1 /* $Id: rsbetween.c,v 1.23 2004-08-31 10:43:36 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).
39 #include <rsbetween.h>
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,
48 int (*cmpfunc)(const void *p1, const void *p2),
49 const void *untilbuf);
50 static int r_read_between (RSFD rfd, void *buf);
51 static int r_write_between (RSFD rfd, const void *buf);
52 static void r_pos_between (RSFD rfd, double *current, double *total);
54 static const struct rset_control control =
61 r_forward_between, /* rset_default_forward, */
68 const struct rset_control *rset_kind_between = &control;
70 struct rset_between_info {
76 int (*cmp)(const void *p1, const void *p2);
77 char *(*printer)(const void *p1, char *buf);
80 struct rset_between_rfd {
94 struct rset_between_rfd *next;
95 struct rset_between_info *info;
100 static void log2 (struct rset_between_rfd *p, char *msg, int cmp_l, int cmp_r)
105 logf(LOG_DEBUG,"btw: %s l=%s(%d/%d) m=%s(%d) r=%s(%d/%d), lev=%d",
107 (*p->info->printer)(p->buf_l, buf_l), p->more_l, cmp_l,
108 (*p->info->printer)(p->buf_m, buf_m), p->more_m,
109 (*p->info->printer)(p->buf_r, buf_r), p->more_r, cmp_r,
114 RSET rsbetween_create( NMEM nmem, int key_size,
115 int (*cmp)(const void *p1, const void *p2),
116 RSET rset_l, RSET rset_m, RSET rset_r, RSET rset_attr,
117 char *(*printer)(const void *p1, char *buf) )
119 RSET rnew=rset_create_base(&control, nmem);
120 struct rset_between_info *info;
121 info = (struct rset_between_info *) nmem_malloc(rnew->nmem,sizeof(*info));
122 info->key_size = key_size;
123 info->rset_l = rset_l;
124 info->rset_m = rset_m;
125 info->rset_r = rset_r;
126 info->rset_attr = rset_attr;
128 info->printer = printer;
135 static void r_delete_between (RSET ct)
137 struct rset_between_info *info = (struct rset_between_info *) ct->priv;
139 rset_delete (info->rset_l);
140 rset_delete (info->rset_m);
141 rset_delete (info->rset_r);
143 rset_delete (info->rset_attr);
147 static RSFD r_open_between (RSET ct, int flag)
149 struct rset_between_info *info = (struct rset_between_info *) ct->priv;
151 struct rset_between_rfd *p;
153 if (flag & RSETF_WRITE)
155 logf (LOG_FATAL, "between set type is read-only");
158 rfd=rfd_create_base(ct);
160 p=(struct rset_between_rfd *)rfd->priv;
162 p = (struct rset_between_rfd *) nmem_malloc(ct->nmem, (sizeof(*p)));
164 p->buf_l = nmem_malloc(ct->nmem, (info->key_size));
165 p->buf_m = nmem_malloc(ct->nmem, (info->key_size));
166 p->buf_r = nmem_malloc(ct->nmem, (info->key_size));
167 p->buf_attr = nmem_malloc(ct->nmem, (info->key_size));
170 p->rfd_l = rset_open (info->rset_l, RSETF_READ);
171 p->rfd_m = rset_open (info->rset_m, RSETF_READ);
172 p->rfd_r = rset_open (info->rset_r, RSETF_READ);
174 p->more_l = rset_read (p->rfd_l, p->buf_l);
175 p->more_m = rset_read (p->rfd_m, p->buf_m);
176 p->more_r = rset_read (p->rfd_r, p->buf_r);
179 p->rfd_attr = rset_open (info->rset_attr, RSETF_READ);
180 p->more_attr = rset_read (p->rfd_attr, p->buf_attr);
187 static void r_close_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;
192 rset_close (p->rfd_l);
193 rset_close (p->rfd_m);
194 rset_close (p->rfd_r);
196 rset_close (p->rfd_attr);
197 rfd_delete_base(rfd);
200 static void r_rewind_between (RSFD rfd)
202 struct rset_between_info *info =(struct rset_between_info *)rfd->rset->priv;
203 struct rset_between_rfd *p=(struct rset_between_rfd *)rfd->priv;
206 logf (LOG_DEBUG, "rsbetween_rewind");
208 rset_rewind (p->rfd_l);
209 rset_rewind (p->rfd_m);
210 rset_rewind (p->rfd_r);
211 p->more_l = rset_read (p->rfd_l, p->buf_l);
212 p->more_m = rset_read (p->rfd_m, p->buf_m);
213 p->more_r = rset_read (p->rfd_r, p->buf_r);
216 rset_rewind (p->rfd_attr);
217 p->more_attr = rset_read (p->rfd_attr, p->buf_attr);
225 static int r_forward_between(RSFD rfd, void *buf,
226 int (*cmpfunc)(const void *p1, const void *p2),
227 const void *untilbuf)
229 struct rset_between_info *info =(struct rset_between_info *)rfd->rset->priv;
230 struct rset_between_rfd *p=(struct rset_between_rfd *)rfd->priv;
233 log2( p, "fwd: before forward", 0,0);
235 /* It is enough to forward the m pointer here, the read will */
236 /* naturally forward the l, m, and attr pointers */
238 p->more_m=rset_forward(p->rfd_m, p->buf_m,
241 log2( p, "fwd: after forward M", 0,0);
243 rc = r_read_between(rfd, buf);
245 log2( p, "fwd: after forward", 0,0);
253 static int r_read_between (RSFD rfd, void *buf)
255 struct rset_between_info *info =(struct rset_between_info *)rfd->rset->priv;
256 struct rset_between_rfd *p=(struct rset_between_rfd *)rfd->priv;
264 log2( p, "start of loop", cmp_l, cmp_r);
267 /* forward L until past m, count levels, note rec boundaries */
269 cmp_l= (*info->cmp)(p->buf_l, p->buf_m);
273 cmp_l=2; /* past this record */
276 log2( p, "after first L", cmp_l, cmp_r);
279 while (cmp_l < 0) /* l before m */
282 p->level=0; /* earlier record */
285 p->level++; /* relevant start tag */
287 if (!info->rset_attr)
295 cmp_attr = (*info->cmp)(p->buf_attr, p->buf_l);
301 else if (cmp_attr > 0)
303 else if (cmp_attr==-1)
304 p->more_attr = rset_read (p->rfd_attr, p->buf_attr);
305 /* if we had a forward that went all the way to
306 * the seqno, we could use that. But fwd only goes
308 else if (cmp_attr==-2)
310 p->more_attr = rset_forward( p->rfd_attr,
311 p->buf_attr, info->cmp, p->buf_l);
313 logf(LOG_DEBUG, "btw: after frowarding attr m=%d",p->more_attr);
316 } /* while more_attr */
325 p->more_l=rset_forward(p->rfd_l,
326 p->buf_l, info->cmp, p->buf_m);
328 cmp_l= (*info->cmp)(p->buf_l, p->buf_m);
332 log2( p, "after forwarding L", cmp_l, cmp_r);
337 p->more_l = rset_read (p->rfd_l, p->buf_l);
340 p->more_l = rset_read (p->rfd_l, p->buf_l);
344 cmp_l= (*info->cmp)(p->buf_l, p->buf_m);
349 log2( p, "end of L loop", cmp_l, cmp_r);
354 /* forward R until past m, count levels */
356 log2( p, "Before moving R", cmp_l, cmp_r);
359 cmp_r= (*info->cmp)(p->buf_r, p->buf_m);
363 log2( p, "after first R", cmp_l, cmp_r);
365 while (cmp_r < 0) /* r before m */
367 /* -2, earlier record, don't count level */
369 p->level--; /* relevant end tag */
375 p->more_r=rset_forward(p->rfd_r,
376 p->buf_r, info->cmp, p->buf_m);
379 p->more_r = rset_read (p->rfd_r, p->buf_r);
382 cmp_r= (*info->cmp)(p->buf_r, p->buf_m);
385 p->more_r = rset_read (p->rfd_r, p->buf_r);
386 cmp_r= (*info->cmp)(p->buf_r, p->buf_m);
392 log2( p, "End of R loop", cmp_l, cmp_r);
396 if ( ( p->level <= 0 ) && ! p->more_l)
397 return 0; /* no more start tags, nothing more to find */
399 if ( attr_match && p->level > 0) /* within a tag pair (or deeper) */
401 memcpy (buf, p->buf_m, info->key_size);
403 log2( p, "Returning a hit (and forwarding m)", cmp_l, cmp_r);
405 p->more_m = rset_read (p->rfd_m, p->buf_m);
411 else if ( ! p->more_l ) /* not in data, no more starts */
414 log2( p, "no more starts, exiting without a hit", cmp_l, cmp_r);
416 return 0; /* ergo, nothing can be found. stop scanning */
422 p->more_m=rset_forward(p->rfd_m,
423 p->buf_m, info->cmp, p->buf_l);
426 p->more_m = rset_read (p->rfd_m, p->buf_m);
431 p->more_m = rset_read (p->rfd_m, p->buf_m);
434 log2( p, "End of M loop", cmp_l, cmp_r);
439 log2( p, "Exiting, nothing more in m", cmp_l, cmp_r);
441 return 0; /* no more data possible */
447 static int r_write_between (RSFD rfd, const void *buf)
449 logf (LOG_FATAL, "between set type is read-only");
454 static void r_pos_between (RSFD rfd, double *current, double *total)
456 struct rset_between_rfd *p=(struct rset_between_rfd *)rfd->priv;
462 rset_pos(p->rfd_l, &lcur, <ot);
463 rset_pos(p->rfd_m, &mcur, &mtot);
464 rset_pos(p->rfd_r, &rcur, &rtot);
465 if ( (ltot<0) && (mtot<0) && (rtot<0) ) { /*no position */
466 *current=mcur; /* return same as you got */
467 *total=mtot; /* probably -1 for not available */
469 if ( ltot<0) { ltot=0; lcur=0;} /* if only one useful, use it */
470 if ( mtot<0) { mtot=0; mcur=0;}
471 if ( rtot<0) { rtot=0; rcur=0;}
472 if ( ltot+mtot+rtot < 1 ) { /* empty rset */
477 r=1.0*(lcur+mcur+rcur)/(ltot+mtot+rtot); /* weighed average of l and r */
481 yaz_log(LOG_DEBUG,"betw_pos: (%s/%s) %0.1f/%0.1f= %0.4f ",
482 info->rset_l->control->desc, info->rset_r->control->desc,
483 *current, *total, r);