1 /* $Id: rsbetween.c,v 1.28 2004-10-22 10:12:51 heikki Exp $
2 Copyright (C) 1995,1996,1997,1998,1999,2000,2001,2002
5 This file is part of the Zebra server.
7 Zebra is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
12 Zebra is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with Zebra; see the file LICENSE.zebra. If not, write to the
19 Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA
24 /* rsbetween is (mostly) used for xml searches. It returns the hits of the
25 * "middle" rset, that are in between the "left" and "right" rsets. For
26 * example "Shakespeare" in between "<title>" and </title>. The thing is
27 * complicated by the inclusion of attributes (from their own rset). If attrs
28 * specified, they must match the "left" rset (start tag). "Hamlet" between
29 * "<title lang=eng>" and "</title>". (This assumes that the attributes are
30 * indexed to the same seqno as the tags).
41 #define RSBETWEEN_DEBUG 0
43 static RSFD r_open_between (RSET ct, int flag);
44 static void r_close_between (RSFD rfd);
45 static void r_delete_between (RSET ct);
46 static int r_forward_between(RSFD rfd, void *buf,
47 TERMID *term, const void *untilbuf);
48 static int r_read_between (RSFD rfd, void *buf, TERMID *term );
49 static int r_write_between (RSFD rfd, const void *buf);
50 static void r_pos_between (RSFD rfd, double *current, double *total);
51 static void r_get_terms(RSET ct, TERMID *terms, int maxterms, int *curterm);
53 static const struct rset_control control =
67 const struct rset_control *rset_kind_between = &control;
69 struct rset_between_info {
70 RSET rset_l; /* left arg, start tag */
71 RSET rset_m; /* the thing itself */
72 RSET rset_r; /* right arg, end tag */
73 RSET rset_attr; /* attributes , optional */
76 struct rset_between_rfd {
89 TERMID term_m; /* we only return terms for the mid argument */
90 int level; /* counting start/end tags */
95 static void log2 (struct rset_between_rfd *p, char *msg, int cmp_l, int cmp_r)
100 logf(LOG_DEBUG,"btw: %s l=%s(%d/%d) m=%s(%d) r=%s(%d/%d), lev=%d",
102 (*p->info->printer)(p->buf_l, buf_l), p->more_l, cmp_l,
103 (*p->info->printer)(p->buf_m, buf_m), p->more_m,
104 (*p->info->printer)(p->buf_r, buf_r), p->more_r, cmp_r,
109 RSET rsbetween_create( NMEM nmem, const struct key_control *kcontrol,
111 RSET rset_l, RSET rset_m, RSET rset_r, RSET rset_attr)
113 RSET rnew=rset_create_base(&control, nmem, kcontrol, scope,0);
114 struct rset_between_info *info=
115 (struct rset_between_info *) nmem_malloc(rnew->nmem,sizeof(*info));
116 info->rset_l = rset_l;
117 info->rset_m = rset_m;
118 info->rset_r = rset_r;
119 info->rset_attr = rset_attr;
125 static void r_delete_between (RSET ct)
127 struct rset_between_info *info = (struct rset_between_info *) ct->priv;
129 rset_delete (info->rset_l);
130 rset_delete (info->rset_m);
131 rset_delete (info->rset_r);
133 rset_delete (info->rset_attr);
137 static RSFD r_open_between (RSET ct, int flag)
139 struct rset_between_info *info = (struct rset_between_info *) ct->priv;
141 struct rset_between_rfd *p;
143 if (flag & RSETF_WRITE)
145 logf (LOG_FATAL, "between set type is read-only");
148 rfd=rfd_create_base(ct);
150 p=(struct rset_between_rfd *)rfd->priv;
152 p = (struct rset_between_rfd *) nmem_malloc(ct->nmem, (sizeof(*p)));
154 p->buf_l = nmem_malloc(ct->nmem, (ct->keycontrol->key_size));
155 p->buf_m = nmem_malloc(ct->nmem, (ct->keycontrol->key_size));
156 p->buf_r = nmem_malloc(ct->nmem, (ct->keycontrol->key_size));
157 p->buf_attr = nmem_malloc(ct->nmem, (ct->keycontrol->key_size));
160 p->rfd_l = rset_open (info->rset_l, RSETF_READ);
161 p->rfd_m = rset_open (info->rset_m, RSETF_READ);
162 p->rfd_r = rset_open (info->rset_r, RSETF_READ);
164 p->more_l = rset_read (p->rfd_l, p->buf_l,NULL);
165 p->more_m = rset_read (p->rfd_m, p->buf_m, &p->term_m);
166 p->more_r = rset_read (p->rfd_r, p->buf_r,NULL);
169 p->rfd_attr = rset_open (info->rset_attr, RSETF_READ);
170 p->more_attr = rset_read (p->rfd_attr, p->buf_attr, NULL);
177 static void r_close_between (RSFD rfd)
179 struct rset_between_info *info =(struct rset_between_info *)rfd->rset->priv;
180 struct rset_between_rfd *p=(struct rset_between_rfd *)rfd->priv;
182 rset_close (p->rfd_l);
183 rset_close (p->rfd_m);
184 rset_close (p->rfd_r);
186 rset_close (p->rfd_attr);
187 rfd_delete_base(rfd);
192 static int r_forward_between(RSFD rfd, void *buf,
193 TERMID *term, const void *untilbuf)
195 struct rset_between_rfd *p=(struct rset_between_rfd *)rfd->priv;
198 log2( p, "fwd: before forward", 0,0);
200 /* It is enough to forward the m pointer here, the read will */
201 /* naturally forward the l, m, and attr pointers */
203 p->more_m=rset_forward(p->rfd_m, p->buf_m, term, untilbuf);
205 log2( p, "fwd: after forward M", 0,0);
207 rc = r_read_between(rfd, buf, term);
209 log2( p, "fwd: after forward", 0,0);
217 static int r_read_between (RSFD rfd, void *buf, TERMID *term)
219 struct rset_between_info *info =(struct rset_between_info *)rfd->rset->priv;
220 struct rset_between_rfd *p=(struct rset_between_rfd *)rfd->priv;
221 const struct key_control *kctrl=rfd->rset->keycontrol;
229 log2( p, "start of loop", cmp_l, cmp_r);
232 /* forward L until past m, count levels, note rec boundaries */
234 cmp_l= (*kctrl->cmp)(p->buf_l, p->buf_m);
238 cmp_l=rfd->rset->scope; /* past this record */
241 log2( p, "after first L", cmp_l, cmp_r);
244 while (cmp_l < 0) /* l before m */
246 if (cmp_l <= - rfd->rset->scope) /* ==-2 */
247 p->level=0; /* earlier record */
248 if (cmp_l > - rfd->rset->scope) /* == -1 */
250 p->level++; /* relevant start tag */
252 if (!info->rset_attr)
260 cmp_attr = (*kctrl->cmp)(p->buf_attr, p->buf_l);
266 else if (cmp_attr > 0)
268 else if (cmp_attr > - rfd->rset->scope) /* == -1 */
269 p->more_attr = rset_read (p->rfd_attr,
271 /* if we had a forward that went all the way to
272 * the seqno, we could use that. But fwd only goes
274 else if (cmp_attr <= - rfd->rset->scope) /* ==-2 */
276 p->more_attr = rset_forward( p->rfd_attr,
277 p->buf_attr, NULL, p->buf_l);
279 logf(LOG_DEBUG, "btw: after frowarding attr m=%d",
283 } /* while more_attr */
288 if (cmp_l <= - rfd->rset->scope )/* ==-2 */
292 p->more_l=rset_forward(p->rfd_l, p->buf_l, NULL, p->buf_m);
294 cmp_l= (*kctrl->cmp)(p->buf_l, p->buf_m);
296 cmp_l=rfd->rset->scope; /*2*/
298 log2( p, "after forwarding L", cmp_l, cmp_r);
303 p->more_l = rset_read (p->rfd_l, p->buf_l, NULL);
306 p->more_l = rset_read (p->rfd_l, p->buf_l, NULL);
310 cmp_l= (*kctrl->cmp)(p->buf_l, p->buf_m);
313 cmp_l=rfd->rset->scope; /*2*/
315 log2( p, "end of L loop", cmp_l, cmp_r);
320 /* forward R until past m, count levels */
322 log2( p, "Before moving R", cmp_l, cmp_r);
325 cmp_r= (*kctrl->cmp)(p->buf_r, p->buf_m);
327 cmp_r=rfd->rset->scope; /*2*/
329 log2( p, "after first R", cmp_l, cmp_r);
331 while (cmp_r < 0) /* r before m */
333 /* -2, earlier record, don't count level */
334 if (cmp_r > -rfd->rset->scope) /* == -1 */
335 p->level--; /* relevant end tag */
339 if (cmp_r <= - rfd->rset->scope) /* == -2 */
341 p->more_r=rset_forward(p->rfd_r, p->buf_r, NULL, p->buf_m);
344 p->more_r = rset_read (p->rfd_r, p->buf_r, NULL);
347 cmp_r= (*kctrl->cmp)(p->buf_r, p->buf_m);
350 p->more_r = rset_read (p->rfd_r, p->buf_r, NULL);
351 cmp_r= (*kctrl->cmp)(p->buf_r, p->buf_m);
355 cmp_r=rfd->rset->scope; /*2*/
357 log2( p, "End of R loop", cmp_l, cmp_r);
361 if ( ( p->level <= 0 ) && ! p->more_l)
362 return 0; /* no more start tags, nothing more to find */
364 if ( attr_match && p->level > 0) /* within a tag pair (or deeper) */
366 memcpy (buf, p->buf_m, kctrl->key_size);
370 log2( p, "Returning a hit (and forwarding m)", cmp_l, cmp_r);
372 p->more_m = rset_read (p->rfd_m, p->buf_m, NULL);
373 if (cmp_l >= rfd->rset->scope) /* == 2 */
378 else if ( ! p->more_l ) /* not in data, no more starts */
381 log2( p, "no more starts, exiting without a hit", cmp_l, cmp_r);
383 return 0; /* ergo, nothing can be found. stop scanning */
386 if (cmp_l >= rfd->rset->scope) /* == 2 */
389 p->more_m=rset_forward(p->rfd_m, p->buf_m, &p->term_m, p->buf_l);
392 p->more_m = rset_read (p->rfd_m, p->buf_m, &p->term_m);
395 if (cmp_l >= rfd->rset->scope ) /* == 2 */
397 p->more_m = rset_read (p->rfd_m, p->buf_m);
400 log2( p, "End of M loop", cmp_l, cmp_r);
405 log2( p, "Exiting, nothing more in m", cmp_l, cmp_r);
407 return 0; /* no more data possible */
413 static int r_write_between (RSFD rfd, const void *buf)
415 logf (LOG_FATAL, "between set type is read-only");
420 static void r_pos_between (RSFD rfd, double *current, double *total)
422 struct rset_between_rfd *p=(struct rset_between_rfd *)rfd->priv;
428 rset_pos(p->rfd_l, &lcur, <ot);
429 rset_pos(p->rfd_m, &mcur, &mtot);
430 rset_pos(p->rfd_r, &rcur, &rtot);
431 if ( (ltot<0) && (mtot<0) && (rtot<0) ) { /*no position */
432 *current=mcur; /* return same as you got */
433 *total=mtot; /* probably -1 for not available */
435 if ( ltot<0) { ltot=0; lcur=0;} /* if only one useful, use it */
436 if ( mtot<0) { mtot=0; mcur=0;}
437 if ( rtot<0) { rtot=0; rcur=0;}
438 if ( ltot+mtot+rtot < 1 ) { /* empty rset */
443 r=1.0*(lcur+mcur+rcur)/(ltot+mtot+rtot); /* weighed average of l and r */
447 yaz_log(LOG_DEBUG,"betw_pos: (%s/%s) %0.1f/%0.1f= %0.4f ",
448 info->rset_l->control->desc, info->rset_r->control->desc,
449 *current, *total, r);
453 static void r_get_terms(RSET ct, TERMID *terms, int maxterms, int *curterm)
455 struct rset_between_info *info = (struct rset_between_info *) ct->priv;
456 rset_getterms(info->rset_m, terms, maxterms, curterm);