1 /*-------------------------------------------------------------------------
2 *
3 * printtup.c
4 * Routines to print out tuples to the destination (both frontend
5 * clients and standalone backends are supported here).
6 *
7 *
8 * Portions Copyright (c) 1996-2017, PostgreSQL Global Development Group
9 * Portions Copyright (c) 1994, Regents of the University of California
10 *
11 * IDENTIFICATION
12 * src/backend/access/common/printtup.c
13 *
14 *-------------------------------------------------------------------------
15 */
16 #include "postgres.h"
17
18 #include "access/printtup.h"
19 #include "libpq/libpq.h"
20 #include "libpq/pqformat.h"
21 #include "tcop/pquery.h"
22 #include "utils/lsyscache.h"
23 #include "utils/memdebug.h"
24 #include "utils/memutils.h"
25
26
27 static void printtup_startup(DestReceiver *self, int operation,
28 TupleDesc typeinfo);
29 static bool printtup(TupleTableSlot *slot, DestReceiver *self);
30 static bool printtup_20(TupleTableSlot *slot, DestReceiver *self);
31 static bool printtup_internal_20(TupleTableSlot *slot, DestReceiver *self);
32 static void printtup_shutdown(DestReceiver *self);
33 static void printtup_destroy(DestReceiver *self);
34
35
36 /* ----------------------------------------------------------------
37 * printtup / debugtup support
38 * ----------------------------------------------------------------
39 */
40
41 /* ----------------
42 * Private state for a printtup destination object
43 *
44 * NOTE: finfo is the lookup info for either typoutput or typsend, whichever
45 * we are using for this column.
46 * ----------------
47 */
48 typedef struct
49 { /* Per-attribute information */
50 Oid typoutput; /* Oid for the type's text output fn */
51 Oid typsend; /* Oid for the type's binary output fn */
52 bool typisvarlena; /* is it varlena (ie possibly toastable)? */
53 int16 format; /* format code for this column */
54 FmgrInfo finfo; /* Precomputed call info for output fn */
55 } PrinttupAttrInfo;
56
57 typedef struct
58 {
59 DestReceiver pub; /* publicly-known function pointers */
60 Portal portal; /* the Portal we are printing from */
61 bool sendDescrip; /* send RowDescription at startup? */
62 TupleDesc attrinfo; /* The attr info we are set up for */
63 int nattrs;
64 PrinttupAttrInfo *myinfo; /* Cached info about each attr */
65 MemoryContext tmpcontext; /* Memory context for per-row workspace */
66 } DR_printtup;
67
68 /* ----------------
69 * Initialize: create a DestReceiver for printtup
70 * ----------------
71 */
72 DestReceiver *
printtup_create_DR(CommandDest dest)73 printtup_create_DR(CommandDest dest)
74 {
75 DR_printtup *self = (DR_printtup *) palloc0(sizeof(DR_printtup));
76
77 self->pub.receiveSlot = printtup; /* might get changed later */
78 self->pub.rStartup = printtup_startup;
79 self->pub.rShutdown = printtup_shutdown;
80 self->pub.rDestroy = printtup_destroy;
81 self->pub.mydest = dest;
82
83 /*
84 * Send T message automatically if DestRemote, but not if
85 * DestRemoteExecute
86 */
87 self->sendDescrip = (dest == DestRemote);
88
89 self->attrinfo = NULL;
90 self->nattrs = 0;
91 self->myinfo = NULL;
92 self->tmpcontext = NULL;
93
94 return (DestReceiver *) self;
95 }
96
97 /*
98 * Set parameters for a DestRemote (or DestRemoteExecute) receiver
99 */
100 void
SetRemoteDestReceiverParams(DestReceiver * self,Portal portal)101 SetRemoteDestReceiverParams(DestReceiver *self, Portal portal)
102 {
103 DR_printtup *myState = (DR_printtup *) self;
104
105 Assert(myState->pub.mydest == DestRemote ||
106 myState->pub.mydest == DestRemoteExecute);
107
108 myState->portal = portal;
109
110 if (PG_PROTOCOL_MAJOR(FrontendProtocol) < 3)
111 {
112 /*
113 * In protocol 2.0 the Bind message does not exist, so there is no way
114 * for the columns to have different print formats; it's sufficient to
115 * look at the first one.
116 */
117 if (portal->formats && portal->formats[0] != 0)
118 myState->pub.receiveSlot = printtup_internal_20;
119 else
120 myState->pub.receiveSlot = printtup_20;
121 }
122 }
123
124 static void
printtup_startup(DestReceiver * self,int operation,TupleDesc typeinfo)125 printtup_startup(DestReceiver *self, int operation, TupleDesc typeinfo)
126 {
127 DR_printtup *myState = (DR_printtup *) self;
128 Portal portal = myState->portal;
129
130 /*
131 * Create a temporary memory context that we can reset once per row to
132 * recover palloc'd memory. This avoids any problems with leaks inside
133 * datatype output routines, and should be faster than retail pfree's
134 * anyway.
135 */
136 myState->tmpcontext = AllocSetContextCreate(CurrentMemoryContext,
137 "printtup",
138 ALLOCSET_DEFAULT_SIZES);
139
140 if (PG_PROTOCOL_MAJOR(FrontendProtocol) < 3)
141 {
142 /*
143 * Send portal name to frontend (obsolete cruft, gone in proto 3.0)
144 *
145 * If portal name not specified, use "blank" portal.
146 */
147 const char *portalName = portal->name;
148
149 if (portalName == NULL || portalName[0] == '\0')
150 portalName = "blank";
151
152 pq_puttextmessage('P', portalName);
153 }
154
155 /*
156 * If we are supposed to emit row descriptions, then send the tuple
157 * descriptor of the tuples.
158 */
159 if (myState->sendDescrip)
160 SendRowDescriptionMessage(typeinfo,
161 FetchPortalTargetList(portal),
162 portal->formats);
163
164 /* ----------------
165 * We could set up the derived attr info at this time, but we postpone it
166 * until the first call of printtup, for 2 reasons:
167 * 1. We don't waste time (compared to the old way) if there are no
168 * tuples at all to output.
169 * 2. Checking in printtup allows us to handle the case that the tuples
170 * change type midway through (although this probably can't happen in
171 * the current executor).
172 * ----------------
173 */
174 }
175
176 /*
177 * SendRowDescriptionMessage --- send a RowDescription message to the frontend
178 *
179 * Notes: the TupleDesc has typically been manufactured by ExecTypeFromTL()
180 * or some similar function; it does not contain a full set of fields.
181 * The targetlist will be NIL when executing a utility function that does
182 * not have a plan. If the targetlist isn't NIL then it is a Query node's
183 * targetlist; it is up to us to ignore resjunk columns in it. The formats[]
184 * array pointer might be NULL (if we are doing Describe on a prepared stmt);
185 * send zeroes for the format codes in that case.
186 */
187 void
SendRowDescriptionMessage(TupleDesc typeinfo,List * targetlist,int16 * formats)188 SendRowDescriptionMessage(TupleDesc typeinfo, List *targetlist, int16 *formats)
189 {
190 Form_pg_attribute *attrs = typeinfo->attrs;
191 int natts = typeinfo->natts;
192 int proto = PG_PROTOCOL_MAJOR(FrontendProtocol);
193 int i;
194 StringInfoData buf;
195 ListCell *tlist_item = list_head(targetlist);
196
197 pq_beginmessage(&buf, 'T'); /* tuple descriptor message type */
198 pq_sendint(&buf, natts, 2); /* # of attrs in tuples */
199
200 for (i = 0; i < natts; ++i)
201 {
202 Oid atttypid = attrs[i]->atttypid;
203 int32 atttypmod = attrs[i]->atttypmod;
204
205 pq_sendstring(&buf, NameStr(attrs[i]->attname));
206 /* column ID info appears in protocol 3.0 and up */
207 if (proto >= 3)
208 {
209 /* Do we have a non-resjunk tlist item? */
210 while (tlist_item &&
211 ((TargetEntry *) lfirst(tlist_item))->resjunk)
212 tlist_item = lnext(tlist_item);
213 if (tlist_item)
214 {
215 TargetEntry *tle = (TargetEntry *) lfirst(tlist_item);
216
217 pq_sendint(&buf, tle->resorigtbl, 4);
218 pq_sendint(&buf, tle->resorigcol, 2);
219 tlist_item = lnext(tlist_item);
220 }
221 else
222 {
223 /* No info available, so send zeroes */
224 pq_sendint(&buf, 0, 4);
225 pq_sendint(&buf, 0, 2);
226 }
227 }
228 /* If column is a domain, send the base type and typmod instead */
229 atttypid = getBaseTypeAndTypmod(atttypid, &atttypmod);
230 pq_sendint(&buf, (int) atttypid, sizeof(atttypid));
231 pq_sendint(&buf, attrs[i]->attlen, sizeof(attrs[i]->attlen));
232 pq_sendint(&buf, atttypmod, sizeof(atttypmod));
233 /* format info appears in protocol 3.0 and up */
234 if (proto >= 3)
235 {
236 if (formats)
237 pq_sendint(&buf, formats[i], 2);
238 else
239 pq_sendint(&buf, 0, 2);
240 }
241 }
242 pq_endmessage(&buf);
243 }
244
245 /*
246 * Get the lookup info that printtup() needs
247 */
248 static void
printtup_prepare_info(DR_printtup * myState,TupleDesc typeinfo,int numAttrs)249 printtup_prepare_info(DR_printtup *myState, TupleDesc typeinfo, int numAttrs)
250 {
251 int16 *formats = myState->portal->formats;
252 int i;
253
254 /* get rid of any old data */
255 if (myState->myinfo)
256 pfree(myState->myinfo);
257 myState->myinfo = NULL;
258
259 myState->attrinfo = typeinfo;
260 myState->nattrs = numAttrs;
261 if (numAttrs <= 0)
262 return;
263
264 myState->myinfo = (PrinttupAttrInfo *)
265 palloc0(numAttrs * sizeof(PrinttupAttrInfo));
266
267 for (i = 0; i < numAttrs; i++)
268 {
269 PrinttupAttrInfo *thisState = myState->myinfo + i;
270 int16 format = (formats ? formats[i] : 0);
271
272 thisState->format = format;
273 if (format == 0)
274 {
275 getTypeOutputInfo(typeinfo->attrs[i]->atttypid,
276 &thisState->typoutput,
277 &thisState->typisvarlena);
278 fmgr_info(thisState->typoutput, &thisState->finfo);
279 }
280 else if (format == 1)
281 {
282 getTypeBinaryOutputInfo(typeinfo->attrs[i]->atttypid,
283 &thisState->typsend,
284 &thisState->typisvarlena);
285 fmgr_info(thisState->typsend, &thisState->finfo);
286 }
287 else
288 ereport(ERROR,
289 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
290 errmsg("unsupported format code: %d", format)));
291 }
292 }
293
294 /* ----------------
295 * printtup --- print a tuple in protocol 3.0
296 * ----------------
297 */
298 static bool
printtup(TupleTableSlot * slot,DestReceiver * self)299 printtup(TupleTableSlot *slot, DestReceiver *self)
300 {
301 TupleDesc typeinfo = slot->tts_tupleDescriptor;
302 DR_printtup *myState = (DR_printtup *) self;
303 MemoryContext oldcontext;
304 StringInfoData buf;
305 int natts = typeinfo->natts;
306 int i;
307
308 /* Set or update my derived attribute info, if needed */
309 if (myState->attrinfo != typeinfo || myState->nattrs != natts)
310 printtup_prepare_info(myState, typeinfo, natts);
311
312 /* Make sure the tuple is fully deconstructed */
313 slot_getallattrs(slot);
314
315 /* Switch into per-row context so we can recover memory below */
316 oldcontext = MemoryContextSwitchTo(myState->tmpcontext);
317
318 /*
319 * Prepare a DataRow message (note buffer is in per-row context)
320 */
321 pq_beginmessage(&buf, 'D');
322
323 pq_sendint(&buf, natts, 2);
324
325 /*
326 * send the attributes of this tuple
327 */
328 for (i = 0; i < natts; ++i)
329 {
330 PrinttupAttrInfo *thisState = myState->myinfo + i;
331 Datum attr = slot->tts_values[i];
332
333 if (slot->tts_isnull[i])
334 {
335 pq_sendint(&buf, -1, 4);
336 continue;
337 }
338
339 /*
340 * Here we catch undefined bytes in datums that are returned to the
341 * client without hitting disk; see comments at the related check in
342 * PageAddItem(). This test is most useful for uncompressed,
343 * non-external datums, but we're quite likely to see such here when
344 * testing new C functions.
345 */
346 if (thisState->typisvarlena)
347 VALGRIND_CHECK_MEM_IS_DEFINED(DatumGetPointer(attr),
348 VARSIZE_ANY(attr));
349
350 if (thisState->format == 0)
351 {
352 /* Text output */
353 char *outputstr;
354
355 outputstr = OutputFunctionCall(&thisState->finfo, attr);
356 pq_sendcountedtext(&buf, outputstr, strlen(outputstr), false);
357 }
358 else
359 {
360 /* Binary output */
361 bytea *outputbytes;
362
363 outputbytes = SendFunctionCall(&thisState->finfo, attr);
364 pq_sendint(&buf, VARSIZE(outputbytes) - VARHDRSZ, 4);
365 pq_sendbytes(&buf, VARDATA(outputbytes),
366 VARSIZE(outputbytes) - VARHDRSZ);
367 }
368 }
369
370 pq_endmessage(&buf);
371
372 /* Return to caller's context, and flush row's temporary memory */
373 MemoryContextSwitchTo(oldcontext);
374 MemoryContextReset(myState->tmpcontext);
375
376 return true;
377 }
378
379 /* ----------------
380 * printtup_20 --- print a tuple in protocol 2.0
381 * ----------------
382 */
383 static bool
printtup_20(TupleTableSlot * slot,DestReceiver * self)384 printtup_20(TupleTableSlot *slot, DestReceiver *self)
385 {
386 TupleDesc typeinfo = slot->tts_tupleDescriptor;
387 DR_printtup *myState = (DR_printtup *) self;
388 MemoryContext oldcontext;
389 StringInfoData buf;
390 int natts = typeinfo->natts;
391 int i,
392 j,
393 k;
394
395 /* Set or update my derived attribute info, if needed */
396 if (myState->attrinfo != typeinfo || myState->nattrs != natts)
397 printtup_prepare_info(myState, typeinfo, natts);
398
399 /* Make sure the tuple is fully deconstructed */
400 slot_getallattrs(slot);
401
402 /* Switch into per-row context so we can recover memory below */
403 oldcontext = MemoryContextSwitchTo(myState->tmpcontext);
404
405 /*
406 * tell the frontend to expect new tuple data (in ASCII style)
407 */
408 pq_beginmessage(&buf, 'D');
409
410 /*
411 * send a bitmap of which attributes are not null
412 */
413 j = 0;
414 k = 1 << 7;
415 for (i = 0; i < natts; ++i)
416 {
417 if (!slot->tts_isnull[i])
418 j |= k; /* set bit if not null */
419 k >>= 1;
420 if (k == 0) /* end of byte? */
421 {
422 pq_sendint(&buf, j, 1);
423 j = 0;
424 k = 1 << 7;
425 }
426 }
427 if (k != (1 << 7)) /* flush last partial byte */
428 pq_sendint(&buf, j, 1);
429
430 /*
431 * send the attributes of this tuple
432 */
433 for (i = 0; i < natts; ++i)
434 {
435 PrinttupAttrInfo *thisState = myState->myinfo + i;
436 Datum attr = slot->tts_values[i];
437 char *outputstr;
438
439 if (slot->tts_isnull[i])
440 continue;
441
442 Assert(thisState->format == 0);
443
444 outputstr = OutputFunctionCall(&thisState->finfo, attr);
445 pq_sendcountedtext(&buf, outputstr, strlen(outputstr), true);
446 }
447
448 pq_endmessage(&buf);
449
450 /* Return to caller's context, and flush row's temporary memory */
451 MemoryContextSwitchTo(oldcontext);
452 MemoryContextReset(myState->tmpcontext);
453
454 return true;
455 }
456
457 /* ----------------
458 * printtup_shutdown
459 * ----------------
460 */
461 static void
printtup_shutdown(DestReceiver * self)462 printtup_shutdown(DestReceiver *self)
463 {
464 DR_printtup *myState = (DR_printtup *) self;
465
466 if (myState->myinfo)
467 pfree(myState->myinfo);
468 myState->myinfo = NULL;
469
470 myState->attrinfo = NULL;
471
472 if (myState->tmpcontext)
473 MemoryContextDelete(myState->tmpcontext);
474 myState->tmpcontext = NULL;
475 }
476
477 /* ----------------
478 * printtup_destroy
479 * ----------------
480 */
481 static void
printtup_destroy(DestReceiver * self)482 printtup_destroy(DestReceiver *self)
483 {
484 pfree(self);
485 }
486
487 /* ----------------
488 * printatt
489 * ----------------
490 */
491 static void
printatt(unsigned attributeId,Form_pg_attribute attributeP,char * value)492 printatt(unsigned attributeId,
493 Form_pg_attribute attributeP,
494 char *value)
495 {
496 printf("\t%2d: %s%s%s%s\t(typeid = %u, len = %d, typmod = %d, byval = %c)\n",
497 attributeId,
498 NameStr(attributeP->attname),
499 value != NULL ? " = \"" : "",
500 value != NULL ? value : "",
501 value != NULL ? "\"" : "",
502 (unsigned int) (attributeP->atttypid),
503 attributeP->attlen,
504 attributeP->atttypmod,
505 attributeP->attbyval ? 't' : 'f');
506 }
507
508 /* ----------------
509 * debugStartup - prepare to print tuples for an interactive backend
510 * ----------------
511 */
512 void
debugStartup(DestReceiver * self,int operation,TupleDesc typeinfo)513 debugStartup(DestReceiver *self, int operation, TupleDesc typeinfo)
514 {
515 int natts = typeinfo->natts;
516 Form_pg_attribute *attinfo = typeinfo->attrs;
517 int i;
518
519 /*
520 * show the return type of the tuples
521 */
522 for (i = 0; i < natts; ++i)
523 printatt((unsigned) i + 1, attinfo[i], NULL);
524 printf("\t----\n");
525 }
526
527 /* ----------------
528 * debugtup - print one tuple for an interactive backend
529 * ----------------
530 */
531 bool
debugtup(TupleTableSlot * slot,DestReceiver * self)532 debugtup(TupleTableSlot *slot, DestReceiver *self)
533 {
534 TupleDesc typeinfo = slot->tts_tupleDescriptor;
535 int natts = typeinfo->natts;
536 int i;
537 Datum attr;
538 char *value;
539 bool isnull;
540 Oid typoutput;
541 bool typisvarlena;
542
543 for (i = 0; i < natts; ++i)
544 {
545 attr = slot_getattr(slot, i + 1, &isnull);
546 if (isnull)
547 continue;
548 getTypeOutputInfo(typeinfo->attrs[i]->atttypid,
549 &typoutput, &typisvarlena);
550
551 value = OidOutputFunctionCall(typoutput, attr);
552
553 printatt((unsigned) i + 1, typeinfo->attrs[i], value);
554 }
555 printf("\t----\n");
556
557 return true;
558 }
559
560 /* ----------------
561 * printtup_internal_20 --- print a binary tuple in protocol 2.0
562 *
563 * We use a different message type, i.e. 'B' instead of 'D' to
564 * indicate a tuple in internal (binary) form.
565 *
566 * This is largely same as printtup_20, except we use binary formatting.
567 * ----------------
568 */
569 static bool
printtup_internal_20(TupleTableSlot * slot,DestReceiver * self)570 printtup_internal_20(TupleTableSlot *slot, DestReceiver *self)
571 {
572 TupleDesc typeinfo = slot->tts_tupleDescriptor;
573 DR_printtup *myState = (DR_printtup *) self;
574 MemoryContext oldcontext;
575 StringInfoData buf;
576 int natts = typeinfo->natts;
577 int i,
578 j,
579 k;
580
581 /* Set or update my derived attribute info, if needed */
582 if (myState->attrinfo != typeinfo || myState->nattrs != natts)
583 printtup_prepare_info(myState, typeinfo, natts);
584
585 /* Make sure the tuple is fully deconstructed */
586 slot_getallattrs(slot);
587
588 /* Switch into per-row context so we can recover memory below */
589 oldcontext = MemoryContextSwitchTo(myState->tmpcontext);
590
591 /*
592 * tell the frontend to expect new tuple data (in binary style)
593 */
594 pq_beginmessage(&buf, 'B');
595
596 /*
597 * send a bitmap of which attributes are not null
598 */
599 j = 0;
600 k = 1 << 7;
601 for (i = 0; i < natts; ++i)
602 {
603 if (!slot->tts_isnull[i])
604 j |= k; /* set bit if not null */
605 k >>= 1;
606 if (k == 0) /* end of byte? */
607 {
608 pq_sendint(&buf, j, 1);
609 j = 0;
610 k = 1 << 7;
611 }
612 }
613 if (k != (1 << 7)) /* flush last partial byte */
614 pq_sendint(&buf, j, 1);
615
616 /*
617 * send the attributes of this tuple
618 */
619 for (i = 0; i < natts; ++i)
620 {
621 PrinttupAttrInfo *thisState = myState->myinfo + i;
622 Datum attr = slot->tts_values[i];
623 bytea *outputbytes;
624
625 if (slot->tts_isnull[i])
626 continue;
627
628 Assert(thisState->format == 1);
629
630 outputbytes = SendFunctionCall(&thisState->finfo, attr);
631 pq_sendint(&buf, VARSIZE(outputbytes) - VARHDRSZ, 4);
632 pq_sendbytes(&buf, VARDATA(outputbytes),
633 VARSIZE(outputbytes) - VARHDRSZ);
634 }
635
636 pq_endmessage(&buf);
637
638 /* Return to caller's context, and flush row's temporary memory */
639 MemoryContextSwitchTo(oldcontext);
640 MemoryContextReset(myState->tmpcontext);
641
642 return true;
643 }
644