commit 15d4eb6871489653cb402a5a63a4481007a8bcf4 Author: Fabio Iotti Date: Sun Oct 27 16:35:33 2024 +0100 Initial commit diff --git a/.gitignore b/.gitignore new file mode 100644 index 0000000..0a079b6 --- /dev/null +++ b/.gitignore @@ -0,0 +1,2 @@ +/bin +/obj \ No newline at end of file diff --git a/COPYING b/COPYING new file mode 100644 index 0000000..be3f7b2 --- /dev/null +++ b/COPYING @@ -0,0 +1,661 @@ + GNU AFFERO GENERAL PUBLIC LICENSE + Version 3, 19 November 2007 + + Copyright (C) 2007 Free Software Foundation, Inc. + Everyone is permitted to copy and distribute verbatim copies + of this license document, but changing it is not allowed. + + Preamble + + The GNU Affero General Public License is a free, copyleft license for +software and other kinds of works, specifically designed to ensure +cooperation with the community in the case of network server software. + + The licenses for most software and other practical works are designed +to take away your freedom to share and change the works. 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It is safest +to attach them to the start of each source file to most effectively +state the exclusion of warranty; and each file should have at least +the "copyright" line and a pointer to where the full notice is found. + + + Copyright (C) + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU Affero General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU Affero General Public License for more details. + + You should have received a copy of the GNU Affero General Public License + along with this program. If not, see . + +Also add information on how to contact you by electronic and paper mail. + + If your software can interact with users remotely through a computer +network, you should also make sure that it provides a way for users to +get its source. For example, if your program is a web application, its +interface could display a "Source" link that leads users to an archive +of the code. There are many ways you could offer source, and different +solutions will be better for different programs; see section 13 for the +specific requirements. + + You should also get your employer (if you work as a programmer) or school, +if any, to sign a "copyright disclaimer" for the program, if necessary. +For more information on this, and how to apply and follow the GNU AGPL, see +. diff --git a/CommentsEngine.csproj b/CommentsEngine.csproj new file mode 100644 index 0000000..8186e5b --- /dev/null +++ b/CommentsEngine.csproj @@ -0,0 +1,11 @@ + + + + net8.0 + enable + enable + true + true + + + diff --git a/CommentsEngine.sln b/CommentsEngine.sln new file mode 100644 index 0000000..1a82332 --- /dev/null +++ b/CommentsEngine.sln @@ -0,0 +1,25 @@ + +Microsoft Visual Studio Solution File, Format Version 12.00 +# Visual Studio Version 17 +VisualStudioVersion = 17.5.002.0 +MinimumVisualStudioVersion = 10.0.40219.1 +Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "CommentsEngine", "CommentsEngine.csproj", "{370DF8BC-BE15-417A-B1F9-941889EFBAD7}" +EndProject +Global + GlobalSection(SolutionConfigurationPlatforms) = preSolution + Debug|Any CPU = Debug|Any CPU + Release|Any CPU = Release|Any CPU + EndGlobalSection + GlobalSection(ProjectConfigurationPlatforms) = postSolution + {370DF8BC-BE15-417A-B1F9-941889EFBAD7}.Debug|Any CPU.ActiveCfg = Debug|Any CPU + {370DF8BC-BE15-417A-B1F9-941889EFBAD7}.Debug|Any CPU.Build.0 = Debug|Any CPU + {370DF8BC-BE15-417A-B1F9-941889EFBAD7}.Release|Any CPU.ActiveCfg = Release|Any CPU + {370DF8BC-BE15-417A-B1F9-941889EFBAD7}.Release|Any CPU.Build.0 = Release|Any CPU + EndGlobalSection + GlobalSection(SolutionProperties) = preSolution + HideSolutionNode = FALSE + EndGlobalSection + GlobalSection(ExtensibilityGlobals) = postSolution + SolutionGuid = {6237834B-61E0-44F0-BEC7-494E71A8777C} + EndGlobalSection +EndGlobal diff --git a/Data/ArrayPoolList.cs b/Data/ArrayPoolList.cs new file mode 100644 index 0000000..f30388c --- /dev/null +++ b/Data/ArrayPoolList.cs @@ -0,0 +1,186 @@ +// SPDX-FileCopyrightText: Copyright 2024 Fabio Iotti +// SPDX-License-Identifier: AGPL-3.0-only + +using System.Buffers; +using System.Collections; +using System.Diagnostics.CodeAnalysis; +using System.Runtime.CompilerServices; + +namespace CommentsEngine.Data; + +class ArrayPoolList : IList, IDisposable +{ + readonly ArrayPool _pool; + readonly bool _clearArray; + + int _count; + T[]? _buffer; + + public ArrayPoolList() : this(16) { } + + public ArrayPoolList(int capacity) : this(capacity, ArrayPool.Shared) { } + + public ArrayPoolList(ArrayPool pool, bool clearArray = false) : this(16, pool, clearArray) { } + + public ArrayPoolList(int capacity, ArrayPool pool, bool clearArray = false) + { + _pool = pool; + _clearArray = clearArray; + + _buffer = _pool.Rent(capacity); + } + + /// + public T this[int index] + { + get + { + CheckNotDisposed(); + + ArgumentOutOfRangeException.ThrowIfLessThanOrEqual(index, _count); + + return _buffer[index]; + } + set + { + CheckNotDisposed(); + + ArgumentOutOfRangeException.ThrowIfLessThanOrEqual(index, _count); + + _buffer[index] = value; + } + } + + /// + public int Count => _count; + + bool ICollection.IsReadOnly => false; + + [MethodImpl(MethodImplOptions.AggressiveInlining)] + [MemberNotNull(nameof(_buffer))] + void CheckNotDisposed() + => ObjectDisposedException.ThrowIf(_buffer is null, typeof(ArrayPoolList)); + + [MethodImpl(MethodImplOptions.AggressiveInlining)] + void EnsureBufferAtLeast(ref T[] _buffer, int size) + { + if (_buffer.Length < size) + { + T[] newBuffer = _pool.Rent(1 + size * 2); + _buffer.CopyTo(newBuffer, 0); + _pool.Return(_buffer, _clearArray); + _buffer = newBuffer; + } + } + + /// + public void Add(T item) + { + CheckNotDisposed(); + EnsureBufferAtLeast(ref _buffer, _count + 1); + + _buffer[_count++] = item; + } + + /// + public void Clear() + { + CheckNotDisposed(); + + _count = 0; + } + + /// + public bool Contains(T item) + => IndexOf(item) is not -1; + + /// + public void CopyTo(T[] array, int arrayIndex) + { + CheckNotDisposed(); + + _buffer.AsSpan(0, _count).CopyTo(array.AsSpan(arrayIndex)); + } + + /// + public int IndexOf(T item) + { + CheckNotDisposed(); + + for (int i = 0; i < _buffer.Length && i < _count; i++) + if (Equals(item, _buffer[i])) + return i; + + return -1; + } + + /// + public void Insert(int index, T item) + { + CheckNotDisposed(); + + ArgumentOutOfRangeException.ThrowIfNegativeOrZero(index); + ArgumentOutOfRangeException.ThrowIfGreaterThanOrEqual(_count, index); + + EnsureBufferAtLeast(ref _buffer, _count + 1); + + Array.Copy(_buffer, index, _buffer, index + 1, _count - index); + _buffer[index] = item; + _count++; + } + + /// + public bool Remove(T item) + { + CheckNotDisposed(); + + int index = IndexOf(item); + if (index is -1) + return false; + + Array.Copy(_buffer, index, _buffer, index - 1, _count - index); + _count--; + + return true; + } + + /// + public void RemoveAt(int index) + { + CheckNotDisposed(); + + ArgumentOutOfRangeException.ThrowIfNegativeOrZero(index); + ArgumentOutOfRangeException.ThrowIfGreaterThanOrEqual(_count, index); + + Array.Copy(_buffer, index, _buffer, index - 1, _count - index); + _count--; + } + + /// + public IEnumerator GetEnumerator() + { + CheckNotDisposed(); + + return _buffer.Take(_count).GetEnumerator(); + } + + IEnumerator IEnumerable.GetEnumerator() + => GetEnumerator(); + + protected virtual void Dispose(bool disposing) + { + if (_buffer is not null) + { + if (disposing) + _pool.Return(_buffer, _clearArray); + + _buffer = null; + } + } + + public void Dispose() + { + Dispose(disposing: true); + GC.SuppressFinalize(this); + } +} \ No newline at end of file diff --git a/Data/PageSlim.cs b/Data/PageSlim.cs new file mode 100644 index 0000000..6bf036b --- /dev/null +++ b/Data/PageSlim.cs @@ -0,0 +1,58 @@ +// SPDX-FileCopyrightText: Copyright 2024 Fabio Iotti +// SPDX-License-Identifier: AGPL-3.0-only + +using System.Buffers; +using System.Diagnostics.CodeAnalysis; +using System.Net; +using System.Net.Mime; + +namespace CommentsEngine.Data; + +/// +/// Kinda behaves like an ASP.NET Core MVC pages. +/// Also, it comes with a lot of limitations. +/// Unlike MVC pages, it is compatible with AOT trimming. +/// +/// +abstract class PageSlim where TSelf : PageSlim +{ + protected virtual string ContentType => MediaTypeNames.Text.Html; + + [StringSyntax(StringSyntaxAttribute.CompositeFormat)] + protected abstract ReadOnlySpan ContentTemplate { get; } + + readonly Utf8CompositeFormat _compositeFormat; + readonly string _contentType; + readonly int _maxArgsCount; + + public PageSlim() + { + _compositeFormat = Utf8CompositeFormat.Parse(ContentTemplate); + _contentType = ContentType.Contains(';') ? ContentType : $"{ContentType};charset=utf-8"; + _maxArgsCount = _compositeFormat.MinimumArgumentCount; + } + + protected abstract ValueTask HandleAsync(HttpContext context, Memory templateArgs); + + async Task HandleAsync(HttpContext context) + { + object?[] templateArgsBuffer = ArrayPool.Shared.Rent(_maxArgsCount); + try + { + Memory templateArgs = templateArgsBuffer.AsMemory(0, _maxArgsCount); + + await HandleAsync(context, templateArgsBuffer); + + context.Response.StatusCode = (int)HttpStatusCode.OK; + context.Response.ContentType = _contentType; + await _compositeFormat.WriteToAsync(context.Response.Body, templateArgs, context.RequestAborted); + } + finally + { + ArrayPool.Shared.Return(templateArgsBuffer); + } + } + + public static implicit operator RequestDelegate(PageSlim page) + => page.HandleAsync; +} diff --git a/Data/Utf8CompositeFormat.cs b/Data/Utf8CompositeFormat.cs new file mode 100644 index 0000000..85a440a --- /dev/null +++ b/Data/Utf8CompositeFormat.cs @@ -0,0 +1,256 @@ +// SPDX-FileCopyrightText: Copyright 2024 Fabio Iotti +// SPDX-License-Identifier: AGPL-3.0-only + +using System.Buffers; +using System.Buffers.Text; +using System.Collections.Immutable; +using System.Diagnostics; +using System.Diagnostics.CodeAnalysis; +using System.Globalization; +using System.Text; + +namespace CommentsEngine.Data; + +/// +readonly struct Utf8CompositeFormat +{ + readonly record struct Segment(int Index, int Length, int ArgumentIndex, StandardFormat? StandardFormat, CompositeFormat? CompositeFormat); + + static readonly CompositeFormat s_placeholderCompositeFormat = CompositeFormat.Parse("{0}"); + + readonly ReadOnlyMemory _format; + readonly ImmutableArray _segments; + readonly int _minimumArgumentCount; + + Utf8CompositeFormat(ReadOnlyMemory format, ImmutableArray segments, int minimumArgumentCount) + { + _format = format; + _segments = segments; + _minimumArgumentCount = minimumArgumentCount; + } + + /// + public ReadOnlyMemory Format => _format; + + /// + public int MinimumArgumentCount => _minimumArgumentCount; + + public static Utf8CompositeFormat Parse([StringSyntax("CompositeFormat")] ReadOnlySpan format) + { + using ArrayPoolList segments = []; + + int minimumArgumentCount = 0; + + int currentSegmentStart = 0; + int i; + for (i = 0; i < format.Length; i++) + { + // Is it the start of a placeholder? + if (format[i] is (byte)'{') + { + int currentSegmentEnd = i; + + // End of the string reached? Then it's not a placeholder. + if (++i > format.Length) + break; + + // Two consecutive '{' represent a single '{', so in this case it's not a placeholder. + if (format[i] is (byte)'{') + { + // Create a new segment without a placeholder. + segments.Add(new(currentSegmentStart, currentSegmentEnd - currentSegmentStart, -1, null, null)); + currentSegmentStart = i + 1; + } + else + { + int currentPlaceholderStart = i; + + // Find the end of the placeholder part. + while (i < format.Length && format[++i] is not (byte)'}'); + + int currentPlaceholderEnd = i; + + int separatorIndexFromStart = format[currentPlaceholderStart..currentPlaceholderEnd].IndexOf((byte)':'); + + ReadOnlySpan argumentIndexRaw = format.Slice(currentPlaceholderStart, (separatorIndexFromStart is -1 ? currentPlaceholderEnd : (currentPlaceholderStart + separatorIndexFromStart)) - currentPlaceholderStart); + ReadOnlySpan standardFormatRaw = format[(separatorIndexFromStart is -1 ? currentPlaceholderEnd : (currentPlaceholderStart + separatorIndexFromStart + 1))..currentPlaceholderEnd]; + + int argumentIndex; + try + { + argumentIndex = int.Parse(argumentIndexRaw, NumberStyles.None, CultureInfo.InvariantCulture); + } + catch (Exception ex) + { + throw new ArgumentException(null, nameof(format), ex); + } + + if (argumentIndex < 0) + throw new ArgumentException(null, nameof(format)); + + if (argumentIndex >= minimumArgumentCount) + minimumArgumentCount = argumentIndex + 1; + + StandardFormat? standardFormat; + CompositeFormat compositeFormat; + if (standardFormatRaw.Length is 0) + { + standardFormat = null; + compositeFormat = s_placeholderCompositeFormat; + } + else + { + try + { + (standardFormat, compositeFormat) = ParseFormatUtf8(standardFormatRaw); + } + catch (Exception ex) + { + throw new ArgumentException(null, nameof(format), ex); + } + } + + // TODO: if standardFormat is null, build a CompositeFormat string with a single argument. + segments.Add(new(currentSegmentStart, currentSegmentEnd - currentSegmentStart, argumentIndex, standardFormat, compositeFormat)); + currentSegmentStart = currentPlaceholderEnd + 1; + } + } + } + + // Create the final segment without a placeholder. + if (currentSegmentStart != format.Length) + segments.Add(new(currentSegmentStart, format.Length - currentSegmentStart, -1, null, null)); + + return new(format.ToArray(), [.. segments], minimumArgumentCount); + } + + static (StandardFormat? Standard, CompositeFormat Composite) ParseFormatUtf8(ReadOnlySpan format) + { + int maxCount = Encoding.UTF8.GetMaxCharCount(format.Length) + "{0:".Length + "}".Length; + Span buffer = maxCount > 4096 ? new char[maxCount] : stackalloc char[maxCount]; + + int standardFormatLength = Encoding.UTF8.GetChars(format, buffer["{0:".Length..^"}".Length]); + + int compositeFormatLength = "{0:".Length + standardFormatLength + "}".Length; + "{0:".CopyTo(buffer); + "}".CopyTo(buffer[("{0:".Length + standardFormatLength)..]); + + StandardFormat? standardFormat = null; + if (StandardFormat.TryParse(buffer[..standardFormatLength], out StandardFormat sf)) + standardFormat = sf; + + string compositeFormatString = new(buffer[..compositeFormatLength]); + CompositeFormat compositeFormat = CompositeFormat.Parse(compositeFormatString); + + return (standardFormat, compositeFormat); + } + + public async Task WriteToAsync(Stream stream, ReadOnlyMemory args, CancellationToken cancellationToken = default) + { + byte[]? buffer = null; + try + { + foreach (Segment segment in _segments) + { + await stream.WriteAsync(_format.Slice(segment.Index, segment.Length), cancellationToken); + + if (segment.ArgumentIndex >= 0) + { + Debug.Assert(segment.CompositeFormat is not null, "CompositeFormat should not be null if ArgumentIndex is not < 0."); + + buffer ??= ArrayPool.Shared.Rent(4096); + + int bytesWritten; + while (!TryFormatUtf8(args.Span[segment.ArgumentIndex], buffer, out bytesWritten, segment.StandardFormat, segment.CompositeFormat)) + { + ArrayPool.Shared.Return(buffer); + buffer = ArrayPool.Shared.Rent(1 + buffer.Length * 2); + } + + await stream.WriteAsync(buffer.AsMemory(0, bytesWritten), cancellationToken); + } + } + } + finally + { + if (buffer is not null) + ArrayPool.Shared.Return(buffer); + } + } + + static bool TryFormatUtf8(object? value, Span destination, out int bytesWritten, StandardFormat? standardFormat, CompositeFormat compositeFormat) + { + if (standardFormat.HasValue) + { + switch (value) + { + case null: + bytesWritten = 0; + return true; + + case bool v: + return Utf8Formatter.TryFormat(v, destination, out bytesWritten, standardFormat.Value); + + case byte v: + return Utf8Formatter.TryFormat(v, destination, out bytesWritten, standardFormat.Value); + + case DateTime v: + return Utf8Formatter.TryFormat(v, destination, out bytesWritten, standardFormat.Value); + + case DateTimeOffset v: + return Utf8Formatter.TryFormat(v, destination, out bytesWritten, standardFormat.Value); + + case decimal v: + return Utf8Formatter.TryFormat(v, destination, out bytesWritten, standardFormat.Value); + + case double v: + return Utf8Formatter.TryFormat(v, destination, out bytesWritten, standardFormat.Value); + + case float v: + return Utf8Formatter.TryFormat(v, destination, out bytesWritten, standardFormat.Value); + + case Guid v: + return Utf8Formatter.TryFormat(v, destination, out bytesWritten, standardFormat.Value); + + case int v: + return Utf8Formatter.TryFormat(v, destination, out bytesWritten, standardFormat.Value); + + case long v: + return Utf8Formatter.TryFormat(v, destination, out bytesWritten, standardFormat.Value); + + case sbyte v: + return Utf8Formatter.TryFormat(v, destination, out bytesWritten, standardFormat.Value); + + case short v: + return Utf8Formatter.TryFormat(v, destination, out bytesWritten, standardFormat.Value); + + case TimeSpan v: + return Utf8Formatter.TryFormat(v, destination, out bytesWritten, standardFormat.Value); + + case uint v: + return Utf8Formatter.TryFormat(v, destination, out bytesWritten, standardFormat.Value); + + case ulong v: + return Utf8Formatter.TryFormat(v, destination, out bytesWritten, standardFormat.Value); + + case ushort v: + return Utf8Formatter.TryFormat(v, destination, out bytesWritten, standardFormat.Value); + } + } + + int maxCharsCount = Encoding.UTF8.GetMaxCharCount(destination.Length); + + char[] buffer = ArrayPool.Shared.Rent(maxCharsCount); + try + { + bool ok = MemoryExtensions.TryWrite(buffer, CultureInfo.InvariantCulture, compositeFormat, out int charsWritten, [value]); + Debug.Assert(ok, "Must fit within maxCharsCount."); + + return Encoding.UTF8.TryGetBytes(buffer.AsSpan(0, charsWritten), destination, out bytesWritten); + } + finally + { + ArrayPool.Shared.Return(buffer); + } + } +} \ No newline at end of file diff --git a/Pages/IndexPage.cs b/Pages/IndexPage.cs new file mode 100644 index 0000000..6c59222 --- /dev/null +++ b/Pages/IndexPage.cs @@ -0,0 +1,33 @@ +// SPDX-FileCopyrightText: Copyright 2024 Fabio Iotti +// SPDX-License-Identifier: AGPL-3.0-only + +using CommentsEngine.Data; + +namespace CommentsEngine; + +class IndexPage : PageSlim +{ + public static IndexPage Instance { get; } = new(); + + IndexPage() { } + + protected override ReadOnlySpan ContentTemplate => """ + + + + + + Document |{0}| |{0:000.000##}| + + + + + + """u8; + + protected override ValueTask HandleAsync(HttpContext context, Memory templateArgs) + { + templateArgs.Span[0] = 12.34; + return ValueTask.CompletedTask; + } +} diff --git a/Program.cs b/Program.cs new file mode 100644 index 0000000..ee3ed2b --- /dev/null +++ b/Program.cs @@ -0,0 +1,33 @@ +using System.Text.Json.Serialization; +using CommentsEngine; + +WebApplicationBuilder builder = WebApplication.CreateSlimBuilder(args); + +builder.Services.ConfigureHttpJsonOptions(options => +{ + options.SerializerOptions.TypeInfoResolverChain.Insert(0, AppJsonSerializerContext.Default); +}); + +WebApplication app = builder.Build(); + +Todo[] sampleTodos = [ + new(1, "Walk the dog"), + new(2, "Do the dishes", DateOnly.FromDateTime(DateTime.Now)), + new(3, "Do the laundry", DateOnly.FromDateTime(DateTime.Now.AddDays(1))), + new(4, "Clean the bathroom"), + new(5, "Clean the car", DateOnly.FromDateTime(DateTime.Now.AddDays(2))) +]; + +RouteGroupBuilder todosApi = app.MapGroup("/todos"); +todosApi.MapGet("/", IndexPage.Instance); +todosApi.MapGet("/{id}", (int id) => + sampleTodos.FirstOrDefault(a => a.Id == id) is { } todo + ? Results.Ok(todo) + : Results.NotFound()); + +await app.RunAsync(); + +record Todo(int Id, string? Title, DateOnly? DueBy = null, bool IsComplete = false); + +[JsonSerializable(typeof(Todo[]))] +partial class AppJsonSerializerContext : JsonSerializerContext; diff --git a/Properties/launchSettings.json b/Properties/launchSettings.json new file mode 100644 index 0000000..fbb88ce --- /dev/null +++ b/Properties/launchSettings.json @@ -0,0 +1,15 @@ +{ + "$schema": "http://json.schemastore.org/launchsettings.json", + "profiles": { + "http": { + "commandName": "Project", + "dotnetRunMessages": true, + "launchBrowser": true, + "launchUrl": "todos", + "applicationUrl": "http://localhost:5246", + "environmentVariables": { + "ASPNETCORE_ENVIRONMENT": "Development" + } + } + } +} diff --git a/README.md b/README.md new file mode 100644 index 0000000..441c4ab --- /dev/null +++ b/README.md @@ -0,0 +1,23 @@ +Comments Engine +=============== + +Tiny self-hosted minimally-invasive engine to let users leave comments on pages. + + +## License + +Copyright (c) 2024 Fabio Iotti + +This program is free software: you can redistribute it and/or modify it under +the terms of the GNU Affero General Public License as published by the Free +Software Foundation, version 3 of the License. + +This program is distributed in the hope that it will be useful, but WITHOUT ANY +WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A +PARTICULAR PURPOSE. See the GNU Affero General Public License for more details. + +You should have received a copy of the GNU Affero General Public License along +with this program. If not, see https://www.gnu.org/licenses/. + +Some files may be licensed under different terms, refer to the header at the +beginning of each individual file for file-specific licenses. diff --git a/appsettings.json b/appsettings.json new file mode 100644 index 0000000..10f68b8 --- /dev/null +++ b/appsettings.json @@ -0,0 +1,9 @@ +{ + "Logging": { + "LogLevel": { + "Default": "Information", + "Microsoft.AspNetCore": "Warning" + } + }, + "AllowedHosts": "*" +}