feat(utxo-rpc): Add support for BlockFetch by Slot or Height and DumpHistory to support BlockHeight

[Mercurial]

Work In Progress to support block fetch not only by hash but also by Slot or Height.

As of right now only fetching by block hash is supported.

async fn fetch_block(
        &self,
        request: Request<FetchBlockRequest>,
    ) -> Result<Response<FetchBlockResponse>, Status> {
        let message = request.into_inner();

        let blocks: Result<Vec<_>, _> = message
            .r#ref
            .iter()
            .map(|r| bytes_to_hash(&r.hash))
            .map(|hash| self.chain.get_block(hash))
            .collect();

        let out: Vec<_> = blocks
            .map_err(|_err| Status::internal("can't query block"))?
            .iter()
            .flatten()
            .map(|b| raw_to_anychain(b))
            .collect();

        let response = FetchBlockResponse { block: out };

        Ok(Response::new(response))
    }

Aswell as next_token in the DumpHistoryResponse needs to support Block->Height according to the BlockRef structure in the U5C specification.

I'm thinking this would need some kind of new KeyValueStore within pallas-rolldb similiar to

// slot => block hash
pub struct HashBySlotKV;

impl KVTable<DBInt, DBHash> for HashBySlotKV {
    const CF_NAME: &'static str = "HashBySlotKV";
}

it could be something like

// height => block hash
pub struct HashBySlotKV;

impl KVTable<DBInt, DBHash> for HashByHeightKV {
    const CF_NAME: &'static str = "HashByHeightKV";
}

but I think the main hurdle is that the block height / number doesn't seem to be a first-class-citizen field within the pipeline.

Looking for feedback / suggestions

[Mercurial]

nvm as per discussion with Santi BlockRef for UTxORPC should only have hash and index to be utxo chain agnostic. So this feature is not needed