fix: Avoid constructing events when telemetry is disabled#332
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The `enabled()` callback pattern now structurally prevents event construction when disabled, making the counter-based test redundant. Removes the static counter, the two helper functions, the four `#[cfg(test)] fetch_add` calls in make_* helpers, and the `hooks_skip_event_construction_when_disabled` test.
- Fix 3 broken rustdoc links: Self::enabled → Self::if_enabled, SharedState::enabled → SharedState::if_enabled - Use is_enabled() instead of if_enabled(|_buf|) in flush_once CPU profiling path, since the EventBuffer token is unused and this is a control-flow decision, not an event-recording path
jlizen
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May 1, 2026
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Change seems fine but some somewhat load-bearing bike shedding about naming since there is an overlap with #256 .
Also, was there any good way to test these events never land in the buffer? Not seeing anything obvious that wouldn't involve adding a lot more machinery, which I don't think is worth it, but just asking
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| /// Returns whether telemetry is enabled | ||
| pub fn enabled() -> bool { |
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yeah is_enabled is fine
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Ok, you should be good to rebase on top of main and unify with #256 shortly, ping when ready for a new review
Unify PR #332 (if_enabled callback pattern) with PR #256 (Option<HandleInner> structure): - TelemetryHandle methods delegate through inner.shared.if_enabled() to avoid event construction when disabled - Replace static TelemetryHandle::enabled() with TelemetryHandle::current().is_enabled() (equivalent after #256) - Keep all work inside with_encoder closures in tracing_layer (the core optimization from #332)
jlizen
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May 2, 2026
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To help ensure we don't regress on this, I extracted an
if_enabledwrapper that can be used as well