Introduction to the ReactPHP library with story of a project Octopus, based on it. Presented in Kyiv, Ukraine in May 2015 on the SymfonyCafé meetup.

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ReactPHP: Practical Intro
Dennis Povshedny, freelance

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Agenda
- Intro about myself and the task
- ReactPHP
- Using of ReactPHP
- Questions / Demo
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About myself
Main tools: C++, PHP, Linux
Preferred area: troubleshooting, optimizations,
proof-of-concept, tech leading
Opensource: Drupal
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Task: check of sitemap.xml
- Rapid check of large sitemap.xml
- Check both local and remote sitemap
- learn something new
- candidates: PHP, C++, Bash, ReactPHP, Go,
Rust, ...
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- Reactor pattern
- Event Driven
- Non-blocking I/O
- Pure PHP, small
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What is ReactPHP?

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Projects based on ReactPHP
- Redis Client/Server
- Asterisk Management
- Munin
- Async SQL client
- … several more
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Reactor

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Core sample: HTTP server
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Layers
- Event loop as a backbone
- Low-level components: DNS resolver,
timers/ticks, sockets, network client/server)
- Middle level: HTTP Server/Clients
- High: Promise, Stream
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Layers in practice
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$loop = ReactEventLoopFactory::create();
$socket = new ReactSocketServer($loop);
$http = new ReactHttpServer($socket);
Higher

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Timers, including periodic
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Event Loop Engines
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if (function_exists('event_base_new')) {
return new LibEventLoop();
} else if (class_exists('libevEventLoop')) {
return new LibEvLoop;
} else if (class_exists('EventBase')) {
return new ExtEventLoop;
}
Installing additional libraries is optional

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More: Async I/O
System: LibEIO package
Binding: eio PECL
GitHub: react/filesystem
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More: Promises
Proxy objects to store values for yet unknown
results
Also known as Deferred, Yield and Futures in
other languages
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- https://github.com/reactphp/react/wiki/Users :
about 40 projects;
- Can be evaluated as alternative when you need to
create multithreaded app
- Community
- Unit tests
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Project state

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Disadvantages
- version is 0.4.x
- complicated to debug an application
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Part II - using of ReactPHP
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The Octopus project
An app which uses two features
of the ReactPHP:
- Async Http Requests;
- Timers.
Purpose: education + simple tool needed to
check sitemap validity
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Parallel execution of GET requests
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❖ ~70 ms per page vs ~300 ms for sequential check;
❖ low memory and CPU usage

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...can’t say the same for server :)
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Extract from settings file

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Application main file
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- a few full days of development, initially with idea of
rapid check of sitemap.xml before Google;
- about 12k of PHP code;
- 1 accepted PR to ReactPHP;
- works faster than script with sequential checking (6x);
- application core was developed relatively easy;
Octopus facts and numbers
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Handlers: named function
Regular named function can be used as well
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OpenSource, Experimental
- code is more Proof-of-concept stype;
- published on GitHub, welcome to fork and
experiment
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Possible evolution & new tools
- Octopus: parse for links, check them as well
- Other project: compare/warmup DNS
servers
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Sum it up
Job is done.
Used two components, there is many more:
- Streams;
- Child processes;
- Futures (Promises)
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Links
See those...
http://reactphp.org
http://blog.wyrihaximus.net/2015/01/reactphp-introduction
https://github.com/dpovshed/octopus
http://marcjschmidt.de/blog/2014/02/08/php-high-performance.html
...and also those
https://github.com/reactphp/react/wiki/FAQ
https://philsturgeon.uk/blog/2013/11/benchmarking-codswallop-nodejs-v-php/
https://github.com/reactphp/react/wiki/Event-Loop-Implementations
https://github.com/php-pm/php-pm
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Questions / Demo
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Thank you!
Dennis Povshedny
http://dennisp.tel
https://ua.linkedin.com/in/1dennis1
Email: basturma@gmail.com
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