push notification helper library

http://windowsteamblog.com/windows_phone/b/wpdev/archive/2011/01/14/windows-push-notification-server-side-helper-library.aspx
http://create.msdn.com/en-us/education/catalog/article/pnhelp-wp7

main/Libs/PushRecipe_WP7_SL/Source/WindowsPhone.Recipes.Push.Server/Services/PushService.cs

@@ -0,0 +1,184 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.ServiceModel;
+using System.ComponentModel.Composition;
+
+using WindowsPhone.Recipes.Push.Server.Models;
+using System.Xml.Linq;
+
+namespace WindowsPhone.Recipes.Push.Server.Services
+{
+    /// <summary>
+    /// Current push server services implementation.
+    /// </summary>
+    [Export, PartCreationPolicy(CreationPolicy.Shared), ServiceBehavior(InstanceContextMode = InstanceContextMode.Single)]
+    internal class PushService : IPushService
+    {        
+        #region Fields
+
+        private ServiceHost _serviceHost;
+
+        /// <value>Dictionary contains users subscription objects.</value>
+        private readonly Dictionary<string, Subscription> _subscribers = new Dictionary<string, Subscription>();
+
+        /// <value>Sync access to the subscribers dictionary.</value>
+        private readonly object SubscribersSync = new object();        
+
+        #endregion
+
+        #region Events
+
+        /// <summary>
+        /// Raise when user subscribed.
+        /// </summary>
+        public event EventHandler<SubscriptionEventArgs> Subscribed;
+
+        /// <summary>
+        /// Raise when current server status is requested.
+        /// </summary>
+        public event EventHandler<ServerInfoEventArgs> GetInfo;
+
+        /// <summary>
+        /// Raise when user requests a tile update.
+        /// </summary>
+        public event EventHandler<TileUpdateRequestEventArgs> TileUpdateRequest;
+
+        #endregion
+
+        #region Properties
+
+        /// <summary>
+        /// Get subscription list.
+        /// </summary>
+        public IEnumerable<Subscription> Subscribers
+        {
+            get
+            {
+                lock (_subscribers)
+                {
+                    var subscribers = new Subscription[_subscribers.Count];
+                    _subscribers.Values.CopyTo(subscribers, 0);
+                    return subscribers;
+                }
+            }
+        }
+
+        /// <summary>
+        /// Get subscription count.
+        /// </summary>
+        public int SubscribersCount
+        {
+            get
+            {
+                lock (_subscribers)
+                {
+                    return _subscribers.Count;
+                }
+            }
+        }
+
+        #endregion
+
+        #region Operations
+
+        /// <summary>
+        /// Register user with notification channel uri.
+        /// </summary>
+        /// <param name="userName">The user name to register.</param>
+        /// <param name="channelUri">The notification channel uri.</param>
+        public void Register(string userName, Uri channelUri)
+        {
+            if (string.IsNullOrEmpty(userName))
+            {
+                throw new ArgumentException("Invalid user name", "userName");
+            }
+
+            if (channelUri == null)
+            {
+                throw new ArgumentNullException("channelUri");
+            }
+
+            var subscription = new Subscription(userName, channelUri);
+
+            lock (SubscribersSync)
+            {
+                // Add or update existing.
+                _subscribers[userName] = subscription;
+            }
+
+            OnSubscribed(new SubscriptionEventArgs(subscription));
+        }        
+
+        /// <summary>
+        /// Gets current server info.
+        /// </summary>
+        /// <returns>An instance info object contains server status.</returns>
+        public ServerInfo GetServerInfo()
+        {
+            var args = new ServerInfoEventArgs();
+            OnGetInfo(args);
+            return args.ServerInfo;
+        }
+
+        /// <summary>
+        /// Send a tile update with given parameter.
+        /// </summary>        
+        /// <param name="channelUri">An instance info object contains server status.</param>
+        /// <param name="parameter">User parameter to send with the tile update request.</param>
+        public void UpdateTile(Uri channelUri, string parameter)
+        {
+            OnTileUpdateRequest(new TileUpdateRequestEventArgs(channelUri, parameter));
+        }
+
+        internal Subscription TryGetSubscription(string userName)
+        {
+            lock (SubscribersSync)
+            {
+                Subscription subscription;
+                if (!_subscribers.TryGetValue(userName, out subscription))
+                {
+                    subscription = null;
+                }
+
+                return subscription;
+            }
+        }
+        
+        #endregion
+
+        #region Privates Logic
+
+        public void Host()
+        {
+            _serviceHost = new ServiceHost(this);
+            _serviceHost.Open();
+        }
+
+        private void OnSubscribed(SubscriptionEventArgs args)
+        {
+            if (Subscribed != null)
+            {
+                Subscribed(this, args);
+            }
+        }
+
+        private void OnGetInfo(ServerInfoEventArgs args)
+        {
+            if (GetInfo != null)
+            {
+                GetInfo(this, args);
+            }
+        }
+
+        private void OnTileUpdateRequest(TileUpdateRequestEventArgs args)
+        {
+            if (TileUpdateRequest != null)
+            {
+                TileUpdateRequest(this, args);
+            }
+        }
+
+        #endregion        
+    }
+}