src/include/access/gistxlog.h

   1 /*-------------------------------------------------------------------------
   2  *
   3  * gistxlog.h
   4  *        gist xlog routines
   5  *
   6  * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
   7  * Portions Copyright (c) 1994, Regents of the University of California
   8  *
   9  * src/include/access/gistxlog.h
  10  *
  11  *-------------------------------------------------------------------------
  12  */
  13 #ifndef GIST_XLOG_H
  14 #define GIST_XLOG_H
  15
  16 #include "access/gist.h"
  17 #include "access/xlogreader.h"
  18 #include "lib/stringinfo.h"
  19
  20 #define XLOG_GIST_PAGE_UPDATE           0x00
  21 #define XLOG_GIST_DELETE                        0x10    /* delete leaf index tuples for a
  22                                                                                          * page */
  23 #define XLOG_GIST_PAGE_REUSE            0x20    /* old page is about to be reused
  24                                                                                          * from FSM */
  25 #define XLOG_GIST_PAGE_SPLIT            0x30
  26  /* #define XLOG_GIST_INSERT_COMPLETE    0x40 */        /* not used anymore */
  27  /* #define XLOG_GIST_CREATE_INDEX               0x50 */        /* not used anymore */
  28 #define XLOG_GIST_PAGE_DELETE           0x60
  29 #define XLOG_GIST_ASSIGN_LSN            0x70    /* nop, assign new LSN */
  30
  31 /*
  32  * Backup Blk 0: updated page.
  33  * Backup Blk 1: If this operation completes a page split, by inserting a
  34  *                               downlink for the split page, the left half of the split
  35  */
  36 typedef struct gistxlogPageUpdate
  37 {
  38         /* number of deleted offsets */
  39         uint16          ntodelete;
  40         uint16          ntoinsert;
  41
  42         /*
  43          * In payload of blk 0 : 1. todelete OffsetNumbers 2. tuples to insert
  44          */
  45 } gistxlogPageUpdate;
  46
  47 /*
  48  * Backup Blk 0: Leaf page, whose index tuples are deleted.
  49  */
  50 typedef struct gistxlogDelete
  51 {
  52         TransactionId latestRemovedXid;
  53         uint16          ntodelete;              /* number of deleted offsets */
  54
  55         /*
  56          * In payload of blk 0 : todelete OffsetNumbers
  57          */
  58 } gistxlogDelete;
  59
  60 #define SizeOfGistxlogDelete    (offsetof(gistxlogDelete, ntodelete) + sizeof(uint16))
  61
  62 /*
  63  * Backup Blk 0: If this operation completes a page split, by inserting a
  64  *                               downlink for the split page, the left half of the split
  65  * Backup Blk 1 - npage: split pages (1 is the original page)
  66  */
  67 typedef struct gistxlogPageSplit
  68 {
  69         BlockNumber origrlink;          /* rightlink of the page before split */
  70         GistNSN         orignsn;                /* NSN of the page before split */
  71         bool            origleaf;               /* was splitted page a leaf page? */
  72
  73         uint16          npage;                  /* # of pages in the split */
  74         bool            markfollowright;        /* set F_FOLLOW_RIGHT flags */
  75
  76         /*
  77          * follow: 1. gistxlogPage and array of IndexTupleData per page
  78          */
  79 } gistxlogPageSplit;
  80
  81 /*
  82  * Backup Blk 0: page that was deleted.
  83  * Backup Blk 1: parent page, containing the downlink to the deleted page.
  84  */
  85 typedef struct gistxlogPageDelete
  86 {
  87         FullTransactionId deleteXid;    /* last Xid which could see page in scan */
  88         OffsetNumber downlinkOffset;    /* Offset of downlink referencing this
  89                                                                          * page */
  90 } gistxlogPageDelete;
  91
  92 #define SizeOfGistxlogPageDelete        (offsetof(gistxlogPageDelete, downlinkOffset) + sizeof(OffsetNumber))
  93
  94
  95 /*
  96  * This is what we need to know about page reuse, for hot standby.
  97  */
  98 typedef struct gistxlogPageReuse
  99 {
 100         RelFileNode node;
 101         BlockNumber block;
 102         FullTransactionId latestRemovedFullXid;
 103 } gistxlogPageReuse;
 104
 105 #define SizeOfGistxlogPageReuse (offsetof(gistxlogPageReuse, latestRemovedFullXid) + sizeof(FullTransactionId))
 106
 107 extern void gist_redo(XLogReaderState *record);
 108 extern void gist_desc(StringInfo buf, XLogReaderState *record);
 109 extern const char *gist_identify(uint8 info);
 110 extern void gist_xlog_startup(void);
 111 extern void gist_xlog_cleanup(void);
 112 extern void gist_mask(char *pagedata, BlockNumber blkno);
 113
 114 #endif