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do the right thing: look for a NOTICE message from the backend before we close our side of the socket. 6.4 libpq did not reliably print the backend's hara-kiri message, 'The Postmaster has informed me ...', because it only did the right thing if connection closure was detected during a read attempt instead of a write attempt.
1925 lines
48 KiB
C
1925 lines
48 KiB
C
/*-------------------------------------------------------------------------
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*
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* fe-exec.c
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* functions related to sending a query down to the backend
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*
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* Copyright (c) 1994, Regents of the University of California
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*
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*
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* IDENTIFICATION
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* $Header: /cvsroot/pgsql/src/interfaces/libpq/fe-exec.c,v 1.81 1999/05/28 01:54:53 tgl Exp $
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*
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*-------------------------------------------------------------------------
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*/
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#include "libpq-fe.h"
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#include "libpq-int.h"
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#include "postgres.h"
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#ifdef WIN32
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#include "win32.h"
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#else
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#if !defined(NO_UNISTD_H)
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#include <unistd.h>
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#endif
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#endif
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#include <stdlib.h>
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#include <string.h>
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#include <errno.h>
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#include <ctype.h>
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/* keep this in same order as ExecStatusType in libpq-fe.h */
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const char *const pgresStatus[] = {
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"PGRES_EMPTY_QUERY",
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"PGRES_COMMAND_OK",
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"PGRES_TUPLES_OK",
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"PGRES_COPY_OUT",
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"PGRES_COPY_IN",
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"PGRES_BAD_RESPONSE",
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"PGRES_NONFATAL_ERROR",
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"PGRES_FATAL_ERROR"
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};
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#define DONOTICE(conn,message) \
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((*(conn)->noticeHook) ((conn)->noticeArg, (message)))
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static int addTuple(PGresult *res, PGresAttValue *tup);
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static void parseInput(PGconn *conn);
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static void handleSendFailure(PGconn *conn);
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static int getRowDescriptions(PGconn *conn);
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static int getAnotherTuple(PGconn *conn, int binary);
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static int getNotify(PGconn *conn);
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static int getNotice(PGconn *conn);
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/* ----------------
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* Space management for PGresult.
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*
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* Formerly, libpq did a separate malloc() for each field of each tuple
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* returned by a query. This was remarkably expensive --- malloc/free
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* consumed a sizable part of the application's runtime. And there is
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* no real need to keep track of the fields separately, since they will
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* all be freed together when the PGresult is released. So now, we grab
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* large blocks of storage from malloc and allocate space for query data
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* within these blocks, using a trivially simple allocator. This reduces
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* the number of malloc/free calls dramatically, and it also avoids
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* fragmentation of the malloc storage arena.
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* The PGresult structure itself is still malloc'd separately. We could
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* combine it with the first allocation block, but that would waste space
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* for the common case that no extra storage is actually needed (that is,
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* the SQL command did not return tuples).
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* We also malloc the top-level array of tuple pointers separately, because
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* we need to be able to enlarge it via realloc, and our trivial space
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* allocator doesn't handle that effectively. (Too bad the FE/BE protocol
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* doesn't tell us up front how many tuples will be returned.)
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* All other subsidiary storage for a PGresult is kept in PGresult_data blocks
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* of size PGRESULT_DATA_BLOCKSIZE. The overhead at the start of each block
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* is just a link to the next one, if any. Free-space management info is
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* kept in the owning PGresult.
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* A query returning a small amount of data will thus require three malloc
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* calls: one for the PGresult, one for the tuples pointer array, and one
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* PGresult_data block.
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* Only the most recently allocated PGresult_data block is a candidate to
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* have more stuff added to it --- any extra space left over in older blocks
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* is wasted. We could be smarter and search the whole chain, but the point
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* here is to be simple and fast. Typical applications do not keep a PGresult
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* around very long anyway, so some wasted space within one is not a problem.
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*
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* Tuning constants for the space allocator are:
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* PGRESULT_DATA_BLOCKSIZE: size of a standard allocation block, in bytes
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* PGRESULT_ALIGN_BOUNDARY: assumed alignment requirement for binary data
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* PGRESULT_SEP_ALLOC_THRESHOLD: objects bigger than this are given separate
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* blocks, instead of being crammed into a regular allocation block.
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* Requirements for correct function are:
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* PGRESULT_ALIGN_BOUNDARY must be a multiple of the alignment requirements
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* of all machine data types. (Currently this is set from configure
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* tests, so it should be OK automatically.)
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* PGRESULT_SEP_ALLOC_THRESHOLD + PGRESULT_BLOCK_OVERHEAD <=
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* PGRESULT_DATA_BLOCKSIZE
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* pqResultAlloc assumes an object smaller than the threshold will fit
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* in a new block.
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* The amount of space wasted at the end of a block could be as much as
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* PGRESULT_SEP_ALLOC_THRESHOLD, so it doesn't pay to make that too large.
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* ----------------
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*/
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#ifdef MAX
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#undef MAX
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#endif
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#define MAX(a,b) ((a) > (b) ? (a) : (b))
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#define PGRESULT_DATA_BLOCKSIZE 2048
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#define PGRESULT_ALIGN_BOUNDARY MAXIMUM_ALIGNOF /* from configure */
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#define PGRESULT_BLOCK_OVERHEAD MAX(sizeof(PGresult_data), PGRESULT_ALIGN_BOUNDARY)
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#define PGRESULT_SEP_ALLOC_THRESHOLD (PGRESULT_DATA_BLOCKSIZE / 2)
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/*
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* PQmakeEmptyPGresult
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* returns a newly allocated, initialized PGresult with given status.
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* If conn is not NULL and status indicates an error, the conn's
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* errorMessage is copied.
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*
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* Note this is exported --- you wouldn't think an application would need
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* to build its own PGresults, but this has proven useful in both libpgtcl
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* and the Perl5 interface, so maybe it's not so unreasonable.
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*/
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PGresult *
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PQmakeEmptyPGresult(PGconn *conn, ExecStatusType status)
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{
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PGresult *result;
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result = (PGresult *) malloc(sizeof(PGresult));
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result->conn = conn; /* might be NULL */
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result->ntups = 0;
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result->numAttributes = 0;
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result->attDescs = NULL;
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result->tuples = NULL;
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result->tupArrSize = 0;
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result->resultStatus = status;
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result->cmdStatus[0] = '\0';
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result->binary = 0;
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result->errMsg = NULL;
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result->null_field[0] = '\0';
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result->curBlock = NULL;
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result->curOffset = 0;
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result->spaceLeft = 0;
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if (conn) /* consider copying conn's errorMessage */
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{
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switch (status)
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{
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case PGRES_EMPTY_QUERY:
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case PGRES_COMMAND_OK:
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case PGRES_TUPLES_OK:
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case PGRES_COPY_OUT:
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case PGRES_COPY_IN:
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/* non-error cases */
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break;
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default:
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pqSetResultError(result, conn->errorMessage);
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break;
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}
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}
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return result;
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}
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/*
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* pqResultAlloc -
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* Allocate subsidiary storage for a PGresult.
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*
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* nBytes is the amount of space needed for the object.
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* If isBinary is true, we assume that we need to align the object on
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* a machine allocation boundary.
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* If isBinary is false, we assume the object is a char string and can
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* be allocated on any byte boundary.
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*/
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void *
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pqResultAlloc(PGresult *res, int nBytes, int isBinary)
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{
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char *space;
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PGresult_data *block;
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if (!res)
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return NULL;
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if (nBytes <= 0)
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return res->null_field;
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/*
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* If alignment is needed, round up the current position to an
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* alignment boundary.
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*/
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if (isBinary)
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{
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int offset = res->curOffset % PGRESULT_ALIGN_BOUNDARY;
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if (offset)
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{
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res->curOffset += PGRESULT_ALIGN_BOUNDARY - offset;
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res->spaceLeft -= PGRESULT_ALIGN_BOUNDARY - offset;
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}
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}
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/* If there's enough space in the current block, no problem. */
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if (nBytes <= res->spaceLeft)
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{
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space = res->curBlock->space + res->curOffset;
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res->curOffset += nBytes;
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res->spaceLeft -= nBytes;
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return space;
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}
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/*
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* If the requested object is very large, give it its own block; this
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* avoids wasting what might be most of the current block to start a
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* new block. (We'd have to special-case requests bigger than the
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* block size anyway.) The object is always given binary alignment in
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* this case.
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*/
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if (nBytes >= PGRESULT_SEP_ALLOC_THRESHOLD)
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{
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block = (PGresult_data *) malloc(nBytes + PGRESULT_BLOCK_OVERHEAD);
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if (!block)
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return NULL;
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space = block->space + PGRESULT_BLOCK_OVERHEAD;
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if (res->curBlock)
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{
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/*
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* Tuck special block below the active block, so that we don't
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* have to waste the free space in the active block.
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*/
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block->next = res->curBlock->next;
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res->curBlock->next = block;
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}
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else
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{
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/* Must set up the new block as the first active block. */
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block->next = NULL;
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res->curBlock = block;
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res->spaceLeft = 0; /* be sure it's marked full */
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}
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return space;
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}
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/* Otherwise, start a new block. */
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block = (PGresult_data *) malloc(PGRESULT_DATA_BLOCKSIZE);
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if (!block)
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return NULL;
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block->next = res->curBlock;
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res->curBlock = block;
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if (isBinary)
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{
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/* object needs full alignment */
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res->curOffset = PGRESULT_BLOCK_OVERHEAD;
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res->spaceLeft = PGRESULT_DATA_BLOCKSIZE - PGRESULT_BLOCK_OVERHEAD;
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}
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else
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{
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/* we can cram it right after the overhead pointer */
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res->curOffset = sizeof(PGresult_data);
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res->spaceLeft = PGRESULT_DATA_BLOCKSIZE - sizeof(PGresult_data);
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}
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space = block->space + res->curOffset;
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res->curOffset += nBytes;
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res->spaceLeft -= nBytes;
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return space;
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}
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/*
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* pqResultStrdup -
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* Like strdup, but the space is subsidiary PGresult space.
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*/
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char *
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pqResultStrdup(PGresult *res, const char *str)
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{
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char *space = (char *) pqResultAlloc(res, strlen(str) + 1, FALSE);
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if (space)
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strcpy(space, str);
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return space;
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}
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/*
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* pqSetResultError -
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* assign a new error message to a PGresult
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*/
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void
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pqSetResultError(PGresult *res, const char *msg)
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{
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if (!res)
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return;
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if (msg && *msg)
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res->errMsg = pqResultStrdup(res, msg);
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else
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res->errMsg = NULL;
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}
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/*
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* PQclear -
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* free's the memory associated with a PGresult
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*/
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void
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PQclear(PGresult *res)
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{
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PGresult_data *block;
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if (!res)
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return;
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/* Free all the subsidiary blocks */
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while ((block = res->curBlock) != NULL)
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{
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res->curBlock = block->next;
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free(block);
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}
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/* Free the top-level tuple pointer array */
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if (res->tuples)
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free(res->tuples);
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/* Free the PGresult structure itself */
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free(res);
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}
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/*
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* Handy subroutine to deallocate any partially constructed async result.
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*/
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void
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pqClearAsyncResult(PGconn *conn)
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{
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if (conn->result)
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PQclear(conn->result);
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conn->result = NULL;
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conn->curTuple = NULL;
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}
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/*
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* addTuple
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* add a row pointer to the PGresult structure, growing it if necessary
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* Returns TRUE if OK, FALSE if not enough memory to add the row
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*/
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static int
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addTuple(PGresult *res, PGresAttValue *tup)
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{
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if (res->ntups >= res->tupArrSize)
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{
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/*
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* Try to grow the array.
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*
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* We can use realloc because shallow copying of the structure is
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* okay. Note that the first time through, res->tuples is NULL.
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* While ANSI says that realloc() should act like malloc() in that
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* case, some old C libraries (like SunOS 4.1.x) coredump instead.
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* On failure realloc is supposed to return NULL without damaging
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* the existing allocation. Note that the positions beyond
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* res->ntups are garbage, not necessarily NULL.
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*/
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int newSize = (res->tupArrSize > 0) ? res->tupArrSize * 2 : 128;
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PGresAttValue **newTuples;
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if (res->tuples == NULL)
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newTuples = (PGresAttValue **)
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malloc(newSize * sizeof(PGresAttValue *));
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else
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newTuples = (PGresAttValue **)
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realloc(res->tuples, newSize * sizeof(PGresAttValue *));
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if (!newTuples)
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return FALSE; /* malloc or realloc failed */
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res->tupArrSize = newSize;
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res->tuples = newTuples;
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}
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res->tuples[res->ntups] = tup;
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res->ntups++;
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return TRUE;
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}
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/*
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* PQsendQuery
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* Submit a query, but don't wait for it to finish
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*
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* Returns: 1 if successfully submitted
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* 0 if error (conn->errorMessage is set)
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*/
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int
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PQsendQuery(PGconn *conn, const char *query)
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{
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if (!conn)
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return 0;
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if (!query)
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{
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sprintf(conn->errorMessage, "PQsendQuery() -- query pointer is null.");
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return 0;
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}
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/* check to see if the query string is too long */
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if (strlen(query) > MAX_MESSAGE_LEN - 2)
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{
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sprintf(conn->errorMessage, "PQsendQuery() -- query is too long. "
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"Maximum length is %d\n", MAX_MESSAGE_LEN - 2);
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return 0;
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}
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/* Don't try to send if we know there's no live connection. */
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if (conn->status != CONNECTION_OK)
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{
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sprintf(conn->errorMessage, "PQsendQuery() -- There is no connection "
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"to the backend.\n");
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return 0;
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}
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/* Can't send while already busy, either. */
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if (conn->asyncStatus != PGASYNC_IDLE)
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{
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sprintf(conn->errorMessage,
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"PQsendQuery() -- another query already in progress.");
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return 0;
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}
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/* clear the error string */
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conn->errorMessage[0] = '\0';
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/* initialize async result-accumulation state */
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conn->result = NULL;
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conn->curTuple = NULL;
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/* send the query to the backend; */
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/* the frontend-backend protocol uses 'Q' to designate queries */
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if (pqPutnchar("Q", 1, conn) ||
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pqPuts(query, conn) ||
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pqFlush(conn))
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{
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handleSendFailure(conn);
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return 0;
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}
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/* OK, it's launched! */
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conn->asyncStatus = PGASYNC_BUSY;
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return 1;
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}
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/*
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* handleSendFailure: try to clean up after failure to send command.
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*
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* Primarily, what we want to accomplish here is to process an async
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* NOTICE message that the backend might have sent just before it died.
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*
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* NOTE: this routine should only be called in PGASYNC_IDLE state.
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*/
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static void
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handleSendFailure(PGconn *conn)
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{
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/* Preserve the error message emitted by the failing output routine */
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char * svErrMsg = strdup(conn->errorMessage);
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/*
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* Accept any available input data, ignoring errors. Note that if
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* pqReadData decides the backend has closed the channel, it will
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* close our side of the socket --- that's just what we want here.
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*/
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while (pqReadData(conn) > 0)
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/* loop until no more data readable */ ;
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|
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/*
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* Parse any available input messages. Since we are in PGASYNC_IDLE
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* state, only NOTICE and NOTIFY messages will be eaten.
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*/
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parseInput(conn);
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|
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/* Restore error message generated by output routine, if any. */
|
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if (*svErrMsg != '\0')
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strcpy(conn->errorMessage, svErrMsg);
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free(svErrMsg);
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}
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|
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/*
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* Consume any available input from the backend
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* 0 return: some kind of trouble
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* 1 return: no problem
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*/
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|
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int
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PQconsumeInput(PGconn *conn)
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{
|
|
if (!conn)
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return 0;
|
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|
|
/*
|
|
* Load more data, if available. We do this no matter what state we
|
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* are in, since we are probably getting called because the
|
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* application wants to get rid of a read-select condition. Note that
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* we will NOT block waiting for more input.
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*/
|
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if (pqReadData(conn) < 0)
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return 0;
|
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/* Parsing of the data waits till later. */
|
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return 1;
|
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}
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|
|
|
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/*
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* parseInput: if appropriate, parse input data from backend
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* until input is exhausted or a stopping state is reached.
|
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* Note that this function will NOT attempt to read more data from the backend.
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*/
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|
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static void
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parseInput(PGconn *conn)
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{
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char id;
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|
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/*
|
|
* Loop to parse successive complete messages available in the buffer.
|
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*/
|
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for (;;)
|
|
{
|
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|
|
/*
|
|
* Quit if in COPY_OUT state: we expect raw data from the server
|
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* until PQendcopy is called. Don't try to parse it according to
|
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* the normal protocol. (This is bogus. The data lines ought to
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* be part of the protocol and have identifying leading
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* characters.)
|
|
*/
|
|
if (conn->asyncStatus == PGASYNC_COPY_OUT)
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return;
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|
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/*
|
|
* OK to try to read a message type code.
|
|
*/
|
|
conn->inCursor = conn->inStart;
|
|
if (pqGetc(&id, conn))
|
|
return;
|
|
|
|
/*
|
|
* NOTIFY and NOTICE messages can happen in any state besides COPY
|
|
* OUT; always process them right away.
|
|
*/
|
|
if (id == 'A')
|
|
{
|
|
if (getNotify(conn))
|
|
return;
|
|
}
|
|
else if (id == 'N')
|
|
{
|
|
if (getNotice(conn))
|
|
return;
|
|
}
|
|
else
|
|
{
|
|
|
|
/*
|
|
* Other messages should only be processed while in BUSY
|
|
* state. (In particular, in READY state we hold off further
|
|
* parsing until the application collects the current
|
|
* PGresult.) If the state is IDLE then we got trouble.
|
|
*/
|
|
if (conn->asyncStatus != PGASYNC_BUSY)
|
|
{
|
|
if (conn->asyncStatus == PGASYNC_IDLE)
|
|
{
|
|
sprintf(conn->errorMessage,
|
|
"Backend message type 0x%02x arrived while idle\n",
|
|
id);
|
|
DONOTICE(conn, conn->errorMessage);
|
|
/* Discard the unexpected message; good idea?? */
|
|
conn->inStart = conn->inEnd;
|
|
}
|
|
return;
|
|
}
|
|
switch (id)
|
|
{
|
|
case 'C': /* command complete */
|
|
if (conn->result == NULL)
|
|
conn->result = PQmakeEmptyPGresult(conn,
|
|
PGRES_COMMAND_OK);
|
|
if (pqGets(conn->result->cmdStatus, CMDSTATUS_LEN, conn))
|
|
return;
|
|
conn->asyncStatus = PGASYNC_READY;
|
|
break;
|
|
case 'E': /* error return */
|
|
if (pqGets(conn->errorMessage, ERROR_MSG_LENGTH, conn))
|
|
return;
|
|
/* delete any partially constructed result */
|
|
pqClearAsyncResult(conn);
|
|
/* and build an error result holding the error message */
|
|
conn->result = PQmakeEmptyPGresult(conn,
|
|
PGRES_FATAL_ERROR);
|
|
conn->asyncStatus = PGASYNC_READY;
|
|
break;
|
|
case 'Z': /* backend is ready for new query */
|
|
conn->asyncStatus = PGASYNC_IDLE;
|
|
break;
|
|
case 'I': /* empty query */
|
|
/* read and throw away the closing '\0' */
|
|
if (pqGetc(&id, conn))
|
|
return;
|
|
if (id != '\0')
|
|
{
|
|
sprintf(conn->errorMessage,
|
|
"unexpected character %c following 'I'\n", id);
|
|
DONOTICE(conn, conn->errorMessage);
|
|
}
|
|
if (conn->result == NULL)
|
|
conn->result = PQmakeEmptyPGresult(conn,
|
|
PGRES_EMPTY_QUERY);
|
|
conn->asyncStatus = PGASYNC_READY;
|
|
break;
|
|
case 'K': /* secret key data from the backend */
|
|
|
|
/*
|
|
* This is expected only during backend startup, but
|
|
* it's just as easy to handle it as part of the main
|
|
* loop. Save the data and continue processing.
|
|
*/
|
|
if (pqGetInt(&(conn->be_pid), 4, conn))
|
|
return;
|
|
if (pqGetInt(&(conn->be_key), 4, conn))
|
|
return;
|
|
break;
|
|
case 'P': /* synchronous (normal) portal */
|
|
if (pqGets(conn->errorMessage, ERROR_MSG_LENGTH, conn))
|
|
return;
|
|
/* We pretty much ignore this message type... */
|
|
break;
|
|
case 'T': /* row descriptions (start of query
|
|
* results) */
|
|
if (conn->result == NULL)
|
|
{
|
|
/* First 'T' in a query sequence */
|
|
if (getRowDescriptions(conn))
|
|
return;
|
|
}
|
|
else
|
|
{
|
|
|
|
/*
|
|
* A new 'T' message is treated as the start of
|
|
* another PGresult. (It is not clear that this
|
|
* is really possible with the current backend.)
|
|
* We stop parsing until the application accepts
|
|
* the current result.
|
|
*/
|
|
conn->asyncStatus = PGASYNC_READY;
|
|
return;
|
|
}
|
|
break;
|
|
case 'D': /* ASCII data tuple */
|
|
if (conn->result != NULL)
|
|
{
|
|
/* Read another tuple of a normal query response */
|
|
if (getAnotherTuple(conn, FALSE))
|
|
return;
|
|
}
|
|
else
|
|
{
|
|
sprintf(conn->errorMessage,
|
|
"Backend sent D message without prior T\n");
|
|
DONOTICE(conn, conn->errorMessage);
|
|
/* Discard the unexpected message; good idea?? */
|
|
conn->inStart = conn->inEnd;
|
|
return;
|
|
}
|
|
break;
|
|
case 'B': /* Binary data tuple */
|
|
if (conn->result != NULL)
|
|
{
|
|
/* Read another tuple of a normal query response */
|
|
if (getAnotherTuple(conn, TRUE))
|
|
return;
|
|
}
|
|
else
|
|
{
|
|
sprintf(conn->errorMessage,
|
|
"Backend sent B message without prior T\n");
|
|
DONOTICE(conn, conn->errorMessage);
|
|
/* Discard the unexpected message; good idea?? */
|
|
conn->inStart = conn->inEnd;
|
|
return;
|
|
}
|
|
break;
|
|
case 'G': /* Start Copy In */
|
|
conn->asyncStatus = PGASYNC_COPY_IN;
|
|
break;
|
|
case 'H': /* Start Copy Out */
|
|
conn->asyncStatus = PGASYNC_COPY_OUT;
|
|
break;
|
|
default:
|
|
sprintf(conn->errorMessage,
|
|
"unknown protocol character '%c' read from backend. "
|
|
"(The protocol character is the first character the "
|
|
"backend sends in response to a query it receives).\n",
|
|
id);
|
|
/* Discard the unexpected message; good idea?? */
|
|
conn->inStart = conn->inEnd;
|
|
/* delete any partially constructed result */
|
|
pqClearAsyncResult(conn);
|
|
/* and build an error result holding the error message */
|
|
conn->result = PQmakeEmptyPGresult(conn,
|
|
PGRES_FATAL_ERROR);
|
|
conn->asyncStatus = PGASYNC_READY;
|
|
return;
|
|
} /* switch on protocol character */
|
|
}
|
|
/* Successfully consumed this message */
|
|
conn->inStart = conn->inCursor;
|
|
}
|
|
}
|
|
|
|
|
|
/*
|
|
* parseInput subroutine to read a 'T' (row descriptions) message.
|
|
* We build a PGresult structure containing the attribute data.
|
|
* Returns: 0 if completed message, EOF if not enough data yet.
|
|
*
|
|
* Note that if we run out of data, we have to release the partially
|
|
* constructed PGresult, and rebuild it again next time. Fortunately,
|
|
* that shouldn't happen often, since 'T' messages usually fit in a packet.
|
|
*/
|
|
|
|
static int
|
|
getRowDescriptions(PGconn *conn)
|
|
{
|
|
PGresult *result;
|
|
int nfields;
|
|
int i;
|
|
|
|
result = PQmakeEmptyPGresult(conn, PGRES_TUPLES_OK);
|
|
|
|
/* parseInput already read the 'T' label. */
|
|
/* the next two bytes are the number of fields */
|
|
if (pqGetInt(&(result->numAttributes), 2, conn))
|
|
{
|
|
PQclear(result);
|
|
return EOF;
|
|
}
|
|
nfields = result->numAttributes;
|
|
|
|
/* allocate space for the attribute descriptors */
|
|
if (nfields > 0)
|
|
{
|
|
result->attDescs = (PGresAttDesc *)
|
|
pqResultAlloc(result, nfields * sizeof(PGresAttDesc), TRUE);
|
|
MemSet((char *) result->attDescs, 0, nfields * sizeof(PGresAttDesc));
|
|
}
|
|
|
|
/* get type info */
|
|
for (i = 0; i < nfields; i++)
|
|
{
|
|
char typName[MAX_MESSAGE_LEN];
|
|
int typid;
|
|
int typlen;
|
|
int atttypmod;
|
|
|
|
if (pqGets(typName, MAX_MESSAGE_LEN, conn) ||
|
|
pqGetInt(&typid, 4, conn) ||
|
|
pqGetInt(&typlen, 2, conn) ||
|
|
pqGetInt(&atttypmod, 4, conn))
|
|
{
|
|
PQclear(result);
|
|
return EOF;
|
|
}
|
|
|
|
/*
|
|
* Since pqGetInt treats 2-byte integers as unsigned, we need to
|
|
* coerce the special value "-1" to signed form. (-1 is sent for
|
|
* variable-length fields.) Formerly, libpq effectively did a
|
|
* sign-extension on the 2-byte value by storing it in a signed
|
|
* short. Now we only coerce the single value 65535 == -1; values
|
|
* 32768..65534 are taken as valid field lengths.
|
|
*/
|
|
if (typlen == 0xFFFF)
|
|
typlen = -1;
|
|
result->attDescs[i].name = pqResultStrdup(result, typName);
|
|
result->attDescs[i].typid = typid;
|
|
result->attDescs[i].typlen = typlen;
|
|
result->attDescs[i].atttypmod = atttypmod;
|
|
}
|
|
|
|
/* Success! */
|
|
conn->result = result;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* parseInput subroutine to read a 'B' or 'D' (row data) message.
|
|
* We add another tuple to the existing PGresult structure.
|
|
* Returns: 0 if completed message, EOF if error or not enough data yet.
|
|
*
|
|
* Note that if we run out of data, we have to suspend and reprocess
|
|
* the message after more data is received. We keep a partially constructed
|
|
* tuple in conn->curTuple, and avoid reallocating already-allocated storage.
|
|
*/
|
|
|
|
static int
|
|
getAnotherTuple(PGconn *conn, int binary)
|
|
{
|
|
PGresult *result = conn->result;
|
|
int nfields = result->numAttributes;
|
|
PGresAttValue *tup;
|
|
char bitmap[MAX_FIELDS]; /* the backend sends us a bitmap
|
|
* of which attributes are null */
|
|
int i;
|
|
int nbytes; /* the number of bytes in bitmap */
|
|
char bmap; /* One byte of the bitmap */
|
|
int bitmap_index; /* Its index */
|
|
int bitcnt; /* number of bits examined in current byte */
|
|
int vlen; /* length of the current field value */
|
|
|
|
result->binary = binary;
|
|
|
|
/* Allocate tuple space if first time for this data message */
|
|
if (conn->curTuple == NULL)
|
|
{
|
|
conn->curTuple = (PGresAttValue *)
|
|
pqResultAlloc(result, nfields * sizeof(PGresAttValue), TRUE);
|
|
if (conn->curTuple == NULL)
|
|
goto outOfMemory;
|
|
MemSet((char *) conn->curTuple, 0, nfields * sizeof(PGresAttValue));
|
|
}
|
|
tup = conn->curTuple;
|
|
|
|
/* Get the null-value bitmap */
|
|
nbytes = (nfields + BYTELEN - 1) / BYTELEN;
|
|
if (nbytes >= MAX_FIELDS)
|
|
{
|
|
/* Replace partially constructed result with an error result */
|
|
pqClearAsyncResult(conn);
|
|
sprintf(conn->errorMessage,
|
|
"getAnotherTuple() -- null-values bitmap is too large\n");
|
|
conn->result = PQmakeEmptyPGresult(conn, PGRES_FATAL_ERROR);
|
|
conn->asyncStatus = PGASYNC_READY;
|
|
/* Discard the broken message */
|
|
conn->inStart = conn->inEnd;
|
|
return EOF;
|
|
}
|
|
|
|
if (pqGetnchar(bitmap, nbytes, conn))
|
|
return EOF;
|
|
|
|
/* Scan the fields */
|
|
bitmap_index = 0;
|
|
bmap = bitmap[bitmap_index];
|
|
bitcnt = 0;
|
|
|
|
for (i = 0; i < nfields; i++)
|
|
{
|
|
if (!(bmap & 0200))
|
|
{
|
|
/* if the field value is absent, make it a null string */
|
|
tup[i].value = result->null_field;
|
|
tup[i].len = NULL_LEN;
|
|
}
|
|
else
|
|
{
|
|
/* get the value length (the first four bytes are for length) */
|
|
if (pqGetInt(&vlen, 4, conn))
|
|
return EOF;
|
|
if (binary == 0)
|
|
vlen = vlen - 4;
|
|
if (vlen < 0)
|
|
vlen = 0;
|
|
if (tup[i].value == NULL)
|
|
{
|
|
tup[i].value = (char *) pqResultAlloc(result, vlen + 1, binary);
|
|
if (tup[i].value == NULL)
|
|
goto outOfMemory;
|
|
}
|
|
tup[i].len = vlen;
|
|
/* read in the value */
|
|
if (vlen > 0)
|
|
if (pqGetnchar((char *) (tup[i].value), vlen, conn))
|
|
return EOF;
|
|
/* we have to terminate this ourselves */
|
|
tup[i].value[vlen] = '\0';
|
|
}
|
|
/* advance the bitmap stuff */
|
|
bitcnt++;
|
|
if (bitcnt == BYTELEN)
|
|
{
|
|
bitmap_index++;
|
|
bmap = bitmap[bitmap_index];
|
|
bitcnt = 0;
|
|
}
|
|
else
|
|
bmap <<= 1;
|
|
}
|
|
|
|
/* Success! Store the completed tuple in the result */
|
|
if (!addTuple(result, tup))
|
|
goto outOfMemory;
|
|
/* and reset for a new message */
|
|
conn->curTuple = NULL;
|
|
return 0;
|
|
|
|
outOfMemory:
|
|
/* Replace partially constructed result with an error result */
|
|
pqClearAsyncResult(conn);
|
|
sprintf(conn->errorMessage,
|
|
"getAnotherTuple() -- out of memory for result\n");
|
|
conn->result = PQmakeEmptyPGresult(conn, PGRES_FATAL_ERROR);
|
|
conn->asyncStatus = PGASYNC_READY;
|
|
/* Discard the failed message --- good idea? */
|
|
conn->inStart = conn->inEnd;
|
|
return EOF;
|
|
}
|
|
|
|
|
|
/*
|
|
* PQisBusy
|
|
* Return TRUE if PQgetResult would block waiting for input.
|
|
*/
|
|
|
|
int
|
|
PQisBusy(PGconn *conn)
|
|
{
|
|
if (!conn)
|
|
return FALSE;
|
|
|
|
/* Parse any available data, if our state permits. */
|
|
parseInput(conn);
|
|
|
|
/* PQgetResult will return immediately in all states except BUSY. */
|
|
return conn->asyncStatus == PGASYNC_BUSY;
|
|
}
|
|
|
|
|
|
/*
|
|
* PQgetResult
|
|
* Get the next PGresult produced by a query.
|
|
* Returns NULL if and only if no query work remains.
|
|
*/
|
|
|
|
PGresult *
|
|
PQgetResult(PGconn *conn)
|
|
{
|
|
PGresult *res;
|
|
|
|
if (!conn)
|
|
return NULL;
|
|
|
|
/* Parse any available data, if our state permits. */
|
|
parseInput(conn);
|
|
|
|
/* If not ready to return something, block until we are. */
|
|
while (conn->asyncStatus == PGASYNC_BUSY)
|
|
{
|
|
/* Wait for some more data, and load it. */
|
|
if (pqWait(TRUE, FALSE, conn) ||
|
|
pqReadData(conn) < 0)
|
|
{
|
|
pqClearAsyncResult(conn);
|
|
conn->asyncStatus = PGASYNC_IDLE;
|
|
/* conn->errorMessage has been set by pqWait or pqReadData. */
|
|
return PQmakeEmptyPGresult(conn, PGRES_FATAL_ERROR);
|
|
}
|
|
/* Parse it. */
|
|
parseInput(conn);
|
|
}
|
|
|
|
/* Return the appropriate thing. */
|
|
switch (conn->asyncStatus)
|
|
{
|
|
case PGASYNC_IDLE:
|
|
res = NULL; /* query is complete */
|
|
break;
|
|
case PGASYNC_READY:
|
|
|
|
/*
|
|
* conn->result is the PGresult to return. If it is NULL
|
|
* (which probably shouldn't happen) we assume there is an
|
|
* appropriate error message in conn->errorMessage.
|
|
*/
|
|
res = conn->result;
|
|
conn->result = NULL;/* handing over ownership to caller */
|
|
conn->curTuple = NULL; /* just in case */
|
|
if (!res)
|
|
res = PQmakeEmptyPGresult(conn, PGRES_FATAL_ERROR);
|
|
else
|
|
{
|
|
|
|
/*
|
|
* Make sure PQerrorMessage agrees with result; it could
|
|
* be that we have done other operations that changed
|
|
* errorMessage since the result's error message was
|
|
* saved.
|
|
*/
|
|
strcpy(conn->errorMessage, PQresultErrorMessage(res));
|
|
}
|
|
/* Set the state back to BUSY, allowing parsing to proceed. */
|
|
conn->asyncStatus = PGASYNC_BUSY;
|
|
break;
|
|
case PGASYNC_COPY_IN:
|
|
res = PQmakeEmptyPGresult(conn, PGRES_COPY_IN);
|
|
break;
|
|
case PGASYNC_COPY_OUT:
|
|
res = PQmakeEmptyPGresult(conn, PGRES_COPY_OUT);
|
|
break;
|
|
default:
|
|
sprintf(conn->errorMessage,
|
|
"PQgetResult: Unexpected asyncStatus %d\n",
|
|
(int) conn->asyncStatus);
|
|
res = PQmakeEmptyPGresult(conn, PGRES_FATAL_ERROR);
|
|
break;
|
|
}
|
|
|
|
return res;
|
|
}
|
|
|
|
|
|
/*
|
|
* PQexec
|
|
* send a query to the backend and package up the result in a PGresult
|
|
*
|
|
* If the query was not even sent, return NULL; conn->errorMessage is set to
|
|
* a relevant message.
|
|
* If the query was sent, a new PGresult is returned (which could indicate
|
|
* either success or failure).
|
|
* The user is responsible for freeing the PGresult via PQclear()
|
|
* when done with it.
|
|
*/
|
|
|
|
PGresult *
|
|
PQexec(PGconn *conn, const char *query)
|
|
{
|
|
PGresult *result;
|
|
PGresult *lastResult;
|
|
|
|
/*
|
|
* Silently discard any prior query result that application didn't
|
|
* eat. This is probably poor design, but it's here for backward
|
|
* compatibility.
|
|
*/
|
|
while ((result = PQgetResult(conn)) != NULL)
|
|
{
|
|
if (result->resultStatus == PGRES_COPY_IN ||
|
|
result->resultStatus == PGRES_COPY_OUT)
|
|
{
|
|
PQclear(result);
|
|
sprintf(conn->errorMessage,
|
|
"PQexec: you gotta get out of a COPY state yourself.\n");
|
|
return NULL;
|
|
}
|
|
PQclear(result);
|
|
}
|
|
|
|
/* OK to send the message */
|
|
if (!PQsendQuery(conn, query))
|
|
return NULL;
|
|
|
|
/*
|
|
* For backwards compatibility, return the last result if there are
|
|
* more than one. We have to stop if we see copy in/out, however. We
|
|
* will resume parsing when application calls PQendcopy.
|
|
*/
|
|
lastResult = NULL;
|
|
while ((result = PQgetResult(conn)) != NULL)
|
|
{
|
|
if (lastResult)
|
|
PQclear(lastResult);
|
|
lastResult = result;
|
|
if (result->resultStatus == PGRES_COPY_IN ||
|
|
result->resultStatus == PGRES_COPY_OUT)
|
|
break;
|
|
}
|
|
return lastResult;
|
|
}
|
|
|
|
|
|
/*
|
|
* Attempt to read a Notice response message.
|
|
* This is possible in several places, so we break it out as a subroutine.
|
|
* Entry: 'N' flag character has already been consumed.
|
|
* Exit: returns 0 if successfully consumed Notice message.
|
|
* returns EOF if not enough data.
|
|
*/
|
|
static int
|
|
getNotice(PGconn *conn)
|
|
{
|
|
if (pqGets(conn->errorMessage, ERROR_MSG_LENGTH, conn))
|
|
return EOF;
|
|
DONOTICE(conn, conn->errorMessage);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Attempt to read a Notify response message.
|
|
* This is possible in several places, so we break it out as a subroutine.
|
|
* Entry: 'A' flag character has already been consumed.
|
|
* Exit: returns 0 if successfully consumed Notify message.
|
|
* returns EOF if not enough data.
|
|
*/
|
|
static int
|
|
getNotify(PGconn *conn)
|
|
{
|
|
PGnotify tempNotify;
|
|
PGnotify *newNotify;
|
|
|
|
if (pqGetInt(&(tempNotify.be_pid), 4, conn))
|
|
return EOF;
|
|
if (pqGets(tempNotify.relname, NAMEDATALEN, conn))
|
|
return EOF;
|
|
newNotify = (PGnotify *) malloc(sizeof(PGnotify));
|
|
memcpy(newNotify, &tempNotify, sizeof(PGnotify));
|
|
DLAddTail(conn->notifyList, DLNewElem(newNotify));
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* PQnotifies
|
|
* returns a PGnotify* structure of the latest async notification
|
|
* that has not yet been handled
|
|
*
|
|
* returns NULL, if there is currently
|
|
* no unhandled async notification from the backend
|
|
*
|
|
* the CALLER is responsible for FREE'ing the structure returned
|
|
*/
|
|
|
|
PGnotify *
|
|
PQnotifies(PGconn *conn)
|
|
{
|
|
Dlelem *e;
|
|
PGnotify *event;
|
|
|
|
if (!conn)
|
|
return NULL;
|
|
|
|
/* Parse any available data to see if we can extract NOTIFY messages. */
|
|
parseInput(conn);
|
|
|
|
/* RemHead returns NULL if list is empty */
|
|
e = DLRemHead(conn->notifyList);
|
|
if (!e)
|
|
return NULL;
|
|
event = (PGnotify *) DLE_VAL(e);
|
|
DLFreeElem(e);
|
|
return event;
|
|
}
|
|
|
|
/*
|
|
* PQgetline - gets a newline-terminated string from the backend.
|
|
*
|
|
* Chiefly here so that applications can use "COPY <rel> to stdout"
|
|
* and read the output string. Returns a null-terminated string in s.
|
|
*
|
|
* PQgetline reads up to maxlen-1 characters (like fgets(3)) but strips
|
|
* the terminating \n (like gets(3)).
|
|
*
|
|
* CAUTION: the caller is responsible for detecting the end-of-copy signal
|
|
* (a line containing just "\.") when using this routine.
|
|
*
|
|
* RETURNS:
|
|
* EOF if it is detected or invalid arguments are given
|
|
* 0 if EOL is reached (i.e., \n has been read)
|
|
* (this is required for backward-compatibility -- this
|
|
* routine used to always return EOF or 0, assuming that
|
|
* the line ended within maxlen bytes.)
|
|
* 1 in other cases (i.e., the buffer was filled before \n is reached)
|
|
*/
|
|
int
|
|
PQgetline(PGconn *conn, char *s, int maxlen)
|
|
{
|
|
int result = 1; /* return value if buffer overflows */
|
|
|
|
if (!s || maxlen <= 0)
|
|
return EOF;
|
|
|
|
if (!conn || conn->sock < 0)
|
|
{
|
|
*s = '\0';
|
|
return EOF;
|
|
}
|
|
|
|
/*
|
|
* Since this is a purely synchronous routine, we don't bother to
|
|
* maintain conn->inCursor; there is no need to back up.
|
|
*/
|
|
while (maxlen > 1)
|
|
{
|
|
if (conn->inStart < conn->inEnd)
|
|
{
|
|
char c = conn->inBuffer[conn->inStart++];
|
|
|
|
if (c == '\n')
|
|
{
|
|
result = 0; /* success exit */
|
|
break;
|
|
}
|
|
*s++ = c;
|
|
maxlen--;
|
|
}
|
|
else
|
|
{
|
|
/* need to load more data */
|
|
if (pqWait(TRUE, FALSE, conn) ||
|
|
pqReadData(conn) < 0)
|
|
{
|
|
result = EOF;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
*s = '\0';
|
|
|
|
return result;
|
|
}
|
|
|
|
/*
|
|
* PQgetlineAsync - gets a newline-terminated string without blocking.
|
|
*
|
|
* This routine is for applications that want to do "COPY <rel> to stdout"
|
|
* asynchronously, that is without blocking. Having issued the COPY command
|
|
* and gotten a PGRES_COPY_OUT response, the app should call PQconsumeInput
|
|
* and this routine until the end-of-data signal is detected. Unlike
|
|
* PQgetline, this routine takes responsibility for detecting end-of-data.
|
|
*
|
|
* On each call, PQgetlineAsync will return data if a complete newline-
|
|
* terminated data line is available in libpq's input buffer, or if the
|
|
* incoming data line is too long to fit in the buffer offered by the caller.
|
|
* Otherwise, no data is returned until the rest of the line arrives.
|
|
*
|
|
* If -1 is returned, the end-of-data signal has been recognized (and removed
|
|
* from libpq's input buffer). The caller *must* next call PQendcopy and
|
|
* then return to normal processing.
|
|
*
|
|
* RETURNS:
|
|
* -1 if the end-of-copy-data marker has been recognized
|
|
* 0 if no data is available
|
|
* >0 the number of bytes returned.
|
|
* The data returned will not extend beyond a newline character. If possible
|
|
* a whole line will be returned at one time. But if the buffer offered by
|
|
* the caller is too small to hold a line sent by the backend, then a partial
|
|
* data line will be returned. This can be detected by testing whether the
|
|
* last returned byte is '\n' or not.
|
|
* The returned string is *not* null-terminated.
|
|
*/
|
|
|
|
int
|
|
PQgetlineAsync(PGconn *conn, char *buffer, int bufsize)
|
|
{
|
|
int avail;
|
|
|
|
if (!conn || conn->asyncStatus != PGASYNC_COPY_OUT)
|
|
return -1; /* we are not doing a copy... */
|
|
|
|
/*
|
|
* Move data from libpq's buffer to the caller's. We want to accept
|
|
* data only in units of whole lines, not partial lines. This ensures
|
|
* that we can recognize the terminator line "\\.\n". (Otherwise, if
|
|
* it happened to cross a packet/buffer boundary, we might hand the
|
|
* first one or two characters off to the caller, which we shouldn't.)
|
|
*/
|
|
|
|
conn->inCursor = conn->inStart;
|
|
|
|
avail = bufsize;
|
|
while (avail > 0 && conn->inCursor < conn->inEnd)
|
|
{
|
|
char c = conn->inBuffer[conn->inCursor++];
|
|
|
|
*buffer++ = c;
|
|
--avail;
|
|
if (c == '\n')
|
|
{
|
|
/* Got a complete line; mark the data removed from libpq */
|
|
conn->inStart = conn->inCursor;
|
|
/* Is it the endmarker line? */
|
|
if (bufsize - avail == 3 && buffer[-3] == '\\' && buffer[-2] == '.')
|
|
return -1;
|
|
/* No, return the data line to the caller */
|
|
return bufsize - avail;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* We don't have a complete line. We'd prefer to leave it in libpq's
|
|
* buffer until the rest arrives, but there is a special case: what if
|
|
* the line is longer than the buffer the caller is offering us? In
|
|
* that case we'd better hand over a partial line, else we'd get into
|
|
* an infinite loop. Do this in a way that ensures we can't
|
|
* misrecognize a terminator line later: leave last 3 characters in
|
|
* libpq buffer.
|
|
*/
|
|
if (avail == 0 && bufsize > 3)
|
|
{
|
|
conn->inStart = conn->inCursor - 3;
|
|
return bufsize - 3;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* PQputline -- sends a string to the backend.
|
|
* Returns 0 if OK, EOF if not.
|
|
*
|
|
* Chiefly here so that applications can use "COPY <rel> from stdin".
|
|
*/
|
|
int
|
|
PQputline(PGconn *conn, const char *s)
|
|
{
|
|
if (!conn || conn->sock < 0)
|
|
return EOF;
|
|
return pqPutnchar(s, strlen(s), conn);
|
|
}
|
|
|
|
/*
|
|
* PQputnbytes -- like PQputline, but buffer need not be null-terminated.
|
|
* Returns 0 if OK, EOF if not.
|
|
*/
|
|
int
|
|
PQputnbytes(PGconn *conn, const char *buffer, int nbytes)
|
|
{
|
|
if (!conn || conn->sock < 0)
|
|
return EOF;
|
|
return pqPutnchar(buffer, nbytes, conn);
|
|
}
|
|
|
|
/*
|
|
* PQendcopy
|
|
* After completing the data transfer portion of a copy in/out,
|
|
* the application must call this routine to finish the command protocol.
|
|
*
|
|
* RETURNS:
|
|
* 0 on success
|
|
* 1 on failure
|
|
*/
|
|
int
|
|
PQendcopy(PGconn *conn)
|
|
{
|
|
PGresult *result;
|
|
|
|
if (!conn)
|
|
return 0;
|
|
|
|
if (conn->asyncStatus != PGASYNC_COPY_IN &&
|
|
conn->asyncStatus != PGASYNC_COPY_OUT)
|
|
{
|
|
sprintf(conn->errorMessage,
|
|
"PQendcopy() -- I don't think there's a copy in progress.");
|
|
return 1;
|
|
}
|
|
|
|
(void) pqFlush(conn); /* make sure no data is waiting to be sent */
|
|
|
|
/* Return to active duty */
|
|
conn->asyncStatus = PGASYNC_BUSY;
|
|
conn->errorMessage[0] = '\0';
|
|
|
|
/* Wait for the completion response */
|
|
result = PQgetResult(conn);
|
|
|
|
/* Expecting a successful result */
|
|
if (result && result->resultStatus == PGRES_COMMAND_OK)
|
|
{
|
|
PQclear(result);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Trouble. The worst case is that we've lost sync with the backend
|
|
* entirely due to application screwup of the copy in/out protocol. To
|
|
* recover, reset the connection (talk about using a sledgehammer...)
|
|
*/
|
|
PQclear(result);
|
|
|
|
if (conn->errorMessage[0])
|
|
DONOTICE(conn, conn->errorMessage);
|
|
|
|
DONOTICE(conn, "PQendcopy: resetting connection\n");
|
|
|
|
PQreset(conn);
|
|
|
|
return 1;
|
|
}
|
|
|
|
|
|
/* ----------------
|
|
* PQfn - Send a function call to the POSTGRES backend.
|
|
*
|
|
* conn : backend connection
|
|
* fnid : function id
|
|
* result_buf : pointer to result buffer (&int if integer)
|
|
* result_len : length of return value.
|
|
* actual_result_len: actual length returned. (differs from result_len
|
|
* for varlena structures.)
|
|
* result_type : If the result is an integer, this must be 1,
|
|
* otherwise this should be 0
|
|
* args : pointer to an array of function arguments.
|
|
* (each has length, if integer, and value/pointer)
|
|
* nargs : # of arguments in args array.
|
|
*
|
|
* RETURNS
|
|
* PGresult with status = PGRES_COMMAND_OK if successful.
|
|
* *actual_result_len is > 0 if there is a return value, 0 if not.
|
|
* PGresult with status = PGRES_FATAL_ERROR if backend returns an error.
|
|
* NULL on communications failure. conn->errorMessage will be set.
|
|
* ----------------
|
|
*/
|
|
|
|
PGresult *
|
|
PQfn(PGconn *conn,
|
|
int fnid,
|
|
int *result_buf,
|
|
int *actual_result_len,
|
|
int result_is_int,
|
|
PQArgBlock *args,
|
|
int nargs)
|
|
{
|
|
bool needInput = false;
|
|
ExecStatusType status = PGRES_FATAL_ERROR;
|
|
char id;
|
|
int i;
|
|
|
|
*actual_result_len = 0;
|
|
|
|
if (!conn)
|
|
return NULL;
|
|
|
|
if (conn->sock < 0 || conn->asyncStatus != PGASYNC_IDLE)
|
|
{
|
|
sprintf(conn->errorMessage, "PQfn() -- connection in wrong state\n");
|
|
return NULL;
|
|
}
|
|
|
|
/* clear the error string */
|
|
conn->errorMessage[0] = '\0';
|
|
|
|
if (pqPuts("F ", conn) || /* function */
|
|
pqPutInt(fnid, 4, conn) || /* function id */
|
|
pqPutInt(nargs, 4, conn)) /* # of args */
|
|
{
|
|
handleSendFailure(conn);
|
|
return NULL;
|
|
}
|
|
|
|
for (i = 0; i < nargs; ++i)
|
|
{ /* len.int4 + contents */
|
|
if (pqPutInt(args[i].len, 4, conn))
|
|
{
|
|
handleSendFailure(conn);
|
|
return NULL;
|
|
}
|
|
|
|
if (args[i].isint)
|
|
{
|
|
if (pqPutInt(args[i].u.integer, 4, conn))
|
|
{
|
|
handleSendFailure(conn);
|
|
return NULL;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
if (pqPutnchar((char *) args[i].u.ptr, args[i].len, conn))
|
|
{
|
|
handleSendFailure(conn);
|
|
return NULL;
|
|
}
|
|
}
|
|
}
|
|
if (pqFlush(conn))
|
|
{
|
|
handleSendFailure(conn);
|
|
return NULL;
|
|
}
|
|
|
|
for (;;)
|
|
{
|
|
if (needInput)
|
|
{
|
|
/* Wait for some data to arrive (or for the channel to close) */
|
|
if (pqWait(TRUE, FALSE, conn) ||
|
|
pqReadData(conn) < 0)
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* Scan the message. If we run out of data, loop around to try
|
|
* again.
|
|
*/
|
|
conn->inCursor = conn->inStart;
|
|
needInput = true;
|
|
|
|
if (pqGetc(&id, conn))
|
|
continue;
|
|
|
|
/*
|
|
* We should see V or E response to the command, but might get N
|
|
* and/or A notices first. We also need to swallow the final Z
|
|
* before returning.
|
|
*/
|
|
switch (id)
|
|
{
|
|
case 'V': /* function result */
|
|
if (pqGetc(&id, conn))
|
|
continue;
|
|
if (id == 'G')
|
|
{
|
|
/* function returned nonempty value */
|
|
if (pqGetInt(actual_result_len, 4, conn))
|
|
continue;
|
|
if (result_is_int)
|
|
{
|
|
if (pqGetInt(result_buf, 4, conn))
|
|
continue;
|
|
}
|
|
else
|
|
{
|
|
if (pqGetnchar((char *) result_buf,
|
|
*actual_result_len,
|
|
conn))
|
|
continue;
|
|
}
|
|
if (pqGetc(&id, conn)) /* get the last '0' */
|
|
continue;
|
|
}
|
|
if (id == '0')
|
|
{
|
|
/* correctly finished function result message */
|
|
status = PGRES_COMMAND_OK;
|
|
}
|
|
else
|
|
{
|
|
/* The backend violates the protocol. */
|
|
sprintf(conn->errorMessage,
|
|
"FATAL: PQfn: protocol error: id=%x\n", id);
|
|
conn->inStart = conn->inCursor;
|
|
return PQmakeEmptyPGresult(conn, PGRES_FATAL_ERROR);
|
|
}
|
|
break;
|
|
case 'E': /* error return */
|
|
if (pqGets(conn->errorMessage, ERROR_MSG_LENGTH, conn))
|
|
continue;
|
|
status = PGRES_FATAL_ERROR;
|
|
break;
|
|
case 'A': /* notify message */
|
|
/* handle notify and go back to processing return values */
|
|
if (getNotify(conn))
|
|
continue;
|
|
break;
|
|
case 'N': /* notice */
|
|
/* handle notice and go back to processing return values */
|
|
if (getNotice(conn))
|
|
continue;
|
|
break;
|
|
case 'Z': /* backend is ready for new query */
|
|
/* consume the message and exit */
|
|
conn->inStart = conn->inCursor;
|
|
return PQmakeEmptyPGresult(conn, status);
|
|
default:
|
|
/* The backend violates the protocol. */
|
|
sprintf(conn->errorMessage,
|
|
"FATAL: PQfn: protocol error: id=%x\n", id);
|
|
conn->inStart = conn->inCursor;
|
|
return PQmakeEmptyPGresult(conn, PGRES_FATAL_ERROR);
|
|
}
|
|
/* Completed this message, keep going */
|
|
conn->inStart = conn->inCursor;
|
|
needInput = false;
|
|
}
|
|
|
|
/* we fall out of the loop only upon failing to read data */
|
|
return PQmakeEmptyPGresult(conn, PGRES_FATAL_ERROR);
|
|
}
|
|
|
|
|
|
/* ====== accessor funcs for PGresult ======== */
|
|
|
|
ExecStatusType
|
|
PQresultStatus(PGresult *res)
|
|
{
|
|
if (!res)
|
|
return PGRES_NONFATAL_ERROR;
|
|
return res->resultStatus;
|
|
}
|
|
|
|
const char *
|
|
PQresStatus(ExecStatusType status)
|
|
{
|
|
if (((int) status) < 0 ||
|
|
((int) status) >= (sizeof(pgresStatus) / sizeof(pgresStatus[0])))
|
|
return "Invalid ExecStatusType code";
|
|
return pgresStatus[status];
|
|
}
|
|
|
|
const char *
|
|
PQresultErrorMessage(PGresult *res)
|
|
{
|
|
if (!res || !res->errMsg)
|
|
return "";
|
|
return res->errMsg;
|
|
}
|
|
|
|
int
|
|
PQntuples(PGresult *res)
|
|
{
|
|
if (!res)
|
|
return 0;
|
|
return res->ntups;
|
|
}
|
|
|
|
int
|
|
PQnfields(PGresult *res)
|
|
{
|
|
if (!res)
|
|
return 0;
|
|
return res->numAttributes;
|
|
}
|
|
|
|
int
|
|
PQbinaryTuples(PGresult *res)
|
|
{
|
|
if (!res)
|
|
return 0;
|
|
return res->binary;
|
|
}
|
|
|
|
/*
|
|
* Helper routines to range-check field numbers and tuple numbers.
|
|
* Return TRUE if OK, FALSE if not
|
|
*/
|
|
|
|
static int
|
|
check_field_number(const char *routineName, PGresult *res, int field_num)
|
|
{
|
|
if (!res)
|
|
return FALSE; /* no way to display error message... */
|
|
if (field_num < 0 || field_num >= res->numAttributes)
|
|
{
|
|
if (res->conn)
|
|
{
|
|
sprintf(res->conn->errorMessage,
|
|
"%s: ERROR! field number %d is out of range 0..%d\n",
|
|
routineName, field_num, res->numAttributes - 1);
|
|
DONOTICE(res->conn, res->conn->errorMessage);
|
|
}
|
|
return FALSE;
|
|
}
|
|
return TRUE;
|
|
}
|
|
|
|
static int
|
|
check_tuple_field_number(const char *routineName, PGresult *res,
|
|
int tup_num, int field_num)
|
|
{
|
|
if (!res)
|
|
return FALSE; /* no way to display error message... */
|
|
if (tup_num < 0 || tup_num >= res->ntups)
|
|
{
|
|
if (res->conn)
|
|
{
|
|
sprintf(res->conn->errorMessage,
|
|
"%s: ERROR! tuple number %d is out of range 0..%d\n",
|
|
routineName, tup_num, res->ntups - 1);
|
|
DONOTICE(res->conn, res->conn->errorMessage);
|
|
}
|
|
return FALSE;
|
|
}
|
|
if (field_num < 0 || field_num >= res->numAttributes)
|
|
{
|
|
if (res->conn)
|
|
{
|
|
sprintf(res->conn->errorMessage,
|
|
"%s: ERROR! field number %d is out of range 0..%d\n",
|
|
routineName, field_num, res->numAttributes - 1);
|
|
DONOTICE(res->conn, res->conn->errorMessage);
|
|
}
|
|
return FALSE;
|
|
}
|
|
return TRUE;
|
|
}
|
|
|
|
/*
|
|
returns NULL if the field_num is invalid
|
|
*/
|
|
char *
|
|
PQfname(PGresult *res, int field_num)
|
|
{
|
|
if (!check_field_number("PQfname", res, field_num))
|
|
return NULL;
|
|
if (res->attDescs)
|
|
return res->attDescs[field_num].name;
|
|
else
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
returns -1 on a bad field name
|
|
*/
|
|
int
|
|
PQfnumber(PGresult *res, const char *field_name)
|
|
{
|
|
int i;
|
|
char *field_case;
|
|
|
|
if (!res)
|
|
return -1;
|
|
|
|
if (field_name == NULL ||
|
|
field_name[0] == '\0' ||
|
|
res->attDescs == NULL)
|
|
return -1;
|
|
|
|
field_case = strdup(field_name);
|
|
if (*field_case == '"')
|
|
{
|
|
strcpy(field_case, field_case + 1);
|
|
*(field_case + strlen(field_case) - 1) = '\0';
|
|
}
|
|
else
|
|
for (i = 0; field_case[i]; i++)
|
|
if (isascii((unsigned char) field_case[i]) &&
|
|
isupper(field_case[i]))
|
|
field_case[i] = tolower(field_case[i]);
|
|
|
|
for (i = 0; i < res->numAttributes; i++)
|
|
{
|
|
if (strcmp(field_case, res->attDescs[i].name) == 0)
|
|
{
|
|
free(field_case);
|
|
return i;
|
|
}
|
|
}
|
|
free(field_case);
|
|
return -1;
|
|
}
|
|
|
|
Oid
|
|
PQftype(PGresult *res, int field_num)
|
|
{
|
|
if (!check_field_number("PQftype", res, field_num))
|
|
return InvalidOid;
|
|
if (res->attDescs)
|
|
return res->attDescs[field_num].typid;
|
|
else
|
|
return InvalidOid;
|
|
}
|
|
|
|
int
|
|
PQfsize(PGresult *res, int field_num)
|
|
{
|
|
if (!check_field_number("PQfsize", res, field_num))
|
|
return 0;
|
|
if (res->attDescs)
|
|
return res->attDescs[field_num].typlen;
|
|
else
|
|
return 0;
|
|
}
|
|
|
|
int
|
|
PQfmod(PGresult *res, int field_num)
|
|
{
|
|
if (!check_field_number("PQfmod", res, field_num))
|
|
return 0;
|
|
if (res->attDescs)
|
|
return res->attDescs[field_num].atttypmod;
|
|
else
|
|
return 0;
|
|
}
|
|
|
|
char *
|
|
PQcmdStatus(PGresult *res)
|
|
{
|
|
if (!res)
|
|
return NULL;
|
|
return res->cmdStatus;
|
|
}
|
|
|
|
/*
|
|
PQoidStatus -
|
|
if the last command was an INSERT, return the oid string
|
|
if not, return ""
|
|
*/
|
|
const char *
|
|
PQoidStatus(PGresult *res)
|
|
{
|
|
char *p,
|
|
*e,
|
|
*scan;
|
|
int slen,
|
|
olen;
|
|
|
|
if (!res)
|
|
return "";
|
|
|
|
if (strncmp(res->cmdStatus, "INSERT ", 7) != 0)
|
|
return "";
|
|
|
|
/*----------
|
|
* The cmdStatus string looks like
|
|
* INSERT oid count\0
|
|
* In order to be able to return an ordinary C string without
|
|
* damaging the result for PQcmdStatus or PQcmdTuples, we copy
|
|
* the oid part of the string to just after the null, so that
|
|
* cmdStatus looks like
|
|
* INSERT oid count\0oid\0
|
|
* ^ our return value points here
|
|
* Pretty klugy eh? This routine should've just returned an Oid value.
|
|
*----------
|
|
*/
|
|
|
|
slen = strlen(res->cmdStatus);
|
|
p = res->cmdStatus + 7; /* where oid is now */
|
|
e = res->cmdStatus + slen + 1; /* where to put the oid string */
|
|
|
|
for (scan = p; *scan && *scan != ' ';)
|
|
scan++;
|
|
olen = scan - p;
|
|
if (slen + olen + 2 > sizeof(res->cmdStatus))
|
|
return ""; /* something very wrong if it doesn't fit */
|
|
|
|
strncpy(e, p, olen);
|
|
e[olen] = '\0';
|
|
|
|
return e;
|
|
}
|
|
|
|
/*
|
|
PQcmdTuples -
|
|
if the last command was an INSERT/UPDATE/DELETE, return number
|
|
of inserted/affected tuples, if not, return ""
|
|
*/
|
|
const char *
|
|
PQcmdTuples(PGresult *res)
|
|
{
|
|
if (!res)
|
|
return "";
|
|
|
|
if (strncmp(res->cmdStatus, "INSERT", 6) == 0 ||
|
|
strncmp(res->cmdStatus, "DELETE", 6) == 0 ||
|
|
strncmp(res->cmdStatus, "UPDATE", 6) == 0)
|
|
{
|
|
char *p = res->cmdStatus + 6;
|
|
|
|
if (*p == 0)
|
|
{
|
|
if (res->conn)
|
|
{
|
|
sprintf(res->conn->errorMessage,
|
|
"PQcmdTuples (%s) -- bad input from server\n",
|
|
res->cmdStatus);
|
|
DONOTICE(res->conn, res->conn->errorMessage);
|
|
}
|
|
return "";
|
|
}
|
|
p++;
|
|
if (*(res->cmdStatus) != 'I') /* UPDATE/DELETE */
|
|
return p;
|
|
while (*p != ' ' && *p)
|
|
p++; /* INSERT: skip oid */
|
|
if (*p == 0)
|
|
{
|
|
if (res->conn)
|
|
{
|
|
sprintf(res->conn->errorMessage,
|
|
"PQcmdTuples (INSERT) -- there's no # of tuples\n");
|
|
DONOTICE(res->conn, res->conn->errorMessage);
|
|
}
|
|
return "";
|
|
}
|
|
p++;
|
|
return p;
|
|
}
|
|
return "";
|
|
}
|
|
|
|
/*
|
|
PQgetvalue:
|
|
return the value of field 'field_num' of row 'tup_num'
|
|
|
|
If res is binary, then the value returned is NOT a null-terminated
|
|
ASCII string, but the binary representation in the server's native
|
|
format.
|
|
|
|
if res is not binary, a null-terminated ASCII string is returned.
|
|
*/
|
|
char *
|
|
PQgetvalue(PGresult *res, int tup_num, int field_num)
|
|
{
|
|
if (!check_tuple_field_number("PQgetvalue", res, tup_num, field_num))
|
|
return NULL;
|
|
return res->tuples[tup_num][field_num].value;
|
|
}
|
|
|
|
/* PQgetlength:
|
|
returns the length of a field value in bytes. If res is binary,
|
|
i.e. a result of a binary portal, then the length returned does
|
|
NOT include the size field of the varlena. (The data returned
|
|
by PQgetvalue doesn't either.)
|
|
*/
|
|
int
|
|
PQgetlength(PGresult *res, int tup_num, int field_num)
|
|
{
|
|
if (!check_tuple_field_number("PQgetlength", res, tup_num, field_num))
|
|
return 0;
|
|
if (res->tuples[tup_num][field_num].len != NULL_LEN)
|
|
return res->tuples[tup_num][field_num].len;
|
|
else
|
|
return 0;
|
|
}
|
|
|
|
/* PQgetisnull:
|
|
returns the null status of a field value.
|
|
*/
|
|
int
|
|
PQgetisnull(PGresult *res, int tup_num, int field_num)
|
|
{
|
|
if (!check_tuple_field_number("PQgetisnull", res, tup_num, field_num))
|
|
return 1; /* pretend it is null */
|
|
if (res->tuples[tup_num][field_num].len == NULL_LEN)
|
|
return 1;
|
|
else
|
|
return 0;
|
|
}
|