readAvailable
Invokes block if it is possible to read at least min byte providing byte buffer to it so lambda can read from the buffer up to ByteBuffer.available bytes. If there are no min bytes available then the invocation returns 0.
Warning: it is not guaranteed that all of available bytes will be represented as a single byte buffer eg: it could be 4 bytes available for read but the provided byte buffer could have only 2 available bytes: in this case you have to invoke read again (with decreased min accordingly).
Return
number of consumed bytes or -1 if the block wasn't executed.
Parameters
min
amount of bytes available for read, should be positive
block
to be invoked when at least min bytes available