733 catch up response receiving (#745)

# Description

- Implemented handling of catch-up responses
- Made changes to the previous logic for collecting preVotes and
preCommits on initiating catch-up response
- Placed "Todo" comments in handling catch-up response, describing what
should be added as logic, to help those who implement play-grandpa-round
and finalizing preVote stage.

Fixes #733 >

---------

Co-authored-by: Hristiyan Mitov <[email protected]>

src/main/java/com/limechain/grandpa/GrandpaService.java

@@ -108,7 +108,7 @@ private boolean isFinalizable(GrandpaRound grandpaRound) {
      *
      * @return if the current round is completable
      */
-    private boolean isCompletable(GrandpaRound grandpaRound) {
+    public boolean isCompletable(GrandpaRound grandpaRound) {
 
         Map<Vote, Long> votes = getDirectVotes(grandpaRound, SubRound.PRE_COMMIT);
         long votesCount = votes.values().stream()
@@ -157,7 +157,7 @@ private boolean isCompletable(GrandpaRound grandpaRound) {
      *
      * @return the best final candidate block
      */
-    private BlockHeader findBestFinalCandidate(GrandpaRound grandpaRound) {
+    public BlockHeader findBestFinalCandidate(GrandpaRound grandpaRound) {
         GrandpaSetState grandpaSetState = stateManager.getGrandpaSetState();
         BlockState blockState = stateManager.getBlockState();
 

src/main/java/com/limechain/grandpa/round/GrandpaRound.java

@@ -16,7 +16,6 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
-import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ScheduledExecutorService;
 
@@ -77,8 +76,8 @@ public class GrandpaRound implements Serializable {
     private Map<Hash256, SignedVote> preCommits = new ConcurrentHashMap<>();
     private SignedVote primaryVote;
 
-    private final Map<Hash256, Set<SignedVote>> pvEquivocations = new ConcurrentHashMap<>();
-    private final Map<Hash256, Set<SignedVote>> pcEquivocations = new ConcurrentHashMap<>();
+    private Map<Hash256, List<SignedVote>> pvEquivocations = new ConcurrentHashMap<>();
+    private Map<Hash256, List<SignedVote>> pcEquivocations = new ConcurrentHashMap<>();
 
     private final transient List<CommitMessage> commitMessagesArchive = new ArrayList<>();
 
@@ -109,13 +108,13 @@ public Vote getPreCommitChoice() {
 
     public long getPvEquivocationsCount() {
         return this.pvEquivocations.values().stream()
-                .mapToLong(Set::size)
+                .mapToLong(List::size)
                 .sum();
     }
 
     public long getPcEquivocationsCount() {
         return this.pcEquivocations.values().stream()
-                .mapToInt(Set::size)
+                .mapToInt(List::size)
                 .sum();
     }
 

src/main/java/com/limechain/network/protocol/grandpa/GrandpaEngine.java

@@ -175,8 +175,11 @@ private void handleCatchupRequestMessage(byte[] message, PeerId peerId) {
     private void handleCatchupResponseMessage(byte[] message, PeerId peerId) {
         ScaleCodecReader reader = new ScaleCodecReader(message);
         CatchUpResMessage catchUpResMessage = reader.read(CatchUpResMessageScaleReader.getInstance());
-        //todo: handle catchup res message (authoring node responsibility)
         log.log(Level.INFO, "Received catch up response message from Peer " + peerId + "\n" + catchUpResMessage);
+
+        if (AbstractState.isActiveAuthority() && connectionManager.checkIfPeerIsAuthorNode(peerId)) {
+            grandpaMessageHandler.handleCatchUpResponse(peerId, catchUpResMessage, connectionManager::getPeerIds);
+        }
     }
 
     /**