module IO::Stream::Readable

def fill_read_buffer(size = @minimum_read_size)
	# Limit the read size to avoid exceeding SSIZE_MAX and to manage memory usage.
	# Very large reads can also hurt interactive performance by blocking for too long.
	if size > @maximum_read_size
		size = @maximum_read_size
	end
	
	# This effectively ties the input and output stream together.
	flush
	
	if @read_buffer.empty?
		if sysread(size, @read_buffer)
			# Console.info(self, name: "read") {@read_buffer.inspect}
			return true
		end
	else
		if chunk = sysread(size, @input_buffer)
			@read_buffer << chunk
			# Console.info(self, name: "read") {@read_buffer.inspect}
			
			return true
		end
	end
	
	# else for both cases above:
	@finished = true
	return false
end