This repo is the result of a take home challenge for a job interview where the theme was "build something using Pup/Sub in C#"

JobStatusReporting

JobStatusReporting is a small library intended to make it easy for your long running batch jobs to produce a live stream of status progression to multiple consumers using Redis Pup/Sub.

How to use

The JobStatusReport class represents the model of the streamed status updates:

public class JobStatusReport
{
  public int PercentageCompleted { get; set; } = 0;
  public JobStatus Status { get; set; } = JobStatus.NotStarted;
  public string? Message { get; set; }
  public string? ErrorMessage { get; set; }

  public string Print()
  {
    return $"Status report: \nStatus: {Status}\nPercentage completed: {PercentageCompleted}\nMessage: {Message}\nError message: {ErrorMessage}\n";
  }
}

Your batch jobs must implement the IBatchJob interface, which exposes a single method that returns a JobStatusReport instance:

public interface IBatchJob
{
  public JobStatusReport GetStatusReport();
}

Note: This interface does not enforce any rules on how you should implement or update the state in your batch jobs. That is completely up to you to decide.

An instance of the JobStatusCollector class can be used to generate an async stream of a batch job's status progression:

  IBatchJob batchJob = new SomeLongRunningJob();
  JobStatusCollector collector = new JobStatusCollector();

  IAsyncEnumerable<JobStatusReport> reportStream = collector.CollectStatusReportsAsync(job: batchJob, pullIntervalMS: 2000);

An instance of the JobStatusPublisher class can be used to publish an async stream of status updates to an arbitrary channel on Redis:

  string redisConnectionString = "localhost:6379";

  await using (JobStatusPublisher publisher = JobStatusPublisher.Build(redisConnectionString)
  {
    publisher.PublishAsync(reportStream, "someRedisChannel")
  }

An instance of the JobStatusSubscriber class can be used to subscribe to Redis channels and consume the status updates in a callback function:

  string redisConnectionString = "localhost:6379";

  await using (JobStatusSubscriber subscriber = JobStatusSubscriber.Build(redisConnectionString)
  {
    subscriber.SubscribeAsync("test", (report) =>
    {
      Console.WriteLine(report.Print());
    });
  }

Running Redis locally using Docker

docker run -p 6379:6379 redis