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

   1 using System;
   2 using System.Collections.Generic;
   3 using System.ComponentModel;
   4 using System.Diagnostics.Contracts;
   5 using System.Linq;
   6 using System.Text;
   7 using System.Net;
   8 using System.IO;
   9 using System.Threading;
  10 using System.Threading.Tasks;
  11 using log4net;
  12
  13 namespace Pithos.Network
  14 {
  15     public static class WebExtensions
  16     {
  17
  18         public static string ReadToEnd(this HttpWebResponse response)
  19         {
  20             using (var stream = response.GetResponseStream())
  21             {
  22                 if (stream == null)
  23                     return null;
  24                 using (var reader = new StreamReader(stream))
  25                 {
  26                     var body = reader.ReadToEnd();
  27                     return body;
  28                 }
  29             }
  30         }
  31
  32         public static void LogError(this ILog log, HttpWebResponse response)
  33         {
  34             if (log.IsDebugEnabled)
  35             {
  36                 if (response != null)
  37                 {
  38                     var body = response.ReadToEnd();
  39                     log.ErrorFormat("Headers:\n{0}\nBody:{1}", response.Headers, body);
  40                 }
  41             }
  42         }
  43
  44         public static TextReader GetLoggedReader(this Stream stream, ILog log)
  45         {
  46             var reader = new StreamReader(stream);
  47             if (!log.IsDebugEnabled)
  48                 return reader;
  49
  50             using (reader)
  51             {
  52                 var body = reader.ReadToEnd();
  53                 log.DebugFormat("JSON response: {0}", body);
  54                 return new StringReader(body);
  55             }
  56         }
  57
  58
  59         public static TOut NullSafe<TIn, TOut>(this TIn obj, Func<TIn, TOut> memberAction)
  60         {
  61             //Note we should not use obj != null because it can not test value types and also
  62             //compiler has to lift the type to a nullable type for doing the comparision with null.
  63             return (!EqualityComparer<TIn>.Default.Equals(obj, default(TIn))) ? memberAction(obj) : default(TOut);
  64
  65         }
  66
  67         public static IEnumerable<T> Range<T>(this IList<T> list, int start, int end)
  68         {
  69             Contract.Requires(start >= 0);
  70             Contract.Requires(end < list.Count);
  71             Contract.Requires(start <= end);
  72
  73             if (list == null)
  74                 yield break;
  75
  76             for (var i = 0; i <= end; i++)
  77             {
  78                 yield return list[i];
  79             }
  80
  81         }
  82
  83         public static Task<byte[]> UploadDataTaskAsync(this WebClient webClient, Uri address, string method, byte[] data, CancellationToken cancellationToken, IProgress<UploadProgressChangedEventArgs> progress)
  84         {
  85             var tcs = new TaskCompletionSource<byte[]>(address);
  86             if (cancellationToken.IsCancellationRequested)
  87             {
  88                 tcs.TrySetCanceled();
  89             }
  90             else
  91             {
  92                 CancellationTokenRegistration ctr = cancellationToken.Register(()=>
  93                 {
  94                     webClient.CancelAsync();
  95                 });
  96                 UploadDataCompletedEventHandler completedHandler = null;
  97                 UploadProgressChangedEventHandler progressHandler = null;
  98                 if (progress != null)
  99                     progressHandler = (s, e) => PithosEAPCommon.HandleProgress(tcs, e, () => e, progress);
 100                 completedHandler =(sender, e) =>PithosEAPCommon.HandleCompletion(tcs, true, e,() => e.Result,() =>
 101                 {
 102                     ctr.Dispose();
 103                     webClient.UploadDataCompleted -= completedHandler;
 104                     webClient.UploadProgressChanged -= progressHandler;
 105                 });
 106                 webClient.UploadDataCompleted += completedHandler;
 107                 webClient.UploadProgressChanged += progressHandler;
 108                 try
 109                 {
 110                     webClient.UploadDataAsync(address, method, data, tcs);
 111                     if (cancellationToken.IsCancellationRequested)
 112                         webClient.CancelAsync();
 113                 }
 114                 catch
 115                 {
 116                     webClient.UploadDataCompleted -= completedHandler;
 117                     webClient.UploadProgressChanged -= progressHandler;
 118                     throw;
 119                 }
 120             }
 121             return tcs.Task;
 122         }
 123
 124     }
 125
 126     internal static class PithosEAPCommon
 127     {
 128         internal static void HandleProgress<T, E>(TaskCompletionSource<T> tcs, ProgressChangedEventArgs eventArgs, Func<E> getProgress, IProgress<E> callback)
 129         {
 130             if (eventArgs.UserState != tcs)
 131                 return;
 132             callback.Report(getProgress());
 133         }
 134
 135         internal static void HandleCompletion<T>(TaskCompletionSource<T> tcs, bool requireMatch, AsyncCompletedEventArgs e, Func<T> getResult, Action unregisterHandler)
 136         {
 137             if (requireMatch)
 138             {
 139                 if (e.UserState != tcs)
 140                     return;
 141             }
 142             try
 143             {
 144                 unregisterHandler();
 145             }
 146             finally
 147             {
 148                 if (e.Cancelled)
 149                     tcs.TrySetCanceled();
 150                 else if (e.Error != null)
 151                     tcs.TrySetException(e.Error);
 152                 else
 153                     tcs.TrySetResult(getResult());
 154             }
 155         }
 156     }
 157
 158 }