contrib/openisis/ldb.h

/*
        openisis - an open implementation of the CDS/ISIS database
        Version 0.8.x (patchlevel see file Version)
        Copyright (C) 2001-2003 by Erik Grziwotz, erik@openisis.org

        This library is free software; you can redistribute it and/or
        modify it under the terms of the GNU Lesser General Public
        License as published by the Free Software Foundation; either
        version 2.1 of the License, or (at your option) any later version.

        This library 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
        Lesser General Public License for more details.

        You should have received a copy of the GNU Lesser General Public
        License along with this library; if not, write to the Free Software
        Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

        see README for more information
EOH */
#ifndef LDB_H

/*
        $Id: ldb.h,v 1.19 2003/04/08 00:20:52 kripke Exp $
        package interface of the general db access functions.
*/

#include "luti.h"
#include "lll.h"

/* #define LDB_MAGIC  0x0FE91515 read OPENISIS */ 


enum { /* MFR members */
        LMFR_MFN = 1, /* the rowid */
        LMFR_RECL,      /* total external length (even), negative for locked record */
        LMFR_BWB, /* block of rec's previous version */
        LMFR_BWP, /* pos of " */
        LMFR_BASE,      /* offset of contents area */
        LMFR_NVF,       /* number of fields */
        LMFR_STAT,      /* state, if != 0, about to be deleted */
        LMFR__FL, /* offset of repeated part */
        LMFR_TAG = 0,
        LMFR_POS,
        LMFR_LEN,
        LMFR__RL /* length of repeated part */
};


extern int *ldb_readRec ( int db, int rowid );


typedef int lxref;


extern int *ldb_readRecAtOff ( int dbid, lxref off, int *nxtoff );




/*
**      ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
**      detailed search structures and functions
**
**      ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
*/

enum {
        LDB_MAX_KEYLEN = 31, /* actually, it's 30 for isis-1 */
        LDB_TERMBUF = 128, /* ints */
        LDB_INDEXES = 2
};


typedef union {
        char bytes[8];
        lll  val;
} LdbP;



/* all macros operate on pointers */
/* access parts */
#define LDBP_ROW( p ) (0xffffffL & (int)((p)->val >> 40))
#define LDBP_TAG( p ) (  0xffffL & (int)((p)->val >> 24))
#define LDBP_POS( p ) (0xff7fffL & (int)((p)->val))
#define LDBP_MARK( p ) (  0x8000 & (int)((p)->val))

#define LDBP_SETMARK( p ) ((p)->val |= LLL(            0x8000))
#define LDBP_CLRMARK( p ) ((p)->val &= LLL(0xffffffffffff7fff))
/* value w/o the mark bit */
#define LDBP_IGNMARK( p ) ((p)->val & LLL(0xffffffffffff7fff))

/* compare according to rowid, tag, pos */
#define LDBP_EQ( a, b ) ((a)->val == (b)->val)
#define LDBP_GT( a, b ) ((a)->val > (b)->val)
/* compare IGNORING MARK according to rowid, tag, pos */
#define LDBP_EQM( a, b ) (LDBP_IGNMARK(a) == LDBP_IGNMARK(b))
#define LDBP_GTM( a, b ) (LDBP_IGNMARK(a) > LDBP_IGNMARK(b))

/* manipulation: set bottom / top for row of given posting */
#define LDBP_SETROWBOT( d, s ) ((d)->val = (s)->val & LLL(0xffffff0000000000))
#define LDBP_SETROWTOP( d, s ) ((d)->val = (s)->val | LLL(      0xffffffffff))


typedef struct {
        short mode; /* in: merge flags */
        short near; /* in: near distance; in OR mode: collect pos info */
        int   tag; /* in: tag, to which postings are restricted */
        int   skp; /* in: ignore mfns < skp */
        int   len; /* in: length (# of postings) of buffer (if 0 : default length) */
        int   fil; /* io: number of postings actually used */
        int   cut; /* io: min mfn ignored due to buffer length */
        LdbP p[OPENISIS_SETLEN];
} LdbPost;

enum {
        LDB_OR,
        LDB_AND,
        LDB_NOT, /* like AND, but keep unmarked postings */
        LDB_PFX = 4, /* prefix match */
        LDB_KEEPMARKS = 8 /* do not compact after AND/NOT */
};

enum {
        LDB_NEAR_F = 0x7fff, /* the (F): same occurence of field */
        LDB_NEAR_G = -0x8000 /* the (G): same field */
};

extern int ldb_search ( int db, const char *key, LdbPost *post,
        OpenIsisRec *rec );


extern int ldb_p2s ( OpenIsisSet *set, LdbPost *post );

extern Db* ldb_getdb (int dbid);

#define LDB_H
#endif /* LDB_H */

---