synonympostlist.h

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/* Copyright 2007,2009 Lemur Consulting Ltd
 * Copyright 2009,2011,2014,2018 Olly Betts
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
 */

#ifndef XAPIAN_INCLUDED_SYNONYMPOSTLIST_H
#define XAPIAN_INCLUDED_SYNONYMPOSTLIST_H

#include "multimatch.h"
#include "api/postlist.h"

class SynonymPostList : public PostList {
    PostList * subtree;

    MultiMatch * matcher;

    const Xapian::Weight * wt;

    bool want_doclength;

    bool want_wdf;

    bool want_unique_terms;

    bool wdf_disjoint;

    Xapian::termcount doclen_lower_bound;

  public:
    SynonymPostList(PostList * subtree_, MultiMatch * matcher_,
                    Xapian::termcount doclen_lower_bound_,
                    bool wdf_disjoint_)
        : subtree(subtree_), matcher(matcher_), wt(NULL),
          want_doclength(false), want_wdf(false), want_unique_terms(false),
          wdf_disjoint(wdf_disjoint_),
          doclen_lower_bound(doclen_lower_bound_) { }

    ~SynonymPostList();

    void set_weight(const Xapian::Weight * wt_);

    PostList *next(double w_min);
    PostList *skip_to(Xapian::docid did, double w_min);

    double get_weight() const;
    double get_maxweight() const;
    double recalc_maxweight();

    // The following methods just call through to the subtree.
    Xapian::termcount get_wdf() const;
    Xapian::doccount get_termfreq_min() const;
    Xapian::doccount get_termfreq_est() const;
    Xapian::doccount get_termfreq_max() const;
    // Note - we don't need to implement get_termfreq_est_using_stats()
    // because a synonym when used as a child of a synonym will be optimised
    // to an OR.
    Xapian::docid get_docid() const;
    Xapian::termcount get_doclength() const;
    Xapian::termcount get_unique_terms() const;
    bool at_end() const;

    Xapian::termcount count_matching_subqs() const;

    std::string get_description() const;
};

#endif /* XAPIAN_INCLUDED_SYNONYMPOSTLIST_H */