PG-310: Bucket is “Done” vs still being current/last. (#321)

A new column is added to mention that bucket is active or done. there is    
some timing based adjustment was required with that too.   

Co-authored-by: Hamid Akhtar <hamid.akhtar@percona.com>

pg_stat_monitor--1.0--2.0.sql

@@ -69,7 +69,8 @@ CREATE FUNCTION pg_stat_monitor_internal(
     OUT wal_fpi 			int8,
     OUT wal_bytes 			numeric,
     OUT comments 			TEXT,
-    OUT toplevel            BOOLEAN
+    OUT toplevel            BOOLEAN,
+	OUT bucket_done			BOOLEAN
 )
 RETURNS SETOF record
 AS 'MODULE_PATHNAME', 'pg_stat_monitor_2_0'
@@ -124,7 +125,8 @@ CREATE VIEW pg_stat_monitor AS SELECT
 	cpu_sys_time,
     wal_records,
     wal_fpi,
-    wal_bytes
+    wal_bytes,
+	bucket_done
 FROM pg_stat_monitor_internal(TRUE) p, pg_database d  WHERE dbid = oid
 ORDER BY bucket_start_time;
 RETURN 0;
@@ -242,6 +244,7 @@ CREATE VIEW pg_stat_monitor AS SELECT
     wal_records,
     wal_fpi,
     wal_bytes,
+	bucket_done,
 
     plans_calls,
 	total_plan_time,

pg_stat_monitor--1.0.sql

@@ -178,7 +178,8 @@ CREATE FUNCTION pg_stat_monitor_internal(
     OUT wal_fpi 			int8,
     OUT wal_bytes 			numeric,
     OUT comments 			TEXT,
-    OUT toplevel            BOOLEAN
+    OUT toplevel            BOOLEAN,
+	OUT	bucket_done			BOOLEAN
 )
 RETURNS SETOF record
 AS 'MODULE_PATHNAME', 'pg_stat_monitor'

pg_stat_monitor--2.0.sql

@@ -126,7 +126,7 @@ CREATE FUNCTION pg_stat_monitor_internal(
 	OUT elevel              int,
     OUT sqlcode             TEXT,
     OUT message             text,
-    OUT bucket_start_time   timestamp,
+    OUT bucket_start_time   timestamptz,
 
 	OUT calls         		int8,  -- 16
 
@@ -165,7 +165,8 @@ CREATE FUNCTION pg_stat_monitor_internal(
     OUT wal_fpi 			int8,
     OUT wal_bytes 			numeric,
     OUT comments 			TEXT,
-    OUT toplevel            BOOLEAN
+    OUT toplevel            BOOLEAN,
+	OUT bucket_done			BOOLEAN
 )
 RETURNS SETOF record
 AS 'MODULE_PATHNAME', 'pg_stat_monitor_2_0'
@@ -219,7 +220,8 @@ CREATE VIEW pg_stat_monitor AS SELECT
 	cpu_sys_time,
     wal_records,
     wal_fpi,
-    wal_bytes
+    wal_bytes,
+	bucket_done
 FROM pg_stat_monitor_internal(TRUE) p, pg_database d  WHERE dbid = oid
 ORDER BY bucket_start_time;
 RETURN 0;
@@ -276,6 +278,7 @@ CREATE VIEW pg_stat_monitor AS SELECT
     wal_records,
     wal_fpi,
     wal_bytes,
+	bucket_done,
     -- PostgreSQL-13 Specific Coulumns
 	plans_calls,
 	total_plan_time,
@@ -338,6 +341,7 @@ CREATE VIEW pg_stat_monitor AS SELECT
     wal_records,
     wal_fpi,
     wal_bytes,
+	bucket_done,
 
     plans_calls,
 	total_plan_time,

pg_stat_monitor.c

@@ -36,7 +36,7 @@
 PG_MODULE_MAGIC;
 
 #define BUILD_VERSION                   "2.0.0-dev"
-#define PG_STAT_STATEMENTS_COLS         52	/* maximum of above */
+#define PG_STAT_STATEMENTS_COLS         53	/* maximum of above */
 #define PGSM_TEXT_FILE PGSTAT_STAT_PERMANENT_DIRECTORY "pg_stat_monitor_query"
 
 #define roundf(x,d) ((floor(((x)*pow(10,d))+.5))/pow(10,d))
@@ -1613,15 +1613,12 @@ pg_stat_monitor(PG_FUNCTION_ARGS)
 static bool
 IsBucketValid(uint64 bucketid)
 {
-	struct tm	tm;
 	time_t		bucket_t,
 				current_t;
 	double		diff_t;
 	pgssSharedState *pgss = pgsm_get_ss();
 
-	memset(&tm, 0, sizeof(tm));
+	bucket_t = mktime(&pgss->bucket_start_time[bucketid]);
-	strptime(pgss->bucket_start_time[bucketid], "%Y-%m-%d %H:%M:%S", &tm);
-	bucket_t = mktime(&tm);
 
 	time(&current_t);
 	diff_t = difftime(current_t, bucket_t);
@@ -1674,7 +1671,7 @@ pg_stat_monitor_internal(FunctionCallInfo fcinfo,
 	if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
 		elog(ERROR, "pg_stat_monitor: return type must be a row type");
 
-	if (tupdesc->natts != 51)
+	if (tupdesc->natts != 52)
 		elog(ERROR, "pg_stat_monitor: incorrect number of output arguments, required %d", tupdesc->natts);
 
 	tupstore = tuplestore_begin_heap(true, false, work_mem);
@@ -1892,7 +1889,11 @@ pg_stat_monitor_internal(FunctionCallInfo fcinfo,
 			values[i++] = CStringGetTextDatum(tmp.error.message);
 
 		/* bucket_start_time at column number 15 */
-		values[i++] = CStringGetDatum(pgss->bucket_start_time[entry->key.bucket_id]);
+		{
+			TimestampTz tm;
+			tm2timestamp((struct pg_tm*) &pgss->bucket_start_time[entry->key.bucket_id], 0, NULL, &tm);
+			values[i++] = TimestampGetDatum(tm);
+		}
 		if (tmp.calls.calls == 0)
 		{
 			/* Query of pg_stat_monitor itslef started from zero count */
@@ -2003,6 +2004,9 @@ pg_stat_monitor_internal(FunctionCallInfo fcinfo,
 				nulls[i++] = true;
 		}
 		values[i++] = BoolGetDatum(toplevel);
+		values[i++] = BoolGetDatum(pg_atomic_read_u64(&pgss->current_wbucket) != bucketid);
+
+		/* clean up and return the tuplestore */
 		tuplestore_putvalues(tupstore, tupdesc, values, nulls);
 	}
 	/* clean up and return the tuplestore */
@@ -2086,13 +2090,16 @@ get_next_wbucket(pgssSharedState *pgss)
 
 		tv.tv_sec = (tv.tv_sec) - (tv.tv_sec % PGSM_BUCKET_TIME);
 		lt = localtime(&tv.tv_sec);
+		/*
+		 * Year is 1900 behind and month is 0 based, therefore we need to
+		 * adjust that.
+		 */
+		lt->tm_year += 1900;
+		lt->tm_mon += 1;
 
 		/* Allign the value in prev_bucket_sec to the bucket start time */
 		pg_atomic_exchange_u64(&pgss->prev_bucket_sec, (uint64)tv.tv_sec);
-
+		memcpy(&pgss->bucket_start_time[new_bucket_id], lt, sizeof(struct tm));
-		snprintf(pgss->bucket_start_time[new_bucket_id], sizeof(pgss->bucket_start_time[new_bucket_id]),
-			"%04d-%02d-%02d %02d:%02d:%02d", lt->tm_year + 1900, lt->tm_mon + 1, lt->tm_mday, lt->tm_hour, lt->tm_min, lt->tm_sec);
-
 		return new_bucket_id;
 	}
 

pg_stat_monitor.h

@@ -317,11 +317,9 @@ typedef struct pgssSharedState
 	pg_atomic_uint64 current_wbucket;
 	pg_atomic_uint64 prev_bucket_sec;
 	uint64		bucket_entry[MAX_BUCKETS];
-	char		bucket_start_time[MAX_BUCKETS][60]; /* start time of the
+	struct tm   bucket_start_time[MAX_BUCKETS]; /* start time of the bucket */
-													 * bucket */
 	LWLock	   *errors_lock;	/* protects errors hashtable
 								 * search/modification */
-
 	/*
 	 * These variables are used when pgsm_overflow_target is ON.
 	 *