Remove PgStat_BackendFunctionEntry

This structure included only PgStat_FunctionCounts, and removing it
facilitates some upcoming refactoring for pgstatfuncs.c to use more
macros rather that mostly-duplicated functions.

Author: Bertrand Drouvot
Reviewed-by: Nathan Bossart
Discussion: https://postgr.es/m/11d531fe-52fc-c6ea-7e8e-62f1b6ec626e@gmail.com

src/backend/utils/activity/pgstat.c

@@ -292,7 +292,7 @@ static const PgStat_KindInfo pgstat_kind_infos[PGSTAT_NUM_KINDS] = {
 		.shared_size = sizeof(PgStatShared_Function),
 		.shared_data_off = offsetof(PgStatShared_Function, stats),
 		.shared_data_len = sizeof(((PgStatShared_Function *) 0)->stats),
-		.pending_size = sizeof(PgStat_BackendFunctionEntry),
+		.pending_size = sizeof(PgStat_FunctionCounts),
 
 		.flush_pending_cb = pgstat_function_flush_cb,
 	},

src/backend/utils/activity/pgstat_function.c

@@ -73,7 +73,7 @@ pgstat_init_function_usage(FunctionCallInfo fcinfo,
 						   PgStat_FunctionCallUsage *fcu)
 {
 	PgStat_EntryRef *entry_ref;
-	PgStat_BackendFunctionEntry *pending;
+	PgStat_FunctionCounts *pending;
 	bool		created_entry;
 
 	if (pgstat_track_functions <= fcinfo->flinfo->fn_stats)
@@ -121,10 +121,10 @@ pgstat_init_function_usage(FunctionCallInfo fcinfo,
 
 	pending = entry_ref->pending;
 
-	fcu->fs = &pending->f_counts;
+	fcu->fs = pending;
 
 	/* save stats for this function, later used to compensate for recursion */
-	fcu->save_f_total_time = pending->f_counts.f_total_time;
+	fcu->save_f_total_time = pending->f_total_time;
 
 	/* save current backend-wide total time */
 	fcu->save_total = total_func_time;
@@ -192,10 +192,10 @@ pgstat_end_function_usage(PgStat_FunctionCallUsage *fcu, bool finalize)
 bool
 pgstat_function_flush_cb(PgStat_EntryRef *entry_ref, bool nowait)
 {
-	PgStat_BackendFunctionEntry *localent;
+	PgStat_FunctionCounts *localent;
 	PgStatShared_Function *shfuncent;
 
-	localent = (PgStat_BackendFunctionEntry *) entry_ref->pending;
+	localent = (PgStat_FunctionCounts *) entry_ref->pending;
 	shfuncent = (PgStatShared_Function *) entry_ref->shared_stats;
 
 	/* localent always has non-zero content */
@@ -203,11 +203,11 @@ pgstat_function_flush_cb(PgStat_EntryRef *entry_ref, bool nowait)
 	if (!pgstat_lock_entry(entry_ref, nowait))
 		return false;
 
-	shfuncent->stats.f_numcalls += localent->f_counts.f_numcalls;
+	shfuncent->stats.f_numcalls += localent->f_numcalls;
 	shfuncent->stats.f_total_time +=
-		INSTR_TIME_GET_MICROSEC(localent->f_counts.f_total_time);
+		INSTR_TIME_GET_MICROSEC(localent->f_total_time);
 	shfuncent->stats.f_self_time +=
-		INSTR_TIME_GET_MICROSEC(localent->f_counts.f_self_time);
+		INSTR_TIME_GET_MICROSEC(localent->f_self_time);
 
 	pgstat_unlock_entry(entry_ref);
 
@@ -215,11 +215,11 @@ pgstat_function_flush_cb(PgStat_EntryRef *entry_ref, bool nowait)
 }
 
 /*
- * find any existing PgStat_BackendFunctionEntry entry for specified function
+ * find any existing PgStat_FunctionCounts entry for specified function
  *
  * If no entry, return NULL, don't create a new one
  */
-PgStat_BackendFunctionEntry *
+PgStat_FunctionCounts *
 find_funcstat_entry(Oid func_id)
 {
 	PgStat_EntryRef *entry_ref;

src/backend/utils/adt/pgstatfuncs.c

@@ -1652,33 +1652,33 @@ Datum
 pg_stat_get_xact_function_calls(PG_FUNCTION_ARGS)
 {
 	Oid			funcid = PG_GETARG_OID(0);
-	PgStat_BackendFunctionEntry *funcentry;
+	PgStat_FunctionCounts *funcentry;
 
 	if ((funcentry = find_funcstat_entry(funcid)) == NULL)
 		PG_RETURN_NULL();
-	PG_RETURN_INT64(funcentry->f_counts.f_numcalls);
+	PG_RETURN_INT64(funcentry->f_numcalls);
 }
 
 Datum
 pg_stat_get_xact_function_total_time(PG_FUNCTION_ARGS)
 {
 	Oid			funcid = PG_GETARG_OID(0);
-	PgStat_BackendFunctionEntry *funcentry;
+	PgStat_FunctionCounts *funcentry;
 
 	if ((funcentry = find_funcstat_entry(funcid)) == NULL)
 		PG_RETURN_NULL();
-	PG_RETURN_FLOAT8(INSTR_TIME_GET_MILLISEC(funcentry->f_counts.f_total_time));
+	PG_RETURN_FLOAT8(INSTR_TIME_GET_MILLISEC(funcentry->f_total_time));
 }
 
 Datum
 pg_stat_get_xact_function_self_time(PG_FUNCTION_ARGS)
 {
 	Oid			funcid = PG_GETARG_OID(0);
-	PgStat_BackendFunctionEntry *funcentry;
+	PgStat_FunctionCounts *funcentry;
 
 	if ((funcentry = find_funcstat_entry(funcid)) == NULL)
 		PG_RETURN_NULL();
-	PG_RETURN_FLOAT8(INSTR_TIME_GET_MILLISEC(funcentry->f_counts.f_self_time));
+	PG_RETURN_FLOAT8(INSTR_TIME_GET_MILLISEC(funcentry->f_self_time));
 }
 
 

src/include/pgstat.h

@@ -111,15 +111,6 @@ typedef struct PgStat_FunctionCounts
 	instr_time	f_self_time;
 } PgStat_FunctionCounts;
 
-/* ----------
- * PgStat_BackendFunctionEntry	Non-flushed function stats.
- * ----------
- */
-typedef struct PgStat_BackendFunctionEntry
-{
-	PgStat_FunctionCounts f_counts;
-} PgStat_BackendFunctionEntry;
-
 /*
  * Working state needed to accumulate per-function-call timing statistics.
  */
@@ -556,7 +547,7 @@ extern void pgstat_end_function_usage(PgStat_FunctionCallUsage *fcu,
 									  bool finalize);
 
 extern PgStat_StatFuncEntry *pgstat_fetch_stat_funcentry(Oid func_id);
-extern PgStat_BackendFunctionEntry *find_funcstat_entry(Oid func_id);
+extern PgStat_FunctionCounts *find_funcstat_entry(Oid func_id);
 
 
 /*

src/tools/pgindent/typedefs.list

@@ -2032,7 +2032,6 @@ PgStatShared_SLRU
 PgStatShared_Subscription
 PgStatShared_Wal
 PgStat_ArchiverStats
-PgStat_BackendFunctionEntry
 PgStat_BackendSubEntry
 PgStat_BgWriterStats
 PgStat_BktypeIO