public void run()

in ratis-server/src/main/java/org/apache/ratis/server/leader/LogAppenderDefault.java [141:179]
37 lines of code
13 McCabe index (conditional complexity)

  public void run() throws InterruptedException, IOException {
    while (isRunning()) {
      if (shouldSendAppendEntries()) {
        SnapshotInfo snapshot = shouldInstallSnapshot();
        if (snapshot != null) {
          LOG.info("{}: followerNextIndex = {} but logStartIndex = {}, send snapshot {} to follower",
              this, getFollower().getNextIndex(), getRaftLog().getStartIndex(), snapshot);

          final InstallSnapshotReplyProto r = installSnapshot(snapshot);
          if (r != null) {
            switch (r.getResult()) {
              case NOT_LEADER:
                onFollowerTerm(r.getTerm());
                break;
              case SUCCESS:
              case SNAPSHOT_UNAVAILABLE:
              case ALREADY_INSTALLED:
              case SNAPSHOT_EXPIRED:
                getFollower().setAttemptedToInstallSnapshot();
                break;
              default:
                break;
            }
          }
          // otherwise if r is null, retry the snapshot installation
        } else {
          final AtomicLong requestFirstIndex = new AtomicLong(RaftLog.INVALID_LOG_INDEX);
          final AppendEntriesReplyProto r = sendAppendEntriesWithRetries(requestFirstIndex);
          if (r != null) {
            handleReply(r, requestFirstIndex.get());
          }
        }
      }
      if (isRunning() && !hasAppendEntries()) {
        getEventAwaitForSignal().await(getHeartbeatWaitTimeMs(), TimeUnit.MILLISECONDS);
      }
      getLeaderState().checkHealth(getFollower());
    }
  }