Colored functions

KPHP brings support of colored functions. It's quite a unique concept that allows you to find undesirable architectural patterns in your code, like “writing logs from performance-critical places is bad” or “deny reading from DB at server-side rendering”.

compiler steps

The concept of colored functions

Historically, this concept was invented for KPHP, but later exposed as a separate project named nocolor.

Colored functions are of course still embedded into KPHP, but for documentation, we'll refer you here:

Visit “Introducing colored functions” page

Differences between KPHP's implementation and nocolor

  1. @kphp-color instead of @color
  2. Max 64 unique colors per project (KPHP stores them in a bitmask, not a string list)
  3. Instead of palette.yaml, you declare the palette in PHP, in the KphpConfiguration class
// a separate file KphpConfiguration.php
class KphpConfiguration {
      'highload no-highload' => "Don't call a no-highload function from a highload one",
      'highload allow-no-highload no-highload' => 1,
      'ssr rpc' => "Don't perform rpc queries from SSR: pass already prepared data",
      'ssr ssr-allow-rpc rpc' => 1,

A demo project with colored functions

Save this folder from kphp-snippets somewhere. Execute

kphp2cpp index.php -M cli

Compilation will fail with the message:

fast slow => Potential performance leak
  This color rule is broken, call chain:
ApiRequestHandler::handleRequest@fast -> Logger::debug -> DBLayer::addToLogTable@slow

If you

  • either remove all @kphp-color from a demo
  • or add @kphp-color slow-ignore over Logger::debug()

then compilation will succeed.

An article about colored functions

Here's an article on Habr (in Russian) which also describes this concept:

Цветные функции: ищем плохие архитектурные паттерны