Missing context memory proc setter

[gilbdev]

Is your feature request related to a problem? Please describe.

i'm trying to integrate eccodes C libraries into a Qt App.
libraries where retrieves via conda v2.44

it seems that eccodes does not expose a way to modify the malloc,free,realloc in the codes_context, which would be useful in my case.

grib_api has the exposed functionality :
grib_context_set_memory_proc

Describe the solution you'd like

it would be great to have this functionality exposed to be able to control the codes_context via a :
codes_context_set_memory_proc

Describe alternatives you've considered

No response

Additional context

No response

Organisation

No response

[gilbdev]

alternative :
use codes_handle_new_from_message instead of codes_grib_handle_new_from_file so eccodes does not handle memory

[joobog]

We are in the process of moving ecCodes from C to C++, which also changes how the memory management works. Therefore, it's no longer practical to use these functions or expose this feature in the API. Could you explain what you are doing in more detail? Maybe we can find another solution.

[gilbdev]

i'm downloading grib files from a Qt App, then processing them to store the data i need in a database.
it's all executing from the Qt app context, which apparently eccodes libs don't like.

but the workaround with codes_handle_new_from_message is working fine for me now. i'll keep an eye when C++ is available, that may simplify some of the code later on.

[joobog]

We're not switching to C++ overnight, but rather doing it step by step. It's a continuous process that has already started. We want to maintain backwards compatibility so the API doesn't change for users. Everything happens internally.

I'm glad that you found a workaround, but what do you mean by "Qt app context, which apparently eccodes libs don't like"? Could you show us how to reproduce the issue? Then there is a good chance that we can fix it in the future.

[gilbdev]

test_eccodes_qt.zip

here is a minimal qt project
required qt6 and eccodes installed via miniconda (adapt path in the .pro files if needed), note that i'm on windows too :)

here is the output

Initializing Qt application...
Qt application initialized successfully.
Testing eccodes library in Qt application with dedicated context...
Attempting to process file: temp_grib_1761060752308.grib
Creating thread for GRIB processing...
Opening file: temp_grib_1761060752308.grib
File opened successfully.
Set print procedure
Calling grib_handle_new_from_file with context...
Signal received: 11
Segmentation fault or other signal caught!
Signal code: 11

testing with a standard cpp app without qt works fine

[joobog]

I compiled and run your example on Linux, but couldn't reproduce the problem. It works fine for me (see the output below). Unfortunately, we don't have a Windows machine to test or debug it on. I can't promise we'll fix this, as our Windows support is very limited. We need to see how we deal with this.

Initializing Qt application...
Qt application initialized successfully.
Testing eccodes library in Qt application with dedicated context...
Attempting to process file: temp_grib_1761060752308.grib
Creating thread for GRIB processing...
Opening file: temp_grib_1761060752308.grib
File opened successfully.
Set print procedure
Calling grib_handle_new_from_file with context...
grib_handle_new_from_file returned. Handle: 0x55ca4c640220 Error code: 0
Successfully created GRIB handle!
Parameter short name: 10u
Handle deleted successfully.
File closed.
Qt test completed.