static PyObject *
psyco_conn_isolation_level_get(connectionObject *self)
{
int rv;
EXC_IF_CONN_CLOSED(self);
EXC_IF_TPC_PREPARED(self, set_isolation_level);
rv = conn_get_isolation_level(self);
if (-1 == rv) { return NULL; }
return PyInt_FromLong((long)rv);
}
RAISES_NEG int
conn_switch_isolation_level(connectionObject *self, int level)
{
PGresult *pgres = NULL;
char *error = NULL;
int curr_level;
int ret = -1;
/* use only supported levels on older PG versions */
if (self->server_version < 80000) {
if (level == ISOLATION_LEVEL_READ_UNCOMMITTED)
level = ISOLATION_LEVEL_READ_COMMITTED;
else if (level == ISOLATION_LEVEL_REPEATABLE_READ)
level = ISOLATION_LEVEL_SERIALIZABLE;
}
if (-1 == (curr_level = conn_get_isolation_level(self))) {
return -1;
}
if (curr_level == level) {
/* no need to change level */
return 0;
}
/* Emulate the previous semantic of set_isolation_level() using the
* functions currently available. */
Py_BEGIN_ALLOW_THREADS;
pthread_mutex_lock(&self->lock);
/* terminate the current transaction if any */
if ((ret = pq_abort_locked(self, &pgres, &error, &_save))) {
goto endlock;
}
if (level == 0) {
if ((ret = pq_set_guc_locked(self,
"default_transaction_isolation", "default",
&pgres, &error, &_save))) {
goto endlock;
}
self->autocommit = 1;
}
else {
/* find the name of the requested level */
const IsolationLevel *isolevel = conn_isolevels;
while ((++isolevel)->name) {
if (level == isolevel->value) {
break;
}
}
if (!isolevel->name) {
ret = -1;
error = strdup("bad isolation level value");
goto endlock;
}
if ((ret = pq_set_guc_locked(self,
"default_transaction_isolation", isolevel->name,
&pgres, &error, &_save))) {
goto endlock;
}
self->autocommit = 0;
}
Dprintf("conn_switch_isolation_level: switched to level %d", level);
endlock:
pthread_mutex_unlock(&self->lock);
Py_END_ALLOW_THREADS;
if (ret < 0) {
pq_complete_error(self, &pgres, &error);
}
return ret;
}