feat: Add dynamic max_bytes/max_chars definition

[loewenheim]

This does for the max_bytes and max_char annotations what #5107 did for PII. In particular, this means that in future we can define the maximum sizes for attributes in sentry-conventions.

Fixes #5499. Fixes RELAY-190.

[linear]

RELAY-190 Implement dynamic computation of maximum data sizes

[cursor]

Bug: Dynamic max_bytes cannot reset size limits

before_process now decides whether to push a new SizeState via state.max_bytes().is_some(). With dynamic max_bytes, a present annotation can legitimately evaluate to None (meaning “no limit”), but this condition won’t push a state, so parent size limits keep applying and the subtree can’t reset/unlimit max_bytes.

relay-event-normalization/src/trimming.rs#L65-L75

relay/relay-event-normalization/src/trimming.rs

Lines 65 to 75 in 8f5b674

	) -> ProcessingResult {
	// If we encounter a max_bytes or max_depth attribute it
	// resets the size and depth that is permitted below it.
	// XXX(iker): test setting only one of the two attributes.
	if state.max_bytes().is_some() || state.attrs().max_depth.is_some() {
	self.size_state.push(SizeState {
	size_remaining: state.max_bytes(),
	encountered_at_depth: state.depth(),
	max_depth: state.attrs().max_depth,
	});
	}

 

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[cursor]

Bug: Dynamic max_bytes may not reset limits

before_process now decides to push a new SizeState using state.max_bytes().is_some(). For dynamic max_bytes, the function can return None to mean “no limit”, but this still needs to reset any inherited size limit. With the current check, inherited limits keep applying, causing unexpected trimming under fields that explicitly set dynamic max_bytes to None.

relay-event-normalization/src/trimming.rs#L65-L75

relay/relay-event-normalization/src/trimming.rs

Lines 65 to 75 in b0883e7

	) -> ProcessingResult {
	// If we encounter a max_bytes or max_depth attribute it
	// resets the size and depth that is permitted below it.
	// XXX(iker): test setting only one of the two attributes.
	if state.max_bytes().is_some() || state.attrs().max_depth.is_some() {
	self.size_state.push(SizeState {
	size_remaining: state.max_bytes(),
	encountered_at_depth: state.depth(),
	max_depth: state.attrs().max_depth,
	});
	}

 

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[jjbayer]

Is this just an improvement over the ad-hoc function, or did you need it for something?

[loewenheim]

It's more a stylistic thing; I saw there's a trait in syn for exactly this use case and decided to implement it.