granicus.if.org Git - postgresql/blob - src/backend/utils/adt/rowtypes.c

   1 /*-------------------------------------------------------------------------
   2  *
   3  * rowtypes.c
   4  *        I/O functions for generic composite types.
   5  *
   6  * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
   7  * Portions Copyright (c) 1994, Regents of the University of California
   8  *
   9  *
  10  * IDENTIFICATION
  11  *        $PostgreSQL: pgsql/src/backend/utils/adt/rowtypes.c,v 1.18 2007/01/05 22:19:42 momjian Exp $
  12  *
  13  *-------------------------------------------------------------------------
  14  */
  15 #include "postgres.h"
  16
  17 #include <ctype.h>
  18
  19 #include "access/heapam.h"
  20 #include "catalog/pg_type.h"
  21 #include "libpq/pqformat.h"
  22 #include "utils/builtins.h"
  23 #include "utils/lsyscache.h"
  24 #include "utils/typcache.h"
  25
  26
  27 /*
  28  * structure to cache metadata needed for record I/O
  29  */
  30 typedef struct ColumnIOData
  31 {
  32         Oid                     column_type;
  33         Oid                     typiofunc;
  34         Oid                     typioparam;
  35         FmgrInfo        proc;
  36 } ColumnIOData;
  37
  38 typedef struct RecordIOData
  39 {
  40         Oid                     record_type;
  41         int32           record_typmod;
  42         int                     ncolumns;
  43         ColumnIOData columns[1];        /* VARIABLE LENGTH ARRAY */
  44 } RecordIOData;
  45
  46
  47 /*
  48  * record_in            - input routine for any composite type.
  49  */
  50 Datum
  51 record_in(PG_FUNCTION_ARGS)
  52 {
  53         char       *string = PG_GETARG_CSTRING(0);
  54         Oid                     tupType = PG_GETARG_OID(1);
  55
  56 #ifdef NOT_USED
  57         int32           typmod = PG_GETARG_INT32(2);
  58 #endif
  59         HeapTupleHeader result;
  60         int32           tupTypmod;
  61         TupleDesc       tupdesc;
  62         HeapTuple       tuple;
  63         RecordIOData *my_extra;
  64         bool            needComma = false;
  65         int                     ncolumns;
  66         int                     i;
  67         char       *ptr;
  68         Datum      *values;
  69         char       *nulls;
  70         StringInfoData buf;
  71
  72         /*
  73          * Use the passed type unless it's RECORD; we can't support input of
  74          * anonymous types, mainly because there's no good way to figure out which
  75          * anonymous type is wanted.  Note that for RECORD, what we'll probably
  76          * actually get is RECORD's typelem, ie, zero.
  77          */
  78         if (tupType == InvalidOid || tupType == RECORDOID)
  79                 ereport(ERROR,
  80                                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
  81                    errmsg("input of anonymous composite types is not implemented")));
  82         tupTypmod = -1;                         /* for all non-anonymous types */
  83         tupdesc = lookup_rowtype_tupdesc(tupType, tupTypmod);
  84         ncolumns = tupdesc->natts;
  85
  86         /*
  87          * We arrange to look up the needed I/O info just once per series of
  88          * calls, assuming the record type doesn't change underneath us.
  89          */
  90         my_extra = (RecordIOData *) fcinfo->flinfo->fn_extra;
  91         if (my_extra == NULL ||
  92                 my_extra->ncolumns != ncolumns)
  93         {
  94                 fcinfo->flinfo->fn_extra =
  95                         MemoryContextAlloc(fcinfo->flinfo->fn_mcxt,
  96                                                            sizeof(RecordIOData) - sizeof(ColumnIOData)
  97                                                            + ncolumns * sizeof(ColumnIOData));
  98                 my_extra = (RecordIOData *) fcinfo->flinfo->fn_extra;
  99                 my_extra->record_type = InvalidOid;
 100                 my_extra->record_typmod = 0;
 101         }
 102
 103         if (my_extra->record_type != tupType ||
 104                 my_extra->record_typmod != tupTypmod)
 105         {
 106                 MemSet(my_extra, 0,
 107                            sizeof(RecordIOData) - sizeof(ColumnIOData)
 108                            + ncolumns * sizeof(ColumnIOData));
 109                 my_extra->record_type = tupType;
 110                 my_extra->record_typmod = tupTypmod;
 111                 my_extra->ncolumns = ncolumns;
 112         }
 113
 114         values = (Datum *) palloc(ncolumns * sizeof(Datum));
 115         nulls = (char *) palloc(ncolumns * sizeof(char));
 116
 117         /*
 118          * Scan the string.  We use "buf" to accumulate the de-quoted data for
 119          * each column, which is then fed to the appropriate input converter.
 120          */
 121         ptr = string;
 122         /* Allow leading whitespace */
 123         while (*ptr && isspace((unsigned char) *ptr))
 124                 ptr++;
 125         if (*ptr++ != '(')
 126                 ereport(ERROR,
 127                                 (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
 128                                  errmsg("malformed record literal: \"%s\"", string),
 129                                  errdetail("Missing left parenthesis.")));
 130
 131         initStringInfo(&buf);
 132
 133         for (i = 0; i < ncolumns; i++)
 134         {
 135                 ColumnIOData *column_info = &my_extra->columns[i];
 136                 Oid                     column_type = tupdesc->attrs[i]->atttypid;
 137                 char       *column_data;
 138
 139                 /* Ignore dropped columns in datatype, but fill with nulls */
 140                 if (tupdesc->attrs[i]->attisdropped)
 141                 {
 142                         values[i] = (Datum) 0;
 143                         nulls[i] = 'n';
 144                         continue;
 145                 }
 146
 147                 if (needComma)
 148                 {
 149                         /* Skip comma that separates prior field from this one */
 150                         if (*ptr == ',')
 151                                 ptr++;
 152                         else
 153                                 /* *ptr must be ')' */
 154                                 ereport(ERROR,
 155                                                 (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
 156                                                  errmsg("malformed record literal: \"%s\"", string),
 157                                                  errdetail("Too few columns.")));
 158                 }
 159
 160                 /* Check for null: completely empty input means null */
 161                 if (*ptr == ',' || *ptr == ')')
 162                 {
 163                         column_data = NULL;
 164                         nulls[i] = 'n';
 165                 }
 166                 else
 167                 {
 168                         /* Extract string for this column */
 169                         bool            inquote = false;
 170
 171                         buf.len = 0;
 172                         buf.data[0] = '\0';
 173                         while (inquote || !(*ptr == ',' || *ptr == ')'))
 174                         {
 175                                 char            ch = *ptr++;
 176
 177                                 if (ch == '\0')
 178                                         ereport(ERROR,
 179                                                         (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
 180                                                          errmsg("malformed record literal: \"%s\"",
 181                                                                         string),
 182                                                          errdetail("Unexpected end of input.")));
 183                                 if (ch == '\\')
 184                                 {
 185                                         if (*ptr == '\0')
 186                                                 ereport(ERROR,
 187                                                                 (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
 188                                                                  errmsg("malformed record literal: \"%s\"",
 189                                                                                 string),
 190                                                                  errdetail("Unexpected end of input.")));
 191                                         appendStringInfoChar(&buf, *ptr++);
 192                                 }
 193                                 else if (ch == '\"')
 194                                 {
 195                                         if (!inquote)
 196                                                 inquote = true;
 197                                         else if (*ptr == '\"')
 198                                         {
 199                                                 /* doubled quote within quote sequence */
 200                                                 appendStringInfoChar(&buf, *ptr++);
 201                                         }
 202                                         else
 203                                                 inquote = false;
 204                                 }
 205                                 else
 206                                         appendStringInfoChar(&buf, ch);
 207                         }
 208
 209                         column_data = buf.data;
 210                         nulls[i] = ' ';
 211                 }
 212
 213                 /*
 214                  * Convert the column value
 215                  */
 216                 if (column_info->column_type != column_type)
 217                 {
 218                         getTypeInputInfo(column_type,
 219                                                          &column_info->typiofunc,
 220                                                          &column_info->typioparam);
 221                         fmgr_info_cxt(column_info->typiofunc, &column_info->proc,
 222                                                   fcinfo->flinfo->fn_mcxt);
 223                         column_info->column_type = column_type;
 224                 }
 225
 226                 values[i] = InputFunctionCall(&column_info->proc,
 227                                                                           column_data,
 228                                                                           column_info->typioparam,
 229                                                                           tupdesc->attrs[i]->atttypmod);
 230
 231                 /*
 232                  * Prep for next column
 233                  */
 234                 needComma = true;
 235         }
 236
 237         if (*ptr++ != ')')
 238                 ereport(ERROR,
 239                                 (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
 240                                  errmsg("malformed record literal: \"%s\"", string),
 241                                  errdetail("Too many columns.")));
 242         /* Allow trailing whitespace */
 243         while (*ptr && isspace((unsigned char) *ptr))
 244                 ptr++;
 245         if (*ptr)
 246                 ereport(ERROR,
 247                                 (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
 248                                  errmsg("malformed record literal: \"%s\"", string),
 249                                  errdetail("Junk after right parenthesis.")));
 250
 251         tuple = heap_formtuple(tupdesc, values, nulls);
 252
 253         /*
 254          * We cannot return tuple->t_data because heap_formtuple allocates it as
 255          * part of a larger chunk, and our caller may expect to be able to pfree
 256          * our result.  So must copy the info into a new palloc chunk.
 257          */
 258         result = (HeapTupleHeader) palloc(tuple->t_len);
 259         memcpy(result, tuple->t_data, tuple->t_len);
 260
 261         heap_freetuple(tuple);
 262         pfree(buf.data);
 263         pfree(values);
 264         pfree(nulls);
 265         ReleaseTupleDesc(tupdesc);
 266
 267         PG_RETURN_HEAPTUPLEHEADER(result);
 268 }
 269
 270 /*
 271  * record_out           - output routine for any composite type.
 272  */
 273 Datum
 274 record_out(PG_FUNCTION_ARGS)
 275 {
 276         HeapTupleHeader rec = PG_GETARG_HEAPTUPLEHEADER(0);
 277         Oid                     tupType;
 278         int32           tupTypmod;
 279         TupleDesc       tupdesc;
 280         HeapTupleData tuple;
 281         RecordIOData *my_extra;
 282         bool            needComma = false;
 283         int                     ncolumns;
 284         int                     i;
 285         Datum      *values;
 286         char       *nulls;
 287         StringInfoData buf;
 288
 289         /* Extract type info from the tuple itself */
 290         tupType = HeapTupleHeaderGetTypeId(rec);
 291         tupTypmod = HeapTupleHeaderGetTypMod(rec);
 292         tupdesc = lookup_rowtype_tupdesc(tupType, tupTypmod);
 293         ncolumns = tupdesc->natts;
 294
 295         /* Build a temporary HeapTuple control structure */
 296         tuple.t_len = HeapTupleHeaderGetDatumLength(rec);
 297         ItemPointerSetInvalid(&(tuple.t_self));
 298         tuple.t_tableOid = InvalidOid;
 299         tuple.t_data = rec;
 300
 301         /*
 302          * We arrange to look up the needed I/O info just once per series of
 303          * calls, assuming the record type doesn't change underneath us.
 304          */
 305         my_extra = (RecordIOData *) fcinfo->flinfo->fn_extra;
 306         if (my_extra == NULL ||
 307                 my_extra->ncolumns != ncolumns)
 308         {
 309                 fcinfo->flinfo->fn_extra =
 310                         MemoryContextAlloc(fcinfo->flinfo->fn_mcxt,
 311                                                            sizeof(RecordIOData) - sizeof(ColumnIOData)
 312                                                            + ncolumns * sizeof(ColumnIOData));
 313                 my_extra = (RecordIOData *) fcinfo->flinfo->fn_extra;
 314                 my_extra->record_type = InvalidOid;
 315                 my_extra->record_typmod = 0;
 316         }
 317
 318         if (my_extra->record_type != tupType ||
 319                 my_extra->record_typmod != tupTypmod)
 320         {
 321                 MemSet(my_extra, 0,
 322                            sizeof(RecordIOData) - sizeof(ColumnIOData)
 323                            + ncolumns * sizeof(ColumnIOData));
 324                 my_extra->record_type = tupType;
 325                 my_extra->record_typmod = tupTypmod;
 326                 my_extra->ncolumns = ncolumns;
 327         }
 328
 329         values = (Datum *) palloc(ncolumns * sizeof(Datum));
 330         nulls = (char *) palloc(ncolumns * sizeof(char));
 331
 332         /* Break down the tuple into fields */
 333         heap_deformtuple(&tuple, tupdesc, values, nulls);
 334
 335         /* And build the result string */
 336         initStringInfo(&buf);
 337
 338         appendStringInfoChar(&buf, '(');
 339
 340         for (i = 0; i < ncolumns; i++)
 341         {
 342                 ColumnIOData *column_info = &my_extra->columns[i];
 343                 Oid                     column_type = tupdesc->attrs[i]->atttypid;
 344                 char       *value;
 345                 char       *tmp;
 346                 bool            nq;
 347
 348                 /* Ignore dropped columns in datatype */
 349                 if (tupdesc->attrs[i]->attisdropped)
 350                         continue;
 351
 352                 if (needComma)
 353                         appendStringInfoChar(&buf, ',');
 354                 needComma = true;
 355
 356                 if (nulls[i] == 'n')
 357                 {
 358                         /* emit nothing... */
 359                         continue;
 360                 }
 361
 362                 /*
 363                  * Convert the column value to text
 364                  */
 365                 if (column_info->column_type != column_type)
 366                 {
 367                         bool            typIsVarlena;
 368
 369                         getTypeOutputInfo(column_type,
 370                                                           &column_info->typiofunc,
 371                                                           &typIsVarlena);
 372                         fmgr_info_cxt(column_info->typiofunc, &column_info->proc,
 373                                                   fcinfo->flinfo->fn_mcxt);
 374                         column_info->column_type = column_type;
 375                 }
 376
 377                 value = OutputFunctionCall(&column_info->proc, values[i]);
 378
 379                 /* Detect whether we need double quotes for this value */
 380                 nq = (value[0] == '\0');        /* force quotes for empty string */
 381                 for (tmp = value; *tmp; tmp++)
 382                 {
 383                         char            ch = *tmp;
 384
 385                         if (ch == '"' || ch == '\\' ||
 386                                 ch == '(' || ch == ')' || ch == ',' ||
 387                                 isspace((unsigned char) ch))
 388                         {
 389                                 nq = true;
 390                                 break;
 391                         }
 392                 }
 393
 394                 /* And emit the string */
 395                 if (nq)
 396                         appendStringInfoChar(&buf, '"');
 397                 for (tmp = value; *tmp; tmp++)
 398                 {
 399                         char            ch = *tmp;
 400
 401                         if (ch == '"' || ch == '\\')
 402                                 appendStringInfoChar(&buf, ch);
 403                         appendStringInfoChar(&buf, ch);
 404                 }
 405                 if (nq)
 406                         appendStringInfoChar(&buf, '"');
 407         }
 408
 409         appendStringInfoChar(&buf, ')');
 410
 411         pfree(values);
 412         pfree(nulls);
 413         ReleaseTupleDesc(tupdesc);
 414
 415         PG_RETURN_CSTRING(buf.data);
 416 }
 417
 418 /*
 419  * record_recv          - binary input routine for any composite type.
 420  */
 421 Datum
 422 record_recv(PG_FUNCTION_ARGS)
 423 {
 424         StringInfo      buf = (StringInfo) PG_GETARG_POINTER(0);
 425         Oid                     tupType = PG_GETARG_OID(1);
 426
 427 #ifdef NOT_USED
 428         int32           typmod = PG_GETARG_INT32(2);
 429 #endif
 430         HeapTupleHeader result;
 431         int32           tupTypmod;
 432         TupleDesc       tupdesc;
 433         HeapTuple       tuple;
 434         RecordIOData *my_extra;
 435         int                     ncolumns;
 436         int                     usercols;
 437         int                     validcols;
 438         int                     i;
 439         Datum      *values;
 440         char       *nulls;
 441
 442         /*
 443          * Use the passed type unless it's RECORD; we can't support input of
 444          * anonymous types, mainly because there's no good way to figure out which
 445          * anonymous type is wanted.  Note that for RECORD, what we'll probably
 446          * actually get is RECORD's typelem, ie, zero.
 447          */
 448         if (tupType == InvalidOid || tupType == RECORDOID)
 449                 ereport(ERROR,
 450                                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 451                    errmsg("input of anonymous composite types is not implemented")));
 452         tupTypmod = -1;                         /* for all non-anonymous types */
 453         tupdesc = lookup_rowtype_tupdesc(tupType, tupTypmod);
 454         ncolumns = tupdesc->natts;
 455
 456         /*
 457          * We arrange to look up the needed I/O info just once per series of
 458          * calls, assuming the record type doesn't change underneath us.
 459          */
 460         my_extra = (RecordIOData *) fcinfo->flinfo->fn_extra;
 461         if (my_extra == NULL ||
 462                 my_extra->ncolumns != ncolumns)
 463         {
 464                 fcinfo->flinfo->fn_extra =
 465                         MemoryContextAlloc(fcinfo->flinfo->fn_mcxt,
 466                                                            sizeof(RecordIOData) - sizeof(ColumnIOData)
 467                                                            + ncolumns * sizeof(ColumnIOData));
 468                 my_extra = (RecordIOData *) fcinfo->flinfo->fn_extra;
 469                 my_extra->record_type = InvalidOid;
 470                 my_extra->record_typmod = 0;
 471         }
 472
 473         if (my_extra->record_type != tupType ||
 474                 my_extra->record_typmod != tupTypmod)
 475         {
 476                 MemSet(my_extra, 0,
 477                            sizeof(RecordIOData) - sizeof(ColumnIOData)
 478                            + ncolumns * sizeof(ColumnIOData));
 479                 my_extra->record_type = tupType;
 480                 my_extra->record_typmod = tupTypmod;
 481                 my_extra->ncolumns = ncolumns;
 482         }
 483
 484         values = (Datum *) palloc(ncolumns * sizeof(Datum));
 485         nulls = (char *) palloc(ncolumns * sizeof(char));
 486
 487         /* Fetch number of columns user thinks it has */
 488         usercols = pq_getmsgint(buf, 4);
 489
 490         /* Need to scan to count nondeleted columns */
 491         validcols = 0;
 492         for (i = 0; i < ncolumns; i++)
 493         {
 494                 if (!tupdesc->attrs[i]->attisdropped)
 495                         validcols++;
 496         }
 497         if (usercols != validcols)
 498                 ereport(ERROR,
 499                                 (errcode(ERRCODE_DATATYPE_MISMATCH),
 500                                  errmsg("wrong number of columns: %d, expected %d",
 501                                                 usercols, validcols)));
 502
 503         /* Process each column */
 504         for (i = 0; i < ncolumns; i++)
 505         {
 506                 ColumnIOData *column_info = &my_extra->columns[i];
 507                 Oid                     column_type = tupdesc->attrs[i]->atttypid;
 508                 Oid                     coltypoid;
 509                 int                     itemlen;
 510                 StringInfoData item_buf;
 511                 StringInfo      bufptr;
 512                 char            csave;
 513
 514                 /* Ignore dropped columns in datatype, but fill with nulls */
 515                 if (tupdesc->attrs[i]->attisdropped)
 516                 {
 517                         values[i] = (Datum) 0;
 518                         nulls[i] = 'n';
 519                         continue;
 520                 }
 521
 522                 /* Verify column datatype */
 523                 coltypoid = pq_getmsgint(buf, sizeof(Oid));
 524                 if (coltypoid != column_type)
 525                         ereport(ERROR,
 526                                         (errcode(ERRCODE_DATATYPE_MISMATCH),
 527                                          errmsg("wrong data type: %u, expected %u",
 528                                                         coltypoid, column_type)));
 529
 530                 /* Get and check the item length */
 531                 itemlen = pq_getmsgint(buf, 4);
 532                 if (itemlen < -1 || itemlen > (buf->len - buf->cursor))
 533                         ereport(ERROR,
 534                                         (errcode(ERRCODE_INVALID_BINARY_REPRESENTATION),
 535                                          errmsg("insufficient data left in message")));
 536
 537                 if (itemlen == -1)
 538                 {
 539                         /* -1 length means NULL */
 540                         bufptr = NULL;
 541                         nulls[i] = 'n';
 542                         csave = 0;                      /* keep compiler quiet */
 543                 }
 544                 else
 545                 {
 546                         /*
 547                          * Rather than copying data around, we just set up a phony
 548                          * StringInfo pointing to the correct portion of the input buffer.
 549                          * We assume we can scribble on the input buffer so as to maintain
 550                          * the convention that StringInfos have a trailing null.
 551                          */
 552                         item_buf.data = &buf->data[buf->cursor];
 553                         item_buf.maxlen = itemlen + 1;
 554                         item_buf.len = itemlen;
 555                         item_buf.cursor = 0;
 556
 557                         buf->cursor += itemlen;
 558
 559                         csave = buf->data[buf->cursor];
 560                         buf->data[buf->cursor] = '\0';
 561
 562                         bufptr = &item_buf;
 563                         nulls[i] = ' ';
 564                 }
 565
 566                 /* Now call the column's receiveproc */
 567                 if (column_info->column_type != column_type)
 568                 {
 569                         getTypeBinaryInputInfo(column_type,
 570                                                                    &column_info->typiofunc,
 571                                                                    &column_info->typioparam);
 572                         fmgr_info_cxt(column_info->typiofunc, &column_info->proc,
 573                                                   fcinfo->flinfo->fn_mcxt);
 574                         column_info->column_type = column_type;
 575                 }
 576
 577                 values[i] = ReceiveFunctionCall(&column_info->proc,
 578                                                                                 bufptr,
 579                                                                                 column_info->typioparam,
 580                                                                                 tupdesc->attrs[i]->atttypmod);
 581
 582                 if (bufptr)
 583                 {
 584                         /* Trouble if it didn't eat the whole buffer */
 585                         if (item_buf.cursor != itemlen)
 586                                 ereport(ERROR,
 587                                                 (errcode(ERRCODE_INVALID_BINARY_REPRESENTATION),
 588                                                  errmsg("improper binary format in record column %d",
 589                                                                 i + 1)));
 590
 591                         buf->data[buf->cursor] = csave;
 592                 }
 593         }
 594
 595         tuple = heap_formtuple(tupdesc, values, nulls);
 596
 597         /*
 598          * We cannot return tuple->t_data because heap_formtuple allocates it as
 599          * part of a larger chunk, and our caller may expect to be able to pfree
 600          * our result.  So must copy the info into a new palloc chunk.
 601          */
 602         result = (HeapTupleHeader) palloc(tuple->t_len);
 603         memcpy(result, tuple->t_data, tuple->t_len);
 604
 605         heap_freetuple(tuple);
 606         pfree(values);
 607         pfree(nulls);
 608         ReleaseTupleDesc(tupdesc);
 609
 610         PG_RETURN_HEAPTUPLEHEADER(result);
 611 }
 612
 613 /*
 614  * record_send          - binary output routine for any composite type.
 615  */
 616 Datum
 617 record_send(PG_FUNCTION_ARGS)
 618 {
 619         HeapTupleHeader rec = PG_GETARG_HEAPTUPLEHEADER(0);
 620         Oid                     tupType;
 621         int32           tupTypmod;
 622         TupleDesc       tupdesc;
 623         HeapTupleData tuple;
 624         RecordIOData *my_extra;
 625         int                     ncolumns;
 626         int                     validcols;
 627         int                     i;
 628         Datum      *values;
 629         char       *nulls;
 630         StringInfoData buf;
 631
 632         /* Extract type info from the tuple itself */
 633         tupType = HeapTupleHeaderGetTypeId(rec);
 634         tupTypmod = HeapTupleHeaderGetTypMod(rec);
 635         tupdesc = lookup_rowtype_tupdesc(tupType, tupTypmod);
 636         ncolumns = tupdesc->natts;
 637
 638         /* Build a temporary HeapTuple control structure */
 639         tuple.t_len = HeapTupleHeaderGetDatumLength(rec);
 640         ItemPointerSetInvalid(&(tuple.t_self));
 641         tuple.t_tableOid = InvalidOid;
 642         tuple.t_data = rec;
 643
 644         /*
 645          * We arrange to look up the needed I/O info just once per series of
 646          * calls, assuming the record type doesn't change underneath us.
 647          */
 648         my_extra = (RecordIOData *) fcinfo->flinfo->fn_extra;
 649         if (my_extra == NULL ||
 650                 my_extra->ncolumns != ncolumns)
 651         {
 652                 fcinfo->flinfo->fn_extra =
 653                         MemoryContextAlloc(fcinfo->flinfo->fn_mcxt,
 654                                                            sizeof(RecordIOData) - sizeof(ColumnIOData)
 655                                                            + ncolumns * sizeof(ColumnIOData));
 656                 my_extra = (RecordIOData *) fcinfo->flinfo->fn_extra;
 657                 my_extra->record_type = InvalidOid;
 658                 my_extra->record_typmod = 0;
 659         }
 660
 661         if (my_extra->record_type != tupType ||
 662                 my_extra->record_typmod != tupTypmod)
 663         {
 664                 MemSet(my_extra, 0,
 665                            sizeof(RecordIOData) - sizeof(ColumnIOData)
 666                            + ncolumns * sizeof(ColumnIOData));
 667                 my_extra->record_type = tupType;
 668                 my_extra->record_typmod = tupTypmod;
 669                 my_extra->ncolumns = ncolumns;
 670         }
 671
 672         values = (Datum *) palloc(ncolumns * sizeof(Datum));
 673         nulls = (char *) palloc(ncolumns * sizeof(char));
 674
 675         /* Break down the tuple into fields */
 676         heap_deformtuple(&tuple, tupdesc, values, nulls);
 677
 678         /* And build the result string */
 679         pq_begintypsend(&buf);
 680
 681         /* Need to scan to count nondeleted columns */
 682         validcols = 0;
 683         for (i = 0; i < ncolumns; i++)
 684         {
 685                 if (!tupdesc->attrs[i]->attisdropped)
 686                         validcols++;
 687         }
 688         pq_sendint(&buf, validcols, 4);
 689
 690         for (i = 0; i < ncolumns; i++)
 691         {
 692                 ColumnIOData *column_info = &my_extra->columns[i];
 693                 Oid                     column_type = tupdesc->attrs[i]->atttypid;
 694                 bytea      *outputbytes;
 695
 696                 /* Ignore dropped columns in datatype */
 697                 if (tupdesc->attrs[i]->attisdropped)
 698                         continue;
 699
 700                 pq_sendint(&buf, column_type, sizeof(Oid));
 701
 702                 if (nulls[i] == 'n')
 703                 {
 704                         /* emit -1 data length to signify a NULL */
 705                         pq_sendint(&buf, -1, 4);
 706                         continue;
 707                 }
 708
 709                 /*
 710                  * Convert the column value to binary
 711                  */
 712                 if (column_info->column_type != column_type)
 713                 {
 714                         bool            typIsVarlena;
 715
 716                         getTypeBinaryOutputInfo(column_type,
 717                                                                         &column_info->typiofunc,
 718                                                                         &typIsVarlena);
 719                         fmgr_info_cxt(column_info->typiofunc, &column_info->proc,
 720                                                   fcinfo->flinfo->fn_mcxt);
 721                         column_info->column_type = column_type;
 722                 }
 723
 724                 outputbytes = SendFunctionCall(&column_info->proc, values[i]);
 725
 726                 /* We assume the result will not have been toasted */
 727                 pq_sendint(&buf, VARSIZE(outputbytes) - VARHDRSZ, 4);
 728                 pq_sendbytes(&buf, VARDATA(outputbytes),
 729                                          VARSIZE(outputbytes) - VARHDRSZ);
 730                 pfree(outputbytes);
 731         }
 732
 733         pfree(values);
 734         pfree(nulls);
 735         ReleaseTupleDesc(tupdesc);
 736
 737         PG_RETURN_BYTEA_P(pq_endtypsend(&buf));
 738 }