backends/flint/flint_alltermslist.h

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/* flint_alltermslist.h: A termlist containing all terms in a flint database.
 *
 * Copyright (C) 2005,2007 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_FLINT_ALLTERMSLIST_H
#define XAPIAN_INCLUDED_FLINT_ALLTERMSLIST_H

#include "alltermslist.h"
#include "flint_database.h"
#include "flint_postlist.h"

class FlintCursor;

class FlintAllTermsList : public AllTermsList {
    FlintAllTermsList(const FlintAllTermsList &);

    void operator=(const FlintAllTermsList &);

    Xapian::Internal::RefCntPtr<const FlintDatabase> database;

    FlintCursor * cursor;

    string current_term;

    string prefix;

    mutable Xapian::termcount termfreq;

    mutable Xapian::termcount collfreq;

    void read_termfreq_and_collfreq() const;

  public:
    FlintAllTermsList(Xapian::Internal::RefCntPtr<const FlintDatabase> database_,
                      const string & prefix_)
            : database(database_), prefix(prefix_), termfreq(0) {
        cursor = database->postlist_table.cursor_get();
        Assert(cursor); // The postlist table isn't optional.

        // Position the cursor on the highest key before the first key we want,
        // so that the first call to next() will put us on the first key we
        // want.
        if (prefix.empty()) {
            cursor->find_entry_lt(string("\x00\xff", 2));
        } else {
            cursor->find_entry_lt(pack_string_preserving_sort(prefix));
        }
    }

    ~FlintAllTermsList();

    string get_termname() const;

    Xapian::doccount get_termfreq() const;

    Xapian::termcount get_collection_freq() const;

    TermList * next();

    TermList * skip_to(const string &tname);

    bool at_end() const;
};

#endif /* XAPIAN_INCLUDED_FLINT_ALLTERMSLIST_H */

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