Summary

First of all, thank you very much for your work on avro-rs! The SchemaAwareDeserializer introduced in #512 is a great addition.

I would like to kindly ask about the status of the resolving counterpart to that deserializer. Today, SchemaAwareDeserializer decodes directly into T only when the reader schema matches the writer schema. As soon as a reader schema differs , the serde path deliberately bails out with a todo!/panic!, pointing at a not-yet-implemented SchemaAwareResolvingDeserializer.

I haven't found a tracking ticket for this.

Where this shows up in the code

The gap is marked with three matching TODOs on main(pinned to 660c655cac0cdf3bc5c6818bf6b5e445eb09bdce):

• GenericDatumReader::read_deser
  avro/src/reader/datum.rs#L149-L150

  // TODO: Implement SchemaAwareResolvingDeserializer
  panic!("Schema aware deserialisation does not resolve schemas yet");

• Reader (object-container path)
  avro/src/reader/mod.rs#L134-L137

  // TODO: Implement SchemaAwareResolvingDeserializer
  ...
  "Schema aware deserialisation does not resolve schemas yet"

• BlockReader
  avro/src/reader/block.rs#L233-L234

  // TODO: Implement SchemaAwareResolvingDeserializer
  panic!("Schema aware deserialisation does not resolve schemas yet");

The non-resolving deserializer itself lives in avro/src/serde/deser_schema/mod.rs and carries a single schema, doing no writer→reader resolution.

Why it matters

Currently, schema evolution is only available on the Value route: decode to Value against the writer schema, then Value::resolve* against the reader schema, then optionally from_value::<T>(). This allocates a full Value tree (and, without a cached ResolvedSchema, a fresh name map) per record — precisely the overhead the schema-aware deserializer was designed to avoid. A resolving deserializer would close that gap and, as noted in the #512 description, could eventually allow deprecating from_value / to_value entirely.

Request

Would you be willing to share the implementation state of a SchemaAwareResolvingDeserializer?

I completely understand this is volunteer-maintained work and that priorities and timelines shift; please take this only as gentle interest, not pressure!

Thanks,

@flxo