/*-------------------------------------------------------------------------

 *

 * 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) 1996-2026, 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 "libpq/protocol.h"

#include "utils/builtins.h"

#include "varatt.h"

/*

 * At startup time, send a RowDescription message.

 */

void

printsimple_startup(DestReceiver *self, int operation, TupleDesc tupdesc)

{

  StringInfoData buf;

  int     i;

  pq_beginmessage(&buf, PqMsg_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, PqMsg_DataRow);

  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));

        }

        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);

        }

        break;

      case INT8OID:

        {

          int64   num = DatumGetInt64(value);

          char    str[MAXINT8LEN + 1];

          int     len;

          len = pg_lltoa(num, str);

          pq_sendcountedtext(&buf, str, len);

        }

        break;

      case OIDOID:

        {

          Oid     num = DatumGetObjectId(value);

          char    str[10];  /* 10 digits */

          int     len;

          len = pg_ultoa_n(num, str);

          pq_sendcountedtext(&buf, str, len);

        }

        break;

      default:

        elog(ERROR, "unsupported type OID: %u", attr->atttypid);

    }

  }

  pq_endmessage(&buf);

  return true;

}