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Diffstat (limited to 'src/include/access/xlog.h')
| -rw-r--r-- | src/include/access/xlog.h | 398 |
1 files changed, 398 insertions, 0 deletions
diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h new file mode 100644 index 0000000..01b3b0a --- /dev/null +++ b/src/include/access/xlog.h @@ -0,0 +1,398 @@ +/* + * xlog.h + * + * PostgreSQL write-ahead log manager + * + * Portions Copyright (c) 1996-2020, 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/rmgr.h" +#include "access/xlogdefs.h" +#include "access/xloginsert.h" +#include "access/xlogreader.h" +#include "datatype/timestamp.h" +#include "lib/stringinfo.h" +#include "nodes/pg_list.h" +#include "storage/fd.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 int sync_method; + +extern PGDLLIMPORT TimeLineID ThisTimeLineID; /* current TLI */ + +/* + * Prior to 8.4, all activity during recovery was carried out by the startup + * process. This local variable continues to be used in many parts of the + * code to indicate actions taken by RecoveryManagers. Other processes that + * potentially perform work during recovery should check RecoveryInProgress(). + * See XLogCtl notes in xlog.c. + */ +extern bool InRecovery; + +/* + * Like InRecovery, standbyState is only valid in the startup process. + * In all other processes it will have the value STANDBY_DISABLED (so + * InHotStandby will read as false). + * + * In DISABLED state, we're performing crash recovery or hot standby was + * disabled in postgresql.conf. + * + * In INITIALIZED state, we've run InitRecoveryTransactionEnvironment, but + * we haven't yet processed a RUNNING_XACTS or shutdown-checkpoint WAL record + * to initialize our master-transaction tracking system. + * + * When the transaction tracking is initialized, we enter the SNAPSHOT_PENDING + * state. The tracked information might still be incomplete, so we can't allow + * connections yet, but redo functions must update the in-memory state when + * appropriate. + * + * In SNAPSHOT_READY mode, we have full knowledge of transactions that are + * (or were) running in the master at the current WAL location. Snapshots + * can be taken, and read-only queries can be run. + */ +typedef enum +{ + STANDBY_DISABLED, + STANDBY_INITIALIZED, + STANDBY_SNAPSHOT_PENDING, + STANDBY_SNAPSHOT_READY +} HotStandbyState; + +extern HotStandbyState standbyState; + +#define InHotStandby (standbyState >= STANDBY_SNAPSHOT_PENDING) + +/* + * Recovery target type. + * Only set during a Point in Time recovery, not when in standby mode. + */ +typedef enum +{ + RECOVERY_TARGET_UNSET, + RECOVERY_TARGET_XID, + RECOVERY_TARGET_TIME, + RECOVERY_TARGET_NAME, + RECOVERY_TARGET_LSN, + RECOVERY_TARGET_IMMEDIATE +} RecoveryTargetType; + +/* + * Recovery target TimeLine goal + */ +typedef enum +{ + RECOVERY_TARGET_TIMELINE_CONTROLFILE, + RECOVERY_TARGET_TIMELINE_LATEST, + RECOVERY_TARGET_TIMELINE_NUMERIC +} RecoveryTargetTimeLineGoal; + +extern XLogRecPtr ProcLastRecPtr; +extern XLogRecPtr XactLastRecEnd; +extern PGDLLIMPORT XLogRecPtr XactLastCommitEnd; + +extern bool reachedConsistency; + +/* these variables are GUC parameters related to XLOG */ +extern int wal_segment_size; +extern int min_wal_size_mb; +extern int max_wal_size_mb; +extern int wal_keep_size_mb; +extern int max_slot_wal_keep_size_mb; +extern int XLOGbuffers; +extern int XLogArchiveTimeout; +extern int wal_retrieve_retry_interval; +extern char *XLogArchiveCommand; +extern bool EnableHotStandby; +extern bool fullPageWrites; +extern bool wal_log_hints; +extern bool wal_compression; +extern bool wal_init_zero; +extern bool wal_recycle; +extern bool *wal_consistency_checking; +extern char *wal_consistency_checking_string; +extern bool log_checkpoints; +extern char *recoveryRestoreCommand; +extern char *recoveryEndCommand; +extern char *archiveCleanupCommand; +extern bool recoveryTargetInclusive; +extern int recoveryTargetAction; +extern int recovery_min_apply_delay; +extern char *PrimaryConnInfo; +extern char *PrimarySlotName; +extern bool wal_receiver_create_temp_slot; + +/* indirectly set via GUC system */ +extern TransactionId recoveryTargetXid; +extern char *recovery_target_time_string; +extern const char *recoveryTargetName; +extern XLogRecPtr recoveryTargetLSN; +extern RecoveryTargetType recoveryTarget; +extern char *PromoteTriggerFile; +extern RecoveryTargetTimeLineGoal recoveryTargetTimeLineGoal; +extern TimeLineID recoveryTargetTLIRequested; +extern TimeLineID recoveryTargetTLI; + +extern int CheckPointSegments; + +/* option set locally in startup process only when signal files exist */ +extern bool StandbyModeRequested; +extern bool StandbyMode; + +/* 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 int XLogArchiveMode; + +/* WAL levels */ +typedef enum WalLevel +{ + WAL_LEVEL_MINIMAL = 0, + WAL_LEVEL_REPLICA, + WAL_LEVEL_LOGICAL +} WalLevel; + +/* 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) +#define XLogArchiveCommandSet() (XLogArchiveCommand[0] != '\0') + +/* + * 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 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 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); +extern void XLogFlush(XLogRecPtr RecPtr); +extern bool XLogBackgroundFlush(void); +extern bool XLogNeedsFlush(XLogRecPtr RecPtr); +extern int XLogFileInit(XLogSegNo segno, bool *use_existent, bool use_lock); +extern int XLogFileOpen(XLogSegNo segno); + +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); + +extern bool RecoveryInProgress(void); +extern RecoveryState GetRecoveryState(void); +extern bool HotStandbyActive(void); +extern bool HotStandbyActiveInReplay(void); +extern bool XLogInsertAllowed(void); +extern void GetXLogReceiptTime(TimestampTz *rtime, bool *fromStream); +extern XLogRecPtr GetXLogReplayRecPtr(TimeLineID *replayTLI); +extern XLogRecPtr GetXLogInsertRecPtr(void); +extern XLogRecPtr GetXLogWriteRecPtr(void); +extern bool RecoveryIsPaused(void); +extern void SetRecoveryPause(bool recoveryPause); +extern TimestampTz GetLatestXTime(void); +extern TimestampTz GetCurrentChunkReplayStartTime(void); + +extern void UpdateControlFile(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 InitXLOGAccess(void); +extern void CreateCheckPoint(int flags); +extern bool CreateRestartPoint(int flags); +extern WALAvailability GetWALAvailability(XLogRecPtr targetLSN); +extern XLogRecPtr CalculateMaxmumSafeLSN(void); +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(void); +extern XLogRecPtr GetLastImportantRecPtr(void); +extern void RemovePromoteSignalFiles(void); + +extern bool PromoteIsTriggered(void); +extern bool CheckPromoteSignal(void); +extern void WakeupRecovery(void); +extern void SetWalWriterSleeping(bool sleeping); + +extern void StartupRequestWalReceiverRestart(void); +extern void XLogRequestWalReceiverReply(void); + +extern void assign_max_wal_size(int newval, void *extra); +extern void assign_checkpoint_completion_target(double newval, void *extra); + +/* + * 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_EXCLUSIVE, + SESSION_BACKUP_NON_EXCLUSIVE +} SessionBackupState; + +extern XLogRecPtr do_pg_start_backup(const char *backupidstr, bool fast, + TimeLineID *starttli_p, StringInfo labelfile, + List **tablespaces, StringInfo tblspcmapfile, bool infotbssize, + bool needtblspcmapfile); +extern XLogRecPtr do_pg_stop_backup(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" +#define FALLBACK_PROMOTE_SIGNAL_FILE "fallback_promote" + +#endif /* XLOG_H */ |