Init TEngine4.0.0

Init TEngine4.0.0

UnityProject/Packages/YooAsset/Runtime/DownloadSystem/DownloadReport.cs

@@ -0,0 +1,30 @@
+
+namespace YooAsset
+{
+	public struct DownloadReport
+	{
+		/// <summary>
+		/// 下载进度（0f~1f）
+		/// </summary>
+		public float Progress;
+
+		/// <summary>
+		/// 需要下载的总字节数
+		/// </summary>
+		public ulong TotalSize;
+
+		/// <summary>
+		/// 已经下载的字节数
+		/// </summary>
+		public ulong DownloadedBytes;
+
+		public static DownloadReport CreateDefaultReport()
+		{
+			DownloadReport report = new DownloadReport();
+			report.Progress = 0f;
+			report.TotalSize = 0;
+			report.DownloadedBytes = 0;
+			return report;
+		}
+	}
+}

UnityProject/Packages/YooAsset/Runtime/DownloadSystem/DownloadReport.cs.meta

@@ -0,0 +1,11 @@
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+guid: d40b8341fcd4ad2478eb1a890ebf0476
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+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

UnityProject/Packages/YooAsset/Runtime/DownloadSystem/DownloadSystem.cs

@@ -0,0 +1,184 @@
+using System;
+using System.IO;
+using System.Collections;
+using System.Collections.Generic;
+using System.Threading;
+using UnityEngine.Networking;
+
+namespace YooAsset
+{
+	/// <summary>
+	/// 自定义下载器的请求委托
+	/// </summary>
+	public delegate UnityWebRequest DownloadRequestDelegate(string url);
+
+	/// <summary>
+	/// 1. 保证每一时刻资源文件只存在一个下载器
+	/// 2. 保证下载器下载完成后立刻验证并缓存
+	/// 3. 保证资源文件不会被重复下载
+	/// </summary>
+	internal static class DownloadSystem
+	{
+		private static readonly Dictionary<string, DownloaderBase> _downloaderDic = new Dictionary<string, DownloaderBase>();
+		private static readonly List<string> _removeList = new List<string>(100);
+
+		/// <summary>
+		/// 自定义下载器的请求委托
+		/// </summary>
+		public static DownloadRequestDelegate RequestDelegate = null;
+
+		/// <summary>
+		/// 自定义的证书认证实例
+		/// </summary>
+		public static CertificateHandler CertificateHandlerInstance = null;
+
+		/// <summary>
+		/// 网络重定向次数
+		/// </summary>
+		public static int RedirectLimit { set; get; } = -1;
+
+		/// <summary>
+		/// 启用断点续传功能文件的最小字节数
+		/// </summary>
+		public static int BreakpointResumeFileSize { set; get; } = int.MaxValue;
+
+		/// <summary>
+		/// 下载失败后清理文件的HTTP错误码
+		/// </summary>
+		public static List<long> ClearFileResponseCodes { set; get; }
+
+
+		/// <summary>
+		/// 初始化下载器
+		/// </summary>
+		public static void Initialize()
+		{
+		}
+
+		/// <summary>
+		/// 更新下载器
+		/// </summary>
+		public static void Update()
+		{
+			// 更新下载器
+			_removeList.Clear();
+			foreach (var valuePair in _downloaderDic)
+			{
+				var downloader = valuePair.Value;
+				downloader.Update();
+				if (downloader.IsDone())
+					_removeList.Add(valuePair.Key);
+			}
+
+			// 移除下载器
+			foreach (var key in _removeList)
+			{
+				_downloaderDic.Remove(key);
+			}
+		}
+
+		/// <summary>
+		/// 销毁所有下载器
+		/// </summary>
+		public static void DestroyAll()
+		{
+			foreach (var valuePair in _downloaderDic)
+			{
+				var downloader = valuePair.Value;
+				downloader.Abort();
+			}
+			_downloaderDic.Clear();
+			_removeList.Clear();
+
+			RequestDelegate = null;
+			CertificateHandlerInstance = null;
+			BreakpointResumeFileSize = int.MaxValue;
+			ClearFileResponseCodes = null;
+		}
+
+
+		/// <summary>
+		/// 创建下载器
+		/// 注意：只有第一次请求的参数才有效
+		/// </summary>
+		public static DownloaderBase CreateDownload(BundleInfo bundleInfo, int failedTryAgain, int timeout = 60)
+		{
+			// 查询存在的下载器
+			if (_downloaderDic.TryGetValue(bundleInfo.Bundle.CachedDataFilePath, out var downloader))
+				return downloader;
+
+			// 如果资源已经缓存
+			if (CacheSystem.IsCached(bundleInfo.Bundle.PackageName, bundleInfo.Bundle.CacheGUID))
+			{
+				var completedDownloader = new CompletedDownloader(bundleInfo);
+				return completedDownloader;
+			}
+
+			// 创建新的下载器	
+			YooLogger.Log($"Beginning to download bundle : {bundleInfo.Bundle.BundleName} URL : {bundleInfo.RemoteMainURL}");
+#if UNITY_WEBGL
+			if (bundleInfo.Bundle.IsRawFile)
+			{
+				FileUtility.CreateFileDirectory(bundleInfo.Bundle.CachedDataFilePath);
+				DownloaderBase newDownloader = new FileGeneralDownloader(bundleInfo, failedTryAgain, timeout);
+				_downloaderDic.Add(bundleInfo.Bundle.CachedDataFilePath, newDownloader);
+				return newDownloader;
+			}
+			else
+			{
+				WebDownloader newDownloader = new WebDownloader(bundleInfo, failedTryAgain, timeout);
+				_downloaderDic.Add(bundleInfo.Bundle.CachedDataFilePath, newDownloader);
+				return newDownloader;
+			}
+#else
+			FileUtility.CreateFileDirectory(bundleInfo.Bundle.CachedDataFilePath);
+			bool resumeDownload = bundleInfo.Bundle.FileSize >= BreakpointResumeFileSize;
+			DownloaderBase newDownloader;
+			if (resumeDownload)
+				newDownloader = new FileResumeDownloader(bundleInfo, failedTryAgain, timeout);
+			else
+				newDownloader = new FileGeneralDownloader(bundleInfo, failedTryAgain, timeout);
+			_downloaderDic.Add(bundleInfo.Bundle.CachedDataFilePath, newDownloader);
+			return newDownloader;
+#endif
+		}
+
+		/// <summary>
+		/// 创建一个新的网络请求
+		/// </summary>
+		public static UnityWebRequest NewRequest(string requestURL)
+		{
+			UnityWebRequest webRequest;
+			if (RequestDelegate != null)
+				webRequest = RequestDelegate.Invoke(requestURL);
+			else
+				webRequest = new UnityWebRequest(requestURL, UnityWebRequest.kHttpVerbGET);
+
+			SetUnityWebRequestParam(webRequest);
+			return webRequest;
+		}
+
+		/// <summary>
+		/// 设置网络请求的自定义参数
+		/// </summary>
+		private static void SetUnityWebRequestParam(UnityWebRequest webRequest)
+		{
+			if (RedirectLimit >= 0)
+				webRequest.redirectLimit = RedirectLimit;
+
+			if (CertificateHandlerInstance != null)
+			{
+				webRequest.certificateHandler = CertificateHandlerInstance;
+				webRequest.disposeCertificateHandlerOnDispose = false;
+			}
+		}
+
+		/// <summary>
+		/// 获取下载器的总数
+		/// </summary>
+		public static int GetDownloaderTotalCount()
+		{
+			return _downloaderDic.Count;
+		}
+	}
+}

UnityProject/Packages/YooAsset/Runtime/DownloadSystem/DownloadSystem.cs.meta

@@ -0,0 +1,11 @@
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+guid: d19eae1f43ecf6347925a06730a6c846
+MonoImporter:
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+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

UnityProject/Packages/YooAsset/Runtime/DownloadSystem/Downloader.meta

@@ -0,0 +1,8 @@
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+guid: a82eeb6a47cd02c4cb38e851c8ed8784
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+  userData: 
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UnityProject/Packages/YooAsset/Runtime/DownloadSystem/Downloader/CompletedDownloader.cs

@@ -0,0 +1,23 @@
+
+namespace YooAsset
+{
+	internal sealed class CompletedDownloader : DownloaderBase
+	{
+		public CompletedDownloader(BundleInfo bundleInfo) : base(bundleInfo, 0, 0)
+		{
+			_downloadProgress = 1f;
+			_downloadedBytes = (ulong)bundleInfo.Bundle.FileSize;
+			_status = EStatus.Succeed;
+		}
+
+		public override void SendRequest(params object[] param)
+		{
+		}
+		public override void Update()
+		{
+		}
+		public override void Abort()
+		{
+		}
+	}
+}

UnityProject/Packages/YooAsset/Runtime/DownloadSystem/Downloader/CompletedDownloader.cs.meta

@@ -0,0 +1,11 @@
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+guid: 3c7907ead85e2f94786308b28c37a8aa
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

UnityProject/Packages/YooAsset/Runtime/DownloadSystem/Downloader/DownloadHandlerFileRange.cs

@@ -0,0 +1,87 @@
+using System;
+using System.IO;
+using UnityEngine;
+using UnityEngine.Networking;
+
+namespace YooAsset
+{
+	/// <summary>
+	/// 支持Unity2018版本的断点续传下载器
+	/// </summary>
+	internal class DownloadHandlerFileRange : DownloadHandlerScript
+	{
+		private string _fileSavePath;
+		private long _fileTotalSize;
+		private UnityWebRequest _webRequest;
+		private FileStream _fileStream;
+
+		private long _localFileSize = 0;
+		private long _curFileSize = 0;
+
+
+		public DownloadHandlerFileRange(string fileSavePath, long fileTotalSize, UnityWebRequest webRequest) : base(new byte[1024 * 1024])
+		{
+			_fileSavePath = fileSavePath;
+			_fileTotalSize = fileTotalSize;
+			_webRequest = webRequest;
+
+			if (File.Exists(fileSavePath))
+			{
+				FileInfo fileInfo = new FileInfo(fileSavePath);
+				_localFileSize = fileInfo.Length;
+			}
+
+			_fileStream = new FileStream(_fileSavePath, FileMode.Append, FileAccess.Write);
+			_curFileSize = _localFileSize;
+		}
+		protected override bool ReceiveData(byte[] data, int dataLength)
+		{
+			if (data == null || dataLength == 0 || _webRequest.responseCode >= 400)
+				return false;
+
+			if (_fileStream == null)
+				return false;
+
+			_fileStream.Write(data, 0, dataLength);
+			_curFileSize += dataLength;
+			return true;
+		}
+
+		/// <summary>
+		/// UnityWebRequest.downloadHandler.data
+		/// </summary>
+		protected override byte[] GetData()
+		{
+			return null;
+		}
+
+		/// <summary>
+		/// UnityWebRequest.downloadHandler.text
+		/// </summary>
+		protected override string GetText()
+		{
+			return null;
+		}
+
+		/// <summary>
+		/// UnityWebRequest.downloadProgress
+		/// </summary>
+		protected override float GetProgress()
+		{
+			return _fileTotalSize == 0 ? 0 : ((float)_curFileSize) / _fileTotalSize;
+		}
+
+		/// <summary>
+		/// 释放下载句柄
+		/// </summary>
+		public void Cleanup()
+		{
+			if (_fileStream != null)
+			{
+				_fileStream.Flush();
+				_fileStream.Dispose();
+				_fileStream = null;
+			}
+		}
+	}
+}

UnityProject/Packages/YooAsset/Runtime/DownloadSystem/Downloader/DownloadHandlerFileRange.cs.meta

@@ -0,0 +1,11 @@
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+guid: 94254ab8e4496214884c11a891c131c6
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

UnityProject/Packages/YooAsset/Runtime/DownloadSystem/Downloader/DownloaderBase.cs

@@ -0,0 +1,193 @@
+using System.IO;
+using UnityEngine;
+using UnityEngine.Networking;
+
+namespace YooAsset
+{
+	internal abstract class DownloaderBase
+	{
+		public enum EStatus
+		{
+			None = 0,
+			Succeed,
+			Failed
+		}
+
+		protected readonly BundleInfo _bundleInfo;
+		protected readonly int _timeout;
+		protected int _failedTryAgain;
+
+		protected UnityWebRequest _webRequest;
+		protected EStatus _status = EStatus.None;
+		protected string _lastError = string.Empty;
+		protected long _lastCode = 0;
+
+		// 请求次数
+		protected int _requestCount = 0;
+		protected string _requestURL;
+
+		// 下载进度
+		protected float _downloadProgress = 0f;
+		protected ulong _downloadedBytes = 0;
+
+		// 超时相关
+		protected bool _isAbort = false;
+		protected ulong _latestDownloadBytes;
+		protected float _latestDownloadRealtime;
+		protected float _tryAgainTimer;
+
+		/// <summary>
+		/// 是否等待异步结束
+		/// 警告：只能用于解压APP内部资源
+		/// </summary>
+		public bool WaitForAsyncComplete = false;
+
+		/// <summary>
+		/// 下载进度（0f~1f）
+		/// </summary>
+		public float DownloadProgress
+		{
+			get { return _downloadProgress; }
+		}
+
+		/// <summary>
+		/// 已经下载的总字节数
+		/// </summary>
+		public ulong DownloadedBytes
+		{
+			get { return _downloadedBytes; }
+		}
+
+
+		public DownloaderBase(BundleInfo bundleInfo, int failedTryAgain, int timeout)
+		{
+			_bundleInfo = bundleInfo;
+			_failedTryAgain = failedTryAgain;
+			_timeout = timeout;
+		}
+		public abstract void SendRequest(params object[] param);
+		public abstract void Update();
+		public abstract void Abort();
+
+		/// <summary>
+		/// 获取下载文件的大小
+		/// </summary>
+		/// <returns></returns>
+		public long GetDownloadFileSize()
+		{
+			return _bundleInfo.Bundle.FileSize;
+		}
+
+		/// <summary>
+		/// 获取下载文件的资源包名
+		/// </summary>
+		public string GetDownloadBundleName()
+		{
+			return _bundleInfo.Bundle.BundleName;
+		}
+
+		/// <summary>
+		/// 检测下载器是否已经完成（无论成功或失败）
+		/// </summary>
+		public bool IsDone()
+		{
+			return _status == EStatus.Succeed || _status == EStatus.Failed;
+		}
+
+		/// <summary>
+		/// 下载过程是否发生错误
+		/// </summary>
+		public bool HasError()
+		{
+			return _status == EStatus.Failed;
+		}
+
+		/// <summary>
+		/// 按照错误级别打印错误
+		/// </summary>
+		public void ReportError()
+		{
+			YooLogger.Error(GetLastError());
+		}
+
+		/// <summary>
+		/// 按照警告级别打印错误
+		/// </summary>
+		public void ReportWarning()
+		{
+			YooLogger.Warning(GetLastError());
+		}
+
+		/// <summary>
+		/// 获取最近发生的错误信息
+		/// </summary>
+		public string GetLastError()
+		{
+			return $"Failed to download : {_requestURL} Error : {_lastError} Code : {_lastCode}";
+		}
+
+
+		/// <summary>
+		/// 获取网络请求地址
+		/// </summary>
+		protected string GetRequestURL()
+		{
+			// 轮流返回请求地址
+			_requestCount++;
+			if (_requestCount % 2 == 0)
+				return _bundleInfo.RemoteFallbackURL;
+			else
+				return _bundleInfo.RemoteMainURL;
+		}
+
+		/// <summary>
+		/// 超时判定方法
+		/// </summary>
+		protected void CheckTimeout()
+		{
+			// 注意：在连续时间段内无新增下载数据及判定为超时
+			if (_isAbort == false)
+			{
+				if (_latestDownloadBytes != DownloadedBytes)
+				{
+					_latestDownloadBytes = DownloadedBytes;
+					_latestDownloadRealtime = Time.realtimeSinceStartup;
+				}
+
+				float offset = Time.realtimeSinceStartup - _latestDownloadRealtime;
+				if (offset > _timeout)
+				{
+					YooLogger.Warning($"Web file request timeout : {_requestURL}");
+					_webRequest.Abort();
+					_isAbort = true;
+				}
+			}
+		}
+
+		/// <summary>
+		/// 缓存下载文件
+		/// </summary>
+		protected void CachingFile(string tempFilePath)
+		{
+			string infoFilePath = _bundleInfo.Bundle.CachedInfoFilePath;
+			string dataFilePath = _bundleInfo.Bundle.CachedDataFilePath;
+			string dataFileCRC = _bundleInfo.Bundle.FileCRC;
+			long dataFileSize = _bundleInfo.Bundle.FileSize;
+
+			if (File.Exists(infoFilePath))
+				File.Delete(infoFilePath);
+			if (File.Exists(dataFilePath))
+				File.Delete(dataFilePath);
+
+			FileInfo fileInfo = new FileInfo(tempFilePath);
+			fileInfo.MoveTo(dataFilePath);
+
+			// 写入信息文件记录验证数据
+			CacheFileInfo.WriteInfoToFile(infoFilePath, dataFileCRC, dataFileSize);
+
+			// 记录缓存文件
+			var wrapper = new PackageCache.RecordWrapper(infoFilePath, dataFilePath, dataFileCRC, dataFileSize);
+			CacheSystem.RecordFile(_bundleInfo.Bundle.PackageName, _bundleInfo.Bundle.CacheGUID, wrapper);
+		}
+	}
+}

UnityProject/Packages/YooAsset/Runtime/DownloadSystem/Downloader/DownloaderBase.cs.meta

@@ -0,0 +1,11 @@
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+guid: dda4d1eafa2c9f34fade509f8dae9c04
+MonoImporter:
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+  defaultReferences: []
+  executionOrder: 0
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+  userData: 
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UnityProject/Packages/YooAsset/Runtime/DownloadSystem/Downloader/FileGeneralDownloader.cs

@@ -0,0 +1,229 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.IO;
+using UnityEngine;
+using UnityEngine.Networking;
+
+namespace YooAsset
+{
+	/// <summary>
+	/// 普通的下载器
+	/// </summary>
+	internal sealed class FileGeneralDownloader : DownloaderBase
+	{
+		private enum ESteps
+		{
+			None,
+			PrepareDownload,
+			CreateDownloader,
+			CheckDownload,
+			VerifyTempFile,
+			WaitingVerifyTempFile,
+			CachingFile,
+			TryAgain,
+			Done,
+		}
+
+		private readonly string _tempFilePath;
+		private VerifyTempFileOperation _verifyFileOp = null;
+		private ESteps _steps = ESteps.None;
+
+
+		public FileGeneralDownloader(BundleInfo bundleInfo, int failedTryAgain, int timeout) : base(bundleInfo, failedTryAgain, timeout)
+		{
+			_tempFilePath = bundleInfo.Bundle.TempDataFilePath;
+		}
+		public override void SendRequest(params object[] param)
+		{
+			if (_steps == ESteps.None)
+			{
+				_steps = ESteps.PrepareDownload;
+			}
+		}
+		public override void Update()
+		{
+			if (_steps == ESteps.None)
+				return;
+			if (IsDone())
+				return;
+
+			// 准备下载
+			if (_steps == ESteps.PrepareDownload)
+			{
+				// 获取请求地址
+				_requestURL = GetRequestURL();
+
+				// 重置变量
+				_downloadProgress = 0f;
+				_downloadedBytes = 0;
+
+				// 重置变量
+				_isAbort = false;
+				_latestDownloadBytes = 0;
+				_latestDownloadRealtime = Time.realtimeSinceStartup;
+
+				// 重置计时器
+				if(_tryAgainTimer > 0f)
+					YooLogger.Warning($"Try again download : {_requestURL}");
+				_tryAgainTimer = 0f;
+
+				// 删除临时文件
+				if (File.Exists(_tempFilePath))
+					File.Delete(_tempFilePath);
+
+				_steps = ESteps.CreateDownloader;
+			}
+
+			// 创建下载器
+			if (_steps == ESteps.CreateDownloader)
+			{
+				_webRequest = DownloadSystem.NewRequest(_requestURL);
+				DownloadHandlerFile handler = new DownloadHandlerFile(_tempFilePath);
+				handler.removeFileOnAbort = true;
+				_webRequest.downloadHandler = handler;
+				_webRequest.disposeDownloadHandlerOnDispose = true;
+				_webRequest.SendWebRequest();
+				_steps = ESteps.CheckDownload;
+			}
+
+			// 检测下载结果
+			if (_steps == ESteps.CheckDownload)
+			{
+				_downloadProgress = _webRequest.downloadProgress;
+				_downloadedBytes = _webRequest.downloadedBytes;
+				if (_webRequest.isDone == false)
+				{
+					CheckTimeout();
+					return;
+				}
+
+				bool hasError = false;
+
+				// 检查网络错误
+#if UNITY_2020_3_OR_NEWER
+				if (_webRequest.result != UnityWebRequest.Result.Success)
+				{
+					hasError = true;
+					_lastError = _webRequest.error;
+					_lastCode = _webRequest.responseCode;
+				}
+#else
+				if (_webRequest.isNetworkError || _webRequest.isHttpError)
+				{
+					hasError = true;
+					_lastError = _webRequest.error;
+					_lastCode = _webRequest.responseCode;
+				}
+#endif
+
+				// 如果网络异常
+				if (hasError)
+				{
+					// 下载失败之后删除文件
+					if (File.Exists(_tempFilePath))
+						File.Delete(_tempFilePath);
+
+					_steps = ESteps.TryAgain;
+				}
+				else
+				{
+					_steps = ESteps.VerifyTempFile;
+				}
+
+				// 最终释放下载器
+				DisposeWebRequest();
+			}
+
+			// 验证下载文件
+			if (_steps == ESteps.VerifyTempFile)
+			{
+				VerifyTempFileElement element = new VerifyTempFileElement(_bundleInfo.Bundle.TempDataFilePath, _bundleInfo.Bundle.FileCRC, _bundleInfo.Bundle.FileSize);
+				_verifyFileOp = VerifyTempFileOperation.CreateOperation(element);
+				OperationSystem.StartOperation(_verifyFileOp);
+				_steps = ESteps.WaitingVerifyTempFile;
+			}
+
+			// 等待验证完成
+			if (_steps == ESteps.WaitingVerifyTempFile)
+			{
+				if (WaitForAsyncComplete)
+					_verifyFileOp.Update();
+
+				if (_verifyFileOp.IsDone == false)
+					return;
+
+				if (_verifyFileOp.Status == EOperationStatus.Succeed)
+				{
+					_steps = ESteps.CachingFile;
+				}
+				else
+				{
+					if (File.Exists(_tempFilePath))
+						File.Delete(_tempFilePath);
+
+					_lastError = _verifyFileOp.Error;
+					_steps = ESteps.TryAgain;
+				}
+			}
+
+			// 缓存下载文件
+			if (_steps == ESteps.CachingFile)
+			{
+				try
+				{
+					CachingFile(_tempFilePath);
+					_status = EStatus.Succeed;
+					_steps = ESteps.Done;
+					_lastError = string.Empty;
+					_lastCode = 0;
+				}
+				catch (Exception e)
+				{
+					_lastError = e.Message;
+					_steps = ESteps.TryAgain;
+				}
+			}
+
+			// 重新尝试下载
+			if (_steps == ESteps.TryAgain)
+			{
+				if (_failedTryAgain <= 0)
+				{
+					ReportError();
+					_status = EStatus.Failed;
+					_steps = ESteps.Done;
+					return;
+				}
+
+				_tryAgainTimer += Time.unscaledDeltaTime;
+				if (_tryAgainTimer > 1f)
+				{
+					_failedTryAgain--;
+					_steps = ESteps.PrepareDownload;
+					ReportWarning();
+				}
+			}
+		}
+		public override void Abort()
+		{
+			if (IsDone() == false)
+			{
+				_status = EStatus.Failed;
+				_steps = ESteps.Done;
+				_lastError = "user abort";
+				_lastCode = 0;
+				DisposeWebRequest();
+			}
+		}
+
+		private void DisposeWebRequest()
+		{
+			if (_webRequest != null)
+			{
+				_webRequest.Dispose();
+				_webRequest = null;
+			}
+		}
+	}
+}

UnityProject/Packages/YooAsset/Runtime/DownloadSystem/Downloader/FileGeneralDownloader.cs.meta

@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: 4c6e1a8bc8d5e664395395daa772ddd7
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

UnityProject/Packages/YooAsset/Runtime/DownloadSystem/Downloader/FileResumeDownloader.cs

@@ -0,0 +1,295 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.IO;
+using UnityEngine;
+using UnityEngine.Networking;
+
+namespace YooAsset
+{
+	/// <summary>
+	/// 断点续传下载器
+	/// </summary>
+	internal sealed class FileResumeDownloader : DownloaderBase
+	{
+		private enum ESteps
+		{
+			None,
+			CheckTempFile,
+			WaitingCheckTempFile,
+			PrepareDownload,
+			CreateDownloader,
+			CheckDownload,
+			VerifyTempFile,
+			WaitingVerifyTempFile,
+			CachingFile,
+			TryAgain,
+			Done,
+		}
+
+		private readonly string _tempFilePath;
+		private DownloadHandlerFileRange _downloadHandle = null;
+		private VerifyTempFileOperation _checkFileOp = null;
+		private VerifyTempFileOperation _verifyFileOp = null;
+		private ESteps _steps = ESteps.None;
+
+		// 重置变量
+		private ulong _fileOriginLength;
+
+
+		public FileResumeDownloader(BundleInfo bundleInfo, int failedTryAgain, int timeout) : base(bundleInfo, failedTryAgain, timeout)
+		{
+			_tempFilePath = bundleInfo.Bundle.TempDataFilePath;
+		}
+		public override void SendRequest(params object[] param)
+		{
+			if (_steps == ESteps.None)
+			{
+				_steps = ESteps.CheckTempFile;
+			}
+		}
+		public override void Update()
+		{
+			if (_steps == ESteps.None)
+				return;
+			if (IsDone())
+				return;
+
+			// 检测临时文件
+			if (_steps == ESteps.CheckTempFile)
+			{
+				VerifyTempFileElement element = new VerifyTempFileElement(_bundleInfo.Bundle.TempDataFilePath, _bundleInfo.Bundle.FileCRC, _bundleInfo.Bundle.FileSize);
+				_checkFileOp = VerifyTempFileOperation.CreateOperation(element);
+				OperationSystem.StartOperation(_checkFileOp);
+				_steps = ESteps.WaitingCheckTempFile;
+			}
+
+			// 等待检测结果
+			if (_steps == ESteps.WaitingCheckTempFile)
+			{
+				if (WaitForAsyncComplete)
+					_checkFileOp.Update();
+
+				if (_checkFileOp.IsDone == false)
+					return;
+
+				if (_checkFileOp.Status == EOperationStatus.Succeed)
+				{
+					_steps = ESteps.CachingFile;
+				}
+				else
+				{
+					if (_checkFileOp.VerifyResult == EVerifyResult.FileOverflow)
+					{
+						if (File.Exists(_tempFilePath))
+							File.Delete(_tempFilePath);
+					}
+					_steps = ESteps.PrepareDownload;
+				}
+			}
+
+			// 创建下载器
+			if (_steps == ESteps.PrepareDownload)
+			{
+				// 获取请求地址
+				_requestURL = GetRequestURL();
+
+				// 重置变量
+				_downloadProgress = 0f;
+				_downloadedBytes = 0;
+
+				// 重置变量
+				_isAbort = false;
+				_latestDownloadBytes = 0;
+				_latestDownloadRealtime = Time.realtimeSinceStartup;
+				_fileOriginLength = 0;
+
+				// 重置计时器
+				if (_tryAgainTimer > 0f)
+					YooLogger.Warning($"Try again download : {_requestURL}");
+				_tryAgainTimer = 0f;
+
+				_steps = ESteps.CreateDownloader;
+			}
+
+			// 创建下载器
+			if (_steps == ESteps.CreateDownloader)
+			{
+				long fileLength = -1;
+				if (File.Exists(_tempFilePath))
+				{
+					FileInfo fileInfo = new FileInfo(_tempFilePath);
+					fileLength = fileInfo.Length;
+					_fileOriginLength = (ulong)fileLength;
+					_downloadedBytes = _fileOriginLength;
+				}
+
+#if UNITY_2019_4_OR_NEWER
+				_webRequest = DownloadSystem.NewRequest(_requestURL);
+				var handler = new DownloadHandlerFile(_tempFilePath, true);
+				handler.removeFileOnAbort = false;
+#else
+				_webRequest = DownloadSystem.NewRequest(_requestURL);
+				var handler = new DownloadHandlerFileRange(_tempFilePath, _bundleInfo.Bundle.FileSize, _webRequest);
+				_downloadHandle = handler;
+#endif
+				_webRequest.downloadHandler = handler;
+				_webRequest.disposeDownloadHandlerOnDispose = true;
+				if (fileLength > 0)
+					_webRequest.SetRequestHeader("Range", $"bytes={fileLength}-");
+				_webRequest.SendWebRequest();
+				_steps = ESteps.CheckDownload;
+			}
+
+			// 检测下载结果
+			if (_steps == ESteps.CheckDownload)
+			{
+				_downloadProgress = _webRequest.downloadProgress;
+				_downloadedBytes = _fileOriginLength + _webRequest.downloadedBytes;
+				if (_webRequest.isDone == false)
+				{
+					CheckTimeout();
+					return;
+				}
+
+				bool hasError = false;
+
+				// 检查网络错误
+#if UNITY_2020_3_OR_NEWER
+				if (_webRequest.result != UnityWebRequest.Result.Success)
+				{
+					hasError = true;
+					_lastError = _webRequest.error;
+					_lastCode = _webRequest.responseCode;
+				}
+#else
+				if (_webRequest.isNetworkError || _webRequest.isHttpError)
+				{
+					hasError = true;
+					_lastError = _webRequest.error;
+					_lastCode = _webRequest.responseCode;
+				}
+#endif
+
+				// 如果网络异常
+				if (hasError)
+				{
+					// 注意：下载断点续传文件发生特殊错误码之后删除文件
+					if (DownloadSystem.ClearFileResponseCodes != null)
+					{
+						if (DownloadSystem.ClearFileResponseCodes.Contains(_webRequest.responseCode))
+						{
+							if (File.Exists(_tempFilePath))
+								File.Delete(_tempFilePath);
+						}
+					}
+
+					_steps = ESteps.TryAgain;
+				}
+				else
+				{
+					_steps = ESteps.VerifyTempFile;
+				}
+
+				// 最终释放下载器
+				DisposeWebRequest();
+			}
+
+			// 验证下载文件
+			if (_steps == ESteps.VerifyTempFile)
+			{
+				VerifyTempFileElement element = new VerifyTempFileElement(_bundleInfo.Bundle.TempDataFilePath, _bundleInfo.Bundle.FileCRC, _bundleInfo.Bundle.FileSize);
+				_verifyFileOp = VerifyTempFileOperation.CreateOperation(element);
+				OperationSystem.StartOperation(_verifyFileOp);
+				_steps = ESteps.WaitingVerifyTempFile;
+			}
+
+			// 等待验证完成
+			if (_steps == ESteps.WaitingVerifyTempFile)
+			{
+				if (WaitForAsyncComplete)
+					_verifyFileOp.Update();
+
+				if (_verifyFileOp.IsDone == false)
+					return;
+
+				if (_verifyFileOp.Status == EOperationStatus.Succeed)
+				{
+					_steps = ESteps.CachingFile;
+				}
+				else
+				{
+					if (File.Exists(_tempFilePath))
+						File.Delete(_tempFilePath);
+
+					_lastError = _verifyFileOp.Error;
+					_steps = ESteps.TryAgain;
+				}
+			}
+
+			// 缓存下载文件
+			if (_steps == ESteps.CachingFile)
+			{
+				try
+				{
+					CachingFile(_tempFilePath);
+					_status = EStatus.Succeed;
+					_steps = ESteps.Done;
+					_lastError = string.Empty;
+					_lastCode = 0;
+				}
+				catch (Exception e)
+				{
+					_lastError = e.Message;
+					_steps = ESteps.TryAgain;
+				}
+			}
+
+			// 重新尝试下载
+			if (_steps == ESteps.TryAgain)
+			{
+				if (_failedTryAgain <= 0)
+				{
+					ReportError();
+					_status = EStatus.Failed;
+					_steps = ESteps.Done;
+					return;
+				}
+
+				_tryAgainTimer += Time.unscaledDeltaTime;
+				if (_tryAgainTimer > 1f)
+				{
+					_failedTryAgain--;
+					_steps = ESteps.PrepareDownload;
+					ReportWarning();
+				}
+			}
+		}
+		public override void Abort()
+		{
+			if (IsDone() == false)
+			{
+				_status = EStatus.Failed;
+				_steps = ESteps.Done;
+				_lastError = "user abort";
+				_lastCode = 0;
+				DisposeWebRequest();
+			}
+		}
+
+		private void DisposeWebRequest()
+		{
+			if (_downloadHandle != null)
+			{
+				_downloadHandle.Cleanup();
+				_downloadHandle = null;
+			}
+
+			if (_webRequest != null)
+			{
+				_webRequest.Dispose();
+				_webRequest = null;
+			}
+		}
+	}
+}

UnityProject/Packages/YooAsset/Runtime/DownloadSystem/Downloader/FileResumeDownloader.cs.meta

@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: a439c9a8f36dcc942b92a8e8af927237
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

UnityProject/Packages/YooAsset/Runtime/DownloadSystem/Downloader/WebDownloader.cs

@@ -0,0 +1,211 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.IO;
+using UnityEngine;
+using UnityEngine.Networking;
+
+namespace YooAsset
+{
+	internal sealed class WebDownloader : DownloaderBase
+	{
+		private enum ESteps
+		{
+			None,
+			PrepareDownload,
+			CreateDownloader,
+			CheckDownload,
+			VerifyTempFile,
+			WaitingVerifyTempFile,
+			CachingFile,
+			TryAgain,
+			Done,
+		}
+
+		private DownloadHandlerAssetBundle _downloadhandler;
+		private ESteps _steps = ESteps.None;
+		private bool _getAssetBundle = false;
+		private AssetBundle _cacheAssetBundle;
+
+		public WebDownloader(BundleInfo bundleInfo, int failedTryAgain, int timeout) : base(bundleInfo, failedTryAgain, timeout)
+		{
+		}
+		public override void SendRequest(params object[] param)
+		{
+			if (_steps == ESteps.None)
+			{
+				if (param.Length > 0)
+				{
+					_getAssetBundle = (bool)param[0];
+				}
+				_steps = ESteps.PrepareDownload;
+			}
+		}
+		public override void Update()
+		{
+			if (_steps == ESteps.None)
+				return;
+			if (IsDone())
+				return;
+
+			// 创建下载器
+			if (_steps == ESteps.PrepareDownload)
+			{
+				// 重置变量
+				_downloadProgress = 0f;
+				_downloadedBytes = 0;
+
+				// 重置变量
+				_isAbort = false;
+				_latestDownloadBytes = 0;
+				_latestDownloadRealtime = Time.realtimeSinceStartup;
+				_tryAgainTimer = 0f;
+
+				// 获取请求地址
+				_requestURL = GetRequestURL();
+				_steps = ESteps.CreateDownloader;
+			}
+
+			// 创建下载器
+			if (_steps == ESteps.CreateDownloader)
+			{
+				_webRequest = DownloadSystem.NewRequest(_requestURL);
+
+				if (CacheSystem.DisableUnityCacheOnWebGL)
+				{
+					uint crc = _bundleInfo.Bundle.UnityCRC;
+					_downloadhandler = new DownloadHandlerAssetBundle(_requestURL, crc);
+#if UNITY_2020_3_OR_NEWER
+					_downloadhandler.autoLoadAssetBundle = false;
+#endif
+				}
+				else
+				{
+					uint crc = _bundleInfo.Bundle.UnityCRC;
+					var hash = Hash128.Parse(_bundleInfo.Bundle.FileHash);
+					_downloadhandler = new DownloadHandlerAssetBundle(_requestURL, hash, crc);
+#if UNITY_2020_3_OR_NEWER
+					_downloadhandler.autoLoadAssetBundle = false;
+#endif
+				}
+
+				_webRequest.downloadHandler = _downloadhandler;
+				_webRequest.disposeDownloadHandlerOnDispose = false;
+				_webRequest.SendWebRequest();
+				_steps = ESteps.CheckDownload;
+			}
+
+			// 检测下载结果
+			if (_steps == ESteps.CheckDownload)
+			{
+				_downloadProgress = _webRequest.downloadProgress;
+				_downloadedBytes = _webRequest.downloadedBytes;
+				if (_webRequest.isDone == false)
+				{
+					CheckTimeout();
+					return;
+				}
+
+				bool hasError = false;
+
+				// 检查网络错误
+#if UNITY_2020_3_OR_NEWER
+				if (_webRequest.result != UnityWebRequest.Result.Success)
+				{
+					hasError = true;
+					_lastError = _webRequest.error;
+					_lastCode = _webRequest.responseCode;
+				}
+#else
+				if (_webRequest.isNetworkError || _webRequest.isHttpError)
+				{
+					hasError = true;
+					_lastError = _webRequest.error;
+					_lastCode = _webRequest.responseCode;
+				}
+#endif
+
+				// 如果网络异常
+				if (hasError)
+				{
+					_steps = ESteps.TryAgain;
+				}
+				else
+				{
+					_status = EStatus.Succeed;
+					_steps = ESteps.Done;
+					_lastError = string.Empty;
+					_lastCode = 0;
+				}
+
+				if (_getAssetBundle)
+				{
+					_cacheAssetBundle = _downloadhandler.assetBundle;
+					if (_cacheAssetBundle == null)
+					{
+						_lastError = "assetBundle is null";
+						_steps = ESteps.TryAgain;
+					}
+				}
+
+				// 最终释放请求
+				DisposeRequest();	
+			}
+
+			// 重新尝试下载
+			if (_steps == ESteps.TryAgain)
+			{
+				if (_failedTryAgain <= 0)
+				{
+					DisposeRequest();
+					ReportError();
+					_status = EStatus.Failed;
+					_steps = ESteps.Done;
+					return;
+				}
+
+				_tryAgainTimer += Time.unscaledDeltaTime;
+				if (_tryAgainTimer > 1f)
+				{
+					_failedTryAgain--;
+					_steps = ESteps.PrepareDownload;
+					ReportWarning();
+					YooLogger.Warning($"Try again download : {_requestURL}");
+				}
+			}
+		}
+		public override void Abort()
+		{
+			if (IsDone() == false)
+			{
+				_status = EStatus.Failed;
+				_steps = ESteps.Done;
+				_lastError = "user abort";
+				_lastCode = 0;
+
+				DisposeRequest();
+			}
+		}
+		private void DisposeRequest()
+		{
+			if (_webRequest != null)
+			{
+				_webRequest.Dispose();
+				_webRequest = null;
+			}
+			if (_downloadhandler != null)
+			{
+				_downloadhandler.Dispose();
+				_downloadhandler = null;
+			}
+		}
+
+		/// <summary>
+		/// 获取资源包
+		/// </summary>
+		public AssetBundle GetAssetBundle()
+		{
+			return _cacheAssetBundle;
+		}
+	}
+}

UnityProject/Packages/YooAsset/Runtime/DownloadSystem/Downloader/WebDownloader.cs.meta

@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: 41bc4bc56f59ddb4b8925f9536bbbfbc
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

UnityProject/Packages/YooAsset/Runtime/DownloadSystem/RequestHelper.cs

@@ -0,0 +1,36 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+
+namespace YooAsset
+{
+	public class RequestHelper
+	{
+		/// <summary>
+		/// 记录网络请求失败事件的次数
+		/// </summary>
+		private static readonly Dictionary<string, int> _requestFailedRecorder = new Dictionary<string, int>(1000);
+
+		/// <summary>
+		/// 记录请求失败事件
+		/// </summary>
+		public static void RecordRequestFailed(string packageName, string eventName)
+		{
+			string key = $"{packageName}_{eventName}";
+			if (_requestFailedRecorder.ContainsKey(key) == false)
+				_requestFailedRecorder.Add(key, 0);
+			_requestFailedRecorder[key]++;
+		}
+
+		/// <summary>
+		/// 获取请求失败的次数
+		/// </summary>
+		public static int GetRequestFailedCount(string packageName, string eventName)
+		{
+			string key = $"{packageName}_{eventName}";
+			if (_requestFailedRecorder.ContainsKey(key) == false)
+				_requestFailedRecorder.Add(key, 0);
+			return _requestFailedRecorder[key];
+		}
+	}
+}

UnityProject/Packages/YooAsset/Runtime/DownloadSystem/RequestHelper.cs.meta

@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: ca9b2c6456d21bb4e9eecd9dc820a641
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

UnityProject/Packages/YooAsset/Runtime/DownloadSystem/ThreadSyncContext.cs

@@ -0,0 +1,38 @@
+using System;
+using System.Collections;
+using System.Collections.Concurrent;
+using System.Threading;
+
+namespace YooAsset
+{
+	/// <summary>
+	/// 同步其它线程里的回调到主线程里
+	/// 注意：Unity3D中需要设置Scripting Runtime Version为.NET4.6
+	/// </summary>
+	internal sealed class ThreadSyncContext : SynchronizationContext
+	{
+		private readonly ConcurrentQueue<Action> _safeQueue = new ConcurrentQueue<Action>();
+
+		/// <summary>
+		/// 更新同步队列
+		/// </summary>
+		public void Update()
+		{
+			while (true)
+			{
+				if (_safeQueue.TryDequeue(out Action action) == false)
+					return;
+				action.Invoke();
+			}
+		}
+
+		/// <summary>
+		/// 向同步队列里投递一个回调方法
+		/// </summary>
+		public override void Post(SendOrPostCallback callback, object state)
+		{
+			Action action = new Action(() => { callback(state); });
+			_safeQueue.Enqueue(action);
+		}
+	}
+}

UnityProject/Packages/YooAsset/Runtime/DownloadSystem/ThreadSyncContext.cs.meta

@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: 1c8ce2c52a3e9964fa50a9c031e4e593
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

UnityProject/Packages/YooAsset/Runtime/DownloadSystem/UnityWebDataRequester.cs

@@ -0,0 +1,51 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using UnityEngine.Networking;
+using UnityEngine;
+
+namespace YooAsset
+{
+	internal class UnityWebDataRequester : UnityWebRequesterBase
+	{
+		/// <summary>
+		/// 发送GET请求
+		/// </summary>
+		public void SendRequest(string url, int timeout = 60)
+		{
+			if (_webRequest == null)
+			{
+				URL = url;
+				ResetTimeout(timeout);
+
+				_webRequest = DownloadSystem.NewRequest(URL);
+				DownloadHandlerBuffer handler = new DownloadHandlerBuffer();
+				_webRequest.downloadHandler = handler;
+				_webRequest.disposeDownloadHandlerOnDispose = true;
+				_operationHandle = _webRequest.SendWebRequest();
+			}
+		}
+
+		/// <summary>
+		/// 获取下载的字节数据
+		/// </summary>
+		public byte[] GetData()
+		{
+			if (_webRequest != null && IsDone())
+				return _webRequest.downloadHandler.data;
+			else
+				return null;
+		}
+
+		/// <summary>
+		/// 获取下载的文本数据
+		/// </summary>
+		public string GetText()
+		{
+			if (_webRequest != null && IsDone())
+				return _webRequest.downloadHandler.text;
+			else
+				return null;
+		}
+	}
+}

UnityProject/Packages/YooAsset/Runtime/DownloadSystem/UnityWebDataRequester.cs.meta

@@ -0,0 +1,11 @@
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+guid: b7557eb146572de49a1ec9b3f3c0b706
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+  externalObjects: {}
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UnityProject/Packages/YooAsset/Runtime/DownloadSystem/UnityWebFileRequester.cs

@@ -0,0 +1,30 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using UnityEngine.Networking;
+using UnityEngine;
+
+namespace YooAsset
+{
+	internal class UnityWebFileRequester : UnityWebRequesterBase
+	{
+		/// <summary>
+		/// 发送GET请求
+		/// </summary>
+		public void SendRequest(string url, string fileSavePath, int timeout = 60)
+		{
+			if (_webRequest == null)
+			{
+				URL = url;
+				ResetTimeout(timeout);
+
+				_webRequest = DownloadSystem.NewRequest(URL);
+				DownloadHandlerFile handler = new DownloadHandlerFile(fileSavePath);
+				handler.removeFileOnAbort = true;
+				_webRequest.downloadHandler = handler;
+				_webRequest.disposeDownloadHandlerOnDispose = true;
+				_operationHandle = _webRequest.SendWebRequest();
+			}
+		}	
+	}
+}

UnityProject/Packages/YooAsset/Runtime/DownloadSystem/UnityWebFileRequester.cs.meta

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UnityProject/Packages/YooAsset/Runtime/DownloadSystem/UnityWebRequesterBase.cs

@@ -0,0 +1,116 @@
+using System;
+using System.Collections;
+using System.Collections.Concurrent;
+using UnityEngine.Networking;
+using UnityEngine;
+
+namespace YooAsset
+{
+	internal abstract class UnityWebRequesterBase
+	{
+		protected UnityWebRequest _webRequest;
+		protected UnityWebRequestAsyncOperation _operationHandle;
+
+		// 超时相关
+		private float _timeout;
+		private bool _isAbort = false;
+		private ulong _latestDownloadBytes;
+		private float _latestDownloadRealtime;
+
+		/// <summary>
+		/// 请求URL地址
+		/// </summary>
+		public string URL { protected set; get; }
+
+
+		protected void ResetTimeout(float timeout)
+		{
+			_timeout = timeout;
+			_latestDownloadBytes = 0;
+			_latestDownloadRealtime = Time.realtimeSinceStartup;
+		}
+
+		/// <summary>
+		/// 释放下载器
+		/// </summary>
+		public void Dispose()
+		{
+			if (_webRequest != null)
+			{
+				_webRequest.Dispose();
+				_webRequest = null;
+				_operationHandle = null;
+			}
+		}
+
+		/// <summary>
+		/// 是否完毕（无论成功失败）
+		/// </summary>
+		public bool IsDone()
+		{
+			if (_operationHandle == null)
+				return false;
+			return _operationHandle.isDone;
+		}
+
+		/// <summary>
+		/// 下载进度
+		/// </summary>
+		public float Progress()
+		{
+			if (_operationHandle == null)
+				return 0;
+			return _operationHandle.progress;
+		}
+
+		/// <summary>
+		/// 下载是否发生错误
+		/// </summary>
+		public bool HasError()
+		{
+#if UNITY_2020_3_OR_NEWER
+			return _webRequest.result != UnityWebRequest.Result.Success;
+#else
+			if (_webRequest.isNetworkError || _webRequest.isHttpError)
+				return true;
+			else
+				return false;
+#endif
+		}
+
+		/// <summary>
+		/// 获取错误信息
+		/// </summary>
+		public string GetError()
+		{
+			if (_webRequest != null)
+			{
+				return $"URL : {URL} Error : {_webRequest.error}";
+			}
+			return string.Empty;
+		}
+
+		/// <summary>
+		/// 检测超时
+		/// </summary>
+		public void CheckTimeout()
+		{
+			// 注意：在连续时间段内无新增下载数据及判定为超时
+			if (_isAbort == false)
+			{
+				if (_latestDownloadBytes != _webRequest.downloadedBytes)
+				{
+					_latestDownloadBytes = _webRequest.downloadedBytes;
+					_latestDownloadRealtime = Time.realtimeSinceStartup;
+				}
+
+				float offset = Time.realtimeSinceStartup - _latestDownloadRealtime;
+				if (offset > _timeout)
+				{
+					_webRequest.Abort();
+					_isAbort = true;
+				}
+			}
+		}
+	}
+}

UnityProject/Packages/YooAsset/Runtime/DownloadSystem/UnityWebRequesterBase.cs.meta

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