1. Scalable language;
Scalable web
Timothy Perrett
ScalaDays 2012

2. Hello.

3. Hello.

5. Outline.

7. Scal•a•ble
Able to be used or produced in a range of
capabilities: it is scalable across a range of
systems.

9. Memory
Lane.

11. package example.java.sucks;
import java.io.*;
import javax.servlet.http.*;
import javax.servlet.*;
public class HelloServlet extends HttpServlet {
public void doGet (HttpServletRequest req,
HttpServletResponse res)
throws ServletException, IOException
{
PrintWriter out = res.getWriter();
out.println("Hello, world!");
out.close();
}
}

17. Vibrant Scala
Ecosystem.

19. Scaling Down.
Less is more.

21. Unfiltered.

23. type Intent[-A,-B] =
PartialFunction[
HttpRequest[A],
ResponseFunction[B]]

25. object Example extends Plan {
def intent = {
case GET(Path("ping")) =>
ResponseString("pong")
}
}

26. HttpRequest[A]
object Example extends Plan {
def intent = {
case GET(Path("ping")) =>
ResponseString("pong")
}
}

27. HttpRequest[A]
object Example extends Plan {
def intent = {
case GET(Path("ping")) =>
ResponseString("pong")
}
}
ResponseFunction[B]

28. Roundup

29. Roundup
๏ Leverage simple language
constructs.

30. Roundup
๏ Leverage simple language
constructs.
๏ Easy to learn.

31. Roundup
๏ Leverage simple language
constructs.
๏ Easy to learn.
๏ Easy to extend.

32. Roundup
๏ Leverage simple language
constructs.
๏ Easy to learn.
๏ Easy to extend.
๏ Micro-framework: less is more.

33. Roundup
๏ Leverage simple language
constructs.
๏ Easy to learn.
๏ Easy to extend.
๏ Micro-framework: less is more.
๏ Used by Meetup, RTM, Novus

35. Scaling Performance.
Building the next Facebook (obviously)

37. Spray.
(and blueeyes)

39. type Route =
RequestContext => Unit

41. path("foobar" / JavaUUID){ uuid =>
get {
_.completeWith {
// load Foo instance by uuid
}
}
}

42. path("foobar" / JavaUUID){ uuid =>
get {
_.completeWith {
// load Foo instance by uuid
}
}
}

43. path("foobar" / JavaUUID){ uuid =>
get {
_.completeWith {
// load Foo instance by uuid
}
}
}
implicit def foo[Foo : Marshaller]

45. case class Foo(whatever: String)
path("foobar" / JavaUUID){ uuid =>
put {
content(as[Foo]){ foo =>
...
}
}
}

47. Actors. Everywhere.

49. Detached
worker
HTTP Request HTTP Detached
worker
Service
Detached
worker

51. def receive = {
case HttpRequest(GET, "/", _, _, _) =>
...
}

52. Roundup

53. Roundup
๏ Totally actor-based

54. Roundup
๏ Totally actor-based
๏ Crazy-fast, non-blocking HTTP
Server

55. Roundup
๏ Totally actor-based
๏ Crazy-fast, non-blocking HTTP
Server
๏ Route definitions are just CPS

56. Roundup
๏ Totally actor-based
๏ Crazy-fast, non-blocking HTTP
Server
๏ Route definitions are just CPS
๏ Typeclass-based (un)marshalling

57. Roundup
๏ Totally actor-based
๏ Crazy-fast, non-blocking HTTP
Server
๏ Route definitions are just CPS
๏ Typeclass-based (un)marshalling
๏ Used by: VMWare, Zeebox, eBay

59. Scaling Features.
Real-time, secure applications.

61. Lift.

63. def foo =
"type=text" #> text(name, name = _) &
"type=submit" #> submit(println _)
<form lift="foo">
<p><input type="text" /></p>
<p><input type="submit" /></p>
</form>

64. NodeSeq => NodeSeq
def foo =
"type=text" #> text(name, name = _) &
"type=submit" #> submit(println _)
<form lift="foo">
<p><input type="text" /></p>
<p><input type="submit" /></p>
</form>

66. <form action="/" method="post">
<p><input type="text" name="F04FS5G5454" /></p>
<p><input type="submit" name="F0S324435" /></p>
</form>

68. NodeSeq.
(a.k.a XSS-safe templates)

70. Unparsed("<strong>ABC</
strong>")

71. Roundup

72. Roundup
๏ Secure by default

73. Roundup
๏ Secure by default
๏ Prevents common CSRF vulnerabilities

74. Roundup
๏ Secure by default
๏ Prevents common CSRF vulnerabilities
๏ XSS impossible without developer input

75. Roundup
๏ Secure by default
๏ Prevents common CSRF vulnerabilities
๏ XSS impossible without developer input
๏ Advocates server-controlled state

76. Roundup
๏ Secure by default
๏ Prevents common CSRF vulnerabilities
๏ XSS impossible without developer input
๏ Advocates server-controlled state
๏ Used by: 4sq, Stackmob, OpenStudy

78. What’s the
bottom line?

80. No.
Such.
Thing.

82. EOF
@timperrett
github.com/timperrett
timperrett.com