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# include/xapian/enquire.h

Go to the documentation of this file.

    00001
    00004 /* Copyright 1999,2000,2001 BrightStation PLC
    00005  * Copyright 2001,2002 Ananova Ltd
    00006  * Copyright 2002,2003,2004,2005,2006,2007 Olly Betts
    00007  *
    00008  * This program is free software; you can redistribute it and/or
    00009  * modify it under the terms of the GNU General Public License as
    00010  * published by the Free Software Foundation; either version 2 of the
    00011  * License, or (at your option) any later version.
    00012  *
    00013  * This program is distributed in the hope that it will be useful,
    00014  * but WITHOUT ANY WARRANTY; without even the implied warranty of
    00015  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    00016  * GNU General Public License for more details.
    00017  *
    00018  * You should have received a copy of the GNU General Public License
    00019  * along with this program; if not, write to the Free Software
    00020  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301
    00021  * USA
    00022  */
    00023
    00024 #ifndef XAPIAN_INCLUDED_ENQUIRE_H
    00025 #define XAPIAN_INCLUDED_ENQUIRE_H
    00026
    00027 #include <string>
    00028
    00029 #include <xapian/base.h>
    00030 #include <xapian/deprecated.h>
    00031 #include <xapian/types.h>
    00032 #include <xapian/termiterator.h>
    00033 #include <xapian/visibility.h>
    00034
    00035 namespace Xapian {
    00036
    00037 class Database;
    00038 class Document;
    00039 class ErrorHandler;
    00040 class ExpandDecider;
    00041 class MSetIterator;
    00042 class Query;
    00043 class Weight;
    00044
    00048 class XAPIAN_VISIBILITY_DEFAULT MSet {
    00049     public:
    00050         class Internal;
    00052         Xapian::Internal::RefCntPtr<Internal> internal;
    00053
    00055         explicit MSet(MSet::Internal * internal_);
    00056
    00058         MSet();
    00059
    00061         ~MSet();
    00062
    00064         MSet(const MSet & other);
    00065
    00067         void operator=(const MSet &other);
    00068
    00084         void fetch(const MSetIterator &begin, const MSetIterator &end) const;
    00085
    00088         void fetch(const MSetIterator &item) const;
    00089
    00092         void fetch() const;
    00093
    00098         Xapian::percent convert_to_percent(Xapian::weight wt) const;
    00099
    00101         Xapian::percent convert_to_percent(const MSetIterator &it) const;
    00102
    00110         Xapian::doccount get_termfreq(const std::string &tname) const;
    00111
    00119         Xapian::weight get_termweight(const std::string &tname) const;
    00120
    00128         Xapian::doccount get_firstitem() const;
    00129
    00139         Xapian::doccount get_matches_lower_bound() const;
    00140
    00153         Xapian::doccount get_matches_estimated() const;
    00154
    00164         Xapian::doccount get_matches_upper_bound() const;
    00165
    00171         Xapian::weight get_max_possible() const;
    00172
    00186         Xapian::weight get_max_attained() const;
    00187
    00189         Xapian::doccount size() const;
    00190
    00192         Xapian::doccount max_size() const { return size(); }
    00193
    00195         bool empty() const;
    00196
    00198         void swap(MSet & other);
    00199
    00201         MSetIterator begin() const;
    00202
    00204         MSetIterator end() const;
    00205
    00207         MSetIterator back() const;
    00208
    00218         MSetIterator operator[](Xapian::doccount i) const;
    00219
    00221
    00222         typedef MSetIterator value_type; // FIXME: not assignable...
    00223         typedef MSetIterator iterator;
    00224         typedef MSetIterator const_iterator;
    00225         typedef MSetIterator & reference; // Hmm
    00226         typedef MSetIterator & const_reference;
    00227         typedef MSetIterator * pointer; // Hmm
    00228         typedef Xapian::doccount_diff difference_type;
    00229         typedef Xapian::doccount size_type;
    00231
    00235         std::string get_description() const;
    00236 };
    00237
    00241 class XAPIAN_VISIBILITY_DEFAULT MSetIterator {
    00242     private:
    00243         friend class MSet;
    00244         friend bool operator==(const MSetIterator &a, const MSetIterator &b);
    00245         friend bool operator!=(const MSetIterator &a, const MSetIterator &b);
    00246
    00247         MSetIterator(Xapian::doccount index_, const MSet & mset_)
    00248             : index(index_), mset(mset_) { }
    00249
    00250         Xapian::doccount index;
    00251         MSet mset;
    00252
    00253     public:
    00257         MSetIterator() : index(0), mset() { }
    00258
    00259         ~MSetIterator() { }
    00260
    00262         MSetIterator(const MSetIterator &other) {
    00263             index = other.index;
    00264             mset = other.mset;
    00265         }
    00266
    00268         void operator=(const MSetIterator &other) {
    00269             index = other.index;
    00270             mset = other.mset;
    00271         }
    00272
    00274         MSetIterator & operator++() {
    00275             ++index;
    00276             return *this;
    00277         }
    00278
    00280         MSetIterator operator++(int) {
    00281             MSetIterator tmp = *this;
    00282             ++index;
    00283             return tmp;
    00284         }
    00285
    00287         MSetIterator & operator--() {
    00288             --index;
    00289             return *this;
    00290         }
    00291
    00293         MSetIterator operator--(int) {
    00294             MSetIterator tmp = *this;
    00295             --index;
    00296             return tmp;
    00297         }
    00298
    00300         Xapian::docid operator*() const;
    00301
    00318         Xapian::Document get_document() const;
    00319
    00326         Xapian::doccount get_rank() const {
    00327             return mset.get_firstitem() + index;
    00328         }
    00329
    00331         Xapian::weight get_weight() const;
    00332
    00335         std::string get_collapse_key() const;
    00336
    00353         Xapian::doccount get_collapse_count() const;
    00354
    00360         Xapian::percent get_percent() const;
    00361
    00365         std::string get_description() const;
    00366
    00368
    00369         typedef std::bidirectional_iterator_tag iterator_category; // FIXME: could enhance to be a randomaccess_iterator
    00370         typedef Xapian::docid value_type;
    00371         typedef Xapian::doccount_diff difference_type;
    00372         typedef Xapian::docid * pointer;
    00373         typedef Xapian::docid & reference;
    00375 };
    00376
    00377 inline bool operator==(const MSetIterator &a, const MSetIterator &b)
    00378 {
    00379     return (a.index == b.index);
    00380 }
    00381
    00382 inline bool operator!=(const MSetIterator &a, const MSetIterator &b)
    00383 {
    00384     return (a.index != b.index);
    00385 }
    00386
    00387 class ESetIterator;
    00388
    00393 class XAPIAN_VISIBILITY_DEFAULT ESet {
    00394     public:
    00395         class Internal;
    00397         Xapian::Internal::RefCntPtr<Internal> internal;
    00398
    00400         ESet();
    00401
    00403         ~ESet();
    00404
    00406         ESet(const ESet & other);
    00407
    00409         void operator=(const ESet &other);
    00410
    00415         Xapian::termcount get_ebound() const;
    00416
    00418         Xapian::termcount size() const;
    00419
    00421         Xapian::termcount max_size() const { return size(); }
    00422
    00424         bool empty() const;
    00425
    00427         void swap(ESet & other);
    00428
    00430         ESetIterator begin() const;
    00431
    00433         ESetIterator end() const;
    00434
    00436         ESetIterator back() const;
    00437
    00439         ESetIterator operator[](Xapian::termcount i) const;
    00440
    00445         std::string get_description() const;
    00446 };
    00447
    00449 class XAPIAN_VISIBILITY_DEFAULT ESetIterator {
    00450     private:
    00451         friend class ESet;
    00452         friend bool operator==(const ESetIterator &a, const ESetIterator &b);
    00453         friend bool operator!=(const ESetIterator &a, const ESetIterator &b);
    00454
    00455         ESetIterator(Xapian::termcount index_, const ESet & eset_)
    00456             : index(index_), eset(eset_) { }
    00457
    00458         Xapian::termcount index;
    00459         ESet eset;
    00460
    00461     public:
    00465         ESetIterator() : index(0), eset() { }
    00466
    00467         ~ESetIterator() { }
    00468
    00470         ESetIterator(const ESetIterator &other) {
    00471             index = other.index;
    00472             eset = other.eset;
    00473         }
    00474
    00476         void operator=(const ESetIterator &other) {
    00477             index = other.index;
    00478             eset = other.eset;
    00479         }
    00480
    00482         ESetIterator & operator++() {
    00483             ++index;
    00484             return *this;
    00485         }
    00486
    00488         ESetIterator operator++(int) {
    00489             ESetIterator tmp = *this;
    00490             ++index;
    00491             return tmp;
    00492         }
    00493
    00495         ESetIterator & operator--() {
    00496             --index;
    00497             return *this;
    00498         }
    00499
    00501         ESetIterator operator--(int) {
    00502             ESetIterator tmp = *this;
    00503             --index;
    00504             return tmp;
    00505         }
    00506
    00508         const std::string & operator *() const;
    00509
    00511         Xapian::weight get_weight() const;
    00512
    00516         std::string get_description() const;
    00517
    00519
    00520         typedef std::bidirectional_iterator_tag iterator_category; // FIXME: go for randomaccess_iterator!
    00521         typedef std::string value_type;
    00522         typedef Xapian::termcount_diff difference_type;
    00523         typedef std::string * pointer;
    00524         typedef std::string & reference;
    00526 };
    00527
    00528 inline bool operator==(const ESetIterator &a, const ESetIterator &b)
    00529 {
    00530     return (a.index == b.index);
    00531 }
    00532
    00533 inline bool operator!=(const ESetIterator &a, const ESetIterator &b)
    00534 {
    00535     return (a.index != b.index);
    00536 }
    00537
    00542 class XAPIAN_VISIBILITY_DEFAULT RSet {
    00543     public:
    00545         class Internal;
    00546
    00548         Xapian::Internal::RefCntPtr<Internal> internal;
    00549
    00551         RSet(const RSet &rset);
    00552
    00554         void operator=(const RSet &rset);
    00555
    00557         RSet();
    00558
    00560         ~RSet();
    00561
    00563         Xapian::doccount size() const;
    00564
    00566         bool empty() const;
    00567
    00569         void add_document(Xapian::docid did);
    00570
    00572         void add_document(const Xapian::MSetIterator & i) { add_document(*i); }
    00573
    00575         void remove_document(Xapian::docid did);
    00576
    00578         void remove_document(const Xapian::MSetIterator & i) { remove_document(*i); }
    00579
    00581         bool contains(Xapian::docid did) const;
    00582
    00584         bool contains(const Xapian::MSetIterator & i) const { return contains(*i); }
    00585
    00590         std::string get_description() const;
    00591 };
    00592
    00595 class XAPIAN_VISIBILITY_DEFAULT MatchDecider {
    00596     public:
    00602         virtual bool operator()(const Xapian::Document &doc) const = 0;
    00603
    00605         virtual ~MatchDecider();
    00606 };
    00607
    00618 class XAPIAN_VISIBILITY_DEFAULT Enquire {
    00619     private:
    00621         Enquire(const Enquire &);
    00622
    00624         void operator=(const Enquire &);
    00625
    00626     public:
    00627         class Internal;
    00629         Xapian::Internal::RefCntPtr<Internal> internal;
    00630
    00655         explicit Enquire(const Database &database, ErrorHandler * errorhandler_ = 0);
    00656
    00659         ~Enquire();
    00660
    00667         void set_query(const Xapian::Query & query, Xapian::termcount qlen = 0);
    00668
    00675         const Xapian::Query & get_query() const;
    00676
    00683         void set_weighting_scheme(const Weight &weight_);
    00684
    00711         void set_collapse_key(Xapian::valueno collapse_key);
    00712
    00713         typedef enum {
    00714             ASCENDING = 1,
    00715             DESCENDING = 0,
    00716             DONT_CARE = 2
    00717         } docid_order;
    00718
    00742         void set_docid_order(docid_order order);
    00743
    00762         void set_cutoff(Xapian::percent percent_cutoff, Xapian::weight weight_cutoff = 0);
    00763
    00768         void set_sort_by_relevance();
    00769
    00782         void set_sort_by_value(Xapian::valueno sort_key, bool ascending = true);
    00783
    00797         void set_sort_by_value_then_relevance(Xapian::valueno sort_key,
    00798                                               bool ascending = true);
    00799
    00819         void set_sort_by_relevance_then_value(Xapian::valueno sort_key,
    00820                                               bool ascending = true);
    00821
    00854         MSet get_mset(Xapian::doccount first, Xapian::doccount maxitems,
    00855                       Xapian::doccount checkatleast = 0,
    00856                       const RSet * omrset = 0,
    00857                       const MatchDecider * mdecider = 0) const;
    00858         MSet get_mset(Xapian::doccount first, Xapian::doccount maxitems,
    00859                       Xapian::doccount checkatleast,
    00860                       const RSet * omrset,
    00861                       const MatchDecider * mdecider,
    00862                       const MatchDecider * matchspy) const;
    00863         MSet get_mset(Xapian::doccount first, Xapian::doccount maxitems,
    00864                       const RSet * omrset,
    00865                       const MatchDecider * mdecider = 0) const {
    00866             return get_mset(first, maxitems, 0, omrset, mdecider);
    00867         }
    00868
    00869         static const int INCLUDE_QUERY_TERMS = 1;
    00870         static const int USE_EXACT_TERMFREQ = 2;
    00871 #ifndef _MSC_VER
    00873         XAPIAN_DEPRECATED(static const int include_query_terms) = 1;
    00875         XAPIAN_DEPRECATED(static const int use_exact_termfreq) = 2;
    00876 #else
    00877         // Work around MSVC stupidity (you get a warning for deprecating a
    00878         // declaration).
    00879         static const int include_query_terms = 1;
    00880         static const int use_exact_termfreq = 2;
    00881 #pragma deprecated("Xapian::Enquire::include_query_terms", "Xapian::Enquire::use_exact_termfreq")
    00882 #endif
    00883
    00906         ESet get_eset(Xapian::termcount maxitems,
    00907                         const RSet & omrset,
    00908                         int flags = 0,
    00909                         double k = 1.0,
    00910                         const Xapian::ExpandDecider * edecider = 0) const;
    00911
    00925         inline ESet get_eset(Xapian::termcount maxitems, const RSet & omrset,
    00926                                const Xapian::ExpandDecider * edecider) const {
    00927             return get_eset(maxitems, omrset, 0, 1.0, edecider);
    00928         }
    00929
    00958         TermIterator get_matching_terms_begin(Xapian::docid did) const;
    00959
    00961         TermIterator get_matching_terms_end(Xapian::docid /*did*/) const {
    00962             return TermIterator(NULL);
    00963         }
    00964
    00987         TermIterator get_matching_terms_begin(const MSetIterator &it) const;
    00988
    00990         TermIterator get_matching_terms_end(const MSetIterator &/*it*/) const {
    00991             return TermIterator(NULL);
    00992         }
    00993
    01006         XAPIAN_DEPRECATED(
    01007         void register_match_decider(const std::string &name,
    01008                                     const MatchDecider *mdecider = NULL));
    01009
    01013         std::string get_description() const;
    01014 };
    01015
    01016 }
    01017
    01018 class RemoteServer;
    01019
    01020 namespace Xapian {
    01021
    01023 class XAPIAN_VISIBILITY_DEFAULT Weight {
    01024     friend class Enquire; // So Enquire can clone us
    01025     friend class ::RemoteServer; // So RemoteServer can clone us - FIXME
    01026     public:
    01027         class Internal;
    01028     protected:
    01029         Weight(const Weight &);
    01030     private:
    01031         void operator=(Weight &);
    01032
    01042         virtual Weight * clone() const = 0;
    01043
    01044     protected:
    01045         const Internal * internal; // Weight::Internal == StatsSource
    01046         Xapian::doclength querysize;
    01047         Xapian::termcount wqf;
    01048         std::string tname;
    01049
    01050     public:
    01051         Weight() { }
    01052         virtual ~Weight();
    01053
    01066         Weight * create(const Internal * internal_, Xapian::doclength querysize_,
    01067                         Xapian::termcount wqf_, const std::string & tname_) const;
    01068
    01073         virtual std::string name() const = 0;
    01074
    01076         virtual std::string serialise() const = 0;
    01077
    01079         virtual Weight * unserialise(const std::string &s) const = 0;
    01080
    01088         virtual Xapian::weight get_sumpart(Xapian::termcount wdf,
    01089                                       Xapian::doclength len) const = 0;
    01090
    01096         virtual Xapian::weight get_maxpart() const = 0;
    01097
    01106         virtual Xapian::weight get_sumextra(Xapian::doclength len) const = 0;
    01107
    01111         virtual Xapian::weight get_maxextra() const = 0;
    01112
    01114         virtual bool get_sumpart_needs_doclength() const; /* { return true; } */
    01115 };
    01116
    01118 class XAPIAN_VISIBILITY_DEFAULT BoolWeight : public Weight {
    01119     public:
    01120         BoolWeight * clone() const;
    01121         BoolWeight() { }
    01122         ~BoolWeight();
    01123         std::string name() const;
    01124         std::string serialise() const;
    01125         BoolWeight * unserialise(const std::string & s) const;
    01126         Xapian::weight get_sumpart(Xapian::termcount wdf, Xapian::doclength len) const;
    01127         Xapian::weight get_maxpart() const;
    01128
    01129         Xapian::weight get_sumextra(Xapian::doclength len) const;
    01130         Xapian::weight get_maxextra() const;
    01131
    01132         bool get_sumpart_needs_doclength() const;
    01133 };
    01134
    01147 class XAPIAN_VISIBILITY_DEFAULT BM25Weight : public Weight {
    01148     private:
    01149         mutable Xapian::weight termweight;
    01150         mutable Xapian::doclength lenpart;
    01151
    01152         double k1, k2, k3, b;
    01153         Xapian::doclength min_normlen;
    01154
    01155         mutable bool weight_calculated;
    01156
    01157         void calc_termweight() const;
    01158
    01159     public:
    01178         BM25Weight(double k1_, double k2_, double k3_, double b_,
    01179                    double min_normlen_)
    01180                 : k1(k1_), k2(k2_), k3(k3_), b(b_), min_normlen(min_normlen_),
    01181                   weight_calculated(false)
    01182         {
    01183             if (k1 < 0) k1 = 0;
    01184             if (k2 < 0) k2 = 0;
    01185             if (k3 < 0) k3 = 0;
    01186             if (b < 0) b = 0; else if (b > 1) b = 1;
    01187         }
    01188         BM25Weight() : k1(1), k2(0), k3(1), b(0.5), min_normlen(0.5),
    01189                        weight_calculated(false) { }
    01190
    01191         BM25Weight * clone() const;
    01192         ~BM25Weight() { }
    01193         std::string name() const;
    01194         std::string serialise() const;
    01195         BM25Weight * unserialise(const std::string & s) const;
    01196         Xapian::weight get_sumpart(Xapian::termcount wdf, Xapian::doclength len) const;
    01197         Xapian::weight get_maxpart() const;
    01198
    01199         Xapian::weight get_sumextra(Xapian::doclength len) const;
    01200         Xapian::weight get_maxextra() const;
    01201
    01202         bool get_sumpart_needs_doclength() const;
    01203 };
    01204
    01222 class XAPIAN_VISIBILITY_DEFAULT TradWeight : public Weight {
    01223     private:
    01224         mutable Xapian::weight termweight;
    01225         mutable Xapian::doclength lenpart;
    01226
    01227         double param_k;
    01228
    01229         mutable bool weight_calculated;
    01230
    01231         void calc_termweight() const;
    01232
    01233     public:
    01241         explicit TradWeight(double k) : param_k(k), weight_calculated(false) {
    01242             if (param_k < 0) param_k = 0;
    01243         }
    01244
    01245         TradWeight() : param_k(1.0), weight_calculated(false) { }
    01246
    01247         TradWeight * clone() const;
    01248         ~TradWeight() { }
    01249         std::string name() const;
    01250         std::string serialise() const;
    01251         TradWeight * unserialise(const std::string & s) const;
    01252
    01253         Xapian::weight get_sumpart(Xapian::termcount wdf, Xapian::doclength len) const;
    01254         Xapian::weight get_maxpart() const;
    01255
    01256         Xapian::weight get_sumextra(Xapian::doclength len) const;
    01257         Xapian::weight get_maxextra() const;
    01258
    01259         bool get_sumpart_needs_doclength() const;
    01260 };
    01261
    01262 }
    01263
    01264 #endif /* XAPIAN_INCLUDED_ENQUIRE_H */