First few external tests with test/unit, some minor tidying of internal data

structures.

tests/flexnbd.rb

@@ -0,0 +1,63 @@
+require 'socket'
+
+# Noddy test class to exercise FlexNBD from the outside for testing.
+#
+class FlexNBD
+  attr_reader :bin, :ctrl, :pid, :ip, :port
+  
+  def initialize(bin, ip, port)
+    @bin  = bin
+    raise "#{bin} not executable" unless File.executable?(bin)
+    @ctrl = "/tmp/.flexnbd.ctrl.#{Time.now.to_i}.#{rand}"
+    @ip = ip
+    @port = port
+  end
+  
+  def serve(ip, port, file, *acl)
+    @pid = fork do
+      exec("#{@bin} serve #{ip} #{port} #{file} #{ctrl} #{acl.join(' ')}")
+    end
+  end
+  
+  def kill
+    Process.kill("INT", @pid)
+    Process.wait(@pid)
+  end
+  
+  def read(offset, length)
+    IO.popen("#{@bin} read #{ip} #{port} #{offset} #{length}","r") do |fh|
+      return fh.read
+    end
+    raise "read failed" unless $?.success?
+  end
+  
+  def write(offset, data)
+    IO.popen("#{@bin} write #{ip} #{port} #{offset} #{data.length}","w") do |fh|
+      fh.write(data)
+    end
+    raise "write failed" unless $?.success?
+    nil
+  end
+  
+  def mirror(bandwidth=nil, action=nil)
+    control_command("mirror", ip, port, bandwidth, action)
+  end
+  
+  def acl(*acl)
+    control_command("acl", *acl)
+  end
+  
+  def status
+  end
+  
+  protected
+  def control_command(*args)
+    raise "Server not running" unless @pid
+    args = args.compact
+    UNIXSocket.open(@ctrl) do |u|
+      u.write(args.join("\n") + "\n")
+      code, message = u.readline.split(": ", 2)
+      return [code, message]
+    end    
+  end
+end