-/* $Id: rsbetween.c,v 1.29 2004-11-01 15:53:57 heikki Exp $
+/* $Id: rsbetween.c,v 1.30 2004-11-05 17:44:32 heikki Exp $
Copyright (C) 1995,1996,1997,1998,1999,2000,2001,2002
Index Data Aps
* "<title lang=eng>" and "</title>". (This assumes that the attributes are
* indexed to the same seqno as the tags).
*
- * Currently fails to return all hits from a record, which breaks the ranking.
- * This is bug #202. Seems like there is no decent way to get that working
- * with the current implementation. I have planned a new method for doing
- * this, see at the end of this file.
- *
*/
#include <stdio.h>
#include <zebrautl.h>
#include <rset.h>
-#define RSBETWEEN_DEBUG 0
-static RSFD r_open_between (RSET ct, int flag);
-static void r_close_between (RSFD rfd);
-static void r_delete_between (RSET ct);
-static int r_forward_between(RSFD rfd, void *buf,
+static RSFD r_open (RSET ct, int flag);
+static void r_close (RSFD rfd);
+static void r_delete (RSET ct);
+static int r_forward(RSFD rfd, void *buf,
TERMID *term, const void *untilbuf);
-static int r_read_between (RSFD rfd, void *buf, TERMID *term );
-static int r_write_between (RSFD rfd, const void *buf);
-static void r_pos_between (RSFD rfd, double *current, double *total);
+static int r_read(RSFD rfd, void *buf, TERMID *term );
+static int r_write(RSFD rfd, const void *buf);
+static void r_pos(RSFD rfd, double *current, double *total);
static void r_get_terms(RSET ct, TERMID *terms, int maxterms, int *curterm);
static const struct rset_control control =
{
"between",
- r_delete_between,
+ r_delete,
r_get_terms,
- r_open_between,
- r_close_between,
- r_forward_between,
- r_pos_between,
- r_read_between,
- r_write_between,
+ r_open,
+ r_close,
+ r_forward,
+ r_pos,
+ r_read,
+ r_write,
};
const struct rset_control *rset_kind_between = &control;
+#define STARTTAG 0
+#define HIT 1
+#define STOPTAG 2
+#define ATTRTAG 3
+
struct rset_between_info {
- RSET rset_l; /* left arg, start tag */
- RSET rset_m; /* the thing itself */
- RSET rset_r; /* right arg, end tag */
- RSET rset_attr; /* attributes , optional */
+ RSET andset; /* the multi-and of the above */
+ TERMID startterm; /* pseudo terms for detecting which one we read from */
+ TERMID stopterm;
+ TERMID attrterm;
};
struct rset_between_rfd {
- RSFD rfd_l;
- RSFD rfd_m;
- RSFD rfd_r;
- RSFD rfd_attr;
- int more_l;
- int more_m;
- int more_r;
- int more_attr;
- void *buf_l;
- void *buf_m;
- void *buf_r;
- void *buf_attr;
- TERMID term_m; /* we only return terms for the mid argument */
- int level; /* counting start/end tags */
- int attr_match; /* did we have a matching attr for L */
+ RSFD andrfd;
+ void *recbuf; /* a key that tells which record we are in */
+ void *startbuf; /* the start tag */
+ int startbufok; /* we have seen the first start tag */
+ void *attrbuf; /* the attr tag. If these two match, we have attr match */
+ int attrbufok; /* we have seen the first attr tag, can compare */
+ int depth; /* number of start-tags without end-tags */
+ int attrdepth; /* on what depth the attr matched */
zint hits;
};
-#if RSBETWEEN_DEBUG
-static void log2 (RSFD rfd, char *msg, int cmp_l, int cmp_r)
-{
- struct rset_between_rfd *p=(struct rset_between_rfd *)rfd->priv;
- RSET ct = rfd->rset;
- logf(LOG_LOG,"between: %s cmp_l=%d cmp_r=%d", msg, cmp_l, cmp_r);
- (*ct->keycontrol->key_logdump_txt)(LOG_LOG, p->buf_l, "between: L");
- (*ct->keycontrol->key_logdump_txt)(LOG_LOG, p->buf_m, "between: M");
- (*ct->keycontrol->key_logdump_txt)(LOG_LOG, p->buf_r, "between: R");
-}
-#endif
+static int log_level=0;
+static int log_level_initialized=0;
+
RSET rsbetween_create( NMEM nmem, const struct key_control *kcontrol,
int scope,
RSET rnew=rset_create_base(&control, nmem, kcontrol, scope,0);
struct rset_between_info *info=
(struct rset_between_info *) nmem_malloc(rnew->nmem,sizeof(*info));
- info->rset_l = rset_l;
- info->rset_m = rset_m;
- info->rset_r = rset_r;
- info->rset_attr = rset_attr;
+ RSET rsetarray[4];
+ int n=4;
+
+ if (!log_level_initialized)
+ {
+ log_level=yaz_log_module_level("rsbetween");
+ log_level_initialized=1;
+ }
+ rsetarray[STARTTAG] = rset_l;
+ rsetarray[HIT] = rset_m;
+ rsetarray[STOPTAG] = rset_r;
+ rsetarray[ATTRTAG] = rset_attr;
+
+ /* make sure we have decent terms for all rsets. Create dummies if needed*/
+ if (!rsetarray[STARTTAG]->term)
+ {
+ rsetarray[STARTTAG]->term=
+ rset_term_create("<starttag>",strlen("<starttag>"),"",0,nmem);
+ rsetarray[STARTTAG]->term->rset=rsetarray[STARTTAG];
+ }
+ info->startterm=rsetarray[STARTTAG]->term;
+
+ if (!rsetarray[STOPTAG]->term)
+ {
+ rsetarray[STOPTAG]->term=
+ rset_term_create("<stoptag>",strlen("<stoptag>"),"",0,nmem);
+ rsetarray[STOPTAG]->term->rset=rsetarray[STOPTAG];
+ }
+ info->stopterm=rsetarray[STOPTAG]->term;
+
+ if (rset_attr)
+ {
+ if (!rsetarray[ATTRTAG]->term)
+ {
+ rsetarray[ATTRTAG]->term=
+ rset_term_create("<attrtag>",strlen("<attrtag>"),"",0,nmem);
+ rsetarray[ATTRTAG]->term->rset=rsetarray[ATTRTAG];
+ }
+ info->attrterm=rsetarray[ATTRTAG]->term;
+ }
+ else
+ {
+ info->attrterm=NULL;
+ n--; /* smaller and */
+ }
+ info->andset=rsmultiand_create( nmem, kcontrol, scope, n, rsetarray);
rnew->priv=info;
+ logf(log_level,"create rset at %p",rnew);
return rnew;
}
-static void r_delete_between (RSET ct)
+static void r_delete (RSET ct)
{
struct rset_between_info *info = (struct rset_between_info *) ct->priv;
-
- rset_delete (info->rset_l);
- rset_delete (info->rset_m);
- rset_delete (info->rset_r);
- if (info->rset_attr)
- rset_delete (info->rset_attr);
+ logf(log_level,"delete rset at %p",ct);
+ rset_delete(info->andset);
}
-static RSFD r_open_between (RSET ct, int flag)
+static RSFD r_open (RSET ct, int flag)
{
struct rset_between_info *info = (struct rset_between_info *) ct->priv;
RSFD rfd;
else {
p = (struct rset_between_rfd *) nmem_malloc(ct->nmem, (sizeof(*p)));
rfd->priv=p;
- p->buf_l = nmem_malloc(ct->nmem, (ct->keycontrol->key_size));
- p->buf_m = nmem_malloc(ct->nmem, (ct->keycontrol->key_size));
- p->buf_r = nmem_malloc(ct->nmem, (ct->keycontrol->key_size));
- p->buf_attr = nmem_malloc(ct->nmem, (ct->keycontrol->key_size));
+ p->recbuf = nmem_malloc(ct->nmem, (ct->keycontrol->key_size));
+ p->startbuf = nmem_malloc(ct->nmem, (ct->keycontrol->key_size));
+ p->attrbuf = nmem_malloc(ct->nmem, (ct->keycontrol->key_size));
}
-
- p->rfd_l = rset_open (info->rset_l, RSETF_READ);
- p->rfd_m = rset_open (info->rset_m, RSETF_READ);
- p->rfd_r = rset_open (info->rset_r, RSETF_READ);
-
- p->more_l = rset_read (p->rfd_l, p->buf_l,NULL);
- p->more_m = rset_read (p->rfd_m, p->buf_m, &p->term_m);
- p->more_r = rset_read (p->rfd_r, p->buf_r,NULL);
- if (info->rset_attr)
- {
- p->rfd_attr = rset_open (info->rset_attr, RSETF_READ);
- p->more_attr = rset_read (p->rfd_attr, p->buf_attr, NULL);
- p->attr_match=0;
- } else
- p->attr_match=1;
- p->level=0;
- p->hits=0;
+ p->andrfd = rset_open (info->andset, RSETF_READ);
+ p->hits=-1;
+ p->depth=0;
+ p->attrdepth=0;
+ p->attrbufok=0;
+ p->startbufok=0;
+ logf(log_level,"open rset=%p rfd=%p", ct, rfd);
return rfd;
}
-static void r_close_between (RSFD rfd)
+static void r_close (RSFD rfd)
{
- struct rset_between_info *info =(struct rset_between_info *)rfd->rset->priv;
struct rset_between_rfd *p=(struct rset_between_rfd *)rfd->priv;
-
-#if RSBETWEEN_DEBUG
- log2( rfd, "fwd: close. hits:", p->hits,0);
-#endif
- rset_close (p->rfd_l);
- rset_close (p->rfd_m);
- rset_close (p->rfd_r);
- if (info->rset_attr)
- rset_close (p->rfd_attr);
+ logf(log_level,"close rfd=%p", rfd);
+ rset_close (p->andrfd);
rfd_delete_base(rfd);
}
-static int r_forward_between(RSFD rfd, void *buf,
- TERMID *term, const void *untilbuf)
+static int r_forward(RSFD rfd, void *buf,
+ TERMID *term, const void *untilbuf)
{
struct rset_between_rfd *p=(struct rset_between_rfd *)rfd->priv;
int rc;
-#if RSBETWEEN_DEBUG
- log2( rfd, "fwd: before forward", 0,0);
-#endif
- /* It is enough to forward the m pointer here, the read will */
- /* naturally forward the l, m, and attr pointers */
- if (p->more_m)
- p->more_m=rset_forward(p->rfd_m, p->buf_m, term, untilbuf);
-#if RSBETWEEN_DEBUG
- log2( rfd, "fwd: after forward M", 0,0);
-#endif
- rc = r_read_between(rfd, buf, term);
-#if RSBETWEEN_DEBUG
- log2( rfd, "fwd: after forward", 0,0);
-#endif
+ logf(log_level, "forwarding ");
+ rc=rset_forward(p->andrfd,buf,term,untilbuf);
return rc;
}
-
-static int r_read_between (RSFD rfd, void *buf, TERMID *term)
+static void checkattr(RSFD rfd)
{
struct rset_between_info *info =(struct rset_between_info *)rfd->rset->priv;
struct rset_between_rfd *p=(struct rset_between_rfd *)rfd->priv;
const struct key_control *kctrl=rfd->rset->keycontrol;
- int cmp_l=0;
- int cmp_r=0;
-/* int attr_match = 0; */
-
- while (p->more_m)
+ int cmp;
+ if (p->attrdepth)
+ return; /* already found one */
+ if (!info->attrterm)
{
-#if RSBETWEEN_DEBUG
- log2( rfd, "start of loop", cmp_l, cmp_r);
- logf(LOG_LOG,"level=%d. more=%d/%d/%d",
- p->level,p->more_l,p->more_m, p->more_r);
-#endif
-
- /* forward L until past m, count levels, note rec boundaries */
- if (p->more_l)
- cmp_l= (*kctrl->cmp)(p->buf_l, p->buf_m);
- else
+ p->attrdepth=-1; /* matches always */
+ return;
+ }
+ if ( p->startbufok && p->attrbufok )
+ { /* have buffers to compare */
+ cmp=(kctrl->cmp)(p->startbuf,p->attrbuf);
+ if (0==cmp) /* and the keys match */
{
- p->level = 0;
- cmp_l=rfd->rset->scope; /* past this record */
+ p->attrdepth=p->depth;
+ logf(log_level, "found attribute match at depth %d",p->attrdepth);
}
-#if RSBETWEEN_DEBUG
- log2( rfd, "after first L", cmp_l, cmp_r);
- logf(LOG_LOG,"level=%d. more=%d/%d/%d",
- p->level,p->more_l,p->more_m, p->more_r);
-#endif
+ }
+}
- while (cmp_l < 0) /* l before m */
- {
- if (cmp_l <= - rfd->rset->scope) /* ==-2 */
- p->level=0; /* earlier record */
- if (cmp_l > - rfd->rset->scope) /* == -1 */
- {
- p->level++; /* relevant start tag */
-
- if (!info->rset_attr)
- p->attr_match = 1;
- else
- {
- int cmp_attr;
- p->attr_match = 0;
- while (p->more_attr)
- {
- cmp_attr = (*kctrl->cmp)(p->buf_attr, p->buf_l);
- if (cmp_attr == 0)
- {
- p->attr_match = 1;
- break;
- }
- else if (cmp_attr > 0)
- break;
- else if (cmp_attr > - rfd->rset->scope) /* == -1 */
- p->more_attr = rset_read (p->rfd_attr,
- p->buf_attr,NULL);
- /* if we had a forward that went all the way to
- * the seqno, we could use that. But fwd only goes
- * to the sysno */
- else if (cmp_attr <= - rfd->rset->scope) /* ==-2 */
- {
- p->more_attr = rset_forward( p->rfd_attr,
- p->buf_attr, NULL, p->buf_l);
-#if RSBETWEEN_DEBUG
- logf(LOG_LOG, "btw: after frowarding attr m=%d",
- p->more_attr);
-#endif
- }
- } /* while more_attr */
- }
- }
-#define NEWCODE 1
-#if NEWCODE
- if (cmp_l <= - rfd->rset->scope )/* ==-2 */
- {
- if (p->more_l)
- {
- p->more_l=rset_forward(p->rfd_l, p->buf_l, NULL, p->buf_m);
- if (p->more_l)
- cmp_l= (*kctrl->cmp)(p->buf_l, p->buf_m);
- else
- cmp_l=rfd->rset->scope; /*2*/
-#if RSBETWEEN_DEBUG
- log2( rfd, "after forwarding L", cmp_l, cmp_r);
- logf(LOG_LOG,"level=%d. more=%d/%d/%d",
- p->level,p->more_l,p->more_m, p->more_r);
-#endif
- }
- } else
- {
- p->more_l = rset_read (p->rfd_l, p->buf_l, NULL);
- }
-#else
- p->more_l = rset_read (p->rfd_l, p->buf_l, NULL);
-#endif
- if (p->more_l)
- {
- cmp_l= (*kctrl->cmp)(p->buf_l, p->buf_m);
- }
- else
- cmp_l=rfd->rset->scope; /*2*/
-#if RSBETWEEN_DEBUG
- log2( rfd, "end of L loop", cmp_l, cmp_r);
- logf(LOG_LOG,"level=%d. more=%d/%d/%d",
- p->level,p->more_l,p->more_m, p->more_r);
-#endif
- } /* forward L */
-
-
- /* forward R until past m, count levels */
-#if RSBETWEEN_DEBUG
- log2( rfd, "Before moving R", cmp_l, cmp_r);
- logf(LOG_LOG,"level=%d. more=%d/%d/%d",
- p->level,p->more_l,p->more_m, p->more_r);
-#endif
- if (p->more_r)
- cmp_r= (*kctrl->cmp)(p->buf_r, p->buf_m);
- else
- cmp_r=rfd->rset->scope; /*2*/
-#if RSBETWEEN_DEBUG
- log2( rfd, "after first R", cmp_l, cmp_r);
- logf(LOG_LOG,"level=%d. more=%d/%d/%d",
- p->level,p->more_l,p->more_m, p->more_r);
-#endif
- while (cmp_r < 0) /* r before m */
- {
- /* -2, earlier record, don't count level */
- if (cmp_r > -rfd->rset->scope) /* == -1 */
- p->level--; /* relevant end tag */
- if (p->more_r)
- {
-#if NEWCODE
- if (cmp_r <= - rfd->rset->scope) /* == -2 */
- {
- p->more_r=rset_forward(p->rfd_r, p->buf_r, NULL, p->buf_m);
- } else
- {
- p->more_r = rset_read (p->rfd_r, p->buf_r, NULL);
- }
- if (p->more_r)
- cmp_r= (*kctrl->cmp)(p->buf_r, p->buf_m);
-
-#else
- p->more_r = rset_read (p->rfd_r, p->buf_r, NULL);
- cmp_r= (*kctrl->cmp)(p->buf_r, p->buf_m);
-#endif
- }
- else
- cmp_r=rfd->rset->scope; /*2*/
-#if RSBETWEEN_DEBUG
- log2( rfd, "End of R loop", cmp_l, cmp_r);
- logf(LOG_LOG,"level=%d. more=%d/%d/%d am=%d",
- p->level,p->more_l,p->more_m, p->more_r, p->attr_match);
-#endif
- } /* forward R */
-
- if ( ( p->level <= 0 ) && ! p->more_l)
- {
-#if RSBETWEEN_DEBUG
- logf(LOG_LOG,"no more_l, returning zero");
-#endif
- return 0; /* no more start tags, nothing more to find */
+
+static int r_read (RSFD rfd, void *buf, TERMID *term)
+{
+ struct rset_between_info *info =(struct rset_between_info *)rfd->rset->priv;
+ struct rset_between_rfd *p=(struct rset_between_rfd *)rfd->priv;
+ const struct key_control *kctrl=rfd->rset->keycontrol;
+ int cmp;
+ logf(log_level,"== read: term=%p",term);
+ TERMID dummyterm=0;
+ if (!term)
+ term=&dummyterm;
+ while ( rset_read(p->andrfd,buf,term) )
+ {
+ logf(log_level,"read loop term=%p d=%d ad=%d",
+ *term,p->depth, p->attrdepth);
+ if (p->hits<0)
+ {/* first time? */
+ memcpy(p->recbuf,buf,kctrl->key_size);
+ p->hits=0;
+ cmp=rfd->rset->scope; /* force newrecord */
}
-
-#if RSBETWEEN_DEBUG
- log2( rfd, "Considering M", cmp_l, cmp_r);
- logf(LOG_LOG,"level=%d. more=%d/%d/%d am=%d",
- p->level,p->more_l,p->more_m, p->more_r, p->attr_match);
-#endif
- if ( p->attr_match && p->level > 0) /* within a tag pair (or deeper) */
- {
- memcpy (buf, p->buf_m, kctrl->key_size);
- if (term)
- *term=p->term_m;
-#if RSBETWEEN_DEBUG
- log2( rfd, "Returning a hit (and forwarding m)", cmp_l, cmp_r);
-#endif
- p->more_m = rset_read (p->rfd_m, p->buf_m, NULL);
-#if RSBETWEEN_DEBUG
- logf(LOG_LOG,"read m. more=%d level=%d "
- "cmp_l=%d scope=%d hits="ZINT_FORMAT,
- p->more_m, p->level,
- cmp_l, rfd->rset->scope, p->hits);
-#endif
- if (cmp_l >= rfd->rset->scope) /* == 2 */
- p->level = 0;
- p->hits++;
- return 1;
+ else {
+ cmp=(kctrl->cmp)(buf,p->recbuf);
+ logf(log_level, "cmp=%d",cmp);
+ }
+
+ if (cmp>=rfd->rset->scope)
+ {
+ logf(log_level,"new record");
+ p->depth=0;
+ p->attrdepth=0;
+ memcpy(p->recbuf,buf,kctrl->key_size);
}
- else if ( ! p->more_l ) /* not in data, no more starts */
+
+ if (*term)
+ logf(log_level," term: '%s'", (*term)->name);
+ if (*term==info->startterm)
{
-#if RSBETWEEN_DEBUG
- log2( rfd, "no more starts, exiting without a hit", cmp_l, cmp_r);
-#endif
- return 0; /* ergo, nothing can be found. stop scanning */
+ p->depth++;
+ logf(log_level,"read start tag. d=%d",p->depth);
+ memcpy(p->startbuf,buf,kctrl->key_size);
+ p->startbufok=1;
+ checkattr(rfd); /* in case we already saw the attr here */
}
-#if NEWCODE
- if (cmp_l >= rfd->rset->scope) /* == 2 */
+ else if (*term==info->stopterm)
{
- p->level = 0;
- p->more_m=rset_forward(p->rfd_m, p->buf_m, &p->term_m, p->buf_l);
- } else
+ if (p->depth == p->attrdepth)
+ p->attrdepth=0; /* ending the tag with attr match */
+ p->depth--;
+ logf(log_level,"read end tag. d=%d ad=%d",p->depth, p->attrdepth);
+ }
+ else if (*term==info->attrterm)
{
- p->more_m = rset_read (p->rfd_m, p->buf_m, &p->term_m);
+ logf(log_level,"read attr");
+ memcpy(p->attrbuf,buf,kctrl->key_size);
+ p->attrbufok=1;
+ checkattr(rfd); /* in case the start tag came first */
}
-#else
- if (cmp_l >= rfd->rset->scope ) /* == 2 */
- p->level = 0;
- p->more_m = rset_read (p->rfd_m, p->buf_m, &p->term_m);
-#endif
-#if RSBETWEEN_DEBUG
- log2( rfd, "End of M loop", cmp_l, cmp_r);
- logf(LOG_LOG,"level=%d. more=%d/%d/%d",
- p->level,p->more_l,p->more_m, p->more_r);
-#endif
- } /* while more_m */
-
-#if RSBETWEEN_DEBUG
- log2( rfd, "Exiting, nothing more in m", cmp_l, cmp_r);
- logf(LOG_LOG,"level=%d. more=%d/%d/%d",
- p->level,p->more_l,p->more_m, p->more_r);
-#endif
- return 0; /* no more data possible */
+ else
+ { /* mut be a real hit */
+ if (p->depth && p->attrdepth)
+ {
+ p->hits++;
+ logf(log_level,"got a hit h="ZINT_FORMAT" d=%d ad=%d",
+ p->hits,p->depth,p->attrdepth);
+ return 1; /* we have everything in place already! */
+ } else
+ logf(log_level, "Ignoring hit. h="ZINT_FORMAT" d=%d ad=%d",
+ p->hits,p->depth,p->attrdepth);
+ }
+ } /* while read */
+ return 0;
} /* r_read */
-static int r_write_between (RSFD rfd, const void *buf)
+static int r_write (RSFD rfd, const void *buf)
{
logf (LOG_FATAL, "between set type is read-only");
return -1;
}
-static void r_pos_between (RSFD rfd, double *current, double *total)
+static void r_pos (RSFD rfd, double *current, double *total)
{
struct rset_between_rfd *p=(struct rset_between_rfd *)rfd->priv;
- double lcur,ltot;
- double mcur,mtot;
- double rcur,rtot;
- double r;
- ltot=-1; rtot=-1;
- rset_pos(p->rfd_l, &lcur, <ot);
- rset_pos(p->rfd_m, &mcur, &mtot);
- rset_pos(p->rfd_r, &rcur, &rtot);
- if ( (ltot<0) && (mtot<0) && (rtot<0) ) { /*no position */
- *current=mcur; /* return same as you got */
- *total=mtot; /* probably -1 for not available */
- }
- if ( ltot<0) { ltot=0; lcur=0;} /* if only one useful, use it */
- if ( mtot<0) { mtot=0; mcur=0;}
- if ( rtot<0) { rtot=0; rcur=0;}
- if ( ltot+mtot+rtot < 1 ) { /* empty rset */
- *current=0;
- *total=0;
- return;
- }
- r=1.0*(lcur+mcur+rcur)/(ltot+mtot+rtot); /* weighed average of l and r */
- *current=p->hits;
- *total=*current/r ;
-#if RSBETWEEN_DEBUG
- {
- struct rset_between_info *info =(struct rset_between_info *)rfd->rset->priv;
- yaz_log(LOG_LOG,"betw_pos: (%s/%s) %0.1f/%0.1f= %0.4f ",
- info->rset_l->control->desc, info->rset_r->control->desc,
- *current, *total, r);
- }
-#endif
+ rset_pos(p->andrfd,current, total);
+ logf(log_level,"pos: %0.1f/%0.1f ", *current, *total);
}
static void r_get_terms(RSET ct, TERMID *terms, int maxterms, int *curterm)
{
struct rset_between_info *info = (struct rset_between_info *) ct->priv;
- rset_getterms(info->rset_m, terms, maxterms, curterm);
+ rset_getterms(info->andset, terms, maxterms, curterm);
}
-/* Better algorithm
- * One of the major problems with rsbetween is the complexity of keeping track
- * of start tags, stop tags, hits, and attributes, together with record
- * boundaries etc.
- *
- * Things can be divided into finding the right records, and then processing
- * hits inside the record.
- *
- * Finding the record is mostly a matter of forwarding until we have a start
- * tag and a hit in the same record.
- *
- * Handling stuff inside a record, we can simplify things by implementing a
- * glorified OR operator that returns all the occurrences in proper order,
- * together with info on what type it was. Then the main logic can just keep
- * reading, and consider each type separately:
- * - if a start tag, increment level (some trickery with attributes!)
- * - if a stop tag, decrement level
- * - if a hit, and we have a level, return it
- * - if a hit, but no level, ignore it
- *
- * The attributes can be detected when ever reading start tags. The main
- * routine needs to keep a stack of attribute match bits, so when ever we read
- * a start tag, we must report back if we have a matching attribute or not.
- *
- */
projects / idzebra-moved-to-github.git / commitdiff