The Wiert Corner – irregular stream of stuff

Jeroen W. Pluimers on .NET, C#, Delphi, databases, and personal interests

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Archive for the ‘Windows Development’ Category

Why does HRESULT begin with H when it’s not a handle to anything? – The Old New Thing

Posted by jpluimers on 2020/02/06

Interesting bit of history: [WayBackWhy does HRESULT begin with H when it’s not a handle to anything? – The Old New Thing.

TL;DR:

  1. It used to be a handle
  2. Few programs cared about the underlying objects
  3. Managing the underlying objects was way too expensive
  4. It got trimmed down to a number, but the name stuck

–jeroen

Posted in Development, History, Software Development, The Old New Thing, Windows Development | Leave a Comment »

Delphi, decoding files to strings and finding line endings: some links, some history on Windows NT and UTF/UCS encodings

Posted by jpluimers on 2019/12/31

A while back there were a few G+ threads sprouted by David Heffernan on decoding big files into line-ending splitted strings:

Code comparison:

Python:

with open(filename, 'r', encoding='utf-16-le') as f:
  for line in f:
    pass

Delphi:

for Line in TLineReader.FromFile(filename, TEncoding.Unicode) do
  ;

This spurred some nice observations and unfounded statements on which encodings should be used, so I posted a bit of history that is included below.

Some tips and observations from the links:

  • Good old text files are not “good” with Unicode support, neither are TextFile Device Drivers; nobody has written a driver supporting a wide range of encodings as of yet.
  • Good old text files are slow as well, even with a changed SetTextBuffer
  • When using the TStreamReader, the decoding takes much more time than the actual reading, which means that [WayBack] Faster FileStream with TBufferedFileStream • DelphiABall does not help much
  • TStringList.LoadFromFile, though fast, is a memory allocation dork and has limits on string size
  • Delphi RTL code is not what it used to be: pre-Delphi Unicode RTL code is of far better quality than Delphi 2009 and up RTL code
  • Supporting various encodings is important
  • EBCDIC days: three kinds of spaces, two kinds of hyphens, multiple codepages
  • Strings are just that: strings. It’s about the encoding from/to the file that needs to be optimal.
  • When processing large files, caching only makes sense when the file fits in memory. Otherwise caching just adds overhead.
  • On Windows, if you read a big text file into memory, open the file in “sequential read” mode, to disable caching. Use the FILE_FLAG_SEQUENTIAL_SCAN flag under Windows, as stated at [WayBack] How do FILE_FLAG_SEQUENTIAL_SCAN and FILE_FLAG_RANDOM_ACCESS affect how the operating system treats my file? – The Old New Thing
  • Python string reading depends on the way you read files (ASCII or Unicode); see [WayBack] unicode – Python codecs line ending – Stack Overflow

Though TLineReader is not part of the RTL, I think it is from [WayBack] For-in Enumeration – ADUG.

Encodings in use

It doesn’t help that on the Windows Console, various encodings are used:

Good reading here is [WayBack] c++ – What unicode encoding (UTF-8, UTF-16, other) does Windows use for its Unicode data types? – Stack Overflow

Encoding history

+A. Bouchez I’m with +David Heffernan here:

At its release in 1993, Windows NT was very early in supporting Unicode. Development of Windows NT started in 1990 where they opted for UCS-2 having 2 bytes per character and had a non-required annex on UTF-1.

UTF-1 – that later evolved into UTF-8 – did not even exist at that time. Even UCS-2 was still young: it got designed in 1989. UTF-8 was outlined late 1992 and became a standard in 1993

Some references:

–jeroen

Read the rest of this entry »

Posted in Delphi, Development, Encoding, PowerShell, PowerShell, Python, Scripting, Software Development, The Old New Thing, Unicode, UTF-16, UTF-8, Windows Development | Leave a Comment »

Sparkle and WinSparkle – frameworks to update your applications on Apple Mac OS X / MacOS and Windows.

Posted by jpluimers on 2019/10/29

Since I will need these one day as native apps are useful:

via: [WayBack] Looking for ideas how to display to the users that ‘New version is available’ info… – Mike Torrettinni – Google+ which also has some good tips on how to notify the user about the availability of new updates.

–jeroen

Posted in Development, Software Development, Windows Development | Leave a Comment »

Terminate threads during application or not?

Posted by jpluimers on 2019/10/02

I got an interesting question a while ago: should an application terminate (anonymous) threads or not?

A problem is that a thread might not execute unless you call WaitFor before Terminate is called. The reason is that the internal function ThreadProc does not start Execute if the thread is already terminated.

The ThreadProc in the System.Classes unit is an ideal place to set breakpoints in order to see which threads might start.

Other useful places to set breakpoints:

  • TAnonymousThread.Execute
  • TExternalThread.Execute

Execute not being called by ThreadProc is a bug, but it is not documented because QC is gone (taking the below entry with it), it is not in QP and the docwiki never got updated.

Given QC has so much information, I am still baffled that Embarcadero took it down.

Sergey Kasandrov (a.k.a. serg or sergworks) wrote in [WayBack] Sleep sort and TThread corner case | The Programming Works about this bug and refers to WayBack: QualityCentral 35451 – TThread implementation doesn’t guarantee that thread’s Execute method will be called at all .

The really bad thing are the WayBack: QualityCentral Resolution Entries for Report #35451 Resolution “As Designed” implying the design is wrong.

In his post, sergworks implemented the Sleep sorting in Delphi. Related:

Note that application shutdown is a much debated topic. Best is to do as little cleanup as possible: your process is going to terminate soon anyway. No need to close handles or free memory: Windows will do that for you anyway. See for instance:

 

Related to waiting:

Related to executing:

–jeroen

Posted in Conference Topics, Conferences, Delphi, Development, Event, Multi-Threading / Concurrency, Software Development, The Old New Thing, Windows Development | Leave a Comment »

Using Image Encoders and Decoders in Managed GDI+ | Microsoft Docs

Posted by jpluimers on 2019/09/17

I forgot who pointed me to this, but it will be useful the next time I need to do image export/import in .NET or GDI+ [WayBackUsing Image Encoders and Decoders in Managed GDI+ | Microsoft Docs.

GDI+ has built-in encoders and decoders that support the following file types:

  • BMP
  • GIF
  • JPEG
  • PNG
  • TIFF

GDI+ also has built-in decoders that support the following file types:

  • WMF
  • EMF
  • ICON

–jeroen

Posted in Development, Software Development, Windows Development | Leave a Comment »

When an installer errors out with “Please re-run this installer as a normal user instead of”…

Posted by jpluimers on 2019/08/12

Via [WayBack] Anyone with a hint on how to work around this: … “Please re-run this installer as a normal user instead of”… – Jeroen Wiert Pluimers – Google+

This happened for instance when trying to install Source Tree 2.x on Windows (1.9.x works fine):

[Window Title]
SourceTreeSetup-2.3.1.0.exe

[Main Instruction]
Installation has failed

[Content]
Please re-run this installer as a normal user instead of “Run as Administrator”.

[Close]

The problem was by accident the machine got in a state to run commands without UAC approval, so the run dialog would already look have “This task will be created with administrative privileges”:

It was odd, as the machine didn’t have it enabled in the security policy (secpo.msc):

So I did a bit more digging, bumped into [WayBack] Why does my Run dialog say that tasks will created with administrative privileges? – The Old New Thing and had one of those #facepalm moments: Explorer had crashed, and I had started it from Process Explorer, forgetting Process Explorer had an UAC token.

The solution is easy:

  1. Logoff / Logon
  2. Verify the Windows-R shows a “normal” run:

Then you can just run the installer:

–jeroen

Posted in Batch-Files, Console (command prompt window), Development, Power User, Scripting, Software Development, The Old New Thing, Windows, Windows Development | Leave a Comment »

Using PE Flags in Delphi – twm’s blog

Posted by jpluimers on 2019/08/08

For my link archive: [WayBackUsing PE Flags in Delphi – twm’s blog with information about and links to:

The flags themselves are documented at [WayBack] IMAGE_FILE_HEADER structure (Windows)

–jeroen

Via: [WayBack] There was a discussion about using the PE flag IMAGE_FILE_LARGE_ADDRESS_AWARE… – Thomas Mueller (dummzeuch) – Google+

Posted in Delphi, Development, Software Development, Windows Development | Leave a Comment »

A COM Object Collection (IEnumVARIANT) – Delphi Tips – CJC Delphi (Cool Delphi Tips)

Posted by jpluimers on 2019/07/04

Summary of [WayBack] A COM Object Collection (IEnumVARIANT) – Delphi Tips – CJC Delphi (Cool Delphi Tips)

Question: How to implements object collection that support Visual Basic’s For Each construct ?

Answer:
In order to implements an object collection your object has to return  IEnumVariant pointer from a special property named _NewEnum.

Via: [WayBack] What interface to I need to implement to allow ForEach in VBA on a COM object written in delphi? – Stack Overflow

–jeroen

Posted in COM/DCOM/COM+, Delphi, Development, Software Development, Windows Development | Leave a Comment »

Detecting if a debugger is present is different from detecting if an IDE is present.

Posted by jpluimers on 2019/04/04

I have seen this happen in various environments: people wanting to detect if their debugger is present, but trying to detect their IDE, or vice versa.

Similar reasoning is for detecting for being running on a console, or your project having been built to run on a console.

People use these decisions, for instance to determine if their application should behave as a service, or as a regular process.

Ways to determine the various permutation points:

  • Running inside a debugger: use the [WayBackIsDebuggerPresent function (which can be true, even if Delphi DebugHook stays zero).
  • Check for the IDE: tricky; as IDEs have different behaviour over time. For Delphi, check for any TAppBuilder Window class with the [WayBack] FindWindow function.
  • Compiled for console: for Delphi check IsConsole, for .NET I could not find good information.
  • Running on a console: check if you can allocate a handle to stdout
  • Running as a service: check the hosting assembly or hosting process

Related links:

–jeroen

Posted in .NET, Delphi, Development, Software Development, Windows Development | Leave a Comment »

sorting – Is there a Windows equivalent to the Unix uniq? – Super User

Posted by jpluimers on 2019/03/08

TL;DR:

  • Windows 10 has an undocumented /unique switch for sort
  • git for Windows ships with uniq (in a default x64 install, it is at C:\Program Files\Git\usr\bin\uniq.exe)

From [WayBack] sorting – Is there a Windows equivalent to the Unix uniq? – Super User

This works fine:

dir /s /b *0*.pas *1*.pas *2*.pas *3*.pas *4*.pas *5*.pas *6*.pas *7*.pas*8*.pas *9*.pas | sort /unique > pas-files-with-numeric-names.txt

I need remove duplicate lines from a text file, it is simple in Linux usingcat file.txt |sort | uniqwhen file.txt containsaaabbbaaacccIt will output aaabbbcccIs there a Windows

 

Posted in Development, Power User, Software Development, Windows, Windows Development | Leave a Comment »