src/include/storage/standbydefs.h

   1 /*-------------------------------------------------------------------------
   2  *
   3  * standbydefs.h
   4  *         Frontend exposed definitions for hot standby mode.
   5  *
   6  *
   7  * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
   8  * Portions Copyright (c) 1994, Regents of the University of California
   9  *
  10  * src/include/storage/standbydefs.h
  11  *
  12  *-------------------------------------------------------------------------
  13  */
  14 #ifndef STANDBYDEFS_H
  15 #define STANDBYDEFS_H
  16
  17 #include "access/xlogreader.h"
  18 #include "lib/stringinfo.h"
  19 #include "storage/lockdefs.h"
  20 #include "storage/sinval.h"
  21
  22 /* Recovery handlers for the Standby Rmgr (RM_STANDBY_ID) */
  23 extern void standby_redo(XLogReaderState *record);
  24 extern void standby_desc(StringInfo buf, XLogReaderState *record);
  25 extern const char *standby_identify(uint8 info);
  26 extern void standby_desc_invalidations(StringInfo buf,
  27                                                                            int nmsgs, SharedInvalidationMessage *msgs,
  28                                                                            Oid dbId, Oid tsId,
  29                                                                            bool relcacheInitFileInval);
  30
  31 /*
  32  * XLOG message types
  33  */
  34 #define XLOG_STANDBY_LOCK                       0x00
  35 #define XLOG_RUNNING_XACTS                      0x10
  36 #define XLOG_INVALIDATIONS                      0x20
  37
  38 typedef struct xl_standby_locks
  39 {
  40         int                     nlocks;                 /* number of entries in locks array */
  41         xl_standby_lock locks[FLEXIBLE_ARRAY_MEMBER];
  42 } xl_standby_locks;
  43
  44 /*
  45  * When we write running xact data to WAL, we use this structure.
  46  */
  47 typedef struct xl_running_xacts
  48 {
  49         int                     xcnt;                   /* # of xact ids in xids[] */
  50         int                     subxcnt;                /* # of subxact ids in xids[] */
  51         bool            subxid_overflow;        /* snapshot overflowed, subxids missing */
  52         TransactionId nextXid;          /* xid from TransamVariables->nextXid */
  53         TransactionId oldestRunningXid; /* *not* oldestXmin */
  54         TransactionId latestCompletedXid;       /* so we can set xmax */
  55
  56         TransactionId xids[FLEXIBLE_ARRAY_MEMBER];
  57 } xl_running_xacts;
  58
  59 /*
  60  * Invalidations for standby, currently only when transactions without an
  61  * assigned xid commit.
  62  */
  63 typedef struct xl_invalidations
  64 {
  65         Oid                     dbId;                   /* MyDatabaseId */
  66         Oid                     tsId;                   /* MyDatabaseTableSpace */
  67         bool            relcacheInitFileInval;  /* invalidate relcache init files */
  68         int                     nmsgs;                  /* number of shared inval msgs */
  69         SharedInvalidationMessage msgs[FLEXIBLE_ARRAY_MEMBER];
  70 } xl_invalidations;
  71
  72 #define MinSizeOfInvalidations offsetof(xl_invalidations, msgs)
  73
  74 #endif                                                  /* STANDBYDEFS_H */