1/*--------------------------------------------------------------------------
2 * ginxlog.h
3 * header file for postgres inverted index xlog implementation.
4 *
5 * Copyright (c) 2006-2019, PostgreSQL Global Development Group
6 *
7 * src/include/access/ginxlog.h
8 *--------------------------------------------------------------------------
9 */
10#ifndef GINXLOG_H
11#define GINXLOG_H
12
13#include "access/ginblock.h"
14#include "access/itup.h"
15#include "access/xlogreader.h"
16#include "lib/stringinfo.h"
17#include "storage/off.h"
18
19#define XLOG_GIN_CREATE_PTREE 0x10
20
21typedef struct ginxlogCreatePostingTree
22{
23 uint32 size;
24 /* A compressed posting list follows */
25} ginxlogCreatePostingTree;
26
27/*
28 * The format of the insertion record varies depending on the page type.
29 * ginxlogInsert is the common part between all variants.
30 *
31 * Backup Blk 0: target page
32 * Backup Blk 1: left child, if this insertion finishes an incomplete split
33 */
34
35#define XLOG_GIN_INSERT 0x20
36
37typedef struct
38{
39 uint16 flags; /* GIN_INSERT_ISLEAF and/or GIN_INSERT_ISDATA */
40
41 /*
42 * FOLLOWS:
43 *
44 * 1. if not leaf page, block numbers of the left and right child pages
45 * whose split this insertion finishes, as BlockIdData[2] (beware of
46 * adding fields in this struct that would make them not 16-bit aligned)
47 *
48 * 2. a ginxlogInsertEntry or ginxlogRecompressDataLeaf struct, depending
49 * on tree type.
50 *
51 * NB: the below structs are only 16-bit aligned when appended to a
52 * ginxlogInsert struct! Beware of adding fields to them that require
53 * stricter alignment.
54 */
55} ginxlogInsert;
56
57typedef struct
58{
59 OffsetNumber offset;
60 bool isDelete;
61 IndexTupleData tuple; /* variable length */
62} ginxlogInsertEntry;
63
64
65typedef struct
66{
67 uint16 nactions;
68
69 /* Variable number of 'actions' follow */
70} ginxlogRecompressDataLeaf;
71
72/*
73 * Note: this struct is currently not used in code, and only acts as
74 * documentation. The WAL record format is as specified here, but the code
75 * uses straight access through a Pointer and memcpy to read/write these.
76 */
77typedef struct
78{
79 uint8 segno; /* segment this action applies to */
80 char type; /* action type (see below) */
81
82 /*
83 * Action-specific data follows. For INSERT and REPLACE actions that is a
84 * GinPostingList struct. For ADDITEMS, a uint16 for the number of items
85 * added, followed by the items themselves as ItemPointers. DELETE actions
86 * have no further data.
87 */
88} ginxlogSegmentAction;
89
90/* Action types */
91#define GIN_SEGMENT_UNMODIFIED 0 /* no action (not used in WAL records) */
92#define GIN_SEGMENT_DELETE 1 /* a whole segment is removed */
93#define GIN_SEGMENT_INSERT 2 /* a whole segment is added */
94#define GIN_SEGMENT_REPLACE 3 /* a segment is replaced */
95#define GIN_SEGMENT_ADDITEMS 4 /* items are added to existing segment */
96
97typedef struct
98{
99 OffsetNumber offset;
100 PostingItem newitem;
101} ginxlogInsertDataInternal;
102
103/*
104 * Backup Blk 0: new left page (= original page, if not root split)
105 * Backup Blk 1: new right page
106 * Backup Blk 2: original page / new root page, if root split
107 * Backup Blk 3: left child, if this insertion completes an earlier split
108 */
109#define XLOG_GIN_SPLIT 0x30
110
111typedef struct ginxlogSplit
112{
113 RelFileNode node;
114 BlockNumber rrlink; /* right link, or root's blocknumber if root
115 * split */
116 BlockNumber leftChildBlkno; /* valid on a non-leaf split */
117 BlockNumber rightChildBlkno;
118 uint16 flags; /* see below */
119} ginxlogSplit;
120
121/*
122 * Flags used in ginxlogInsert and ginxlogSplit records
123 */
124#define GIN_INSERT_ISDATA 0x01 /* for both insert and split records */
125#define GIN_INSERT_ISLEAF 0x02 /* ditto */
126#define GIN_SPLIT_ROOT 0x04 /* only for split records */
127
128/*
129 * Vacuum simply WAL-logs the whole page, when anything is modified. This
130 * is functionally identical to heap_newpage records, but is kept separate for
131 * debugging purposes. (When inspecting the WAL stream, it's easier to see
132 * what's going on when GIN vacuum records are marked as such, not as heap
133 * records.) This is currently only used for entry tree leaf pages.
134 */
135#define XLOG_GIN_VACUUM_PAGE 0x40
136
137/*
138 * Vacuuming posting tree leaf page is WAL-logged like recompression caused
139 * by insertion.
140 */
141#define XLOG_GIN_VACUUM_DATA_LEAF_PAGE 0x90
142
143typedef struct ginxlogVacuumDataLeafPage
144{
145 ginxlogRecompressDataLeaf data;
146} ginxlogVacuumDataLeafPage;
147
148/*
149 * Backup Blk 0: deleted page
150 * Backup Blk 1: parent
151 * Backup Blk 2: left sibling
152 */
153#define XLOG_GIN_DELETE_PAGE 0x50
154
155typedef struct ginxlogDeletePage
156{
157 OffsetNumber parentOffset;
158 BlockNumber rightLink;
159 TransactionId deleteXid; /* last Xid which could see this page in scan */
160} ginxlogDeletePage;
161
162#define XLOG_GIN_UPDATE_META_PAGE 0x60
163
164/*
165 * Backup Blk 0: metapage
166 * Backup Blk 1: tail page
167 */
168typedef struct ginxlogUpdateMeta
169{
170 RelFileNode node;
171 GinMetaPageData metadata;
172 BlockNumber prevTail;
173 BlockNumber newRightlink;
174 int32 ntuples; /* if ntuples > 0 then metadata.tail was
175 * updated with that many tuples; else new sub
176 * list was inserted */
177 /* array of inserted tuples follows */
178} ginxlogUpdateMeta;
179
180#define XLOG_GIN_INSERT_LISTPAGE 0x70
181
182typedef struct ginxlogInsertListPage
183{
184 BlockNumber rightlink;
185 int32 ntuples;
186 /* array of inserted tuples follows */
187} ginxlogInsertListPage;
188
189/*
190 * Backup Blk 0: metapage
191 * Backup Blk 1 to (ndeleted + 1): deleted pages
192 */
193
194#define XLOG_GIN_DELETE_LISTPAGE 0x80
195
196/*
197 * The WAL record for deleting list pages must contain a block reference to
198 * all the deleted pages, so the number of pages that can be deleted in one
199 * record is limited by XLR_MAX_BLOCK_ID. (block_id 0 is used for the
200 * metapage.)
201 */
202#define GIN_NDELETE_AT_ONCE Min(16, XLR_MAX_BLOCK_ID - 1)
203typedef struct ginxlogDeleteListPages
204{
205 GinMetaPageData metadata;
206 int32 ndeleted;
207} ginxlogDeleteListPages;
208
209extern void gin_redo(XLogReaderState *record);
210extern void gin_desc(StringInfo buf, XLogReaderState *record);
211extern const char *gin_identify(uint8 info);
212extern void gin_xlog_startup(void);
213extern void gin_xlog_cleanup(void);
214extern void gin_mask(char *pagedata, BlockNumber blkno);
215
216#endif /* GINXLOG_H */
217