private RequestVoteReplyProto requestVote()

in ratis-server/src/main/java/org/apache/ratis/server/impl/RaftServerImpl.java [1470:1517]
44 lines of code
10 McCabe index (conditional complexity)

  private RequestVoteReplyProto requestVote(Phase phase,
      RaftPeerId candidateId, RaftGroupId candidateGroupId,
      long candidateTerm, TermIndex candidateLastEntry) throws IOException {
    CodeInjectionForTesting.execute(REQUEST_VOTE, getId(),
        candidateId, candidateTerm, candidateLastEntry);
    LOG.info("{}: receive requestVote({}, {}, {}, {}, {})",
        getMemberId(), phase, candidateId, candidateGroupId, candidateTerm, candidateLastEntry);
    assertLifeCycleState(LifeCycle.States.RUNNING);
    assertGroup(getMemberId(), candidateId, candidateGroupId);

    boolean shouldShutdown = false;
    final RequestVoteReplyProto reply;
    CompletableFuture<Void> future = null;
    synchronized (this) {
      // Check life cycle state again to avoid the PAUSING/PAUSED state.
      assertLifeCycleState(LifeCycle.States.RUNNING);

      final VoteContext context = new VoteContext(this, phase, candidateId);
      final RaftPeer candidate = context.recognizeCandidate(candidateTerm);
      final boolean voteGranted = context.decideVote(candidate, candidateLastEntry);
      if (candidate != null && phase == Phase.ELECTION) {
        // change server state in the ELECTION phase
        final AtomicBoolean termUpdated = new AtomicBoolean();
        future = changeToFollower(candidateTerm, true, false, "candidate:" + candidateId, termUpdated);
        if (voteGranted) {
          state.grantVote(candidate.getId());
        }
        if (termUpdated.get() || voteGranted) {
          state.persistMetadata(); // sync metafile
        }
      }
      if (voteGranted) {
        role.getFollowerState().ifPresent(fs -> fs.updateLastRpcTime(FollowerState.UpdateType.REQUEST_VOTE));
      } else if(shouldSendShutdown(candidateId, candidateLastEntry)) {
        shouldShutdown = true;
      }
      reply = toRequestVoteReplyProto(candidateId, getMemberId(),
          voteGranted, state.getCurrentTerm(), shouldShutdown);
      if (LOG.isInfoEnabled()) {
        LOG.info("{} replies to {} vote request: {}. Peer's state: {}",
            getMemberId(), phase, toRequestVoteReplyString(reply), state);
      }
    }
    if (future != null) {
      future.join();
    }
    return reply;
  }