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fe-exec.c
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1 /*-------------------------------------------------------------------------
2  *
3  * fe-exec.c
4  * functions related to sending a query down to the backend
5  *
6  * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
7  * Portions Copyright (c) 1994, Regents of the University of California
8  *
9  *
10  * IDENTIFICATION
11  * src/interfaces/libpq/fe-exec.c
12  *
13  *-------------------------------------------------------------------------
14  */
15 #include "postgres_fe.h"
16 
17 #include <ctype.h>
18 #include <fcntl.h>
19 #include <limits.h>
20 
21 #ifdef WIN32
22 #include "win32.h"
23 #else
24 #include <unistd.h>
25 #endif
26 
27 #include "libpq-fe.h"
28 #include "libpq-int.h"
29 #include "mb/pg_wchar.h"
30 
31 /* keep this in same order as ExecStatusType in libpq-fe.h */
32 char *const pgresStatus[] = {
33  "PGRES_EMPTY_QUERY",
34  "PGRES_COMMAND_OK",
35  "PGRES_TUPLES_OK",
36  "PGRES_COPY_OUT",
37  "PGRES_COPY_IN",
38  "PGRES_BAD_RESPONSE",
39  "PGRES_NONFATAL_ERROR",
40  "PGRES_FATAL_ERROR",
41  "PGRES_COPY_BOTH",
42  "PGRES_SINGLE_TUPLE",
43  "PGRES_PIPELINE_SYNC",
44  "PGRES_PIPELINE_ABORTED"
45 };
46 
47 /*
48  * static state needed by PQescapeString and PQescapeBytea; initialize to
49  * values that result in backward-compatible behavior
50  */
52 static bool static_std_strings = false;
53 
54 
55 static PGEvent *dupEvents(PGEvent *events, int count, size_t *memSize);
56 static bool pqAddTuple(PGresult *res, PGresAttValue *tup,
57  const char **errmsgp);
58 static int PQsendQueryInternal(PGconn *conn, const char *query, bool newQuery);
59 static bool PQsendQueryStart(PGconn *conn, bool newQuery);
60 static int PQsendQueryGuts(PGconn *conn,
61  const char *command,
62  const char *stmtName,
63  int nParams,
64  const Oid *paramTypes,
65  const char *const *paramValues,
66  const int *paramLengths,
67  const int *paramFormats,
68  int resultFormat);
69 static void parseInput(PGconn *conn);
70 static PGresult *getCopyResult(PGconn *conn, ExecStatusType copytype);
71 static bool PQexecStart(PGconn *conn);
73 static int PQsendDescribe(PGconn *conn, char desc_type,
74  const char *desc_target);
75 static int check_field_number(const PGresult *res, int field_num);
76 static void pqPipelineProcessQueue(PGconn *conn);
77 static int pqPipelineFlush(PGconn *conn);
78 
79 
80 /* ----------------
81  * Space management for PGresult.
82  *
83  * Formerly, libpq did a separate malloc() for each field of each tuple
84  * returned by a query. This was remarkably expensive --- malloc/free
85  * consumed a sizable part of the application's runtime. And there is
86  * no real need to keep track of the fields separately, since they will
87  * all be freed together when the PGresult is released. So now, we grab
88  * large blocks of storage from malloc and allocate space for query data
89  * within these blocks, using a trivially simple allocator. This reduces
90  * the number of malloc/free calls dramatically, and it also avoids
91  * fragmentation of the malloc storage arena.
92  * The PGresult structure itself is still malloc'd separately. We could
93  * combine it with the first allocation block, but that would waste space
94  * for the common case that no extra storage is actually needed (that is,
95  * the SQL command did not return tuples).
96  *
97  * We also malloc the top-level array of tuple pointers separately, because
98  * we need to be able to enlarge it via realloc, and our trivial space
99  * allocator doesn't handle that effectively. (Too bad the FE/BE protocol
100  * doesn't tell us up front how many tuples will be returned.)
101  * All other subsidiary storage for a PGresult is kept in PGresult_data blocks
102  * of size PGRESULT_DATA_BLOCKSIZE. The overhead at the start of each block
103  * is just a link to the next one, if any. Free-space management info is
104  * kept in the owning PGresult.
105  * A query returning a small amount of data will thus require three malloc
106  * calls: one for the PGresult, one for the tuples pointer array, and one
107  * PGresult_data block.
108  *
109  * Only the most recently allocated PGresult_data block is a candidate to
110  * have more stuff added to it --- any extra space left over in older blocks
111  * is wasted. We could be smarter and search the whole chain, but the point
112  * here is to be simple and fast. Typical applications do not keep a PGresult
113  * around very long anyway, so some wasted space within one is not a problem.
114  *
115  * Tuning constants for the space allocator are:
116  * PGRESULT_DATA_BLOCKSIZE: size of a standard allocation block, in bytes
117  * PGRESULT_ALIGN_BOUNDARY: assumed alignment requirement for binary data
118  * PGRESULT_SEP_ALLOC_THRESHOLD: objects bigger than this are given separate
119  * blocks, instead of being crammed into a regular allocation block.
120  * Requirements for correct function are:
121  * PGRESULT_ALIGN_BOUNDARY must be a multiple of the alignment requirements
122  * of all machine data types. (Currently this is set from configure
123  * tests, so it should be OK automatically.)
124  * PGRESULT_SEP_ALLOC_THRESHOLD + PGRESULT_BLOCK_OVERHEAD <=
125  * PGRESULT_DATA_BLOCKSIZE
126  * pqResultAlloc assumes an object smaller than the threshold will fit
127  * in a new block.
128  * The amount of space wasted at the end of a block could be as much as
129  * PGRESULT_SEP_ALLOC_THRESHOLD, so it doesn't pay to make that too large.
130  * ----------------
131  */
132 
133 #define PGRESULT_DATA_BLOCKSIZE 2048
134 #define PGRESULT_ALIGN_BOUNDARY MAXIMUM_ALIGNOF /* from configure */
135 #define PGRESULT_BLOCK_OVERHEAD Max(sizeof(PGresult_data), PGRESULT_ALIGN_BOUNDARY)
136 #define PGRESULT_SEP_ALLOC_THRESHOLD (PGRESULT_DATA_BLOCKSIZE / 2)
137 
138 
139 /*
140  * PQmakeEmptyPGresult
141  * returns a newly allocated, initialized PGresult with given status.
142  * If conn is not NULL and status indicates an error, the conn's
143  * errorMessage is copied. Also, any PGEvents are copied from the conn.
144  */
145 PGresult *
147 {
148  PGresult *result;
149 
150  result = (PGresult *) malloc(sizeof(PGresult));
151  if (!result)
152  return NULL;
153 
154  result->ntups = 0;
155  result->numAttributes = 0;
156  result->attDescs = NULL;
157  result->tuples = NULL;
158  result->tupArrSize = 0;
159  result->numParameters = 0;
160  result->paramDescs = NULL;
161  result->resultStatus = status;
162  result->cmdStatus[0] = '\0';
163  result->binary = 0;
164  result->events = NULL;
165  result->nEvents = 0;
166  result->errMsg = NULL;
167  result->errFields = NULL;
168  result->errQuery = NULL;
169  result->null_field[0] = '\0';
170  result->curBlock = NULL;
171  result->curOffset = 0;
172  result->spaceLeft = 0;
173  result->memorySize = sizeof(PGresult);
174 
175  if (conn)
176  {
177  /* copy connection data we might need for operations on PGresult */
178  result->noticeHooks = conn->noticeHooks;
179  result->client_encoding = conn->client_encoding;
180 
181  /* consider copying conn's errorMessage */
182  switch (status)
183  {
184  case PGRES_EMPTY_QUERY:
185  case PGRES_COMMAND_OK:
186  case PGRES_TUPLES_OK:
187  case PGRES_COPY_OUT:
188  case PGRES_COPY_IN:
189  case PGRES_COPY_BOTH:
190  case PGRES_SINGLE_TUPLE:
191  /* non-error cases */
192  break;
193  default:
194  pqSetResultError(result, &conn->errorMessage);
195  break;
196  }
197 
198  /* copy events last; result must be valid if we need to PQclear */
199  if (conn->nEvents > 0)
200  {
201  result->events = dupEvents(conn->events, conn->nEvents,
202  &result->memorySize);
203  if (!result->events)
204  {
205  PQclear(result);
206  return NULL;
207  }
208  result->nEvents = conn->nEvents;
209  }
210  }
211  else
212  {
213  /* defaults... */
214  result->noticeHooks.noticeRec = NULL;
215  result->noticeHooks.noticeRecArg = NULL;
216  result->noticeHooks.noticeProc = NULL;
217  result->noticeHooks.noticeProcArg = NULL;
218  result->client_encoding = PG_SQL_ASCII;
219  }
220 
221  return result;
222 }
223 
224 /*
225  * PQsetResultAttrs
226  *
227  * Set the attributes for a given result. This function fails if there are
228  * already attributes contained in the provided result. The call is
229  * ignored if numAttributes is zero or attDescs is NULL. If the
230  * function fails, it returns zero. If the function succeeds, it
231  * returns a non-zero value.
232  */
233 int
234 PQsetResultAttrs(PGresult *res, int numAttributes, PGresAttDesc *attDescs)
235 {
236  int i;
237 
238  /* If attrs already exist, they cannot be overwritten. */
239  if (!res || res->numAttributes > 0)
240  return false;
241 
242  /* ignore no-op request */
243  if (numAttributes <= 0 || !attDescs)
244  return true;
245 
246  res->attDescs = (PGresAttDesc *)
247  PQresultAlloc(res, numAttributes * sizeof(PGresAttDesc));
248 
249  if (!res->attDescs)
250  return false;
251 
252  res->numAttributes = numAttributes;
253  memcpy(res->attDescs, attDescs, numAttributes * sizeof(PGresAttDesc));
254 
255  /* deep-copy the attribute names, and determine format */
256  res->binary = 1;
257  for (i = 0; i < res->numAttributes; i++)
258  {
259  if (res->attDescs[i].name)
260  res->attDescs[i].name = pqResultStrdup(res, res->attDescs[i].name);
261  else
262  res->attDescs[i].name = res->null_field;
263 
264  if (!res->attDescs[i].name)
265  return false;
266 
267  if (res->attDescs[i].format == 0)
268  res->binary = 0;
269  }
270 
271  return true;
272 }
273 
274 /*
275  * PQcopyResult
276  *
277  * Returns a deep copy of the provided 'src' PGresult, which cannot be NULL.
278  * The 'flags' argument controls which portions of the result will or will
279  * NOT be copied. The created result is always put into the
280  * PGRES_TUPLES_OK status. The source result error message is not copied,
281  * although cmdStatus is.
282  *
283  * To set custom attributes, use PQsetResultAttrs. That function requires
284  * that there are no attrs contained in the result, so to use that
285  * function you cannot use the PG_COPYRES_ATTRS or PG_COPYRES_TUPLES
286  * options with this function.
287  *
288  * Options:
289  * PG_COPYRES_ATTRS - Copy the source result's attributes
290  *
291  * PG_COPYRES_TUPLES - Copy the source result's tuples. This implies
292  * copying the attrs, seeing how the attrs are needed by the tuples.
293  *
294  * PG_COPYRES_EVENTS - Copy the source result's events.
295  *
296  * PG_COPYRES_NOTICEHOOKS - Copy the source result's notice hooks.
297  */
298 PGresult *
299 PQcopyResult(const PGresult *src, int flags)
300 {
301  PGresult *dest;
302  int i;
303 
304  if (!src)
305  return NULL;
306 
307  dest = PQmakeEmptyPGresult(NULL, PGRES_TUPLES_OK);
308  if (!dest)
309  return NULL;
310 
311  /* Always copy these over. Is cmdStatus really useful here? */
312  dest->client_encoding = src->client_encoding;
313  strcpy(dest->cmdStatus, src->cmdStatus);
314 
315  /* Wants attrs? */
316  if (flags & (PG_COPYRES_ATTRS | PG_COPYRES_TUPLES))
317  {
318  if (!PQsetResultAttrs(dest, src->numAttributes, src->attDescs))
319  {
320  PQclear(dest);
321  return NULL;
322  }
323  }
324 
325  /* Wants to copy tuples? */
326  if (flags & PG_COPYRES_TUPLES)
327  {
328  int tup,
329  field;
330 
331  for (tup = 0; tup < src->ntups; tup++)
332  {
333  for (field = 0; field < src->numAttributes; field++)
334  {
335  if (!PQsetvalue(dest, tup, field,
336  src->tuples[tup][field].value,
337  src->tuples[tup][field].len))
338  {
339  PQclear(dest);
340  return NULL;
341  }
342  }
343  }
344  }
345 
346  /* Wants to copy notice hooks? */
347  if (flags & PG_COPYRES_NOTICEHOOKS)
348  dest->noticeHooks = src->noticeHooks;
349 
350  /* Wants to copy PGEvents? */
351  if ((flags & PG_COPYRES_EVENTS) && src->nEvents > 0)
352  {
353  dest->events = dupEvents(src->events, src->nEvents,
354  &dest->memorySize);
355  if (!dest->events)
356  {
357  PQclear(dest);
358  return NULL;
359  }
360  dest->nEvents = src->nEvents;
361  }
362 
363  /* Okay, trigger PGEVT_RESULTCOPY event */
364  for (i = 0; i < dest->nEvents; i++)
365  {
366  if (src->events[i].resultInitialized)
367  {
368  PGEventResultCopy evt;
369 
370  evt.src = src;
371  evt.dest = dest;
372  if (!dest->events[i].proc(PGEVT_RESULTCOPY, &evt,
373  dest->events[i].passThrough))
374  {
375  PQclear(dest);
376  return NULL;
377  }
378  dest->events[i].resultInitialized = true;
379  }
380  }
381 
382  return dest;
383 }
384 
385 /*
386  * Copy an array of PGEvents (with no extra space for more).
387  * Does not duplicate the event instance data, sets this to NULL.
388  * Also, the resultInitialized flags are all cleared.
389  * The total space allocated is added to *memSize.
390  */
391 static PGEvent *
392 dupEvents(PGEvent *events, int count, size_t *memSize)
393 {
394  PGEvent *newEvents;
395  size_t msize;
396  int i;
397 
398  if (!events || count <= 0)
399  return NULL;
400 
401  msize = count * sizeof(PGEvent);
402  newEvents = (PGEvent *) malloc(msize);
403  if (!newEvents)
404  return NULL;
405 
406  for (i = 0; i < count; i++)
407  {
408  newEvents[i].proc = events[i].proc;
409  newEvents[i].passThrough = events[i].passThrough;
410  newEvents[i].data = NULL;
411  newEvents[i].resultInitialized = false;
412  newEvents[i].name = strdup(events[i].name);
413  if (!newEvents[i].name)
414  {
415  while (--i >= 0)
416  free(newEvents[i].name);
417  free(newEvents);
418  return NULL;
419  }
420  msize += strlen(events[i].name) + 1;
421  }
422 
423  *memSize += msize;
424  return newEvents;
425 }
426 
427 
428 /*
429  * Sets the value for a tuple field. The tup_num must be less than or
430  * equal to PQntuples(res). If it is equal, a new tuple is created and
431  * added to the result.
432  * Returns a non-zero value for success and zero for failure.
433  * (On failure, we report the specific problem via pqInternalNotice.)
434  */
435 int
436 PQsetvalue(PGresult *res, int tup_num, int field_num, char *value, int len)
437 {
438  PGresAttValue *attval;
439  const char *errmsg = NULL;
440 
441  /* Note that this check also protects us against null "res" */
442  if (!check_field_number(res, field_num))
443  return false;
444 
445  /* Invalid tup_num, must be <= ntups */
446  if (tup_num < 0 || tup_num > res->ntups)
447  {
449  "row number %d is out of range 0..%d",
450  tup_num, res->ntups);
451  return false;
452  }
453 
454  /* need to allocate a new tuple? */
455  if (tup_num == res->ntups)
456  {
457  PGresAttValue *tup;
458  int i;
459 
460  tup = (PGresAttValue *)
461  pqResultAlloc(res, res->numAttributes * sizeof(PGresAttValue),
462  true);
463 
464  if (!tup)
465  goto fail;
466 
467  /* initialize each column to NULL */
468  for (i = 0; i < res->numAttributes; i++)
469  {
470  tup[i].len = NULL_LEN;
471  tup[i].value = res->null_field;
472  }
473 
474  /* add it to the array */
475  if (!pqAddTuple(res, tup, &errmsg))
476  goto fail;
477  }
478 
479  attval = &res->tuples[tup_num][field_num];
480 
481  /* treat either NULL_LEN or NULL value pointer as a NULL field */
482  if (len == NULL_LEN || value == NULL)
483  {
484  attval->len = NULL_LEN;
485  attval->value = res->null_field;
486  }
487  else if (len <= 0)
488  {
489  attval->len = 0;
490  attval->value = res->null_field;
491  }
492  else
493  {
494  attval->value = (char *) pqResultAlloc(res, len + 1, true);
495  if (!attval->value)
496  goto fail;
497  attval->len = len;
498  memcpy(attval->value, value, len);
499  attval->value[len] = '\0';
500  }
501 
502  return true;
503 
504  /*
505  * Report failure via pqInternalNotice. If preceding code didn't provide
506  * an error message, assume "out of memory" was meant.
507  */
508 fail:
509  if (!errmsg)
510  errmsg = libpq_gettext("out of memory");
511  pqInternalNotice(&res->noticeHooks, "%s", errmsg);
512 
513  return false;
514 }
515 
516 /*
517  * pqResultAlloc - exported routine to allocate local storage in a PGresult.
518  *
519  * We force all such allocations to be maxaligned, since we don't know
520  * whether the value might be binary.
521  */
522 void *
523 PQresultAlloc(PGresult *res, size_t nBytes)
524 {
525  return pqResultAlloc(res, nBytes, true);
526 }
527 
528 /*
529  * pqResultAlloc -
530  * Allocate subsidiary storage for a PGresult.
531  *
532  * nBytes is the amount of space needed for the object.
533  * If isBinary is true, we assume that we need to align the object on
534  * a machine allocation boundary.
535  * If isBinary is false, we assume the object is a char string and can
536  * be allocated on any byte boundary.
537  */
538 void *
539 pqResultAlloc(PGresult *res, size_t nBytes, bool isBinary)
540 {
541  char *space;
542  PGresult_data *block;
543 
544  if (!res)
545  return NULL;
546 
547  if (nBytes <= 0)
548  return res->null_field;
549 
550  /*
551  * If alignment is needed, round up the current position to an alignment
552  * boundary.
553  */
554  if (isBinary)
555  {
556  int offset = res->curOffset % PGRESULT_ALIGN_BOUNDARY;
557 
558  if (offset)
559  {
560  res->curOffset += PGRESULT_ALIGN_BOUNDARY - offset;
561  res->spaceLeft -= PGRESULT_ALIGN_BOUNDARY - offset;
562  }
563  }
564 
565  /* If there's enough space in the current block, no problem. */
566  if (nBytes <= (size_t) res->spaceLeft)
567  {
568  space = res->curBlock->space + res->curOffset;
569  res->curOffset += nBytes;
570  res->spaceLeft -= nBytes;
571  return space;
572  }
573 
574  /*
575  * If the requested object is very large, give it its own block; this
576  * avoids wasting what might be most of the current block to start a new
577  * block. (We'd have to special-case requests bigger than the block size
578  * anyway.) The object is always given binary alignment in this case.
579  */
580  if (nBytes >= PGRESULT_SEP_ALLOC_THRESHOLD)
581  {
582  size_t alloc_size = nBytes + PGRESULT_BLOCK_OVERHEAD;
583 
584  block = (PGresult_data *) malloc(alloc_size);
585  if (!block)
586  return NULL;
587  res->memorySize += alloc_size;
588  space = block->space + PGRESULT_BLOCK_OVERHEAD;
589  if (res->curBlock)
590  {
591  /*
592  * Tuck special block below the active block, so that we don't
593  * have to waste the free space in the active block.
594  */
595  block->next = res->curBlock->next;
596  res->curBlock->next = block;
597  }
598  else
599  {
600  /* Must set up the new block as the first active block. */
601  block->next = NULL;
602  res->curBlock = block;
603  res->spaceLeft = 0; /* be sure it's marked full */
604  }
605  return space;
606  }
607 
608  /* Otherwise, start a new block. */
610  if (!block)
611  return NULL;
613  block->next = res->curBlock;
614  res->curBlock = block;
615  if (isBinary)
616  {
617  /* object needs full alignment */
620  }
621  else
622  {
623  /* we can cram it right after the overhead pointer */
624  res->curOffset = sizeof(PGresult_data);
626  }
627 
628  space = block->space + res->curOffset;
629  res->curOffset += nBytes;
630  res->spaceLeft -= nBytes;
631  return space;
632 }
633 
634 /*
635  * PQresultMemorySize -
636  * Returns total space allocated for the PGresult.
637  */
638 size_t
640 {
641  if (!res)
642  return 0;
643  return res->memorySize;
644 }
645 
646 /*
647  * pqResultStrdup -
648  * Like strdup, but the space is subsidiary PGresult space.
649  */
650 char *
651 pqResultStrdup(PGresult *res, const char *str)
652 {
653  char *space = (char *) pqResultAlloc(res, strlen(str) + 1, false);
654 
655  if (space)
656  strcpy(space, str);
657  return space;
658 }
659 
660 /*
661  * pqSetResultError -
662  * assign a new error message to a PGresult
663  */
664 void
666 {
667  char *msg;
668 
669  if (!res)
670  return;
671 
672  /*
673  * We handle two OOM scenarios here. The errorMessage buffer might be
674  * marked "broken" due to having previously failed to allocate enough
675  * memory for the message, or it might be fine but pqResultStrdup fails
676  * and returns NULL. In either case, just make res->errMsg point directly
677  * at a constant "out of memory" string.
678  */
679  if (!PQExpBufferBroken(errorMessage))
680  msg = pqResultStrdup(res, errorMessage->data);
681  else
682  msg = NULL;
683  if (msg)
684  res->errMsg = msg;
685  else
686  res->errMsg = libpq_gettext("out of memory\n");
687 }
688 
689 /*
690  * PQclear -
691  * free's the memory associated with a PGresult
692  */
693 void
695 {
696  PGresult_data *block;
697  int i;
698 
699  if (!res)
700  return;
701 
702  for (i = 0; i < res->nEvents; i++)
703  {
704  /* only send DESTROY to successfully-initialized event procs */
705  if (res->events[i].resultInitialized)
706  {
708 
709  evt.result = res;
710  (void) res->events[i].proc(PGEVT_RESULTDESTROY, &evt,
711  res->events[i].passThrough);
712  }
713  free(res->events[i].name);
714  }
715 
716  if (res->events)
717  free(res->events);
718 
719  /* Free all the subsidiary blocks */
720  while ((block = res->curBlock) != NULL)
721  {
722  res->curBlock = block->next;
723  free(block);
724  }
725 
726  /* Free the top-level tuple pointer array */
727  if (res->tuples)
728  free(res->tuples);
729 
730  /* zero out the pointer fields to catch programming errors */
731  res->attDescs = NULL;
732  res->tuples = NULL;
733  res->paramDescs = NULL;
734  res->errFields = NULL;
735  res->events = NULL;
736  res->nEvents = 0;
737  /* res->curBlock was zeroed out earlier */
738 
739  /* Free the PGresult structure itself */
740  free(res);
741 }
742 
743 /*
744  * Handy subroutine to deallocate any partially constructed async result.
745  *
746  * Any "next" result gets cleared too.
747  */
748 void
750 {
751  if (conn->result)
752  PQclear(conn->result);
753  conn->result = NULL;
754  if (conn->next_result)
755  PQclear(conn->next_result);
756  conn->next_result = NULL;
757 }
758 
759 /*
760  * This subroutine deletes any existing async result, sets conn->result
761  * to a PGresult with status PGRES_FATAL_ERROR, and stores the current
762  * contents of conn->errorMessage into that result.
763  */
764 void
766 {
767  pqClearAsyncResult(conn);
769 }
770 
771 /*
772  * As above, after appending conn->write_err_msg to whatever other error we
773  * have. This is used when we've detected a write failure and have exhausted
774  * our chances of reporting something else instead.
775  */
776 static void
778 {
779  /*
780  * If write_err_msg is null because of previous strdup failure, do what we
781  * can. (It's likely our machinations here will get OOM failures as well,
782  * but might as well try.)
783  */
784  if (conn->write_err_msg)
785  {
787  /* Avoid possibly appending the same message twice */
788  conn->write_err_msg[0] = '\0';
789  }
790  else
792  libpq_gettext("write to server failed\n"));
793 
794  pqSaveErrorResult(conn);
795 }
796 
797 /*
798  * This subroutine prepares an async result object for return to the caller.
799  * If there is not already an async result object, build an error object
800  * using whatever is in conn->errorMessage. In any case, clear the async
801  * result storage.
802  */
803 PGresult *
805 {
806  PGresult *res;
807 
808  /*
809  * conn->result is the PGresult to return. If it is NULL (which probably
810  * shouldn't happen) we assume there is an appropriate error message in
811  * conn->errorMessage.
812  */
813  res = conn->result;
814  if (!res)
816 
817  /*
818  * Replace conn->result with next_result, if any. In the normal case
819  * there isn't a next result and we're just dropping ownership of the
820  * current result. In single-row mode this restores the situation to what
821  * it was before we created the current single-row result.
822  */
823  conn->result = conn->next_result;
824  conn->next_result = NULL;
825 
826  return res;
827 }
828 
829 /*
830  * pqInternalNotice - produce an internally-generated notice message
831  *
832  * A format string and optional arguments can be passed. Note that we do
833  * libpq_gettext() here, so callers need not.
834  *
835  * The supplied text is taken as primary message (ie., it should not include
836  * a trailing newline, and should not be more than one line).
837  */
838 void
839 pqInternalNotice(const PGNoticeHooks *hooks, const char *fmt,...)
840 {
841  char msgBuf[1024];
842  va_list args;
843  PGresult *res;
844 
845  if (hooks->noticeRec == NULL)
846  return; /* nobody home to receive notice? */
847 
848  /* Format the message */
849  va_start(args, fmt);
850  vsnprintf(msgBuf, sizeof(msgBuf), libpq_gettext(fmt), args);
851  va_end(args);
852  msgBuf[sizeof(msgBuf) - 1] = '\0'; /* make real sure it's terminated */
853 
854  /* Make a PGresult to pass to the notice receiver */
856  if (!res)
857  return;
858  res->noticeHooks = *hooks;
859 
860  /*
861  * Set up fields of notice.
862  */
866  /* XXX should provide a SQLSTATE too? */
867 
868  /*
869  * Result text is always just the primary message + newline. If we can't
870  * allocate it, substitute "out of memory", as in pqSetResultError.
871  */
872  res->errMsg = (char *) pqResultAlloc(res, strlen(msgBuf) + 2, false);
873  if (res->errMsg)
874  sprintf(res->errMsg, "%s\n", msgBuf);
875  else
876  res->errMsg = libpq_gettext("out of memory\n");
877 
878  /*
879  * Pass to receiver, then free it.
880  */
881  res->noticeHooks.noticeRec(res->noticeHooks.noticeRecArg, res);
882  PQclear(res);
883 }
884 
885 /*
886  * pqAddTuple
887  * add a row pointer to the PGresult structure, growing it if necessary
888  * Returns true if OK, false if an error prevented adding the row
889  *
890  * On error, *errmsgp can be set to an error string to be returned.
891  * If it is left NULL, the error is presumed to be "out of memory".
892  */
893 static bool
894 pqAddTuple(PGresult *res, PGresAttValue *tup, const char **errmsgp)
895 {
896  if (res->ntups >= res->tupArrSize)
897  {
898  /*
899  * Try to grow the array.
900  *
901  * We can use realloc because shallow copying of the structure is
902  * okay. Note that the first time through, res->tuples is NULL. While
903  * ANSI says that realloc() should act like malloc() in that case,
904  * some old C libraries (like SunOS 4.1.x) coredump instead. On
905  * failure realloc is supposed to return NULL without damaging the
906  * existing allocation. Note that the positions beyond res->ntups are
907  * garbage, not necessarily NULL.
908  */
909  int newSize;
910  PGresAttValue **newTuples;
911 
912  /*
913  * Since we use integers for row numbers, we can't support more than
914  * INT_MAX rows. Make sure we allow that many, though.
915  */
916  if (res->tupArrSize <= INT_MAX / 2)
917  newSize = (res->tupArrSize > 0) ? res->tupArrSize * 2 : 128;
918  else if (res->tupArrSize < INT_MAX)
919  newSize = INT_MAX;
920  else
921  {
922  *errmsgp = libpq_gettext("PGresult cannot support more than INT_MAX tuples");
923  return false;
924  }
925 
926  /*
927  * Also, on 32-bit platforms we could, in theory, overflow size_t even
928  * before newSize gets to INT_MAX. (In practice we'd doubtless hit
929  * OOM long before that, but let's check.)
930  */
931 #if INT_MAX >= (SIZE_MAX / 2)
932  if (newSize > SIZE_MAX / sizeof(PGresAttValue *))
933  {
934  *errmsgp = libpq_gettext("size_t overflow");
935  return false;
936  }
937 #endif
938 
939  if (res->tuples == NULL)
940  newTuples = (PGresAttValue **)
941  malloc(newSize * sizeof(PGresAttValue *));
942  else
943  newTuples = (PGresAttValue **)
944  realloc(res->tuples, newSize * sizeof(PGresAttValue *));
945  if (!newTuples)
946  return false; /* malloc or realloc failed */
947  res->memorySize +=
948  (newSize - res->tupArrSize) * sizeof(PGresAttValue *);
949  res->tupArrSize = newSize;
950  res->tuples = newTuples;
951  }
952  res->tuples[res->ntups] = tup;
953  res->ntups++;
954  return true;
955 }
956 
957 /*
958  * pqSaveMessageField - save one field of an error or notice message
959  */
960 void
961 pqSaveMessageField(PGresult *res, char code, const char *value)
962 {
963  PGMessageField *pfield;
964 
965  pfield = (PGMessageField *)
966  pqResultAlloc(res,
967  offsetof(PGMessageField, contents) +
968  strlen(value) + 1,
969  true);
970  if (!pfield)
971  return; /* out of memory? */
972  pfield->code = code;
973  strcpy(pfield->contents, value);
974  pfield->next = res->errFields;
975  res->errFields = pfield;
976 }
977 
978 /*
979  * pqSaveParameterStatus - remember parameter status sent by backend
980  */
981 void
982 pqSaveParameterStatus(PGconn *conn, const char *name, const char *value)
983 {
984  pgParameterStatus *pstatus;
985  pgParameterStatus *prev;
986 
987  /*
988  * Forget any old information about the parameter
989  */
990  for (pstatus = conn->pstatus, prev = NULL;
991  pstatus != NULL;
992  prev = pstatus, pstatus = pstatus->next)
993  {
994  if (strcmp(pstatus->name, name) == 0)
995  {
996  if (prev)
997  prev->next = pstatus->next;
998  else
999  conn->pstatus = pstatus->next;
1000  free(pstatus); /* frees name and value strings too */
1001  break;
1002  }
1003  }
1004 
1005  /*
1006  * Store new info as a single malloc block
1007  */
1008  pstatus = (pgParameterStatus *) malloc(sizeof(pgParameterStatus) +
1009  strlen(name) + strlen(value) + 2);
1010  if (pstatus)
1011  {
1012  char *ptr;
1013 
1014  ptr = ((char *) pstatus) + sizeof(pgParameterStatus);
1015  pstatus->name = ptr;
1016  strcpy(ptr, name);
1017  ptr += strlen(name) + 1;
1018  pstatus->value = ptr;
1019  strcpy(ptr, value);
1020  pstatus->next = conn->pstatus;
1021  conn->pstatus = pstatus;
1022  }
1023 
1024  /*
1025  * Save values of settings that are of interest to libpq in fields of the
1026  * PGconn object. We keep client_encoding and standard_conforming_strings
1027  * in static variables as well, so that PQescapeString and PQescapeBytea
1028  * can behave somewhat sanely (at least in single-connection-using
1029  * programs).
1030  */
1031  if (strcmp(name, "client_encoding") == 0)
1032  {
1033  conn->client_encoding = pg_char_to_encoding(value);
1034  /* if we don't recognize the encoding name, fall back to SQL_ASCII */
1035  if (conn->client_encoding < 0)
1036  conn->client_encoding = PG_SQL_ASCII;
1038  }
1039  else if (strcmp(name, "standard_conforming_strings") == 0)
1040  {
1041  conn->std_strings = (strcmp(value, "on") == 0);
1043  }
1044  else if (strcmp(name, "server_version") == 0)
1045  {
1046  /* We convert the server version to numeric form. */
1047  int cnt;
1048  int vmaj,
1049  vmin,
1050  vrev;
1051 
1052  cnt = sscanf(value, "%d.%d.%d", &vmaj, &vmin, &vrev);
1053 
1054  if (cnt == 3)
1055  {
1056  /* old style, e.g. 9.6.1 */
1057  conn->sversion = (100 * vmaj + vmin) * 100 + vrev;
1058  }
1059  else if (cnt == 2)
1060  {
1061  if (vmaj >= 10)
1062  {
1063  /* new style, e.g. 10.1 */
1064  conn->sversion = 100 * 100 * vmaj + vmin;
1065  }
1066  else
1067  {
1068  /* old style without minor version, e.g. 9.6devel */
1069  conn->sversion = (100 * vmaj + vmin) * 100;
1070  }
1071  }
1072  else if (cnt == 1)
1073  {
1074  /* new style without minor version, e.g. 10devel */
1075  conn->sversion = 100 * 100 * vmaj;
1076  }
1077  else
1078  conn->sversion = 0; /* unknown */
1079  }
1080  else if (strcmp(name, "default_transaction_read_only") == 0)
1081  {
1083  (strcmp(value, "on") == 0) ? PG_BOOL_YES : PG_BOOL_NO;
1084  }
1085  else if (strcmp(name, "in_hot_standby") == 0)
1086  {
1087  conn->in_hot_standby =
1088  (strcmp(value, "on") == 0) ? PG_BOOL_YES : PG_BOOL_NO;
1089  }
1090 }
1091 
1092 
1093 /*
1094  * pqRowProcessor
1095  * Add the received row to the current async result (conn->result).
1096  * Returns 1 if OK, 0 if error occurred.
1097  *
1098  * On error, *errmsgp can be set to an error string to be returned.
1099  * If it is left NULL, the error is presumed to be "out of memory".
1100  *
1101  * In single-row mode, we create a new result holding just the current row,
1102  * stashing the previous result in conn->next_result so that it becomes
1103  * active again after pqPrepareAsyncResult(). This allows the result metadata
1104  * (column descriptions) to be carried forward to each result row.
1105  */
1106 int
1107 pqRowProcessor(PGconn *conn, const char **errmsgp)
1108 {
1109  PGresult *res = conn->result;
1110  int nfields = res->numAttributes;
1111  const PGdataValue *columns = conn->rowBuf;
1112  PGresAttValue *tup;
1113  int i;
1114 
1115  /*
1116  * In single-row mode, make a new PGresult that will hold just this one
1117  * row; the original conn->result is left unchanged so that it can be used
1118  * again as the template for future rows.
1119  */
1120  if (conn->singleRowMode)
1121  {
1122  /* Copy everything that should be in the result at this point */
1123  res = PQcopyResult(res,
1126  if (!res)
1127  return 0;
1128  }
1129 
1130  /*
1131  * Basically we just allocate space in the PGresult for each field and
1132  * copy the data over.
1133  *
1134  * Note: on malloc failure, we return 0 leaving *errmsgp still NULL, which
1135  * caller will take to mean "out of memory". This is preferable to trying
1136  * to set up such a message here, because evidently there's not enough
1137  * memory for gettext() to do anything.
1138  */
1139  tup = (PGresAttValue *)
1140  pqResultAlloc(res, nfields * sizeof(PGresAttValue), true);
1141  if (tup == NULL)
1142  goto fail;
1143 
1144  for (i = 0; i < nfields; i++)
1145  {
1146  int clen = columns[i].len;
1147 
1148  if (clen < 0)
1149  {
1150  /* null field */
1151  tup[i].len = NULL_LEN;
1152  tup[i].value = res->null_field;
1153  }
1154  else
1155  {
1156  bool isbinary = (res->attDescs[i].format != 0);
1157  char *val;
1158 
1159  val = (char *) pqResultAlloc(res, clen + 1, isbinary);
1160  if (val == NULL)
1161  goto fail;
1162 
1163  /* copy and zero-terminate the data (even if it's binary) */
1164  memcpy(val, columns[i].value, clen);
1165  val[clen] = '\0';
1166 
1167  tup[i].len = clen;
1168  tup[i].value = val;
1169  }
1170  }
1171 
1172  /* And add the tuple to the PGresult's tuple array */
1173  if (!pqAddTuple(res, tup, errmsgp))
1174  goto fail;
1175 
1176  /*
1177  * Success. In single-row mode, make the result available to the client
1178  * immediately.
1179  */
1180  if (conn->singleRowMode)
1181  {
1182  /* Change result status to special single-row value */
1184  /* Stash old result for re-use later */
1185  conn->next_result = conn->result;
1186  conn->result = res;
1187  /* And mark the result ready to return */
1189  }
1190 
1191  return 1;
1192 
1193 fail:
1194  /* release locally allocated PGresult, if we made one */
1195  if (res != conn->result)
1196  PQclear(res);
1197  return 0;
1198 }
1199 
1200 
1201 /*
1202  * pqAllocCmdQueueEntry
1203  * Get a command queue entry for caller to fill.
1204  *
1205  * If the recycle queue has a free element, that is returned; if not, a
1206  * fresh one is allocated. Caller is responsible for adding it to the
1207  * command queue (pqAppendCmdQueueEntry) once the struct is filled in, or
1208  * releasing the memory (pqRecycleCmdQueueEntry) if an error occurs.
1209  *
1210  * If allocation fails, sets the error message and returns NULL.
1211  */
1212 static PGcmdQueueEntry *
1214 {
1215  PGcmdQueueEntry *entry;
1216 
1217  if (conn->cmd_queue_recycle == NULL)
1218  {
1219  entry = (PGcmdQueueEntry *) malloc(sizeof(PGcmdQueueEntry));
1220  if (entry == NULL)
1221  {
1223  libpq_gettext("out of memory\n"));
1224  return NULL;
1225  }
1226  }
1227  else
1228  {
1229  entry = conn->cmd_queue_recycle;
1230  conn->cmd_queue_recycle = entry->next;
1231  }
1232  entry->next = NULL;
1233  entry->query = NULL;
1234 
1235  return entry;
1236 }
1237 
1238 /*
1239  * pqAppendCmdQueueEntry
1240  * Append a caller-allocated entry to the command queue, and update
1241  * conn->asyncStatus to account for it.
1242  *
1243  * The query itself must already have been put in the output buffer by the
1244  * caller.
1245  */
1246 static void
1248 {
1249  Assert(entry->next == NULL);
1250 
1251  if (conn->cmd_queue_head == NULL)
1252  conn->cmd_queue_head = entry;
1253  else
1254  conn->cmd_queue_tail->next = entry;
1255 
1256  conn->cmd_queue_tail = entry;
1257 
1258  switch (conn->pipelineStatus)
1259  {
1260  case PQ_PIPELINE_OFF:
1261  case PQ_PIPELINE_ON:
1262 
1263  /*
1264  * When not in pipeline aborted state, if there's a result ready
1265  * to be consumed, let it be so (that is, don't change away from
1266  * READY or READY_MORE); otherwise set us busy to wait for
1267  * something to arrive from the server.
1268  */
1269  if (conn->asyncStatus == PGASYNC_IDLE)
1270  conn->asyncStatus = PGASYNC_BUSY;
1271  break;
1272 
1273  case PQ_PIPELINE_ABORTED:
1274 
1275  /*
1276  * In aborted pipeline state, we don't expect anything from the
1277  * server (since we don't send any queries that are queued).
1278  * Therefore, if IDLE then do what PQgetResult would do to let
1279  * itself consume commands from the queue; if we're in any other
1280  * state, we don't have to do anything.
1281  */
1282  if (conn->asyncStatus == PGASYNC_IDLE)
1283  {
1285  pqPipelineProcessQueue(conn);
1286  }
1287  break;
1288  }
1289 }
1290 
1291 /*
1292  * pqRecycleCmdQueueEntry
1293  * Push a command queue entry onto the freelist.
1294  */
1295 static void
1297 {
1298  if (entry == NULL)
1299  return;
1300 
1301  /* recyclable entries should not have a follow-on command */
1302  Assert(entry->next == NULL);
1303 
1304  if (entry->query)
1305  {
1306  free(entry->query);
1307  entry->query = NULL;
1308  }
1309 
1310  entry->next = conn->cmd_queue_recycle;
1311  conn->cmd_queue_recycle = entry;
1312 }
1313 
1314 
1315 /*
1316  * PQsendQuery
1317  * Submit a query, but don't wait for it to finish
1318  *
1319  * Returns: 1 if successfully submitted
1320  * 0 if error (conn->errorMessage is set)
1321  *
1322  * PQsendQueryContinue is a non-exported version that behaves identically
1323  * except that it doesn't reset conn->errorMessage.
1324  */
1325 int
1326 PQsendQuery(PGconn *conn, const char *query)
1327 {
1328  return PQsendQueryInternal(conn, query, true);
1329 }
1330 
1331 int
1332 PQsendQueryContinue(PGconn *conn, const char *query)
1333 {
1334  return PQsendQueryInternal(conn, query, false);
1335 }
1336 
1337 static int
1338 PQsendQueryInternal(PGconn *conn, const char *query, bool newQuery)
1339 {
1340  PGcmdQueueEntry *entry = NULL;
1341 
1342  if (!PQsendQueryStart(conn, newQuery))
1343  return 0;
1344 
1345  /* check the argument */
1346  if (!query)
1347  {
1349  libpq_gettext("command string is a null pointer\n"));
1350  return 0;
1351  }
1352 
1353  entry = pqAllocCmdQueueEntry(conn);
1354  if (entry == NULL)
1355  return 0; /* error msg already set */
1356 
1357  /* Send the query message(s) */
1358  if (conn->pipelineStatus == PQ_PIPELINE_OFF)
1359  {
1360  /* construct the outgoing Query message */
1361  if (pqPutMsgStart('Q', conn) < 0 ||
1362  pqPuts(query, conn) < 0 ||
1363  pqPutMsgEnd(conn) < 0)
1364  {
1365  /* error message should be set up already */
1366  pqRecycleCmdQueueEntry(conn, entry);
1367  return 0;
1368  }
1369 
1370  /* remember we are using simple query protocol */
1371  entry->queryclass = PGQUERY_SIMPLE;
1372  /* and remember the query text too, if possible */
1373  entry->query = strdup(query);
1374  }
1375  else
1376  {
1377  /*
1378  * In pipeline mode we cannot use the simple protocol, so we send
1379  * Parse, Bind, Describe Portal, Execute, Close Portal (with the
1380  * unnamed portal).
1381  */
1382  if (pqPutMsgStart('P', conn) < 0 ||
1383  pqPuts("", conn) < 0 ||
1384  pqPuts(query, conn) < 0 ||
1385  pqPutInt(0, 2, conn) < 0 ||
1386  pqPutMsgEnd(conn) < 0)
1387  goto sendFailed;
1388  if (pqPutMsgStart('B', conn) < 0 ||
1389  pqPuts("", conn) < 0 ||
1390  pqPuts("", conn) < 0 ||
1391  pqPutInt(0, 2, conn) < 0 ||
1392  pqPutInt(0, 2, conn) < 0 ||
1393  pqPutInt(0, 2, conn) < 0 ||
1394  pqPutMsgEnd(conn) < 0)
1395  goto sendFailed;
1396  if (pqPutMsgStart('D', conn) < 0 ||
1397  pqPutc('P', conn) < 0 ||
1398  pqPuts("", conn) < 0 ||
1399  pqPutMsgEnd(conn) < 0)
1400  goto sendFailed;
1401  if (pqPutMsgStart('E', conn) < 0 ||
1402  pqPuts("", conn) < 0 ||
1403  pqPutInt(0, 4, conn) < 0 ||
1404  pqPutMsgEnd(conn) < 0)
1405  goto sendFailed;
1406  if (pqPutMsgStart('C', conn) < 0 ||
1407  pqPutc('P', conn) < 0 ||
1408  pqPuts("", conn) < 0 ||
1409  pqPutMsgEnd(conn) < 0)
1410  goto sendFailed;
1411 
1412  entry->queryclass = PGQUERY_EXTENDED;
1413  entry->query = strdup(query);
1414  }
1415 
1416  /*
1417  * Give the data a push. In nonblock mode, don't complain if we're unable
1418  * to send it all; PQgetResult() will do any additional flushing needed.
1419  */
1420  if (pqPipelineFlush(conn) < 0)
1421  goto sendFailed;
1422 
1423  /* OK, it's launched! */
1424  pqAppendCmdQueueEntry(conn, entry);
1425  return 1;
1426 
1427 sendFailed:
1428  pqRecycleCmdQueueEntry(conn, entry);
1429  /* error message should be set up already */
1430  return 0;
1431 }
1432 
1433 /*
1434  * PQsendQueryParams
1435  * Like PQsendQuery, but use extended query protocol so we can pass parameters
1436  */
1437 int
1439  const char *command,
1440  int nParams,
1441  const Oid *paramTypes,
1442  const char *const *paramValues,
1443  const int *paramLengths,
1444  const int *paramFormats,
1445  int resultFormat)
1446 {
1447  if (!PQsendQueryStart(conn, true))
1448  return 0;
1449 
1450  /* check the arguments */
1451  if (!command)
1452  {
1454  libpq_gettext("command string is a null pointer\n"));
1455  return 0;
1456  }
1457  if (nParams < 0 || nParams > PQ_QUERY_PARAM_MAX_LIMIT)
1458  {
1460  libpq_gettext("number of parameters must be between 0 and %d\n"),
1461  PQ_QUERY_PARAM_MAX_LIMIT);
1462  return 0;
1463  }
1464 
1465  return PQsendQueryGuts(conn,
1466  command,
1467  "", /* use unnamed statement */
1468  nParams,
1469  paramTypes,
1470  paramValues,
1471  paramLengths,
1472  paramFormats,
1473  resultFormat);
1474 }
1475 
1476 /*
1477  * PQsendPrepare
1478  * Submit a Parse message, but don't wait for it to finish
1479  *
1480  * Returns: 1 if successfully submitted
1481  * 0 if error (conn->errorMessage is set)
1482  */
1483 int
1485  const char *stmtName, const char *query,
1486  int nParams, const Oid *paramTypes)
1487 {
1488  PGcmdQueueEntry *entry = NULL;
1489 
1490  if (!PQsendQueryStart(conn, true))
1491  return 0;
1492 
1493  /* check the arguments */
1494  if (!stmtName)
1495  {
1497  libpq_gettext("statement name is a null pointer\n"));
1498  return 0;
1499  }
1500  if (!query)
1501  {
1503  libpq_gettext("command string is a null pointer\n"));
1504  return 0;
1505  }
1506  if (nParams < 0 || nParams > PQ_QUERY_PARAM_MAX_LIMIT)
1507  {
1509  libpq_gettext("number of parameters must be between 0 and %d\n"),
1510  PQ_QUERY_PARAM_MAX_LIMIT);
1511  return 0;
1512  }
1513 
1514  entry = pqAllocCmdQueueEntry(conn);
1515  if (entry == NULL)
1516  return 0; /* error msg already set */
1517 
1518  /* construct the Parse message */
1519  if (pqPutMsgStart('P', conn) < 0 ||
1520  pqPuts(stmtName, conn) < 0 ||
1521  pqPuts(query, conn) < 0)
1522  goto sendFailed;
1523 
1524  if (nParams > 0 && paramTypes)
1525  {
1526  int i;
1527 
1528  if (pqPutInt(nParams, 2, conn) < 0)
1529  goto sendFailed;
1530  for (i = 0; i < nParams; i++)
1531  {
1532  if (pqPutInt(paramTypes[i], 4, conn) < 0)
1533  goto sendFailed;
1534  }
1535  }
1536  else
1537  {
1538  if (pqPutInt(0, 2, conn) < 0)
1539  goto sendFailed;
1540  }
1541  if (pqPutMsgEnd(conn) < 0)
1542  goto sendFailed;
1543 
1544  /* Add a Sync, unless in pipeline mode. */
1545  if (conn->pipelineStatus == PQ_PIPELINE_OFF)
1546  {
1547  if (pqPutMsgStart('S', conn) < 0 ||
1548  pqPutMsgEnd(conn) < 0)
1549  goto sendFailed;
1550  }
1551 
1552  /* remember we are doing just a Parse */
1553  entry->queryclass = PGQUERY_PREPARE;
1554 
1555  /* and remember the query text too, if possible */
1556  /* if insufficient memory, query just winds up NULL */
1557  entry->query = strdup(query);
1558 
1559  /*
1560  * Give the data a push (in pipeline mode, only if we're past the size
1561  * threshold). In nonblock mode, don't complain if we're unable to send
1562  * it all; PQgetResult() will do any additional flushing needed.
1563  */
1564  if (pqPipelineFlush(conn) < 0)
1565  goto sendFailed;
1566 
1567  /* OK, it's launched! */
1568  pqAppendCmdQueueEntry(conn, entry);
1569 
1570  return 1;
1571 
1572 sendFailed:
1573  pqRecycleCmdQueueEntry(conn, entry);
1574  /* error message should be set up already */
1575  return 0;
1576 }
1577 
1578 /*
1579  * PQsendQueryPrepared
1580  * Like PQsendQuery, but execute a previously prepared statement,
1581  * using extended query protocol so we can pass parameters
1582  */
1583 int
1585  const char *stmtName,
1586  int nParams,
1587  const char *const *paramValues,
1588  const int *paramLengths,
1589  const int *paramFormats,
1590  int resultFormat)
1591 {
1592  if (!PQsendQueryStart(conn, true))
1593  return 0;
1594 
1595  /* check the arguments */
1596  if (!stmtName)
1597  {
1599  libpq_gettext("statement name is a null pointer\n"));
1600  return 0;
1601  }
1602  if (nParams < 0 || nParams > PQ_QUERY_PARAM_MAX_LIMIT)
1603  {
1605  libpq_gettext("number of parameters must be between 0 and %d\n"),
1606  PQ_QUERY_PARAM_MAX_LIMIT);
1607  return 0;
1608  }
1609 
1610  return PQsendQueryGuts(conn,
1611  NULL, /* no command to parse */
1612  stmtName,
1613  nParams,
1614  NULL, /* no param types */
1615  paramValues,
1616  paramLengths,
1617  paramFormats,
1618  resultFormat);
1619 }
1620 
1621 /*
1622  * PQsendQueryStart
1623  * Common startup code for PQsendQuery and sibling routines
1624  */
1625 static bool
1626 PQsendQueryStart(PGconn *conn, bool newQuery)
1627 {
1628  if (!conn)
1629  return false;
1630 
1631  /*
1632  * If this is the beginning of a query cycle, reset the error buffer.
1633  */
1634  if (newQuery)
1636 
1637  /* Don't try to send if we know there's no live connection. */
1638  if (conn->status != CONNECTION_OK)
1639  {
1641  libpq_gettext("no connection to the server\n"));
1642  return false;
1643  }
1644 
1645  /* Can't send while already busy, either, unless enqueuing for later */
1646  if (conn->asyncStatus != PGASYNC_IDLE &&
1648  {
1650  libpq_gettext("another command is already in progress\n"));
1651  return false;
1652  }
1653 
1654  if (conn->pipelineStatus != PQ_PIPELINE_OFF)
1655  {
1656  /*
1657  * When enqueuing commands we don't change much of the connection
1658  * state since it's already in use for the current command. The
1659  * connection state will get updated when pqPipelineProcessQueue()
1660  * advances to start processing the queued message.
1661  *
1662  * Just make sure we can safely enqueue given the current connection
1663  * state. We can enqueue behind another queue item, or behind a
1664  * non-queue command (one that sends its own sync), but we can't
1665  * enqueue if the connection is in a copy state.
1666  */
1667  switch (conn->asyncStatus)
1668  {
1669  case PGASYNC_IDLE:
1670  case PGASYNC_READY:
1671  case PGASYNC_READY_MORE:
1672  case PGASYNC_BUSY:
1673  /* ok to queue */
1674  break;
1675  case PGASYNC_COPY_IN:
1676  case PGASYNC_COPY_OUT:
1677  case PGASYNC_COPY_BOTH:
1679  libpq_gettext("cannot queue commands during COPY\n"));
1680  return false;
1681  }
1682  }
1683  else
1684  {
1685  /*
1686  * This command's results will come in immediately. Initialize async
1687  * result-accumulation state
1688  */
1689  pqClearAsyncResult(conn);
1690 
1691  /* reset single-row processing mode */
1692  conn->singleRowMode = false;
1693 
1694  }
1695  /* ready to send command message */
1696  return true;
1697 }
1698 
1699 /*
1700  * PQsendQueryGuts
1701  * Common code for sending a query with extended query protocol
1702  * PQsendQueryStart should be done already
1703  *
1704  * command may be NULL to indicate we use an already-prepared statement
1705  */
1706 static int
1708  const char *command,
1709  const char *stmtName,
1710  int nParams,
1711  const Oid *paramTypes,
1712  const char *const *paramValues,
1713  const int *paramLengths,
1714  const int *paramFormats,
1715  int resultFormat)
1716 {
1717  int i;
1718  PGcmdQueueEntry *entry;
1719 
1720  entry = pqAllocCmdQueueEntry(conn);
1721  if (entry == NULL)
1722  return 0; /* error msg already set */
1723 
1724  /*
1725  * We will send Parse (if needed), Bind, Describe Portal, Execute, Sync
1726  * (if not in pipeline mode), using specified statement name and the
1727  * unnamed portal.
1728  */
1729 
1730  if (command)
1731  {
1732  /* construct the Parse message */
1733  if (pqPutMsgStart('P', conn) < 0 ||
1734  pqPuts(stmtName, conn) < 0 ||
1735  pqPuts(command, conn) < 0)
1736  goto sendFailed;
1737  if (nParams > 0 && paramTypes)
1738  {
1739  if (pqPutInt(nParams, 2, conn) < 0)
1740  goto sendFailed;
1741  for (i = 0; i < nParams; i++)
1742  {
1743  if (pqPutInt(paramTypes[i], 4, conn) < 0)
1744  goto sendFailed;
1745  }
1746  }
1747  else
1748  {
1749  if (pqPutInt(0, 2, conn) < 0)
1750  goto sendFailed;
1751  }
1752  if (pqPutMsgEnd(conn) < 0)
1753  goto sendFailed;
1754  }
1755 
1756  /* Construct the Bind message */
1757  if (pqPutMsgStart('B', conn) < 0 ||
1758  pqPuts("", conn) < 0 ||
1759  pqPuts(stmtName, conn) < 0)
1760  goto sendFailed;
1761 
1762  /* Send parameter formats */
1763  if (nParams > 0 && paramFormats)
1764  {
1765  if (pqPutInt(nParams, 2, conn) < 0)
1766  goto sendFailed;
1767  for (i = 0; i < nParams; i++)
1768  {
1769  if (pqPutInt(paramFormats[i], 2, conn) < 0)
1770  goto sendFailed;
1771  }
1772  }
1773  else
1774  {
1775  if (pqPutInt(0, 2, conn) < 0)
1776  goto sendFailed;
1777  }
1778 
1779  if (pqPutInt(nParams, 2, conn) < 0)
1780  goto sendFailed;
1781 
1782  /* Send parameters */
1783  for (i = 0; i < nParams; i++)
1784  {
1785  if (paramValues && paramValues[i])
1786  {
1787  int nbytes;
1788 
1789  if (paramFormats && paramFormats[i] != 0)
1790  {
1791  /* binary parameter */
1792  if (paramLengths)
1793  nbytes = paramLengths[i];
1794  else
1795  {
1797  libpq_gettext("length must be given for binary parameter\n"));
1798  goto sendFailed;
1799  }
1800  }
1801  else
1802  {
1803  /* text parameter, do not use paramLengths */
1804  nbytes = strlen(paramValues[i]);
1805  }
1806  if (pqPutInt(nbytes, 4, conn) < 0 ||
1807  pqPutnchar(paramValues[i], nbytes, conn) < 0)
1808  goto sendFailed;
1809  }
1810  else
1811  {
1812  /* take the param as NULL */
1813  if (pqPutInt(-1, 4, conn) < 0)
1814  goto sendFailed;
1815  }
1816  }
1817  if (pqPutInt(1, 2, conn) < 0 ||
1818  pqPutInt(resultFormat, 2, conn))
1819  goto sendFailed;
1820  if (pqPutMsgEnd(conn) < 0)
1821  goto sendFailed;
1822 
1823  /* construct the Describe Portal message */
1824  if (pqPutMsgStart('D', conn) < 0 ||
1825  pqPutc('P', conn) < 0 ||
1826  pqPuts("", conn) < 0 ||
1827  pqPutMsgEnd(conn) < 0)
1828  goto sendFailed;
1829 
1830  /* construct the Execute message */
1831  if (pqPutMsgStart('E', conn) < 0 ||
1832  pqPuts("", conn) < 0 ||
1833  pqPutInt(0, 4, conn) < 0 ||
1834  pqPutMsgEnd(conn) < 0)
1835  goto sendFailed;
1836 
1837  /* construct the Sync message if not in pipeline mode */
1838  if (conn->pipelineStatus == PQ_PIPELINE_OFF)
1839  {
1840  if (pqPutMsgStart('S', conn) < 0 ||
1841  pqPutMsgEnd(conn) < 0)
1842  goto sendFailed;
1843  }
1844 
1845  /* remember we are using extended query protocol */
1846  entry->queryclass = PGQUERY_EXTENDED;
1847 
1848  /* and remember the query text too, if possible */
1849  /* if insufficient memory, query just winds up NULL */
1850  if (command)
1851  entry->query = strdup(command);
1852 
1853  /*
1854  * Give the data a push (in pipeline mode, only if we're past the size
1855  * threshold). In nonblock mode, don't complain if we're unable to send
1856  * it all; PQgetResult() will do any additional flushing needed.
1857  */
1858  if (pqPipelineFlush(conn) < 0)
1859  goto sendFailed;
1860 
1861  /* OK, it's launched! */
1862  pqAppendCmdQueueEntry(conn, entry);
1863 
1864  return 1;
1865 
1866 sendFailed:
1867  pqRecycleCmdQueueEntry(conn, entry);
1868  /* error message should be set up already */
1869  return 0;
1870 }
1871 
1872 /*
1873  * Select row-by-row processing mode
1874  */
1875 int
1877 {
1878  /*
1879  * Only allow setting the flag when we have launched a query and not yet
1880  * received any results.
1881  */
1882  if (!conn)
1883  return 0;
1884  if (conn->asyncStatus != PGASYNC_BUSY)
1885  return 0;
1886  if (!conn->cmd_queue_head ||
1889  return 0;
1890  if (conn->result)
1891  return 0;
1892 
1893  /* OK, set flag */
1894  conn->singleRowMode = true;
1895  return 1;
1896 }
1897 
1898 /*
1899  * Consume any available input from the backend
1900  * 0 return: some kind of trouble
1901  * 1 return: no problem
1902  */
1903 int
1905 {
1906  if (!conn)
1907  return 0;
1908 
1909  /*
1910  * for non-blocking connections try to flush the send-queue, otherwise we
1911  * may never get a response for something that may not have already been
1912  * sent because it's in our write buffer!
1913  */
1914  if (pqIsnonblocking(conn))
1915  {
1916  if (pqFlush(conn) < 0)
1917  return 0;
1918  }
1919 
1920  /*
1921  * Load more data, if available. We do this no matter what state we are
1922  * in, since we are probably getting called because the application wants
1923  * to get rid of a read-select condition. Note that we will NOT block
1924  * waiting for more input.
1925  */
1926  if (pqReadData(conn) < 0)
1927  return 0;
1928 
1929  /* Parsing of the data waits till later. */
1930  return 1;
1931 }
1932 
1933 
1934 /*
1935  * parseInput: if appropriate, parse input data from backend
1936  * until input is exhausted or a stopping state is reached.
1937  * Note that this function will NOT attempt to read more data from the backend.
1938  */
1939 static void
1941 {
1942  pqParseInput3(conn);
1943 }
1944 
1945 /*
1946  * PQisBusy
1947  * Return true if PQgetResult would block waiting for input.
1948  */
1949 
1950 int
1952 {
1953  if (!conn)
1954  return false;
1955 
1956  /* Parse any available data, if our state permits. */
1957  parseInput(conn);
1958 
1959  /*
1960  * PQgetResult will return immediately in all states except BUSY, or if we
1961  * had a write failure.
1962  */
1963  return conn->asyncStatus == PGASYNC_BUSY || conn->write_failed;
1964 }
1965 
1966 /*
1967  * PQgetResult
1968  * Get the next PGresult produced by a query. Returns NULL if no
1969  * query work remains or an error has occurred (e.g. out of
1970  * memory).
1971  *
1972  * In pipeline mode, once all the result of a query have been returned,
1973  * PQgetResult returns NULL to let the user know that the next
1974  * query is being processed. At the end of the pipeline, returns a
1975  * result with PQresultStatus(result) == PGRES_PIPELINE_SYNC.
1976  */
1977 PGresult *
1979 {
1980  PGresult *res;
1981 
1982  if (!conn)
1983  return NULL;
1984 
1985  /* Parse any available data, if our state permits. */
1986  parseInput(conn);
1987 
1988  /* If not ready to return something, block until we are. */
1989  while (conn->asyncStatus == PGASYNC_BUSY)
1990  {
1991  int flushResult;
1992 
1993  /*
1994  * If data remains unsent, send it. Else we might be waiting for the
1995  * result of a command the backend hasn't even got yet.
1996  */
1997  while ((flushResult = pqFlush(conn)) > 0)
1998  {
1999  if (pqWait(false, true, conn))
2000  {
2001  flushResult = -1;
2002  break;
2003  }
2004  }
2005 
2006  /*
2007  * Wait for some more data, and load it. (Note: if the connection has
2008  * been lost, pqWait should return immediately because the socket
2009  * should be read-ready, either with the last server data or with an
2010  * EOF indication. We expect therefore that this won't result in any
2011  * undue delay in reporting a previous write failure.)
2012  */
2013  if (flushResult ||
2014  pqWait(true, false, conn) ||
2015  pqReadData(conn) < 0)
2016  {
2017  /*
2018  * conn->errorMessage has been set by pqWait or pqReadData. We
2019  * want to append it to any already-received error message.
2020  */
2021  pqSaveErrorResult(conn);
2022  conn->asyncStatus = PGASYNC_IDLE;
2023  return pqPrepareAsyncResult(conn);
2024  }
2025 
2026  /* Parse it. */
2027  parseInput(conn);
2028 
2029  /*
2030  * If we had a write error, but nothing above obtained a query result
2031  * or detected a read error, report the write error.
2032  */
2033  if (conn->write_failed && conn->asyncStatus == PGASYNC_BUSY)
2034  {
2035  pqSaveWriteError(conn);
2036  conn->asyncStatus = PGASYNC_IDLE;
2037  return pqPrepareAsyncResult(conn);
2038  }
2039  }
2040 
2041  /* Return the appropriate thing. */
2042  switch (conn->asyncStatus)
2043  {
2044  case PGASYNC_IDLE:
2045  res = NULL; /* query is complete */
2046  if (conn->pipelineStatus != PQ_PIPELINE_OFF)
2047  {
2048  /*
2049  * We're about to return the NULL that terminates the round of
2050  * results from the current query; prepare to send the results
2051  * of the next query when we're called next. Also, since this
2052  * is the start of the results of the next query, clear any
2053  * prior error message.
2054  */
2056  pqPipelineProcessQueue(conn);
2057  }
2058  break;
2059  case PGASYNC_READY:
2060 
2061  /*
2062  * For any query type other than simple query protocol, we advance
2063  * the command queue here. This is because for simple query
2064  * protocol we can get the READY state multiple times before the
2065  * command is actually complete, since the command string can
2066  * contain many queries. In simple query protocol, the queue
2067  * advance is done by fe-protocol3 when it receives ReadyForQuery.
2068  */
2069  if (conn->cmd_queue_head &&
2071  pqCommandQueueAdvance(conn);
2072  res = pqPrepareAsyncResult(conn);
2073  if (conn->pipelineStatus != PQ_PIPELINE_OFF)
2074  {
2075  /*
2076  * We're about to send the results of the current query. Set
2077  * us idle now, and ...
2078  */
2079  conn->asyncStatus = PGASYNC_IDLE;
2080 
2081  /*
2082  * ... in cases when we're sending a pipeline-sync result,
2083  * move queue processing forwards immediately, so that next
2084  * time we're called, we're prepared to return the next result
2085  * received from the server. In all other cases, leave the
2086  * queue state change for next time, so that a terminating
2087  * NULL result is sent.
2088  *
2089  * (In other words: we don't return a NULL after a pipeline
2090  * sync.)
2091  */
2092  if (res && res->resultStatus == PGRES_PIPELINE_SYNC)
2093  pqPipelineProcessQueue(conn);
2094  }
2095  else
2096  {
2097  /* Set the state back to BUSY, allowing parsing to proceed. */
2098  conn->asyncStatus = PGASYNC_BUSY;
2099  }
2100  break;
2101  case PGASYNC_READY_MORE:
2102  res = pqPrepareAsyncResult(conn);
2103  /* Set the state back to BUSY, allowing parsing to proceed. */
2104  conn->asyncStatus = PGASYNC_BUSY;
2105  break;
2106  case PGASYNC_COPY_IN:
2107  res = getCopyResult(conn, PGRES_COPY_IN);
2108  break;
2109  case PGASYNC_COPY_OUT:
2110  res = getCopyResult(conn, PGRES_COPY_OUT);
2111  break;
2112  case PGASYNC_COPY_BOTH:
2113  res = getCopyResult(conn, PGRES_COPY_BOTH);
2114  break;
2115  default:
2117  libpq_gettext("unexpected asyncStatus: %d\n"),
2118  (int) conn->asyncStatus);
2120  break;
2121  }
2122 
2123  if (res)
2124  {
2125  int i;
2126 
2127  for (i = 0; i < res->nEvents; i++)
2128  {
2129  PGEventResultCreate evt;
2130 
2131  evt.conn = conn;
2132  evt.result = res;
2133  if (!res->events[i].proc(PGEVT_RESULTCREATE, &evt,
2134  res->events[i].passThrough))
2135  {
2137  libpq_gettext("PGEventProc \"%s\" failed during PGEVT_RESULTCREATE event\n"),
2138  res->events[i].name);
2139  pqSetResultError(res, &conn->errorMessage);
2141  break;
2142  }
2143  res->events[i].resultInitialized = true;
2144  }
2145  }
2146 
2147  return res;
2148 }
2149 
2150 /*
2151  * getCopyResult
2152  * Helper for PQgetResult: generate result for COPY-in-progress cases
2153  */
2154 static PGresult *
2156 {
2157  /*
2158  * If the server connection has been lost, don't pretend everything is
2159  * hunky-dory; instead return a PGRES_FATAL_ERROR result, and reset the
2160  * asyncStatus to idle (corresponding to what we'd do if we'd detected I/O
2161  * error in the earlier steps in PQgetResult). The text returned in the
2162  * result is whatever is in conn->errorMessage; we hope that was filled
2163  * with something relevant when the lost connection was detected.
2164  */
2165  if (conn->status != CONNECTION_OK)
2166  {
2167  pqSaveErrorResult(conn);
2168  conn->asyncStatus = PGASYNC_IDLE;
2169  return pqPrepareAsyncResult(conn);
2170  }
2171 
2172  /* If we have an async result for the COPY, return that */
2173  if (conn->result && conn->result->resultStatus == copytype)
2174  return pqPrepareAsyncResult(conn);
2175 
2176  /* Otherwise, invent a suitable PGresult */
2177  return PQmakeEmptyPGresult(conn, copytype);
2178 }
2179 
2180 
2181 /*
2182  * PQexec
2183  * send a query to the backend and package up the result in a PGresult
2184  *
2185  * If the query was not even sent, return NULL; conn->errorMessage is set to
2186  * a relevant message.
2187  * If the query was sent, a new PGresult is returned (which could indicate
2188  * either success or failure).
2189  * The user is responsible for freeing the PGresult via PQclear()
2190  * when done with it.
2191  */
2192 PGresult *
2193 PQexec(PGconn *conn, const char *query)
2194 {
2195  if (!PQexecStart(conn))
2196  return NULL;
2197  if (!PQsendQuery(conn, query))
2198  return NULL;
2199  return PQexecFinish(conn);
2200 }
2201 
2202 /*
2203  * PQexecParams
2204  * Like PQexec, but use extended query protocol so we can pass parameters
2205  */
2206 PGresult *
2208  const char *command,
2209  int nParams,
2210  const Oid *paramTypes,
2211  const char *const *paramValues,
2212  const int *paramLengths,
2213  const int *paramFormats,
2214  int resultFormat)
2215 {
2216  if (!PQexecStart(conn))
2217  return NULL;
2218  if (!PQsendQueryParams(conn, command,
2219  nParams, paramTypes, paramValues, paramLengths,
2220  paramFormats, resultFormat))
2221  return NULL;
2222  return PQexecFinish(conn);
2223 }
2224 
2225 /*
2226  * PQprepare
2227  * Creates a prepared statement by issuing a Parse message.
2228  *
2229  * If the query was not even sent, return NULL; conn->errorMessage is set to
2230  * a relevant message.
2231  * If the query was sent, a new PGresult is returned (which could indicate
2232  * either success or failure).
2233  * The user is responsible for freeing the PGresult via PQclear()
2234  * when done with it.
2235  */
2236 PGresult *
2238  const char *stmtName, const char *query,
2239  int nParams, const Oid *paramTypes)
2240 {
2241  if (!PQexecStart(conn))
2242  return NULL;
2243  if (!PQsendPrepare(conn, stmtName, query, nParams, paramTypes))
2244  return NULL;
2245  return PQexecFinish(conn);
2246 }
2247 
2248 /*
2249  * PQexecPrepared
2250  * Like PQexec, but execute a previously prepared statement,
2251  * using extended query protocol so we can pass parameters
2252  */
2253 PGresult *
2255  const char *stmtName,
2256  int nParams,
2257  const char *const *paramValues,
2258  const int *paramLengths,
2259  const int *paramFormats,
2260  int resultFormat)
2261 {
2262  if (!PQexecStart(conn))
2263  return NULL;
2264  if (!PQsendQueryPrepared(conn, stmtName,
2265  nParams, paramValues, paramLengths,
2266  paramFormats, resultFormat))
2267  return NULL;
2268  return PQexecFinish(conn);
2269 }
2270 
2271 /*
2272  * Common code for PQexec and sibling routines: prepare to send command
2273  */
2274 static bool
2276 {
2277  PGresult *result;
2278 
2279  if (!conn)
2280  return false;
2281 
2282  if (conn->pipelineStatus != PQ_PIPELINE_OFF)
2283  {
2285  libpq_gettext("synchronous command execution functions are not allowed in pipeline mode\n"));
2286  return false;
2287  }
2288 
2289  /*
2290  * Since this is the beginning of a query cycle, reset the error buffer.
2291  */
2293 
2294  /*
2295  * Silently discard any prior query result that application didn't eat.
2296  * This is probably poor design, but it's here for backward compatibility.
2297  */
2298  while ((result = PQgetResult(conn)) != NULL)
2299  {
2300  ExecStatusType resultStatus = result->resultStatus;
2301 
2302  PQclear(result); /* only need its status */
2303  if (resultStatus == PGRES_COPY_IN)
2304  {
2305  /* get out of a COPY IN state */
2306  if (PQputCopyEnd(conn,
2307  libpq_gettext("COPY terminated by new PQexec")) < 0)
2308  return false;
2309  /* keep waiting to swallow the copy's failure message */
2310  }
2311  else if (resultStatus == PGRES_COPY_OUT)
2312  {
2313  /*
2314  * Get out of a COPY OUT state: we just switch back to BUSY and
2315  * allow the remaining COPY data to be dropped on the floor.
2316  */
2317  conn->asyncStatus = PGASYNC_BUSY;
2318  /* keep waiting to swallow the copy's completion message */
2319  }
2320  else if (resultStatus == PGRES_COPY_BOTH)
2321  {
2322  /* We don't allow PQexec during COPY BOTH */
2324  libpq_gettext("PQexec not allowed during COPY BOTH\n"));
2325  return false;
2326  }
2327  /* check for loss of connection, too */
2328  if (conn->status == CONNECTION_BAD)
2329  return false;
2330  }
2331 
2332  /* OK to send a command */
2333  return true;
2334 }
2335 
2336 /*
2337  * Common code for PQexec and sibling routines: wait for command result
2338  */
2339 static PGresult *
2341 {
2342  PGresult *result;
2343  PGresult *lastResult;
2344 
2345  /*
2346  * For backwards compatibility, return the last result if there are more
2347  * than one. (We used to have logic here to concatenate successive error
2348  * messages, but now that happens automatically, since conn->errorMessage
2349  * will continue to accumulate errors throughout this loop.)
2350  *
2351  * We have to stop if we see copy in/out/both, however. We will resume
2352  * parsing after application performs the data transfer.
2353  *
2354  * Also stop if the connection is lost (else we'll loop infinitely).
2355  */
2356  lastResult = NULL;
2357  while ((result = PQgetResult(conn)) != NULL)
2358  {
2359  if (lastResult)
2360  PQclear(lastResult);
2361  lastResult = result;
2362  if (result->resultStatus == PGRES_COPY_IN ||
2363  result->resultStatus == PGRES_COPY_OUT ||
2364  result->resultStatus == PGRES_COPY_BOTH ||
2365  conn->status == CONNECTION_BAD)
2366  break;
2367  }
2368 
2369  return lastResult;
2370 }
2371 
2372 /*
2373  * PQdescribePrepared
2374  * Obtain information about a previously prepared statement
2375  *
2376  * If the query was not even sent, return NULL; conn->errorMessage is set to
2377  * a relevant message.
2378  * If the query was sent, a new PGresult is returned (which could indicate
2379  * either success or failure). On success, the PGresult contains status
2380  * PGRES_COMMAND_OK, and its parameter and column-heading fields describe
2381  * the statement's inputs and outputs respectively.
2382  * The user is responsible for freeing the PGresult via PQclear()
2383  * when done with it.
2384  */
2385 PGresult *
2386 PQdescribePrepared(PGconn *conn, const char *stmt)
2387 {
2388  if (!PQexecStart(conn))
2389  return NULL;
2390  if (!PQsendDescribe(conn, 'S', stmt))
2391  return NULL;
2392  return PQexecFinish(conn);
2393 }
2394 
2395 /*
2396  * PQdescribePortal
2397  * Obtain information about a previously created portal
2398  *
2399  * This is much like PQdescribePrepared, except that no parameter info is
2400  * returned. Note that at the moment, libpq doesn't really expose portals
2401  * to the client; but this can be used with a portal created by a SQL
2402  * DECLARE CURSOR command.
2403  */
2404 PGresult *
2405 PQdescribePortal(PGconn *conn, const char *portal)
2406 {
2407  if (!PQexecStart(conn))
2408  return NULL;
2409  if (!PQsendDescribe(conn, 'P', portal))
2410  return NULL;
2411  return PQexecFinish(conn);
2412 }
2413 
2414 /*
2415  * PQsendDescribePrepared
2416  * Submit a Describe Statement command, but don't wait for it to finish
2417  *
2418  * Returns: 1 if successfully submitted
2419  * 0 if error (conn->errorMessage is set)
2420  */
2421 int
2423 {
2424  return PQsendDescribe(conn, 'S', stmt);
2425 }
2426 
2427 /*
2428  * PQsendDescribePortal
2429  * Submit a Describe Portal command, but don't wait for it to finish
2430  *
2431  * Returns: 1 if successfully submitted
2432  * 0 if error (conn->errorMessage is set)
2433  */
2434 int
2435 PQsendDescribePortal(PGconn *conn, const char *portal)
2436 {
2437  return PQsendDescribe(conn, 'P', portal);
2438 }
2439 
2440 /*
2441  * PQsendDescribe
2442  * Common code to send a Describe command
2443  *
2444  * Available options for desc_type are
2445  * 'S' to describe a prepared statement; or
2446  * 'P' to describe a portal.
2447  * Returns 1 on success and 0 on failure.
2448  */
2449 static int
2450 PQsendDescribe(PGconn *conn, char desc_type, const char *desc_target)
2451 {
2452  PGcmdQueueEntry *entry = NULL;
2453 
2454  /* Treat null desc_target as empty string */
2455  if (!desc_target)
2456  desc_target = "";
2457 
2458  if (!PQsendQueryStart(conn, true))
2459  return 0;
2460 
2461  entry = pqAllocCmdQueueEntry(conn);
2462  if (entry == NULL)
2463  return 0; /* error msg already set */
2464 
2465  /* construct the Describe message */
2466  if (pqPutMsgStart('D', conn) < 0 ||
2467  pqPutc(desc_type, conn) < 0 ||
2468  pqPuts(desc_target, conn) < 0 ||
2469  pqPutMsgEnd(conn) < 0)
2470  goto sendFailed;
2471 
2472  /* construct the Sync message */
2473  if (conn->pipelineStatus == PQ_PIPELINE_OFF)
2474  {
2475  if (pqPutMsgStart('S', conn) < 0 ||
2476  pqPutMsgEnd(conn) < 0)
2477  goto sendFailed;
2478  }
2479 
2480  /* remember we are doing a Describe */
2481  entry->queryclass = PGQUERY_DESCRIBE;
2482 
2483  /*
2484  * Give the data a push (in pipeline mode, only if we're past the size
2485  * threshold). In nonblock mode, don't complain if we're unable to send
2486  * it all; PQgetResult() will do any additional flushing needed.
2487  */
2488  if (pqPipelineFlush(conn) < 0)
2489  goto sendFailed;
2490 
2491  /* OK, it's launched! */
2492  pqAppendCmdQueueEntry(conn, entry);
2493 
2494  return 1;
2495 
2496 sendFailed:
2497  pqRecycleCmdQueueEntry(conn, entry);
2498  /* error message should be set up already */
2499  return 0;
2500 }
2501 
2502 /*
2503  * PQnotifies
2504  * returns a PGnotify* structure of the latest async notification
2505  * that has not yet been handled
2506  *
2507  * returns NULL, if there is currently
2508  * no unhandled async notification from the backend
2509  *
2510  * the CALLER is responsible for FREE'ing the structure returned
2511  *
2512  * Note that this function does not read any new data from the socket;
2513  * so usually, caller should call PQconsumeInput() first.
2514  */
2515 PGnotify *
2517 {
2518  PGnotify *event;
2519 
2520  if (!conn)
2521  return NULL;
2522 
2523  /* Parse any available data to see if we can extract NOTIFY messages. */
2524  parseInput(conn);
2525 
2526  event = conn->notifyHead;
2527  if (event)
2528  {
2529  conn->notifyHead = event->next;
2530  if (!conn->notifyHead)
2531  conn->notifyTail = NULL;
2532  event->next = NULL; /* don't let app see the internal state */
2533  }
2534  return event;
2535 }
2536 
2537 /*
2538  * PQputCopyData - send some data to the backend during COPY IN or COPY BOTH
2539  *
2540  * Returns 1 if successful, 0 if data could not be sent (only possible
2541  * in nonblock mode), or -1 if an error occurs.
2542  */
2543 int
2544 PQputCopyData(PGconn *conn, const char *buffer, int nbytes)
2545 {
2546  if (!conn)
2547  return -1;
2548  if (conn->asyncStatus != PGASYNC_COPY_IN &&
2549  conn->asyncStatus != PGASYNC_COPY_BOTH)
2550  {
2552  libpq_gettext("no COPY in progress\n"));
2553  return -1;
2554  }
2555 
2556  /*
2557  * Process any NOTICE or NOTIFY messages that might be pending in the
2558  * input buffer. Since the server might generate many notices during the
2559  * COPY, we want to clean those out reasonably promptly to prevent
2560  * indefinite expansion of the input buffer. (Note: the actual read of
2561  * input data into the input buffer happens down inside pqSendSome, but
2562  * it's not authorized to get rid of the data again.)
2563  */
2564  parseInput(conn);
2565 
2566  if (nbytes > 0)
2567  {
2568  /*
2569  * Try to flush any previously sent data in preference to growing the
2570  * output buffer. If we can't enlarge the buffer enough to hold the
2571  * data, return 0 in the nonblock case, else hard error. (For
2572  * simplicity, always assume 5 bytes of overhead.)
2573  */
2574  if ((conn->outBufSize - conn->outCount - 5) < nbytes)
2575  {
2576  if (pqFlush(conn) < 0)
2577  return -1;
2578  if (pqCheckOutBufferSpace(conn->outCount + 5 + (size_t) nbytes,
2579  conn))
2580  return pqIsnonblocking(conn) ? 0 : -1;
2581  }
2582  /* Send the data (too simple to delegate to fe-protocol files) */
2583  if (pqPutMsgStart('d', conn) < 0 ||
2584  pqPutnchar(buffer, nbytes, conn) < 0 ||
2585  pqPutMsgEnd(conn) < 0)
2586  return -1;
2587  }
2588  return 1;
2589 }
2590 
2591 /*
2592  * PQputCopyEnd - send EOF indication to the backend during COPY IN
2593  *
2594  * After calling this, use PQgetResult() to check command completion status.
2595  *
2596  * Returns 1 if successful, 0 if data could not be sent (only possible
2597  * in nonblock mode), or -1 if an error occurs.
2598  */
2599 int
2600 PQputCopyEnd(PGconn *conn, const char *errormsg)
2601 {
2602  if (!conn)
2603  return -1;
2604  if (conn->asyncStatus != PGASYNC_COPY_IN &&
2605  conn->asyncStatus != PGASYNC_COPY_BOTH)
2606  {
2608  libpq_gettext("no COPY in progress\n"));
2609  return -1;
2610  }
2611 
2612  /*
2613  * Send the COPY END indicator. This is simple enough that we don't
2614  * bother delegating it to the fe-protocol files.
2615  */
2616  if (errormsg)
2617  {
2618  /* Send COPY FAIL */
2619  if (pqPutMsgStart('f', conn) < 0 ||
2620  pqPuts(errormsg, conn) < 0 ||
2621  pqPutMsgEnd(conn) < 0)
2622  return -1;
2623  }
2624  else
2625  {
2626  /* Send COPY DONE */
2627  if (pqPutMsgStart('c', conn) < 0 ||
2628  pqPutMsgEnd(conn) < 0)
2629  return -1;
2630  }
2631 
2632  /*
2633  * If we sent the COPY command in extended-query mode, we must issue a
2634  * Sync as well.
2635  */
2636  if (conn->cmd_queue_head &&
2638  {
2639  if (pqPutMsgStart('S', conn) < 0 ||
2640  pqPutMsgEnd(conn) < 0)
2641  return -1;
2642  }
2643 
2644  /* Return to active duty */
2645  if (conn->asyncStatus == PGASYNC_COPY_BOTH)
2646  conn->asyncStatus = PGASYNC_COPY_OUT;
2647  else
2648  conn->asyncStatus = PGASYNC_BUSY;
2649 
2650  /* Try to flush data */
2651  if (pqFlush(conn) < 0)
2652  return -1;
2653 
2654  return 1;
2655 }
2656 
2657 /*
2658  * PQgetCopyData - read a row of data from the backend during COPY OUT
2659  * or COPY BOTH
2660  *
2661  * If successful, sets *buffer to point to a malloc'd row of data, and
2662  * returns row length (always > 0) as result.
2663  * Returns 0 if no row available yet (only possible if async is true),
2664  * -1 if end of copy (consult PQgetResult), or -2 if error (consult
2665  * PQerrorMessage).
2666  */
2667 int
2668 PQgetCopyData(PGconn *conn, char **buffer, int async)
2669 {
2670  *buffer = NULL; /* for all failure cases */
2671  if (!conn)
2672  return -2;
2673  if (conn->asyncStatus != PGASYNC_COPY_OUT &&
2674  conn->asyncStatus != PGASYNC_COPY_BOTH)
2675  {
2677  libpq_gettext("no COPY in progress\n"));
2678  return -2;
2679  }
2680  return pqGetCopyData3(conn, buffer, async);
2681 }
2682 
2683 /*
2684  * PQgetline - gets a newline-terminated string from the backend.
2685  *
2686  * Chiefly here so that applications can use "COPY <rel> to stdout"
2687  * and read the output string. Returns a null-terminated string in s.
2688  *
2689  * XXX this routine is now deprecated, because it can't handle binary data.
2690  * If called during a COPY BINARY we return EOF.
2691  *
2692  * PQgetline reads up to maxlen-1 characters (like fgets(3)) but strips
2693  * the terminating \n (like gets(3)).
2694  *
2695  * CAUTION: the caller is responsible for detecting the end-of-copy signal
2696  * (a line containing just "\.") when using this routine.
2697  *
2698  * RETURNS:
2699  * EOF if error (eg, invalid arguments are given)
2700  * 0 if EOL is reached (i.e., \n has been read)
2701  * (this is required for backward-compatibility -- this
2702  * routine used to always return EOF or 0, assuming that
2703  * the line ended within maxlen bytes.)
2704  * 1 in other cases (i.e., the buffer was filled before \n is reached)
2705  */
2706 int
2707 PQgetline(PGconn *conn, char *s, int maxlen)
2708 {
2709  if (!s || maxlen <= 0)
2710  return EOF;
2711  *s = '\0';
2712  /* maxlen must be at least 3 to hold the \. terminator! */
2713  if (maxlen < 3)
2714  return EOF;
2715 
2716  if (!conn)
2717  return EOF;
2718 
2719  return pqGetline3(conn, s, maxlen);
2720 }
2721 
2722 /*
2723  * PQgetlineAsync - gets a COPY data row without blocking.
2724  *
2725  * This routine is for applications that want to do "COPY <rel> to stdout"
2726  * asynchronously, that is without blocking. Having issued the COPY command
2727  * and gotten a PGRES_COPY_OUT response, the app should call PQconsumeInput
2728  * and this routine until the end-of-data signal is detected. Unlike
2729  * PQgetline, this routine takes responsibility for detecting end-of-data.
2730  *
2731  * On each call, PQgetlineAsync will return data if a complete data row
2732  * is available in libpq's input buffer. Otherwise, no data is returned
2733  * until the rest of the row arrives.
2734  *
2735  * If -1 is returned, the end-of-data signal has been recognized (and removed
2736  * from libpq's input buffer). The caller *must* next call PQendcopy and
2737  * then return to normal processing.
2738  *
2739  * RETURNS:
2740  * -1 if the end-of-copy-data marker has been recognized
2741  * 0 if no data is available
2742  * >0 the number of bytes returned.
2743  *
2744  * The data returned will not extend beyond a data-row boundary. If possible
2745  * a whole row will be returned at one time. But if the buffer offered by
2746  * the caller is too small to hold a row sent by the backend, then a partial
2747  * data row will be returned. In text mode this can be detected by testing
2748  * whether the last returned byte is '\n' or not.
2749  *
2750  * The returned data is *not* null-terminated.
2751  */
2752 
2753 int
2754 PQgetlineAsync(PGconn *conn, char *buffer, int bufsize)
2755 {
2756  if (!conn)
2757  return -1;
2758 
2759  return pqGetlineAsync3(conn, buffer, bufsize);
2760 }
2761 
2762 /*
2763  * PQputline -- sends a string to the backend during COPY IN.
2764  * Returns 0 if OK, EOF if not.
2765  *
2766  * This is deprecated primarily because the return convention doesn't allow
2767  * caller to tell the difference between a hard error and a nonblock-mode
2768  * send failure.
2769  */
2770 int
2771 PQputline(PGconn *conn, const char *s)
2772 {
2773  return PQputnbytes(conn, s, strlen(s));
2774 }
2775 
2776 /*
2777  * PQputnbytes -- like PQputline, but buffer need not be null-terminated.
2778  * Returns 0 if OK, EOF if not.
2779  */
2780 int
2781 PQputnbytes(PGconn *conn, const char *buffer, int nbytes)
2782 {
2783  if (PQputCopyData(conn, buffer, nbytes) > 0)
2784  return 0;
2785  else
2786  return EOF;
2787 }
2788 
2789 /*
2790  * PQendcopy
2791  * After completing the data transfer portion of a copy in/out,
2792  * the application must call this routine to finish the command protocol.
2793  *
2794  * This is deprecated; it's cleaner to use PQgetResult to get the transfer
2795  * status.
2796  *
2797  * RETURNS:
2798  * 0 on success
2799  * 1 on failure
2800  */
2801 int
2803 {
2804  if (!conn)
2805  return 0;
2806 
2807  return pqEndcopy3(conn);
2808 }
2809 
2810 
2811 /* ----------------
2812  * PQfn - Send a function call to the POSTGRES backend.
2813  *
2814  * conn : backend connection
2815  * fnid : OID of function to be called
2816  * result_buf : pointer to result buffer
2817  * result_len : actual length of result is returned here
2818  * result_is_int : If the result is an integer, this must be 1,
2819  * otherwise this should be 0
2820  * args : pointer to an array of function arguments
2821  * (each has length, if integer, and value/pointer)
2822  * nargs : # of arguments in args array.
2823  *
2824  * RETURNS
2825  * PGresult with status = PGRES_COMMAND_OK if successful.
2826  * *result_len is > 0 if there is a return value, 0 if not.
2827  * PGresult with status = PGRES_FATAL_ERROR if backend returns an error.
2828  * NULL on communications failure. conn->errorMessage will be set.
2829  * ----------------
2830  */
2831 
2832 PGresult *
2834  int fnid,
2835  int *result_buf,
2836  int *result_len,
2837  int result_is_int,
2838  const PQArgBlock *args,
2839  int nargs)
2840 {
2841  *result_len = 0;
2842 
2843  if (!conn)
2844  return NULL;
2845 
2846  /*
2847  * Since this is the beginning of a query cycle, reset the error buffer.
2848  */
2850 
2851  if (conn->pipelineStatus != PQ_PIPELINE_OFF)
2852  {
2854  libpq_gettext("PQfn not allowed in pipeline mode\n"));
2855  return NULL;
2856  }
2857 
2858  if (conn->sock == PGINVALID_SOCKET || conn->asyncStatus != PGASYNC_IDLE ||
2859  conn->result != NULL)
2860  {
2862  libpq_gettext("connection in wrong state\n"));
2863  return NULL;
2864  }
2865 
2866  return pqFunctionCall3(conn, fnid,
2867  result_buf, result_len,
2868  result_is_int,
2869  args, nargs);
2870 }
2871 
2872 /* ====== Pipeline mode support ======== */
2873 
2874 /*
2875  * PQenterPipelineMode
2876  * Put an idle connection in pipeline mode.
2877  *
2878  * Returns 1 on success. On failure, errorMessage is set and 0 is returned.
2879  *
2880  * Commands submitted after this can be pipelined on the connection;
2881  * there's no requirement to wait for one to finish before the next is
2882  * dispatched.
2883  *
2884  * Queuing of a new query or syncing during COPY is not allowed.
2885  *
2886  * A set of commands is terminated by a PQpipelineSync. Multiple sync
2887  * points can be established while in pipeline mode. Pipeline mode can
2888  * be exited by calling PQexitPipelineMode() once all results are processed.
2889  *
2890  * This doesn't actually send anything on the wire, it just puts libpq
2891  * into a state where it can pipeline work.
2892  */
2893 int
2895 {
2896  if (!conn)
2897  return 0;
2898 
2899  /* succeed with no action if already in pipeline mode */
2900  if (conn->pipelineStatus != PQ_PIPELINE_OFF)
2901  return 1;
2902 
2903  if (conn->asyncStatus != PGASYNC_IDLE)
2904  {
2906  libpq_gettext("cannot enter pipeline mode, connection not idle\n"));
2907  return 0;
2908  }
2909 
2911 
2912  return 1;
2913 }
2914 
2915 /*
2916  * PQexitPipelineMode
2917  * End pipeline mode and return to normal command mode.
2918  *
2919  * Returns 1 in success (pipeline mode successfully ended, or not in pipeline
2920  * mode).
2921  *
2922  * Returns 0 if in pipeline mode and cannot be ended yet. Error message will
2923  * be set.
2924  */
2925 int
2927 {
2928  if (!conn)
2929  return 0;
2930 
2931  if (conn->pipelineStatus == PQ_PIPELINE_OFF)
2932  return 1;
2933 
2934  switch (conn->asyncStatus)
2935  {
2936  case PGASYNC_READY:
2937  case PGASYNC_READY_MORE:
2938  /* there are some uncollected results */
2940  libpq_gettext("cannot exit pipeline mode with uncollected results\n"));
2941  return 0;
2942 
2943  case PGASYNC_BUSY:
2945  libpq_gettext("cannot exit pipeline mode while busy\n"));
2946  return 0;
2947 
2948  default:
2949  /* OK */
2950  break;
2951  }
2952 
2953  /* still work to process */
2954  if (conn->cmd_queue_head != NULL)
2955  {
2957  libpq_gettext("cannot exit pipeline mode with uncollected results\n"));
2958  return 0;
2959  }
2960 
2962  conn->asyncStatus = PGASYNC_IDLE;
2963 
2964  /* Flush any pending data in out buffer */
2965  if (pqFlush(conn) < 0)
2966  return 0; /* error message is setup already */
2967  return 1;
2968 }
2969 
2970 /*
2971  * pqCommandQueueAdvance
2972  * Remove one query from the command queue, when we receive
2973  * all results from the server that pertain to it.
2974  */
2975 void
2977 {
2978  PGcmdQueueEntry *prevquery;
2979 
2980  if (conn->cmd_queue_head == NULL)
2981  return;
2982 
2983  /* delink from queue */
2984  prevquery = conn->cmd_queue_head;
2985  conn->cmd_queue_head = conn->cmd_queue_head->next;
2986 
2987  /* and make it recyclable */
2988  prevquery->next = NULL;
2989  pqRecycleCmdQueueEntry(conn, prevquery);
2990 }
2991 
2992 /*
2993  * pqPipelineProcessQueue: subroutine for PQgetResult
2994  * In pipeline mode, start processing the results of the next query in the queue.
2995  */
2996 static void
2998 {
2999  switch (conn->asyncStatus)
3000  {
3001  case PGASYNC_COPY_IN:
3002  case PGASYNC_COPY_OUT:
3003  case PGASYNC_COPY_BOTH:
3004  case PGASYNC_READY:
3005  case PGASYNC_READY_MORE:
3006  case PGASYNC_BUSY:
3007  /* client still has to process current query or results */
3008  return;
3009  case PGASYNC_IDLE:
3010  /* next query please */
3011  break;
3012  }
3013 
3014  /* Nothing to do if not in pipeline mode, or queue is empty */
3015  if (conn->pipelineStatus == PQ_PIPELINE_OFF ||
3016  conn->cmd_queue_head == NULL)
3017  return;
3018 
3019  /* Initialize async result-accumulation state */
3020  pqClearAsyncResult(conn);
3021 
3022  /*
3023  * Reset single-row processing mode. (Client has to set it up for each
3024  * query, if desired.)
3025  */
3026  conn->singleRowMode = false;
3027 
3028  if (conn->pipelineStatus == PQ_PIPELINE_ABORTED &&
3030  {
3031  /*
3032  * In an aborted pipeline we don't get anything from the server for
3033  * each result; we're just discarding commands from the queue until we
3034  * get to the next sync from the server.
3035  *
3036  * The PGRES_PIPELINE_ABORTED results tell the client that its queries
3037  * got aborted.
3038  */
3040  if (!conn->result)
3041  {
3043  libpq_gettext("out of memory\n"));
3044  pqSaveErrorResult(conn);
3045  return;
3046  }
3047  conn->asyncStatus = PGASYNC_READY;
3048  }
3049  else
3050  {
3051  /* allow parsing to continue */
3052  conn->asyncStatus = PGASYNC_BUSY;
3053  }
3054 }
3055 
3056 /*
3057  * PQpipelineSync
3058  * Send a Sync message as part of a pipeline, and flush to server
3059  *
3060  * It's legal to start submitting more commands in the pipeline immediately,
3061  * without waiting for the results of the current pipeline. There's no need to
3062  * end pipeline mode and start it again.
3063  *
3064  * If a command in a pipeline fails, every subsequent command up to and including
3065  * the result to the Sync message sent by PQpipelineSync gets set to
3066  * PGRES_PIPELINE_ABORTED state. If the whole pipeline is processed without
3067  * error, a PGresult with PGRES_PIPELINE_SYNC is produced.
3068  *
3069  * Queries can already have been sent before PQpipelineSync is called, but
3070  * PQpipelineSync need to be called before retrieving command results.
3071  *
3072  * The connection will remain in pipeline mode and unavailable for new
3073  * synchronous command execution functions until all results from the pipeline
3074  * are processed by the client.
3075  */
3076 int
3078 {
3079  PGcmdQueueEntry *entry;
3080 
3081  if (!conn)
3082  return 0;
3083 
3084  if (conn->pipelineStatus == PQ_PIPELINE_OFF)
3085  {
3087  libpq_gettext("cannot send pipeline when not in pipeline mode\n"));
3088  return 0;
3089  }
3090 
3091  switch (conn->asyncStatus)
3092  {
3093  case PGASYNC_COPY_IN:
3094  case PGASYNC_COPY_OUT:
3095  case PGASYNC_COPY_BOTH:
3096  /* should be unreachable */
3098  "internal error: cannot send pipeline while in COPY\n");
3099  return 0;
3100  case PGASYNC_READY:
3101  case PGASYNC_READY_MORE:
3102  case PGASYNC_BUSY:
3103  case PGASYNC_IDLE:
3104  /* OK to send sync */
3105  break;
3106  }
3107 
3108  entry = pqAllocCmdQueueEntry(conn);
3109  if (entry == NULL)
3110  return 0; /* error msg already set */
3111 
3112  entry->queryclass = PGQUERY_SYNC;
3113  entry->query = NULL;
3114 
3115  /* construct the Sync message */
3116  if (pqPutMsgStart('S', conn) < 0 ||
3117  pqPutMsgEnd(conn) < 0)
3118  goto sendFailed;
3119 
3120  /*
3121  * Give the data a push. In nonblock mode, don't complain if we're unable
3122  * to send it all; PQgetResult() will do any additional flushing needed.
3123  */
3124  if (PQflush(conn) < 0)
3125  goto sendFailed;
3126 
3127  /* OK, it's launched! */
3128  pqAppendCmdQueueEntry(conn, entry);
3129 
3130  return 1;
3131 
3132 sendFailed:
3133  pqRecycleCmdQueueEntry(conn, entry);
3134  /* error message should be set up already */
3135  return 0;
3136 }
3137 
3138 /*
3139  * PQsendFlushRequest
3140  * Send request for server to flush its buffer. Useful in pipeline
3141  * mode when a sync point is not desired.
3142  */
3143 int
3145 {
3146  if (!conn)
3147  return 0;
3148 
3149  /* Don't try to send if we know there's no live connection. */
3150  if (conn->status != CONNECTION_OK)
3151  {
3153  libpq_gettext("no connection to the server\n"));
3154  return 0;
3155  }
3156 
3157  /* Can't send while already busy, either, unless enqueuing for later */
3158  if (conn->asyncStatus != PGASYNC_IDLE &&
3160  {
3162  libpq_gettext("another command is already in progress\n"));
3163  return 0;
3164  }
3165 
3166  if (pqPutMsgStart('H', conn) < 0 ||
3167  pqPutMsgEnd(conn) < 0)
3168  {
3169  return 0;
3170  }
3171 
3172  return 1;
3173 }
3174 
3175 /* ====== accessor funcs for PGresult ======== */
3176 
3179 {
3180  if (!res)
3181  return PGRES_FATAL_ERROR;
3182  return res->resultStatus;
3183 }
3184 
3185 char *
3187 {
3188  if ((unsigned int) status >= lengthof(pgresStatus))
3189  return libpq_gettext("invalid ExecStatusType code");
3190  return pgresStatus[status];
3191 }
3192 
3193 char *
3195 {
3196  if (!res || !res->errMsg)
3197  return "";
3198  return res->errMsg;
3199 }
3200 
3201 char *
3203  PGVerbosity verbosity,
3204  PGContextVisibility show_context)
3205 {
3206  PQExpBufferData workBuf;
3207 
3208  /*
3209  * Because the caller is expected to free the result string, we must
3210  * strdup any constant result. We use plain strdup and document that
3211  * callers should expect NULL if out-of-memory.
3212  */
3213  if (!res ||
3214  (res->resultStatus != PGRES_FATAL_ERROR &&
3216  return strdup(libpq_gettext("PGresult is not an error result\n"));
3217 
3218  initPQExpBuffer(&workBuf);
3219 
3220  pqBuildErrorMessage3(&workBuf, res, verbosity, show_context);
3221 
3222  /* If insufficient memory to format the message, fail cleanly */
3223  if (PQExpBufferDataBroken(workBuf))
3224  {
3225  termPQExpBuffer(&workBuf);
3226  return strdup(libpq_gettext("out of memory\n"));
3227  }
3228 
3229  return workBuf.data;
3230 }
3231 
3232 char *
3233 PQresultErrorField(const PGresult *res, int fieldcode)
3234 {
3235  PGMessageField *pfield;
3236 
3237  if (!res)
3238  return NULL;
3239  for (pfield = res->errFields; pfield != NULL; pfield = pfield->next)
3240  {
3241  if (pfield->code == fieldcode)
3242  return pfield->contents;
3243  }
3244  return NULL;
3245 }
3246 
3247 int
3248 PQntuples(const PGresult *res)
3249 {
3250  if (!res)
3251  return 0;
3252  return res->ntups;
3253 }
3254 
3255 int
3256 PQnfields(const PGresult *res)
3257 {
3258  if (!res)
3259  return 0;
3260  return res->numAttributes;
3261 }
3262 
3263 int
3265 {
3266  if (!res)
3267  return 0;
3268  return res->binary;
3269 }
3270 
3271 /*
3272  * Helper routines to range-check field numbers and tuple numbers.
3273  * Return true if OK, false if not
3274  */
3275 
3276 static int
3277 check_field_number(const PGresult *res, int field_num)
3278 {
3279  if (!res)
3280  return false; /* no way to display error message... */
3281  if (field_num < 0 || field_num >= res->numAttributes)
3282  {
3284  "column number %d is out of range 0..%d",
3285  field_num, res->numAttributes - 1);
3286  return false;
3287  }
3288  return true;
3289 }
3290 
3291 static int
3293  int tup_num, int field_num)
3294 {
3295  if (!res)
3296  return false; /* no way to display error message... */
3297  if (tup_num < 0 || tup_num >= res->ntups)
3298  {
3300  "row number %d is out of range 0..%d",
3301  tup_num, res->ntups - 1);
3302  return false;
3303  }
3304  if (field_num < 0 || field_num >= res->numAttributes)
3305  {
3307  "column number %d is out of range 0..%d",
3308  field_num, res->numAttributes - 1);
3309  return false;
3310  }
3311  return true;
3312 }
3313 
3314 static int
3315 check_param_number(const PGresult *res, int param_num)
3316 {
3317  if (!res)
3318  return false; /* no way to display error message... */
3319  if (param_num < 0 || param_num >= res->numParameters)
3320  {
3322  "parameter number %d is out of range 0..%d",
3323  param_num, res->numParameters - 1);
3324  return false;
3325  }
3326 
3327  return true;
3328 }
3329 
3330 /*
3331  * returns NULL if the field_num is invalid
3332  */
3333 char *
3334 PQfname(const PGresult *res, int field_num)
3335 {
3336  if (!check_field_number(res, field_num))
3337  return NULL;
3338  if (res->attDescs)
3339  return res->attDescs[field_num].name;
3340  else
3341  return NULL;
3342 }
3343 
3344 /*
3345  * PQfnumber: find column number given column name
3346  *
3347  * The column name is parsed as if it were in a SQL statement, including
3348  * case-folding and double-quote processing. But note a possible gotcha:
3349  * downcasing in the frontend might follow different locale rules than
3350  * downcasing in the backend...
3351  *
3352  * Returns -1 if no match. In the present backend it is also possible
3353  * to have multiple matches, in which case the first one is found.
3354  */
3355 int
3356 PQfnumber(const PGresult *res, const char *field_name)
3357 {
3358  char *field_case;
3359  bool in_quotes;
3360  bool all_lower = true;
3361  const char *iptr;
3362  char *optr;
3363  int i;
3364 
3365  if (!res)
3366  return -1;
3367 
3368  /*
3369  * Note: it is correct to reject a zero-length input string; the proper
3370  * input to match a zero-length field name would be "".
3371  */
3372  if (field_name == NULL ||
3373  field_name[0] == '\0' ||
3374  res->attDescs == NULL)
3375  return -1;
3376 
3377  /*
3378  * Check if we can avoid the strdup() and related work because the
3379  * passed-in string wouldn't be changed before we do the check anyway.
3380  */
3381  for (iptr = field_name; *iptr; iptr++)
3382  {
3383  char c = *iptr;
3384 
3385  if (c == '"' || c != pg_tolower((unsigned char) c))
3386  {
3387  all_lower = false;
3388  break;
3389  }
3390  }
3391 
3392  if (all_lower)
3393  for (i = 0; i < res->numAttributes; i++)
3394  if (strcmp(field_name, res->attDescs[i].name) == 0)
3395  return i;
3396 
3397  /* Fall through to the normal check if that didn't work out. */
3398 
3399  /*
3400  * Note: this code will not reject partially quoted strings, eg
3401  * foo"BAR"foo will become fooBARfoo when it probably ought to be an error
3402  * condition.
3403  */
3404  field_case = strdup(field_name);
3405  if (field_case == NULL)
3406  return -1; /* grotty */
3407 
3408  in_quotes = false;
3409  optr = field_case;
3410  for (iptr = field_case; *iptr; iptr++)
3411  {
3412  char c = *iptr;
3413 
3414  if (in_quotes)
3415  {
3416  if (c == '"')
3417  {
3418  if (iptr[1] == '"')
3419  {
3420  /* doubled quotes become a single quote */
3421  *optr++ = '"';
3422  iptr++;
3423  }
3424  else
3425  in_quotes = false;
3426  }
3427  else
3428  *optr++ = c;
3429  }
3430  else if (c == '"')
3431  in_quotes = true;
3432  else
3433  {
3434  c = pg_tolower((unsigned char) c);
3435  *optr++ = c;
3436  }
3437  }
3438  *optr = '\0';
3439 
3440  for (i = 0; i < res->numAttributes; i++)
3441  {
3442  if (strcmp(field_case, res->attDescs[i].name) == 0)
3443  {
3444  free(field_case);
3445  return i;
3446  }
3447  }
3448  free(field_case);
3449  return -1;
3450 }
3451 
3452 Oid
3453 PQftable(const PGresult *res, int field_num)
3454 {
3455  if (!check_field_number(res, field_num))
3456  return InvalidOid;
3457  if (res->attDescs)
3458  return res->attDescs[field_num].tableid;
3459  else
3460  return InvalidOid;
3461 }
3462 
3463 int
3464 PQftablecol(const PGresult *res, int field_num)
3465 {
3466  if (!check_field_number(res, field_num))
3467  return 0;
3468  if (res->attDescs)
3469  return res->attDescs[field_num].columnid;
3470  else
3471  return 0;
3472 }
3473 
3474 int
3475 PQfformat(const PGresult *res, int field_num)
3476 {
3477  if (!check_field_number(res, field_num))
3478  return 0;
3479  if (res->attDescs)
3480  return res->attDescs[field_num].format;
3481  else
3482  return 0;
3483 }
3484 
3485 Oid
3486 PQftype(const PGresult *res, int field_num)
3487 {
3488  if (!check_field_number(res, field_num))
3489  return InvalidOid;
3490  if (res->attDescs)
3491  return res->attDescs[field_num].typid;
3492  else
3493  return InvalidOid;
3494 }
3495 
3496 int
3497 PQfsize(const PGresult *res, int field_num)
3498 {
3499  if (!check_field_number(res, field_num))
3500  return 0;
3501  if (res->attDescs)
3502  return res->attDescs[field_num].typlen;
3503  else
3504  return 0;
3505 }
3506 
3507 int
3508 PQfmod(const PGresult *res, int field_num)
3509 {
3510  if (!check_field_number(res, field_num))
3511  return 0;
3512  if (res->attDescs)
3513  return res->attDescs[field_num].atttypmod;
3514  else
3515  return 0;
3516 }
3517 
3518 char *
3520 {
3521  if (!res)
3522  return NULL;
3523  return res->cmdStatus;
3524 }
3525 
3526 /*
3527  * PQoidStatus -
3528  * if the last command was an INSERT, return the oid string
3529  * if not, return ""
3530  */
3531 char *
3533 {
3534  /*
3535  * This must be enough to hold the result. Don't laugh, this is better
3536  * than what this function used to do.
3537  */
3538  static char buf[24];
3539 
3540  size_t len;
3541 
3542  if (!res || strncmp(res->cmdStatus, "INSERT ", 7) != 0)
3543  return "";
3544 
3545  len = strspn(res->cmdStatus + 7, "0123456789");
3546  if (len > sizeof(buf) - 1)
3547  len = sizeof(buf) - 1;
3548  memcpy(buf, res->cmdStatus + 7, len);
3549  buf[len] = '\0';
3550 
3551  return buf;
3552 }
3553 
3554 /*
3555  * PQoidValue -
3556  * a perhaps preferable form of the above which just returns
3557  * an Oid type
3558  */
3559 Oid
3561 {
3562  char *endptr = NULL;
3563  unsigned long result;
3564 
3565  if (!res ||
3566  strncmp(res->cmdStatus, "INSERT ", 7) != 0 ||
3567  res->cmdStatus[7] < '0' ||
3568  res->cmdStatus[7] > '9')
3569  return InvalidOid;
3570 
3571  result = strtoul(res->cmdStatus + 7, &endptr, 10);
3572 
3573  if (!endptr || (*endptr != ' ' && *endptr != '\0'))
3574  return InvalidOid;
3575  else
3576  return (Oid) result;
3577 }
3578 
3579 
3580 /*
3581  * PQcmdTuples -
3582  * If the last command was INSERT/UPDATE/DELETE/MOVE/FETCH/COPY, return
3583  * a string containing the number of inserted/affected tuples. If not,
3584  * return "".
3585  *
3586  * XXX: this should probably return an int
3587  */
3588 char *
3590 {
3591  char *p,
3592  *c;
3593 
3594  if (!res)
3595  return "";
3596 
3597  if (strncmp(res->cmdStatus, "INSERT ", 7) == 0)
3598  {
3599  p = res->cmdStatus + 7;
3600  /* INSERT: skip oid and space */
3601  while (*p && *p != ' ')
3602  p++;
3603  if (*p == 0)
3604  goto interpret_error; /* no space? */
3605  p++;
3606  }
3607  else if (strncmp(res->cmdStatus, "SELECT ", 7) == 0 ||
3608  strncmp(res->cmdStatus, "DELETE ", 7) == 0 ||
3609  strncmp(res->cmdStatus, "UPDATE ", 7) == 0)
3610  p = res->cmdStatus + 7;
3611  else if (strncmp(res->cmdStatus, "FETCH ", 6) == 0)
3612  p = res->cmdStatus + 6;
3613  else if (strncmp(res->cmdStatus, "MOVE ", 5) == 0 ||
3614  strncmp(res->cmdStatus, "COPY ", 5) == 0)
3615  p = res->cmdStatus + 5;
3616  else
3617  return "";
3618 
3619  /* check that we have an integer (at least one digit, nothing else) */
3620  for (c = p; *c; c++)
3621  {
3622  if (!isdigit((unsigned char) *c))
3623  goto interpret_error;
3624  }
3625  if (c == p)
3626  goto interpret_error;
3627 
3628  return p;
3629 
3630 interpret_error:
3632  "could not interpret result from server: %s",
3633  res->cmdStatus);
3634  return "";
3635 }
3636 
3637 /*
3638  * PQgetvalue:
3639  * return the value of field 'field_num' of row 'tup_num'
3640  */
3641 char *
3642 PQgetvalue(const PGresult *res, int tup_num, int field_num)
3643 {
3644  if (!check_tuple_field_number(res, tup_num, field_num))
3645  return NULL;
3646  return res->tuples[tup_num][field_num].value;
3647 }
3648 
3649 /* PQgetlength:
3650  * returns the actual length of a field value in bytes.
3651  */
3652 int
3653 PQgetlength(const PGresult *res, int tup_num, int field_num)
3654 {
3655  if (!check_tuple_field_number(res, tup_num, field_num))
3656  return 0;
3657  if (res->tuples[tup_num][field_num].len != NULL_LEN)
3658  return res->tuples[tup_num][field_num].len;
3659  else
3660  return 0;
3661 }
3662 
3663 /* PQgetisnull:
3664  * returns the null status of a field value.
3665  */
3666 int
3667 PQgetisnull(const PGresult *res, int tup_num, int field_num)
3668 {
3669  if (!check_tuple_field_number(res, tup_num, field_num))
3670  return 1; /* pretend it is null */
3671  if (res->tuples[tup_num][field_num].len == NULL_LEN)
3672  return 1;
3673  else
3674  return 0;
3675 }
3676 
3677 /* PQnparams:
3678  * returns the number of input parameters of a prepared statement.
3679  */
3680 int
3681 PQnparams(const PGresult *res)
3682 {
3683  if (!res)
3684  return 0;
3685  return res->numParameters;
3686 }
3687 
3688 /* PQparamtype:
3689  * returns type Oid of the specified statement parameter.
3690  */
3691 Oid
3692 PQparamtype(const PGresult *res, int param_num)
3693 {
3694  if (!check_param_number(res, param_num))
3695  return InvalidOid;
3696  if (res->paramDescs)
3697  return res->paramDescs[param_num].typid;
3698  else
3699  return InvalidOid;
3700 }
3701 
3702 
3703 /* PQsetnonblocking:
3704  * sets the PGconn's database connection non-blocking if the arg is true
3705  * or makes it blocking if the arg is false, this will not protect
3706  * you from PQexec(), you'll only be safe when using the non-blocking API.
3707  * Needs to be called only on a connected database connection.
3708  */
3709 int
3711 {
3712  bool barg;
3713 
3714  if (!conn || conn->status == CONNECTION_BAD)
3715  return -1;
3716 
3717  barg = (arg ? true : false);
3718 
3719  /* early out if the socket is already in the state requested */
3720  if (barg == conn->nonblocking)
3721  return 0;
3722 
3723  /*
3724  * to guarantee constancy for flushing/query/result-polling behavior we
3725  * need to flush the send queue at this point in order to guarantee proper
3726  * behavior. this is ok because either they are making a transition _from_
3727  * or _to_ blocking mode, either way we can block them.
3728  *
3729  * Clear errorMessage in case pqFlush adds to it.
3730  */
3732 
3733  /* if we are going from blocking to non-blocking flush here */
3734  if (pqFlush(conn))
3735  return -1;
3736 
3737  conn->nonblocking = barg;
3738 
3739  return 0;
3740 }
3741 
3742 /*
3743  * return the blocking status of the database connection
3744  * true == nonblocking, false == blocking
3745  */
3746 int
3748 {
3749  return pqIsnonblocking(conn);
3750 }
3751 
3752 /* libpq is thread-safe? */
3753 int
3755 {
3756 #ifdef ENABLE_THREAD_SAFETY
3757  return true;
3758 #else
3759  return false;
3760 #endif
3761 }
3762 
3763 
3764 /* try to force data out, really only useful for non-blocking users */
3765 int
3767 {
3768  return pqFlush(conn);
3769 }
3770 
3771 /*
3772  * pqPipelineFlush
3773  *
3774  * In pipeline mode, data will be flushed only when the out buffer reaches the
3775  * threshold value. In non-pipeline mode, it behaves as stock pqFlush.
3776  *
3777  * Returns 0 on success.
3778  */
3779 static int
3781 {
3782  if ((conn->pipelineStatus != PQ_PIPELINE_ON) ||
3783  (conn->outCount >= OUTBUFFER_THRESHOLD))
3784  return pqFlush(conn);
3785  return 0;
3786 }
3787 
3788 
3789 /*
3790  * PQfreemem - safely frees memory allocated
3791  *
3792  * Needed mostly by Win32, unless multithreaded DLL (/MD in VC6)
3793  * Used for freeing memory from PQescapeBytea()/PQunescapeBytea()
3794  */
3795 void
3796 PQfreemem(void *ptr)
3797 {
3798  free(ptr);
3799 }
3800 
3801 /*
3802  * PQfreeNotify - free's the memory associated with a PGnotify
3803  *
3804  * This function is here only for binary backward compatibility.
3805  * New code should use PQfreemem(). A macro will automatically map
3806  * calls to PQfreemem. It should be removed in the future. bjm 2003-03-24
3807  */
3808 
3809 #undef PQfreeNotify
3810 void PQfreeNotify(PGnotify *notify);
3811 
3812 void
3814 {
3815  PQfreemem(notify);
3816 }
3817 
3818 
3819 /*
3820  * Escaping arbitrary strings to get valid SQL literal strings.
3821  *
3822  * Replaces "'" with "''", and if not std_strings, replaces "\" with "\\".
3823  *
3824  * length is the length of the source string. (Note: if a terminating NUL
3825  * is encountered sooner, PQescapeString stops short of "length"; the behavior
3826  * is thus rather like strncpy.)
3827  *
3828  * For safety the buffer at "to" must be at least 2*length + 1 bytes long.
3829  * A terminating NUL character is added to the output string, whether the
3830  * input is NUL-terminated or not.
3831  *
3832  * Returns the actual length of the output (not counting the terminating NUL).
3833  */
3834 static size_t
3836  char *to, const char *from, size_t length,
3837  int *error,
3838  int encoding, bool std_strings)
3839 {
3840  const char *source = from;
3841  char *target = to;
3842  size_t remaining = length;
3843 
3844  if (error)
3845  *error = 0;
3846 
3847  while (remaining > 0 && *source != '\0')
3848  {
3849  char c = *source;
3850  int len;
3851  int i;
3852 
3853  /* Fast path for plain ASCII */
3854  if (!IS_HIGHBIT_SET(c))
3855  {
3856  /* Apply quoting if needed */
3857  if (SQL_STR_DOUBLE(c, !std_strings))
3858  *target++ = c;
3859  /* Copy the character */
3860  *target++ = c;
3861  source++;
3862  remaining--;
3863  continue;
3864  }
3865 
3866  /* Slow path for possible multibyte characters */
3867  len = pg_encoding_mblen(encoding, source);
3868 
3869  /* Copy the character */
3870  for (i = 0; i < len; i++)
3871  {
3872  if (remaining == 0 || *source == '\0')
3873  break;
3874  *target++ = *source++;
3875  remaining--;
3876  }
3877 
3878  /*
3879  * If we hit premature end of string (ie, incomplete multibyte
3880  * character), try to pad out to the correct length with spaces. We
3881  * may not be able to pad completely, but we will always be able to
3882  * insert at least one pad space (since we'd not have quoted a
3883  * multibyte character). This should be enough to make a string that
3884  * the server will error out on.
3885  */
3886  if (i < len)
3887  {
3888  if (error)
3889  *error = 1;
3890  if (conn)
3892  libpq_gettext("incomplete multibyte character\n"));
3893  for (; i < len; i++)
3894  {
3895  if (((size_t) (target - to)) / 2 >= length)
3896  break;
3897  *target++ = ' ';
3898  }
3899  break;
3900  }
3901  }
3902 
3903  /* Write the terminating NUL character. */
3904  *target = '\0';
3905 
3906  return target - to;
3907 }
3908 
3909 size_t
3911  char *to, const char *from, size_t length,
3912  int *error)
3913 {
3914  if (!conn)
3915  {
3916  /* force empty-string result */
3917  *to = '\0';
3918  if (error)
3919  *error = 1;
3920  return 0;
3921  }
3922 
3924 
3925  return PQescapeStringInternal(conn, to, from, length, error,
3926  conn->client_encoding,
3927  conn->std_strings);
3928 }
3929 
3930 size_t
3931 PQescapeString(char *to, const char *from, size_t length)
3932 {
3933  return PQescapeStringInternal(NULL, to, from, length, NULL,
3936 }
3937 
3938 
3939 /*
3940  * Escape arbitrary strings. If as_ident is true, we escape the result
3941  * as an identifier; if false, as a literal. The result is returned in
3942  * a newly allocated buffer. If we fail due to an encoding violation or out
3943  * of memory condition, we return NULL, storing an error message into conn.
3944  */
3945 static char *
3946 PQescapeInternal(PGconn *conn, const char *str, size_t len, bool as_ident)
3947 {
3948  const char *s;
3949  char *result;
3950  char *rp;
3951  int num_quotes = 0; /* single or double, depending on as_ident */
3952  int num_backslashes = 0;
3953  int input_len;
3954  int result_size;
3955  char quote_char = as_ident ? '"' : '\'';
3956 
3957  /* We must have a connection, else fail immediately. */
3958  if (!conn)
3959  return NULL;
3960 
3962 
3963  /* Scan the string for characters that must be escaped. */
3964  for (s = str; (s - str) < len && *s != '\0'; ++s)
3965  {
3966  if (*s == quote_char)
3967  ++num_quotes;
3968  else if (*s == '\\')
3969  ++num_backslashes;
3970  else if (IS_HIGHBIT_SET(*s))
3971  {
3972  int charlen;
3973 
3974  /* Slow path for possible multibyte characters */
3975  charlen = pg_encoding_mblen(conn->client_encoding, s);
3976 
3977  /* Multibyte character overruns allowable length. */
3978  if ((s - str) + charlen > len || memchr(s, 0, charlen) != NULL)
3979  {
3981  libpq_gettext("incomplete multibyte character\n"));
3982  return NULL;
3983  }
3984 
3985  /* Adjust s, bearing in mind that for loop will increment it. */
3986  s += charlen - 1;
3987  }
3988  }
3989 
3990  /* Allocate output buffer. */
3991  input_len = s - str;
3992  result_size = input_len + num_quotes + 3; /* two quotes, plus a NUL */
3993  if (!as_ident && num_backslashes > 0)
3994  result_size += num_backslashes + 2;
3995  result = rp = (char *) malloc(result_size);
3996  if (rp == NULL)
3997  {
3999  libpq_gettext("out of memory\n"));
4000  return NULL;
4001  }
4002 
4003  /*
4004  * If we are escaping a literal that contains backslashes, we use the
4005  * escape string syntax so that the result is correct under either value
4006  * of standard_conforming_strings. We also emit a leading space in this
4007  * case, to guard against the possibility that the result might be
4008  * interpolated immediately following an identifier.
4009  */
4010  if (!as_ident && num_backslashes > 0)
4011  {
4012  *rp++ = ' ';
4013  *rp++ = 'E';
4014  }
4015 
4016  /* Opening quote. */
4017  *rp++ = quote_char;
4018 
4019  /*
4020  * Use fast path if possible.
4021  *
4022  * We've already verified that the input string is well-formed in the
4023  * current encoding. If it contains no quotes and, in the case of
4024  * literal-escaping, no backslashes, then we can just copy it directly to
4025  * the output buffer, adding the necessary quotes.
4026  *
4027  * If not, we must rescan the input and process each character
4028  * individually.
4029  */
4030  if (num_quotes == 0 && (num_backslashes == 0 || as_ident))
4031  {
4032  memcpy(rp, str, input_len);
4033  rp += input_len;
4034  }
4035  else
4036  {
4037  for (s = str; s - str < input_len; ++s)
4038  {
4039  if (*s == quote_char || (!as_ident && *s == '\\'))
4040  {
4041  *rp++ = *s;
4042  *rp++ = *s;
4043  }
4044  else if (!IS_HIGHBIT_SET(*s))
4045  *rp++ = *s;
4046  else
4047  {
4048  int i = pg_encoding_mblen(conn->client_encoding, s);
4049 
4050  while (1)
4051  {
4052  *rp++ = *s;
4053  if (--i == 0)
4054  break;
4055  ++s; /* for loop will provide the final increment */
4056  }
4057  }
4058  }
4059  }
4060 
4061  /* Closing quote and terminating NUL. */
4062  *rp++ = quote_char;
4063  *rp = '\0';
4064 
4065  return result;
4066 }
4067 
4068 char *
4069 PQescapeLiteral(PGconn *conn, const char *str, size_t len)
4070 {
4071  return PQescapeInternal(conn, str, len, false);
4072 }
4073 
4074 char *
4075 PQescapeIdentifier(PGconn *conn, const char *str, size_t len)
4076 {
4077  return PQescapeInternal(conn, str, len, true);
4078 }
4079 
4080 /* HEX encoding support for bytea */
4081 static const char hextbl[] = "0123456789abcdef";
4082 
4083 static const int8 hexlookup[128] = {
4084  -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
4085  -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
4086  -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
4087  0, 1, 2, 3, 4, 5, 6, 7, 8, 9, -1, -1, -1, -1, -1, -1,
4088  -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1,
4089  -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
4090  -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1,
4091  -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
4092 };
4093 
4094 static inline char
4095 get_hex(char c)
4096 {
4097  int res = -1;
4098 
4099  if (c > 0 && c < 127)
4100  res = hexlookup[(unsigned char) c];
4101 
4102  return (char) res;
4103 }
4104 
4105 
4106 /*
4107  * PQescapeBytea - converts from binary string to the
4108  * minimal encoding necessary to include the string in an SQL
4109  * INSERT statement with a bytea type column as the target.
4110  *
4111  * We can use either hex or escape (traditional) encoding.
4112  * In escape mode, the following transformations are applied:
4113  * '\0' == ASCII 0 == \000
4114  * '\'' == ASCII 39 == ''
4115  * '\\' == ASCII 92 == \\
4116  * anything < 0x20, or > 0x7e ---> \ooo
4117  * (where ooo is an octal expression)
4118  *
4119  * If not std_strings, all backslashes sent to the output are doubled.
4120  */
4121 static unsigned char *
4123  const unsigned char *from, size_t from_length,
4124  size_t *to_length, bool std_strings, bool use_hex)
4125 {
4126  const unsigned char *vp;
4127  unsigned char *rp;
4128  unsigned char *result;
4129  size_t i;
4130  size_t len;
4131  size_t bslash_len = (std_strings ? 1 : 2);
4132 
4133  /*
4134  * empty string has 1 char ('\0')
4135  */
4136  len = 1;
4137 
4138  if (use_hex)
4139  {
4140  len += bslash_len + 1 + 2 * from_length;
4141  }
4142  else
4143  {
4144  vp = from;
4145  for (i = from_length; i > 0; i--, vp++)
4146  {
4147  if (*vp < 0x20 || *vp > 0x7e)
4148  len += bslash_len + 3;
4149  else if (*vp == '\'')
4150  len += 2;
4151  else if (*vp == '\\')
4152  len += bslash_len + bslash_len;
4153  else
4154  len++;
4155  }
4156  }
4157 
4158  *to_length = len;
4159  rp = result = (unsigned char *) malloc(len);
4160  if (rp == NULL)
4161  {
4162  if (conn)
4164  libpq_gettext("out of memory\n"));
4165  return NULL;
4166  }
4167 
4168  if (use_hex)
4169  {
4170  if (!std_strings)
4171  *rp++ = '\\';
4172  *rp++ = '\\';
4173  *rp++ = 'x';
4174  }
4175 
4176  vp = from;
4177  for (i = from_length; i > 0; i--, vp++)
4178  {
4179  unsigned char c = *vp;
4180 
4181  if (use_hex)
4182  {
4183  *rp++ = hextbl[(c >> 4) & 0xF];
4184  *rp++ = hextbl[c & 0xF];
4185  }
4186  else if (c < 0x20 || c > 0x7e)
4187  {
4188  if (!std_strings)
4189  *rp++ = '\\';
4190  *rp++ = '\\';
4191  *rp++ = (c >> 6) + '0';
4192  *rp++ = ((c >> 3) & 07) + '0';
4193  *rp++ = (c & 07) + '0';
4194  }
4195  else if (c == '\'')
4196  {
4197  *rp++ = '\'';
4198  *rp++ = '\'';
4199  }
4200  else if (c == '\\')
4201  {
4202  if (!std_strings)
4203  {
4204  *rp++ = '\\';
4205  *rp++ = '\\';
4206  }
4207  *rp++ = '\\';
4208  *rp++ = '\\';
4209  }
4210  else
4211  *rp++ = c;
4212  }
4213  *rp = '\0';
4214 
4215  return result;
4216 }
4217 
4218 unsigned char *
4220  const unsigned char *from, size_t from_length,
4221  size_t *to_length)
4222 {
4223  if (!conn)
4224  return NULL;
4225 
4227 
4228  return PQescapeByteaInternal(conn, from, from_length, to_length,
4229  conn->std_strings,
4230  (conn->sversion >= 90000));
4231 }
4232 
4233 unsigned char *
4234 PQescapeBytea(const unsigned char *from, size_t from_length, size_t *to_length)
4235 {
4236  return PQescapeByteaInternal(NULL, from, from_length, to_length,
4238  false /* can't use hex */ );
4239 }
4240 
4241 
4242 #define ISFIRSTOCTDIGIT(CH) ((CH) >= '0' && (CH) <= '3')
4243 #define ISOCTDIGIT(CH) ((CH) >= '0' && (CH) <= '7')
4244 #define OCTVAL(CH) ((CH) - '0')
4245 
4246 /*
4247  * PQunescapeBytea - converts the null terminated string representation
4248  * of a bytea, strtext, into binary, filling a buffer. It returns a
4249  * pointer to the buffer (or NULL on error), and the size of the
4250  * buffer in retbuflen. The pointer may subsequently be used as an
4251  * argument to the function PQfreemem.
4252  *
4253  * The following transformations are made:
4254  * \\ == ASCII 92 == \
4255  * \ooo == a byte whose value = ooo (ooo is an octal number)
4256  * \x == x (x is any character not matched by the above transformations)
4257  */
4258 unsigned char *
4259 PQunescapeBytea(const unsigned char *strtext, size_t *retbuflen)
4260 {
4261  size_t strtextlen,
4262  buflen;
4263  unsigned char *buffer,
4264  *tmpbuf;
4265  size_t i,
4266  j;
4267 
4268  if (strtext == NULL)
4269  return NULL;
4270 
4271  strtextlen = strlen((const char *) strtext);
4272 
4273  if (strtext[0] == '\\' && strtext[1] == 'x')
4274  {
4275  const unsigned char *s;
4276  unsigned char *p;
4277 
4278  buflen = (strtextlen - 2) / 2;
4279  /* Avoid unportable malloc(0) */
4280  buffer = (unsigned char *) malloc(buflen > 0 ? buflen : 1);
4281  if (buffer == NULL)
4282  return NULL;
4283 
4284  s = strtext + 2;
4285  p = buffer;
4286  while (*s)
4287  {
4288  char v1,
4289  v2;
4290 
4291  /*
4292  * Bad input is silently ignored. Note that this includes
4293  * whitespace between hex pairs, which is allowed by byteain.
4294  */
4295  v1 = get_hex(*s++);
4296  if (!*s || v1 == (char) -1)
4297  continue;
4298  v2 = get_hex(*s++);
4299  if (v2 != (char) -1)
4300  *p++ = (v1 << 4) | v2;
4301  }
4302 
4303  buflen = p - buffer;
4304  }
4305  else
4306  {
4307  /*
4308  * Length of input is max length of output, but add one to avoid
4309  * unportable malloc(0) if input is zero-length.
4310  */
4311  buffer = (unsigned char *) malloc(strtextlen + 1);
4312  if (buffer == NULL)
4313  return NULL;
4314 
4315  for (i = j = 0; i < strtextlen;)
4316  {
4317  switch (strtext[i])
4318  {
4319  case '\\':
4320  i++;
4321  if (strtext[i] == '\\')
4322  buffer[j++] = strtext[i++];
4323  else
4324  {
4325  if ((ISFIRSTOCTDIGIT(strtext[i])) &&
4326  (ISOCTDIGIT(strtext[i + 1])) &&
4327  (ISOCTDIGIT(strtext[i + 2])))
4328  {
4329  int byte;
4330 
4331  byte = OCTVAL(strtext[i++]);
4332  byte = (byte << 3) + OCTVAL(strtext[i++]);
4333  byte = (byte << 3) + OCTVAL(strtext[i++]);
4334  buffer[j++] = byte;
4335  }
4336  }
4337 
4338  /*
4339  * Note: if we see '\' followed by something that isn't a
4340  * recognized escape sequence, we loop around having done
4341  * nothing except advance i. Therefore the something will
4342  * be emitted as ordinary data on the next cycle. Corner
4343  * case: '\' at end of string will just be discarded.
4344  */
4345  break;
4346 
4347  default:
4348  buffer[j++] = strtext[i++];
4349  break;
4350  }
4351  }
4352  buflen = j; /* buflen is the length of the dequoted data */
4353  }
4354 
4355  /* Shrink the buffer to be no larger than necessary */
4356  /* +1 avoids unportable behavior when buflen==0 */
4357  tmpbuf = realloc(buffer, buflen + 1);
4358 
4359  /* It would only be a very brain-dead realloc that could fail, but... */
4360  if (!tmpbuf)
4361  {
4362  free(buffer);
4363  return NULL;
4364  }
4365 
4366  *retbuflen = buflen;
4367  return tmpbuf;
4368 }
int remaining
Definition: informix.c:667
int PQputCopyData(PGconn *conn, const char *buffer, int nbytes)
Definition: fe-exec.c:2544
struct PGEvent PGEvent
int pqFlush(PGconn *conn)
Definition: fe-misc.c:965
int pqRowProcessor(PGconn *conn, const char **errmsgp)
Definition: fe-exec.c:1107
static bool static_std_strings
Definition: fe-exec.c:52
int PQgetlength(const PGresult *res, int tup_num, int field_num)
Definition: fe-exec.c:3653
size_t memorySize
Definition: libpq-int.h:213
PGresult * PQexecPrepared(PGconn *conn, const char *stmtName, int nParams, const char *const *paramValues, const int *paramLengths, const int *paramFormats, int resultFormat)
Definition: fe-exec.c:2254
int PQnfields(const PGresult *res)
Definition: fe-exec.c:3256
PGresult * PQprepare(PGconn *conn, const char *stmtName, const char *query, int nParams, const Oid *paramTypes)
Definition: fe-exec.c:2237
PGresult * PQdescribePrepared(PGconn *conn, const char *stmt)
Definition: fe-exec.c:2386
PGMessageField * errFields
Definition: libpq-int.h:198
int PQftablecol(const PGresult *res, int field_num)
Definition: fe-exec.c:3464
size_t PQresultMemorySize(const PGresult *res)
Definition: fe-exec.c:639
int pg_char_to_encoding(const char *name)
Definition: encnames.c:550
char space[1]
Definition: libpq-int.h:107
int PQisnonblocking(const PGconn *conn)
Definition: fe-exec.c:3747
#define PG_DIAG_MESSAGE_PRIMARY
Definition: postgres_ext.h:58
#define ISFIRSTOCTDIGIT(CH)
Definition: fe-exec.c:4242
size_t PQescapeString(char *to, const char *from, size_t length)
Definition: fe-exec.c:3931
const PGresult * src
Definition: libpq-events.h:60
int PQexitPipelineMode(PGconn *conn)
Definition: fe-exec.c:2926
PGEvent * events
Definition: libpq-int.h:405
int PQsendQueryParams(PGconn *conn, const char *command, int nParams, const Oid *paramTypes, const char *const *paramValues, const int *paramLengths, const int *paramFormats, int resultFormat)
Definition: fe-exec.c:1438
int pqGetline3(PGconn *conn, char *s, int maxlen)
char * PQgetvalue(const PGresult *res, int tup_num, int field_num)
Definition: fe-exec.c:3642
int pqCheckOutBufferSpace(size_t bytes_needed, PGconn *conn)
Definition: fe-misc.c:290
static void error(void)
Definition: sql-dyntest.c:147
static int check_tuple_field_number(const PGresult *res, int tup_num, int field_num)
Definition: fe-exec.c:3292
int PQenterPipelineMode(PGconn *conn)
Definition: fe-exec.c:2894
int PQfsize(const PGresult *res, int field_num)
Definition: fe-exec.c:3497
bool singleRowMode
Definition: libpq-int.h:418
PGnotify * PQnotifies(PGconn *conn)
Definition: fe-exec.c:2516
char * PQfname(const PGresult *res, int field_num)
Definition: fe-exec.c:3334
void pqSaveParameterStatus(PGconn *conn, const char *name, const char *value)
Definition: fe-exec.c:982
static int check_param_number(const PGresult *res, int param_num)
Definition: fe-exec.c:3315
bool resultInitialized
Definition: libpq-int.h:165
void termPQExpBuffer(PQExpBuffer str)
Definition: pqexpbuffer.c:131
#define OCTVAL(CH)
Definition: fe-exec.c:4244
#define pqIsnonblocking(conn)
Definition: libpq-int.h:830
char * PQcmdTuples(PGresult *res)
Definition: fe-exec.c:3589
PGresult * pqFunctionCall3(PGconn *conn, Oid fnid, int *result_buf, int *actual_result_len, int result_is_int, const PQArgBlock *args, int nargs)
void appendPQExpBufferStr(PQExpBuffer str, const char *data)
Definition: pqexpbuffer.c:369
int PQputnbytes(PGconn *conn, const char *buffer, int nbytes)
Definition: fe-exec.c:2781
int outCount
Definition: libpq-int.h:488
int PQsetvalue(PGresult *res, int tup_num, int field_num, char *value, int len)
Definition: fe-exec.c:436
Oid PQoidValue(const PGresult *res)
Definition: fe-exec.c:3560
Oid PQftable(const PGresult *res, int field_num)
Definition: fe-exec.c:3453
PGcmdQueueEntry * cmd_queue_head
Definition: libpq-int.h:434
PGpipelineStatus pipelineStatus
Definition: libpq-int.h:417
struct PGcmdQueueEntry * next
Definition: libpq-int.h:324
int PQsendDescribePortal(PGconn *conn, const char *portal)
Definition: fe-exec.c:2435
int tupArrSize
Definition: libpq-int.h:175
static int PQsendQueryGuts(PGconn *conn, const char *command, const char *stmtName, int nParams, const Oid *paramTypes, const char *const *paramValues, const int *paramLengths, const int *paramFormats, int resultFormat)
Definition: fe-exec.c:1707
PGresult_data * next
Definition: libpq-int.h:106
PGresult * PQcopyResult(const PGresult *src, int flags)
Definition: fe-exec.c:299
union pgresult_data PGresult_data
Definition: libpq-int.h:102
char * PQresStatus(ExecStatusType status)
Definition: fe-exec.c:3186
Oid PQparamtype(const PGresult *res, int param_num)
Definition: fe-exec.c:3692
int PQgetlineAsync(PGconn *conn, char *buffer, int bufsize)
Definition: fe-exec.c:2754
PGnotify * notifyHead
Definition: libpq-int.h:421
unsigned char pg_tolower(unsigned char ch)
Definition: pgstrcasecmp.c:122
int PQputCopyEnd(PGconn *conn, const char *errormsg)
Definition: fe-exec.c:2600
struct pgMessageField * next
Definition: libpq-int.h:145
ExecStatusType
Definition: libpq-fe.h:92
int spaceLeft
Definition: libpq-int.h:211
#define lengthof(array)
Definition: c.h:734
PGresult * PQdescribePortal(PGconn *conn, const char *portal)
Definition: fe-exec.c:2405
int PQbinaryTuples(const PGresult *res)
Definition: fe-exec.c:3264
int nEvents
Definition: libpq-int.h:189
static void pqRecycleCmdQueueEntry(PGconn *conn, PGcmdQueueEntry *entry)
Definition: fe-exec.c:1296
unsigned int Oid
Definition: postgres_ext.h:31
#define NULL_LEN
Definition: libpq-int.h:134
char * PQoidStatus(const PGresult *res)
Definition: fe-exec.c:3532
int PQntuples(const PGresult *res)
Definition: fe-exec.c:3248
char * errMsg
Definition: libpq-int.h:197
char * write_err_msg
Definition: libpq-int.h:455
PGresult * PQfn(PGconn *conn, int fnid, int *result_buf, int *result_len, int result_is_int, const PQArgBlock *args, int nargs)
Definition: fe-exec.c:2833
PGresult * pqPrepareAsyncResult(PGconn *conn)
Definition: fe-exec.c:804
int columnid
Definition: libpq-fe.h:263
ExecStatusType PQresultStatus(const PGresult *res)
Definition: fe-exec.c:3178
char null_field[1]
Definition: libpq-int.h:202
PGresAttDesc * attDescs
Definition: libpq-int.h:172
#define PG_COPYRES_TUPLES
Definition: libpq-fe.h:44
int PQgetCopyData(PGconn *conn, char **buffer, int async)
Definition: fe-exec.c:2668
PGresult * result
Definition: libpq-int.h:500
PGresAttValue ** tuples
Definition: libpq-int.h:173
static int PQsendDescribe(PGconn *conn, char desc_type, const char *desc_target)
Definition: fe-exec.c:2450
#define malloc(a)
Definition: header.h:50
int pqPutInt(int value, size_t bytes, PGconn *conn)
Definition: fe-misc.c:256
int sversion
Definition: libpq-int.h:449
int PQputline(PGconn *conn, const char *s)
Definition: fe-exec.c:2771
int pqGetlineAsync3(PGconn *conn, char *buffer, int bufsize)
static char get_hex(char c)
Definition: fe-exec.c:4095
#define sprintf
Definition: port.h:218
#define PGRESULT_ALIGN_BOUNDARY
Definition: fe-exec.c:134
#define true
Definition: c.h:395
int PQsendQuery(PGconn *conn, const char *query)
Definition: fe-exec.c:1326
char * PQescapeIdentifier(PGconn *conn, const char *str, size_t len)
Definition: fe-exec.c:4075
PGresult * next_result
Definition: libpq-int.h:501
PGAsyncStatusType asyncStatus
Definition: libpq-int.h:411
struct pg_result PGresult
Definition: libpq-fe.h:171
PGTernaryBool default_transaction_read_only
Definition: libpq-int.h:472
PGQueryClass queryclass
Definition: libpq-int.h:322
#define IS_HIGHBIT_SET(ch)
Definition: c.h:1156
#define PG_COPYRES_EVENTS
Definition: libpq-fe.h:45
int pqEndcopy3(PGconn *conn)
static bool pqAddTuple(PGresult *res, PGresAttValue *tup, const char **errmsgp)
Definition: fe-exec.c:894
bool write_failed
Definition: libpq-int.h:454
void PQfreeNotify(PGnotify *notify)
Definition: fe-exec.c:3813
PGNoticeHooks noticeHooks
Definition: libpq-int.h:187
PGconn * conn
Definition: streamutil.c:54
#define vsnprintf
Definition: port.h:215
static int pqPipelineFlush(PGconn *conn)
Definition: fe-exec.c:3780
#define PG_COPYRES_NOTICEHOOKS
Definition: libpq-fe.h:46
int PQsendFlushRequest(PGconn *conn)
Definition: fe-exec.c:3144
struct pgParameterStatus pgParameterStatus
void appendPQExpBuffer(PQExpBuffer str, const char *fmt,...)
Definition: pqexpbuffer.c:267
PGNoticeHooks noticeHooks
Definition: libpq-int.h:402
int curOffset
Definition: libpq-int.h:210
int PQflush(PGconn *conn)
Definition: fe-exec.c:3766
Oid PQftype(const PGresult *res, int field_num)
Definition: fe-exec.c:3486
int pqReadData(PGconn *conn)
Definition: fe-misc.c:568
void * noticeProcArg
Definition: libpq-int.h:156
int PQsetResultAttrs(PGresult *res, int numAttributes, PGresAttDesc *attDescs)
Definition: fe-exec.c:234
char * PQresultVerboseErrorMessage(const PGresult *res, PGVerbosity verbosity, PGContextVisibility show_context)
Definition: fe-exec.c:3202
static const int8 hexlookup[128]
Definition: fe-exec.c:4083
char * c
static bool PQsendQueryStart(PGconn *conn, bool newQuery)
Definition: fe-exec.c:1626
static int static_client_encoding
Definition: fe-exec.c:51
int pqWait(int forRead, int forWrite, PGconn *conn)
Definition: fe-misc.c:990
static char * buf
Definition: pg_test_fsync.c:68
#define PGRESULT_BLOCK_OVERHEAD
Definition: fe-exec.c:135
int PQsetSingleRowMode(PGconn *conn)
Definition: fe-exec.c:1876
static PGresult * getCopyResult(PGconn *conn, ExecStatusType copytype)
Definition: fe-exec.c:2155
PQnoticeReceiver noticeRec
Definition: libpq-int.h:153
int pg_encoding_mblen(int encoding, const char *mbstr)
Definition: wchar.c:1914
void pqInternalNotice(const PGNoticeHooks *hooks, const char *fmt,...)
Definition: fe-exec.c:839
static void pqPipelineProcessQueue(PGconn *conn)
Definition: fe-exec.c:2997
#define PG_DIAG_SEVERITY
Definition: postgres_ext.h:55
int PQsendDescribePrepared(PGconn *conn, const char *stmt)
Definition: fe-exec.c:2422
PGresult_data * curBlock
Definition: libpq-int.h:209
size_t PQescapeStringConn(PGconn *conn, char *to, const char *from, size_t length, int *error)
Definition: fe-exec.c:3910
int numParameters
Definition: libpq-int.h:176
PGresult * PQmakeEmptyPGresult(PGconn *conn, ExecStatusType status)
Definition: fe-exec.c:146
int pqPutc(char c, PGconn *conn)
Definition: fe-misc.c:95
int pqPuts(const char *s, PGconn *conn)
Definition: fe-misc.c:155
static void parseInput(PGconn *conn)
Definition: fe-exec.c:1940
PGcmdQueueEntry * cmd_queue_tail
Definition: libpq-int.h:435
PGdataValue * rowBuf
Definition: libpq-int.h:496
int binary
Definition: libpq-int.h:180
void pqSetResultError(PGresult *res, PQExpBuffer errorMessage)
Definition: fe-exec.c:665
#define byte(x, n)
Definition: rijndael.c:68
int PQpipelineSync(PGconn *conn)
Definition: fe-exec.c:3077
pgsocket sock
Definition: libpq-int.h:444
char * errQuery
Definition: libpq-int.h:199
int numAttributes
Definition: libpq-int.h:171
signed char int8
Definition: c.h:427
int pqGetCopyData3(PGconn *conn, char **buffer, int async)
unsigned char * PQunescapeBytea(const unsigned char *strtext, size_t *retbuflen)
Definition: fe-exec.c:4259
char * PQcmdStatus(PGresult *res)
Definition: fe-exec.c:3519
PGTernaryBool in_hot_standby
Definition: libpq-int.h:473
void pqCommandQueueAdvance(PGconn *conn)
Definition: fe-exec.c:2976
void pqSaveMessageField(PGresult *res, char code, const char *value)
Definition: fe-exec.c:961
pgParameterStatus * pstatus
Definition: libpq-int.h:469
PGContextVisibility
Definition: libpq-fe.h:131
#define PGRESULT_SEP_ALLOC_THRESHOLD
Definition: fe-exec.c:136
#define PGINVALID_SOCKET
Definition: port.h:33
int PQfnumber(const PGresult *res, const char *field_name)
Definition: fe-exec.c:3356
int PQconsumeInput(PGconn *conn)
Definition: fe-exec.c:1904
int PQsetnonblocking(PGconn *conn, int arg)
Definition: fe-exec.c:3710
struct pgNotify * next
Definition: libpq-fe.h:191
PGVerbosity
Definition: libpq-fe.h:123
int atttypmod
Definition: libpq-fe.h:267
PQnoticeProcessor noticeProc
Definition: libpq-int.h:155
int PQgetline(PGconn *conn, char *s, int maxlen)
Definition: fe-exec.c:2707
char * PQescapeLiteral(PGconn *conn, const char *str, size_t len)
Definition: fe-exec.c:4069
PQExpBufferData errorMessage
Definition: libpq-int.h:571
#define PG_DIAG_SEVERITY_NONLOCALIZED
Definition: postgres_ext.h:56
#define PG_COPYRES_ATTRS
Definition: libpq-fe.h:43
bool std_strings
Definition: libpq-int.h:471
#define InvalidOid
Definition: postgres_ext.h:36
static struct @143 value
void PQclear(PGresult *res)
Definition: fe-exec.c:694
static int check_field_number(const PGresult *res, int field_num)
Definition: fe-exec.c:3277
#define free(a)
Definition: header.h:65
#define PQExpBufferDataBroken(buf)
Definition: pqexpbuffer.h:67
int PQendcopy(PGconn *conn)
Definition: fe-exec.c:2802
int outBufSize
Definition: libpq-int.h:487
void * pqResultAlloc(PGresult *res, size_t nBytes, bool isBinary)
Definition: fe-exec.c:539
PGresParamDesc * paramDescs
Definition: libpq-int.h:177
char * PQresultErrorField(const PGresult *res, int fieldcode)
Definition: fe-exec.c:3233
int ntups
Definition: libpq-int.h:170
#define Assert(condition)
Definition: c.h:804
int pqPutnchar(const char *s, size_t len, PGconn *conn)
Definition: fe-misc.c:205
static size_t PQescapeStringInternal(PGconn *conn, char *to, const char *from, size_t length, int *error, int encoding, bool std_strings)
Definition: fe-exec.c:3835
int PQisBusy(PGconn *conn)
Definition: fe-exec.c:1951
PGcmdQueueEntry * cmd_queue_recycle
Definition: libpq-int.h:441
#define OUTBUFFER_THRESHOLD
Definition: libpq-int.h:835
struct pgParameterStatus * next
Definition: libpq-int.h:261
static rewind_source * source
Definition: pg_rewind.c:79
char contents[FLEXIBLE_ARRAY_MEMBER]
Definition: libpq-int.h:147
#define PQ_QUERY_PARAM_MAX_LIMIT
Definition: libpq-fe.h:441
static void pqAppendCmdQueueEntry(PGconn *conn, PGcmdQueueEntry *entry)
Definition: fe-exec.c:1247
#define PQExpBufferBroken(str)
Definition: pqexpbuffer.h:59
PGEventProc proc
Definition: libpq-int.h:161
char cmdStatus[CMDSTATUS_LEN]
Definition: libpq-int.h:179
ConnStatusType status
Definition: libpq-int.h:410
int PQfmod(const PGresult *res, int field_num)
Definition: fe-exec.c:3508
int pqPutMsgStart(char msg_type, PGconn *conn)
Definition: fe-misc.c:461
static char * PQescapeInternal(PGconn *conn, const char *str, size_t len, bool as_ident)
Definition: fe-exec.c:3946
int pqPutMsgEnd(PGconn *conn)
Definition: fe-misc.c:520
int32 encoding
Definition: pg_database.h:41
PGnotify * notifyTail
Definition: libpq-int.h:422
#define realloc(a, b)
Definition: header.h:60
const char * name
Definition: encode.c:561
static PGresult * PQexecFinish(PGconn *conn)
Definition: fe-exec.c:2340
int PQsendQueryPrepared(PGconn *conn, const char *stmtName, int nParams, const char *const *paramValues, const int *paramLengths, const int *paramFormats, int resultFormat)
Definition: fe-exec.c:1584
static StringInfoData tmpbuf
Definition: walsender.c:159
static void pqSaveWriteError(PGconn *conn)
Definition: fe-exec.c:777
bool nonblocking
Definition: libpq-int.h:415
int PQisthreadsafe(void)
Definition: fe-exec.c:3754
char * PQresultErrorMessage(const PGresult *res)
Definition: fe-exec.c:3194
#define PGRESULT_DATA_BLOCKSIZE
Definition: fe-exec.c:133
static bool PQexecStart(PGconn *conn)
Definition: fe-exec.c:2275
PGresult * PQexecParams(PGconn *conn, const char *command, int nParams, const Oid *paramTypes, const char *const *paramValues, const int *paramLengths, const int *paramFormats, int resultFormat)
Definition: fe-exec.c:2207
int errmsg(const char *fmt,...)
Definition: elog.c:909
int nEvents
Definition: libpq-int.h:406
static const char hextbl[]
Definition: fe-exec.c:4081
int i
void * passThrough
Definition: libpq-int.h:163
char * name
Definition: libpq-fe.h:261
PGresult * PQexec(PGconn *conn, const char *query)
Definition: fe-exec.c:2193
int client_encoding
Definition: libpq-int.h:470
void * arg
#define SQL_STR_DOUBLE(ch, escape_backslash)
Definition: c.h:1164
char * value
Definition: libpq-int.h:139
void pqBuildErrorMessage3(PQExpBuffer msg, const PGresult *res, PGVerbosity verbosity, PGContextVisibility show_context)
char *const pgresStatus[]
Definition: fe-exec.c:32
int PQsendQueryContinue(PGconn *conn, const char *query)
Definition: fe-exec.c:1332
unsigned char * PQescapeBytea(const unsigned char *from, size_t from_length, size_t *to_length)
Definition: fe-exec.c:4234
void pqClearAsyncResult(PGconn *conn)
Definition: fe-exec.c:749
void pqSaveErrorResult(PGconn *conn)
Definition: fe-exec.c:765
static PGEvent * dupEvents(PGEvent *events, int count, size_t *memSize)
Definition: fe-exec.c:392
PGEvent * events
Definition: libpq-int.h:188
void pqParseInput3(PGconn *conn)
Definition: fe-protocol3.c:63
void resetPQExpBuffer(PQExpBuffer str)
Definition: pqexpbuffer.c:148
static void static void status(const char *fmt,...) pg_attribute_printf(1
Definition: pg_regress.c:227
int PQgetisnull(const PGresult *res, int tup_num, int field_num)
Definition: fe-exec.c:3667
static PGcmdQueueEntry * pqAllocCmdQueueEntry(PGconn *conn)
Definition: fe-exec.c:1213
unsigned char * PQescapeByteaConn(PGconn *conn, const unsigned char *from, size_t from_length, size_t *to_length)
Definition: fe-exec.c:4219
static unsigned char * PQescapeByteaInternal(PGconn *conn, const unsigned char *from, size_t from_length, size_t *to_length, bool std_strings, bool use_hex)
Definition: fe-exec.c:4122
int PQfformat(const PGresult *res, int field_num)
Definition: fe-exec.c:3475
PGresult * dest
Definition: libpq-events.h:61
char * name
Definition: libpq-int.h:162
ExecStatusType resultStatus
Definition: libpq-int.h:178
void PQfreemem(void *ptr)
Definition: fe-exec.c:3796
static int PQsendQueryInternal(PGconn *conn, const char *query, bool newQuery)
Definition: fe-exec.c:1338
long val
Definition: informix.c:664
PGresult * PQgetResult(PGconn *conn)
Definition: fe-exec.c:1978
int PQnparams(const PGresult *res)
Definition: fe-exec.c:3681
#define ISOCTDIGIT(CH)
Definition: fe-exec.c:4243
void initPQExpBuffer(PQExpBuffer str)
Definition: pqexpbuffer.c:92
#define offsetof(type, field)
Definition: c.h:727
int PQsendPrepare(PGconn *conn, const char *stmtName, const char *query, int nParams, const Oid *paramTypes)
Definition: fe-exec.c:1484
#define libpq_gettext(x)
Definition: libpq-int.h:841
char * pqResultStrdup(PGresult *res, const char *str)
Definition: fe-exec.c:651
void * PQresultAlloc(PGresult *res, size_t nBytes)
Definition: fe-exec.c:523
void * noticeRecArg
Definition: libpq-int.h:154
int client_encoding
Definition: libpq-int.h:190