Use only the isolation levels available on old PG versions

This commit is contained in:
Daniele Varrazzo 2011-06-03 00:40:54 +01:00
parent c2d1f1f2e6
commit 4d3c6865ee
3 changed files with 36 additions and 13 deletions

View File

@ -1042,6 +1042,13 @@ conn_switch_isolation_level(connectionObject *self, int level)
{
int curr_level;
/* use only supported levels on older PG versions */
if (self->server_version < 80000) {
if (level == 1 || level == 3) {
++level;
}
}
if (-1 == (curr_level = conn_get_isolation_level(self))) {
return -1;
}

View File

@ -384,10 +384,9 @@ psyco_conn_tpc_recover(connectionObject *self, PyObject *args)
extern const IsolationLevel conn_isolevels[];
static const char *
_psyco_conn_parse_isolevel(PyObject *pyval)
_psyco_conn_parse_isolevel(connectionObject *self, PyObject *pyval)
{
const char *rv = NULL;
const IsolationLevel *value = NULL;
const IsolationLevel *isolevel = NULL;
Py_INCREF(pyval); /* for ensure_bytes */
@ -400,22 +399,22 @@ _psyco_conn_parse_isolevel(PyObject *pyval)
"isolation_level must be between 1 and 4");
goto exit;
}
rv = conn_isolevels[level].name;
isolevel = conn_isolevels + level;
}
/* parse from the string -- this includes "default" */
else {
value = conn_isolevels;
while ((++value)->name) {
isolevel = conn_isolevels;
while ((++isolevel)->name) {
if (!(pyval = psycopg_ensure_bytes(pyval))) {
goto exit;
}
if (0 == strcasecmp(value->name, Bytes_AS_STRING(pyval))) {
rv = value->name;
if (0 == strcasecmp(isolevel->name, Bytes_AS_STRING(pyval))) {
break;
}
}
if (!rv) {
if (!isolevel->name) {
char msg[256];
snprintf(msg, sizeof(msg),
"bad value for isolation_level: '%s'", Bytes_AS_STRING(pyval));
@ -423,9 +422,17 @@ _psyco_conn_parse_isolevel(PyObject *pyval)
}
}
/* use only supported levels on older PG versions */
if (isolevel && self->server_version < 80000) {
if (isolevel->value == 1 || isolevel->value == 3) {
++isolevel;
}
}
exit:
Py_XDECREF(pyval);
return rv;
return isolevel ? isolevel->name : NULL;
}
/* convert True/False/"default" into a C string */
@ -477,7 +484,7 @@ psyco_conn_set_transaction(connectionObject *self, PyObject *args, PyObject *kwa
if (Py_None != isolation_level) {
const char *value = NULL;
if (!(value = _psyco_conn_parse_isolevel(isolation_level))) {
if (!(value = _psyco_conn_parse_isolevel(self, isolation_level))) {
return NULL;
}
if (0 != conn_set(self, "default_transaction_isolation", value)) {

View File

@ -204,14 +204,23 @@ class IsolationLevelsTestCase(unittest.TestCase):
conn = self.connect()
curs = conn.cursor()
for name, level in (
levels = (
(None, psycopg2.extensions.ISOLATION_LEVEL_AUTOCOMMIT),
('read uncommitted', psycopg2.extensions.ISOLATION_LEVEL_READ_UNCOMMITTED),
('read committed', psycopg2.extensions.ISOLATION_LEVEL_READ_COMMITTED),
('repeatable read', psycopg2.extensions.ISOLATION_LEVEL_REPEATABLE_READ),
('serializable', psycopg2.extensions.ISOLATION_LEVEL_SERIALIZABLE),
):
)
for name, level in levels:
conn.set_isolation_level(level)
# the only values available on prehistoric PG versions
if conn.server_version < 80000:
if level in (
psycopg2.extensions.ISOLATION_LEVEL_READ_UNCOMMITTED,
psycopg2.extensions.ISOLATION_LEVEL_REPEATABLE_READ):
name, level = levels[levels.index((name, level)) + 1]
self.assertEqual(conn.isolation_level, level)
curs.execute('show transaction_isolation;')