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 :
26 :
27 : static void printtup_startup(DestReceiver *self, int operation,
28 : TupleDesc typeinfo);
29 : static bool printtup(TupleTableSlot *slot, DestReceiver *self);
30 : static void printtup_shutdown(DestReceiver *self);
31 : static void printtup_destroy(DestReceiver *self);
32 :
33 : /* ----------------------------------------------------------------
34 : * printtup / debugtup support
35 : * ----------------------------------------------------------------
36 : */
37 :
38 : /* ----------------
39 : * Private state for a printtup destination object
40 : *
41 : * NOTE: finfo is the lookup info for either typoutput or typsend, whichever
42 : * we are using for this column.
43 : * ----------------
44 : */
45 : typedef struct
46 : { /* Per-attribute information */
47 : Oid typoutput; /* Oid for the type's text output fn */
48 : Oid typsend; /* Oid for the type's binary output fn */
49 : bool typisvarlena; /* is it varlena (ie possibly toastable)? */
50 : int16 format; /* format code for this column */
51 : FmgrInfo finfo; /* Precomputed call info for output fn */
52 : } PrinttupAttrInfo;
53 :
54 : typedef struct
55 : {
56 : DestReceiver pub; /* publicly-known function pointers */
57 : Portal portal; /* the Portal we are printing from */
58 : bool sendDescrip; /* send RowDescription at startup? */
59 : TupleDesc attrinfo; /* The attr info we are set up for */
60 : int nattrs;
61 : PrinttupAttrInfo *myinfo; /* Cached info about each attr */
62 : StringInfoData buf; /* output buffer (*not* in tmpcontext) */
63 : MemoryContext tmpcontext; /* Memory context for per-row workspace */
64 : } DR_printtup;
65 :
66 : /* ----------------
67 : * Initialize: create a DestReceiver for printtup
68 : * ----------------
69 : */
70 : DestReceiver *
71 658420 : printtup_create_DR(CommandDest dest)
72 : {
73 658420 : DR_printtup *self = (DR_printtup *) palloc0(sizeof(DR_printtup));
74 :
75 658420 : self->pub.receiveSlot = printtup; /* might get changed later */
76 658420 : self->pub.rStartup = printtup_startup;
77 658420 : self->pub.rShutdown = printtup_shutdown;
78 658420 : self->pub.rDestroy = printtup_destroy;
79 658420 : self->pub.mydest = dest;
80 :
81 : /*
82 : * Send T message automatically if DestRemote, but not if
83 : * DestRemoteExecute
84 : */
85 658420 : self->sendDescrip = (dest == DestRemote);
86 :
87 658420 : self->attrinfo = NULL;
88 658420 : self->nattrs = 0;
89 658420 : self->myinfo = NULL;
90 658420 : self->buf.data = NULL;
91 658420 : self->tmpcontext = NULL;
92 :
93 658420 : return (DestReceiver *) self;
94 : }
95 :
96 : /*
97 : * Set parameters for a DestRemote (or DestRemoteExecute) receiver
98 : */
99 : void
100 658420 : SetRemoteDestReceiverParams(DestReceiver *self, Portal portal)
101 : {
102 658420 : DR_printtup *myState = (DR_printtup *) self;
103 :
104 : Assert(myState->pub.mydest == DestRemote ||
105 : myState->pub.mydest == DestRemoteExecute);
106 :
107 658420 : myState->portal = portal;
108 658420 : }
109 :
110 : static void
111 318902 : printtup_startup(DestReceiver *self, int operation, TupleDesc typeinfo)
112 : {
113 318902 : DR_printtup *myState = (DR_printtup *) self;
114 318902 : Portal portal = myState->portal;
115 :
116 : /*
117 : * Create I/O buffer to be used for all messages. This cannot be inside
118 : * tmpcontext, since we want to re-use it across rows.
119 : */
120 318902 : initStringInfo(&myState->buf);
121 :
122 : /*
123 : * Create a temporary memory context that we can reset once per row to
124 : * recover palloc'd memory. This avoids any problems with leaks inside
125 : * datatype output routines, and should be faster than retail pfree's
126 : * anyway.
127 : */
128 318902 : myState->tmpcontext = AllocSetContextCreate(CurrentMemoryContext,
129 : "printtup",
130 : ALLOCSET_DEFAULT_SIZES);
131 :
132 : /*
133 : * If we are supposed to emit row descriptions, then send the tuple
134 : * descriptor of the tuples.
135 : */
136 318902 : if (myState->sendDescrip)
137 310006 : SendRowDescriptionMessage(&myState->buf,
138 : typeinfo,
139 : FetchPortalTargetList(portal),
140 : portal->formats);
141 :
142 : /* ----------------
143 : * We could set up the derived attr info at this time, but we postpone it
144 : * until the first call of printtup, for 2 reasons:
145 : * 1. We don't waste time (compared to the old way) if there are no
146 : * tuples at all to output.
147 : * 2. Checking in printtup allows us to handle the case that the tuples
148 : * change type midway through (although this probably can't happen in
149 : * the current executor).
150 : * ----------------
151 : */
152 318902 : }
153 :
154 : /*
155 : * SendRowDescriptionMessage --- send a RowDescription message to the frontend
156 : *
157 : * Notes: the TupleDesc has typically been manufactured by ExecTypeFromTL()
158 : * or some similar function; it does not contain a full set of fields.
159 : * The targetlist will be NIL when executing a utility function that does
160 : * not have a plan. If the targetlist isn't NIL then it is a Query node's
161 : * targetlist; it is up to us to ignore resjunk columns in it. The formats[]
162 : * array pointer might be NULL (if we are doing Describe on a prepared stmt);
163 : * send zeroes for the format codes in that case.
164 : */
165 : void
166 319036 : SendRowDescriptionMessage(StringInfo buf, TupleDesc typeinfo,
167 : List *targetlist, int16 *formats)
168 : {
169 319036 : int natts = typeinfo->natts;
170 : int i;
171 319036 : ListCell *tlist_item = list_head(targetlist);
172 :
173 : /* tuple descriptor message type */
174 319036 : pq_beginmessage_reuse(buf, PqMsg_RowDescription);
175 : /* # of attrs in tuples */
176 319036 : pq_sendint16(buf, natts);
177 :
178 : /*
179 : * Preallocate memory for the entire message to be sent. That allows to
180 : * use the significantly faster inline pqformat.h functions and to avoid
181 : * reallocations.
182 : *
183 : * Have to overestimate the size of the column-names, to account for
184 : * character set overhead.
185 : */
186 319036 : enlargeStringInfo(buf, (NAMEDATALEN * MAX_CONVERSION_GROWTH /* attname */
187 : + sizeof(Oid) /* resorigtbl */
188 : + sizeof(AttrNumber) /* resorigcol */
189 : + sizeof(Oid) /* atttypid */
190 : + sizeof(int16) /* attlen */
191 : + sizeof(int32) /* attypmod */
192 : + sizeof(int16) /* format */
193 : ) * natts);
194 :
195 1389550 : for (i = 0; i < natts; ++i)
196 : {
197 1070514 : Form_pg_attribute att = TupleDescAttr(typeinfo, i);
198 1070514 : Oid atttypid = att->atttypid;
199 1070514 : int32 atttypmod = att->atttypmod;
200 : Oid resorigtbl;
201 : AttrNumber resorigcol;
202 : int16 format;
203 :
204 : /*
205 : * If column is a domain, send the base type and typmod instead.
206 : * Lookup before sending any ints, for efficiency.
207 : */
208 1070514 : atttypid = getBaseTypeAndTypmod(atttypid, &atttypmod);
209 :
210 : /* Do we have a non-resjunk tlist item? */
211 1070514 : while (tlist_item &&
212 1053960 : ((TargetEntry *) lfirst(tlist_item))->resjunk)
213 0 : tlist_item = lnext(targetlist, tlist_item);
214 1070514 : if (tlist_item)
215 : {
216 1053960 : TargetEntry *tle = (TargetEntry *) lfirst(tlist_item);
217 :
218 1053960 : resorigtbl = tle->resorigtbl;
219 1053960 : resorigcol = tle->resorigcol;
220 1053960 : tlist_item = lnext(targetlist, tlist_item);
221 : }
222 : else
223 : {
224 : /* No info available, so send zeroes */
225 16554 : resorigtbl = 0;
226 16554 : resorigcol = 0;
227 : }
228 :
229 1070514 : if (formats)
230 1070086 : format = formats[i];
231 : else
232 428 : format = 0;
233 :
234 1070514 : pq_writestring(buf, NameStr(att->attname));
235 1070514 : pq_writeint32(buf, resorigtbl);
236 1070514 : pq_writeint16(buf, resorigcol);
237 1070514 : pq_writeint32(buf, atttypid);
238 1070514 : pq_writeint16(buf, att->attlen);
239 1070514 : pq_writeint32(buf, atttypmod);
240 1070514 : pq_writeint16(buf, format);
241 : }
242 :
243 319036 : pq_endmessage_reuse(buf);
244 319036 : }
245 :
246 : /*
247 : * Get the lookup info that printtup() needs
248 : */
249 : static void
250 262980 : printtup_prepare_info(DR_printtup *myState, TupleDesc typeinfo, int numAttrs)
251 : {
252 262980 : int16 *formats = myState->portal->formats;
253 : int i;
254 :
255 : /* get rid of any old data */
256 262980 : if (myState->myinfo)
257 1614 : pfree(myState->myinfo);
258 262980 : myState->myinfo = NULL;
259 :
260 262980 : myState->attrinfo = typeinfo;
261 262980 : myState->nattrs = numAttrs;
262 262980 : if (numAttrs <= 0)
263 196 : return;
264 :
265 262784 : myState->myinfo = (PrinttupAttrInfo *)
266 262784 : palloc0(numAttrs * sizeof(PrinttupAttrInfo));
267 :
268 1096554 : for (i = 0; i < numAttrs; i++)
269 : {
270 833770 : PrinttupAttrInfo *thisState = myState->myinfo + i;
271 833770 : int16 format = (formats ? formats[i] : 0);
272 833770 : Form_pg_attribute attr = TupleDescAttr(typeinfo, i);
273 :
274 833770 : thisState->format = format;
275 833770 : if (format == 0)
276 : {
277 833684 : getTypeOutputInfo(attr->atttypid,
278 : &thisState->typoutput,
279 : &thisState->typisvarlena);
280 833684 : fmgr_info(thisState->typoutput, &thisState->finfo);
281 : }
282 86 : else if (format == 1)
283 : {
284 86 : getTypeBinaryOutputInfo(attr->atttypid,
285 : &thisState->typsend,
286 : &thisState->typisvarlena);
287 86 : fmgr_info(thisState->typsend, &thisState->finfo);
288 : }
289 : else
290 0 : ereport(ERROR,
291 : (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
292 : errmsg("unsupported format code: %d", format)));
293 : }
294 : }
295 :
296 : /* ----------------
297 : * printtup --- send a tuple to the client
298 : *
299 : * Note: if you change this function, see also serializeAnalyzeReceive
300 : * in explain.c, which is meant to replicate the computations done here.
301 : * ----------------
302 : */
303 : static bool
304 7999778 : printtup(TupleTableSlot *slot, DestReceiver *self)
305 : {
306 7999778 : TupleDesc typeinfo = slot->tts_tupleDescriptor;
307 7999778 : DR_printtup *myState = (DR_printtup *) self;
308 : MemoryContext oldcontext;
309 7999778 : StringInfo buf = &myState->buf;
310 7999778 : int natts = typeinfo->natts;
311 : int i;
312 :
313 : /* Set or update my derived attribute info, if needed */
314 7999778 : if (myState->attrinfo != typeinfo || myState->nattrs != natts)
315 262980 : printtup_prepare_info(myState, typeinfo, natts);
316 :
317 : /* Make sure the tuple is fully deconstructed */
318 7999778 : slot_getallattrs(slot);
319 :
320 : /* Switch into per-row context so we can recover memory below */
321 7999778 : oldcontext = MemoryContextSwitchTo(myState->tmpcontext);
322 :
323 : /*
324 : * Prepare a DataRow message (note buffer is in per-query context)
325 : */
326 7999778 : pq_beginmessage_reuse(buf, PqMsg_DataRow);
327 :
328 7999778 : pq_sendint16(buf, natts);
329 :
330 : /*
331 : * send the attributes of this tuple
332 : */
333 48607580 : for (i = 0; i < natts; ++i)
334 : {
335 40607802 : PrinttupAttrInfo *thisState = myState->myinfo + i;
336 40607802 : Datum attr = slot->tts_values[i];
337 :
338 40607802 : if (slot->tts_isnull[i])
339 : {
340 2437564 : pq_sendint32(buf, -1);
341 2437564 : continue;
342 : }
343 :
344 : /*
345 : * Here we catch undefined bytes in datums that are returned to the
346 : * client without hitting disk; see comments at the related check in
347 : * PageAddItem(). This test is most useful for uncompressed,
348 : * non-external datums, but we're quite likely to see such here when
349 : * testing new C functions.
350 : */
351 38170238 : if (thisState->typisvarlena)
352 : VALGRIND_CHECK_MEM_IS_DEFINED(DatumGetPointer(attr),
353 : VARSIZE_ANY(attr));
354 :
355 38170238 : if (thisState->format == 0)
356 : {
357 : /* Text output */
358 : char *outputstr;
359 :
360 38155614 : outputstr = OutputFunctionCall(&thisState->finfo, attr);
361 38155614 : pq_sendcountedtext(buf, outputstr, strlen(outputstr));
362 : }
363 : else
364 : {
365 : /* Binary output */
366 : bytea *outputbytes;
367 :
368 14624 : outputbytes = SendFunctionCall(&thisState->finfo, attr);
369 14624 : pq_sendint32(buf, VARSIZE(outputbytes) - VARHDRSZ);
370 14624 : pq_sendbytes(buf, VARDATA(outputbytes),
371 14624 : VARSIZE(outputbytes) - VARHDRSZ);
372 : }
373 : }
374 :
375 7999778 : pq_endmessage_reuse(buf);
376 :
377 : /* Return to caller's context, and flush row's temporary memory */
378 7999778 : MemoryContextSwitchTo(oldcontext);
379 7999778 : MemoryContextReset(myState->tmpcontext);
380 :
381 7999778 : return true;
382 : }
383 :
384 : /* ----------------
385 : * printtup_shutdown
386 : * ----------------
387 : */
388 : static void
389 311728 : printtup_shutdown(DestReceiver *self)
390 : {
391 311728 : DR_printtup *myState = (DR_printtup *) self;
392 :
393 311728 : if (myState->myinfo)
394 260974 : pfree(myState->myinfo);
395 311728 : myState->myinfo = NULL;
396 :
397 311728 : myState->attrinfo = NULL;
398 :
399 311728 : if (myState->buf.data)
400 311728 : pfree(myState->buf.data);
401 311728 : myState->buf.data = NULL;
402 :
403 311728 : if (myState->tmpcontext)
404 311728 : MemoryContextDelete(myState->tmpcontext);
405 311728 : myState->tmpcontext = NULL;
406 311728 : }
407 :
408 : /* ----------------
409 : * printtup_destroy
410 : * ----------------
411 : */
412 : static void
413 630262 : printtup_destroy(DestReceiver *self)
414 : {
415 630262 : pfree(self);
416 630262 : }
417 :
418 : /* ----------------
419 : * printatt
420 : * ----------------
421 : */
422 : static void
423 376 : printatt(unsigned attributeId,
424 : Form_pg_attribute attributeP,
425 : char *value)
426 : {
427 376 : printf("\t%2d: %s%s%s%s\t(typeid = %u, len = %d, typmod = %d, byval = %c)\n",
428 : attributeId,
429 : NameStr(attributeP->attname),
430 : value != NULL ? " = \"" : "",
431 : value != NULL ? value : "",
432 : value != NULL ? "\"" : "",
433 : (unsigned int) (attributeP->atttypid),
434 : attributeP->attlen,
435 : attributeP->atttypmod,
436 : attributeP->attbyval ? 't' : 'f');
437 376 : }
438 :
439 : /* ----------------
440 : * debugStartup - prepare to print tuples for an interactive backend
441 : * ----------------
442 : */
443 : void
444 188 : debugStartup(DestReceiver *self, int operation, TupleDesc typeinfo)
445 : {
446 188 : int natts = typeinfo->natts;
447 : int i;
448 :
449 : /*
450 : * show the return type of the tuples
451 : */
452 376 : for (i = 0; i < natts; ++i)
453 188 : printatt((unsigned) i + 1, TupleDescAttr(typeinfo, i), NULL);
454 188 : printf("\t----\n");
455 188 : }
456 :
457 : /* ----------------
458 : * debugtup - print one tuple for an interactive backend
459 : * ----------------
460 : */
461 : bool
462 188 : debugtup(TupleTableSlot *slot, DestReceiver *self)
463 : {
464 188 : TupleDesc typeinfo = slot->tts_tupleDescriptor;
465 188 : int natts = typeinfo->natts;
466 : int i;
467 : Datum attr;
468 : char *value;
469 : bool isnull;
470 : Oid typoutput;
471 : bool typisvarlena;
472 :
473 376 : for (i = 0; i < natts; ++i)
474 : {
475 188 : attr = slot_getattr(slot, i + 1, &isnull);
476 188 : if (isnull)
477 0 : continue;
478 188 : getTypeOutputInfo(TupleDescAttr(typeinfo, i)->atttypid,
479 : &typoutput, &typisvarlena);
480 :
481 188 : value = OidOutputFunctionCall(typoutput, attr);
482 :
483 188 : printatt((unsigned) i + 1, TupleDescAttr(typeinfo, i), value);
484 : }
485 188 : printf("\t----\n");
486 :
487 188 : return true;
488 : }
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