code.grnet.gr Git - pithos-ms-client/blob - trunk/Pithos.Network/WebExtensions.cs

   1 using System;\r
   2 using System.Collections.Generic;\r
   3 using System.ComponentModel;\r
   4 using System.Diagnostics.Contracts;\r
   5 using System.Linq;\r
   6 using System.Text;\r
   7 using System.Net;\r
   8 using System.IO;\r
   9 using System.Threading;\r
  10 using System.Threading.Tasks;\r
  11 using log4net;\r
  12 \r
  13 namespace Pithos.Network\r
  14 {\r
  15     public static class WebExtensions\r
  16     {\r
  17         public static string ReadToEnd(this HttpWebResponse response)\r
  18         {\r
  19             using (var stream = response.GetResponseStream())\r
  20             {\r
  21                 if (stream == null)\r
  22                     return null;\r
  23                 using (var reader = new StreamReader(stream))\r
  24                 {\r
  25                     var body = reader.ReadToEnd();\r
  26                     return body;\r
  27                 }\r
  28             }\r
  29         }\r
  30 \r
  31         public static void LogError(this ILog log, HttpWebResponse response)\r
  32         {\r
  33             if (log.IsDebugEnabled)\r
  34             {\r
  35                 if (response != null)\r
  36                 {\r
  37                     var body = response.ReadToEnd();\r
  38                     log.ErrorFormat("Headers:\n{0}\nBody:{1}", response.Headers, body);\r
  39                 }\r
  40             }\r
  41         }\r
  42 \r
  43         public static TextReader GetLoggedReader(this Stream stream, ILog log)\r
  44         {\r
  45             var reader = new StreamReader(stream);\r
  46             if (!log.IsDebugEnabled)\r
  47                 return reader;\r
  48 \r
  49             using (reader)\r
  50             {\r
  51                 var body = reader.ReadToEnd();\r
  52                 log.DebugFormat("JSON response: {0}", body);\r
  53                 return new StringReader(body);\r
  54             }\r
  55         }\r
  56 \r
  57 \r
  58         public static IEnumerable<T> Range<T>(this IList<T> list, int start, int end)\r
  59         {\r
  60             Contract.Requires(start >= 0);\r
  61             Contract.Requires(end < list.Count);\r
  62             Contract.Requires(start <= end);\r
  63 \r
  64             if (list == null)\r
  65                 yield break;\r
  66 \r
  67             for (var i = 0; i <= end; i++)\r
  68             {\r
  69                 yield return list[i];\r
  70             }\r
  71 \r
  72         }\r
  73 \r
  74         public static Task<byte[]> UploadDataTaskAsync(this WebClient webClient, Uri address, string method, byte[] data, CancellationToken cancellationToken, IProgress<UploadProgressChangedEventArgs> progress)\r
  75         {\r
  76             var tcs = new TaskCompletionSource<byte[]>(address);\r
  77             if (cancellationToken.IsCancellationRequested)\r
  78             {\r
  79                 tcs.TrySetCanceled();\r
  80             }\r
  81             else\r
  82             {\r
  83                 CancellationTokenRegistration ctr = cancellationToken.Register(()=>\r
  84                 {\r
  85                     webClient.CancelAsync();\r
  86                 });\r
  87                 UploadDataCompletedEventHandler completedHandler = null;\r
  88                 UploadProgressChangedEventHandler progressHandler = null;\r
  89                 if (progress != null)\r
  90                     progressHandler = (s, e) => PithosEAPCommon.HandleProgress(tcs, e, () => e, progress);\r
  91                 completedHandler =(sender, e) =>PithosEAPCommon.HandleCompletion(tcs, true, e,() => e.Result,() =>\r
  92                 { \r
  93                     ctr.Dispose();\r
  94                     webClient.UploadDataCompleted -= completedHandler;\r
  95                     webClient.UploadProgressChanged -= progressHandler;\r
  96                 });\r
  97                 webClient.UploadDataCompleted += completedHandler;\r
  98                 webClient.UploadProgressChanged += progressHandler;\r
  99                 try\r
 100                 {\r
 101                     webClient.UploadDataAsync(address, method, data, tcs);\r
 102                     if (cancellationToken.IsCancellationRequested)\r
 103                         webClient.CancelAsync();\r
 104                 }\r
 105                 catch\r
 106                 {\r
 107                     webClient.UploadDataCompleted -= completedHandler;\r
 108                     webClient.UploadProgressChanged -= progressHandler;\r
 109                     throw;\r
 110                 }\r
 111             }\r
 112             return tcs.Task;\r
 113         }\r
 114 \r
 115         public static async Task<T> WithRetries<T>(this Func<Task<T>> func, int retries)\r
 116         {\r
 117             while (retries > 0)\r
 118             {\r
 119                 try\r
 120                 {\r
 121                     var result = await func();\r
 122                     return result;\r
 123                 }\r
 124                 catch (Exception exc)\r
 125                 {\r
 126                     if (--retries == 0)\r
 127                         throw new RetryException("Failed too many times", exc);\r
 128                 }\r
 129             }\r
 130             throw new RetryException();\r
 131         }\r
 132 \r
 133     }\r
 134 \r
 135     internal static class PithosEAPCommon\r
 136     {\r
 137         internal static void HandleProgress<T, E>(TaskCompletionSource<T> tcs, ProgressChangedEventArgs eventArgs, Func<E> getProgress, IProgress<E> callback)\r
 138         {\r
 139             if (eventArgs.UserState != tcs)\r
 140                 return;\r
 141             callback.Report(getProgress());\r
 142         }\r
 143 \r
 144         internal static void HandleCompletion<T>(TaskCompletionSource<T> tcs, bool requireMatch, AsyncCompletedEventArgs e, Func<T> getResult, Action unregisterHandler)\r
 145         {\r
 146             if (requireMatch)\r
 147             {\r
 148                 if (e.UserState != tcs)\r
 149                     return;\r
 150             }\r
 151             try\r
 152             {\r
 153                 unregisterHandler();\r
 154             }\r
 155             finally\r
 156             {\r
 157                 if (e.Cancelled)\r
 158                     tcs.TrySetCanceled();\r
 159                 else if (e.Error != null)\r
 160                     tcs.TrySetException(e.Error);\r
 161                 else\r
 162                     tcs.TrySetResult(getResult());\r
 163             }\r
 164         }\r
 165     }\r
 166 \r
 167 }\r