logging in bro

I have been working with the log files in bro (weird.log, bro.log,
ftp.log, etc) and have noticed that they are written out in chunks of 4096

I know that this is possibly done for performance reasons, but has anyone
tried/done writing out to the log files in "real-time" (i.e., as soon
there is data to be written out (i.e., without buffering))?

I have looked through the code looking for how and where this "buffering"
is specified and how the "chunk size" is specified to be 4096, but have
not had much success.

Does anyone know?

Thanks in advance!