Add retry policy for 429 responses

DiscordChatExporter.Core/DiscordChatExporter.Core.csproj

@@ -23,6 +23,7 @@
     <ItemGroup>
         <PackageReference Include="Newtonsoft.Json" Version="11.0.2" />
         <PackageReference Include="Onova" Version="2.1.0" />
+        <PackageReference Include="Polly" Version="6.0.1" />
         <PackageReference Include="Scriban" Version="1.2.1" />
         <PackageReference Include="Tyrrrz.Extensions" Version="1.5.1" />
         <PackageReference Include="Tyrrrz.Settings" Version="1.3.2" />

DiscordChatExporter.Core/Exceptions/HttpErrorStatusCodeException.cs

@@ -7,9 +7,13 @@ namespace DiscordChatExporter.Core.Exceptions
     {
         public HttpStatusCode StatusCode { get; }
 
-        public HttpErrorStatusCodeException(HttpStatusCode statusCode)
+        public string ReasonPhrase { get; }
+
+        public HttpErrorStatusCodeException(HttpStatusCode statusCode, string reasonPhrase)
+            : base($"Error HTTP status code: {statusCode} - {reasonPhrase}")
         {
             StatusCode = statusCode;
+            ReasonPhrase = reasonPhrase;
         }
     }
 }

DiscordChatExporter.Core/Services/DataService.cs

@@ -7,6 +7,7 @@ using DiscordChatExporter.Core.Exceptions;
 using DiscordChatExporter.Core.Models;
 using Newtonsoft.Json.Linq;
 using DiscordChatExporter.Core.Internal;
+using Polly;
 
 namespace DiscordChatExporter.Core.Services
 {
@@ -25,20 +26,28 @@ namespace DiscordChatExporter.Core.Services
             foreach (var parameter in parameters)
                 url += $"&{parameter}";
 
+            // Create request policy
+            var policy = Policy
+                .Handle<HttpErrorStatusCodeException>(e => (int) e.StatusCode == 429)
+                .WaitAndRetryAsync(10, i => TimeSpan.FromSeconds(0.4));
+
             // Send request
-            using (var response = await _httpClient.GetAsync(url))
+            return await policy.ExecuteAsync(async () =>
             {
-                // Check status code
+                using (var response = await _httpClient.GetAsync(url))
-                // We throw our own exception here because default one doesn't have status code
+                {
-                if (!response.IsSuccessStatusCode)
+                    // Check status code
-                    throw new HttpErrorStatusCodeException(response.StatusCode);
+                    // We throw our own exception here because default one doesn't have status code
+                    if (!response.IsSuccessStatusCode)
+                        throw new HttpErrorStatusCodeException(response.StatusCode, response.ReasonPhrase);
 
-                // Get content
+                    // Get content
-                var raw = await response.Content.ReadAsStringAsync();
+                    var raw = await response.Content.ReadAsStringAsync();
 
-                // Parse
+                    // Parse
-                return JToken.Parse(raw);
+                    return JToken.Parse(raw);
-            }
+                }
+            });
         }
 
         public async Task<Guild> GetGuildAsync(string token, string guildId)

Readme.md

@@ -41,6 +41,7 @@ DiscordChatExporter can be used to export message history from a [Discord](https
 - [MaterialDesignInXamlToolkit](https://github.com/ButchersBoy/MaterialDesignInXamlToolkit)
 - [Newtonsoft.Json](http://www.newtonsoft.com/json)
 - [Scriban](https://github.com/lunet-io/scriban)
+- [Polly](https://github.com/App-vNext/Polly)
 - [Onova](https://github.com/Tyrrrz/Onova)
 - [FluentCommandLineParser](https://github.com/fclp/fluent-command-line-parser)
 - [Tyrrrz.Extensions](https://github.com/Tyrrrz/Extensions)