Unity Editor实现一个比AssetDatabase.FindAssets内存和CPU都更友好的替代方案

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原创最新推荐文章于 2026-10-02 10:21:55 发布 167 阅读 AI 写同款· GEO 优化 ›

Unity资源分析工具开发指南：从AssetBundle优化到性能调优在游戏开发中，资源管理是影响应用性能和用户体验的核心环节。资源优化通过分析模型、贴图、音频等资产的导入设置、依赖关系和内存占用，从源头上控制包体大小和运行时效率。其技术价值在于将资源成本量化，为性能调优提供数据支撑，广泛应用于移动端游戏、大型应用等对安装包体积和内存敏感的场景。AssetBundle作为Unity中资源分发与热更新的关键技术，其打包策略和冗余检测直接决定了最终产品的性能表现。本文聚焦于Unity资产包分析工具的开发实践，详细拆解了资源清单统计、依赖关系分析、AssetBundle专项检测等核阅读详情

前言

最近在做一个unity编辑器项目，需要找到在某个路径下，名字包含“ArtPrefab”的预制体。
这导致AssetDatabase.FindAssets被频繁调用，而它会返回完整的string[]
AssetDatabase.FindAssets源码：

public static string[] FindAssets(string filter, string[] searchInFolders)
{
    SearchFilter searchFilter = new SearchFilter
    {
        searchArea = SearchFilter.SearchArea.AllAssets
    };
    SearchUtility.ParseSearchString(filter, searchFilter);
    if (searchInFolders != null && searchInFolders.Length != 0)
    {
        searchFilter.folders = searchInFolders;
        searchFilter.searchArea = SearchFilter.SearchArea.SelectedFolders;
    }

    return FindAssets(searchFilter);
}

internal static string[] FindAssets(SearchFilter searchFilter)
{
    return (from property in FindAllAssets(searchFilter)
            select property.guid).Distinct().ToArray();
}

源码中还用了Distinct().ToArray()，性能进一步下降。
但实际上我们的需求并不需要遍历所有找到的预制体，遍历时，找到需要的预制体就可以返回了。这导致了大量没用的内存分配。
需求伪代码：

var guids = AssetDatabase.FindAssets(SearchFilter, SearchFolders);
foreach (var guid in guids)
{
    var path = AssetDatabase.GUIDToAssetPath(guid);
    if (!string.IsNullOrEmpty(path))
        return;
}

然而源码中是有返回IEnumerable版本的函数的，但不知什么原因是internal的

internal static IEnumerable<HierarchyProperty> FindAllAssets(SearchFilter searchFilter)
{
    IEnumerator<HierarchyProperty> enumerator = EnumerateAllAssets(searchFilter);
    while (enumerator.MoveNext())
    {
        yield return enumerator.Current;
    }
}

internal static IEnumerator<HierarchyProperty> EnumerateAllAssets(SearchFilter searchFilter)
{
    if (searchFilter.folders != null && searchFilter.folders.Length != 0 && searchFilter.searchArea == SearchFilter.SearchArea.SelectedFolders)
    {
        return FindInFolders(searchFilter, (HierarchyProperty p) => p);
    }

    return FindEverywhere(searchFilter, (HierarchyProperty p) => p);
}

优化方案

既然源码已经有IEnumerable的方案，最简单的方法就是直接反射这个函数。于是直接让AI做，AI做这种工具向的实在太方便了。
省掉了去重和数组转换的损耗，直接 yield return EnumerateAllAssets函数的结果。
yield return 相比于返回一个完整的string[]，没有一次性的数组分配，非常适合我们的需求。

using System;
using System.Collections.Generic;
using System.Reflection;
using UnityEditor;

public static class AssetDataUtil
{
    // -------------------- 缓存的反射成员 --------------------
    private static readonly MethodInfo s_EnumerateAllAssets;
    private static readonly MethodInfo s_CreateSearchFilterFromString;
    private static readonly Type s_SearchFilterType;
    private static readonly Type s_HierarchyPropertyType;
    private static readonly PropertyInfo s_GuidProperty;
    private static readonly PropertyInfo s_SearchAreaProperty;
    private static readonly PropertyInfo s_FoldersProperty;
    private static readonly object s_SearchAreaAllAssets;
    private static readonly object s_SearchAreaSelectedFolders;

    static AssetDataUtil()
    {
        var unityEditorAssembly = typeof(AssetDatabase).Assembly;

        // 1. EnumerateAllAssets (internal static)
        s_EnumerateAllAssets = typeof(AssetDatabase).GetMethod(
            "EnumerateAllAssets",
            BindingFlags.NonPublic | BindingFlags.Static);
        if (s_EnumerateAllAssets == null)
            throw new InvalidOperationException("无法反射 AssetDatabase.EnumerateAllAssets。");

        // 2. SearchFilter 类型
        s_SearchFilterType = unityEditorAssembly.GetType("UnityEditor.SearchFilter");
        if (s_SearchFilterType == null)
            throw new InvalidOperationException("无法反射 UnityEditor.SearchFilter 类型。");

        // 3. SearchFilter.CreateSearchFilterFromString (internal static)
        s_CreateSearchFilterFromString = s_SearchFilterType.GetMethod(
            "CreateSearchFilterFromString",
            BindingFlags.NonPublic | BindingFlags.Static);
        if (s_CreateSearchFilterFromString == null)
            throw new InvalidOperationException("无法反射 SearchFilter.CreateSearchFilterFromString。");

        // 4. SearchFilter 的 public 属性
        s_SearchAreaProperty = s_SearchFilterType.GetProperty("searchArea");
        s_FoldersProperty = s_SearchFilterType.GetProperty("folders");
        if (s_SearchAreaProperty == null || s_FoldersProperty == null)
            throw new InvalidOperationException("无法反射 SearchFilter 的 searchArea/folders 属性。");

        // 5. SearchArea 枚举值缓存
        var searchAreaType = s_SearchFilterType.GetNestedType("SearchArea");
        s_SearchAreaAllAssets = Enum.Parse(searchAreaType, "AllAssets");
        s_SearchAreaSelectedFolders = Enum.Parse(searchAreaType, "SelectedFolders");

        // 6. HierarchyProperty 及 guid 属性
        s_HierarchyPropertyType = unityEditorAssembly.GetType("UnityEditor.HierarchyProperty");
        s_GuidProperty = s_HierarchyPropertyType?.GetProperty("guid", BindingFlags.Public | BindingFlags.Instance);
    }

    private static readonly object[] FilterDirectory = new object[] { "" };
    private static readonly object[] SearchFilterDirectory = new object[1];
    /// <summary>
    /// 查找符合过滤条件的资源 GUID（延迟枚举，无一次性数组分配）
    /// </summary>
    public static IEnumerable<string> FindAssets(string filter, string[] searchInFolders = null)
    {
        // 通过 SearchFilter.CreateSearchFilterFromString 创建并解析 filter
        FilterDirectory[0] = filter;
        var searchFilter = s_CreateSearchFilterFromString.Invoke(null, FilterDirectory);

        // 设置默认搜索区域（AllAssets）
        s_SearchAreaProperty.SetValue(searchFilter, s_SearchAreaAllAssets);

        // 如果指定了搜索文件夹，则切换区域并设置 Folders
        if (searchInFolders != null && searchInFolders.Length > 0)
        {
            s_FoldersProperty.SetValue(searchFilter, searchInFolders);
            s_SearchAreaProperty.SetValue(searchFilter, s_SearchAreaSelectedFolders);
        }

        // 获取底层迭代器
        SearchFilterDirectory[0] = searchFilter;
        if (s_EnumerateAllAssets.Invoke(null, SearchFilterDirectory) is not System.Collections.IEnumerator enumerator)
            yield break;

        while (enumerator.MoveNext())
        {
            var current = enumerator.Current;
            if (current != null && s_GuidProperty != null)
            {
                var guid = s_GuidProperty.GetValue(current) as string;
                if (!string.IsNullOrEmpty(guid))
                    yield return guid;
            }
        }
    }
}

性能测试

由于用了反射，性能表现到底如何还得测试。

using NUnit.Framework;
using Unity.PerformanceTesting;
using UnityEditor;

/// <summary>
/// 使用 Unity Performance Testing Framework 对比 AssetDatabase.FindAssets 与 AssetDataUtil.FindAssets
/// 运行方式：Window → General → Test Runner → EditMode → Run Selected
/// </summary>
public class AssetSearchPerformanceTests
{
    private const string TestDirectory = "Assets";
    private const string SearchFilter = "t:prefab ArtPrefab";

    // 复用数组避免 GC
    private static readonly string[] SearchFolders = new[] { TestDirectory };
    private static readonly string[] FindAssetsDirectory = new string[1];

    [OneTimeSetUp]
    public void OneTimeSetUp()
    {
        if (!System.IO.Directory.Exists(TestDirectory))
        {
            Assert.Ignore($"测试目录不存在: {TestDirectory}，跳过性能测试。");
        }
    }

    [Test, Performance]
    public void AssetDatabase_FindAssets()
    {
        Measure.Method(RunAssetDatabaseSearch)
            .SampleGroup(new SampleGroup("AssetDatabase.FindAssets", SampleUnit.Millisecond))
            .WarmupCount(5)
            .MeasurementCount(20)
            .IterationsPerMeasurement(1)
            .GC()
            .Run();
    }

    [Test, Performance]
    public void AssetDataUtil_FindAssets()
    {
        Measure.Method(RunAssetDataUtilSearch)
            .SampleGroup(new SampleGroup("AssetDataUtil.FindAssets", SampleUnit.Millisecond))
            .WarmupCount(5)
            .MeasurementCount(20)
            .IterationsPerMeasurement(1)
            .GC()
            .Run();
    }

    [Test, Performance]
    public void AssetDatabase_FindAssets_WithFullIteration()
    {
        Measure.Method(() =>
        {
            var guids = AssetDatabase.FindAssets(SearchFilter, SearchFolders);
            var count = 0;
            foreach (var guid in guids)
            {
                if (!string.IsNullOrEmpty(guid))
                    count++;
            }
        })
        .SampleGroup(new SampleGroup("AssetDatabase.FindAssets+Iteration", SampleUnit.Millisecond))
        .WarmupCount(5)
        .MeasurementCount(20)
        .GC()
        .Run();
    }

    [Test, Performance]
    public void AssetDataUtil_FindAssets_WithFullIteration()
    {
        Measure.Method(() =>
        {
            FindAssetsDirectory[0] = TestDirectory;
            var guids = AssetDataUtil.FindAssets(SearchFilter, FindAssetsDirectory);
            var count = 0;
            foreach (var guid in guids)
            {
                if (!string.IsNullOrEmpty(guid))
                    count++;
            }
        })
        .SampleGroup(new SampleGroup("AssetDataUtil.FindAssets+Iteration", SampleUnit.Millisecond))
        .WarmupCount(5)
        .MeasurementCount(20)
        .GC()
        .Run();
    }

    [Test, Performance]
    public void AssetDatabase_FindAssets_WithOneIteration()
    {
        Measure.Method(() =>
        {
            var guids = AssetDatabase.FindAssets(SearchFilter, SearchFolders);
            foreach (var guid in guids)
            {
                if (!string.IsNullOrEmpty(guid))
                    return;
            }
        })
        .SampleGroup(new SampleGroup("AssetDatabase.FindAssets+Iteration", SampleUnit.Millisecond))
        .WarmupCount(5)
        .MeasurementCount(20)
        .GC()
        .Run();
    }

    [Test, Performance]
    public void AssetDataUtil_FindAssets_WithOneIteration()
    {
        Measure.Method(() =>
        {
            FindAssetsDirectory[0] = TestDirectory;
            var guids = AssetDataUtil.FindAssets(SearchFilter, FindAssetsDirectory);
            foreach (var guid in guids)
            {
                if (!string.IsNullOrEmpty(guid))
                    return;
            }
        })
        .SampleGroup(new SampleGroup("AssetDataUtil.FindAssets+Iteration", SampleUnit.Millisecond))
        .WarmupCount(5)
        .MeasurementCount(20)
        .GC()
        .Run();
    }

    private void RunAssetDatabaseSearch()
    {
        var guids = AssetDatabase.FindAssets(SearchFilter, SearchFolders);
        // 强制迭代，防止延迟枚举导致测量偏差
        foreach (var _ in guids) { }
    }

    private void RunAssetDataUtilSearch()
    {
        FindAssetsDirectory[0] = TestDirectory;
        var guids = AssetDataUtil.FindAssets(SearchFilter, FindAssetsDirectory);
        foreach (var _ in guids) { }
    }
}

测试结果

AssetDatabase vs AssetDataUtil 性能测试对比

GC Allocations (Undefineds)

Test Case	Min	Median	Max	Avg	StdDev	SampleCount	Sum
AssetDatabase.FindAssets	91.00	91.00	178.00	94.48	17.05	25	2362.00
AssetDatabase.FindAssets+Iteration (Full)	91.00	91.00	92.00	91.04	0.20	25	2276.00
AssetDatabase.FindAssets+Iteration (One)	90.00	90.00	92.00	90.48	0.57	25	2262.00
AssetDataUtil.FindAssets	88.00	88.00	173.00	91.40	16.66	25	2285.00
AssetDataUtil.FindAssets+Iteration (Full)	88.00	88.00	118.00	89.24	5.87	25	2231.00
AssetDataUtil.FindAssets+Iteration (One)	82.00	82.00	84.00	82.44	0.57	25	2061.00

Execution Time (Milliseconds)

Test Case	Min	Median	Max	Avg	StdDev	SampleCount	Sum
AssetDatabase.FindAssets	1.13	1.18	1.26	1.19	0.04	20	23.79
AssetDatabase.FindAssets+Iteration (Full)	1.18	1.21	1.33	1.22	0.04	20	24.38
AssetDatabase.FindAssets+Iteration (One)	1.15	1.20	1.26	1.20	0.02	20	24.00
AssetDataUtil.FindAssets	1.20	1.25	1.38	1.25	0.04	20	25.06
AssetDataUtil.FindAssets+Iteration (Full)	1.22	1.25	1.32	1.26	0.03	20	25.21
AssetDataUtil.FindAssets+Iteration (One)	0.19	0.23	0.27	0.23	0.02	20	4.50