1/*-------------------------------------------------------------------------
2 *
3 * standbydef.h
4 * Frontend exposed definitions for hot standby mode.
5 *
6 *
7 * Portions Copyright (c) 1996-2019, 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) */
23extern void standby_redo(XLogReaderState *record);
24extern void standby_desc(StringInfo buf, XLogReaderState *record);
25extern const char *standby_identify(uint8 info);
26extern 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
38typedef 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 */
47typedef 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 ShmemVariableCache->nextFullXid */
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 */
63typedef 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 */
75