BililiveRecorder/BililiveRecorder.Core/Api/Danmaku/DanmakuClient.cs
2021-03-02 23:40:14 +08:00

422 lines
14 KiB
C#

using System;
using System.Buffers;
using System.Buffers.Binary;
using System.IO;
using System.IO.Compression;
using System.IO.Pipelines;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using System.Timers;
using Nerdbank.Streams;
using Newtonsoft.Json;
using Serilog;
using Timer = System.Timers.Timer;
namespace BililiveRecorder.Core.Api.Danmaku
{
public class DanmakuClient : IDanmakuClient, IDisposable
{
private readonly ILogger logger;
private readonly IDanmakuServerApiClient apiClient;
private readonly Timer timer;
private readonly SemaphoreSlim semaphoreSlim = new SemaphoreSlim(1, 1);
private Stream? danmakuStream;
private bool disposedValue;
public bool Connected => this.danmakuStream != null;
public event EventHandler<StatusChangedEventArgs>? StatusChanged;
public event EventHandler<DanmakuReceivedEventArgs>? DanmakuReceived;
public DanmakuClient(IDanmakuServerApiClient apiClient, ILogger logger)
{
this.apiClient = apiClient ?? throw new ArgumentNullException(nameof(apiClient));
this.logger = logger?.ForContext<DanmakuClient>() ?? throw new ArgumentNullException(nameof(logger));
this.timer = new Timer(interval: 1000 * 30)
{
AutoReset = true,
Enabled = false
};
this.timer.Elapsed += this.SendPingMessageTimerCallback;
}
public async Task DisconnectAsync()
{
await this.semaphoreSlim.WaitAsync().ConfigureAwait(false);
try
{
this.danmakuStream?.Dispose();
this.danmakuStream = null;
this.timer.Stop();
}
finally
{
this.semaphoreSlim.Release();
}
StatusChanged?.Invoke(this, StatusChangedEventArgs.False);
}
public async Task ConnectAsync(int roomid, CancellationToken cancellationToken)
{
if (this.disposedValue)
throw new ObjectDisposedException(nameof(DanmakuClient));
await this.semaphoreSlim.WaitAsync().ConfigureAwait(false);
try
{
if (this.danmakuStream != null)
return;
var serverInfo = await this.apiClient.GetDanmakuServerAsync(roomid).ConfigureAwait(false);
if (serverInfo.Data is null)
return;
serverInfo.Data.ChooseOne(out var host, out var port, out var token);
if (cancellationToken.IsCancellationRequested)
return;
var tcp = new TcpClient();
await tcp.ConnectAsync(host, port).ConfigureAwait(false);
this.danmakuStream = tcp.GetStream();
await SendHelloAsync(this.danmakuStream, roomid, token).ConfigureAwait(false);
await SendPingAsync(this.danmakuStream);
if (cancellationToken.IsCancellationRequested)
{
tcp.Dispose();
this.danmakuStream.Dispose();
this.danmakuStream = null;
return;
}
this.timer.Start();
_ = Task.Run(async () =>
{
try
{
await ProcessDataAsync(this.danmakuStream, this.ProcessCommand).ConfigureAwait(false);
}
catch (ObjectDisposedException) { }
catch (Exception ex)
{
this.logger.Warning(ex, "Error running ProcessDataAsync");
}
try
{
await this.DisconnectAsync().ConfigureAwait(false);
}
catch (Exception) { }
});
}
finally
{
this.semaphoreSlim.Release();
}
StatusChanged?.Invoke(this, StatusChangedEventArgs.True);
}
private void ProcessCommand(string json)
{
try
{
var d = new DanmakuModel(json);
DanmakuReceived?.Invoke(this, new DanmakuReceivedEventArgs(d));
}
catch (Exception ex)
{
this.logger.Warning(ex, "Error running ProcessCommand");
}
}
#pragma warning disable VSTHRD100 // Avoid async void methods
private async void SendPingMessageTimerCallback(object sender, ElapsedEventArgs e)
#pragma warning restore VSTHRD100 // Avoid async void methods
{
try
{
await this.semaphoreSlim.WaitAsync().ConfigureAwait(false);
try
{
if (this.danmakuStream is null)
return;
await SendPingAsync(this.danmakuStream).ConfigureAwait(false);
}
finally
{
this.semaphoreSlim.Release();
}
}
catch (Exception ex)
{
this.logger.Warning(ex, "Error running SendPingMessageTimerCallback");
}
}
#region Dispose
protected virtual void Dispose(bool disposing)
{
if (!this.disposedValue)
{
if (disposing)
{
// dispose managed state (managed objects)
this.timer.Dispose();
this.danmakuStream?.Dispose();
this.semaphoreSlim.Dispose();
}
// free unmanaged resources (unmanaged objects) and override finalizer
// set large fields to null
this.disposedValue = true;
}
}
// override finalizer only if 'Dispose(bool disposing)' has code to free unmanaged resources
// ~DanmakuClient()
// {
// // Do not change this code. Put cleanup code in 'Dispose(bool disposing)' method
// Dispose(disposing: false);
// }
public void Dispose()
{
// Do not change this code. Put cleanup code in 'Dispose(bool disposing)' method
this.Dispose(disposing: true);
GC.SuppressFinalize(this);
}
#endregion
#region Send
private static Task SendHelloAsync(Stream stream, int roomid, string token) =>
SendMessageAsync(stream, 7, JsonConvert.SerializeObject(new
{
uid = 0,
roomid = roomid,
protover = 0,
platform = "web",
clientver = "2.6.25",
type = 2,
key = token,
}, Formatting.None));
private static Task SendPingAsync(Stream stream) =>
SendMessageAsync(stream, 2);
private static async Task SendMessageAsync(Stream stream, int action, string body = "")
{
if (stream is null)
throw new ArgumentNullException(nameof(stream));
var playload = Encoding.UTF8.GetBytes(body);
var size = playload.Length + 16;
var buffer = ArrayPool<byte>.Shared.Rent(16);
try
{
BinaryPrimitives.WriteUInt32BigEndian(new Span<byte>(buffer, 0, 4), (uint)size);
BinaryPrimitives.WriteUInt16BigEndian(new Span<byte>(buffer, 4, 2), 16);
BinaryPrimitives.WriteUInt16BigEndian(new Span<byte>(buffer, 6, 2), 1);
BinaryPrimitives.WriteUInt32BigEndian(new Span<byte>(buffer, 8, 4), (uint)action);
BinaryPrimitives.WriteUInt32BigEndian(new Span<byte>(buffer, 12, 4), 1);
await stream.WriteAsync(buffer, 0, buffer.Length).ConfigureAwait(false);
if (playload.Length > 0)
await stream.WriteAsync(playload, 0, playload.Length).ConfigureAwait(false);
await stream.FlushAsync().ConfigureAwait(false);
}
finally
{
ArrayPool<byte>.Shared.Return(buffer);
}
}
#endregion
#region Receive
private static async Task ProcessDataAsync(Stream stream, Action<string> callback)
{
var reader = PipeReader.Create(stream);
await ReadPipeAsync(reader, callback).ConfigureAwait(false);
}
private static async Task ReadPipeAsync(PipeReader reader, Action<string> callback)
{
while (true)
{
var result = await reader.ReadAsync();
var buffer = result.Buffer;
while (TryParseCommand(ref buffer, callback)) { }
reader.AdvanceTo(buffer.Start, buffer.End);
if (result.IsCompleted)
break;
}
await reader.CompleteAsync();
}
private static bool TryParseCommand(ref ReadOnlySequence<byte> buffer, Action<string> callback)
{
if (buffer.Length < 4)
return false;
int length;
{
var lengthSlice = buffer.Slice(buffer.Start, 4);
if (lengthSlice.IsSingleSegment)
{
length = BinaryPrimitives.ReadInt32BigEndian(lengthSlice.First.Span);
}
else
{
Span<byte> stackBuffer = stackalloc byte[4];
lengthSlice.CopyTo(stackBuffer);
length = BinaryPrimitives.ReadInt32BigEndian(stackBuffer);
}
}
if (buffer.Length < length)
return false;
var headerSlice = buffer.Slice(buffer.Start, 16);
buffer = buffer.Slice(headerSlice.End);
var bodySlice = buffer.Slice(buffer.Start, length - 16);
buffer = buffer.Slice(bodySlice.End);
DanmakuProtocol header;
if (headerSlice.IsSingleSegment)
{
Parse2Protocol(headerSlice.First.Span, out header);
}
else
{
Span<byte> stackBuffer = stackalloc byte[16];
headerSlice.CopyTo(stackBuffer);
Parse2Protocol(stackBuffer, out header);
}
if (header.Version == 2 && header.Action == 5)
ParseCommandDeflateBody(ref bodySlice, callback);
else
ParseCommandNormalBody(ref bodySlice, header.Action, callback);
return true;
}
private static void ParseCommandDeflateBody(ref ReadOnlySequence<byte> buffer, Action<string> callback)
{
using var deflate = new DeflateStream(buffer.Slice(2, buffer.End).AsStream(), CompressionMode.Decompress, leaveOpen: false);
var reader = PipeReader.Create(deflate);
while (true)
{
#pragma warning disable VSTHRD002 // Avoid problematic synchronous waits
// 全内存内运行同步返回,所以不会有问题
var result = reader.ReadAsync().Result;
#pragma warning restore VSTHRD002 // Avoid problematic synchronous waits
var inner_buffer = result.Buffer;
while (TryParseCommand(ref inner_buffer, callback)) { }
reader.AdvanceTo(inner_buffer.Start, inner_buffer.End);
if (result.IsCompleted)
break;
}
reader.Complete();
}
private static void ParseCommandNormalBody(ref ReadOnlySequence<byte> buffer, int action, Action<string> callback)
{
switch (action)
{
case 5:
{
if (buffer.Length > int.MaxValue)
throw new ArgumentOutOfRangeException("ParseCommandNormalBody buffer length larger than int.MaxValue");
var b = ArrayPool<byte>.Shared.Rent((int)buffer.Length);
try
{
buffer.CopyTo(b);
var json = Encoding.UTF8.GetString(b, 0, (int)buffer.Length);
callback(json);
}
finally
{
ArrayPool<byte>.Shared.Return(b);
}
}
break;
case 3:
break;
default:
break;
}
}
private static unsafe void Parse2Protocol(ReadOnlySpan<byte> buffer, out DanmakuProtocol protocol)
{
fixed (byte* ptr = buffer)
{
protocol = *(DanmakuProtocol*)ptr;
}
protocol.ChangeEndian();
}
private struct DanmakuProtocol
{
/// <summary>
/// 消息总长度 (协议头 + 数据长度)
/// </summary>
public int PacketLength;
/// <summary>
/// 消息头长度 (固定为16[sizeof(DanmakuProtocol)])
/// </summary>
public short HeaderLength;
/// <summary>
/// 消息版本号
/// </summary>
public short Version;
/// <summary>
/// 消息类型
/// </summary>
public int Action;
/// <summary>
/// 参数, 固定为1
/// </summary>
public int Parameter;
/// <summary>
/// 转为本机字节序
/// </summary>
public void ChangeEndian()
{
this.PacketLength = IPAddress.HostToNetworkOrder(this.PacketLength);
this.HeaderLength = IPAddress.HostToNetworkOrder(this.HeaderLength);
this.Version = IPAddress.HostToNetworkOrder(this.Version);
this.Action = IPAddress.HostToNetworkOrder(this.Action);
this.Parameter = IPAddress.HostToNetworkOrder(this.Parameter);
}
}
#endregion
}
}