Code and more

   1: using System;

   2: using System.Collections;

   3: using System.Collections.Generic;

   4: using System.Threading;

   5:  

   6: namespace Utilities

   7: {

   8:     /// <summary>

   9:     /// Provides a thread-safe and lock-efficient dictionary.  Key must

  10:     /// implement the generic IComparable interface, and the value must

  11:     /// be a reference type.

  12:     /// Enumerations are thread-safe, but will block changes to the

  13:     /// dictionary.

  14:     /// The Keys and Values properties are NOT thread-safe and will throw

  15:     /// exceptions if the dictionary is modified while enumerating those

  16:     /// objects.

  17:     /// 

  18:     /// Matthew Potter

  19:     /// 2007-08-31

  20:     /// matthew@synapseware.com

  21:     /// 

  22:     /// You are free to use this code, as long as you leave my author

  23:     /// information intact.

  24:     /// </summary>

  25:     public class SyncLockDictionary<TKey, UValue> : Dictionary<TKey, UValue>

  26:         where TKey: IComparable<TKey>

  27:         where UValue: class

  28:     {

  29:         /// <summary>

  30:         /// Defines the read-lock timeout, in milliseconds.

  31:         /// </summary>

  32:         protected const int READLOCK_TIMEOUT = 100;

  33:  

  34:         /// <summary>

  35:         /// Defines the write-lock timeout, in milliseconds.

  36:         /// </summary>

  37:         protected const int WRITELOCK_TIMEOUT = 250;

  38:  

  39:         /// <summary>

  40:         /// The locking mechanism that provides the thread-safety

  41:         /// </summary>

  42:         private ReaderWriterLock _lock = new ReaderWriterLock ();

  43:  

  44:         /// <summary>

  45:         /// Default Constructor

  46:         /// </summary>

  47:         public SyncLockDictionary ()

  48:             : base ()

  49:         {}

  50:  

  51:         /// <summary>

  52:         /// Copy Constructor

  53:         /// </summary>

  54:         /// <param name="copy"></param>

  55:         public SyncLockDictionary (Dictionary<TKey, UValue> copy)

  56:             : base (copy)

  57:         {}

  58:  

  59:         /// <summary>

  60:         /// Constructor

  61:         /// </summary>

  62:         /// <param name="comparer"></param>

  63:         public SyncLockDictionary (IEqualityComparer<TKey> comparer)

  64:             : base (comparer)

  65:         {}

  66:  

  67:         /// <summary>

  68:         /// Constructor

  69:         /// </summary>

  70:         /// <param name="capacity"></param>

  71:         public SyncLockDictionary (int capacity)

  72:             : base (capacity)

  73:         {}

  74:  

  75:         /// <summary>

  76:         /// Constructor

  77:         /// </summary>

  78:         /// <param name="capacity"></param>

  79:         /// <param name="comparer"></param>

  80:         public SyncLockDictionary (int capacity, IEqualityComparer<TKey> comparer)

  81:             : base (capacity, comparer)

  82:         {

  83:         }

  84:  

  85:         /// <summary>

  86:         /// Add a new value to the dictionary.

  87:         /// </summary>

  88:         /// <param name="key"></param>

  89:         /// <param name="value"></param>

  90:         public new void Add (TKey key, UValue value)

  91:         {

  92:             try

  93:             {

  94:                 _lock.AcquireWriterLock (READLOCK_TIMEOUT);

  95:                 if (base.ContainsKey (key))

  96:                     base [key] = value;

  97:                 else

  98:                     base.Add (key, value);

  99:             }

 100:             finally

 101:             {

 102:                 // release reader lock

 103:                 _lock.ReleaseWriterLock ();

 104:             }

 105:         }

 106:  

 107:         /// <summary>

 108:         /// Remove a value from the dictionary.

 109:         /// </summary>

 110:         /// <param name="key"></param>

 111:         public new void Remove (TKey key)

 112:         {

 113:             try

 114:             {

 115:                 // get read lock and return if nothing to remove

 116:                 _lock.AcquireReaderLock (READLOCK_TIMEOUT);

 117:                 if (!base.ContainsKey (key))

 118:                     return;

 119:  

 120:                 // upgrade to writer lock so we can safely remove the item

 121:                 LockCookie lc = _lock.UpgradeToWriterLock (WRITELOCK_TIMEOUT);

 122:  

 123:                 // remove the item

 124:                 base.Remove (key);

 125:  

 126:                 // downgrade writer lock

 127:                 _lock.DowngradeFromWriterLock (ref lc);

 128:             }

 129:             finally

 130:             {

 131:                 // release reader lock

 132:                 _lock.ReleaseReaderLock ();

 133:             }

 134:         }

 135:  

 136:         /// <summary>

 137:         /// Returns true if the specified key exists in the collection.

 138:         /// </summary>

 139:         /// <param name="key"></param>

 140:         /// <returns></returns>

 141:         public new bool ContainsKey (TKey key)

 142:         {

 143:             try

 144:             {

 145:                 _lock.AcquireReaderLock (READLOCK_TIMEOUT);

 146:  

 147:                 return base.ContainsKey (key);

 148:             }

 149:             finally

 150:             { _lock.ReleaseReaderLock (); }

 151:         }

 152:  

 153:         /// <summary>

 154:         /// Returns true if the specified value exists in the collection.

 155:         /// </summary>

 156:         /// <param name="value"></param>

 157:         /// <returns></returns>

 158:         public new bool ContainsValue (UValue value)

 159:         {

 160:             try

 161:             {

 162:                 _lock.AcquireReaderLock (READLOCK_TIMEOUT);

 163:  

 164:                 return base.ContainsValue (value);

 165:             }

 166:             finally

 167:             { _lock.ReleaseReaderLock (); }

 168:         }

 169:  

 170:         /// <summary>

 171:         /// Gets the value associated with the specified key.  Returns

 172:         /// false if the specified key does not exist in the dictionary.

 173:         /// </summary>

 174:         /// <param name="key"></param>

 175:         /// <param name="value"></param>

 176:         /// <returns></returns>

 177:         public new bool TryGetValue (TKey key, out UValue value)

 178:         {

 179:             try

 180:             {

 181:                 _lock.AcquireReaderLock (READLOCK_TIMEOUT);

 182:  

 183:                 return base.TryGetValue (key, out value);

 184:             }

 185:             finally

 186:             { _lock.ReleaseReaderLock (); }

 187:         }

 188:  

 189:         /// <summary>

 190:         /// Returns the number of items currently in the dictionary.

 191:         /// </summary>

 192:         public new int Count

 193:         {

 194:             get

 195:             {

 196:                 try

 197:                 {

 198:                     _lock.AcquireReaderLock (READLOCK_TIMEOUT);

 199:  

 200:                     return base.Count;

 201:                 }

 202:                 finally

 203:                 { _lock.ReleaseReaderLock (); }

 204:             }

 205:         }

 206:  

 207:         /// <summary>

 208:         /// Returns a thread-safe enumerator for this dictionary (changes

 209:         /// to the dictionary will not be reflected during an enumeration).

 210:         /// </summary>

 211:         /// <returns></returns>

 212:         public new SafeEnumerator GetEnumerator ()

 213:         {

 214:             try

 215:             {

 216:                 _lock.AcquireReaderLock (READLOCK_TIMEOUT);

 217:  

 218:                 ArrayList items = new ArrayList ();

 219:                 Enumerator en = base.GetEnumerator ();

 220:                 while (en.MoveNext ())

 221:                     items.Add (en.Current);

 222:  

 223:                 return new SafeEnumerator (items);

 224:             }

 225:             finally

 226:             { _lock.ReleaseReaderLock (); }

 227:         }

 228:  

 229:         /// <summary>

 230:         /// Returns a reference to the Keys collection.

 231:         /// </summary>

 232:         public new SafeEnumerator Keys

 233:         {

 234:             get

 235:             {

 236:                 try

 237:                 {

 238:                     _lock.AcquireReaderLock (READLOCK_TIMEOUT);

 239:  

 240:                     ArrayList items = new ArrayList ();

 241:                     foreach (object key in base.Keys)

 242:                         items.Add (key.ToString ());

 243:  

 244:                     return new SafeEnumerator (items);

 245:                 }

 246:                 finally

 247:                 { _lock.ReleaseReaderLock (); }

 248:             }

 249:         }

 250:  

 251:         /// <summary>

 252:         /// Returns a reference to the Values collection.

 253:         /// </summary>

 254:         public new SafeEnumerator Values

 255:         {

 256:             get

 257:             {

 258:                 try

 259:                 {

 260:                     _lock.AcquireReaderLock (READLOCK_TIMEOUT);

 261:  

 262:                     ArrayList items = new ArrayList ();

 263:                     foreach (object key in base.Values)

 264:                         items.Add (key);

 265:  

 266:                     return new SafeEnumerator (items);

 267:                 }

 268:                 finally

 269:                 { _lock.ReleaseReaderLock (); }

 270:             }

 271:         }

 272:  

 273:         /// <summary>

 274:         /// Thread-safe accessor property.

 275:         /// </summary>

 276:         /// <param name="key"></param>

 277:         /// <returns></returns>

 278:         public new UValue this [TKey key]

 279:         {

 280:             get

 281:             {

 282:                 try

 283:                 {

 284:                     _lock.AcquireReaderLock (READLOCK_TIMEOUT);

 285:  

 286:                     UValue value = null;

 287:                     if (base.TryGetValue (key, out value))

 288:                         return value;

 289:  

 290:                     return null;

 291:                 }

 292:                 finally

 293:                 { _lock.ReleaseReaderLock (); }

 294:             }

 295:             set

 296:             {

 297:                 try

 298:                 {

 299:                     _lock.AcquireWriterLock (WRITELOCK_TIMEOUT);

 300:                     try

 301:                     {

 302:                         if (base.ContainsKey (key))

 303:                             base [key] = value;

 304:                         else

 305:                             base.Add (key, value);

 306:                     }

 307:                     finally

 308:                     { _lock.ReleaseWriterLock (); }

 309:                 }

 310:                 finally

 311:                 {}

 312:             }

 313:         }

 314:  

 315:         /// <summary>

 316:         /// Gets an object that can be used to synchronize

 317:         /// access to the dictionary.

 318:         /// </summary>

 319:         public object SyncRoot

 320:         {

 321:             get

 322:             { return this; }

 323:         }

 324:     }

 325:  

 326:     /// <summary>

 327:     /// Provides a thread-safe enumerator for a SyncLockDictionary object.

 328:     /// </summary>

 329:     public class SafeEnumerator : System.Collections.IEnumerator, IEnumerable

 330:     {

 331:         private IList    _items;

 332:         private int        _current;

 333:  

 334:  

 335:         /// <summary>

 336:         /// 

 337:         /// </summary>

 338:         /// <param name="synclock"></param>

 339:         public SafeEnumerator (IList items)

 340:         {

 341:             _items        = items;

 342:             _current    = -1;

 343:         }

 344:  

 345:         /// <summary>

 346:         /// 

 347:         /// </summary>

 348:         public object Current

 349:         {

 350:             get

 351:             {

 352:                 if (_current < 0 || 0 == _items.Count)

 353:                     return null;

 354:  

 355:                 return _items [_current];

 356:             }

 357:         }

 358:  

 359:         /// <summary>

 360:         /// 

 361:         /// </summary>

 362:         public void Dispose ()

 363:         {}

 364:  

 365:         /// <summary>

 366:         /// 

 367:         /// </summary>

 368:         object IEnumerator.Current

 369:         {

 370:             get

 371:             {

 372:                 return this.Current;

 373:             }

 374:         }

 375:  

 376:         /// <summary>

 377:         /// 

 378:         /// </summary>

 379:         /// <returns></returns>

 380:         public bool MoveNext ()

 381:         {

 382:             if (_current >= _items.Count)

 383:                 return false;

 384:  

 385:             _current++;

 386:             if (_current < _items.Count)

 387:                 return true;

 388:  

 389:             return false;

 390:         }

 391:  

 392:         /// <summary>

 393:         /// 

 394:         /// </summary>

 395:         public void Reset ()

 396:         {

 397:             _current = -1;

 398:         }

 399:  

 400:         /// <summary>

 401:         /// 

 402:         /// </summary>

 403:         /// <returns></returns>

 404:         IEnumerator IEnumerable.GetEnumerator ()

 405:         {

 406:             return _items.GetEnumerator ();

 407:         }

 408:     }

 409: }

   1: using System;

   2: using System.Collections.Generic;

   3: using System.IO;

   4: using System.Net;

   5: using System.Net.Sockets;

   6: using System.Text;

   7: using System.Threading;

   8: using System.Xml;

   9:  

  10: namespace Synapseware.Web

  11: {

  12:     /// <summary>

  13:     /// HttpClient class

  14:     /// </summary>

  15:     public static class HttpClient

  16:     {

  17:         /// <summary>

  18:         /// Calls the target site using an HTTP/1.0 GET.

  19:         /// </summary>

  20:         /// <param name="url">Request URL</param>

  21:         /// <param name="timeOut">Timeout to wait for response, in milliseconds.</param>

  22:         /// <returns></returns>

  23:         public static string GetString (string url, int timeOut)

  24:         {

  25:             Socket        sock            = null;

  26:             string        host            = null;                // host name of request

  27:             string        path            = null;                // path portion of request

  28:             string        request            = null;

  29:             string        response        = null;                // body of HTTP response

  30:             string []    data            = null;                // header block converted to string []

  31:             string []    parts            = null;

  32:             int            pos                = 0;

  33:             int            status            = 0;                // HTTP response code

  34:             int            hdrLen            = 0;                // length of header block

  35:             SocketState    state            = null;

  36:             Dictionary<string, string>

  37:                         headers            = null;                // HTTP headers

  38:  

  39:             try

  40:             {

  41:                 // we don't support SSL!

  42:                 if (url.StartsWith ("https://"))

  43:                     return null;

  44:  

  45:                 // parse up the request string

  46:                 if (url.StartsWith ("http://"))

  47:                     host = url.Substring (7);

  48:                 else

  49:                     host = url;

  50:  

  51:                 // split at the first path delimiter

  52:                 if (-1 != (pos = host.IndexOf ('/')))

  53:                 {

  54:                     path = host.Substring (pos);

  55:                     host = host.Substring (0, pos);

  56:                 }

  57:  

  58:                 // make sure path is correct

  59:                 if (String.IsNullOrEmpty (path) || !path.StartsWith ("/"))

  60:                     path = String.Concat ("/", (path ?? ""));

  61:  

  62:                 // connect to server

  63:                 sock = new Socket (AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);

  64:                 sock.Blocking = true;

  65:                 sock.Connect (host, 80);

  66:  

  67:                 // create state object

  68:                 state = new SocketState (sock);

  69:  

  70:                 // build request

  71:                 request = String.Format (

  72: @"GET {0} HTTP/1.0

  73: HOST: {1}

  74: Accept: text/\*

  75: Accept-Language: en-us

  76: Cache-Control: no-cache

  77: Content-Length: 0

  78:  

  79: ", path, host);

  80:  

  81:                 // send request and wait for it to complete

  82:                 Send (state, request);

  83:                 state.Done.WaitOne (5000, false);

  84:                 state.Done.Reset ();

  85:  

  86:                 // get the response

  87:                 StartReceive (state);

  88:                 state.Done.WaitOne ();

  89:  

  90:                 // convert the response bytes

  91:                 response = state.Data.ToString ();

  92:  

  93:                 // check for HTTP header end

  94:                 if (-1 == (hdrLen = response.IndexOf ("\r\n\r\n")))

  95:                     return null;

  96:  

  97:                 // parse out header data

  98:                 data = response.Substring (0, hdrLen).Replace ("\r\n", "\n").Split ('\n');

  99:                 if (null == data || 0 == data.Length)

 100:                     return null;

 101:  

 102:                 // get response status code

 103:                 parts = data [0].Split (' ');

 104:                 status = Int32.Parse (parts [1]);

 105:                 if (200 != status)

 106:                     return null;

 107:  

 108:                 // turn header array collection into a collection

 109:                 headers = new Dictionary<string, string> ();

 110:                 foreach (string hdr in data)

 111:                 {

 112:                     if (-1 == (pos = hdr.IndexOf (' ')))

 113:                         continue;

 114:                     if (hdr.StartsWith ("HTTP"))

 115:                         continue;

 116:                     headers.Add (hdr.Substring (0, pos), hdr.Substring (pos + 1));

 117:                 }

 118:  

 119:                 return response.Substring (hdrLen + 4);

 120:             }

 121:             catch

 122:             {

 123:                 return null;

 124:             }

 125:             finally

 126:             {

 127:                 // close the connection

 128:                 if (null != sock && sock.Connected)

 129:                 {

 130:                     sock.Disconnect (false);

 131:                     sock.Close ();

 132:                 }

 133:             }

 134:         }

 135:  

 136:         /// <summary>

 137:         /// Sends string data over the socket.

 138:         /// </summary>

 139:         /// <param name="client"></param>

 140:         /// <param name="data"></param>

 141:         private static void Send (SocketState state, string data)

 142:         {

 143:             // Convert the string data to byte data using ASCII encoding.

 144:             byte [] byteData = Encoding.ASCII.GetBytes (data);

 145:  

 146:             // Begin sending the data to the remote device.

 147:             state.Socket.BeginSend (byteData, 0, byteData.Length, 0,

 148:                 new AsyncCallback (SendCallback), state);

 149:         }

 150:  

 151:         /// <summary>

 152:         /// Send data callback.

 153:         /// </summary>

 154:         /// <param name="ar"></param>

 155:         private static void SendCallback (IAsyncResult ar)

 156:         {

 157:             SocketState    state        = null;

 158:             Socket        client        = null;

 159:  

 160:             try

 161:             {

 162:                 // Retrieve the socket from the state object.

 163:                 state = ar.AsyncState as SocketState;

 164:                 client = state.Socket;

 165:  

 166:                 // Complete sending the data to the remote device.

 167:                 client.EndSend (ar);

 168:  

 169:                 // Signal that all bytes have been sent.

 170:                 state.Done.Set ();

 171:             }

 172:             catch

 173:             { }

 174:         }

 175:  

 176:         /// <summary>

 177:         /// Main receive thread entry point

 178:         /// </summary>

 179:         /// <param name="stateInfo"></param>

 180:         private static void StartReceive (SocketState state)

 181:         {

 182:             if (null == state)

 183:                 return;

 184:  

 185:             state.Socket.BeginReceive (

 186:                   state.ReadBuffer,

 187:                   0,

 188:                   state.ReadBuffer.Length,

 189:                   SocketFlags.None,

 190:                   new AsyncCallback (OnReceiveData),

 191:                   state

 192:             );

 193:         }

 194:  

 195:         /// <summary>

 196:         /// Receive data callback.

 197:         /// </summary>

 198:         /// <param name="stateInfo"></param>

 199:         private static void OnReceiveData (IAsyncResult result)

 200:         {

 201:             SocketState        state        = null;

 202:             Socket            sock        = null;

 203:             int                read        = 0;

 204:  

 205:             if (null == result)

 206:                 return;

 207:  

 208:             if (null == (state = result.AsyncState as SocketState))

 209:                 return;

 210:  

 211:             // get socket

 212:             sock = state.Socket;

 213:  

 214:             // end the read

 215:             if (0 != (read = sock.EndReceive (result)))

 216:             {

 217:                 state.Data.Append (Encoding.ASCII.GetString (state.ReadBuffer, 0, read));

 218:  

 219:                 // start another read

 220:                 sock.BeginReceive (

 221:                        state.ReadBuffer,

 222:                        0,

 223:                        state.ReadBuffer.Length,

 224:                        SocketFlags.None,

 225:                        new AsyncCallback (OnReceiveData),

 226:                        state

 227:                 );

 228:             }

 229:             else

 230:             {

 231:                 if (state.Data.Length > 0)

 232:                 {

 233:                     state.Socket.Close ();

 234:                     state.Done.Set ();

 235:                 }

 236:             }

 237:         }

 238:     }

 239:  

 240:     /// <summary>

 241:     /// SocketState class

 242:     /// 

 243:     /// Used to track an async TCP/IP data, and maintain all data received over the async operation.

 244:     /// </summary>

 245:     internal class SocketState

 246:     {

 247:         /// <summary>

 248:         /// Constructor

 249:         /// </summary>

 250:         public SocketState ()

 251:         {

 252:             Socket        = null;

 253:             ReadBuffer    = new byte [BUFFER_SIZE];

 254:             Data        = new StringBuilder ();

 255:             Done        = new ManualResetEvent (false);

 256:         }

 257:  

 258:         /// <summary>

 259:         /// Constructor

 260:         /// </summary>

 261:         /// <param name="socket"></param>

 262:         public SocketState (Socket socket)

 263:             : this ()

 264:         {

 265:             Socket = socket;

 266:         }

 267:  

 268:         /// <summary>

 269:         /// TCP/IP socket.

 270:         /// </summary>

 271:         public Socket Socket = null;

 272:  

 273:         /// <summary>

 274:         /// Size of download buffer.

 275:         /// </summary>

 276:         public const int BUFFER_SIZE = 1024;

 277:  

 278:         /// <summary>

 279:         /// Download buffer.

 280:         /// </summary>

 281:         public byte [] ReadBuffer;

 282:  

 283:         /// <summary>

 284:         /// Downloaded data converted to a string builder.

 285:         /// </summary>

 286:         public StringBuilder Data;

 287:  

 288:         /// <summary>

 289:         /// Reset event for synchronization.

 290:         /// </summary>

 291:         public ManualResetEvent Done;

 292:     }

 293: }