implement a reader and writer interface

apps/fortuna/src/chain/chain.rs

@@ -0,0 +1,47 @@
+use {
+ anyhow::{
+ Error,
+ Result,
+ },
+ axum::async_trait,
+};
+
+pub type ChainBlockNumber = u64;
+
+#[derive(Clone, Debug)]
+pub struct RequestWithCallbackData {
+ pub sequence_number: u64,
+ /// The random number submitted by the user while requesting a callback.
+ pub user_random_number: [u8; 32],
+}
+
+#[async_trait]
+pub trait ChainReader: Send + Sync {
+ /// Returns data of all the requests with callback made on chain between
+ /// the given block numbers.
+ async fn get_requests_with_callback_data(
+ &self,
+ from_block: ChainBlockNumber,
+ to_block: ChainBlockNumber,
+ ) -> Result<Vec<RequestWithCallbackData>>;
+
+ /// Returns the latest block which we consider to be included into the chain and
+ /// is safe from reorgs.
+ async fn get_latest_safe_block(&self) -> Result<ChainBlockNumber>;
+}
+
+pub enum RevealError {
+ HashChainRevealFailed(Error),
+ ContractError(Error),
+ RpcError(Error),
+}
+
+#[async_trait]
+pub trait ChainWriter: Send + Sync + ChainReader {
+ /// Fulfill the given request on chain with the given provider revelation.
+ async fn reveal_with_callback(
+ &self,
+ request_with_callback_data: RequestWithCallbackData,
+ provider_revelation: [u8; 32],
+ ) -> Result<(), RevealError>;
+}