The Wiert Corner – irregular stream of stuff

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

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Current state: still fighting the metastases of the rectum cancer; chemos are done, major liver surgery in about 3 weeks

Posted by jpluimers on 2020/08/23

A long follow-up of Current state: still fighting with rectum cancer, but chances for better quality of life which does not even include everything, because so much happened.

So this is the current state; browse back via Twitter for more of the history which you can find at [] Jeroen Pluimers on Twitter: “Too much to let sink in …” and [] Jeroen Pluimers (@jpluimers) | Twitter.

Too much to let sink in, not just about the hospital results and upcoming surgery, but also about Cindy and Danny Thorpe who just lost their house in the California forest fires, despite it being on the humid side of the Santa Cruz mountains.
If you can help anybody affected by the #CZULightningComplex, please do. Many families there are going through a rough time for the foreseeable future especially because of the combination of fires and COVID.
If you are in that area: be careful, be safe.
For me it is mixed emotions time.
The chemo did make the cancer operable. Some tumors have shrunken, a few small ones are invisible, probably because of the chemo-induced hepatic steatosis, and no new tumor were found.
The prolapse has grown big: extended it is at least 10cm of bowel pushing itself outside of the abdomen causing many stoma leaks (5 full ones in 2 weeks time and 2 almost ones yesterday).
The good news is that it means there is hardly any intestinal adhesion.
The bad news: it takes 4-8 hours a day (of which 1-2 hours during the night) pushing the bowel back into the stoma so the output opening becomes unblocked and the poo can get out.
Though a temporary situation, this eats a lot of energy.
It means I need to find a way to keep my body in shape to prepare for surgery which is in 3-4 weeks (likely mid September).
The surgery will be tough as it will focus on 2 things:
  1. Removing areas of of the liver where the tumors are and were (which is about 30-50% of the liver).
  2. Likely remove the gallbladder, to minimise the chance of bile leakage (which is devastating when it gets into the abdomen)

    (Good news: no chance to get gallstones)

  3. repair the small intestine and remove the stoma.
It is going to be bloody surgery (because of the liver part) taking some 4 hours or more, likely ending up in the IC because the post-surgery risks.
This scares the hell out of me.
In addition recovery will take a long time, and even longer for liver tissue growing back (it will never reach 100%, but should be much more than 50% in a few years time).
I also need to re-learn how to poop, which likely means back to diaper age for quite a while.
So all of this means I feel very confused. Glad on the one side because I will loose the cancer and the stoma, but mixed about the risks and recovery.
More later.


Via [Wayback] Thread by @jpluimers on Thread Reader App: Too much to let sink in, not just about the hospital results and upcoming surgery, but also about Cindy and @danny_thorpe who just lost their house in the California forest fires…

Posted in About, Personal | 1 Comment »

The biggest lie I tell myself is not about new years resolutions.

Posted by jpluimers on 2019/01/01

The biggest lie I tell myself is “I don’t need to write that down, I’ll remember it”

It’s likely older, but the oldest reference I could find was 2012 [WayBack].

So before I forget:

Happy New Year everyone!

With the above quote, it is no coincidence I started my blog even earlier (in 2009): it’s my off-line memory, way better readable than my hand-writing and indexed by various search engines.

Read the rest of this entry »

Posted in About, LifeHacker, Personal, Power User | Leave a Comment »

How to calculate bitmap size? – Stack Overflow

Posted by jpluimers on 2021/05/13

A while ago I needed an estimate for [WayBack] How to calculate bitmap size? – Stack Overflow, which does an accurate calculation for the size of the pixel storage (i.e. without headers):

pixelStorageSize = (( width*bitsPerPixel + 31) / 32) * 4 * height


  • 4 is the number of bytes per quad-byte as bitmaps are stored with pixel lines aligned on quad-byte boundaries
  • 32 is the bits per quad-byte
  • 31 helps to round up to the quad-word boundary

It was derived from [WayBack] Capturing an Image – Windows applications | Microsoft Docs and shorthand for what is explained at [WayBack] BMP file format: Pixel storage – Wikipedia

The bits representing the bitmap pixels are packed in rows. The size of each row is rounded up to a multiple of 4 bytes (a 32-bit DWORD) by padding.

For images with height above 1, multiple padded rows are stored consecutively, forming a Pixel Array.

The total number of bytes necessary to store one row of pixels can be calculated as:

{\displaystyle {\text{RowSize}}=\left\lceil {\frac {{\text{BitsPerPixel}}\cdot {\text{ImageWidth}}}{32}}\right\rceil \cdot 4=\left\lfloor {\frac {{\text{BitsPerPixel}}\cdot {\text{ImageWidth}}+31}{32}}\right\rfloor \cdot 4,}
ImageWidth is expressed in pixels, note the special parentheses.

The total amount of bytes necessary to store an array of pixels in an n bits per pixel (bpp) image, with 2ncolors, can be calculated by accounting for the effect of rounding up the size of each row to a multiple of 4 bytes, as follows:

PixelArraySize = RowSize · |ImageHeight|
ImageHeight is expressed in pixels. The absolute value is necessary because ImageHeight can be negative.

I think I needed this to estimate how many bitmaps would fit in

[WayBack] Virtual address space – Wikipedia, which on 32-bit Windows by default is limited to 2 GiB, and can be extended to 3 GIB by enabling the IMAGE_FILE_LARGE_ADDRESS_AWARE executable header flag.

This flag imposes the risk of many libraries and DLLs to fail because they do not get the pointer math right. You often do not have control of future versions of DLLs being loaded in your process space and their risks, so do not ever use that flag.


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

Chocolatey: installing Oracle SQL Developer and updating the chocolatey package

Posted by jpluimers on 2021/05/13

Sometimes an install is not just as simple as C:\>choco install --yes oracle-sql-developer.

I started with the below failing command, tried a lot of things, then finally almost gave up: Oracle stuff does not want to be automated, which means I should try to less of their stuff.

First of all you need an Oracle account (I dislike companies doing that for free product installs; I’m looking at Embarcadero too) by going to

[WayBack] Chocolatey Gallery | Oracle SQL Developer 18.4.0 (also:


  • This version supports both 32bit and 64bit and subsequently does not have a JDK bundled with it. It has a
    dependency on the jdk8 package to meet the application’s JDK requirement.
  • An Oracle account is required to download this package. See the “Package Parameters” section below for
    details on how to provide your Oracle credentials to the installer. If you don’t have an existing account, you can
    create one for free here:

Package Parameters

The following package parameters are required:

/Username: – Oracle username
/Password: – Oracle password

(e.g. choco install oracle-sql-developer --params "'/Username:MyUsername /Password:MyPassword'")

To have choco remember parameters on upgrade, be sure to set choco feature enable -n=useRememberedArgumentsForUpgrades.

Then the installation failed fail again: ERROR: The response content cannot be parsed because the Internet Explorer engine is not available, or Internet Explorer's first-launch configuration is not complete. Specify the UseBasicParsing parameter and try again.


The reason is that the package uses Invoke-WebRequest which requires Internet Explorer and PowerShell 3. Chocolatey packages however need to be able to run on just PowerShell 2 without Invoke-WebRequest.

Maybe using cURL can remedy that; adding a dependency to is is possible, as cURL can be installed via chocolatey: [WayBack] How to Install cURL on Windows – I Don’t Know, Read The Manual. Another alternative might be [WayBack] Replace Invoke-RestMethod in PowerShell 2.0 to use [WayBack] WebRequest Class (System.Net) | Microsoft Docs.

Read the rest of this entry »

Posted in Chocolatey, CommandLine, Database Development, Development, DVCS - Distributed Version Control, git, OracleDB, Power User, PowerShell, Software Development, Source Code Management, Windows, XML, XML/XSD | Leave a Comment »

Notities over corona vaccinatie, gele vaccinatieboekje en vaccinatieboekje app

Posted by jpluimers on 2021/05/13

In het internationaal erkende gele vaccinatieboekje (ook wel vaccinatiepaspoort) kun je je corona vaccinatie laten bijschrijven. Dit kan ter plekke na de vaccinatie of op een later moment (maar op een later moment is het veel lastiger).

[Wayback] Je vaccinatie tegen corona mag in je vaccinatiepaspoort, maar je moet er wel zelf om vragen – EenVandaag

Het ministerie van Volksgezondheid Welzijn en Sport zegt in een reactie dat je als je wil, je een geel boekje kan gebruiken wanneer je wordt gevaccineerd. Maar dat het ze zelf geen boekjes aanbieden en dat er zéker geen verplichting is.

[Wayback] Gele vaccinatieboekje | Sdu

vaccinatieboekje: het internationale bewijs van inenting waar vaccinaties voor bijvoorbeeld gele koorts, dtp, hepatitis A en B in geregistreerd worden. Hier kan de coronavaccinatie (Covid-19) eenvoudig aan toegevoegd worden.

De [Wayback] Vaccinatieboekje app lijkt niet rechtsgeldig, maar wel handig voor reminders.

Registreer je (rijks) vaccinaties online en download de app: Vaccinatieboekje. Lees welke vaccinaties als je op reis gaat en leer meer over infectie-ziekten.





Posted in About, Health, LifeHacker, Personal, Power User, Vaccinations | Leave a Comment »

Het hopelijk tijdelijke afscheid door Haagse Insider🕵🏻‍♂️ (@HaagseInsider) | Twitter

Posted by jpluimers on 2021/05/13

Gisteren was er een (hopelijk tijdelijk) afscheid door [] Haagse Insider🕵🏻‍♂️ (@HaagseInsider) | Twitter.

De indrukwekkende draad is helaas niet beschikbaar op, maar wel beschikbaar op het web archief.

Sowieso wens ik meer rust en afstand voor HaagseInsider. Daarnaast duim ik dat het een weerzien wordt.


Posted in Power User, SocialMedia, Twitter | Leave a Comment »

Delphi: EInvalidOp exception, might just mean you have a use-after free scenario, or an out-of-bounds value

Posted by jpluimers on 2021/05/13

Quite some time ago, I was researching spurious exceptions in a Delphi application, then finally replicated them in a unit test suite.

One of them was occurring almost all of the time: EInvalidOp.

It is one of the floating point exceptions (incidentally exampled at [WayBack] Exceptions: Declaring Exception Types) all inheriting from the [WayBack] EMathError Class:

EMathError is the base class for floating-point math exception classes. EMathError itself is never raised.

The following exceptions descend from EMathError:

Parameter out of range
Processor encountered an undefined instruction
Floating-point operation produced result too large to store
Floating-point operation produced result with no precision
Attempt to divide by zero

Run-time exception information is saved in fields provided by [WayBack] EExternal.


In my first case (which I described in delphi – Invalid floating point operation calling Trunc()), not all input scenarios had been tested in a certain scenario. In a production environment, one of the inputs was really high.

In a later case, the actual cause was not a floating point problem at all, but a use-after-free scenario that overwrite a floating point value with something not so compatible also causing a simple Trunc statement to fail in the same way.

In that case, the production data could never reach the big numbers that failed, so no new tests were needed.


Posted in Conference Topics, Conferences, Delphi, Development, Event, Software Development | Leave a Comment »

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