update

[feat][editor]:增加差异包提取工具
[fix][runtime]:修复偏移加密的bug

Assets/CatAsset/Editor/BuildPipeline/Task/EncryptBundles.cs

@@ -32,7 +32,7 @@ public ReturnCode Run()
         {
             if (configParam.TargetPlatform == BuildTarget.WebGL)
             {
-                //WebGL平台不加密 因为无法偏移加密 而异或加密内存开销太高会爆WebGL平台的内存
+                //WebGL平台不允许加密 因为无法偏移加密 而异或加密内存开销太高会爆WebGL平台的内存
                 return ReturnCode.SuccessNotRun;
             }
 

Assets/CatAsset/Editor/Window/DifferenceBundleWindow.cs

@@ -0,0 +1,138 @@
+
+using System;
+using System.Collections.Generic;
+using System.IO;
+using CatAsset.Runtime;
+using UnityEditor;
+using UnityEngine;
+
+namespace CatAsset.Editor
+{
+    /// <summary>
+    /// 差异包提取窗口
+    /// </summary>
+    public class DifferenceBundleWindow : EditorWindow
+    {
+        private string oldBundlesFolder;
+        private string newBundlesFolder;
+        private string outputFolder;
+
+        [MenuItem("CatAsset/打开差异包提取窗口", priority = 2)]
+        private static void OpenWindow()
+        {
+            var window = GetWindow<DifferenceBundleWindow>(false, "差异包提取窗口");
+            window.minSize = new Vector2(800, 600);
+            window.Show();
+        }
+
+        private void OnGUI()
+        {
+
+            DrawSelectFolder(ref oldBundlesFolder,"旧版本的资源目录:");
+            DrawSelectFolder(ref newBundlesFolder,"新版本的资源目录:");
+            DrawSelectFolder(ref outputFolder,"差异包输出目录:");
+
+            if (GUILayout.Button("提取差异包",GUILayout.Width(200)))
+            {
+                OutputDifferenceBundles();
+            }
+
+        }
+
+        /// <summary>
+        /// 绘制选择目录的界面
+        /// </summary>
+        private void DrawSelectFolder(ref string targetFolder,string tips)
+        {
+            using (new GUILayout.HorizontalScope())
+            {
+                GUILayout.Label(tips, GUILayout.Width(150));
+                targetFolder = GUILayout.TextField(targetFolder,GUILayout.Width(500));
+                if (GUILayout.Button("选择目录", GUILayout.Width(100)))
+                {
+                    string folder = EditorUtility.OpenFolderPanel($"选择{tips}", targetFolder,string.Empty);
+                    if (!string.IsNullOrEmpty(folder))
+                    {
+                        targetFolder = folder;
+                    }
+                }
+            }
+        }
+
+        /// <summary>
+        /// 提取差异包
+        /// </summary>
+        private void OutputDifferenceBundles()
+        {
+            string oldManifestPath = Path.Combine(oldBundlesFolder, CatAssetManifest.ManifestBinaryFileName);
+            string newManifestPath = Path.Combine(newBundlesFolder, CatAssetManifest.ManifestBinaryFileName);
+
+            if (!File.Exists(oldManifestPath))
+            {
+                Debug.LogError($"{oldManifestPath}不存在");
+                return;
+            }
+
+            if (!File.Exists(newManifestPath))
+            {
+                Debug.LogError($"{newManifestPath}不存在");
+                return;
+            }
+
+            byte[] bytes = File.ReadAllBytes(oldManifestPath);
+            CatAssetManifest oldManifest = CatAssetManifest.DeserializeFromBinary(bytes);
+
+            bytes = File.ReadAllBytes(newManifestPath);
+            CatAssetManifest newManifest = CatAssetManifest.DeserializeFromBinary(bytes);
+
+            //旧资源包集合
+            HashSet<BundleManifestInfo> oldBundleSet = new HashSet<BundleManifestInfo>(oldManifest.Bundles);
+
+            //差异资源包
+            List<BundleManifestInfo> diffBundles = new List<BundleManifestInfo>();
+
+            foreach (BundleManifestInfo bundleManifestInfo in newManifest.Bundles)
+            {
+                if (!oldBundleSet.Contains(bundleManifestInfo))
+                {
+                    diffBundles.Add(bundleManifestInfo);
+                    Debug.Log("差异包:"  + bundleManifestInfo);
+                }
+            }
+
+            //将差异包输出到指定目录下
+            FileInfo fi;
+            string targetPath;
+            EditorUtil.CreateEmptyDirectory(outputFolder);
+            foreach (BundleManifestInfo diffBundle in diffBundles)
+            {
+                fi = new FileInfo(Path.Combine(newBundlesFolder, diffBundle.RelativePath));
+                targetPath = Path.Combine(outputFolder, diffBundle.RelativePath);
+
+                //冗余资源包没有diffBundle.Directory
+                if (!string.IsNullOrEmpty(diffBundle.Directory))
+                {
+                    string targetDirectory = Path.Combine(outputFolder, diffBundle.Directory);
+                    if (!Directory.Exists(targetDirectory))
+                    {
+                        //输出目录不存在则创建
+                        Directory.CreateDirectory(targetDirectory);
+                    }
+                }
+
+                fi.CopyTo(targetPath);
+            }
+
+            //复制资源清单
+            fi = new FileInfo(Path.Combine(newBundlesFolder, CatAssetManifest.ManifestBinaryFileName));
+            targetPath = Path.Combine(outputFolder, CatAssetManifest.ManifestBinaryFileName);
+            fi.CopyTo(targetPath);
+
+            fi = new FileInfo(Path.Combine(newBundlesFolder, CatAssetManifest.ManifestJsonFileName));
+            targetPath = Path.Combine(outputFolder, CatAssetManifest.ManifestJsonFileName);
+            fi.CopyTo(targetPath);
+
+            Debug.Log($"已将差异包复制到{outputFolder}下");
+        }
+    }
+}

Assets/CatAsset/Runtime/Misc/EncryptUtil.cs

@@ -16,6 +16,11 @@ public static class EncryptUtil
         /// 加密字节长度
         /// </summary>
         public const int EncryptBytesLength = 64;
+
+        /// <summary>
+        /// 偏移加密的头部字节值
+        /// </summary>
+        private const byte encryptOffsetHead = 64;
 
         /// <summary>
         /// 异或加密Key
@@ -58,18 +63,18 @@ public static void EncryptOffset(string filePath)
             //写入额外的头部数据
             for (int i = 0; i < EncryptBytesLength; i++)
             {
-                cachedBytes[i] = (byte)UnityEngine.Random.Range(byte.MinValue, byte.MaxValue);
+                cachedBytes[i] = encryptOffsetHead;
             }
 
             //写入原始数据
             Array.Copy(bytes,0,cachedBytes,EncryptBytesLength,bytes.Length);
-
             using (FileStream fs = File.OpenWrite(filePath))
             {
-                fs.Write(cachedBytes, 0, cachedBytes.Length);
+                fs.Position = 0;
+                fs.Write(cachedBytes, 0, newLength);
             }
 
-            Array.Clear(cachedBytes,0,cachedBytes.Length);
+            Array.Clear(cachedBytes,0,newLength);
             ReleaseCachedBytes(cachedBytes);
         }
 

Assets/CatAsset/Runtime/TaskSystem/Task/BundleTask/LoadBundleTask.cs

@@ -358,10 +358,12 @@ protected virtual void LoadAsync()
                     break;
 
                 case BundleEncryptOptions.XOr:
+                    //异或加密的资源包
                     if (BundleRuntimeInfo.BundleState == BundleRuntimeInfo.State.InReadWrite ||
                         Application.platform != RuntimePlatform.Android) 
                     {
                         //存在于读写区 或 非安卓平台 可以进行IO操作 使用Stream进行解密
+                        //这里不考虑WebGL平台，因为WebGL平台不允许加密
                         BundleRuntimeInfo.Stream = new DecryptXOrStream(BundleRuntimeInfo.LoadPath, FileMode.Open, FileAccess.Read);
                         request = AssetBundle.LoadFromStreamAsync(BundleRuntimeInfo.Stream,0,1024*1024);
                     }
@@ -371,8 +373,6 @@ protected virtual void LoadAsync()
                         CatAssetManager.AddWebRequestTask(BundleRuntimeInfo.LoadPath, BundleRuntimeInfo.LoadPath,
                             onBundleBinaryLoadedCallback, TaskPriority.Middle);
                     }
-
-
                     break;
 
                 default: