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printsimple.c
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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) 1996-2017, 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 "fmgr.h"
24 #include "libpq/pqformat.h"
25 #include "utils/builtins.h"
26 
27 /*
28  * At startup time, send a RowDescription message.
29  */
30 void
31 printsimple_startup(DestReceiver *self, int operation, TupleDesc tupdesc)
32 {
34  int i;
35 
36  pq_beginmessage(&buf, 'T'); /* RowDescription */
37  pq_sendint(&buf, tupdesc->natts, 2);
38 
39  for (i = 0; i < tupdesc->natts; ++i)
40  {
41  Form_pg_attribute attr = tupdesc->attrs[i];
42 
43  pq_sendstring(&buf, NameStr(attr->attname));
44  pq_sendint(&buf, 0, 4); /* table oid */
45  pq_sendint(&buf, 0, 2); /* attnum */
46  pq_sendint(&buf, (int) attr->atttypid, 4);
47  pq_sendint(&buf, attr->attlen, 2);
48  pq_sendint(&buf, attr->atttypmod, 4);
49  pq_sendint(&buf, 0, 2); /* format code */
50  }
51 
52  pq_endmessage(&buf);
53 }
54 
55 /*
56  * For each tuple, send a DataRow message.
57  */
58 bool
60 {
61  TupleDesc tupdesc = slot->tts_tupleDescriptor;
63  int i;
64 
65  /* Make sure the tuple is fully deconstructed */
66  slot_getallattrs(slot);
67 
68  /* Prepare and send message */
69  pq_beginmessage(&buf, 'D');
70  pq_sendint(&buf, tupdesc->natts, 2);
71 
72  for (i = 0; i < tupdesc->natts; ++i)
73  {
74  Form_pg_attribute attr = tupdesc->attrs[i];
75  Datum value;
76 
77  if (slot->tts_isnull[i])
78  {
79  pq_sendint(&buf, -1, 4);
80  continue;
81  }
82 
83  value = slot->tts_values[i];
84 
85  /*
86  * We can't call the regular type output functions here because we
87  * might not have catalog access. Instead, we must hard-wire
88  * knowledge of the required types.
89  */
90  switch (attr->atttypid)
91  {
92  case TEXTOID:
93  {
94  text *t = DatumGetTextPP(value);
95 
96  pq_sendcountedtext(&buf,
97  VARDATA_ANY(t),
99  false);
100  }
101  break;
102 
103  case INT4OID:
104  {
105  int32 num = DatumGetInt32(value);
106  char str[12]; /* sign, 10 digits and '\0' */
107 
108  pg_ltoa(num, str);
109  pq_sendcountedtext(&buf, str, strlen(str), false);
110  }
111  break;
112 
113  case INT8OID:
114  {
115  int64 num = DatumGetInt64(value);
116  char str[23]; /* sign, 21 digits and '\0' */
117 
118  pg_lltoa(num, str);
119  pq_sendcountedtext(&buf, str, strlen(str), false);
120  }
121  break;
122 
123  default:
124  elog(ERROR, "unsupported type OID: %u", attr->atttypid);
125  }
126  }
127 
128  pq_endmessage(&buf);
129 
130  return true;
131 }
static struct @76 value
#define VARDATA_ANY(PTR)
Definition: postgres.h:349
#define DatumGetInt32(X)
Definition: postgres.h:480
#define TEXTOID
Definition: pg_type.h:324
#define DatumGetTextPP(X)
Definition: fmgr.h:249
Form_pg_attribute * attrs
Definition: tupdesc.h:74
#define INT4OID
Definition: pg_type.h:316
Datum * tts_values
Definition: tuptable.h:125
void pq_sendstring(StringInfo buf, const char *str)
Definition: pqformat.c:186
bool printsimple(TupleTableSlot *slot, DestReceiver *self)
Definition: printsimple.c:59
int natts
Definition: tupdesc.h:73
void pq_beginmessage(StringInfo buf, char msgtype)
Definition: pqformat.c:88
signed int int32
Definition: c.h:253
#define ERROR
Definition: elog.h:43
#define DatumGetInt64(X)
Definition: postgres.h:615
static char * buf
Definition: pg_test_fsync.c:65
bool * tts_isnull
Definition: tuptable.h:126
FormData_pg_attribute * Form_pg_attribute
Definition: pg_attribute.h:184
void pq_sendcountedtext(StringInfo buf, const char *str, int slen, bool countincludesself)
Definition: pqformat.c:131
void slot_getallattrs(TupleTableSlot *slot)
Definition: heaptuple.c:1239
void printsimple_startup(DestReceiver *self, int operation, TupleDesc tupdesc)
Definition: printsimple.c:31
TupleDesc tts_tupleDescriptor
Definition: tuptable.h:121
uintptr_t Datum
Definition: postgres.h:374
#define INT8OID
Definition: pg_type.h:304
void pg_lltoa(int64 value, char *a)
Definition: numutils.c:186
#define VARSIZE_ANY_EXHDR(PTR)
Definition: postgres.h:342
void pq_sendint(StringInfo buf, int i, int b)
Definition: pqformat.c:236
void pq_endmessage(StringInfo buf)
Definition: pqformat.c:344
int i
#define NameStr(name)
Definition: c.h:495
Definition: c.h:435
#define elog
Definition: elog.h:219
void pg_ltoa(int32 value, char *a)
Definition: numutils.c:132