BFT-457: Generic read_map

node/libs/protobuf/src/proto_fmt.rs

@@ -285,6 +285,26 @@ pub fn read_optional<T: ProtoFmt>(field: &Option<T::Proto>) -> anyhow::Result<Op
     field.as_ref().map(ProtoFmt::read).transpose()
 }
 
+/// Parses a repeated proto struct into a map.
+pub fn read_map<T, K, V, F, G>(items: &[T], k: F, v: G) -> anyhow::Result<BTreeMap<K, V>>
+where
+    K: ProtoFmt + Ord,
+    V: ProtoFmt,
+    F: Fn(&T) -> &Option<K::Proto>,
+    G: Fn(&T) -> &Option<V::Proto>,
+{
+    let items: Vec<(K, V)> = items
+        .iter()
+        .map(|item| {
+            let k = read_required(k(item)).context("key")?;
+            let v = read_required(v(item)).context("value")?;
+            Ok((k, v))
+        })
+        .collect::<anyhow::Result<Vec<_>>>()?;
+
+    Ok(items.into_iter().collect())
+}
+
 /// Extracts a required field.
 pub fn required<T>(field: &Option<T>) -> anyhow::Result<&T> {
     field.as_ref().context("missing")

node/libs/roles/src/attester/conv.rs

@@ -6,7 +6,7 @@ use crate::proto::attester::{self as proto, Attestation};
 use anyhow::Context as _;
 use zksync_consensus_crypto::ByteFmt;
 use zksync_consensus_utils::enum_util::Variant;
-use zksync_protobuf::{read_required, required, ProtoFmt};
+use zksync_protobuf::{read_map, read_required, required, ProtoFmt};
 
 impl ProtoFmt for Batch {
     type Proto = proto::Batch;
@@ -132,21 +132,9 @@ impl ProtoFmt for BatchQC {
     type Proto = proto::BatchQc;
 
     fn read(r: &Self::Proto) -> anyhow::Result<Self> {
-        let signatures: Vec<(PublicKey, Signature)> = r
-            .signatures
-            .iter()
-            .map(|s| {
-                let key = read_required(&s.key).context("key")?;
-                let sig = read_required(&s.sig).context("sig")?;
-                Ok((key, sig))
-            })
-            .collect::<anyhow::Result<Vec<_>>>()?;
-
-        let signatures = signatures.into_iter().collect();
-
         Ok(Self {
             message: read_required(&r.msg).context("message")?,
-            signatures,
+            signatures: read_map(&r.signatures, |s| &s.key, |s| &s.sig).context("signatures")?,
         })
     }