rpc/interface: impl thiserror::Error

Cargo.lock

@@ -800,6 +800,7 @@ name = "cuprate-rpc-interface"
 version = "0.0.0"
 dependencies = [
  "axum",
+ "cuprate-database",
  "cuprate-epee-encoding",
  "cuprate-helper",
  "cuprate-json-rpc",
@@ -809,6 +810,7 @@ dependencies = [
  "paste",
  "serde",
  "serde_json",
+ "thiserror",
  "tokio",
  "tower",
  "ureq",

rpc/interface/Cargo.toml

@@ -9,18 +9,20 @@ repository  = "https://github.com/Cuprate/cuprate/tree/main/rpc/cuprate-rpc-inte
 keywords    = ["cuprate", "rpc", "interface"]
 
 [features]
-default = ["dummy", "serde"]
-dummy   = []
+default  = ["dummy", "serde"]
+dummy    = []
 
 [dependencies]
 cuprate-epee-encoding = { path = "../../net/epee-encoding", default-features = false }
 cuprate-json-rpc      = { path = "../json-rpc", default-features = false }
 cuprate-rpc-types     = { path = "../types", features = ["serde", "epee"], default-features = false }
 cuprate-helper        = { path = "../../helper", features = ["asynch"], default-features = false }
+cuprate-database      = { path = "../../storage/database" }
 
 axum       = { version = "0.7.5", features = ["json"], default-features = false }
 serde      = { workspace = true, optional = true }
 tower      = { workspace = true }
+thiserror  = { workspace = true }
 paste      = { workspace = true }
 futures    = { workspace = true }
 

rpc/interface/README.md

@@ -33,7 +33,7 @@ This crate simply handles:
 - Defining handler function signatures
 - (De)serialization of requests/responses (JSON-RPC, binary, JSON)
 
-The actual server details are all handled by the [`axum`] and [`tower`] ecosystem.a
+The actual server details are all handled by the [`axum`] and [`tower`] ecosystem.
 
 The proper usage of this crate is to:
 1. Implement a [`RpcHandler`]
@@ -45,8 +45,8 @@ The proper usage of this crate is to:
 This is your [`tower::Service`] that converts `Request`s into `Response`s,
 i.e. the "inner handler".
 
-Said concretely, `RpcHandler` is 3 `tower::Service`s where the associated types are
-the 3 endpoint enums from [`cuprate_rpc_types`] and the error type from this crate:
+Said concretely, `RpcHandler` is 3 `tower::Service`s where the request/response types are
+the 3 endpoint enums from [`cuprate_rpc_types`] and the error type is from this crate:
 - [`JsonRpcRequest`](cuprate_rpc_types::json::JsonRpcRequest) & [`JsonRpcResponse`](cuprate_rpc_types::json::JsonRpcResponse)
 - [`BinRequest`](cuprate_rpc_types::bin::BinRequest) & [`BinResponse`](cuprate_rpc_types::bin::BinRequest)
 - [`OtherRequest`](cuprate_rpc_types::other::OtherRequest) & [`OtherResponse`](cuprate_rpc_types::other::OtherRequest)

rpc/interface/src/rpc_error.rs

@@ -2,8 +2,8 @@
 
 //---------------------------------------------------------------------------------------------------- Import
 use axum::http::StatusCode;
-#[cfg(feature = "serde")]
-use serde::{Deserialize, Serialize};
+
+use cuprate_database::RuntimeError;
 
 //---------------------------------------------------------------------------------------------------- RpcError
 /// Possible errors during RPC operation.
@@ -16,9 +16,16 @@ use serde::{Deserialize, Serialize};
 ///
 /// TODO: This is empty as possible errors will be
 /// enumerated when the handler functions are created.
-#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
-#[cfg_attr(feature = "serde", derive(Deserialize, Serialize))]
-pub enum RpcError {}
+#[derive(Debug, thiserror::Error)]
+pub enum RpcError {
+    /// A [`std::io::Error`] from the database.
+    #[error("database I/O error: {0}")]
+    DatabaseIo(#[from] std::io::Error),
+
+    /// A (non-I/O related) database error.
+    #[error("database error: {0}")]
+    DatabaseError(RuntimeError),
+}
 
 impl From<RpcError> for StatusCode {
     fn from(_: RpcError) -> Self {
@@ -27,6 +34,18 @@ impl From<RpcError> for StatusCode {
     }
 }
 
+impl From<RuntimeError> for RpcError {
+    fn from(error: RuntimeError) -> Self {
+        match error {
+            RuntimeError::Io(io) => Self::DatabaseIo(io),
+            RuntimeError::KeyExists
+            | RuntimeError::KeyNotFound
+            | RuntimeError::ResizeNeeded
+            | RuntimeError::TableNotFound => Self::DatabaseError(error),
+        }
+    }
+}
+
 //---------------------------------------------------------------------------------------------------- Tests
 #[cfg(test)]
 mod test {

rpc/interface/src/rpc_service.rs

@@ -32,7 +32,7 @@ pub trait RpcService<Request, Response>:
         Request,
         Response = Response,
         Error = RpcError,
-        Future: Future<Output = Result<Response, RpcError>> + Send + Sync + 'static,
+        Future: Future<Output = Result<Response, RpcError>> + Send + 'static,
     >
 {
 }
@@ -46,7 +46,7 @@ impl<Request, Response, T> RpcService<Request, Response> for T where
             Request,
             Response = Response,
             Error = RpcError,
-            Future: Future<Output = Result<Response, RpcError>> + Send + Sync + 'static,
+            Future: Future<Output = Result<Response, RpcError>> + Send + 'static,
         >
 {
 }