Shared File Fix for Upload

[pithos-ms-client] / trunk / Pithos.Core / TaskExtensions.cs

diff --git a/trunk/Pithos.Core/TaskExtensions.cs b/trunk/Pithos.Core/TaskExtensions.cs
index b94dafb..fce3827 100644 (file)
--- a/trunk/Pithos.Core/TaskExtensions.cs
+++ b/trunk/Pithos.Core/TaskExtensions.cs
@@ -1,5 +1,48 @@
-using System;
+#region
+/* -----------------------------------------------------------------------
+ * <copyright file="TaskExtensions.cs" company="GRNet">
+ * 
+ * Copyright 2011-2012 GRNET S.A. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ *   1. Redistributions of source code must retain the above
+ *      copyright notice, this list of conditions and the following
+ *      disclaimer.
+ *
+ *   2. Redistributions in binary form must reproduce the above
+ *      copyright notice, this list of conditions and the following
+ *      disclaimer in the documentation and/or other materials
+ *      provided with the distribution.
+ *
+ *
+ * THIS SOFTWARE IS PROVIDED BY GRNET S.A. ``AS IS'' AND ANY EXPRESS
+ * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL GRNET S.A OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * The views and conclusions contained in the software and
+ * documentation are those of the authors and should not be
+ * interpreted as representing official policies, either expressed
+ * or implied, of GRNET S.A.
+ * </copyright>
+ * -----------------------------------------------------------------------
+ */
+#endregion
+using System;
+using System.Collections.Concurrent;
 using System.Collections.Generic;
+using System.Diagnostics.Contracts;
 using System.Linq;
 using System.Text;
 using System.Threading;
@@ -7,22 +50,36 @@ using System.Threading.Tasks;
 
 namespace Pithos.Core
 {
-    static class TaskExtensions
+    public static class TaskExtensions
     {
         public static Task<T2> Then<T1, T2>(this Task<T1> first, Func<T1, Task<T2>> next)
         {
+            if (first == null)
+                throw new ArgumentNullException("first");
+            if (next == null)
+                throw new ArgumentNullException("next");
+            Contract.EndContractBlock();
             return Then(first, next, CancellationToken.None);
         }
 
         public static Task Then<T1>(this Task<T1> first, Func<T1, Task> next)
         {
+            if (first == null)
+                throw new ArgumentNullException("first");
+            if (next == null)
+                throw new ArgumentNullException("next");
+            Contract.EndContractBlock();
             return Then(first, next, CancellationToken.None);
         }
 
         public static Task<T2> Then<T1, T2>(this Task<T1> first, Func<T1, Task<T2>> next, CancellationToken cancellationToken)
         {
-            if (first == null) throw new ArgumentNullException("first");
-            if (next == null) throw new ArgumentNullException("next");
+            if (first == null) 
+                throw new ArgumentNullException("first");
+            if (next == null) 
+                throw new ArgumentNullException("next");
+            Contract.EndContractBlock();
+            Contract.Assume(TaskScheduler.Current!=null);
 
             var tcs = new TaskCompletionSource<T2>();
             first.ContinueWith(delegate
@@ -50,8 +107,12 @@ namespace Pithos.Core
 
         public static Task Then<T1>(this Task<T1> first, Func<T1, Task> next, CancellationToken cancellationToken)
         {
-            if (first == null) throw new ArgumentNullException("first");
-            if (next == null) throw new ArgumentNullException("next");
+            if (first == null)
+                throw new ArgumentNullException("first");
+            if (next == null)
+                throw new ArgumentNullException("next");
+            Contract.EndContractBlock();
+            Contract.Assume(TaskScheduler.Current != null);
 
             var tcs = new TaskCompletionSource<object>();
             first.ContinueWith(delegate
@@ -94,5 +155,41 @@ namespace Pithos.Core
             }
         }
 
+        public static bool TryRemove<T>(this ObservableConcurrentCollection<T> collection,T item) where T:class
+        {
+            var found = false;
+            IProducerConsumerCollection<T> items= collection;
+            //Store the initial count
+            var count = items.Count;
+            for (var i = 0; i < count; i++)
+            {
+                T tempItem;
+                //Take an item
+                if (!items.TryTake(out tempItem)) 
+                    return false;
+                //If it isn't the one we are looking for
+                if (tempItem != item)
+                    //put it back
+                    items.TryAdd(tempItem);
+                else
+                    //otherwise skip it and flag succcess
+                    found = true;
+            }
+            return found;
+        }
+
+        public static bool TryAdd<T>(this ObservableConcurrentCollection<T> collection,T item) where T:class
+        {
+            if (collection==null)
+                throw new ArgumentNullException("collection");
+            Contract.EndContractBlock();
+
+            if (item == null)
+                return false;
+
+            IProducerConsumerCollection<T> items= collection;            
+            return items.TryAdd(item);
+        }
+
     }
 }
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