Refactor SPI_cursor_open/SPI_cursor_open_with_args so that the latter sets

the PARAM_FLAG_CONST flag on the parameters that are passed into the portal,
while the former's behavior is unchanged.  This should only affect the case
where the portal is executing an EXPLAIN; it will cause the generated plan to
look more like what would be generated if the portal were actually executing
the command being explained.  Per gripe from Pavel.

diff --git a/src/backend/executor/spi.c b/src/backend/executor/spi.c
index 555bdd1..32e5326 100644 (file)
--- a/src/backend/executor/spi.c
+++ b/src/backend/executor/spi.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/backend/executor/spi.c,v 1.195 2008/05/12 20:02:00 alvherre Exp $
+ *       $PostgreSQL: pgsql/src/backend/executor/spi.c,v 1.196 2008/06/01 17:32:48 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -36,6 +36,10 @@ static int   _SPI_stack_depth = 0;           /* allocated size of _SPI_stack */
 static int     _SPI_connected = -1;
 static int     _SPI_curid = -1;
 
+static Portal SPI_cursor_open_internal(const char *name, SPIPlanPtr plan,
+                                                                          Datum *Values, const char *Nulls,
+                                                                          bool read_only, int pflags);
+
 static void _SPI_prepare_plan(const char *src, SPIPlanPtr plan,
                                                          ParamListInfo boundParams);
 
@@ -917,6 +921,80 @@ SPI_cursor_open(const char *name, SPIPlanPtr plan,
                                Datum *Values, const char *Nulls,
                                bool read_only)
 {
+       return SPI_cursor_open_internal(name, plan, Values, Nulls,
+                                                                       read_only, 0);
+}
+
+
+/*
+ * SPI_cursor_open_with_args()
+ *
+ * Parse and plan a query and open it as a portal.  Like SPI_execute_with_args,
+ * we can tell the planner to rely on the parameter values as constants,
+ * because the plan will only be used once.
+ */
+Portal
+SPI_cursor_open_with_args(const char *name,
+                                                 const char *src,
+                                                 int nargs, Oid *argtypes,
+                                                 Datum *Values, const char *Nulls,
+                                                 bool read_only, int cursorOptions)
+{
+       Portal          result;
+       _SPI_plan       plan;
+       ParamListInfo paramLI;
+
+       if (src == NULL || nargs < 0)
+               elog(ERROR, "SPI_cursor_open_with_args called with invalid arguments");
+
+       if (nargs > 0 && (argtypes == NULL || Values == NULL))
+               elog(ERROR, "SPI_cursor_open_with_args called with missing parameters");
+
+       SPI_result = _SPI_begin_call(true);
+       if (SPI_result < 0)
+               elog(ERROR, "SPI_cursor_open_with_args called while not connected");
+
+       memset(&plan, 0, sizeof(_SPI_plan));
+       plan.magic = _SPI_PLAN_MAGIC;
+       plan.cursor_options = cursorOptions;
+       plan.nargs = nargs;
+       plan.argtypes = argtypes;
+
+       paramLI = _SPI_convert_params(nargs, argtypes,
+                                                                 Values, Nulls,
+                                                                 PARAM_FLAG_CONST);
+
+       _SPI_prepare_plan(src, &plan, paramLI);
+
+       /* We needn't copy the plan; SPI_cursor_open_internal will do so */
+
+       /* Adjust stack so that SPI_cursor_open_internal doesn't complain */
+       _SPI_curid--;
+
+       /* SPI_cursor_open_internal must be called in procedure memory context */
+       _SPI_procmem();
+
+       result = SPI_cursor_open_internal(name, &plan, Values, Nulls,
+                                                                         read_only, PARAM_FLAG_CONST);
+
+       /* And clean up */
+       _SPI_curid++;
+       _SPI_end_call(true);
+
+       return result;
+}
+
+
+/*
+ * SPI_cursor_open_internal()
+ *
+ *     Common code for SPI_cursor_open and SPI_cursor_open_with_args
+ */
+static Portal
+SPI_cursor_open_internal(const char *name, SPIPlanPtr plan,
+                                                Datum *Values, const char *Nulls,
+                                                bool read_only, int pflags)
+{
        CachedPlanSource *plansource;
        CachedPlan *cplan;
        List       *stmt_list;
@@ -997,7 +1075,7 @@ SPI_cursor_open(const char *name, SPIPlanPtr plan,
                        ParamExternData *prm = &paramLI->params[k];
 
                        prm->ptype = plan->argtypes[k];
-                       prm->pflags = 0;
+                       prm->pflags = pflags;
                        prm->isnull = (Nulls && Nulls[k] == 'n');
                        if (prm->isnull)
                        {
@@ -1130,64 +1208,6 @@ SPI_cursor_open(const char *name, SPIPlanPtr plan,
 
 
 /*
- * SPI_cursor_open_with_args()
- *
- * Parse and plan a query and open it as a portal.  Like SPI_execute_with_args,
- * we can tell the planner to rely on the parameter values as constants,
- * because the plan will only be used once.
- */
-Portal
-SPI_cursor_open_with_args(const char *name,
-                                                 const char *src,
-                                                 int nargs, Oid *argtypes,
-                                                 Datum *Values, const char *Nulls,
-                                                 bool read_only, int cursorOptions)
-{
-       Portal          result;
-       _SPI_plan       plan;
-       ParamListInfo paramLI;
-
-       if (src == NULL || nargs < 0)
-               elog(ERROR, "SPI_cursor_open_with_args called with invalid arguments");
-
-       if (nargs > 0 && (argtypes == NULL || Values == NULL))
-               elog(ERROR, "SPI_cursor_open_with_args called with missing parameters");
-
-       SPI_result = _SPI_begin_call(true);
-       if (SPI_result < 0)
-               elog(ERROR, "SPI_cursor_open_with_args called while not connected");
-
-       memset(&plan, 0, sizeof(_SPI_plan));
-       plan.magic = _SPI_PLAN_MAGIC;
-       plan.cursor_options = cursorOptions;
-       plan.nargs = nargs;
-       plan.argtypes = argtypes;
-
-       paramLI = _SPI_convert_params(nargs, argtypes,
-                                                                 Values, Nulls,
-                                                                 PARAM_FLAG_CONST);
-
-       _SPI_prepare_plan(src, &plan, paramLI);
-
-       /* We needn't copy the plan; SPI_cursor_open will do so */
-
-       /* Adjust stack so that SPI_cursor_open doesn't complain */
-       _SPI_curid--;
-
-       /* SPI_cursor_open expects to be called in procedure memory context */
-       _SPI_procmem();
-
-       result = SPI_cursor_open(name, &plan, Values, Nulls, read_only);
-
-       /* And clean up */
-       _SPI_curid++;
-       _SPI_end_call(true);
-
-       return result;
-}
-
-
-/*
  * SPI_cursor_find()
  *
  *     Find the portal of an existing open cursor