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view rdf/SimpleSPARQLQuery.h @ 670:9e29bf7ce1ff
* Permit user CFLAGS, if given, to override our CXXFLAGS if no user CXXFLAGS is given
author | Chris Cannam |
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date | Tue, 08 Mar 2011 10:21:21 +0000 |
parents | a03aafaacb5a |
children | b4a8d8221eaf |
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/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*- vi:set ts=8 sts=4 sw=4: */ /* Sonic Visualiser An audio file viewer and annotation editor. Centre for Digital Music, Queen Mary, University of London. This file copyright 2008 QMUL. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. See the file COPYING included with this distribution for more information. */ #ifndef _SIMPLE_SPARQL_QUERY_H_ #define _SIMPLE_SPARQL_QUERY_H_ #include <QString> #include <map> #include <vector> class ProgressReporter; class SimpleSPARQLQuery { public: enum ValueType { NoValue, URIValue, LiteralValue, BlankValue }; struct Value { Value() : type(NoValue), value() { } Value(ValueType t, QString v) : type(t), value(v) { } ValueType type; QString value; }; typedef std::map<QString, Value> KeyValueMap; typedef std::vector<KeyValueMap> ResultList; /** * QueryType specifies the context in which the query will be * evaluated. SimpleSPARQLQuery maintains a general global data * model, into which data can be loaded using addSourceToModel(), * as well as permitting one-time queries directly on data sources * identified by URL. * * The query type QueryFromModel indicates a query to be evaluated * over the general global model; the query type * QueryFromSingleSource indicates that the query should be * evaluated in the context of a model generated solely by parsing * the FROM url found in the query. * * Even in QueryFromSingleSource mode, the parsed data remains in * memory and will be reused in subsequent queries with the same * mode and FROM url. To release data loaded in this way once all * queries across it are complete, pass the said FROM url to * closeSingleSource(). */ enum QueryType { QueryFromModel, QueryFromSingleSource }; /** * Construct a query of the given type (indicating the data model * context for the query) using the given SPARQL query content. */ SimpleSPARQLQuery(QueryType type, QString query); ~SimpleSPARQLQuery(); /** * Add the given URI to the general global model used for * QueryFromModel queries. */ static bool addSourceToModel(QString sourceUri); /** * Release any data that has been loaded from the given source as * part of a QueryFromSingleSource query with this source in the * FROM clause. Note this will not prevent any subsequent queries * on the source from working -- it will just make them slower as * the data will need to be re-parsed. */ static void closeSingleSource(QString sourceUri); void setProgressReporter(ProgressReporter *reporter); bool wasCancelled() const; ResultList execute(); bool isOK() const; QString getErrorString() const; /** * Construct and execute a query, and return the first result * value for the given binding. */ static Value singleResultQuery(QueryType type, QString query, QString binding); protected: class Impl; Impl *m_impl; private: SimpleSPARQLQuery(const SimpleSPARQLQuery &); // not provided SimpleSPARQLQuery &operator=(const SimpleSPARQLQuery &); // not provided }; #endif