WaterFlush/Assets/Scripts/TextureLoadHelp.cs

using System;
using System.Collections;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using UnityEngine;
using UnityEngine.Networking;
using UnityEngine.UI;

public class TextureLoadHelp : MonoBehaviour
{
    public static TextureLoadHelp _Instance;

    private Dictionary<string, TempTexData> tempTexList;

    private Dictionary<long, Material> waitLoadImgActionList;
    
    public float currentTotalSize = 0;
    public float maxSize = 500; //图片缓存-m

    private Dictionary<string, AssetBundle> loadDoneABList;
    private Dictionary<string, int> loadingABList;

    public Texture map_def;
    
    private void Awake()
    {
        _Instance = this;
        tempTexList = new Dictionary<string, TempTexData>();
        waitLoadImgActionList = new Dictionary<long, Material>();

        loadDoneABList = new Dictionary<string, AssetBundle>();
        loadingABList = new Dictionary<string, int>();
    }
    
    /// <summary>
    /// 加载图片
    /// </summary>
    /// <param name="path"></param>
    /// <param name="mat"></param>
    /// <returns></returns>
    public long LoadTexFromUrl(string path, Material mat)
    {
        long loadId = GetDownId();
        if (CheckCache(path))
        {
            mat.mainTexture=LoadFromCache(path);
            return 0;
        }
        if (tempTexList.TryGetValue(path, out var value))
        {
            value.isUsing = true;
            mat.mainTexture = value.tex;
            loadId = 0;
        }
        else
        {
            waitLoadImgActionList.Add(loadId, mat);
            StartCoroutine(DownLoadTex(path, loadId));
        }
        return loadId;
    }
    
    public long LoadTexFromUrl_AB(string ab_Name,string FileName, Material mat)
    {
        if (tempTexList.TryGetValue(FileName, out var value))
        {
            value.isUsing = true;
            mat.mainTexture = value.tex;
            return 0;
        }
        mat.mainTexture = map_def;
        long loadId = GetDownId();
        waitLoadImgActionList.Add(loadId, mat);
        StartCoroutine(DownLoadTex_AB(ab_Name,FileName,loadId));
        return loadId;
    }
    
    /// <summary>
    /// 取消加载
    /// </summary>
    /// <param name="loadId"></param>
    public void CancelLoad(long loadId)
    {
        if (waitLoadImgActionList.ContainsKey(loadId))
        {
            waitLoadImgActionList.Remove(loadId);
        }
    }
    
    /// <summary>
    /// 标记缓存图片为未使用
    /// </summary>
    /// <param name="path"></param>
    public void UnUsingTex(string path)
    {
        if (tempTexList.TryGetValue(path, out TempTexData disposeData))
        {
            disposeData.isUsing = false;
        }
        else
        {
            Debug.Log($"不存在缓存:{path}");
        }
    }
    
    IEnumerator DownLoadTex_AB(string ab_Name,string fileName, long loadId)
    {
        if (loadingABList.ContainsKey(ab_Name))
        {
            //Debug.Log($"{ab_Name} downloading...wait");
            yield return new WaitUntil(() => loadingABList[ab_Name] > 0);
            // if (loadingABList.ContainsKey(ab_Name))
            // {
            //     loadingABList.Remove(ab_Name);
            // }
        }
        AssetBundle tempAb;
        Texture2D tex;
        if (loadDoneABList.TryGetValue(ab_Name, out var value))
        {
            tempAb = value;
            tex=tempAb.LoadAsset<Texture2D>(fileName);
            if (waitLoadImgActionList.TryGetValue(loadId, out Material targetMat))
            {
                if (targetMat != null)
                {
                    targetMat.mainTexture = tex;
                }
                waitLoadImgActionList.Remove(loadId);
            }
        }
        else
        {
            //添加到正在下载
            loadingABList.TryAdd(ab_Name,0);
            WWW www = WWW.LoadFromCacheOrDownload($"{Application.streamingAssetsPath}/{ab_Name}",0);
            yield return www;
            if (www.isDone)
            {
                tempAb = www.assetBundle;
                loadDoneABList.Add(ab_Name,tempAb);
                
                loadingABList[ab_Name]=1;
                
                tex=tempAb.LoadAsset<Texture2D>(fileName);
                tempTexList.TryAdd(fileName, new TempTexData()
                {
                    loadTime = GetTimeStamp(),
                    name = fileName,
                    tex = tex,
                    size = 0,
                    isUsing = true
                });
                if (waitLoadImgActionList.TryGetValue(loadId, out Material targetMat))
                {
                    if (targetMat != null)
                    {
                        targetMat.mainTexture = tex;
                    }
                    waitLoadImgActionList.Remove(loadId);
                }
            }
            else
            {
                loadingABList[ab_Name]=2;
                Debug.LogError($"{ab_Name}下载失败：{www.error}");
            }
            www.Dispose();
        }
    }
    
    IEnumerator DownLoadTex(string path, long loadId)
    {
        UnityWebRequest www = UnityWebRequestTexture.GetTexture(path);
        yield return www.SendWebRequest();
        if (www.downloadHandler.isDone)
        {
            if (waitLoadImgActionList.ContainsKey(loadId))
            {
                var texture = ((DownloadHandlerTexture)www.downloadHandler).texture;
                float tempSize = GetSize_m(www.downloadedBytes);
                tempTexList.TryAdd(path, new TempTexData()
                {
                    loadTime = GetTimeStamp(),
                    name = path,
                    tex = texture,
                    size = tempSize,
                    isUsing = true
                });
                currentTotalSize += tempSize;
                CheckSize();
                if (waitLoadImgActionList.TryGetValue(loadId, out Material targetMat))
                {
                    if (targetMat != null)
                    {
                        targetMat.mainTexture = texture;
                    }
                    waitLoadImgActionList.Remove(loadId);
                }
                SaveInCache(path, www.downloadHandler.data);
            }
            else
            {
                www.disposeDownloadHandlerOnDispose = true;
                Debug.Log(path + " 下载已取消");
            }
        }
        else
        {
            Debug.LogError($"{path}下载失败：{www.downloadHandler.error}");
        }
    
        www.Dispose();
    }

    private void SaveInCache(string url,byte[] data)
    {
        string fileName = Path.GetFileName(url);
        string path = Application.persistentDataPath;
        File.WriteAllBytes(path+fileName,data);
        Debug.Log($"缓存:{path}{fileName}");
    }

    private Texture2D LoadFromCache(string url)
    {
        string fileName = Path.GetFileName(url);
        string path = Application.persistentDataPath;
        byte[] texBytes=File.ReadAllBytes(path+fileName);
        currentTotalSize += GetSize_m((ulong)texBytes.Length);
        Texture2D tempTex = new Texture2D(2,2);
        tempTex.LoadImage(texBytes);
        tempTex.Apply();
        return tempTex;
    }

    private bool CheckCache(string url)
    {
        string fileName = Path.GetFileName(url);
        string path = Application.persistentDataPath;
        //Debug.Log($"CaChe:{path}");
        return File.Exists(path + fileName);
    }

    public void CheckSize()
    {
        if (currentTotalSize >= maxSize)
        {
            List<TempTexData> values = tempTexList.Values.ToList();
            values.Sort();
            for (int i = 0; i < values.Count; i++)
            {
                if (!values[i].isUsing)
                {
                    if (tempTexList.TryGetValue(values[i].name, out TempTexData disposeData))
                    {
                        disposeData.tex = null;
                        currentTotalSize -= disposeData.size;
                        tempTexList.Remove(disposeData.name);
                    }
                }
                if (currentTotalSize < maxSize)
                {
                    break;
                }
            }
            if (currentTotalSize >= maxSize)
            {
                Debug.Log($"临时图片已超过限制大小且无可释放项！！！：{currentTotalSize}/{maxSize}");
            }
        }
    }

    /// <summary>
    /// 清空全部缓存
    /// </summary>
    public void ClearAllTempTex()
    {
        List<TempTexData> values = tempTexList.Values.ToList();
        for (int i = 0; i < values.Count; i++)
        {
            if (tempTexList.TryGetValue(values[i].name, out TempTexData disposeData))
            {
                disposeData.tex = null;
                currentTotalSize -= disposeData.size;
                tempTexList.Remove(disposeData.name);
            }
        }
        waitLoadImgActionList.Clear();
        tempTexList.Clear();
        Resources.UnloadUnusedAssets();
        GC.Collect();
    }

    private long GetDownId()
    {
        long id = ((DateTime.Now.ToUniversalTime().Ticks - 621355968000000000) / 10000000);
        while (waitLoadImgActionList.ContainsKey(id))
        {
            id++;
        }

        return id;
    }

    private long GetTimeStamp()
    {
        return (DateTime.Now.ToUniversalTime().Ticks - 621355968000000000) / 10000000;
    }

    private float GetSize_m(ulong size_b)
    {
        return (size_b*1.0f / (1024.0f * 1024.0f));
    }
}


public class TempTexData : IComparable<TempTexData>
{
    public string name;
    public Texture tex;
    public long loadTime;
    public float size;
    public bool isUsing = true;

    public int CompareTo(TempTexData other)
    {
        if (other.loadTime < loadTime)
        {
            return 1;
        }

        if (other.loadTime == loadTime)
        {
            return 0;
        }

        return -1;
    }
}