glass_database.h

Go to the documentation of this file.

/* Copyright 1999,2000,2001 BrightStation PLC
 * Copyright 2002 Ananova Ltd
 * Copyright 2002,2003,2004,2005,2006,2007,2008,2009,2010,2011,2012,2013,2014,2015,2016,2019 Olly Betts
 * Copyright 2008 Lemur Consulting Ltd
 *
 * 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 OM_HGUARD_GLASS_DATABASE_H
#define OM_HGUARD_GLASS_DATABASE_H

#include "backends/backends.h"
#include "backends/database.h"
#include "glass_changes.h"
#include "glass_docdata.h"
#include "glass_inverter.h"
#include "glass_positionlist.h"
#include "glass_postlist.h"
#include "glass_spelling.h"
#include "glass_synonym.h"
#include "glass_termlisttable.h"
#include "glass_values.h"
#include "glass_version.h"
#include "../flint_lock.h"
#include "glass_defs.h"
#include "backends/valuestats.h"

#include "noreturn.h"

#include "xapian/compactor.h"
#include "xapian/constants.h"

#include <map>

class GlassTermList;
class GlassAllDocsPostList;
class RemoteConnection;

class GlassDatabase : public Xapian::Database::Internal {
    friend class GlassWritableDatabase;
    friend class GlassTermList;
    friend class GlassPostList;
    friend class GlassAllTermsList;
    friend class GlassAllDocsPostList;

  private:
    std::string db_dir;

    bool readonly;

    GlassVersion version_file;

    mutable GlassPostListTable postlist_table;

    mutable GlassPositionListTable position_table;

    GlassTermListTable termlist_table;

    mutable GlassValueManager value_manager;

    mutable GlassSynonymTable synonym_table;

    mutable GlassSpellingTable spelling_table;

    GlassDocDataTable docdata_table;

    FlintLock lock;

    GlassChanges changes;

    bool database_exists();

    void create_and_open_tables(int flags, unsigned int blocksize);

    bool open_tables(int flags);

    void get_database_write_lock(int flags, bool creating);

    glass_revision_number_t get_next_revision_number() const;

    void set_revision_number(int flags, glass_revision_number_t new_revision);

    bool reopen();

    void close();

    void modifications_failed(glass_revision_number_t new_revision,
                              const std::string & msg);

    void apply();

    void cancel();

    void send_whole_database(RemoteConnection & conn, double end_time);

    void get_changeset_revisions(const string & path,
                                 glass_revision_number_t * startrev,
                                 glass_revision_number_t * endrev) const;

  public:
    explicit GlassDatabase(const string& db_dir_,
                           int flags = Xapian::DB_READONLY_,
                           unsigned int block_size = 0u);

    explicit GlassDatabase(int fd);

    ~GlassDatabase();

    GlassCursor * get_postlist_cursor() const {
        return postlist_table.cursor_get();
    }

    glass_revision_number_t get_revision_number() const;

    Xapian::doccount get_doccount() const;
    Xapian::docid get_lastdocid() const;
    Xapian::totallength get_total_length() const;
    Xapian::termcount get_doclength(Xapian::docid did) const;
    Xapian::termcount get_unique_terms(Xapian::docid did) const;
    void get_freqs(const string & term,
                   Xapian::doccount * termfreq_ptr,
                   Xapian::termcount * collfreq_ptr) const;
    Xapian::doccount get_value_freq(Xapian::valueno slot) const;
    std::string get_value_lower_bound(Xapian::valueno slot) const;
    std::string get_value_upper_bound(Xapian::valueno slot) const;
    Xapian::termcount get_doclength_lower_bound() const;
    Xapian::termcount get_doclength_upper_bound() const;
    Xapian::termcount get_wdf_upper_bound(const string & term) const;
    bool term_exists(const string & tname) const;
    bool has_positions() const;

    LeafPostList * open_post_list(const string & tname) const;
    ValueList * open_value_list(Xapian::valueno slot) const;
    Xapian::Document::Internal* open_document(Xapian::docid did,
                                              bool lazy) const;

    virtual void read_position_list(GlassPositionList* pos_list,
                                    Xapian::docid did,
                                    const string& term) const;
    virtual Xapian::termcount positionlist_count(Xapian::docid did,
                                                 const string& term) const;
    PositionList* open_position_list(Xapian::docid did,
                                     const string& term) const;
    TermList * open_term_list(Xapian::docid did) const;
    TermList * open_allterms(const string & prefix) const;

    TermList * open_spelling_termlist(const string & word) const;
    TermList * open_spelling_wordlist() const;
    Xapian::doccount get_spelling_frequency(const string & word) const;

    TermList * open_synonym_termlist(const string & term) const;
    TermList * open_synonym_keylist(const string & prefix) const;

    string get_metadata(const string & key) const;
    TermList * open_metadata_keylist(const std::string &prefix) const;
    void write_changesets_to_fd(int fd,
                                const string & start_revision,
                                bool need_whole_db,
                                Xapian::ReplicationInfo * info);
    string get_revision_info() const;
    string get_uuid() const;

    void request_document(Xapian::docid /*did*/) const;
    void readahead_for_query(const Xapian::Query &query);

    XAPIAN_NORETURN(void throw_termlist_table_close_exception() const);

    int get_backend_info(string * path) const {
        if (path) *path = db_dir;
        return BACKEND_GLASS;
    }

    bool single_file() const { return version_file.single_file(); }

    void get_used_docid_range(Xapian::docid & first,
                              Xapian::docid & last) const;

    virtual bool has_uncommitted_changes() const;

    bool locked() const;

    static void compact(Xapian::Compactor * compactor,
                        const char * destdir,
                        int fd,
                        const std::vector<Xapian::Database::Internal*>& sources,
                        const std::vector<Xapian::docid> & offset,
                        size_t block_size,
                        Xapian::Compactor::compaction_level compaction,
                        unsigned flags,
                        Xapian::docid last_docid);
};

class GlassWritableDatabase : public GlassDatabase {
    mutable Inverter inverter;

    mutable map<Xapian::valueno, ValueStats> value_stats;

    mutable Xapian::doccount change_count;

    Xapian::doccount flush_threshold;

    mutable Xapian::Document::Internal * modify_shortcut_document;

    mutable Xapian::docid modify_shortcut_docid;

    void check_flush_threshold();

    void flush_postlist_changes();

    void close();

    void apply();


    void commit();

    void cancel();

    Xapian::docid add_document(const Xapian::Document& document);
    Xapian::docid add_document_(Xapian::docid did,
                                const Xapian::Document& document);
    // Stop the default implementation of delete_document(term) and
    // replace_document(term) from being hidden.  This isn't really
    // a problem as we only try to call them through the base class
    // (where they aren't hidden) but some compilers generate a warning
    // about the hiding.
    using Xapian::Database::Internal::delete_document;
    using Xapian::Database::Internal::replace_document;
    void delete_document(Xapian::docid did);
    void replace_document(Xapian::docid did, const Xapian::Document & document);

    Xapian::Document::Internal * open_document(Xapian::docid did,
                                               bool lazy) const;


  public:
    GlassWritableDatabase(const string &dir, int flags, int block_size);

    ~GlassWritableDatabase();

    Xapian::termcount get_doclength(Xapian::docid did) const;
    Xapian::termcount get_unique_terms(Xapian::docid did) const;
    void get_freqs(const string & term,
                   Xapian::doccount * termfreq_ptr,
                   Xapian::termcount * collfreq_ptr) const;
    Xapian::doccount get_value_freq(Xapian::valueno slot) const;
    std::string get_value_lower_bound(Xapian::valueno slot) const;
    std::string get_value_upper_bound(Xapian::valueno slot) const;
    bool term_exists(const string & tname) const;
    bool has_positions() const;

    LeafPostList * open_post_list(const string & tname) const;
    ValueList * open_value_list(Xapian::valueno slot) const;

    void read_position_list(GlassPositionList* pos_list,
                            Xapian::docid did,
                            const string& term) const;
    Xapian::termcount positionlist_count(Xapian::docid did,
                                         const string& term) const;
    PositionList* open_position_list(Xapian::docid did,
                                     const string& term) const;
    TermList * open_allterms(const string & prefix) const;

    void add_spelling(const string & word, Xapian::termcount freqinc) const;
    void remove_spelling(const string & word,
                         Xapian::termcount freqdec) const;
    TermList * open_spelling_wordlist() const;

    TermList * open_synonym_keylist(const string & prefix) const;
    void add_synonym(const string & word, const string & synonym) const;
    void remove_synonym(const string & word, const string & synonym) const;
    void clear_synonyms(const string & word) const;

    void set_metadata(const string & key, const string & value);
    void invalidate_doc_object(Xapian::Document::Internal * obj) const;

    bool has_uncommitted_changes() const;
};

#endif /* OM_HGUARD_GLASS_DATABASE_H */