Make randomized string equality comparers implement IAlternateEqualityComparer #104252
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
eiriktsarpalis
approved these changes
Jul 1, 2024
stephentoub
force-pushed
the
fixrandomcomparers
branch
from
1d9d5d9
to
20d0208
Compare
This was referenced Jul 2, 2024
Open
Sign up for free
to subscribe to this conversation on GitHub.
Already have an account?
Sign in.
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Outdated suggestions cannot be applied.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.
When
Dictionary<string,TValue>andHashSet<string>upgrade from a non-randomized comparer to a randomized comparer, they don't just switch to usingStringComparer.Xx... for an extra layer of protection, they create a dedicated comparer with its own random seed rather than sharing the global one. This is accomplished with a couple of dedicated comparer types. When I added IAlternateEqualityComparer implementations to all the things, I missed these two cases. That means when if a dictionary/hashset experienced enough collisions to upgrade, it could lose its ability to perform alternate key lookups. This PR just fixes those two stragglers.(This will not pass CI until #104202 is merged, as the tests here expect that the default comparer supports alternates.)