DD.WellWorkover.Cloud/AsbCloudWebApi/Middlewares/UserConnectionsLimitMiddlware.cs

using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.Configuration;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace AsbCloudWebApi.Middlewares;


/// <summary>
/// This is not real middleware it`s part of PermissionsMiddlware.
/// DO NOT register it in setup.cs as middleware.
/// </summary>
class UserConnectionsLimitMiddlware
{
    private readonly int parallelRequestsToController;
    private readonly RequestDelegate next;
    private readonly byte[] responseBody;
    private readonly ConcurrentDictionary<int, ConcurrentDictionary<string, int>> stat = new ();
    private readonly IEnumerable<string>? controllerNames;

    public UserConnectionsLimitMiddlware(RequestDelegate next, IConfiguration configuration)
    {
        const int parallelRequestsToControllerDefault = 8;
        this.next = next;
        
        var parallelRequestsToController = configuration.GetSection("userLimits")?.GetValue<int>("parallelRequestsToController") ?? parallelRequestsToControllerDefault;
        this.parallelRequestsToController = parallelRequestsToController > 0 
            ? parallelRequestsToController 
            : parallelRequestsToControllerDefault;

        controllerNames = configuration.GetSection("userLimits")?.GetValue<IEnumerable<string>>("controllerNames");

        var bodyText = $"<html><head><title>Too Many Requests</title></head><body><h1>Too Many Requests</h1><p>I only allow {this.parallelRequestsToController} parallel requests per user. Try again soon.</p></body></html>";
        responseBody = System.Text.Encoding.UTF8.GetBytes(bodyText);
    }

    public async Task InvokeAsync(HttpContext context, int idUser, string controllerName)
    {
        if(controllerNames?.Any(n => controllerName.StartsWith(n)) == false)
        {
            await next(context);
            return;
        }

        var userStat = stat.GetOrAdd(idUser, idUser => new());            
        var count = userStat.AddOrUpdate(controllerName, 0, (k, v) => v);
        
        if(count + 1 < parallelRequestsToController)
        {
            try
            {
                userStat[controllerName]++;
                await next(context);
            }
            finally
            {
                userStat[controllerName]--;
            }
        }
        else
        {
            context.Response.Clear();
            context.Response.StatusCode = (int)System.Net.HttpStatusCode.TooManyRequests;
            context.Response.Headers.RetryAfter = "1000";
            context.Response.Headers.ContentType = "text/html";
            await context.Response.BodyWriter.WriteAsync(responseBody);
        }
    }
}
fix encoding to utf8 (without bom), u200b, line endings, tabs to 3 spaces, variants of minus char to base minus char 2024-07-04 11:02:45 +05:00			`using Microsoft.AspNetCore.Http;`
#7582867 add UserConnectionsLimitMiddlware. 2022-11-01 17:14:19 +05:00			`using Microsoft.Extensions.Configuration;`
			`using System.Collections.Concurrent;`
			`using System.Collections.Generic;`
			`using System.Linq;`
			`using System.Threading.Tasks;`

namespace to fileScope 2024-08-19 10:01:07 +05:00			`namespace AsbCloudWebApi.Middlewares;`


			`/// <summary>`
			/// This is not real middleware it`s part of PermissionsMiddlware.
			`/// DO NOT register it in setup.cs as middleware.`
			`/// </summary>`
			`class UserConnectionsLimitMiddlware`
#7582867 add UserConnectionsLimitMiddlware. 2022-11-01 17:14:19 +05:00			`{`
namespace to fileScope 2024-08-19 10:01:07 +05:00			`private readonly int parallelRequestsToController;`
			`private readonly RequestDelegate next;`
			`private readonly byte[] responseBody;`
			`private readonly ConcurrentDictionary<int, ConcurrentDictionary<string, int>> stat = new ();`
			`private readonly IEnumerable<string>? controllerNames;`
remove #nullable 2023-05-19 16:51:41 +05:00
namespace to fileScope 2024-08-19 10:01:07 +05:00			`public UserConnectionsLimitMiddlware(RequestDelegate next, IConfiguration configuration)`
#7582867 add UserConnectionsLimitMiddlware. 2022-11-01 17:14:19 +05:00			`{`
namespace to fileScope 2024-08-19 10:01:07 +05:00			`const int parallelRequestsToControllerDefault = 8;`
			`this.next = next;`

			`var parallelRequestsToController = configuration.GetSection("userLimits")?.GetValue<int>("parallelRequestsToController") ?? parallelRequestsToControllerDefault;`
			`this.parallelRequestsToController = parallelRequestsToController > 0`
			`? parallelRequestsToController`
			`: parallelRequestsToControllerDefault;`
#7582867 add UserConnectionsLimitMiddlware. 2022-11-01 17:14:19 +05:00
namespace to fileScope 2024-08-19 10:01:07 +05:00			`controllerNames = configuration.GetSection("userLimits")?.GetValue<IEnumerable<string>>("controllerNames");`
#7582867 add UserConnectionsLimitMiddlware. 2022-11-01 17:14:19 +05:00
namespace to fileScope 2024-08-19 10:01:07 +05:00			`var bodyText = $"<html><head><title>Too Many Requests</title></head><body><h1>Too Many Requests</h1><p>I only allow {this.parallelRequestsToController} parallel requests per user. Try again soon.</p></body></html>";`
			`responseBody = System.Text.Encoding.UTF8.GetBytes(bodyText);`
			`}`
#7582867 add UserConnectionsLimitMiddlware. 2022-11-01 17:14:19 +05:00
namespace to fileScope 2024-08-19 10:01:07 +05:00			`public async Task InvokeAsync(HttpContext context, int idUser, string controllerName)`
			`{`
			`if(controllerNames?.Any(n => controllerName.StartsWith(n)) == false)`
			`{`
			`await next(context);`
			`return;`
#7582867 add UserConnectionsLimitMiddlware. 2022-11-01 17:14:19 +05:00			`}`

namespace to fileScope 2024-08-19 10:01:07 +05:00			`var userStat = stat.GetOrAdd(idUser, idUser => new());`
			`var count = userStat.AddOrUpdate(controllerName, 0, (k, v) => v);`

			`if(count + 1 < parallelRequestsToController)`
#7582867 add UserConnectionsLimitMiddlware. 2022-11-01 17:14:19 +05:00			`{`
namespace to fileScope 2024-08-19 10:01:07 +05:00			`try`
#7582867 add UserConnectionsLimitMiddlware. 2022-11-01 17:14:19 +05:00			`{`
namespace to fileScope 2024-08-19 10:01:07 +05:00			`userStat[controllerName]++;`
#7582867 add UserConnectionsLimitMiddlware. 2022-11-01 17:14:19 +05:00			`await next(context);`
fix #7582867 2022-11-10 13:59:48 +05:00			`}`
namespace to fileScope 2024-08-19 10:01:07 +05:00			`finally`
#7582867 add UserConnectionsLimitMiddlware. 2022-11-01 17:14:19 +05:00			`{`
namespace to fileScope 2024-08-19 10:01:07 +05:00			`userStat[controllerName]--;`
#7582867 add UserConnectionsLimitMiddlware. 2022-11-01 17:14:19 +05:00			`}`
			`}`
namespace to fileScope 2024-08-19 10:01:07 +05:00			`else`
			`{`
			`context.Response.Clear();`
			`context.Response.StatusCode = (int)System.Net.HttpStatusCode.TooManyRequests;`
			`context.Response.Headers.RetryAfter = "1000";`
			`context.Response.Headers.ContentType = "text/html";`
			`await context.Response.BodyWriter.WriteAsync(responseBody);`
			`}`
#7582867 add UserConnectionsLimitMiddlware. 2022-11-01 17:14:19 +05:00			`}`
			`}`