1 files changed, 161 insertions, 0 deletions
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
new file mode 100644
index 00000000000..abbb4f8d964
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+++ b/src/include/utils/pgstat_internal.h
@@ -0,0 +1,161 @@
+/* ----------
+ * pgstat_internal.h
+ *
+ * Definitions for the PostgreSQL activity statistics facility that should
+ * only be needed by files implementing statistics support (rather than ones
+ * reporting / querying stats).
+ *
+ * Copyright (c) 2001-2022, PostgreSQL Global Development Group
+ *
+ * src/include/utils/pgstat_internal.h
+ * ----------
+ */
+#ifndef PGSTAT_INTERNAL_H
+#define PGSTAT_INTERNAL_H
+
+
+#include "pgstat.h"
+
+
+#define PGSTAT_STAT_INTERVAL	500 /* Minimum time between stats file
+									 * updates; in milliseconds. */
+
+/* ----------
+ * The initial size hints for the hash tables used in the collector.
+ * ----------
+ */
+#define PGSTAT_DB_HASH_SIZE		16
+#define PGSTAT_TAB_HASH_SIZE	512
+#define PGSTAT_FUNCTION_HASH_SIZE	512
+#define PGSTAT_SUBSCRIPTION_HASH_SIZE	32
+#define PGSTAT_REPLSLOT_HASH_SIZE	32
+
+
+/*
+ * Some stats changes are transactional. To maintain those, a stack of
+ * PgStat_SubXactStatus entries is maintained, which contain data pertaining
+ * to the current transaction and its active subtransactions.
+ */
+typedef struct PgStat_SubXactStatus
+{
+	int			nest_level;		/* subtransaction nest level */
+
+	struct PgStat_SubXactStatus *prev;	/* higher-level subxact if any */
+
+	/*
+	 * Tuple insertion/deletion counts for an open transaction can't be
+	 * propagated into PgStat_TableStatus counters until we know if it is
+	 * going to commit or abort.  Hence, we keep these counts in per-subxact
+	 * structs that live in TopTransactionContext.  This data structure is
+	 * designed on the assumption that subxacts won't usually modify very many
+	 * tables.
+	 */
+	PgStat_TableXactStatus *first;	/* head of list for this subxact */
+} PgStat_SubXactStatus;
+
+
+/*
+ * List of SLRU names that we keep stats for.  There is no central registry of
+ * SLRUs, so we use this fixed list instead.  The "other" entry is used for
+ * all SLRUs without an explicit entry (e.g. SLRUs in extensions).
+ */
+static const char *const slru_names[] = {
+	"CommitTs",
+	"MultiXactMember",
+	"MultiXactOffset",
+	"Notify",
+	"Serial",
+	"Subtrans",
+	"Xact",
+	"other"						/* has to be last */
+};
+
+#define SLRU_NUM_ELEMENTS	lengthof(slru_names)
+
+
+/*
+ * Functions in pgstat.c
+ */
+
+extern PgStat_SubXactStatus *pgstat_xact_stack_level_get(int nest_level);
+extern void pgstat_setheader(PgStat_MsgHdr *hdr, StatMsgType mtype);
+extern void pgstat_send(void *msg, int len);
+#ifdef USE_ASSERT_CHECKING
+extern void pgstat_assert_is_up(void);
+#else
+#define pgstat_assert_is_up() ((void)true)
+#endif
+
+
+/*
+ * Functions in pgstat_database.c
+ */
+
+extern void AtEOXact_PgStat_Database(bool isCommit, bool parallel);
+extern void pgstat_report_disconnect(Oid dboid);
+extern void pgstat_update_dbstats(PgStat_MsgTabstat *tsmsg, TimestampTz now);
+
+
+/*
+ * Functions in pgstat_function.c
+ */
+
+extern void pgstat_send_funcstats(void);
+
+
+/*
+ * Functions in pgstat_relation.c
+ */
+
+extern void AtEOXact_PgStat_Relations(PgStat_SubXactStatus *xact_state, bool isCommit);
+extern void AtEOSubXact_PgStat_Relations(PgStat_SubXactStatus *xact_state, bool isCommit, int nestDepth);
+extern void AtPrepare_PgStat_Relations(PgStat_SubXactStatus *xact_state);
+extern void PostPrepare_PgStat_Relations(PgStat_SubXactStatus *xact_state);
+extern void pgstat_send_tabstats(TimestampTz now, bool disconnect);
+
+
+/*
+ * Functions in pgstat_slru.c
+ */
+
+extern void pgstat_send_slru(void);
+
+
+/*
+ * Functions in pgstat_wal.c
+ */
+
+extern void pgstat_wal_initialize(void);
+extern bool pgstat_wal_pending(void);
+
+
+/*
+ * Variables in pgstat.c
+ */
+
+extern pgsocket pgStatSock;
+
+
+/*
+ * Variables in pgstat_database.c
+ */
+
+extern int	pgStatXactCommit;
+extern int	pgStatXactRollback;
+
+
+/*
+ * Variables in pgstat_functions.c
+ */
+
+extern bool have_function_stats;
+
+
+/*
+ * Variables in pgstat_relation.c
+ */
+
+extern bool have_relation_stats;
+
+
+#endif							/* PGSTAT_INTERNAL_H */