FormatUtf8: Is there an internal limit on the number of arguments?

Kabiri · Yesterday 06:48:26

Does mORMot 2 have an internal limit on the number of arguments that can be passed to `FormatUtf8`?

When I pass more than 31 arguments, I get the following exception:

`ESynException: TFormatUtf8: too many arguments`

Is there a built-in limit, or am I doing something wrong?

ab · Yesterday 16:48:09

There is a limit indeed.

It is hardcoded.

Kabiri · Yesterday 17:33:20

Was there a specific reason for that? Does it cause any additional issues?

ab · Yesterday 20:09:42

Some temporary allocation is done on the stack, and 31 parameters take 3KB.

ab · Yesterday 20:11:58

Do you really pass more than 31 arguments to FormatUtf8?
How could it stay on the same line of code?

Use a TTextWriter or a TSynTempAdder then.

Kabiri · Today 06:21:20

Yes, I really did. I needed to pass 37 arguments to FormatUtf8.
For now, I split it into two calls and concatenate the results:

FormatUtf8(...) + FormatUtf8(...)

Thanks for the suggestion! I'll also take a look at TTextWriter and TSynTempAdder.

Last edited by Kabiri (Today 06:22:15)

ab · Today 12:30:37

I have enhanced to up to 40 arguments - and may be more for %%% patterns.
https://github.com/synopse/mORMot2/commit/149397043

Kabiri · Today 13:22:40

Thanks

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