首次加载URL时增加重试机制 (#413)

#355

.gitignore

@@ -40,6 +40,9 @@ bld/
 # Uncomment if you have tasks that create the project's static files in wwwroot
 #wwwroot/
 
+# Rider
+.idea
+
 # Visual Studio 2017 auto generated files
 Generated\ Files/
 

src/N_m3u8DL-RE.Common/Util/RetryUtil.cs

@@ -0,0 +1,38 @@
+using System.Net;
+using N_m3u8DL_RE.Common.Log;
+using Spectre.Console;
+
+namespace N_m3u8DL_RE.Common.Util;
+
+public class RetryUtil
+{
+    public static async Task<T?> WebRequestRetryAsync<T>(Func<Task<T>> funcAsync, int maxRetries = 10, int retryDelayMilliseconds = 1500, int retryDelayIncrementMilliseconds = 0)
+    {
+        var retryCount = 0;
+        var result = default(T);
+        Exception currentException = new();
+
+        while (retryCount < maxRetries)
+        {
+            try
+            {
+                result = await funcAsync();
+                break;
+            }
+            catch (Exception ex) when (ex is WebException or IOException or HttpRequestException)
+            {
+                currentException = ex;
+                retryCount++;
+                Logger.WarnMarkUp($"[grey]{ex.Message.EscapeMarkup()} ({retryCount}/{maxRetries})[/]");
+                await Task.Delay(retryDelayMilliseconds + (retryDelayIncrementMilliseconds * (retryCount - 1)));
+            }
+        }
+
+        if (retryCount == maxRetries)
+        {
+            throw new Exception($"Failed to execute action after {maxRetries} retries.", currentException);
+        }
+
+        return result;
+    }
+}

src/N_m3u8DL-RE.Parser/StreamExtractor.cs

@@ -30,25 +30,25 @@ namespace N_m3u8DL_RE.Parser
             this.parserConfig = parserConfig;
         }
 
-        public void LoadSourceFromUrl(string url)
+        public async Task LoadSourceFromUrlAsync(string url)
         {
             Logger.Info(ResString.loadingUrl + url);
             if (url.StartsWith("file:"))
             {
                 var uri = new Uri(url);
-                this.rawText = File.ReadAllText(uri.LocalPath);
+                this.rawText = await File.ReadAllTextAsync(uri.LocalPath);
                 parserConfig.OriginalUrl = parserConfig.Url = url;
             }
             else if (url.StartsWith("http"))
             {
                 parserConfig.OriginalUrl = url;
-                (this.rawText, url) = HTTPUtil.GetWebSourceAndNewUrlAsync(url, parserConfig.Headers).Result;
+                (this.rawText, url) = await HTTPUtil.GetWebSourceAndNewUrlAsync(url, parserConfig.Headers);
                 parserConfig.Url = url;
             }
             else if (File.Exists(url))
             {
                 url = Path.GetFullPath(url);
-                this.rawText = File.ReadAllText(url);
+                this.rawText = await File.ReadAllTextAsync(url);
                 parserConfig.OriginalUrl = parserConfig.Url = new Uri(url).AbsoluteUri;
             }
             this.rawText = rawText.Trim();
@@ -134,22 +134,11 @@ namespace N_m3u8DL_RE.Parser
             try
             {
                 await semaphore.WaitAsync();
-                int retryCount = 5; //增加重试
-            reGet:
-                try
+                await RetryUtil.WebRequestRetryAsync(async () =>
                 {
                     await extractor.RefreshPlayListAsync(streamSpecs);
-                }
-                catch (Exception ex)
-                {
-                    if (retryCount-- > 0)
-                    {
-                        Logger.WarnMarkUp($"[grey]Refresh Exception: {ex.Message.EscapeMarkup()} retryCount: {retryCount}[/]");
-                        await Task.Delay(1000);
-                        goto reGet;
-                    }
-                    else throw;
-                }
+                    return true;
+                }, retryDelayMilliseconds: 1000, maxRetries: 5);
             }
             finally
             {

src/N_m3u8DL-RE/Program.cs

@@ -62,11 +62,9 @@ namespace N_m3u8DL_RE
         static int GetOrder(StreamSpec streamSpec)
         {
             if (streamSpec.Channels == null) return 0;
-            else
-            {
-                var str = streamSpec.Channels.Split('/')[0];
-                return int.TryParse(str, out var order) ? order : 0;
-            }
+            
+            var str = streamSpec.Channels.Split('/')[0];
+            return int.TryParse(str, out var order) ? order : 0;
         }
 
         static async Task DoWorkAsync(MyOption option)
@@ -208,8 +206,12 @@ namespace N_m3u8DL_RE
 
             //流提取器配置
             var extractor = new StreamExtractor(parserConfig);
-            extractor.LoadSourceFromUrl(url);
-
+            // 从链接加载内容
+            await RetryUtil.WebRequestRetryAsync(async () =>
+            {
+                await extractor.LoadSourceFromUrlAsync(url);
+                return true;
+            });
             //解析流信息
             var streams = await extractor.ExtractStreamsAsync();