1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
|
/*-------------------------------------------------------------------------
* relpath.c
* Shared frontend/backend code to compute pathnames of relation files
*
* This module also contains some logic associated with fork names.
*
* Portions Copyright (c) 1996-2022, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* src/common/relpath.c
*
*-------------------------------------------------------------------------
*/
#ifndef FRONTEND
#include "postgres.h"
#else
#include "postgres_fe.h"
#endif
#include "catalog/pg_tablespace_d.h"
#include "common/relpath.h"
#include "storage/backendid.h"
/*
* Lookup table of fork name by fork number.
*
* If you add a new entry, remember to update the errhint in
* forkname_to_number() below, and update the SGML documentation for
* pg_relation_size().
*/
const char *const forkNames[] = {
"main", /* MAIN_FORKNUM */
"fsm", /* FSM_FORKNUM */
"vm", /* VISIBILITYMAP_FORKNUM */
"init" /* INIT_FORKNUM */
};
StaticAssertDecl(lengthof(forkNames) == (MAX_FORKNUM + 1),
"array length mismatch");
/*
* forkname_to_number - look up fork number by name
*
* In backend, we throw an error for no match; in frontend, we just
* return InvalidForkNumber.
*/
ForkNumber
forkname_to_number(const char *forkName)
{
ForkNumber forkNum;
for (forkNum = 0; forkNum <= MAX_FORKNUM; forkNum++)
if (strcmp(forkNames[forkNum], forkName) == 0)
return forkNum;
#ifndef FRONTEND
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("invalid fork name"),
errhint("Valid fork names are \"main\", \"fsm\", "
"\"vm\", and \"init\".")));
#endif
return InvalidForkNumber;
}
/*
* forkname_chars
* We use this to figure out whether a filename could be a relation
* fork (as opposed to an oddly named stray file that somehow ended
* up in the database directory). If the passed string begins with
* a fork name (other than the main fork name), we return its length,
* and set *fork (if not NULL) to the fork number. If not, we return 0.
*
* Note that the present coding assumes that there are no fork names which
* are prefixes of other fork names.
*/
int
forkname_chars(const char *str, ForkNumber *fork)
{
ForkNumber forkNum;
for (forkNum = 1; forkNum <= MAX_FORKNUM; forkNum++)
{
int len = strlen(forkNames[forkNum]);
if (strncmp(forkNames[forkNum], str, len) == 0)
{
if (fork)
*fork = forkNum;
return len;
}
}
if (fork)
*fork = InvalidForkNumber;
return 0;
}
/*
* GetDatabasePath - construct path to a database directory
*
* Result is a palloc'd string.
*
* XXX this must agree with GetRelationPath()!
*/
char *
GetDatabasePath(Oid dbNode, Oid spcNode)
{
if (spcNode == GLOBALTABLESPACE_OID)
{
/* Shared system relations live in {datadir}/global */
Assert(dbNode == 0);
return pstrdup("global");
}
else if (spcNode == DEFAULTTABLESPACE_OID)
{
/* The default tablespace is {datadir}/base */
return psprintf("base/%u", dbNode);
}
else
{
/* All other tablespaces are accessed via symlinks */
return psprintf("pg_tblspc/%u/%s/%u",
spcNode, TABLESPACE_VERSION_DIRECTORY, dbNode);
}
}
/*
* GetRelationPath - construct path to a relation's file
*
* Result is a palloc'd string.
*
* Note: ideally, backendId would be declared as type BackendId, but relpath.h
* would have to include a backend-only header to do that; doesn't seem worth
* the trouble considering BackendId is just int anyway.
*/
char *
GetRelationPath(Oid dbNode, Oid spcNode, Oid relNode,
int backendId, ForkNumber forkNumber)
{
char *path;
if (spcNode == GLOBALTABLESPACE_OID)
{
/* Shared system relations live in {datadir}/global */
Assert(dbNode == 0);
Assert(backendId == InvalidBackendId);
if (forkNumber != MAIN_FORKNUM)
path = psprintf("global/%u_%s",
relNode, forkNames[forkNumber]);
else
path = psprintf("global/%u", relNode);
}
else if (spcNode == DEFAULTTABLESPACE_OID)
{
/* The default tablespace is {datadir}/base */
if (backendId == InvalidBackendId)
{
if (forkNumber != MAIN_FORKNUM)
path = psprintf("base/%u/%u_%s",
dbNode, relNode,
forkNames[forkNumber]);
else
path = psprintf("base/%u/%u",
dbNode, relNode);
}
else
{
if (forkNumber != MAIN_FORKNUM)
path = psprintf("base/%u/t%d_%u_%s",
dbNode, backendId, relNode,
forkNames[forkNumber]);
else
path = psprintf("base/%u/t%d_%u",
dbNode, backendId, relNode);
}
}
else
{
/* All other tablespaces are accessed via symlinks */
if (backendId == InvalidBackendId)
{
if (forkNumber != MAIN_FORKNUM)
path = psprintf("pg_tblspc/%u/%s/%u/%u_%s",
spcNode, TABLESPACE_VERSION_DIRECTORY,
dbNode, relNode,
forkNames[forkNumber]);
else
path = psprintf("pg_tblspc/%u/%s/%u/%u",
spcNode, TABLESPACE_VERSION_DIRECTORY,
dbNode, relNode);
}
else
{
if (forkNumber != MAIN_FORKNUM)
path = psprintf("pg_tblspc/%u/%s/%u/t%d_%u_%s",
spcNode, TABLESPACE_VERSION_DIRECTORY,
dbNode, backendId, relNode,
forkNames[forkNumber]);
else
path = psprintf("pg_tblspc/%u/%s/%u/t%d_%u",
spcNode, TABLESPACE_VERSION_DIRECTORY,
dbNode, backendId, relNode);
}
}
return path;
}
|
