util.getCallSites(): rationale for 200-frame cap and possibility to make it configurable

[scull06]

Hi,

I’ve been evaluating util.getCallSites() for use in runtime analysis, and I noticed that the API enforces a limit of 200 frames. I could not find documentation explaining the rationale behind this cap.

The limit is enforced at the Node.js util layer, not by V8 itself.
V8’s stack trace facilities (e.g., Error.stackTraceLimit) do not seem to impose such a low fixed bound.

This raises a few questions:
What is the motivation for the 200-frame cap?
Is it purely a performance safeguard?
Are there known pathological cases that justify this specific bound?
Is the limit intended to be a permanent API constraint, or just a conservative initial choice?

[deokjinkim]

Thanks for raising this.
According to document, allowable range of frameCount is between 1 and 200.
https://nodejs.org/docs/latest/api/util.html#utilgetcallsitesframecount-options
So I think this is intended operation.

According to code, use kDefaultMaxCallStackSizeToCapture as reference.

node/lib/util.js

Lines 537 to 538 in 9c4ca0a

	// Using kDefaultMaxCallStackSizeToCapture as reference
	validateInteger(frameCount, 'frameCount', 1, 200);

node/deps/v8/src/inspector/v8-stack-trace-impl.h

Line 54 in 9c4ca0a

static constexpr int kDefaultMaxCallStackSizeToCapture = 200;

@RafaelGSS I think you're author of this code. Can I get your feedback if possible?
Refs: #54380

[RafaelGSS]

Yes, this is a default set by V8 as pointed by @deokjinkim. Through the inspector from V8 object you could do:

inspector->debugger()->setMaxCallStackSizeToCapture(this, 200000);

But this API is not available through util.getCallSites().