Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * printsimple.c
4 : * Routines to print out tuples containing only a limited range of
5 : * builtin types without catalog access. This is intended for
6 : * backends that don't have catalog access because they are not bound
7 : * to a specific database, such as some walsender processes. It
8 : * doesn't handle standalone backends or protocol versions other than
9 : * 3.0, because we don't need such handling for current applications.
10 : *
11 : * Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group
12 : * Portions Copyright (c) 1994, Regents of the University of California
13 : *
14 : * IDENTIFICATION
15 : * src/backend/access/common/printsimple.c
16 : *
17 : *-------------------------------------------------------------------------
18 : */
19 : #include "postgres.h"
20 :
21 : #include "access/printsimple.h"
22 : #include "catalog/pg_type.h"
23 : #include "libpq/pqformat.h"
24 : #include "libpq/protocol.h"
25 : #include "utils/builtins.h"
26 : #include "varatt.h"
27 :
28 : /*
29 : * At startup time, send a RowDescription message.
30 : */
31 : void
32 2391 : printsimple_startup(DestReceiver *self, int operation, TupleDesc tupdesc)
33 : {
34 : StringInfoData buf;
35 : int i;
36 :
37 2391 : pq_beginmessage(&buf, PqMsg_RowDescription);
38 2391 : pq_sendint16(&buf, tupdesc->natts);
39 :
40 9288 : for (i = 0; i < tupdesc->natts; ++i)
41 : {
42 6897 : Form_pg_attribute attr = TupleDescAttr(tupdesc, i);
43 :
44 6897 : pq_sendstring(&buf, NameStr(attr->attname));
45 6897 : pq_sendint32(&buf, 0); /* table oid */
46 6897 : pq_sendint16(&buf, 0); /* attnum */
47 6897 : pq_sendint32(&buf, (int) attr->atttypid);
48 6897 : pq_sendint16(&buf, attr->attlen);
49 6897 : pq_sendint32(&buf, attr->atttypmod);
50 6897 : pq_sendint16(&buf, 0); /* format code */
51 : }
52 :
53 2391 : pq_endmessage(&buf);
54 2391 : }
55 :
56 : /*
57 : * For each tuple, send a DataRow message.
58 : */
59 : bool
60 3232 : printsimple(TupleTableSlot *slot, DestReceiver *self)
61 : {
62 3232 : TupleDesc tupdesc = slot->tts_tupleDescriptor;
63 : StringInfoData buf;
64 : int i;
65 :
66 : /* Make sure the tuple is fully deconstructed */
67 3232 : slot_getallattrs(slot);
68 :
69 : /* Prepare and send message */
70 3232 : pq_beginmessage(&buf, PqMsg_DataRow);
71 3232 : pq_sendint16(&buf, tupdesc->natts);
72 :
73 12665 : for (i = 0; i < tupdesc->natts; ++i)
74 : {
75 9433 : Form_pg_attribute attr = TupleDescAttr(tupdesc, i);
76 : Datum value;
77 :
78 9433 : if (slot->tts_isnull[i])
79 : {
80 1474 : pq_sendint32(&buf, -1);
81 1474 : continue;
82 : }
83 :
84 7959 : value = slot->tts_values[i];
85 :
86 : /*
87 : * We can't call the regular type output functions here because we
88 : * might not have catalog access. Instead, we must hard-wire
89 : * knowledge of the required types.
90 : */
91 7959 : switch (attr->atttypid)
92 : {
93 6606 : case TEXTOID:
94 : {
95 6606 : text *t = DatumGetTextPP(value);
96 :
97 6606 : pq_sendcountedtext(&buf,
98 6606 : VARDATA_ANY(t),
99 6606 : VARSIZE_ANY_EXHDR(t));
100 : }
101 6606 : break;
102 :
103 0 : case INT4OID:
104 : {
105 0 : int32 num = DatumGetInt32(value);
106 : char str[12]; /* sign, 10 digits and '\0' */
107 : int len;
108 :
109 0 : len = pg_ltoa(num, str);
110 0 : pq_sendcountedtext(&buf, str, len);
111 : }
112 0 : break;
113 :
114 1316 : case INT8OID:
115 : {
116 1316 : int64 num = DatumGetInt64(value);
117 : char str[MAXINT8LEN + 1];
118 : int len;
119 :
120 1316 : len = pg_lltoa(num, str);
121 1316 : pq_sendcountedtext(&buf, str, len);
122 : }
123 1316 : break;
124 :
125 37 : case OIDOID:
126 : {
127 37 : Oid num = DatumGetObjectId(value);
128 : char str[10]; /* 10 digits */
129 : int len;
130 :
131 37 : len = pg_ultoa_n(num, str);
132 37 : pq_sendcountedtext(&buf, str, len);
133 : }
134 37 : break;
135 :
136 0 : default:
137 0 : elog(ERROR, "unsupported type OID: %u", attr->atttypid);
138 : }
139 : }
140 :
141 3232 : pq_endmessage(&buf);
142 :
143 3232 : return true;
144 : }
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