1
/*-------------------------------------------------------------------------
4
* functions related to sending a query down to the backend
6
* Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
7
* Portions Copyright (c) 1994, Regents of the University of California
11
* $PostgreSQL: pgsql/src/interfaces/libpq/fe-exec.c,v 1.166 2004-12-31 22:03:50 pgsql Exp $
13
*-------------------------------------------------------------------------
15
#include "postgres_fe.h"
22
#include "libpq-int.h"
24
#include "mb/pg_wchar.h"
32
/* keep this in same order as ExecStatusType in libpq-fe.h */
33
char *const pgresStatus[] = {
40
"PGRES_NONFATAL_ERROR",
46
static bool PQsendQueryStart(PGconn *conn);
47
static int PQsendQueryGuts(PGconn *conn,
51
const Oid *paramTypes,
52
const char *const * paramValues,
53
const int *paramLengths,
54
const int *paramFormats,
56
static void parseInput(PGconn *conn);
57
static bool PQexecStart(PGconn *conn);
58
static PGresult *PQexecFinish(PGconn *conn);
62
* Space management for PGresult.
64
* Formerly, libpq did a separate malloc() for each field of each tuple
65
* returned by a query. This was remarkably expensive --- malloc/free
66
* consumed a sizable part of the application's runtime. And there is
67
* no real need to keep track of the fields separately, since they will
68
* all be freed together when the PGresult is released. So now, we grab
69
* large blocks of storage from malloc and allocate space for query data
70
* within these blocks, using a trivially simple allocator. This reduces
71
* the number of malloc/free calls dramatically, and it also avoids
72
* fragmentation of the malloc storage arena.
73
* The PGresult structure itself is still malloc'd separately. We could
74
* combine it with the first allocation block, but that would waste space
75
* for the common case that no extra storage is actually needed (that is,
76
* the SQL command did not return tuples).
78
* We also malloc the top-level array of tuple pointers separately, because
79
* we need to be able to enlarge it via realloc, and our trivial space
80
* allocator doesn't handle that effectively. (Too bad the FE/BE protocol
81
* doesn't tell us up front how many tuples will be returned.)
82
* All other subsidiary storage for a PGresult is kept in PGresult_data blocks
83
* of size PGRESULT_DATA_BLOCKSIZE. The overhead at the start of each block
84
* is just a link to the next one, if any. Free-space management info is
85
* kept in the owning PGresult.
86
* A query returning a small amount of data will thus require three malloc
87
* calls: one for the PGresult, one for the tuples pointer array, and one
88
* PGresult_data block.
90
* Only the most recently allocated PGresult_data block is a candidate to
91
* have more stuff added to it --- any extra space left over in older blocks
92
* is wasted. We could be smarter and search the whole chain, but the point
93
* here is to be simple and fast. Typical applications do not keep a PGresult
94
* around very long anyway, so some wasted space within one is not a problem.
96
* Tuning constants for the space allocator are:
97
* PGRESULT_DATA_BLOCKSIZE: size of a standard allocation block, in bytes
98
* PGRESULT_ALIGN_BOUNDARY: assumed alignment requirement for binary data
99
* PGRESULT_SEP_ALLOC_THRESHOLD: objects bigger than this are given separate
100
* blocks, instead of being crammed into a regular allocation block.
101
* Requirements for correct function are:
102
* PGRESULT_ALIGN_BOUNDARY must be a multiple of the alignment requirements
103
* of all machine data types. (Currently this is set from configure
104
* tests, so it should be OK automatically.)
105
* PGRESULT_SEP_ALLOC_THRESHOLD + PGRESULT_BLOCK_OVERHEAD <=
106
* PGRESULT_DATA_BLOCKSIZE
107
* pqResultAlloc assumes an object smaller than the threshold will fit
109
* The amount of space wasted at the end of a block could be as much as
110
* PGRESULT_SEP_ALLOC_THRESHOLD, so it doesn't pay to make that too large.
114
#define PGRESULT_DATA_BLOCKSIZE 2048
115
#define PGRESULT_ALIGN_BOUNDARY MAXIMUM_ALIGNOF /* from configure */
116
#define PGRESULT_BLOCK_OVERHEAD Max(sizeof(PGresult_data), PGRESULT_ALIGN_BOUNDARY)
117
#define PGRESULT_SEP_ALLOC_THRESHOLD (PGRESULT_DATA_BLOCKSIZE / 2)
121
* PQmakeEmptyPGresult
122
* returns a newly allocated, initialized PGresult with given status.
123
* If conn is not NULL and status indicates an error, the conn's
124
* errorMessage is copied.
126
* Note this is exported --- you wouldn't think an application would need
127
* to build its own PGresults, but this has proven useful in both libpgtcl
128
* and the Perl5 interface, so maybe it's not so unreasonable.
132
PQmakeEmptyPGresult(PGconn *conn, ExecStatusType status)
136
result = (PGresult *) malloc(sizeof(PGresult));
139
result->numAttributes = 0;
140
result->attDescs = NULL;
141
result->tuples = NULL;
142
result->tupArrSize = 0;
143
result->resultStatus = status;
144
result->cmdStatus[0] = '\0';
146
result->errMsg = NULL;
147
result->errFields = NULL;
148
result->null_field[0] = '\0';
149
result->curBlock = NULL;
150
result->curOffset = 0;
151
result->spaceLeft = 0;
155
/* copy connection data we might need for operations on PGresult */
156
result->noticeHooks = conn->noticeHooks;
157
result->client_encoding = conn->client_encoding;
159
/* consider copying conn's errorMessage */
162
case PGRES_EMPTY_QUERY:
163
case PGRES_COMMAND_OK:
164
case PGRES_TUPLES_OK:
167
/* non-error cases */
170
pqSetResultError(result, conn->errorMessage.data);
177
result->noticeHooks.noticeRec = NULL;
178
result->noticeHooks.noticeRecArg = NULL;
179
result->noticeHooks.noticeProc = NULL;
180
result->noticeHooks.noticeProcArg = NULL;
181
result->client_encoding = PG_SQL_ASCII;
189
* Allocate subsidiary storage for a PGresult.
191
* nBytes is the amount of space needed for the object.
192
* If isBinary is true, we assume that we need to align the object on
193
* a machine allocation boundary.
194
* If isBinary is false, we assume the object is a char string and can
195
* be allocated on any byte boundary.
198
pqResultAlloc(PGresult *res, size_t nBytes, bool isBinary)
201
PGresult_data *block;
207
return res->null_field;
210
* If alignment is needed, round up the current position to an
211
* alignment boundary.
215
int offset = res->curOffset % PGRESULT_ALIGN_BOUNDARY;
219
res->curOffset += PGRESULT_ALIGN_BOUNDARY - offset;
220
res->spaceLeft -= PGRESULT_ALIGN_BOUNDARY - offset;
224
/* If there's enough space in the current block, no problem. */
225
if (nBytes <= (size_t) res->spaceLeft)
227
space = res->curBlock->space + res->curOffset;
228
res->curOffset += nBytes;
229
res->spaceLeft -= nBytes;
234
* If the requested object is very large, give it its own block; this
235
* avoids wasting what might be most of the current block to start a
236
* new block. (We'd have to special-case requests bigger than the
237
* block size anyway.) The object is always given binary alignment in
240
if (nBytes >= PGRESULT_SEP_ALLOC_THRESHOLD)
242
block = (PGresult_data *) malloc(nBytes + PGRESULT_BLOCK_OVERHEAD);
245
space = block->space + PGRESULT_BLOCK_OVERHEAD;
249
* Tuck special block below the active block, so that we don't
250
* have to waste the free space in the active block.
252
block->next = res->curBlock->next;
253
res->curBlock->next = block;
257
/* Must set up the new block as the first active block. */
259
res->curBlock = block;
260
res->spaceLeft = 0; /* be sure it's marked full */
265
/* Otherwise, start a new block. */
266
block = (PGresult_data *) malloc(PGRESULT_DATA_BLOCKSIZE);
269
block->next = res->curBlock;
270
res->curBlock = block;
273
/* object needs full alignment */
274
res->curOffset = PGRESULT_BLOCK_OVERHEAD;
275
res->spaceLeft = PGRESULT_DATA_BLOCKSIZE - PGRESULT_BLOCK_OVERHEAD;
279
/* we can cram it right after the overhead pointer */
280
res->curOffset = sizeof(PGresult_data);
281
res->spaceLeft = PGRESULT_DATA_BLOCKSIZE - sizeof(PGresult_data);
284
space = block->space + res->curOffset;
285
res->curOffset += nBytes;
286
res->spaceLeft -= nBytes;
292
* Like strdup, but the space is subsidiary PGresult space.
295
pqResultStrdup(PGresult *res, const char *str)
297
char *space = (char *) pqResultAlloc(res, strlen(str) + 1, FALSE);
306
* assign a new error message to a PGresult
309
pqSetResultError(PGresult *res, const char *msg)
314
res->errMsg = pqResultStrdup(res, msg);
320
* pqCatenateResultError -
321
* concatenate a new error message to the one already in a PGresult
324
pqCatenateResultError(PGresult *res, const char *msg)
326
PQExpBufferData errorBuf;
330
initPQExpBuffer(&errorBuf);
332
appendPQExpBufferStr(&errorBuf, res->errMsg);
333
appendPQExpBufferStr(&errorBuf, msg);
334
pqSetResultError(res, errorBuf.data);
335
termPQExpBuffer(&errorBuf);
340
* free's the memory associated with a PGresult
343
PQclear(PGresult *res)
345
PGresult_data *block;
350
/* Free all the subsidiary blocks */
351
while ((block = res->curBlock) != NULL)
353
res->curBlock = block->next;
357
/* Free the top-level tuple pointer array */
361
/* Free the PGresult structure itself */
366
* Handy subroutine to deallocate any partially constructed async result.
370
pqClearAsyncResult(PGconn *conn)
373
PQclear(conn->result);
375
conn->curTuple = NULL;
379
* This subroutine deletes any existing async result, sets conn->result
380
* to a PGresult with status PGRES_FATAL_ERROR, and stores the current
381
* contents of conn->errorMessage into that result. It differs from a
382
* plain call on PQmakeEmptyPGresult() in that if there is already an
383
* async result with status PGRES_FATAL_ERROR, the current error message
384
* is APPENDED to the old error message instead of replacing it. This
385
* behavior lets us report multiple error conditions properly, if necessary.
386
* (An example where this is needed is when the backend sends an 'E' message
387
* and immediately closes the connection --- we want to report both the
388
* backend error and the connection closure error.)
391
pqSaveErrorResult(PGconn *conn)
394
* If no old async result, just let PQmakeEmptyPGresult make one.
395
* Likewise if old result is not an error message.
397
if (conn->result == NULL ||
398
conn->result->resultStatus != PGRES_FATAL_ERROR ||
399
conn->result->errMsg == NULL)
401
pqClearAsyncResult(conn);
402
conn->result = PQmakeEmptyPGresult(conn, PGRES_FATAL_ERROR);
406
/* Else, concatenate error message to existing async result. */
407
pqCatenateResultError(conn->result, conn->errorMessage.data);
412
* This subroutine prepares an async result object for return to the caller.
413
* If there is not already an async result object, build an error object
414
* using whatever is in conn->errorMessage. In any case, clear the async
415
* result storage and make sure PQerrorMessage will agree with the result's
419
pqPrepareAsyncResult(PGconn *conn)
424
* conn->result is the PGresult to return. If it is NULL (which
425
* probably shouldn't happen) we assume there is an appropriate error
426
* message in conn->errorMessage.
429
conn->result = NULL; /* handing over ownership to caller */
430
conn->curTuple = NULL; /* just in case */
432
res = PQmakeEmptyPGresult(conn, PGRES_FATAL_ERROR);
436
* Make sure PQerrorMessage agrees with result; it could be
437
* different if we have concatenated messages.
439
resetPQExpBuffer(&conn->errorMessage);
440
appendPQExpBufferStr(&conn->errorMessage,
441
PQresultErrorMessage(res));
447
* pqInternalNotice - produce an internally-generated notice message
449
* A format string and optional arguments can be passed. Note that we do
450
* libpq_gettext() here, so callers need not.
452
* The supplied text is taken as primary message (ie., it should not include
453
* a trailing newline, and should not be more than one line).
456
pqInternalNotice(const PGNoticeHooks *hooks, const char *fmt,...)
462
if (hooks->noticeRec == NULL)
463
return; /* nobody home to receive notice? */
465
/* Format the message */
467
vsnprintf(msgBuf, sizeof(msgBuf), libpq_gettext(fmt), args);
469
msgBuf[sizeof(msgBuf) - 1] = '\0'; /* make real sure it's terminated */
471
/* Make a PGresult to pass to the notice receiver */
472
res = PQmakeEmptyPGresult(NULL, PGRES_NONFATAL_ERROR);
473
res->noticeHooks = *hooks;
476
* Set up fields of notice.
478
pqSaveMessageField(res, PG_DIAG_MESSAGE_PRIMARY, msgBuf);
479
pqSaveMessageField(res, PG_DIAG_SEVERITY, libpq_gettext("NOTICE"));
480
/* XXX should provide a SQLSTATE too? */
483
* Result text is always just the primary message + newline.
485
res->errMsg = (char *) pqResultAlloc(res, strlen(msgBuf) + 2, FALSE);
486
sprintf(res->errMsg, "%s\n", msgBuf);
489
* Pass to receiver, then free it.
491
(*res->noticeHooks.noticeRec) (res->noticeHooks.noticeRecArg, res);
497
* add a row pointer to the PGresult structure, growing it if necessary
498
* Returns TRUE if OK, FALSE if not enough memory to add the row
501
pqAddTuple(PGresult *res, PGresAttValue *tup)
503
if (res->ntups >= res->tupArrSize)
506
* Try to grow the array.
508
* We can use realloc because shallow copying of the structure is
509
* okay. Note that the first time through, res->tuples is NULL.
510
* While ANSI says that realloc() should act like malloc() in that
511
* case, some old C libraries (like SunOS 4.1.x) coredump instead.
512
* On failure realloc is supposed to return NULL without damaging
513
* the existing allocation. Note that the positions beyond
514
* res->ntups are garbage, not necessarily NULL.
516
int newSize = (res->tupArrSize > 0) ? res->tupArrSize * 2 : 128;
517
PGresAttValue **newTuples;
519
if (res->tuples == NULL)
520
newTuples = (PGresAttValue **)
521
malloc(newSize * sizeof(PGresAttValue *));
523
newTuples = (PGresAttValue **)
524
realloc(res->tuples, newSize * sizeof(PGresAttValue *));
526
return FALSE; /* malloc or realloc failed */
527
res->tupArrSize = newSize;
528
res->tuples = newTuples;
530
res->tuples[res->ntups] = tup;
536
* pqSaveMessageField - save one field of an error or notice message
539
pqSaveMessageField(PGresult *res, char code, const char *value)
541
PGMessageField *pfield;
543
pfield = (PGMessageField *)
545
sizeof(PGMessageField) + strlen(value),
548
return; /* out of memory? */
550
strcpy(pfield->contents, value);
551
pfield->next = res->errFields;
552
res->errFields = pfield;
556
* pqSaveParameterStatus - remember parameter status sent by backend
559
pqSaveParameterStatus(PGconn *conn, const char *name, const char *value)
561
pgParameterStatus *pstatus;
562
pgParameterStatus *prev;
565
fprintf(conn->Pfdebug, "pqSaveParameterStatus: '%s' = '%s'\n",
569
* Forget any old information about the parameter
571
for (pstatus = conn->pstatus, prev = NULL;
573
prev = pstatus, pstatus = pstatus->next)
575
if (strcmp(pstatus->name, name) == 0)
578
prev->next = pstatus->next;
580
conn->pstatus = pstatus->next;
581
free(pstatus); /* frees name and value strings too */
587
* Store new info as a single malloc block
589
pstatus = (pgParameterStatus *) malloc(sizeof(pgParameterStatus) +
590
strlen(name) +strlen(value) + 2);
595
ptr = ((char *) pstatus) + sizeof(pgParameterStatus);
598
ptr += strlen(name) + 1;
599
pstatus->value = ptr;
601
pstatus->next = conn->pstatus;
602
conn->pstatus = pstatus;
606
* Special hacks: remember client_encoding as a numeric value, and
607
* convert server version to a numeric form as well.
609
if (strcmp(name, "client_encoding") == 0)
610
conn->client_encoding = pg_char_to_encoding(value);
611
else if (strcmp(name, "server_version") == 0)
618
cnt = sscanf(value, "%d.%d.%d", &vmaj, &vmin, &vrev);
621
conn->sversion = 0; /* unknown */
626
conn->sversion = (100 * vmaj + vmin) * 100 + vrev;
634
* Submit a query, but don't wait for it to finish
636
* Returns: 1 if successfully submitted
637
* 0 if error (conn->errorMessage is set)
640
PQsendQuery(PGconn *conn, const char *query)
642
if (!PQsendQueryStart(conn))
647
printfPQExpBuffer(&conn->errorMessage,
648
libpq_gettext("command string is a null pointer\n"));
652
/* construct the outgoing Query message */
653
if (pqPutMsgStart('Q', false, conn) < 0 ||
654
pqPuts(query, conn) < 0 ||
655
pqPutMsgEnd(conn) < 0)
657
pqHandleSendFailure(conn);
661
/* remember we are using simple query protocol */
662
conn->queryclass = PGQUERY_SIMPLE;
665
* Give the data a push. In nonblock mode, don't complain if we're
666
* unable to send it all; PQgetResult() will do any additional
669
if (pqFlush(conn) < 0)
671
pqHandleSendFailure(conn);
675
/* OK, it's launched! */
676
conn->asyncStatus = PGASYNC_BUSY;
682
* Like PQsendQuery, but use protocol 3.0 so we can pass parameters
685
PQsendQueryParams(PGconn *conn,
688
const Oid *paramTypes,
689
const char *const * paramValues,
690
const int *paramLengths,
691
const int *paramFormats,
694
if (!PQsendQueryStart(conn))
699
printfPQExpBuffer(&conn->errorMessage,
700
libpq_gettext("command string is a null pointer\n"));
704
return PQsendQueryGuts(conn,
706
"", /* use unnamed statement */
717
* Submit a Parse message, but don't wait for it to finish
719
* Returns: 1 if successfully submitted
720
* 0 if error (conn->errorMessage is set)
723
PQsendPrepare(PGconn *conn,
724
const char *stmtName, const char *query,
725
int nParams, const Oid *paramTypes)
727
if (!PQsendQueryStart(conn))
732
printfPQExpBuffer(&conn->errorMessage,
733
libpq_gettext("statement name is a null pointer\n"));
739
printfPQExpBuffer(&conn->errorMessage,
740
libpq_gettext("command string is a null pointer\n"));
744
/* This isn't gonna work on a 2.0 server */
745
if (PG_PROTOCOL_MAJOR(conn->pversion) < 3)
747
printfPQExpBuffer(&conn->errorMessage,
748
libpq_gettext("function requires at least protocol version 3.0\n"));
752
/* construct the Parse message */
753
if (pqPutMsgStart('P', false, conn) < 0 ||
754
pqPuts(stmtName, conn) < 0 ||
755
pqPuts(query, conn) < 0)
758
if (nParams > 0 && paramTypes)
762
if (pqPutInt(nParams, 2, conn) < 0)
764
for (i = 0; i < nParams; i++)
766
if (pqPutInt(paramTypes[i], 4, conn) < 0)
772
if (pqPutInt(0, 2, conn) < 0)
775
if (pqPutMsgEnd(conn) < 0)
778
/* construct the Sync message */
779
if (pqPutMsgStart('S', false, conn) < 0 ||
780
pqPutMsgEnd(conn) < 0)
783
/* remember we are doing just a Parse */
784
conn->queryclass = PGQUERY_PREPARE;
787
* Give the data a push. In nonblock mode, don't complain if we're
788
* unable to send it all; PQgetResult() will do any additional
791
if (pqFlush(conn) < 0)
794
/* OK, it's launched! */
795
conn->asyncStatus = PGASYNC_BUSY;
799
pqHandleSendFailure(conn);
804
* PQsendQueryPrepared
805
* Like PQsendQuery, but execute a previously prepared statement,
806
* using protocol 3.0 so we can pass parameters
809
PQsendQueryPrepared(PGconn *conn,
810
const char *stmtName,
812
const char *const * paramValues,
813
const int *paramLengths,
814
const int *paramFormats,
817
if (!PQsendQueryStart(conn))
822
printfPQExpBuffer(&conn->errorMessage,
823
libpq_gettext("statement name is a null pointer\n"));
827
return PQsendQueryGuts(conn,
828
NULL, /* no command to parse */
831
NULL, /* no param types */
839
* Common startup code for PQsendQuery and sibling routines
842
PQsendQueryStart(PGconn *conn)
847
/* clear the error string */
848
resetPQExpBuffer(&conn->errorMessage);
850
/* Don't try to send if we know there's no live connection. */
851
if (conn->status != CONNECTION_OK)
853
printfPQExpBuffer(&conn->errorMessage,
854
libpq_gettext("no connection to the server\n"));
857
/* Can't send while already busy, either. */
858
if (conn->asyncStatus != PGASYNC_IDLE)
860
printfPQExpBuffer(&conn->errorMessage,
861
libpq_gettext("another command is already in progress\n"));
865
/* initialize async result-accumulation state */
867
conn->curTuple = NULL;
869
/* ready to send command message */
875
* Common code for protocol-3.0 query sending
876
* PQsendQueryStart should be done already
878
* command may be NULL to indicate we use an already-prepared statement
881
PQsendQueryGuts(PGconn *conn,
883
const char *stmtName,
885
const Oid *paramTypes,
886
const char *const * paramValues,
887
const int *paramLengths,
888
const int *paramFormats,
893
/* This isn't gonna work on a 2.0 server */
894
if (PG_PROTOCOL_MAJOR(conn->pversion) < 3)
896
printfPQExpBuffer(&conn->errorMessage,
897
libpq_gettext("function requires at least protocol version 3.0\n"));
902
* We will send Parse (if needed), Bind, Describe Portal, Execute,
903
* Sync, using specified statement name and the unnamed portal.
908
/* construct the Parse message */
909
if (pqPutMsgStart('P', false, conn) < 0 ||
910
pqPuts(stmtName, conn) < 0 ||
911
pqPuts(command, conn) < 0)
913
if (nParams > 0 && paramTypes)
915
if (pqPutInt(nParams, 2, conn) < 0)
917
for (i = 0; i < nParams; i++)
919
if (pqPutInt(paramTypes[i], 4, conn) < 0)
925
if (pqPutInt(0, 2, conn) < 0)
928
if (pqPutMsgEnd(conn) < 0)
932
/* construct the Bind message */
933
if (pqPutMsgStart('B', false, conn) < 0 ||
934
pqPuts("", conn) < 0 ||
935
pqPuts(stmtName, conn) < 0)
937
if (nParams > 0 && paramFormats)
939
if (pqPutInt(nParams, 2, conn) < 0)
941
for (i = 0; i < nParams; i++)
943
if (pqPutInt(paramFormats[i], 2, conn) < 0)
949
if (pqPutInt(0, 2, conn) < 0)
952
if (pqPutInt(nParams, 2, conn) < 0)
954
for (i = 0; i < nParams; i++)
956
if (paramValues && paramValues[i])
960
if (paramFormats && paramFormats[i] != 0)
962
/* binary parameter */
963
nbytes = paramLengths[i];
967
/* text parameter, do not use paramLengths */
968
nbytes = strlen(paramValues[i]);
970
if (pqPutInt(nbytes, 4, conn) < 0 ||
971
pqPutnchar(paramValues[i], nbytes, conn) < 0)
976
/* take the param as NULL */
977
if (pqPutInt(-1, 4, conn) < 0)
981
if (pqPutInt(1, 2, conn) < 0 ||
982
pqPutInt(resultFormat, 2, conn))
984
if (pqPutMsgEnd(conn) < 0)
987
/* construct the Describe Portal message */
988
if (pqPutMsgStart('D', false, conn) < 0 ||
989
pqPutc('P', conn) < 0 ||
990
pqPuts("", conn) < 0 ||
991
pqPutMsgEnd(conn) < 0)
994
/* construct the Execute message */
995
if (pqPutMsgStart('E', false, conn) < 0 ||
996
pqPuts("", conn) < 0 ||
997
pqPutInt(0, 4, conn) < 0 ||
998
pqPutMsgEnd(conn) < 0)
1001
/* construct the Sync message */
1002
if (pqPutMsgStart('S', false, conn) < 0 ||
1003
pqPutMsgEnd(conn) < 0)
1006
/* remember we are using extended query protocol */
1007
conn->queryclass = PGQUERY_EXTENDED;
1010
* Give the data a push. In nonblock mode, don't complain if we're
1011
* unable to send it all; PQgetResult() will do any additional
1014
if (pqFlush(conn) < 0)
1017
/* OK, it's launched! */
1018
conn->asyncStatus = PGASYNC_BUSY;
1022
pqHandleSendFailure(conn);
1027
* pqHandleSendFailure: try to clean up after failure to send command.
1029
* Primarily, what we want to accomplish here is to process an async
1030
* NOTICE message that the backend might have sent just before it died.
1032
* NOTE: this routine should only be called in PGASYNC_IDLE state.
1035
pqHandleSendFailure(PGconn *conn)
1038
* Accept any available input data, ignoring errors. Note that if
1039
* pqReadData decides the backend has closed the channel, it will
1040
* close our side of the socket --- that's just what we want here.
1042
while (pqReadData(conn) > 0)
1043
/* loop until no more data readable */ ;
1046
* Parse any available input messages. Since we are in PGASYNC_IDLE
1047
* state, only NOTICE and NOTIFY messages will be eaten.
1053
* Consume any available input from the backend
1054
* 0 return: some kind of trouble
1055
* 1 return: no problem
1058
PQconsumeInput(PGconn *conn)
1064
* for non-blocking connections try to flush the send-queue, otherwise
1065
* we may never get a response for something that may not have already
1066
* been sent because it's in our write buffer!
1068
if (pqIsnonblocking(conn))
1070
if (pqFlush(conn) < 0)
1075
* Load more data, if available. We do this no matter what state we
1076
* are in, since we are probably getting called because the
1077
* application wants to get rid of a read-select condition. Note that
1078
* we will NOT block waiting for more input.
1080
if (pqReadData(conn) < 0)
1083
/* Parsing of the data waits till later. */
1089
* parseInput: if appropriate, parse input data from backend
1090
* until input is exhausted or a stopping state is reached.
1091
* Note that this function will NOT attempt to read more data from the backend.
1094
parseInput(PGconn *conn)
1096
if (PG_PROTOCOL_MAJOR(conn->pversion) >= 3)
1097
pqParseInput3(conn);
1099
pqParseInput2(conn);
1104
* Return TRUE if PQgetResult would block waiting for input.
1108
PQisBusy(PGconn *conn)
1113
/* Parse any available data, if our state permits. */
1116
/* PQgetResult will return immediately in all states except BUSY. */
1117
return conn->asyncStatus == PGASYNC_BUSY;
1123
* Get the next PGresult produced by a query.
1124
* Returns NULL if and only if no query work remains.
1128
PQgetResult(PGconn *conn)
1135
/* Parse any available data, if our state permits. */
1138
/* If not ready to return something, block until we are. */
1139
while (conn->asyncStatus == PGASYNC_BUSY)
1144
* If data remains unsent, send it. Else we might be waiting for
1145
* the result of a command the backend hasn't even got yet.
1147
while ((flushResult = pqFlush(conn)) > 0)
1149
if (pqWait(FALSE, TRUE, conn))
1156
/* Wait for some more data, and load it. */
1158
pqWait(TRUE, FALSE, conn) ||
1159
pqReadData(conn) < 0)
1162
* conn->errorMessage has been set by pqWait or pqReadData. We
1163
* want to append it to any already-received error message.
1165
pqSaveErrorResult(conn);
1166
conn->asyncStatus = PGASYNC_IDLE;
1167
return pqPrepareAsyncResult(conn);
1174
/* Return the appropriate thing. */
1175
switch (conn->asyncStatus)
1178
res = NULL; /* query is complete */
1181
res = pqPrepareAsyncResult(conn);
1182
/* Set the state back to BUSY, allowing parsing to proceed. */
1183
conn->asyncStatus = PGASYNC_BUSY;
1185
case PGASYNC_COPY_IN:
1186
if (conn->result && conn->result->resultStatus == PGRES_COPY_IN)
1187
res = pqPrepareAsyncResult(conn);
1189
res = PQmakeEmptyPGresult(conn, PGRES_COPY_IN);
1191
case PGASYNC_COPY_OUT:
1192
if (conn->result && conn->result->resultStatus == PGRES_COPY_OUT)
1193
res = pqPrepareAsyncResult(conn);
1195
res = PQmakeEmptyPGresult(conn, PGRES_COPY_OUT);
1198
printfPQExpBuffer(&conn->errorMessage,
1199
libpq_gettext("unexpected asyncStatus: %d\n"),
1200
(int) conn->asyncStatus);
1201
res = PQmakeEmptyPGresult(conn, PGRES_FATAL_ERROR);
1211
* send a query to the backend and package up the result in a PGresult
1213
* If the query was not even sent, return NULL; conn->errorMessage is set to
1214
* a relevant message.
1215
* If the query was sent, a new PGresult is returned (which could indicate
1216
* either success or failure).
1217
* The user is responsible for freeing the PGresult via PQclear()
1218
* when done with it.
1221
PQexec(PGconn *conn, const char *query)
1223
if (!PQexecStart(conn))
1225
if (!PQsendQuery(conn, query))
1227
return PQexecFinish(conn);
1232
* Like PQexec, but use protocol 3.0 so we can pass parameters
1235
PQexecParams(PGconn *conn,
1236
const char *command,
1238
const Oid *paramTypes,
1239
const char *const * paramValues,
1240
const int *paramLengths,
1241
const int *paramFormats,
1244
if (!PQexecStart(conn))
1246
if (!PQsendQueryParams(conn, command,
1247
nParams, paramTypes, paramValues, paramLengths,
1248
paramFormats, resultFormat))
1250
return PQexecFinish(conn);
1255
* Creates a prepared statement by issuing a v3.0 parse message.
1257
* If the query was not even sent, return NULL; conn->errorMessage is set to
1258
* a relevant message.
1259
* If the query was sent, a new PGresult is returned (which could indicate
1260
* either success or failure).
1261
* The user is responsible for freeing the PGresult via PQclear()
1262
* when done with it.
1265
PQprepare(PGconn *conn,
1266
const char *stmtName, const char *query,
1267
int nParams, const Oid *paramTypes)
1269
if (!PQexecStart(conn))
1271
if (!PQsendPrepare(conn, stmtName, query, nParams, paramTypes))
1273
return PQexecFinish(conn);
1278
* Like PQexec, but execute a previously prepared statement,
1279
* using protocol 3.0 so we can pass parameters
1282
PQexecPrepared(PGconn *conn,
1283
const char *stmtName,
1285
const char *const * paramValues,
1286
const int *paramLengths,
1287
const int *paramFormats,
1290
if (!PQexecStart(conn))
1292
if (!PQsendQueryPrepared(conn, stmtName,
1293
nParams, paramValues, paramLengths,
1294
paramFormats, resultFormat))
1296
return PQexecFinish(conn);
1300
* Common code for PQexec and sibling routines: prepare to send command
1303
PQexecStart(PGconn *conn)
1311
* Silently discard any prior query result that application didn't
1312
* eat. This is probably poor design, but it's here for backward
1315
while ((result = PQgetResult(conn)) != NULL)
1317
ExecStatusType resultStatus = result->resultStatus;
1319
PQclear(result); /* only need its status */
1320
if (resultStatus == PGRES_COPY_IN)
1322
if (PG_PROTOCOL_MAJOR(conn->pversion) >= 3)
1324
/* In protocol 3, we can get out of a COPY IN state */
1325
if (PQputCopyEnd(conn,
1326
libpq_gettext("COPY terminated by new PQexec")) < 0)
1328
/* keep waiting to swallow the copy's failure message */
1332
/* In older protocols we have to punt */
1333
printfPQExpBuffer(&conn->errorMessage,
1334
libpq_gettext("COPY IN state must be terminated first\n"));
1338
else if (resultStatus == PGRES_COPY_OUT)
1340
if (PG_PROTOCOL_MAJOR(conn->pversion) >= 3)
1343
* In protocol 3, we can get out of a COPY OUT state: we
1344
* just switch back to BUSY and allow the remaining COPY
1345
* data to be dropped on the floor.
1347
conn->asyncStatus = PGASYNC_BUSY;
1348
/* keep waiting to swallow the copy's completion message */
1352
/* In older protocols we have to punt */
1353
printfPQExpBuffer(&conn->errorMessage,
1354
libpq_gettext("COPY OUT state must be terminated first\n"));
1358
/* check for loss of connection, too */
1359
if (conn->status == CONNECTION_BAD)
1363
/* OK to send a command */
1368
* Common code for PQexec and sibling routines: wait for command result
1371
PQexecFinish(PGconn *conn)
1374
PGresult *lastResult;
1377
* For backwards compatibility, return the last result if there are
1378
* more than one --- but merge error messages if we get more than one
1381
* We have to stop if we see copy in/out, however. We will resume parsing
1382
* after application performs the data transfer.
1384
* Also stop if the connection is lost (else we'll loop infinitely).
1387
while ((result = PQgetResult(conn)) != NULL)
1391
if (lastResult->resultStatus == PGRES_FATAL_ERROR &&
1392
result->resultStatus == PGRES_FATAL_ERROR)
1394
pqCatenateResultError(lastResult, result->errMsg);
1396
result = lastResult;
1399
* Make sure PQerrorMessage agrees with concatenated
1402
resetPQExpBuffer(&conn->errorMessage);
1403
appendPQExpBufferStr(&conn->errorMessage, result->errMsg);
1406
PQclear(lastResult);
1408
lastResult = result;
1409
if (result->resultStatus == PGRES_COPY_IN ||
1410
result->resultStatus == PGRES_COPY_OUT ||
1411
conn->status == CONNECTION_BAD)
1420
* returns a PGnotify* structure of the latest async notification
1421
* that has not yet been handled
1423
* returns NULL, if there is currently
1424
* no unhandled async notification from the backend
1426
* the CALLER is responsible for FREE'ing the structure returned
1429
PQnotifies(PGconn *conn)
1436
/* Parse any available data to see if we can extract NOTIFY messages. */
1439
event = conn->notifyHead;
1442
conn->notifyHead = event->next;
1443
if (!conn->notifyHead)
1444
conn->notifyTail = NULL;
1445
event->next = NULL; /* don't let app see the internal state */
1451
* PQputCopyData - send some data to the backend during COPY IN
1453
* Returns 1 if successful, 0 if data could not be sent (only possible
1454
* in nonblock mode), or -1 if an error occurs.
1457
PQputCopyData(PGconn *conn, const char *buffer, int nbytes)
1461
if (conn->asyncStatus != PGASYNC_COPY_IN)
1463
printfPQExpBuffer(&conn->errorMessage,
1464
libpq_gettext("no COPY in progress\n"));
1469
* Check for NOTICE messages coming back from the server. Since the
1470
* server might generate multiple notices during the COPY, we have to
1471
* consume those in a reasonably prompt fashion to prevent the comm
1472
* buffers from filling up and possibly blocking the server.
1474
if (!PQconsumeInput(conn))
1475
return -1; /* I/O failure */
1481
* Try to flush any previously sent data in preference to growing
1482
* the output buffer. If we can't enlarge the buffer enough to
1483
* hold the data, return 0 in the nonblock case, else hard error.
1484
* (For simplicity, always assume 5 bytes of overhead even in
1485
* protocol 2.0 case.)
1487
if ((conn->outBufSize - conn->outCount - 5) < nbytes)
1489
if (pqFlush(conn) < 0)
1491
if (pqCheckOutBufferSpace(conn->outCount + 5 + nbytes, conn))
1492
return pqIsnonblocking(conn) ? 0 : -1;
1494
/* Send the data (too simple to delegate to fe-protocol files) */
1495
if (PG_PROTOCOL_MAJOR(conn->pversion) >= 3)
1497
if (pqPutMsgStart('d', false, conn) < 0 ||
1498
pqPutnchar(buffer, nbytes, conn) < 0 ||
1499
pqPutMsgEnd(conn) < 0)
1504
if (pqPutMsgStart(0, false, conn) < 0 ||
1505
pqPutnchar(buffer, nbytes, conn) < 0 ||
1506
pqPutMsgEnd(conn) < 0)
1514
* PQputCopyEnd - send EOF indication to the backend during COPY IN
1516
* After calling this, use PQgetResult() to check command completion status.
1518
* Returns 1 if successful, 0 if data could not be sent (only possible
1519
* in nonblock mode), or -1 if an error occurs.
1522
PQputCopyEnd(PGconn *conn, const char *errormsg)
1526
if (conn->asyncStatus != PGASYNC_COPY_IN)
1528
printfPQExpBuffer(&conn->errorMessage,
1529
libpq_gettext("no COPY in progress\n"));
1534
* Send the COPY END indicator. This is simple enough that we don't
1535
* bother delegating it to the fe-protocol files.
1537
if (PG_PROTOCOL_MAJOR(conn->pversion) >= 3)
1541
/* Send COPY FAIL */
1542
if (pqPutMsgStart('f', false, conn) < 0 ||
1543
pqPuts(errormsg, conn) < 0 ||
1544
pqPutMsgEnd(conn) < 0)
1549
/* Send COPY DONE */
1550
if (pqPutMsgStart('c', false, conn) < 0 ||
1551
pqPutMsgEnd(conn) < 0)
1556
* If we sent the COPY command in extended-query mode, we must
1557
* issue a Sync as well.
1559
if (conn->queryclass != PGQUERY_SIMPLE)
1561
if (pqPutMsgStart('S', false, conn) < 0 ||
1562
pqPutMsgEnd(conn) < 0)
1570
/* Ooops, no way to do this in 2.0 */
1571
printfPQExpBuffer(&conn->errorMessage,
1572
libpq_gettext("function requires at least protocol version 3.0\n"));
1577
/* Send old-style end-of-data marker */
1578
if (pqPutMsgStart(0, false, conn) < 0 ||
1579
pqPutnchar("\\.\n", 3, conn) < 0 ||
1580
pqPutMsgEnd(conn) < 0)
1585
/* Return to active duty */
1586
conn->asyncStatus = PGASYNC_BUSY;
1587
resetPQExpBuffer(&conn->errorMessage);
1589
/* Try to flush data */
1590
if (pqFlush(conn) < 0)
1597
* PQgetCopyData - read a row of data from the backend during COPY OUT
1599
* If successful, sets *buffer to point to a malloc'd row of data, and
1600
* returns row length (always > 0) as result.
1601
* Returns 0 if no row available yet (only possible if async is true),
1602
* -1 if end of copy (consult PQgetResult), or -2 if error (consult
1606
PQgetCopyData(PGconn *conn, char **buffer, int async)
1608
*buffer = NULL; /* for all failure cases */
1611
if (conn->asyncStatus != PGASYNC_COPY_OUT)
1613
printfPQExpBuffer(&conn->errorMessage,
1614
libpq_gettext("no COPY in progress\n"));
1617
if (PG_PROTOCOL_MAJOR(conn->pversion) >= 3)
1618
return pqGetCopyData3(conn, buffer, async);
1620
return pqGetCopyData2(conn, buffer, async);
1624
* PQgetline - gets a newline-terminated string from the backend.
1626
* Chiefly here so that applications can use "COPY <rel> to stdout"
1627
* and read the output string. Returns a null-terminated string in s.
1629
* XXX this routine is now deprecated, because it can't handle binary data.
1630
* If called during a COPY BINARY we return EOF.
1632
* PQgetline reads up to maxlen-1 characters (like fgets(3)) but strips
1633
* the terminating \n (like gets(3)).
1635
* CAUTION: the caller is responsible for detecting the end-of-copy signal
1636
* (a line containing just "\.") when using this routine.
1639
* EOF if error (eg, invalid arguments are given)
1640
* 0 if EOL is reached (i.e., \n has been read)
1641
* (this is required for backward-compatibility -- this
1642
* routine used to always return EOF or 0, assuming that
1643
* the line ended within maxlen bytes.)
1644
* 1 in other cases (i.e., the buffer was filled before \n is reached)
1647
PQgetline(PGconn *conn, char *s, int maxlen)
1649
if (!s || maxlen <= 0)
1652
/* maxlen must be at least 3 to hold the \. terminator! */
1659
if (PG_PROTOCOL_MAJOR(conn->pversion) >= 3)
1660
return pqGetline3(conn, s, maxlen);
1662
return pqGetline2(conn, s, maxlen);
1666
* PQgetlineAsync - gets a COPY data row without blocking.
1668
* This routine is for applications that want to do "COPY <rel> to stdout"
1669
* asynchronously, that is without blocking. Having issued the COPY command
1670
* and gotten a PGRES_COPY_OUT response, the app should call PQconsumeInput
1671
* and this routine until the end-of-data signal is detected. Unlike
1672
* PQgetline, this routine takes responsibility for detecting end-of-data.
1674
* On each call, PQgetlineAsync will return data if a complete data row
1675
* is available in libpq's input buffer. Otherwise, no data is returned
1676
* until the rest of the row arrives.
1678
* If -1 is returned, the end-of-data signal has been recognized (and removed
1679
* from libpq's input buffer). The caller *must* next call PQendcopy and
1680
* then return to normal processing.
1683
* -1 if the end-of-copy-data marker has been recognized
1684
* 0 if no data is available
1685
* >0 the number of bytes returned.
1687
* The data returned will not extend beyond a data-row boundary. If possible
1688
* a whole row will be returned at one time. But if the buffer offered by
1689
* the caller is too small to hold a row sent by the backend, then a partial
1690
* data row will be returned. In text mode this can be detected by testing
1691
* whether the last returned byte is '\n' or not.
1693
* The returned data is *not* null-terminated.
1697
PQgetlineAsync(PGconn *conn, char *buffer, int bufsize)
1702
if (PG_PROTOCOL_MAJOR(conn->pversion) >= 3)
1703
return pqGetlineAsync3(conn, buffer, bufsize);
1705
return pqGetlineAsync2(conn, buffer, bufsize);
1709
* PQputline -- sends a string to the backend during COPY IN.
1710
* Returns 0 if OK, EOF if not.
1712
* This is deprecated primarily because the return convention doesn't allow
1713
* caller to tell the difference between a hard error and a nonblock-mode
1717
PQputline(PGconn *conn, const char *s)
1719
return PQputnbytes(conn, s, strlen(s));
1723
* PQputnbytes -- like PQputline, but buffer need not be null-terminated.
1724
* Returns 0 if OK, EOF if not.
1727
PQputnbytes(PGconn *conn, const char *buffer, int nbytes)
1729
if (PQputCopyData(conn, buffer, nbytes) > 0)
1737
* After completing the data transfer portion of a copy in/out,
1738
* the application must call this routine to finish the command protocol.
1740
* When using protocol 3.0 this is deprecated; it's cleaner to use PQgetResult
1741
* to get the transfer status. Note however that when using 2.0 protocol,
1742
* recovering from a copy failure often requires a PQreset. PQendcopy will
1743
* take care of that, PQgetResult won't.
1750
PQendcopy(PGconn *conn)
1755
if (PG_PROTOCOL_MAJOR(conn->pversion) >= 3)
1756
return pqEndcopy3(conn);
1758
return pqEndcopy2(conn);
1763
* PQfn - Send a function call to the POSTGRES backend.
1765
* conn : backend connection
1766
* fnid : function id
1767
* result_buf : pointer to result buffer (&int if integer)
1768
* result_len : length of return value.
1769
* actual_result_len: actual length returned. (differs from result_len
1770
* for varlena structures.)
1771
* result_type : If the result is an integer, this must be 1,
1772
* otherwise this should be 0
1773
* args : pointer to an array of function arguments.
1774
* (each has length, if integer, and value/pointer)
1775
* nargs : # of arguments in args array.
1778
* PGresult with status = PGRES_COMMAND_OK if successful.
1779
* *actual_result_len is > 0 if there is a return value, 0 if not.
1780
* PGresult with status = PGRES_FATAL_ERROR if backend returns an error.
1781
* NULL on communications failure. conn->errorMessage will be set.
1789
int *actual_result_len,
1791
const PQArgBlock *args,
1794
*actual_result_len = 0;
1799
/* clear the error string */
1800
resetPQExpBuffer(&conn->errorMessage);
1802
if (conn->sock < 0 || conn->asyncStatus != PGASYNC_IDLE ||
1803
conn->result != NULL)
1805
printfPQExpBuffer(&conn->errorMessage,
1806
libpq_gettext("connection in wrong state\n"));
1810
if (PG_PROTOCOL_MAJOR(conn->pversion) >= 3)
1811
return pqFunctionCall3(conn, fnid,
1812
result_buf, actual_result_len,
1816
return pqFunctionCall2(conn, fnid,
1817
result_buf, actual_result_len,
1823
/* ====== accessor funcs for PGresult ======== */
1826
PQresultStatus(const PGresult *res)
1829
return PGRES_FATAL_ERROR;
1830
return res->resultStatus;
1834
PQresStatus(ExecStatusType status)
1836
if (status < 0 || status >= sizeof pgresStatus / sizeof pgresStatus[0])
1837
return libpq_gettext("invalid ExecStatusType code");
1838
return pgresStatus[status];
1842
PQresultErrorMessage(const PGresult *res)
1844
if (!res || !res->errMsg)
1850
PQresultErrorField(const PGresult *res, int fieldcode)
1852
PGMessageField *pfield;
1856
for (pfield = res->errFields; pfield != NULL; pfield = pfield->next)
1858
if (pfield->code == fieldcode)
1859
return pfield->contents;
1865
PQntuples(const PGresult *res)
1873
PQnfields(const PGresult *res)
1877
return res->numAttributes;
1881
PQbinaryTuples(const PGresult *res)
1889
* Helper routines to range-check field numbers and tuple numbers.
1890
* Return TRUE if OK, FALSE if not
1894
check_field_number(const PGresult *res, int field_num)
1897
return FALSE; /* no way to display error message... */
1898
if (field_num < 0 || field_num >= res->numAttributes)
1900
pqInternalNotice(&res->noticeHooks,
1901
"column number %d is out of range 0..%d",
1902
field_num, res->numAttributes - 1);
1909
check_tuple_field_number(const PGresult *res,
1910
int tup_num, int field_num)
1913
return FALSE; /* no way to display error message... */
1914
if (tup_num < 0 || tup_num >= res->ntups)
1916
pqInternalNotice(&res->noticeHooks,
1917
"row number %d is out of range 0..%d",
1918
tup_num, res->ntups - 1);
1921
if (field_num < 0 || field_num >= res->numAttributes)
1923
pqInternalNotice(&res->noticeHooks,
1924
"column number %d is out of range 0..%d",
1925
field_num, res->numAttributes - 1);
1932
* returns NULL if the field_num is invalid
1935
PQfname(const PGresult *res, int field_num)
1937
if (!check_field_number(res, field_num))
1940
return res->attDescs[field_num].name;
1946
* PQfnumber: find column number given column name
1948
* The column name is parsed as if it were in a SQL statement, including
1949
* case-folding and double-quote processing. But note a possible gotcha:
1950
* downcasing in the frontend might follow different locale rules than
1951
* downcasing in the backend...
1953
* Returns -1 if no match. In the present backend it is also possible
1954
* to have multiple matches, in which case the first one is found.
1957
PQfnumber(const PGresult *res, const char *field_name)
1969
* Note: it is correct to reject a zero-length input string; the
1970
* proper input to match a zero-length field name would be "".
1972
if (field_name == NULL ||
1973
field_name[0] == '\0' ||
1974
res->attDescs == NULL)
1978
* Note: this code will not reject partially quoted strings, eg
1979
* foo"BAR"foo will become fooBARfoo when it probably ought to be an
1982
field_case = strdup(field_name);
1983
if (field_case == NULL)
1984
return -1; /* grotty */
1988
for (iptr = field_case; *iptr; iptr++)
1998
/* doubled quotes become a single quote */
2012
c = pg_tolower((unsigned char) c);
2018
for (i = 0; i < res->numAttributes; i++)
2020
if (strcmp(field_case, res->attDescs[i].name) == 0)
2031
PQftable(const PGresult *res, int field_num)
2033
if (!check_field_number(res, field_num))
2036
return res->attDescs[field_num].tableid;
2042
PQftablecol(const PGresult *res, int field_num)
2044
if (!check_field_number(res, field_num))
2047
return res->attDescs[field_num].columnid;
2053
PQfformat(const PGresult *res, int field_num)
2055
if (!check_field_number(res, field_num))
2058
return res->attDescs[field_num].format;
2064
PQftype(const PGresult *res, int field_num)
2066
if (!check_field_number(res, field_num))
2069
return res->attDescs[field_num].typid;
2075
PQfsize(const PGresult *res, int field_num)
2077
if (!check_field_number(res, field_num))
2080
return res->attDescs[field_num].typlen;
2086
PQfmod(const PGresult *res, int field_num)
2088
if (!check_field_number(res, field_num))
2091
return res->attDescs[field_num].atttypmod;
2097
PQcmdStatus(PGresult *res)
2101
return res->cmdStatus;
2106
* if the last command was an INSERT, return the oid string
2110
PQoidStatus(const PGresult *res)
2113
* This must be enough to hold the result. Don't laugh, this is better
2114
* than what this function used to do.
2116
static char buf[24];
2120
if (!res || !res->cmdStatus || strncmp(res->cmdStatus, "INSERT ", 7) != 0)
2123
len = strspn(res->cmdStatus + 7, "0123456789");
2126
strncpy(buf, res->cmdStatus + 7, len);
2134
* a perhaps preferable form of the above which just returns
2138
PQoidValue(const PGresult *res)
2140
char *endptr = NULL;
2141
unsigned long result;
2143
if (!res || !res->cmdStatus || strncmp(res->cmdStatus, "INSERT ", 7) != 0)
2151
result = strtoul(res->cmdStatus + 7, &endptr, 10);
2153
if (!endptr || (*endptr != ' ' && *endptr != '\0') || errno == ERANGE)
2156
return (Oid) result;
2162
* If the last command was an INSERT/UPDATE/DELETE/MOVE/FETCH, return a
2163
* string containing the number of inserted/affected tuples. If not,
2166
* XXX: this should probably return an int
2169
PQcmdTuples(PGresult *res)
2176
if (strncmp(res->cmdStatus, "INSERT ", 7) == 0)
2178
p = res->cmdStatus + 6;
2180
/* INSERT: skip oid */
2181
while (*p != ' ' && *p)
2184
else if (strncmp(res->cmdStatus, "DELETE ", 7) == 0 ||
2185
strncmp(res->cmdStatus, "UPDATE ", 7) == 0)
2186
p = res->cmdStatus + 6;
2187
else if (strncmp(res->cmdStatus, "FETCH ", 6) == 0)
2188
p = res->cmdStatus + 5;
2189
else if (strncmp(res->cmdStatus, "MOVE ", 5) == 0)
2190
p = res->cmdStatus + 4;
2198
pqInternalNotice(&res->noticeHooks,
2199
"could not interpret result from server: %s",
2209
* return the value of field 'field_num' of row 'tup_num'
2212
PQgetvalue(const PGresult *res, int tup_num, int field_num)
2214
if (!check_tuple_field_number(res, tup_num, field_num))
2216
return res->tuples[tup_num][field_num].value;
2220
* returns the actual length of a field value in bytes.
2223
PQgetlength(const PGresult *res, int tup_num, int field_num)
2225
if (!check_tuple_field_number(res, tup_num, field_num))
2227
if (res->tuples[tup_num][field_num].len != NULL_LEN)
2228
return res->tuples[tup_num][field_num].len;
2234
* returns the null status of a field value.
2237
PQgetisnull(const PGresult *res, int tup_num, int field_num)
2239
if (!check_tuple_field_number(res, tup_num, field_num))
2240
return 1; /* pretend it is null */
2241
if (res->tuples[tup_num][field_num].len == NULL_LEN)
2247
/* PQsetnonblocking:
2248
* sets the PGconn's database connection non-blocking if the arg is TRUE
2249
* or makes it non-blocking if the arg is FALSE, this will not protect
2250
* you from PQexec(), you'll only be safe when using the non-blocking API.
2251
* Needs to be called only on a connected database connection.
2254
PQsetnonblocking(PGconn *conn, int arg)
2258
if (!conn || conn->status == CONNECTION_BAD)
2261
barg = (arg ? TRUE : FALSE);
2263
/* early out if the socket is already in the state requested */
2264
if (barg == conn->nonblocking)
2268
* to guarantee constancy for flushing/query/result-polling behavior
2269
* we need to flush the send queue at this point in order to guarantee
2270
* proper behavior. this is ok because either they are making a
2271
* transition _from_ or _to_ blocking mode, either way we can block
2274
/* if we are going from blocking to non-blocking flush here */
2278
conn->nonblocking = barg;
2284
* return the blocking status of the database connection
2285
* TRUE == nonblocking, FALSE == blocking
2288
PQisnonblocking(const PGconn *conn)
2290
return (pqIsnonblocking(conn));
2293
/* try to force data out, really only useful for non-blocking users */
2295
PQflush(PGconn *conn)
2297
return (pqFlush(conn));
2302
* PQfreemem - safely frees memory allocated
2304
* Needed mostly by Win32, unless multithreaded DLL (/MD in VC6)
2305
* Used for freeing memory from PQescapeByte()a/PQunescapeBytea()
2308
PQfreemem(void *ptr)
2314
* PQfreeNotify - free's the memory associated with a PGnotify
2316
* This function is here only for binary backward compatibility.
2317
* New code should use PQfreemem(). A macro will automatically map
2318
* calls to PQfreemem. It should be removed in the future. bjm 2003-03-24
2322
void PQfreeNotify(PGnotify *notify);
2325
PQfreeNotify(PGnotify *notify)
2332
* Escaping arbitrary strings to get valid SQL literal strings.
2334
* Replaces "\\" with "\\\\" and "'" with "''".
2336
* length is the length of the source string. (Note: if a terminating NUL
2337
* is encountered sooner, PQescapeString stops short of "length"; the behavior
2338
* is thus rather like strncpy.)
2340
* For safety the buffer at "to" must be at least 2*length + 1 bytes long.
2341
* A terminating NUL character is added to the output string, whether the
2342
* input is NUL-terminated or not.
2344
* Returns the actual length of the output (not counting the terminating NUL).
2347
PQescapeString(char *to, const char *from, size_t length)
2349
const char *source = from;
2351
size_t remaining = length;
2353
while (remaining > 0 && *source != '\0')
2368
*target++ = *source;
2375
/* Write the terminating NUL character. */
2382
* PQescapeBytea - converts from binary string to the
2383
* minimal encoding necessary to include the string in an SQL
2384
* INSERT statement with a bytea type column as the target.
2386
* The following transformations are applied
2387
* '\0' == ASCII 0 == \\000
2388
* '\'' == ASCII 39 == \'
2389
* '\\' == ASCII 92 == \\\\
2390
* anything < 0x20, or > 0x7e ---> \\ooo
2391
* (where ooo is an octal expression)
2394
PQescapeBytea(const unsigned char *bintext, size_t binlen, size_t *bytealen)
2396
const unsigned char *vp;
2398
unsigned char *result;
2403
* empty string has 1 char ('\0')
2408
for (i = binlen; i > 0; i--, vp++)
2410
if (*vp < 0x20 || *vp > 0x7e)
2411
len += 5; /* '5' is for '\\ooo' */
2412
else if (*vp == '\'')
2414
else if (*vp == '\\')
2420
rp = result = (unsigned char *) malloc(len);
2427
for (i = binlen; i > 0; i--, vp++)
2429
if (*vp < 0x20 || *vp > 0x7e)
2431
(void) sprintf(rp, "\\\\%03o", *vp);
2434
else if (*vp == '\'')
2440
else if (*vp == '\\')
2456
#define ISFIRSTOCTDIGIT(CH) ((CH) >= '0' && (CH) <= '3')
2457
#define ISOCTDIGIT(CH) ((CH) >= '0' && (CH) <= '7')
2458
#define OCTVAL(CH) ((CH) - '0')
2461
* PQunescapeBytea - converts the null terminated string representation
2462
* of a bytea, strtext, into binary, filling a buffer. It returns a
2463
* pointer to the buffer (or NULL on error), and the size of the
2464
* buffer in retbuflen. The pointer may subsequently be used as an
2465
* argument to the function free(3). It is the reverse of PQescapeBytea.
2467
* The following transformations are made:
2468
* \\ == ASCII 92 == \
2469
* \ooo == a byte whose value = ooo (ooo is an octal number)
2470
* \x == x (x is any character not matched by the above transformations)
2473
PQunescapeBytea(const unsigned char *strtext, size_t *retbuflen)
2477
unsigned char *buffer,
2482
if (strtext == NULL)
2485
strtextlen = strlen(strtext);
2488
* Length of input is max length of output, but add one to avoid
2489
* unportable malloc(0) if input is zero-length.
2491
buffer = (unsigned char *) malloc(strtextlen + 1);
2495
for (i = j = 0; i < strtextlen;)
2501
if (strtext[i] == '\\')
2502
buffer[j++] = strtext[i++];
2505
if ((ISFIRSTOCTDIGIT(strtext[i])) &&
2506
(ISOCTDIGIT(strtext[i + 1])) &&
2507
(ISOCTDIGIT(strtext[i + 2])))
2511
byte = OCTVAL(strtext[i++]);
2512
byte = (byte << 3) + OCTVAL(strtext[i++]);
2513
byte = (byte << 3) + OCTVAL(strtext[i++]);
2519
* Note: if we see '\' followed by something that isn't a
2520
* recognized escape sequence, we loop around having done
2521
* nothing except advance i. Therefore the something will
2522
* be emitted as ordinary data on the next cycle. Corner
2523
* case: '\' at end of string will just be discarded.
2528
buffer[j++] = strtext[i++];
2532
buflen = j; /* buflen is the length of the dequoted
2535
/* Shrink the buffer to be no larger than necessary */
2536
/* +1 avoids unportable behavior when buflen==0 */
2537
tmpbuf = realloc(buffer, buflen + 1);
2539
/* It would only be a very brain-dead realloc that could fail, but... */
2546
*retbuflen = buflen;
added
removed
src/interfaces/libpq/fe-exec.c
