AutoMapper需要4秒来映射19个对象

Question

我被困在这一段时间，我很难过。 Automapper需要4秒钟来映射19个对象。我的机器上的操作应该花费几毫秒或几纳秒（24gb ram，3.6Ghz i7）。

这是映射调用。

using UnityEngine;
using UnityEditor;
using System.Collections;
using System.Collections.Generic;
using System.IO;
using System.Text;
using System;
using System.Linq;

struct ObjMaterial
{
    public string name;
    public string textureName;
}

public class Menu : MonoBehaviour { 

    public int window; 

    void Start () { 
        window = 1;

    } 

    private static int vertexOffset = 0;
    private static int normalOffset = 0;
    private static int uvOffset = 0;


    //User should probably be able to change this. It is currently left as an excercise for
    //the reader.
    private static string targetFolder = "ExportedObj";


    private static string MeshToString(Component mf, Dictionary<string, ObjMaterial> materialList) 
    {



        Mesh m;
        Material[] mats;

        if(mf is MeshFilter)
        {
            m = (mf as MeshFilter).mesh;
            mats = mf.GetComponent<Renderer>().sharedMaterials;
        }
        else if(mf is SkinnedMeshRenderer)
        {
            m = (mf as SkinnedMeshRenderer).sharedMesh;
            mats = (mf as SkinnedMeshRenderer).sharedMaterials;
        }
        else
        {
            return "";
        }

        StringBuilder sb = new StringBuilder();

        sb.Append("g ").Append(mf.name).Append("\n");
        foreach(Vector3 lv in m.vertices) 
        {
            Vector3 wv = mf.transform.TransformPoint(lv);

            //This is sort of ugly - inverting x-component since we're in
            //a different coordinate system than "everyone" is "used to".
            sb.Append(string.Format("v {0} {1} {2}\n",-wv.x,wv.y,wv.z));
        }
        sb.Append("\n");

        foreach(Vector3 lv in m.normals) 
        {
            Vector3 wv = mf.transform.TransformDirection(lv);

            sb.Append(string.Format("vn {0} {1} {2}\n",-wv.x,wv.y,wv.z));
        }
        sb.Append("\n");

        foreach(Vector3 v in m.uv) 
        {
            sb.Append(string.Format("vt {0} {1}\n",v.x,v.y));
        }

        for (int material=0; material < m.subMeshCount; material ++) {
            sb.Append("\n");
            sb.Append("usemtl ").Append(mats[material].name).Append("\n");
            sb.Append("usemap ").Append(mats[material].name).Append("\n");

            //See if this material is already in the materiallist.
            try
            {
                ObjMaterial objMaterial = new ObjMaterial();

                objMaterial.name = mats[material].name;


                objMaterial.textureName = EditorUtility.GetAssetPath(mats[material].mainTexture);
                //else 
                    //objMaterial.textureName = null;

                materialList.Add(objMaterial.name, objMaterial);
            }
            catch (ArgumentException)
            {
                //Already in the dictionary
            }


            int[] triangles = m.GetTriangles(material);
            for (int i=0;i<triangles.Length;i+=3) 
            {
                //Because we inverted the x-component, we also needed to alter the triangle winding.
                sb.Append(string.Format("f {1}/{1}/{1} {0}/{0}/{0} {2}/{2}/{2}\n", 
                    triangles[i]+1 + vertexOffset, triangles[i+1]+1 + normalOffset, triangles[i+2]+1 + uvOffset));
            }
        }

        vertexOffset += m.vertices.Length;
        normalOffset += m.normals.Length;
        uvOffset += m.uv.Length;

        return sb.ToString();
    }

    private static void Clear()
    {
        vertexOffset = 0;
        normalOffset = 0;
        uvOffset = 0;
    }

    private static Dictionary<string, ObjMaterial> PrepareFileWrite()
    {
        Clear();

        return new Dictionary<string, ObjMaterial>();
    }

    private static void MaterialsToFile(Dictionary<string, ObjMaterial> materialList, string folder, string filename)
    {
        using (StreamWriter sw = new StreamWriter(folder + "/" + filename + ".mtl")) 
        {
            foreach( KeyValuePair<string, ObjMaterial> kvp in materialList )
            {
                sw.Write("\n");
                sw.Write("newmtl {0}\n", kvp.Key);
                sw.Write("Ka  0.6 0.6 0.6\n");
                sw.Write("Kd  0.6 0.6 0.6\n");
                sw.Write("Ks  0.9 0.9 0.9\n");
                sw.Write("d  1.0\n");
                sw.Write("Ns  0.0\n");
                sw.Write("illum 2\n");

                if (kvp.Value.textureName != null)
                {
                    string destinationFile = kvp.Value.textureName;


                    int stripIndex = destinationFile.LastIndexOf('/');//FIXME: Should be Path.PathSeparator;

                    if (stripIndex >= 0)
                        destinationFile = destinationFile.Substring(stripIndex + 1).Trim();


                    string relativeFile = destinationFile;

                    destinationFile = folder + "/" + destinationFile;

                    Debug.Log("Copying texture from " + kvp.Value.textureName + " to " + destinationFile);

                    try
                    {
                        //Copy the source file
                        File.Copy(kvp.Value.textureName, destinationFile);
                    }
                    catch
                    {

                    }   


                    sw.Write("map_Kd {0}", relativeFile);
                }

                sw.Write("\n\n\n");
            }
        }
    }

    private static void MeshToFile(Component mf, string folder, string filename) 
    {
        Dictionary<string, ObjMaterial> materialList = PrepareFileWrite();

        using (StreamWriter sw = new StreamWriter(folder +"/" + filename + ".obj")) 
        {
            sw.Write("mtllib ./" + filename + ".mtl\n");

            sw.Write(MeshToString(mf, materialList));
        }

        MaterialsToFile(materialList, folder, filename);
    }

    private static void MeshesToFile(Component[] mf, string folder, string filename) 
    {
        Dictionary<string, ObjMaterial> materialList = PrepareFileWrite();

        using (StreamWriter sw = new StreamWriter(folder +"/" + filename + ".obj")) 
        {
            sw.Write("mtllib ./" + filename + ".mtl\n");

            for (int i = 0; i < mf.Length; i++)
            {
                sw.Write(MeshToString(mf[i], materialList));
            }
        }

        MaterialsToFile(materialList, folder, filename);
    }

    private static bool CreateTargetFolder()
    {
        try
        {
            System.IO.Directory.CreateDirectory(targetFolder);
        }
        catch
        {
            //EditorUtility.DisplayDialog("Error!", "Failed to create target folder!", "");
            return false;
        }

        return true;
    }



    void OnGUI () { 
        GUI.BeginGroup (new Rect (Screen.width / 2 - 100, Screen.height / 2 - 100, 200, 200)); 
        if(window == 1) 
        { 
            if(GUI.Button (new Rect (10,30,180,30), "Экспортировать")) 
            { 

                if (!CreateTargetFolder())
                    return;

                //GameObject[] gos = GameObject.FindGameObjectsWithTag("Boat");
                //Selection.objects = gos;

                GameObject[] selection = GameObject.FindGameObjectsWithTag("Boat");
                //Transform[] selection = Selection.GetTransforms(SelectionMode.Editable | SelectionMode.ExcludePrefab);

                if (selection.Length == 0)
                {
                    //EditorUtility.DisplayDialog("No source object selected!", "Please select one or more target objects", "");
                    return;
                }

                int exportedObjects = 0;

                ArrayList mfList = new ArrayList();

                for (int i = 0; i < selection.Length; i++)
                {
                    Component[] meshfilter = selection[i].GetComponentsInChildren(typeof(MeshFilter)).Concat(selection[i].GetComponentsInChildren(typeof(SkinnedMeshRenderer))).ToArray();

                    for (int m = 0; m < meshfilter.Length; m++)
                    {
                        exportedObjects++;
                        mfList.Add(meshfilter[m]);
                    }
                }

                if (exportedObjects > 0) 
                {
                    Component[] mf = new Component[mfList.Count];

                    for (int i = 0; i < mfList.Count; i++) {
                        mf [i] = (Component)mfList [i];
                    }

                    string filename = /*EditorApplication.currentScene +*/ "_" + exportedObjects;

                    int stripIndex = filename.LastIndexOf ('/');//FIXME: Should be Path.PathSeparator

                    if (stripIndex >= 0)
                        filename = filename.Substring (stripIndex + 1).Trim ();

                    MeshesToFile (mf, targetFolder, filename);

                }

            } 

            if(GUI.Button (new Rect (10,150,180,30), "Выход")) 
            { 
                window = 5; 
            } 
        } 

        if(window == 5) 
        { 
            GUI.Label(new Rect(50, 10, 180, 30), "Вы уже выходите?");   
            if(GUI.Button (new Rect (10,40,180,30), "Да")) 
            { 
                Application.Quit(); 
            } 
            if(GUI.Button (new Rect (10,80,180,30), "Нет")) 
            { 
                window = 1; 
            } 
        } 
        GUI.EndGroup (); 
    } 
} 

这是我的Automapper配置

 var messageDtos = AutoMapperConfig.Mapper.Map<List<Message>, List<MessageDTO>>(messages);

以下是相关对象。他们并不疯狂。

    public static class AutoMapperConfig
{
    public static IMapper Mapper;
    public static void Configure()
    {
        MapperConfiguration config = new MapperConfiguration(cfg =>
        {
            cfg.CreateMap<User, UserDTO>();
            cfg.CreateMap<UserDTO, User>();
            cfg.CreateMap<ConversationUser, ConversationUserDTO>();
            cfg.CreateMap<ConversationUserDTO, ConversationUser>();
            cfg.CreateMap<Conversation, ConversationDTO>();
            cfg.CreateMap<ConversationDTO, Conversation>()
            .ForMember(dest => dest.ConversationUsers, opt => opt.MapFrom(src => src.ConversationUsers));

            cfg.CreateMap<Message, MessageDTO>();
            cfg.CreateMap<MessageDTO, Message>();

        });

        Mapper = config.CreateMapper();

    }
}

这是一个点迹线的屏幕截图，显示Automapper的使用时间，不确定它提供了多少洞察力，我昨天刚刚安装了dotrace来解决这个问题。

Answer 1

简而言之，正在进行数据库调用。

AutoMapper正在调用您的关系属性getter，它正在使用EntityFramework从数据库加载数据。

快速解决方法是禁用延迟加载的集合。

Answer 2

您的Message类是Entity Framework模型的一部分，您似乎启用了延迟加载。因此，在从Message类映射时，属性MediaMessages和ReadReceipts尚未从数据库加载，而AutoMapper会触发它们延迟加载。因此，这4秒实际上是映射期间发生的2个数据库调用。

在映射实体之前，您应该急切地加载实体。可能更好的方法是在查询期间禁用延迟加载并手动.Include()。