Task Queue

The Task Queue file provides a queue management system to handle asynchronous jobs. It uses Redis to store jobs in the queue and supports retries when a job fails. Below is a detailed explanation of each function:

push()

public static function push($queueName, $eventName, $payload = null, $attempts = 0) {}

• Functionality: Pushes a job into the queue.

• Parameters:

  • $queueName: The name of the queue (e.g., 'email', 'notifications').

  • $eventName: The name of the event to be triggered when the job is processed (e.g., 'SendEmailEvent').

  • $payload: Data associated with the job (e.g., email information to be sent).

  • $attempts: The number of retry attempts (default is 0).

Example:

<?php
TaskQueue::push(
    'email', 
    'SendEmailEvent', 
    ['to' => '[email protected]', 'subject' => 'Welcome'], 
    0
);

// Result: The job is added to the task_queue:email queue.

pop()

public static function pop($queueName, $timeout = 5) {}

• Functionality: Retrieves a job from the queue (uses blocking pop if available).

• Parameters:

  • $queueName: The name of the queue.

  • $timeout: Timeout duration (in seconds) if the queue is empty.

Example:

<?php
$job = TaskQueue::pop('email');
print_r($job);

// Output
// [
//    'event' => 'SendEmailEvent',
//    'payload' => ['to' => '[email protected]', 'subject' => 'Welcome'],
//    'timestamp' => 1681111111,
//    'attempts' => 0
// ]

del()

Completely clears all session data, effectively logging out the user and resetting the session

Example:

Session::del('user_id'); // Deletes the user_id session variable

processJob()

public static function processJob($queueName, $maxRetries = 3) {}

• Functionality: Processes a job from the queue.

• Parameters:

  • $queueName: The name of the queue.

  • $maxRetries: The maximum number of retry attempts (default is 3).

Example:

<?php
TaskQueue::processJob('email');

// Result:
// If the job succeeds: The event is processed.
// If the job fails: The job is retried or moved to the failed queue.

pushFailed()

public static function pushFailed($queueName, $job) {}

• Functionality: Pushes a failed job into the failed queue.

• Parameters:

  • $queueName: The name of the original queue.

  • $job: The job as an array.

Example:

<?php
$job = [
    'event' => 'SendEmailEvent',
    'payload' => ['to' => '[email protected]', 'subject' => 'Welcome'],
    'timestamp' => 1681111111,
    'attempts' => 4
];
TaskQueue::pushFailed('email', $job);

// Result: The job is stored in the failed_task_queue:email queue

runWorker()

public static function runWorker($queueName, $maxRetries = 3, $timeout = 5) {}

• Functionality: Runs a worker to continuously retrieve and process jobs from the queue.

• Parameters:

  • $queueName: The name of the queue.

  • $maxRetries: The maximum number of retry attempts.

  • $timeout: Timeout duration (in seconds) for blocking pop.

Example:

<?php
TaskQueue::runWorker('email');

// Result: The worker continuously processes jobs in the email queue

Example

<?php
// Register the event
Events::on('SendEmailEvent', function ($payload) {
    echo "Sending email to {$payload['to']} with subject '{$payload['subject']}'<br>";
});

// Push a job into the queue
TaskQueue::push('email', 'SendEmailEvent', ['to' => '[email protected]', 'subject' => 'Welcome']);

// Run the worker to process the job
TaskQueue::runWorker('email');

// Output
// Sending email to [email protected] with subject 'Welcome'

Summary

• push(): Pushes a job into the queue.

• pop(): Retrieves a job from the queue.

• processJob(): Processes a single job.

• pushFailed(): Pushes a failed job into the failed queue.

• runWorker(): Runs a worker to continuously process jobs.