[BEAM-13736] [Go SDK] Fix hash collision risk in Combiner Lifting cache

• Type: Improvement
• Status: Resolved
• Priority: P2
• Resolution: Fixed
• Component/s: sdk-go
• Assignee: Robert Burke
• Reporter: Robert Burke
• Created: 25/Jan/22 04:53
• Updated: 25/Jan/22 17:15
• Resolved: 25/Jan/22 16:55

Description

Relying only on a hash is brittle for map implementations, and can lead to correctness issues when keys collide.

While the Go SDK implementation is leaning on the Go map, we need to rely on byte equality so we need to fend for ourselves a bit, and handle overflow buckets and the like.

We won't go so far as to do a rehash or similar balancing techniques as it's not clear that between the caches' size constraint, and the evenness of the hash function that they are all that likely.

Issue Links

• links to: GitHub Pull Request #16603