feat: add eth2wrap/valcache (#122)

* Initial `eth2wrap` module

* Add initial `version`

* Add tests

* Merge remote-tracking branch 'origin/main' into emlautarom1/eth2wrap

* Use `SemVer::parse` instead of `SemVer::try_from` for version parsing

* Replace function with static HashMap

- Avoids parsing on each request

* Fix clippy lint errors

* Add `RUSTC_BOOTSTRAP`

- Prevents VSCode from rebuilding everything during tests

* Prefer `&str` for `TryFrom`

- Makes it easier to use `String` and `str` at the same time

* Add `eth2api` and `anyhow` as deps

* Add `valcache` as module

* Add `eth2api` extensions module

- Redices boilerplate when dealing with the `eth2api` lib
- Use `eth2api` types in `valcache`

* Implement `get_by_head`

* Add `get_by_slot`

* Extract common mapping code

* Reduce the scope of locks

* Apply suggestions

- Remove redundant code
- Use `From` for `PoisonError`
- Code cleanup

* Update docs

* Use raw Validator type

- Prefer `GetStateValidatorsResponseResponseDatum` over custom `Validator`

* Apply clippy suggestions

* Update docs

- Make them closer to the original implementation

* Update lockfile

* Include `Serialize` for all types

- Useful for mocking requests/responses in tests

* Initial test for `valcache`

* Add test for failing request

- Use `POST` endpoint since reqwest cannot deal with complex query params
- Use `wiremock` to fake an HTTP server

* Test cache population

* Test for cache population

- Beacon should be called once

* Port `validator_cache` test

* Remove tests

- Superseded by Go tests

* Add `get_by_slot_successful_fetch`

* Refactor

- Extract common code
- Rename tests
- Inline methods

* Add `get_by_slot_fallback_to_head`

* Update lockfile

* Apply Slippy suggestions

* Apply Copilot suggestions

* Use tokio mutex

- Hold lock across awaits
- Match the original Go implementation
- Simplify internals

* Use `tokio::sync::RwLock` instead

* Merge remote-tracking branch 'origin/main' into emlautarom1/eth2wrap/valcache

Author: emlautarom1

Cargo.lock

@@ -14,7 +14,7 @@ members = [
     "crates/tracing",
     "crates/peerinfo",
     "crates/eth2api",
-    "crates/relay-server"
+    "crates/relay-server",
 ]
 resolver = "3"
 
@@ -72,6 +72,7 @@ oas3-gen-support = "0.24"
 bon = "3.8"
 testcontainers = "0.26"
 vise = "0.3"
+wiremock = "0.6"
 
 # Crates in the workspace
 charon = { path = "crates/charon" }

Cargo.toml

@@ -220,11 +220,11 @@ impl Serialize for PubKey {
     }
 }
 
-impl TryFrom<String> for PubKey {
+impl TryFrom<&str> for PubKey {
     type Error = PubKeyError;
 
-    fn try_from(value: String) -> Result<Self, Self::Error> {
-        let value = value.strip_prefix("0x").unwrap_or(&value);
+    fn try_from(value: &str) -> Result<Self, Self::Error> {
+        let value = value.strip_prefix("0x").unwrap_or(value);
         let hex_value = hex::decode(value).map_err(|_| PubKeyError::InvalidString)?;
         PubKey::try_from(hex_value.as_slice())
     }
@@ -890,7 +890,7 @@ mod tests {
     #[test]
     fn test_pub_key_from_string() {
         let pk_str = "0x7f790ba343adf8891fac21a94b02d6ca93d0bc2199a5ec083ff6676e8c2f9f78b08bb122f1093675f9d24c8b5e7af241".to_string();
-        let pk = PubKey::try_from(pk_str).unwrap();
+        let pk = PubKey::try_from(pk_str.as_str()).unwrap();
         assert_eq!(
             pk,
             PubKey::new([
@@ -904,7 +904,7 @@ mod tests {
     #[test]
     fn test_pub_key_from_string_invalid_length() {
         let pk_str = "0x7f790ba343adf8891fac21a94b02d6ca93d0bc2199a5ec083ff6676e8c2f9f78b08bb121093675f9d24c8b5e7af241".to_string();
-        let result = PubKey::try_from(pk_str);
+        let result = PubKey::try_from(pk_str.as_str());
         assert!(result.is_err());
     }
 }

crates/charon-core/src/types.rs

@@ -11,6 +11,8 @@ backon.workspace = true
 chrono.workspace = true
 charon-core.workspace = true
 charon-tracing.workspace = true
+eth2api.workspace = true
+anyhow.workspace = true
 tokio.workspace = true
 tokio-util.workspace = true
 prost.workspace = true
@@ -30,10 +32,12 @@ bon.workspace = true
 charon-cluster = { workspace = true }
 charon-k1util = { workspace = true }
 charon-crypto = { workspace = true }
-eth2api = { workspace = true }
 
 [build-dependencies]
 charon-build-proto.workspace = true
 
+[dev-dependencies]
+wiremock.workspace = true
+
 [lints]
 workspace = true

crates/charon/Cargo.toml

@@ -0,0 +1,38 @@
+use eth2api::ValidatorStatus;
+
+/// Error that can occur when using the [`eth2api::EthBeaconNodeApiClient`].
+#[derive(Debug, thiserror::Error)]
+pub enum EthBeaconNodeApiClientError {
+    /// Underlying error from [`eth2api::EthBeaconNodeApiClient`] when making a
+    /// request.
+    #[error("Request error: {0}")]
+    RequestError(#[from] anyhow::Error),
+
+    /// Unexpected response, e.g, got an error when an Ok response was expected
+    #[error("Unexpected response")]
+    UnexpectedResponse,
+
+    /// Unexpected type in response
+    #[error("Unexpected type in response")]
+    UnexpectedType,
+}
+
+/// Type alias for validator index.
+pub type ValidatorIndex = u64;
+
+/// Extension methods on [`ValidatorStatus`].
+pub trait ValidatorStatusExt {
+    /// Returns true if the validator is in one of the active states.
+    fn is_active(&self) -> bool;
+}
+
+impl ValidatorStatusExt for ValidatorStatus {
+    fn is_active(&self) -> bool {
+        matches!(
+            self,
+            ValidatorStatus::ActiveOngoing
+                | ValidatorStatus::ActiveExiting
+                | ValidatorStatus::ActiveSlashed
+        )
+    }
+}

crates/charon/src/eth2wrap/eth2api.rs

@@ -1,2 +1,11 @@
-/// Validate Beacon Node versions
+/// Validate Beacon node versions
 pub mod version;
+
+/// Cache of Validators retrieved from the Beacon node
+pub mod valcache;
+
+/// Extensions module to the Eth2Api crate
+///
+/// Includes additional data types and functions to reduce the boilerplate when
+/// interacting with `eth2api`.
+pub mod eth2api;