[AVRO-3939] [Rust] Make it possible to use custom schema comparators

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.12.0, 1.11.4
• Component/s: rust
• Labels: pull-request-available
• Assignee: Martin Tzvetanov Grigorov
• Reporter: Martin Tzvetanov Grigorov
• Created: 15/Feb/24 13:20
• Updated: 01/Mar/24 12:24
• Resolved: 20/Feb/24 09:18

Description

Currently comparing two schemas for equality compares their canonical forms - https://github.com/apache/avro/blob/main/lang/rust/avro/src/schema.rs#L160.
I.e. the schemas are first serialized to their canonical forms and then compared as strings.

The main issue here is the performance! The serialization takes it time!
Comparing the schemas field by field (following the same rules as the canonical forms - https://avro.apache.org/docs/1.11.1/specification/#parsing-canonical-form-for-schemas) will return as soon as a field is different. For example: record schema with a different name will return false without comparing all the fields.

Another request by users is to compare the schemas even with fields which are not part of the canonical form, e.g. the custom attributes - https://github.com/apache/avro/pull/2708#discussion_r1467183416

Issue Links

• links to: GitHub Pull Request #2739