Example #1
0
        public static QueryPostfixForm ParseQuery(string query)
        {
            Initialize();
            _query = query.Trim().ToLower();

            QueryPostfixForm form;

            try
            {
                QueryParserNode nodeRoot = ParseExpression();
                QueryParserNode newRoot  = null;

                PropagateSectionOpInside(ref newRoot, nodeRoot);
                if (newRoot == null)
                {
                    newRoot = nodeRoot;
                }

                form = new QueryPostfixForm();
                Tree2Postfix(newRoot, form);
            }
            catch (Exception)
            {
                form = null;
            }

            return(form);
        }
Example #2
0
        public static Entry[]  ProcessQuery(QueryPostfixForm postfixForm, TermIndexAccessor termIndex, bool appendIdMappings)
        {
            Stack opStack = new Stack();

            Entry[] result = null;
            Error = ErrorStatus.NoError;
            MappedInstances.Clear();

            if (!appendIdMappings)
            {
                Lexemes.Clear();
                Stopwords.Clear();
            }

            try
            {
                IteratePostfixExpression(postfixForm, termIndex, opStack);

                //-----------------------------------------------------------------
                //  Now only one Entry[] must remain on the top of the stack. It may
                //  be null if no document correspond to the query
                //-----------------------------------------------------------------
                if (opStack.Count != 1)
                {
                    throw new ApplicationException("QueryParser -- Illegal query statement found");
                }

                if (!(opStack.Peek() is StopwordTerm))
                {
                    result = ExtractOperandFromStack(opStack);
                    if (result != null)
                    {
                        Array.Sort(result, new CompareByTfIdf());
                    }
                }
            }
            catch (Exception exc)
            {
                Trace.WriteLine("QueryProcessor -- exception [" + exc.Message + "] occured.");
                //  Exception is raised if the expression was constructed with
                //  the syntactic errors.
                //  Clear the stack and put special marker on the top of it
                Error  = ErrorStatus.IllegalQuerySyntax;
                result = null;
            }
            opStack.Clear();
            return(result);
        }
Example #3
0
        private static void Tree2Postfix(QueryParserNode root, QueryPostfixForm form)
        {
            if (root == null)
            {
                return;
            }

            if (root.NodeType != QueryParserNode.Type.eoTerm)
            {
                foreach (QueryParserNode node in ((OpNode)root).Branches())
                {
                    Tree2Postfix(node, form);
                }
            }
            form.Add(root);
        }
Example #4
0
        public bool MatchQuery(string query, int resId, int dummy)
        {
            #region Preconditions
            if (resId != _lastDocID)
            {
                throw new ArgumentException("MatchQuery (FullTextIndexer) -- Input resource Id does not match internal data");
            }
            #endregion Preconditions

            bool result = false;
            if (isValidQuery(query))
            {
                QueryPostfixForm form = QueryParser.ParseQuery(query);
                if (form != null)
                {
                    result = MatchProcessor.MatchQuery(form, _tokens);
                }
            }
            return(result);
        }
Example #5
0
        public static bool  MatchQuery(QueryPostfixForm postfixForm, IntHashTable tokens)
        {
            Stack <List <long> > opStack = new Stack <List <long> >();
            bool result;

            try
            {
                IteratePostfixExpression(postfixForm, tokens, opStack);
                if (opStack.Count != 1)
                {
                    throw new ApplicationException("QueryParser -- Illegal query statement found");
                }

                result = (opStack.Peek() != null);
            }
            catch (Exception exc)
            {
                Trace.WriteLine("MatchProcessor -- exception [" + exc.Message + "] occured.");
                result = true;
            }

            opStack.Clear();
            return(result);
        }
Example #6
0
        /// <summary>
        /// This public method is designed for simplified processing and is used in tests.
        /// </summary>
        public Entry[]  ProcessQueryInternal(string query)
        {
            Entry[] resultEntries = null;

            if (isValidQuery(query))
            {
                QueryPostfixForm form = QueryParser.ParseQuery(query);
                resultEntries = QueryProcessor.ProcessQuery(form, TermIndexAccessor);

                if (resultEntries != null)
                {
                    ArrayList list = new ArrayList();
                    foreach (Entry e in resultEntries)
                    {
                        if (IsDocumentPresentInternal(e.DocIndex))
                        {
                            list.Add(e);
                        }
                    }
                    resultEntries = (list.Count > 0) ? (Entry[])list.ToArray(typeof(Entry)) : null;
                }
            }
            return(resultEntries);
        }
Example #7
0
        private QueryResult PerformInitialSearch(string query)
        {
            QueryResult qResult = new QueryResult();

            //  perform search only if input query string is of "reasonable" length
            if (isValidQuery(query))
            {
                QueryPostfixForm form = QueryParser.ParseQuery(query);
                if (form != null)
                {
                    qResult.IsSingularTerm = (form.TermNodesCount == 1);
                    qResult.Result         = QueryProcessor.ProcessQuery(form, TermIndexAccessor);
                    if (QueryProcessor.Status == QueryProcessor.ErrorStatus.IllegalSectionName)
                    {
                        qResult.ErrorMessage = "Illegal document section name specified. Please consult help file for valid secion names.";
                    }
                }
                else
                {
                    qResult.ErrorMessage = QueryParser.Error;
                }
            }
            return(qResult);
        }
Example #8
0
 public static Entry[]  ProcessQuery(QueryPostfixForm postfixForm, TermIndexAccessor termIndex)
 {
     return(ProcessQuery(postfixForm, termIndex, false));
 }