Best way for buffered reading from binary stream (in FP-manner)

Is there best way (in FP-manner) for buffered reading from binary stream? The following code has some problems - e.g. buffer creating in each iteration.

val size = 1024
val is = new BufferedInputStream(someInputStream, size)
var read = 0

do {
   val buffer = new Array[Byte](size)
   read = is.read(buffer) 

   // handle buffer data

} while (readed > 0)

How can I use single buffer instance?