/* Copyright (C) 2004 J.F.Dockes
* 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.,
* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#ifndef _DB_H_INCLUDED_
#define _DB_H_INCLUDED_
#include <string>
#include <list>
#include <vector>
#include "refcntr.h"
#include "rcldoc.h"
#include "stoplist.h"
#ifndef NO_NAMESPACES
using std::string;
using std::list;
using std::vector;
#endif
// rcldb defines an interface for a 'real' text database. The current
// implementation uses xapian only, and xapian-related code is in rcldb.cpp
// If support was added for other backend, the xapian code would be moved in
// rclxapian.cpp, another file would be created for the new backend, and the
// configuration/compile/link code would be adjusted to allow choosing. There
// is no plan for supporting multiple different backends.
//
// In no case does this try to implement a useful virtualized text-db interface
// The main goal is simplicity and good matching to usage inside the recoll
// user interface. In other words, this is not exhaustive or well-designed or
// reusable.
//
// Unique Document Identifier: uniquely identifies a document in its
// source storage (file system or other). Used for up to date checks
// etc. "udi". Our user is responsible for making sure it's not too
// big, cause it's stored as a Xapian term (< 150 bytes would be
// reasonable)
class RclConfig;
#ifndef NO_NAMESPACES
namespace Rcl {
#endif
class SearchData;
class TermIter;
class Query;
/** Used for returning result lists for index terms matching some criteria */
class TermMatchEntry {
public:
TermMatchEntry() : wcf(0) {}
TermMatchEntry(const string&t, int f, int d) : term(t), wcf(f), docs(d) {}
TermMatchEntry(const string&t) : term(t), wcf(0) {}
bool operator==(const TermMatchEntry &o) { return term == o.term;}
bool operator<(const TermMatchEntry &o) { return term < o.term;}
string term;
int wcf; // Total count of occurrences within collection.
int docs; // Number of documents countaining term.
};
class TermMatchResult {
public:
TermMatchResult() {clear();}
void clear() {entries.clear(); dbdoccount = 0; dbavgdoclen = 0;}
list<TermMatchEntry> entries;
unsigned int dbdoccount;
double dbavgdoclen;
};
/**
* Wrapper class for the native database.
*/
class Db {
public:
// A place for things we don't want visible here.
class Native;
friend class Native;
/* General stuff (valid for query or update) ****************************/
Db(RclConfig *cfp);
~Db();
enum OpenMode {DbRO, DbUpd, DbTrunc};
enum OpenError {DbOpenNoError, DbOpenMainDb, DbOpenExtraDb};
bool open(OpenMode mode, OpenError *error = 0);
bool close();
bool isopen();
/** Get explanation about last error */
string getReason() const {return m_reason;}
/** List possible stemmer names */
static list<string> getStemmerNames();
/** Test word for spelling correction candidate: not too long, no
special chars... */
static bool isSpellingCandidate(const string& term)
{
if (term.empty() || term.length() > 50)
return false;
if (term.find_first_of(" !\"#$%&()*+,-./0123456789:;<=>?@[\\]^_`{|}~")
!= string::npos)
return false;
return true;
}
/** List existing stemming databases */
std::list<std::string> getStemLangs();
#ifdef TESTING_XAPIAN_SPELL
/** Return spelling suggestion */
string getSpellingSuggestion(const string& word);
#endif
/* The next two, only for searchdata, should be somehow hidden */
/* Return list of configured stop words */
const StopList& getStopList() const {return m_stops;}
/* Field name to prefix translation (ie: author -> 'A') */
bool fieldToPrefix(const string& fldname, string &pfx);
/* Update-related methods ******************************************/
/** Test if the db entry for the given udi is up to date (by
* comparing the input and stored sigs).
* Side-effect: set the existence flag for the file document
* and all subdocs if any (for later use by 'purge()')
*/
bool needUpdate(const string &udi, const string& sig);
/** Add or update document. The Doc class should have been filled as much as
* possible depending on the document type. parent_udi is only
* use for subdocs, else set it to empty */
bool addOrUpdate(const string &udi, const string &parent_udi,
const Doc &doc);
/** Delete document(s) for given UDI, including subdocs */
bool purgeFile(const string &udi, bool *existed = 0);
/** Remove documents that no longer exist in the file system. This
* depends on the update map, which is built during
* indexing (needUpdate()).
*
* This should only be called after a full walk of
* the file system, else the update map will not be complete, and
* many documents will be deleted that shouldn't, which is why this
* has to be called externally, rcldb can't know if the indexing
* pass was complete or partial.
*/
bool purge();
/** Create stem expansion database for given language. */
bool createStemDb(const string &lang);
/** Delete stem expansion database for given language. */
bool deleteStemDb(const string &lang);
/* Query-related methods ************************************/
/** Return total docs in db */
int docCnt();
/** Add extra database for querying */
bool addQueryDb(const string &dir);
/** Remove extra database. if dir == "", remove all. */
bool rmQueryDb(const string &dir);
/** Tell if directory seems to hold xapian db */
static bool testDbDir(const string &dir);
/** Return a list of index terms that match the input string
* Expansion is performed either with either wildcard or regexp processing
* Stem expansion is performed if lang is not empty */
enum MatchType {ET_WILD, ET_REGEXP, ET_STEM};
bool termMatch(MatchType typ, const string &lang, const string &s,
TermMatchResult& result, int max = -1,
const string& field = "",
string *prefix = 0
);
/** Return min and max years for doc mod times in db */
bool maxYearSpan(int *minyear, int *maxyear);
/** Special filename wildcard to XSFN terms expansion.
internal/searchdata use only */
bool filenameWildExp(const string& exp, list<string>& names);
/** Set parameters for synthetic abstract generation */
void setAbstractParams(int idxTrunc, int synthLen, int syntCtxLen);
/** Build synthetic abstract for document, extracting chunks relevant for
* the input query. This uses index data only (no access to the file) */
bool makeDocAbstract(Doc &doc, Query *query, string& abstract);
/** Get document for given udi
*
* Used by the 'history' feature (and nothing else?)
*/
bool getDoc(const string &udi, Doc &doc);
/* The following are mainly for the aspell module */
/** Whole term list walking. */
TermIter *termWalkOpen();
bool termWalkNext(TermIter *, string &term);
void termWalkClose(TermIter *);
/** Test term existence */
bool termExists(const string& term);
/** Test if terms stem to different roots. */
bool stemDiffers(const string& lang, const string& term,
const string& base);
RclConfig *getConf() {return m_config;}
/* This has to be public for access by embedded Query::Native */
Native *m_ndb;
private:
// Internal form of close, can be called during destruction
bool i_close(bool final);
RclConfig *m_config;
string m_reason; // Error explanation
/* Parameters cached out of the configuration files */
// This is how long an abstract we keep or build from beginning of
// text when indexing. It only has an influence on the size of the
// db as we are free to shorten it again when displaying
int m_idxAbsTruncLen;
// This is the size of the abstract that we synthetize out of query
// term contexts at *query time*
int m_synthAbsLen;
// This is how many words (context size) we keep around query terms
// when building the abstract
int m_synthAbsWordCtxLen;
// Flush threshold. Megabytes of text indexed before we flush.
int m_flushMb;
// Text bytes indexed since beginning
long long m_curtxtsz;
// Text bytes at last flush
long long m_flushtxtsz;
// Text bytes at last fsoccup check
long long m_occtxtsz;
// First fs occup check ?
int m_occFirstCheck;
// Maximum file system occupation percentage
int m_maxFsOccupPc;
// Database directory
string m_basedir;
// List of directories for additional databases to query
list<string> m_extraDbs;
OpenMode m_mode;
vector<bool> updated;
StopList m_stops;
// Reinitialize when adding/removing additional dbs
bool adjustdbs();
bool stemExpand(const string &lang, const string &s,
TermMatchResult& result, int max = -1);
/* Copyconst and assignemt private and forbidden */
Db(const Db &) {}
Db& operator=(const Db &) {return *this;};
};
// This has to go somewhere, and as it needs the Xapian version, this is
// the most reasonable place.
string version_string();
extern const string pathelt_prefix;
#ifndef NO_NAMESPACES
}
#endif // NO_NAMESPACES
#endif /* _DB_H_INCLUDED_ */