Need example how to use max_files=n and max_fields=n

[Yrij-Zhavoronkov]

Hello everyone, I came across page, which states that, if necessary, you can increase the limit by affecting the max_files and max_fields parameters, but there is no example of how to do this.

For example, there is a method:

@app.post("/images")
async def upload_images(
    field_0: Annotated[str, Body(...)],
   ...
   field_k: Annotated[str, Body(...)],
   images: Annotated[List[UploadFile], File()]):

How can I influence the max_files and max_fields parameters here?

[jhominal]

The page that you link to describes arguments of starlette's Request.form method.

Unless I am mistaken, the sample code that you are giving here uses FastAPI's system for reading request data. You should ask the people there for how to work with potential limits of number of files/parameters in multipart forms, e.g. on the FastAPI GitHub discussions page.

[Yrij-Zhavoronkov]

They don't have that option yet. I'm wondering why this was done, and why not take out these parameters separately so that I can change them once and not have problems with the frameworks?
Example:

MAX_FILES = 1000
MAX_FIELDS = 1000

def form(
        self,
        *,
        max_files: int | float = MAX_FILES ,  # w/o conts 1000
        max_fields: int | float = MAX_FIELDS ,  #w/o const 1000
        max_part_size: int = 1024 * 1024,
    ) -> AwaitableOrContextManager[FormData]:
        return AwaitableOrContextManagerWrapper(
            self._get_form(max_files=max_files, max_fields=max_fields, max_part_size=max_part_size)
        )

[jhominal]

The main issue (that I see) with your suggestion is that it scales badly if two actors in the same process modify the same configuration value. It is safer and more scalable to ask the callers to provide, on a call-by-call basis, the value that they need.

[Yrij-Zhavoronkov]

The main issue (that I see) with your suggestion is that it scales badly if two actors in the same process modify the same configuration value. It is safer and more scalable to ask the callers to provide, on a call-by-call basis, the value that they need.

Yes, there is such a thing. But it's still better than it is now (at least for my case).
Ideally, of course, adding parameterization support using frameworks.