Generate pg_stat_get*() functions for tables using macros

The same code pattern is repeated 17 times for int64 counters (0 for
missing entry) and 5 times for timestamps (NULL for missing entry) on
table entries.  This code is switched to use a macro for the basic code
instead, shaving a few hundred lines of originally-duplicated code.  The
function names remain the same, but some fields of PgStat_StatTabEntry
have to be renamed to cope with the new style.

Author: Bertrand Drouvot
Reviewed-by: Nathan Bossart
Discussion: https:/postgr.es/m/20221204173207.GA2669116@nathanxps13

1 files changed, 100 insertions, 357 deletions

diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index ae3365d9171..973979508d2 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -36,363 +36,106 @@
 
 #define HAS_PGSTAT_PERMISSIONS(role)	 (has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS) || has_privs_of_role(GetUserId(), role))
 
-Datum
-pg_stat_get_numscans(PG_FUNCTION_ARGS)
-{
-	Oid			relid = PG_GETARG_OID(0);
-	int64		result;
-	PgStat_StatTabEntry *tabentry;
-
-	if ((tabentry = pgstat_fetch_stat_tabentry(relid)) == NULL)
-		result = 0;
-	else
-		result = (int64) (tabentry->numscans);
-
-	PG_RETURN_INT64(result);
-}
-
-
-Datum
-pg_stat_get_lastscan(PG_FUNCTION_ARGS)
-{
-	Oid			relid = PG_GETARG_OID(0);
-	TimestampTz result;
-	PgStat_StatTabEntry *tabentry;
-
-	if ((tabentry = pgstat_fetch_stat_tabentry(relid)) == NULL)
-		result = 0;
-	else
-		result = tabentry->lastscan;
-
-	if (result == 0)
-		PG_RETURN_NULL();
-	else
-		PG_RETURN_TIMESTAMPTZ(result);
-}
-
-
-Datum
-pg_stat_get_tuples_returned(PG_FUNCTION_ARGS)
-{
-	Oid			relid = PG_GETARG_OID(0);
-	int64		result;
-	PgStat_StatTabEntry *tabentry;
-
-	if ((tabentry = pgstat_fetch_stat_tabentry(relid)) == NULL)
-		result = 0;
-	else
-		result = (int64) (tabentry->tuples_returned);
-
-	PG_RETURN_INT64(result);
-}
-
-
-Datum
-pg_stat_get_tuples_fetched(PG_FUNCTION_ARGS)
-{
-	Oid			relid = PG_GETARG_OID(0);
-	int64		result;
-	PgStat_StatTabEntry *tabentry;
-
-	if ((tabentry = pgstat_fetch_stat_tabentry(relid)) == NULL)
-		result = 0;
-	else
-		result = (int64) (tabentry->tuples_fetched);
-
-	PG_RETURN_INT64(result);
-}
-
-
-Datum
-pg_stat_get_tuples_inserted(PG_FUNCTION_ARGS)
-{
-	Oid			relid = PG_GETARG_OID(0);
-	int64		result;
-	PgStat_StatTabEntry *tabentry;
-
-	if ((tabentry = pgstat_fetch_stat_tabentry(relid)) == NULL)
-		result = 0;
-	else
-		result = (int64) (tabentry->tuples_inserted);
-
-	PG_RETURN_INT64(result);
-}
-
-
-Datum
-pg_stat_get_tuples_updated(PG_FUNCTION_ARGS)
-{
-	Oid			relid = PG_GETARG_OID(0);
-	int64		result;
-	PgStat_StatTabEntry *tabentry;
-
-	if ((tabentry = pgstat_fetch_stat_tabentry(relid)) == NULL)
-		result = 0;
-	else
-		result = (int64) (tabentry->tuples_updated);
-
-	PG_RETURN_INT64(result);
-}
-
-
-Datum
-pg_stat_get_tuples_deleted(PG_FUNCTION_ARGS)
-{
-	Oid			relid = PG_GETARG_OID(0);
-	int64		result;
-	PgStat_StatTabEntry *tabentry;
-
-	if ((tabentry = pgstat_fetch_stat_tabentry(relid)) == NULL)
-		result = 0;
-	else
-		result = (int64) (tabentry->tuples_deleted);
-
-	PG_RETURN_INT64(result);
-}
-
-
-Datum
-pg_stat_get_tuples_hot_updated(PG_FUNCTION_ARGS)
-{
-	Oid			relid = PG_GETARG_OID(0);
-	int64		result;
-	PgStat_StatTabEntry *tabentry;
-
-	if ((tabentry = pgstat_fetch_stat_tabentry(relid)) == NULL)
-		result = 0;
-	else
-		result = (int64) (tabentry->tuples_hot_updated);
-
-	PG_RETURN_INT64(result);
-}
-
-
-Datum
-pg_stat_get_live_tuples(PG_FUNCTION_ARGS)
-{
-	Oid			relid = PG_GETARG_OID(0);
-	int64		result;
-	PgStat_StatTabEntry *tabentry;
-
-	if ((tabentry = pgstat_fetch_stat_tabentry(relid)) == NULL)
-		result = 0;
-	else
-		result = (int64) (tabentry->n_live_tuples);
-
-	PG_RETURN_INT64(result);
-}
-
-
-Datum
-pg_stat_get_dead_tuples(PG_FUNCTION_ARGS)
-{
-	Oid			relid = PG_GETARG_OID(0);
-	int64		result;
-	PgStat_StatTabEntry *tabentry;
-
-	if ((tabentry = pgstat_fetch_stat_tabentry(relid)) == NULL)
-		result = 0;
-	else
-		result = (int64) (tabentry->n_dead_tuples);
-
-	PG_RETURN_INT64(result);
-}
-
-
-Datum
-pg_stat_get_mod_since_analyze(PG_FUNCTION_ARGS)
-{
-	Oid			relid = PG_GETARG_OID(0);
-	int64		result;
-	PgStat_StatTabEntry *tabentry;
-
-	if ((tabentry = pgstat_fetch_stat_tabentry(relid)) == NULL)
-		result = 0;
-	else
-		result = (int64) (tabentry->changes_since_analyze);
-
-	PG_RETURN_INT64(result);
-}
-
-
-Datum
-pg_stat_get_ins_since_vacuum(PG_FUNCTION_ARGS)
-{
-	Oid			relid = PG_GETARG_OID(0);
-	int64		result;
-	PgStat_StatTabEntry *tabentry;
-
-	if ((tabentry = pgstat_fetch_stat_tabentry(relid)) == NULL)
-		result = 0;
-	else
-		result = (int64) (tabentry->inserts_since_vacuum);
-
-	PG_RETURN_INT64(result);
-}
-
-
-Datum
-pg_stat_get_blocks_fetched(PG_FUNCTION_ARGS)
-{
-	Oid			relid = PG_GETARG_OID(0);
-	int64		result;
-	PgStat_StatTabEntry *tabentry;
-
-	if ((tabentry = pgstat_fetch_stat_tabentry(relid)) == NULL)
-		result = 0;
-	else
-		result = (int64) (tabentry->blocks_fetched);
-
-	PG_RETURN_INT64(result);
-}
-
-
-Datum
-pg_stat_get_blocks_hit(PG_FUNCTION_ARGS)
-{
-	Oid			relid = PG_GETARG_OID(0);
-	int64		result;
-	PgStat_StatTabEntry *tabentry;
-
-	if ((tabentry = pgstat_fetch_stat_tabentry(relid)) == NULL)
-		result = 0;
-	else
-		result = (int64) (tabentry->blocks_hit);
-
-	PG_RETURN_INT64(result);
-}
-
-Datum
-pg_stat_get_last_vacuum_time(PG_FUNCTION_ARGS)
-{
-	Oid			relid = PG_GETARG_OID(0);
-	TimestampTz result;
-	PgStat_StatTabEntry *tabentry;
-
-	if ((tabentry = pgstat_fetch_stat_tabentry(relid)) == NULL)
-		result = 0;
-	else
-		result = tabentry->vacuum_timestamp;
-
-	if (result == 0)
-		PG_RETURN_NULL();
-	else
-		PG_RETURN_TIMESTAMPTZ(result);
-}
-
-Datum
-pg_stat_get_last_autovacuum_time(PG_FUNCTION_ARGS)
-{
-	Oid			relid = PG_GETARG_OID(0);
-	TimestampTz result;
-	PgStat_StatTabEntry *tabentry;
-
-	if ((tabentry = pgstat_fetch_stat_tabentry(relid)) == NULL)
-		result = 0;
-	else
-		result = tabentry->autovac_vacuum_timestamp;
-
-	if (result == 0)
-		PG_RETURN_NULL();
-	else
-		PG_RETURN_TIMESTAMPTZ(result);
-}
-
-Datum
-pg_stat_get_last_analyze_time(PG_FUNCTION_ARGS)
-{
-	Oid			relid = PG_GETARG_OID(0);
-	TimestampTz result;
-	PgStat_StatTabEntry *tabentry;
-
-	if ((tabentry = pgstat_fetch_stat_tabentry(relid)) == NULL)
-		result = 0;
-	else
-		result = tabentry->analyze_timestamp;
-
-	if (result == 0)
-		PG_RETURN_NULL();
-	else
-		PG_RETURN_TIMESTAMPTZ(result);
-}
-
-Datum
-pg_stat_get_last_autoanalyze_time(PG_FUNCTION_ARGS)
-{
-	Oid			relid = PG_GETARG_OID(0);
-	TimestampTz result;
-	PgStat_StatTabEntry *tabentry;
-
-	if ((tabentry = pgstat_fetch_stat_tabentry(relid)) == NULL)
-		result = 0;
-	else
-		result = tabentry->autovac_analyze_timestamp;
-
-	if (result == 0)
-		PG_RETURN_NULL();
-	else
-		PG_RETURN_TIMESTAMPTZ(result);
-}
-
-Datum
-pg_stat_get_vacuum_count(PG_FUNCTION_ARGS)
-{
-	Oid			relid = PG_GETARG_OID(0);
-	int64		result;
-	PgStat_StatTabEntry *tabentry;
-
-	if ((tabentry = pgstat_fetch_stat_tabentry(relid)) == NULL)
-		result = 0;
-	else
-		result = (int64) (tabentry->vacuum_count);
-
-	PG_RETURN_INT64(result);
-}
-
-Datum
-pg_stat_get_autovacuum_count(PG_FUNCTION_ARGS)
-{
-	Oid			relid = PG_GETARG_OID(0);
-	int64		result;
-	PgStat_StatTabEntry *tabentry;
-
-	if ((tabentry = pgstat_fetch_stat_tabentry(relid)) == NULL)
-		result = 0;
-	else
-		result = (int64) (tabentry->autovac_vacuum_count);
-
-	PG_RETURN_INT64(result);
-}
-
-Datum
-pg_stat_get_analyze_count(PG_FUNCTION_ARGS)
-{
-	Oid			relid = PG_GETARG_OID(0);
-	int64		result;
-	PgStat_StatTabEntry *tabentry;
-
-	if ((tabentry = pgstat_fetch_stat_tabentry(relid)) == NULL)
-		result = 0;
-	else
-		result = (int64) (tabentry->analyze_count);
-
-	PG_RETURN_INT64(result);
-}
-
-Datum
-pg_stat_get_autoanalyze_count(PG_FUNCTION_ARGS)
-{
-	Oid			relid = PG_GETARG_OID(0);
-	int64		result;
-	PgStat_StatTabEntry *tabentry;
-
-	if ((tabentry = pgstat_fetch_stat_tabentry(relid)) == NULL)
-		result = 0;
-	else
-		result = (int64) (tabentry->autovac_analyze_count);
-
-	PG_RETURN_INT64(result);
-}
+#define PG_STAT_GET_RELENTRY_INT64(stat)						\
+Datum															\
+CppConcat(pg_stat_get_,stat)(PG_FUNCTION_ARGS)					\
+{																\
+	Oid			relid = PG_GETARG_OID(0);						\
+	int64		result;											\
+	PgStat_StatTabEntry *tabentry;								\
+																\
+	if ((tabentry = pgstat_fetch_stat_tabentry(relid)) == NULL)	\
+		result = 0;												\
+	else														\
+		result = (int64) (tabentry->stat);						\
+																\
+	PG_RETURN_INT64(result);									\
+}																\
+
+/* pg_stat_get_analyze_count */
+PG_STAT_GET_RELENTRY_INT64(analyze_count);
+
+/* pg_stat_get_autoanalyze_count */
+PG_STAT_GET_RELENTRY_INT64(autoanalyze_count);
+
+/* pg_stat_get_autovacuum_count */
+PG_STAT_GET_RELENTRY_INT64(autovacuum_count);
+
+/* pg_stat_get_blocks_fetched */
+PG_STAT_GET_RELENTRY_INT64(blocks_fetched);
+
+/* pg_stat_get_blocks_hit */
+PG_STAT_GET_RELENTRY_INT64(blocks_hit);
+
+/* pg_stat_get_dead_tuples */
+PG_STAT_GET_RELENTRY_INT64(dead_tuples);
+
+/* pg_stat_get_ins_since_vacuum */
+PG_STAT_GET_RELENTRY_INT64(ins_since_vacuum);
+
+/* pg_stat_get_live_tuples */
+PG_STAT_GET_RELENTRY_INT64(live_tuples);
+
+/* pg_stat_get_mods_since_analyze */
+PG_STAT_GET_RELENTRY_INT64(mod_since_analyze);
+
+/* pg_stat_get_numscans */
+PG_STAT_GET_RELENTRY_INT64(numscans);
+
+/* pg_stat_get_tuples_deleted */
+PG_STAT_GET_RELENTRY_INT64(tuples_deleted);
+
+/* pg_stat_get_tuples_fetched */
+PG_STAT_GET_RELENTRY_INT64(tuples_fetched);
+
+/* pg_stat_get_tuples_hot_updated */
+PG_STAT_GET_RELENTRY_INT64(tuples_hot_updated);
+
+/* pg_stat_get_tuples_inserted */
+PG_STAT_GET_RELENTRY_INT64(tuples_inserted);
+
+/* pg_stat_get_tuples_returned */
+PG_STAT_GET_RELENTRY_INT64(tuples_returned);
+
+/* pg_stat_get_tuples_updated */
+PG_STAT_GET_RELENTRY_INT64(tuples_updated);
+
+/* pg_stat_get_vacuum_count */
+PG_STAT_GET_RELENTRY_INT64(vacuum_count);
+
+#define PG_STAT_GET_RELENTRY_TIMESTAMPTZ(stat)					\
+Datum															\
+CppConcat(pg_stat_get_,stat)(PG_FUNCTION_ARGS)					\
+{																\
+	Oid			relid = PG_GETARG_OID(0);						\
+	TimestampTz result;											\
+	PgStat_StatTabEntry *tabentry;								\
+																\
+	if ((tabentry = pgstat_fetch_stat_tabentry(relid)) == NULL)	\
+		result = 0;												\
+	else														\
+		result = tabentry->stat;								\
+																\
+	if (result == 0)											\
+		PG_RETURN_NULL();										\
+	else														\
+		PG_RETURN_TIMESTAMPTZ(result);							\
+}																\
+
+/* pg_stat_get_last_analyze_time */
+PG_STAT_GET_RELENTRY_TIMESTAMPTZ(last_analyze_time);
+
+/* pg_stat_get_last_autoanalyze_time */
+PG_STAT_GET_RELENTRY_TIMESTAMPTZ(last_autoanalyze_time);
+
+/* pg_stat_get_last_autovacuum_time */
+PG_STAT_GET_RELENTRY_TIMESTAMPTZ(last_autovacuum_time);
+
+/* pg_stat_get_last_vacuum_time */
+PG_STAT_GET_RELENTRY_TIMESTAMPTZ(last_vacuum_time);
+
+/* pg_stat_get_lastscan */
+PG_STAT_GET_RELENTRY_TIMESTAMPTZ(lastscan);
 
 Datum
 pg_stat_get_function_calls(PG_FUNCTION_ARGS)