/* 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 "autoconfig.h"
#include <string>
#include <vector>
#include "cstr.h"
#include "refcntr.h"
#include "rcldoc.h"
#include "stoplist.h"
#include "rclconfig.h"
using std::string;
using std::vector;
// 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
// Omega compatible values. We leave a hole for future omega values. Not sure
// it makes any sense to keep any level of omega compat given that the index
// is incompatible anyway.
enum value_slot {
// Omega-compatible values:
VALUE_LASTMOD = 0, // 4 byte big endian value - seconds since 1970.
VALUE_MD5 = 1, // 16 byte MD5 checksum of original document.
VALUE_SIZE = 2, // sortable_serialise(<file size in bytes>)
// Recoll only:
VALUE_SIG = 10 // Doc sig as chosen by app (ex: mtime+size
};
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) const
{
return term == o.term;
}
bool operator<(const TermMatchEntry &o) const
{
return term < o.term;
}
string term;
int wcf; // Total count of occurrences within collection.
int docs; // Number of documents countaining term.
};
/** Term match result list header: statistics and global info */
class TermMatchResult {
public:
TermMatchResult()
{
clear();
}
void clear()
{
entries.clear();
dbdoccount = 0;
dbavgdoclen = 0;
}
// Term expansion
vector<TermMatchEntry> entries;
// If a field was specified, this is the corresponding index prefix
string prefix;
// Index-wide stats
unsigned int dbdoccount;
double dbavgdoclen;
};
#ifdef IDX_THREADS
extern void *DbUpdWorker(void*);
#endif // IDX_THREADS
inline bool has_prefix(const string& trm)
{
#ifndef RCL_INDEX_STRIPCHARS
if (o_index_stripchars) {
#endif
return !trm.empty() && 'A' <= trm[0] && trm[0] <= 'Z';
#ifndef RCL_INDEX_STRIPCHARS
} else {
return !trm.empty() && trm[0] == ':';
}
#endif
}
inline string wrap_prefix(const string& pfx)
{
#ifndef RCL_INDEX_STRIPCHARS
if (o_index_stripchars) {
#endif
return pfx;
#ifndef RCL_INDEX_STRIPCHARS
} else {
return cstr_colon + pfx + cstr_colon;
}
#endif
}
/**
* Wrapper class for the native database.
*/
class Db {
public:
// A place for things we don't want visible here.
class Native;
friend class Native;
#ifdef IDX_THREADS
friend void *DbUpdWorker(void*);
#endif // IDX_THREADS
/* 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;}
/** Return all possible stemmer names */
static vector<string> getStemmerNames();
/** Return existing stemming databases */
vector<string> getStemLangs();
/** 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 (has_prefix(term))
return false;
if (term.find_first_of(" !\"#$%&()*+,-./0123456789:;<=>?@[\\]^_`{|}~")
!= string::npos)
return false;
return true;
}
#ifdef TESTING_XAPIAN_SPELL
/** Return spelling suggestion */
string getSpellingSuggestion(const string& word);
#endif
/* The next two, only for searchdata, should be somehow hidden */
/* Return configured stop words */
const StopList& getStopList() const {return m_stops;}
/* Field name to prefix translation (ie: author -> 'A') */
bool fieldToTraits(const string& fldname, const FieldTraits **ftpp);
/* 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,
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 createStemDbs(const std::vector<std::string> &langs);
/** Delete stem expansion database for given language. */
bool deleteStemDb(const string &lang);
/* Query-related methods ************************************/
/** Return total docs in db */
int docCnt();
/** Return count of docs which have an occurrence of term */
int termDocCnt(const string& term);
/** Add extra database for querying */
bool addQueryDb(const string &dir);
/** Remove extra database. if dir == "", remove all. */
bool rmQueryDb(const string &dir);
/** Look where the doc result comes from.
* @return: 0 main index, (size_t)-1 don't know,
* other: order of database in add_database() sequence.
*/
size_t whatDbIdx(const Doc& doc);
/** Tell if directory seems to hold xapian db */
static bool testDbDir(const string &dir);
/** Return the 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
*
* @param typ defines the kind of expansion: wildcard, regexp or stemming
* @param lang sets the stemming language(s). Can be a space-separated list
* @param term is the term to expand
* @param result is the main output
* @param max defines the maximum result count
* @param field if set, defines the field within with the expansion should
* be performed. Only used for wildcards and regexps, stemming is
* always global. If this is set, the resulting output terms
* will be appropriately prefix and the prefix value will be set
* in the TermMatchResult header
*/
enum MatchType {ET_WILD, ET_REGEXP, ET_STEM};
bool termMatch(MatchType typ, const string &lang, const string &term,
TermMatchResult& result, int max = -1,
const string& field = cstr_null
);
/** Return min and max years for doc mod times in db */
bool maxYearSpan(int *minyear, int *maxyear);
/** Wildcard expansion specific to file names. Internal/sdata use only */
bool filenameWildExp(const string& exp, vector<string>& names);
/** Set parameters for synthetic abstract generation */
void setAbstractParams(int idxTrunc, int synthLen, int syntCtxLen);
int getAbsCtxLen() const
{
return m_synthAbsWordCtxLen;
}
int getAbsLen() const
{
return m_synthAbsLen;
}
/** 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;}
/**
Activate the "in place reset" mode where all documents are
considered as needing update. This is a global/per-process
option, and can't be reset. It should be set at the start of
the indexing pass
*/
static void setInPlaceReset() {o_inPlaceReset = true;}
/* 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;
// Xapian directories for additional databases to query
vector<string> m_extraDbs;
OpenMode m_mode;
// File existence vector: this is filled during the indexing pass. Any
// document whose bit is not set at the end is purged
vector<bool> updated;
// Stop terms: those don't get indexed.
StopList m_stops;
// When this is set, all documents are considered as needing a reindex.
// This implements an alternative to just erasing the index before
// beginning, with the advantage that, for small index formats updates,
// between releases the index remains available while being recreated.
static bool o_inPlaceReset;
// Reinitialize when adding/removing additional dbs
bool adjustdbs();
bool stemExpand(const string &lang, const string &s,
TermMatchResult& result, int max = -1);
// Flush when idxflushmb is reached
bool maybeflush(off_t moretext);
/* Copyconst and assignement 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;
#ifdef RCL_INDEX_STRIPCHARS
extern const string start_of_field_term;
extern const string end_of_field_term;
#else
extern string start_of_field_term;
extern string end_of_field_term;
#endif
}
#endif /* _DB_H_INCLUDED_ */