1 files changed, 303 insertions, 0 deletions
diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h
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+/*
+ * xlog.h
+ *
+ * PostgreSQL write-ahead log manager
+ *
+ * Portions Copyright (c) 1996-2022, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/access/xlog.h
+ */
+#ifndef XLOG_H
+#define XLOG_H
+
+#include "access/xlogdefs.h"
+#include "access/xlogreader.h"
+#include "datatype/timestamp.h"
+#include "lib/stringinfo.h"
+#include "nodes/pg_list.h"
+
+
+/* Sync methods */
+#define SYNC_METHOD_FSYNC		0
+#define SYNC_METHOD_FDATASYNC	1
+#define SYNC_METHOD_OPEN		2	/* for O_SYNC */
+#define SYNC_METHOD_FSYNC_WRITETHROUGH	3
+#define SYNC_METHOD_OPEN_DSYNC	4	/* for O_DSYNC */
+extern PGDLLIMPORT int sync_method;
+
+extern PGDLLIMPORT XLogRecPtr ProcLastRecPtr;
+extern PGDLLIMPORT XLogRecPtr XactLastRecEnd;
+extern PGDLLIMPORT XLogRecPtr XactLastCommitEnd;
+
+/* these variables are GUC parameters related to XLOG */
+extern PGDLLIMPORT int wal_segment_size;
+extern PGDLLIMPORT int min_wal_size_mb;
+extern PGDLLIMPORT int max_wal_size_mb;
+extern PGDLLIMPORT int wal_keep_size_mb;
+extern PGDLLIMPORT int max_slot_wal_keep_size_mb;
+extern PGDLLIMPORT int XLOGbuffers;
+extern PGDLLIMPORT int XLogArchiveTimeout;
+extern PGDLLIMPORT int wal_retrieve_retry_interval;
+extern PGDLLIMPORT char *XLogArchiveCommand;
+extern PGDLLIMPORT bool EnableHotStandby;
+extern PGDLLIMPORT bool fullPageWrites;
+extern PGDLLIMPORT bool wal_log_hints;
+extern PGDLLIMPORT int wal_compression;
+extern PGDLLIMPORT bool wal_init_zero;
+extern PGDLLIMPORT bool wal_recycle;
+extern PGDLLIMPORT bool *wal_consistency_checking;
+extern PGDLLIMPORT char *wal_consistency_checking_string;
+extern PGDLLIMPORT bool log_checkpoints;
+extern PGDLLIMPORT bool track_wal_io_timing;
+extern PGDLLIMPORT int wal_decode_buffer_size;
+
+extern PGDLLIMPORT int CheckPointSegments;
+
+/* Archive modes */
+typedef enum ArchiveMode
+{
+	ARCHIVE_MODE_OFF = 0,		/* disabled */
+	ARCHIVE_MODE_ON,			/* enabled while server is running normally */
+	ARCHIVE_MODE_ALWAYS			/* enabled always (even during recovery) */
+} ArchiveMode;
+extern PGDLLIMPORT int XLogArchiveMode;
+
+/* WAL levels */
+typedef enum WalLevel
+{
+	WAL_LEVEL_MINIMAL = 0,
+	WAL_LEVEL_REPLICA,
+	WAL_LEVEL_LOGICAL
+} WalLevel;
+
+/* Compression algorithms for WAL */
+typedef enum WalCompression
+{
+	WAL_COMPRESSION_NONE = 0,
+	WAL_COMPRESSION_PGLZ,
+	WAL_COMPRESSION_LZ4,
+	WAL_COMPRESSION_ZSTD
+} WalCompression;
+
+/* Recovery states */
+typedef enum RecoveryState
+{
+	RECOVERY_STATE_CRASH = 0,	/* crash recovery */
+	RECOVERY_STATE_ARCHIVE,		/* archive recovery */
+	RECOVERY_STATE_DONE			/* currently in production */
+} RecoveryState;
+
+extern PGDLLIMPORT int wal_level;
+
+/* Is WAL archiving enabled (always or only while server is running normally)? */
+#define XLogArchivingActive() \
+	(AssertMacro(XLogArchiveMode == ARCHIVE_MODE_OFF || wal_level >= WAL_LEVEL_REPLICA), XLogArchiveMode > ARCHIVE_MODE_OFF)
+/* Is WAL archiving enabled always (even during recovery)? */
+#define XLogArchivingAlways() \
+	(AssertMacro(XLogArchiveMode == ARCHIVE_MODE_OFF || wal_level >= WAL_LEVEL_REPLICA), XLogArchiveMode == ARCHIVE_MODE_ALWAYS)
+
+/*
+ * Is WAL-logging necessary for archival or log-shipping, or can we skip
+ * WAL-logging if we fsync() the data before committing instead?
+ */
+#define XLogIsNeeded() (wal_level >= WAL_LEVEL_REPLICA)
+
+/*
+ * Is a full-page image needed for hint bit updates?
+ *
+ * Normally, we don't WAL-log hint bit updates, but if checksums are enabled,
+ * we have to protect them against torn page writes.  When you only set
+ * individual bits on a page, it's still consistent no matter what combination
+ * of the bits make it to disk, but the checksum wouldn't match.  Also WAL-log
+ * them if forced by wal_log_hints=on.
+ */
+#define XLogHintBitIsNeeded() (DataChecksumsEnabled() || wal_log_hints)
+
+/* Do we need to WAL-log information required only for Hot Standby and logical replication? */
+#define XLogStandbyInfoActive() (wal_level >= WAL_LEVEL_REPLICA)
+
+/* Do we need to WAL-log information required only for logical replication? */
+#define XLogLogicalInfoActive() (wal_level >= WAL_LEVEL_LOGICAL)
+
+#ifdef WAL_DEBUG
+extern PGDLLIMPORT bool XLOG_DEBUG;
+#endif
+
+/*
+ * OR-able request flag bits for checkpoints.  The "cause" bits are used only
+ * for logging purposes.  Note: the flags must be defined so that it's
+ * sensible to OR together request flags arising from different requestors.
+ */
+
+/* These directly affect the behavior of CreateCheckPoint and subsidiaries */
+#define CHECKPOINT_IS_SHUTDOWN	0x0001	/* Checkpoint is for shutdown */
+#define CHECKPOINT_END_OF_RECOVERY	0x0002	/* Like shutdown checkpoint, but
+											 * issued at end of WAL recovery */
+#define CHECKPOINT_IMMEDIATE	0x0004	/* Do it without delays */
+#define CHECKPOINT_FORCE		0x0008	/* Force even if no activity */
+#define CHECKPOINT_FLUSH_ALL	0x0010	/* Flush all pages, including those
+										 * belonging to unlogged tables */
+/* These are important to RequestCheckpoint */
+#define CHECKPOINT_WAIT			0x0020	/* Wait for completion */
+#define CHECKPOINT_REQUESTED	0x0040	/* Checkpoint request has been made */
+/* These indicate the cause of a checkpoint request */
+#define CHECKPOINT_CAUSE_XLOG	0x0080	/* XLOG consumption */
+#define CHECKPOINT_CAUSE_TIME	0x0100	/* Elapsed time */
+
+/*
+ * Flag bits for the record being inserted, set using XLogSetRecordFlags().
+ */
+#define XLOG_INCLUDE_ORIGIN		0x01	/* include the replication origin */
+#define XLOG_MARK_UNIMPORTANT	0x02	/* record not important for durability */
+
+
+/* Checkpoint statistics */
+typedef struct CheckpointStatsData
+{
+	TimestampTz ckpt_start_t;	/* start of checkpoint */
+	TimestampTz ckpt_write_t;	/* start of flushing buffers */
+	TimestampTz ckpt_sync_t;	/* start of fsyncs */
+	TimestampTz ckpt_sync_end_t;	/* end of fsyncs */
+	TimestampTz ckpt_end_t;		/* end of checkpoint */
+
+	int			ckpt_bufs_written;	/* # of buffers written */
+
+	int			ckpt_segs_added;	/* # of new xlog segments created */
+	int			ckpt_segs_removed;	/* # of xlog segments deleted */
+	int			ckpt_segs_recycled; /* # of xlog segments recycled */
+
+	int			ckpt_sync_rels; /* # of relations synced */
+	uint64		ckpt_longest_sync;	/* Longest sync for one relation */
+	uint64		ckpt_agg_sync_time; /* The sum of all the individual sync
+									 * times, which is not necessarily the
+									 * same as the total elapsed time for the
+									 * entire sync phase. */
+} CheckpointStatsData;
+
+extern PGDLLIMPORT CheckpointStatsData CheckpointStats;
+
+/*
+ * GetWALAvailability return codes
+ */
+typedef enum WALAvailability
+{
+	WALAVAIL_INVALID_LSN,		/* parameter error */
+	WALAVAIL_RESERVED,			/* WAL segment is within max_wal_size */
+	WALAVAIL_EXTENDED,			/* WAL segment is reserved by a slot or
+								 * wal_keep_size */
+	WALAVAIL_UNRESERVED,		/* no longer reserved, but not removed yet */
+	WALAVAIL_REMOVED			/* WAL segment has been removed */
+} WALAvailability;
+
+struct XLogRecData;
+
+extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata,
+								   XLogRecPtr fpw_lsn,
+								   uint8 flags,
+								   int num_fpi,
+								   bool topxid_included);
+extern void XLogFlush(XLogRecPtr RecPtr);
+extern bool XLogBackgroundFlush(void);
+extern bool XLogNeedsFlush(XLogRecPtr RecPtr);
+extern int	XLogFileInit(XLogSegNo segno, TimeLineID tli);
+extern int	XLogFileOpen(XLogSegNo segno, TimeLineID tli);
+
+extern void CheckXLogRemoved(XLogSegNo segno, TimeLineID tli);
+extern XLogSegNo XLogGetLastRemovedSegno(void);
+extern void XLogSetAsyncXactLSN(XLogRecPtr record);
+extern void XLogSetReplicationSlotMinimumLSN(XLogRecPtr lsn);
+
+extern void xlog_redo(XLogReaderState *record);
+extern void xlog_desc(StringInfo buf, XLogReaderState *record);
+extern const char *xlog_identify(uint8 info);
+
+extern void issue_xlog_fsync(int fd, XLogSegNo segno, TimeLineID tli);
+
+extern bool RecoveryInProgress(void);
+extern RecoveryState GetRecoveryState(void);
+extern bool XLogInsertAllowed(void);
+extern XLogRecPtr GetXLogInsertRecPtr(void);
+extern XLogRecPtr GetXLogWriteRecPtr(void);
+
+extern uint64 GetSystemIdentifier(void);
+extern char *GetMockAuthenticationNonce(void);
+extern bool DataChecksumsEnabled(void);
+extern XLogRecPtr GetFakeLSNForUnloggedRel(void);
+extern Size XLOGShmemSize(void);
+extern void XLOGShmemInit(void);
+extern void BootStrapXLOG(void);
+extern void LocalProcessControlFile(bool reset);
+extern void StartupXLOG(void);
+extern void ShutdownXLOG(int code, Datum arg);
+extern void CreateCheckPoint(int flags);
+extern bool CreateRestartPoint(int flags);
+extern WALAvailability GetWALAvailability(XLogRecPtr targetLSN);
+extern void XLogPutNextOid(Oid nextOid);
+extern XLogRecPtr XLogRestorePoint(const char *rpName);
+extern void UpdateFullPageWrites(void);
+extern void GetFullPageWriteInfo(XLogRecPtr *RedoRecPtr_p, bool *doPageWrites_p);
+extern XLogRecPtr GetRedoRecPtr(void);
+extern XLogRecPtr GetInsertRecPtr(void);
+extern XLogRecPtr GetFlushRecPtr(TimeLineID *insertTLI);
+extern TimeLineID GetWALInsertionTimeLine(void);
+extern XLogRecPtr GetLastImportantRecPtr(void);
+
+extern void SetWalWriterSleeping(bool sleeping);
+
+extern void assign_max_wal_size(int newval, void *extra);
+extern void assign_checkpoint_completion_target(double newval, void *extra);
+
+/*
+ * Routines used by xlogrecovery.c to call back into xlog.c during recovery.
+ */
+extern void RemoveNonParentXlogFiles(XLogRecPtr switchpoint, TimeLineID newTLI);
+extern bool XLogCheckpointNeeded(XLogSegNo new_segno);
+extern void SwitchIntoArchiveRecovery(XLogRecPtr EndRecPtr, TimeLineID replayTLI);
+extern void ReachedEndOfBackup(XLogRecPtr EndRecPtr, TimeLineID tli);
+extern void SetInstallXLogFileSegmentActive(void);
+extern bool IsInstallXLogFileSegmentActive(void);
+extern void XLogShutdownWalRcv(void);
+
+/*
+ * Routines to start, stop, and get status of a base backup.
+ */
+
+/*
+ * Session-level status of base backups
+ *
+ * This is used in parallel with the shared memory status to control parallel
+ * execution of base backup functions for a given session, be it a backend
+ * dedicated to replication or a normal backend connected to a database. The
+ * update of the session-level status happens at the same time as the shared
+ * memory counters to keep a consistent global and local state of the backups
+ * running.
+ */
+typedef enum SessionBackupState
+{
+	SESSION_BACKUP_NONE,
+	SESSION_BACKUP_RUNNING,
+} SessionBackupState;
+
+extern XLogRecPtr do_pg_backup_start(const char *backupidstr, bool fast,
+									 TimeLineID *starttli_p, StringInfo labelfile,
+									 List **tablespaces, StringInfo tblspcmapfile);
+extern XLogRecPtr do_pg_backup_stop(char *labelfile, bool waitforarchive,
+									TimeLineID *stoptli_p);
+extern void do_pg_abort_backup(int code, Datum arg);
+extern void register_persistent_abort_backup_handler(void);
+extern SessionBackupState get_backup_status(void);
+
+/* File path names (all relative to $PGDATA) */
+#define RECOVERY_SIGNAL_FILE	"recovery.signal"
+#define STANDBY_SIGNAL_FILE		"standby.signal"
+#define BACKUP_LABEL_FILE		"backup_label"
+#define BACKUP_LABEL_OLD		"backup_label.old"
+
+#define TABLESPACE_MAP			"tablespace_map"
+#define TABLESPACE_MAP_OLD		"tablespace_map.old"
+
+/* files to signal promotion to primary */
+#define PROMOTE_SIGNAL_FILE		"promote"
+
+#endif							/* XLOG_H */