*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/tsearch/wparser_def.c,v 1.16 2008/10/17 17:27:46 teodor Exp $
+ * $PostgreSQL: pgsql/src/backend/tsearch/wparser_def.c,v 1.17 2008/10/17 18:05:19 teodor Exp $
*
*-------------------------------------------------------------------------
*/
return false;
}
-Datum
-prsd_headline(PG_FUNCTION_ARGS)
+static void
+mark_fragment(HeadlineParsedText *prs, int highlight, int startpos, int endpos)
{
- HeadlineParsedText *prs = (HeadlineParsedText *) PG_GETARG_POINTER(0);
- List *prsoptions = (List *) PG_GETARG_POINTER(1);
- TSQuery query = PG_GETARG_TSQUERY(2);
+ int i;
- /* from opt + start and and tag */
- int min_words = 15;
- int max_words = 35;
- int shortword = 3;
+ for (i = startpos; i <= endpos; i++)
+ {
+ if (prs->words[i].item)
+ prs->words[i].selected = 1;
+ if (highlight == 0)
+ {
+ if (HLIDIGNORE(prs->words[i].type))
+ prs->words[i].replace = 1;
+ }
+ else
+ {
+ if (XMLHLIDIGNORE(prs->words[i].type))
+ prs->words[i].replace = 1;
+ }
+
+ prs->words[i].in = (prs->words[i].repeated) ? 0 : 1;
+ }
+}
+
+typedef struct
+{
+ int4 startpos;
+ int4 endpos;
+ int4 poslen;
+ int4 curlen;
+ int2 in;
+ int2 excluded;
+} CoverPos;
+
+static void
+get_next_fragment(HeadlineParsedText *prs, int *startpos, int *endpos,
+ int *curlen, int *poslen, int max_words)
+{
+ int i;
+ /* Objective: Generate a fragment of words between startpos and endpos
+ * such that it has at most max_words and both ends has query words.
+ * If the startpos and endpos are the endpoints of the cover and the
+ * cover has fewer words than max_words, then this function should
+ * just return the cover
+ */
+ /* first move startpos to an item */
+ for(i = *startpos; i <= *endpos; i++)
+ {
+ *startpos = i;
+ if (prs->words[i].item && !prs->words[i].repeated)
+ break;
+ }
+ /* cut endpos to have only max_words */
+ *curlen = 0;
+ *poslen = 0;
+ for(i = *startpos; i <= *endpos && *curlen < max_words; i++)
+ {
+ if (!NONWORDTOKEN(prs->words[i].type))
+ *curlen += 1;
+ if (prs->words[i].item && !prs->words[i].repeated)
+ *poslen += 1;
+ }
+ /* if the cover was cut then move back endpos to a query item */
+ if (*endpos > i)
+ {
+ *endpos = i;
+ for(i = *endpos; i >= *startpos; i --)
+ {
+ *endpos = i;
+ if (prs->words[i].item && !prs->words[i].repeated)
+ break;
+ if (!NONWORDTOKEN(prs->words[i].type))
+ *curlen -= 1;
+ }
+ }
+}
+
+static void
+mark_hl_fragments(HeadlineParsedText *prs, TSQuery query, int highlight,
+ int shortword, int min_words,
+ int max_words, int max_fragments)
+{
+ int4 poslen, curlen, i, f, num_f = 0;
+ int4 stretch, maxstretch, posmarker;
+
+ int4 startpos = 0,
+ endpos = 0,
+ p = 0,
+ q = 0;
+
+ int4 numcovers = 0,
+ maxcovers = 32;
+
+ int4 minI, minwords, maxitems;
+ CoverPos *covers;
+
+ covers = palloc(maxcovers * sizeof(CoverPos));
+
+ /* get all covers */
+ while (hlCover(prs, query, &p, &q))
+ {
+ startpos = p;
+ endpos = q;
+
+ /* Break the cover into smaller fragments such that each fragment
+ * has at most max_words. Also ensure that each end of the fragment
+ * is a query word. This will allow us to stretch the fragment in
+ * either direction
+ */
+
+ while (startpos <= endpos)
+ {
+ get_next_fragment(prs, &startpos, &endpos, &curlen, &poslen, max_words);
+ if (numcovers >= maxcovers)
+ {
+ maxcovers *= 2;
+ covers = repalloc(covers, sizeof(CoverPos) * maxcovers);
+ }
+ covers[numcovers].startpos = startpos;
+ covers[numcovers].endpos = endpos;
+ covers[numcovers].curlen = curlen;
+ covers[numcovers].poslen = poslen;
+ covers[numcovers].in = 0;
+ covers[numcovers].excluded = 0;
+ numcovers ++;
+ startpos = endpos + 1;
+ endpos = q;
+ }
+ /* move p to generate the next cover */
+ p++;
+ }
+ /* choose best covers */
+ for (f = 0; f < max_fragments; f++)
+ {
+ maxitems = 0;
+ minwords = 0x7fffffff;
+ minI = -1;
+ /* Choose the cover that contains max items.
+ * In case of tie choose the one with smaller
+ * number of words.
+ */
+ for (i = 0; i < numcovers; i ++)
+ {
+ if (!covers[i].in && !covers[i].excluded &&
+ (maxitems < covers[i].poslen || (maxitems == covers[i].poslen
+ && minwords > covers[i].curlen)))
+ {
+ maxitems = covers[i].poslen;
+ minwords = covers[i].curlen;
+ minI = i;
+ }
+ }
+ /* if a cover was found mark it */
+ if (minI >= 0)
+ {
+ covers[minI].in = 1;
+ /* adjust the size of cover */
+ startpos = covers[minI].startpos;
+ endpos = covers[minI].endpos;
+ curlen = covers[minI].curlen;
+ /* stretch the cover if cover size is lower than max_words */
+ if (curlen < max_words)
+ {
+ /* divide the stretch on both sides of cover */
+ maxstretch = (max_words - curlen)/2;
+ /* first stretch the startpos
+ * stop stretching if
+ * 1. we hit the beginning of document
+ * 2. exceed maxstretch
+ * 3. we hit an already marked fragment
+ */
+ stretch = 0;
+ posmarker = startpos;
+ for (i = startpos - 1; i >= 0 && stretch < maxstretch && !prs->words[i].in; i--)
+ {
+ if (!NONWORDTOKEN(prs->words[i].type))
+ {
+ curlen ++;
+ stretch ++;
+ }
+ posmarker = i;
+ }
+ /* cut back startpos till we find a non short token */
+ for (i = posmarker; i < startpos && (NOENDTOKEN(prs->words[i].type) || prs->words[i].len <= shortword); i++)
+ {
+ if (!NONWORDTOKEN(prs->words[i].type))
+ curlen --;
+ }
+ startpos = i;
+ /* now stretch the endpos as much as possible*/
+ posmarker = endpos;
+ for (i = endpos + 1; i < prs->curwords && curlen < max_words && !prs->words[i].in; i++)
+ {
+ if (!NONWORDTOKEN(prs->words[i].type))
+ curlen ++;
+ posmarker = i;
+ }
+ /* cut back endpos till we find a non-short token */
+ for ( i = posmarker; i > endpos && (NOENDTOKEN(prs->words[i].type) || prs->words[i].len <= shortword); i--)
+ {
+ if (!NONWORDTOKEN(prs->words[i].type))
+ curlen --;
+ }
+ endpos = i;
+ }
+ covers[minI].startpos = startpos;
+ covers[minI].endpos = endpos;
+ covers[minI].curlen = curlen;
+ /* Mark the chosen fragments (covers) */
+ mark_fragment(prs, highlight, startpos, endpos);
+ num_f ++;
+ /* exclude overlapping covers */
+ for (i = 0; i < numcovers; i ++)
+ {
+ if (i != minI && ( (covers[i].startpos >= covers[minI].startpos && covers[i].startpos <= covers[minI].endpos) || (covers[i].endpos >= covers[minI].startpos && covers[i].endpos <= covers[minI].endpos)))
+ covers[i].excluded = 1;
+ }
+ }
+ else
+ break;
+ }
+
+ /* show at least min_words we have not marked anything*/
+ if (num_f <= 0)
+ {
+ startpos = endpos = curlen = 0;
+ for (i = 0; i < prs->curwords && curlen < min_words; i++)
+ {
+ if (!NONWORDTOKEN(prs->words[i].type))
+ curlen++;
+ endpos = i;
+ }
+ mark_fragment(prs, highlight, startpos, endpos);
+ }
+ pfree(covers);
+}
+static void
+mark_hl_words(HeadlineParsedText *prs, TSQuery query, int highlight,
+ int shortword, int min_words, int max_words)
+{
int p = 0,
q = 0;
int bestb = -1,
curlen;
int i;
- int highlight = 0;
- ListCell *l;
-
- /* config */
- prs->startsel = NULL;
- prs->stopsel = NULL;
- foreach(l, prsoptions)
- {
- DefElem *defel = (DefElem *) lfirst(l);
- char *val = defGetString(defel);
-
- if (pg_strcasecmp(defel->defname, "MaxWords") == 0)
- max_words = pg_atoi(val, sizeof(int32), 0);
- else if (pg_strcasecmp(defel->defname, "MinWords") == 0)
- min_words = pg_atoi(val, sizeof(int32), 0);
- else if (pg_strcasecmp(defel->defname, "ShortWord") == 0)
- shortword = pg_atoi(val, sizeof(int32), 0);
- else if (pg_strcasecmp(defel->defname, "StartSel") == 0)
- prs->startsel = pstrdup(val);
- else if (pg_strcasecmp(defel->defname, "StopSel") == 0)
- prs->stopsel = pstrdup(val);
- else if (pg_strcasecmp(defel->defname, "HighlightAll") == 0)
- highlight = (pg_strcasecmp(val, "1") == 0 ||
- pg_strcasecmp(val, "on") == 0 ||
- pg_strcasecmp(val, "true") == 0 ||
- pg_strcasecmp(val, "t") == 0 ||
- pg_strcasecmp(val, "y") == 0 ||
- pg_strcasecmp(val, "yes") == 0);
- else
- ereport(ERROR,
- (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
- errmsg("unrecognized headline parameter: \"%s\"",
- defel->defname)));
- }
if (highlight == 0)
{
- if (min_words >= max_words)
- ereport(ERROR,
- (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
- errmsg("MinWords should be less than MaxWords")));
- if (min_words <= 0)
- ereport(ERROR,
- (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
- errmsg("MinWords should be positive")));
- if (shortword < 0)
- ereport(ERROR,
- (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
- errmsg("ShortWord should be >= 0")));
-
while (hlCover(prs, query, &p, &q))
{
/* find cover len in words */
prs->words[i].in = (prs->words[i].repeated) ? 0 : 1;
}
+}
+
+Datum
+prsd_headline(PG_FUNCTION_ARGS)
+{
+ HeadlineParsedText *prs = (HeadlineParsedText *) PG_GETARG_POINTER(0);
+ List *prsoptions = (List *) PG_GETARG_POINTER(1);
+ TSQuery query = PG_GETARG_TSQUERY(2);
+
+ /* from opt + start and and tag */
+ int min_words = 15;
+ int max_words = 35;
+ int shortword = 3;
+ int max_fragments = 0;
+ int highlight = 0;
+ ListCell *l;
+
+ /* config */
+ prs->startsel = NULL;
+ prs->stopsel = NULL;
+ foreach(l, prsoptions)
+ {
+ DefElem *defel = (DefElem *) lfirst(l);
+ char *val = defGetString(defel);
+
+ if (pg_strcasecmp(defel->defname, "MaxWords") == 0)
+ max_words = pg_atoi(val, sizeof(int32), 0);
+ else if (pg_strcasecmp(defel->defname, "MinWords") == 0)
+ min_words = pg_atoi(val, sizeof(int32), 0);
+ else if (pg_strcasecmp(defel->defname, "ShortWord") == 0)
+ shortword = pg_atoi(val, sizeof(int32), 0);
+ else if (pg_strcasecmp(defel->defname, "MaxFragments") == 0)
+ max_fragments = pg_atoi(val, sizeof(int32), 0);
+ else if (pg_strcasecmp(defel->defname, "StartSel") == 0)
+ prs->startsel = pstrdup(val);
+ else if (pg_strcasecmp(defel->defname, "StopSel") == 0)
+ prs->stopsel = pstrdup(val);
+ else if (pg_strcasecmp(defel->defname, "FragmentDelimiter") == 0)
+ prs->fragdelim = pstrdup(val);
+ else if (pg_strcasecmp(defel->defname, "HighlightAll") == 0)
+ highlight = (pg_strcasecmp(val, "1") == 0 ||
+ pg_strcasecmp(val, "on") == 0 ||
+ pg_strcasecmp(val, "true") == 0 ||
+ pg_strcasecmp(val, "t") == 0 ||
+ pg_strcasecmp(val, "y") == 0 ||
+ pg_strcasecmp(val, "yes") == 0);
+ else
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("unrecognized headline parameter: \"%s\"",
+ defel->defname)));
+ }
+
+ if (highlight == 0)
+ {
+ if (min_words >= max_words)
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("MinWords should be less than MaxWords")));
+ if (min_words <= 0)
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("MinWords should be positive")));
+ if (shortword < 0)
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("ShortWord should be >= 0")));
+ if (max_fragments < 0)
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("MaxFragments should be >= 0")));
+ }
+
+ if (max_fragments == 0)
+ /* call the default headline generator */
+ mark_hl_words(prs, query, highlight, shortword, min_words, max_words);
+ else
+ mark_hl_fragments(prs, query, highlight, shortword, min_words, max_words, max_fragments);
+
if (!prs->startsel)
prs->startsel = pstrdup("");
if (!prs->stopsel)
prs->stopsel = pstrdup("");
+ if (!prs->fragdelim)
+ prs->fragdelim = pstrdup(" ... ");
prs->startsellen = strlen(prs->startsel);
prs->stopsellen = strlen(prs->stopsel);
+ prs->fragdelimlen = strlen(prs->fragdelim);
PG_RETURN_POINTER(prs);
}
+
projects / postgresql.git / commitdiff