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/*-------------------------------------------------------------------------
*
* printsimple.c
* Routines to print out tuples containing only a limited range of
* builtin types without catalog access. This is intended for
* backends that don't have catalog access because they are not bound
* to a specific database, such as some walsender processes. It
* doesn't handle standalone backends or protocol versions other than
* 3.0, because we don't need such handling for current applications.
*
* Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* src/backend/access/common/printsimple.c
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "access/printsimple.h"
#include "catalog/pg_type.h"
#include "libpq/pqformat.h"
#include "utils/builtins.h"
/*
* At startup time, send a RowDescription message.
*/
void
printsimple_startup(DestReceiver *self, int operation, TupleDesc tupdesc)
{
StringInfoData buf;
int i;
pq_beginmessage(&buf, 'T'); /* RowDescription */
pq_sendint16(&buf, tupdesc->natts);
for (i = 0; i < tupdesc->natts; ++i)
{
Form_pg_attribute attr = TupleDescAttr(tupdesc, i);
pq_sendstring(&buf, NameStr(attr->attname));
pq_sendint32(&buf, 0); /* table oid */
pq_sendint16(&buf, 0); /* attnum */
pq_sendint32(&buf, (int) attr->atttypid);
pq_sendint16(&buf, attr->attlen);
pq_sendint32(&buf, attr->atttypmod);
pq_sendint16(&buf, 0); /* format code */
}
pq_endmessage(&buf);
}
/*
* For each tuple, send a DataRow message.
*/
bool
printsimple(TupleTableSlot *slot, DestReceiver *self)
{
TupleDesc tupdesc = slot->tts_tupleDescriptor;
StringInfoData buf;
int i;
/* Make sure the tuple is fully deconstructed */
slot_getallattrs(slot);
/* Prepare and send message */
pq_beginmessage(&buf, 'D');
pq_sendint16(&buf, tupdesc->natts);
for (i = 0; i < tupdesc->natts; ++i)
{
Form_pg_attribute attr = TupleDescAttr(tupdesc, i);
Datum value;
if (slot->tts_isnull[i])
{
pq_sendint32(&buf, -1);
continue;
}
value = slot->tts_values[i];
/*
* We can't call the regular type output functions here because we
* might not have catalog access. Instead, we must hard-wire
* knowledge of the required types.
*/
switch (attr->atttypid)
{
case TEXTOID:
{
text *t = DatumGetTextPP(value);
pq_sendcountedtext(&buf,
VARDATA_ANY(t),
VARSIZE_ANY_EXHDR(t),
false);
}
break;
case INT4OID:
{
int32 num = DatumGetInt32(value);
char str[12]; /* sign, 10 digits and '\0' */
int len;
len = pg_ltoa(num, str);
pq_sendcountedtext(&buf, str, len, false);
}
break;
case INT8OID:
{
int64 num = DatumGetInt64(value);
char str[MAXINT8LEN + 1];
int len;
len = pg_lltoa(num, str);
pq_sendcountedtext(&buf, str, len, false);
}
break;
case OIDOID:
{
Oid num = ObjectIdGetDatum(value);
char str[10]; /* 10 digits */
int len;
len = pg_ultoa_n(num, str);
pq_sendcountedtext(&buf, str, len, false);
}
break;
default:
elog(ERROR, "unsupported type OID: %u", attr->atttypid);
}
}
pq_endmessage(&buf);
return true;
}
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