/src/postgres/src/backend/storage/freespace/indexfsm.c
Line | Count | Source |
1 | | /*------------------------------------------------------------------------- |
2 | | * |
3 | | * indexfsm.c |
4 | | * POSTGRES free space map for quickly finding free pages in relations |
5 | | * |
6 | | * |
7 | | * Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group |
8 | | * Portions Copyright (c) 1994, Regents of the University of California |
9 | | * |
10 | | * IDENTIFICATION |
11 | | * src/backend/storage/freespace/indexfsm.c |
12 | | * |
13 | | * |
14 | | * NOTES: |
15 | | * |
16 | | * This is similar to the FSM used for heap, in freespace.c, but instead |
17 | | * of tracking the amount of free space on pages, we only track whether |
18 | | * pages are completely free or in-use. We use the same FSM implementation |
19 | | * as for heaps, using 0 to denote used pages, and (BLCKSZ - 1) for unused. |
20 | | * |
21 | | *------------------------------------------------------------------------- |
22 | | */ |
23 | | #include "postgres.h" |
24 | | |
25 | | #include "storage/freespace.h" |
26 | | #include "storage/indexfsm.h" |
27 | | |
28 | | /* |
29 | | * Exported routines |
30 | | */ |
31 | | |
32 | | /* |
33 | | * GetFreeIndexPage - return a free page from the FSM |
34 | | * |
35 | | * As a side effect, the page is marked as used in the FSM. |
36 | | */ |
37 | | BlockNumber |
38 | | GetFreeIndexPage(Relation rel) |
39 | 0 | { |
40 | 0 | BlockNumber blkno = GetPageWithFreeSpace(rel, BLCKSZ / 2); |
41 | |
|
42 | 0 | if (blkno != InvalidBlockNumber) |
43 | 0 | RecordUsedIndexPage(rel, blkno); |
44 | |
|
45 | 0 | return blkno; |
46 | 0 | } |
47 | | |
48 | | /* |
49 | | * RecordFreeIndexPage - mark a page as free in the FSM |
50 | | */ |
51 | | void |
52 | | RecordFreeIndexPage(Relation rel, BlockNumber freeBlock) |
53 | 0 | { |
54 | 0 | RecordPageWithFreeSpace(rel, freeBlock, BLCKSZ - 1); |
55 | 0 | } |
56 | | |
57 | | |
58 | | /* |
59 | | * RecordUsedIndexPage - mark a page as used in the FSM |
60 | | */ |
61 | | void |
62 | | RecordUsedIndexPage(Relation rel, BlockNumber usedBlock) |
63 | 0 | { |
64 | 0 | RecordPageWithFreeSpace(rel, usedBlock, 0); |
65 | 0 | } |
66 | | |
67 | | /* |
68 | | * IndexFreeSpaceMapVacuum - scan and fix any inconsistencies in the FSM |
69 | | */ |
70 | | void |
71 | | IndexFreeSpaceMapVacuum(Relation rel) |
72 | 0 | { |
73 | 0 | FreeSpaceMapVacuum(rel); |
74 | 0 | } |