1Click(Sender: TObject); begin if Supports( fBaseFrameClass, ISupportTask ) then (fBaseFrame as ISupportTask).CheckTask; end; { TMyFrame } function TMyFrame.CheckTask: Boolean; begin Result := True; end; destructor TMyFrame.Destroy; begin fDummy := True; inherited; end; function TMyFrame.ListCount: Integer; begin Result := 42; end; function TMyFrame.SaveItem: Boolean; begin Result := False; end; procedure TForm22.FormCreate(Sender: TObject); begin fBaseFrameClass := TMyFrame; fBaseFrame := fBaseFrameClass.Create; end; procedure TForm22.FormDestroy(Sender: TObject); begin fBaseFrame.Free; end; end.
  19. Hi Gustav, The sample code and example program you provided are helping me a lot! Thanks you!
  20. Hi Remy, Thank you very much for your insight! I learn something new every day! I will do some testing and get back.. This subject is cool!
  21. I'm considering this implementation... I was hoping there was another way.
  22. Hi David, I tried every Support overload with the same effect. As it says in the documentation, there's a big Warning explaining exactly what I'm experience. Either I forget about freeing the class, which is Ok because I will always implement some interface in my Classes, or I'll have to change overload the reference count methods. I was hoping for a third choice..
  23. Hi Dalija, My class implements several interfaces, I want to check which interfaces are implemented and call the corresponding methods using some parameters. I wasn't expecting that Supports would also have this "side effect", although the documentation is clear about the destroying part...
  24. Happy new year! By the end of 2020 I was surprised by a new customer who said he didn't want a "Delphi software", because Delphi was unsafe for his business. His software got hacked. Since that was a first, I got more information about what happened and what that security breach was all about. The hacker discovered the manager's password by tampering the application executable. I don't know what tool was used, but all password editors were showing the actual password instead of '*'. Not only in editors, but in grids too. The application had a feature that requested a manager password to allow changes in some fields. That screen was gone! Any employee could modify, delete, or include data without restrictions. Even some restricted data were display for everyone. I couldn't see the application source code, or get more information. But have you ever heard of such a tool that could tamper resources as much as this ? Clément
  25. From what I can tell, usually the first requests are most "dangerous". For example, you can hash a password, all a hacker have to do is use that same hash. If he knows where to send it, you got a problem. But if I can hide the URL of the "firsts" connections it will make harder for a hacker to identity what the protection schema is, and buy us some time until he is figures out what he is dealing with. My WebServer is already using JWT with AES encryption. After the initial requests it will get harder to hack. I'm considering using also encrypted URL for all the other requests. But still, something to look forward to. Another trick I'm using to gain time ( I guess it's safe to comment here ) : I'm going "hacker fishing" . Some of you may remember I fell victim of a nasty ransomware a few months ago. I was able to recover everything. I've being drinking coffee over this and what caught my attention was the time spend to encrypt my HUGE glyph image library. The security factor here is HUGE and TIME. The more time hacker spend hacking, the more time we gain to react! ( I know, I know, I'm a modest genius ) I googled RFCs for anything I could use, and this is what I came up with: 1 - Some ports are bound to some specific protocols, and some protocols have initial banners. 2 - Some ports are bound to some specific functions, or remote operations, like directory listings and or file downloads. 3 - Brute force attack usually try to find opened ports, but still, they search for ports in a certain order. 4 - Most of firewalls shut ports closed. This will help them scanning all the range port set looking for a breach. There are tons of code in google helping them scan for opened ports in seconds! But what would happened if some ports are intentionally opened with "fake server" listening to them? And why not "add more security" with a nice user/password: admin/1234 ? For 1: there's nothing on RFC that limits the size of a Banner. The server is generating a 20TB banner for our unwanted guest. If he stores the banner it will create a disk space problem, or at least, this would slow down his attack until the whole banner is downloaded. For 2: the server generates over a million files to download. Had any of you try to use Windows Explorer with a folder with over a millions of files? Again, it will slowdown the attack. And while the fake server is keeping our unwanted guess busy, it is also including their IPs addresses to the firewall black list ...
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