RedisDependencyInjectionExtensions.cs

// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.

using Microsoft.AspNetCore.SignalR;
using Microsoft.AspNetCore.SignalR.StackExchangeRedis;
using StackExchange.Redis;

namespace Microsoft.Extensions.DependencyInjection;

/// <summary>
/// Extension methods for configuring Redis-based scale-out for a SignalR Server in an <see cref="ISignalRServerBuilder" />.
/// </summary>
public static class StackExchangeRedisDependencyInjectionExtensions
{
    /// <summary>
    /// Adds scale-out to a <see cref="ISignalRServerBuilder"/>, using a shared Redis server.
    /// </summary>
    /// <param name="signalrBuilder">The <see cref="ISignalRServerBuilder"/>.</param>
    /// <returns>The same instance of the <see cref="ISignalRServerBuilder"/> for chaining.</returns>
    public static ISignalRServerBuilder AddStackExchangeRedis(this ISignalRServerBuilder signalrBuilder)
    {
        return AddStackExchangeRedis(signalrBuilder, o => { });
    }

    /// <summary>
    /// Adds scale-out to a <see cref="ISignalRServerBuilder"/>, using a shared Redis server.
    /// </summary>
    /// <param name="signalrBuilder">The <see cref="ISignalRServerBuilder"/>.</param>
    /// <param name="redisConnectionString">The connection string used to connect to the Redis server.</param>
    /// <returns>The same instance of the <see cref="ISignalRServerBuilder"/> for chaining.</returns>
    public static ISignalRServerBuilder AddStackExchangeRedis(this ISignalRServerBuilder signalrBuilder, string redisConnectionString)
    {
        return AddStackExchangeRedis(signalrBuilder, o =>
        {
            o.Configuration = ConfigurationOptions.Parse(redisConnectionString);
        });
    }

    /// <summary>
    /// Adds scale-out to a <see cref="ISignalRServerBuilder"/>, using a shared Redis server.
    /// </summary>
    /// <param name="signalrBuilder">The <see cref="ISignalRServerBuilder"/>.</param>
    /// <param name="configure">A callback to configure the Redis options.</param>
    /// <returns>The same instance of the <see cref="ISignalRServerBuilder"/> for chaining.</returns>
    public static ISignalRServerBuilder AddStackExchangeRedis(this ISignalRServerBuilder signalrBuilder, Action<RedisOptions> configure)
    {
        signalrBuilder.Services.Configure(configure);
        signalrBuilder.Services.AddSingleton(typeof(HubLifetimeManager<>), typeof(RedisHubLifetimeManager<>));
        return signalrBuilder;
    }

    /// <summary>
    /// Adds scale-out to a <see cref="ISignalRServerBuilder"/>, using a shared Redis server.
    /// </summary>
    /// <param name="signalrBuilder">The <see cref="ISignalRServerBuilder"/>.</param>
    /// <param name="redisConnectionString">The connection string used to connect to the Redis server.</param>
    /// <param name="configure">A callback to configure the Redis options.</param>
    /// <returns>The same instance of the <see cref="ISignalRServerBuilder"/> for chaining.</returns>
    public static ISignalRServerBuilder AddStackExchangeRedis(this ISignalRServerBuilder signalrBuilder, string redisConnectionString, Action<RedisOptions> configure)
    {
        return AddStackExchangeRedis(signalrBuilder, o =>
        {
            o.Configuration = ConfigurationOptions.Parse(redisConnectionString);
            configure(o);
        });
    }
}