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SuperKernel Context

super-kernel/context keeps the application container of a process and stores short-lived values for the code that is running now, separately for each Swoole coroutine and thread.

Installation

composer require super-kernel/context

The package has no requirement beyond PHP. With the Swoole extension (>=6.2.3 <6.3), values are kept per coroutine and per thread. With super-kernel/di, the first request for the container creates it from the metadata of skernel build; without it, set a PSR-11 container yourself.

What it provides

• ApplicationContext::getContainer(), which returns the process's container and creates it on first use when super-kernel/di is installed.
• ApplicationContext::setContainer(), which sets the process's container to any PSR-11 container.
• Context::get(), has(), set(), and clear(), static access to values of the current execution.
• Separate values for each Swoole coroutine and Swoole thread, and process-wide values elsewhere, chosen anew on every call.

It does not:

• replace injection: services should receive their dependencies, not look them up;
• clear values when a coroutine, request, or job ends, outside Swoole coroutines;
• give native Fibers or Swow coroutines values of their own;
• require a container implementation.

Quick start

Store, read, and clear values of the current execution. Save the script as bin/context.php:

<?php

declare(strict_types=1);

use SuperKernel\Context\Context;

require dirname(__DIR__) . '/vendor/autoload.php';

Context::set('request-id', 'req-1');
Context::set('user', null);

var_dump(Context::get('request-id'));
var_dump(Context::has('user'), Context::get('locale', 'en'));

Context::clear();

var_dump(Context::has('request-id'));

Run the script:

php bin/context.php

It prints:

string(5) "req-1"
bool(true)
string(2) "en"
bool(false)

Public surface

Behavior to know

• getContainer() raises SuperKernel\Context\Exception\ContainerNotSetException with the message The application context has no container. when no container was set and super-kernel/di is not installed.
• When creating the container fails, getContainer() raises SuperKernel\Context\Exception\ContainerInitializationException with the message Unable to initialize the application container through SuperKernel\Di\Provider\ContainerProvider. and the cause as its previous exception, such as the BuildRequiredException of a missing skernel build. A later call tries again.
• Context uses the current Swoole coroutine first, then the current Swoole thread, then the process. Values stored outside a coroutine stay for the life of the process until you clear them.
• has() reports a key that holds null; get() returns the given default only for a missing key.

Documentation

The developer documentation describes the container and the execution values with complete examples, including Swoole coroutines, and what not to do: SuperKernel Context.

License

Released under the MIT License. See LICENSE.