xapian-core/backends/multi/multi_database.h

   1 /** @file multi_database.h
   2  *  @brief Sharded database backend
   3  */
   4 /* Copyright 2017 Olly Betts
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License as
   8  * published by the Free Software Foundation; either version 2 of the
   9  * License, or (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_MULTI_DATABASE_H
  22 #define XAPIAN_INCLUDED_MULTI_DATABASE_H
  23
  24 #include "api/postlist.h"
  25 #include "api/termlist.h"
  26 #include "backends/databaseinternal.h"
  27 #include "backends/valuelist.h"
  28
  29 class Matcher;
  30 class ValueStreamDocument;
  31
  32 namespace Xapian {
  33 struct ReplicationInfo;
  34 }
  35
  36 /// Sharded database backend.
  37 class MultiDatabase : public Xapian::Database::Internal {
  38     friend class Matcher;
  39     friend class ValueStreamDocument;
  40     friend class Xapian::Database;
  41
  42     Xapian::SmallVectorI<Xapian::Database::Internal> shards;
  43
  44   public:
  45     explicit MultiDatabase(size_type reserve_size, bool read_only)
  46         : Xapian::Database::Internal(read_only ?
  47                                      TRANSACTION_READONLY :
  48                                      TRANSACTION_NONE),
  49           shards(reserve_size) {}
  50
  51     size_type size() const;
  52
  53     void reserve(size_type new_size) { shards.reserve(new_size); }
  54
  55     void push_back(Xapian::Database::Internal* shard) {
  56         shards.push_back(shard);
  57     }
  58
  59     bool reopen();
  60
  61     void close();
  62
  63     PostList* open_post_list(const std::string& term) const;
  64
  65     LeafPostList* open_leaf_post_list(const std::string& term,
  66                                       bool need_pos) const;
  67
  68     TermList* open_term_list(Xapian::docid did) const;
  69
  70     TermList* open_term_list_direct(Xapian::docid did) const;
  71
  72     TermList* open_allterms(const std::string& prefix) const;
  73
  74     bool has_positions() const;
  75
  76     PositionList* open_position_list(Xapian::docid did,
  77                                      const std::string& term) const;
  78     Xapian::doccount get_doccount() const;
  79
  80     Xapian::docid get_lastdocid() const;
  81
  82     Xapian::totallength get_total_length() const;
  83
  84     void get_freqs(const std::string& term,
  85                    Xapian::doccount* tf_ptr,
  86                    Xapian::termcount* cf_ptr) const;
  87
  88     Xapian::doccount get_value_freq(Xapian::valueno slot) const;
  89
  90     std::string get_value_lower_bound(Xapian::valueno slot) const;
  91
  92     std::string get_value_upper_bound(Xapian::valueno slot) const;
  93
  94     Xapian::termcount get_doclength_lower_bound() const;
  95
  96     Xapian::termcount get_doclength_upper_bound() const;
  97
  98     Xapian::termcount get_wdf_upper_bound(const std::string& term) const;
  99
 100     ValueList* open_value_list(Xapian::valueno slot) const;
 101
 102     Xapian::termcount get_doclength(Xapian::docid did) const;
 103
 104     Xapian::termcount get_unique_terms(Xapian::docid did) const;
 105
 106     Xapian::Document::Internal* open_document(Xapian::docid did,
 107                                               bool lazy) const;
 108
 109     bool term_exists(const std::string& term) const;
 110
 111     void keep_alive();
 112
 113     TermList* open_spelling_termlist(const std::string& word) const;
 114
 115     TermList* open_spelling_wordlist() const;
 116
 117     Xapian::doccount get_spelling_frequency(const std::string& word) const;
 118
 119     TermList* open_synonym_termlist(const std::string& term) const;
 120
 121     TermList* open_synonym_keylist(const std::string& prefix) const;
 122
 123     std::string get_metadata(const std::string& key) const;
 124
 125     TermList* open_metadata_keylist(const std::string& prefix) const;
 126
 127     std::string get_uuid() const;
 128
 129     bool locked() const;
 130
 131     void write_changesets_to_fd(int fd,
 132                                 const std::string& start_revision,
 133                                 bool need_whole_db,
 134                                 Xapian::ReplicationInfo* info);
 135
 136     void invalidate_doc_object(Xapian::Document::Internal* obj) const;
 137
 138     Xapian::rev get_revision() const;
 139
 140     int get_backend_info(std::string* path) const;
 141
 142     void commit();
 143
 144     void cancel();
 145
 146     void begin_transaction(bool flushed);
 147
 148     void end_transaction_(bool do_commit);
 149
 150     Xapian::docid add_document(const Xapian::Document& doc);
 151
 152     void delete_document(Xapian::docid did);
 153
 154     void delete_document(const std::string& term);
 155
 156     void replace_document(Xapian::docid did, const Xapian::Document& doc);
 157
 158     Xapian::docid replace_document(const std::string& term,
 159                                    const Xapian::Document& doc);
 160
 161     void request_document(Xapian::docid did) const;
 162
 163     void add_spelling(const std::string& word, Xapian::termcount freqinc) const;
 164
 165     Xapian::termcount remove_spelling(const std::string& word,
 166                                       Xapian::termcount freqdec) const;
 167
 168     void add_synonym(const std::string& term, const std::string& synonym) const;
 169
 170     void remove_synonym(const std::string& term,
 171                         const std::string& synonym) const;
 172
 173     void clear_synonyms(const std::string& term) const;
 174
 175     void set_metadata(const std::string& key, const std::string& value);
 176
 177     std::string get_description() const;
 178 };
 179
 180 #endif // XAPIAN_INCLUDED_MULTI_DATABASE_H