rset/rsprox.c

   1 /* This file is part of the Zebra server.
   2    Copyright (C) 1994-2011 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     {
 108         p = (struct rset_prox_rfd *) nmem_malloc(ct->nmem,sizeof(*p));
 109         rfd->priv = p;
 110         p->more = nmem_malloc(ct->nmem,sizeof(*p->more) * ct->no_children);
 111         p->buf = nmem_malloc(ct->nmem,sizeof(*p->buf) * ct->no_children);
 112         p->terms = nmem_malloc(ct->nmem,sizeof(*p->terms) * ct->no_children);
 113         for (i = 0; i < ct->no_children; i++)
 114         {
 115             p->buf[i] = nmem_malloc(ct->nmem,ct->keycontrol->key_size);
 116             p->terms[i] = 0;
 117         }
 118         p->rfd = nmem_malloc(ct->nmem,sizeof(*p->rfd) * ct->no_children);
 119     }
 120     yaz_log(YLOG_DEBUG,"rsprox (%s) open [%p] n=%d",
 121             ct->control->desc, rfd, ct->no_children);
 122
 123     for (i = 0; i < ct->no_children; i++)
 124     {
 125         p->rfd[i] = rset_open(ct->children[i], RSETF_READ);
 126         p->more[i] = rset_read(p->rfd[i], p->buf[i], &p->terms[i]);
 127     }
 128     p->hits = 0;
 129     return rfd;
 130 }
 131
 132 static void r_close(RSFD rfd)
 133 {
 134     RSET ct = rfd->rset;
 135     struct rset_prox_rfd *p = (struct rset_prox_rfd *)(rfd->priv);
 136
 137     int i;
 138     for (i = 0; i < ct->no_children; i++)
 139         rset_close(p->rfd[i]);
 140 }
 141
 142 static int r_forward(RSFD rfd, void *buf, TERMID *term, const void *untilbuf)
 143 {
 144     RSET ct = rfd->rset;
 145     struct rset_prox_info *info = (struct rset_prox_info *)(ct->priv);
 146     struct rset_prox_rfd *p = (struct rset_prox_rfd *)(rfd->priv);
 147     const struct rset_key_control *kctrl = ct->keycontrol;
 148     int cmp = 0;
 149     int i;
 150
 151     if (untilbuf)
 152     {
 153         /* it is enough to forward first one. Other will follow. */
 154         if (p->more[0] &&   /* was: cmp >=2 */
 155             ((kctrl->cmp)(untilbuf, p->buf[0]) >= rfd->rset->scope) )
 156             p->more[0] = rset_forward(p->rfd[0], p->buf[0],
 157                                       &p->terms[0], untilbuf);
 158     }
 159     if (info->ordered && info->relation <= 3 && info->exclusion == 0)
 160     {
 161         while (p->more[0])
 162         {
 163             for (i = 1; i < ct->no_children; i++)
 164             {
 165                 if (!p->more[i])
 166                 {
 167                     p->more[0] = 0; /* saves us a goto out of while loop. */
 168                     break;
 169                 }
 170                 cmp = (*kctrl->cmp)(p->buf[i], p->buf[i-1]);
 171                 if (cmp >= rfd->rset->scope)  /* not same record */
 172                 {
 173                     p->more[i-1] = rset_forward(p->rfd[i-1],
 174                                                 p->buf[i-1],
 175                                                 &p->terms[i-1],
 176                                                 p->buf[i]);
 177                     break;
 178                 }
 179                 else if (cmp > 0) /* within record and ordered */
 180                 {
 181                     zint diff = (*kctrl->getseq)(p->buf[i]) -
 182                         (*kctrl->getseq)(p->buf[i-1]);
 183                     if (info->relation == 3 && diff == info->distance)
 184                         continue;
 185                     else if (info->relation == 2 && diff <= info->distance)
 186                         continue;
 187                     else if (info->relation == 1 && diff < info->distance)
 188                         continue;
 189
 190                     p->more[i-1] = rset_read(p->rfd[i-1], p->buf[i-1],
 191                                              &p->terms[i-1]);
 192                     break;
 193                 }
 194                 else  /* within record - wrong order */
 195                 {
 196                     p->more[i] = rset_forward(p->rfd[i], p->buf[i],
 197                                               &p->terms[i], p->buf[i-1]);
 198                     break;
 199                 }
 200             }
 201             if (i == ct->no_children)
 202             {
 203                 i = ct->no_children-1;
 204                 memcpy(buf, p->buf[i], kctrl->key_size);
 205                 if (term)
 206                     *term = p->terms[i];
 207                 p->more[i] = rset_read(p->rfd[i], p->buf[i], &p->terms[i]);
 208                 p->hits++;
 209                 return 1;
 210             }
 211         }
 212     }
 213     else if (ct->no_children == 2)
 214     {
 215         while (p->more[0] && p->more[1])
 216         {
 217             int cmp = (*kctrl->cmp)(p->buf[0], p->buf[1]);
 218             if ( cmp <= - rfd->rset->scope) /* cmp<-1*/
 219                 p->more[0] = rset_forward(p->rfd[0], p->buf[0],
 220                                           &p->terms[0],p->buf[1]);
 221             else if ( cmp >= rfd->rset->scope ) /* cmp>1 */
 222                 p->more[1] = rset_forward(p->rfd[1], p->buf[1],
 223                                           &p->terms[1],p->buf[0]);
 224             else
 225             {
 226                 zint seqno[500]; /* FIXME - why 500 ?? */
 227                 int n = 0;
 228
 229                 seqno[n++] = (*kctrl->getseq)(p->buf[0]);
 230                 while ((p->more[0] = rset_read(p->rfd[0],
 231                                                p->buf[0], &p->terms[0])))
 232                 {
 233                     cmp = (*kctrl->cmp)(p->buf[0], p->buf[1]);
 234                     if (cmp <= - rfd->rset->scope || cmp >= rfd->rset->scope)
 235                         break;
 236                     if (n < 500)
 237                         seqno[n++] = (*kctrl->getseq)(p->buf[0]);
 238                 }
 239                 /* set up return buffer.. (save buf[1]) */
 240                 memcpy(buf, p->buf[1], kctrl->key_size);
 241                 if (term)
 242                     *term = p->terms[1];
 243                 while (1)
 244                 {
 245                     for (i = 0; i < n; i++)
 246                     {
 247                         zint diff = (*kctrl->getseq)(p->buf[1]) - seqno[i];
 248                         int excl = info->exclusion;
 249                         if (!info->ordered && diff < 0)
 250                             diff = -diff;
 251                         switch (info->relation)
 252                         {
 253                         case 1:      /* < */
 254                             if (diff < info->distance && diff >= 0)
 255                                 excl = !excl;
 256                             break;
 257                         case 2:      /* <= */
 258                             if (diff <= info->distance && diff >= 0)
 259                                 excl = !excl;
 260                             break;
 261                         case 3:      /* == */
 262                             if (diff == info->distance && diff >= 0)
 263                                 excl = !excl;
 264                             break;
 265                         case 4:      /* >= */
 266                             if (diff >= info->distance && diff >= 0)
 267                                 excl = !excl;
 268                             break;
 269                         case 5:      /* > */
 270                             if (diff > info->distance && diff >= 0)
 271                                 excl = !excl;
 272                             break;
 273                         case 6:      /* != */
 274                             if (diff != info->distance && diff >= 0)
 275                                 excl = !excl;
 276                             break;
 277                         }
 278                         if (excl)
 279                         {
 280                             p->more[1] = rset_read( p->rfd[1], p->buf[1],
 281                                                     &p->terms[1]);
 282                             p->hits++;
 283                             return 1;
 284                         }
 285                     }
 286                     p->more[1] = rset_read(p->rfd[1], p->buf[1], &p->terms[1]);
 287                     if (!p->more[1])
 288                         break;
 289                     cmp = (*kctrl->cmp)(buf, p->buf[1]);
 290                     if (cmp <= - rfd->rset->scope || cmp >= rfd->rset->scope)
 291                         break;
 292                 }
 293             }
 294         }
 295     }
 296     return 0;
 297 }
 298
 299
 300 static int r_read(RSFD rfd, void *buf, TERMID *term)
 301 {
 302     return r_forward(rfd, buf, term, 0);
 303 }
 304
 305 static int r_write(RSFD rfd, const void *buf)
 306 {
 307     yaz_log(YLOG_FATAL, "prox set type is read-only");
 308     return -1;
 309 }
 310
 311 static void r_pos(RSFD rfd, double *current, double *total)
 312 {
 313     RSET ct = rfd->rset;
 314     struct rset_prox_rfd *p = (struct rset_prox_rfd *)(rfd->priv);
 315     int i;
 316     double r = 0.0;
 317     double cur, tot = -1.0;
 318     double scur = 0.0, stot = 0.0;
 319
 320     yaz_log(YLOG_DEBUG, "rsprox_pos");
 321
 322     for (i = 0; i < ct->no_children; i++)
 323     {
 324         rset_pos(p->rfd[i],  &cur, &tot);
 325         if (tot > 0)
 326         {
 327             scur += cur;
 328             stot += tot;
 329         }
 330     }
 331     if (tot < 0)
 332     {  /* nothing found */
 333         *current = -1;
 334         *total = -1;
 335     }
 336     else if (tot < 1)
 337     { /* most likely tot==0 */
 338         *current = 0;
 339         *total = 0;
 340     }
 341     else
 342     {
 343         r = scur/stot;
 344         *current = (double) p->hits;
 345         *total = *current/r ;
 346     }
 347     yaz_log(YLOG_DEBUG,"prox_pos: [%d] %0.1f/%0.1f= %0.4f ",
 348             i,*current, *total, r);
 349 }
 350
 351 static void r_get_terms(RSET ct, TERMID *terms, int maxterms, int *curterm)
 352 {
 353     int i;
 354     for (i = 0; i < ct->no_children; i++)
 355         rset_getterms(ct->children[i], terms, maxterms, curterm);
 356 }
 357
 358 /*
 359  * Local variables:
 360  * c-basic-offset: 4
 361  * c-file-style: "Stroustrup"
 362  * indent-tabs-mode: nil
 363  * End:
 364  * vim: shiftwidth=4 tabstop=8 expandtab
 365  */
 366