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Improve more precise speed limits
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Co-authored-by: DismissedLight <[email protected]>
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@Eric-Joker @Lightczx
Eric-Joker and Lightczx committed Aug 8, 2024
1 parent ed5821c commit 4c2f2a0
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Showing 5 changed files with 58 additions and 75 deletions.
3 changes: 2 additions & 1 deletion src/Starward/Pages/Setting/DownloadSettingPage.xaml.cs
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Expand Up @@ -5,6 +5,7 @@
using Starward.Services.Download;
using System;
using System.IO;
using System.Threading;
using System.Threading.Tasks;
using Windows.Storage;
using Windows.System;
Expand Down Expand Up @@ -70,7 +71,7 @@ partial void OnDefaultInstallPathChanged(string? value)
partial void OnSpeedLimitChanged(int value)
{
int speed = value <= 0 ? int.MaxValue : value * 1024;
InstallGameManager.SpeedLimitBytesPerSecond = speed;
Interlocked.Exchange(ref InstallGameManager.SpeedLimitBytesPerSecond, speed);
AppConfig.SpeedLimitKBPerSecond = value;
InstallGameManager.SetRateLimit();
}
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27 changes: 5 additions & 22 deletions src/Starward/Services/Download/InstallGameManager.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -5,9 +5,8 @@
using System;
using System.Collections.Concurrent;
using System.Diagnostics.CodeAnalysis;
using System.Threading.RateLimiting;
using System.Threading;
using System.Threading.Tasks;
using System.Threading.RateLimiting;

namespace Starward.Services.Download;

Expand All @@ -32,18 +31,13 @@ private InstallGameManager()



public static int SpeedLimitBytesPerSecond { get; set; }
public static long SpeedLimitBytesPerSecond;


public static TokenBucketRateLimiter RateLimiter { get; private set; }


public static bool IsEnableSpeedLimit => SpeedLimitBytesPerSecond != int.MaxValue;


// BUFFER_SIZE越大限速时保留速度也会越大，可以用来抵消迷之原因造成的超速¿
// speedLimit<=2MB/s → 16Bytes else 1KB
public static int BUFFER_SIZE => (SpeedLimitBytesPerSecond <= (1 << 21)) ? (1 << 4) : (1 << 10);
public static bool IsEnableSpeedLimit => Interlocked.Read(ref SpeedLimitBytesPerSecond) != int.MaxValue;


public event EventHandler<InstallGameStateModel> InstallTaskAdded;
Expand All @@ -54,27 +48,20 @@ private InstallGameManager()



public static event EventHandler LimitStateChanged;




public static void SetRateLimit()
{
// 小于speedLimitBytesPerSecond的最大能被BUFFER_SIZE整除的值
var speedLimitBytesPerPeriod = Math.Max(SpeedLimitBytesPerSecond / 25 / BUFFER_SIZE * BUFFER_SIZE, BUFFER_SIZE);
var speedLimitBytesPerPeriod = (int)SpeedLimitBytesPerSecond / 25;
RateLimiter = new TokenBucketRateLimiter(new TokenBucketRateLimiterOptions
{
TokenLimit = speedLimitBytesPerPeriod,
// 0.04: 将每秒切割为上面的25份，间隔越小速度越精准。
// 因补充令牌逻辑运行耗时远大于期望，若间隔极小，将无法达到最高限速。
ReplenishmentPeriod = TimeSpan.FromSeconds(Math.Max(BUFFER_SIZE / (double)SpeedLimitBytesPerSecond, 0.04)),
ReplenishmentPeriod = TimeSpan.FromSeconds(0.04),
TokensPerPeriod = speedLimitBytesPerPeriod,
QueueProcessingOrder = QueueProcessingOrder.OldestFirst,
AutoReplenishment = true
});
if (LimitStateChanged != null && LimitStateChanged.GetInvocationList().Length > 0)
Task.Run(() => LimitStateChanged.Invoke(null, EventArgs.Empty));
}


Expand Down Expand Up @@ -105,8 +92,6 @@ public void AddInstallService(InstallGameService service)
model.InstallFailed += Model_InstallFailed;
model.InstallCanceled -= Model_InstallCanceled;
model.InstallCanceled += Model_InstallCanceled;
LimitStateChanged -= model._manager_LimitStateChanged;
LimitStateChanged += model._manager_LimitStateChanged;
InstallTaskAdded?.Invoke(this, model);
}

Expand All @@ -121,7 +106,6 @@ private void Model_InstallFinished(object? sender, EventArgs e)
model.InstallFinished -= Model_InstallFinished;
model.InstallFailed -= Model_InstallFailed;
model.InstallCanceled -= Model_InstallCanceled;
LimitStateChanged -= model._manager_LimitStateChanged;
InstallTaskRemoved?.Invoke(this, model);
WeakReferenceMessenger.Default.Send(new InstallGameFinishedMessage(model.GameBiz));
NotificationBehavior.Instance.Success(Lang.InstallGameManager_DownloadTaskCompleted, $"{InstallTaskToString(model.Service.InstallTask)} - {model.GameBiz.ToGameName()} - {model.GameBiz.ToGameServer()}", 0);
Expand Down Expand Up @@ -150,7 +134,6 @@ private void Model_InstallCanceled(object? sender, EventArgs e)
model.InstallFinished -= Model_InstallFinished;
model.InstallFailed -= Model_InstallFailed;
model.InstallCanceled -= Model_InstallCanceled;
LimitStateChanged -= model._manager_LimitStateChanged;
InstallTaskRemoved?.Invoke(this, model);
}
}
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52 changes: 16 additions & 36 deletions src/Starward/Services/Download/InstallGameService.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -21,7 +21,6 @@
using System.Text;
using System.Text.Json.Nodes;
using System.Threading;
using System.Threading.RateLimiting;
using System.Threading.Tasks;
using Vanara.PInvoke;

Expand Down Expand Up @@ -1073,14 +1072,6 @@ protected void Finish()



public long HTTP_BUFFER_SIZE = InstallGameManager.BUFFER_SIZE;



public bool IsEnableSpeedLimit = InstallGameManager.IsEnableSpeedLimit;



protected int _totalCount;
public int TotalCount => _totalCount;

Expand Down Expand Up @@ -1203,9 +1194,7 @@ protected async Task DownloadItemAsync(InstallGameItem item, CancellationToken c
{
file_target = item.WriteAsTempFile ? file_tmp : file;
}
var httpBuffer = ArrayPool<byte>.Shared.Rent((int)Interlocked.Read(ref HTTP_BUFFER_SIZE));
var buffer = ArrayPool<byte>.Shared.Rent(BUFFER_SIZE);
int bufferOffset = 0;
try
{
using var fs = File.Open(file_target, FileMode.OpenOrCreate);
Expand All @@ -1218,43 +1207,34 @@ protected async Task DownloadItemAsync(InstallGameItem item, CancellationToken c
response.EnsureSuccessStatusCode();
using var hs = await response.Content.ReadAsStreamAsync(cancellationToken).ConfigureAwait(false);
int length;
while ((length = await hs.ReadAsync(IsEnableSpeedLimit ? httpBuffer : buffer, cancellationToken).ConfigureAwait(false)) != 0)
while ((length = await hs.ReadAsync(buffer, cancellationToken).ConfigureAwait(false)) != 0)
{
if (IsEnableSpeedLimit)
if (InstallGameManager.IsEnableSpeedLimit)
{
RateLimitLease lease;
do
int totalWritten = 0;
while (totalWritten < length)
{
lease = await InstallGameManager.RateLimiter.AcquireAsync(length, cancellationToken).ConfigureAwait(false);
if (!lease.IsAcquired && lease.TryGetMetadata(MetadataName.RetryAfter, out TimeSpan retryAfter))
await Task.Delay((int)Math.Max(Math.Sqrt(retryAfter.TotalMilliseconds), 1), cancellationToken).ConfigureAwait(false);
} while (!lease.IsAcquired);
int remainingSpace = buffer.Length - bufferOffset;
if (length > remainingSpace)
{
Buffer.BlockCopy(httpBuffer, 0, buffer, bufferOffset, remainingSpace);
await fs.WriteAsync(buffer.AsMemory(0, buffer.Length), cancellationToken).ConfigureAwait(false);
Buffer.BlockCopy(httpBuffer, remainingSpace, buffer, 0, length - remainingSpace);
bufferOffset = length - remainingSpace;
}
else
{
Buffer.BlockCopy(httpBuffer, 0, buffer, bufferOffset, length);
bufferOffset += length;
int remaining = length - totalWritten;
if (TokenBucketRateLimiterExtension.TryAcquire(InstallGameManager.RateLimiter, remaining, out int tokensAcquired, out _))
await Task.Delay(1, cancellationToken).ConfigureAwait(false);
else
{
await fs.WriteAsync(buffer.AsMemory(totalWritten, tokensAcquired), cancellationToken).ConfigureAwait(false);
totalWritten += tokensAcquired;
Interlocked.Add(ref _finishBytes, tokensAcquired);
}
}
}
else
{
await fs.WriteAsync(buffer.AsMemory(0, length), cancellationToken).ConfigureAwait(false);
Interlocked.Add(ref _finishBytes, length);
Interlocked.Add(ref _finishBytes, length);
}
}
// Write any remaining data in buffer
if (bufferOffset > 0)
await fs.WriteAsync(buffer.AsMemory(0, bufferOffset), cancellationToken).ConfigureAwait(false);
}
}
finally
{
ArrayPool<byte>.Shared.Return(httpBuffer);
ArrayPool<byte>.Shared.Return(buffer);
}
}
Expand Down
26 changes: 10 additions & 16 deletions src/Starward/Services/Download/InstallGameStateModel.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -244,8 +244,16 @@ private void ComputeSpeed(InstallGameState state)
}
else
{
_recentSpeed.RemoveAll(value => Math.Abs(value - _speedBytesPerSecond) / _speedBytesPerSecond > 0.25);
_recentSpeed.RemoveRange(0, Math.Max(_recentSpeed.Count - 9, 0));
if (InstallGameManager.IsEnableSpeedLimit)
{
_recentSpeed.RemoveAll(value => Math.Abs(value - _speedBytesPerSecond) / _speedBytesPerSecond > 0.05);
_recentSpeed.RemoveRange(0, Math.Max(_recentSpeed.Count - 59, 0));
}
else
{
_recentSpeed.RemoveAll(value => Math.Abs(value - _speedBytesPerSecond) / _speedBytesPerSecond > 0.25);
_recentSpeed.RemoveRange(0, Math.Max(_recentSpeed.Count - 9, 0));
}
_recentSpeed.Add(_speedBytesPerSecond);
averageSpeed = _recentSpeed.Average();
var seconds = (Service.TotalBytes - Service.FinishBytes) / averageSpeed;
Expand All @@ -270,7 +278,6 @@ private void ComputeSpeed(InstallGameState state)
private void _service_StateChanged(object? sender, InstallGameState e)
{
uiContext.Post(_ => UpdateState(), null);

}


Expand All @@ -281,17 +288,4 @@ private void Service_InstallFailed(object? sender, Exception e)
}



public void _manager_LimitStateChanged(object? sender, EventArgs e)
{
if (Service.State is InstallGameState.Download && Service.HTTP_BUFFER_SIZE != InstallGameManager.BUFFER_SIZE || Service.IsEnableSpeedLimit != InstallGameManager.IsEnableSpeedLimit)
{
Service.Pause();
Task.WhenAll(Service.TaskItems).Wait();
Service.HTTP_BUFFER_SIZE = InstallGameManager.BUFFER_SIZE;
Service.IsEnableSpeedLimit = InstallGameManager.IsEnableSpeedLimit;
Service.Continue();
InstallStarted?.Invoke(this, EventArgs.Empty);
}
}
}
25 changes: 25 additions & 0 deletions src/Starward/Services/Download/TokenBucketRateLimiterExtension.cs
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Original file line number Diff line number Diff line change
@@ -0,0 +1,25 @@
using System;
using System.Threading;
using System.Threading.RateLimiting;
using System.Runtime.CompilerServices;

namespace Starward.Services.Download;

internal static class TokenBucketRateLimiterExtension
{
// IMPORTANT: acquired can be none 0 values if false is returned
public static bool TryAcquire(this TokenBucketRateLimiter rateLimiter, int permits, out int acquired, out TimeSpan retryAfter)
{
lock (PrivateGetLock(rateLimiter))
acquired = Math.Min(permits, (int)Volatile.Read(ref PrivateGetTokenCount(rateLimiter)));
return rateLimiter.AttemptAcquire(acquired).TryGetMetadata(MetadataName.RetryAfter, out retryAfter);
}

// private object Lock → _queue
[UnsafeAccessor(UnsafeAccessorKind.Method, Name = "get_Lock")]
private static extern object PrivateGetLock(TokenBucketRateLimiter rateLimiter);

// private double _tokenCount;
[UnsafeAccessor(UnsafeAccessorKind.Field, Name = "_tokenCount")]
private static extern ref double PrivateGetTokenCount(TokenBucketRateLimiter rateLimiter);
}

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