Learn.VideoAnalysis/VideoAnalysisCore/Common/DownloadFile.cs

using AntDesign;
using Downloader;
using System;
using System.ComponentModel;
using System.Diagnostics;
using System.IO;
using System.Net;
using System.Threading.Tasks;

namespace VideoAnalysisCore.Common
{
    /// <summary>
    /// 
    /// </summary>
    public class DownloadFile
    {
        static DownloadConfiguration Opt { get; set; } = default!;
        /// <summary>
        /// 初始化下载器
        /// </summary>
        /// <param name="DownloadSpeed">下载速度mb/s 默认8</param>
        static void Init(int DownloadSpeed = 8)
        {
            Opt = new DownloadConfiguration()
            {
                // 通常，主机支持的最大值为8000字节，默认值是8000
                BufferBlockSize = 10240,
                // 要下载的文件部分数量，默认值是1
                ChunkCount = 8,
                // 下载速度限制为2MB/秒，默认值为零（即无限制）
                MaximumBytesPerSecond = 1024 * 1024 * DownloadSpeed,
                // 故障转移时的最大重试次数
                MaxTryAgainOnFailover = 5,
                // 每50MB后释放内存缓冲区
                MaximumMemoryBufferBytes = 1024 * 1024 * 50,
                // 是否并行下载文件的各个部分。默认值为false
                ParallelDownload = true,
                // 并行下载的数量。默认值与分块数量相同
                ParallelCount = 4,
                // 每个流块读取器的超时时间（毫秒），默认值是1000
                Timeout = 1000,
                // 如果只想下载大型文件的特定字节范围，则设置为true
                RangeDownload = false,
                // 大型文件下载范围的起始偏移量
                RangeLow = 0,
                // 大型文件下载范围的结束偏移量
                RangeHigh = 0,
                // 下载失败完成时清除包块数据，默认值为false
                ClearPackageOnCompletionWithFailure = true,
                // 将文件分多个部分下载时的最小分块大小，默认值是512
                MinimumSizeOfChunking = 1024,
                // 在开始下载之前，按照文件大小预留文件的存储空间，默认值为false
                ReserveStorageSpaceBeforeStartingDownload = true,
                // 在下载进度改变事件中，通过ReceivedBytes获取按需下载的数据
                EnableLiveStreaming = false,
                // 配置和自定义请求头
                RequestConfiguration =
                {
                    Accept = "*/*",
                    //CookieContainer = cookies,
                    Headers = new WebHeaderCollection(), // { 你的自定义头部信息 }
                    KeepAlive = true, // 默认值为false
                    ProtocolVersion = HttpVersion.Version11, // 默认值是HTTP 1.1
                    UseDefaultCredentials = false,
                    // 你的自定义用户代理或你的应用名称/应用版本。
                    UserAgent = "Mozilla/5.0 (Windows NT 10.0; Win64; x64)",
                    //Proxy = new WebProxy()//使用代理
                    //{
                    //    Address = new Uri("http://Learn.VideoAnalysis"),
                    //    UseDefaultCredentials = false,
                    //    Credentials = System.Net.CredentialCache.DefaultNetworkCredentials,
                    //    BypassProxyOnLocal = true
                    //}
                }
            };
        }

        // 根据 Content-Type 映射文件后缀
        static string GetExtensionFromContentType(HttpResponseMessage res)
        {
            var contentType = res.Content.Headers.ContentType?.MediaType;
            return contentType switch
            {
                "application/pdf" => ".pdf",
                "image/jpeg" => ".jpg",
                "image/png" => ".png",
                "application/zip" => ".zip",
                "text/html" => ".html",
                "audio/wav" => ".wav",
                "audio/mp4" => ".mp4",
                "audio/mp3" => ".mp3",
                // 根据需要添加其他 Content-Type 映射
                _ => ".mp4", // 默认二进制文件
            };
        }

        /// <summary>
        /// 使用 HttpClient 下载任务的资源文件到本地
        /// </summary>
        /// <param name="task"></param>
        /// <returns></returns>
        public static async Task RunTask(string task)
        {
            if (Opt is null)
                Init();
            //获取资源文件 地址
            var fileUrl = RedisExpand.Redis.HMGet(RedisExpandKey.Task(task), "MediaUrl")
                .FirstOrDefault();
            if (string.IsNullOrEmpty(fileUrl))
                throw new Exception($"任务id[{task}] 资源地址无效 {fileUrl}");

            // 尝试从 URL 中获取文件后缀
            string fileExtension = Path.GetExtension(new Uri(fileUrl).AbsolutePath);
            //否则 获取 从Content-Type 获取文件后缀
            if (string.IsNullOrEmpty(fileExtension))
                throw new Exception($"未能从资源路径中获取文件后缀");

            //创建下载文件缓存路径
            if (!Directory.Exists(AppCommon.TaskCachedFile)) Directory.CreateDirectory(AppCommon.TaskCachedFile);

            var localPath = task.LocalPath();
            var outputPath = Path.Combine(localPath, task + fileExtension);
            if (!Directory.Exists(localPath)) Directory.CreateDirectory(localPath);

            RedisExpand.Redis.HSet(RedisExpandKey.Task(task), "LocalMediaPath", outputPath);
            IDownload download = DownloadBuilder.New()
                .WithUrl(fileUrl)
                .WithDirectory(localPath)
                .WithFileName(task + fileExtension)
                .WithConfiguration(Opt)
                .Build();
            download.DownloadProgressChanged += (object? sender, Downloader.DownloadProgressChangedEventArgs e) =>
            {
                RedisExpand.SetTaskProgress(task, e.ProgressPercentage);
            };
            download.DownloadFileCompleted +=async (object? sender, AsyncCompletedEventArgs e) => 
            {
                if (download.Status == DownloadStatus.Failed && e.Error!=null)
                {
                    await RedisExpand.SetTaskErrorMessage(long.Parse(task), e.Error)
                        .ConfigureAwait(false);//不切回上下文
                    return;
                }
                else if (download.Status == DownloadStatus.Completed)
                {
                    //加入下一队列
                    RedisExpand.InsertChannel(Enum.RedisChannelEnum.SeparateAudio, task);
                    return;
                }

            };
            await download.StartAsync();

        }
    }
}