/*-------------------------------------------------------------------------
*
* fe-exec.c
* functions related to sending a query down to the backend
*
* Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/interfaces/libpq/fe-exec.c,v 1.209 2010/02/16 20:58:14 momjian Exp $
*
*-------------------------------------------------------------------------
*/
#include "postgres_fe.h"
#include <ctype.h>
#include <fcntl.h>
#include "libpq-fe.h"
#include "libpq-int.h"
#include "mb/pg_wchar.h"
#ifdef WIN32
#include "win32.h"
#else
#include <unistd.h>
#endif
/* keep this in same order as ExecStatusType in libpq-fe.h */
char *const pgresStatus[] = {
"PGRES_EMPTY_QUERY",
"PGRES_COMMAND_OK",
"PGRES_TUPLES_OK",
"PGRES_COPY_OUT",
"PGRES_COPY_IN",
"PGRES_BAD_RESPONSE",
"PGRES_NONFATAL_ERROR",
"PGRES_FATAL_ERROR"
};
/*
* static state needed by PQescapeString and PQescapeBytea; initialize to
* values that result in backward-compatible behavior
*/
static int static_client_encoding = PG_SQL_ASCII;
static bool static_std_strings = false;
static PGEvent *dupEvents(PGEvent *events, int count);
static bool PQsendQueryStart(PGconn *conn);
static int PQsendQueryGuts(PGconn *conn,
const char *command,
const char *stmtName,
int nParams,
const Oid *paramTypes,
const char *const * paramValues,
const int *paramLengths,
const int *paramFormats,
int resultFormat);
static void parseInput(PGconn *conn);
static bool PQexecStart(PGconn *conn);
static PGresult *PQexecFinish(PGconn *conn);
static int PQsendDescribe(PGconn *conn, char desc_type,
const char *desc_target);
static int check_field_number(const PGresult *res, int field_num);
/* ----------------
* Space management for PGresult.
*
* Formerly, libpq did a separate malloc() for each field of each tuple
* returned by a query. This was remarkably expensive --- malloc/free
* consumed a sizable part of the application's runtime. And there is
* no real need to keep track of the fields separately, since they will
* all be freed together when the PGresult is released. So now, we grab
* large blocks of storage from malloc and allocate space for query data
* within these blocks, using a trivially simple allocator. This reduces
* the number of malloc/free calls dramatically, and it also avoids
* fragmentation of the malloc storage arena.
* The PGresult structure itself is still malloc'd separately. We could
* combine it with the first allocation block, but that would waste space
* for the common case that no extra storage is actually needed (that is,
* the SQL command did not return tuples).
*
* We also malloc the top-level array of tuple pointers separately, because
* we need to be able to enlarge it via realloc, and our trivial space
* allocator doesn't handle that effectively. (Too bad the FE/BE protocol
* doesn't tell us up front how many tuples will be returned.)
* All other subsidiary storage for a PGresult is kept in PGresult_data blocks
* of size PGRESULT_DATA_BLOCKSIZE. The overhead at the start of each block
* is just a link to the next one, if any. Free-space management info is
* kept in the owning PGresult.
* A query returning a small amount of data will thus require three malloc
* calls: one for the PGresult, one for the tuples pointer array, and one
* PGresult_data block.
*
* Only the most recently allocated PGresult_data block is a candidate to
* have more stuff added to it --- any extra space left over in older blocks
* is wasted. We could be smarter and search the whole chain, but the point
* here is to be simple and fast. Typical applications do not keep a PGresult
* around very long anyway, so some wasted space within one is not a problem.
*
* Tuning constants for the space allocator are:
* PGRESULT_DATA_BLOCKSIZE: size of a standard allocation block, in bytes
* PGRESULT_ALIGN_BOUNDARY: assumed alignment requirement for binary data
* PGRESULT_SEP_ALLOC_THRESHOLD: objects bigger than this are given separate
* blocks, instead of being crammed into a regular allocation block.
* Requirements for correct function are:
* PGRESULT_ALIGN_BOUNDARY must be a multiple of the alignment requirements
* of all machine data types. (Currently this is set from configure
* tests, so it should be OK automatically.)
* PGRESULT_SEP_ALLOC_THRESHOLD + PGRESULT_BLOCK_OVERHEAD <=
* PGRESULT_DATA_BLOCKSIZE
* pqResultAlloc assumes an object smaller than the threshold will fit
* in a new block.
* The amount of space wasted at the end of a block could be as much as
* PGRESULT_SEP_ALLOC_THRESHOLD, so it doesn't pay to make that too large.
* ----------------
*/
#define PGRESULT_DATA_BLOCKSIZE 2048
#define PGRESULT_ALIGN_BOUNDARY MAXIMUM_ALIGNOF /* from configure */
#define PGRESULT_BLOCK_OVERHEAD Max(sizeof(PGresult_data), PGRESULT_ALIGN_BOUNDARY)
#define PGRESULT_SEP_ALLOC_THRESHOLD (PGRESULT_DATA_BLOCKSIZE / 2)
/*
* PQmakeEmptyPGresult
* returns a newly allocated, initialized PGresult with given status.
* If conn is not NULL and status indicates an error, the conn's
* errorMessage is copied. Also, any PGEvents are copied from the conn.
*/
PGresult *
PQmakeEmptyPGresult(PGconn *conn, ExecStatusType status)
{
PGresult *result;
result = (PGresult *) malloc(sizeof(PGresult));
if (!result)
return NULL;
result->ntups = 0;
result->numAttributes = 0;
result->attDescs = NULL;
result->tuples = NULL;
result->tupArrSize = 0;
result->numParameters = 0;
result->paramDescs = NULL;
result->resultStatus = status;
result->cmdStatus[0] = '\0';
result->binary = 0;
result->events = NULL;
result->nEvents = 0;
result->errMsg = NULL;
result->errFields = NULL;
result->null_field[0] = '\0';
result->curBlock = NULL;
result->curOffset = 0;
result->spaceLeft = 0;
if (conn)
{
/* copy connection data we might need for operations on PGresult */
result->noticeHooks = conn->noticeHooks;
result->client_encoding = conn->client_encoding;
/* consider copying conn's errorMessage */
switch (status)
{
case PGRES_EMPTY_QUERY:
case PGRES_COMMAND_OK:
case PGRES_TUPLES_OK:
case PGRES_COPY_OUT:
case PGRES_COPY_IN:
/* non-error cases */
break;
default:
pqSetResultError(result, conn->errorMessage.data);
break;
}
/* copy events last; result must be valid if we need to PQclear */
if (conn->nEvents > 0)
{
result->events = dupEvents(conn->events, conn->nEvents);
if (!result->events)
{
PQclear(result);
return NULL;
}
result->nEvents = conn->nEvents;
}
}
else
{
/* defaults... */
result->noticeHooks.noticeRec = NULL;
result->noticeHooks.noticeRecArg = NULL;
result->noticeHooks.noticeProc = NULL;
result->noticeHooks.noticeProcArg = NULL;
result->client_encoding = PG_SQL_ASCII;
}
return result;
}
/*
* PQsetResultAttrs
*
* Set the attributes for a given result. This function fails if there are
* already attributes contained in the provided result. The call is
* ignored if numAttributes is is zero or attDescs is NULL. If the
* function fails, it returns zero. If the function succeeds, it
* returns a non-zero value.
*/
int
PQsetResultAttrs(PGresult *res, int numAttributes, PGresAttDesc *attDescs)
{
int i;
/* If attrs already exist, they cannot be overwritten. */
if (!res || res->numAttributes > 0)
return FALSE;
/* ignore no-op request */
if (numAttributes <= 0 || !attDescs)
return TRUE;
res->attDescs = (PGresAttDesc *)
PQresultAlloc(res, numAttributes * sizeof(PGresAttDesc));
if (!res->attDescs)
return FALSE;
res->numAttributes = numAttributes;
memcpy(res->attDescs, attDescs, numAttributes * sizeof(PGresAttDesc));
/* deep-copy the attribute names, and determine format */
res->binary = 1;
for (i = 0; i < res->numAttributes; i++)
{
if (res->attDescs[i].name)
res->attDescs[i].name = pqResultStrdup(res, res->attDescs[i].name);
else
res->attDescs[i].name = res->null_field;
if (!res->attDescs[i].name)
return FALSE;
if (res->attDescs[i].format == 0)
res->binary = 0;
}
return TRUE;
}
/*
* PQcopyResult
*
* Returns a deep copy of the provided 'src' PGresult, which cannot be NULL.
* The 'flags' argument controls which portions of the result will or will
* NOT be copied. The created result is always put into the
* PGRES_TUPLES_OK status. The source result error message is not copied,
* although cmdStatus is.
*
* To set custom attributes, use PQsetResultAttrs. That function requires
* that there are no attrs contained in the result, so to use that
* function you cannot use the PG_COPYRES_ATTRS or PG_COPYRES_TUPLES
* options with this function.
*
* Options:
* PG_COPYRES_ATTRS - Copy the source result's attributes
*
* PG_COPYRES_TUPLES - Copy the source result's tuples. This implies
* copying the attrs, seeeing how the attrs are needed by the tuples.
*
* PG_COPYRES_EVENTS - Copy the source result's events.
*
* PG_COPYRES_NOTICEHOOKS - Copy the source result's notice hooks.
*/
PGresult *
PQcopyResult(const PGresult *src, int flags)
{
PGresult *dest;
int i;
if (!src)
return NULL;
dest = PQmakeEmptyPGresult(NULL, PGRES_TUPLES_OK);
if (!dest)
return NULL;
/* Always copy these over. Is cmdStatus really useful here? */
dest->client_encoding = src->client_encoding;
strcpy(dest->cmdStatus, src->cmdStatus);
/* Wants attrs? */
if (flags & (PG_COPYRES_ATTRS | PG_COPYRES_TUPLES))
{
if (!PQsetResultAttrs(dest, src->numAttributes, src->attDescs))
{
PQclear(dest);
return NULL;
}
}
/* Wants to copy tuples? */
if (flags & PG_COPYRES_TUPLES)
{
int tup,
field;
for (tup = 0; tup < src->ntups; tup++)
{
for (field = 0; field < src->numAttributes; field++)
{
if (!PQsetvalue(dest, tup, field,
src->tuples[tup][field].value,
src->tuples[tup][field].len))
{
PQclear(dest);
return NULL;
}
}
}
}
/* Wants to copy notice hooks? */
if (flags & PG_COPYRES_NOTICEHOOKS)
dest->noticeHooks = src->noticeHooks;
/* Wants to copy PGEvents? */
if ((flags & PG_COPYRES_EVENTS) && src->nEvents > 0)
{
dest->events = dupEvents(src->events, src->nEvents);
if (!dest->events)
{
PQclear(dest);
return NULL;
}
dest->nEvents = src->nEvents;
}
/* Okay, trigger PGEVT_RESULTCOPY event */
for (i = 0; i < dest->nEvents; i++)
{
if (src->events[i].resultInitialized)
{
PGEventResultCopy evt;
evt.src = src;
evt.dest = dest;
if (!dest->events[i].proc(PGEVT_RESULTCOPY, &evt,
dest->events[i].passThrough))
{
PQclear(dest);
return NULL;
}
dest->events[i].resultInitialized = TRUE;
}
}
return dest;
}
/*
* Copy an array of PGEvents (with no extra space for more).
* Does not duplicate the event instance data, sets this to NULL.
* Also, the resultInitialized flags are all cleared.
*/
static PGEvent *
dupEvents(PGEvent *events, int count)
{
PGEvent *newEvents;
int i;
if (!events || count <= 0)
return NULL;
newEvents = (PGEvent *) malloc(count * sizeof(PGEvent));
if (!newEvents)
return NULL;
for (i = 0; i < count; i++)
{
newEvents[i].proc = events[i].proc;
newEvents[i].passThrough = events[i].passThrough;
newEvents[i].data = NULL;
newEvents[i].resultInitialized = FALSE;
newEvents[i].name = strdup(events[i].name);
if (!newEvents[i].name)
{
while (--i >= 0)
free(newEvents[i].name);
free(newEvents);
return NULL;
}
}
return newEvents;
}
/*
* Sets the value for a tuple field. The tup_num must be less than or
* equal to PQntuples(res). If it is equal, a new tuple is created and
* added to the result.
* Returns a non-zero value for success and zero for failure.
*/
int
PQsetvalue(PGresult *res, int tup_num, int field_num, char *value, int len)
{
PGresAttValue *attval;
if (!check_field_number(res, field_num))
return FALSE;
/* Invalid tup_num, must be <= ntups */
if (tup_num < 0 || tup_num > res->ntups)
return FALSE;
/* need to grow the tuple table? */
if (res->ntups >= res->tupArrSize)
{
int n = res->tupArrSize ? res->tupArrSize * 2 : 128;
PGresAttValue **tups;
if (res->tuples)
tups = (PGresAttValue **) realloc(res->tuples, n * sizeof(PGresAttValue *));
else
tups = (PGresAttValue **) malloc(n * sizeof(PGresAttValue *));
if (!tups)
return FALSE;
memset(tups + res->tupArrSize, 0,
(n - res->tupArrSize) * sizeof(PGresAttValue *));
res->tuples = tups;
res->tupArrSize = n;
}
/* need to allocate a new tuple? */
if (tup_num == res->ntups && !res->tuples[tup_num])
{
PGresAttValue *tup;
int i;
tup = (PGresAttValue *)
pqResultAlloc(res, res->numAttributes * sizeof(PGresAttValue),
TRUE);
if (!tup)
return FALSE;
/* initialize each column to NULL */
for (i = 0; i < res->numAttributes; i++)
{
tup[i].len = NULL_LEN;
tup[i].value = res->null_field;
}
res->tuples[tup_num] = tup;
res->ntups++;
}
attval = &res->tuples[tup_num][field_num];
/* treat either NULL_LEN or NULL value pointer as a NULL field */
if (len == NULL_LEN || value == NULL)
{
attval->len = NULL_LEN;
attval->value = res->null_field;
}
else if (len <= 0)
{
attval->len = 0;
attval->value = res->null_field;
}
else
{
attval->value = (char *) pqResultAlloc(res, len + 1, TRUE);
if (!attval->value)
return FALSE;
attval->len = len;
memcpy(attval->value, value, len);
attval->value[len] = '\0';
}
return TRUE;
}
/*
* pqResultAlloc - exported routine to allocate local storage in a PGresult.
*
* We force all such allocations to be maxaligned, since we don't know
* whether the value might be binary.
*/
void *
PQresultAlloc(PGresult *res, size_t nBytes)
{
return pqResultAlloc(res, nBytes, TRUE);
}
/*
* pqResultAlloc -
* Allocate subsidiary storage for a PGresult.
*
* nBytes is the amount of space needed for the object.
* If isBinary is true, we assume that we need to align the object on
* a machine allocation boundary.
* If isBinary is false, we assume the object is a char string and can
* be allocated on any byte boundary.
*/
void *
pqResultAlloc(PGresult *res, size_t nBytes, bool isBinary)
{
char *space;
PGresult_data *block;
if (!res)
return NULL;
if (nBytes <= 0)
return res->null_field;
/*
* If alignment is needed, round up the current position to an alignment
* boundary.
*/
if (isBinary)
{
int offset = res->curOffset % PGRESULT_ALIGN_BOUNDARY;
if (offset)
{
res->curOffset += PGRESULT_ALIGN_BOUNDARY - offset;
res->spaceLeft -= PGRESULT_ALIGN_BOUNDARY - offset;
}
}
/* If there's enough space in the current block, no problem. */
if (nBytes <= (size_t) res->spaceLeft)
{
space = res->curBlock->space + res->curOffset;
res->curOffset += nBytes;
res->spaceLeft -= nBytes;
return space;
}
/*
* If the requested object is very large, give it its own block; this
* avoids wasting what might be most of the current block to start a new
* block. (We'd have to special-case requests bigger than the block size
* anyway.) The object is always given binary alignment in this case.
*/
if (nBytes >= PGRESULT_SEP_ALLOC_THRESHOLD)
{
block = (PGresult_data *) malloc(nBytes + PGRESULT_BLOCK_OVERHEAD);
if (!block)
return NULL;
space = block->space + PGRESULT_BLOCK_OVERHEAD;
if (res->curBlock)
{
/*
* Tuck special block below the active block, so that we don't
* have to waste the free space in the active block.
*/
block->next = res->curBlock->next;
res->curBlock->next = block;
}
else
{
/* Must set up the new block as the first active block. */
block->next = NULL;
res->curBlock = block;
res->spaceLeft = 0; /* be sure it's marked full */
}
return space;
}
/* Otherwise, start a new block. */
block = (PGresult_data *) malloc(PGRESULT_DATA_BLOCKSIZE);
if (!block)
return NULL;
block->next = res->curBlock;
res->curBlock = block;
if (isBinary)
{
/* object needs full alignment */
res->curOffset = PGRESULT_BLOCK_OVERHEAD;
res->spaceLeft = PGRESULT_DATA_BLOCKSIZE - PGRESULT_BLOCK_OVERHEAD;
}
else
{
/* we can cram it right after the overhead pointer */
res->curOffset = sizeof(PGresult_data);
res->spaceLeft = PGRESULT_DATA_BLOCKSIZE - sizeof(PGresult_data);
}
space = block->space + res->curOffset;
res->curOffset += nBytes;
res->spaceLeft -= nBytes;
return space;
}
/*
* pqResultStrdup -
* Like strdup, but the space is subsidiary PGresult space.
*/
char *
pqResultStrdup(PGresult *res, const char *str)
{
char *space = (char *) pqResultAlloc(res, strlen(str) + 1, FALSE);
if (space)
strcpy(space, str);
return space;
}
/*
* pqSetResultError -
* assign a new error message to a PGresult
*/
void
pqSetResultError(PGresult *res, const char *msg)
{
if (!res)
return;
if (msg && *msg)
res->errMsg = pqResultStrdup(res, msg);
else
res->errMsg = NULL;
}
/*
* pqCatenateResultError -
* concatenate a new error message to the one already in a PGresult
*/
void
pqCatenateResultError(PGresult *res, const char *msg)
{
PQExpBufferData errorBuf;
if (!res || !msg)
return;
initPQExpBuffer(&errorBuf);
if (res->errMsg)
appendPQExpBufferStr(&errorBuf, res->errMsg);
appendPQExpBufferStr(&errorBuf, msg);
pqSetResultError(res, errorBuf.data);
termPQExpBuffer(&errorBuf);
}
/*
* PQclear -
* free's the memory associated with a PGresult
*/
void
PQclear(PGresult *res)
{
PGresult_data *block;
int i;
if (!res)
return;
for (i = 0; i < res->nEvents; i++)
{
/* only send DESTROY to successfully-initialized event procs */
if (res->events[i].resultInitialized)
{
PGEventResultDestroy evt;
evt.result = res;
(void) res->events[i].proc(PGEVT_RESULTDESTROY, &evt,
res->events[i].passThrough);
}
free(res->events[i].name);
}
if (res->events)
free(res->events);
/* Free all the subsidiary blocks */
while ((block = res->curBlock) != NULL)
{
res->curBlock = block->next;
free(block);
}
/* Free the top-level tuple pointer array */
if (res->tuples)
free(res->tuples);
/* zero out the pointer fields to catch programming errors */
res->attDescs = NULL;
res->tuples = NULL;
res->paramDescs = NULL;
res->errFields = NULL;
res->events = NULL;
res->nEvents = 0;
/* res->curBlock was zeroed out earlier */
/* Free the PGresult structure itself */
free(res);
}
/*
* Handy subroutine to deallocate any partially constructed async result.
*/
void
pqClearAsyncResult(PGconn *conn)
{
if (conn->result)
PQclear(conn->result);
conn->result = NULL;
conn->curTuple = NULL;
}
/*
* This subroutine deletes any existing async result, sets conn->result
* to a PGresult with status PGRES_FATAL_ERROR, and stores the current
* contents of conn->errorMessage into that result. It differs from a
* plain call on PQmakeEmptyPGresult() in that if there is already an
* async result with status PGRES_FATAL_ERROR, the current error message
* is APPENDED to the old error message instead of replacing it. This
* behavior lets us report multiple error conditions properly, if necessary.
* (An example where this is needed is when the backend sends an 'E' message
* and immediately closes the connection --- we want to report both the
* backend error and the connection closure error.)
*/
void
pqSaveErrorResult(PGconn *conn)
{
/*
* If no old async result, just let PQmakeEmptyPGresult make one. Likewise
* if old result is not an error message.
*/
if (conn->result == NULL ||
conn->result->resultStatus != PGRES_FATAL_ERROR ||
conn->result->errMsg == NULL)
{
pqClearAsyncResult(conn);
conn->result = PQmakeEmptyPGresult(conn, PGRES_FATAL_ERROR);
}
else
{
/* Else, concatenate error message to existing async result. */
pqCatenateResultError(conn->result, conn->errorMessage.data);
}
}
/*
* This subroutine prepares an async result object for return to the caller.
* If there is not already an async result object, build an error object
* using whatever is in conn->errorMessage. In any case, clear the async
* result storage and make sure PQerrorMessage will agree with the result's
* error string.
*/
PGresult *
pqPrepareAsyncResult(PGconn *conn)
{
PGresult *res;
/*
* 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 different
* if we have concatenated messages.
*/
resetPQExpBuffer(&conn->errorMessage);
appendPQExpBufferStr(&conn->errorMessage,
PQresultErrorMessage(res));
}
return res;
}
/*
* pqInternalNotice - produce an internally-generated notice message
*
* A format string and optional arguments can be passed. Note that we do
* libpq_gettext() here, so callers need not.
*
* The supplied text is taken as primary message (ie., it should not include
* a trailing newline, and should not be more than one line).
*/
void
pqInternalNotice(const PGNoticeHooks *hooks, const char *fmt,...)
{
char msgBuf[1024];
va_list args;
PGresult *res;
if (hooks->noticeRec == NULL)
return; /* nobody home to receive notice? */
/* Format the message */
va_start(args, fmt);
vsnprintf(msgBuf, sizeof(msgBuf), libpq_gettext(fmt), args);
va_end(args);
msgBuf[sizeof(msgBuf) - 1] = '\0'; /* make real sure it's terminated */
/* Make a PGresult to pass to the notice receiver */
res = PQmakeEmptyPGresult(NULL, PGRES_NONFATAL_ERROR);
if (!res)
return;
res->noticeHooks = *hooks;
/*
* Set up fields of notice.
*/
pqSaveMessageField(res, PG_DIAG_MESSAGE_PRIMARY, msgBuf);
pqSaveMessageField(res, PG_DIAG_SEVERITY, libpq_gettext("NOTICE"));
/* XXX should provide a SQLSTATE too? */
/*
* Result text is always just the primary message + newline. If we can't
* allocate it, don't bother invoking the receiver.
*/
res->errMsg = (char *) pqResultAlloc(res, strlen(msgBuf) + 2, FALSE);
if (res->errMsg)
{
sprintf(res->errMsg, "%s\n", msgBuf);
/*
* Pass to receiver, then free it.
*/
(*res->noticeHooks.noticeRec) (res->noticeHooks.noticeRecArg, res);
}
PQclear(res);
}
/*
* pqAddTuple
* add a row pointer to the PGresult structure, growing it if necessary
* Returns TRUE if OK, FALSE if not enough memory to add the row
*/
int
pqAddTuple(PGresult *res, PGresAttValue *tup)
{
if (res->ntups >= res->tupArrSize)
{
/*
* Try to grow the array.
*
* We can use realloc because shallow copying of the structure is
* okay. Note that the first time through, res->tuples is NULL. While
* ANSI says that realloc() should act like malloc() in that case,
* some old C libraries (like SunOS 4.1.x) coredump instead. On
* failure realloc is supposed to return NULL without damaging the
* existing allocation. Note that the positions beyond res->ntups are
* garbage, not necessarily NULL.
*/
int newSize = (res->tupArrSize > 0) ? res->tupArrSize * 2 : 128;
PGresAttValue **newTuples;
if (res->tuples == NULL)
newTuples = (PGresAttValue **)
malloc(newSize * sizeof(PGresAttValue *));
else
newTuples = (PGresAttValue **)
realloc(res->tuples, newSize * sizeof(PGresAttValue *));
if (!newTuples)
return FALSE; /* malloc or realloc failed */
res->tupArrSize = newSize;
res->tuples = newTuples;
}
res->tuples[res->ntups] = tup;
res->ntups++;
return TRUE;
}
/*
* pqSaveMessageField - save one field of an error or notice message
*/
void
pqSaveMessageField(PGresult *res, char code, const char *value)
{
PGMessageField *pfield;
pfield = (PGMessageField *)
pqResultAlloc(res,
sizeof(PGMessageField) + strlen(value),
TRUE);
if (!pfield)
return; /* out of memory? */
pfield->code = code;
strcpy(pfield->contents, value);
pfield->next = res->errFields;
res->errFields = pfield;
}
/*
* pqSaveParameterStatus - remember parameter status sent by backend
*/
void
pqSaveParameterStatus(PGconn *conn, const char *name, const char *value)
{
pgParameterStatus *pstatus;
pgParameterStatus *prev;
if (conn->Pfdebug)
fprintf(conn->Pfdebug, "pqSaveParameterStatus: '%s' = '%s'\n",
name, value);
/*
* Forget any old information about the parameter
*/
for (pstatus = conn->pstatus, prev = NULL;
pstatus != NULL;
prev = pstatus, pstatus = pstatus->next)
{
if (strcmp(pstatus->name, name) == 0)
{
if (prev)
prev->next = pstatus->next;
else
conn->pstatus = pstatus->next;
free(pstatus); /* frees name and value strings too */
break;
}
}
/*
* Store new info as a single malloc block
*/
pstatus = (pgParameterStatus *) malloc(sizeof(pgParameterStatus) +
strlen(name) +strlen(value) + 2);
if (pstatus)
{
char *ptr;
ptr = ((char *) pstatus) + sizeof(pgParameterStatus);
pstatus->name = ptr;
strcpy(ptr, name);
ptr += strlen(name) + 1;
pstatus->value = ptr;
strcpy(ptr, value);
pstatus->next = conn->pstatus;
conn->pstatus = pstatus;
}
/*
* Special hacks: remember client_encoding and
* standard_conforming_strings, and convert server version to a numeric
* form. We keep the first two of these in static variables as well, so
* that PQescapeString and PQescapeBytea can behave somewhat sanely (at
* least in single-connection-using programs).
*/
if (strcmp(name, "client_encoding") == 0)
{
conn->client_encoding = pg_char_to_encoding(value);
/* if we don't recognize the encoding name, fall back to SQL_ASCII */
if (conn->client_encoding < 0)
conn->client_encoding = PG_SQL_ASCII;
static_client_encoding = conn->client_encoding;
}
else if (strcmp(name, "standard_conforming_strings") == 0)
{
conn->std_strings = (strcmp(value, "on") == 0);
static_std_strings = conn->std_strings;
}
else if (strcmp(name, "server_version") == 0)
{
int cnt;
int vmaj,
vmin,
vrev;
cnt = sscanf(value, "%d.%d.%d", &vmaj, &vmin, &vrev);
if (cnt < 2)
conn->sversion = 0; /* unknown */
else
{
if (cnt == 2)
vrev = 0;
conn->sversion = (100 * vmaj + vmin) * 100 + vrev;
}
}
}
/*
* PQsendQuery
* Submit a query, but don't wait for it to finish
*
* Returns: 1 if successfully submitted
* 0 if error (conn->errorMessage is set)
*/
int
PQsendQuery(PGconn *conn, const char *query)
{
if (!PQsendQueryStart(conn))
return 0;
if (!query)
{
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("command string is a null pointer\n"));
return 0;
}
/* construct the outgoing Query message */
if (pqPutMsgStart('Q', false, conn) < 0 ||
pqPuts(query, conn) < 0 ||
pqPutMsgEnd(conn) < 0)
{
pqHandleSendFailure(conn);
return 0;
}
/* remember we are using simple query protocol */
conn->queryclass = PGQUERY_SIMPLE;
/* and remember the query text too, if possible */
/* if insufficient memory, last_query just winds up NULL */
if (conn->last_query)
free(conn->last_query);
conn->last_query = strdup(query);
/*
* Give the data a push. In nonblock mode, don't complain if we're unable
* to send it all; PQgetResult() will do any additional flushing needed.
*/
if (pqFlush(conn) < 0)
{
pqHandleSendFailure(conn);
return 0;
}
/* OK, it's launched! */
conn->asyncStatus = PGASYNC_BUSY;
return 1;
}
/*
* PQsendQueryParams
* Like PQsendQuery, but use protocol 3.0 so we can pass parameters
*/
int
PQsendQueryParams(PGconn *conn,
const char *command,
int nParams,
const Oid *paramTypes,
const char *const * paramValues,
const int *paramLengths,
const int *paramFormats,
int resultFormat)
{
if (!PQsendQueryStart(conn))
return 0;
if (!command)
{
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("command string is a null pointer\n"));
return 0;
}
return PQsendQueryGuts(conn,
command,
"", /* use unnamed statement */
nParams,
paramTypes,
paramValues,
paramLengths,
paramFormats,
resultFormat);
}
/*
* PQsendPrepare
* Submit a Parse message, but don't wait for it to finish
*
* Returns: 1 if successfully submitted
* 0 if error (conn->errorMessage is set)
*/
int
PQsendPrepare(PGconn *conn,
const char *stmtName, const char *query,
int nParams, const Oid *paramTypes)
{
if (!PQsendQueryStart(conn))
return 0;
if (!stmtName)
{
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("statement name is a null pointer\n"));
return 0;
}
if (!query)
{
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("command string is a null pointer\n"));
return 0;
}
/* This isn't gonna work on a 2.0 server */
if (PG_PROTOCOL_MAJOR(conn->pversion) < 3)
{
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("function requires at least protocol version 3.0\n"));
return 0;
}
/* construct the Parse message */
if (pqPutMsgStart('P', false, conn) < 0 ||
pqPuts(stmtName, conn) < 0 ||
pqPuts(query, conn) < 0)
goto sendFailed;
if (nParams > 0 && paramTypes)
{
int i;
if (pqPutInt(nParams, 2, conn) < 0)
goto sendFailed;
for (i = 0; i < nParams; i++)
{
if (pqPutInt(paramTypes[i], 4, conn) < 0)
goto sendFailed;
}
}
else
{
if (pqPutInt(0, 2, conn) < 0)
goto sendFailed;
}
if (pqPutMsgEnd(conn) < 0)
goto sendFailed;
/* construct the Sync message */
if (pqPutMsgStart('S', false, conn) < 0 ||
pqPutMsgEnd(conn) < 0)
goto sendFailed;
/* remember we are doing just a Parse */
conn->queryclass = PGQUERY_PREPARE;
/* and remember the query text too, if possible */
/* if insufficient memory, last_query just winds up NULL */
if (conn->last_query)
free(conn->last_query);
conn->last_query = strdup(query);
/*
* Give the data a push. In nonblock mode, don't complain if we're unable
* to send it all; PQgetResult() will do any additional flushing needed.
*/
if (pqFlush(conn) < 0)
goto sendFailed;
/* OK, it's launched! */
conn->asyncStatus = PGASYNC_BUSY;
return 1;
sendFailed:
pqHandleSendFailure(conn);
return 0;
}
/*
* PQsendQueryPrepared
* Like PQsendQuery, but execute a previously prepared statement,
* using protocol 3.0 so we can pass parameters
*/
int
PQsendQueryPrepared(PGconn *conn,
const char *stmtName,
int nParams,
const char *const * paramValues,
const int *paramLengths,
const int *paramFormats,
int resultFormat)
{
if (!PQsendQueryStart(conn))
return 0;
if (!stmtName)
{
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("statement name is a null pointer\n"));
return 0;
}
return PQsendQueryGuts(conn,
NULL, /* no command to parse */
stmtName,
nParams,
NULL, /* no param types */
paramValues,
paramLengths,
paramFormats,
resultFormat);
}
/*
* Common startup code for PQsendQuery and sibling routines
*/
static bool
PQsendQueryStart(PGconn *conn)
{
if (!conn)
return false;
/* clear the error string */
resetPQExpBuffer(&conn->errorMessage);
/* Don't try to send if we know there's no live connection. */
if (conn->status != CONNECTION_OK)
{
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("no connection to the server\n"));
return false;
}
/* Can't send while already busy, either. */
if (conn->asyncStatus != PGASYNC_IDLE)
{
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("another command is already in progress\n"));
return false;
}
/* initialize async result-accumulation state */
conn->result = NULL;
conn->curTuple = NULL;
/* ready to send command message */
return true;
}
/*
* PQsendQueryGuts
* Common code for protocol-3.0 query sending
* PQsendQueryStart should be done already
*
* command may be NULL to indicate we use an already-prepared statement
*/
static int
PQsendQueryGuts(PGconn *conn,
const char *command,
const char *stmtName,
int nParams,
const Oid *paramTypes,
const char *const * paramValues,
const int *paramLengths,
const int *paramFormats,
int resultFormat)
{
int i;
/* This isn't gonna work on a 2.0 server */
if (PG_PROTOCOL_MAJOR(conn->pversion) < 3)
{
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("function requires at least protocol version 3.0\n"));
return 0;
}
/*
* We will send Parse (if needed), Bind, Describe Portal, Execute, Sync,
* using specified statement name and the unnamed portal.
*/
if (command)
{
/* construct the Parse message */
if (pqPutMsgStart('P', false, conn) < 0 ||
pqPuts(stmtName, conn) < 0 ||
pqPuts(command, conn) < 0)
goto sendFailed;
if (nParams > 0 && paramTypes)
{
if (pqPutInt(nParams, 2, conn) < 0)
goto sendFailed;
for (i = 0; i < nParams; i++)
{
if (pqPutInt(paramTypes[i], 4, conn) < 0)
goto sendFailed;
}
}
else
{
if (pqPutInt(0, 2, conn) < 0)
goto sendFailed;
}
if (pqPutMsgEnd(conn) < 0)
goto sendFailed;
}
/* Construct the Bind message */
if (pqPutMsgStart('B', false, conn) < 0 ||
pqPuts("", conn) < 0 ||
pqPuts(stmtName, conn) < 0)
goto sendFailed;
/* Send parameter formats */
if (nParams > 0 && paramFormats)
{
if (pqPutInt(nParams, 2, conn) < 0)
goto sendFailed;
for (i = 0; i < nParams; i++)
{
if (pqPutInt(paramFormats[i], 2, conn) < 0)
goto sendFailed;
}
}
else
{
if (pqPutInt(0, 2, conn) < 0)
goto sendFailed;
}
if (pqPutInt(nParams, 2, conn) < 0)
goto sendFailed;
/* Send parameters */
for (i = 0; i < nParams; i++)
{
if (paramValues && paramValues[i])
{
int nbytes;
if (paramFormats && paramFormats[i] != 0)
{
/* binary parameter */
if (paramLengths)
nbytes = paramLengths[i];
else
{
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("length must be given for binary parameter\n"));
goto sendFailed;
}
}
else
{
/* text parameter, do not use paramLengths */
nbytes = strlen(paramValues[i]);
}
if (pqPutInt(nbytes, 4, conn) < 0 ||
pqPutnchar(paramValues[i], nbytes, conn) < 0)
goto sendFailed;
}
else
{
/* take the param as NULL */
if (pqPutInt(-1, 4, conn) < 0)
goto sendFailed;
}
}
if (pqPutInt(1, 2, conn) < 0 ||
pqPutInt(resultFormat, 2, conn))
goto sendFailed;
if (pqPutMsgEnd(conn) < 0)
goto sendFailed;
/* construct the Describe Portal message */
if (pqPutMsgStart('D', false, conn) < 0 ||
pqPutc('P', conn) < 0 ||
pqPuts("", conn) < 0 ||
pqPutMsgEnd(conn) < 0)
goto sendFailed;
/* construct the Execute message */
if (pqPutMsgStart('E', false, conn) < 0 ||
pqPuts("", conn) < 0 ||
pqPutInt(0, 4, conn) < 0 ||
pqPutMsgEnd(conn) < 0)
goto sendFailed;
/* construct the Sync message */
if (pqPutMsgStart('S', false, conn) < 0 ||
pqPutMsgEnd(conn) < 0)
goto sendFailed;
/* remember we are using extended query protocol */
conn->queryclass = PGQUERY_EXTENDED;
/* and remember the query text too, if possible */
/* if insufficient memory, last_query just winds up NULL */
if (conn->last_query)
free(conn->last_query);
if (command)
conn->last_query = strdup(command);
else
conn->last_query = NULL;
/*
* Give the data a push. In nonblock mode, don't complain if we're unable
* to send it all; PQgetResult() will do any additional flushing needed.
*/
if (pqFlush(conn) < 0)
goto sendFailed;
/* OK, it's launched! */
conn->asyncStatus = PGASYNC_BUSY;
return 1;
sendFailed:
pqHandleSendFailure(conn);
return 0;
}
/*
* pqHandleSendFailure: try to clean up after failure to send command.
*
* Primarily, what we want to accomplish here is to process an async
* NOTICE message that the backend might have sent just before it died.
*
* NOTE: this routine should only be called in PGASYNC_IDLE state.
*/
void
pqHandleSendFailure(PGconn *conn)
{
/*
* Accept any available input data, ignoring errors. Note that if
* pqReadData decides the backend has closed the channel, it will close
* our side of the socket --- that's just what we want here.
*/
while (pqReadData(conn) > 0)
/* loop until no more data readable */ ;
/*
* Parse any available input messages. Since we are in PGASYNC_IDLE
* state, only NOTICE and NOTIFY messages will be eaten.
*/
parseInput(conn);
}
/*
* Consume any available input from the backend
* 0 return: some kind of trouble
* 1 return: no problem
*/
int
PQconsumeInput(PGconn *conn)
{
if (!conn)
return 0;
/*
* for non-blocking connections try to flush the send-queue, otherwise we
* may never get a response for something that may not have already been
* sent because it's in our write buffer!
*/
if (pqIsnonblocking(conn))
{
if (pqFlush(conn) < 0)
return 0;
}
/*
* Load more data, if available. We do this no matter what state we are
* in, since we are probably getting called because the application wants
* to get rid of a read-select condition. Note that we will NOT block
* waiting for more input.
*/
if (pqReadData(conn) < 0)
return 0;
/* Parsing of the data waits till later. */
return 1;
}
/*
* parseInput: if appropriate, parse input data from backend
* until input is exhausted or a stopping state is reached.
* Note that this function will NOT attempt to read more data from the backend.
*/
static void
parseInput(PGconn *conn)
{
if (PG_PROTOCOL_MAJOR(conn->pversion) >= 3)
pqParseInput3(conn);
else
pqParseInput2(conn);
}
/*
* 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 no
* query work remains or an error has occurred (e.g. out of
* memory).
*/
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)
{
int flushResult;
/*
* If data remains unsent, send it. Else we might be waiting for the
* result of a command the backend hasn't even got yet.
*/
while ((flushResult = pqFlush(conn)) > 0)
{
if (pqWait(FALSE, TRUE, conn))
{
flushResult = -1;
break;
}
}
/* Wait for some more data, and load it. */
if (flushResult ||
pqWait(TRUE, FALSE, conn) ||
pqReadData(conn) < 0)
{
/*
* conn->errorMessage has been set by pqWait or pqReadData. We
* want to append it to any already-received error message.
*/
pqSaveErrorResult(conn);
conn->asyncStatus = PGASYNC_IDLE;
return pqPrepareAsyncResult(conn);
}
/* Parse it. */
parseInput(conn);
}
/* Return the appropriate thing. */
switch (conn->asyncStatus)
{
case PGASYNC_IDLE:
res = NULL; /* query is complete */
break;
case PGASYNC_READY:
res = pqPrepareAsyncResult(conn);
/* Set the state back to BUSY, allowing parsing to proceed. */
conn->asyncStatus = PGASYNC_BUSY;
break;
case PGASYNC_COPY_IN:
if (conn->result && conn->result->resultStatus == PGRES_COPY_IN)
res = pqPrepareAsyncResult(conn);
else
res = PQmakeEmptyPGresult(conn, PGRES_COPY_IN);
break;
case PGASYNC_COPY_OUT:
if (conn->result && conn->result->resultStatus == PGRES_COPY_OUT)
res = pqPrepareAsyncResult(conn);
else
res = PQmakeEmptyPGresult(conn, PGRES_COPY_OUT);
break;
default:
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("unexpected asyncStatus: %d\n"),
(int) conn->asyncStatus);
res = PQmakeEmptyPGresult(conn, PGRES_FATAL_ERROR);
break;
}
if (res)
{
int i;
for (i = 0; i < res->nEvents; i++)
{
PGEventResultCreate evt;
evt.conn = conn;
evt.result = res;
if (!res->events[i].proc(PGEVT_RESULTCREATE, &evt,
res->events[i].passThrough))
{
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("PGEventProc \"%s\" failed during PGEVT_RESULTCREATE event\n"),
res->events[i].name);
pqSetResultError(res, conn->errorMessage.data);
res->resultStatus = PGRES_FATAL_ERROR;
break;
}
res->events[i].resultInitialized = TRUE;
}
}
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)
{
if (!PQexecStart(conn))
return NULL;
if (!PQsendQuery(conn, query))
return NULL;
return PQexecFinish(conn);
}
/*
* PQexecParams
* Like PQexec, but use protocol 3.0 so we can pass parameters
*/
PGresult *
PQexecParams(PGconn *conn,
const char *command,
int nParams,
const Oid *paramTypes,
const char *const * paramValues,
const int *paramLengths,
const int *paramFormats,
int resultFormat)
{
if (!PQexecStart(conn))
return NULL;
if (!PQsendQueryParams(conn, command,
nParams, paramTypes, paramValues, paramLengths,
paramFormats, resultFormat))
return NULL;
return PQexecFinish(conn);
}
/*
* PQprepare
* Creates a prepared statement by issuing a v3.0 parse message.
*
* 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 *
PQprepare(PGconn *conn,
const char *stmtName, const char *query,
int nParams, const Oid *paramTypes)
{
if (!PQexecStart(conn))
return NULL;
if (!PQsendPrepare(conn, stmtName, query, nParams, paramTypes))
return NULL;
return PQexecFinish(conn);
}
/*
* PQexecPrepared
* Like PQexec, but execute a previously prepared statement,
* using protocol 3.0 so we can pass parameters
*/
PGresult *
PQexecPrepared(PGconn *conn,
const char *stmtName,
int nParams,
const char *const * paramValues,
const int *paramLengths,
const int *paramFormats,
int resultFormat)
{
if (!PQexecStart(conn))
return NULL;
if (!PQsendQueryPrepared(conn, stmtName,
nParams, paramValues, paramLengths,
paramFormats, resultFormat))
return NULL;
return PQexecFinish(conn);
}
/*
* Common code for PQexec and sibling routines: prepare to send command
*/
static bool
PQexecStart(PGconn *conn)
{
PGresult *result;
if (!conn)
return false;
/*
* 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)
{
ExecStatusType resultStatus = result->resultStatus;
PQclear(result); /* only need its status */
if (resultStatus == PGRES_COPY_IN)
{
if (PG_PROTOCOL_MAJOR(conn->pversion) >= 3)
{
/* In protocol 3, we can get out of a COPY IN state */
if (PQputCopyEnd(conn,
libpq_gettext("COPY terminated by new PQexec")) < 0)
return false;
/* keep waiting to swallow the copy's failure message */
}
else
{
/* In older protocols we have to punt */
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("COPY IN state must be terminated first\n"));
return false;
}
}
else if (resultStatus == PGRES_COPY_OUT)
{
if (PG_PROTOCOL_MAJOR(conn->pversion) >= 3)
{
/*
* In protocol 3, we can get out of a COPY OUT state: we just
* switch back to BUSY and allow the remaining COPY data to be
* dropped on the floor.
*/
conn->asyncStatus = PGASYNC_BUSY;
/* keep waiting to swallow the copy's completion message */
}
else
{
/* In older protocols we have to punt */
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("COPY OUT state must be terminated first\n"));
return false;
}
}
/* check for loss of connection, too */
if (conn->status == CONNECTION_BAD)
return false;
}
/* OK to send a command */
return true;
}
/*
* Common code for PQexec and sibling routines: wait for command result
*/
static PGresult *
PQexecFinish(PGconn *conn)
{
PGresult *result;
PGresult *lastResult;
/*
* For backwards compatibility, return the last result if there are more
* than one --- but merge error messages if we get more than one error
* result.
*
* We have to stop if we see copy in/out, however. We will resume parsing
* after application performs the data transfer.
*
* Also stop if the connection is lost (else we'll loop infinitely).
*/
lastResult = NULL;
while ((result = PQgetResult(conn)) != NULL)
{
if (lastResult)
{
if (lastResult->resultStatus == PGRES_FATAL_ERROR &&
result->resultStatus == PGRES_FATAL_ERROR)
{
pqCatenateResultError(lastResult, result->errMsg);
PQclear(result);
result = lastResult;
/*
* Make sure PQerrorMessage agrees with concatenated result
*/
resetPQExpBuffer(&conn->errorMessage);
appendPQExpBufferStr(&conn->errorMessage, result->errMsg);
}
else
PQclear(lastResult);
}
lastResult = result;
if (result->resultStatus == PGRES_COPY_IN ||
result->resultStatus == PGRES_COPY_OUT ||
conn->status == CONNECTION_BAD)
break;
}
return lastResult;
}
/*
* PQdescribePrepared
* Obtain information about a previously prepared statement
*
* 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). On success, the PGresult contains status
* PGRES_COMMAND_OK, and its parameter and column-heading fields describe
* the statement's inputs and outputs respectively.
* The user is responsible for freeing the PGresult via PQclear()
* when done with it.
*/
PGresult *
PQdescribePrepared(PGconn *conn, const char *stmt)
{
if (!PQexecStart(conn))
return NULL;
if (!PQsendDescribe(conn, 'S', stmt))
return NULL;
return PQexecFinish(conn);
}
/*
* PQdescribePortal
* Obtain information about a previously created portal
*
* This is much like PQdescribePrepared, except that no parameter info is
* returned. Note that at the moment, libpq doesn't really expose portals
* to the client; but this can be used with a portal created by a SQL
* DECLARE CURSOR command.
*/
PGresult *
PQdescribePortal(PGconn *conn, const char *portal)
{
if (!PQexecStart(conn))
return NULL;
if (!PQsendDescribe(conn, 'P', portal))
return NULL;
return PQexecFinish(conn);
}
/*
* PQsendDescribePrepared
* Submit a Describe Statement command, but don't wait for it to finish
*
* Returns: 1 if successfully submitted
* 0 if error (conn->errorMessage is set)
*/
int
PQsendDescribePrepared(PGconn *conn, const char *stmt)
{
return PQsendDescribe(conn, 'S', stmt);
}
/*
* PQsendDescribePortal
* Submit a Describe Portal command, but don't wait for it to finish
*
* Returns: 1 if successfully submitted
* 0 if error (conn->errorMessage is set)
*/
int
PQsendDescribePortal(PGconn *conn, const char *portal)
{
return PQsendDescribe(conn, 'P', portal);
}
/*
* PQsendDescribe
* Common code to send a Describe command
*
* Available options for desc_type are
* 'S' to describe a prepared statement; or
* 'P' to describe a portal.
* Returns 1 on success and 0 on failure.
*/
static int
PQsendDescribe(PGconn *conn, char desc_type, const char *desc_target)
{
/* Treat null desc_target as empty string */
if (!desc_target)
desc_target = "";
if (!PQsendQueryStart(conn))
return 0;
/* This isn't gonna work on a 2.0 server */
if (PG_PROTOCOL_MAJOR(conn->pversion) < 3)
{
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("function requires at least protocol version 3.0\n"));
return 0;
}
/* construct the Describe message */
if (pqPutMsgStart('D', false, conn) < 0 ||
pqPutc(desc_type, conn) < 0 ||
pqPuts(desc_target, conn) < 0 ||
pqPutMsgEnd(conn) < 0)
goto sendFailed;
/* construct the Sync message */
if (pqPutMsgStart('S', false, conn) < 0 ||
pqPutMsgEnd(conn) < 0)
goto sendFailed;
/* remember we are doing a Describe */
conn->queryclass = PGQUERY_DESCRIBE;
/* reset last-query string (not relevant now) */
if (conn->last_query)
{
free(conn->last_query);
conn->last_query = NULL;
}
/*
* Give the data a push. In nonblock mode, don't complain if we're unable
* to send it all; PQgetResult() will do any additional flushing needed.
*/
if (pqFlush(conn) < 0)
goto sendFailed;
/* OK, it's launched! */
conn->asyncStatus = PGASYNC_BUSY;
return 1;
sendFailed:
pqHandleSendFailure(conn);
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)
{
PGnotify *event;
if (!conn)
return NULL;
/* Parse any available data to see if we can extract NOTIFY messages. */
parseInput(conn);
event = conn->notifyHead;
if (event)
{
conn->notifyHead = event->next;
if (!conn->notifyHead)
conn->notifyTail = NULL;
event->next = NULL; /* don't let app see the internal state */
}
return event;
}
/*
* PQputCopyData - send some data to the backend during COPY IN
*
* Returns 1 if successful, 0 if data could not be sent (only possible
* in nonblock mode), or -1 if an error occurs.
*/
int
PQputCopyData(PGconn *conn, const char *buffer, int nbytes)
{
if (!conn)
return -1;
if (conn->asyncStatus != PGASYNC_COPY_IN)
{
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("no COPY in progress\n"));
return -1;
}
/*
* Process any NOTICE or NOTIFY messages that might be pending in the
* input buffer. Since the server might generate many notices during the
* COPY, we want to clean those out reasonably promptly to prevent
* indefinite expansion of the input buffer. (Note: the actual read of
* input data into the input buffer happens down inside pqSendSome, but
* it's not authorized to get rid of the data again.)
*/
parseInput(conn);
if (nbytes > 0)
{
/*
* Try to flush any previously sent data in preference to growing the
* output buffer. If we can't enlarge the buffer enough to hold the
* data, return 0 in the nonblock case, else hard error. (For
* simplicity, always assume 5 bytes of overhead even in protocol 2.0
* case.)
*/
if ((conn->outBufSize - conn->outCount - 5) < nbytes)
{
if (pqFlush(conn) < 0)
return -1;
if (pqCheckOutBufferSpace(conn->outCount + 5 + (size_t) nbytes,
conn))
return pqIsnonblocking(conn) ? 0 : -1;
}
/* Send the data (too simple to delegate to fe-protocol files) */
if (PG_PROTOCOL_MAJOR(conn->pversion) >= 3)
{
if (pqPutMsgStart('d', false, conn) < 0 ||
pqPutnchar(buffer, nbytes, conn) < 0 ||
pqPutMsgEnd(conn) < 0)
return -1;
}
else
{
if (pqPutMsgStart(0, false, conn) < 0 ||
pqPutnchar(buffer, nbytes, conn) < 0 ||
pqPutMsgEnd(conn) < 0)
return -1;
}
}
return 1;
}
/*
* PQputCopyEnd - send EOF indication to the backend during COPY IN
*
* After calling this, use PQgetResult() to check command completion status.
*
* Returns 1 if successful, 0 if data could not be sent (only possible
* in nonblock mode), or -1 if an error occurs.
*/
int
PQputCopyEnd(PGconn *conn, const char *errormsg)
{
if (!conn)
return -1;
if (conn->asyncStatus != PGASYNC_COPY_IN)
{
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("no COPY in progress\n"));
return -1;
}
/*
* Send the COPY END indicator. This is simple enough that we don't
* bother delegating it to the fe-protocol files.
*/
if (PG_PROTOCOL_MAJOR(conn->pversion) >= 3)
{
if (errormsg)
{
/* Send COPY FAIL */
if (pqPutMsgStart('f', false, conn) < 0 ||
pqPuts(errormsg, conn) < 0 ||
pqPutMsgEnd(conn) < 0)
return -1;
}
else
{
/* Send COPY DONE */
if (pqPutMsgStart('c', false, conn) < 0 ||
pqPutMsgEnd(conn) < 0)
return -1;
}
/*
* If we sent the COPY command in extended-query mode, we must issue a
* Sync as well.
*/
if (conn->queryclass != PGQUERY_SIMPLE)
{
if (pqPutMsgStart('S', false, conn) < 0 ||
pqPutMsgEnd(conn) < 0)
return -1;
}
}
else
{
if (errormsg)
{
/* Ooops, no way to do this in 2.0 */
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("function requires at least protocol version 3.0\n"));
return -1;
}
else
{
/* Send old-style end-of-data marker */
if (pqPutMsgStart(0, false, conn) < 0 ||
pqPutnchar("\\.\n", 3, conn) < 0 ||
pqPutMsgEnd(conn) < 0)
return -1;
}
}
/* Return to active duty */
conn->asyncStatus = PGASYNC_BUSY;
resetPQExpBuffer(&conn->errorMessage);
/* Try to flush data */
if (pqFlush(conn) < 0)
return -1;
return 1;
}
/*
* PQgetCopyData - read a row of data from the backend during COPY OUT
*
* If successful, sets *buffer to point to a malloc'd row of data, and
* returns row length (always > 0) as result.
* Returns 0 if no row available yet (only possible if async is true),
* -1 if end of copy (consult PQgetResult), or -2 if error (consult
* PQerrorMessage).
*/
int
PQgetCopyData(PGconn *conn, char **buffer, int async)
{
*buffer = NULL; /* for all failure cases */
if (!conn)
return -2;
if (conn->asyncStatus != PGASYNC_COPY_OUT)
{
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("no COPY in progress\n"));
return -2;
}
if (PG_PROTOCOL_MAJOR(conn->pversion) >= 3)
return pqGetCopyData3(conn, buffer, async);
else
return pqGetCopyData2(conn, buffer, async);
}
/*
* 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.
*
* XXX this routine is now deprecated, because it can't handle binary data.
* If called during a COPY BINARY we return EOF.
*
* 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 error (eg, 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)
{
if (!s || maxlen <= 0)
return EOF;
*s = '\0';
/* maxlen must be at least 3 to hold the \. terminator! */
if (maxlen < 3)
return EOF;
if (!conn)
return EOF;
if (PG_PROTOCOL_MAJOR(conn->pversion) >= 3)
return pqGetline3(conn, s, maxlen);
else
return pqGetline2(conn, s, maxlen);
}
/*
* PQgetlineAsync - gets a COPY data row 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 data row
* is available in libpq's input buffer. Otherwise, no data is returned
* until the rest of the row 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 data-row boundary. If possible
* a whole row will be returned at one time. But if the buffer offered by
* the caller is too small to hold a row sent by the backend, then a partial
* data row will be returned. In text mode this can be detected by testing
* whether the last returned byte is '\n' or not.
*
* The returned data is *not* null-terminated.
*/
int
PQgetlineAsync(PGconn *conn, char *buffer, int bufsize)
{
if (!conn)
return -1;
if (PG_PROTOCOL_MAJOR(conn->pversion) >= 3)
return pqGetlineAsync3(conn, buffer, bufsize);
else
return pqGetlineAsync2(conn, buffer, bufsize);
}
/*
* PQputline -- sends a string to the backend during COPY IN.
* Returns 0 if OK, EOF if not.
*
* This is deprecated primarily because the return convention doesn't allow
* caller to tell the difference between a hard error and a nonblock-mode
* send failure.
*/
int
PQputline(PGconn *conn, const char *s)
{
return PQputnbytes(conn, s, strlen(s));
}
/*
* 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 (PQputCopyData(conn, buffer, nbytes) > 0)
return 0;
else
return EOF;
}
/*
* PQendcopy
* After completing the data transfer portion of a copy in/out,
* the application must call this routine to finish the command protocol.
*
* When using protocol 3.0 this is deprecated; it's cleaner to use PQgetResult
* to get the transfer status. Note however that when using 2.0 protocol,
* recovering from a copy failure often requires a PQreset. PQendcopy will
* take care of that, PQgetResult won't.
*
* RETURNS:
* 0 on success
* 1 on failure
*/
int
PQendcopy(PGconn *conn)
{
if (!conn)
return 0;
if (PG_PROTOCOL_MAJOR(conn->pversion) >= 3)
return pqEndcopy3(conn);
else
return pqEndcopy2(conn);
}
/* ----------------
* 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,
const PQArgBlock *args,
int nargs)
{
*actual_result_len = 0;
if (!conn)
return NULL;
/* clear the error string */
resetPQExpBuffer(&conn->errorMessage);
if (conn->sock < 0 || conn->asyncStatus != PGASYNC_IDLE ||
conn->result != NULL)
{
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("connection in wrong state\n"));
return NULL;
}
if (PG_PROTOCOL_MAJOR(conn->pversion) >= 3)
return pqFunctionCall3(conn, fnid,
result_buf, actual_result_len,
result_is_int,
args, nargs);
else
return pqFunctionCall2(conn, fnid,
result_buf, actual_result_len,
result_is_int,
args, nargs);
}
/* ====== accessor funcs for PGresult ======== */
ExecStatusType
PQresultStatus(const PGresult *res)
{
if (!res)
return PGRES_FATAL_ERROR;
return res->resultStatus;
}
char *
PQresStatus(ExecStatusType status)
{
if (status < 0 || status >= sizeof pgresStatus / sizeof pgresStatus[0])
return libpq_gettext("invalid ExecStatusType code");
return pgresStatus[status];
}
char *
PQresultErrorMessage(const PGresult *res)
{
if (!res || !res->errMsg)
return "";
return res->errMsg;
}
char *
PQresultErrorField(const PGresult *res, int fieldcode)
{
PGMessageField *pfield;
if (!res)
return NULL;
for (pfield = res->errFields; pfield != NULL; pfield = pfield->next)
{
if (pfield->code == fieldcode)
return pfield->contents;
}
return NULL;
}
int
PQntuples(const PGresult *res)
{
if (!res)
return 0;
return res->ntups;
}
int
PQnfields(const PGresult *res)
{
if (!res)
return 0;
return res->numAttributes;
}
int
PQbinaryTuples(const 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 PGresult *res, int field_num)
{
if (!res)
return FALSE; /* no way to display error message... */
if (field_num < 0 || field_num >= res->numAttributes)
{
pqInternalNotice(&res->noticeHooks,
"column number %d is out of range 0..%d",
field_num, res->numAttributes - 1);
return FALSE;
}
return TRUE;
}
static int
check_tuple_field_number(const 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)
{
pqInternalNotice(&res->noticeHooks,
"row number %d is out of range 0..%d",
tup_num, res->ntups - 1);
return FALSE;
}
if (field_num < 0 || field_num >= res->numAttributes)
{
pqInternalNotice(&res->noticeHooks,
"column number %d is out of range 0..%d",
field_num, res->numAttributes - 1);
return FALSE;
}
return TRUE;
}
static int
check_param_number(const PGresult *res, int param_num)
{
if (!res)
return FALSE; /* no way to display error message... */
if (param_num < 0 || param_num >= res->numParameters)
{
pqInternalNotice(&res->noticeHooks,
"parameter number %d is out of range 0..%d",
param_num, res->numParameters - 1);
return FALSE;
}
return TRUE;
}
/*
* returns NULL if the field_num is invalid
*/
char *
PQfname(const PGresult *res, int field_num)
{
if (!check_field_number(res, field_num))
return NULL;
if (res->attDescs)
return res->attDescs[field_num].name;
else
return NULL;
}
/*
* PQfnumber: find column number given column name
*
* The column name is parsed as if it were in a SQL statement, including
* case-folding and double-quote processing. But note a possible gotcha:
* downcasing in the frontend might follow different locale rules than
* downcasing in the backend...
*
* Returns -1 if no match. In the present backend it is also possible
* to have multiple matches, in which case the first one is found.
*/
int
PQfnumber(const PGresult *res, const char *field_name)
{
char *field_case;
bool in_quotes;
char *iptr;
char *optr;
int i;
if (!res)
return -1;
/*
* Note: it is correct to reject a zero-length input string; the proper
* input to match a zero-length field name would be "".
*/
if (field_name == NULL ||
field_name[0] == '\0' ||
res->attDescs == NULL)
return -1;
/*
* Note: this code will not reject partially quoted strings, eg
* foo"BAR"foo will become fooBARfoo when it probably ought to be an error
* condition.
*/
field_case = strdup(field_name);
if (field_case == NULL)
return -1; /* grotty */
in_quotes = false;
optr = field_case;
for (iptr = field_case; *iptr; iptr++)
{
char c = *iptr;
if (in_quotes)
{
if (c == '"')
{
if (iptr[1] == '"')
{
/* doubled quotes become a single quote */
*optr++ = '"';
iptr++;
}
else
in_quotes = false;
}
else
*optr++ = c;
}
else if (c == '"')
in_quotes = true;
else
{
c = pg_tolower((unsigned char) c);
*optr++ = c;
}
}
*optr = '\0';
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
PQftable(const PGresult *res, int field_num)
{
if (!check_field_number(res, field_num))
return InvalidOid;
if (res->attDescs)
return res->attDescs[field_num].tableid;
else
return InvalidOid;
}
int
PQftablecol(const PGresult *res, int field_num)
{
if (!check_field_number(res, field_num))
return 0;
if (res->attDescs)
return res->attDescs[field_num].columnid;
else
return 0;
}
int
PQfformat(const PGresult *res, int field_num)
{
if (!check_field_number(res, field_num))
return 0;
if (res->attDescs)
return res->attDescs[field_num].format;
else
return 0;
}
Oid
PQftype(const PGresult *res, int field_num)
{
if (!check_field_number(res, field_num))
return InvalidOid;
if (res->attDescs)
return res->attDescs[field_num].typid;
else
return InvalidOid;
}
int
PQfsize(const PGresult *res, int field_num)
{
if (!check_field_number(res, field_num))
return 0;
if (res->attDescs)
return res->attDescs[field_num].typlen;
else
return 0;
}
int
PQfmod(const PGresult *res, int field_num)
{
if (!check_field_number(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 ""
*/
char *
PQoidStatus(const PGresult *res)
{
/*
* This must be enough to hold the result. Don't laugh, this is better
* than what this function used to do.
*/
static char buf[24];
size_t len;
if (!res || !res->cmdStatus || strncmp(res->cmdStatus, "INSERT ", 7) != 0)
return "";
len = strspn(res->cmdStatus + 7, "0123456789");
if (len > 23)
len = 23;
strncpy(buf, res->cmdStatus + 7, len);
buf[len] = '\0';
return buf;
}
/*
* PQoidValue -
* a perhaps preferable form of the above which just returns
* an Oid type
*/
Oid
PQoidValue(const PGresult *res)
{
char *endptr = NULL;
unsigned long result;
if (!res ||
!res->cmdStatus ||
strncmp(res->cmdStatus, "INSERT ", 7) != 0 ||
res->cmdStatus[7] < '0' ||
res->cmdStatus[7] > '9')
return InvalidOid;
result = strtoul(res->cmdStatus + 7, &endptr, 10);
if (!endptr || (*endptr != ' ' && *endptr != '\0'))
return InvalidOid;
else
return (Oid) result;
}
/*
* PQcmdTuples -
* If the last command was INSERT/UPDATE/DELETE/MOVE/FETCH/COPY, return
* a string containing the number of inserted/affected tuples. If not,
* return "".
*
* XXX: this should probably return an int
*/
char *
PQcmdTuples(PGresult *res)
{
char *p,
*c;
if (!res)
return "";
if (strncmp(res->cmdStatus, "INSERT ", 7) == 0)
{
p = res->cmdStatus + 7;
/* INSERT: skip oid and space */
while (*p && *p != ' ')
p++;
if (*p == 0)
goto interpret_error; /* no space? */
p++;
}
else if (strncmp(res->cmdStatus, "SELECT ", 7) == 0 ||
strncmp(res->cmdStatus, "DELETE ", 7) == 0 ||
strncmp(res->cmdStatus, "UPDATE ", 7) == 0)
p = res->cmdStatus + 7;
else if (strncmp(res->cmdStatus, "FETCH ", 6) == 0)
p = res->cmdStatus + 6;
else if (strncmp(res->cmdStatus, "MOVE ", 5) == 0 ||
strncmp(res->cmdStatus, "COPY ", 5) == 0)
p = res->cmdStatus + 5;
else
return "";
/* check that we have an integer (at least one digit, nothing else) */
for (c = p; *c; c++)
{
if (!isdigit((unsigned char) *c))
goto interpret_error;
}
if (c == p)
goto interpret_error;
return p;
interpret_error:
pqInternalNotice(&res->noticeHooks,
"could not interpret result from server: %s",
res->cmdStatus);
return "";
}
/*
* PQgetvalue:
* return the value of field 'field_num' of row 'tup_num'
*/
char *
PQgetvalue(const PGresult *res, int tup_num, int field_num)
{
if (!check_tuple_field_number(res, tup_num, field_num))
return NULL;
return res->tuples[tup_num][field_num].value;
}
/* PQgetlength:
* returns the actual length of a field value in bytes.
*/
int
PQgetlength(const PGresult *res, int tup_num, int field_num)
{
if (!check_tuple_field_number(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(const PGresult *res, int tup_num, int field_num)
{
if (!check_tuple_field_number(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;
}
/* PQnparams:
* returns the number of input parameters of a prepared statement.
*/
int
PQnparams(const PGresult *res)
{
if (!res)
return 0;
return res->numParameters;
}
/* PQparamtype:
* returns type Oid of the specified statement parameter.
*/
Oid
PQparamtype(const PGresult *res, int param_num)
{
if (!check_param_number(res, param_num))
return InvalidOid;
if (res->paramDescs)
return res->paramDescs[param_num].typid;
else
return InvalidOid;
}
/* PQsetnonblocking:
* sets the PGconn's database connection non-blocking if the arg is TRUE
* or makes it non-blocking if the arg is FALSE, this will not protect
* you from PQexec(), you'll only be safe when using the non-blocking API.
* Needs to be called only on a connected database connection.
*/
int
PQsetnonblocking(PGconn *conn, int arg)
{
bool barg;
if (!conn || conn->status == CONNECTION_BAD)
return -1;
barg = (arg ? TRUE : FALSE);
/* early out if the socket is already in the state requested */
if (barg == conn->nonblocking)
return 0;
/*
* to guarantee constancy for flushing/query/result-polling behavior we
* need to flush the send queue at this point in order to guarantee proper
* behavior. this is ok because either they are making a transition _from_
* or _to_ blocking mode, either way we can block them.
*/
/* if we are going from blocking to non-blocking flush here */
if (pqFlush(conn))
return -1;
conn->nonblocking = barg;
return 0;
}
/*
* return the blocking status of the database connection
* TRUE == nonblocking, FALSE == blocking
*/
int
PQisnonblocking(const PGconn *conn)
{
return pqIsnonblocking(conn);
}
/* libpq is thread-safe? */
int
PQisthreadsafe(void)
{
#ifdef ENABLE_THREAD_SAFETY
return true;
#else
return false;
#endif
}
/* try to force data out, really only useful for non-blocking users */
int
PQflush(PGconn *conn)
{
return pqFlush(conn);
}
/*
* PQfreemem - safely frees memory allocated
*
* Needed mostly by Win32, unless multithreaded DLL (/MD in VC6)
* Used for freeing memory from PQescapeByte()a/PQunescapeBytea()
*/
void
PQfreemem(void *ptr)
{
free(ptr);
}
/*
* PQfreeNotify - free's the memory associated with a PGnotify
*
* This function is here only for binary backward compatibility.
* New code should use PQfreemem(). A macro will automatically map
* calls to PQfreemem. It should be removed in the future. bjm 2003-03-24
*/
#undef PQfreeNotify
void PQfreeNotify(PGnotify *notify);
void
PQfreeNotify(PGnotify *notify)
{
PQfreemem(notify);
}
/*
* Escaping arbitrary strings to get valid SQL literal strings.
*
* Replaces "'" with "''", and if not std_strings, replaces "\" with "\\".
*
* length is the length of the source string. (Note: if a terminating NUL
* is encountered sooner, PQescapeString stops short of "length"; the behavior
* is thus rather like strncpy.)
*
* For safety the buffer at "to" must be at least 2*length + 1 bytes long.
* A terminating NUL character is added to the output string, whether the
* input is NUL-terminated or not.
*
* Returns the actual length of the output (not counting the terminating NUL).
*/
static size_t
PQescapeStringInternal(PGconn *conn,
char *to, const char *from, size_t length,
int *error,
int encoding, bool std_strings)
{
const char *source = from;
char *target = to;
size_t remaining = length;
if (error)
*error = 0;
while (remaining > 0 && *source != '\0')
{
char c = *source;
int len;
int i;
/* Fast path for plain ASCII */
if (!IS_HIGHBIT_SET(c))
{
/* Apply quoting if needed */
if (SQL_STR_DOUBLE(c, !std_strings))
*target++ = c;
/* Copy the character */
*target++ = c;
source++;
remaining--;
continue;
}
/* Slow path for possible multibyte characters */
len = pg_encoding_mblen(encoding, source);
/* Copy the character */
for (i = 0; i < len; i++)
{
if (remaining == 0 || *source == '\0')
break;
*target++ = *source++;
remaining--;
}
/*
* If we hit premature end of string (ie, incomplete multibyte
* character), try to pad out to the correct length with spaces. We
* may not be able to pad completely, but we will always be able to
* insert at least one pad space (since we'd not have quoted a
* multibyte character). This should be enough to make a string that
* the server will error out on.
*/
if (i < len)
{
if (error)
*error = 1;
if (conn)
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("incomplete multibyte character\n"));
for (; i < len; i++)
{
if (((size_t) (target - to)) / 2 >= length)
break;
*target++ = ' ';
}
break;
}
}
/* Write the terminating NUL character. */
*target = '\0';
return target - to;
}
size_t
PQescapeStringConn(PGconn *conn,
char *to, const char *from, size_t length,
int *error)
{
if (!conn)
{
/* force empty-string result */
*to = '\0';
if (error)
*error = 1;
return 0;
}
return PQescapeStringInternal(conn, to, from, length, error,
conn->client_encoding,
conn->std_strings);
}
size_t
PQescapeString(char *to, const char *from, size_t length)
{
return PQescapeStringInternal(NULL, to, from, length, NULL,
static_client_encoding,
static_std_strings);
}
/*
* Escape arbitrary strings. If as_ident is true, we escape the result
* as an identifier; if false, as a literal. The result is returned in
* a newly allocated buffer. If we fail due to an encoding violation or out
* of memory condition, we return NULL, storing an error message into conn.
*/
static char *
PQescapeInternal(PGconn *conn, const char *str, size_t len, bool as_ident)
{
const char *s;
char *result;
char *rp;
int num_quotes = 0; /* single or double, depending on as_ident */
int num_backslashes = 0;
int input_len;
int result_size;
char quote_char = as_ident ? '"' : '\'';
/* We must have a connection, else fail immediately. */
if (!conn)
return NULL;
/* Scan the string for characters that must be escaped. */
for (s = str; (s - str) < len && *s != '\0'; ++s)
{
if (*s == quote_char)
++num_quotes;
else if (*s == '\\')
++num_backslashes;
else if (IS_HIGHBIT_SET(*s))
{
int charlen;
/* Slow path for possible multibyte characters */
charlen = pg_encoding_mblen(conn->client_encoding, s);
/* Multibyte character overruns allowable length. */
if ((s - str) + charlen > len || memchr(s, 0, charlen) != NULL)
{
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("incomplete multibyte character\n"));
return NULL;
}
/* Adjust s, bearing in mind that for loop will increment it. */
s += charlen - 1;
}
}
/* Allocate output buffer. */
input_len = s - str;
result_size = input_len + num_quotes + 3; /* two quotes, plus a NUL */
if (!as_ident && num_backslashes > 0)
result_size += num_backslashes + 2;
result = rp = (char *) malloc(result_size);
if (rp == NULL)
{
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("out of memory\n"));
return NULL;
}
/*
* If we are escaping a literal that contains backslashes, we use the
* escape string syntax so that the result is correct under either value
* of standard_conforming_strings. We also emit a leading space in this
* case, to guard against the possibility that the result might be
* interpolated immediately following an identifier.
*/
if (!as_ident && num_backslashes > 0)
{
*rp++ = ' ';
*rp++ = 'E';
}
/* Opening quote. */
*rp++ = quote_char;
/*
* Use fast path if possible.
*
* We've already verified that the input string is well-formed in the
* current encoding. If it contains no quotes and, in the case of
* literal-escaping, no backslashes, then we can just copy it directly
* to the output buffer, adding the necessary quotes.
*
* If not, we must rescan the input and process each character
* individually.
*/
if (num_quotes == 0 && (num_backslashes == 0 || as_ident))
{
memcpy(rp, str, input_len);
rp += input_len;
}
else
{
for (s = str; s - str < input_len; ++s)
{
if (*s == quote_char || (!as_ident && *s == '\\'))
{
*rp++ = *s;
*rp++ = *s;
}
else if (!IS_HIGHBIT_SET(*s))
*rp++ = *s;
else
{
int i = pg_encoding_mblen(conn->client_encoding, s);
while (1)
{
*rp++ = *s;
if (--i == 0)
break;
++s; /* for loop will provide the final increment */
}
}
}
}
/* Closing quote and terminating NUL. */
*rp++ = quote_char;
*rp = '\0';
return result;
}
char *
PQescapeLiteral(PGconn *conn, const char *str, size_t len)
{
return PQescapeInternal(conn, str, len, false);
}
char *
PQescapeIdentifier(PGconn *conn, const char *str, size_t len)
{
return PQescapeInternal(conn, str, len, true);
}
/* HEX encoding support for bytea */
static const char hextbl[] = "0123456789abcdef";
static const int8 hexlookup[128] = {
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, -1, -1, -1, -1, -1, -1,
-1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
};
static inline char
get_hex(char c)
{
int res = -1;
if (c > 0 && c < 127)
res = hexlookup[(unsigned char) c];
return (char) res;
}
/*
* PQescapeBytea - converts from binary string to the
* minimal encoding necessary to include the string in an SQL
* INSERT statement with a bytea type column as the target.
*
* We can use either hex or escape (traditional) encoding.
* In escape mode, the following transformations are applied:
* '\0' == ASCII 0 == \000
* '\'' == ASCII 39 == ''
* '\\' == ASCII 92 == \\
* anything < 0x20, or > 0x7e ---> \ooo
* (where ooo is an octal expression)
*
* If not std_strings, all backslashes sent to the output are doubled.
*/
static unsigned char *
PQescapeByteaInternal(PGconn *conn,
const unsigned char *from, size_t from_length,
size_t *to_length, bool std_strings, bool use_hex)
{
const unsigned char *vp;
unsigned char *rp;
unsigned char *result;
size_t i;
size_t len;
size_t bslash_len = (std_strings ? 1 : 2);
/*
* empty string has 1 char ('\0')
*/
len = 1;
if (use_hex)
{
len += bslash_len + 1 + 2 * from_length;
}
else
{
vp = from;
for (i = from_length; i > 0; i--, vp++)
{
if (*vp < 0x20 || *vp > 0x7e)
len += bslash_len + 3;
else if (*vp == '\'')
len += 2;
else if (*vp == '\\')
len += bslash_len + bslash_len;
else
len++;
}
}
*to_length = len;
rp = result = (unsigned char *) malloc(len);
if (rp == NULL)
{
if (conn)
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("out of memory\n"));
return NULL;
}
if (use_hex)
{
if (!std_strings)
*rp++ = '\\';
*rp++ = '\\';
*rp++ = 'x';
}
vp = from;
for (i = from_length; i > 0; i--, vp++)
{
unsigned char c = *vp;
if (use_hex)
{
*rp++ = hextbl[(c >> 4) & 0xF];
*rp++ = hextbl[c & 0xF];
}
else if (c < 0x20 || c > 0x7e)
{
if (!std_strings)
*rp++ = '\\';
*rp++ = '\\';
*rp++ = (c >> 6) + '0';
*rp++ = ((c >> 3) & 07) + '0';
*rp++ = (c & 07) + '0';
}
else if (c == '\'')
{
*rp++ = '\'';
*rp++ = '\'';
}
else if (c == '\\')
{
if (!std_strings)
{
*rp++ = '\\';
*rp++ = '\\';
}
*rp++ = '\\';
*rp++ = '\\';
}
else
*rp++ = c;
}
*rp = '\0';
return result;
}
unsigned char *
PQescapeByteaConn(PGconn *conn,
const unsigned char *from, size_t from_length,
size_t *to_length)
{
if (!conn)
return NULL;
return PQescapeByteaInternal(conn, from, from_length, to_length,
conn->std_strings,
(conn->sversion >= 80500));
}
unsigned char *
PQescapeBytea(const unsigned char *from, size_t from_length, size_t *to_length)
{
return PQescapeByteaInternal(NULL, from, from_length, to_length,
static_std_strings,
false /* can't use hex */ );
}
#define ISFIRSTOCTDIGIT(CH) ((CH) >= '0' && (CH) <= '3')
#define ISOCTDIGIT(CH) ((CH) >= '0' && (CH) <= '7')
#define OCTVAL(CH) ((CH) - '0')
/*
* PQunescapeBytea - converts the null terminated string representation
* of a bytea, strtext, into binary, filling a buffer. It returns a
* pointer to the buffer (or NULL on error), and the size of the
* buffer in retbuflen. The pointer may subsequently be used as an
* argument to the function PQfreemem.
*
* The following transformations are made:
* \\ == ASCII 92 == \
* \ooo == a byte whose value = ooo (ooo is an octal number)
* \x == x (x is any character not matched by the above transformations)
*/
unsigned char *
PQunescapeBytea(const unsigned char *strtext, size_t *retbuflen)
{
size_t strtextlen,
buflen;
unsigned char *buffer,
*tmpbuf;
size_t i,
j;
if (strtext == NULL)
return NULL;
strtextlen = strlen((const char *) strtext);
if (strtext[0] == '\\' && strtext[1] == 'x')
{
const unsigned char *s;
unsigned char *p;
buflen = (strtextlen - 2)/2;
/* Avoid unportable malloc(0) */
buffer = (unsigned char *) malloc(buflen > 0 ? buflen : 1);
if (buffer == NULL)
return NULL;
s = strtext + 2;
p = buffer;
while (*s)
{
char v1,
v2;
/*
* Bad input is silently ignored. Note that this includes
* whitespace between hex pairs, which is allowed by byteain.
*/
v1 = get_hex(*s++);
if (!*s || v1 == (char) -1)
continue;
v2 = get_hex(*s++);
if (v2 != (char) -1)
*p++ = (v1 << 4) | v2;
}
buflen = p - buffer;
}
else
{
/*
* Length of input is max length of output, but add one to avoid
* unportable malloc(0) if input is zero-length.
*/
buffer = (unsigned char *) malloc(strtextlen + 1);
if (buffer == NULL)
return NULL;
for (i = j = 0; i < strtextlen;)
{
switch (strtext[i])
{
case '\\':
i++;
if (strtext[i] == '\\')
buffer[j++] = strtext[i++];
else
{
if ((ISFIRSTOCTDIGIT(strtext[i])) &&
(ISOCTDIGIT(strtext[i + 1])) &&
(ISOCTDIGIT(strtext[i + 2])))
{
int byte;
byte = OCTVAL(strtext[i++]);
byte = (byte <<3) +OCTVAL(strtext[i++]);
byte = (byte <<3) +OCTVAL(strtext[i++]);
buffer[j++] = byte;
}
}
/*
* Note: if we see '\' followed by something that isn't a
* recognized escape sequence, we loop around having done
* nothing except advance i. Therefore the something will be
* emitted as ordinary data on the next cycle. Corner case:
* '\' at end of string will just be discarded.
*/
break;
default:
buffer[j++] = strtext[i++];
break;
}
}
buflen = j; /* buflen is the length of the dequoted data */
}
/* Shrink the buffer to be no larger than necessary */
/* +1 avoids unportable behavior when buflen==0 */
tmpbuf = realloc(buffer, buflen + 1);
/* It would only be a very brain-dead realloc that could fail, but... */
if (!tmpbuf)
{
free(buffer);
return NULL;
}
*retbuflen = buflen;
return tmpbuf;
}