rset/rsprox.c

   1 /* This file is part of the Zebra server.
   2    Copyright (C) 1994-2009 Index Data
   3
   4 Zebra is free software; you can redistribute it and/or modify it under
   5 the terms of the GNU General Public License as published by the Free
   6 Software Foundation; either version 2, or (at your option) any later
   7 version.
   8
   9 Zebra is distributed in the hope that it will be useful, but WITHOUT ANY
  10 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12 for more details.
  13
  14 You should have received a copy of the GNU General Public License
  15 along with this program; if not, write to the Free Software
  16 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17
  18 */
  19
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <assert.h>
  24
  25 #include <idzebra/util.h>
  26 #include <rset.h>
  27
  28 #ifndef RSET_DEBUG
  29 #define RSET_DEBUG 0
  30 #endif
  31
  32 static RSFD r_open (RSET ct, int flag);
  33 static void r_close (RSFD rfd);
  34 static void r_delete (RSET ct);
  35 static int r_forward(RSFD rfd, void *buf, TERMID *term, const void *untilbuf);
  36 static int r_read (RSFD rfd, void *buf, TERMID *term);
  37 static int r_write (RSFD rfd, const void *buf);
  38 static void r_pos (RSFD rfd, double *current, double *total);
  39 static void r_get_terms(RSET ct, TERMID *terms, int maxterms, int *curterm);
  40
  41 static const struct rset_control control =
  42 {
  43     "prox",
  44     r_delete,
  45     r_get_terms,
  46     r_open,
  47     r_close,
  48     r_forward,
  49     r_pos,
  50     r_read,
  51     r_write,
  52 };
  53
  54 struct rset_prox_info {
  55     int ordered;
  56     int exclusion;
  57     int relation;
  58     int distance;
  59 };
  60
  61 struct rset_prox_rfd {
  62     RSFD *rfd;
  63     char **buf;  /* lookahead key buffers */
  64     char *more;  /* more in each lookahead? */
  65     TERMID *terms; /* lookahead terms */
  66     zint hits;
  67 };
  68
  69
  70 RSET rset_create_prox(NMEM nmem, struct rset_key_control *kcontrol,
  71                       int scope,
  72                       int rset_no, RSET *rset,
  73                       int ordered, int exclusion,
  74                       int relation, int distance)
  75 {
  76     RSET rnew = rset_create_base(&control, nmem, kcontrol, scope, 0,
  77                                  rset_no, rset);
  78     struct rset_prox_info *info;
  79     info = (struct rset_prox_info *) nmem_malloc(rnew->nmem,sizeof(*info));
  80     info->ordered = ordered;
  81     info->exclusion = exclusion;
  82     info->relation = relation;
  83     info->distance = distance;
  84     rnew->priv = info;
  85     return rnew;
  86 }
  87
  88 static void r_delete (RSET ct)
  89 {
  90 }
  91
  92 static RSFD r_open (RSET ct, int flag)
  93 {
  94     RSFD rfd;
  95     struct rset_prox_rfd *p;
  96     int i;
  97
  98     if (flag & RSETF_WRITE)
  99     {
 100         yaz_log(YLOG_FATAL, "prox set type is read-only");
 101         return NULL;
 102     }
 103     rfd = rfd_create_base(ct);
 104     if (rfd->priv)
 105         p = (struct rset_prox_rfd *)(rfd->priv);
 106     else {
 107         p = (struct rset_prox_rfd *) nmem_malloc(ct->nmem,sizeof(*p));
 108         rfd->priv = p;
 109         p->more = nmem_malloc (ct->nmem,sizeof(*p->more) * ct->no_children);
 110         p->buf = nmem_malloc(ct->nmem,sizeof(*p->buf) * ct->no_children);
 111         p->terms = nmem_malloc(ct->nmem,sizeof(*p->terms) * ct->no_children);
 112         for (i = 0; i < ct->no_children; i++)
 113         {
 114             p->buf[i] = nmem_malloc(ct->nmem,ct->keycontrol->key_size);
 115             p->terms[i] = 0;
 116         }
 117         p->rfd = nmem_malloc(ct->nmem,sizeof(*p->rfd) * ct->no_children);
 118     }
 119     yaz_log(YLOG_DEBUG,"rsprox (%s) open [%p] n=%d",
 120             ct->control->desc, rfd, ct->no_children);
 121
 122     for (i = 0; i < ct->no_children; i++) {
 123         p->rfd[i] = rset_open (ct->children[i], RSETF_READ);
 124         p->more[i] = rset_read (p->rfd[i], p->buf[i], &p->terms[i]);
 125     }
 126     p->hits = 0;
 127     return rfd;
 128 }
 129
 130 static void r_close (RSFD rfd)
 131 {
 132     RSET ct = rfd->rset;
 133     struct rset_prox_rfd *p = (struct rset_prox_rfd *)(rfd->priv);
 134
 135     int i;
 136     for (i = 0; i<ct->no_children; i++)
 137         rset_close(p->rfd[i]);
 138 }
 139
 140 static int r_forward(RSFD rfd, void *buf, TERMID *term, const void *untilbuf)
 141 {
 142     RSET ct = rfd->rset;
 143     struct rset_prox_info *info = (struct rset_prox_info *)(ct->priv);
 144     struct rset_prox_rfd *p = (struct rset_prox_rfd *)(rfd->priv);
 145     const struct rset_key_control *kctrl = ct->keycontrol;
 146     int cmp = 0;
 147     int i;
 148
 149     if (untilbuf)
 150     {
 151         /* it is enough to forward first one. Other will follow. */
 152         if ( p->more[0] &&   /* was: cmp >=2 */
 153            ((kctrl->cmp)(untilbuf, p->buf[0]) >= rfd->rset->scope) )
 154             p->more[0] = rset_forward(p->rfd[0], p->buf[0],
 155                                       &p->terms[0], untilbuf);
 156     }
 157     if (info->ordered && info->relation == 3 && info->exclusion == 0
 158         && info->distance == 1)
 159     {
 160         while (p->more[0])
 161         {
 162             for (i = 1; i < ct->no_children; i++)
 163             {
 164                 if (!p->more[i])
 165                 {
 166                     p->more[0] = 0; /* saves us a goto out of while loop. */
 167                     break;
 168                 }
 169                 cmp = (*kctrl->cmp) (p->buf[i], p->buf[i-1]);
 170                 if (cmp >= rfd->rset->scope )  /* cmp>1 */
 171                 {
 172                     p->more[i-1] = rset_forward (p->rfd[i-1],
 173                                                  p->buf[i-1],
 174                                                  &p->terms[i-1],
 175                                                  p->buf[i]);
 176                     break;
 177                 }
 178                 else if ( cmp>0 ) /* cmp == 1*/
 179                 {
 180                     if ((*kctrl->getseq)(p->buf[i-1]) +1 !=
 181                         (*kctrl->getseq)(p->buf[i]))
 182                     { /* FIXME - We need more flexible multilevel stuff */
 183                         p->more[i-1] = rset_read ( p->rfd[i-1], p->buf[i-1],
 184                                                    &p->terms[i-1]);
 185                         break;
 186                     }
 187                 }
 188                 else
 189                 {
 190                     p->more[i] = rset_forward (p->rfd[i],
 191                                   p->buf[i], &p->terms[i], p->buf[i-1]);
 192                     break;
 193                 }
 194             }
 195             if (i == ct->no_children)
 196             {
 197                 i = ct->no_children-1;
 198                 memcpy(buf, p->buf[i], kctrl->key_size);
 199                 if (term)
 200                     *term = p->terms[i];
 201                 p->more[i] = rset_read(p->rfd[i], p->buf[i], &p->terms[i]);
 202                 p->hits++;
 203                 return 1;
 204             }
 205         }
 206     }
 207     else if (ct->no_children == 2)
 208     {
 209         while (p->more[0] && p->more[1])
 210         {
 211             int cmp = (*kctrl->cmp)(p->buf[0], p->buf[1]);
 212             if ( cmp <= - rfd->rset->scope) /* cmp<-1*/
 213                 p->more[0] = rset_forward (p->rfd[0], p->buf[0],
 214                                            &p->terms[0],p->buf[1]);
 215             else if ( cmp >= rfd->rset->scope ) /* cmp>1 */
 216                 p->more[1] = rset_forward (p->rfd[1], p->buf[1],
 217                                            &p->terms[1],p->buf[0]);
 218             else
 219             {
 220                 zint seqno[500]; /* FIXME - why 500 ?? */
 221                 int n = 0;
 222
 223                 seqno[n++] = (*kctrl->getseq)(p->buf[0]);
 224                 while ((p->more[0] = rset_read (p->rfd[0],
 225                                         p->buf[0], &p->terms[0])))
 226                 {
 227                     cmp = (*kctrl->cmp)(p->buf[0], p->buf[1]);
 228                     if (cmp <= - rfd->rset->scope || cmp >= rfd->rset->scope)
 229                         break;
 230                     if (n < 500)
 231                         seqno[n++] = (*kctrl->getseq)(p->buf[0]);
 232                 }
 233                 for (i = 0; i<n; i++)
 234                 {
 235                     zint diff = (*kctrl->getseq)(p->buf[1]) - seqno[i];
 236                     int excl = info->exclusion;
 237                     if (!info->ordered && diff < 0)
 238                         diff = -diff;
 239                     switch (info->relation)
 240                     {
 241                     case 1:      /* < */
 242                         if (diff < info->distance && diff >= 0)
 243                             excl = !excl;
 244                         break;
 245                     case 2:      /* <= */
 246                         if (diff <= info->distance && diff >= 0)
 247                             excl = !excl;
 248                         break;
 249                     case 3:      /* == */
 250                         if (diff == info->distance && diff >= 0)
 251                             excl = !excl;
 252                         break;
 253                     case 4:      /* >= */
 254                         if (diff >= info->distance && diff >= 0)
 255                             excl = !excl;
 256                         break;
 257                     case 5:      /* > */
 258                         if (diff > info->distance && diff >= 0)
 259                             excl = !excl;
 260                         break;
 261                     case 6:      /* != */
 262                         if (diff != info->distance && diff >= 0)
 263                             excl = !excl;
 264                         break;
 265                     }
 266                     if (excl)
 267                     {
 268                         memcpy (buf, p->buf[1], kctrl->key_size);
 269                         if (term)
 270                             *term = p->terms[1];
 271                         p->more[1] = rset_read ( p->rfd[1], p->buf[1],
 272                                                  &p->terms[1]);
 273                         p->hits++;
 274                         return 1;
 275                     }
 276                 }
 277                 p->more[1] = rset_read (p->rfd[1], p->buf[1], &p->terms[1]);
 278             }
 279         }
 280     }
 281     return 0;
 282 }
 283
 284
 285 static int r_read (RSFD rfd, void *buf, TERMID *term)
 286 {
 287     return r_forward(rfd, buf, term, 0);
 288 }
 289
 290 static int r_write (RSFD rfd, const void *buf)
 291 {
 292     yaz_log(YLOG_FATAL, "prox set type is read-only");
 293     return -1;
 294 }
 295
 296 static void r_pos (RSFD rfd, double *current, double *total)
 297 {
 298     RSET ct = rfd->rset;
 299     struct rset_prox_rfd *p = (struct rset_prox_rfd *)(rfd->priv);
 300     int i;
 301     double r = 0.0;
 302     double cur, tot = -1.0;
 303     double scur = 0.0, stot = 0.0;
 304
 305     yaz_log(YLOG_DEBUG, "rsprox_pos");
 306
 307     for (i = 0; i < ct->no_children; i++)
 308     {
 309         rset_pos(p->rfd[i],  &cur, &tot);
 310         if (tot>0) {
 311             scur += cur;
 312             stot += tot;
 313         }
 314     }
 315     if (tot <0) {  /* nothing found */
 316         *current = -1;
 317         *total = -1;
 318     } else if (tot < 1) { /* most likely tot==0 */
 319         *current = 0;
 320         *total = 0;
 321     } else {
 322         r = scur/stot;
 323         *current = (double) p->hits;
 324         *total=*current/r ;
 325     }
 326     yaz_log(YLOG_DEBUG,"prox_pos: [%d] %0.1f/%0.1f= %0.4f ",
 327                     i,*current, *total, r);
 328 }
 329
 330 static void r_get_terms(RSET ct, TERMID *terms, int maxterms, int *curterm)
 331 {
 332     int i;
 333     for (i = 0; i<ct->no_children; i++)
 334         rset_getterms(ct->children[i], terms, maxterms, curterm);
 335 }
 336
 337 /*
 338  * Local variables:
 339  * c-basic-offset: 4
 340  * c-file-style: "Stroustrup"
 341  * indent-tabs-mode: nil
 342  * End:
 343  * vim: shiftwidth=4 tabstop=8 expandtab
 344  */
 345