beagled/WebServices/NetBeagleQueryable.cs

   1 //
   2 // NetBeagleQueryable.cs
   3 //
   4 // Copyright (C) 2005 Novell, Inc.
   5 //
   6 // Authors:
   7 //      Vijay K. Nanjundaswamy (knvijay@novell.com)
   8 //
   9
  10 //
  11 // Permission is hereby granted, free of charge, to any person obtaining a
  12 // copy of this software and associated documentation files (the "Software"),
  13 // to deal in the Software without restriction, including without limitation
  14 // the rights to use, copy, modify, merge, publish, distribute, sublicense,
  15 // and/or sell copies of the Software, and to permit persons to whom the
  16 // Software is furnished to do so, subject to the following conditions:
  17 //
  18 // The above copyright notice and this permission notice shall be included in
  19 // all copies or substantial portions of the Software.
  20 //
  21 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  22 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  23 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  24 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  25 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  26 // FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  27 // DEALINGS IN THE SOFTWARE.
  28 //
  29
  30 using System;
  31 using System.IO;
  32 using System.Timers;
  33 using System.Threading;
  34 using System.Collections;
  35
  36 using Beagle;
  37 using Beagle.Util;
  38
  39 namespace Beagle.Daemon {
  40
  41         [QueryableFlavor (Name="NetworkedBeagle", Domain=QueryDomain.Global, RequireInotify=false)]
  42         public class NetworkedBeagle : IQueryable
  43         {
  44                 static Logger log = Logger.Get ("NetworkedBeagle");
  45             static readonly string NetBeagleConfigFile = "netbeagle.cfg";
  46                 public static readonly string BeagleNetPrefix = "netbeagle://";
  47                 public static bool NetBeagleListActive = false;
  48
  49                 ArrayList NetBeagleList;
  50
  51                 public NetworkedBeagle ()
  52                 {
  53                         NetBeagleList = new ArrayList ();
  54                         NetBeagleListActive = false;
  55                 }
  56
  57 /////////////////////////////////////////////////////////////////////////////////////////
  58                 private static Hashtable requestTable   = Hashtable.Synchronized(new Hashtable());
  59                 private static Hashtable timerTable     = Hashtable.Synchronized(new Hashtable());
  60
  61                 private static int TimerInterval = 15000;       //15 sec timer
  62                 private static int RequestCacheTime = 20;  //Cache requests for 5 minutes
  63
  64                 private static System.Timers.Timer cTimer = null;
  65
  66                 static NetworkedBeagle () {
  67                         cTimer = new System.Timers.Timer(TimerInterval);
  68                         cTimer.Elapsed += new ElapsedEventHandler(TimerEventHandler);
  69                         cTimer.AutoReset = true;
  70                         cTimer.Enabled = false;
  71                 }
  72
  73                 ~NetworkedBeagle()
  74                 {
  75                         cTimer.Close();
  76                 }
  77 /////////////////////////////////////////////////////////////////////////////////////////
  78                 public string Name {
  79                         get { return "NetworkedBeagle"; }
  80                 }
  81
  82                 public void Start ()
  83                 {
  84                         SetupNetBeagleList ();
  85                         Conf.Subscribe (typeof (Conf.NetworkingConfig), new Conf.ConfigUpdateHandler (NetBeagleConfigurationChanged));
  86                 }
  87
  88                 void SetupNetBeagleList ()
  89                 {
  90                         //First check for ~/.beagle/config/networking.xml configuration
  91                         ArrayList NetBeagleNodes = Conf.Networking.NetBeagleNodes;
  92
  93                         if ((NetBeagleNodes != null) && (NetBeagleNodes.Count > 0)) {
  94
  95                                         foreach (string nb in NetBeagleNodes) {
  96                                                 if (nb == null || nb == "")
  97                                                         continue;
  98                                                 string[] data = nb.Split (':');
  99                                                 if (data.Length < 2) {
 100                                                         log.Warn("NetBeagleQueryable: Ignoring improper NetBeagle entry: {0}", nb);
 101                                                         continue;
 102                                                 }
 103                                                 string host = data[0];
 104                                                 string port = data[1];
 105                                                 NetBeagleList.Add (new NetBeagleHandler (host, port, this));
 106                                         }
 107
 108                                 if (NetBeagleList.Count > 0) {
 109                                         NetBeagleListActive = true;
 110                                         if (File.Exists (Path.Combine (PathFinder.StorageDir, NetBeagleConfigFile)))
 111                                         {
 112                                                 log.Warn("NetBeagleQueryable: Duplicate configuration of networked Beagles detected!");
 113                                                 log.Info("NetBeagleQueryable: Remove '~/.beagle/netbeagle.cfg' file. Use 'beagle-config' instead to setup networked Beagle nodes.");
 114                                                 log.Info("Using ~/.beagle/config/networking.xml");
 115                                         }
 116                                         return;
 117                                 }
 118                         }
 119
 120                         //Fallback to ~/.beagle/netbeagle.cfg
 121                         if (!File.Exists (Path.Combine (PathFinder.StorageDir, NetBeagleConfigFile)))
 122                                 return;
 123
 124                         StreamReader reader = new StreamReader(Path.Combine
 125                                                                                 (PathFinder.StorageDir, NetBeagleConfigFile));
 126
 127                         string entry;
 128                         while ( ((entry = reader.ReadLine ()) != null) && (entry.Trim().Length > 1)) {
 129
 130                                 if ((entry[0] != '#') && (entry.IndexOf(':') > 0)) {
 131                                         string[] data = entry.Split (':');
 132                                         if (data.Length < 2) {
 133                                                 log.Warn("NetBeagleQueryable: Ignoring improper NetBeagle entry: {0}", entry);
 134                                                 continue;
 135                                         }
 136
 137                                         string host = data[0];
 138                                         string port = data[1];
 139                                         NetBeagleList.Add (new NetBeagleHandler (host, port, this));
 140                                 }
 141                         }
 142
 143                         if (NetBeagleList.Count > 0) {
 144                                 NetBeagleListActive = true;
 145                                 //log.Warn("NetBeagleQueryable: 'netbeagle.cfg' based configuration deprecated.\n Use 'beagle-config' or 'beagle-settings' instead to configure Networked Beagles");
 146                                 log.Warn("NetBeagleQueryable: 'netbeagle.cfg' based configuration deprecated.\n Use 'beagle-config' instead to configure Networked Beagles");
 147                         }
 148                 }
 149
 150                 private void NetBeagleConfigurationChanged (Conf.Section section)
 151                 {
 152                         Logger.Log.Info("NetBeagleConfigurationChanged EventHandler invoked");
 153                         if (! (section is Conf.NetworkingConfig))
 154                                 return;
 155
 156                         Conf.NetworkingConfig nc = (Conf.NetworkingConfig) section;
 157
 158                         //if (nc.NetBeagleNodes.Count == 0)
 159                         //      return;
 160
 161                         ArrayList newList = new ArrayList();
 162                         foreach (string nb in nc.NetBeagleNodes) {
 163                                         if (nb == null || nb == "")
 164                                                 continue;
 165                                         string[] data = nb.Split (':');
 166                                         if (data.Length < 2) {
 167                                                 log.Warn("NetBeagleQueryable: Ignoring improper NetBeagle entry: {0}", nb);
 168                                                 continue;
 169                                         }
 170                                         string host = data[0];
 171                                         string port = data[1];
 172                                         newList.Add (new NetBeagleHandler (host, port, this));
 173                         }
 174
 175                         lock (this) {
 176                                 NetBeagleList = newList;
 177                                 NetBeagleListActive = (newList.Count == 0) ? false:true;
 178                         }
 179                 }
 180
 181                 public bool AcceptQuery (Query query)
 182                 {
 183                     if (query.Text.Count <= 0)
 184                                 return false;
 185
 186                     if (! query.AllowsDomain (QueryDomain.Global))
 187                                 return false;
 188
 189                         return true;
 190                 }
 191
 192                 public string GetSnippet (string[] query_terms, Hit hit)
 193                 {
 194                         string s = "";
 195
 196                         if (hit is NetworkHit)
 197                                 s = ((NetworkHit)hit).snippet;
 198
 199                         return s;
 200                 }
 201 /*
 202                 public int GetItemCount ()
 203                 {
 204                         return -1;
 205                 }
 206 */
 207                 public QueryableStatus GetQueryableStatus ()
 208                 {
 209
 210                         QueryableStatus status = new QueryableStatus ();
 211                         return status;
 212                 }
 213
 214                 public void DoQuery (Query query,IQueryResult result,
 215                                                  IQueryableChangeData changeData)
 216                 {
 217                         if (NetBeagleList.Count == 0)
 218                                 return;
 219
 220                         ArrayList resultHandleList = new ArrayList();
 221                         lock (NetBeagleList) {
 222                                 log.Debug("NetBeagleQueryable: DoQuery ... Starting NetBeagleHandler queries");
 223                                 foreach (NetBeagleHandler nb in NetBeagleList)
 224                                 {
 225                                         IAsyncResult iar = nb.DoQuery (query, result, changeData);
 226                                         resultHandleList.Add (iar);
 227                                 }
 228                         }
 229
 230                         int i = 0;
 231                         foreach (IAsyncResult iar in resultHandleList)
 232                                 while (! ((ReqContext)(iar.AsyncState)).RequestProcessed) {
 233                                                 Thread.Sleep(1000);
 234                                                 if (++i > 20)   //Don't wait more than 20 secs
 235                                                         break;
 236                                 }
 237
 238                         log.Debug("NetBeagleQueryable:DoQuery ... Done");
 239                 }
 240
 241 /////////////////////////////////////////////////////////////////////////////////////////
 242                 //Methods related to checking & caching of networked search requests,
 243                 //to prevent duplicate queries in cascaded network operation
 244
 245                 class TimerHopCount {
 246                         int ttl = 0;
 247                         int hops = 0;
 248
 249                         public TimerHopCount (int h) {
 250                                 this.hops = h;
 251                                 this.ttl = RequestCacheTime;
 252                         }
 253
 254                         public int TTL {
 255                                 get {return ttl;}
 256                                 set {ttl = value;}
 257                         }
 258
 259                         public int Hops {
 260                                 get {return hops;}
 261                                 //set {hops = value;}
 262                         }
 263                 }
 264
 265                 public static int AddRequest(Query q)
 266                 {
 267                         int searchId = 0;
 268                         lock (timerTable) {
 269
 270                                 if (requestTable.Contains(q))
 271                                         return  (int) requestTable[q];
 272
 273                                 searchId = System.Guid.NewGuid().GetHashCode();
 274
 275                                 if (searchId < 0)
 276                                         searchId = -searchId;
 277
 278                                 requestTable.Add(q, searchId);
 279                                 timerTable.Add(q, new TimerHopCount(1));
 280
 281                                 if (!cTimer.Enabled) {
 282                                         cTimer.Start();
 283                                         log.Debug("CachedRequestCleanupTimer started");
 284                                 }
 285                         }
 286
 287                         return searchId;
 288                 }
 289
 290                 public static int HopCount(Query q)
 291                 {
 292                         int hops = -1;
 293
 294                         lock (timerTable)
 295                         {
 296                                 if (timerTable.Contains(q))
 297                                         hops = ((TimerHopCount) timerTable[q]).Hops;
 298                         }
 299
 300                         return hops;
 301                 }
 302
 303                 public static void CacheRequest(Query q, int searchId, int hops)
 304                 {
 305                         lock (timerTable) {
 306
 307                                 if (requestTable.Contains(q)) {
 308                                         requestTable[q] = searchId;
 309                                         timerTable[q] = new TimerHopCount(hops);
 310                                 }
 311                                 else {
 312                                         requestTable.Add(q, searchId);
 313                                         timerTable.Add(q, new TimerHopCount(hops));
 314                                 }
 315
 316                                 if (!cTimer.Enabled) {
 317                                         cTimer.Start();
 318                                         log.Info("CachedRequestCleanupTimer started");
 319                                 }
 320
 321                                 log.Info("CacheRequest: HopCount = " + hops);
 322                         }
 323                 }
 324
 325                 public static bool IsCachedRequest(int searchId)
 326                 {
 327                         bool cached = false;
 328
 329                         lock (timerTable)
 330                                 cached = requestTable.ContainsValue(searchId);
 331
 332                         return cached;
 333                 }
 334
 335                 private static void TimerEventHandler(object source, ElapsedEventArgs e)
 336                 {
 337                         int c = 0;
 338
 339                         ArrayList keys = new ArrayList();
 340                         keys.AddRange(timerTable.Keys);
 341
 342                         foreach (Query q in keys)
 343                 {
 344                         TimerHopCount thc = (TimerHopCount) timerTable[q];
 345                                 c = thc.TTL;
 346                                 if (c > 0)
 347                                         c--;
 348
 349                                 if (c == 0)
 350                                         RemoveRequest(q);
 351                                 else
 352                                         thc.TTL = c;
 353                         }
 354
 355                         if ((c % 4) == 0)               //Log status every 1 minute
 356                                 log.Info("CachedRequestCleanupTimer-EventHandler: requestTable has {0} elements, Last entry count={1}", requestTable.Count, c);
 357
 358                         if (timerTable.Count == 0) {
 359                                 cTimer.Stop();
 360                                 log.Info("Stopping CachedRequestCleanupTimer");
 361                         }
 362                 }
 363
 364                 private static void RemoveRequest(Query q)
 365                 {
 366                         lock (timerTable) {
 367
 368                                 if (requestTable.Contains(q))
 369                                         requestTable.Remove(q);
 370
 371                                 if (timerTable.Contains(q))
 372                                         timerTable.Remove(q);
 373                         }
 374                 }
 375         }
 376 }