feat: implement GetCBOR local state query (#413)

examples/n2c-miniprotocols/src/main.rs

@@ -68,6 +68,13 @@ async fn do_localstate_query(client: &mut NodeClient) {
     let result = queries_v16::get_genesis_config(client, era).await.unwrap();
     println!("result: {:?}", result);
 
+    // Ensure decoding across version disparities by always receiving a valid
+    // response using the wrap function for the query result with CBOR-in-CBOR
+    // concept.
+    let query = queries_v16::BlockQuery::GetCurrentPParams;
+    let result = queries_v16::get_cbor(client, era, query).await.unwrap();
+    println!("result: {:?}", result);
+
     client.send_release().await.unwrap();
 }
 

pallas-network/src/miniprotocols/localstate/queries_v16/codec.rs

@@ -138,7 +138,7 @@ impl<'b> Decode<'b, ()> for BlockQuery {
             6 => Ok(Self::GetUTxOByAddress(d.decode()?)),
             // 7 => Ok(Self::GetUTxOWhole),
             // 8 => Ok(Self::DebugEpochState),
-            // 9 => Ok(Self::GetCBOR(())),
+            9 => Ok(Self::GetCBOR(d.decode()?)),
             // 10 => Ok(Self::GetFilteredDelegationsAndRewardAccounts(())),
             11 => Ok(Self::GetGenesisConfig),
             // 12 => Ok(Self::DebugNewEpochState),

pallas-network/src/miniprotocols/localstate/queries_v16/mod.rs

@@ -31,7 +31,7 @@ pub enum BlockQuery {
     GetUTxOByAddress(Addrs),
     GetUTxOWhole,
     DebugEpochState,
-    GetCBOR(AnyCbor),
+    GetCBOR(Box<BlockQuery>),
     GetFilteredDelegationsAndRewardAccounts(AnyCbor),
     GetGenesisConfig,
     DebugNewEpochState,
@@ -435,6 +435,19 @@ pub async fn get_stake_snapshots(
     Ok(result)
 }
 
+pub async fn get_cbor(
+    client: &mut Client,
+    era: u16,
+    query: BlockQuery,
+) -> Result<Vec<TagWrap<Bytes, 24>>, ClientError> {
+    let query = BlockQuery::GetCBOR(Box::new(query));
+    let query = LedgerQuery::BlockQuery(era, query);
+    let query = Request::LedgerQuery(query);
+    let result = client.query(query).await?;
+
+    Ok(result)
+}
+
 /// Get the genesis configuration for the given era.
 pub async fn get_genesis_config(
     client: &mut Client,