/* Copyright (C) 2007 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 _rcldb_p_h_included_
#define _rcldb_p_h_included_
#include "autoconfig.h"
#include <map>
#include <mutex>
#include <xapian.h>
#ifdef IDX_THREADS
#include "workqueue.h"
#endif // IDX_THREADS
#include "xmacros.h"
namespace Rcl {
class Query;
#ifdef IDX_THREADS
// Task for the index update thread. This can be
// - add/update for a new / update documment
// - delete for a deleted document
// - purgeOrphans when a multidoc file is updated during a partial pass (no
// general purge). We want to remove subDocs that possibly don't
// exist anymore. We find them by their different sig
// txtlen and doc are only valid for add/update else, len is (size_t)-1 and doc
// is empty
class DbUpdTask {
public:
enum Op {AddOrUpdate, Delete, PurgeOrphans};
// Note that udi and uniterm are strictly equivalent and are
// passed both just to avoid recomputing uniterm which is
// available on the caller site.
// Take some care to avoid sharing string data (if string impl is cow)
DbUpdTask(Op _op, const string& ud, const string& un,
Xapian::Document *d, size_t tl)
: op(_op), udi(ud.begin(), ud.end()), uniterm(un.begin(), un.end()),
doc(d), txtlen(tl)
{}
// Udi and uniterm equivalently designate the doc
Op op;
string udi;
string uniterm;
Xapian::Document *doc;
// txtlen is used to update the flush interval. It's -1 for a
// purge because we actually don't know it, and the code fakes a
// text length based on the term count.
size_t txtlen;
};
#endif // IDX_THREADS
class TextSplitDb;
// A class for data and methods that would have to expose
// Xapian-specific stuff if they were in Rcl::Db. There could actually be
// 2 different ones for indexing or query as there is not much in
// common.
class Db::Native {
public:
Db *m_rcldb; // Parent
bool m_isopen;
bool m_iswritable;
bool m_noversionwrite; //Set if open failed because of version mismatch!
#ifdef IDX_THREADS
WorkQueue<DbUpdTask*> m_wqueue;
std::mutex m_mutex;
long long m_totalworkns;
bool m_havewriteq;
void maybeStartThreads();
#endif // IDX_THREADS
// Indexing
Xapian::WritableDatabase xwdb;
// Querying (active even if the wdb is too)
Xapian::Database xrdb;
Native(Db *db);
~Native();
#ifdef IDX_THREADS
friend void *DbUpdWorker(void*);
#endif // IDX_THREADS
// Final steps of doc update, part which need to be single-threaded
bool addOrUpdateWrite(const string& udi, const string& uniterm,
Xapian::Document *doc, size_t txtlen);
/** Delete all documents which are contained in the input document,
* which must be a file-level one.
*
* @param onlyOrphans if true, only delete documents which have
* not the same signature as the input. This is used to delete docs
* which do not exist any more in the file after an update, for
* example the tail messages after a folder truncation). If false,
* delete all.
* @param udi the parent document identifier.
* @param uniterm equivalent to udi, passed just to avoid recomputing.
*/
bool purgeFileWrite(bool onlyOrphans, const string& udi,
const string& uniterm);
bool getPagePositions(Xapian::docid docid, vector<int>& vpos);
int getPageNumberForPosition(const vector<int>& pbreaks, int pos);
bool dbDataToRclDoc(Xapian::docid docid, std::string &data, Doc &doc);
size_t whatDbIdx(Xapian::docid id);
/** Retrieve Xapian::docid, given unique document identifier,
* using the posting list for the derived term.
*
* @param udi the unique document identifier (opaque hashed path+ipath).
* @param idxi the database index, at query time, when using external
* databases.
* @param[out] xdoc the xapian document.
* @return 0 if not found
*/
Xapian::docid getDoc(const string& udi, int idxi, Xapian::Document& xdoc);
/** Retrieve unique document identifier for given Xapian document,
* using the document termlist
*/
bool xdocToUdi(Xapian::Document& xdoc, string &udi);
/** Check if doc is indexed by term */
bool hasTerm(const string& udi, int idxi, const string& term);
/** Update existing Xapian document for pure extended attrs change */
bool docToXdocXattrOnly(TextSplitDb *splitter, const string &udi,
Doc &doc, Xapian::Document& xdoc);
/** Remove all terms currently indexed for field defined by idx prefix */
bool clearField(Xapian::Document& xdoc, const string& pfx,
Xapian::termcount wdfdec);
/** Check if term wdf is 0 and remove term if so */
bool clearDocTermIfWdf0(Xapian::Document& xdoc, const string& term);
/** Compute list of subdocuments for a given udi. We look for documents
* indexed by a parent term matching the udi, the posting list for the
* parentterm(udi) (As suggested by James Aylett)
*
* Note that this is not currently recursive: all subdocs are supposed
* to be children of the file doc.
* Ie: in a mail folder, all messages, attachments, attachments of
* attached messages etc. must have the folder file document as
* parent.
*
* Finer grain parent-child relationships are defined by the
* indexer (rcldb user), using the ipath.
*
*/
bool subDocs(const string &udi, int idxi, vector<Xapian::docid>& docids);
/** Check if a page position list is defined */
bool hasPages(Xapian::docid id);
};
// This is the word position offset at which we index the body text
// (abstract, keywords, etc.. are stored before this)
static const unsigned int baseTextPosition = 100000;
}
#endif /* _rcldb_p_h_included_ */