override def toBinary()

in cluster-sharding/src/main/scala/org/apache/pekko/cluster/sharding/protobuf/ClusterShardingMessageSerializer.scala [272:324]
46 lines of code
43 McCabe index (conditional complexity)

  override def toBinary(obj: AnyRef): Array[Byte] = obj match {
    case m: State                        => compress(coordinatorStateToProto(m))
    case ShardRegionRegistered(ref)      => actorRefMessageToProto(ref).toByteArray
    case ShardRegionProxyRegistered(ref) => actorRefMessageToProto(ref).toByteArray
    case ShardRegionTerminated(ref)      => actorRefMessageToProto(ref).toByteArray
    case ShardRegionProxyTerminated(ref) => actorRefMessageToProto(ref).toByteArray
    case m: ShardHomeAllocated           => shardHomeAllocatedToProto(m).toByteArray
    case ShardHomeDeallocated(shardId)   => shardIdMessageToProto(shardId).toByteArray

    case Register(ref)            => actorRefMessageToProto(ref).toByteArray
    case RegisterProxy(ref)       => actorRefMessageToProto(ref).toByteArray
    case RegisterAck(ref)         => actorRefMessageToProto(ref).toByteArray
    case GetShardHome(shardId)    => shardIdMessageToProto(shardId).toByteArray
    case m: ShardHome             => shardHomeToProto(m).toByteArray
    case sh: ShardHomes           => shardHomesToProto(sh).toByteArray
    case HostShard(shardId)       => shardIdMessageToProto(shardId).toByteArray
    case ShardStarted(shardId)    => shardIdMessageToProto(shardId).toByteArray
    case BeginHandOff(shardId)    => shardIdMessageToProto(shardId).toByteArray
    case BeginHandOffAck(shardId) => shardIdMessageToProto(shardId).toByteArray
    case HandOff(shardId)         => shardIdMessageToProto(shardId).toByteArray
    case ShardStopped(shardId)    => shardIdMessageToProto(shardId).toByteArray
    case GracefulShutdownReq(ref) =>
      actorRefMessageToProto(ref).toByteArray
    case RegionStopped(ref) => actorRefMessageToProto(ref).toByteArray

    case m: EntityState     => entityStateToProto(m).toByteArray
    case m: EntitiesStarted => entitiesStartedToProto(m).toByteArray
    case m: EntitiesStopped => entitiesStoppedToProto(m).toByteArray

    case s: StartEntity    => startEntityToByteArray(s)
    case s: StartEntityAck => startEntityAckToByteArray(s)

    case GetShardStats              => Array.emptyByteArray
    case m: ShardStats              => shardStatsToProto(m).toByteArray
    case GetShardRegionStats        => Array.emptyByteArray
    case m: ShardRegionStats        => shardRegionStatsToProto(m).toByteArray
    case m: GetClusterShardingStats => getClusterShardingStatsToProto(m).toByteArray
    case m: ClusterShardingStats    => clusterShardingStatsToProto(m).toByteArray
    case GetCurrentRegions          => Array.emptyByteArray
    case m: CurrentRegions          => currentRegionsToProto(m).toByteArray

    case GetCurrentShardState       => Array.emptyByteArray
    case m: CurrentShardState       => currentShardStateToProto(m).toByteArray
    case GetShardRegionState        => Array.emptyByteArray
    case m: ShardState              => shardStateToProto(m).toByteArray
    case m: CurrentShardRegionState => currentShardRegionStateToProto(m).toByteArray

    case MigrationMarker        => Array.emptyByteArray
    case m: RememberShardsState => rememberShardsStateToProto(m).toByteArray

    case _ =>
      throw new IllegalArgumentException(s"Can't serialize object of type ${obj.getClass} in [${getClass.getName}]")
  }