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) 1996-2024, 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 "tcop/pquery.h"
21 : #include "utils/lsyscache.h"
22 : #include "utils/memdebug.h"
23 : #include "utils/memutils.h"
24 :
25 :
26 : static void printtup_startup(DestReceiver *self, int operation,
27 : TupleDesc typeinfo);
28 : static bool printtup(TupleTableSlot *slot, DestReceiver *self);
29 : static void printtup_shutdown(DestReceiver *self);
30 : static void printtup_destroy(DestReceiver *self);
31 :
32 : /* ----------------------------------------------------------------
33 : * printtup / debugtup support
34 : * ----------------------------------------------------------------
35 : */
36 :
37 : /* ----------------
38 : * Private state for a printtup destination object
39 : *
40 : * NOTE: finfo is the lookup info for either typoutput or typsend, whichever
41 : * we are using for this column.
42 : * ----------------
43 : */
44 : typedef struct
45 : { /* Per-attribute information */
46 : Oid typoutput; /* Oid for the type's text output fn */
47 : Oid typsend; /* Oid for the type's binary output fn */
48 : bool typisvarlena; /* is it varlena (ie possibly toastable)? */
49 : int16 format; /* format code for this column */
50 : FmgrInfo finfo; /* Precomputed call info for output fn */
51 : } PrinttupAttrInfo;
52 :
53 : typedef struct
54 : {
55 : DestReceiver pub; /* publicly-known function pointers */
56 : Portal portal; /* the Portal we are printing from */
57 : bool sendDescrip; /* send RowDescription at startup? */
58 : TupleDesc attrinfo; /* The attr info we are set up for */
59 : int nattrs;
60 : PrinttupAttrInfo *myinfo; /* Cached info about each attr */
61 : StringInfoData buf; /* output buffer (*not* in tmpcontext) */
62 : MemoryContext tmpcontext; /* Memory context for per-row workspace */
63 : } DR_printtup;
64 :
65 : /* ----------------
66 : * Initialize: create a DestReceiver for printtup
67 : * ----------------
68 : */
69 : DestReceiver *
70 564660 : printtup_create_DR(CommandDest dest)
71 : {
72 564660 : DR_printtup *self = (DR_printtup *) palloc0(sizeof(DR_printtup));
73 :
74 564660 : self->pub.receiveSlot = printtup; /* might get changed later */
75 564660 : self->pub.rStartup = printtup_startup;
76 564660 : self->pub.rShutdown = printtup_shutdown;
77 564660 : self->pub.rDestroy = printtup_destroy;
78 564660 : self->pub.mydest = dest;
79 :
80 : /*
81 : * Send T message automatically if DestRemote, but not if
82 : * DestRemoteExecute
83 : */
84 564660 : self->sendDescrip = (dest == DestRemote);
85 :
86 564660 : self->attrinfo = NULL;
87 564660 : self->nattrs = 0;
88 564660 : self->myinfo = NULL;
89 564660 : self->buf.data = NULL;
90 564660 : self->tmpcontext = NULL;
91 :
92 564660 : return (DestReceiver *) self;
93 : }
94 :
95 : /*
96 : * Set parameters for a DestRemote (or DestRemoteExecute) receiver
97 : */
98 : void
99 564660 : SetRemoteDestReceiverParams(DestReceiver *self, Portal portal)
100 : {
101 564660 : DR_printtup *myState = (DR_printtup *) self;
102 :
103 : Assert(myState->pub.mydest == DestRemote ||
104 : myState->pub.mydest == DestRemoteExecute);
105 :
106 564660 : myState->portal = portal;
107 564660 : }
108 :
109 : static void
110 261902 : printtup_startup(DestReceiver *self, int operation, TupleDesc typeinfo)
111 : {
112 261902 : DR_printtup *myState = (DR_printtup *) self;
113 261902 : Portal portal = myState->portal;
114 :
115 : /*
116 : * Create I/O buffer to be used for all messages. This cannot be inside
117 : * tmpcontext, since we want to re-use it across rows.
118 : */
119 261902 : initStringInfo(&myState->buf);
120 :
121 : /*
122 : * Create a temporary memory context that we can reset once per row to
123 : * recover palloc'd memory. This avoids any problems with leaks inside
124 : * datatype output routines, and should be faster than retail pfree's
125 : * anyway.
126 : */
127 261902 : myState->tmpcontext = AllocSetContextCreate(CurrentMemoryContext,
128 : "printtup",
129 : ALLOCSET_DEFAULT_SIZES);
130 :
131 : /*
132 : * If we are supposed to emit row descriptions, then send the tuple
133 : * descriptor of the tuples.
134 : */
135 261902 : if (myState->sendDescrip)
136 254036 : SendRowDescriptionMessage(&myState->buf,
137 : typeinfo,
138 : FetchPortalTargetList(portal),
139 : portal->formats);
140 :
141 : /* ----------------
142 : * We could set up the derived attr info at this time, but we postpone it
143 : * until the first call of printtup, for 2 reasons:
144 : * 1. We don't waste time (compared to the old way) if there are no
145 : * tuples at all to output.
146 : * 2. Checking in printtup allows us to handle the case that the tuples
147 : * change type midway through (although this probably can't happen in
148 : * the current executor).
149 : * ----------------
150 : */
151 261902 : }
152 :
153 : /*
154 : * SendRowDescriptionMessage --- send a RowDescription message to the frontend
155 : *
156 : * Notes: the TupleDesc has typically been manufactured by ExecTypeFromTL()
157 : * or some similar function; it does not contain a full set of fields.
158 : * The targetlist will be NIL when executing a utility function that does
159 : * not have a plan. If the targetlist isn't NIL then it is a Query node's
160 : * targetlist; it is up to us to ignore resjunk columns in it. The formats[]
161 : * array pointer might be NULL (if we are doing Describe on a prepared stmt);
162 : * send zeroes for the format codes in that case.
163 : */
164 : void
165 262036 : SendRowDescriptionMessage(StringInfo buf, TupleDesc typeinfo,
166 : List *targetlist, int16 *formats)
167 : {
168 262036 : int natts = typeinfo->natts;
169 : int i;
170 262036 : ListCell *tlist_item = list_head(targetlist);
171 :
172 : /* tuple descriptor message type */
173 262036 : pq_beginmessage_reuse(buf, 'T');
174 : /* # of attrs in tuples */
175 262036 : pq_sendint16(buf, natts);
176 :
177 : /*
178 : * Preallocate memory for the entire message to be sent. That allows to
179 : * use the significantly faster inline pqformat.h functions and to avoid
180 : * reallocations.
181 : *
182 : * Have to overestimate the size of the column-names, to account for
183 : * character set overhead.
184 : */
185 262036 : enlargeStringInfo(buf, (NAMEDATALEN * MAX_CONVERSION_GROWTH /* attname */
186 : + sizeof(Oid) /* resorigtbl */
187 : + sizeof(AttrNumber) /* resorigcol */
188 : + sizeof(Oid) /* atttypid */
189 : + sizeof(int16) /* attlen */
190 : + sizeof(int32) /* attypmod */
191 : + sizeof(int16) /* format */
192 : ) * natts);
193 :
194 1062052 : for (i = 0; i < natts; ++i)
195 : {
196 800016 : Form_pg_attribute att = TupleDescAttr(typeinfo, i);
197 800016 : Oid atttypid = att->atttypid;
198 800016 : int32 atttypmod = att->atttypmod;
199 : Oid resorigtbl;
200 : AttrNumber resorigcol;
201 : int16 format;
202 :
203 : /*
204 : * If column is a domain, send the base type and typmod instead.
205 : * Lookup before sending any ints, for efficiency.
206 : */
207 800016 : atttypid = getBaseTypeAndTypmod(atttypid, &atttypmod);
208 :
209 : /* Do we have a non-resjunk tlist item? */
210 800016 : while (tlist_item &&
211 785420 : ((TargetEntry *) lfirst(tlist_item))->resjunk)
212 0 : tlist_item = lnext(targetlist, tlist_item);
213 800016 : if (tlist_item)
214 : {
215 785420 : TargetEntry *tle = (TargetEntry *) lfirst(tlist_item);
216 :
217 785420 : resorigtbl = tle->resorigtbl;
218 785420 : resorigcol = tle->resorigcol;
219 785420 : tlist_item = lnext(targetlist, tlist_item);
220 : }
221 : else
222 : {
223 : /* No info available, so send zeroes */
224 14596 : resorigtbl = 0;
225 14596 : resorigcol = 0;
226 : }
227 :
228 800016 : if (formats)
229 799660 : format = formats[i];
230 : else
231 356 : format = 0;
232 :
233 800016 : pq_writestring(buf, NameStr(att->attname));
234 800016 : pq_writeint32(buf, resorigtbl);
235 800016 : pq_writeint16(buf, resorigcol);
236 800016 : pq_writeint32(buf, atttypid);
237 800016 : pq_writeint16(buf, att->attlen);
238 800016 : pq_writeint32(buf, atttypmod);
239 800016 : pq_writeint16(buf, format);
240 : }
241 :
242 262036 : pq_endmessage_reuse(buf);
243 262036 : }
244 :
245 : /*
246 : * Get the lookup info that printtup() needs
247 : */
248 : static void
249 221384 : printtup_prepare_info(DR_printtup *myState, TupleDesc typeinfo, int numAttrs)
250 : {
251 221384 : int16 *formats = myState->portal->formats;
252 : int i;
253 :
254 : /* get rid of any old data */
255 221384 : if (myState->myinfo)
256 1592 : pfree(myState->myinfo);
257 221384 : myState->myinfo = NULL;
258 :
259 221384 : myState->attrinfo = typeinfo;
260 221384 : myState->nattrs = numAttrs;
261 221384 : if (numAttrs <= 0)
262 112 : return;
263 :
264 221272 : myState->myinfo = (PrinttupAttrInfo *)
265 221272 : palloc0(numAttrs * sizeof(PrinttupAttrInfo));
266 :
267 860094 : for (i = 0; i < numAttrs; i++)
268 : {
269 638822 : PrinttupAttrInfo *thisState = myState->myinfo + i;
270 638822 : int16 format = (formats ? formats[i] : 0);
271 638822 : Form_pg_attribute attr = TupleDescAttr(typeinfo, i);
272 :
273 638822 : thisState->format = format;
274 638822 : if (format == 0)
275 : {
276 638736 : getTypeOutputInfo(attr->atttypid,
277 : &thisState->typoutput,
278 : &thisState->typisvarlena);
279 638736 : fmgr_info(thisState->typoutput, &thisState->finfo);
280 : }
281 86 : else if (format == 1)
282 : {
283 86 : getTypeBinaryOutputInfo(attr->atttypid,
284 : &thisState->typsend,
285 : &thisState->typisvarlena);
286 86 : fmgr_info(thisState->typsend, &thisState->finfo);
287 : }
288 : else
289 0 : ereport(ERROR,
290 : (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
291 : errmsg("unsupported format code: %d", format)));
292 : }
293 : }
294 :
295 : /* ----------------
296 : * printtup --- send a tuple to the client
297 : *
298 : * Note: if you change this function, see also serializeAnalyzeReceive
299 : * in explain.c, which is meant to replicate the computations done here.
300 : * ----------------
301 : */
302 : static bool
303 5963138 : printtup(TupleTableSlot *slot, DestReceiver *self)
304 : {
305 5963138 : TupleDesc typeinfo = slot->tts_tupleDescriptor;
306 5963138 : DR_printtup *myState = (DR_printtup *) self;
307 : MemoryContext oldcontext;
308 5963138 : StringInfo buf = &myState->buf;
309 5963138 : int natts = typeinfo->natts;
310 : int i;
311 :
312 : /* Set or update my derived attribute info, if needed */
313 5963138 : if (myState->attrinfo != typeinfo || myState->nattrs != natts)
314 221384 : printtup_prepare_info(myState, typeinfo, natts);
315 :
316 : /* Make sure the tuple is fully deconstructed */
317 5963138 : slot_getallattrs(slot);
318 :
319 : /* Switch into per-row context so we can recover memory below */
320 5963138 : oldcontext = MemoryContextSwitchTo(myState->tmpcontext);
321 :
322 : /*
323 : * Prepare a DataRow message (note buffer is in per-query context)
324 : */
325 5963138 : pq_beginmessage_reuse(buf, 'D');
326 :
327 5963138 : pq_sendint16(buf, natts);
328 :
329 : /*
330 : * send the attributes of this tuple
331 : */
332 33029748 : for (i = 0; i < natts; ++i)
333 : {
334 27066610 : PrinttupAttrInfo *thisState = myState->myinfo + i;
335 27066610 : Datum attr = slot->tts_values[i];
336 :
337 27066610 : if (slot->tts_isnull[i])
338 : {
339 1381542 : pq_sendint32(buf, -1);
340 1381542 : continue;
341 : }
342 :
343 : /*
344 : * Here we catch undefined bytes in datums that are returned to the
345 : * client without hitting disk; see comments at the related check in
346 : * PageAddItem(). This test is most useful for uncompressed,
347 : * non-external datums, but we're quite likely to see such here when
348 : * testing new C functions.
349 : */
350 25685068 : if (thisState->typisvarlena)
351 : VALGRIND_CHECK_MEM_IS_DEFINED(DatumGetPointer(attr),
352 : VARSIZE_ANY(attr));
353 :
354 25685068 : if (thisState->format == 0)
355 : {
356 : /* Text output */
357 : char *outputstr;
358 :
359 25670366 : outputstr = OutputFunctionCall(&thisState->finfo, attr);
360 25670366 : pq_sendcountedtext(buf, outputstr, strlen(outputstr));
361 : }
362 : else
363 : {
364 : /* Binary output */
365 : bytea *outputbytes;
366 :
367 14702 : outputbytes = SendFunctionCall(&thisState->finfo, attr);
368 14702 : pq_sendint32(buf, VARSIZE(outputbytes) - VARHDRSZ);
369 14702 : pq_sendbytes(buf, VARDATA(outputbytes),
370 14702 : VARSIZE(outputbytes) - VARHDRSZ);
371 : }
372 : }
373 :
374 5963138 : pq_endmessage_reuse(buf);
375 :
376 : /* Return to caller's context, and flush row's temporary memory */
377 5963138 : MemoryContextSwitchTo(oldcontext);
378 5963138 : MemoryContextReset(myState->tmpcontext);
379 :
380 5963138 : return true;
381 : }
382 :
383 : /* ----------------
384 : * printtup_shutdown
385 : * ----------------
386 : */
387 : static void
388 255482 : printtup_shutdown(DestReceiver *self)
389 : {
390 255482 : DR_printtup *myState = (DR_printtup *) self;
391 :
392 255482 : if (myState->myinfo)
393 219492 : pfree(myState->myinfo);
394 255482 : myState->myinfo = NULL;
395 :
396 255482 : myState->attrinfo = NULL;
397 :
398 255482 : if (myState->buf.data)
399 255482 : pfree(myState->buf.data);
400 255482 : myState->buf.data = NULL;
401 :
402 255482 : if (myState->tmpcontext)
403 255482 : MemoryContextDelete(myState->tmpcontext);
404 255482 : myState->tmpcontext = NULL;
405 255482 : }
406 :
407 : /* ----------------
408 : * printtup_destroy
409 : * ----------------
410 : */
411 : static void
412 538806 : printtup_destroy(DestReceiver *self)
413 : {
414 538806 : pfree(self);
415 538806 : }
416 :
417 : /* ----------------
418 : * printatt
419 : * ----------------
420 : */
421 : static void
422 304 : printatt(unsigned attributeId,
423 : Form_pg_attribute attributeP,
424 : char *value)
425 : {
426 304 : printf("\t%2d: %s%s%s%s\t(typeid = %u, len = %d, typmod = %d, byval = %c)\n",
427 : attributeId,
428 : NameStr(attributeP->attname),
429 : value != NULL ? " = \"" : "",
430 : value != NULL ? value : "",
431 : value != NULL ? "\"" : "",
432 : (unsigned int) (attributeP->atttypid),
433 : attributeP->attlen,
434 : attributeP->atttypmod,
435 : attributeP->attbyval ? 't' : 'f');
436 304 : }
437 :
438 : /* ----------------
439 : * debugStartup - prepare to print tuples for an interactive backend
440 : * ----------------
441 : */
442 : void
443 152 : debugStartup(DestReceiver *self, int operation, TupleDesc typeinfo)
444 : {
445 152 : int natts = typeinfo->natts;
446 : int i;
447 :
448 : /*
449 : * show the return type of the tuples
450 : */
451 304 : for (i = 0; i < natts; ++i)
452 152 : printatt((unsigned) i + 1, TupleDescAttr(typeinfo, i), NULL);
453 152 : printf("\t----\n");
454 152 : }
455 :
456 : /* ----------------
457 : * debugtup - print one tuple for an interactive backend
458 : * ----------------
459 : */
460 : bool
461 152 : debugtup(TupleTableSlot *slot, DestReceiver *self)
462 : {
463 152 : TupleDesc typeinfo = slot->tts_tupleDescriptor;
464 152 : int natts = typeinfo->natts;
465 : int i;
466 : Datum attr;
467 : char *value;
468 : bool isnull;
469 : Oid typoutput;
470 : bool typisvarlena;
471 :
472 304 : for (i = 0; i < natts; ++i)
473 : {
474 152 : attr = slot_getattr(slot, i + 1, &isnull);
475 152 : if (isnull)
476 0 : continue;
477 152 : getTypeOutputInfo(TupleDescAttr(typeinfo, i)->atttypid,
478 : &typoutput, &typisvarlena);
479 :
480 152 : value = OidOutputFunctionCall(typoutput, attr);
481 :
482 152 : printatt((unsigned) i + 1, TupleDescAttr(typeinfo, i), value);
483 : }
484 152 : printf("\t----\n");
485 :
486 152 : return true;
487 : }
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