I am using Lucene.Net for Searching and wanted to know how I can handle this threading issue.
I have a single instance of class Test, but the searcher is not threadsafe in this case, since the timer thread can update the index at the same time the request is served, and I do see exception due to that. Any pointers on how to make it thread safe.
public class Test
{
private static object syncObj = new object();
private System.Threading.Timer timer;
private Searcher searcher;
private RAMDirectory idx = new RAMDirectory();
public Test()
{
this.timer = new System.Threading.Timer(this.Timer_Elapsed, null, TimeSpan.Zero, TimeSpan.FromMinutes(3));
}
private Searcher ESearcher
{
get
{
return this.searcher;
}
set
{
lock (syncObj)
{
this.searcher = value;
}
}
}
public Document CreateDocument(string title, string content)
{
Document doc = new Document();
doc.Add(new Field("A", title, Field.Store.YES, Field.Index.NO));
doc.Add(new Field("B", content, Field.Store.YES, Field.Index.ANALYZED));
return doc;
}
public List<Document> Search(Searcher searcher, string queryString)
{
List<Document> documents = new List<Document>();
QueryParser parser = new QueryParser(Lucene.Net.Util.Version.LUCENE_30, "B", new StandardAnalyzer(Lucene.Net.Util.Version.LUCENE_30));
Query query = parser.Parse(queryString);
int hitsPerPage = 5;
TopScoreDocCollector collector = TopScoreDocCollector.Create(2 * hitsPerPage, true);
this.ESearcher.Search(query, collector);
ScoreDoc[] hits = collector.TopDocs().ScoreDocs;
int hitCount = collector.TotalHits > 10 ? 10 : collector.TotalHits;
for (int i = 0; i < hitCount; i++)
{
ScoreDoc scoreDoc = hits[i];
int docId = scoreDoc.Doc;
float docScore = scoreDoc.Score;
Document doc = searcher.Doc(docId);
documents.Add(doc);
}
return documents;
}
private void Timer_Elapsed(object sender)
{
this.Log("Started Updating the Search Indexing");
// Get New data to Index
using (IndexWriter writer = new IndexWriter(this.idx, new StandardAnalyzer(Lucene.Net.Util.Version.LUCENE_30), true, IndexWriter.MaxFieldLength.LIMITED))
{
foreach (var e in es)
{
writer.AddDocument(this.CreateDocument(e.Value.ToString(), e.Key));
}
writer.Optimize();
}
this.ESearcher = new IndexSearcher(this.idx);
this.Log("Completed Updating the Search Indexing");
}
public Result ServeRequest()
{
var documents = this.Search(this.EntitySearcher, searchTerm);
//somelogic
return result;
}
}
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