beagled/QueryExecutor.cs

   1 //
   2 // QueryExecutor.cs
   3 //
   4 // Copyright (C) 2005 Novell, Inc.
   5 //
   6
   7 //
   8 // Permission is hereby granted, free of charge, to any person obtaining a
   9 // copy of this software and associated documentation files (the "Software"),
  10 // to deal in the Software without restriction, including without limitation
  11 // the rights to use, copy, modify, merge, publish, distribute, sublicense,
  12 // and/or sell copies of the Software, and to permit persons to whom the
  13 // Software is furnished to do so, subject to the following conditions:
  14 //
  15 // The above copyright notice and this permission notice shall be included in
  16 // all copies or substantial portions of the Software.
  17 //
  18 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  19 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  21 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  22 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  23 // FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  24 // DEALINGS IN THE SOFTWARE.
  25 //
  26
  27 using System;
  28 using System.Collections;
  29 using System.Xml.Serialization;
  30
  31 using Beagle.Util;
  32
  33 namespace Beagle.Daemon {
  34
  35         [RequestMessage (typeof (Query))]
  36         public class QueryExecutor : RequestMessageExecutor {
  37
  38                 private Query query;
  39                 private QueryResult result;
  40
  41                 private void DisconnectResult ()
  42                 {
  43                         this.result.HitsAddedEvent -= OnResultHitsAdded;
  44                         this.result.HitsSubtractedEvent -= OnResultHitsSubtracted;
  45                         this.result.FinishedEvent -= OnResultFinished;
  46
  47                         this.result.Cancel ();
  48                         this.result.Dispose ();
  49                 }
  50
  51                 private void AttachResult ()
  52                 {
  53                         this.result.HitsAddedEvent += OnResultHitsAdded;
  54                         this.result.HitsSubtractedEvent += OnResultHitsSubtracted;
  55                         this.result.FinishedEvent += OnResultFinished;
  56                 }
  57
  58                 public void OnResultHitsAdded (QueryResult result, ICollection some_hits)
  59                 {
  60                         HitsAddedResponse response = new HitsAddedResponse (some_hits);
  61
  62                         this.SendAsyncResponse (response);
  63                 }
  64
  65                 public void OnResultHitsSubtracted (QueryResult result, ICollection some_uris)
  66                 {
  67                         HitsSubtractedResponse response = new HitsSubtractedResponse (some_uris);
  68
  69                         this.SendAsyncResponse (response);
  70                 }
  71
  72                 public void OnResultFinished (QueryResult result)
  73                 {
  74                         this.SendAsyncResponse (new FinishedResponse ());
  75                 }
  76
  77                 private void OnQueryDriverChanged (Queryable queryable, IQueryableChangeData change_data)
  78                 {
  79                         if (this.result != null)
  80                                 QueryDriver.DoOneQuery (queryable, this.query, this.result, change_data);
  81                 }
  82
  83                 public override ResponseMessage Execute (RequestMessage req)
  84                 {
  85                         this.query = (Query) req;
  86
  87                         this.result = new QueryResult ();
  88                         this.result.IsIndexListener = this.query.IsIndexListener;
  89                         AttachResult ();
  90
  91                         QueryDriver.ChangedEvent += OnQueryDriverChanged;
  92                         QueryDriver.DoQuery (query,
  93                                              this.result,
  94                                              new RequestMessageExecutor.AsyncResponse (this.SendAsyncResponse));
  95
  96                         // Don't send a response; we'll be sending them async
  97                         return null;
  98                 }
  99
 100                 public override void Cleanup ()
 101                 {
 102                         QueryDriver.ChangedEvent -= OnQueryDriverChanged;
 103                         DisconnectResult ();
 104                 }
 105         }
 106 }