wip(aggregator-discovery): add 'CapableAggregatorDiscoverer' decorator

Author: jpraynaud

Cargo.lock

@@ -20,6 +20,7 @@ rand = ["dep:rand"]
 anyhow = { workspace = true }
 async-trait = { workspace = true }
 mithril-common = { path = "../../mithril-common" }
+mithril-aggregator-client = { path = "../mithril-aggregator-client" }
 rand = { version = "0.9.2", optional = true}
 reqwest = { workspace = true, features = [
     "default",

internal/mithril-aggregator-discovery/Cargo.toml

@@ -0,0 +1,156 @@
+use std::sync::Arc;
+
+use mithril_common::{StdResult, messages::AggregatorCapabilities};
+
+use crate::{AggregatorDiscoverer, AggregatorEndpoint, MithrilNetwork};
+
+/// An aggregator discoverer for specific capabilities.
+pub struct CapableAggregatorDiscoverer {
+    capabilities: AggregatorCapabilities,
+    inner_discoverer: Arc<dyn AggregatorDiscoverer>,
+}
+
+impl CapableAggregatorDiscoverer {
+    /// Creates a new `CapableAggregatorDiscoverer` instance with the provided capabilities.
+    pub fn new(
+        capabilities: AggregatorCapabilities,
+        inner_discoverer: Arc<dyn AggregatorDiscoverer>,
+    ) -> Self {
+        Self {
+            capabilities,
+            inner_discoverer,
+        }
+    }
+
+    /// Check if the available capabilities match the required capabilities.
+    ///
+    /// Returns true if:
+    /// - The aggregate signature types are the same.
+    /// - All required signed entity types are included in the available signed entity types.
+    fn capabilities_match(
+        required: &AggregatorCapabilities,
+        available: &AggregatorCapabilities,
+    ) -> bool {
+        if available.aggregate_signature_type != required.aggregate_signature_type {
+            return false;
+        }
+
+        let available_signed_entity_types = &available.signed_entity_types;
+        let required_signed_entity_types = &required.signed_entity_types;
+
+        required_signed_entity_types
+            .iter()
+            .all(|req| available_signed_entity_types.contains(req))
+    }
+}
+
+/// An iterator over aggregator endpoints filtered by capabilities.
+struct CapableAggregatorDiscovererIterator {
+    capabilities: AggregatorCapabilities,
+    inner_iterator: Box<dyn Iterator<Item = AggregatorEndpoint>>,
+}
+
+impl Iterator for CapableAggregatorDiscovererIterator {
+    type Item = AggregatorEndpoint;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        for aggregator_endpoint in &mut self.inner_iterator {
+            let aggregator_capabilities = tokio::runtime::Handle::current()
+                .block_on(async { aggregator_endpoint.retrieve_capabilities().await });
+            if CapableAggregatorDiscoverer::capabilities_match(
+                &self.capabilities,
+                &aggregator_capabilities.ok()?,
+            ) {
+                return Some(aggregator_endpoint);
+            }
+        }
+
+        None
+    }
+}
+
+#[async_trait::async_trait]
+impl AggregatorDiscoverer for CapableAggregatorDiscoverer {
+    async fn get_available_aggregators(
+        &self,
+        network: MithrilNetwork,
+    ) -> StdResult<Box<dyn Iterator<Item = AggregatorEndpoint>>> {
+        let aggregator_endpoints = self.inner_discoverer.get_available_aggregators(network).await?;
+
+        Ok(Box::new(CapableAggregatorDiscovererIterator {
+            capabilities: self.capabilities.clone(),
+            inner_iterator: aggregator_endpoints,
+        }))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use std::collections::BTreeSet;
+
+    use mithril_common::{
+        AggregateSignatureType,
+        entities::SignedEntityTypeDiscriminants::{
+            CardanoDatabase, CardanoStakeDistribution, CardanoTransactions,
+        },
+    };
+
+    use super::*;
+
+    #[test]
+    fn capabilities_match_success() {
+        let required = AggregatorCapabilities {
+            aggregate_signature_type: AggregateSignatureType::Concatenation,
+            signed_entity_types: BTreeSet::from([CardanoTransactions, CardanoStakeDistribution]),
+            cardano_transactions_prover: None,
+        };
+
+        let available = AggregatorCapabilities {
+            aggregate_signature_type: AggregateSignatureType::Concatenation,
+            signed_entity_types: BTreeSet::from([
+                CardanoTransactions,
+                CardanoStakeDistribution,
+                CardanoDatabase,
+            ]),
+            cardano_transactions_prover: None,
+        };
+
+        assert!(CapableAggregatorDiscoverer::capabilities_match(
+            &required, &available
+        ));
+    }
+
+    #[test]
+    fn capabilities_match_failure() {
+        let required = AggregatorCapabilities {
+            aggregate_signature_type: AggregateSignatureType::Concatenation,
+            signed_entity_types: BTreeSet::from([CardanoTransactions, CardanoStakeDistribution]),
+            cardano_transactions_prover: None,
+        };
+
+        let available = AggregatorCapabilities {
+            aggregate_signature_type: AggregateSignatureType::Concatenation,
+            signed_entity_types: BTreeSet::from([CardanoTransactions]),
+            cardano_transactions_prover: None,
+        };
+
+        assert!(!CapableAggregatorDiscoverer::capabilities_match(
+            &required, &available
+        ));
+    }
+
+    #[tokio::test]
+    async fn get_available_aggregators_success() {
+        todo!()
+    }
+
+    #[tokio::test]
+    async fn get_available_aggregators_success_when_one_aggregator_capabilities_does_not_match() {
+        todo!()
+    }
+
+    #[tokio::test]
+    async fn get_available_aggregators_success_when_one_aggregator_retruns_an_error() {
+        todo!()
+    }
+}

internal/mithril-aggregator-discovery/src/capabilities_discoverer.rs

@@ -1,6 +1,7 @@
 #![warn(missing_docs)]
 //! This crate provides mechanisms to discover aggregators in a Mithril network.
 
+mod capabilities_discoverer;
 mod http_config_discoverer;
 mod interface;
 mod model;

internal/mithril-aggregator-discovery/src/lib.rs

@@ -1,4 +1,5 @@
-use mithril_common::StdResult;
+use mithril_aggregator_client::{AggregatorHttpClient, query::GetAggregatorFeaturesQuery};
+use mithril_common::{StdResult, messages::AggregatorCapabilities};
 
 /// Representation of a Mithril network
 // TODO: to move to mithril common
@@ -35,7 +36,12 @@ impl AggregatorEndpoint {
     }
 
     /// Retrieve the capabilities of the aggregator
-    pub fn capabilities(&self) -> StdResult<()> {
-        todo!("Implement capabilities retrieval")
+    pub async fn retrieve_capabilities(&self) -> StdResult<AggregatorCapabilities> {
+        let aggregator_client = AggregatorHttpClient::builder(self.url.clone()).build()?;
+
+        Ok(aggregator_client
+            .send(GetAggregatorFeaturesQuery::current())
+            .await?
+            .capabilities)
     }
 }