Should the hook only be called when the conn or result was
> successfull or should the hooks be called for failed
connections/commands as well?
ISTM that the hooks should be called on success and error (doesn't
include cases where a NULL conn or result is returned). I think this
makes things more useful. If the hooker (pun intended) isn't interested
in error results or conns, it can easily ignore them.
connCreate: The best solution I found was to hook into PQconnectPoll.
This required making the current PQconnectPoll a static named
connectPoll and making PQconnectPoll a wrapper to it. The wrapper just
calls connectPoll and checks the status for hook points.
resultCreate: PQgetResult seemed like the best place. I only notify the
hooks if the resultStatus is NOT copyin or copyout.
I diff'd fe-connect.c and fe-exec.c against cvs which shows these changes.
--
Andrew Chernow
eSilo, LLC
every bit counts
http://www.esilo.com/
Index: fe-connect.c
===================================================================
RCS file: /projects/cvsroot/pgsql/src/interfaces/libpq/fe-connect.c,v
retrieving revision 1.357
diff -C6 -r1.357 fe-connect.c
*** fe-connect.c 31 Mar 2008 02:43:14 -0000 1.357
--- fe-connect.c 12 Apr 2008 13:22:30 -0000
***************
*** 240,252 ****
static int parseServiceInfo(PQconninfoOption *options,
PQExpBuffer errorMessage);
static char *pwdfMatchesString(char *buf, char *token);
static char *PasswordFromFile(char *hostname, char *port, char *dbname,
char *username);
static void default_threadlock(int acquire);
!
/* global variable because fe-auth.c needs to access it */
pgthreadlock_t pg_g_threadlock = default_threadlock;
/*
--- 240,252 ----
static int parseServiceInfo(PQconninfoOption *options,
PQExpBuffer errorMessage);
static char *pwdfMatchesString(char *buf, char *token);
static char *PasswordFromFile(char *hostname, char *port, char *dbname,
char *username);
static void default_threadlock(int acquire);
! static void notifyConnCreateHooks(PGconn *conn);
/* global variable because fe-auth.c needs to access it */
pgthreadlock_t pg_g_threadlock = default_threadlock;
/*
***************
*** 891,903 ****
--- 891,907 ----
connectDBComplete(PGconn *conn)
{
PostgresPollingStatusType flag = PGRES_POLLING_WRITING;
time_t finish_time = ((time_t) -1);
if (conn == NULL || conn->status == CONNECTION_BAD)
+ {
+ if(conn)
+ notifyConnCreateHooks(conn);
return 0;
+ }
/*
* Set up a time limit, if connect_timeout isn't zero.
*/
if (conn->connect_timeout != NULL)
{
***************
*** 979,992 ****
* o If your backend wants to use Kerberos authentication then you
must
* supply both a host name and a host address, otherwise this
function
* may block on gethostname.
*
* ----------------
*/
! PostgresPollingStatusType
! PQconnectPoll(PGconn *conn)
{
PGresult *res;
char sebuf[256];
if (conn == NULL)
return PGRES_POLLING_FAILED;
--- 983,997 ----
* o If your backend wants to use Kerberos authentication then you
must
* supply both a host name and a host address, otherwise this
function
* may block on gethostname.
*
* ----------------
*/
!
! static PostgresPollingStatusType
! connectPoll(PGconn *conn)
{
PGresult *res;
char sebuf[256];
if (conn == NULL)
return PGRES_POLLING_FAILED;
***************
*** 1875,1886 ****
--- 1880,1908 ----
* the connection structure must be freed).
*/
conn->status = CONNECTION_BAD;
return PGRES_POLLING_FAILED;
}
+ /* See connectPoll. All this does is wrap the real PQconnectPoll so
+ * we can trap PGRES_POLLING_OK or PGRES_POLLING_FAILED statuses. This
+ * could be done in the real connectPoll, but that requires littering the
+ * function with notifyConnCreateHooks calls because there are many
+ * places the function returns a status. This solution is much less
+ * obtrusive and avoids messing with the black magic of connectPoll.
+ */
+ PostgresPollingStatusType
+ PQconnectPoll(PGconn *conn)
+ {
+ PostgresPollingStatusType status = connectPoll(conn);
+
+ if(status == PGRES_POLLING_OK || status == PGRES_POLLING_FAILED)
+ notifyConnCreateHooks(conn);
+
+ return status;
+ }
/*
* makeEmptyPGconn
* - create a PGconn data structure with (as yet) no interesting data
*/
static PGconn *
***************
*** 1970,1981 ****
--- 1992,2015 ----
* release data that is to be held for the life of the PGconn structure.
* If a value ought to be cleared/freed during PQreset(), do it there not
here.
*/
static void
freePGconn(PGconn *conn)
{
+ int objHooksCount;
+ const PGobjectHooks *objHooks;
+
+ if((objHooksCount = pqGetObjectHooks(&objHooks)) > 0)
+ {
+ int i;
+
+ for(i=0; i < objHooksCount; i++)
+ if(objHooks[i].connDestroy)
+ objHooks[i].connDestroy(objHooks[i].name,
(const PGconn *)conn);
+ }
+ pqReleaseObjectHooks();
if (conn->pghost)
free(conn->pghost);
if (conn->pghostaddr)
free(conn->pghostaddr);
if (conn->pgport)
free(conn->pgport);
***************
*** 3843,3854 ****
--- 3877,3904 ----
pthread_mutex_lock(&singlethread_lock);
else
pthread_mutex_unlock(&singlethread_lock);
#endif
}
+ /* Calls the connCreate hook. */
+ static void notifyConnCreateHooks(PGconn *conn)
+ {
+ int objHooksCount;
+ const PGobjectHooks *objHooks;
+
+ if((objHooksCount = pqGetObjectHooks(&objHooks)) > 0)
+ {
+ int i;
+ for(i=0; i < objHooksCount; i++)
+ if(objHooks[i].connCreate)
+ objHooks[i].connCreate(objHooks[i].name, (const
PGconn *)conn);
+ }
+
+ pqReleaseObjectHooks();
+ }
pgthreadlock_t
PQregisterThreadLock(pgthreadlock_t newhandler)
{
pgthreadlock_t prev = pg_g_threadlock;
if (newhandler)
Index: fe-exec.c
===================================================================
RCS file: /projects/cvsroot/pgsql/src/interfaces/libpq/fe-exec.c,v
retrieving revision 1.194
diff -C6 -r1.194 fe-exec.c
*** fe-exec.c 1 Jan 2008 19:46:00 -0000 1.194
--- fe-exec.c 12 Apr 2008 13:22:31 -0000
***************
*** 60,72 ****
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);
!
/* ----------------
* 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
--- 60,72 ----
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
***************
*** 192,203 ****
--- 192,331 ----
result->client_encoding = PG_SQL_ASCII;
}
return result;
}
+ PGresult *PQmakeResult(
+ PGconn *conn,
+ int numAttributes,
+ PGresAttDesc *attDescs)
+ {
+ int i;
+ PGresult *res;
+
+ if(numAttributes <= 0 || !attDescs)
+ return NULL;
+
+ res = PQmakeEmptyPGresult(conn, PGRES_TUPLES_OK);
+ if(!res)
+ return NULL;
+
+ res->attDescs = (PGresAttDesc *)
+ pqResultAlloc(res, numAttributes * sizeof(PGresAttDesc), TRUE);
+
+ if(!res->attDescs)
+ {
+ PQclear(res);
+ return NULL;
+ }
+
+ res->numAttributes = numAttributes;
+ memcpy(res->attDescs, attDescs, numAttributes * sizeof(PGresAttDesc));
+
+ /* resultalloc the attribute names. */
+ res->binary = 1;
+ for(i=0; i < numAttributes; i++)
+ {
+ if(attDescs[i].name)
+ res->attDescs[i].name = pqResultStrdup(res,
attDescs[i].name);
+ else
+ res->attDescs[i].name = res->null_field;
+
+ if(!res->attDescs[i].name)
+ {
+ PQclear(res);
+ return NULL;
+ }
+
+ /* Although deprecated, because results can have text+binary
columns,
+ * its easy enough to deduce so set it for completeness.
+ */
+ if(res->attDescs[i].format == 0)
+ res->binary = 0;
+ }
+
+ return res;
+ }
+
+ 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 > res->ntups)
+ return FALSE;
+
+ /* need to grow the tuple table */
+ if(res->ntups >= res->tupArrSize)
+ {
+ int n = res->tupArrSize ? (res->tupArrSize*3)/2 : 64;
+ PGresAttValue **tups = (PGresAttValue **)
+ (res->tuples ? realloc(res->tuples,
n*sizeof(PGresAttValue *)) :
+ malloc(n*sizeof(PGresAttValue *)));
+
+ if(!tups)
+ return FALSE;
+
+ res->tuples = tups;
+ res->tupArrSize = n;
+ }
+
+ /* new to allocate a new tuple */
+ if(tup_num == res->ntups && !res->tuples[tup_num])
+ {
+ int i;
+ PGresAttValue *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];
+
+ /* On top of NULL_LEN, treat a NULL value as a NULL field */
+ if(len == NULL_LEN || value == NULL)
+ {
+ attval->len = NULL_LEN;
+ attval->value = res->null_field;
+ }
+ else
+ {
+ if(len < 0)
+ len = 0;
+
+ 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 -
* 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
***************
*** 350,365 ****
--- 478,504 ----
* free's the memory associated with a PGresult
*/
void
PQclear(PGresult *res)
{
PGresult_data *block;
+ int objHooksCount;
+ const PGobjectHooks *objHooks;
if (!res)
return;
+ if((objHooksCount = pqGetObjectHooks(&objHooks)) > 0)
+ {
+ int i;
+
+ for(i=0; i < objHooksCount; i++)
+ if(objHooks[i].resultDestroy)
+ objHooks[i].resultDestroy(objHooks[i].name,
(const PGresult *)res);
+ }
+ pqReleaseObjectHooks();
/* Free all the subsidiary blocks */
while ((block = res->curBlock) != NULL)
{
res->curBlock = block->next;
free(block);
}
***************
*** 1179,1190 ****
--- 1318,1346 ----
parseInput(conn);
/* PQgetResult will return immediately in all states except BUSY. */
return conn->asyncStatus == PGASYNC_BUSY;
}
+ /* Used by PQgetResult */
+ static void notifyResultCreateHooks(PGconn *conn, PGresult *res)
+ {
+ int objHooksCount;
+ const PGobjectHooks *objHooks;
+
+ if((objHooksCount = pqGetObjectHooks(&objHooks)) > 0)
+ {
+ int i;
+ for(i=0; i < objHooksCount; i++)
+ if(objHooks[i].resultCreate)
+ objHooks[i].resultCreate(objHooks[i].name,
(const PGconn *)conn,
+ (const PGresult *)res);
+ }
+
+ pqReleaseObjectHooks();
+ }
/*
* 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).
***************
*** 1227,1239 ****
/*
* 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);
}
--- 1383,1403 ----
/*
* 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;
! res = pqPrepareAsyncResult(conn);
!
! if(res && res->resultStatus != PGRES_COPY_IN &&
! res->resultStatus != PGRES_COPY_OUT)
! {
! notifyResultCreateHooks(conn, res);
! }
!
! return res;
}
/* Parse it. */
parseInput(conn);
}
***************
*** 1265,1276 ****
--- 1429,1446 ----
libpq_gettext("unexpected asyncStatus: %d\n"),
(int)
conn->asyncStatus);
res = PQmakeEmptyPGresult(conn, PGRES_FATAL_ERROR);
break;
}
+ if(res && res->resultStatus != PGRES_COPY_IN &&
+ res->resultStatus != PGRES_COPY_OUT)
+ {
+ notifyResultCreateHooks(conn, res);
+ }
+
return res;
}
/*
* PQexec
--
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