打包出来的热更文件，如果每次都要全部上传到CDN文件服务器，不进耗费时间长，还浪费流量。

所以让AI写了个简单的文件比较工具类，然后修改了一下可用。记录一下。

路径可自行更改。校验算法这里使用的是MD5，如果使用SHA256校验，时间会长达1分钟，MD5只有5秒左右。一般用MD5即可。同步拷贝的写法时间太长，改为异步拷贝的写法，时间减半，只需30秒和3秒。（项目的热更文件67个，总大小在700M左右）

代码如下，放到Assets/Editor/路径下即可。
 

using System;
using System.IO;
using System.Security.Cryptography;
using System.Collections.Generic;
using System.Threading.Tasks;
using UnityEngine;
using UnityEditor;

/// <summary>
/// 比较热更文件的差异 拷贝到另一个文件夹
/// </summary>
public class HotfixComparerAsync
{
#if UNITY_ANDROID
    static string SourceFolder = Application.dataPath + "/../ServerData/Android"; // 源文件夹路径
    static string TargetFolder = Application.dataPath + "/../ServerData/Android_server"; // 目标文件夹路径
    static string OutputFolder = Application.dataPath + "/../ServerData/Android_hotfix"; // 输出文件夹路径，存放复制的文件
#endif
#if UNITY_IOS
    static string SourceFolder = Application.dataPath + "/../ServerData/iOS"; // 源文件夹路径
    static string TargetFolder = Application.dataPath + "/../ServerData/iOS_server"; // 目标文件夹路径
    static string OutputFolder = Application.dataPath + "/../ServerData/iOS_hotfix"; // 输出文件夹路径，存放复制的文件
#endif
#if UNITY_STANDALONE_WIN
    static string SourceFolder = Application.dataPath + "/../ServerData/StandaloneWindows64"; // 源文件夹路径
    static string TargetFolder = Application.dataPath + "/../ServerData/StandaloneWindows64_server"; // 目标文件夹路径
    static string OutputFolder = Application.dataPath + "/../ServerData/StandaloneWindows64_hotfix"; // 输出文件夹路径，存放复制的文件
#endif


    [MenuItem("Tools/比较并拷贝热更文件Async")]
    public static void CompareAndCopyFiles()
    {
        DateTime startTime = DateTime.Now;

        if (!Directory.Exists(OutputFolder))
        {
            Directory.CreateDirectory(OutputFolder);
        }

        var sourceFiles = new HashSet<string>(Directory.GetFiles(SourceFolder, "*.*", SearchOption.AllDirectories));
        var targetFilesHashes = new Dictionary<string, string>();

        foreach (var file in Directory.GetFiles(TargetFolder, "*.*", SearchOption.AllDirectories))
        {
            string relativePath = MakeRelativePath(file, TargetFolder);
            targetFilesHashes[relativePath] = FileHash(file);
        }

        var tasks = new List<Task>();
        foreach (var sourceFile in sourceFiles)
        {
            string relativePath = MakeRelativePath(sourceFile, SourceFolder);
            tasks.Add(Task.Run(() => ProcessFile(sourceFile, relativePath, targetFilesHashes)));
        }

        Task.WhenAll(tasks.ToArray()).Wait();
        TimeSpan diff = DateTime.Now - startTime;
        Debug.Log($"比较完成耗费：{diff.Minutes}分{diff.Seconds}秒");
    }

    private static void ProcessFile(string sourceFile, string relativePath, Dictionary<string, string> targetFilesHashes)
    {
        if (targetFilesHashes.ContainsKey(relativePath))
        {
            string hash = FileHash(sourceFile);
            if (targetFilesHashes[relativePath] != hash)
            {
                CopyFile(sourceFile, Path.Combine(OutputFolder, relativePath));
            }
        }
        else
        {
            CopyFile(sourceFile, Path.Combine(OutputFolder, relativePath));
        }
    }

    private static string MakeRelativePath(string path, string rootDirectory)
    {
        return path.Substring(rootDirectory.Length + 1);
    }

    private static string FileHash(string file)
    {
        using (var stream = File.OpenRead(file))
        {
            using (var hash = MD5.Create())
            {
                byte[] hashBytes = hash.ComputeHash(stream);
                return BitConverter.ToString(hashBytes).Replace("-", "").ToLowerInvariant();
            }
        }
    }

    private static void CopyFile(string sourceFile, string targetFile)
    {
        //File.Copy(sourceFile, targetFile, true);

        // 获取目标文件的目录路径
        string targetDirectory = Path.GetDirectoryName(targetFile);
        // 如果目标目录不存在，则创建它
        if (!Directory.Exists(targetDirectory))
        {
            Directory.CreateDirectory(targetDirectory);
        }

        try
        {
            // 尝试复制文件
            File.Copy(sourceFile, targetFile, true);
        }
        catch (Exception e)
        {
            // 处理可能的异常
            Debug.LogError($"Failed to copy file from {sourceFile} to {targetFile}. Error: {e.Message}");
        }
    }
}