update file system

下载器相关逻辑代码重构
2026-05-14 19:40:47 +00:00 · 2025-07-10 10:58:14 +08:00
parent 236468b4a8
commit b90ab01fe9
26 changed files with 644 additions and 943 deletions
--- a/Assets/YooAsset/Runtime/FileSystem/DefaultBuildinFileSystem/DefaultBuildinFileSystem.cs
+++ b/Assets/YooAsset/Runtime/FileSystem/DefaultBuildinFileSystem/DefaultBuildinFileSystem.cs
@@ -125,7 +125,7 @@ namespace YooAsset
        }
        public virtual FSDownloadFileOperation DownloadFileAsync(PackageBundle bundle, DownloadFileOptions options)
        {
-            // 注意：业务层的解压下载器会依赖内置文件系统的下载方法
+            // 注意：业务层的解压器会依赖该方法
            options.ImportFilePath = GetBuildinFileLoadPath(bundle);
            return _unpackFileSystem.DownloadFileAsync(bundle, options);
        }
--- a/Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/DefaultCacheFileSystem.cs
+++ b/Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/DefaultCacheFileSystem.cs
@@ -166,12 +166,23 @@ namespace YooAsset
        }
        public virtual FSDownloadFileOperation DownloadFileAsync(PackageBundle bundle, DownloadFileOptions options)
        {
-            var downloader = DownloadCenter.DownloadFileAsync(bundle, options);
-            downloader.Reference(); //增加下载器的引用计数
+            // 获取下载地址
+            if (string.IsNullOrEmpty(options.ImportFilePath))
+            {
+                // 注意：如果是解压文件系统类，这里会返回本地内置文件的下载路径
+                string mainURL = RemoteServices.GetRemoteMainURL(bundle.FileName);
+                string fallbackURL = RemoteServices.GetRemoteFallbackURL(bundle.FileName);
+                options.SetURL(mainURL, fallbackURL);
+            }
+            else
+            {
+                // 注意：把本地导入文件路径转换为下载器请求地址
+                string mainURL = DownloadSystemHelper.ConvertToWWWPath(options.ImportFilePath);
+                options.SetURL(mainURL, mainURL);
+            }

-            // 注意：将下载器进行包裹，可以避免父类任务终止的时候，连带子任务里的下载器也一起被终止！
-            var wrapper = new DownloadFileWrapper(downloader);
-            return wrapper;
+            var downloader = new DownloadPackageBundleOperation(this, bundle, options);
+            return downloader;
        }
        public virtual FSLoadBundleOperation LoadBundleFile(PackageBundle bundle)
        {
--- a/Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/DCFSLoadBundleOperation.cs
+++ b/Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/DCFSLoadBundleOperation.cs
@@ -55,7 +55,6 @@ namespace YooAsset

            if (_steps == ESteps.DownloadFile)
            {
-                // 注意：边玩边下下载器引用计数没有Release
                if (_downloadFileOp == null)
                {
                    DownloadFileOptions options = new DownloadFileOptions(int.MaxValue, 60);
@@ -303,7 +302,6 @@ namespace YooAsset

            if (_steps == ESteps.DownloadFile)
            {
-                // 注意：边玩边下下载器引用计数没有Release
                if (_downloadFileOp == null)
                {
                    DownloadFileOptions options = new DownloadFileOptions(int.MaxValue, 60);
--- a/Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/internal/DownloadCenterOperation.cs
+++ b/Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/internal/DownloadCenterOperation.cs
@@ -3,10 +3,21 @@ using System.Collections.Generic;

 namespace YooAsset
 {
+    /// <summary>
+    /// 下载器单元测试
+    /// 1. 下载失败重试机制
+    /// 2. 下载引用计数机制
+    /// 3. 最大下载并发机制
+    /// 4. 异步下载远端资源
+    /// 5. 同步下载远端资源
+    /// 6. 异步拷贝本地资源
+    /// 7. 同步拷贝本地资源
+    /// 9. 断点续传下载器
+    /// </summary>
    internal class DownloadCenterOperation : AsyncOperationBase
    {
        private readonly DefaultCacheFileSystem _fileSystem;
-        protected readonly Dictionary<string, DefaultDownloadFileOperation> _downloaders = new Dictionary<string, DefaultDownloadFileOperation>(1000);
+        protected readonly Dictionary<string, UnityDownloadFileOperation> _downloaders = new Dictionary<string, UnityDownloadFileOperation>(1000);
        protected readonly List<string> _removeDownloadList = new List<string>(1000);

        public DownloadCenterOperation(DefaultCacheFileSystem fileSystem)
@@ -74,34 +85,21 @@ namespace YooAsset
        /// <summary>
        /// 创建下载任务
        /// </summary>
-        public FSDownloadFileOperation DownloadFileAsync(PackageBundle bundle, DownloadFileOptions options)
+        public UnityDownloadFileOperation DownloadFileAsync(PackageBundle bundle, string url, int timeout)
        {
            // 查询旧的下载器
            if (_downloaders.TryGetValue(bundle.BundleGUID, out var oldDownloader))
            {
+                oldDownloader.Reference();
                return oldDownloader;
            }

-            // 获取下载地址
-            if (string.IsNullOrEmpty(options.ImportFilePath))
-            {
-                // 注意：如果是解压文件系统类，这里会返回本地内置文件的下载路径
-                options.MainURL = _fileSystem.RemoteServices.GetRemoteMainURL(bundle.FileName);
-                options.FallbackURL = _fileSystem.RemoteServices.GetRemoteFallbackURL(bundle.FileName);
-            }
-            else
-            {
-                // 注意：把本地导入文件路径转换为下载器请求地址
-                options.MainURL = DownloadSystemHelper.ConvertToWWWPath(options.ImportFilePath);
-                options.FallbackURL = options.MainURL;
-            }
-
            // 创建新的下载器
-            DefaultDownloadFileOperation newDownloader;
-            bool isRequestLocalFile = DownloadSystemHelper.IsRequestLocalFile(options.MainURL);
+            UnityDownloadFileOperation newDownloader;
+            bool isRequestLocalFile = DownloadSystemHelper.IsRequestLocalFile(url);
            if (isRequestLocalFile)
            {
-                newDownloader = new DownloadLocalFileOperation(_fileSystem, bundle, options);
+                newDownloader = new UnityDownloadLocalFileOperation(_fileSystem, bundle, url, timeout);
                AddChildOperation(newDownloader);
                _downloaders.Add(bundle.BundleGUID, newDownloader);
            }
@@ -109,17 +107,19 @@ namespace YooAsset
            {
                if (bundle.FileSize >= _fileSystem.ResumeDownloadMinimumSize)
                {
-                    newDownloader = new DownloadResumeFileOperation(_fileSystem, bundle, options);
+                    newDownloader = new UnityDownloadResumeFileOperation(_fileSystem, bundle, url, timeout);
                    AddChildOperation(newDownloader);
                    _downloaders.Add(bundle.BundleGUID, newDownloader);
                }
                else
                {
-                    newDownloader = new DownloadNormalFileOperation(_fileSystem, bundle, options);
+                    newDownloader = new UnityDownloadNormalFileOperation(_fileSystem, bundle, url, timeout);
                    AddChildOperation(newDownloader);
                    _downloaders.Add(bundle.BundleGUID, newDownloader);
                }
            }
+
+            newDownloader.Reference();
            return newDownloader;
        }

--- a/Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/internal/DownloadHandlerFileRange.cs
+++ b/Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/internal/DownloadHandlerFileRange.cs
@@ -1,87 +0,0 @@
-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;
-            }
-        }
-    }
-}
--- a/Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/internal/DownloadHandlerFileRange.cs.meta
+++ b/Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/internal/DownloadHandlerFileRange.cs.meta
@@ -1,11 +0,0 @@
-fileFormatVersion: 2
-guid: 94254ab8e4496214884c11a891c131c6
-MonoImporter:
-  externalObjects: {}
-  serializedVersion: 2
-  defaultReferences: []
-  executionOrder: 0
-  icon: {instanceID: 0}
-  userData: 
-  assetBundleName: 
-  assetBundleVariant: 
--- a/Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/internal/DownloadNormalFileOperation.cs
+++ b/Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/internal/DownloadNormalFileOperation.cs
@@ -1,194 +0,0 @@
-using System.IO;
-using UnityEngine;
-using UnityEngine.Networking;
-
-namespace YooAsset
-{
-    internal sealed class DownloadNormalFileOperation : DefaultDownloadFileOperation
-    {
-        private readonly DefaultCacheFileSystem _fileSystem;
-        private VerifyTempFileOperation _verifyOperation;
-        private string _tempFilePath;
-        private ESteps _steps = ESteps.None;
-
-        internal DownloadNormalFileOperation(DefaultCacheFileSystem fileSystem, PackageBundle bundle, DownloadFileOptions options) : base(bundle, options)
-        {
-            _fileSystem = fileSystem;
-        }
-        internal override void InternalStart()
-        {
-            _tempFilePath = _fileSystem.GetTempFilePath(Bundle);
-            _steps = ESteps.CheckExists;
-        }
-        internal override void InternalUpdate()
-        {
-            if (_steps == ESteps.None || _steps == ESteps.Done)
-                return;
-
-            // 检测文件是否存在
-            if (_steps == ESteps.CheckExists)
-            {
-                if (_fileSystem.Exists(Bundle))
-                {
-                    _steps = ESteps.Done;
-                    Status = EOperationStatus.Succeed;
-                }
-                else
-                {
-                    _steps = ESteps.CreateRequest;
-                }
-            }
-
-            // 创建下载器
-            if (_steps == ESteps.CreateRequest)
-            {
-                FileUtility.CreateFileDirectory(_tempFilePath);
-
-                // 删除临时文件
-                if (File.Exists(_tempFilePath))
-                    File.Delete(_tempFilePath);
-
-                // 获取请求地址
-                _requestURL = GetRequestURL();
-
-                // 重置请求
-                ResetRequestFiled();
-
-                // 创建下载器
-                CreateWebRequest();
-
-                _steps = ESteps.CheckRequest;
-            }
-
-            // 检测下载结果
-            if (_steps == ESteps.CheckRequest)
-            {
-                DownloadProgress = _webRequest.downloadProgress;
-                DownloadedBytes = (long)_webRequest.downloadedBytes;
-                Progress = DownloadProgress;
-                if (_webRequest.isDone == false)
-                {
-                    CheckRequestTimeout();
-                    return;
-                }
-
-                // 检查网络错误
-                if (CheckRequestResult())
-                    _steps = ESteps.VerifyTempFile;
-                else
-                    _steps = ESteps.TryAgain;
-
-                // 注意：最终释放请求器
-                DisposeWebRequest();
-            }
-
-            // 验证下载文件
-            if (_steps == ESteps.VerifyTempFile)
-            {
-                var element = new TempFileElement(_tempFilePath, Bundle.FileCRC, Bundle.FileSize);
-                _verifyOperation = new VerifyTempFileOperation(element);
-                _verifyOperation.StartOperation();
-                AddChildOperation(_verifyOperation);
-                _steps = ESteps.CheckVerifyTempFile;
-            }
-
-            // 等待验证完成
-            if (_steps == ESteps.CheckVerifyTempFile)
-            {
-                if (IsWaitForAsyncComplete)
-                    _verifyOperation.WaitForAsyncComplete();
-
-                _verifyOperation.UpdateOperation();
-                if (_verifyOperation.IsDone == false)
-                    return;
-
-                if (_verifyOperation.Status == EOperationStatus.Succeed)
-                {
-                    if (_fileSystem.WriteCacheBundleFile(Bundle, _tempFilePath))
-                    {
-                        _steps = ESteps.Done;
-                        Status = EOperationStatus.Succeed;
-                    }
-                    else
-                    {
-                        _steps = ESteps.Done;
-                        Status = EOperationStatus.Failed;
-                        Error = $"{_fileSystem.GetType().FullName} failed to write file !";
-                        YooLogger.Error(Error);
-                    }
-                }
-                else
-                {
-                    _steps = ESteps.TryAgain;
-                    Error = _verifyOperation.Error;
-                }
-
-                // 注意：验证完成后直接删除文件
-                if (File.Exists(_tempFilePath))
-                    File.Delete(_tempFilePath);
-            }
-
-            // 重新尝试下载
-            if (_steps == ESteps.TryAgain)
-            {
-                if (FailedTryAgain <= 0)
-                {
-                    Status = EOperationStatus.Failed;
-                    _steps = ESteps.Done;
-                    YooLogger.Error(Error);
-                    return;
-                }
-
-                _tryAgainTimer += Time.unscaledDeltaTime;
-                if (_tryAgainTimer > 1f)
-                {
-                    FailedTryAgain--;
-                    _steps = ESteps.CreateRequest;
-                    YooLogger.Warning(Error);
-                }
-            }
-        }
-        internal override void InternalAbort()
-        {
-            _steps = ESteps.Done;
-            DisposeWebRequest();
-        }
-        internal override void InternalWaitForAsyncComplete()
-        {
-            while (true)
-            {
-                if (ExecuteWhileDone())
-                {
-                    //TODO 尝试同步加载远端的资源文件失败
-                    if (Status == EOperationStatus.Failed)
-                    {
-                        YooLogger.Error($"Try load bundle {Bundle.BundleName} from remote !");
-                        YooLogger.Error($"The load remote bundle url : {_requestURL}");
-                    }
-
-                    _steps = ESteps.Done;
-                    break;
-                }
-            }
-        }
-
-        private void CreateWebRequest()
-        {
-            _webRequest = DownloadSystemHelper.NewUnityWebRequestGet(_requestURL);
-            DownloadHandlerFile handler = new DownloadHandlerFile(_tempFilePath);
-            handler.removeFileOnAbort = true;
-            _webRequest.downloadHandler = handler;
-            _webRequest.disposeDownloadHandlerOnDispose = true;
-            _webRequest.SendWebRequest();
-        }
-        private void DisposeWebRequest()
-        {
-            if (_webRequest != null)
-            {
-                //注意：引擎底层会自动调用Abort方法
-                _webRequest.Dispose();
-                _webRequest = null;
-            }
-        }
-    }
-}
--- a/Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/internal/DownloadPackageBundleOperation.cs
+++ b/Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/internal/DownloadPackageBundleOperation.cs
@@ -0,0 +1,164 @@
+using UnityEngine;
+
+namespace YooAsset
+{
+    internal class DownloadPackageBundleOperation : FSDownloadFileOperation
+    {
+        protected enum ESteps
+        {
+            None,
+            CheckExists,
+            CreateRequest,
+            CheckRequest,
+            TryAgain,
+            Done,
+        }
+
+        // 下载参数
+        protected readonly DefaultCacheFileSystem _fileSystem;
+        protected readonly DownloadFileOptions _options;
+        private UnityDownloadFileOperation _unityDownloadFileOp;
+
+        protected int _requestCount = 0;
+        protected float _tryAgainTimer;
+        protected int _failedTryAgain;
+        private ESteps _steps = ESteps.None;
+
+
+        internal DownloadPackageBundleOperation(DefaultCacheFileSystem fileSystem, PackageBundle bundle, DownloadFileOptions options) : base(bundle)
+        {
+            _fileSystem = fileSystem;
+            _options = options;
+            _failedTryAgain = options.FailedTryAgain;
+        }
+        internal override void InternalStart()
+        {
+            _steps = ESteps.CheckExists;
+        }
+        internal override void InternalUpdate()
+        {
+            if (_steps == ESteps.None || _steps == ESteps.Done)
+                return;
+
+            // 检测文件是否存在
+            if (_steps == ESteps.CheckExists)
+            {
+                if (_fileSystem.Exists(Bundle))
+                {
+                    _steps = ESteps.Done;
+                    Status = EOperationStatus.Succeed;
+                }
+                else
+                {
+                    _steps = ESteps.CreateRequest;
+                }
+            }
+
+            // 创建下载器
+            if (_steps == ESteps.CreateRequest)
+            {
+                if (_options.IsValid() == false)
+                {
+                    _steps = ESteps.Done;
+                    Status = EOperationStatus.Failed;
+                    Error = "Download file options is invalid !";
+                    Debug.Log(Error);
+                    return;
+                }
+
+                string url = GetRequestURL();
+                _unityDownloadFileOp = _fileSystem.DownloadCenter.DownloadFileAsync(Bundle, url, _options.Timeout);
+                _steps = ESteps.CheckRequest;
+            }
+
+            // 检测下载结果
+            if (_steps == ESteps.CheckRequest)
+            {
+                if (IsWaitForAsyncComplete)
+                    _unityDownloadFileOp.WaitForAsyncComplete();
+
+                // 因为并发数量限制，下载器可能被挂起！
+                if (_unityDownloadFileOp.Status == EOperationStatus.None)
+                    return;
+
+                _unityDownloadFileOp.UpdateOperation();
+                Progress = _unityDownloadFileOp.Progress;
+                DownloadedBytes = _unityDownloadFileOp.DownloadedBytes;
+                DownloadProgress = _unityDownloadFileOp.DownloadProgress;
+                if (_unityDownloadFileOp.IsDone == false)
+                    return;
+
+                if (_unityDownloadFileOp.Status == EOperationStatus.Succeed)
+                {
+                    _steps = ESteps.Done;
+                    Status = EOperationStatus.Succeed;
+                }
+                else
+                {
+                    if (IsWaitForAsyncComplete == false && _failedTryAgain > 0)
+                    {
+                        _steps = ESteps.TryAgain;
+                        YooLogger.Warning($"Failed download : {_unityDownloadFileOp.URL} Try again !");
+                    }
+                    else
+                    {
+                        _steps = ESteps.Done;
+                        Status = EOperationStatus.Failed;
+                        Error = _unityDownloadFileOp.Error;
+                        YooLogger.Error(Error);
+                    }
+                }
+            }
+
+            // 重新尝试下载
+            if (_steps == ESteps.TryAgain)
+            {
+                _tryAgainTimer += Time.unscaledDeltaTime;
+                if (_tryAgainTimer > 1f)
+                {
+                    _tryAgainTimer = 0f;
+                    _failedTryAgain--;
+                    Progress = 0f;
+                    DownloadProgress = 0f;
+                    DownloadedBytes = 0;
+                    _steps = ESteps.CreateRequest;
+                }
+            }
+        }
+        internal override void InternalWaitForAsyncComplete()
+        {
+            while (true)
+            {
+                if (ExecuteWhileDone())
+                {
+                    _steps = ESteps.Done;
+                    break;
+                }
+            }
+        }
+        internal override void InternalAbort()
+        {
+            // 注意：取消下载任务的时候引用计数减一
+            if (_steps != ESteps.Done)
+            {
+                if (_unityDownloadFileOp != null)
+                {
+                    _unityDownloadFileOp.Release();
+                }
+            }
+        }
+
+        /// <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 _options.FallbackURL;
+            else
+                return _options.MainURL;
+        }
+    }
+}
--- a/Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/internal/DownloadPackageBundleOperation.cs.meta
+++ b/Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/internal/DownloadPackageBundleOperation.cs.meta
--- a/Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/internal/UnityDownloadFileOperation.cs
+++ b/Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/internal/UnityDownloadFileOperation.cs
@@ -0,0 +1,52 @@
+
+namespace YooAsset
+{
+    internal abstract class UnityDownloadFileOperation : UnityWebRequestOperation
+    {
+        protected enum ESteps
+        {
+            None,
+            CreateRequest,
+            Download,
+            CopyLocalFile,
+            VerifyFile,
+            Done,
+        }
+
+        protected readonly DefaultCacheFileSystem _fileSystem;
+        protected readonly PackageBundle _bundle;
+        protected readonly string _tempFilePath;
+
+        /// <summary>
+        /// 引用计数
+        /// </summary>
+        public int RefCount { private set; get; }
+
+        internal UnityDownloadFileOperation(DefaultCacheFileSystem fileSystem, PackageBundle bundle, string url, int timeout) : base(url, timeout)
+        {
+            _fileSystem = fileSystem;
+            _bundle = bundle;
+            _tempFilePath = _fileSystem.GetTempFilePath(bundle);
+        }
+        internal override string InternalGetDesc()
+        {
+            return $"RefCount : {RefCount}";
+        }
+
+        /// <summary>
+        /// 减少引用计数
+        /// </summary>
+        public void Release()
+        {
+            RefCount--;
+        }
+
+        /// <summary>
+        /// 增加引用计数
+        /// </summary>
+        public void Reference()
+        {
+            RefCount++;
+        }
+    }
+}
--- a/Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/internal/UnityDownloadFileOperation.cs.meta
+++ b/Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/internal/UnityDownloadFileOperation.cs.meta
@@ -1,5 +1,5 @@
 fileFormatVersion: 2
-guid: 8088863fc7dfbd441bc897380cd7b97f
+guid: 40bb5e9391f413c42ae70e48ca90c4b7
 MonoImporter:
  externalObjects: {}
  serializedVersion: 2
--- a/Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/internal/UnityDownloadLocalFileOperation.cs
+++ b/Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/internal/UnityDownloadLocalFileOperation.cs
@@ -4,67 +4,41 @@ using UnityEngine.Networking;

 namespace YooAsset
 {
-    internal class DownloadLocalFileOperation : DefaultDownloadFileOperation
+    internal class UnityDownloadLocalFileOperation : UnityDownloadFileOperation
    {
-        private readonly DefaultCacheFileSystem _fileSystem;
        private VerifyTempFileOperation _verifyOperation;
-        private string _tempFilePath;
        private ESteps _steps = ESteps.None;

-        internal DownloadLocalFileOperation(DefaultCacheFileSystem fileSystem, PackageBundle bundle, DownloadFileOptions options) : base(bundle, options)
+        internal UnityDownloadLocalFileOperation(DefaultCacheFileSystem fileSystem, PackageBundle bundle, string url, int timeout = 60)
+            : base(fileSystem, bundle, url, timeout)
        {
-            _fileSystem = fileSystem;
        }
        internal override void InternalStart()
        {
-            _tempFilePath = _fileSystem.GetTempFilePath(Bundle);
-            _steps = ESteps.CheckExists;
+            if (_fileSystem.CopyLocalFileServices != null)
+                _steps = ESteps.CopyLocalFile;
+            else
+                _steps = ESteps.CreateRequest;
        }
        internal override void InternalUpdate()
        {
            if (_steps == ESteps.None || _steps == ESteps.Done)
                return;

-            // 检测文件是否存在
-            if (_steps == ESteps.CheckExists)
-            {
-                if (_fileSystem.Exists(Bundle))
-                {
-                    _steps = ESteps.Done;
-                    Status = EOperationStatus.Succeed;
-                }
-                else
-                {
-                    if (_fileSystem.CopyLocalFileServices != null)
-                        _steps = ESteps.CopyBuildinBundle;
-                    else
-                        _steps = ESteps.CreateRequest;
-                }
-            }
-
            // 创建下载器
            if (_steps == ESteps.CreateRequest)
            {
                FileUtility.CreateFileDirectory(_tempFilePath);
-
-                // 删除临时文件
                if (File.Exists(_tempFilePath))
                    File.Delete(_tempFilePath);

-                // 获取请求地址
-                _requestURL = GetRequestURL();
-
-                // 重置请求
-                ResetRequestFiled();
-
-                // 创建下载器
+                ResetTimeout();
                CreateWebRequest();
-
-                _steps = ESteps.CheckRequest;
+                _steps = ESteps.Download;
            }

            // 检测下载结果
-            if (_steps == ESteps.CheckRequest)
+            if (_steps == ESteps.Download)
            {
                DownloadProgress = _webRequest.downloadProgress;
                DownloadedBytes = (long)_webRequest.downloadedBytes;
@@ -77,67 +51,67 @@ namespace YooAsset

                // 检查网络错误
                if (CheckRequestResult())
-                    _steps = ESteps.VerifyTempFile;
+                {
+                    _steps = ESteps.VerifyFile;
+                }
                else
-                    _steps = ESteps.TryAgain;
+                {
+                    _steps = ESteps.Done;
+                    Status = EOperationStatus.Failed;
+                }

                // 注意：最终释放请求器
-                DisposeWebRequest();
+                DisposeRequest();
            }

            // 拷贝内置文件
-            if (_steps == ESteps.CopyBuildinBundle)
+            if (_steps == ESteps.CopyLocalFile)
            {
                FileUtility.CreateFileDirectory(_tempFilePath);
-
-                // 删除临时文件
                if (File.Exists(_tempFilePath))
                    File.Delete(_tempFilePath);

-                // 获取请求地址
-                _requestURL = GetRequestURL();
-
                try
                {
                    //TODO 团结引擎，在某些机型（红米），拷贝包内文件会小概率失败！需要借助其它方式来拷贝包内文件。
                    var localFileInfo = new LocalFileInfo();
                    localFileInfo.PackageName = _fileSystem.PackageName;
-                    localFileInfo.BundleName = Bundle.BundleName;
+                    localFileInfo.BundleName = _bundle.BundleName;
                    localFileInfo.SourceFileURL = _requestURL;
                    _fileSystem.CopyLocalFileServices.CopyFile(localFileInfo, _tempFilePath);
                    if (File.Exists(_tempFilePath))
                    {
                        DownloadProgress = 1f;
-                        DownloadedBytes = Bundle.FileSize;
+                        DownloadedBytes = _bundle.FileSize;
                        Progress = DownloadProgress;
-                        _steps = ESteps.VerifyTempFile;
+                        _steps = ESteps.VerifyFile;
                    }
                    else
                    {
+                        _steps = ESteps.Done;
+                        Status = EOperationStatus.Failed;
                        Error = $"Failed copy local file : {_requestURL}";
-                        _steps = ESteps.TryAgain;
                    }
                }
                catch (System.Exception ex)
                {
+                    _steps = ESteps.Done;
+                    Status = EOperationStatus.Failed;
                    Error = $"Failed copy local file : {ex.Message}";
-                    _steps = ESteps.TryAgain;
                }
            }

            // 验证下载文件
-            if (_steps == ESteps.VerifyTempFile)
+            if (_steps == ESteps.VerifyFile)
            {
-                var element = new TempFileElement(_tempFilePath, Bundle.FileCRC, Bundle.FileSize);
-                _verifyOperation = new VerifyTempFileOperation(element);
-                _verifyOperation.StartOperation();
-                AddChildOperation(_verifyOperation);
-                _steps = ESteps.CheckVerifyTempFile;
-            }
+                if (_verifyOperation == null)
+                {
+                    var element = new TempFileElement(_tempFilePath, _bundle.FileCRC, _bundle.FileSize);
+                    _verifyOperation = new VerifyTempFileOperation(element);
+                    _verifyOperation.StartOperation();
+                    AddChildOperation(_verifyOperation);
+                }

-            // 等待验证完成
-            if (_steps == ESteps.CheckVerifyTempFile)
-            {
                if (IsWaitForAsyncComplete)
                    _verifyOperation.WaitForAsyncComplete();

@@ -147,7 +121,7 @@ namespace YooAsset

                if (_verifyOperation.Status == EOperationStatus.Succeed)
                {
-                    if (_fileSystem.WriteCacheBundleFile(Bundle, _tempFilePath))
+                    if (_fileSystem.WriteCacheBundleFile(_bundle, _tempFilePath))
                    {
                        _steps = ESteps.Done;
                        Status = EOperationStatus.Succeed;
@@ -157,12 +131,12 @@ namespace YooAsset
                        _steps = ESteps.Done;
                        Status = EOperationStatus.Failed;
                        Error = $"{_fileSystem.GetType().FullName} failed to write file !";
-                        YooLogger.Error(Error);
                    }
                }
                else
                {
-                    _steps = ESteps.TryAgain;
+                    _steps = ESteps.Done;
+                    Status = EOperationStatus.Failed;
                    Error = _verifyOperation.Error;
                }

@@ -170,20 +144,6 @@ namespace YooAsset
                if (File.Exists(_tempFilePath))
                    File.Delete(_tempFilePath);
            }
-
-            // 重新尝试下载
-            if (_steps == ESteps.TryAgain)
-            {
-                //TODO 拷贝本地文件失败后不再尝试！
-                Status = EOperationStatus.Failed;
-                _steps = ESteps.Done;
-                YooLogger.Error(Error);
-            }
-        }
-        internal override void InternalAbort()
-        {
-            _steps = ESteps.Done;
-            DisposeWebRequest();
        }
        internal override void InternalWaitForAsyncComplete()
        {
@@ -208,14 +168,5 @@ namespace YooAsset
            _webRequest.disposeDownloadHandlerOnDispose = true;
            _webRequest.SendWebRequest();
        }
-        private void DisposeWebRequest()
-        {
-            if (_webRequest != null)
-            {
-                //注意：引擎底层会自动调用Abort方法
-                _webRequest.Dispose();
-                _webRequest = null;
-            }
-        }
    }
 }
--- a/Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/internal/UnityDownloadLocalFileOperation.cs.meta
+++ b/Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/internal/UnityDownloadLocalFileOperation.cs.meta
--- a/Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/internal/UnityDownloadNormalFileOperation.cs
+++ b/Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/internal/UnityDownloadNormalFileOperation.cs
@@ -0,0 +1,126 @@
+using System.IO;
+using UnityEngine;
+using UnityEngine.Networking;
+
+namespace YooAsset
+{
+    internal sealed class UnityDownloadNormalFileOperation : UnityDownloadFileOperation
+    {
+        private VerifyTempFileOperation _verifyOperation;
+        private ESteps _steps = ESteps.None;
+
+        internal UnityDownloadNormalFileOperation(DefaultCacheFileSystem fileSystem, PackageBundle bundle, string url, int timeout = 60)
+            : base(fileSystem, bundle, url, timeout)
+        {
+        }
+        internal override void InternalStart()
+        {
+            _steps = ESteps.CreateRequest;
+        }
+        internal override void InternalUpdate()
+        {
+            if (_steps == ESteps.None || _steps == ESteps.Done)
+                return;
+
+            // 创建下载器
+            if (_steps == ESteps.CreateRequest)
+            {
+                FileUtility.CreateFileDirectory(_tempFilePath);
+                if (File.Exists(_tempFilePath))
+                    File.Delete(_tempFilePath);
+
+                ResetTimeout();
+                CreateWebRequest();
+                _steps = ESteps.Download;
+            }
+
+            // 检测下载结果
+            if (_steps == ESteps.Download)
+            {
+                DownloadProgress = _webRequest.downloadProgress;
+                DownloadedBytes = (long)_webRequest.downloadedBytes;
+                Progress = DownloadProgress;
+                if (_webRequest.isDone == false)
+                {
+                    CheckRequestTimeout();
+                    return;
+                }
+
+                // 检查网络错误
+                if (CheckRequestResult())
+                {
+                    _steps = ESteps.VerifyFile;
+                }
+                else
+                {
+                    _steps = ESteps.Done;
+                    Status = EOperationStatus.Failed;
+                }
+
+                // 注意：最终释放请求器
+                DisposeRequest();
+            }
+
+            // 验证下载文件
+            if (_steps == ESteps.VerifyFile)
+            {
+                if (_verifyOperation == null)
+                {
+                    var element = new TempFileElement(_tempFilePath, _bundle.FileCRC, _bundle.FileSize);
+                    _verifyOperation = new VerifyTempFileOperation(element);
+                    _verifyOperation.StartOperation();
+                    AddChildOperation(_verifyOperation);
+                }
+
+                if (IsWaitForAsyncComplete)
+                    _verifyOperation.WaitForAsyncComplete();
+
+                _verifyOperation.UpdateOperation();
+                if (_verifyOperation.IsDone == false)
+                    return;
+
+                if (_verifyOperation.Status == EOperationStatus.Succeed)
+                {
+                    if (_fileSystem.WriteCacheBundleFile(_bundle, _tempFilePath))
+                    {
+                        _steps = ESteps.Done;
+                        Status = EOperationStatus.Succeed;
+                    }
+                    else
+                    {
+                        _steps = ESteps.Done;
+                        Status = EOperationStatus.Failed;
+                        Error = $"{_fileSystem.GetType().FullName} failed to write file ! {_tempFilePath}";
+                    }
+                }
+                else
+                {
+                    _steps = ESteps.Done;
+                    Status = EOperationStatus.Failed;
+                    Error = _verifyOperation.Error;
+                }
+
+                // 注意：验证完成后直接删除文件
+                if (File.Exists(_tempFilePath))
+                    File.Delete(_tempFilePath);
+            }
+        }
+        internal override void InternalWaitForAsyncComplete()
+        {
+            if (_steps != ESteps.Done)
+            {
+                YooLogger.Error($"Try load bundle {_bundle.BundleName} from remote : {_requestURL} !");
+            }
+        }
+
+        private void CreateWebRequest()
+        {
+            _webRequest = DownloadSystemHelper.NewUnityWebRequestGet(_requestURL);
+            DownloadHandlerFile handler = new DownloadHandlerFile(_tempFilePath);
+            handler.removeFileOnAbort = true;
+            _webRequest.downloadHandler = handler;
+            _webRequest.disposeDownloadHandlerOnDispose = true;
+            _webRequest.SendWebRequest();
+        }
+    }
+}
--- a/Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/internal/UnityDownloadNormalFileOperation.cs.meta
+++ b/Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/internal/UnityDownloadNormalFileOperation.cs.meta
--- a/Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/internal/UnityDownloadResumeFileOperation.cs
+++ b/Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/internal/UnityDownloadResumeFileOperation.cs
@@ -4,63 +4,38 @@ using UnityEngine.Networking;

 namespace YooAsset
 {
-    internal sealed class DownloadResumeFileOperation : DefaultDownloadFileOperation
+    internal sealed class UnityDownloadResumeFileOperation : UnityDownloadFileOperation
    {
-        private readonly DefaultCacheFileSystem _fileSystem;
-        private DownloadHandlerFileRange _downloadHandle;
        private VerifyTempFileOperation _verifyOperation;
        private long _fileOriginLength = 0;
-        private string _tempFilePath;
        private ESteps _steps = ESteps.None;

-        internal DownloadResumeFileOperation(DefaultCacheFileSystem fileSystem, PackageBundle bundle, DownloadFileOptions options) : base(bundle, options)
+        internal UnityDownloadResumeFileOperation(DefaultCacheFileSystem fileSystem, PackageBundle bundle, string url, int timeout = 60)
+            : base(fileSystem, bundle, url, timeout)
        {
-            _fileSystem = fileSystem;
        }
        internal override void InternalStart()
        {
-            _tempFilePath = _fileSystem.GetTempFilePath(Bundle);
-            _steps = ESteps.CheckExists;
+            _steps = ESteps.CreateRequest;
        }
        internal override void InternalUpdate()
        {
            if (_steps == ESteps.None || _steps == ESteps.Done)
                return;

-            // 检测文件是否存在
-            if (_steps == ESteps.CheckExists)
-            {
-                if (_fileSystem.Exists(Bundle))
-                {
-                    _steps = ESteps.Done;
-                    Status = EOperationStatus.Succeed;
-                }
-                else
-                {
-                    _steps = ESteps.CreateRequest;
-                }
-            }
-
            // 创建下载器
            if (_steps == ESteps.CreateRequest)
            {
                FileUtility.CreateFileDirectory(_tempFilePath);

-                // 获取请求地址
-                _requestURL = GetRequestURL();
-
-                // 重置变量
-                ResetRequestFiled();
-
                // 获取下载起始位置
                _fileOriginLength = 0;
                long fileBeginLength = -1;
                if (File.Exists(_tempFilePath))
                {
                    FileInfo fileInfo = new FileInfo(_tempFilePath);
-                    if (fileInfo.Length >= Bundle.FileSize)
+                    if (fileInfo.Length >= _bundle.FileSize)
                    {
-                        // 删除临时文件
                        File.Delete(_tempFilePath);
                    }
                    else
@@ -71,17 +46,17 @@ namespace YooAsset
                    }
                }

-                // 创建下载器
+                ResetTimeout();
                CreateWebRequest(fileBeginLength);
-
-                _steps = ESteps.CheckRequest;
+                _steps = ESteps.Download;
            }

            // 检测下载结果
-            if (_steps == ESteps.CheckRequest)
+            if (_steps == ESteps.Download)
            {
                DownloadProgress = _webRequest.downloadProgress;
                DownloadedBytes = _fileOriginLength + (long)_webRequest.downloadedBytes;
+                Progress = DownloadProgress;
                if (_webRequest.isDone == false)
                {
                    CheckRequestTimeout();
@@ -90,30 +65,33 @@ namespace YooAsset

                // 检查网络错误
                if (CheckRequestResult())
-                    _steps = ESteps.VerifyTempFile;
+                {
+                    _steps = ESteps.VerifyFile;
+                }
                else
-                    _steps = ESteps.TryAgain;
+                {
+                    _steps = ESteps.Done;
+                    Status = EOperationStatus.Failed;
+                }

                // 在遇到特殊错误的时候删除文件
                ClearTempFileWhenError();

                // 注意：最终释放请求器
-                DisposeWebRequest();
+                DisposeRequest();
            }

            // 验证下载文件
-            if (_steps == ESteps.VerifyTempFile)
+            if (_steps == ESteps.VerifyFile)
            {
-                var element = new TempFileElement(_tempFilePath, Bundle.FileCRC, Bundle.FileSize);
-                _verifyOperation = new VerifyTempFileOperation(element);
-                _verifyOperation.StartOperation();
-                AddChildOperation(_verifyOperation);
-                _steps = ESteps.CheckVerifyTempFile;
-            }
+                if (_verifyOperation == null)
+                {
+                    var element = new TempFileElement(_tempFilePath, _bundle.FileCRC, _bundle.FileSize);
+                    _verifyOperation = new VerifyTempFileOperation(element);
+                    _verifyOperation.StartOperation();
+                    AddChildOperation(_verifyOperation);
+                }

-            // 等待验证完成
-            if (_steps == ESteps.CheckVerifyTempFile)
-            {
                if (IsWaitForAsyncComplete)
                    _verifyOperation.WaitForAsyncComplete();

@@ -123,104 +101,38 @@ namespace YooAsset

                if (_verifyOperation.Status == EOperationStatus.Succeed)
                {
-                    if (_fileSystem.WriteCacheBundleFile(Bundle, _tempFilePath))
+                    if (_fileSystem.WriteCacheBundleFile(_bundle, _tempFilePath))
                    {
-                        Status = EOperationStatus.Succeed;
                        _steps = ESteps.Done;
+                        Status = EOperationStatus.Succeed;
                    }
                    else
                    {
-                        Error = $"{_fileSystem.GetType().FullName} failed to write file !";
-                        Status = EOperationStatus.Failed;
                        _steps = ESteps.Done;
+                        Status = EOperationStatus.Failed;
+                        Error = $"{_fileSystem.GetType().FullName} failed to write file !";
                    }
                }
                else
                {
+                    _steps = ESteps.Done;
+                    Status = EOperationStatus.Failed;
                    Error = _verifyOperation.Error;
-                    _steps = ESteps.TryAgain;
                }

                // 注意：验证完成后直接删除文件
                if (File.Exists(_tempFilePath))
                    File.Delete(_tempFilePath);
            }
-
-            // 重新尝试下载
-            if (_steps == ESteps.TryAgain)
-            {
-                if (FailedTryAgain <= 0)
-                {
-                    Status = EOperationStatus.Failed;
-                    _steps = ESteps.Done;
-                    YooLogger.Error(Error);
-                    return;
-                }
-
-                _tryAgainTimer += Time.unscaledDeltaTime;
-                if (_tryAgainTimer > 1f)
-                {
-                    FailedTryAgain--;
-                    _steps = ESteps.CreateRequest;
-                    YooLogger.Warning(Error);
-                }
-            }
-        }
-        internal override void InternalAbort()
-        {
-            _steps = ESteps.Done;
-            DisposeWebRequest();
        }
        internal override void InternalWaitForAsyncComplete()
        {
-            while (true)
+            if (_steps != ESteps.Done)
            {
-                if (ExecuteWhileDone())
-                {
-                    //TODO 尝试同步加载远端的资源文件失败
-                    if (Status == EOperationStatus.Failed)
-                    {
-                        YooLogger.Error($"Try load bundle {Bundle.BundleName} from remote !");
-                        YooLogger.Error($"The load remote bundle url : {_requestURL}");
-                    }
-
-                    _steps = ESteps.Done;
-                    break;
-                }
+                YooLogger.Error($"Try load bundle {_bundle.BundleName} from remote : {_requestURL} !");
            }
        }

-        private void CreateWebRequest(long beginLength)
-        {
-            _webRequest = DownloadSystemHelper.NewUnityWebRequestGet(_requestURL);
-#if UNITY_2019_4_OR_NEWER
-            var handler = new DownloadHandlerFile(_tempFilePath, true);
-            handler.removeFileOnAbort = false;
-#else
-            var handler = new DownloadHandlerFileRange(FileSavePath, Bundle.FileSize, _webRequest);
-            _downloadHandle = handler;
-#endif
-            _webRequest.downloadHandler = handler;
-            _webRequest.disposeDownloadHandlerOnDispose = true;
-            if (beginLength > 0)
-                _webRequest.SetRequestHeader("Range", $"bytes={beginLength}-");
-            _webRequest.SendWebRequest();
-        }
-        private void DisposeWebRequest()
-        {
-            if (_downloadHandle != null)
-            {
-                _downloadHandle.Cleanup();
-                _downloadHandle = null;
-            }
-
-            if (_webRequest != null)
-            {
-                //注意：引擎底层会自动调用Abort方法
-                _webRequest.Dispose();
-                _webRequest = null;
-            }
-        }
        private void ClearTempFileWhenError()
        {
            if (_fileSystem.ResumeDownloadResponseCodes == null)
@@ -233,5 +145,16 @@ namespace YooAsset
                    File.Delete(_tempFilePath);
            }
        }
+        private void CreateWebRequest(long fileBeginLength)
+        {
+            _webRequest = DownloadSystemHelper.NewUnityWebRequestGet(_requestURL);
+            var handler = new DownloadHandlerFile(_tempFilePath, true);
+            handler.removeFileOnAbort = false;
+            _webRequest.downloadHandler = handler;
+            _webRequest.disposeDownloadHandlerOnDispose = true;
+            if (fileBeginLength > 0)
+                _webRequest.SetRequestHeader("Range", $"bytes={fileBeginLength}-");
+            _webRequest.SendWebRequest();
+        }
    }
 }
--- a/Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/internal/UnityDownloadResumeFileOperation.cs.meta
+++ b/Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/internal/UnityDownloadResumeFileOperation.cs.meta
--- a/Assets/YooAsset/Runtime/FileSystem/DefaultWebRemoteFileSystem/Operation/DWRFSLoadBundleOperation.cs
+++ b/Assets/YooAsset/Runtime/FileSystem/DefaultWebRemoteFileSystem/Operation/DWRFSLoadBundleOperation.cs
@@ -34,19 +34,20 @@ namespace YooAsset
            {
                if (_downloadAssetBundleOp == null)
                {
+                    string mainURL = _fileSystem.RemoteServices.GetRemoteMainURL(_bundle.FileName);
+                    string fallbackURL = _fileSystem.RemoteServices.GetRemoteFallbackURL(_bundle.FileName);
                    DownloadFileOptions options = new DownloadFileOptions(int.MaxValue, 60);
-                    options.MainURL = _fileSystem.RemoteServices.GetRemoteMainURL(_bundle.FileName);
-                    options.FallbackURL = _fileSystem.RemoteServices.GetRemoteFallbackURL(_bundle.FileName);
-
+                    options.SetURL(mainURL, fallbackURL);
+                    
                    if (_bundle.Encrypted)
                    {
-                        _downloadAssetBundleOp = new DownloadWebEncryptAssetBundleOperation(true, _fileSystem.DecryptionServices, _bundle, options);
+                        _downloadAssetBundleOp = new DownloadEncryptAssetBundleOperation(_bundle, options, true, _fileSystem.DecryptionServices);
                        _downloadAssetBundleOp.StartOperation();
                        AddChildOperation(_downloadAssetBundleOp);
                    }
                    else
                    {
-                        _downloadAssetBundleOp = new DownloadWebNormalAssetBundleOperation(_fileSystem.DisableUnityWebCache, _bundle, options);
+                        _downloadAssetBundleOp = new DownloadNormalAssetBundleOperation(_bundle, options, _fileSystem.DisableUnityWebCache);
                        _downloadAssetBundleOp.StartOperation();
                        AddChildOperation(_downloadAssetBundleOp);
                    }
--- a/Assets/YooAsset/Runtime/FileSystem/DefaultWebServerFileSystem/Operation/DWSFSLoadBundleOperation.cs
+++ b/Assets/YooAsset/Runtime/FileSystem/DefaultWebServerFileSystem/Operation/DWSFSLoadBundleOperation.cs
@@ -34,20 +34,20 @@ namespace YooAsset
            {
                if (_downloadAssetBundleOp == null)
                {
-                    DownloadFileOptions options = new DownloadFileOptions(int.MaxValue, 60);
                    string fileLoadPath = _fileSystem.GetWebFileLoadPath(_bundle);
-                    options.MainURL = DownloadSystemHelper.ConvertToWWWPath(fileLoadPath);
-                    options.FallbackURL = options.MainURL;
+                    string mainURL = DownloadSystemHelper.ConvertToWWWPath(fileLoadPath);
+                    DownloadFileOptions options = new DownloadFileOptions(int.MaxValue, 60);
+                    options.SetURL(mainURL, mainURL);

                    if (_bundle.Encrypted)
                    {
-                        _downloadAssetBundleOp = new DownloadWebEncryptAssetBundleOperation(true, _fileSystem.DecryptionServices, _bundle, options);
+                        _downloadAssetBundleOp = new DownloadEncryptAssetBundleOperation(_bundle, options,  true, _fileSystem.DecryptionServices);
                        _downloadAssetBundleOp.StartOperation();
                        AddChildOperation(_downloadAssetBundleOp);
                    }
                    else
                    {
-                        _downloadAssetBundleOp = new DownloadWebNormalAssetBundleOperation(_fileSystem.DisableUnityWebCache, _bundle, options);
+                        _downloadAssetBundleOp = new DownloadNormalAssetBundleOperation(_bundle, options, _fileSystem.DisableUnityWebCache);
                        _downloadAssetBundleOp.StartOperation();
                        AddChildOperation(_downloadAssetBundleOp);
                    }
--- a/Assets/YooAsset/Runtime/FileSystem/Operation/FSDownloadFileOperation.cs
+++ b/Assets/YooAsset/Runtime/FileSystem/Operation/FSDownloadFileOperation.cs
@@ -16,12 +16,12 @@ namespace YooAsset
        /// <summary>
        /// 主资源地址
        /// </summary>
-        public string MainURL { set; get; }
+        public string MainURL { private set; get; }

        /// <summary>
        /// 备用资源地址
        /// </summary>
-        public string FallbackURL { set; get; }
+        public string FallbackURL { private set; get; }

        /// <summary>
        /// 拷贝的本地文件路径
@@ -33,22 +33,32 @@ namespace YooAsset
            FailedTryAgain = failedTryAgain;
            Timeout = timeout;
        }
+
+        /// <summary>
+        /// 设置下载地址
+        /// </summary>
+        public void SetURL(string mainURL, string fallbackURL)
+        {
+            MainURL = mainURL;
+            FallbackURL = fallbackURL;
+        }
+
+        /// <summary>
+        /// 是否有效
+        /// </summary>
+        public bool IsValid()
+        {
+            if (string.IsNullOrEmpty(MainURL) || string.IsNullOrEmpty(FallbackURL))
+                return false;
+
+            return true;
+        }
    }

    internal abstract class FSDownloadFileOperation : AsyncOperationBase
    {
        public PackageBundle Bundle { private set; get; }

-        /// <summary>
-        /// 引用计数
-        /// </summary>
-        public int RefCount { private set; get; }
-
-        /// <summary>
-        /// HTTP返回码
-        /// </summary>
-        public long HttpCode { protected set; get; }
-
        /// <summary>
        /// 当前下载的字节数
        /// </summary>
@@ -63,31 +73,8 @@ namespace YooAsset
        public FSDownloadFileOperation(PackageBundle bundle)
        {
            Bundle = bundle;
-            RefCount = 0;
-            HttpCode = 0;
            DownloadedBytes = 0;
            DownloadProgress = 0;
        }
-
-        internal override string InternalGetDesc()
-        {
-            return $"RefCount : {RefCount}";
-        }
-
-        /// <summary>
-        /// 减少引用计数
-        /// </summary>
-        public virtual void Release()
-        {
-            RefCount--;
-        }
-
-        /// <summary>
-        /// 增加引用计数
-        /// </summary>
-        public virtual void Reference()
-        {
-            RefCount++;
-        }
    }
 }
--- a/Assets/YooAsset/Runtime/FileSystem/Operation/Internal/DefaultDownloadFileOperation.cs
+++ b/Assets/YooAsset/Runtime/FileSystem/Operation/Internal/DefaultDownloadFileOperation.cs
@@ -1,131 +0,0 @@
-using UnityEngine;
-using UnityEngine.Networking;
-
-namespace YooAsset
-{
-    internal abstract class DefaultDownloadFileOperation : FSDownloadFileOperation
-    {
-        protected enum ESteps
-        {
-            None,
-            CheckExists,
-            CreateRequest,
-            CheckRequest,
-            CopyBuildinBundle,
-            VerifyTempFile,
-            CheckVerifyTempFile,
-            TryAgain,
-            Done,
-        }
-
-        // 下载参数
-        protected readonly DownloadFileOptions Options;
-
-        // 请求相关
-        protected UnityWebRequest _webRequest;
-        protected string _requestURL;
-        protected int _requestCount = 0;
-
-        // 超时相关
-        protected bool _isAbort = false;
-        protected long _latestDownloadBytes;
-        protected float _latestDownloadRealtime;
-        protected float _tryAgainTimer;
-
-        // 失败相关
-        protected int FailedTryAgain;
-
-
-        internal DefaultDownloadFileOperation(PackageBundle bundle, DownloadFileOptions options) : base(bundle)
-        {
-            Options = options;
-            FailedTryAgain = options.FailedTryAgain;
-        }
-
-        /// <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 Options.FallbackURL;
-            else
-                return Options.MainURL;
-        }
-
-        /// <summary>
-        /// 重置请求字段
-        /// </summary>
-        protected void ResetRequestFiled()
-        {
-            // 重置变量
-            _isAbort = false;
-            _latestDownloadBytes = 0;
-            _latestDownloadRealtime = Time.realtimeSinceStartup;
-            DownloadProgress = 0f;
-            DownloadedBytes = 0;
-
-            // 重置计时器
-            if (_tryAgainTimer > 0f)
-                YooLogger.Warning($"Try again download : {_requestURL}");
-            _tryAgainTimer = 0f;
-        }
-
-        /// <summary>
-        /// 检测请求超时
-        /// </summary>
-        protected void CheckRequestTimeout()
-        {
-            // 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 = UnityEngine.Time.realtimeSinceStartup;
-                }
-
-                float offset = UnityEngine.Time.realtimeSinceStartup - _latestDownloadRealtime;
-                if (offset > Options.Timeout)
-                {
-                    YooLogger.Warning($"Download request timeout : {_requestURL}");
-                    if (_webRequest != null)
-                        _webRequest.Abort();
-                    _isAbort = true;
-                }
-            }
-        }
-
-        /// <summary>
-        /// 检测请求结果
-        /// </summary>
-        protected bool CheckRequestResult()
-        {
-            HttpCode = _webRequest.responseCode;
-
-#if UNITY_2020_3_OR_NEWER
-            if (_webRequest.result != UnityWebRequest.Result.Success)
-            {
-                Error = _webRequest.error;
-                return false;
-            }
-            else
-            {
-                return true;
-            }
-#else
-            if (_webRequest.isNetworkError || _webRequest.isHttpError)
-            {
-                Error = _webRequest.error;
-                return false;
-            }
-            else
-            {
-                return true;
-            }
-#endif
-        }
-    }
-}
--- a/Assets/YooAsset/Runtime/FileSystem/Operation/Internal/DownloadAssetBundleOperation.cs
+++ b/Assets/YooAsset/Runtime/FileSystem/Operation/Internal/DownloadAssetBundleOperation.cs
@@ -2,12 +2,21 @@

 namespace YooAsset
 {
-    internal abstract class DownloadAssetBundleOperation : DefaultDownloadFileOperation
+    internal abstract class DownloadAssetBundleOperation : AsyncOperationBase
    {
-        internal DownloadAssetBundleOperation(PackageBundle bundle, DownloadFileOptions options) : base(bundle, options)
-        {
-        }
-
+        /// <summary>
+        /// AssetBundle对象
+        /// </summary>
        public AssetBundle Result;
+
+        /// <summary>
+        /// 下载进度
+        /// </summary>
+        public float DownloadProgress { protected set; get; } = 0;
+
+        /// <summary>
+        /// 下载大小
+        /// </summary>
+        public long DownloadedBytes { protected set; get; } = 0;
    }
 }
--- a/Assets/YooAsset/Runtime/FileSystem/Operation/Internal/DownloadFileWrapper.cs
+++ b/Assets/YooAsset/Runtime/FileSystem/Operation/Internal/DownloadFileWrapper.cs
@@ -1,71 +0,0 @@
-
-namespace YooAsset
-{
-    internal class DownloadFileWrapper : FSDownloadFileOperation
-    {
-        private enum ESteps
-        {
-            None,
-            Download,
-            Done,
-        }
-
-        private readonly FSDownloadFileOperation _downloadFileOp;
-        private ESteps _steps = ESteps.None;
-
-        internal DownloadFileWrapper(FSDownloadFileOperation downloadFileOp) : base(downloadFileOp.Bundle)
-        {
-            _downloadFileOp = downloadFileOp;
-        }
-        internal override void InternalStart()
-        {
-            _steps = ESteps.Download;
-        }
-        internal override void InternalUpdate()
-        {
-            if (_steps == ESteps.None || _steps == ESteps.Done)
-                return;
-
-            if (_steps == ESteps.Download)
-            {
-                if (IsWaitForAsyncComplete)
-                    _downloadFileOp.WaitForAsyncComplete();
-
-                if (_downloadFileOp.Status == EOperationStatus.None)
-                    return;
-
-                _downloadFileOp.UpdateOperation();
-                Progress = _downloadFileOp.Progress;
-                DownloadedBytes = _downloadFileOp.DownloadedBytes;
-                DownloadProgress = _downloadFileOp.DownloadProgress;
-                if (_downloadFileOp.IsDone == false)
-                    return;
-
-                _steps = ESteps.Done;
-                Status = _downloadFileOp.Status;
-                Error = _downloadFileOp.Error;
-                HttpCode = _downloadFileOp.HttpCode;
-            }
-        }
-        internal override void InternalWaitForAsyncComplete()
-        {
-            while (true)
-            {
-                if (ExecuteWhileDone())
-                {
-                    _steps = ESteps.Done;
-                    break;
-                }
-            }
-        }
-
-        public override void Release()
-        {
-            _downloadFileOp.Release();
-        }
-        public override void Reference()
-        {
-            _downloadFileOp.Reference();
-        }
-    }
-}
--- a/Assets/YooAsset/Runtime/FileSystem/Operation/Internal/DownloadWebEncryptAssetBundleOperation.cs
+++ b/Assets/YooAsset/Runtime/FileSystem/Operation/Internal/DownloadWebEncryptAssetBundleOperation.cs
@@ -1,17 +1,33 @@
 using UnityEngine;
-using UnityEngine.Networking;

 namespace YooAsset
 {
-    internal class DownloadWebEncryptAssetBundleOperation : DownloadAssetBundleOperation
+    internal class DownloadEncryptAssetBundleOperation : DownloadAssetBundleOperation
    {
+        protected enum ESteps
+        {
+            None,
+            CreateRequest,
+            CheckRequest,
+            TryAgain,
+            Done,
+        }
+
+        private UnityWebDataRequestOperation _unityWebDataRequestOp;
+        private readonly PackageBundle _bundle;
+        private readonly DownloadFileOptions _options;
        private readonly bool _checkTimeout;
        private readonly IWebDecryptionServices _decryptionServices;
-        private DownloadHandlerBuffer _downloadhandler;
+
+        protected int _requestCount = 0;
+        protected float _tryAgainTimer;
+        protected int _failedTryAgain;
        private ESteps _steps = ESteps.None;

-        internal DownloadWebEncryptAssetBundleOperation(bool checkTimeout, IWebDecryptionServices decryptionServices, PackageBundle bundle, DownloadFileOptions options) : base(bundle, options)
+        internal DownloadEncryptAssetBundleOperation(PackageBundle bundle, DownloadFileOptions options, bool checkTimeout, IWebDecryptionServices decryptionServices)
        {
+            _bundle = bundle;
+            _options = options;
            _checkTimeout = checkTimeout;
            _decryptionServices = decryptionServices;
        }
@@ -27,118 +43,87 @@ namespace YooAsset
            // 创建下载器
            if (_steps == ESteps.CreateRequest)
            {
-                // 获取请求地址
-                _requestURL = GetRequestURL();
-
-                // 重置变量
-                ResetRequestFiled();
-
-                // 创建下载器
-                CreateWebRequest();
+                if (_decryptionServices == null)
+                {
+                    _steps = ESteps.Done;
+                    Status = EOperationStatus.Failed;
+                    Error = $"The {nameof(IWebDecryptionServices)} is null !";
+                    YooLogger.Error(Error);
+                    return;
+                }

+                string url = GetRequestURL();
+                _unityWebDataRequestOp = new UnityWebDataRequestOperation(url, _options.Timeout);
+                _unityWebDataRequestOp.StartOperation();
+                if (_checkTimeout == false)
+                    _unityWebDataRequestOp.DontCheckTimeout();
                _steps = ESteps.CheckRequest;
            }

            // 检测下载结果
            if (_steps == ESteps.CheckRequest)
            {
-                DownloadProgress = _webRequest.downloadProgress;
-                DownloadedBytes = (long)_webRequest.downloadedBytes;
-                Progress = DownloadProgress;
-                if (_webRequest.isDone == false)
-                {
-                    if (_checkTimeout)
-                        CheckRequestTimeout();
+                _unityWebDataRequestOp.UpdateOperation();
+                Progress = _unityWebDataRequestOp.Progress;
+                DownloadProgress = _unityWebDataRequestOp.DownloadProgress;
+                DownloadedBytes = _unityWebDataRequestOp.DownloadedBytes;
+                if (_unityWebDataRequestOp.IsDone == false)
                    return;
-                }

                // 检查网络错误
-                if (CheckRequestResult())
+                if (_unityWebDataRequestOp.Status == EOperationStatus.Succeed)
                {
-                    if (_decryptionServices == null)
-                    {
-                        _steps = ESteps.Done;
-                        Status = EOperationStatus.Failed;
-                        Error = $"The {nameof(IWebDecryptionServices)} is null !";
-                        YooLogger.Error(Error);
-                        return;
-                    }
-
-                    var fileData = _downloadhandler.data;
-                    if (fileData == null || fileData.Length == 0)
-                    {
-                        _steps = ESteps.Done;
-                        Status = EOperationStatus.Failed;
-                        Error = $"The download handler data is null or empty !";
-                        YooLogger.Error(Error);
-                        return;
-                    }
-
-                    AssetBundle assetBundle = LoadEncryptedAssetBundle(fileData);
+                    AssetBundle assetBundle = LoadEncryptedAssetBundle(_unityWebDataRequestOp.Result);
                    if (assetBundle == null)
                    {
                        _steps = ESteps.Done;
                        Status = EOperationStatus.Failed;
-                        Error = "Download handler asset bundle object is null !";
+                        Error = "Failed load encrypted AssetBundle !";
                    }
                    else
                    {
                        _steps = ESteps.Done;
-                        Result = assetBundle;
                        Status = EOperationStatus.Succeed;
+                        Result = assetBundle;
                    }
                }
                else
                {
-                    _steps = ESteps.TryAgain;
+                    if (_failedTryAgain > 0)
+                    {
+                        _steps = ESteps.TryAgain;
+                        YooLogger.Warning($"Failed download : {_unityWebDataRequestOp.URL} Try again !");
+                    }
+                    else
+                    {
+                        _steps = ESteps.Done;
+                        Status = EOperationStatus.Failed;
+                        Error = _unityWebDataRequestOp.Error;
+                        YooLogger.Error(Error);
+                    }
                }
-
-                // 注意：最终释放请求器
-                DisposeWebRequest();
            }

            // 重新尝试下载
            if (_steps == ESteps.TryAgain)
            {
-                if (FailedTryAgain <= 0)
-                {
-                    Status = EOperationStatus.Failed;
-                    _steps = ESteps.Done;
-                    YooLogger.Error(Error);
-                    return;
-                }
-
                _tryAgainTimer += Time.unscaledDeltaTime;
                if (_tryAgainTimer > 1f)
                {
-                    FailedTryAgain--;
+                    _tryAgainTimer = 0f;
+                    _failedTryAgain--;
+                    Progress = 0f;
+                    DownloadProgress = 0f;
+                    DownloadedBytes = 0;
                    _steps = ESteps.CreateRequest;
-                    YooLogger.Warning(Error);
                }
            }
        }
        internal override void InternalAbort()
        {
            _steps = ESteps.Done;
-            DisposeWebRequest();
-        }
-
-        private void CreateWebRequest()
-        {
-            _downloadhandler = new DownloadHandlerBuffer();
-            _webRequest = DownloadSystemHelper.NewUnityWebRequestGet(_requestURL);
-            _webRequest.downloadHandler = _downloadhandler;
-            _webRequest.disposeDownloadHandlerOnDispose = true;
-            _webRequest.SendWebRequest();
-        }
-        private void DisposeWebRequest()
-        {
-            if (_webRequest != null)
-            {
-                //注意：引擎底层会自动调用Abort方法
-                _webRequest.Dispose();
-                _webRequest = null;
-            }
+            if (_unityWebDataRequestOp != null)
+                _unityWebDataRequestOp.AbortOperation();
        }

        /// <summary>
@@ -147,11 +132,24 @@ namespace YooAsset
        private AssetBundle LoadEncryptedAssetBundle(byte[] fileData)
        {
            var fileInfo = new WebDecryptFileInfo();
-            fileInfo.BundleName = Bundle.BundleName;
-            fileInfo.FileLoadCRC = Bundle.UnityCRC;
+            fileInfo.BundleName = _bundle.BundleName;
+            fileInfo.FileLoadCRC = _bundle.UnityCRC;
            fileInfo.FileData = fileData;
            var decryptResult = _decryptionServices.LoadAssetBundle(fileInfo);
            return decryptResult.Result;
        }
+
+        /// <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 _options.FallbackURL;
+            else
+                return _options.MainURL;
+        }
    }
 }
--- a/Assets/YooAsset/Runtime/FileSystem/Operation/Internal/DownloadWebNormalAssetBundleOperation.cs
+++ b/Assets/YooAsset/Runtime/FileSystem/Operation/Internal/DownloadWebNormalAssetBundleOperation.cs
@@ -1,16 +1,33 @@
 using UnityEngine;
-using UnityEngine.Networking;

 namespace YooAsset
 {
-    internal class DownloadWebNormalAssetBundleOperation : DownloadAssetBundleOperation
+    internal class DownloadNormalAssetBundleOperation : DownloadAssetBundleOperation
    {
+        protected enum ESteps
+        {
+            None,
+            CreateRequest,
+            CheckRequest,
+            TryAgain,
+            Done,
+        }
+
+        private UnityAssetBundleRequestOperation _unityAssetBundleRequestOp;
+        private readonly PackageBundle _bundle;
+        private readonly DownloadFileOptions _options;
        private readonly bool _disableUnityWebCache;
-        private DownloadHandlerAssetBundle _downloadhandler;
+       
+        protected int _requestCount = 0;
+        protected float _tryAgainTimer;
+        protected int _failedTryAgain;
        private ESteps _steps = ESteps.None;

-        internal DownloadWebNormalAssetBundleOperation(bool disableUnityWebCache, PackageBundle bundle, DownloadFileOptions options) : base(bundle, options)
+
+        internal DownloadNormalAssetBundleOperation(PackageBundle bundle, DownloadFileOptions options, bool disableUnityWebCache)
        {
+            _bundle = bundle;
+            _options = options;
            _disableUnityWebCache = disableUnityWebCache;
        }
        internal override void InternalStart()
@@ -25,120 +42,78 @@ namespace YooAsset
            // 创建下载器
            if (_steps == ESteps.CreateRequest)
            {
-                // 获取请求地址
-                _requestURL = GetRequestURL();
-
-                // 重置变量
-                ResetRequestFiled();
-
-                // 创建下载器
-                CreateWebRequest();
-
+                string url = GetRequestURL();
+                _unityAssetBundleRequestOp = new UnityAssetBundleRequestOperation(_bundle, _disableUnityWebCache, url, _options.Timeout);
+                _unityAssetBundleRequestOp.StartOperation();
                _steps = ESteps.CheckRequest;
            }

            // 检测下载结果
            if (_steps == ESteps.CheckRequest)
            {
-                DownloadProgress = _webRequest.downloadProgress;
-                DownloadedBytes = (long)_webRequest.downloadedBytes;
-                Progress = DownloadProgress;
-                if (_webRequest.isDone == false)
-                {
-                    CheckRequestTimeout();
+                _unityAssetBundleRequestOp.UpdateOperation();
+                Progress = _unityAssetBundleRequestOp.Progress;
+                DownloadedBytes = _unityAssetBundleRequestOp.DownloadedBytes;
+                DownloadProgress = _unityAssetBundleRequestOp.DownloadProgress;
+                if (_unityAssetBundleRequestOp.IsDone == false)
                    return;
-                }

-                // 检查网络错误
-                if (CheckRequestResult())
+                if (_unityAssetBundleRequestOp.Status == EOperationStatus.Succeed)
                {
-                    AssetBundle assetBundle = _downloadhandler.assetBundle;
-                    if (assetBundle == null)
+                    _steps = ESteps.Done;
+                    Status = EOperationStatus.Succeed;
+                    Result = _unityAssetBundleRequestOp.Result;
+                }
+                else
+                {
+                    if (_failedTryAgain > 0)
                    {
-                        _steps = ESteps.Done;
-                        Status = EOperationStatus.Failed;
-                        Error = "Download handler asset bundle object is null !";
+                        _steps = ESteps.TryAgain;
+                        YooLogger.Warning($"Failed download : {_unityAssetBundleRequestOp.URL} Try again !");
                    }
                    else
                    {
                        _steps = ESteps.Done;
-                        Result = assetBundle;
-                        Status = EOperationStatus.Succeed;
+                        Status = EOperationStatus.Failed;
+                        Error = _unityAssetBundleRequestOp.Error;
+                        YooLogger.Error(Error);
                    }
                }
-                else
-                {
-                    _steps = ESteps.TryAgain;
-                }
-
-                // 注意：最终释放请求器
-                DisposeWebRequest();
            }

            // 重新尝试下载
            if (_steps == ESteps.TryAgain)
            {
-                if (FailedTryAgain <= 0)
-                {
-                    Status = EOperationStatus.Failed;
-                    _steps = ESteps.Done;
-                    YooLogger.Error(Error);
-                    return;
-                }
-
                _tryAgainTimer += Time.unscaledDeltaTime;
                if (_tryAgainTimer > 1f)
                {
-                    FailedTryAgain--;
+                    _tryAgainTimer = 0f;
+                    _failedTryAgain--;
+                    Progress = 0f;
+                    DownloadProgress = 0f;
+                    DownloadedBytes = 0;
                    _steps = ESteps.CreateRequest;
-                    YooLogger.Warning(Error);
                }
            }
        }
        internal override void InternalAbort()
        {
            _steps = ESteps.Done;
-            DisposeWebRequest();
+            if (_unityAssetBundleRequestOp != null)
+                _unityAssetBundleRequestOp.AbortOperation();
        }

-        private void CreateWebRequest()
+        /// <summary>
+        /// 获取网络请求地址
+        /// </summary>
+        protected string GetRequestURL()
        {
-            _downloadhandler = CreateWebDownloadHandler();
-            _webRequest = DownloadSystemHelper.NewUnityWebRequestGet(_requestURL);
-            _webRequest.downloadHandler = _downloadhandler;
-            _webRequest.disposeDownloadHandlerOnDispose = true;
-            _webRequest.SendWebRequest();
-        }
-        private void DisposeWebRequest()
-        {
-            if (_webRequest != null)
-            {
-                //注意：引擎底层会自动调用Abort方法
-                _webRequest.Dispose();
-                _webRequest = null;
-            }
-        }
-        private DownloadHandlerAssetBundle CreateWebDownloadHandler()
-        {
-            if (_disableUnityWebCache)
-            {
-                var downloadhandler = new DownloadHandlerAssetBundle(_requestURL, Bundle.UnityCRC);
-#if UNITY_2020_3_OR_NEWER
-                downloadhandler.autoLoadAssetBundle = false;
-#endif
-                return downloadhandler;
-            }
+            // 轮流返回请求地址
+            _requestCount++;
+            if (_requestCount % 2 == 0)
+                return _options.FallbackURL;
            else
-            {
-                // 注意：优先从浏览器缓存里获取文件
-                // The file hash defining the version of the asset bundle.
-                Hash128 fileHash = Hash128.Parse(Bundle.FileHash);
-                var downloadhandler = new DownloadHandlerAssetBundle(_requestURL, fileHash, Bundle.UnityCRC);
-#if UNITY_2020_3_OR_NEWER
-                downloadhandler.autoLoadAssetBundle = false;
-#endif
-                return downloadhandler;
-            }
+                return _options.MainURL;
        }
    }
 }
--- a/Assets/YooAsset/Runtime/ResourcePackage/Operation/DownloaderOperation.cs
+++ b/Assets/YooAsset/Runtime/ResourcePackage/Operation/DownloaderOperation.cs
@@ -366,7 +366,7 @@ namespace YooAsset

                foreach (var downloader in _downloaders)
                {
-                    downloader.Release();
+                    downloader.AbortOperation();
                }
            }
        }