MeVitae.RedisWorkQueue 0.1.5

RedisWorkQueue: Dotnet Implementation

A work queue, on top of a redis database, with implementations in Python, Rust, Go, Node.js (TypeScript) and Dotnet (C#).

This is the Dotnet implementations. For an overview of how the work queue works, it's limitations, and the general concepts and implementations in other languages, please read the redis-work-queue readme.

Documentation

Below is a brief overview and an example. More details on the core concepts can be found in the readme, and full API documentation can be found in ../RedisWorkQueue.pdf.

WorkQueue

The WorkQueue class represents a work queue backed by a Redis database. It provides methods to add items to the queue, lease items from the queue, and mark completed items as done.

Properties

• Session: Gets or sets the unique identifier for the current session.

Methods

• AddItem(IRedisClient db, Item item): Adds an item to the work queue. The db parameter is the Redis instance and the item parameter is the item to be added.

• QueueLength(IRedisClient db): Gets the length of the main queue. The db parameter is the Redis instance.

• Processing(IRedisClient db): Gets the length of the processing queue. The db parameter is the Redis instance.

• LeaseExists(IRedisClient db, string itemId): Checks if a lease exists for the specified item ID. The db parameter is the Redis instance and the itemId parameter is the ID of the item to check.

• Lease(IRedisClient db, int leaseSeconds, bool block, int timeout = 0): Requests a work lease from the work queue. This should be called by a worker to get work to complete. The db parameter is the Redis instance, the leaseSeconds parameter is the number of seconds to lease the item for, the block parameter indicates whether to block and wait for an item to be available if the main queue is empty, and the timeout parameter is the maximum time to block in milliseconds.

• Complete(IRedisClient db, Item item): Marks a job as completed and removes it from the work queue. The db parameter is the Redis instance and the item parameter is the item to be completed.

Example Usage

using FreeRedis;
using RedisWorkQueue;

var redis = new RedisClient("localhost");
var workQueue = new WorkQueue("work_queue");

var item = new Item(Encoding.UTF8.GetBytes("data"), "item_1");

workQueue.AddItem(redis, item);

var queueLength = workQueue.QueueLength(redis);
Console.WriteLine($"Queue Length: {queueLength}");

var lease = workQueue.Lease(redis, 30, true, 10000);
if (lease != null)
{
    Console.WriteLine($"Leased Item: {lease.ID}");
    // Do the work here
    workQueue.Complete(redis, lease);
}
else
{
    Console.WriteLine("No item available to lease");
}

In this example, we create a Redis client and a new instance of the WorkQueue class. We then add an item to the work queue using the AddItem method and get the length of the main queue using the QueueLength method.

We then try to lease an item from the work queue using the Lease method. If an item is available, we do the work and mark the item as completed using the Complete method.

Note that in this example, we pass true for the block parameter of the Lease method, which means the method will block and wait for an item to be available if the main queue is empty. We also pass a timeout value of 10000 milliseconds, which means that if there are no items available after 10 seconds, the method will return null.