paulormart
commented
2 months ago Ok, as mentioned here https://github.com/paritytech/subxt/issues/1453#issuecomment-2011922808 using the unstable backend and also using the latest smoldot v0.18.0 updated in #1722 fixes the issue with duplicate storage entries, but doesn't work with the current smoldot v0.16.0 available in subxt v0.37. In this case, the following error is raised Error driving unstable backend: Rpc error: RPC error: RPC Error: {"code":-32601,"message":"The method does not exist / is not available."}.
Example tested:
#![allow(missing_docs)]
use std::collections::BTreeMap;
use futures::StreamExt;
use subxt::{
backend::unstable::UnstableBackend, client::OnlineClient, lightclient::LightClient,
PolkadotConfig,
};
// Generate an interface that we can use from the node's metadata.
#[subxt::subxt(runtime_metadata_path = "../artifacts/polkadot_metadata_full.scale")]
pub mod polkadot {}
const POLKADOT_SPEC: &str = include_str!("../../artifacts/demo_chain_specs/polkadot.json");
#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
// The lightclient logs are informative:
tracing_subscriber::fmt::init();
let (_, polkadot_rpc) = LightClient::relay_chain(POLKADOT_SPEC)?;
let (unstable_backend, mut driver) = UnstableBackend::builder().build(polkadot_rpc);
tokio::spawn(async move {
while let Some(val) = driver.next().await {
if let Err(e) = val {
// Something went wrong driving unstable backend.
eprintln!("Error driving unstable backend: {e}");
break;
}
}
});
// Create Subxt clients from this unstable backend (ie using new RPCs).
let api = OnlineClient::<PolkadotConfig>::from_backend(unstable_backend.into()).await?;
// Create Subxt clients from these Smoldot backed RPC clients.
// let api = OnlineClient::<PolkadotConfig>::from_rpc_client(polkadot_rpc).await?;
let address = polkadot::storage().bounties().bounties_iter();
let mut iter = api.storage().at_latest().await?.iter(address).await?;
let mut data = BTreeMap::new();
while let Some(Ok(storage)) = iter.next().await {
let id = get_bounty_id_from_storage_key(storage.key_bytes);
data.entry(id).and_modify(|n| *n += 1).or_insert(1);
assert_eq!(data.len() as u32, data.iter().map(|(_, v)| v).sum::<u32>());
}
println!("{:?}", data);
Ok(())
}
pub fn get_bounty_id_from_storage_key(key: Vec<u8>) -> u32 {
let s = &key[key.len() - 4..];
let v: [u8; 4] = s.try_into().expect("slice with incorrect length");
u32::from_le_bytes(v)
}
niklasad1
jsdw
Hi there,
This issue is a follow up of #1722
Fetching storage items through an iterator returns duplicates when using lightclient, hanging the loop forever with the current version of subxt. The behaviour is improved using the latest smoldot dependencies but there are still duplicates.
This isue can be confirmed when running the example below: