Generate a few more functions of pgstatfuncs.c with macros

Two new macros are added with their respective functions switched to
use them.  These are for functions with millisecond stats, with and
without "xact" in their names (for the stats that can be tracked within
a transaction).

While on it, prefix the macro for float8 on database entries with "_MS",
as it does a us->ms conversion, based on a suggestion from Andres
Freund.

Author: Bertrand Drouvot
Discussion: https://postgr.es/m/6e2efb4f-6fd0-807e-f6bf-94207db8183a@gmail.com

Author: michaelpq

src/backend/utils/adt/pgstatfuncs.c

@@ -152,29 +152,26 @@ pg_stat_get_function_calls(PG_FUNCTION_ARGS)
 	PG_RETURN_INT64(funcentry->numcalls);
 }
 
-Datum
-pg_stat_get_function_total_time(PG_FUNCTION_ARGS)
-{
-	Oid			funcid = PG_GETARG_OID(0);
-	PgStat_StatFuncEntry *funcentry;
-
-	if ((funcentry = pgstat_fetch_stat_funcentry(funcid)) == NULL)
-		PG_RETURN_NULL();
-	/* convert counter from microsec to millisec for display */
-	PG_RETURN_FLOAT8(((double) funcentry->total_time) / 1000.0);
-}
-
-Datum
-pg_stat_get_function_self_time(PG_FUNCTION_ARGS)
-{
-	Oid			funcid = PG_GETARG_OID(0);
-	PgStat_StatFuncEntry *funcentry;
-
-	if ((funcentry = pgstat_fetch_stat_funcentry(funcid)) == NULL)
-		PG_RETURN_NULL();
-	/* convert counter from microsec to millisec for display */
-	PG_RETURN_FLOAT8(((double) funcentry->self_time) / 1000.0);
-}
+/* convert counter from microsec to millisec for display */
+#define PG_STAT_GET_FUNCENTRY_FLOAT8_MS(stat)						\
+Datum																\
+CppConcat(pg_stat_get_function_,stat)(PG_FUNCTION_ARGS)				\
+{																	\
+	Oid			funcid = PG_GETARG_OID(0);							\
+	double		result;												\
+	PgStat_StatFuncEntry *funcentry;								\
+																	\
+	if ((funcentry = pgstat_fetch_stat_funcentry(funcid)) == NULL)	\
+		PG_RETURN_NULL();											\
+	result = ((double) funcentry->stat) / 1000.0;					\
+	PG_RETURN_FLOAT8(result);										\
+}
+
+/* pg_stat_get_function_total_time */
+PG_STAT_GET_FUNCENTRY_FLOAT8_MS(total_time)
+
+/* pg_stat_get_function_self_time */
+PG_STAT_GET_FUNCENTRY_FLOAT8_MS(self_time)
 
 Datum
 pg_stat_get_backend_idset(PG_FUNCTION_ARGS)
@@ -1147,7 +1144,8 @@ pg_stat_get_db_checksum_last_failure(PG_FUNCTION_ARGS)
 		PG_RETURN_TIMESTAMPTZ(result);
 }
 
-#define PG_STAT_GET_DBENTRY_FLOAT8(stat)						\
+/* convert counter from microsec to millisec for display */
+#define PG_STAT_GET_DBENTRY_FLOAT8_MS(stat)						\
 Datum															\
 CppConcat(pg_stat_get_db_,stat)(PG_FUNCTION_ARGS)				\
 {																\
@@ -1164,19 +1162,19 @@ CppConcat(pg_stat_get_db_,stat)(PG_FUNCTION_ARGS)				\
 }
 
 /* pg_stat_get_db_active_time */
-PG_STAT_GET_DBENTRY_FLOAT8(active_time)
+PG_STAT_GET_DBENTRY_FLOAT8_MS(active_time)
 
 /* pg_stat_get_db_blk_read_time */
-PG_STAT_GET_DBENTRY_FLOAT8(blk_read_time)
+PG_STAT_GET_DBENTRY_FLOAT8_MS(blk_read_time)
 
 /* pg_stat_get_db_blk_write_time */
-PG_STAT_GET_DBENTRY_FLOAT8(blk_write_time)
+PG_STAT_GET_DBENTRY_FLOAT8_MS(blk_write_time)
 
 /* pg_stat_get_db_idle_in_transaction_time */
-PG_STAT_GET_DBENTRY_FLOAT8(idle_in_transaction_time)
+PG_STAT_GET_DBENTRY_FLOAT8_MS(idle_in_transaction_time)
 
 /* pg_stat_get_db_session_time */
-PG_STAT_GET_DBENTRY_FLOAT8(session_time)
+PG_STAT_GET_DBENTRY_FLOAT8_MS(session_time)
 
 Datum
 pg_stat_get_bgwriter_timed_checkpoints(PG_FUNCTION_ARGS)
@@ -1609,28 +1607,23 @@ pg_stat_get_xact_function_calls(PG_FUNCTION_ARGS)
 	PG_RETURN_INT64(funcentry->numcalls);
 }
 
-Datum
-pg_stat_get_xact_function_total_time(PG_FUNCTION_ARGS)
-{
-	Oid			funcid = PG_GETARG_OID(0);
-	PgStat_FunctionCounts *funcentry;
-
-	if ((funcentry = find_funcstat_entry(funcid)) == NULL)
-		PG_RETURN_NULL();
-	PG_RETURN_FLOAT8(INSTR_TIME_GET_MILLISEC(funcentry->total_time));
+#define PG_STAT_GET_XACT_FUNCENTRY_FLOAT8_MS(stat)				\
+Datum															\
+CppConcat(pg_stat_get_xact_function_,stat)(PG_FUNCTION_ARGS)	\
+{																\
+	Oid			funcid = PG_GETARG_OID(0);						\
+	PgStat_FunctionCounts *funcentry;							\
+																\
+	if ((funcentry = find_funcstat_entry(funcid)) == NULL)		\
+		PG_RETURN_NULL();										\
+	PG_RETURN_FLOAT8(INSTR_TIME_GET_MILLISEC(funcentry->stat));	\
 }
 
-Datum
-pg_stat_get_xact_function_self_time(PG_FUNCTION_ARGS)
-{
-	Oid			funcid = PG_GETARG_OID(0);
-	PgStat_FunctionCounts *funcentry;
-
-	if ((funcentry = find_funcstat_entry(funcid)) == NULL)
-		PG_RETURN_NULL();
-	PG_RETURN_FLOAT8(INSTR_TIME_GET_MILLISEC(funcentry->self_time));
-}
+/* pg_stat_get_xact_function_total_time */
+PG_STAT_GET_XACT_FUNCENTRY_FLOAT8_MS(total_time)
 
+/* pg_stat_get_xact_function_self_time */
+PG_STAT_GET_XACT_FUNCENTRY_FLOAT8_MS(self_time)
 
 /* Get the timestamp of the current statistics snapshot */
 Datum