Writing Faster PHP with HHVM and Hack

Writing Faster PHP with
HHVM and Hack

View Slide

Proprietary and Confidential
•Community Engineer at Engine
Yard
•Author of Zend PHP 5
Certification Study Guide,
Sitepoints PHP Anthology: 101
Essential Tips, Tricks & Hacks &
PHP Master: Write Cutting Edge
Code
•A contributor to Zend Framework
1 & 2, phpdoc, & PHP internals
• Original creator of PHAR/
PHP_Archive
• Lead for PHPWomen US
•@dshafik
Davey Shafik

View Slide

Let’s start a conversation about
mental health in tech
prompt.engineyard.com

View Slide

About These Slides

View Slide

Two slides per “slide”!
Title Slide (for when I’m talking)!
Details slide (for later)!
Nobody likes it when you can read the slide just as well as the speaker
can!
I like slides that are useful
About These Slides

View Slide

A Brief History of HipHop VM
Better known as HHVM

View Slide

HPHPc
2009 - 2012

View Slide

• Cross-compiler: PHP -> C++!
• Needed to compile for every change, which took hours!
• Created huge binaries (approaching 2GB Linux “limit”)!
• PHP 5.2 (ish) feature-set!
• Missing support for large parts of the language (e.g. all 5.3+ features
including namespaces, closures, and dynamic features like
create_function(), and eval())!
• Broke the developer workflow
HPHPc — 2009 - 2012

View Slide

HipHop VM (HHVM)
2013 -

View Slide

• Alternate interpreted runtime with JIT compiler!
• No compiling process!
• Twice as fast as PHP in interpreted mode.!
• Ludicrous speed for JITed code!
• Bug-for-bug compatible with PHP!
• Almost up-to 5.6 feature set (e.g. support for variadics, splat)
HHVM

View Slide

Hack
A super-set of PHP

View Slide

• AKA Hacklang (because “Hack” is un-google-able)!
• A syntactic super-set of PHP that allows for strong typing via static
analysis. Adds support for:!
• type hinting!
• generics!
• async functions!
• annotations!
• more…!
• A language sub-set of PHP that disallows a number of bad practices !
• variable-variables!
• globals!
• mixing HTML & PHP!
• more…
Hack

View Slide

Performance

View Slide

0
75
150
225
300
Wordpress 3.9
SugarCRM CE 6.5.16 - login page
Drupal 7.28 homepage
Symfony 2.5 ACME app home page
ZF 2.3.1 Skeleton App
Magento 1.9 Homepage
Magento 1.9 item page
PHP 5.4 (no OPcache) PHP 5.5 PHP 5.6 hhvm 3.1 (prebuilt binaries) hhvm 3.2-dev(src) PHPNG
Source: Zeev Suraski http://zsuraski.blogspot.com/2014/07/benchmarking-phpng.html

View Slide

Agenda
• Facebook (#2)!
• Baidu (#5, #1 Search Engine in China)!
• Wikimedia (incl. Wikipedia, #6)!
!
That’s 3 of the top 4 PHP sites in the world, and ~1/3 of the top 10
overall. (Yahoo! is the outlier, FYI)
Actual Users

View Slide

Repo Authoritative Mode
Ludicrous Speed!

View Slide

• When code “never” changes (e.g. production)!
• Extra 20-25% performance increase (similar to apc.stat = 0)!
• Spends extra time on caching/JITing for maximum performance
Repo Authoritative Mode

View Slide

HHVM Setup

View Slide

login.php
HHVM Setup
Nginx php-fpm mysql,pgsql,mongo, 
gearman,redis, etc.
index.php

View Slide

login.php
HHVM Setup
Nginx mysql,pgsql,mongo, 
gearman,redis, etc.
index.php
HHVM

View Slide

server {
server_name _;
root /var/www;
index index.php;
location ~ \.php$ {
fastcgi_pass unix:/var/run/hhvm.sock;
fastcgi_index index.php;
fastcgi_param SCRIPT_FILENAME /var/www$fastcgi_script_name;
include fastcgi_param;
}
}
HHVM Setup

View Slide

hhvm.server.file_socket = /var/run/hhvm.sock
hhvm.server.type = fastcgi
hhvm.server.source_root = /var/www
hhvm.log.level = Error
hhvm.log.user_log_file = true
hhvm.log.file = /var/log/hhvm-error.log
hhvm.log.access.0.file = /var/log/hhvm-access.log
hhvm.log.access.0.format=%h %l %u %t \"%r\" %>s %b
HHVM Setup
$ hhvm -m daemon -c /etc/hhvm/hhvm.ini -u www-data

View Slide

Long Term Support

View Slide

Long Term Support
Version name Intended release date LTS? End of support
3.3 11 Sep 2014 yes 13 Aug 2015
3.4 6 Nov 2014
3.5 1 Jan 2015
3.6 26 Feb 2015 yes 28 Jan 2016
3.7 23 Apr 2015
3.8 18 Jun 2015
3.9 13 Aug 2015 yes 14 Jul 2016
3.10 8 Oct 2015
3.11 3 Dec 2015
3.12 28 Jan 2016 yes 29 Dec 2016
3.13 24 Mar 2016
3.14* 19 May 2016
3.15* 14 Jul 2016 yes 15 Jun 2017

View Slide

Hack
A better PHP

View Slide

• Not a new language!
• Runs through the same HHVM runtime!
• Strongly typed… but thrown away at run time (type erasure)!
• Super-fast static analysis!
• Strict typing informs the runtime to enable better performance
Hack
A primary goal of hack is to not
[negatively] impact the developers
workflow — especially the REPL;
whereby we can edit code and refresh our
browser to immediately see changes.
“
”
- Davey Shafik

View Slide

Editor Support
Supports any editor (so long it’s vim or emacs)

View Slide

File Semantics

View Slide

• To promote best practices, you cannot mix Hack with HTML (or other
non-code text)!
• All hack files must start with • There is no closing tag for hack files!
• Hack also has multiple modes!
• XHTML can be embedded using XHP, which makes XHTML tags into
language constructs
File Semantics

View Slide

Hack Modes

View Slide

Partial Mode

View Slide

• Default!
• Gradual Typing!
• Types are strictly adhered to however:!
• Not everything must be typed!
• May call into regular PHP code without error
Partial Mode
// Code goes here

View Slide

Strict Mode

View Slide

• All code must be typed!
• Cannot call into non-Hack code!
• No top-level code!
• This means your codebase cannot be 100% strict!
• Arrays must be type hinted!
• Collections (Vector, Set, Map, Tuple) are preferred
Strict Mode
// Code goes here

View Slide

Declarations Mode
AKA Decl

View Slide

• Type hints are trusted but not required
Declarations Mode
// Code goes here

View Slide

Ignoring Errors

View Slide

• You can ignore errors by marking code as UNSAFE!
• Applied from the comment to the end of the current block: typically the
next curly brace “}”!
• Should be the last resort!
• May result in run-time errors due to the lack of validation
Ignoring Errors
// UNSAFE

View Slide

Type Hints

View Slide

• Method Arguments!
• Return Values!
• Class Properties
Type Hints

View Slide

Types
Type
bool Boolean true/false
Type Name
int Integer numbers
float Floating Point numbers
string Strings
array Arrays (that can be typed)
resource Resources (e.g. ﬁle streams)
Class/Interface Name An object type-hint

View Slide

Types (Cont.)
Type Name
mixed Any (not recommended)
Vector Numerical contiguously indexed Arrays
Map A typed (both keys and values) associative
array
Set An unindexed collection of typed unique
values
Tuple A ﬁxed size set of typed values
Pair A ﬁxed size set of typed values restricted to
two values, indexed as 0 and 1.

View Slide

• void — for functions with no return value!
• this — always refers to $this
Special Types

View Slide

Nullable Types

View Slide

• Allows for nulls to be passed in addition to the specified type!
• Prefix the type with a ?!
• e.g. ?int or ?\DateTime.
Nullable Types
class DBAdapter {
public function connect(?string $dsn): ?\PDO
{
// $dsn may be null
// may return an instance of \PDO or null on error
}
}

View Slide

Soft Types

View Slide

• You can denote the a type-failure should not error by using soft types.!
• This is great for migrating codebases!
• To do this precede the type with an @!
• e.g. @int or @\DateTime.
Soft Types
class Calculator {
public function add(@int $a, @int $b): @int
{
// Both $a and $b may not be ints
// May not return an int
}
}
$calc = new Calculator();
$calc->add("1", "2");

View Slide

Custom Types

View Slide

• Type Aliases (type)!
• Opaque Types (newtype)!
• Only used for static analysis.
Custom Types

View Slide

type HTTPStatusCode = int;
!
class HTTPStatus {
const HTTPStatusCode OK = 200;
const HTTPStatusCode FOUND = 302;
const HTTPStatusCode NOT_FOUND = 404;
!
protected Map $status = Map {
self::OK => "200 OK",
self::FOUND => "302 Found",
self::NOT_FOUND => "404 Not Found",
};
!
public function send(HTTPStatusCode $code): bool
{
if (isset($this->status[$code])) {
header('HTTP/1.1 ' .$this->status[$code]);
return true;
}
!
return false;
}
}

View Slide

function notFound() {
$status = new HTTPStatus();
$status->send(404);
}

View Slide

• Allows you to give more appropriate names to existing types!
• e.g. unixtime for int
Type Aliases

View Slide

• Opaque types hide their underlying implementation outside of the file in
which the type is defined.!
• This means they become immutable except when calling called defined in
that file!
• This restriction is not enforced at runtime
Opaque Types

View Slide

newtype HTTPStatusCode = int;

View Slide

function notFound() {
$status = new HTTPStatus();
$status->send(HTTPStatus::NOT_FOUND);
}

View Slide

Constructor Argument Promotion

View Slide

• Automatically create properties from constructor arguments!
• Just precede the argument with a visibility keyword: public, private,
protected
Constructor Argument Promotion
class Adder {
public function __construct(private int $left, private int $right): void { }
public function get(): int {
return $this->left + $this->right;
}
}
$adder = new Adder(1, 3);
$result = $adder->get(); // 4

View Slide

Collections

View Slide

• Arrays — must be typed in strict mode!
• Tuples — typed arrays!
• Pairs — can only contain 2 pieces of data!
• Vectors — numerically, consecutively keyed only!
• Maps — ordered dictionaries that allow int or string keys!
• Sets — unordered collection of unique values!
!
• Immutable variants
Collections

View Slide

Arrays

View Slide

• array — Untyped (only allowed in partial mode)!
• array<[type]> — [type] typed values, with integer keys!
• array<[type1], [type2]> — [type1] typed keys, with [type2]
typed values.
Arrays
function createArray(): array {
return array(1, 2, 3);
}

View Slide

Tuples

View Slide

• Internally identical to arrays!
• Fixed size!
• Implicitly Type hinted by the values used to define it or!
• Explicitly Type hinted using the literal syntax
Tuples
function createTuple(): void {
$foo = tuple(1, 2, "3");
// Do more with the tuple
}
function createTuple(): (int, int, string) {
return tuple(1, 2, "3");
}

View Slide

Pairs

View Slide

• Can contain only two values, keyed as 0 and 1!
• Immutable
Pairs
function getTask(): Pair {
return Pair { "C039D17D", "checkPing" };
}

View Slide

Vectors

View Slide

• Vectors can only use integer keys
Vectors
function getCommunityEngineers(): Vector {
return Vector {"Davey", "PJ", "You?"};
}

View Slide

Maps

View Slide

• Maps are an ordered dictionary, which can have integer or string keys.!
• Must specify both key and values types when type hinting.
Maps
function getTags(): Map {
return Map {"php" => "PHP", "hack" => "Hack"};
}

View Slide

Sets

View Slide

• Unordered Collection with no keys!
• Unique values
function getTags(): Set {
return Set { "php", "hack", "hhvm" };
}

View Slide

Immutability

View Slide

• Simply prefix the class name with Imm
Immutability
function getTags(): ImmMap {
$map = ImmMap {"php" => "PHP", "hack" => "Hack"};
$map["hhvm"] = "HHVM";
}
|13 col 6 error| You cannot mutate this
|12 col 13 error| This is an object of type ImmMap

View Slide

Appending Elements

View Slide

• Only Vectors allow $foo[] = "bar" syntax!
• Pairs and Tuples do not allow additional elements!
• Maps allow appending of Pairs. First value is key, second value is value
Appending Elements
function appendToMap(): void {
$m = Map { 0 => "foo", 1 => "bar" };
$m[] = Pair { 5, "bat" };
var_dump($m);
}

View Slide

Object Oriented Interface

View Slide

• Based on the SPL!
• Allows adding/removing/manipulation methods!
• Allows you to use them as objects, rather than just “better” arrays
Object Oriented Interface

View Slide

Breaking Iteration

View Slide

• Because collections are objects, you cannot modify them during
iteration.
Breaking Iteration
Fatal error: Uncaught exception
'InvalidOperationException' with message
'Collection was modified during iteration' in

View Slide

Shapes

View Slide

• Tuples with a pre-defined structure!
• Can be used as a form of validation!
• Ensures integrity
Shapes
newtype HTTPRequest = shape(
'status' => HTTPStatusCode,
'headers' => Map,
'data' => shape (
'GET' => ?Map,
'POST' => ?Map,
'COOKIE' => ?Map,
'SERVER' => Map
),
'body' => ?string
);

View Slide

Anonymous Functions

View Slide

• Like closures but they inherit parent scope!
• Much more concise!
!
• Multiple Expressions
Anonymous Functions
$fn = $args ==> expression;
$fn = ($arg1, $arg2) ==> { expression; return ...; };
$list = ;
array_walk($items, $item ==> $list->appendChild({$item});
!
echo $list;

View Slide

XHP — XML Fragments as Expressions

View Slide

• Makes XML syntax a top-level syntax!
• No longer strings!
• Auto-escapes for security!
• Allows for OO semantics, for composable widgets, for tempting!
• Must be XML, e.g.

XHP — XML Fragments as Expression
echo Hello World;

View Slide

• Classes are defined by prefixing the class name with a colon!
• Classes extend the :x:element base class which has DOM-like
methods:!
• appendChild()
• prependChild()
• replaceChildren()
• getChildren()
• getFirstChild()
• getLastChild()
• getAttribute(), getAttributes()
• setAttribute(), setAttributes()
• isAttributeSet()
• removeAttribute()
XHP (Cont.)

View Slide

The PHP Way
echo '';
foreach ($items as $item) {
echo '';
echo htmlentities($item, ENT_QUOTES, 'UTF-8');
echo '';
}
echo '';
?>

View Slide

The Hack Way
$list = ;
foreach ($items as $item) {
$list->appendChild({$item});
}

View Slide

Feedback & Questions: !
 
Twitter: @dshafik
Email: [email protected]
Slides: http://daveyshafik.com/slides

View Slide

• Hack Lang: http://hacklang.org!
• HHVM: http://hhvm.com!
• Building a Better PHP: https://blog.engineyard.com/2014/hhvm-hack
(Engine Yard Blog)
Resources
http://ey.io/hhvm-hack

View Slide

Writing Faster PHP with HHVM and Hack

Writing Faster PHP with HHVM and Hack

Davey Shafik

More Decks by Davey Shafik

Other Decks in Programming

Featured

Transcript