private static Query ParseQuery(string searchTerm)
        {
            var fields = new Dictionary<string, float> { { "Id", 1.2f }, { "Title", 1.0f }, { "Tags", 0.8f }, { "Description", 0.1f },
                                                         { "Author", 1.0f } };
            var analyzer = new StandardAnalyzer(LuceneCommon.LuceneVersion);
            var queryParser = new MultiFieldQueryParser(LuceneCommon.LuceneVersion, fields.Keys.ToArray(), analyzer, fields);

            var conjuctionQuery = new BooleanQuery();
            conjuctionQuery.SetBoost(2.0f);
            var disjunctionQuery = new BooleanQuery();
            disjunctionQuery.SetBoost(0.1f);
            var wildCardQuery = new BooleanQuery();
            wildCardQuery.SetBoost(0.5f);

            // Escape the entire term we use for exact searches.
            var escapedSearchTerm = Escape(searchTerm);
            var exactIdQuery = new TermQuery(new Term("Id-Exact", escapedSearchTerm));
            exactIdQuery.SetBoost(2.5f);
            var wildCardIdQuery = new WildcardQuery(new Term("Id-Exact", "*" + escapedSearchTerm + "*"));

            foreach(var term in GetSearchTerms(searchTerm))
            {
                var termQuery = queryParser.Parse(term);
                conjuctionQuery.Add(termQuery, BooleanClause.Occur.MUST);
                disjunctionQuery.Add(termQuery, 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);
                }
            }

            var downloadCountBooster = new FieldScoreQuery("DownloadCount", FieldScoreQuery.Type.INT);
            return new CustomScoreQuery(conjuctionQuery.Combine(new Query[] { exactIdQuery, wildCardIdQuery, conjuctionQuery, disjunctionQuery, wildCardQuery }),
                                       downloadCountBooster);
        }
Esempio n. 2
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        private static Query BuildGeneralQuery(
            bool doExactId,
            string originalSearchText,
            Analyzer analyzer,
            IEnumerable<NuGetSearchTerm> generalTerms, 
            IEnumerable<Query> generalQueries)
        {
            // All terms in the multi-term query appear in at least one of the target fields.
            var conjuctionQuery = new BooleanQuery();
            conjuctionQuery.SetBoost(2.0f);

            // Some terms in the multi-term query appear in at least one of the target fields.
            var disjunctionQuery = new BooleanQuery();
            disjunctionQuery.SetBoost(0.1f);

            // Suffix wildcard search e.g. jquer*
            var wildCardQuery = new BooleanQuery();
            wildCardQuery.SetBoost(0.5f);

            string escapedExactId = originalSearchText.ToLowerInvariant();

            Query exactIdQuery = null;
            Query wildCardIdQuery = null;
            if (doExactId)
            {
                exactIdQuery = new TermQuery(new Term("Id-Exact", escapedExactId));
                exactIdQuery.SetBoost(7.5f);

                wildCardIdQuery = new WildcardQuery(new Term("Id-Exact", "*" + escapedExactId + "*"));
            }

            Query nearlyExactIdQuery = null;
            if (generalTerms.Any())
            {
                string escapedApproximateId = string.Join(" ", generalTerms.Select(c => c.TermOrPhrase));
                nearlyExactIdQuery = AnalysisHelper.GetFieldQuery(analyzer, "Id", escapedApproximateId);
                nearlyExactIdQuery.SetBoost(2.0f);
            }

            foreach (var termQuery in generalQueries)
            {
                conjuctionQuery.Add(termQuery, BooleanClause.Occur.MUST);
                disjunctionQuery.Add(termQuery, BooleanClause.Occur.SHOULD);
            }

            var sanitizedTerms = generalTerms.Select(c => c.TermOrPhrase.ToLowerInvariant());
            foreach (var sanitizedTerm in sanitizedTerms)
            {
                foreach (var field in Fields)
                {
                    var wildCardTermQuery = new WildcardQuery(new Term(field, sanitizedTerm + "*"));
                    wildCardTermQuery.SetBoost(0.7f);
                    wildCardQuery.Add(wildCardTermQuery, BooleanClause.Occur.SHOULD);
                }
            }

            // OR of all the applicable queries
            var queries = new Query[]
            {
                exactIdQuery, wildCardIdQuery, nearlyExactIdQuery, conjuctionQuery, disjunctionQuery, wildCardQuery
            };

            var queriesToCombine = queries.Where(q => !IsDegenerateQuery(q));
            var query = conjuctionQuery.Combine(queriesToCombine.ToArray());
            return query;
        }
        private static Query ParseQuery(SearchFilter searchFilter)
        {
            var fields = new[] { "Id", "Title", "Tags", "Description", "Author" };
            var analyzer = new StandardAnalyzer(LuceneCommon.LuceneVersion);
            var queryParser = new MultiFieldQueryParser(LuceneCommon.LuceneVersion, fields, analyzer);

            // All terms in the multi-term query appear in at least one of the fields.
            var conjuctionQuery = new BooleanQuery();
            conjuctionQuery.SetBoost(2.0f);

            // Some terms in the multi-term query appear in at least one of the fields.
            var disjunctionQuery = new BooleanQuery();
            disjunctionQuery.SetBoost(0.1f);

            // Suffix wildcard search e.g. jquer*
            var wildCardQuery = new BooleanQuery();
            wildCardQuery.SetBoost(0.5f);

            // Escape the entire term we use for exact searches.
            var escapedSearchTerm = Escape(searchFilter.SearchTerm);
            var exactIdQuery = new TermQuery(new Term("Id-Exact", escapedSearchTerm));
            exactIdQuery.SetBoost(2.5f);
            var wildCardIdQuery = new WildcardQuery(new Term("Id-Exact", "*" + escapedSearchTerm + "*"));

            foreach (var term in GetSearchTerms(searchFilter.SearchTerm))
            {
                var termQuery = queryParser.Parse(term);
                conjuctionQuery.Add(termQuery, BooleanClause.Occur.MUST);
                disjunctionQuery.Add(termQuery, BooleanClause.Occur.SHOULD);

                foreach (var field in fields)
                {
                    var wildCardTermQuery = new WildcardQuery(new Term(field, term + "*"));
                    wildCardTermQuery.SetBoost(0.7f);
                    wildCardQuery.Add(wildCardTermQuery, BooleanClause.Occur.SHOULD);
                }
            }

            // Create an OR of all the queries that we have
            var combinedQuery = conjuctionQuery.Combine(new Query[] { exactIdQuery, wildCardIdQuery, conjuctionQuery, disjunctionQuery, wildCardQuery });

            if (searchFilter.SortProperty == SortProperty.Relevance)
            {
                // If searching by relevance, boost scores by download count.
                var downloadCountBooster = new FieldScoreQuery("DownloadCount", FieldScoreQuery.Type.INT);
                return new CustomScoreQuery(combinedQuery, downloadCountBooster);
            }
            return combinedQuery;
        }
        private static Query ParseQuery(string searchTerm)
        {
            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);
            searchTerm = QueryParser.Escape(searchTerm).ToLowerInvariant();

            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))
            {
                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 });
        }