HHVM is a PHP execution engine created by Facebook that converts PHP code to bytecode, which is then JIT compiled to machine code for improved performance over traditional PHP interpreters. It originated from Facebook's HPHPc compiler and has nearly full PHP compatibility while also supporting a new typed programming language called Hack. A benchmark test demo showed HHVM can provide better performance than traditional PHP interpreters.

1. What the HACK is HHVM?
Leong Hean Hong
2014-06-06 @ HackerspaceJB

2. About
● Web/mobile developer
● Android instructor
● Experienced in developing web services
● Interest in Linux, web, mobile

3. Agenda
● What is HHVM
● Where does HHVM come from?
● Why use HHVM?
● What is Hack?
● Demo (benchmark test)

4. What is HHVM?
PHP
Code
Hack
Code
Zend Engine
(Interpreter)
HHVM
HipHop Virtual Machine
● PHP execution engine created by
Facebook
● Convert PHP to bytecode
● Bytecode translated to machine code
at runtime by JIT (just-in-time)
compiler
● Similar to .NET/CLR, Java/JVM
JIT

5. Once upon a time...
● 2008 - Facebook create HPHPc to convert
PHP to C++
● Performance boost over Zend PHP
● Don’t fully support PHP language
● Deployment includes pushing 1GB+ binary
to multiple servers
● Need to maintain production+debug builds

6. the story continues...
● 2010 - Facebook decided to build VM for
PHP
● HHVM built on top of HPHPc
● 2013 - Facebook.com started running on
HHVM, replacing HPHPc

7. Why use HHVM?
● Better performance than Zend PHP
● Nearly full compatibility with PHP 5.4
● 100% support CI, Drupal, Laravel, PHPUnit,
… (http://hhvm.com/frameworks/)
● Supports Hack

8. Note on using HHVM
● Not available in many Linux repos
○ Installation guide: http://bit.ly/1kP9aWS
○ Some prebuilt packages provided on GitHub (http:
//bit.ly/1oj3SIK)
● Usage with webservers: FastCGI (http://bit.
ly/1xgplGA)
● Installation on Mac is unsupported and
experimental (as of 2014-06-06)

9. What is Hack?
● Programming language for HHVM
● Can mix PHP
Some of the features
● Static typing
● Generics
● Collections: Vector, Map, Set, Pair

10. Type Annotation
<?hh
class MyClass {
const int MyConst = 0;
private string $x = '';
public function increment( int $x): int {
$y = $x + 1;
return $y;
}
}
// Source: http://hacklang.org/

11. Generics
<?hh
class Box<T> {
protected T $data;
public function __construct( T $data) {
$this->data = $data;
}
public function getData(): T {
return $this->data;
}
}
// Source: http://hacklang.org/

12. Vector
<?hh
// Hack introduces new collection types (Vector, Set and Map).
function test(): int {
// Vector is preferred over array(1, 2, 3)
$vector = Vector {1, 2, 3};
$sum = 0;
foreach ($vector as $val) {
$sum += $val;
}
return $sum;
}
// Source: http://hacklang.org/tutorial/

13. Demo