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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) 1996-2024, 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  "PGRES_TUPLES_CHUNK"
46 };
47 
48 /* We return this if we're unable to make a PGresult at all */
49 static const PGresult OOM_result = {
51  .client_encoding = PG_SQL_ASCII,
52  .errMsg = "out of memory\n",
53 };
54 
55 /*
56  * static state needed by PQescapeString and PQescapeBytea; initialize to
57  * values that result in backward-compatible behavior
58  */
60 static bool static_std_strings = false;
61 
62 
63 static PGEvent *dupEvents(PGEvent *events, int count, size_t *memSize);
64 static bool pqAddTuple(PGresult *res, PGresAttValue *tup,
65  const char **errmsgp);
66 static int PQsendQueryInternal(PGconn *conn, const char *query, bool newQuery);
67 static bool PQsendQueryStart(PGconn *conn, bool newQuery);
68 static int PQsendQueryGuts(PGconn *conn,
69  const char *command,
70  const char *stmtName,
71  int nParams,
72  const Oid *paramTypes,
73  const char *const *paramValues,
74  const int *paramLengths,
75  const int *paramFormats,
76  int resultFormat);
77 static void parseInput(PGconn *conn);
78 static PGresult *getCopyResult(PGconn *conn, ExecStatusType copytype);
79 static bool PQexecStart(PGconn *conn);
81 static int PQsendTypedCommand(PGconn *conn, char command, char type,
82  const char *target);
83 static int check_field_number(const PGresult *res, int field_num);
84 static void pqPipelineProcessQueue(PGconn *conn);
85 static int pqPipelineSyncInternal(PGconn *conn, bool immediate_flush);
86 static int pqPipelineFlush(PGconn *conn);
87 
88 
89 /* ----------------
90  * Space management for PGresult.
91  *
92  * Formerly, libpq did a separate malloc() for each field of each tuple
93  * returned by a query. This was remarkably expensive --- malloc/free
94  * consumed a sizable part of the application's runtime. And there is
95  * no real need to keep track of the fields separately, since they will
96  * all be freed together when the PGresult is released. So now, we grab
97  * large blocks of storage from malloc and allocate space for query data
98  * within these blocks, using a trivially simple allocator. This reduces
99  * the number of malloc/free calls dramatically, and it also avoids
100  * fragmentation of the malloc storage arena.
101  * The PGresult structure itself is still malloc'd separately. We could
102  * combine it with the first allocation block, but that would waste space
103  * for the common case that no extra storage is actually needed (that is,
104  * the SQL command did not return tuples).
105  *
106  * We also malloc the top-level array of tuple pointers separately, because
107  * we need to be able to enlarge it via realloc, and our trivial space
108  * allocator doesn't handle that effectively. (Too bad the FE/BE protocol
109  * doesn't tell us up front how many tuples will be returned.)
110  * All other subsidiary storage for a PGresult is kept in PGresult_data blocks
111  * of size PGRESULT_DATA_BLOCKSIZE. The overhead at the start of each block
112  * is just a link to the next one, if any. Free-space management info is
113  * kept in the owning PGresult.
114  * A query returning a small amount of data will thus require three malloc
115  * calls: one for the PGresult, one for the tuples pointer array, and one
116  * PGresult_data block.
117  *
118  * Only the most recently allocated PGresult_data block is a candidate to
119  * have more stuff added to it --- any extra space left over in older blocks
120  * is wasted. We could be smarter and search the whole chain, but the point
121  * here is to be simple and fast. Typical applications do not keep a PGresult
122  * around very long anyway, so some wasted space within one is not a problem.
123  *
124  * Tuning constants for the space allocator are:
125  * PGRESULT_DATA_BLOCKSIZE: size of a standard allocation block, in bytes
126  * PGRESULT_ALIGN_BOUNDARY: assumed alignment requirement for binary data
127  * PGRESULT_SEP_ALLOC_THRESHOLD: objects bigger than this are given separate
128  * blocks, instead of being crammed into a regular allocation block.
129  * Requirements for correct function are:
130  * PGRESULT_ALIGN_BOUNDARY must be a multiple of the alignment requirements
131  * of all machine data types. (Currently this is set from configure
132  * tests, so it should be OK automatically.)
133  * PGRESULT_SEP_ALLOC_THRESHOLD + PGRESULT_BLOCK_OVERHEAD <=
134  * PGRESULT_DATA_BLOCKSIZE
135  * pqResultAlloc assumes an object smaller than the threshold will fit
136  * in a new block.
137  * The amount of space wasted at the end of a block could be as much as
138  * PGRESULT_SEP_ALLOC_THRESHOLD, so it doesn't pay to make that too large.
139  * ----------------
140  */
141 
142 #define PGRESULT_DATA_BLOCKSIZE 2048
143 #define PGRESULT_ALIGN_BOUNDARY MAXIMUM_ALIGNOF /* from configure */
144 #define PGRESULT_BLOCK_OVERHEAD Max(sizeof(PGresult_data), PGRESULT_ALIGN_BOUNDARY)
145 #define PGRESULT_SEP_ALLOC_THRESHOLD (PGRESULT_DATA_BLOCKSIZE / 2)
146 
147 
148 /*
149  * PQmakeEmptyPGresult
150  * returns a newly allocated, initialized PGresult with given status.
151  * If conn is not NULL and status indicates an error, the conn's
152  * errorMessage is copied. Also, any PGEvents are copied from the conn.
153  *
154  * Note: the logic to copy the conn's errorMessage is now vestigial;
155  * no internal caller uses it. However, that behavior is documented for
156  * outside callers, so we'd better keep it.
157  */
158 PGresult *
160 {
161  PGresult *result;
162 
163  result = (PGresult *) malloc(sizeof(PGresult));
164  if (!result)
165  return NULL;
166 
167  result->ntups = 0;
168  result->numAttributes = 0;
169  result->attDescs = NULL;
170  result->tuples = NULL;
171  result->tupArrSize = 0;
172  result->numParameters = 0;
173  result->paramDescs = NULL;
174  result->resultStatus = status;
175  result->cmdStatus[0] = '\0';
176  result->binary = 0;
177  result->events = NULL;
178  result->nEvents = 0;
179  result->errMsg = NULL;
180  result->errFields = NULL;
181  result->errQuery = NULL;
182  result->null_field[0] = '\0';
183  result->curBlock = NULL;
184  result->curOffset = 0;
185  result->spaceLeft = 0;
186  result->memorySize = sizeof(PGresult);
187 
188  if (conn)
189  {
190  /* copy connection data we might need for operations on PGresult */
191  result->noticeHooks = conn->noticeHooks;
193 
194  /* consider copying conn's errorMessage */
195  switch (status)
196  {
197  case PGRES_EMPTY_QUERY:
198  case PGRES_COMMAND_OK:
199  case PGRES_TUPLES_OK:
200  case PGRES_COPY_OUT:
201  case PGRES_COPY_IN:
202  case PGRES_COPY_BOTH:
203  case PGRES_SINGLE_TUPLE:
204  case PGRES_TUPLES_CHUNK:
205  /* non-error cases */
206  break;
207  default:
208  /* we intentionally do not use or modify errorReported here */
209  pqSetResultError(result, &conn->errorMessage, 0);
210  break;
211  }
212 
213  /* copy events last; result must be valid if we need to PQclear */
214  if (conn->nEvents > 0)
215  {
216  result->events = dupEvents(conn->events, conn->nEvents,
217  &result->memorySize);
218  if (!result->events)
219  {
220  PQclear(result);
221  return NULL;
222  }
223  result->nEvents = conn->nEvents;
224  }
225  }
226  else
227  {
228  /* defaults... */
229  result->noticeHooks.noticeRec = NULL;
230  result->noticeHooks.noticeRecArg = NULL;
231  result->noticeHooks.noticeProc = NULL;
232  result->noticeHooks.noticeProcArg = NULL;
233  result->client_encoding = PG_SQL_ASCII;
234  }
235 
236  return result;
237 }
238 
239 /*
240  * PQsetResultAttrs
241  *
242  * Set the attributes for a given result. This function fails if there are
243  * already attributes contained in the provided result. The call is
244  * ignored if numAttributes is zero or attDescs is NULL. If the
245  * function fails, it returns zero. If the function succeeds, it
246  * returns a non-zero value.
247  */
248 int
249 PQsetResultAttrs(PGresult *res, int numAttributes, PGresAttDesc *attDescs)
250 {
251  int i;
252 
253  /* Fail if argument is NULL or OOM_result */
254  if (!res || (const PGresult *) res == &OOM_result)
255  return false;
256 
257  /* If attrs already exist, they cannot be overwritten. */
258  if (res->numAttributes > 0)
259  return false;
260 
261  /* ignore no-op request */
262  if (numAttributes <= 0 || !attDescs)
263  return true;
264 
265  res->attDescs = (PGresAttDesc *)
266  PQresultAlloc(res, numAttributes * sizeof(PGresAttDesc));
267 
268  if (!res->attDescs)
269  return false;
270 
271  res->numAttributes = numAttributes;
272  memcpy(res->attDescs, attDescs, numAttributes * sizeof(PGresAttDesc));
273 
274  /* deep-copy the attribute names, and determine format */
275  res->binary = 1;
276  for (i = 0; i < res->numAttributes; i++)
277  {
278  if (res->attDescs[i].name)
280  else
282 
283  if (!res->attDescs[i].name)
284  return false;
285 
286  if (res->attDescs[i].format == 0)
287  res->binary = 0;
288  }
289 
290  return true;
291 }
292 
293 /*
294  * PQcopyResult
295  *
296  * Returns a deep copy of the provided 'src' PGresult, which cannot be NULL.
297  * The 'flags' argument controls which portions of the result will or will
298  * NOT be copied. The created result is always put into the
299  * PGRES_TUPLES_OK status. The source result error message is not copied,
300  * although cmdStatus is.
301  *
302  * To set custom attributes, use PQsetResultAttrs. That function requires
303  * that there are no attrs contained in the result, so to use that
304  * function you cannot use the PG_COPYRES_ATTRS or PG_COPYRES_TUPLES
305  * options with this function.
306  *
307  * Options:
308  * PG_COPYRES_ATTRS - Copy the source result's attributes
309  *
310  * PG_COPYRES_TUPLES - Copy the source result's tuples. This implies
311  * copying the attrs, seeing how the attrs are needed by the tuples.
312  *
313  * PG_COPYRES_EVENTS - Copy the source result's events.
314  *
315  * PG_COPYRES_NOTICEHOOKS - Copy the source result's notice hooks.
316  */
317 PGresult *
318 PQcopyResult(const PGresult *src, int flags)
319 {
320  PGresult *dest;
321  int i;
322 
323  if (!src)
324  return NULL;
325 
327  if (!dest)
328  return NULL;
329 
330  /* Always copy these over. Is cmdStatus really useful here? */
331  dest->client_encoding = src->client_encoding;
332  strcpy(dest->cmdStatus, src->cmdStatus);
333 
334  /* Wants attrs? */
335  if (flags & (PG_COPYRES_ATTRS | PG_COPYRES_TUPLES))
336  {
337  if (!PQsetResultAttrs(dest, src->numAttributes, src->attDescs))
338  {
339  PQclear(dest);
340  return NULL;
341  }
342  }
343 
344  /* Wants to copy tuples? */
345  if (flags & PG_COPYRES_TUPLES)
346  {
347  int tup,
348  field;
349 
350  for (tup = 0; tup < src->ntups; tup++)
351  {
352  for (field = 0; field < src->numAttributes; field++)
353  {
354  if (!PQsetvalue(dest, tup, field,
355  src->tuples[tup][field].value,
356  src->tuples[tup][field].len))
357  {
358  PQclear(dest);
359  return NULL;
360  }
361  }
362  }
363  }
364 
365  /* Wants to copy notice hooks? */
366  if (flags & PG_COPYRES_NOTICEHOOKS)
367  dest->noticeHooks = src->noticeHooks;
368 
369  /* Wants to copy PGEvents? */
370  if ((flags & PG_COPYRES_EVENTS) && src->nEvents > 0)
371  {
372  dest->events = dupEvents(src->events, src->nEvents,
373  &dest->memorySize);
374  if (!dest->events)
375  {
376  PQclear(dest);
377  return NULL;
378  }
379  dest->nEvents = src->nEvents;
380  }
381 
382  /* Okay, trigger PGEVT_RESULTCOPY event */
383  for (i = 0; i < dest->nEvents; i++)
384  {
385  /* We don't fire events that had some previous failure */
386  if (src->events[i].resultInitialized)
387  {
388  PGEventResultCopy evt;
389 
390  evt.src = src;
391  evt.dest = dest;
392  if (dest->events[i].proc(PGEVT_RESULTCOPY, &evt,
393  dest->events[i].passThrough))
394  dest->events[i].resultInitialized = true;
395  }
396  }
397 
398  return dest;
399 }
400 
401 /*
402  * Copy an array of PGEvents (with no extra space for more).
403  * Does not duplicate the event instance data, sets this to NULL.
404  * Also, the resultInitialized flags are all cleared.
405  * The total space allocated is added to *memSize.
406  */
407 static PGEvent *
408 dupEvents(PGEvent *events, int count, size_t *memSize)
409 {
410  PGEvent *newEvents;
411  size_t msize;
412  int i;
413 
414  if (!events || count <= 0)
415  return NULL;
416 
417  msize = count * sizeof(PGEvent);
418  newEvents = (PGEvent *) malloc(msize);
419  if (!newEvents)
420  return NULL;
421 
422  for (i = 0; i < count; i++)
423  {
424  newEvents[i].proc = events[i].proc;
425  newEvents[i].passThrough = events[i].passThrough;
426  newEvents[i].data = NULL;
427  newEvents[i].resultInitialized = false;
428  newEvents[i].name = strdup(events[i].name);
429  if (!newEvents[i].name)
430  {
431  while (--i >= 0)
432  free(newEvents[i].name);
433  free(newEvents);
434  return NULL;
435  }
436  msize += strlen(events[i].name) + 1;
437  }
438 
439  *memSize += msize;
440  return newEvents;
441 }
442 
443 
444 /*
445  * Sets the value for a tuple field. The tup_num must be less than or
446  * equal to PQntuples(res). If it is equal, a new tuple is created and
447  * added to the result.
448  * Returns a non-zero value for success and zero for failure.
449  * (On failure, we report the specific problem via pqInternalNotice.)
450  */
451 int
452 PQsetvalue(PGresult *res, int tup_num, int field_num, char *value, int len)
453 {
454  PGresAttValue *attval;
455  const char *errmsg = NULL;
456 
457  /* Fail if argument is NULL or OOM_result */
458  if (!res || (const PGresult *) res == &OOM_result)
459  return false;
460 
461  /* Invalid field_num? */
462  if (!check_field_number(res, field_num))
463  return false;
464 
465  /* Invalid tup_num, must be <= ntups */
466  if (tup_num < 0 || tup_num > res->ntups)
467  {
469  "row number %d is out of range 0..%d",
470  tup_num, res->ntups);
471  return false;
472  }
473 
474  /* need to allocate a new tuple? */
475  if (tup_num == res->ntups)
476  {
477  PGresAttValue *tup;
478  int i;
479 
480  tup = (PGresAttValue *)
482  true);
483 
484  if (!tup)
485  goto fail;
486 
487  /* initialize each column to NULL */
488  for (i = 0; i < res->numAttributes; i++)
489  {
490  tup[i].len = NULL_LEN;
491  tup[i].value = res->null_field;
492  }
493 
494  /* add it to the array */
495  if (!pqAddTuple(res, tup, &errmsg))
496  goto fail;
497  }
498 
499  attval = &res->tuples[tup_num][field_num];
500 
501  /* treat either NULL_LEN or NULL value pointer as a NULL field */
502  if (len == NULL_LEN || value == NULL)
503  {
504  attval->len = NULL_LEN;
505  attval->value = res->null_field;
506  }
507  else if (len <= 0)
508  {
509  attval->len = 0;
510  attval->value = res->null_field;
511  }
512  else
513  {
514  attval->value = (char *) pqResultAlloc(res, len + 1, true);
515  if (!attval->value)
516  goto fail;
517  attval->len = len;
518  memcpy(attval->value, value, len);
519  attval->value[len] = '\0';
520  }
521 
522  return true;
523 
524  /*
525  * Report failure via pqInternalNotice. If preceding code didn't provide
526  * an error message, assume "out of memory" was meant.
527  */
528 fail:
529  if (!errmsg)
530  errmsg = libpq_gettext("out of memory");
532 
533  return false;
534 }
535 
536 /*
537  * pqResultAlloc - exported routine to allocate local storage in a PGresult.
538  *
539  * We force all such allocations to be maxaligned, since we don't know
540  * whether the value might be binary.
541  */
542 void *
543 PQresultAlloc(PGresult *res, size_t nBytes)
544 {
545  /* Fail if argument is NULL or OOM_result */
546  if (!res || (const PGresult *) res == &OOM_result)
547  return NULL;
548 
549  return pqResultAlloc(res, nBytes, true);
550 }
551 
552 /*
553  * pqResultAlloc -
554  * Allocate subsidiary storage for a PGresult.
555  *
556  * nBytes is the amount of space needed for the object.
557  * If isBinary is true, we assume that we need to align the object on
558  * a machine allocation boundary.
559  * If isBinary is false, we assume the object is a char string and can
560  * be allocated on any byte boundary.
561  */
562 void *
563 pqResultAlloc(PGresult *res, size_t nBytes, bool isBinary)
564 {
565  char *space;
566  PGresult_data *block;
567 
568  if (!res)
569  return NULL;
570 
571  if (nBytes <= 0)
572  return res->null_field;
573 
574  /*
575  * If alignment is needed, round up the current position to an alignment
576  * boundary.
577  */
578  if (isBinary)
579  {
580  int offset = res->curOffset % PGRESULT_ALIGN_BOUNDARY;
581 
582  if (offset)
583  {
586  }
587  }
588 
589  /* If there's enough space in the current block, no problem. */
590  if (nBytes <= (size_t) res->spaceLeft)
591  {
592  space = res->curBlock->space + res->curOffset;
593  res->curOffset += nBytes;
594  res->spaceLeft -= nBytes;
595  return space;
596  }
597 
598  /*
599  * If the requested object is very large, give it its own block; this
600  * avoids wasting what might be most of the current block to start a new
601  * block. (We'd have to special-case requests bigger than the block size
602  * anyway.) The object is always given binary alignment in this case.
603  */
604  if (nBytes >= PGRESULT_SEP_ALLOC_THRESHOLD)
605  {
606  size_t alloc_size = nBytes + PGRESULT_BLOCK_OVERHEAD;
607 
608  block = (PGresult_data *) malloc(alloc_size);
609  if (!block)
610  return NULL;
611  res->memorySize += alloc_size;
612  space = block->space + PGRESULT_BLOCK_OVERHEAD;
613  if (res->curBlock)
614  {
615  /*
616  * Tuck special block below the active block, so that we don't
617  * have to waste the free space in the active block.
618  */
619  block->next = res->curBlock->next;
620  res->curBlock->next = block;
621  }
622  else
623  {
624  /* Must set up the new block as the first active block. */
625  block->next = NULL;
626  res->curBlock = block;
627  res->spaceLeft = 0; /* be sure it's marked full */
628  }
629  return space;
630  }
631 
632  /* Otherwise, start a new block. */
634  if (!block)
635  return NULL;
637  block->next = res->curBlock;
638  res->curBlock = block;
639  if (isBinary)
640  {
641  /* object needs full alignment */
644  }
645  else
646  {
647  /* we can cram it right after the overhead pointer */
648  res->curOffset = sizeof(PGresult_data);
650  }
651 
652  space = block->space + res->curOffset;
653  res->curOffset += nBytes;
654  res->spaceLeft -= nBytes;
655  return space;
656 }
657 
658 /*
659  * PQresultMemorySize -
660  * Returns total space allocated for the PGresult.
661  */
662 size_t
664 {
665  if (!res)
666  return 0;
667  return res->memorySize;
668 }
669 
670 /*
671  * pqResultStrdup -
672  * Like strdup, but the space is subsidiary PGresult space.
673  */
674 char *
676 {
677  char *space = (char *) pqResultAlloc(res, strlen(str) + 1, false);
678 
679  if (space)
680  strcpy(space, str);
681  return space;
682 }
683 
684 /*
685  * pqSetResultError -
686  * assign a new error message to a PGresult
687  *
688  * Copy text from errorMessage buffer beginning at given offset
689  * (it's caller's responsibility that offset is valid)
690  */
691 void
692 pqSetResultError(PGresult *res, PQExpBuffer errorMessage, int offset)
693 {
694  char *msg;
695 
696  if (!res)
697  return;
698 
699  /*
700  * We handle two OOM scenarios here. The errorMessage buffer might be
701  * marked "broken" due to having previously failed to allocate enough
702  * memory for the message, or it might be fine but pqResultStrdup fails
703  * and returns NULL. In either case, just make res->errMsg point directly
704  * at a constant "out of memory" string.
705  */
706  if (!PQExpBufferBroken(errorMessage))
707  msg = pqResultStrdup(res, errorMessage->data + offset);
708  else
709  msg = NULL;
710  if (msg)
711  res->errMsg = msg;
712  else
713  res->errMsg = libpq_gettext("out of memory\n");
714 }
715 
716 /*
717  * PQclear -
718  * free's the memory associated with a PGresult
719  */
720 void
722 {
723  PGresult_data *block;
724  int i;
725 
726  /* As a convenience, do nothing for a NULL pointer */
727  if (!res)
728  return;
729  /* Also, do nothing if the argument is OOM_result */
730  if ((const PGresult *) res == &OOM_result)
731  return;
732 
733  /* Close down any events we may have */
734  for (i = 0; i < res->nEvents; i++)
735  {
736  /* only send DESTROY to successfully-initialized event procs */
738  {
740 
741  evt.result = res;
742  (void) res->events[i].proc(PGEVT_RESULTDESTROY, &evt,
743  res->events[i].passThrough);
744  }
745  free(res->events[i].name);
746  }
747 
748  free(res->events);
749 
750  /* Free all the subsidiary blocks */
751  while ((block = res->curBlock) != NULL)
752  {
753  res->curBlock = block->next;
754  free(block);
755  }
756 
757  /* Free the top-level tuple pointer array */
758  free(res->tuples);
759 
760  /* zero out the pointer fields to catch programming errors */
761  res->attDescs = NULL;
762  res->tuples = NULL;
763  res->paramDescs = NULL;
764  res->errFields = NULL;
765  res->events = NULL;
766  res->nEvents = 0;
767  /* res->curBlock was zeroed out earlier */
768 
769  /* Free the PGresult structure itself */
770  free(res);
771 }
772 
773 /*
774  * Handy subroutine to deallocate any partially constructed async result.
775  *
776  * Any "saved" result gets cleared too.
777  */
778 void
780 {
781  PQclear(conn->result);
782  conn->result = NULL;
783  conn->error_result = false;
785  conn->saved_result = NULL;
786 }
787 
788 /*
789  * pqSaveErrorResult -
790  * remember that we have an error condition
791  *
792  * In much of libpq, reporting an error just requires appending text to
793  * conn->errorMessage and returning a failure code to one's caller.
794  * Where returning a failure code is impractical, instead call this
795  * function to remember that an error needs to be reported.
796  *
797  * (It might seem that appending text to conn->errorMessage should be
798  * sufficient, but we can't rely on that working under out-of-memory
799  * conditions. The OOM hazard is also why we don't try to make a new
800  * PGresult right here.)
801  */
802 void
804 {
805  /* Drop any pending result ... */
807  /* ... and set flag to remember to make an error result later */
808  conn->error_result = true;
809 }
810 
811 /*
812  * pqSaveWriteError -
813  * report a write failure
814  *
815  * As above, after appending conn->write_err_msg to whatever other error we
816  * have. This is used when we've detected a write failure and have exhausted
817  * our chances of reporting something else instead.
818  */
819 static void
821 {
822  /*
823  * If write_err_msg is null because of previous strdup failure, do what we
824  * can. (It's likely our machinations here will get OOM failures as well,
825  * but might as well try.)
826  */
827  if (conn->write_err_msg)
828  {
830  /* Avoid possibly appending the same message twice */
831  conn->write_err_msg[0] = '\0';
832  }
833  else
834  libpq_append_conn_error(conn, "write to server failed");
835 
837 }
838 
839 /*
840  * pqPrepareAsyncResult -
841  * prepare the current async result object for return to the caller
842  *
843  * If there is not already an async result object, build an error object
844  * using whatever is in conn->errorMessage. In any case, clear the async
845  * result storage, and update our notion of how much error text has been
846  * returned to the application.
847  *
848  * Note that in no case (not even OOM) do we return NULL.
849  */
850 PGresult *
852 {
853  PGresult *res;
854 
855  res = conn->result;
856  if (res)
857  {
858  /*
859  * If the pre-existing result is an ERROR (presumably something
860  * received from the server), assume that it represents whatever is in
861  * conn->errorMessage, and advance errorReported.
862  */
865  }
866  else
867  {
868  /*
869  * We get here after internal-to-libpq errors. We should probably
870  * always have error_result = true, but if we don't, gin up some error
871  * text.
872  */
873  if (!conn->error_result)
874  libpq_append_conn_error(conn, "no error text available");
875 
876  /* Paranoia: be sure errorReported offset is sane */
877  if (conn->errorReported < 0 ||
879  conn->errorReported = 0;
880 
881  /*
882  * Make a PGresult struct for the error. We temporarily lie about the
883  * result status, so that PQmakeEmptyPGresult doesn't uselessly copy
884  * all of conn->errorMessage.
885  */
887  if (res)
888  {
889  /*
890  * Report whatever new error text we have, and advance
891  * errorReported.
892  */
896  }
897  else
898  {
899  /*
900  * Ouch, not enough memory for a PGresult. Fortunately, we have a
901  * card up our sleeve: we can use the static OOM_result. Casting
902  * away const here is a bit ugly, but it seems best to declare
903  * OOM_result as const, in hopes it will be allocated in read-only
904  * storage.
905  */
907 
908  /*
909  * Don't advance errorReported. Perhaps we'll be able to report
910  * the text later.
911  */
912  }
913  }
914 
915  /*
916  * Replace conn->result with saved_result, if any. In the normal case
917  * there isn't a saved result and we're just dropping ownership of the
918  * current result. In partial-result mode this restores the situation to
919  * what it was before we created the current partial result.
920  */
922  conn->error_result = false; /* saved_result is never an error */
923  conn->saved_result = NULL;
924 
925  return res;
926 }
927 
928 /*
929  * pqInternalNotice - produce an internally-generated notice message
930  *
931  * A format string and optional arguments can be passed. Note that we do
932  * libpq_gettext() here, so callers need not.
933  *
934  * The supplied text is taken as primary message (ie., it should not include
935  * a trailing newline, and should not be more than one line).
936  */
937 void
938 pqInternalNotice(const PGNoticeHooks *hooks, const char *fmt,...)
939 {
940  char msgBuf[1024];
941  va_list args;
942  PGresult *res;
943 
944  if (hooks->noticeRec == NULL)
945  return; /* nobody home to receive notice? */
946 
947  /* Format the message */
948  va_start(args, fmt);
949  vsnprintf(msgBuf, sizeof(msgBuf), libpq_gettext(fmt), args);
950  va_end(args);
951  msgBuf[sizeof(msgBuf) - 1] = '\0'; /* make real sure it's terminated */
952 
953  /* Make a PGresult to pass to the notice receiver */
955  if (!res)
956  return;
957  res->noticeHooks = *hooks;
958 
959  /*
960  * Set up fields of notice.
961  */
965  /* XXX should provide a SQLSTATE too? */
966 
967  /*
968  * Result text is always just the primary message + newline. If we can't
969  * allocate it, substitute "out of memory", as in pqSetResultError.
970  */
971  res->errMsg = (char *) pqResultAlloc(res, strlen(msgBuf) + 2, false);
972  if (res->errMsg)
973  sprintf(res->errMsg, "%s\n", msgBuf);
974  else
975  res->errMsg = libpq_gettext("out of memory\n");
976 
977  /*
978  * Pass to receiver, then free it.
979  */
981  PQclear(res);
982 }
983 
984 /*
985  * pqAddTuple
986  * add a row pointer to the PGresult structure, growing it if necessary
987  * Returns true if OK, false if an error prevented adding the row
988  *
989  * On error, *errmsgp can be set to an error string to be returned.
990  * If it is left NULL, the error is presumed to be "out of memory".
991  */
992 static bool
993 pqAddTuple(PGresult *res, PGresAttValue *tup, const char **errmsgp)
994 {
995  if (res->ntups >= res->tupArrSize)
996  {
997  /*
998  * Try to grow the array.
999  *
1000  * We can use realloc because shallow copying of the structure is
1001  * okay. Note that the first time through, res->tuples is NULL. While
1002  * ANSI says that realloc() should act like malloc() in that case,
1003  * some old C libraries (like SunOS 4.1.x) coredump instead. On
1004  * failure realloc is supposed to return NULL without damaging the
1005  * existing allocation. Note that the positions beyond res->ntups are
1006  * garbage, not necessarily NULL.
1007  */
1008  int newSize;
1009  PGresAttValue **newTuples;
1010 
1011  /*
1012  * Since we use integers for row numbers, we can't support more than
1013  * INT_MAX rows. Make sure we allow that many, though.
1014  */
1015  if (res->tupArrSize <= INT_MAX / 2)
1016  newSize = (res->tupArrSize > 0) ? res->tupArrSize * 2 : 128;
1017  else if (res->tupArrSize < INT_MAX)
1018  newSize = INT_MAX;
1019  else
1020  {
1021  *errmsgp = libpq_gettext("PGresult cannot support more than INT_MAX tuples");
1022  return false;
1023  }
1024 
1025  /*
1026  * Also, on 32-bit platforms we could, in theory, overflow size_t even
1027  * before newSize gets to INT_MAX. (In practice we'd doubtless hit
1028  * OOM long before that, but let's check.)
1029  */
1030 #if INT_MAX >= (SIZE_MAX / 2)
1031  if (newSize > SIZE_MAX / sizeof(PGresAttValue *))
1032  {
1033  *errmsgp = libpq_gettext("size_t overflow");
1034  return false;
1035  }
1036 #endif
1037 
1038  if (res->tuples == NULL)
1039  newTuples = (PGresAttValue **)
1040  malloc(newSize * sizeof(PGresAttValue *));
1041  else
1042  newTuples = (PGresAttValue **)
1043  realloc(res->tuples, newSize * sizeof(PGresAttValue *));
1044  if (!newTuples)
1045  return false; /* malloc or realloc failed */
1046  res->memorySize +=
1047  (newSize - res->tupArrSize) * sizeof(PGresAttValue *);
1048  res->tupArrSize = newSize;
1049  res->tuples = newTuples;
1050  }
1051  res->tuples[res->ntups] = tup;
1052  res->ntups++;
1053  return true;
1054 }
1055 
1056 /*
1057  * pqSaveMessageField - save one field of an error or notice message
1058  */
1059 void
1060 pqSaveMessageField(PGresult *res, char code, const char *value)
1061 {
1062  PGMessageField *pfield;
1063 
1064  pfield = (PGMessageField *)
1066  offsetof(PGMessageField, contents) +
1067  strlen(value) + 1,
1068  true);
1069  if (!pfield)
1070  return; /* out of memory? */
1071  pfield->code = code;
1072  strcpy(pfield->contents, value);
1073  pfield->next = res->errFields;
1074  res->errFields = pfield;
1075 }
1076 
1077 /*
1078  * pqSaveParameterStatus - remember parameter status sent by backend
1079  */
1080 void
1081 pqSaveParameterStatus(PGconn *conn, const char *name, const char *value)
1082 {
1083  pgParameterStatus *pstatus;
1084  pgParameterStatus *prev;
1085 
1086  /*
1087  * Forget any old information about the parameter
1088  */
1089  for (pstatus = conn->pstatus, prev = NULL;
1090  pstatus != NULL;
1091  prev = pstatus, pstatus = pstatus->next)
1092  {
1093  if (strcmp(pstatus->name, name) == 0)
1094  {
1095  if (prev)
1096  prev->next = pstatus->next;
1097  else
1098  conn->pstatus = pstatus->next;
1099  free(pstatus); /* frees name and value strings too */
1100  break;
1101  }
1102  }
1103 
1104  /*
1105  * Store new info as a single malloc block
1106  */
1107  pstatus = (pgParameterStatus *) malloc(sizeof(pgParameterStatus) +
1108  strlen(name) + strlen(value) + 2);
1109  if (pstatus)
1110  {
1111  char *ptr;
1112 
1113  ptr = ((char *) pstatus) + sizeof(pgParameterStatus);
1114  pstatus->name = ptr;
1115  strcpy(ptr, name);
1116  ptr += strlen(name) + 1;
1117  pstatus->value = ptr;
1118  strcpy(ptr, value);
1119  pstatus->next = conn->pstatus;
1120  conn->pstatus = pstatus;
1121  }
1122 
1123  /*
1124  * Save values of settings that are of interest to libpq in fields of the
1125  * PGconn object. We keep client_encoding and standard_conforming_strings
1126  * in static variables as well, so that PQescapeString and PQescapeBytea
1127  * can behave somewhat sanely (at least in single-connection-using
1128  * programs).
1129  */
1130  if (strcmp(name, "client_encoding") == 0)
1131  {
1133  /* if we don't recognize the encoding name, fall back to SQL_ASCII */
1134  if (conn->client_encoding < 0)
1137  }
1138  else if (strcmp(name, "standard_conforming_strings") == 0)
1139  {
1140  conn->std_strings = (strcmp(value, "on") == 0);
1142  }
1143  else if (strcmp(name, "server_version") == 0)
1144  {
1145  /* We convert the server version to numeric form. */
1146  int cnt;
1147  int vmaj,
1148  vmin,
1149  vrev;
1150 
1151  cnt = sscanf(value, "%d.%d.%d", &vmaj, &vmin, &vrev);
1152 
1153  if (cnt == 3)
1154  {
1155  /* old style, e.g. 9.6.1 */
1156  conn->sversion = (100 * vmaj + vmin) * 100 + vrev;
1157  }
1158  else if (cnt == 2)
1159  {
1160  if (vmaj >= 10)
1161  {
1162  /* new style, e.g. 10.1 */
1163  conn->sversion = 100 * 100 * vmaj + vmin;
1164  }
1165  else
1166  {
1167  /* old style without minor version, e.g. 9.6devel */
1168  conn->sversion = (100 * vmaj + vmin) * 100;
1169  }
1170  }
1171  else if (cnt == 1)
1172  {
1173  /* new style without minor version, e.g. 10devel */
1174  conn->sversion = 100 * 100 * vmaj;
1175  }
1176  else
1177  conn->sversion = 0; /* unknown */
1178  }
1179  else if (strcmp(name, "default_transaction_read_only") == 0)
1180  {
1182  (strcmp(value, "on") == 0) ? PG_BOOL_YES : PG_BOOL_NO;
1183  }
1184  else if (strcmp(name, "in_hot_standby") == 0)
1185  {
1186  conn->in_hot_standby =
1187  (strcmp(value, "on") == 0) ? PG_BOOL_YES : PG_BOOL_NO;
1188  }
1189  else if (strcmp(name, "scram_iterations") == 0)
1190  {
1192  }
1193 }
1194 
1195 
1196 /*
1197  * pqRowProcessor
1198  * Add the received row to the current async result (conn->result).
1199  * Returns 1 if OK, 0 if error occurred.
1200  *
1201  * On error, *errmsgp can be set to an error string to be returned.
1202  * (Such a string should already be translated via libpq_gettext().)
1203  * If it is left NULL, the error is presumed to be "out of memory".
1204  */
1205 int
1206 pqRowProcessor(PGconn *conn, const char **errmsgp)
1207 {
1208  PGresult *res = conn->result;
1209  int nfields = res->numAttributes;
1210  const PGdataValue *columns = conn->rowBuf;
1211  PGresAttValue *tup;
1212  int i;
1213 
1214  /*
1215  * In partial-result mode, if we don't already have a partial PGresult
1216  * then make one by cloning conn->result (which should hold the correct
1217  * result metadata by now). Then the original conn->result is moved over
1218  * to saved_result so that we can re-use it as a reference for future
1219  * partial results. The saved result will become active again after
1220  * pqPrepareAsyncResult() returns the partial result to the application.
1221  */
1222  if (conn->partialResMode && conn->saved_result == NULL)
1223  {
1224  /* Copy everything that should be in the result at this point */
1225  res = PQcopyResult(res,
1228  if (!res)
1229  return 0;
1230  /* Change result status to appropriate special value */
1232  /* And stash it as the active result */
1234  conn->result = res;
1235  }
1236 
1237  /*
1238  * Basically we just allocate space in the PGresult for each field and
1239  * copy the data over.
1240  *
1241  * Note: on malloc failure, we return 0 leaving *errmsgp still NULL, which
1242  * caller will take to mean "out of memory". This is preferable to trying
1243  * to set up such a message here, because evidently there's not enough
1244  * memory for gettext() to do anything.
1245  */
1246  tup = (PGresAttValue *)
1247  pqResultAlloc(res, nfields * sizeof(PGresAttValue), true);
1248  if (tup == NULL)
1249  return 0;
1250 
1251  for (i = 0; i < nfields; i++)
1252  {
1253  int clen = columns[i].len;
1254 
1255  if (clen < 0)
1256  {
1257  /* null field */
1258  tup[i].len = NULL_LEN;
1259  tup[i].value = res->null_field;
1260  }
1261  else
1262  {
1263  bool isbinary = (res->attDescs[i].format != 0);
1264  char *val;
1265 
1266  val = (char *) pqResultAlloc(res, clen + 1, isbinary);
1267  if (val == NULL)
1268  return 0;
1269 
1270  /* copy and zero-terminate the data (even if it's binary) */
1271  memcpy(val, columns[i].value, clen);
1272  val[clen] = '\0';
1273 
1274  tup[i].len = clen;
1275  tup[i].value = val;
1276  }
1277  }
1278 
1279  /* And add the tuple to the PGresult's tuple array */
1280  if (!pqAddTuple(res, tup, errmsgp))
1281  return 0;
1282 
1283  /*
1284  * Success. In partial-result mode, if we have enough rows then make the
1285  * result available to the client immediately.
1286  */
1289 
1290  return 1;
1291 }
1292 
1293 
1294 /*
1295  * pqAllocCmdQueueEntry
1296  * Get a command queue entry for caller to fill.
1297  *
1298  * If the recycle queue has a free element, that is returned; if not, a
1299  * fresh one is allocated. Caller is responsible for adding it to the
1300  * command queue (pqAppendCmdQueueEntry) once the struct is filled in, or
1301  * releasing the memory (pqRecycleCmdQueueEntry) if an error occurs.
1302  *
1303  * If allocation fails, sets the error message and returns NULL.
1304  */
1305 static PGcmdQueueEntry *
1307 {
1308  PGcmdQueueEntry *entry;
1309 
1310  if (conn->cmd_queue_recycle == NULL)
1311  {
1312  entry = (PGcmdQueueEntry *) malloc(sizeof(PGcmdQueueEntry));
1313  if (entry == NULL)
1314  {
1315  libpq_append_conn_error(conn, "out of memory");
1316  return NULL;
1317  }
1318  }
1319  else
1320  {
1321  entry = conn->cmd_queue_recycle;
1322  conn->cmd_queue_recycle = entry->next;
1323  }
1324  entry->next = NULL;
1325  entry->query = NULL;
1326 
1327  return entry;
1328 }
1329 
1330 /*
1331  * pqAppendCmdQueueEntry
1332  * Append a caller-allocated entry to the command queue, and update
1333  * conn->asyncStatus to account for it.
1334  *
1335  * The query itself must already have been put in the output buffer by the
1336  * caller.
1337  */
1338 static void
1340 {
1341  Assert(entry->next == NULL);
1342 
1343  if (conn->cmd_queue_head == NULL)
1344  conn->cmd_queue_head = entry;
1345  else
1346  conn->cmd_queue_tail->next = entry;
1347 
1348  conn->cmd_queue_tail = entry;
1349 
1350  switch (conn->pipelineStatus)
1351  {
1352  case PQ_PIPELINE_OFF:
1353  case PQ_PIPELINE_ON:
1354 
1355  /*
1356  * When not in pipeline aborted state, if there's a result ready
1357  * to be consumed, let it be so (that is, don't change away from
1358  * READY or READY_MORE); otherwise set us busy to wait for
1359  * something to arrive from the server.
1360  */
1361  if (conn->asyncStatus == PGASYNC_IDLE)
1363  break;
1364 
1365  case PQ_PIPELINE_ABORTED:
1366 
1367  /*
1368  * In aborted pipeline state, we don't expect anything from the
1369  * server (since we don't send any queries that are queued).
1370  * Therefore, if IDLE then do what PQgetResult would do to let
1371  * itself consume commands from the queue; if we're in any other
1372  * state, we don't have to do anything.
1373  */
1374  if (conn->asyncStatus == PGASYNC_IDLE ||
1377  break;
1378  }
1379 }
1380 
1381 /*
1382  * pqRecycleCmdQueueEntry
1383  * Push a command queue entry onto the freelist.
1384  */
1385 static void
1387 {
1388  if (entry == NULL)
1389  return;
1390 
1391  /* recyclable entries should not have a follow-on command */
1392  Assert(entry->next == NULL);
1393 
1394  if (entry->query)
1395  {
1396  free(entry->query);
1397  entry->query = NULL;
1398  }
1399 
1400  entry->next = conn->cmd_queue_recycle;
1401  conn->cmd_queue_recycle = entry;
1402 }
1403 
1404 
1405 /*
1406  * PQsendQuery
1407  * Submit a query, but don't wait for it to finish
1408  *
1409  * Returns: 1 if successfully submitted
1410  * 0 if error (conn->errorMessage is set)
1411  *
1412  * PQsendQueryContinue is a non-exported version that behaves identically
1413  * except that it doesn't reset conn->errorMessage.
1414  */
1415 int
1416 PQsendQuery(PGconn *conn, const char *query)
1417 {
1418  return PQsendQueryInternal(conn, query, true);
1419 }
1420 
1421 int
1422 PQsendQueryContinue(PGconn *conn, const char *query)
1423 {
1424  return PQsendQueryInternal(conn, query, false);
1425 }
1426 
1427 static int
1428 PQsendQueryInternal(PGconn *conn, const char *query, bool newQuery)
1429 {
1430  PGcmdQueueEntry *entry = NULL;
1431 
1432  if (!PQsendQueryStart(conn, newQuery))
1433  return 0;
1434 
1435  /* check the argument */
1436  if (!query)
1437  {
1438  libpq_append_conn_error(conn, "command string is a null pointer");
1439  return 0;
1440  }
1441 
1443  {
1444  libpq_append_conn_error(conn, "%s not allowed in pipeline mode",
1445  "PQsendQuery");
1446  return 0;
1447  }
1448 
1449  entry = pqAllocCmdQueueEntry(conn);
1450  if (entry == NULL)
1451  return 0; /* error msg already set */
1452 
1453  /* Send the query message(s) */
1454  /* construct the outgoing Query message */
1455  if (pqPutMsgStart(PqMsg_Query, conn) < 0 ||
1456  pqPuts(query, conn) < 0 ||
1457  pqPutMsgEnd(conn) < 0)
1458  {
1459  /* error message should be set up already */
1460  pqRecycleCmdQueueEntry(conn, entry);
1461  return 0;
1462  }
1463 
1464  /* remember we are using simple query protocol */
1465  entry->queryclass = PGQUERY_SIMPLE;
1466  /* and remember the query text too, if possible */
1467  entry->query = strdup(query);
1468 
1469  /*
1470  * Give the data a push. In nonblock mode, don't complain if we're unable
1471  * to send it all; PQgetResult() will do any additional flushing needed.
1472  */
1473  if (pqFlush(conn) < 0)
1474  goto sendFailed;
1475 
1476  /* OK, it's launched! */
1477  pqAppendCmdQueueEntry(conn, entry);
1478 
1479  return 1;
1480 
1481 sendFailed:
1482  pqRecycleCmdQueueEntry(conn, entry);
1483  /* error message should be set up already */
1484  return 0;
1485 }
1486 
1487 /*
1488  * PQsendQueryParams
1489  * Like PQsendQuery, but use extended query protocol so we can pass parameters
1490  */
1491 int
1493  const char *command,
1494  int nParams,
1495  const Oid *paramTypes,
1496  const char *const *paramValues,
1497  const int *paramLengths,
1498  const int *paramFormats,
1499  int resultFormat)
1500 {
1501  if (!PQsendQueryStart(conn, true))
1502  return 0;
1503 
1504  /* check the arguments */
1505  if (!command)
1506  {
1507  libpq_append_conn_error(conn, "command string is a null pointer");
1508  return 0;
1509  }
1510  if (nParams < 0 || nParams > PQ_QUERY_PARAM_MAX_LIMIT)
1511  {
1512  libpq_append_conn_error(conn, "number of parameters must be between 0 and %d",
1514  return 0;
1515  }
1516 
1517  return PQsendQueryGuts(conn,
1518  command,
1519  "", /* use unnamed statement */
1520  nParams,
1521  paramTypes,
1522  paramValues,
1523  paramLengths,
1524  paramFormats,
1525  resultFormat);
1526 }
1527 
1528 /*
1529  * PQsendPrepare
1530  * Submit a Parse message, but don't wait for it to finish
1531  *
1532  * Returns: 1 if successfully submitted
1533  * 0 if error (conn->errorMessage is set)
1534  */
1535 int
1537  const char *stmtName, const char *query,
1538  int nParams, const Oid *paramTypes)
1539 {
1540  PGcmdQueueEntry *entry = NULL;
1541 
1542  if (!PQsendQueryStart(conn, true))
1543  return 0;
1544 
1545  /* check the arguments */
1546  if (!stmtName)
1547  {
1548  libpq_append_conn_error(conn, "statement name is a null pointer");
1549  return 0;
1550  }
1551  if (!query)
1552  {
1553  libpq_append_conn_error(conn, "command string is a null pointer");
1554  return 0;
1555  }
1556  if (nParams < 0 || nParams > PQ_QUERY_PARAM_MAX_LIMIT)
1557  {
1558  libpq_append_conn_error(conn, "number of parameters must be between 0 and %d",
1560  return 0;
1561  }
1562 
1563  entry = pqAllocCmdQueueEntry(conn);
1564  if (entry == NULL)
1565  return 0; /* error msg already set */
1566 
1567  /* construct the Parse message */
1568  if (pqPutMsgStart(PqMsg_Parse, conn) < 0 ||
1569  pqPuts(stmtName, conn) < 0 ||
1570  pqPuts(query, conn) < 0)
1571  goto sendFailed;
1572 
1573  if (nParams > 0 && paramTypes)
1574  {
1575  int i;
1576 
1577  if (pqPutInt(nParams, 2, conn) < 0)
1578  goto sendFailed;
1579  for (i = 0; i < nParams; i++)
1580  {
1581  if (pqPutInt(paramTypes[i], 4, conn) < 0)
1582  goto sendFailed;
1583  }
1584  }
1585  else
1586  {
1587  if (pqPutInt(0, 2, conn) < 0)
1588  goto sendFailed;
1589  }
1590  if (pqPutMsgEnd(conn) < 0)
1591  goto sendFailed;
1592 
1593  /* Add a Sync, unless in pipeline mode. */
1595  {
1596  if (pqPutMsgStart(PqMsg_Sync, conn) < 0 ||
1597  pqPutMsgEnd(conn) < 0)
1598  goto sendFailed;
1599  }
1600 
1601  /* remember we are doing just a Parse */
1602  entry->queryclass = PGQUERY_PREPARE;
1603 
1604  /* and remember the query text too, if possible */
1605  /* if insufficient memory, query just winds up NULL */
1606  entry->query = strdup(query);
1607 
1608  /*
1609  * Give the data a push (in pipeline mode, only if we're past the size
1610  * threshold). In nonblock mode, don't complain if we're unable to send
1611  * it all; PQgetResult() will do any additional flushing needed.
1612  */
1613  if (pqPipelineFlush(conn) < 0)
1614  goto sendFailed;
1615 
1616  /* OK, it's launched! */
1617  pqAppendCmdQueueEntry(conn, entry);
1618 
1619  return 1;
1620 
1621 sendFailed:
1622  pqRecycleCmdQueueEntry(conn, entry);
1623  /* error message should be set up already */
1624  return 0;
1625 }
1626 
1627 /*
1628  * PQsendQueryPrepared
1629  * Like PQsendQuery, but execute a previously prepared statement,
1630  * using extended query protocol so we can pass parameters
1631  */
1632 int
1634  const char *stmtName,
1635  int nParams,
1636  const char *const *paramValues,
1637  const int *paramLengths,
1638  const int *paramFormats,
1639  int resultFormat)
1640 {
1641  if (!PQsendQueryStart(conn, true))
1642  return 0;
1643 
1644  /* check the arguments */
1645  if (!stmtName)
1646  {
1647  libpq_append_conn_error(conn, "statement name is a null pointer");
1648  return 0;
1649  }
1650  if (nParams < 0 || nParams > PQ_QUERY_PARAM_MAX_LIMIT)
1651  {
1652  libpq_append_conn_error(conn, "number of parameters must be between 0 and %d",
1654  return 0;
1655  }
1656 
1657  return PQsendQueryGuts(conn,
1658  NULL, /* no command to parse */
1659  stmtName,
1660  nParams,
1661  NULL, /* no param types */
1662  paramValues,
1663  paramLengths,
1664  paramFormats,
1665  resultFormat);
1666 }
1667 
1668 /*
1669  * PQsendQueryStart
1670  * Common startup code for PQsendQuery and sibling routines
1671  */
1672 static bool
1673 PQsendQueryStart(PGconn *conn, bool newQuery)
1674 {
1675  if (!conn)
1676  return false;
1677 
1678  /*
1679  * If this is the beginning of a query cycle, reset the error state.
1680  * However, in pipeline mode with something already queued, the error
1681  * buffer belongs to that command and we shouldn't clear it.
1682  */
1683  if (newQuery && conn->cmd_queue_head == NULL)
1685 
1686  /* Don't try to send if we know there's no live connection. */
1687  if (conn->status != CONNECTION_OK)
1688  {
1689  libpq_append_conn_error(conn, "no connection to the server");
1690  return false;
1691  }
1692 
1693  /* Can't send while already busy, either, unless enqueuing for later */
1694  if (conn->asyncStatus != PGASYNC_IDLE &&
1696  {
1697  libpq_append_conn_error(conn, "another command is already in progress");
1698  return false;
1699  }
1700 
1702  {
1703  /*
1704  * When enqueuing commands we don't change much of the connection
1705  * state since it's already in use for the current command. The
1706  * connection state will get updated when pqPipelineProcessQueue()
1707  * advances to start processing the queued message.
1708  *
1709  * Just make sure we can safely enqueue given the current connection
1710  * state. We can enqueue behind another queue item, or behind a
1711  * non-queue command (one that sends its own sync), but we can't
1712  * enqueue if the connection is in a copy state.
1713  */
1714  switch (conn->asyncStatus)
1715  {
1716  case PGASYNC_IDLE:
1717  case PGASYNC_PIPELINE_IDLE:
1718  case PGASYNC_READY:
1719  case PGASYNC_READY_MORE:
1720  case PGASYNC_BUSY:
1721  /* ok to queue */
1722  break;
1723 
1724  case PGASYNC_COPY_IN:
1725  case PGASYNC_COPY_OUT:
1726  case PGASYNC_COPY_BOTH:
1727  libpq_append_conn_error(conn, "cannot queue commands during COPY");
1728  return false;
1729  }
1730  }
1731  else
1732  {
1733  /*
1734  * This command's results will come in immediately. Initialize async
1735  * result-accumulation state
1736  */
1738 
1739  /* reset partial-result mode */
1740  conn->partialResMode = false;
1741  conn->singleRowMode = false;
1742  conn->maxChunkSize = 0;
1743  }
1744 
1745  /* ready to send command message */
1746  return true;
1747 }
1748 
1749 /*
1750  * PQsendQueryGuts
1751  * Common code for sending a query with extended query protocol
1752  * PQsendQueryStart should be done already
1753  *
1754  * command may be NULL to indicate we use an already-prepared statement
1755  */
1756 static int
1758  const char *command,
1759  const char *stmtName,
1760  int nParams,
1761  const Oid *paramTypes,
1762  const char *const *paramValues,
1763  const int *paramLengths,
1764  const int *paramFormats,
1765  int resultFormat)
1766 {
1767  int i;
1768  PGcmdQueueEntry *entry;
1769 
1770  entry = pqAllocCmdQueueEntry(conn);
1771  if (entry == NULL)
1772  return 0; /* error msg already set */
1773 
1774  /*
1775  * We will send Parse (if needed), Bind, Describe Portal, Execute, Sync
1776  * (if not in pipeline mode), using specified statement name and the
1777  * unnamed portal.
1778  */
1779 
1780  if (command)
1781  {
1782  /* construct the Parse message */
1783  if (pqPutMsgStart(PqMsg_Parse, conn) < 0 ||
1784  pqPuts(stmtName, conn) < 0 ||
1785  pqPuts(command, conn) < 0)
1786  goto sendFailed;
1787  if (nParams > 0 && paramTypes)
1788  {
1789  if (pqPutInt(nParams, 2, conn) < 0)
1790  goto sendFailed;
1791  for (i = 0; i < nParams; i++)
1792  {
1793  if (pqPutInt(paramTypes[i], 4, conn) < 0)
1794  goto sendFailed;
1795  }
1796  }
1797  else
1798  {
1799  if (pqPutInt(0, 2, conn) < 0)
1800  goto sendFailed;
1801  }
1802  if (pqPutMsgEnd(conn) < 0)
1803  goto sendFailed;
1804  }
1805 
1806  /* Construct the Bind message */
1807  if (pqPutMsgStart(PqMsg_Bind, conn) < 0 ||
1808  pqPuts("", conn) < 0 ||
1809  pqPuts(stmtName, conn) < 0)
1810  goto sendFailed;
1811 
1812  /* Send parameter formats */
1813  if (nParams > 0 && paramFormats)
1814  {
1815  if (pqPutInt(nParams, 2, conn) < 0)
1816  goto sendFailed;
1817  for (i = 0; i < nParams; i++)
1818  {
1819  if (pqPutInt(paramFormats[i], 2, conn) < 0)
1820  goto sendFailed;
1821  }
1822  }
1823  else
1824  {
1825  if (pqPutInt(0, 2, conn) < 0)
1826  goto sendFailed;
1827  }
1828 
1829  if (pqPutInt(nParams, 2, conn) < 0)
1830  goto sendFailed;
1831 
1832  /* Send parameters */
1833  for (i = 0; i < nParams; i++)
1834  {
1835  if (paramValues && paramValues[i])
1836  {
1837  int nbytes;
1838 
1839  if (paramFormats && paramFormats[i] != 0)
1840  {
1841  /* binary parameter */
1842  if (paramLengths)
1843  nbytes = paramLengths[i];
1844  else
1845  {
1846  libpq_append_conn_error(conn, "length must be given for binary parameter");
1847  goto sendFailed;
1848  }
1849  }
1850  else
1851  {
1852  /* text parameter, do not use paramLengths */
1853  nbytes = strlen(paramValues[i]);
1854  }
1855  if (pqPutInt(nbytes, 4, conn) < 0 ||
1856  pqPutnchar(paramValues[i], nbytes, conn) < 0)
1857  goto sendFailed;
1858  }
1859  else
1860  {
1861  /* take the param as NULL */
1862  if (pqPutInt(-1, 4, conn) < 0)
1863  goto sendFailed;
1864  }
1865  }
1866  if (pqPutInt(1, 2, conn) < 0 ||
1867  pqPutInt(resultFormat, 2, conn))
1868  goto sendFailed;
1869  if (pqPutMsgEnd(conn) < 0)
1870  goto sendFailed;
1871 
1872  /* construct the Describe Portal message */
1873  if (pqPutMsgStart(PqMsg_Describe, conn) < 0 ||
1874  pqPutc('P', conn) < 0 ||
1875  pqPuts("", conn) < 0 ||
1876  pqPutMsgEnd(conn) < 0)
1877  goto sendFailed;
1878 
1879  /* construct the Execute message */
1880  if (pqPutMsgStart(PqMsg_Execute, conn) < 0 ||
1881  pqPuts("", conn) < 0 ||
1882  pqPutInt(0, 4, conn) < 0 ||
1883  pqPutMsgEnd(conn) < 0)
1884  goto sendFailed;
1885 
1886  /* construct the Sync message if not in pipeline mode */
1888  {
1889  if (pqPutMsgStart(PqMsg_Sync, conn) < 0 ||
1890  pqPutMsgEnd(conn) < 0)
1891  goto sendFailed;
1892  }
1893 
1894  /* remember we are using extended query protocol */
1895  entry->queryclass = PGQUERY_EXTENDED;
1896 
1897  /* and remember the query text too, if possible */
1898  /* if insufficient memory, query just winds up NULL */
1899  if (command)
1900  entry->query = strdup(command);
1901 
1902  /*
1903  * Give the data a push (in pipeline mode, only if we're past the size
1904  * threshold). In nonblock mode, don't complain if we're unable to send
1905  * it all; PQgetResult() will do any additional flushing needed.
1906  */
1907  if (pqPipelineFlush(conn) < 0)
1908  goto sendFailed;
1909 
1910  /* OK, it's launched! */
1911  pqAppendCmdQueueEntry(conn, entry);
1912 
1913  return 1;
1914 
1915 sendFailed:
1916  pqRecycleCmdQueueEntry(conn, entry);
1917  /* error message should be set up already */
1918  return 0;
1919 }
1920 
1921 /*
1922  * Is it OK to change partial-result mode now?
1923  */
1924 static bool
1926 {
1927  /*
1928  * Only allow changing the mode when we have launched a query and not yet
1929  * received any results.
1930  */
1931  if (!conn)
1932  return false;
1933  if (conn->asyncStatus != PGASYNC_BUSY)
1934  return false;
1935  if (!conn->cmd_queue_head ||
1938  return false;
1940  return false;
1941  return true;
1942 }
1943 
1944 /*
1945  * Select row-by-row processing mode
1946  */
1947 int
1949 {
1951  {
1952  conn->partialResMode = true;
1953  conn->singleRowMode = true;
1954  conn->maxChunkSize = 1;
1955  return 1;
1956  }
1957  else
1958  return 0;
1959 }
1960 
1961 /*
1962  * Select chunked results processing mode
1963  */
1964 int
1966 {
1967  if (chunkSize > 0 && canChangeResultMode(conn))
1968  {
1969  conn->partialResMode = true;
1970  conn->singleRowMode = false;
1971  conn->maxChunkSize = chunkSize;
1972  return 1;
1973  }
1974  else
1975  return 0;
1976 }
1977 
1978 /*
1979  * Consume any available input from the backend
1980  * 0 return: some kind of trouble
1981  * 1 return: no problem
1982  */
1983 int
1985 {
1986  if (!conn)
1987  return 0;
1988 
1989  /*
1990  * for non-blocking connections try to flush the send-queue, otherwise we
1991  * may never get a response for something that may not have already been
1992  * sent because it's in our write buffer!
1993  */
1994  if (pqIsnonblocking(conn))
1995  {
1996  if (pqFlush(conn) < 0)
1997  return 0;
1998  }
1999 
2000  /*
2001  * Load more data, if available. We do this no matter what state we are
2002  * in, since we are probably getting called because the application wants
2003  * to get rid of a read-select condition. Note that we will NOT block
2004  * waiting for more input.
2005  */
2006  if (pqReadData(conn) < 0)
2007  return 0;
2008 
2009  /* Parsing of the data waits till later. */
2010  return 1;
2011 }
2012 
2013 
2014 /*
2015  * parseInput: if appropriate, parse input data from backend
2016  * until input is exhausted or a stopping state is reached.
2017  * Note that this function will NOT attempt to read more data from the backend.
2018  */
2019 static void
2021 {
2023 }
2024 
2025 /*
2026  * PQisBusy
2027  * Return true if PQgetResult would block waiting for input.
2028  */
2029 
2030 int
2032 {
2033  if (!conn)
2034  return false;
2035 
2036  /* Parse any available data, if our state permits. */
2037  parseInput(conn);
2038 
2039  /*
2040  * PQgetResult will return immediately in all states except BUSY. Also,
2041  * if we've detected read EOF and dropped the connection, we can expect
2042  * that PQgetResult will fail immediately. Note that we do *not* check
2043  * conn->write_failed here --- once that's become set, we know we have
2044  * trouble, but we need to keep trying to read until we have a complete
2045  * server message or detect read EOF.
2046  */
2048 }
2049 
2050 /*
2051  * PQgetResult
2052  * Get the next PGresult produced by a query. Returns NULL if no
2053  * query work remains or an error has occurred (e.g. out of
2054  * memory).
2055  *
2056  * In pipeline mode, once all the result of a query have been returned,
2057  * PQgetResult returns NULL to let the user know that the next
2058  * query is being processed. At the end of the pipeline, returns a
2059  * result with PQresultStatus(result) == PGRES_PIPELINE_SYNC.
2060  */
2061 PGresult *
2063 {
2064  PGresult *res;
2065 
2066  if (!conn)
2067  return NULL;
2068 
2069  /* Parse any available data, if our state permits. */
2070  parseInput(conn);
2071 
2072  /* If not ready to return something, block until we are. */
2073  while (conn->asyncStatus == PGASYNC_BUSY)
2074  {
2075  int flushResult;
2076 
2077  /*
2078  * If data remains unsent, send it. Else we might be waiting for the
2079  * result of a command the backend hasn't even got yet.
2080  */
2081  while ((flushResult = pqFlush(conn)) > 0)
2082  {
2083  if (pqWait(false, true, conn))
2084  {
2085  flushResult = -1;
2086  break;
2087  }
2088  }
2089 
2090  /*
2091  * Wait for some more data, and load it. (Note: if the connection has
2092  * been lost, pqWait should return immediately because the socket
2093  * should be read-ready, either with the last server data or with an
2094  * EOF indication. We expect therefore that this won't result in any
2095  * undue delay in reporting a previous write failure.)
2096  */
2097  if (flushResult ||
2098  pqWait(true, false, conn) ||
2099  pqReadData(conn) < 0)
2100  {
2101  /* Report the error saved by pqWait or pqReadData */
2104  return pqPrepareAsyncResult(conn);
2105  }
2106 
2107  /* Parse it. */
2108  parseInput(conn);
2109 
2110  /*
2111  * If we had a write error, but nothing above obtained a query result
2112  * or detected a read error, report the write error.
2113  */
2115  {
2118  return pqPrepareAsyncResult(conn);
2119  }
2120  }
2121 
2122  /* Return the appropriate thing. */
2123  switch (conn->asyncStatus)
2124  {
2125  case PGASYNC_IDLE:
2126  res = NULL; /* query is complete */
2127  break;
2128  case PGASYNC_PIPELINE_IDLE:
2130 
2131  /*
2132  * We're about to return the NULL that terminates the round of
2133  * results from the current query; prepare to send the results of
2134  * the next query, if any, when we're called next. If there's no
2135  * next element in the command queue, this gets us in IDLE state.
2136  */
2138  res = NULL; /* query is complete */
2139  break;
2140 
2141  case PGASYNC_READY:
2143 
2144  /*
2145  * Normally pqPrepareAsyncResult will have left conn->result
2146  * empty. Otherwise, "res" must be a not-full PGRES_TUPLES_CHUNK
2147  * result, which we want to return to the caller while staying in
2148  * PGASYNC_READY state. Then the next call here will return the
2149  * empty PGRES_TUPLES_OK result that was restored from
2150  * saved_result, after which we can proceed.
2151  */
2152  if (conn->result)
2153  {
2155  break;
2156  }
2157 
2158  /* Advance the queue as appropriate */
2159  pqCommandQueueAdvance(conn, false,
2161 
2163  {
2164  /*
2165  * We're about to send the results of the current query. Set
2166  * us idle now, and ...
2167  */
2169 
2170  /*
2171  * ... in cases when we're sending a pipeline-sync result,
2172  * move queue processing forwards immediately, so that next
2173  * time we're called, we're prepared to return the next result
2174  * received from the server. In all other cases, leave the
2175  * queue state change for next time, so that a terminating
2176  * NULL result is sent.
2177  *
2178  * (In other words: we don't return a NULL after a pipeline
2179  * sync.)
2180  */
2183  }
2184  else
2185  {
2186  /* Set the state back to BUSY, allowing parsing to proceed. */
2188  }
2189  break;
2190  case PGASYNC_READY_MORE:
2192  /* Set the state back to BUSY, allowing parsing to proceed. */
2194  break;
2195  case PGASYNC_COPY_IN:
2197  break;
2198  case PGASYNC_COPY_OUT:
2200  break;
2201  case PGASYNC_COPY_BOTH:
2203  break;
2204  default:
2205  libpq_append_conn_error(conn, "unexpected asyncStatus: %d", (int) conn->asyncStatus);
2207  conn->asyncStatus = PGASYNC_IDLE; /* try to restore valid state */
2209  break;
2210  }
2211 
2212  /* Time to fire PGEVT_RESULTCREATE events, if there are any */
2213  if (res && res->nEvents > 0)
2215 
2216  return res;
2217 }
2218 
2219 /*
2220  * getCopyResult
2221  * Helper for PQgetResult: generate result for COPY-in-progress cases
2222  */
2223 static PGresult *
2225 {
2226  /*
2227  * If the server connection has been lost, don't pretend everything is
2228  * hunky-dory; instead return a PGRES_FATAL_ERROR result, and reset the
2229  * asyncStatus to idle (corresponding to what we'd do if we'd detected I/O
2230  * error in the earlier steps in PQgetResult). The text returned in the
2231  * result is whatever is in conn->errorMessage; we hope that was filled
2232  * with something relevant when the lost connection was detected.
2233  */
2234  if (conn->status != CONNECTION_OK)
2235  {
2238  return pqPrepareAsyncResult(conn);
2239  }
2240 
2241  /* If we have an async result for the COPY, return that */
2242  if (conn->result && conn->result->resultStatus == copytype)
2243  return pqPrepareAsyncResult(conn);
2244 
2245  /* Otherwise, invent a suitable PGresult */
2246  return PQmakeEmptyPGresult(conn, copytype);
2247 }
2248 
2249 
2250 /*
2251  * PQexec
2252  * send a query to the backend and package up the result in a PGresult
2253  *
2254  * If the query was not even sent, return NULL; conn->errorMessage is set to
2255  * a relevant message.
2256  * If the query was sent, a new PGresult is returned (which could indicate
2257  * either success or failure).
2258  * The user is responsible for freeing the PGresult via PQclear()
2259  * when done with it.
2260  */
2261 PGresult *
2262 PQexec(PGconn *conn, const char *query)
2263 {
2264  if (!PQexecStart(conn))
2265  return NULL;
2266  if (!PQsendQuery(conn, query))
2267  return NULL;
2268  return PQexecFinish(conn);
2269 }
2270 
2271 /*
2272  * PQexecParams
2273  * Like PQexec, but use extended query protocol so we can pass parameters
2274  */
2275 PGresult *
2277  const char *command,
2278  int nParams,
2279  const Oid *paramTypes,
2280  const char *const *paramValues,
2281  const int *paramLengths,
2282  const int *paramFormats,
2283  int resultFormat)
2284 {
2285  if (!PQexecStart(conn))
2286  return NULL;
2287  if (!PQsendQueryParams(conn, command,
2288  nParams, paramTypes, paramValues, paramLengths,
2289  paramFormats, resultFormat))
2290  return NULL;
2291  return PQexecFinish(conn);
2292 }
2293 
2294 /*
2295  * PQprepare
2296  * Creates a prepared statement by issuing a Parse message.
2297  *
2298  * If the query was not even sent, return NULL; conn->errorMessage is set to
2299  * a relevant message.
2300  * If the query was sent, a new PGresult is returned (which could indicate
2301  * either success or failure).
2302  * The user is responsible for freeing the PGresult via PQclear()
2303  * when done with it.
2304  */
2305 PGresult *
2307  const char *stmtName, const char *query,
2308  int nParams, const Oid *paramTypes)
2309 {
2310  if (!PQexecStart(conn))
2311  return NULL;
2312  if (!PQsendPrepare(conn, stmtName, query, nParams, paramTypes))
2313  return NULL;
2314  return PQexecFinish(conn);
2315 }
2316 
2317 /*
2318  * PQexecPrepared
2319  * Like PQexec, but execute a previously prepared statement,
2320  * using extended query protocol so we can pass parameters
2321  */
2322 PGresult *
2324  const char *stmtName,
2325  int nParams,
2326  const char *const *paramValues,
2327  const int *paramLengths,
2328  const int *paramFormats,
2329  int resultFormat)
2330 {
2331  if (!PQexecStart(conn))
2332  return NULL;
2333  if (!PQsendQueryPrepared(conn, stmtName,
2334  nParams, paramValues, paramLengths,
2335  paramFormats, resultFormat))
2336  return NULL;
2337  return PQexecFinish(conn);
2338 }
2339 
2340 /*
2341  * Common code for PQexec and sibling routines: prepare to send command
2342  */
2343 static bool
2345 {
2346  PGresult *result;
2347 
2348  if (!conn)
2349  return false;
2350 
2351  /*
2352  * Since this is the beginning of a query cycle, reset the error state.
2353  * However, in pipeline mode with something already queued, the error
2354  * buffer belongs to that command and we shouldn't clear it.
2355  */
2356  if (conn->cmd_queue_head == NULL)
2358 
2360  {
2361  libpq_append_conn_error(conn, "synchronous command execution functions are not allowed in pipeline mode");
2362  return false;
2363  }
2364 
2365  /*
2366  * Silently discard any prior query result that application didn't eat.
2367  * This is probably poor design, but it's here for backward compatibility.
2368  */
2369  while ((result = PQgetResult(conn)) != NULL)
2370  {
2371  ExecStatusType resultStatus = result->resultStatus;
2372 
2373  PQclear(result); /* only need its status */
2374  if (resultStatus == PGRES_COPY_IN)
2375  {
2376  /* get out of a COPY IN state */
2377  if (PQputCopyEnd(conn,
2378  libpq_gettext("COPY terminated by new PQexec")) < 0)
2379  return false;
2380  /* keep waiting to swallow the copy's failure message */
2381  }
2382  else if (resultStatus == PGRES_COPY_OUT)
2383  {
2384  /*
2385  * Get out of a COPY OUT state: we just switch back to BUSY and
2386  * allow the remaining COPY data to be dropped on the floor.
2387  */
2389  /* keep waiting to swallow the copy's completion message */
2390  }
2391  else if (resultStatus == PGRES_COPY_BOTH)
2392  {
2393  /* We don't allow PQexec during COPY BOTH */
2394  libpq_append_conn_error(conn, "PQexec not allowed during COPY BOTH");
2395  return false;
2396  }
2397  /* check for loss of connection, too */
2398  if (conn->status == CONNECTION_BAD)
2399  return false;
2400  }
2401 
2402  /* OK to send a command */
2403  return true;
2404 }
2405 
2406 /*
2407  * Common code for PQexec and sibling routines: wait for command result
2408  */
2409 static PGresult *
2411 {
2412  PGresult *result;
2413  PGresult *lastResult;
2414 
2415  /*
2416  * For backwards compatibility, return the last result if there are more
2417  * than one. (We used to have logic here to concatenate successive error
2418  * messages, but now that happens automatically, since conn->errorMessage
2419  * will continue to accumulate errors throughout this loop.)
2420  *
2421  * We have to stop if we see copy in/out/both, however. We will resume
2422  * parsing after application performs the data transfer.
2423  *
2424  * Also stop if the connection is lost (else we'll loop infinitely).
2425  */
2426  lastResult = NULL;
2427  while ((result = PQgetResult(conn)) != NULL)
2428  {
2429  PQclear(lastResult);
2430  lastResult = result;
2431  if (result->resultStatus == PGRES_COPY_IN ||
2432  result->resultStatus == PGRES_COPY_OUT ||
2433  result->resultStatus == PGRES_COPY_BOTH ||
2435  break;
2436  }
2437 
2438  return lastResult;
2439 }
2440 
2441 /*
2442  * PQdescribePrepared
2443  * Obtain information about a previously prepared statement
2444  *
2445  * If the query was not even sent, return NULL; conn->errorMessage is set to
2446  * a relevant message.
2447  * If the query was sent, a new PGresult is returned (which could indicate
2448  * either success or failure). On success, the PGresult contains status
2449  * PGRES_COMMAND_OK, and its parameter and column-heading fields describe
2450  * the statement's inputs and outputs respectively.
2451  * The user is responsible for freeing the PGresult via PQclear()
2452  * when done with it.
2453  */
2454 PGresult *
2456 {
2457  if (!PQexecStart(conn))
2458  return NULL;
2460  return NULL;
2461  return PQexecFinish(conn);
2462 }
2463 
2464 /*
2465  * PQdescribePortal
2466  * Obtain information about a previously created portal
2467  *
2468  * This is much like PQdescribePrepared, except that no parameter info is
2469  * returned. Note that at the moment, libpq doesn't really expose portals
2470  * to the client; but this can be used with a portal created by a SQL
2471  * DECLARE CURSOR command.
2472  */
2473 PGresult *
2474 PQdescribePortal(PGconn *conn, const char *portal)
2475 {
2476  if (!PQexecStart(conn))
2477  return NULL;
2478  if (!PQsendTypedCommand(conn, PqMsg_Describe, 'P', portal))
2479  return NULL;
2480  return PQexecFinish(conn);
2481 }
2482 
2483 /*
2484  * PQsendDescribePrepared
2485  * Submit a Describe Statement command, but don't wait for it to finish
2486  *
2487  * Returns: 1 if successfully submitted
2488  * 0 if error (conn->errorMessage is set)
2489  */
2490 int
2492 {
2493  return PQsendTypedCommand(conn, PqMsg_Describe, 'S', stmt);
2494 }
2495 
2496 /*
2497  * PQsendDescribePortal
2498  * Submit a Describe Portal command, but don't wait for it to finish
2499  *
2500  * Returns: 1 if successfully submitted
2501  * 0 if error (conn->errorMessage is set)
2502  */
2503 int
2504 PQsendDescribePortal(PGconn *conn, const char *portal)
2505 {
2506  return PQsendTypedCommand(conn, PqMsg_Describe, 'P', portal);
2507 }
2508 
2509 /*
2510  * PQclosePrepared
2511  * Close a previously prepared statement
2512  *
2513  * If the query was not even sent, return NULL; conn->errorMessage is set to
2514  * a relevant message.
2515  * If the query was sent, a new PGresult is returned (which could indicate
2516  * either success or failure). On success, the PGresult contains status
2517  * PGRES_COMMAND_OK. The user is responsible for freeing the PGresult via
2518  * PQclear() when done with it.
2519  */
2520 PGresult *
2522 {
2523  if (!PQexecStart(conn))
2524  return NULL;
2525  if (!PQsendTypedCommand(conn, PqMsg_Close, 'S', stmt))
2526  return NULL;
2527  return PQexecFinish(conn);
2528 }
2529 
2530 /*
2531  * PQclosePortal
2532  * Close a previously created portal
2533  *
2534  * This is exactly like PQclosePrepared, but for portals. Note that at the
2535  * moment, libpq doesn't really expose portals to the client; but this can be
2536  * used with a portal created by a SQL DECLARE CURSOR command.
2537  */
2538 PGresult *
2539 PQclosePortal(PGconn *conn, const char *portal)
2540 {
2541  if (!PQexecStart(conn))
2542  return NULL;
2543  if (!PQsendTypedCommand(conn, PqMsg_Close, 'P', portal))
2544  return NULL;
2545  return PQexecFinish(conn);
2546 }
2547 
2548 /*
2549  * PQsendClosePrepared
2550  * Submit a Close Statement command, but don't wait for it to finish
2551  *
2552  * Returns: 1 if successfully submitted
2553  * 0 if error (conn->errorMessage is set)
2554  */
2555 int
2557 {
2558  return PQsendTypedCommand(conn, PqMsg_Close, 'S', stmt);
2559 }
2560 
2561 /*
2562  * PQsendClosePortal
2563  * Submit a Close Portal command, but don't wait for it to finish
2564  *
2565  * Returns: 1 if successfully submitted
2566  * 0 if error (conn->errorMessage is set)
2567  */
2568 int
2569 PQsendClosePortal(PGconn *conn, const char *portal)
2570 {
2571  return PQsendTypedCommand(conn, PqMsg_Close, 'P', portal);
2572 }
2573 
2574 /*
2575  * PQsendTypedCommand
2576  * Common code to send a Describe or Close command
2577  *
2578  * Available options for "command" are
2579  * PqMsg_Close for Close; or
2580  * PqMsg_Describe for Describe.
2581  *
2582  * Available options for "type" are
2583  * 'S' to run a command on a prepared statement; or
2584  * 'P' to run a command on a portal.
2585  *
2586  * Returns 1 on success and 0 on failure.
2587  */
2588 static int
2589 PQsendTypedCommand(PGconn *conn, char command, char type, const char *target)
2590 {
2591  PGcmdQueueEntry *entry = NULL;
2592 
2593  /* Treat null target as empty string */
2594  if (!target)
2595  target = "";
2596 
2597  if (!PQsendQueryStart(conn, true))
2598  return 0;
2599 
2600  entry = pqAllocCmdQueueEntry(conn);
2601  if (entry == NULL)
2602  return 0; /* error msg already set */
2603 
2604  /* construct the Close message */
2605  if (pqPutMsgStart(command, conn) < 0 ||
2606  pqPutc(type, conn) < 0 ||
2607  pqPuts(target, conn) < 0 ||
2608  pqPutMsgEnd(conn) < 0)
2609  goto sendFailed;
2610 
2611  /* construct the Sync message */
2613  {
2614  if (pqPutMsgStart(PqMsg_Sync, conn) < 0 ||
2615  pqPutMsgEnd(conn) < 0)
2616  goto sendFailed;
2617  }
2618 
2619  /* remember if we are doing a Close or a Describe */
2620  if (command == PqMsg_Close)
2621  {
2622  entry->queryclass = PGQUERY_CLOSE;
2623  }
2624  else if (command == PqMsg_Describe)
2625  {
2626  entry->queryclass = PGQUERY_DESCRIBE;
2627  }
2628  else
2629  {
2630  libpq_append_conn_error(conn, "unrecognized message type \"%c\"", command);
2631  goto sendFailed;
2632  }
2633 
2634  /*
2635  * Give the data a push (in pipeline mode, only if we're past the size
2636  * threshold). In nonblock mode, don't complain if we're unable to send
2637  * it all; PQgetResult() will do any additional flushing needed.
2638  */
2639  if (pqPipelineFlush(conn) < 0)
2640  goto sendFailed;
2641 
2642  /* OK, it's launched! */
2643  pqAppendCmdQueueEntry(conn, entry);
2644 
2645  return 1;
2646 
2647 sendFailed:
2648  pqRecycleCmdQueueEntry(conn, entry);
2649  /* error message should be set up already */
2650  return 0;
2651 }
2652 
2653 /*
2654  * PQnotifies
2655  * returns a PGnotify* structure of the latest async notification
2656  * that has not yet been handled
2657  *
2658  * returns NULL, if there is currently
2659  * no unhandled async notification from the backend
2660  *
2661  * the CALLER is responsible for FREE'ing the structure returned
2662  *
2663  * Note that this function does not read any new data from the socket;
2664  * so usually, caller should call PQconsumeInput() first.
2665  */
2666 PGnotify *
2668 {
2669  PGnotify *event;
2670 
2671  if (!conn)
2672  return NULL;
2673 
2674  /* Parse any available data to see if we can extract NOTIFY messages. */
2675  parseInput(conn);
2676 
2677  event = conn->notifyHead;
2678  if (event)
2679  {
2680  conn->notifyHead = event->next;
2681  if (!conn->notifyHead)
2682  conn->notifyTail = NULL;
2683  event->next = NULL; /* don't let app see the internal state */
2684  }
2685  return event;
2686 }
2687 
2688 /*
2689  * PQputCopyData - send some data to the backend during COPY IN or COPY BOTH
2690  *
2691  * Returns 1 if successful, 0 if data could not be sent (only possible
2692  * in nonblock mode), or -1 if an error occurs.
2693  */
2694 int
2695 PQputCopyData(PGconn *conn, const char *buffer, int nbytes)
2696 {
2697  if (!conn)
2698  return -1;
2699  if (conn->asyncStatus != PGASYNC_COPY_IN &&
2701  {
2702  libpq_append_conn_error(conn, "no COPY in progress");
2703  return -1;
2704  }
2705 
2706  /*
2707  * Process any NOTICE or NOTIFY messages that might be pending in the
2708  * input buffer. Since the server might generate many notices during the
2709  * COPY, we want to clean those out reasonably promptly to prevent
2710  * indefinite expansion of the input buffer. (Note: the actual read of
2711  * input data into the input buffer happens down inside pqSendSome, but
2712  * it's not authorized to get rid of the data again.)
2713  */
2714  parseInput(conn);
2715 
2716  if (nbytes > 0)
2717  {
2718  /*
2719  * Try to flush any previously sent data in preference to growing the
2720  * output buffer. If we can't enlarge the buffer enough to hold the
2721  * data, return 0 in the nonblock case, else hard error. (For
2722  * simplicity, always assume 5 bytes of overhead.)
2723  */
2724  if ((conn->outBufSize - conn->outCount - 5) < nbytes)
2725  {
2726  if (pqFlush(conn) < 0)
2727  return -1;
2728  if (pqCheckOutBufferSpace(conn->outCount + 5 + (size_t) nbytes,
2729  conn))
2730  return pqIsnonblocking(conn) ? 0 : -1;
2731  }
2732  /* Send the data (too simple to delegate to fe-protocol files) */
2733  if (pqPutMsgStart(PqMsg_CopyData, conn) < 0 ||
2734  pqPutnchar(buffer, nbytes, conn) < 0 ||
2735  pqPutMsgEnd(conn) < 0)
2736  return -1;
2737  }
2738  return 1;
2739 }
2740 
2741 /*
2742  * PQputCopyEnd - send EOF indication to the backend during COPY IN
2743  *
2744  * After calling this, use PQgetResult() to check command completion status.
2745  *
2746  * Returns 1 if successful, or -1 if an error occurs.
2747  */
2748 int
2749 PQputCopyEnd(PGconn *conn, const char *errormsg)
2750 {
2751  if (!conn)
2752  return -1;
2753  if (conn->asyncStatus != PGASYNC_COPY_IN &&
2755  {
2756  libpq_append_conn_error(conn, "no COPY in progress");
2757  return -1;
2758  }
2759 
2760  /*
2761  * Send the COPY END indicator. This is simple enough that we don't
2762  * bother delegating it to the fe-protocol files.
2763  */
2764  if (errormsg)
2765  {
2766  /* Send COPY FAIL */
2767  if (pqPutMsgStart(PqMsg_CopyFail, conn) < 0 ||
2768  pqPuts(errormsg, conn) < 0 ||
2769  pqPutMsgEnd(conn) < 0)
2770  return -1;
2771  }
2772  else
2773  {
2774  /* Send COPY DONE */
2775  if (pqPutMsgStart(PqMsg_CopyDone, conn) < 0 ||
2776  pqPutMsgEnd(conn) < 0)
2777  return -1;
2778  }
2779 
2780  /*
2781  * If we sent the COPY command in extended-query mode, we must issue a
2782  * Sync as well.
2783  */
2784  if (conn->cmd_queue_head &&
2786  {
2787  if (pqPutMsgStart(PqMsg_Sync, conn) < 0 ||
2788  pqPutMsgEnd(conn) < 0)
2789  return -1;
2790  }
2791 
2792  /* Return to active duty */
2795  else
2797 
2798  /* Try to flush data */
2799  if (pqFlush(conn) < 0)
2800  return -1;
2801 
2802  return 1;
2803 }
2804 
2805 /*
2806  * PQgetCopyData - read a row of data from the backend during COPY OUT
2807  * or COPY BOTH
2808  *
2809  * If successful, sets *buffer to point to a malloc'd row of data, and
2810  * returns row length (always > 0) as result.
2811  * Returns 0 if no row available yet (only possible if async is true),
2812  * -1 if end of copy (consult PQgetResult), or -2 if error (consult
2813  * PQerrorMessage).
2814  */
2815 int
2816 PQgetCopyData(PGconn *conn, char **buffer, int async)
2817 {
2818  *buffer = NULL; /* for all failure cases */
2819  if (!conn)
2820  return -2;
2821  if (conn->asyncStatus != PGASYNC_COPY_OUT &&
2823  {
2824  libpq_append_conn_error(conn, "no COPY in progress");
2825  return -2;
2826  }
2827  return pqGetCopyData3(conn, buffer, async);
2828 }
2829 
2830 /*
2831  * PQgetline - gets a newline-terminated string from the backend.
2832  *
2833  * Chiefly here so that applications can use "COPY <rel> to stdout"
2834  * and read the output string. Returns a null-terminated string in `buffer`.
2835  *
2836  * XXX this routine is now deprecated, because it can't handle binary data.
2837  * If called during a COPY BINARY we return EOF.
2838  *
2839  * PQgetline reads up to `length`-1 characters (like fgets(3)) but strips
2840  * the terminating \n (like gets(3)).
2841  *
2842  * CAUTION: the caller is responsible for detecting the end-of-copy signal
2843  * (a line containing just "\.") when using this routine.
2844  *
2845  * RETURNS:
2846  * EOF if error (eg, invalid arguments are given)
2847  * 0 if EOL is reached (i.e., \n has been read)
2848  * (this is required for backward-compatibility -- this
2849  * routine used to always return EOF or 0, assuming that
2850  * the line ended within `length` bytes.)
2851  * 1 in other cases (i.e., the buffer was filled before \n is reached)
2852  */
2853 int
2854 PQgetline(PGconn *conn, char *buffer, int length)
2855 {
2856  if (!buffer || length <= 0)
2857  return EOF;
2858  *buffer = '\0';
2859  /* length must be at least 3 to hold the \. terminator! */
2860  if (length < 3)
2861  return EOF;
2862 
2863  if (!conn)
2864  return EOF;
2865 
2866  return pqGetline3(conn, buffer, length);
2867 }
2868 
2869 /*
2870  * PQgetlineAsync - gets a COPY data row without blocking.
2871  *
2872  * This routine is for applications that want to do "COPY <rel> to stdout"
2873  * asynchronously, that is without blocking. Having issued the COPY command
2874  * and gotten a PGRES_COPY_OUT response, the app should call PQconsumeInput
2875  * and this routine until the end-of-data signal is detected. Unlike
2876  * PQgetline, this routine takes responsibility for detecting end-of-data.
2877  *
2878  * On each call, PQgetlineAsync will return data if a complete data row
2879  * is available in libpq's input buffer. Otherwise, no data is returned
2880  * until the rest of the row arrives.
2881  *
2882  * If -1 is returned, the end-of-data signal has been recognized (and removed
2883  * from libpq's input buffer). The caller *must* next call PQendcopy and
2884  * then return to normal processing.
2885  *
2886  * RETURNS:
2887  * -1 if the end-of-copy-data marker has been recognized
2888  * 0 if no data is available
2889  * >0 the number of bytes returned.
2890  *
2891  * The data returned will not extend beyond a data-row boundary. If possible
2892  * a whole row will be returned at one time. But if the buffer offered by
2893  * the caller is too small to hold a row sent by the backend, then a partial
2894  * data row will be returned. In text mode this can be detected by testing
2895  * whether the last returned byte is '\n' or not.
2896  *
2897  * The returned data is *not* null-terminated.
2898  */
2899 
2900 int
2901 PQgetlineAsync(PGconn *conn, char *buffer, int bufsize)
2902 {
2903  if (!conn)
2904  return -1;
2905 
2906  return pqGetlineAsync3(conn, buffer, bufsize);
2907 }
2908 
2909 /*
2910  * PQputline -- sends a string to the backend during COPY IN.
2911  * Returns 0 if OK, EOF if not.
2912  *
2913  * This is deprecated primarily because the return convention doesn't allow
2914  * caller to tell the difference between a hard error and a nonblock-mode
2915  * send failure.
2916  */
2917 int
2918 PQputline(PGconn *conn, const char *string)
2919 {
2920  return PQputnbytes(conn, string, strlen(string));
2921 }
2922 
2923 /*
2924  * PQputnbytes -- like PQputline, but buffer need not be null-terminated.
2925  * Returns 0 if OK, EOF if not.
2926  */
2927 int
2928 PQputnbytes(PGconn *conn, const char *buffer, int nbytes)
2929 {
2930  if (PQputCopyData(conn, buffer, nbytes) > 0)
2931  return 0;
2932  else
2933  return EOF;
2934 }
2935 
2936 /*
2937  * PQendcopy
2938  * After completing the data transfer portion of a copy in/out,
2939  * the application must call this routine to finish the command protocol.
2940  *
2941  * This is deprecated; it's cleaner to use PQgetResult to get the transfer
2942  * status.
2943  *
2944  * RETURNS:
2945  * 0 on success
2946  * 1 on failure
2947  */
2948 int
2950 {
2951  if (!conn)
2952  return 0;
2953 
2954  return pqEndcopy3(conn);
2955 }
2956 
2957 
2958 /* ----------------
2959  * PQfn - Send a function call to the POSTGRES backend.
2960  *
2961  * conn : backend connection
2962  * fnid : OID of function to be called
2963  * result_buf : pointer to result buffer
2964  * result_len : actual length of result is returned here
2965  * result_is_int : If the result is an integer, this must be 1,
2966  * otherwise this should be 0
2967  * args : pointer to an array of function arguments
2968  * (each has length, if integer, and value/pointer)
2969  * nargs : # of arguments in args array.
2970  *
2971  * RETURNS
2972  * PGresult with status = PGRES_COMMAND_OK if successful.
2973  * *result_len is > 0 if there is a return value, 0 if not.
2974  * PGresult with status = PGRES_FATAL_ERROR if backend returns an error.
2975  * NULL on communications failure. conn->errorMessage will be set.
2976  * ----------------
2977  */
2978 
2979 PGresult *
2981  int fnid,
2982  int *result_buf,
2983  int *result_len,
2984  int result_is_int,
2985  const PQArgBlock *args,
2986  int nargs)
2987 {
2988  *result_len = 0;
2989 
2990  if (!conn)
2991  return NULL;
2992 
2993  /*
2994  * Since this is the beginning of a query cycle, reset the error state.
2995  * However, in pipeline mode with something already queued, the error
2996  * buffer belongs to that command and we shouldn't clear it.
2997  */
2998  if (conn->cmd_queue_head == NULL)
3000 
3002  {
3003  libpq_append_conn_error(conn, "%s not allowed in pipeline mode", "PQfn");
3004  return NULL;
3005  }
3006 
3009  {
3010  libpq_append_conn_error(conn, "connection in wrong state");
3011  return NULL;
3012  }
3013 
3014  return pqFunctionCall3(conn, fnid,
3015  result_buf, result_len,
3016  result_is_int,
3017  args, nargs);
3018 }
3019 
3020 /* ====== Pipeline mode support ======== */
3021 
3022 /*
3023  * PQenterPipelineMode
3024  * Put an idle connection in pipeline mode.
3025  *
3026  * Returns 1 on success. On failure, errorMessage is set and 0 is returned.
3027  *
3028  * Commands submitted after this can be pipelined on the connection;
3029  * there's no requirement to wait for one to finish before the next is
3030  * dispatched.
3031  *
3032  * Queuing of a new query or syncing during COPY is not allowed.
3033  *
3034  * A set of commands is terminated by a PQpipelineSync. Multiple sync
3035  * points can be established while in pipeline mode. Pipeline mode can
3036  * be exited by calling PQexitPipelineMode() once all results are processed.
3037  *
3038  * This doesn't actually send anything on the wire, it just puts libpq
3039  * into a state where it can pipeline work.
3040  */
3041 int
3043 {
3044  if (!conn)
3045  return 0;
3046 
3047  /* succeed with no action if already in pipeline mode */
3049  return 1;
3050 
3051  if (conn->asyncStatus != PGASYNC_IDLE)
3052  {
3053  libpq_append_conn_error(conn, "cannot enter pipeline mode, connection not idle");
3054  return 0;
3055  }
3056 
3058 
3059  return 1;
3060 }
3061 
3062 /*
3063  * PQexitPipelineMode
3064  * End pipeline mode and return to normal command mode.
3065  *
3066  * Returns 1 in success (pipeline mode successfully ended, or not in pipeline
3067  * mode).
3068  *
3069  * Returns 0 if in pipeline mode and cannot be ended yet. Error message will
3070  * be set.
3071  */
3072 int
3074 {
3075  if (!conn)
3076  return 0;
3077 
3079  (conn->asyncStatus == PGASYNC_IDLE ||
3081  conn->cmd_queue_head == NULL)
3082  return 1;
3083 
3084  switch (conn->asyncStatus)
3085  {
3086  case PGASYNC_READY:
3087  case PGASYNC_READY_MORE:
3088  /* there are some uncollected results */
3089  libpq_append_conn_error(conn, "cannot exit pipeline mode with uncollected results");
3090  return 0;
3091 
3092  case PGASYNC_BUSY:
3093  libpq_append_conn_error(conn, "cannot exit pipeline mode while busy");
3094  return 0;
3095 
3096  case PGASYNC_IDLE:
3097  case PGASYNC_PIPELINE_IDLE:
3098  /* OK */
3099  break;
3100 
3101  case PGASYNC_COPY_IN:
3102  case PGASYNC_COPY_OUT:
3103  case PGASYNC_COPY_BOTH:
3104  libpq_append_conn_error(conn, "cannot exit pipeline mode while in COPY");
3105  }
3106 
3107  /* still work to process */
3108  if (conn->cmd_queue_head != NULL)
3109  {
3110  libpq_append_conn_error(conn, "cannot exit pipeline mode with uncollected results");
3111  return 0;
3112  }
3113 
3116 
3117  /* Flush any pending data in out buffer */
3118  if (pqFlush(conn) < 0)
3119  return 0; /* error message is setup already */
3120  return 1;
3121 }
3122 
3123 /*
3124  * pqCommandQueueAdvance
3125  * Remove one query from the command queue, if appropriate.
3126  *
3127  * If we have received all results corresponding to the head element
3128  * in the command queue, remove it.
3129  *
3130  * In simple query protocol we must not advance the command queue until the
3131  * ReadyForQuery message has been received. This is because in simple mode a
3132  * command can have multiple queries, and we must process result for all of
3133  * them before moving on to the next command.
3134  *
3135  * Another consideration is synchronization during error processing in
3136  * extended query protocol: we refuse to advance the queue past a SYNC queue
3137  * element, unless the result we've received is also a SYNC. In particular
3138  * this protects us from advancing when an error is received at an
3139  * inappropriate moment.
3140  */
3141 void
3142 pqCommandQueueAdvance(PGconn *conn, bool isReadyForQuery, bool gotSync)
3143 {
3144  PGcmdQueueEntry *prevquery;
3145 
3146  if (conn->cmd_queue_head == NULL)
3147  return;
3148 
3149  /*
3150  * If processing a query of simple query protocol, we only advance the
3151  * queue when we receive the ReadyForQuery message for it.
3152  */
3153  if (conn->cmd_queue_head->queryclass == PGQUERY_SIMPLE && !isReadyForQuery)
3154  return;
3155 
3156  /*
3157  * If we're waiting for a SYNC, don't advance the queue until we get one.
3158  */
3159  if (conn->cmd_queue_head->queryclass == PGQUERY_SYNC && !gotSync)
3160  return;
3161 
3162  /* delink element from queue */
3163  prevquery = conn->cmd_queue_head;
3165 
3166  /* If the queue is now empty, reset the tail too */
3167  if (conn->cmd_queue_head == NULL)
3168  conn->cmd_queue_tail = NULL;
3169 
3170  /* and make the queue element recyclable */
3171  prevquery->next = NULL;
3172  pqRecycleCmdQueueEntry(conn, prevquery);
3173 }
3174 
3175 /*
3176  * pqPipelineProcessQueue: subroutine for PQgetResult
3177  * In pipeline mode, start processing the results of the next query in the queue.
3178  */
3179 static void
3181 {
3182  switch (conn->asyncStatus)
3183  {
3184  case PGASYNC_COPY_IN:
3185  case PGASYNC_COPY_OUT:
3186  case PGASYNC_COPY_BOTH:
3187  case PGASYNC_READY:
3188  case PGASYNC_READY_MORE:
3189  case PGASYNC_BUSY:
3190  /* client still has to process current query or results */
3191  return;
3192 
3193  case PGASYNC_IDLE:
3194 
3195  /*
3196  * If we're in IDLE mode and there's some command in the queue,
3197  * get us into PIPELINE_IDLE mode and process normally. Otherwise
3198  * there's nothing for us to do.
3199  */
3200  if (conn->cmd_queue_head != NULL)
3201  {
3203  break;
3204  }
3205  return;
3206 
3207  case PGASYNC_PIPELINE_IDLE:
3209  /* next query please */
3210  break;
3211  }
3212 
3213  /*
3214  * Reset partial-result mode. (Client has to set it up for each query, if
3215  * desired.)
3216  */
3217  conn->partialResMode = false;
3218  conn->singleRowMode = false;
3219  conn->maxChunkSize = 0;
3220 
3221  /*
3222  * If there are no further commands to process in the queue, get us in
3223  * "real idle" mode now.
3224  */
3225  if (conn->cmd_queue_head == NULL)
3226  {
3228  return;
3229  }
3230 
3231  /*
3232  * Reset the error state. This and the next couple of steps correspond to
3233  * what PQsendQueryStart didn't do for this query.
3234  */
3236 
3237  /* Initialize async result-accumulation state */
3239 
3242  {
3243  /*
3244  * In an aborted pipeline we don't get anything from the server for
3245  * each result; we're just discarding commands from the queue until we
3246  * get to the next sync from the server.
3247  *
3248  * The PGRES_PIPELINE_ABORTED results tell the client that its queries
3249  * got aborted.
3250  */
3252  if (!conn->result)
3253  {
3254  libpq_append_conn_error(conn, "out of memory");
3256  return;
3257  }
3259  }
3260  else
3261  {
3262  /* allow parsing to continue */
3264  }
3265 }
3266 
3267 /*
3268  * PQpipelineSync
3269  * Send a Sync message as part of a pipeline, and flush to server
3270  */
3271 int
3273 {
3274  return pqPipelineSyncInternal(conn, true);
3275 }
3276 
3277 /*
3278  * PQsendPipelineSync
3279  * Send a Sync message as part of a pipeline, without flushing to server
3280  */
3281 int
3283 {
3284  return pqPipelineSyncInternal(conn, false);
3285 }
3286 
3287 /*
3288  * Workhorse function for PQpipelineSync and PQsendPipelineSync.
3289  *
3290  * immediate_flush controls if the flush happens immediately after sending the
3291  * Sync message or not.
3292  */
3293 static int
3294 pqPipelineSyncInternal(PGconn *conn, bool immediate_flush)
3295 {
3296  PGcmdQueueEntry *entry;
3297 
3298  if (!conn)
3299  return 0;
3300 
3302  {
3303  libpq_append_conn_error(conn, "cannot send pipeline when not in pipeline mode");
3304  return 0;
3305  }
3306 
3307  switch (conn->asyncStatus)
3308  {
3309  case PGASYNC_COPY_IN:
3310  case PGASYNC_COPY_OUT:
3311  case PGASYNC_COPY_BOTH:
3312  /* should be unreachable */
3314  "internal error: cannot send pipeline while in COPY\n");
3315  return 0;
3316  case PGASYNC_READY:
3317  case PGASYNC_READY_MORE:
3318  case PGASYNC_BUSY:
3319  case PGASYNC_IDLE:
3320  case PGASYNC_PIPELINE_IDLE:
3321  /* OK to send sync */
3322  break;
3323  }
3324 
3325  entry = pqAllocCmdQueueEntry(conn);
3326  if (entry == NULL)
3327  return 0; /* error msg already set */
3328 
3329  entry->queryclass = PGQUERY_SYNC;
3330  entry->query = NULL;
3331 
3332  /* construct the Sync message */
3333  if (pqPutMsgStart(PqMsg_Sync, conn) < 0 ||
3334  pqPutMsgEnd(conn) < 0)
3335  goto sendFailed;
3336 
3337  /*
3338  * Give the data a push. In nonblock mode, don't complain if we're unable
3339  * to send it all; PQgetResult() will do any additional flushing needed.
3340  * If immediate_flush is disabled, the data is pushed if we are past the
3341  * size threshold.
3342  */
3343  if (immediate_flush)
3344  {
3345  if (pqFlush(conn) < 0)
3346  goto sendFailed;
3347  }
3348  else
3349  {
3350  if (pqPipelineFlush(conn) < 0)
3351  goto sendFailed;
3352  }
3353 
3354  /* OK, it's launched! */
3355  pqAppendCmdQueueEntry(conn, entry);
3356 
3357  return 1;
3358 
3359 sendFailed:
3360  pqRecycleCmdQueueEntry(conn, entry);
3361  /* error message should be set up already */
3362  return 0;
3363 }
3364 
3365 /*
3366  * PQsendFlushRequest
3367  * Send request for server to flush its buffer. Useful in pipeline
3368  * mode when a sync point is not desired.
3369  */
3370 int
3372 {
3373  if (!conn)
3374  return 0;
3375 
3376  /* Don't try to send if we know there's no live connection. */
3377  if (conn->status != CONNECTION_OK)
3378  {
3379  libpq_append_conn_error(conn, "no connection to the server");
3380  return 0;
3381  }
3382 
3383  /* Can't send while already busy, either, unless enqueuing for later */
3384  if (conn->asyncStatus != PGASYNC_IDLE &&
3386  {
3387  libpq_append_conn_error(conn, "another command is already in progress");
3388  return 0;
3389  }
3390 
3391  if (pqPutMsgStart(PqMsg_Flush, conn) < 0 ||
3392  pqPutMsgEnd(conn) < 0)
3393  {
3394  return 0;
3395  }
3396 
3397  /*
3398  * Give the data a push (in pipeline mode, only if we're past the size
3399  * threshold). In nonblock mode, don't complain if we're unable to send
3400  * it all; PQgetResult() will do any additional flushing needed.
3401  */
3402  if (pqPipelineFlush(conn) < 0)
3403  return 0;
3404 
3405  return 1;
3406 }
3407 
3408 /* ====== accessor funcs for PGresult ======== */
3409 
3412 {
3413  if (!res)
3414  return PGRES_FATAL_ERROR;
3415  return res->resultStatus;
3416 }
3417 
3418 char *
3420 {
3421  if ((unsigned int) status >= lengthof(pgresStatus))
3422  return libpq_gettext("invalid ExecStatusType code");
3423  return pgresStatus[status];
3424 }
3425 
3426 char *
3428 {
3429  if (!res || !res->errMsg)
3430  return "";
3431  return res->errMsg;
3432 }
3433 
3434 char *
3436  PGVerbosity verbosity,
3437  PGContextVisibility show_context)
3438 {
3439  PQExpBufferData workBuf;
3440 
3441  /*
3442  * Because the caller is expected to free the result string, we must
3443  * strdup any constant result. We use plain strdup and document that
3444  * callers should expect NULL if out-of-memory.
3445  */
3446  if (!res ||
3449  return strdup(libpq_gettext("PGresult is not an error result\n"));
3450 
3451  initPQExpBuffer(&workBuf);
3452 
3453  pqBuildErrorMessage3(&workBuf, res, verbosity, show_context);
3454 
3455  /* If insufficient memory to format the message, fail cleanly */
3456  if (PQExpBufferDataBroken(workBuf))
3457  {
3458  termPQExpBuffer(&workBuf);
3459  return strdup(libpq_gettext("out of memory\n"));
3460  }
3461 
3462  return workBuf.data;
3463 }
3464 
3465 char *
3466 PQresultErrorField(const PGresult *res, int fieldcode)
3467 {
3468  PGMessageField *pfield;
3469 
3470  if (!res)
3471  return NULL;
3472  for (pfield = res->errFields; pfield != NULL; pfield = pfield->next)
3473  {
3474  if (pfield->code == fieldcode)
3475  return pfield->contents;
3476  }
3477  return NULL;
3478 }
3479 
3480 int
3482 {
3483  if (!res)
3484  return 0;
3485  return res->ntups;
3486 }
3487 
3488 int
3490 {
3491  if (!res)
3492  return 0;
3493  return res->numAttributes;
3494 }
3495 
3496 int
3498 {
3499  if (!res)
3500  return 0;
3501  return res->binary;
3502 }
3503 
3504 /*
3505  * Helper routines to range-check field numbers and tuple numbers.
3506  * Return true if OK, false if not
3507  */
3508 
3509 static int
3510 check_field_number(const PGresult *res, int field_num)
3511 {
3512  if (!res)
3513  return false; /* no way to display error message... */
3514  if (field_num < 0 || field_num >= res->numAttributes)
3515  {
3517  "column number %d is out of range 0..%d",
3518  field_num, res->numAttributes - 1);
3519  return false;
3520  }
3521  return true;
3522 }
3523 
3524 static int
3526  int tup_num, int field_num)
3527 {
3528  if (!res)
3529  return false; /* no way to display error message... */
3530  if (tup_num < 0 || tup_num >= res->ntups)
3531  {
3533  "row number %d is out of range 0..%d",
3534  tup_num, res->ntups - 1);
3535  return false;
3536  }
3537  if (field_num < 0 || field_num >= res->numAttributes)
3538  {
3540  "column number %d is out of range 0..%d",
3541  field_num, res->numAttributes - 1);
3542  return false;
3543  }
3544  return true;
3545 }
3546 
3547 static int
3548 check_param_number(const PGresult *res, int param_num)
3549 {
3550  if (!res)
3551  return false; /* no way to display error message... */
3552  if (param_num < 0 || param_num >= res->numParameters)
3553  {
3555  "parameter number %d is out of range 0..%d",
3556  param_num, res->numParameters - 1);
3557  return false;
3558  }
3559 
3560  return true;
3561 }
3562 
3563 /*
3564  * returns NULL if the field_num is invalid
3565  */
3566 char *
3567 PQfname(const PGresult *res, int field_num)
3568 {
3569  if (!check_field_number(res, field_num))
3570  return NULL;
3571  if (res->attDescs)
3572  return res->attDescs[field_num].name;
3573  else
3574  return NULL;
3575 }
3576 
3577 /*
3578  * PQfnumber: find column number given column name
3579  *
3580  * The column name is parsed as if it were in a SQL statement, including
3581  * case-folding and double-quote processing. But note a possible gotcha:
3582  * downcasing in the frontend might follow different locale rules than
3583  * downcasing in the backend...
3584  *
3585  * Returns -1 if no match. In the present backend it is also possible
3586  * to have multiple matches, in which case the first one is found.
3587  */
3588 int
3589 PQfnumber(const PGresult *res, const char *field_name)
3590 {
3591  char *field_case;
3592  bool in_quotes;
3593  bool all_lower = true;
3594  const char *iptr;
3595  char *optr;
3596  int i;
3597 
3598  if (!res)
3599  return -1;
3600 
3601  /*
3602  * Note: it is correct to reject a zero-length input string; the proper
3603  * input to match a zero-length field name would be "".
3604  */
3605  if (field_name == NULL ||
3606  field_name[0] == '\0' ||
3607  res->attDescs == NULL)
3608  return -1;
3609 
3610  /*
3611  * Check if we can avoid the strdup() and related work because the
3612  * passed-in string wouldn't be changed before we do the check anyway.
3613  */
3614  for (iptr = field_name; *iptr; iptr++)
3615  {
3616  char c = *iptr;
3617 
3618  if (c == '"' || c != pg_tolower((unsigned char) c))
3619  {
3620  all_lower = false;
3621  break;
3622  }
3623  }
3624 
3625  if (all_lower)
3626  for (i = 0; i < res->numAttributes; i++)
3627  if (strcmp(field_name, res->attDescs[i].name) == 0)
3628  return i;
3629 
3630  /* Fall through to the normal check if that didn't work out. */
3631 
3632  /*
3633  * Note: this code will not reject partially quoted strings, eg
3634  * foo"BAR"foo will become fooBARfoo when it probably ought to be an error
3635  * condition.
3636  */
3637  field_case = strdup(field_name);
3638  if (field_case == NULL)
3639  return -1; /* grotty */
3640 
3641  in_quotes = false;
3642  optr = field_case;
3643  for (iptr = field_case; *iptr; iptr++)
3644  {
3645  char c = *iptr;
3646 
3647  if (in_quotes)
3648  {
3649  if (c == '"')
3650  {
3651  if (iptr[1] == '"')
3652  {
3653  /* doubled quotes become a single quote */
3654  *optr++ = '"';
3655  iptr++;
3656  }
3657  else
3658  in_quotes = false;
3659  }
3660  else
3661  *optr++ = c;
3662  }
3663  else if (c == '"')
3664  in_quotes = true;
3665  else
3666  {
3667  c = pg_tolower((unsigned char) c);
3668  *optr++ = c;
3669  }
3670  }
3671  *optr = '\0';
3672 
3673  for (i = 0; i < res->numAttributes; i++)
3674  {
3675  if (strcmp(field_case, res->attDescs[i].name) == 0)
3676  {
3677  free(field_case);
3678  return i;
3679  }
3680  }
3681  free(field_case);
3682  return -1;
3683 }
3684 
3685 Oid
3686 PQftable(const PGresult *res, int field_num)
3687 {
3688  if (!check_field_number(res, field_num))
3689  return InvalidOid;
3690  if (res->attDescs)
3691  return res->attDescs[field_num].tableid;
3692  else
3693  return InvalidOid;
3694 }
3695 
3696 int
3697 PQftablecol(const PGresult *res, int field_num)
3698 {
3699  if (!check_field_number(res, field_num))
3700  return 0;
3701  if (res->attDescs)
3702  return res->attDescs[field_num].columnid;
3703  else
3704  return 0;
3705 }
3706 
3707 int
3708 PQfformat(const PGresult *res, int field_num)
3709 {
3710  if (!check_field_number(res, field_num))
3711  return 0;
3712  if (res->attDescs)
3713  return res->attDescs[field_num].format;
3714  else
3715  return 0;
3716 }
3717 
3718 Oid
3719 PQftype(const PGresult *res, int field_num)
3720 {
3721  if (!check_field_number(res, field_num))
3722  return InvalidOid;
3723  if (res->attDescs)
3724  return res->attDescs[field_num].typid;
3725  else
3726  return InvalidOid;
3727 }
3728 
3729 int
3730 PQfsize(const PGresult *res, int field_num)
3731 {
3732  if (!check_field_number(res, field_num))
3733  return 0;
3734  if (res->attDescs)
3735  return res->attDescs[field_num].typlen;
3736  else
3737  return 0;
3738 }
3739 
3740 int
3741 PQfmod(const PGresult *res, int field_num)
3742 {
3743  if (!check_field_number(res, field_num))
3744  return 0;
3745  if (res->attDescs)
3746  return res->attDescs[field_num].atttypmod;
3747  else
3748  return 0;
3749 }
3750 
3751 char *
3753 {
3754  if (!res)
3755  return NULL;
3756  return res->cmdStatus;
3757 }
3758 
3759 /*
3760  * PQoidStatus -
3761  * if the last command was an INSERT, return the oid string
3762  * if not, return ""
3763  */
3764 char *
3766 {
3767  /*
3768  * This must be enough to hold the result. Don't laugh, this is better
3769  * than what this function used to do.
3770  */
3771  static char buf[24];
3772 
3773  size_t len;
3774 
3775  if (!res || strncmp(res->cmdStatus, "INSERT ", 7) != 0)
3776  return "";
3777 
3778  len = strspn(res->cmdStatus + 7, "0123456789");
3779  if (len > sizeof(buf) - 1)
3780  len = sizeof(buf) - 1;
3781  memcpy(buf, res->cmdStatus + 7, len);
3782  buf[len] = '\0';
3783 
3784  return buf;
3785 }
3786 
3787 /*
3788  * PQoidValue -
3789  * a perhaps preferable form of the above which just returns
3790  * an Oid type
3791  */
3792 Oid
3794 {
3795  char *endptr = NULL;
3796  unsigned long result;
3797 
3798  if (!res ||
3799  strncmp(res->cmdStatus, "INSERT ", 7) != 0 ||
3800  res->cmdStatus[7] < '0' ||
3801  res->cmdStatus[7] > '9')
3802  return InvalidOid;
3803 
3804  result = strtoul(res->cmdStatus + 7, &endptr, 10);
3805 
3806  if (!endptr || (*endptr != ' ' && *endptr != '\0'))
3807  return InvalidOid;
3808  else
3809  return (Oid) result;
3810 }
3811 
3812 
3813 /*
3814  * PQcmdTuples -
3815  * If the last command was INSERT/UPDATE/DELETE/MERGE/MOVE/FETCH/COPY,
3816  * return a string containing the number of inserted/affected tuples.
3817  * If not, return "".
3818  *
3819  * XXX: this should probably return an int
3820  */
3821 char *
3823 {
3824  char *p,
3825  *c;
3826 
3827  if (!res)
3828  return "";
3829 
3830  if (strncmp(res->cmdStatus, "INSERT ", 7) == 0)
3831  {
3832  p = res->cmdStatus + 7;
3833  /* INSERT: skip oid and space */
3834  while (*p && *p != ' ')
3835  p++;
3836  if (*p == 0)
3837  goto interpret_error; /* no space? */
3838  p++;
3839  }
3840  else if (strncmp(res->cmdStatus, "SELECT ", 7) == 0 ||
3841  strncmp(res->cmdStatus, "DELETE ", 7) == 0 ||
3842  strncmp(res->cmdStatus, "UPDATE ", 7) == 0)
3843  p = res->cmdStatus + 7;
3844  else if (strncmp(res->cmdStatus, "FETCH ", 6) == 0 ||
3845  strncmp(res->cmdStatus, "MERGE ", 6) == 0)
3846  p = res->cmdStatus + 6;
3847  else if (strncmp(res->cmdStatus, "MOVE ", 5) == 0 ||
3848  strncmp(res->cmdStatus, "COPY ", 5) == 0)
3849  p = res->cmdStatus + 5;
3850  else
3851  return "";
3852 
3853  /* check that we have an integer (at least one digit, nothing else) */
3854  for (c = p; *c; c++)
3855  {
3856  if (!isdigit((unsigned char) *c))
3857  goto interpret_error;
3858  }
3859  if (c == p)
3860  goto interpret_error;
3861 
3862  return p;
3863 
3864 interpret_error:
3866  "could not interpret result from server: %s",
3867  res->cmdStatus);
3868  return "";
3869 }
3870 
3871 /*
3872  * PQgetvalue:
3873  * return the value of field 'field_num' of row 'tup_num'
3874  */
3875 char *
3876 PQgetvalue(const PGresult *res, int tup_num, int field_num)
3877 {
3878  if (!check_tuple_field_number(res, tup_num, field_num))
3879  return NULL;
3880  return res->tuples[tup_num][field_num].value;
3881 }
3882 
3883 /* PQgetlength:
3884  * returns the actual length of a field value in bytes.
3885  */
3886 int
3887 PQgetlength(const PGresult *res, int tup_num, int field_num)
3888 {
3889  if (!check_tuple_field_number(res, tup_num, field_num))
3890  return 0;
3891  if (res->tuples[tup_num][field_num].len != NULL_LEN)
3892  return res->tuples[tup_num][field_num].len;
3893  else
3894  return 0;
3895 }
3896 
3897 /* PQgetisnull:
3898  * returns the null status of a field value.
3899  */
3900 int
3901 PQgetisnull(const PGresult *res, int tup_num, int field_num)
3902 {
3903  if (!check_tuple_field_number(res, tup_num, field_num))
3904  return 1; /* pretend it is null */
3905  if (res->tuples[tup_num][field_num].len == NULL_LEN)
3906  return 1;
3907  else
3908  return 0;
3909 }
3910 
3911 /* PQnparams:
3912  * returns the number of input parameters of a prepared statement.
3913  */
3914 int
3916 {
3917  if (!res)
3918  return 0;
3919  return res->numParameters;
3920 }
3921 
3922 /* PQparamtype:
3923  * returns type Oid of the specified statement parameter.
3924  */
3925 Oid
3926 PQparamtype(const PGresult *res, int param_num)
3927 {
3928  if (!check_param_number(res, param_num))
3929  return InvalidOid;
3930  if (res->paramDescs)
3931  return res->paramDescs[param_num].typid;
3932  else
3933  return InvalidOid;
3934 }
3935 
3936 
3937 /* PQsetnonblocking:
3938  * sets the PGconn's database connection non-blocking if the arg is true
3939  * or makes it blocking if the arg is false, this will not protect
3940  * you from PQexec(), you'll only be safe when using the non-blocking API.
3941  * Needs to be called only on a connected database connection.
3942  */
3943 int
3945 {
3946  bool barg;
3947 
3948  if (!conn || conn->status == CONNECTION_BAD)
3949  return -1;
3950 
3951  barg = (arg ? true : false);
3952 
3953  /* early out if the socket is already in the state requested */
3954  if (barg == conn->nonblocking)
3955  return 0;
3956 
3957  /*
3958  * to guarantee constancy for flushing/query/result-polling behavior we
3959  * need to flush the send queue at this point in order to guarantee proper
3960  * behavior. this is ok because either they are making a transition _from_
3961  * or _to_ blocking mode, either way we can block them.
3962  *
3963  * Clear error state in case pqFlush adds to it, unless we're actively
3964  * pipelining, in which case it seems best not to.
3965  */
3966  if (conn->cmd_queue_head == NULL)
3968 
3969  /* if we are going from blocking to non-blocking flush here */
3970  if (pqFlush(conn))
3971  return -1;
3972 
3973  conn->nonblocking = barg;
3974 
3975  return 0;
3976 }
3977 
3978 /*
3979  * return the blocking status of the database connection
3980  * true == nonblocking, false == blocking
3981  */
3982 int
3984 {
3985  if (!conn || conn->status == CONNECTION_BAD)
3986  return false;
3987  return pqIsnonblocking(conn);
3988 }
3989 
3990 /* libpq is thread-safe? */
3991 int
3993 {
3994  return true;
3995 }
3996 
3997 
3998 /* try to force data out, really only useful for non-blocking users */
3999 int
4001 {
4002  if (!conn || conn->status == CONNECTION_BAD)
4003  return -1;
4004  return pqFlush(conn);
4005 }
4006 
4007 /*
4008  * pqPipelineFlush
4009  *
4010  * In pipeline mode, data will be flushed only when the out buffer reaches the
4011  * threshold value. In non-pipeline mode, it behaves as stock pqFlush.
4012  *
4013  * Returns 0 on success.
4014  */
4015 static int
4017 {
4018  if ((conn->pipelineStatus != PQ_PIPELINE_ON) ||
4020  return pqFlush(conn);
4021  return 0;
4022 }
4023 
4024 
4025 /*
4026  * PQfreemem - safely frees memory allocated
4027  *
4028  * Needed mostly by Win32, unless multithreaded DLL (/MD in VC6)
4029  * Used for freeing memory from PQescapeBytea()/PQunescapeBytea()
4030  */
4031 void
4032 PQfreemem(void *ptr)
4033 {
4034  free(ptr);
4035 }
4036 
4037 /*
4038  * PQfreeNotify - free's the memory associated with a PGnotify
4039  *
4040  * This function is here only for binary backward compatibility.
4041  * New code should use PQfreemem(). A macro will automatically map
4042  * calls to PQfreemem. It should be removed in the future. bjm 2003-03-24
4043  */
4044 
4045 #undef PQfreeNotify
4046 void PQfreeNotify(PGnotify *notify);
4047 
4048 void
4050 {
4051  PQfreemem(notify);
4052 }
4053 
4054 
4055 /*
4056  * Escaping arbitrary strings to get valid SQL literal strings.
4057  *
4058  * Replaces "'" with "''", and if not std_strings, replaces "\" with "\\".
4059  *
4060  * length is the length of the source string. (Note: if a terminating NUL
4061  * is encountered sooner, PQescapeString stops short of "length"; the behavior
4062  * is thus rather like strncpy.)
4063  *
4064  * For safety the buffer at "to" must be at least 2*length + 1 bytes long.
4065  * A terminating NUL character is added to the output string, whether the
4066  * input is NUL-terminated or not.
4067  *
4068  * Returns the actual length of the output (not counting the terminating NUL).
4069  */
4070 static size_t
4072  char *to, const char *from, size_t length,
4073  int *error,
4074  int encoding, bool std_strings)
4075 {
4076  const char *source = from;
4077  char *target = to;
4078  size_t remaining = length;
4079 
4080  if (error)
4081  *error = 0;
4082 
4083  while (remaining > 0 && *source != '\0')
4084  {
4085  char c = *source;
4086  int len;
4087  int i;
4088 
4089  /* Fast path for plain ASCII */
4090  if (!IS_HIGHBIT_SET(c))
4091  {
4092  /* Apply quoting if needed */
4093  if (SQL_STR_DOUBLE(c, !std_strings))
4094  *target++ = c;
4095  /* Copy the character */
4096  *target++ = c;
4097  source++;
4098  remaining--;
4099  continue;
4100  }
4101 
4102  /* Slow path for possible multibyte characters */
4104 
4105  /* Copy the character */
4106  for (i = 0; i < len; i++)
4107  {
4108  if (remaining == 0 || *source == '\0')
4109  break;
4110  *target++ = *source++;
4111  remaining--;
4112  }
4113 
4114  /*
4115  * If we hit premature end of string (ie, incomplete multibyte
4116  * character), try to pad out to the correct length with spaces. We
4117  * may not be able to pad completely, but we will always be able to
4118  * insert at least one pad space (since we'd not have quoted a
4119  * multibyte character). This should be enough to make a string that
4120  * the server will error out on.
4121  */
4122  if (i < len)
4123  {
4124  if (error)
4125  *error = 1;
4126  if (conn)
4127  libpq_append_conn_error(conn, "incomplete multibyte character");
4128  for (; i < len; i++)
4129  {
4130  if (((size_t) (target - to)) / 2 >= length)
4131  break;
4132  *target++ = ' ';
4133  }
4134  break;
4135  }
4136  }
4137 
4138  /* Write the terminating NUL character. */
4139  *target = '\0';
4140 
4141  return target - to;
4142 }
4143 
4144 size_t
4146  char *to, const char *from, size_t length,
4147  int *error)
4148 {
4149  if (!conn)
4150  {
4151  /* force empty-string result */
4152  *to = '\0';
4153  if (error)
4154  *error = 1;
4155  return 0;
4156  }
4157 
4158  if (conn->cmd_queue_head == NULL)
4160 
4161  return PQescapeStringInternal(conn, to, from, length, error,
4163  conn->std_strings);
4164 }
4165 
4166 size_t
4167 PQescapeString(char *to, const char *from, size_t length)
4168 {
4169  return PQescapeStringInternal(NULL, to, from, length, NULL,
4172 }
4173 
4174 
4175 /*
4176  * Escape arbitrary strings. If as_ident is true, we escape the result
4177  * as an identifier; if false, as a literal. The result is returned in
4178  * a newly allocated buffer. If we fail due to an encoding violation or out
4179  * of memory condition, we return NULL, storing an error message into conn.
4180  */
4181 static char *
4182 PQescapeInternal(PGconn *conn, const char *str, size_t len, bool as_ident)
4183 {
4184  const char *s;
4185  char *result;
4186  char *rp;
4187  int num_quotes = 0; /* single or double, depending on as_ident */
4188  int num_backslashes = 0;
4189  int input_len;
4190  int result_size;
4191  char quote_char = as_ident ? '"' : '\'';
4192 
4193  /* We must have a connection, else fail immediately. */
4194  if (!conn)
4195  return NULL;
4196 
4197  if (conn->cmd_queue_head == NULL)
4199 
4200  /* Scan the string for characters that must be escaped. */
4201  for (s = str; (s - str) < len && *s != '\0'; ++s)
4202  {
4203  if (*s == quote_char)
4204  ++num_quotes;
4205  else if (*s == '\\')
4206  ++num_backslashes;
4207  else if (IS_HIGHBIT_SET(*s))
4208  {
4209  int charlen;
4210 
4211  /* Slow path for possible multibyte characters */
4212  charlen = pg_encoding_mblen(conn->client_encoding, s);
4213 
4214  /* Multibyte character overruns allowable length. */
4215  if ((s - str) + charlen > len || memchr(s, 0, charlen) != NULL)
4216  {
4217  libpq_append_conn_error(conn, "incomplete multibyte character");
4218  return NULL;
4219  }
4220 
4221  /* Adjust s, bearing in mind that for loop will increment it. */
4222  s += charlen - 1;
4223  }
4224  }
4225 
4226  /* Allocate output buffer. */
4227  input_len = s - str;
4228  result_size = input_len + num_quotes + 3; /* two quotes, plus a NUL */
4229  if (!as_ident && num_backslashes > 0)
4230  result_size += num_backslashes + 2;
4231  result = rp = (char *) malloc(result_size);
4232  if (rp == NULL)
4233  {
4234  libpq_append_conn_error(conn, "out of memory");
4235  return NULL;
4236  }
4237 
4238  /*
4239  * If we are escaping a literal that contains backslashes, we use the
4240  * escape string syntax so that the result is correct under either value
4241  * of standard_conforming_strings. We also emit a leading space in this
4242  * case, to guard against the possibility that the result might be
4243  * interpolated immediately following an identifier.
4244  */
4245  if (!as_ident && num_backslashes > 0)
4246  {
4247  *rp++ = ' ';
4248  *rp++ = 'E';
4249  }
4250 
4251  /* Opening quote. */
4252  *rp++ = quote_char;
4253 
4254  /*
4255  * Use fast path if possible.
4256  *
4257  * We've already verified that the input string is well-formed in the
4258  * current encoding. If it contains no quotes and, in the case of
4259  * literal-escaping, no backslashes, then we can just copy it directly to
4260  * the output buffer, adding the necessary quotes.
4261  *
4262  * If not, we must rescan the input and process each character
4263  * individually.
4264  */
4265  if (num_quotes == 0 && (num_backslashes == 0 || as_ident))
4266  {
4267  memcpy(rp, str, input_len);
4268  rp += input_len;
4269  }
4270  else
4271  {
4272  for (s = str; s - str < input_len; ++s)
4273  {
4274  if (*s == quote_char || (!as_ident && *s == '\\'))
4275  {
4276  *rp++ = *s;
4277  *rp++ = *s;
4278  }
4279  else if (!IS_HIGHBIT_SET(*s))
4280  *rp++ = *s;
4281  else
4282  {
4284 
4285  while (1)
4286  {
4287  *rp++ = *s;
4288  if (--i == 0)
4289  break;
4290  ++s; /* for loop will provide the final increment */
4291  }
4292  }
4293  }
4294  }
4295 
4296  /* Closing quote and terminating NUL. */
4297  *rp++ = quote_char;
4298  *rp = '\0';
4299 
4300  return result;
4301 }
4302 
4303 char *
4304 PQescapeLiteral(PGconn *conn, const char *str, size_t len)
4305 {
4306  return PQescapeInternal(conn, str, len, false);
4307 }
4308 
4309 char *
4310 PQescapeIdentifier(PGconn *conn, const char *str, size_t len)
4311 {
4312  return PQescapeInternal(conn, str, len, true);
4313 }
4314 
4315 /* HEX encoding support for bytea */
4316 static const char hextbl[] = "0123456789abcdef";
4317 
4318 static const int8 hexlookup[128] = {
4319  -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
4320  -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
4321  -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
4322  0, 1, 2, 3, 4, 5, 6, 7, 8, 9, -1, -1, -1, -1, -1, -1,
4323  -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1,
4324  -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
4325  -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1,
4326  -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
4327 };
4328 
4329 static inline char
4330 get_hex(char c)
4331 {
4332  int res = -1;
4333 
4334  if (c > 0 && c < 127)
4335  res = hexlookup[(unsigned char) c];
4336 
4337  return (char) res;
4338 }
4339 
4340 
4341 /*
4342  * PQescapeBytea - converts from binary string to the
4343  * minimal encoding necessary to include the string in an SQL
4344  * INSERT statement with a bytea type column as the target.
4345  *
4346  * We can use either hex or escape (traditional) encoding.
4347  * In escape mode, the following transformations are applied:
4348  * '\0' == ASCII 0 == \000
4349  * '\'' == ASCII 39 == ''
4350  * '\\' == ASCII 92 == \\
4351  * anything < 0x20, or > 0x7e ---> \ooo
4352  * (where ooo is an octal expression)
4353  *
4354  * If not std_strings, all backslashes sent to the output are doubled.
4355  */
4356 static unsigned char *
4358  const unsigned char *from, size_t from_length,
4359  size_t *to_length, bool std_strings, bool use_hex)
4360 {
4361  const unsigned char *vp;
4362  unsigned char *rp;
4363  unsigned char *result;
4364  size_t i;
4365  size_t len;
4366  size_t bslash_len = (std_strings ? 1 : 2);
4367 
4368  /*
4369  * empty string has 1 char ('\0')
4370  */
4371  len = 1;
4372 
4373  if (use_hex)
4374  {
4375  len += bslash_len + 1 + 2 * from_length;
4376  }
4377  else
4378  {
4379  vp = from;
4380  for (i = from_length; i > 0; i--, vp++)
4381  {
4382  if (*vp < 0x20 || *vp > 0x7e)
4383  len += bslash_len + 3;
4384  else if (*vp == '\'')
4385  len += 2;
4386  else if (*vp == '\\')
4387  len += bslash_len + bslash_len;
4388  else
4389  len++;
4390  }
4391  }
4392 
4393  *to_length = len;
4394  rp = result = (unsigned char *) malloc(len);
4395  if (rp == NULL)
4396  {
4397  if (conn)
4398  libpq_append_conn_error(conn, "out of memory");
4399  return NULL;
4400  }
4401 
4402  if (use_hex)
4403  {
4404  if (!std_strings)
4405  *rp++ = '\\';
4406  *rp++ = '\\';
4407  *rp++ = 'x';
4408  }
4409 
4410  vp = from;
4411  for (i = from_length; i > 0; i--, vp++)
4412  {
4413  unsigned char c = *vp;
4414 
4415  if (use_hex)
4416  {
4417  *rp++ = hextbl[(c >> 4) & 0xF];
4418  *rp++ = hextbl[c & 0xF];
4419  }
4420  else if (c < 0x20 || c > 0x7e)
4421  {
4422  if (!std_strings)
4423  *rp++ = '\\';
4424  *rp++ = '\\';
4425  *rp++ = (c >> 6) + '0';
4426  *rp++ = ((c >> 3) & 07) + '0';
4427  *rp++ = (c & 07) + '0';
4428  }
4429  else if (c == '\'')
4430  {
4431  *rp++ = '\'';
4432  *rp++ = '\'';
4433  }
4434  else if (c == '\\')
4435  {
4436  if (!std_strings)
4437  {
4438  *rp++ = '\\';
4439  *rp++ = '\\';
4440  }
4441  *rp++ = '\\';
4442  *rp++ = '\\';
4443  }
4444  else
4445  *rp++ = c;
4446  }
4447  *rp = '\0';
4448 
4449  return result;
4450 }
4451 
4452 unsigned char *
4454  const unsigned char *from, size_t from_length,
4455  size_t *to_length)
4456 {
4457  if (!conn)
4458  return NULL;
4459 
4460  if (conn->cmd_queue_head == NULL)
4462 
4463  return PQescapeByteaInternal(conn, from, from_length, to_length,
4464  conn->std_strings,
4465  (conn->sversion >= 90000));
4466 }
4467 
4468 unsigned char *
4469 PQescapeBytea(const unsigned char *from, size_t from_length, size_t *to_length)
4470 {
4471  return PQescapeByteaInternal(NULL, from, from_length, to_length,
4473  false /* can't use hex */ );
4474 }
4475 
4476 
4477 #define ISFIRSTOCTDIGIT(CH) ((CH) >= '0' && (CH) <= '3')
4478 #define ISOCTDIGIT(CH) ((CH) >= '0' && (CH) <= '7')
4479 #define OCTVAL(CH) ((CH) - '0')
4480 
4481 /*
4482  * PQunescapeBytea - converts the null terminated string representation
4483  * of a bytea, strtext, into binary, filling a buffer. It returns a
4484  * pointer to the buffer (or NULL on error), and the size of the
4485  * buffer in retbuflen. The pointer may subsequently be used as an
4486  * argument to the function PQfreemem.
4487  *
4488  * The following transformations are made:
4489  * \\ == ASCII 92 == \
4490  * \ooo == a byte whose value = ooo (ooo is an octal number)
4491  * \x == x (x is any character not matched by the above transformations)
4492  */
4493 unsigned char *
4494 PQunescapeBytea(const unsigned char *strtext, size_t *retbuflen)
4495 {
4496  size_t strtextlen,
4497  buflen;
4498  unsigned char *buffer,
4499  *tmpbuf;
4500  size_t i,
4501  j;
4502 
4503  if (strtext == NULL)
4504  return NULL;
4505 
4506  strtextlen = strlen((const char *) strtext);
4507 
4508  if (strtext[0] == '\\' && strtext[1] == 'x')
4509  {
4510  const unsigned char *s;
4511  unsigned char *p;
4512 
4513  buflen = (strtextlen - 2) / 2;
4514  /* Avoid unportable malloc(0) */
4515  buffer = (unsigned char *) malloc(buflen > 0 ? buflen : 1);
4516  if (buffer == NULL)
4517  return NULL;
4518 
4519  s = strtext + 2;
4520  p = buffer;
4521  while (*s)
4522  {
4523  char v1,
4524  v2;
4525 
4526  /*
4527  * Bad input is silently ignored. Note that this includes
4528  * whitespace between hex pairs, which is allowed by byteain.
4529  */
4530  v1 = get_hex(*s++);
4531  if (!*s || v1 == (char) -1)
4532  continue;
4533  v2 = get_hex(*s++);
4534  if (v2 != (char) -1)
4535  *p++ = (v1 << 4) | v2;
4536  }
4537 
4538  buflen = p - buffer;
4539  }
4540  else
4541  {
4542  /*
4543  * Length of input is max length of output, but add one to avoid
4544  * unportable malloc(0) if input is zero-length.
4545  */
4546  buffer = (unsigned char *) malloc(strtextlen + 1);
4547  if (buffer == NULL)
4548  return NULL;
4549 
4550  for (i = j = 0; i < strtextlen;)
4551  {
4552  switch (strtext[i])
4553  {
4554  case '\\':
4555  i++;
4556  if (strtext[i] == '\\')
4557  buffer[j++] = strtext[i++];
4558  else
4559  {
4560  if ((ISFIRSTOCTDIGIT(strtext[i])) &&
4561  (ISOCTDIGIT(strtext[i + 1])) &&
4562  (ISOCTDIGIT(strtext[i + 2])))
4563  {
4564  int byte;
4565 
4566  byte = OCTVAL(strtext[i++]);
4567  byte = (byte << 3) + OCTVAL(strtext[i++]);
4568  byte = (byte << 3) + OCTVAL(strtext[i++]);
4569  buffer[j++] = byte;
4570  }
4571  }
4572 
4573  /*
4574  * Note: if we see '\' followed by something that isn't a
4575  * recognized escape sequence, we loop around having done
4576  * nothing except advance i. Therefore the something will
4577  * be emitted as ordinary data on the next cycle. Corner
4578  * case: '\' at end of string will just be discarded.
4579  */
4580  break;
4581 
4582  default:
4583  buffer[j++] = strtext[i++];
4584  break;
4585  }
4586  }
4587  buflen = j; /* buflen is the length of the dequoted data */
4588  }
4589 
4590  /* Shrink the buffer to be no larger than necessary */
4591  /* +1 avoids unportable behavior when buflen==0 */
4592  tmpbuf = realloc(buffer, buflen + 1);
4593 
4594  /* It would only be a very brain-dead realloc that could fail, but... */
4595  if (!tmpbuf)
4596  {
4597  free(buffer);
4598  return NULL;
4599  }
4600 
4601  *retbuflen = buflen;
4602  return tmpbuf;
4603 }
#define unconstify(underlying_type, expr)
Definition: c.h:1245
signed char int8
Definition: c.h:492
#define IS_HIGHBIT_SET(ch)
Definition: c.h:1155
#define Assert(condition)
Definition: c.h:858
#define SQL_STR_DOUBLE(ch, escape_backslash)
Definition: c.h:1163
#define lengthof(array)
Definition: c.h:788
int errmsg(const char *fmt,...)
Definition: elog.c:1068
static char * PQescapeInternal(PGconn *conn, const char *str, size_t len, bool as_ident)
Definition: fe-exec.c:4182
static int PQsendQueryInternal(PGconn *conn, const char *query, bool newQuery)
Definition: fe-exec.c:1428
unsigned char * PQescapeBytea(const unsigned char *from, size_t from_length, size_t *to_length)
Definition: fe-exec.c:4469
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:2980
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:1492
int PQsendQueryContinue(PGconn *conn, const char *query)
Definition: fe-exec.c:1422
int PQgetlength(const PGresult *res, int tup_num, int field_num)
Definition: fe-exec.c:3887
int PQsetSingleRowMode(PGconn *conn)
Definition: fe-exec.c:1948
static char get_hex(char c)
Definition: fe-exec.c:4330
int PQbinaryTuples(const PGresult *res)
Definition: fe-exec.c:3497
int PQflush(PGconn *conn)
Definition: fe-exec.c:4000
void PQfreemem(void *ptr)
Definition: fe-exec.c:4032
PGnotify * PQnotifies(PGconn *conn)
Definition: fe-exec.c:2667
PGresult * PQprepare(PGconn *conn, const char *stmtName, const char *query, int nParams, const Oid *paramTypes)
Definition: fe-exec.c:2306
int PQgetline(PGconn *conn, char *buffer, int length)
Definition: fe-exec.c:2854
unsigned char * PQunescapeBytea(const unsigned char *strtext, size_t *retbuflen)
Definition: fe-exec.c:4494
static bool canChangeResultMode(PGconn *conn)
Definition: fe-exec.c:1925
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:4071
Oid PQftype(const PGresult *res, int field_num)
Definition: fe-exec.c:3719
int PQexitPipelineMode(PGconn *conn)
Definition: fe-exec.c:3073
int PQsendClosePortal(PGconn *conn, const char *portal)
Definition: fe-exec.c:2569
int PQsetResultAttrs(PGresult *res, int numAttributes, PGresAttDesc *attDescs)
Definition: fe-exec.c:249
#define ISOCTDIGIT(CH)
Definition: fe-exec.c:4478
void pqSaveMessageField(PGresult *res, char code, const char *value)
Definition: fe-exec.c:1060
char * PQescapeIdentifier(PGconn *conn, const char *str, size_t len)
Definition: fe-exec.c:4310
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:4357
static int check_tuple_field_number(const PGresult *res, int tup_num, int field_num)
Definition: fe-exec.c:3525
static void pqSaveWriteError(PGconn *conn)
Definition: fe-exec.c:820
int PQenterPipelineMode(PGconn *conn)
Definition: fe-exec.c:3042
void pqCommandQueueAdvance(PGconn *conn, bool isReadyForQuery, bool gotSync)
Definition: fe-exec.c:3142
void pqSetResultError(PGresult *res, PQExpBuffer errorMessage, int offset)
Definition: fe-exec.c:692
size_t PQescapeStringConn(PGconn *conn, char *to, const char *from, size_t length, int *error)
Definition: fe-exec.c:4145
void pqSaveErrorResult(PGconn *conn)
Definition: fe-exec.c:803
char *const pgresStatus[]
Definition: fe-exec.c:32
#define OCTVAL(CH)
Definition: fe-exec.c:4479
char * pqResultStrdup(PGresult *res, const char *str)
Definition: fe-exec.c:675
#define PGRESULT_DATA_BLOCKSIZE
Definition: fe-exec.c:142
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:2276
static int pqPipelineSyncInternal(PGconn *conn, bool immediate_flush)
Definition: fe-exec.c:3294
ExecStatusType PQresultStatus(const PGresult *res)
Definition: fe-exec.c:3411
Oid PQparamtype(const PGresult *res, int param_num)
Definition: fe-exec.c:3926
static int check_param_number(const PGresult *res, int param_num)
Definition: fe-exec.c:3548
int pqRowProcessor(PGconn *conn, const char **errmsgp)
Definition: fe-exec.c:1206
PGresult * PQdescribePrepared(PGconn *conn, const char *stmt)
Definition: fe-exec.c:2455
int PQnparams(const PGresult *res)
Definition: fe-exec.c:3915
void PQclear(PGresult *res)
Definition: fe-exec.c:721
int PQsendClosePrepared(PGconn *conn, const char *stmt)
Definition: fe-exec.c:2556
char * PQcmdTuples(PGresult *res)
Definition: fe-exec.c:3822
char * PQresultErrorMessage(const PGresult *res)
Definition: fe-exec.c:3427
static PGresult * PQexecFinish(PGconn *conn)
Definition: fe-exec.c:2410
int PQfformat(const PGresult *res, int field_num)
Definition: fe-exec.c:3708
static void pqAppendCmdQueueEntry(PGconn *conn, PGcmdQueueEntry *entry)
Definition: fe-exec.c:1339
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:1757
PGresult * PQclosePortal(PGconn *conn, const char *portal)
Definition: fe-exec.c:2539
int PQendcopy(PGconn *conn)
Definition: fe-exec.c:2949
static int pqPipelineFlush(PGconn *conn)
Definition: fe-exec.c:4016
int PQputCopyEnd(PGconn *conn, const char *errormsg)
Definition: fe-exec.c:2749
static int PQsendTypedCommand(PGconn *conn, char command, char type, const char *target)
Definition: fe-exec.c:2589
int PQsendPipelineSync(PGconn *conn)
Definition: fe-exec.c:3282
int PQntuples(const PGresult *res)
Definition: fe-exec.c:3481
int PQputnbytes(PGconn *conn, const char *buffer, int nbytes)
Definition: fe-exec.c:2928
int PQputline(PGconn *conn, const char *string)
Definition: fe-exec.c:2918
int PQgetlineAsync(PGconn *conn, char *buffer, int bufsize)
Definition: fe-exec.c:2901
static const PGresult OOM_result
Definition: fe-exec.c:49
#define PGRESULT_BLOCK_OVERHEAD
Definition: fe-exec.c:144
int PQputCopyData(PGconn *conn, const char *buffer, int nbytes)
Definition: fe-exec.c:2695
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:2323
static PGcmdQueueEntry * pqAllocCmdQueueEntry(PGconn *conn)
Definition: fe-exec.c:1306
static PGresult * getCopyResult(PGconn *conn, ExecStatusType copytype)
Definition: fe-exec.c:2224
static PGEvent * dupEvents(PGEvent *events, int count, size_t *memSize)
Definition: fe-exec.c:408
int PQisthreadsafe(void)
Definition: fe-exec.c:3992
char * PQfname(const PGresult *res, int field_num)
Definition: fe-exec.c:3567
static bool static_std_strings
Definition: fe-exec.c:60
char * PQescapeLiteral(PGconn *conn, const char *str, size_t len)
Definition: fe-exec.c:4304
void pqInternalNotice(const PGNoticeHooks *hooks, const char *fmt,...)
Definition: fe-exec.c:938
PGresult * PQdescribePortal(PGconn *conn, const char *portal)
Definition: fe-exec.c:2474
int PQsendDescribePrepared(PGconn *conn, const char *stmt)
Definition: fe-exec.c:2491
PGresult * PQmakeEmptyPGresult(PGconn *conn, ExecStatusType status)
Definition: fe-exec.c:159
PGresult * PQexec(PGconn *conn, const char *query)
Definition: fe-exec.c:2262
unsigned char * PQescapeByteaConn(PGconn *conn, const unsigned char *from, size_t from_length, size_t *to_length)
Definition: fe-exec.c:4453
static const char hextbl[]
Definition: fe-exec.c:4316
static bool PQexecStart(PGconn *conn)
Definition: fe-exec.c:2344
size_t PQescapeString(char *to, const char *from, size_t length)
Definition: fe-exec.c:4167
int PQconsumeInput(PGconn *conn)
Definition: fe-exec.c:1984
#define ISFIRSTOCTDIGIT(CH)
Definition: fe-exec.c:4477
static void parseInput(PGconn *conn)
Definition: fe-exec.c:2020
char * PQgetvalue(const PGresult *res, int tup_num, int field_num)
Definition: fe-exec.c:3876
Oid PQftable(const PGresult *res, int field_num)
Definition: fe-exec.c:3686
int PQfnumber(const PGresult *res, const char *field_name)
Definition: fe-exec.c:3589
char * PQcmdStatus(PGresult *res)
Definition: fe-exec.c:3752
void pqSaveParameterStatus(PGconn *conn, const char *name, const char *value)
Definition: fe-exec.c:1081
int PQsetnonblocking(PGconn *conn, int arg)
Definition: fe-exec.c:3944
int PQsendPrepare(PGconn *conn, const char *stmtName, const char *query, int nParams, const Oid *paramTypes)
Definition: fe-exec.c:1536
#define PGRESULT_SEP_ALLOC_THRESHOLD
Definition: fe-exec.c:145
int PQfmod(const PGresult *res, int field_num)
Definition: fe-exec.c:3741
void pqClearAsyncResult(PGconn *conn)
Definition: fe-exec.c:779
int PQgetisnull(const PGresult *res, int tup_num, int field_num)
Definition: fe-exec.c:3901
int PQftablecol(const PGresult *res, int field_num)
Definition: fe-exec.c:3697
int PQsetChunkedRowsMode(PGconn *conn, int chunkSize)
Definition: fe-exec.c:1965
static int static_client_encoding
Definition: fe-exec.c:59
int PQsetvalue(PGresult *res, int tup_num, int field_num, char *value, int len)
Definition: fe-exec.c:452
int PQsendQuery(PGconn *conn, const char *query)
Definition: fe-exec.c:1416
int PQpipelineSync(PGconn *conn)
Definition: fe-exec.c:3272
char * PQresStatus(ExecStatusType status)
Definition: fe-exec.c:3419
int PQsendDescribePortal(PGconn *conn, const char *portal)
Definition: fe-exec.c:2504
PGresult * PQclosePrepared(PGconn *conn, const char *stmt)
Definition: fe-exec.c:2521
size_t PQresultMemorySize(const PGresult *res)
Definition: fe-exec.c:663
int PQisBusy(PGconn *conn)
Definition: fe-exec.c:2031
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:1633
static void pqPipelineProcessQueue(PGconn *conn)
Definition: fe-exec.c:3180
int PQsendFlushRequest(PGconn *conn)
Definition: fe-exec.c:3371
void * pqResultAlloc(PGresult *res, size_t nBytes, bool isBinary)
Definition: fe-exec.c:563
char * PQoidStatus(const PGresult *res)
Definition: fe-exec.c:3765
char * PQresultErrorField(const PGresult *res, int fieldcode)
Definition: fe-exec.c:3466
int PQisnonblocking(const PGconn *conn)
Definition: fe-exec.c:3983
PGresult * PQcopyResult(const PGresult *src, int flags)
Definition: fe-exec.c:318
void * PQresultAlloc(PGresult *res, size_t nBytes)
Definition: fe-exec.c:543
Oid PQoidValue(const PGresult *res)
Definition: fe-exec.c:3793
static bool pqAddTuple(PGresult *res, PGresAttValue *tup, const char **errmsgp)
Definition: fe-exec.c:993
char * PQresultVerboseErrorMessage(const PGresult *res, PGVerbosity verbosity, PGContextVisibility show_context)
Definition: fe-exec.c:3435
#define PGRESULT_ALIGN_BOUNDARY
Definition: fe-exec.c:143
int PQnfields(const PGresult *res)
Definition: fe-exec.c:3489
static int check_field_number(const PGresult *res, int field_num)
Definition: fe-exec.c:3510
PGresult * PQgetResult(PGconn *conn)
Definition: fe-exec.c:2062
PGresult * pqPrepareAsyncResult(PGconn *conn)
Definition: fe-exec.c:851
int PQfsize(const PGresult *res, int field_num)
Definition: fe-exec.c:3730
static bool PQsendQueryStart(PGconn *conn, bool newQuery)
Definition: fe-exec.c:1673
static const int8 hexlookup[128]
Definition: fe-exec.c:4318
int PQgetCopyData(PGconn *conn, char **buffer, int async)
Definition: fe-exec.c:2816
static void pqRecycleCmdQueueEntry(PGconn *conn, PGcmdQueueEntry *entry)
Definition: fe-exec.c:1386
void PQfreeNotify(PGnotify *notify)
Definition: fe-exec.c:4049
int pqPutc(char c, PGconn *conn)
Definition: fe-misc.c:92
int pqReadData(PGconn *conn)
Definition: fe-misc.c:565
int pqPutInt(int value, size_t bytes, PGconn *conn)
Definition: fe-misc.c:253
int pqCheckOutBufferSpace(size_t bytes_needed, PGconn *conn)
Definition: fe-misc.c:287
int pqFlush(PGconn *conn)
Definition: fe-misc.c:953
int pqPutMsgStart(char msg_type, PGconn *conn)
Definition: fe-misc.c:458
int pqWait(int forRead, int forWrite, PGconn *conn)
Definition: fe-misc.c:978
int pqPutnchar(const char *s, size_t len, PGconn *conn)
Definition: fe-misc.c:202
int pqPuts(const char *s, PGconn *conn)
Definition: fe-misc.c:152
void libpq_append_conn_error(PGconn *conn, const char *fmt,...)
Definition: fe-misc.c:1357
int pqPutMsgEnd(PGconn *conn)
Definition: fe-misc.c:517
void pqBuildErrorMessage3(PQExpBuffer msg, const PGresult *res, PGVerbosity verbosity, PGContextVisibility show_context)
void pqParseInput3(PGconn *conn)
Definition: fe-protocol3.c:66
int pqEndcopy3(PGconn *conn)
PGresult * pqFunctionCall3(PGconn *conn, Oid fnid, int *result_buf, int *actual_result_len, int result_is_int, const PQArgBlock *args, int nargs)
int pqGetlineAsync3(PGconn *conn, char *buffer, int bufsize)
int pqGetCopyData3(PGconn *conn, char **buffer, int async)
int pqGetline3(PGconn *conn, char *s, int maxlen)
const char * str
#define realloc(a, b)
Definition: header.h:60
#define free(a)
Definition: header.h:65
#define malloc(a)
Definition: header.h:50
#define stmt
Definition: indent_codes.h:59
#define bufsize
Definition: indent_globs.h:36
long val
Definition: informix.c:670
static struct @155 value
int remaining
Definition: informix.c:673
return true
Definition: isn.c:126
int j
Definition: isn.c:74
int i
Definition: isn.c:73
if(TABLE==NULL||TABLE_index==NULL)
Definition: isn.c:77
int PQfireResultCreateEvents(PGconn *conn, PGresult *res)
Definition: libpq-events.c:185
@ PGEVT_RESULTDESTROY
Definition: libpq-events.h:34
@ PGEVT_RESULTCOPY
Definition: libpq-events.h:33
@ CONNECTION_BAD
Definition: libpq-fe.h:61
@ CONNECTION_OK
Definition: libpq-fe.h:60
ExecStatusType
Definition: libpq-fe.h:97
@ PGRES_COPY_IN
Definition: libpq-fe.h:106
@ PGRES_COPY_BOTH
Definition: libpq-fe.h:111
@ PGRES_COMMAND_OK
Definition: libpq-fe.h:99
@ PGRES_TUPLES_CHUNK
Definition: libpq-fe.h:116
@ PGRES_FATAL_ERROR
Definition: libpq-fe.h:110
@ PGRES_SINGLE_TUPLE
Definition: libpq-fe.h:112
@ PGRES_COPY_OUT
Definition: libpq-fe.h:105
@ PGRES_EMPTY_QUERY
Definition: libpq-fe.h:98
@ PGRES_PIPELINE_SYNC
Definition: libpq-fe.h:113
@ PGRES_PIPELINE_ABORTED
Definition: libpq-fe.h:114
@ PGRES_NONFATAL_ERROR
Definition: libpq-fe.h:109
@ PGRES_TUPLES_OK
Definition: libpq-fe.h:102
PGContextVisibility
Definition: libpq-fe.h:137
#define PG_COPYRES_TUPLES
Definition: libpq-fe.h:46
@ PQ_PIPELINE_OFF
Definition: libpq-fe.h:161
@ PQ_PIPELINE_ABORTED
Definition: libpq-fe.h:163
@ PQ_PIPELINE_ON
Definition: libpq-fe.h:162
#define PG_COPYRES_ATTRS
Definition: libpq-fe.h:45
struct pg_result PGresult
Definition: libpq-fe.h:181
PGVerbosity
Definition: libpq-fe.h:129
#define PG_COPYRES_EVENTS
Definition: libpq-fe.h:47
#define PG_COPYRES_NOTICEHOOKS
Definition: libpq-fe.h:48
#define PQ_QUERY_PARAM_MAX_LIMIT
Definition: libpq-fe.h:473
struct PGEvent PGEvent
@ PGASYNC_COPY_OUT
Definition: libpq-int.h:229
@ PGASYNC_READY_MORE
Definition: libpq-int.h:225
@ PGASYNC_READY
Definition: libpq-int.h:223
@ PGASYNC_COPY_BOTH
Definition: libpq-int.h:230
@ PGASYNC_IDLE
Definition: libpq-int.h:221
@ PGASYNC_COPY_IN
Definition: libpq-int.h:228
@ PGASYNC_BUSY
Definition: libpq-int.h:222
@ PGASYNC_PIPELINE_IDLE
Definition: libpq-int.h:231
#define libpq_gettext(x)
Definition: libpq-int.h:911
@ PGQUERY_SIMPLE
Definition: libpq-int.h:326
@ PGQUERY_SYNC
Definition: libpq-int.h:330
@ PGQUERY_EXTENDED
Definition: libpq-int.h:327
@ PGQUERY_DESCRIBE
Definition: libpq-int.h:329
@ PGQUERY_CLOSE
Definition: libpq-int.h:331
@ PGQUERY_PREPARE
Definition: libpq-int.h:328
#define NULL_LEN
Definition: libpq-int.h:136
struct pgParameterStatus pgParameterStatus
#define pqClearConnErrorState(conn)
Definition: libpq-int.h:884
union pgresult_data PGresult_data
Definition: libpq-int.h:104
@ PG_BOOL_YES
Definition: libpq-int.h:263
@ PG_BOOL_NO
Definition: libpq-int.h:264
#define pqIsnonblocking(conn)
Definition: libpq-int.h:900
#define OUTBUFFER_THRESHOLD
Definition: libpq-int.h:905
#define pgHavePendingResult(conn)
Definition: libpq-int.h:893
static void const char * fmt
va_end(args)
va_start(args, fmt)
void * arg
const void size_t len
int32 encoding
Definition: pg_database.h:41
static rewind_source * source
Definition: pg_rewind.c:89
static char * buf
Definition: pg_test_fsync.c:73
@ PG_SQL_ASCII
Definition: pg_wchar.h:226
#define pg_char_to_encoding
Definition: pg_wchar.h:629
#define vsnprintf
Definition: port.h:237
#define sprintf
Definition: port.h:240
unsigned char pg_tolower(unsigned char ch)
Definition: pgstrcasecmp.c:122
#define PGINVALID_SOCKET
Definition: port.h:31
#define InvalidOid
Definition: postgres_ext.h:36
unsigned int Oid
Definition: postgres_ext.h:31
#define PG_DIAG_SEVERITY_NONLOCALIZED
Definition: postgres_ext.h:55
#define PG_DIAG_MESSAGE_PRIMARY
Definition: postgres_ext.h:57
#define PG_DIAG_SEVERITY
Definition: postgres_ext.h:54
void initPQExpBuffer(PQExpBuffer str)
Definition: pqexpbuffer.c:90
void appendPQExpBufferStr(PQExpBuffer str, const char *data)
Definition: pqexpbuffer.c:367
void termPQExpBuffer(PQExpBuffer str)
Definition: pqexpbuffer.c:129
#define PQExpBufferBroken(str)
Definition: pqexpbuffer.h:59
#define PQExpBufferDataBroken(buf)
Definition: pqexpbuffer.h:67
char * c
#define PqMsg_CopyDone
Definition: protocol.h:64
#define PqMsg_CopyData
Definition: protocol.h:65
#define PqMsg_Describe
Definition: protocol.h:21
#define PqMsg_Parse
Definition: protocol.h:25
#define PqMsg_Bind
Definition: protocol.h:19
#define PqMsg_Sync
Definition: protocol.h:27
#define PqMsg_CopyFail
Definition: protocol.h:29
#define PqMsg_Flush
Definition: protocol.h:24
#define PqMsg_Query
Definition: protocol.h:26
#define PqMsg_Execute
Definition: protocol.h:22
#define PqMsg_Close
Definition: protocol.h:20
static void error(void)
Definition: sql-dyntest.c:147
PGconn * conn
Definition: streamutil.c:55
const PGresult * src
Definition: libpq-events.h:60
PGresult * dest
Definition: libpq-events.h:61
void * passThrough
Definition: libpq-int.h:165
char * name
Definition: libpq-int.h:164
void * data
Definition: libpq-int.h:166
PGEventProc proc
Definition: libpq-int.h:163
bool resultInitialized
Definition: libpq-int.h:167
void * noticeProcArg
Definition: libpq-int.h:158
PQnoticeReceiver noticeRec
Definition: libpq-int.h:155
PQnoticeProcessor noticeProc
Definition: libpq-int.h:157
void * noticeRecArg
Definition: libpq-int.h:156
PGQueryClass queryclass
Definition: libpq-int.h:339
struct PGcmdQueueEntry * next
Definition: libpq-int.h:341
struct pgMessageField * next
Definition: libpq-int.h:147
char contents[FLEXIBLE_ARRAY_MEMBER]
Definition: libpq-int.h:149
struct pgNotify * next
Definition: libpq-fe.h:201
struct pgParameterStatus * next
Definition: libpq-int.h:277
char * write_err_msg
Definition: libpq-int.h:485
PGnotify * notifyHead
Definition: libpq-int.h:450
int maxChunkSize
Definition: libpq-int.h:446
PGdataValue * rowBuf
Definition: libpq-int.h:539
bool singleRowMode
Definition: libpq-int.h:445
pgsocket sock
Definition: libpq-int.h:473
bool std_strings
Definition: libpq-int.h:512
int errorReported
Definition: libpq-int.h:634
bool write_failed
Definition: libpq-int.h:484
PGTernaryBool in_hot_standby
Definition: libpq-int.h:514
PGcmdQueueEntry * cmd_queue_recycle
Definition: libpq-int.h:470
PGcmdQueueEntry * cmd_queue_tail
Definition: libpq-int.h:464
PGnotify * notifyTail
Definition: libpq-int.h:451
bool nonblocking
Definition: libpq-int.h:441
int client_encoding
Definition: libpq-int.h:511
int sversion
Definition: libpq-int.h:478
PGTernaryBool default_transaction_read_only
Definition: libpq-int.h:513
pgParameterStatus * pstatus
Definition: libpq-int.h:510
PGresult * result
Definition: libpq-int.h:552
PGresult * saved_result
Definition: libpq-int.h:554
PQExpBufferData errorMessage
Definition: libpq-int.h:633
int nEvents
Definition: libpq-int.h:432
bool error_result
Definition: libpq-int.h:553
PGAsyncStatusType asyncStatus
Definition: libpq-int.h:437
int scram_sha_256_iterations
Definition: libpq-int.h:559
PGpipelineStatus pipelineStatus
Definition: libpq-int.h:443
int outBufSize
Definition: libpq-int.h:530
bool partialResMode
Definition: libpq-int.h:444
PGNoticeHooks noticeHooks
Definition: libpq-int.h:428
PGcmdQueueEntry * cmd_queue_head
Definition: libpq-int.h:463
int outCount
Definition: libpq-int.h:531
PGEvent * events
Definition: libpq-int.h:431
ConnStatusType status
Definition: libpq-int.h:436
size_t memorySize
Definition: libpq-int.h:215
int ntups
Definition: libpq-int.h:172
int curOffset
Definition: libpq-int.h:212
int binary
Definition: libpq-int.h:182
PGNoticeHooks noticeHooks
Definition: libpq-int.h:189
char null_field[1]
Definition: libpq-int.h:204
char * errMsg
Definition: libpq-int.h:199
int nEvents
Definition: libpq-int.h:191
PGresAttValue ** tuples
Definition: libpq-int.h:175
int numParameters
Definition: libpq-int.h:178
int spaceLeft
Definition: libpq-int.h:213
PGresAttDesc * attDescs
Definition: libpq-int.h:174
int numAttributes
Definition: libpq-int.h:173
char cmdStatus[CMDSTATUS_LEN]
Definition: libpq-int.h:181
PGMessageField * errFields
Definition: libpq-int.h:200
PGresParamDesc * paramDescs
Definition: libpq-int.h:179
PGEvent * events
Definition: libpq-int.h:190
PGresult_data * curBlock
Definition: libpq-int.h:211
int tupArrSize
Definition: libpq-int.h:177
ExecStatusType resultStatus
Definition: libpq-int.h:180
char * errQuery
Definition: libpq-int.h:201
int client_encoding
Definition: libpq-int.h:192
char * name
Definition: libpq-fe.h:274
int columnid
Definition: libpq-fe.h:276
int atttypmod
Definition: libpq-fe.h:280
char * value
Definition: libpq-int.h:141
PGresult_data * next
Definition: libpq-int.h:108
char space[1]
Definition: libpq-int.h:109
const char * type
const char * name
static StringInfoData tmpbuf
Definition: walsender.c:170
int pg_encoding_mblen(int encoding, const char *mbstr)
Definition: wchar.c:2069