diff --git a/src/backend/tsearch/wparser_def.c b/src/backend/tsearch/wparser_def.c
index 2f84259..6bf7e49 100644
--- a/src/backend/tsearch/wparser_def.c
+++ b/src/backend/tsearch/wparser_def.c
@@ -1966,75 +1966,97 @@ checkcondition_HL(void *opaque, QueryOperand *val, ExecPhraseData *data)
return false;
}
-
-static bool
-hlCover(HeadlineParsedText *prs, TSQuery query, int *p, int *q)
+/*
+ * hlFirstIndex: find first index >= pos containing any word used in query
+ *
+ * Returns -1 if no such index
+ */
+static int
+hlFirstIndex(HeadlineParsedText *prs, TSQuery query, int pos)
{
- int i,
- j;
- QueryItem *item = GETQUERY(query);
- int pos = *p;
-
- *q = -1;
- *p = INT_MAX;
+ int i;
- for (j = 0; j < query->size; j++)
+ /* For each word ... */
+ for (i = pos; i < prs->curwords; i++)
{
- if (item->type != QI_VAL)
+ /* ... scan the query to see if this word matches any operand */
+ QueryItem *item = GETQUERY(query);
+ int j;
+
+ for (j = 0; j < query->size; j++)
{
+ if (item->type == QI_VAL &&
+ prs->words[i].item == &item->qoperand)
+ return i;
item++;
- continue;
}
- for (i = pos; i < prs->curwords; i++)
- {
- if (prs->words[i].item == &item->qoperand)
- {
- if (i > *q)
- *q = i;
- break;
- }
- }
- item++;
}
+ return -1;
+}
- if (*q < 0)
- return false;
+/*
+ * hlCover: try to find a substring of prs' word list that satisfies query
+ *
+ * At entry, *p must be the first word index to consider (initialize this to
+ * zero, or to the next index after a previous successful search).
+ *
+ * On success, sets *p to first word index and *q to last word index of the
+ * cover substring, and returns true.
+ *
+ * The result is a minimal cover, in the sense that both *p and *q will be
+ * words used in the query.
+ */
+static bool
+hlCover(HeadlineParsedText *prs, TSQuery query, int *p, int *q)
+{
+ int pmin,
+ pmax,
+ nextpmin,
+ nextpmax;
+ hlCheck ch;
- item = GETQUERY(query);
- for (j = 0; j < query->size; j++)
+ /*
+ * We look for the earliest, shortest substring of prs->words that
+ * satisfies the query. Both the pmin and pmax indices must be words
+ * appearing in the query; there's no point in trying endpoints in between
+ * such points.
+ */
+ pmin = hlFirstIndex(prs, query, *p);
+ while (pmin >= 0)
{
- if (item->type != QI_VAL)
+ /* This useless assignment just keeps stupider compilers quiet */
+ nextpmin = -1;
+ /* Consider substrings starting at pmin */
+ ch.words = &(prs->words[pmin]);
+ /* Consider the length-one substring first, then longer substrings */
+ pmax = pmin;
+ do
{
- item++;
- continue;
- }
- for (i = *q; i >= pos; i--)
- {
- if (prs->words[i].item == &item->qoperand)
+ /* Try to match query against pmin .. pmax substring */
+ ch.len = pmax - pmin + 1;
+ if (TS_execute(GETQUERY(query), &ch,
+ TS_EXEC_EMPTY, checkcondition_HL))
{
- if (i < *p)
- *p = i;
- break;
+ *p = pmin;
+ *q = pmax;
+ return true;
}
- }
- item++;
- }
-
- if (*p <= *q)
- {
- hlCheck ch;
+ /* Nope, so advance pmax to next feasible endpoint */
+ nextpmax = hlFirstIndex(prs, query, pmax + 1);
- ch.words = &(prs->words[*p]);
- ch.len = *q - *p + 1;
- if (TS_execute(GETQUERY(query), &ch, TS_EXEC_EMPTY, checkcondition_HL))
- return true;
- else
- {
- (*p)++;
- return hlCover(prs, query, p, q);
+ /*
+ * If this is our first advance past pmin, then the result is also
+ * the next feasible value of pmin; remember it to save a
+ * redundant search.
+ */
+ if (pmax == pmin)
+ nextpmin = nextpmax;
+ pmax = nextpmax;
}
+ while (pmax >= 0);
+ /* No luck here, so try next feasible startpoint */
+ pmin = nextpmin;
}
-
return false;
}
diff --git a/src/test/regress/expected/tsearch.out b/src/test/regress/expected/tsearch.out
index 36e995b..d6e0ba6 100644
--- a/src/test/regress/expected/tsearch.out
+++ b/src/test/regress/expected/tsearch.out
@@ -1301,12 +1301,12 @@ Water, water, every where,
Nor any drop to drink.
S. T. Coleridge (1772-1834)
', phraseto_tsquery('english', 'painted Ocean'));
- ts_headline
-----------------------------------
- painted Ocean. +
- Water, water, every where +
- And all the boards did shrink;+
- Water, water, every
+ ts_headline
+---------------------------------------
+ painted Ship +
+ Upon a painted Ocean.+
+ Water, water, every where +
+ And all the boards did shrink
(1 row)
SELECT ts_headline('english', '
@@ -1332,9 +1332,9 @@ SELECT ts_headline('english',
'Lorem ipsum urna. Nullam nullam ullamcorper urna.',
to_tsquery('english','Lorem') && phraseto_tsquery('english','ullamcorper urna'),
'MaxWords=100, MinWords=1');
- ts_headline
---------------
- Lorem
+ ts_headline
+-------------------------------------------------------------------------------
+ Lorem ipsum urna. Nullam nullam ullamcorper urna
(1 row)
SELECT ts_headline('english', '
@@ -1379,9 +1379,9 @@ SELECT ts_headline('simple', '1 2 3 1 3'::text, '1 & 3', 'MaxWords=4, MinWords=1
(1 row)
SELECT ts_headline('simple', '1 2 3 1 3'::text, '1 <-> 3', 'MaxWords=4, MinWords=1');
- ts_headline
--------------------
- 1 3
+ ts_headline
+----------------------------
+ 3 1 3
(1 row)
--Check if headline fragments work
@@ -1481,9 +1481,9 @@ SELECT ts_headline('english',
'Lorem ipsum urna. Nullam nullam ullamcorper urna.',
to_tsquery('english','Lorem') && phraseto_tsquery('english','ullamcorper urna'),
'MaxFragments=100, MaxWords=100, MinWords=1');
- ts_headline
---------------
- Lorem
+ ts_headline
+-------------------------------------------------------------------------------
+ Lorem ipsum urna. Nullam nullam ullamcorper urna
(1 row)
--Rewrite sub system