mcs/class/System/System.Net/ServicePointManager.cs

   1 //\r
   2 // System.Net.ServicePointManager\r
   3 //\r
   4 // Author:\r
   5 //   Lawrence Pit (loz@cable.a2000.nl)\r
   6 //\r
   7 \r
   8 using System;\r
   9 using System.Collections;\r
  10 using System.Collections.Specialized;\r
  11 using System.Configuration;\r
  12 using System.Net.Configuration;\r
  13 using System.Security.Cryptography.X509Certificates;\r
  14 \r
  15 //\r
  16 // notes:\r
  17 // A service point manager manages service points (duh!).\r
  18 // A service point maintains a list of connections (per scheme + authority).\r
  19 // According to HttpWebRequest.ConnectionGroupName each connection group\r
  20 // creates additional connections. therefor, a service point has a hashtable\r
  21 // of connection groups where each value is a list of connections.\r
  22 // \r
  23 // when we need to make an HttpWebRequest, we need to do the following:\r
  24 // 1. find service point, given Uri and Proxy \r
  25 // 2. find connection group, given service point and group name\r
  26 // 3. find free connection in connection group, or create one (if ok due to limits)\r
  27 // 4. lease connection\r
  28 // 5. execute request\r
  29 // 6. when finished, return connection\r
  30 //\r
  31 \r
  32 \r
  33 namespace System.Net \r
  34 {\r
  35         class DummyPolicy : ICertificatePolicy\r
  36         {\r
  37                 public bool CheckValidationResult (ServicePoint point,\r
  38                                                    X509Certificate certificate,\r
  39                                                    WebRequest request,\r
  40                                                    int certificateProblem)\r
  41                 {\r
  42                         return (certificateProblem == 0);\r
  43                 }\r
  44         }\r
  45         \r
  46         public class ServicePointManager\r
  47         {\r
  48                 private static HybridDictionary servicePoints = new HybridDictionary ();\r
  49                 \r
  50                 // Static properties\r
  51                 \r
  52                 private static ICertificatePolicy policy = new DummyPolicy ();\r
  53                 private static int defaultConnectionLimit = DefaultPersistentConnectionLimit;\r
  54                 private static int maxServicePointIdleTime = 900000; // 15 minutes\r
  55                 private static int maxServicePoints = 0;\r
  56                 \r
  57                 // Fields\r
  58                 \r
  59                 public const int DefaultNonPersistentConnectionLimit = 4;\r
  60                 public const int DefaultPersistentConnectionLimit = 2;\r
  61 \r
  62                 const string configKey = "system.net/connectionManagement";\r
  63                 static Hashtable config;\r
  64                 \r
  65                 static ServicePointManager ()\r
  66                 {\r
  67                         ConnectionManagementData manager;\r
  68                         manager = (ConnectionManagementData) ConfigurationSettings.GetConfig (configKey);\r
  69                         config = manager.Data;\r
  70                 }\r
  71                 // Constructors\r
  72                 private ServicePointManager ()\r
  73                 {\r
  74                 }               \r
  75                 \r
  76                 // Properties\r
  77                 \r
  78                 public static ICertificatePolicy CertificatePolicy {\r
  79                         get { return policy; }\r
  80                         set { policy = value; }\r
  81                 }\r
  82                 \r
  83                 public static int DefaultConnectionLimit {\r
  84                         get { return defaultConnectionLimit; }\r
  85                         set { \r
  86                                 if (value <= 0)\r
  87                                         throw new ArgumentOutOfRangeException ("value");\r
  88 \r
  89                                 defaultConnectionLimit = value; \r
  90                         }\r
  91                 }\r
  92                 \r
  93                 public static int MaxServicePointIdleTime {\r
  94                         get { \r
  95                                 return maxServicePointIdleTime;\r
  96                         }\r
  97                         set { \r
  98                                 if (value < -2 || value > Int32.MaxValue)\r
  99                                         throw new ArgumentOutOfRangeException ("value");\r
 100                                 maxServicePointIdleTime = value;\r
 101                         }\r
 102                 }\r
 103                 \r
 104                 public static int MaxServicePoints {\r
 105                         get { \r
 106                                 return maxServicePoints; \r
 107                         }\r
 108                         set {  \r
 109                                 if (value < 0)\r
 110                                         throw new ArgumentException ("value");                          \r
 111 \r
 112                                 maxServicePoints = value;\r
 113                                 RecycleServicePoints ();\r
 114                         }\r
 115                 }\r
 116                 \r
 117                 // Methods\r
 118                 \r
 119                 public static ServicePoint FindServicePoint (Uri address) \r
 120                 {\r
 121                         return FindServicePoint (address, GlobalProxySelection.Select);\r
 122                 }\r
 123                 \r
 124                 public static ServicePoint FindServicePoint (string uriString, IWebProxy proxy)\r
 125                 {\r
 126                         return FindServicePoint (new Uri(uriString), proxy);\r
 127                 }\r
 128                 \r
 129                 public static ServicePoint FindServicePoint (Uri address, IWebProxy proxy)\r
 130                 {\r
 131                         if (address == null)\r
 132                                 throw new ArgumentNullException ("address");\r
 133 \r
 134                         RecycleServicePoints ();\r
 135                         \r
 136                         bool usesProxy = false;\r
 137                         if (proxy != null && !proxy.IsBypassed(address)) {\r
 138                                 usesProxy = true;\r
 139                                 address = proxy.GetProxy (address);\r
 140                                 if (address.Scheme != "http" && address.Scheme != "https")\r
 141                                         throw new NotSupportedException ("Proxy scheme not supported.");\r
 142                         } \r
 143 \r
 144                         address = new Uri (address.Scheme + "://" + address.Authority);\r
 145                         \r
 146                         ServicePoint sp = null;\r
 147                         lock (servicePoints) {\r
 148                                 sp = servicePoints [address] as ServicePoint;\r
 149                                 if (sp != null)\r
 150                                         return sp;\r
 151 \r
 152                                 if (maxServicePoints > 0 && servicePoints.Count >= maxServicePoints)\r
 153                                         throw new InvalidOperationException ("maximum number of service points reached");\r
 154 \r
 155                                 string addr = address.ToString ();\r
 156                                 int limit = defaultConnectionLimit;\r
 157                                 if (config.Contains (addr))\r
 158                                         limit = (int) config [addr];\r
 159                                 \r
 160                                 sp = new ServicePoint (address, limit, maxServicePointIdleTime);\r
 161                                 sp.UsesProxy = usesProxy;\r
 162                                 servicePoints.Add (address, sp);\r
 163                         }\r
 164                         \r
 165                         return sp;\r
 166                 }\r
 167                 \r
 168                 // Internal Methods\r
 169 \r
 170                 internal static void RecycleServicePoints ()\r
 171                 {\r
 172                         ArrayList toRemove = new ArrayList ();\r
 173                         lock (servicePoints) {\r
 174                                 IDictionaryEnumerator e = servicePoints.GetEnumerator ();\r
 175                                 while (e.MoveNext ()) {\r
 176                                         ServicePoint sp = (ServicePoint) e.Value;\r
 177                                         if (sp.AvailableForRecycling) {\r
 178                                                 toRemove.Add (e.Key);\r
 179                                                 Console.WriteLine ("Reciclo: {0}", e.Key);\r
 180                                         }\r
 181                                 }\r
 182                                 \r
 183                                 for (int i = 0; i < toRemove.Count; i++) \r
 184                                         servicePoints.Remove (toRemove [i]);\r
 185 \r
 186                                 if (maxServicePoints == 0 || servicePoints.Count <= maxServicePoints)\r
 187                                         return;\r
 188 \r
 189                                 // get rid of the ones with the longest idle time\r
 190                                 SortedList list = new SortedList (servicePoints.Count);\r
 191                                 e = servicePoints.GetEnumerator ();\r
 192                                 while (e.MoveNext ()) {\r
 193                                         ServicePoint sp = (ServicePoint) e.Value;\r
 194                                         if (sp.CurrentConnections == 0) {\r
 195                                                 while (list.ContainsKey (sp.IdleSince))\r
 196                                                         sp.IdleSince.AddMilliseconds (1);\r
 197                                                 list.Add (sp.IdleSince, sp.Address);\r
 198                                         }\r
 199                                 }\r
 200                                 \r
 201                                 for (int i = 0; i < list.Count && servicePoints.Count > maxServicePoints; i++)\r
 202                                         servicePoints.Remove (list.GetByIndex (i));\r
 203                         }\r
 204                 }\r
 205         }\r
 206 }\r