Add a top level function to parity-util-mem #298
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| trait Augmented : MallocSizeOf { } | ||
| impl Augmented for Vec<u8> { } | ||
| let val: Arc<dyn Augmented> = Arc::new(vec![0u8; 1024]); | ||
| assert!(malloc_size(&*val) > 1000); |
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Does it actually use Arc in calculation? Dereference implies that it doesn't?
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No, it does not, it uses those of the dereferenced trait.
This is for cases when you know that Arc is the primary reference
MallocSizeOf is not defined for Arc<T: ?Sized>
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Hmm, measuring MallocSizeOf for an Arc is tricky, but I wonder why a type is required to be Sized for Arc (in MallocUnconditionalShallowSizeOf), but not for Box.
Anyway, my point was that using Arc in tests causes a bit of confusion, we can use a trait object here directly, something like
let val = vec![0u8; 1024];
let val_ref: &dyn Augmented = &val as _;
assert!(malloc_size(val_ref) > 1000);There was a problem hiding this comment.
I am also wondering about those constraints.
About the test, I only wanted to show how to measure Arc in the test, also to ensure the exactly Arc<dyn Trait> can be measured -- it is a higher-level requirement, so hope we can have it as it is.
Co-Authored-By: cheme <emericchevalier.pro@gmail.com>
Co-Authored-By: cheme <emericchevalier.pro@gmail.com>
* master: (27 commits) update parity-util-mem (#309) Update features and feature dependencies (#307) Use proper memory queries to rocksdb (#308) Draft version updates and changelog (#299) Use custom error type for `from_hex` (#305) Fix typo. (#303) kvdb: remove KeyValueDBHandler (#304) extract common kvdb tests into a crate (#301) Expose to_hex and from_hex from impl-serde (#302) Add a top level function to parity-util-mem (#298) I/O statistic for key-value databases (#294) use for_tuples (#300) Add memory extensions for LRUCache, hashbrown (#293) Add memory stats for kvdb-s (#292) Provide #[derive(MallocSizeOf)] that is actually working (#291) Move and extend impls for locking primitives (#290) Update uint README (#288) Update README.md (#287) [ci]: remove feature flags in virtual workspace (#289) Prepare releases (#286) ...
Arc<dyn SomeTrait: MallocSizeOf>, if user needs to