xapian-core/backends/honey/honey_postlisttable.h

   1 /** @file honey_postlisttable.h
   2  * @brief Subclass of HoneyTable which holds postlists.
   3  */
   4 /* Copyright (C) 2007,2008,2009,2010,2013,2014,2015,2016 Olly Betts
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
  19  */
  20
  21 #ifndef XAPIAN_INCLUDED_HONEY_POSTLISTTABLE_H
  22 #define XAPIAN_INCLUDED_HONEY_POSTLISTTABLE_H
  23
  24 #include <xapian/constants.h>
  25 #include <xapian/types.h>
  26
  27 #include "honey_inverter.h"
  28 #include "honey_postlist.h"
  29 #include "honey_table.h"
  30 #include "pack.h"
  31
  32 #include <string>
  33
  34 class HoneyDatabase;
  35 class PostingChanges;
  36
  37 class HoneyPostListTable : public HoneyTable {
  38   public:
  39     /** Create a new HoneyPostListTable object.
  40      *
  41      *  This method does not create or open the table on disk - you
  42      *  must call the create() or open() methods respectively!
  43      *
  44      *  @param dbdir        The directory the honey database is stored in.
  45      *  @param readonly     true if we're opening read-only, else false.
  46      */
  47     HoneyPostListTable(const std::string & dbdir, bool readonly)
  48         : HoneyTable("postlist", dbdir + "/postlist.", readonly) { }
  49
  50     HoneyPostListTable(int fd, off_t offset_, bool readonly)
  51         : HoneyTable("postlist", fd, offset_, readonly) { }
  52
  53     bool term_exists(const std::string& term) const {
  54         return key_exists(pack_honey_postlist_key(term));
  55     }
  56
  57     HoneyPostList* open_post_list(const HoneyDatabase* db,
  58                                   const std::string& term,
  59                                   bool need_pos) const;
  60
  61     void get_freqs(const std::string& term,
  62                    Xapian::doccount* termfreq_ptr,
  63                    Xapian::termcount* collfreq_ptr) const;
  64
  65     void get_used_docid_range(Xapian::docid& first, Xapian::docid& last) const;
  66
  67     std::string get_metadata(const std::string& key) const {
  68         std::string value;
  69         (void)get_exact_entry(std::string("\0", 2) + key, value);
  70         return value;
  71     }
  72
  73     void merge_doclen_changes(const std::map<Xapian::docid, Xapian::termcount>& changes) {
  74         // Honey doesn't support update currently.
  75         (void)changes;
  76     }
  77
  78     void merge_changes(const std::string& term,
  79                        const HoneyInverter::PostingChanges& changes) {
  80         // Honey doesn't support update currently.
  81         (void)term;
  82         (void)changes;
  83     }
  84 };
  85
  86 #endif // XAPIAN_INCLUDED_HONEY_POSTLISTTABLE_H