Crate pallet_sidechain_rpc 

Json RPC for the Sidechain pallet

Usage

Implementing runtime APIs

Your runtime should implement the GetGenesisUtxo and GetEpochDurationApi runtime APIs. For example, if your chain uses Aura for consensus, they may be implemented similar to this:

impl sp_sidechain::GetGenesisUtxo<Block> for Runtime {
  fn genesis_utxo() -> UtxoId {
    Sidechain::genesis_utxo()
  }
}

impl sp_sidechain::GetEpochDurationApi<Block> for Runtime {
	fn get_epoch_duration_millis() -> u64 {
		BLOCKS_PER_EPOCH * MILLISECS_PER_BLOCK
	}
}

Adding to the RPC stack

Once the runtime APIs are in place, the RPC can be added to the node:

fn create_rpc<B: BlockT, C: Send + Sync + 'static>(
   client: Arc<C>,
   time_source: Arc<dyn TimeSource + Send + Sync>,
   data_source: Arc<dyn SidechainRpcDataSource + Send + Sync>,
) -> Result<RpcModule<()>, Box<dyn std::error::Error + Send + Sync>>
where
    C: ProvideRuntimeApi<B> + GetBestHash<B> + CallApiAt<B>,
    C::Api: GetGenesisUtxo<B> + GetEpochDurationApi<B>
{

    let mut module = RpcModule::new(());
    module.merge(
        SidechainRpc::new(
            client.clone(),
            MainchainEpochConfig::read_from_env().unwrap(),
            data_source,
            time_source,
        )
        .into_rpc(),
    )?;

    // ... other RPCs
    Ok(module)
}

Note that your node should already have necessary time and data sources wired in. A Db-Sync-based data source is provided by the Partner Chain toolkit in the partner_chains_db_sync_data_sources crate.

Legacy compatibility mode

In previous versions of the Partner Chains toolkit, the RPC services in this crate relied on now deprecated runtime api sp_sidechain::SlotApi to compute Partner Chain epochs and current slot. For Partner Chains that started before this dependency was removed, a compatibility mode is provided behind the legacy-slotapi-compat feature flag. Enabling this flag will cause the nodes to use this runtime API when present and optionally include information about current Patner Chain slot in sidechain.slot field of sidechain_getStatus response.

Modules

types

Response types returned by RPC endpoints for Sidechain pallet

Structs

GetParamsOutput

Response type of the crate::SidechainRpcApiServer::get_params method

SidechainRpc

Json RPC service implementing SidechainRpcApiServer

Traits

SidechainRpcApiClient

Client implementation for the SidechainRpcApi RPC API.

SidechainRpcApiServer

Server trait implementation for the SidechainRpcApi RPC API.

SidechainRpcDataSource

Data source used by SidechainRpc for querying latest block