Merge branch 'alic/refactor_proto_consensus' into 'master'

chore(consensus): Use ProxyDecodeError for deserialization (RandomBeacon)

We have a dedicated error type related to protobuf (de)serialization, called `ProxyDecodeError`. This is cleaner than using Strings. 

See merge request dfinity-lab/public/ic!11535

rs/replay/src/backup.rs

@@ -292,6 +292,8 @@ pub(crate) fn deserialize_consensus_artifacts(
             RandomBeacon::try_from(
                 pb::RandomBeacon::decode(buffer.as_slice()).expect("Protobuf decoding failed"),
             )
+            // TODO: Remove after switching to ProxyDecodeError
+            .map_err(|e| format!("{}", e))
             .unwrap_or_else(|err| panic!("{}", deserialization_error(&rb_path, err)))
             .into_message(),
         );
@@ -381,6 +383,7 @@ pub(crate) fn deserialize_consensus_artifacts(
     }
 }
 
+// TODO: Replace String with ProxyDecodeError once structures have been migrated
 fn deserialization_error(file: &Path, err: String) -> String {
     format!("Couldn't deserialize artifact {:?}: {}", file, err)
 }

rs/types/types/src/consensus.rs

@@ -8,8 +8,11 @@ use crate::{
     signature::*,
     *,
 };
-use ic_protobuf::log::block_log_entry::v1::BlockLogEntry;
 use ic_protobuf::types::v1 as pb;
+use ic_protobuf::{
+    log::block_log_entry::v1::BlockLogEntry,
+    proxy::{try_from_option_field, ProxyDecodeError},
+};
 use serde::{Deserialize, Serialize};
 use std::cmp::PartialOrd;
 use std::convert::TryInto;
@@ -562,23 +565,18 @@ impl From<&RandomBeacon> for pb::RandomBeacon {
 }
 
 impl TryFrom<pb::RandomBeacon> for RandomBeacon {
-    type Error = String;
+    type Error = ProxyDecodeError;
     fn try_from(beacon: pb::RandomBeacon) -> Result<Self, Self::Error> {
         Ok(Signed {
             content: RandomBeaconContent {
                 version: ReplicaVersion::try_from(beacon.version.as_str())
-                    .map_err(|e| format!("RandomBeacon replica version failed to parse {:?}", e))?,
+                    .map_err(|e| ProxyDecodeError::ReplicaVersionParseError(Box::new(e)))?,
                 height: Height::from(beacon.height),
                 parent: CryptoHashOf::from(CryptoHash(beacon.parent)),
             },
             signature: ThresholdSignature {
                 signature: CombinedThresholdSigOf::new(CombinedThresholdSig(beacon.signature)),
-                signer: NiDkgId::try_from(
-                    beacon
-                        .signer
-                        .ok_or_else(|| String::from("Error: RandomBeacon signer not present"))?,
-                )
-                .map_err(|e| format!("Unable to decode Random beacon signer {:?}", e))?,
+                signer: try_from_option_field(beacon.signer, "RandomBeacon::signer")?,
             },
         })
     }

rs/types/types/src/consensus/catchup.rs

@@ -99,7 +99,10 @@ impl TryFrom<pb::CatchUpContent> for CatchUpContent {
             content
                 .random_beacon
                 .ok_or_else(|| String::from("Error: CUP missing block"))?,
-        )?;
+        )
+        // TODO: Remove after switching to ProxyDecodeError
+        .map_err(|e| format!("{}", e))?;
+
         Ok(Self::new(
             HashedBlock {
                 hash: CryptoHashOf::from(CryptoHash(content.block_hash)),