From a4a1dce54b8542c74e39117e77b2f1d005341501 Mon Sep 17 00:00:00 2001 From: Bertrand Drouvot Date: Mon, 6 Jan 2025 07:51:27 +0000 Subject: [PATCH v8 1/3] Extract logic filling pg_stat_get_wal()'s tuple into its own routine This commit adds pg_stat_wal_build_tuple(), a helper routine for pg_stat_get_wal(), that fills its tuple based on the contents of PgStat_WalStats. This will be used in a follow-up commit that uses the same structures as pg_stat_wal for reporting, but for the PGSTAT_KIND_BACKEND statistics kind. --- src/backend/utils/adt/pgstatfuncs.c | 48 +++++++++++++++++++---------- 1 file changed, 32 insertions(+), 16 deletions(-) 100.0% src/backend/utils/adt/ diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c index 68e16e52ab6..620d60a0938 100644 --- a/src/backend/utils/adt/pgstatfuncs.c +++ b/src/backend/utils/adt/pgstatfuncs.c @@ -1632,20 +1632,22 @@ pg_stat_get_backend_io(PG_FUNCTION_ARGS) } /* - * Returns statistics of WAL activity + * pg_stat_wal_build_tuple + * + * Helper routine for pg_stat_get_wal() returning one tuple based on the contents + * of wal_stats. */ -Datum -pg_stat_get_wal(PG_FUNCTION_ARGS) +static Datum +pg_stat_wal_build_tuple(PgStat_WalStats wal_stats) { -#define PG_STAT_GET_WAL_COLS 5 +#define PG_STAT_WAL_COLS 5 TupleDesc tupdesc; - Datum values[PG_STAT_GET_WAL_COLS] = {0}; - bool nulls[PG_STAT_GET_WAL_COLS] = {0}; + Datum values[PG_STAT_WAL_COLS] = {0}; + bool nulls[PG_STAT_WAL_COLS] = {0}; char buf[256]; - PgStat_WalStats *wal_stats; /* Initialise attributes information in the tuple descriptor */ - tupdesc = CreateTemplateTupleDesc(PG_STAT_GET_WAL_COLS); + tupdesc = CreateTemplateTupleDesc(PG_STAT_WAL_COLS); TupleDescInitEntry(tupdesc, (AttrNumber) 1, "wal_records", INT8OID, -1, 0); TupleDescInitEntry(tupdesc, (AttrNumber) 2, "wal_fpi", @@ -1659,28 +1661,42 @@ pg_stat_get_wal(PG_FUNCTION_ARGS) BlessTupleDesc(tupdesc); - /* Get statistics about WAL activity */ - wal_stats = pgstat_fetch_stat_wal(); - /* Fill values and NULLs */ - values[0] = Int64GetDatum(wal_stats->wal_records); - values[1] = Int64GetDatum(wal_stats->wal_fpi); + values[0] = Int64GetDatum(wal_stats.wal_records); + values[1] = Int64GetDatum(wal_stats.wal_fpi); /* Convert to numeric. */ - snprintf(buf, sizeof buf, UINT64_FORMAT, wal_stats->wal_bytes); + snprintf(buf, sizeof buf, UINT64_FORMAT, wal_stats.wal_bytes); values[2] = DirectFunctionCall3(numeric_in, CStringGetDatum(buf), ObjectIdGetDatum(0), Int32GetDatum(-1)); - values[3] = Int64GetDatum(wal_stats->wal_buffers_full); + values[3] = Int64GetDatum(wal_stats.wal_buffers_full); - values[4] = TimestampTzGetDatum(wal_stats->stat_reset_timestamp); + if (wal_stats.stat_reset_timestamp != 0) + values[4] = TimestampTzGetDatum(wal_stats.stat_reset_timestamp); + else + nulls[4] = true; /* Returns the record as Datum */ PG_RETURN_DATUM(HeapTupleGetDatum(heap_form_tuple(tupdesc, values, nulls))); } +/* + * Returns statistics of WAL activity + */ +Datum +pg_stat_get_wal(PG_FUNCTION_ARGS) +{ + PgStat_WalStats *wal_stats; + + /* Get statistics about WAL activity */ + wal_stats = pgstat_fetch_stat_wal(); + + return (pg_stat_wal_build_tuple(*wal_stats)); +} + /* * Returns statistics of SLRU caches. */ -- 2.34.1