AssetBundle 対象のフォルダついて、Asset の依存関係も含めて実ファイルのハッシュ値を計算する

gistfile1.txt

using System;
using System.Collections;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Security.Cryptography;
using System.Text;
using System.Text.RegularExpressions;
using UnityEditor;
using UnityEngine;

public static class AssetDirHashSample
{

    /// <summary>
    /// テスト実行
    /// </summary>
    [MenuItem(@"Test/CalculateDirHash", false)]
    private static void Test()
    {
        DirectoryInfo directoryInfo = new DirectoryInfo (<AssetBundle 対象のフォルダを指定>);
        Debug.Log("Dir=" + directoryInfo);
        Debug.Log("CalculateDirHash=" + CalculateDirHash(directoryInfo));
    }

    /// <summary>
    /// AssetBundle 対象のフォルダついて、Asset の依存関係も含めて実ファイルのハッシュ値を計算する
    /// </summary>
    /// <returns>AssetBundle 対象のフォルダの実ファイルハッシュ値</returns>
    /// <param name="baseDir">AssetBundle 対象のフォルダ</param>
    public static string CalculateDirHash(DirectoryInfo baseDir)
    { 
        var dirQueue = new Queue<DirectoryInfo>();
        dirQueue.Enqueue(baseDir);
        string checksum = ""; 
        while (dirQueue.Count > 0) {
            var dir = dirQueue.Dequeue();
            var subDirList = new List<DirectoryInfo>(dir.GetDirectories());
            subDirList.Sort((d1, d2) => d1.FullName.CompareTo(d2.FullName));

            foreach (var subDir in subDirList) {
                dirQueue.Enqueue(subDir);
            }
            var fileList = new List<FileInfo>(dir.GetFiles());
            fileList.Sort((f1, f2) => f1.FullName.CompareTo(f2.FullName));
            foreach (var file in fileList) {
                var path = GetAssetPathFromGlobalPath(file.FullName);
                var mainAsset = AssetDatabase.LoadMainAssetAtPath(path);
                if (mainAsset == null) {
                    continue;
                }
                checksum += path + "\n";
                checksum += CalculateHash(mainAsset);
            }
        }
        checksum = Md5Sum(checksum);
        return checksum;
    }

    private static string CalculateHash(UnityEngine.Object asset)
    {   
        string checksum = CalcAssetChecksum(asset);
        UnityEngine.Object[] depAssets = EditorUtility.CollectDependencies(new UnityEngine.Object[] { asset });
        List<UnityEngine.Object> depAssetList = new List<UnityEngine.Object>(depAssets);
        depAssetList.Sort((a1, a2) => {   
            int ret = a1.GetType().FullName.CompareTo(a2.GetType().FullName);
            if (ret != 0) {   
                return ret;
            }
            else {   
                return a1.name.CompareTo(a2.name);
            }   
        }); 

        foreach (UnityEngine.Object depAsset in depAssetList) {   
            Debug.Log("\tTargetAsset - " + depAsset.GetType() + ":" +depAsset.name);
            checksum += depAsset.name + " : " + depAsset.GetType() + "\n";
            checksum += CalcAssetChecksum(depAsset) + "\n";
        }   
        return Md5Sum(checksum);
    }

    private static string CalcAssetChecksum(UnityEngine.Object asset)
    {
        string assetPath = AssetDatabase.GetAssetPath(asset);
        string filePath = Application.dataPath.Replace("Assets", "") + assetPath;

        if (string.IsNullOrEmpty(assetPath) || !System.IO.File.Exists(filePath)) {
            return Md5Sum(asset.name);
        }
        else {
            byte[] binaryData = File.ReadAllBytes(assetPath);
            string metaInfo = File.ReadAllText(assetPath + ".meta");
            return Md5Sum(Md5Sum(binaryData) + Md5Sum(metaInfo));
        }
    }

    private static string GetAssetPathFromGlobalPath(string globalPath)
    {
        var startIndex = globalPath.IndexOf("Assets/");
        if (startIndex > 0) {
            return globalPath.Remove(0, startIndex);
        }
        return globalPath;
    }

    private static string Md5Sum(string strToEncrypt)
    {
        System.Text.UTF8Encoding ue = new System.Text.UTF8Encoding();
        return Md5Sum(ue.GetBytes(strToEncrypt));
    }

    private static string Md5Sum(byte[] bytesToEncrypt)
    {
        MD5CryptoServiceProvider md5 = new MD5CryptoServiceProvider();
        byte[] hashBytes = md5.ComputeHash(bytesToEncrypt);

        string hashString = "";
        for (int i = 0; i < hashBytes.Length; i++) {
            hashString += System.Convert.ToString(hashBytes[i], 16).PadLeft(2, '0');
        }
        return hashString.PadLeft(32, '0');
    }

}