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
|
/*-------------------------------------------------------------------------
*
* tupdesc.h
* POSTGRES tuple descriptor definitions.
*
*
* Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* src/include/access/tupdesc.h
*
*-------------------------------------------------------------------------
*/
#ifndef TUPDESC_H
#define TUPDESC_H
#include "access/attnum.h"
#include "catalog/pg_attribute.h"
#include "nodes/pg_list.h"
typedef struct AttrDefault
{
AttrNumber adnum;
char *adbin; /* nodeToString representation of expr */
} AttrDefault;
typedef struct ConstrCheck
{
char *ccname;
char *ccbin; /* nodeToString representation of expr */
bool ccvalid;
bool ccnoinherit; /* this is a non-inheritable constraint */
} ConstrCheck;
/* This structure contains constraints of a tuple */
typedef struct TupleConstr
{
AttrDefault *defval; /* array */
ConstrCheck *check; /* array */
struct AttrMissing *missing; /* missing attributes values, NULL if none */
uint16 num_defval;
uint16 num_check;
bool has_not_null;
bool has_generated_stored;
} TupleConstr;
/*
* This struct is passed around within the backend to describe the structure
* of tuples. For tuples coming from on-disk relations, the information is
* collected from the pg_attribute, pg_attrdef, and pg_constraint catalogs.
* Transient row types (such as the result of a join query) have anonymous
* TupleDesc structs that generally omit any constraint info; therefore the
* structure is designed to let the constraints be omitted efficiently.
*
* Note that only user attributes, not system attributes, are mentioned in
* TupleDesc.
*
* If the tupdesc is known to correspond to a named rowtype (such as a table's
* rowtype) then tdtypeid identifies that type and tdtypmod is -1. Otherwise
* tdtypeid is RECORDOID, and tdtypmod can be either -1 for a fully anonymous
* row type, or a value >= 0 to allow the rowtype to be looked up in the
* typcache.c type cache.
*
* Note that tdtypeid is never the OID of a domain over composite, even if
* we are dealing with values that are known (at some higher level) to be of
* a domain-over-composite type. This is because tdtypeid/tdtypmod need to
* match up with the type labeling of composite Datums, and those are never
* explicitly marked as being of a domain type, either.
*
* Tuple descriptors that live in caches (relcache or typcache, at present)
* are reference-counted: they can be deleted when their reference count goes
* to zero. Tuple descriptors created by the executor need no reference
* counting, however: they are simply created in the appropriate memory
* context and go away when the context is freed. We set the tdrefcount
* field of such a descriptor to -1, while reference-counted descriptors
* always have tdrefcount >= 0.
*/
typedef struct TupleDescData
{
int natts; /* number of attributes in the tuple */
Oid tdtypeid; /* composite type ID for tuple type */
int32 tdtypmod; /* typmod for tuple type */
int tdrefcount; /* reference count, or -1 if not counting */
TupleConstr *constr; /* constraints, or NULL if none */
/* attrs[N] is the description of Attribute Number N+1 */
FormData_pg_attribute attrs[FLEXIBLE_ARRAY_MEMBER];
} TupleDescData;
typedef struct TupleDescData *TupleDesc;
/* Accessor for the i'th attribute of tupdesc. */
#define TupleDescAttr(tupdesc, i) (&(tupdesc)->attrs[(i)])
extern TupleDesc CreateTemplateTupleDesc(int natts);
extern TupleDesc CreateTupleDesc(int natts, Form_pg_attribute *attrs);
extern TupleDesc CreateTupleDescCopy(TupleDesc tupdesc);
extern TupleDesc CreateTupleDescCopyConstr(TupleDesc tupdesc);
#define TupleDescSize(src) \
(offsetof(struct TupleDescData, attrs) + \
(src)->natts * sizeof(FormData_pg_attribute))
extern void TupleDescCopy(TupleDesc dst, TupleDesc src);
extern void TupleDescCopyEntry(TupleDesc dst, AttrNumber dstAttno,
TupleDesc src, AttrNumber srcAttno);
extern void FreeTupleDesc(TupleDesc tupdesc);
extern void IncrTupleDescRefCount(TupleDesc tupdesc);
extern void DecrTupleDescRefCount(TupleDesc tupdesc);
#define PinTupleDesc(tupdesc) \
do { \
if ((tupdesc)->tdrefcount >= 0) \
IncrTupleDescRefCount(tupdesc); \
} while (0)
#define ReleaseTupleDesc(tupdesc) \
do { \
if ((tupdesc)->tdrefcount >= 0) \
DecrTupleDescRefCount(tupdesc); \
} while (0)
extern bool equalTupleDescs(TupleDesc tupdesc1, TupleDesc tupdesc2);
extern uint32 hashTupleDesc(TupleDesc tupdesc);
extern void TupleDescInitEntry(TupleDesc desc,
AttrNumber attributeNumber,
const char *attributeName,
Oid oidtypeid,
int32 typmod,
int attdim);
extern void TupleDescInitBuiltinEntry(TupleDesc desc,
AttrNumber attributeNumber,
const char *attributeName,
Oid oidtypeid,
int32 typmod,
int attdim);
extern void TupleDescInitEntryCollation(TupleDesc desc,
AttrNumber attributeNumber,
Oid collationid);
extern TupleDesc BuildDescForRelation(List *schema);
extern TupleDesc BuildDescFromLists(List *names, List *types, List *typmods, List *collations);
#endif /* TUPDESC_H */
|
