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
|
/*-------------------------------------------------------------------------
*
* amapi.c
* Support routines for API for Postgres index access methods.
*
* Copyright (c) 2015-2016, PostgreSQL Global Development Group
*
*
* IDENTIFICATION
* src/backend/access/index/amapi.c
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "access/amapi.h"
#include "access/htup_details.h"
#include "catalog/pg_am.h"
#include "catalog/pg_opclass.h"
#include "utils/syscache.h"
/*
* GetIndexAmRoutine - call the specified access method handler routine to get
* its IndexAmRoutine struct, which will be palloc'd in the caller's context.
*
* Note that if the amhandler function is built-in, this will not involve
* any catalog access. It's therefore safe to use this while bootstrapping
* indexes for the system catalogs. relcache.c relies on that.
*/
IndexAmRoutine *
GetIndexAmRoutine(Oid amhandler)
{
Datum datum;
IndexAmRoutine *routine;
datum = OidFunctionCall0(amhandler);
routine = (IndexAmRoutine *) DatumGetPointer(datum);
if (routine == NULL || !IsA(routine, IndexAmRoutine))
elog(ERROR, "index access method handler function %u did not return an IndexAmRoutine struct",
amhandler);
return routine;
}
/*
* GetIndexAmRoutineByAmId - look up the handler of the index access method
* with the given OID, and get its IndexAmRoutine struct.
*/
IndexAmRoutine *
GetIndexAmRoutineByAmId(Oid amoid)
{
HeapTuple tuple;
Form_pg_am amform;
regproc amhandler;
/* Get handler function OID for the access method */
tuple = SearchSysCache1(AMOID, ObjectIdGetDatum(amoid));
if (!HeapTupleIsValid(tuple))
elog(ERROR, "cache lookup failed for access method %u",
amoid);
amform = (Form_pg_am) GETSTRUCT(tuple);
/* Check if it's index access method */
if (amform->amtype != AMTYPE_INDEX)
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("access method \"%s\" is not of type %s",
NameStr(amform->amname), "INDEX")));
amhandler = amform->amhandler;
/* Complain if handler OID is invalid */
if (!RegProcedureIsValid(amhandler))
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("index access method \"%s\" does not have a handler",
NameStr(amform->amname))));
ReleaseSysCache(tuple);
/* And finally, call the handler function to get the API struct. */
return GetIndexAmRoutine(amhandler);
}
/*
* Ask appropriate access method to validate the specified opclass.
*/
Datum
amvalidate(PG_FUNCTION_ARGS)
{
Oid opclassoid = PG_GETARG_OID(0);
bool result;
HeapTuple classtup;
Form_pg_opclass classform;
Oid amoid;
IndexAmRoutine *amroutine;
classtup = SearchSysCache1(CLAOID, ObjectIdGetDatum(opclassoid));
if (!HeapTupleIsValid(classtup))
elog(ERROR, "cache lookup failed for operator class %u", opclassoid);
classform = (Form_pg_opclass) GETSTRUCT(classtup);
amoid = classform->opcmethod;
ReleaseSysCache(classtup);
amroutine = GetIndexAmRoutineByAmId(amoid);
if (amroutine->amvalidate == NULL)
elog(ERROR, "function amvalidate is not defined for index access method %u",
amoid);
result = amroutine->amvalidate(opclassoid);
pfree(amroutine);
PG_RETURN_BOOL(result);
}
|
