Age Owner Branch data TLA Line data Source code
1 : : /*-------------------------------------------------------------------------
2 : : *
3 : : * smgr.h
4 : : * storage manager switch public interface declarations.
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/smgr.h
11 : : *
12 : : *-------------------------------------------------------------------------
13 : : */
14 : : #ifndef SMGR_H
15 : : #define SMGR_H
16 : :
17 : : #include "lib/ilist.h"
18 : : #include "storage/block.h"
19 : : #include "storage/relfilelocator.h"
20 : :
21 : : /*
22 : : * smgr.c maintains a table of SMgrRelation objects, which are essentially
23 : : * cached file handles. An SMgrRelation is created (if not already present)
24 : : * by smgropen(), and destroyed by smgrdestroy(). Note that neither of these
25 : : * operations imply I/O, they just create or destroy a hashtable entry. (But
26 : : * smgrdestroy() may release associated resources, such as OS-level file
27 : : * descriptors.)
28 : : *
29 : : * An SMgrRelation may be "pinned", to prevent it from being destroyed while
30 : : * it's in use. We use this to prevent pointers relcache to smgr from being
31 : : * invalidated. SMgrRelations that are not pinned are deleted at end of
32 : : * transaction.
33 : : */
34 : : typedef struct SMgrRelationData
35 : : {
36 : : /* rlocator is the hashtable lookup key, so it must be first! */
37 : : RelFileLocatorBackend smgr_rlocator; /* relation physical identifier */
38 : :
39 : : /*
40 : : * The following fields are reset to InvalidBlockNumber upon a cache flush
41 : : * event, and hold the last known size for each fork. This information is
42 : : * currently only reliable during recovery, since there is no cache
43 : : * invalidation for fork extension.
44 : : */
45 : : BlockNumber smgr_targblock; /* current insertion target block */
46 : : BlockNumber smgr_cached_nblocks[MAX_FORKNUM + 1]; /* last known size */
47 : :
48 : : /* additional public fields may someday exist here */
49 : :
50 : : /*
51 : : * Fields below here are intended to be private to smgr.c and its
52 : : * submodules. Do not touch them from elsewhere.
53 : : */
54 : : int smgr_which; /* storage manager selector */
55 : :
56 : : /*
57 : : * for md.c; per-fork arrays of the number of open segments
58 : : * (md_num_open_segs) and the segments themselves (md_seg_fds).
59 : : */
60 : : int md_num_open_segs[MAX_FORKNUM + 1];
61 : : struct _MdfdVec *md_seg_fds[MAX_FORKNUM + 1];
62 : :
63 : : /*
64 : : * Pinning support. If unpinned (ie. pincount == 0), 'node' is a list
65 : : * link in list of all unpinned SMgrRelations.
66 : : */
67 : : int pincount;
68 : : dlist_node node;
69 : : } SMgrRelationData;
70 : :
71 : : typedef SMgrRelationData *SMgrRelation;
72 : :
73 : : #define SmgrIsTemp(smgr) \
74 : : RelFileLocatorBackendIsTemp((smgr)->smgr_rlocator)
75 : :
76 : : extern void smgrinit(void);
77 : : extern SMgrRelation smgropen(RelFileLocator rlocator, ProcNumber backend);
78 : : extern bool smgrexists(SMgrRelation reln, ForkNumber forknum);
79 : : extern void smgrpin(SMgrRelation reln);
80 : : extern void smgrunpin(SMgrRelation reln);
81 : : extern void smgrclose(SMgrRelation reln);
82 : : extern void smgrdestroyall(void);
83 : : extern void smgrrelease(SMgrRelation reln);
84 : : extern void smgrreleaseall(void);
85 : : extern void smgrreleaserellocator(RelFileLocatorBackend rlocator);
86 : : extern void smgrcreate(SMgrRelation reln, ForkNumber forknum, bool isRedo);
87 : : extern void smgrdosyncall(SMgrRelation *rels, int nrels);
88 : : extern void smgrdounlinkall(SMgrRelation *rels, int nrels, bool isRedo);
89 : : extern void smgrextend(SMgrRelation reln, ForkNumber forknum,
90 : : BlockNumber blocknum, const void *buffer, bool skipFsync);
91 : : extern void smgrzeroextend(SMgrRelation reln, ForkNumber forknum,
92 : : BlockNumber blocknum, int nblocks, bool skipFsync);
93 : : extern bool smgrprefetch(SMgrRelation reln, ForkNumber forknum,
94 : : BlockNumber blocknum, int nblocks);
95 : : extern void smgrreadv(SMgrRelation reln, ForkNumber forknum,
96 : : BlockNumber blocknum,
97 : : void **buffer, BlockNumber nblocks);
98 : : extern void smgrwritev(SMgrRelation reln, ForkNumber forknum,
99 : : BlockNumber blocknum,
100 : : const void **buffer, BlockNumber nblocks,
101 : : bool skipFsync);
102 : : extern void smgrwriteback(SMgrRelation reln, ForkNumber forknum,
103 : : BlockNumber blocknum, BlockNumber nblocks);
104 : : extern BlockNumber smgrnblocks(SMgrRelation reln, ForkNumber forknum);
105 : : extern BlockNumber smgrnblocks_cached(SMgrRelation reln, ForkNumber forknum);
106 : : extern void smgrtruncate(SMgrRelation reln, ForkNumber *forknum,
107 : : int nforks, BlockNumber *nblocks);
108 : : extern void smgrimmedsync(SMgrRelation reln, ForkNumber forknum);
109 : : extern void smgrregistersync(SMgrRelation reln, ForkNumber forknum);
110 : : extern void AtEOXact_SMgr(void);
111 : : extern bool ProcessBarrierSmgrRelease(void);
112 : :
113 : : static inline void
118 tmunro@postgresql.or 114 :GNC 595 : smgrread(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum,
115 : : void *buffer)
116 : : {
117 : 595 : smgrreadv(reln, forknum, blocknum, &buffer, 1);
118 : 595 : }
119 : :
120 : : static inline void
121 : 531288 : smgrwrite(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum,
122 : : const void *buffer, bool skipFsync)
123 : : {
124 : 531288 : smgrwritev(reln, forknum, blocknum, &buffer, 1, skipFsync);
125 : 531288 : }
126 : :
127 : : #endif /* SMGR_H */
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