Fix ts_delete(tsvector, text[]) to cope with duplicate array entries.

Such cases either failed an Assert, or produced a corrupt tsvector in
non-Assert builds, as reported by Andreas Seltenreich.  The reason is
that tsvector_delete_by_indices() just assumed that its input array had
no duplicates.  Fix by explicitly de-duping.

In passing, improve some comments, and fix a number of tests for null
values to use ERRCODE_NULL_VALUE_NOT_ALLOWED not
ERRCODE_INVALID_PARAMETER_VALUE.

Discussion: <87invhoj6e.fsf@credativ.de>

diff --git a/src/backend/utils/adt/tsvector_op.c b/src/backend/utils/adt/tsvector_op.c
index 63ae4330ef1fbf2c12cd5a998bb91dfdfee6d5aa..29cc687643c1746d5a8b270ee1cbaa3ca548ae67 100644 (file)
--- a/src/backend/utils/adt/tsvector_op.c
+++ b/src/backend/utils/adt/tsvector_op.c
@@ -317,7 +317,7 @@ tsvector_setweight_by_filter(PG_FUNCTION_ARGS)
 
                if (nulls[i])
                        ereport(ERROR,
-                                       (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+                                       (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
                                         errmsg("lexeme array may not contain nulls")));
 
                lex = VARDATA(dlexemes[i]);
@@ -430,7 +430,7 @@ compareint(const void *va, const void *vb)
 /*
  * Internal routine to delete lexemes from TSVector by array of offsets.
  *
- * int *indices_to_delete -- array of lexeme offsets to delete
+ * int *indices_to_delete -- array of lexeme offsets to delete (modified here!)
  * int indices_count -- size of that array
  *
  * Returns new TSVector without given lexemes along with their positions
@@ -445,35 +445,51 @@ tsvector_delete_by_indices(TSVector tsv, int *indices_to_delete,
                           *arrout;
        char       *data = STRPTR(tsv),
                           *dataout;
-       int                     i,
-                               j,
-                               k,
-                               curoff;
+       int                     i,                              /* index in arrin */
+                               j,                              /* index in arrout */
+                               k,                              /* index in indices_to_delete */
+                               curoff;                 /* index in dataout area */
 
        /*
-        * Here we overestimates tsout size, since we don't know exact size
-        * occupied by positions and weights. We will set exact size later after a
-        * pass through TSVector.
+        * Sort the filter array to simplify membership checks below.  Also, get
+        * rid of any duplicate entries, so that we can assume that indices_count
+        * is exactly equal to the number of lexemes that will be removed.
         */
-       tsout = (TSVector) palloc0(VARSIZE(tsv));
-       arrout = ARRPTR(tsout);
-       tsout->size = tsv->size - indices_count;
-
-       /* Sort our filter array to simplify membership check later. */
        if (indices_count > 1)
+       {
+               int                     kp;
+
                qsort(indices_to_delete, indices_count, sizeof(int), compareint);
+               kp = 0;
+               for (k = 1; k < indices_count; k++)
+               {
+                       if (indices_to_delete[k] != indices_to_delete[kp])
+                               indices_to_delete[++kp] = indices_to_delete[k];
+               }
+               indices_count = ++kp;
+       }
 
        /*
-        * Copy tsv to tsout skipping lexemes that enlisted in indices_to_delete.
+        * Here we overestimate tsout size, since we don't know how much space is
+        * used by the deleted lexeme(s).  We will set exact size below.
         */
-       curoff = 0;
+       tsout = (TSVector) palloc0(VARSIZE(tsv));
+
+       /* This count must be correct because STRPTR(tsout) relies on it. */
+       tsout->size = tsv->size - indices_count;
+
+       /*
+        * Copy tsv to tsout, skipping lexemes listed in indices_to_delete.
+        */
+       arrout = ARRPTR(tsout);
        dataout = STRPTR(tsout);
+       curoff = 0;
        for (i = j = k = 0; i < tsv->size; i++)
        {
                /*
-                * Here we should check whether current i is present in
-                * indices_to_delete or not. Since indices_to_delete is already sorted
-                * we can advance it index only when we have match.
+                * If current i is present in indices_to_delete, skip this lexeme.
+                * Since indices_to_delete is already sorted, we only need to check
+                * the current (k'th) entry.
                 */
                if (k < indices_count && i == indices_to_delete[k])
                {
@@ -481,7 +497,7 @@ tsvector_delete_by_indices(TSVector tsv, int *indices_to_delete,
                        continue;
                }
 
-               /* Copy lexeme, it's positions and weights */
+               /* Copy lexeme and its positions and weights */
                memcpy(dataout + curoff, data + arrin[i].pos, arrin[i].len);
                arrout[j].haspos = arrin[i].haspos;
                arrout[j].len = arrin[i].len;
@@ -489,8 +505,8 @@ tsvector_delete_by_indices(TSVector tsv, int *indices_to_delete,
                curoff += arrin[i].len;
                if (arrin[i].haspos)
                {
-                       int                     len = POSDATALEN(tsv, arrin + i) * sizeof(WordEntryPos) +
-                       sizeof(uint16);
+                       int                     len = POSDATALEN(tsv, arrin + i) * sizeof(WordEntryPos)
+                       + sizeof(uint16);
 
                        curoff = SHORTALIGN(curoff);
                        memcpy(dataout + curoff,
@@ -503,10 +519,9 @@ tsvector_delete_by_indices(TSVector tsv, int *indices_to_delete,
        }
 
        /*
-        * After the pass through TSVector k should equals exactly to
-        * indices_count. If it isn't then the caller provided us with indices
-        * outside of [0, tsv->size) range and estimation of tsout's size is
-        * wrong.
+        * k should now be exactly equal to indices_count. If it isn't then the
+        * caller provided us with indices outside of [0, tsv->size) range and
+        * estimation of tsout's size is wrong.
         */
        Assert(k == indices_count);
 
@@ -560,7 +575,7 @@ tsvector_delete_arr(PG_FUNCTION_ARGS)
 
        /*
         * In typical use case array of lexemes to delete is relatively small. So
-        * here we optimizing things for that scenario: iterate through lexarr
+        * here we optimize things for that scenario: iterate through lexarr
         * performing binary search of each lexeme from lexarr in tsvector.
         */
        skip_indices = palloc0(nlex * sizeof(int));
@@ -572,10 +587,10 @@ tsvector_delete_arr(PG_FUNCTION_ARGS)
 
                if (nulls[i])
                        ereport(ERROR,
-                                       (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+                                       (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
                                         errmsg("lexeme array may not contain nulls")));
 
-               lex = VARDATA(dlexemes[i]);
+               lex = VARDATA_ANY(dlexemes[i]);
                lex_len = VARSIZE_ANY_EXHDR(dlexemes[i]);
                lex_pos = tsvector_bsearch(tsin, lex, lex_len);
 
@@ -738,7 +753,7 @@ array_to_tsvector(PG_FUNCTION_ARGS)
        {
                if (nulls[i])
                        ereport(ERROR,
-                                       (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+                                       (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
                                         errmsg("lexeme array may not contain nulls")));
 
                datalen += VARSIZE_ANY_EXHDR(dlexemes[i]);
@@ -797,7 +812,7 @@ tsvector_filter(PG_FUNCTION_ARGS)
 
                if (nulls[i])
                        ereport(ERROR,
-                                       (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+                                       (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
                                         errmsg("weight array may not contain nulls")));
 
                char_weight = DatumGetChar(dweights[i]);

diff --git a/src/test/regress/expected/tstypes.out b/src/test/regress/expected/tstypes.out
index 886ea747f17733f6b38e15bbd48bbf43b55fa316..73f43c5ff027364d1b8ed7ad093245f2ba32147c 100644 (file)
--- a/src/test/regress/expected/tstypes.out
+++ b/src/test/regress/expected/tstypes.out
@@ -1087,6 +1087,12 @@ SELECT ts_delete('base hidden rebel spaceship strike'::tsvector, ARRAY['spaceshi
  'base' 'hidden' 'strike'
 (1 row)
 
+SELECT ts_delete('base hidden rebel spaceship strike'::tsvector, ARRAY['spaceship','leya','rebel','rebel']);
+        ts_delete         
+--------------------------
+ 'base' 'hidden' 'strike'
+(1 row)
+
 SELECT ts_delete('base hidden rebel spaceship strike'::tsvector, ARRAY['spaceship','leya','rebel', NULL]);
 ERROR:  lexeme array may not contain nulls
 SELECT unnest('base:7 hidden:6 rebel:1 spaceship:2,33A,34B,35C,36D strike:3'::tsvector);

diff --git a/src/test/regress/sql/tstypes.sql b/src/test/regress/sql/tstypes.sql
index 724234d94d25daae8dc7708f2c010791696579c1..f0c06ba5f5a6e1c37ca51521bb5ad7690579da11 100644 (file)
--- a/src/test/regress/sql/tstypes.sql
+++ b/src/test/regress/sql/tstypes.sql
@@ -212,6 +212,7 @@ SELECT ts_delete('base:7 hidden:6 rebel:1 spaceship:2,33A,34B,35C,36D strike:3':
 SELECT ts_delete('base:7 hidden:6 rebel:1 spaceship:2,33A,34B,35C,36D strike:3'::tsvector, ARRAY['spaceshi','rebel']);
 SELECT ts_delete('base:7 hidden:6 rebel:1 spaceship:2,33A,34B,35C,36D strike:3'::tsvector, ARRAY['spaceship','leya','rebel']);
 SELECT ts_delete('base hidden rebel spaceship strike'::tsvector, ARRAY['spaceship','leya','rebel']);
+SELECT ts_delete('base hidden rebel spaceship strike'::tsvector, ARRAY['spaceship','leya','rebel','rebel']);
 SELECT ts_delete('base hidden rebel spaceship strike'::tsvector, ARRAY['spaceship','leya','rebel', NULL]);
 
 SELECT unnest('base:7 hidden:6 rebel:1 spaceship:2,33A,34B,35C,36D strike:3'::tsvector);