Updating Lucene search

nisbus · Feb 28, 2012 · 0064ddb · 0064ddb
1 parent fad5a05
commit 0064ddb
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Showing 2 changed files with 29 additions and 18 deletions.
diff --git a/Website/Infrastructure/Lucene/LuceneIndexingService.cs b/Website/Infrastructure/Lucene/LuceneIndexingService.cs
@@ -107,8 +107,7 @@ private static void AddPackages(IndexWriter indexWriter, List<PackageIndexEntity
                     document.Add(new Field("Tags", package.Tags, Field.Store.NO, Field.Index.ANALYZED));
                 }
                 document.Add(new Field("Author", package.Authors, Field.Store.NO, Field.Index.ANALYZED));
-
-                document.SetBoost(GetNormalizedBoostValue(package.DownloadCount));
+                document.Add(new Field("DownloadCount", package.DownloadCount.ToString(CultureInfo.InvariantCulture), Field.Store.YES, Field.Index.NO));
 
                 indexWriter.AddDocument(document);
             }
@@ -202,10 +201,5 @@ private static IEnumerable<string> CamelCaseTokenize(string term)
             }
             yield return term.Substring(tokenStart);
         }
-
-        private static float GetNormalizedBoostValue(int downloadCount)
-        {
-            return (float)(0.5 + Math.Log(downloadCount, 1000));
-        }
     }
 }
diff --git a/Website/Infrastructure/Lucene/LuceneSearchService.cs b/Website/Infrastructure/Lucene/LuceneSearchService.cs
@@ -6,6 +6,7 @@
 using Lucene.Net.Analysis.Standard;
 using Lucene.Net.QueryParsers;
 using Lucene.Net.Search;
+using Lucene.Net.Index;
 
 namespace NuGetGallery
 {
@@ -74,29 +75,45 @@ private static IEnumerable<int> SearchCore(string searchTerm)
             using (var directory = new LuceneFileSystem(LuceneCommon.IndexDirectory))
             {
                 var searcher = new IndexSearcher(directory, readOnly: true);
-                var query = TryParseQuery(searchTerm);
-                var results = searcher.Search(query, filter: null, n: 1000, sort: Sort.RELEVANCE);
+                var query = ParseQuery(searchTerm);
+                var results = searcher.Search(query, filter: null, n: 1000, sort: new Sort(new[] { SortField.FIELD_SCORE, new SortField("DownloadCount", SortField.INT, reverse: true) }));
                 var keys = results.scoreDocs.Select(c => Int32.Parse(searcher.Doc(c.doc).Get("Key"), CultureInfo.InvariantCulture))
                                             .ToList();
                 searcher.Close();
                 return keys;
             }
         }
 
-        private static Query TryParseQuery(string searchTerm)
+        private static Query ParseQuery(string searchTerm)
         {
-            var boosts = new Dictionary<string, float> { { "Id-Exact", 2.0f }, { "Id", 1.2f }, { "Description", 0.6f } };
+            var fields = new Dictionary<string, float> { { "Id", 1.2f }, { "Title", 1.0f }, { "Tags", 1.0f}, { "Description", 0.8f }, { "Author", 0.6f } };
             var analyzer = new StandardAnalyzer(LuceneCommon.LuceneVersion);
-            var queryParser = new MultiFieldQueryParser(LuceneCommon.LuceneVersion, new[] { "Id-Exact", "Id", "Title", "Author", "Description", "Tags" }, analyzer, boosts);
+            searchTerm = QueryParser.Escape(searchTerm).ToLowerInvariant();
 
-            try
-            {
-                return queryParser.Parse(searchTerm);
-            }
-            catch (ParseException)
+            var queryParser = new MultiFieldQueryParser(LuceneCommon.LuceneVersion, fields.Keys.ToArray(), analyzer, fields);
+
+            var conjuctionQuery = new BooleanQuery();
+            conjuctionQuery.SetBoost(1.5f);
+            var disjunctionQuery = new BooleanQuery();
+            var wildCardQuery = new BooleanQuery();
+            wildCardQuery.SetBoost(0.7f);
+            var exactIdQuery = new TermQuery(new Term("Id-Exact", searchTerm));
+            exactIdQuery.SetBoost(2.5f);
+
+            foreach(var term in searchTerm.Split(new[] { ' ' }, StringSplitOptions.RemoveEmptyEntries))
             {
-                return queryParser.Parse(QueryParser.Escape(searchTerm));
+                conjuctionQuery.Add(queryParser.Parse(term), BooleanClause.Occur.MUST);
+                disjunctionQuery.Add(queryParser.Parse(term), BooleanClause.Occur.SHOULD);
+
+                foreach (var field in fields)
+                {
+                    var wildCardTermQuery = new WildcardQuery(new Term(field.Key, term + "*"));
+                    wildCardTermQuery.SetBoost(0.7f * field.Value);
+                    wildCardQuery.Add(wildCardTermQuery, BooleanClause.Occur.SHOULD);
+                }
             }
+
+            return conjuctionQuery.Combine(new Query[] { exactIdQuery, conjuctionQuery, disjunctionQuery, wildCardQuery });
         }
     }
 }