Line data Source code
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) 1996-2025, 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/pqformat.h"
20 : #include "libpq/protocol.h"
21 : #include "tcop/pquery.h"
22 : #include "utils/lsyscache.h"
23 : #include "utils/memdebug.h"
24 : #include "utils/memutils.h"
25 : #include "varatt.h"
26 :
27 :
28 : static void printtup_startup(DestReceiver *self, int operation,
29 : TupleDesc typeinfo);
30 : static bool printtup(TupleTableSlot *slot, DestReceiver *self);
31 : static void printtup_shutdown(DestReceiver *self);
32 : static void printtup_destroy(DestReceiver *self);
33 :
34 : /* ----------------------------------------------------------------
35 : * printtup / debugtup support
36 : * ----------------------------------------------------------------
37 : */
38 :
39 : /* ----------------
40 : * Private state for a printtup destination object
41 : *
42 : * NOTE: finfo is the lookup info for either typoutput or typsend, whichever
43 : * we are using for this column.
44 : * ----------------
45 : */
46 : typedef struct
47 : { /* Per-attribute information */
48 : Oid typoutput; /* Oid for the type's text output fn */
49 : Oid typsend; /* Oid for the type's binary output fn */
50 : bool typisvarlena; /* is it varlena (ie possibly toastable)? */
51 : int16 format; /* format code for this column */
52 : FmgrInfo finfo; /* Precomputed call info for output fn */
53 : } PrinttupAttrInfo;
54 :
55 : typedef struct
56 : {
57 : DestReceiver pub; /* publicly-known function pointers */
58 : Portal portal; /* the Portal we are printing from */
59 : bool sendDescrip; /* send RowDescription at startup? */
60 : TupleDesc attrinfo; /* The attr info we are set up for */
61 : int nattrs;
62 : PrinttupAttrInfo *myinfo; /* Cached info about each attr */
63 : StringInfoData buf; /* output buffer (*not* in tmpcontext) */
64 : MemoryContext tmpcontext; /* Memory context for per-row workspace */
65 : } DR_printtup;
66 :
67 : /* ----------------
68 : * Initialize: create a DestReceiver for printtup
69 : * ----------------
70 : */
71 : DestReceiver *
72 627582 : printtup_create_DR(CommandDest dest)
73 : {
74 627582 : DR_printtup *self = (DR_printtup *) palloc0(sizeof(DR_printtup));
75 :
76 627582 : self->pub.receiveSlot = printtup; /* might get changed later */
77 627582 : self->pub.rStartup = printtup_startup;
78 627582 : self->pub.rShutdown = printtup_shutdown;
79 627582 : self->pub.rDestroy = printtup_destroy;
80 627582 : self->pub.mydest = dest;
81 :
82 : /*
83 : * Send T message automatically if DestRemote, but not if
84 : * DestRemoteExecute
85 : */
86 627582 : self->sendDescrip = (dest == DestRemote);
87 :
88 627582 : self->attrinfo = NULL;
89 627582 : self->nattrs = 0;
90 627582 : self->myinfo = NULL;
91 627582 : self->buf.data = NULL;
92 627582 : self->tmpcontext = NULL;
93 :
94 627582 : return (DestReceiver *) self;
95 : }
96 :
97 : /*
98 : * Set parameters for a DestRemote (or DestRemoteExecute) receiver
99 : */
100 : void
101 627582 : SetRemoteDestReceiverParams(DestReceiver *self, Portal portal)
102 : {
103 627582 : DR_printtup *myState = (DR_printtup *) self;
104 :
105 : Assert(myState->pub.mydest == DestRemote ||
106 : myState->pub.mydest == DestRemoteExecute);
107 :
108 627582 : myState->portal = portal;
109 627582 : }
110 :
111 : static void
112 307100 : printtup_startup(DestReceiver *self, int operation, TupleDesc typeinfo)
113 : {
114 307100 : DR_printtup *myState = (DR_printtup *) self;
115 307100 : Portal portal = myState->portal;
116 :
117 : /*
118 : * Create I/O buffer to be used for all messages. This cannot be inside
119 : * tmpcontext, since we want to re-use it across rows.
120 : */
121 307100 : initStringInfo(&myState->buf);
122 :
123 : /*
124 : * Create a temporary memory context that we can reset once per row to
125 : * recover palloc'd memory. This avoids any problems with leaks inside
126 : * datatype output routines, and should be faster than retail pfree's
127 : * anyway.
128 : */
129 307100 : myState->tmpcontext = AllocSetContextCreate(CurrentMemoryContext,
130 : "printtup",
131 : ALLOCSET_DEFAULT_SIZES);
132 :
133 : /*
134 : * If we are supposed to emit row descriptions, then send the tuple
135 : * descriptor of the tuples.
136 : */
137 307100 : if (myState->sendDescrip)
138 296866 : SendRowDescriptionMessage(&myState->buf,
139 : typeinfo,
140 : FetchPortalTargetList(portal),
141 : portal->formats);
142 :
143 : /* ----------------
144 : * We could set up the derived attr info at this time, but we postpone it
145 : * until the first call of printtup, for 2 reasons:
146 : * 1. We don't waste time (compared to the old way) if there are no
147 : * tuples at all to output.
148 : * 2. Checking in printtup allows us to handle the case that the tuples
149 : * change type midway through (although this probably can't happen in
150 : * the current executor).
151 : * ----------------
152 : */
153 307100 : }
154 :
155 : /*
156 : * SendRowDescriptionMessage --- send a RowDescription message to the frontend
157 : *
158 : * Notes: the TupleDesc has typically been manufactured by ExecTypeFromTL()
159 : * or some similar function; it does not contain a full set of fields.
160 : * The targetlist will be NIL when executing a utility function that does
161 : * not have a plan. If the targetlist isn't NIL then it is a Query node's
162 : * targetlist; it is up to us to ignore resjunk columns in it. The formats[]
163 : * array pointer might be NULL (if we are doing Describe on a prepared stmt);
164 : * send zeroes for the format codes in that case.
165 : */
166 : void
167 307234 : SendRowDescriptionMessage(StringInfo buf, TupleDesc typeinfo,
168 : List *targetlist, int16 *formats)
169 : {
170 307234 : int natts = typeinfo->natts;
171 : int i;
172 307234 : ListCell *tlist_item = list_head(targetlist);
173 :
174 : /* tuple descriptor message type */
175 307234 : pq_beginmessage_reuse(buf, PqMsg_RowDescription);
176 : /* # of attrs in tuples */
177 307234 : pq_sendint16(buf, natts);
178 :
179 : /*
180 : * Preallocate memory for the entire message to be sent. That allows to
181 : * use the significantly faster inline pqformat.h functions and to avoid
182 : * reallocations.
183 : *
184 : * Have to overestimate the size of the column-names, to account for
185 : * character set overhead.
186 : */
187 307234 : enlargeStringInfo(buf, (NAMEDATALEN * MAX_CONVERSION_GROWTH /* attname */
188 : + sizeof(Oid) /* resorigtbl */
189 : + sizeof(AttrNumber) /* resorigcol */
190 : + sizeof(Oid) /* atttypid */
191 : + sizeof(int16) /* attlen */
192 : + sizeof(int32) /* attypmod */
193 : + sizeof(int16) /* format */
194 : ) * natts);
195 :
196 1288542 : for (i = 0; i < natts; ++i)
197 : {
198 981308 : Form_pg_attribute att = TupleDescAttr(typeinfo, i);
199 981308 : Oid atttypid = att->atttypid;
200 981308 : int32 atttypmod = att->atttypmod;
201 : Oid resorigtbl;
202 : AttrNumber resorigcol;
203 : int16 format;
204 :
205 : /*
206 : * If column is a domain, send the base type and typmod instead.
207 : * Lookup before sending any ints, for efficiency.
208 : */
209 981308 : atttypid = getBaseTypeAndTypmod(atttypid, &atttypmod);
210 :
211 : /* Do we have a non-resjunk tlist item? */
212 981308 : while (tlist_item &&
213 964150 : ((TargetEntry *) lfirst(tlist_item))->resjunk)
214 0 : tlist_item = lnext(targetlist, tlist_item);
215 981308 : if (tlist_item)
216 : {
217 964150 : TargetEntry *tle = (TargetEntry *) lfirst(tlist_item);
218 :
219 964150 : resorigtbl = tle->resorigtbl;
220 964150 : resorigcol = tle->resorigcol;
221 964150 : tlist_item = lnext(targetlist, tlist_item);
222 : }
223 : else
224 : {
225 : /* No info available, so send zeroes */
226 17158 : resorigtbl = 0;
227 17158 : resorigcol = 0;
228 : }
229 :
230 981308 : if (formats)
231 980880 : format = formats[i];
232 : else
233 428 : format = 0;
234 :
235 981308 : pq_writestring(buf, NameStr(att->attname));
236 981308 : pq_writeint32(buf, resorigtbl);
237 981308 : pq_writeint16(buf, resorigcol);
238 981308 : pq_writeint32(buf, atttypid);
239 981308 : pq_writeint16(buf, att->attlen);
240 981308 : pq_writeint32(buf, atttypmod);
241 981308 : pq_writeint16(buf, format);
242 : }
243 :
244 307234 : pq_endmessage_reuse(buf);
245 307234 : }
246 :
247 : /*
248 : * Get the lookup info that printtup() needs
249 : */
250 : static void
251 254408 : printtup_prepare_info(DR_printtup *myState, TupleDesc typeinfo, int numAttrs)
252 : {
253 254408 : int16 *formats = myState->portal->formats;
254 : int i;
255 :
256 : /* get rid of any old data */
257 254408 : if (myState->myinfo)
258 2022 : pfree(myState->myinfo);
259 254408 : myState->myinfo = NULL;
260 :
261 254408 : myState->attrinfo = typeinfo;
262 254408 : myState->nattrs = numAttrs;
263 254408 : if (numAttrs <= 0)
264 322 : return;
265 :
266 254086 : myState->myinfo = (PrinttupAttrInfo *)
267 254086 : palloc0(numAttrs * sizeof(PrinttupAttrInfo));
268 :
269 1021452 : for (i = 0; i < numAttrs; i++)
270 : {
271 767366 : PrinttupAttrInfo *thisState = myState->myinfo + i;
272 767366 : int16 format = (formats ? formats[i] : 0);
273 767366 : Form_pg_attribute attr = TupleDescAttr(typeinfo, i);
274 :
275 767366 : thisState->format = format;
276 767366 : if (format == 0)
277 : {
278 767280 : getTypeOutputInfo(attr->atttypid,
279 : &thisState->typoutput,
280 : &thisState->typisvarlena);
281 767280 : fmgr_info(thisState->typoutput, &thisState->finfo);
282 : }
283 86 : else if (format == 1)
284 : {
285 86 : getTypeBinaryOutputInfo(attr->atttypid,
286 : &thisState->typsend,
287 : &thisState->typisvarlena);
288 86 : fmgr_info(thisState->typsend, &thisState->finfo);
289 : }
290 : else
291 0 : ereport(ERROR,
292 : (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
293 : errmsg("unsupported format code: %d", format)));
294 : }
295 : }
296 :
297 : /* ----------------
298 : * printtup --- send a tuple to the client
299 : *
300 : * Note: if you change this function, see also serializeAnalyzeReceive
301 : * in explain.c, which is meant to replicate the computations done here.
302 : * ----------------
303 : */
304 : static bool
305 6913140 : printtup(TupleTableSlot *slot, DestReceiver *self)
306 : {
307 6913140 : TupleDesc typeinfo = slot->tts_tupleDescriptor;
308 6913140 : DR_printtup *myState = (DR_printtup *) self;
309 : MemoryContext oldcontext;
310 6913140 : StringInfo buf = &myState->buf;
311 6913140 : int natts = typeinfo->natts;
312 : int i;
313 :
314 : /* Set or update my derived attribute info, if needed */
315 6913140 : if (myState->attrinfo != typeinfo || myState->nattrs != natts)
316 254408 : printtup_prepare_info(myState, typeinfo, natts);
317 :
318 : /* Make sure the tuple is fully deconstructed */
319 6913140 : slot_getallattrs(slot);
320 :
321 : /* Switch into per-row context so we can recover memory below */
322 6913140 : oldcontext = MemoryContextSwitchTo(myState->tmpcontext);
323 :
324 : /*
325 : * Prepare a DataRow message (note buffer is in per-query context)
326 : */
327 6913140 : pq_beginmessage_reuse(buf, PqMsg_DataRow);
328 :
329 6913140 : pq_sendint16(buf, natts);
330 :
331 : /*
332 : * send the attributes of this tuple
333 : */
334 41340718 : for (i = 0; i < natts; ++i)
335 : {
336 34427578 : PrinttupAttrInfo *thisState = myState->myinfo + i;
337 34427578 : Datum attr = slot->tts_values[i];
338 :
339 34427578 : if (slot->tts_isnull[i])
340 : {
341 1979950 : pq_sendint32(buf, -1);
342 1979950 : continue;
343 : }
344 :
345 : /*
346 : * Here we catch undefined bytes in datums that are returned to the
347 : * client without hitting disk; see comments at the related check in
348 : * PageAddItem(). This test is most useful for uncompressed,
349 : * non-external datums, but we're quite likely to see such here when
350 : * testing new C functions.
351 : */
352 32447628 : if (thisState->typisvarlena)
353 : VALGRIND_CHECK_MEM_IS_DEFINED(DatumGetPointer(attr),
354 : VARSIZE_ANY(DatumGetPointer(attr)));
355 :
356 32447628 : if (thisState->format == 0)
357 : {
358 : /* Text output */
359 : char *outputstr;
360 :
361 32433484 : outputstr = OutputFunctionCall(&thisState->finfo, attr);
362 32433484 : pq_sendcountedtext(buf, outputstr, strlen(outputstr));
363 : }
364 : else
365 : {
366 : /* Binary output */
367 : bytea *outputbytes;
368 :
369 14144 : outputbytes = SendFunctionCall(&thisState->finfo, attr);
370 14144 : pq_sendint32(buf, VARSIZE(outputbytes) - VARHDRSZ);
371 14144 : pq_sendbytes(buf, VARDATA(outputbytes),
372 14144 : VARSIZE(outputbytes) - VARHDRSZ);
373 : }
374 : }
375 :
376 6913140 : pq_endmessage_reuse(buf);
377 :
378 : /* Return to caller's context, and flush row's temporary memory */
379 6913140 : MemoryContextSwitchTo(oldcontext);
380 6913140 : MemoryContextReset(myState->tmpcontext);
381 :
382 6913140 : return true;
383 : }
384 :
385 : /* ----------------
386 : * printtup_shutdown
387 : * ----------------
388 : */
389 : static void
390 299736 : printtup_shutdown(DestReceiver *self)
391 : {
392 299736 : DR_printtup *myState = (DR_printtup *) self;
393 :
394 299736 : if (myState->myinfo)
395 251868 : pfree(myState->myinfo);
396 299736 : myState->myinfo = NULL;
397 :
398 299736 : myState->attrinfo = NULL;
399 :
400 299736 : if (myState->buf.data)
401 299736 : pfree(myState->buf.data);
402 299736 : myState->buf.data = NULL;
403 :
404 299736 : if (myState->tmpcontext)
405 299736 : MemoryContextDelete(myState->tmpcontext);
406 299736 : myState->tmpcontext = NULL;
407 299736 : }
408 :
409 : /* ----------------
410 : * printtup_destroy
411 : * ----------------
412 : */
413 : static void
414 599188 : printtup_destroy(DestReceiver *self)
415 : {
416 599188 : pfree(self);
417 599188 : }
418 :
419 : /* ----------------
420 : * printatt
421 : * ----------------
422 : */
423 : static void
424 428 : printatt(unsigned attributeId,
425 : Form_pg_attribute attributeP,
426 : char *value)
427 : {
428 428 : printf("\t%2d: %s%s%s%s\t(typeid = %u, len = %d, typmod = %d, byval = %c)\n",
429 : attributeId,
430 : NameStr(attributeP->attname),
431 : value != NULL ? " = \"" : "",
432 : value != NULL ? value : "",
433 : value != NULL ? "\"" : "",
434 : (unsigned int) (attributeP->atttypid),
435 : attributeP->attlen,
436 : attributeP->atttypmod,
437 : attributeP->attbyval ? 't' : 'f');
438 428 : }
439 :
440 : /* ----------------
441 : * debugStartup - prepare to print tuples for an interactive backend
442 : * ----------------
443 : */
444 : void
445 212 : debugStartup(DestReceiver *self, int operation, TupleDesc typeinfo)
446 : {
447 212 : int natts = typeinfo->natts;
448 : int i;
449 :
450 : /*
451 : * show the return type of the tuples
452 : */
453 424 : for (i = 0; i < natts; ++i)
454 212 : printatt((unsigned) i + 1, TupleDescAttr(typeinfo, i), NULL);
455 212 : printf("\t----\n");
456 212 : }
457 :
458 : /* ----------------
459 : * debugtup - print one tuple for an interactive backend
460 : * ----------------
461 : */
462 : bool
463 216 : debugtup(TupleTableSlot *slot, DestReceiver *self)
464 : {
465 216 : TupleDesc typeinfo = slot->tts_tupleDescriptor;
466 216 : int natts = typeinfo->natts;
467 : int i;
468 : Datum attr;
469 : char *value;
470 : bool isnull;
471 : Oid typoutput;
472 : bool typisvarlena;
473 :
474 432 : for (i = 0; i < natts; ++i)
475 : {
476 216 : attr = slot_getattr(slot, i + 1, &isnull);
477 216 : if (isnull)
478 0 : continue;
479 216 : getTypeOutputInfo(TupleDescAttr(typeinfo, i)->atttypid,
480 : &typoutput, &typisvarlena);
481 :
482 216 : value = OidOutputFunctionCall(typoutput, attr);
483 :
484 216 : printatt((unsigned) i + 1, TupleDescAttr(typeinfo, i), value);
485 : }
486 216 : printf("\t----\n");
487 :
488 216 : return true;
489 : }
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