Add managed cancellation support

Closes #716

DiscordChatExporter.Cli/Commands/Base/ExportCommandBase.cs

@@ -15,7 +15,6 @@ using DiscordChatExporter.Core.Exporting;
 using DiscordChatExporter.Core.Exporting.Filtering;
 using DiscordChatExporter.Core.Exporting.Partitioning;
 using DiscordChatExporter.Core.Utils.Extensions;
-using Tyrrrz.Extensions;
 
 namespace DiscordChatExporter.Cli.Commands.Base
 {
@@ -56,6 +55,8 @@ namespace DiscordChatExporter.Cli.Commands.Base
 
         protected async ValueTask ExecuteAsync(IConsole console, IReadOnlyList<Channel> channels)
         {
+            var cancellationToken = console.RegisterCancellationHandler();
+
             if (ShouldReuseMedia && !ShouldDownloadMedia)
             {
                 throw new CommandException("Option --reuse-media cannot be used without --media.");
@@ -73,7 +74,7 @@ namespace DiscordChatExporter.Cli.Commands.Base
                     {
                         await progressContext.StartTaskAsync($"{channel.Category} / {channel.Name}", async progress =>
                         {
-                            var guild = await Discord.GetGuildAsync(channel.GuildId);
+                            var guild = await Discord.GetGuildAsync(channel.GuildId, cancellationToken);
 
                             var request = new ExportRequest(
                                 guild,
@@ -89,14 +90,14 @@ namespace DiscordChatExporter.Cli.Commands.Base
                                 DateFormat
                             );
 
-                            await Exporter.ExportChannelAsync(request, progress);
+                            await Exporter.ExportChannelAsync(request, progress, cancellationToken);
                         });
                     }
                     catch (DiscordChatExporterException ex) when (!ex.IsFatal)
                     {
                         errors[channel] = ex.Message;
                     }
-                }, ParallelLimit.ClampMin(1));
+                }, Math.Max(ParallelLimit, 1), cancellationToken);
             });
 
             // Print result
@@ -140,11 +141,12 @@ namespace DiscordChatExporter.Cli.Commands.Base
 
         protected async ValueTask ExecuteAsync(IConsole console, IReadOnlyList<Snowflake> channelIds)
         {
+            var cancellationToken = console.RegisterCancellationHandler();
             var channels = new List<Channel>();
 
             foreach (var channelId in channelIds)
             {
-                var channel = await Discord.GetChannelAsync(channelId);
+                var channel = await Discord.GetChannelAsync(channelId, cancellationToken);
                 channels.Add(channel);
             }
 

DiscordChatExporter.Cli/Commands/ExportAllCommand.cs

@@ -15,16 +15,17 @@ namespace DiscordChatExporter.Cli.Commands
 
         public override async ValueTask ExecuteAsync(IConsole console)
         {
+            var cancellationToken = console.RegisterCancellationHandler();
             var channels = new List<Channel>();
 
             await console.Output.WriteLineAsync("Fetching channels...");
-            await foreach (var guild in Discord.GetUserGuildsAsync())
+            await foreach (var guild in Discord.GetUserGuildsAsync(cancellationToken))
             {
                 // Skip DMs if instructed to
                 if (!IncludeDirectMessages && guild.Id == Guild.DirectMessages.Id)
                     continue;
 
-                await foreach (var channel in Discord.GetGuildChannelsAsync(guild.Id))
+                await foreach (var channel in Discord.GetGuildChannelsAsync(guild.Id, cancellationToken))
                 {
                     // Skip non-text channels
                     if (!channel.IsTextChannel)

DiscordChatExporter.Cli/Commands/ExportDirectMessagesCommand.cs

@@ -13,8 +13,10 @@ namespace DiscordChatExporter.Cli.Commands
     {
         public override async ValueTask ExecuteAsync(IConsole console)
         {
+            var cancellationToken = console.RegisterCancellationHandler();
+
             await console.Output.WriteLineAsync("Fetching channels...");
-            var channels = await Discord.GetGuildChannelsAsync(Guild.DirectMessages.Id);
+            var channels = await Discord.GetGuildChannelsAsync(Guild.DirectMessages.Id, cancellationToken);
             var textChannels = channels.Where(c => c.IsTextChannel).ToArray();
 
             await base.ExecuteAsync(console, textChannels);

DiscordChatExporter.Cli/Commands/ExportGuildCommand.cs

@@ -16,8 +16,10 @@ namespace DiscordChatExporter.Cli.Commands
 
         public override async ValueTask ExecuteAsync(IConsole console)
         {
+            var cancellationToken = console.RegisterCancellationHandler();
+
             await console.Output.WriteLineAsync("Fetching channels...");
-            var channels = await Discord.GetGuildChannelsAsync(GuildId);
+            var channels = await Discord.GetGuildChannelsAsync(GuildId, cancellationToken);
             var textChannels = channels.Where(c => c.IsTextChannel).ToArray();
 
             await base.ExecuteAsync(console, textChannels);

DiscordChatExporter.Cli/Commands/GetChannelsCommand.cs

@@ -17,7 +17,9 @@ namespace DiscordChatExporter.Cli.Commands
 
         public override async ValueTask ExecuteAsync(IConsole console)
         {
-            var channels = await Discord.GetGuildChannelsAsync(GuildId);
+            var cancellationToken = console.RegisterCancellationHandler();
+
+            var channels = await Discord.GetGuildChannelsAsync(GuildId, cancellationToken);
 
             var textChannels = channels
                 .Where(c => c.IsTextChannel)

DiscordChatExporter.Cli/Commands/GetDirectMessageChannelsCommand.cs

@@ -14,7 +14,9 @@ namespace DiscordChatExporter.Cli.Commands
     {
         public override async ValueTask ExecuteAsync(IConsole console)
         {
-            var channels = await Discord.GetGuildChannelsAsync(Guild.DirectMessages.Id);
+            var cancellationToken = console.RegisterCancellationHandler();
+
+            var channels = await Discord.GetGuildChannelsAsync(Guild.DirectMessages.Id, cancellationToken);
 
             var textChannels = channels
                 .Where(c => c.IsTextChannel)

DiscordChatExporter.Cli/Commands/GetGuildsCommand.cs

@@ -13,7 +13,9 @@ namespace DiscordChatExporter.Cli.Commands
     {
         public override async ValueTask ExecuteAsync(IConsole console)
         {
-            var guilds = await Discord.GetUserGuildsAsync();
+            var cancellationToken = console.RegisterCancellationHandler();
+
+            var guilds = await Discord.GetUserGuildsAsync(cancellationToken);
 
             foreach (var guild in guilds.OrderBy(g => g.Name))
             {

DiscordChatExporter.Core/Discord/DiscordClient.cs

@@ -3,7 +3,9 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Net;
 using System.Net.Http;
+using System.Runtime.CompilerServices;
 using System.Text.Json;
+using System.Threading;
 using System.Threading.Tasks;
 using DiscordChatExporter.Core.Discord.Data;
 using DiscordChatExporter.Core.Exceptions;
@@ -21,18 +23,28 @@ namespace DiscordChatExporter.Core.Discord
 
         public DiscordClient(AuthToken token) => _token = token;
 
-        private async ValueTask<HttpResponseMessage> GetResponseAsync(string url) =>
+        private async ValueTask<HttpResponseMessage> GetResponseAsync(
-            await Http.ResponsePolicy.ExecuteAsync(async () =>
+            string url,
+            CancellationToken cancellationToken = default)
+        {
+            return await Http.ResponsePolicy.ExecuteAsync(async innerCancellationToken =>
             {
                 using var request = new HttpRequestMessage(HttpMethod.Get, new Uri(_baseUri, url));
                 request.Headers.Authorization = _token.GetAuthenticationHeader();
 
-                return await Http.Client.SendAsync(request, HttpCompletionOption.ResponseHeadersRead);
+                return await Http.Client.SendAsync(
-            });
+                    request,
+                    HttpCompletionOption.ResponseHeadersRead,
+                    innerCancellationToken
+                );
+            }, cancellationToken);
+        }
 
-        private async ValueTask<JsonElement> GetJsonResponseAsync(string url)
+        private async ValueTask<JsonElement> GetJsonResponseAsync(
+            string url,
+            CancellationToken cancellationToken = default)
         {
-            using var response = await GetResponseAsync(url);
+            using var response = await GetResponseAsync(url, cancellationToken);
 
             if (!response.IsSuccessStatusCode)
             {
@@ -45,19 +57,22 @@ namespace DiscordChatExporter.Core.Discord
                 };
             }
 
-            return await response.Content.ReadAsJsonAsync();
+            return await response.Content.ReadAsJsonAsync(cancellationToken);
         }
 
-        private async ValueTask<JsonElement?> TryGetJsonResponseAsync(string url)
+        private async ValueTask<JsonElement?> TryGetJsonResponseAsync(
+            string url,
+            CancellationToken cancellationToken = default)
         {
-            using var response = await GetResponseAsync(url);
+            using var response = await GetResponseAsync(url, cancellationToken);
 
             return response.IsSuccessStatusCode
-                ? await response.Content.ReadAsJsonAsync()
+                ? await response.Content.ReadAsJsonAsync(cancellationToken)
                 : null;
         }
 
-        public async IAsyncEnumerable<Guild> GetUserGuildsAsync()
+        public async IAsyncEnumerable<Guild> GetUserGuildsAsync(
+            [EnumeratorCancellation] CancellationToken cancellationToken = default)
         {
             yield return Guild.DirectMessages;
 
@@ -71,7 +86,7 @@ namespace DiscordChatExporter.Core.Discord
                     .SetQueryParameter("after", currentAfter.ToString())
                     .Build();
 
-                var response = await GetJsonResponseAsync(url);
+                var response = await GetJsonResponseAsync(url, cancellationToken);
 
                 var isEmpty = true;
                 foreach (var guild in response.EnumerateArray().Select(Guild.Parse))
@@ -87,26 +102,30 @@ namespace DiscordChatExporter.Core.Discord
             }
         }
 
-        public async ValueTask<Guild> GetGuildAsync(Snowflake guildId)
+        public async ValueTask<Guild> GetGuildAsync(
+            Snowflake guildId,
+            CancellationToken cancellationToken = default)
         {
             if (guildId == Guild.DirectMessages.Id)
                 return Guild.DirectMessages;
 
-            var response = await GetJsonResponseAsync($"guilds/{guildId}");
+            var response = await GetJsonResponseAsync($"guilds/{guildId}", cancellationToken);
             return Guild.Parse(response);
         }
 
-        public async IAsyncEnumerable<Channel> GetGuildChannelsAsync(Snowflake guildId)
+        public async IAsyncEnumerable<Channel> GetGuildChannelsAsync(
+            Snowflake guildId,
+            [EnumeratorCancellation] CancellationToken cancellationToken = default)
         {
             if (guildId == Guild.DirectMessages.Id)
             {
-                var response = await GetJsonResponseAsync("users/@me/channels");
+                var response = await GetJsonResponseAsync("users/@me/channels", cancellationToken);
                 foreach (var channelJson in response.EnumerateArray())
                     yield return Channel.Parse(channelJson);
             }
             else
             {
-                var response = await GetJsonResponseAsync($"guilds/{guildId}/channels");
+                var response = await GetJsonResponseAsync($"guilds/{guildId}/channels", cancellationToken);
 
                 var responseOrdered = response
                     .EnumerateArray()
@@ -138,31 +157,38 @@ namespace DiscordChatExporter.Core.Discord
             }
         }
 
-        public async IAsyncEnumerable<Role> GetGuildRolesAsync(Snowflake guildId)
+        public async IAsyncEnumerable<Role> GetGuildRolesAsync(
+            Snowflake guildId,
+            [EnumeratorCancellation] CancellationToken cancellationToken = default)
         {
             if (guildId == Guild.DirectMessages.Id)
                 yield break;
 
-            var response = await GetJsonResponseAsync($"guilds/{guildId}/roles");
+            var response = await GetJsonResponseAsync($"guilds/{guildId}/roles", cancellationToken);
 
             foreach (var roleJson in response.EnumerateArray())
                 yield return Role.Parse(roleJson);
         }
 
-        public async ValueTask<Member> GetGuildMemberAsync(Snowflake guildId, User user)
+        public async ValueTask<Member> GetGuildMemberAsync(
+            Snowflake guildId,
+            User user,
+            CancellationToken cancellationToken = default)
         {
             if (guildId == Guild.DirectMessages.Id)
                 return Member.CreateForUser(user);
 
-            var response = await TryGetJsonResponseAsync($"guilds/{guildId}/members/{user.Id}");
+            var response = await TryGetJsonResponseAsync($"guilds/{guildId}/members/{user.Id}", cancellationToken);
             return response?.Pipe(Member.Parse) ?? Member.CreateForUser(user);
         }
 
-        public async ValueTask<ChannelCategory> GetChannelCategoryAsync(Snowflake channelId)
+        public async ValueTask<ChannelCategory> GetChannelCategoryAsync(
+            Snowflake channelId,
+            CancellationToken cancellationToken = default)
         {
             try
             {
-                var response = await GetJsonResponseAsync($"channels/{channelId}");
+                var response = await GetJsonResponseAsync($"channels/{channelId}", cancellationToken);
                 return ChannelCategory.Parse(response);
             }
             // In some cases, the Discord API returns an empty body when requesting channel category.
@@ -173,20 +199,25 @@ namespace DiscordChatExporter.Core.Discord
             }
         }
 
-        public async ValueTask<Channel> GetChannelAsync(Snowflake channelId)
+        public async ValueTask<Channel> GetChannelAsync(
+            Snowflake channelId,
+            CancellationToken cancellationToken = default)
         {
-            var response = await GetJsonResponseAsync($"channels/{channelId}");
+            var response = await GetJsonResponseAsync($"channels/{channelId}", cancellationToken);
 
             var parentId = response.GetPropertyOrNull("parent_id")?.GetString().Pipe(Snowflake.Parse);
 
             var category = parentId is not null
-                ? await GetChannelCategoryAsync(parentId.Value)
+                ? await GetChannelCategoryAsync(parentId.Value, cancellationToken)
                 : null;
 
             return Channel.Parse(response, category);
         }
 
-        private async ValueTask<Message?> TryGetLastMessageAsync(Snowflake channelId, Snowflake? before = null)
+        private async ValueTask<Message?> TryGetLastMessageAsync(
+            Snowflake channelId,
+            Snowflake? before = null,
+            CancellationToken cancellationToken = default)
         {
             var url = new UrlBuilder()
                 .SetPath($"channels/{channelId}/messages")
@@ -194,7 +225,7 @@ namespace DiscordChatExporter.Core.Discord
                 .SetQueryParameter("before", before?.ToString())
                 .Build();
 
-            var response = await GetJsonResponseAsync(url);
+            var response = await GetJsonResponseAsync(url, cancellationToken);
             return response.EnumerateArray().Select(Message.Parse).LastOrDefault();
         }
 
@@ -202,13 +233,14 @@ namespace DiscordChatExporter.Core.Discord
             Snowflake channelId,
             Snowflake? after = null,
             Snowflake? before = null,
-            IProgress<double>? progress = null)
+            IProgress<double>? progress = null,
+            [EnumeratorCancellation] CancellationToken cancellationToken = default)
         {
             // Get the last message in the specified range.
             // This snapshots the boundaries, which means that messages posted after the export started
             // will not appear in the output.
             // Additionally, it provides the date of the last message, which is used to calculate progress.
-            var lastMessage = await TryGetLastMessageAsync(channelId, before);
+            var lastMessage = await TryGetLastMessageAsync(channelId, before, cancellationToken);
             if (lastMessage is null || lastMessage.Timestamp < after?.ToDate())
                 yield break;
 
@@ -224,7 +256,7 @@ namespace DiscordChatExporter.Core.Discord
                     .SetQueryParameter("after", currentAfter.ToString())
                     .Build();
 
-                var response = await GetJsonResponseAsync(url);
+                var response = await GetJsonResponseAsync(url, cancellationToken);
 
                 var messages = response
                     .EnumerateArray()

DiscordChatExporter.Core/DiscordChatExporter.Core.csproj

@@ -6,7 +6,7 @@
 
   <ItemGroup>
     <PackageReference Include="JsonExtensions" Version="1.1.0" />
-    <PackageReference Include="MiniRazor.CodeGen" Version="2.1.4" />
+    <PackageReference Include="MiniRazor.CodeGen" Version="2.2.0" />
     <PackageReference Include="Polly" Version="7.2.2" />
     <PackageReference Include="Superpower" Version="3.0.0" />
     <PackageReference Include="Tyrrrz.Extensions" Version="1.6.5" />

DiscordChatExporter.Core/Exporting/ChannelExporter.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Threading;
 using System.Threading.Tasks;
 using DiscordChatExporter.Core.Discord;
 using DiscordChatExporter.Core.Discord.Data;
@@ -18,12 +19,15 @@ namespace DiscordChatExporter.Core.Exporting
 
         public ChannelExporter(AuthToken token) : this(new DiscordClient(token)) {}
 
-        public async ValueTask ExportChannelAsync(ExportRequest request, IProgress<double>? progress = null)
+        public async ValueTask ExportChannelAsync(
+            ExportRequest request,
+            IProgress<double>? progress = null,
+            CancellationToken cancellationToken = default)
         {
             // Build context
             var contextMembers = new HashSet<Member>(IdBasedEqualityComparer.Instance);
-            var contextChannels = await _discord.GetGuildChannelsAsync(request.Guild.Id);
+            var contextChannels = await _discord.GetGuildChannelsAsync(request.Guild.Id, cancellationToken);
-            var contextRoles = await _discord.GetGuildRolesAsync(request.Guild.Id);
+            var contextRoles = await _discord.GetGuildRolesAsync(request.Guild.Id, cancellationToken);
 
             var context = new ExportContext(
                 request,
@@ -37,8 +41,16 @@ namespace DiscordChatExporter.Core.Exporting
 
             var exportedAnything = false;
             var encounteredUsers = new HashSet<User>(IdBasedEqualityComparer.Instance);
-            await foreach (var message in _discord.GetMessagesAsync(request.Channel.Id, request.After, request.Before, progress))
+
+            await foreach (var message in _discord.GetMessagesAsync(
+                request.Channel.Id,
+                request.After,
+                request.Before,
+                progress,
+                cancellationToken))
             {
+                cancellationToken.ThrowIfCancellationRequested();
+
                 // Skips any messages that fail to pass the supplied filter
                 if (!request.MessageFilter.IsMatch(message))
                     continue;
@@ -49,12 +61,17 @@ namespace DiscordChatExporter.Core.Exporting
                     if (!encounteredUsers.Add(referencedUser))
                         continue;
 
-                    var member = await _discord.GetGuildMemberAsync(request.Guild.Id, referencedUser);
+                    var member = await _discord.GetGuildMemberAsync(
+                        request.Guild.Id,
+                        referencedUser,
+                        cancellationToken
+                    );
+
                     contextMembers.Add(member);
                 }
 
                 // Export message
-                await messageExporter.ExportMessageAsync(message);
+                await messageExporter.ExportMessageAsync(message, cancellationToken);
                 exportedAnything = true;
             }
 

DiscordChatExporter.Core/Exporting/ExportContext.cs

@@ -4,11 +4,11 @@ using System.Drawing;
 using System.IO;
 using System.Linq;
 using System.Net.Http;
+using System.Threading;
 using System.Threading.Tasks;
 using DiscordChatExporter.Core.Discord;
 using DiscordChatExporter.Core.Discord.Data;
 using DiscordChatExporter.Core.Utils.Extensions;
-using Tyrrrz.Extensions;
 
 namespace DiscordChatExporter.Core.Exporting
 {
@@ -63,14 +63,14 @@ namespace DiscordChatExporter.Core.Exporting
                 .FirstOrDefault();
         }
 
-        public async ValueTask<string> ResolveMediaUrlAsync(string url)
+        public async ValueTask<string> ResolveMediaUrlAsync(string url, CancellationToken cancellationToken = default)
         {
             if (!Request.ShouldDownloadMedia)
                 return url;
 
             try
             {
-                var filePath = await _mediaDownloader.DownloadAsync(url);
+                var filePath = await _mediaDownloader.DownloadAsync(url, cancellationToken);
 
                 // We want relative path so that the output files can be copied around without breaking.
                 // Base directory path may be null if the file is stored at the root or relative to working directory.
@@ -82,10 +82,12 @@ namespace DiscordChatExporter.Core.Exporting
                 if (Request.Format is ExportFormat.HtmlDark or ExportFormat.HtmlLight)
                 {
                     // Need to escape each path segment while keeping the directory separators intact
-                    return relativeFilePath
+                    return string.Join(
-                        .Split(Path.DirectorySeparatorChar, Path.AltDirectorySeparatorChar)
+                        Path.AltDirectorySeparatorChar,
-                        .Select(Uri.EscapeDataString)
+                        relativeFilePath
-                        .JoinToString(Path.AltDirectorySeparatorChar.ToString());
+                            .Split(Path.DirectorySeparatorChar, Path.AltDirectorySeparatorChar)
+                            .Select(Uri.EscapeDataString)
+                    );
                 }
 
                 return relativeFilePath;

DiscordChatExporter.Core/Exporting/MediaDownloader.cs

@@ -5,6 +5,7 @@ using System.IO;
 using System.Security.Cryptography;
 using System.Text;
 using System.Text.RegularExpressions;
+using System.Threading;
 using System.Threading.Tasks;
 using DiscordChatExporter.Core.Utils;
 using DiscordChatExporter.Core.Utils.Extensions;
@@ -25,7 +26,7 @@ namespace DiscordChatExporter.Core.Exporting
             _reuseMedia = reuseMedia;
         }
 
-        public async ValueTask<string> DownloadAsync(string url)
+        public async ValueTask<string> DownloadAsync(string url, CancellationToken cancellationToken = default)
         {
             if (_pathCache.TryGetValue(url, out var cachedFilePath))
                 return cachedFilePath;
@@ -43,7 +44,7 @@ namespace DiscordChatExporter.Core.Exporting
             await Http.ExceptionPolicy.ExecuteAsync(async () =>
             {
                 // Download the file
-                using var response = await Http.Client.GetAsync(url);
+                using var response = await Http.Client.GetAsync(url, cancellationToken);
                 await using (var output = File.Create(filePath))
                 {
                     await response.Content.CopyToAsync(output);

DiscordChatExporter.Core/Exporting/MessageExporter.cs

@@ -1,5 +1,6 @@
 using System;
 using System.IO;
+using System.Threading;
 using System.Threading.Tasks;
 using DiscordChatExporter.Core.Discord.Data;
 using DiscordChatExporter.Core.Exporting.Writers;
@@ -18,23 +19,23 @@ namespace DiscordChatExporter.Core.Exporting
             _context = context;
         }
 
-        private async ValueTask ResetWriterAsync()
+        private async ValueTask ResetWriterAsync(CancellationToken cancellationToken = default)
         {
             if (_writer is not null)
             {
-                await _writer.WritePostambleAsync();
+                await _writer.WritePostambleAsync(cancellationToken);
                 await _writer.DisposeAsync();
                 _writer = null;
             }
         }
 
-        private async ValueTask<MessageWriter> GetWriterAsync()
+        private async ValueTask<MessageWriter> GetWriterAsync(CancellationToken cancellationToken = default)
         {
             // Ensure partition limit has not been reached
             if (_writer is not null &&
                 _context.Request.PartitionLimit.IsReached(_writer.MessagesWritten, _writer.BytesWritten))
             {
-                await ResetWriterAsync();
+                await ResetWriterAsync(cancellationToken);
                 _partitionIndex++;
             }
 
@@ -49,15 +50,15 @@ namespace DiscordChatExporter.Core.Exporting
                 Directory.CreateDirectory(dirPath);
 
             var writer = CreateMessageWriter(filePath, _context.Request.Format, _context);
-            await writer.WritePreambleAsync();
+            await writer.WritePreambleAsync(cancellationToken);
 
             return _writer = writer;
         }
 
-        public async ValueTask ExportMessageAsync(Message message)
+        public async ValueTask ExportMessageAsync(Message message, CancellationToken cancellationToken = default)
         {
-            var writer = await GetWriterAsync();
+            var writer = await GetWriterAsync(cancellationToken);
-            await writer.WriteMessageAsync(message);
+            await writer.WriteMessageAsync(message, cancellationToken);
         }
 
         public async ValueTask DisposeAsync() => await ResetWriterAsync();

DiscordChatExporter.Core/Exporting/Writers/CsvMessageWriter.cs

@@ -1,6 +1,7 @@
 using System.Collections.Generic;
 using System.IO;
 using System.Text;
+using System.Threading;
 using System.Threading.Tasks;
 using DiscordChatExporter.Core.Discord.Data;
 using DiscordChatExporter.Core.Exporting.Writers.MarkdownVisitors;
@@ -21,29 +22,37 @@ namespace DiscordChatExporter.Core.Exporting.Writers
         private string FormatMarkdown(string? markdown) =>
             PlainTextMarkdownVisitor.Format(Context, markdown ?? "");
 
-        public override async ValueTask WritePreambleAsync() =>
+        public override async ValueTask WritePreambleAsync(CancellationToken cancellationToken = default) =>
             await _writer.WriteLineAsync("AuthorID,Author,Date,Content,Attachments,Reactions");
 
-        private async ValueTask WriteAttachmentsAsync(IReadOnlyList<Attachment> attachments)
+        private async ValueTask WriteAttachmentsAsync(
+            IReadOnlyList<Attachment> attachments,
+            CancellationToken cancellationToken = default)
         {
             var buffer = new StringBuilder();
 
             foreach (var attachment in attachments)
             {
+                cancellationToken.ThrowIfCancellationRequested();
+
                 buffer
                     .AppendIfNotEmpty(',')
-                    .Append(await Context.ResolveMediaUrlAsync(attachment.Url));
+                    .Append(await Context.ResolveMediaUrlAsync(attachment.Url, cancellationToken));
             }
 
             await _writer.WriteAsync(CsvEncode(buffer.ToString()));
         }
 
-        private async ValueTask WriteReactionsAsync(IReadOnlyList<Reaction> reactions)
+        private async ValueTask WriteReactionsAsync(
+            IReadOnlyList<Reaction> reactions,
+            CancellationToken cancellationToken = default)
         {
             var buffer = new StringBuilder();
 
             foreach (var reaction in reactions)
             {
+                cancellationToken.ThrowIfCancellationRequested();
+
                 buffer
                     .AppendIfNotEmpty(',')
                     .Append(reaction.Emoji.Name)
@@ -56,9 +65,11 @@ namespace DiscordChatExporter.Core.Exporting.Writers
             await _writer.WriteAsync(CsvEncode(buffer.ToString()));
         }
 
-        public override async ValueTask WriteMessageAsync(Message message)
+        public override async ValueTask WriteMessageAsync(
+            Message message,
+            CancellationToken cancellationToken = default)
         {
-            await base.WriteMessageAsync(message);
+            await base.WriteMessageAsync(message, cancellationToken);
 
             // Author ID
             await _writer.WriteAsync(CsvEncode(message.Author.Id.ToString()));
@@ -77,11 +88,11 @@ namespace DiscordChatExporter.Core.Exporting.Writers
             await _writer.WriteAsync(',');
 
             // Attachments
-            await WriteAttachmentsAsync(message.Attachments);
+            await WriteAttachmentsAsync(message.Attachments, cancellationToken);
             await _writer.WriteAsync(',');
 
             // Reactions
-            await WriteReactionsAsync(message.Reactions);
+            await WriteReactionsAsync(message.Reactions, cancellationToken);
 
             // Finish row
             await _writer.WriteLineAsync();

DiscordChatExporter.Core/Exporting/Writers/Html/PreambleTemplate.cshtml

@@ -13,7 +13,7 @@
 
     string FormatDate(DateTimeOffset date) => Model.ExportContext.FormatDate(date);
 
-    ValueTask<string> ResolveUrlAsync(string url) => Model.ExportContext.ResolveMediaUrlAsync(url);
+    ValueTask<string> ResolveUrlAsync(string url) => Model.ExportContext.ResolveMediaUrlAsync(url, CancellationToken);
 }
 
 <!DOCTYPE html>

DiscordChatExporter.Core/Exporting/Writers/HtmlMessageWriter.cs

@@ -1,6 +1,7 @@
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
+using System.Threading;
 using System.Threading.Tasks;
 using DiscordChatExporter.Core.Discord.Data;
 using DiscordChatExporter.Core.Exporting.Writers.Html;
@@ -21,31 +22,35 @@ namespace DiscordChatExporter.Core.Exporting.Writers
             _themeName = themeName;
         }
 
-        public override async ValueTask WritePreambleAsync()
+        public override async ValueTask WritePreambleAsync(CancellationToken cancellationToken = default)
         {
             var templateContext = new PreambleTemplateContext(Context, _themeName);
 
             // We are not writing directly to output because Razor
             // does not actually do asynchronous writes to stream.
             await _writer.WriteLineAsync(
-                await PreambleTemplate.RenderAsync(templateContext)
+                await PreambleTemplate.RenderAsync(templateContext, cancellationToken)
             );
         }
 
-        private async ValueTask WriteMessageGroupAsync(MessageGroup messageGroup)
+        private async ValueTask WriteMessageGroupAsync(
+            MessageGroup messageGroup,
+            CancellationToken cancellationToken = default)
         {
             var templateContext = new MessageGroupTemplateContext(Context, messageGroup);
 
             // We are not writing directly to output because Razor
             // does not actually do asynchronous writes to stream.
             await _writer.WriteLineAsync(
-                await MessageGroupTemplate.RenderAsync(templateContext)
+                await MessageGroupTemplate.RenderAsync(templateContext, cancellationToken)
             );
         }
 
-        public override async ValueTask WriteMessageAsync(Message message)
+        public override async ValueTask WriteMessageAsync(
+            Message message,
+            CancellationToken cancellationToken = default)
         {
-            await base.WriteMessageAsync(message);
+            await base.WriteMessageAsync(message, cancellationToken);
 
             // If message group is empty or the given message can be grouped, buffer the given message
             if (!_messageGroupBuffer.Any() || MessageGroup.CanJoin(_messageGroupBuffer.Last(), message))
@@ -55,25 +60,30 @@ namespace DiscordChatExporter.Core.Exporting.Writers
             // Otherwise, flush the group and render messages
             else
             {
-                await WriteMessageGroupAsync(MessageGroup.Join(_messageGroupBuffer));
+                await WriteMessageGroupAsync(MessageGroup.Join(_messageGroupBuffer), cancellationToken);
 
                 _messageGroupBuffer.Clear();
                 _messageGroupBuffer.Add(message);
             }
         }
 
-        public override async ValueTask WritePostambleAsync()
+        public override async ValueTask WritePostambleAsync(CancellationToken cancellationToken = default)
         {
             // Flush current message group
             if (_messageGroupBuffer.Any())
-                await WriteMessageGroupAsync(MessageGroup.Join(_messageGroupBuffer));
+            {
+                await WriteMessageGroupAsync(
+                    MessageGroup.Join(_messageGroupBuffer),
+                    cancellationToken
+                );
+            }
 
             var templateContext = new PostambleTemplateContext(Context, MessagesWritten);
 
             // We are not writing directly to output because Razor
             // does not actually do asynchronous writes to stream.
             await _writer.WriteLineAsync(
-                await PostambleTemplate.RenderAsync(templateContext)
+                await PostambleTemplate.RenderAsync(templateContext, cancellationToken)
             );
         }
 

DiscordChatExporter.Core/Exporting/Writers/JsonMessageWriter.cs

@@ -1,6 +1,7 @@
 using System.IO;
 using System.Text.Encodings.Web;
 using System.Text.Json;
+using System.Threading;
 using System.Threading.Tasks;
 using DiscordChatExporter.Core.Discord.Data;
 using DiscordChatExporter.Core.Discord.Data.Embeds;
@@ -30,20 +31,24 @@ namespace DiscordChatExporter.Core.Exporting.Writers
         private string FormatMarkdown(string? markdown) =>
             PlainTextMarkdownVisitor.Format(Context, markdown ?? "");
 
-        private async ValueTask WriteAttachmentAsync(Attachment attachment)
+        private async ValueTask WriteAttachmentAsync(
+            Attachment attachment,
+            CancellationToken cancellationToken = default)
         {
             _writer.WriteStartObject();
 
             _writer.WriteString("id", attachment.Id.ToString());
-            _writer.WriteString("url", await Context.ResolveMediaUrlAsync(attachment.Url));
+            _writer.WriteString("url", await Context.ResolveMediaUrlAsync(attachment.Url, cancellationToken));
             _writer.WriteString("fileName", attachment.FileName);
             _writer.WriteNumber("fileSizeBytes", attachment.FileSize.TotalBytes);
 
             _writer.WriteEndObject();
-            await _writer.FlushAsync();
+            await _writer.FlushAsync(cancellationToken);
         }
 
-        private async ValueTask WriteEmbedAuthorAsync(EmbedAuthor embedAuthor)
+        private async ValueTask WriteEmbedAuthorAsync(
+            EmbedAuthor embedAuthor,
+            CancellationToken cancellationToken = default)
         {
             _writer.WriteStartObject("author");
 
@@ -51,54 +56,62 @@ namespace DiscordChatExporter.Core.Exporting.Writers
             _writer.WriteString("url", embedAuthor.Url);
 
             if (!string.IsNullOrWhiteSpace(embedAuthor.IconUrl))
-                _writer.WriteString("iconUrl", await Context.ResolveMediaUrlAsync(embedAuthor.IconProxyUrl ?? embedAuthor.IconUrl));
+                _writer.WriteString("iconUrl", await Context.ResolveMediaUrlAsync(embedAuthor.IconProxyUrl ?? embedAuthor.IconUrl, cancellationToken));
 
             _writer.WriteEndObject();
-            await _writer.FlushAsync();
+            await _writer.FlushAsync(cancellationToken);
         }
 
-        private async ValueTask WriteEmbedThumbnailAsync(EmbedImage embedThumbnail)
+        private async ValueTask WriteEmbedThumbnailAsync(
+            EmbedImage embedThumbnail,
+            CancellationToken cancellationToken = default)
         {
             _writer.WriteStartObject("thumbnail");
 
             if (!string.IsNullOrWhiteSpace(embedThumbnail.Url))
-                _writer.WriteString("url", await Context.ResolveMediaUrlAsync(embedThumbnail.ProxyUrl ?? embedThumbnail.Url));
+                _writer.WriteString("url", await Context.ResolveMediaUrlAsync(embedThumbnail.ProxyUrl ?? embedThumbnail.Url, cancellationToken));
 
             _writer.WriteNumber("width", embedThumbnail.Width);
             _writer.WriteNumber("height", embedThumbnail.Height);
 
             _writer.WriteEndObject();
-            await _writer.FlushAsync();
+            await _writer.FlushAsync(cancellationToken);
         }
 
-        private async ValueTask WriteEmbedImageAsync(EmbedImage embedImage)
+        private async ValueTask WriteEmbedImageAsync(
+            EmbedImage embedImage,
+            CancellationToken cancellationToken = default)
         {
             _writer.WriteStartObject("image");
 
             if (!string.IsNullOrWhiteSpace(embedImage.Url))
-                _writer.WriteString("url", await Context.ResolveMediaUrlAsync(embedImage.ProxyUrl ?? embedImage.Url));
+                _writer.WriteString("url", await Context.ResolveMediaUrlAsync(embedImage.ProxyUrl ?? embedImage.Url, cancellationToken));
 
             _writer.WriteNumber("width", embedImage.Width);
             _writer.WriteNumber("height", embedImage.Height);
 
             _writer.WriteEndObject();
-            await _writer.FlushAsync();
+            await _writer.FlushAsync(cancellationToken);
         }
 
-        private async ValueTask WriteEmbedFooterAsync(EmbedFooter embedFooter)
+        private async ValueTask WriteEmbedFooterAsync(
+            EmbedFooter embedFooter,
+            CancellationToken cancellationToken = default)
         {
             _writer.WriteStartObject("footer");
 
             _writer.WriteString("text", embedFooter.Text);
 
             if (!string.IsNullOrWhiteSpace(embedFooter.IconUrl))
-                _writer.WriteString("iconUrl", await Context.ResolveMediaUrlAsync(embedFooter.IconProxyUrl ?? embedFooter.IconUrl));
+                _writer.WriteString("iconUrl", await Context.ResolveMediaUrlAsync(embedFooter.IconProxyUrl ?? embedFooter.IconUrl, cancellationToken));
 
             _writer.WriteEndObject();
-            await _writer.FlushAsync();
+            await _writer.FlushAsync(cancellationToken);
         }
 
-        private async ValueTask WriteEmbedFieldAsync(EmbedField embedField)
+        private async ValueTask WriteEmbedFieldAsync(
+            EmbedField embedField,
+            CancellationToken cancellationToken = default)
         {
             _writer.WriteStartObject();
 
@@ -107,10 +120,12 @@ namespace DiscordChatExporter.Core.Exporting.Writers
             _writer.WriteBoolean("isInline", embedField.IsInline);
 
             _writer.WriteEndObject();
-            await _writer.FlushAsync();
+            await _writer.FlushAsync(cancellationToken);
         }
 
-        private async ValueTask WriteEmbedAsync(Embed embed)
+        private async ValueTask WriteEmbedAsync(
+            Embed embed,
+            CancellationToken cancellationToken = default)
         {
             _writer.WriteStartObject();
 
@@ -123,30 +138,32 @@ namespace DiscordChatExporter.Core.Exporting.Writers
                 _writer.WriteString("color", embed.Color.Value.ToHex());
 
             if (embed.Author is not null)
-                await WriteEmbedAuthorAsync(embed.Author);
+                await WriteEmbedAuthorAsync(embed.Author, cancellationToken);
 
             if (embed.Thumbnail is not null)
-                await WriteEmbedThumbnailAsync(embed.Thumbnail);
+                await WriteEmbedThumbnailAsync(embed.Thumbnail, cancellationToken);
 
             if (embed.Image is not null)
-                await WriteEmbedImageAsync(embed.Image);
+                await WriteEmbedImageAsync(embed.Image, cancellationToken);
 
             if (embed.Footer is not null)
-                await WriteEmbedFooterAsync(embed.Footer);
+                await WriteEmbedFooterAsync(embed.Footer, cancellationToken);
 
             // Fields
             _writer.WriteStartArray("fields");
 
             foreach (var field in embed.Fields)
-                await WriteEmbedFieldAsync(field);
+                await WriteEmbedFieldAsync(field, cancellationToken);
 
             _writer.WriteEndArray();
 
             _writer.WriteEndObject();
-            await _writer.FlushAsync();
+            await _writer.FlushAsync(cancellationToken);
         }
 
-        private async ValueTask WriteReactionAsync(Reaction reaction)
+        private async ValueTask WriteReactionAsync(
+            Reaction reaction,
+            CancellationToken cancellationToken = default)
         {
             _writer.WriteStartObject();
 
@@ -155,16 +172,18 @@ namespace DiscordChatExporter.Core.Exporting.Writers
             _writer.WriteString("id", reaction.Emoji.Id);
             _writer.WriteString("name", reaction.Emoji.Name);
             _writer.WriteBoolean("isAnimated", reaction.Emoji.IsAnimated);
-            _writer.WriteString("imageUrl", await Context.ResolveMediaUrlAsync(reaction.Emoji.ImageUrl));
+            _writer.WriteString("imageUrl", await Context.ResolveMediaUrlAsync(reaction.Emoji.ImageUrl, cancellationToken));
             _writer.WriteEndObject();
 
             _writer.WriteNumber("count", reaction.Count);
 
             _writer.WriteEndObject();
-            await _writer.FlushAsync();
+            await _writer.FlushAsync(cancellationToken);
         }
 
-        private async ValueTask WriteMentionAsync(User mentionedUser)
+        private async ValueTask WriteMentionAsync(
+            User mentionedUser,
+            CancellationToken cancellationToken = default)
         {
             _writer.WriteStartObject();
 
@@ -175,10 +194,10 @@ namespace DiscordChatExporter.Core.Exporting.Writers
             _writer.WriteBoolean("isBot", mentionedUser.IsBot);
 
             _writer.WriteEndObject();
-            await _writer.FlushAsync();
+            await _writer.FlushAsync(cancellationToken);
         }
 
-        public override async ValueTask WritePreambleAsync()
+        public override async ValueTask WritePreambleAsync(CancellationToken cancellationToken = default)
         {
             // Root object (start)
             _writer.WriteStartObject();
@@ -187,7 +206,7 @@ namespace DiscordChatExporter.Core.Exporting.Writers
             _writer.WriteStartObject("guild");
             _writer.WriteString("id", Context.Request.Guild.Id.ToString());
             _writer.WriteString("name", Context.Request.Guild.Name);
-            _writer.WriteString("iconUrl", await Context.ResolveMediaUrlAsync(Context.Request.Guild.IconUrl));
+            _writer.WriteString("iconUrl", await Context.ResolveMediaUrlAsync(Context.Request.Guild.IconUrl, cancellationToken));
             _writer.WriteEndObject();
 
             // Channel
@@ -208,12 +227,14 @@ namespace DiscordChatExporter.Core.Exporting.Writers
 
             // Message array (start)
             _writer.WriteStartArray("messages");
-            await _writer.FlushAsync();
+            await _writer.FlushAsync(cancellationToken);
         }
 
-        public override async ValueTask WriteMessageAsync(Message message)
+        public override async ValueTask WriteMessageAsync(
+            Message message,
+            CancellationToken cancellationToken = default)
         {
-            await base.WriteMessageAsync(message);
+            await base.WriteMessageAsync(message, cancellationToken);
 
             _writer.WriteStartObject();
 
@@ -236,14 +257,14 @@ namespace DiscordChatExporter.Core.Exporting.Writers
             _writer.WriteString("nickname", Context.TryGetMember(message.Author.Id)?.Nick ?? message.Author.Name);
             _writer.WriteString("color", Context.TryGetUserColor(message.Author.Id)?.ToHex());
             _writer.WriteBoolean("isBot", message.Author.IsBot);
-            _writer.WriteString("avatarUrl", await Context.ResolveMediaUrlAsync(message.Author.AvatarUrl));
+            _writer.WriteString("avatarUrl", await Context.ResolveMediaUrlAsync(message.Author.AvatarUrl, cancellationToken));
             _writer.WriteEndObject();
 
             // Attachments
             _writer.WriteStartArray("attachments");
 
             foreach (var attachment in message.Attachments)
-                await WriteAttachmentAsync(attachment);
+                await WriteAttachmentAsync(attachment, cancellationToken);
 
             _writer.WriteEndArray();
 
@@ -251,7 +272,7 @@ namespace DiscordChatExporter.Core.Exporting.Writers
             _writer.WriteStartArray("embeds");
 
             foreach (var embed in message.Embeds)
-                await WriteEmbedAsync(embed);
+                await WriteEmbedAsync(embed, cancellationToken);
 
             _writer.WriteEndArray();
 
@@ -259,7 +280,7 @@ namespace DiscordChatExporter.Core.Exporting.Writers
             _writer.WriteStartArray("reactions");
 
             foreach (var reaction in message.Reactions)
-                await WriteReactionAsync(reaction);
+                await WriteReactionAsync(reaction, cancellationToken);
 
             _writer.WriteEndArray();
 
@@ -267,7 +288,7 @@ namespace DiscordChatExporter.Core.Exporting.Writers
             _writer.WriteStartArray("mentions");
 
             foreach (var mention in message.MentionedUsers)
-                await WriteMentionAsync(mention);
+                await WriteMentionAsync(mention, cancellationToken);
 
             _writer.WriteEndArray();
 
@@ -282,10 +303,10 @@ namespace DiscordChatExporter.Core.Exporting.Writers
             }
 
             _writer.WriteEndObject();
-            await _writer.FlushAsync();
+            await _writer.FlushAsync(cancellationToken);
         }
 
-        public override async ValueTask WritePostambleAsync()
+        public override async ValueTask WritePostambleAsync(CancellationToken cancellationToken = default)
         {
             // Message array (end)
             _writer.WriteEndArray();
@@ -294,7 +315,7 @@ namespace DiscordChatExporter.Core.Exporting.Writers
 
             // Root object (end)
             _writer.WriteEndObject();
-            await _writer.FlushAsync();
+            await _writer.FlushAsync(cancellationToken);
         }
 
         public override async ValueTask DisposeAsync()

DiscordChatExporter.Core/Exporting/Writers/MessageWriter.cs

@@ -1,5 +1,6 @@
 using System;
 using System.IO;
+using System.Threading;
 using System.Threading.Tasks;
 using DiscordChatExporter.Core.Discord.Data;
 
@@ -21,15 +22,15 @@ namespace DiscordChatExporter.Core.Exporting.Writers
             Context = context;
         }
 
-        public virtual ValueTask WritePreambleAsync() => default;
+        public virtual ValueTask WritePreambleAsync(CancellationToken cancellationToken = default) => default;
 
-        public virtual ValueTask WriteMessageAsync(Message message)
+        public virtual ValueTask WriteMessageAsync(Message message, CancellationToken cancellationToken = default)
         {
             MessagesWritten++;
             return default;
         }
 
-        public virtual ValueTask WritePostambleAsync() => default;
+        public virtual ValueTask WritePostambleAsync(CancellationToken cancellationToken = default) => default;
 
         public virtual async ValueTask DisposeAsync() => await Stream.DisposeAsync();
     }

DiscordChatExporter.Core/Exporting/Writers/PlainTextMessageWriter.cs

@@ -1,6 +1,7 @@
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
+using System.Threading;
 using System.Threading.Tasks;
 using DiscordChatExporter.Core.Discord.Data;
 using DiscordChatExporter.Core.Discord.Data.Embeds;
@@ -35,7 +36,9 @@ namespace DiscordChatExporter.Core.Exporting.Writers
             await _writer.WriteLineAsync();
         }
 
-        private async ValueTask WriteAttachmentsAsync(IReadOnlyList<Attachment> attachments)
+        private async ValueTask WriteAttachmentsAsync(
+            IReadOnlyList<Attachment> attachments,
+            CancellationToken cancellationToken = default)
         {
             if (!attachments.Any())
                 return;
@@ -43,15 +46,23 @@ namespace DiscordChatExporter.Core.Exporting.Writers
             await _writer.WriteLineAsync("{Attachments}");
 
             foreach (var attachment in attachments)
-                await _writer.WriteLineAsync(await Context.ResolveMediaUrlAsync(attachment.Url));
+            {
+                cancellationToken.ThrowIfCancellationRequested();
+
+                await _writer.WriteLineAsync(await Context.ResolveMediaUrlAsync(attachment.Url, cancellationToken));
+            }
 
             await _writer.WriteLineAsync();
         }
 
-        private async ValueTask WriteEmbedsAsync(IReadOnlyList<Embed> embeds)
+        private async ValueTask WriteEmbedsAsync(
+            IReadOnlyList<Embed> embeds,
+            CancellationToken cancellationToken = default)
         {
             foreach (var embed in embeds)
             {
+                cancellationToken.ThrowIfCancellationRequested();
+
                 await _writer.WriteLineAsync("{Embed}");
 
                 if (!string.IsNullOrWhiteSpace(embed.Author?.Name))
@@ -76,10 +87,10 @@ namespace DiscordChatExporter.Core.Exporting.Writers
                 }
 
                 if (!string.IsNullOrWhiteSpace(embed.Thumbnail?.Url))
-                    await _writer.WriteLineAsync(await Context.ResolveMediaUrlAsync(embed.Thumbnail.ProxyUrl ?? embed.Thumbnail.Url));
+                    await _writer.WriteLineAsync(await Context.ResolveMediaUrlAsync(embed.Thumbnail.ProxyUrl ?? embed.Thumbnail.Url, cancellationToken));
 
                 if (!string.IsNullOrWhiteSpace(embed.Image?.Url))
-                    await _writer.WriteLineAsync(await Context.ResolveMediaUrlAsync(embed.Image.ProxyUrl ?? embed.Image.Url));
+                    await _writer.WriteLineAsync(await Context.ResolveMediaUrlAsync(embed.Image.ProxyUrl ?? embed.Image.Url, cancellationToken));
 
                 if (!string.IsNullOrWhiteSpace(embed.Footer?.Text))
                     await _writer.WriteLineAsync(embed.Footer.Text);
@@ -88,7 +99,9 @@ namespace DiscordChatExporter.Core.Exporting.Writers
             }
         }
 
-        private async ValueTask WriteReactionsAsync(IReadOnlyList<Reaction> reactions)
+        private async ValueTask WriteReactionsAsync(
+            IReadOnlyList<Reaction> reactions,
+            CancellationToken cancellationToken = default)
         {
             if (!reactions.Any())
                 return;
@@ -97,6 +110,8 @@ namespace DiscordChatExporter.Core.Exporting.Writers
 
             foreach (var reaction in reactions)
             {
+                cancellationToken.ThrowIfCancellationRequested();
+
                 await _writer.WriteAsync(reaction.Emoji.Name);
 
                 if (reaction.Count > 1)
@@ -108,7 +123,7 @@ namespace DiscordChatExporter.Core.Exporting.Writers
             await _writer.WriteLineAsync();
         }
 
-        public override async ValueTask WritePreambleAsync()
+        public override async ValueTask WritePreambleAsync(CancellationToken cancellationToken = default)
         {
             await _writer.WriteLineAsync('='.Repeat(62));
             await _writer.WriteLineAsync($"Guild: {Context.Request.Guild.Name}");
@@ -127,9 +142,11 @@ namespace DiscordChatExporter.Core.Exporting.Writers
             await _writer.WriteLineAsync();
         }
 
-        public override async ValueTask WriteMessageAsync(Message message)
+        public override async ValueTask WriteMessageAsync(
+            Message message,
+            CancellationToken cancellationToken = default)
         {
-            await base.WriteMessageAsync(message);
+            await base.WriteMessageAsync(message, cancellationToken);
 
             // Header
             await WriteMessageHeaderAsync(message);
@@ -141,14 +158,14 @@ namespace DiscordChatExporter.Core.Exporting.Writers
             await _writer.WriteLineAsync();
 
             // Attachments, embeds, reactions
-            await WriteAttachmentsAsync(message.Attachments);
+            await WriteAttachmentsAsync(message.Attachments, cancellationToken);
-            await WriteEmbedsAsync(message.Embeds);
+            await WriteEmbedsAsync(message.Embeds, cancellationToken);
-            await WriteReactionsAsync(message.Reactions);
+            await WriteReactionsAsync(message.Reactions, cancellationToken);
 
             await _writer.WriteLineAsync();
         }
 
-        public override async ValueTask WritePostambleAsync()
+        public override async ValueTask WritePostambleAsync(CancellationToken cancellationToken = default)
         {
             await _writer.WriteLineAsync('='.Repeat(62));
             await _writer.WriteLineAsync($"Exported {MessagesWritten:N0} message(s)");

DiscordChatExporter.Core/Utils/Extensions/AsyncExtensions.cs

@@ -27,14 +27,15 @@ namespace DiscordChatExporter.Core.Utils.Extensions
         public static async ValueTask ParallelForEachAsync<T>(
             this IEnumerable<T> source,
             Func<T, ValueTask> handleAsync,
-            int degreeOfParallelism)
+            int degreeOfParallelism,
+            CancellationToken cancellationToken = default)
         {
             using var semaphore = new SemaphoreSlim(degreeOfParallelism);
 
             await Task.WhenAll(source.Select(async item =>
             {
                 // ReSharper disable once AccessToDisposedClosure
-                await semaphore.WaitAsync();
+                await semaphore.WaitAsync(cancellationToken);
 
                 try
                 {

DiscordChatExporter.Gui/DiscordChatExporter.Gui.csproj

@@ -19,7 +19,7 @@
     <PackageReference Include="Gress" Version="1.2.0" />
     <PackageReference Include="MaterialDesignColors" Version="2.0.1" />
     <PackageReference Include="MaterialDesignThemes" Version="4.0.0" />
-    <PackageReference Include="Microsoft.Xaml.Behaviors.Wpf" Version="1.1.31" />
+    <PackageReference Include="Microsoft.Xaml.Behaviors.Wpf" Version="1.1.37" />
     <PackageReference Include="Ookii.Dialogs.Wpf" Version="4.0.0" />
     <PackageReference Include="Onova" Version="2.6.2" />
     <PackageReference Include="Stylet" Version="1.3.6" />