builds deduper hashers once per reset cycle #4177
Open
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Problem
Deduper does
RandomState::build_hasher
on every item:https://github.com/anza-xyz/agave/blob/22c89518c/perf/src/deduper.rs#L70
Summary of Changes
The commit avoids
RandomState::build_hasher
on each item and instead just clones initialized hahsers which are pretty cheap to clone: https://github.com/tkaitchuck/aHash/blob/7d5c661a7/src/aes_hash.rs#L18-L23