SessionTracker

Library that allows working with distributed "sessions".

Features

• Session tracking via starting, updating, finishing, resuming, locking and fetching finished Session objects.
• Configurable caching settings per Session type.
• Redis implementations provided out of the box.

Description

A session is encapsulated data that has to be passed around a distributed cache or any other backing-store custom implementation. It is helpful when dealing with for example Discord API interactions that may need some data passed between them while there are multiple service instances.

Installation

To register the session tracker service use the following extension methods:

For base services with no backing-store implementation registration:

builder.AddSessionTracker(options);

For In-Memory implementation:

builder.AddSessionTracker(options).AddInMemoryProviders(memoryOptions);

For Redis implementation:

builder.AddSessionTracker(options).AddRedisProviders(redisOptions);

If you wish to configure the JsonSerializerOptions used for serializing/deserializing session instances within Redis provider use:

builder.AddSessionTracker(options).AddRedisProviders(redisOptions => redisOptions.JsonSerializerConfiguration = ...);

or

services.Configure<JsonSerializerOptions>(RedisSessionSettings.JsonSerializerName, yourOptions);

You can implement your own backing store provider and lock provider by implementing ISessionTrackerDataProvider or ISessionLockProvder interfaces respectively and registering your new services with the container manually or with helper methods like so:

services.AddSessionTracker(options).AddDataProvider<YourDataProviderType>();
services.AddSessionTracker(options).AddLockProvider<YourLockProviderType>();

// or 

services.AddSessionTracker(options).AddDataProvider(AnInstanceOfYourDataProvider);
services.AddSessionTracker(options).AddLockProvider(AnInstanceOfYourLockProvider);

or register different implementations of suitable interfaces yourself.

These will overwrite any other provider implementation currently registered with the container.

Documentation

Documentation available at https://mikym.github.io/SessionTracker.

Example usage

Create your own Session type:

public CustomSession : Session
{
    public bool IsThisASuperSession { get; set; }
    
    public CustomSession(string key, bool isSuper = true) : base(key)
        => IsThisASuperSession = isSuper;
}

Inject ISessionTracker to your handlers/services/controllers/whatnot:

Start session inside one handler:

public FirstSimpleInteractionHandler
{
    private readonly ISessionTracker _tracker;

    public FirstSimpleInteractionHandler(ISessionTracker tracker)
        => _tracker = tracker;

    public async Task HandleAsync()
    {
        var session = new CustomSession("superKeyForThisSession", false);

        var result = await _tracker.StartAsync(session);
        if (!result.IsSuccess)
            return;
    }
}

Update from another:

public SecondSimpleInteractionHandler
{
    private readonly ISessionTracker _tracker;

    public SecondSimpleInteractionHandler(ISessionTracker tracker)
        => _tracker = tracker;

    public async Task HandleAsync()
    {
        var result = await _tracker.GetLockedAsync<CustomSession>("superKeyForThisSession");
        if (!result.IsDefined(out var lockedSession))
            return;

        await using var @lock = lockedSession.Lock;

        lockedSession.Session.IsThisASuperSession = true;

        await _tracker.UpdateSessionAsync(lockedSession.Session);
    }
}

Finalize in fourth:

public FourthSimpleInteractionHandler
{
    private readonly ISessionTracker _tracker;

    public FourthSimpleInteractionHandler(ISessionTracker tracker)
        => _tracker = tracker;

    public async Task HandleAsync()
    {
        await _tracker.FinishAsync<CustomSession>("superKeyForThisSession");
    }
}