anchor.diff:  	#log{status = ok, format = external} when Format =:= internal ->
   	    notify_owners({format_external, B}),
   	    loop(S);
  -	#log{status = ok} ->
  -	    log_loop(S, [], [B], []);
  +	#log{status = ok, format=LogFormat} ->
  +	    log_loop(S, [], [B], [], iolist_size(B), LogFormat);
   	#log{status = {blocked, false}} ->
   	    notify_owners({blocked_log, B}),
   	    loop(S);
  
positive.code: 	    reply(From, {error, {read_only_mode, L#log.name}}, S);
  	#log{status = ok, format=external}=L when Format =:= internal ->
  	    reply(From, {error, {format_external, L#log.name}}, S);
  	#log{status = ok} ->
  	    log_loop(S, From, [B], []);
  	#log{status = {blocked, false}}=L ->
  	    reply(From, {error, {blocked_log, L#log.name}}, S);
  	#log{blocked_by = From}=L ->
  
negative.code:     case get(log) of
  	#log{mode = read_only}=L ->
  	    reply(From, {error, {read_only_mode, L#log.name}}, S);
  	#log{status = ok, format=LogFormat} ->
              log_loop(S, [], [], [From], 0, LogFormat);
  	#log{status = {blocked, false}}=L ->
  	    reply(From, {error, {blocked_log, L#log.name}}, S);
  	#log{blocked_by = From}=L ->
  