1 /* $Id: rsbetween.c,v 1.24 2004-09-01 15:01:32 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 void r_rewind_between (RSFD rfd);
47 static int r_forward_between(RSFD rfd, void *buf, const void *untilbuf);
48 static int r_read_between (RSFD rfd, void *buf);
49 static int r_write_between (RSFD rfd, const void *buf);
50 static void r_pos_between (RSFD rfd, double *current, double *total);
52 static const struct rset_control control =
66 const struct rset_control *rset_kind_between = &control;
68 struct rset_between_info {
69 RSET rset_l; /* left arg, start tag */
70 RSET rset_m; /* the thing itself */
71 RSET rset_r; /* right arg, end tag */
72 RSET rset_attr; /* attributes , optional */
75 struct rset_between_rfd {
88 int level; /* counting start/end tags */
93 static void log2 (struct rset_between_rfd *p, char *msg, int cmp_l, int cmp_r)
98 logf(LOG_DEBUG,"btw: %s l=%s(%d/%d) m=%s(%d) r=%s(%d/%d), lev=%d",
100 (*p->info->printer)(p->buf_l, buf_l), p->more_l, cmp_l,
101 (*p->info->printer)(p->buf_m, buf_m), p->more_m,
102 (*p->info->printer)(p->buf_r, buf_r), p->more_r, cmp_r,
107 RSET rsbetween_create( NMEM nmem, const struct key_control *kcontrol,
108 RSET rset_l, RSET rset_m, RSET rset_r, RSET rset_attr)
110 RSET rnew=rset_create_base(&control, nmem, kcontrol);
111 struct rset_between_info *info=
112 (struct rset_between_info *) nmem_malloc(rnew->nmem,sizeof(*info));
113 info->rset_l = rset_l;
114 info->rset_m = rset_m;
115 info->rset_r = rset_r;
116 info->rset_attr = rset_attr;
122 static void r_delete_between (RSET ct)
124 struct rset_between_info *info = (struct rset_between_info *) ct->priv;
126 rset_delete (info->rset_l);
127 rset_delete (info->rset_m);
128 rset_delete (info->rset_r);
130 rset_delete (info->rset_attr);
134 static RSFD r_open_between (RSET ct, int flag)
136 struct rset_between_info *info = (struct rset_between_info *) ct->priv;
138 struct rset_between_rfd *p;
140 if (flag & RSETF_WRITE)
142 logf (LOG_FATAL, "between set type is read-only");
145 rfd=rfd_create_base(ct);
147 p=(struct rset_between_rfd *)rfd->priv;
149 p = (struct rset_between_rfd *) nmem_malloc(ct->nmem, (sizeof(*p)));
151 p->buf_l = nmem_malloc(ct->nmem, (ct->keycontrol->key_size));
152 p->buf_m = nmem_malloc(ct->nmem, (ct->keycontrol->key_size));
153 p->buf_r = nmem_malloc(ct->nmem, (ct->keycontrol->key_size));
154 p->buf_attr = nmem_malloc(ct->nmem, (ct->keycontrol->key_size));
157 p->rfd_l = rset_open (info->rset_l, RSETF_READ);
158 p->rfd_m = rset_open (info->rset_m, RSETF_READ);
159 p->rfd_r = rset_open (info->rset_r, RSETF_READ);
161 p->more_l = rset_read (p->rfd_l, p->buf_l);
162 p->more_m = rset_read (p->rfd_m, p->buf_m);
163 p->more_r = rset_read (p->rfd_r, p->buf_r);
166 p->rfd_attr = rset_open (info->rset_attr, RSETF_READ);
167 p->more_attr = rset_read (p->rfd_attr, p->buf_attr);
174 static void r_close_between (RSFD rfd)
176 struct rset_between_info *info =(struct rset_between_info *)rfd->rset->priv;
177 struct rset_between_rfd *p=(struct rset_between_rfd *)rfd->priv;
179 rset_close (p->rfd_l);
180 rset_close (p->rfd_m);
181 rset_close (p->rfd_r);
183 rset_close (p->rfd_attr);
184 rfd_delete_base(rfd);
187 static void r_rewind_between (RSFD rfd)
189 struct rset_between_info *info =(struct rset_between_info *)rfd->rset->priv;
190 struct rset_between_rfd *p=(struct rset_between_rfd *)rfd->priv;
193 logf (LOG_DEBUG, "rsbetween_rewind");
195 rset_rewind (p->rfd_l);
196 rset_rewind (p->rfd_m);
197 rset_rewind (p->rfd_r);
198 p->more_l = rset_read (p->rfd_l, p->buf_l);
199 p->more_m = rset_read (p->rfd_m, p->buf_m);
200 p->more_r = rset_read (p->rfd_r, p->buf_r);
203 rset_rewind (p->rfd_attr);
204 p->more_attr = rset_read (p->rfd_attr, p->buf_attr);
212 static int r_forward_between(RSFD rfd, void *buf, const void *untilbuf)
214 struct rset_between_rfd *p=(struct rset_between_rfd *)rfd->priv;
217 log2( p, "fwd: before forward", 0,0);
219 /* It is enough to forward the m pointer here, the read will */
220 /* naturally forward the l, m, and attr pointers */
222 p->more_m=rset_forward(p->rfd_m, p->buf_m,untilbuf);
224 log2( p, "fwd: after forward M", 0,0);
226 rc = r_read_between(rfd, buf);
228 log2( p, "fwd: after forward", 0,0);
236 static int r_read_between (RSFD rfd, void *buf)
238 struct rset_between_info *info =(struct rset_between_info *)rfd->rset->priv;
239 struct rset_between_rfd *p=(struct rset_between_rfd *)rfd->priv;
240 const struct key_control *kctrl=rfd->rset->keycontrol;
248 log2( p, "start of loop", cmp_l, cmp_r);
251 /* forward L until past m, count levels, note rec boundaries */
253 cmp_l= (*kctrl->cmp)(p->buf_l, p->buf_m);
257 cmp_l=2; /* past this record */
260 log2( p, "after first L", cmp_l, cmp_r);
263 while (cmp_l < 0) /* l before m */
266 p->level=0; /* earlier record */
269 p->level++; /* relevant start tag */
271 if (!info->rset_attr)
279 cmp_attr = (*kctrl->cmp)(p->buf_attr, p->buf_l);
285 else if (cmp_attr > 0)
287 else if (cmp_attr==-1)
288 p->more_attr = rset_read (p->rfd_attr, p->buf_attr);
289 /* if we had a forward that went all the way to
290 * the seqno, we could use that. But fwd only goes
292 else if (cmp_attr==-2)
294 p->more_attr = rset_forward( p->rfd_attr,
295 p->buf_attr, p->buf_l);
297 logf(LOG_DEBUG, "btw: after frowarding attr m=%d",
301 } /* while more_attr */
310 p->more_l=rset_forward(p->rfd_l, p->buf_l, p->buf_m);
312 cmp_l= (*kctrl->cmp)(p->buf_l, p->buf_m);
316 log2( p, "after forwarding L", cmp_l, cmp_r);
321 p->more_l = rset_read (p->rfd_l, p->buf_l);
324 p->more_l = rset_read (p->rfd_l, p->buf_l);
328 cmp_l= (*kctrl->cmp)(p->buf_l, p->buf_m);
333 log2( p, "end of L loop", cmp_l, cmp_r);
338 /* forward R until past m, count levels */
340 log2( p, "Before moving R", cmp_l, cmp_r);
343 cmp_r= (*kctrl->cmp)(p->buf_r, p->buf_m);
347 log2( p, "after first R", cmp_l, cmp_r);
349 while (cmp_r < 0) /* r before m */
351 /* -2, earlier record, don't count level */
353 p->level--; /* relevant end tag */
359 p->more_r=rset_forward(p->rfd_r, p->buf_r, p->buf_m);
362 p->more_r = rset_read (p->rfd_r, p->buf_r);
365 cmp_r= (*kctrl->cmp)(p->buf_r, p->buf_m);
368 p->more_r = rset_read (p->rfd_r, p->buf_r);
369 cmp_r= (*kctrl->cmp)(p->buf_r, p->buf_m);
375 log2( p, "End of R loop", cmp_l, cmp_r);
379 if ( ( p->level <= 0 ) && ! p->more_l)
380 return 0; /* no more start tags, nothing more to find */
382 if ( attr_match && p->level > 0) /* within a tag pair (or deeper) */
384 memcpy (buf, p->buf_m, kctrl->key_size);
386 log2( p, "Returning a hit (and forwarding m)", cmp_l, cmp_r);
388 p->more_m = rset_read (p->rfd_m, p->buf_m);
394 else if ( ! p->more_l ) /* not in data, no more starts */
397 log2( p, "no more starts, exiting without a hit", cmp_l, cmp_r);
399 return 0; /* ergo, nothing can be found. stop scanning */
405 p->more_m=rset_forward(p->rfd_m, p->buf_m, p->buf_l);
408 p->more_m = rset_read (p->rfd_m, p->buf_m);
413 p->more_m = rset_read (p->rfd_m, p->buf_m);
416 log2( p, "End of M loop", cmp_l, cmp_r);
421 log2( p, "Exiting, nothing more in m", cmp_l, cmp_r);
423 return 0; /* no more data possible */
429 static int r_write_between (RSFD rfd, const void *buf)
431 logf (LOG_FATAL, "between set type is read-only");
436 static void r_pos_between (RSFD rfd, double *current, double *total)
438 struct rset_between_rfd *p=(struct rset_between_rfd *)rfd->priv;
444 rset_pos(p->rfd_l, &lcur, <ot);
445 rset_pos(p->rfd_m, &mcur, &mtot);
446 rset_pos(p->rfd_r, &rcur, &rtot);
447 if ( (ltot<0) && (mtot<0) && (rtot<0) ) { /*no position */
448 *current=mcur; /* return same as you got */
449 *total=mtot; /* probably -1 for not available */
451 if ( ltot<0) { ltot=0; lcur=0;} /* if only one useful, use it */
452 if ( mtot<0) { mtot=0; mcur=0;}
453 if ( rtot<0) { rtot=0; rcur=0;}
454 if ( ltot+mtot+rtot < 1 ) { /* empty rset */
459 r=1.0*(lcur+mcur+rcur)/(ltot+mtot+rtot); /* weighed average of l and r */
463 yaz_log(LOG_DEBUG,"betw_pos: (%s/%s) %0.1f/%0.1f= %0.4f ",
464 info->rset_l->control->desc, info->rset_r->control->desc,
465 *current, *total, r);