1 files changed, 424 insertions, 0 deletions
diff --git a/src/backend/utils/activity/pgstat_database.c b/src/backend/utils/activity/pgstat_database.c
new file mode 100644
index 0000000..d927561
--- /dev/null
+++ b/src/backend/utils/activity/pgstat_database.c
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+/* -------------------------------------------------------------------------
+ *
+ * pgstat_database.c
+ *	  Implementation of database statistics.
+ *
+ * This file contains the implementation of database statistics. It is kept
+ * separate from pgstat.c to enforce the line between the statistics access /
+ * storage implementation and the details about individual types of
+ * statistics.
+ *
+ * Copyright (c) 2001-2022, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/activity/pgstat_database.c
+ * -------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+
+#include "utils/pgstat_internal.h"
+#include "utils/timestamp.h"
+#include "storage/procsignal.h"
+
+
+static bool pgstat_should_report_connstat(void);
+
+
+PgStat_Counter pgStatBlockReadTime = 0;
+PgStat_Counter pgStatBlockWriteTime = 0;
+PgStat_Counter pgStatActiveTime = 0;
+PgStat_Counter pgStatTransactionIdleTime = 0;
+SessionEndType pgStatSessionEndCause = DISCONNECT_NORMAL;
+
+
+static int	pgStatXactCommit = 0;
+static int	pgStatXactRollback = 0;
+static PgStat_Counter pgLastSessionReportTime = 0;
+
+
+/*
+ * Remove entry for the database being dropped.
+ */
+void
+pgstat_drop_database(Oid databaseid)
+{
+	pgstat_drop_transactional(PGSTAT_KIND_DATABASE, databaseid, InvalidOid);
+}
+
+/*
+ * Called from autovacuum.c to report startup of an autovacuum process.
+ * We are called before InitPostgres is done, so can't rely on MyDatabaseId;
+ * the db OID must be passed in, instead.
+ */
+void
+pgstat_report_autovac(Oid dboid)
+{
+	PgStat_EntryRef *entry_ref;
+	PgStatShared_Database *dbentry;
+
+	/* can't get here in single user mode */
+	Assert(IsUnderPostmaster);
+
+	/*
+	 * End-of-vacuum is reported instantly. Report the start the same way for
+	 * consistency. Vacuum doesn't run frequently and is a long-lasting
+	 * operation so it doesn't matter if we get blocked here a little.
+	 */
+	entry_ref = pgstat_get_entry_ref_locked(PGSTAT_KIND_DATABASE,
+											dboid, InvalidOid, false);
+
+	dbentry = (PgStatShared_Database *) entry_ref->shared_stats;
+	dbentry->stats.last_autovac_time = GetCurrentTimestamp();
+
+	pgstat_unlock_entry(entry_ref);
+}
+
+/*
+ * Report a Hot Standby recovery conflict.
+ */
+void
+pgstat_report_recovery_conflict(int reason)
+{
+	PgStat_StatDBEntry *dbentry;
+
+	Assert(IsUnderPostmaster);
+	if (!pgstat_track_counts)
+		return;
+
+	dbentry = pgstat_prep_database_pending(MyDatabaseId);
+
+	switch (reason)
+	{
+		case PROCSIG_RECOVERY_CONFLICT_DATABASE:
+
+			/*
+			 * Since we drop the information about the database as soon as it
+			 * replicates, there is no point in counting these conflicts.
+			 */
+			break;
+		case PROCSIG_RECOVERY_CONFLICT_TABLESPACE:
+			dbentry->n_conflict_tablespace++;
+			break;
+		case PROCSIG_RECOVERY_CONFLICT_LOCK:
+			dbentry->n_conflict_lock++;
+			break;
+		case PROCSIG_RECOVERY_CONFLICT_SNAPSHOT:
+			dbentry->n_conflict_snapshot++;
+			break;
+		case PROCSIG_RECOVERY_CONFLICT_BUFFERPIN:
+			dbentry->n_conflict_bufferpin++;
+			break;
+		case PROCSIG_RECOVERY_CONFLICT_STARTUP_DEADLOCK:
+			dbentry->n_conflict_startup_deadlock++;
+			break;
+	}
+}
+
+/*
+ * Report a detected deadlock.
+ */
+void
+pgstat_report_deadlock(void)
+{
+	PgStat_StatDBEntry *dbent;
+
+	if (!pgstat_track_counts)
+		return;
+
+	dbent = pgstat_prep_database_pending(MyDatabaseId);
+	dbent->n_deadlocks++;
+}
+
+/*
+ * Report one or more checksum failures.
+ */
+void
+pgstat_report_checksum_failures_in_db(Oid dboid, int failurecount)
+{
+	PgStat_EntryRef *entry_ref;
+	PgStatShared_Database *sharedent;
+
+	if (!pgstat_track_counts)
+		return;
+
+	/*
+	 * Update the shared stats directly - checksum failures should never be
+	 * common enough for that to be a problem.
+	 */
+	entry_ref =
+		pgstat_get_entry_ref_locked(PGSTAT_KIND_DATABASE, dboid, InvalidOid, false);
+
+	sharedent = (PgStatShared_Database *) entry_ref->shared_stats;
+	sharedent->stats.n_checksum_failures += failurecount;
+	sharedent->stats.last_checksum_failure = GetCurrentTimestamp();
+
+	pgstat_unlock_entry(entry_ref);
+}
+
+/*
+ * Report one checksum failure in the current database.
+ */
+void
+pgstat_report_checksum_failure(void)
+{
+	pgstat_report_checksum_failures_in_db(MyDatabaseId, 1);
+}
+
+/*
+ * Report creation of temporary file.
+ */
+void
+pgstat_report_tempfile(size_t filesize)
+{
+	PgStat_StatDBEntry *dbent;
+
+	if (!pgstat_track_counts)
+		return;
+
+	dbent = pgstat_prep_database_pending(MyDatabaseId);
+	dbent->n_temp_bytes += filesize;
+	dbent->n_temp_files++;
+}
+
+/*
+ * Notify stats system of a new connection.
+ */
+void
+pgstat_report_connect(Oid dboid)
+{
+	PgStat_StatDBEntry *dbentry;
+
+	if (!pgstat_should_report_connstat())
+		return;
+
+	pgLastSessionReportTime = MyStartTimestamp;
+
+	dbentry = pgstat_prep_database_pending(MyDatabaseId);
+	dbentry->n_sessions++;
+}
+
+/*
+ * Notify the stats system of a disconnect.
+ */
+void
+pgstat_report_disconnect(Oid dboid)
+{
+	PgStat_StatDBEntry *dbentry;
+
+	if (!pgstat_should_report_connstat())
+		return;
+
+	dbentry = pgstat_prep_database_pending(MyDatabaseId);
+
+	switch (pgStatSessionEndCause)
+	{
+		case DISCONNECT_NOT_YET:
+		case DISCONNECT_NORMAL:
+			/* we don't collect these */
+			break;
+		case DISCONNECT_CLIENT_EOF:
+			dbentry->n_sessions_abandoned++;
+			break;
+		case DISCONNECT_FATAL:
+			dbentry->n_sessions_fatal++;
+			break;
+		case DISCONNECT_KILLED:
+			dbentry->n_sessions_killed++;
+			break;
+	}
+}
+
+/*
+ * Support function for the SQL-callable pgstat* functions. Returns
+ * the collected statistics for one database or NULL. NULL doesn't mean
+ * that the database doesn't exist, just that there are no statistics, so the
+ * caller is better off to report ZERO instead.
+ */
+PgStat_StatDBEntry *
+pgstat_fetch_stat_dbentry(Oid dboid)
+{
+	return (PgStat_StatDBEntry *)
+		pgstat_fetch_entry(PGSTAT_KIND_DATABASE, dboid, InvalidOid);
+}
+
+void
+AtEOXact_PgStat_Database(bool isCommit, bool parallel)
+{
+	/* Don't count parallel worker transaction stats */
+	if (!parallel)
+	{
+		/*
+		 * Count transaction commit or abort.  (We use counters, not just
+		 * bools, in case the reporting message isn't sent right away.)
+		 */
+		if (isCommit)
+			pgStatXactCommit++;
+		else
+			pgStatXactRollback++;
+	}
+}
+
+/*
+ * Subroutine for pgstat_report_stat(): Handle xact commit/rollback and I/O
+ * timings.
+ */
+void
+pgstat_update_dbstats(TimestampTz ts)
+{
+	PgStat_StatDBEntry *dbentry;
+
+	dbentry = pgstat_prep_database_pending(MyDatabaseId);
+
+	/*
+	 * Accumulate xact commit/rollback and I/O timings to stats entry of the
+	 * current database.
+	 */
+	dbentry->n_xact_commit += pgStatXactCommit;
+	dbentry->n_xact_rollback += pgStatXactRollback;
+	dbentry->n_block_read_time += pgStatBlockReadTime;
+	dbentry->n_block_write_time += pgStatBlockWriteTime;
+
+	if (pgstat_should_report_connstat())
+	{
+		long		secs;
+		int			usecs;
+
+		/*
+		 * pgLastSessionReportTime is initialized to MyStartTimestamp by
+		 * pgstat_report_connect().
+		 */
+		TimestampDifference(pgLastSessionReportTime, ts, &secs, &usecs);
+		pgLastSessionReportTime = ts;
+		dbentry->total_session_time += (PgStat_Counter) secs * 1000000 + usecs;
+		dbentry->total_active_time += pgStatActiveTime;
+		dbentry->total_idle_in_xact_time += pgStatTransactionIdleTime;
+	}
+
+	pgStatXactCommit = 0;
+	pgStatXactRollback = 0;
+	pgStatBlockReadTime = 0;
+	pgStatBlockWriteTime = 0;
+	pgStatActiveTime = 0;
+	pgStatTransactionIdleTime = 0;
+}
+
+/*
+ * We report session statistics only for normal backend processes.  Parallel
+ * workers run in parallel, so they don't contribute to session times, even
+ * though they use CPU time. Walsender processes could be considered here,
+ * but they have different session characteristics from normal backends (for
+ * example, they are always "active"), so they would skew session statistics.
+ */
+static bool
+pgstat_should_report_connstat(void)
+{
+	return MyBackendType == B_BACKEND;
+}
+
+/*
+ * Find or create a local PgStat_StatDBEntry entry for dboid.
+ */
+PgStat_StatDBEntry *
+pgstat_prep_database_pending(Oid dboid)
+{
+	PgStat_EntryRef *entry_ref;
+
+	entry_ref = pgstat_prep_pending_entry(PGSTAT_KIND_DATABASE, dboid, InvalidOid,
+										  NULL);
+
+	return entry_ref->pending;
+}
+
+/*
+ * Reset the database's reset timestamp, without resetting the contents of the
+ * database stats.
+ */
+void
+pgstat_reset_database_timestamp(Oid dboid, TimestampTz ts)
+{
+	PgStat_EntryRef *dbref;
+	PgStatShared_Database *dbentry;
+
+	dbref = pgstat_get_entry_ref_locked(PGSTAT_KIND_DATABASE, MyDatabaseId, InvalidOid,
+										false);
+
+	dbentry = (PgStatShared_Database *) dbref->shared_stats;
+	dbentry->stats.stat_reset_timestamp = ts;
+
+	pgstat_unlock_entry(dbref);
+}
+
+/*
+ * Flush out pending stats for the entry
+ *
+ * If nowait is true, this function returns false if lock could not
+ * immediately acquired, otherwise true is returned.
+ */
+bool
+pgstat_database_flush_cb(PgStat_EntryRef *entry_ref, bool nowait)
+{
+	PgStatShared_Database *sharedent;
+	PgStat_StatDBEntry *pendingent;
+
+	pendingent = (PgStat_StatDBEntry *) entry_ref->pending;
+	sharedent = (PgStatShared_Database *) entry_ref->shared_stats;
+
+	if (!pgstat_lock_entry(entry_ref, nowait))
+		return false;
+
+#define PGSTAT_ACCUM_DBCOUNT(item)		\
+	(sharedent)->stats.item += (pendingent)->item
+
+	PGSTAT_ACCUM_DBCOUNT(n_xact_commit);
+	PGSTAT_ACCUM_DBCOUNT(n_xact_rollback);
+	PGSTAT_ACCUM_DBCOUNT(n_blocks_fetched);
+	PGSTAT_ACCUM_DBCOUNT(n_blocks_hit);
+
+	PGSTAT_ACCUM_DBCOUNT(n_tuples_returned);
+	PGSTAT_ACCUM_DBCOUNT(n_tuples_fetched);
+	PGSTAT_ACCUM_DBCOUNT(n_tuples_inserted);
+	PGSTAT_ACCUM_DBCOUNT(n_tuples_updated);
+	PGSTAT_ACCUM_DBCOUNT(n_tuples_deleted);
+
+	/* last_autovac_time is reported immediately */
+	Assert(pendingent->last_autovac_time == 0);
+
+	PGSTAT_ACCUM_DBCOUNT(n_conflict_tablespace);
+	PGSTAT_ACCUM_DBCOUNT(n_conflict_lock);
+	PGSTAT_ACCUM_DBCOUNT(n_conflict_snapshot);
+	PGSTAT_ACCUM_DBCOUNT(n_conflict_bufferpin);
+	PGSTAT_ACCUM_DBCOUNT(n_conflict_startup_deadlock);
+
+	PGSTAT_ACCUM_DBCOUNT(n_temp_bytes);
+	PGSTAT_ACCUM_DBCOUNT(n_temp_files);
+	PGSTAT_ACCUM_DBCOUNT(n_deadlocks);
+
+	/* checksum failures are reported immediately */
+	Assert(pendingent->n_checksum_failures == 0);
+	Assert(pendingent->last_checksum_failure == 0);
+
+	PGSTAT_ACCUM_DBCOUNT(n_block_read_time);
+	PGSTAT_ACCUM_DBCOUNT(n_block_write_time);
+
+	PGSTAT_ACCUM_DBCOUNT(n_sessions);
+	PGSTAT_ACCUM_DBCOUNT(total_session_time);
+	PGSTAT_ACCUM_DBCOUNT(total_active_time);
+	PGSTAT_ACCUM_DBCOUNT(total_idle_in_xact_time);
+	PGSTAT_ACCUM_DBCOUNT(n_sessions_abandoned);
+	PGSTAT_ACCUM_DBCOUNT(n_sessions_fatal);
+	PGSTAT_ACCUM_DBCOUNT(n_sessions_killed);
+#undef PGSTAT_ACCUM_DBCOUNT
+
+	pgstat_unlock_entry(entry_ref);
+
+	memset(pendingent, 0, sizeof(*pendingent));
+
+	return true;
+}
+
+void
+pgstat_database_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts)
+{
+	((PgStatShared_Database *) header)->stats.stat_reset_timestamp = ts;
+}