codekingpro/portable-devtools

1/*2 * xlog_internal.h3 *4 * PostgreSQL write-ahead log internal declarations5 *6 * NOTE: this file is intended to contain declarations useful for7 * manipulating the XLOG files directly, but it is not supposed to be8 * needed by rmgr routines (redo support for individual record types).9 * So the XLogRecord typedef and associated stuff appear in xlogrecord.h.10 *11 * Note: This file must be includable in both frontend and backend contexts,12 * to allow stand-alone tools like pg_receivewal to deal with WAL files.13 *14 * Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group15 * Portions Copyright (c) 1994, Regents of the University of California16 *17 * src/include/access/xlog_internal.h18 */19#ifndef XLOG_INTERNAL_H20#define XLOG_INTERNAL_H21 22#include "access/xlogdefs.h"23#include "access/xlogreader.h"24#include "datatype/timestamp.h"25#include "lib/stringinfo.h"26#include "pgtime.h"27#include "storage/block.h"28#include "storage/relfilelocator.h"29 30 31/*32 * Each page of XLOG file has a header like this:33 */34#define XLOG_PAGE_MAGIC 0xD113	/* can be used as WAL version indicator */35 36typedef struct XLogPageHeaderData37{38	uint16		xlp_magic;		/* magic value for correctness checks */39	uint16		xlp_info;		/* flag bits, see below */40	TimeLineID	xlp_tli;		/* TimeLineID of first record on page */41	XLogRecPtr	xlp_pageaddr;	/* XLOG address of this page */42 43	/*44	 * When there is not enough space on current page for whole record, we45	 * continue on the next page.  xlp_rem_len is the number of bytes46	 * remaining from a previous page; it tracks xl_tot_len in the initial47	 * header.  Note that the continuation data isn't necessarily aligned.48	 */49	uint32		xlp_rem_len;	/* total len of remaining data for record */50} XLogPageHeaderData;51 52#define SizeOfXLogShortPHD	MAXALIGN(sizeof(XLogPageHeaderData))53 54typedef XLogPageHeaderData *XLogPageHeader;55 56/*57 * When the XLP_LONG_HEADER flag is set, we store additional fields in the58 * page header.  (This is ordinarily done just in the first page of an59 * XLOG file.)	The additional fields serve to identify the file accurately.60 */61typedef struct XLogLongPageHeaderData62{63	XLogPageHeaderData std;		/* standard header fields */64	uint64		xlp_sysid;		/* system identifier from pg_control */65	uint32		xlp_seg_size;	/* just as a cross-check */66	uint32		xlp_xlog_blcksz;	/* just as a cross-check */67} XLogLongPageHeaderData;68 69#define SizeOfXLogLongPHD	MAXALIGN(sizeof(XLogLongPageHeaderData))70 71typedef XLogLongPageHeaderData *XLogLongPageHeader;72 73/* When record crosses page boundary, set this flag in new page's header */74#define XLP_FIRST_IS_CONTRECORD		0x000175/* This flag indicates a "long" page header */76#define XLP_LONG_HEADER				0x000277/* This flag indicates backup blocks starting in this page are optional */78#define XLP_BKP_REMOVABLE			0x000479/* Replaces a missing contrecord; see CreateOverwriteContrecordRecord */80#define XLP_FIRST_IS_OVERWRITE_CONTRECORD 0x000881/* All defined flag bits in xlp_info (used for validity checking of header) */82#define XLP_ALL_FLAGS				0x000F83 84#define XLogPageHeaderSize(hdr)		\85	(((hdr)->xlp_info & XLP_LONG_HEADER) ? SizeOfXLogLongPHD : SizeOfXLogShortPHD)86 87/* wal_segment_size can range from 1MB to 1GB */88#define WalSegMinSize 1024 * 102489#define WalSegMaxSize 1024 * 1024 * 102490/* default number of min and max wal segments */91#define DEFAULT_MIN_WAL_SEGS 592#define DEFAULT_MAX_WAL_SEGS 6493 94/* check that the given size is a valid wal_segment_size */95#define IsPowerOf2(x) (x > 0 && ((x) & ((x)-1)) == 0)96#define IsValidWalSegSize(size) \97	 (IsPowerOf2(size) && \98	 ((size) >= WalSegMinSize && (size) <= WalSegMaxSize))99 100#define XLogSegmentsPerXLogId(wal_segsz_bytes)	\101	(UINT64CONST(0x100000000) / (wal_segsz_bytes))102 103#define XLogSegNoOffsetToRecPtr(segno, offset, wal_segsz_bytes, dest) \104		(dest) = (segno) * (wal_segsz_bytes) + (offset)105 106#define XLogSegmentOffset(xlogptr, wal_segsz_bytes)	\107	((xlogptr) & ((wal_segsz_bytes) - 1))108 109/*110 * Compute a segment number from an XLogRecPtr.111 *112 * For XLByteToSeg, do the computation at face value.  For XLByteToPrevSeg,113 * a boundary byte is taken to be in the previous segment.  This is suitable114 * for deciding which segment to write given a pointer to a record end,115 * for example.116 */117#define XLByteToSeg(xlrp, logSegNo, wal_segsz_bytes) \118	logSegNo = (xlrp) / (wal_segsz_bytes)119 120#define XLByteToPrevSeg(xlrp, logSegNo, wal_segsz_bytes) \121	logSegNo = ((xlrp) - 1) / (wal_segsz_bytes)122 123/*124 * Convert values of GUCs measured in megabytes to equiv. segment count.125 * Rounds down.126 */127#define XLogMBVarToSegs(mbvar, wal_segsz_bytes) \128	((mbvar) / ((wal_segsz_bytes) / (1024 * 1024)))129 130/*131 * Is an XLogRecPtr within a particular XLOG segment?132 *133 * For XLByteInSeg, do the computation at face value.  For XLByteInPrevSeg,134 * a boundary byte is taken to be in the previous segment.135 */136#define XLByteInSeg(xlrp, logSegNo, wal_segsz_bytes) \137	(((xlrp) / (wal_segsz_bytes)) == (logSegNo))138 139#define XLByteInPrevSeg(xlrp, logSegNo, wal_segsz_bytes) \140	((((xlrp) - 1) / (wal_segsz_bytes)) == (logSegNo))141 142/* Check if an XLogRecPtr value is in a plausible range */143#define XRecOffIsValid(xlrp) \144		((xlrp) % XLOG_BLCKSZ >= SizeOfXLogShortPHD)145 146/*147 * The XLog directory and control file (relative to $PGDATA)148 */149#define XLOGDIR				"pg_wal"150#define XLOG_CONTROL_FILE	"global/pg_control"151 152/*153 * These macros encapsulate knowledge about the exact layout of XLog file154 * names, timeline history file names, and archive-status file names.155 */156#define MAXFNAMELEN		64157 158/* Length of XLog file name */159#define XLOG_FNAME_LEN	   24160 161/*162 * Generate a WAL segment file name.  Do not use this function in a helper163 * function allocating the result generated.164 */165static inline void166XLogFileName(char *fname, TimeLineID tli, XLogSegNo logSegNo, int wal_segsz_bytes)167{168	snprintf(fname, MAXFNAMELEN, "%08X%08X%08X", tli,169			 (uint32) (logSegNo / XLogSegmentsPerXLogId(wal_segsz_bytes)),170			 (uint32) (logSegNo % XLogSegmentsPerXLogId(wal_segsz_bytes)));171}172 173static inline void174XLogFileNameById(char *fname, TimeLineID tli, uint32 log, uint32 seg)175{176	snprintf(fname, MAXFNAMELEN, "%08X%08X%08X", tli, log, seg);177}178 179static inline bool180IsXLogFileName(const char *fname)181{182	return (strlen(fname) == XLOG_FNAME_LEN && \183			strspn(fname, "0123456789ABCDEF") == XLOG_FNAME_LEN);184}185 186/*187 * XLOG segment with .partial suffix.  Used by pg_receivewal and at end of188 * archive recovery, when we want to archive a WAL segment but it might not189 * be complete yet.190 */191static inline bool192IsPartialXLogFileName(const char *fname)193{194	return (strlen(fname) == XLOG_FNAME_LEN + strlen(".partial") &&195			strspn(fname, "0123456789ABCDEF") == XLOG_FNAME_LEN &&196			strcmp(fname + XLOG_FNAME_LEN, ".partial") == 0);197}198 199static inline void200XLogFromFileName(const char *fname, TimeLineID *tli, XLogSegNo *logSegNo, int wal_segsz_bytes)201{202	uint32		log;203	uint32		seg;204 205	sscanf(fname, "%08X%08X%08X", tli, &log, &seg);206	*logSegNo = (uint64) log * XLogSegmentsPerXLogId(wal_segsz_bytes) + seg;207}208 209static inline void210XLogFilePath(char *path, TimeLineID tli, XLogSegNo logSegNo, int wal_segsz_bytes)211{212	snprintf(path, MAXPGPATH, XLOGDIR "/%08X%08X%08X", tli,213			 (uint32) (logSegNo / XLogSegmentsPerXLogId(wal_segsz_bytes)),214			 (uint32) (logSegNo % XLogSegmentsPerXLogId(wal_segsz_bytes)));215}216 217static inline void218TLHistoryFileName(char *fname, TimeLineID tli)219{220	snprintf(fname, MAXFNAMELEN, "%08X.history", tli);221}222 223static inline bool224IsTLHistoryFileName(const char *fname)225{226	return (strlen(fname) == 8 + strlen(".history") &&227			strspn(fname, "0123456789ABCDEF") == 8 &&228			strcmp(fname + 8, ".history") == 0);229}230 231static inline void232TLHistoryFilePath(char *path, TimeLineID tli)233{234	snprintf(path, MAXPGPATH, XLOGDIR "/%08X.history", tli);235}236 237static inline void238StatusFilePath(char *path, const char *xlog, const char *suffix)239{240	snprintf(path, MAXPGPATH, XLOGDIR "/archive_status/%s%s", xlog, suffix);241}242 243static inline void244BackupHistoryFileName(char *fname, TimeLineID tli, XLogSegNo logSegNo, XLogRecPtr startpoint, int wal_segsz_bytes)245{246	snprintf(fname, MAXFNAMELEN, "%08X%08X%08X.%08X.backup", tli,247			 (uint32) (logSegNo / XLogSegmentsPerXLogId(wal_segsz_bytes)),248			 (uint32) (logSegNo % XLogSegmentsPerXLogId(wal_segsz_bytes)),249			 (uint32) (XLogSegmentOffset(startpoint, wal_segsz_bytes)));250}251 252static inline bool253IsBackupHistoryFileName(const char *fname)254{255	return (strlen(fname) > XLOG_FNAME_LEN &&256			strspn(fname, "0123456789ABCDEF") == XLOG_FNAME_LEN &&257			strcmp(fname + strlen(fname) - strlen(".backup"), ".backup") == 0);258}259 260static inline void261BackupHistoryFilePath(char *path, TimeLineID tli, XLogSegNo logSegNo, XLogRecPtr startpoint, int wal_segsz_bytes)262{263	snprintf(path, MAXPGPATH, XLOGDIR "/%08X%08X%08X.%08X.backup", tli,264			 (uint32) (logSegNo / XLogSegmentsPerXLogId(wal_segsz_bytes)),265			 (uint32) (logSegNo % XLogSegmentsPerXLogId(wal_segsz_bytes)),266			 (uint32) (XLogSegmentOffset((startpoint), wal_segsz_bytes)));267}268 269/*270 * Information logged when we detect a change in one of the parameters271 * important for Hot Standby.272 */273typedef struct xl_parameter_change274{275	int			MaxConnections;276	int			max_worker_processes;277	int			max_wal_senders;278	int			max_prepared_xacts;279	int			max_locks_per_xact;280	int			wal_level;281	bool		wal_log_hints;282	bool		track_commit_timestamp;283} xl_parameter_change;284 285/* logs restore point */286typedef struct xl_restore_point287{288	TimestampTz rp_time;289	char		rp_name[MAXFNAMELEN];290} xl_restore_point;291 292/* Overwrite of prior contrecord */293typedef struct xl_overwrite_contrecord294{295	XLogRecPtr	overwritten_lsn;296	TimestampTz overwrite_time;297} xl_overwrite_contrecord;298 299/* End of recovery mark, when we don't do an END_OF_RECOVERY checkpoint */300typedef struct xl_end_of_recovery301{302	TimestampTz end_time;303	TimeLineID	ThisTimeLineID; /* new TLI */304	TimeLineID	PrevTimeLineID; /* previous TLI we forked off from */305} xl_end_of_recovery;306 307/*308 * The functions in xloginsert.c construct a chain of XLogRecData structs309 * to represent the final WAL record.310 */311typedef struct XLogRecData312{313	struct XLogRecData *next;	/* next struct in chain, or NULL */314	char	   *data;			/* start of rmgr data to include */315	uint32		len;			/* length of rmgr data to include */316} XLogRecData;317 318/*319 * Recovery target action.320 */321typedef enum322{323	RECOVERY_TARGET_ACTION_PAUSE,324	RECOVERY_TARGET_ACTION_PROMOTE,325	RECOVERY_TARGET_ACTION_SHUTDOWN326}			RecoveryTargetAction;327 328struct LogicalDecodingContext;329struct XLogRecordBuffer;330 331/*332 * Method table for resource managers.333 *334 * This struct must be kept in sync with the PG_RMGR definition in335 * rmgr.c.336 *337 * rm_identify must return a name for the record based on xl_info (without338 * reference to the rmid). For example, XLOG_BTREE_VACUUM would be named339 * "VACUUM". rm_desc can then be called to obtain additional detail for the340 * record, if available (e.g. the last block).341 *342 * rm_mask takes as input a page modified by the resource manager and masks343 * out bits that shouldn't be flagged by wal_consistency_checking.344 *345 * RmgrTable[] is indexed by RmgrId values (see rmgrlist.h). If rm_name is346 * NULL, the corresponding RmgrTable entry is considered invalid.347 */348typedef struct RmgrData349{350	const char *rm_name;351	void		(*rm_redo) (XLogReaderState *record);352	void		(*rm_desc) (StringInfo buf, XLogReaderState *record);353	const char *(*rm_identify) (uint8 info);354	void		(*rm_startup) (void);355	void		(*rm_cleanup) (void);356	void		(*rm_mask) (char *pagedata, BlockNumber blkno);357	void		(*rm_decode) (struct LogicalDecodingContext *ctx,358							  struct XLogRecordBuffer *buf);359} RmgrData;360 361extern PGDLLIMPORT RmgrData RmgrTable[];362extern void RmgrStartup(void);363extern void RmgrCleanup(void);364extern void RmgrNotFound(RmgrId rmid);365extern void RegisterCustomRmgr(RmgrId rmid, const RmgrData *rmgr);366 367#ifndef FRONTEND368static inline bool369RmgrIdExists(RmgrId rmid)370{371	return RmgrTable[rmid].rm_name != NULL;372}373 374static inline RmgrData375GetRmgr(RmgrId rmid)376{377	if (unlikely(!RmgrIdExists(rmid)))378		RmgrNotFound(rmid);379	return RmgrTable[rmid];380}381#endif382 383/*384 * Exported to support xlog switching from checkpointer385 */386extern pg_time_t GetLastSegSwitchData(XLogRecPtr *lastSwitchLSN);387extern XLogRecPtr RequestXLogSwitch(bool mark_unimportant);388 389extern void GetOldestRestartPoint(XLogRecPtr *oldrecptr, TimeLineID *oldtli);390 391extern void XLogRecGetBlockRefInfo(XLogReaderState *record, bool pretty,392								   bool detailed_format, StringInfo buf,393								   uint32 *fpi_len);394 395/*396 * Exported for the functions in timeline.c and xlogarchive.c.  Only valid397 * in the startup process.398 */399extern PGDLLIMPORT bool ArchiveRecoveryRequested;400extern PGDLLIMPORT bool InArchiveRecovery;401extern PGDLLIMPORT bool StandbyMode;402extern PGDLLIMPORT char *recoveryRestoreCommand;403 404#endif							/* XLOG_INTERNAL_H */405