def _get_field(self, field):
from psycopg2cffi._impl.adapters import bytes_to_ascii
if self._exc and self._exc._pgres:
b = libpq.PQresultErrorField(self._exc._pgres, field)
if b:
b = ffi.string(b)
if six.PY3: # py2 tests insist on str here
b = bytes_to_ascii(b)
return b
def _create_exception(self, pgres=None, msg=None, cursor=None):
"""Return the appropriate exception instance for the current status.
IMPORTANT: the new exception takes ownership of pgres: if pgres is
passed as parameter, the callee must delete its pointer (e.g. it may
be set to null). If there is a pgres in the cursor it is "stolen": the
cursor will have it set to Null.
"""
assert pgres is None or cursor is None, \
"cannot specify pgres and cursor together"
if cursor and cursor._pgres:
pgres, cursor._pgres = cursor._pgres, ffi.NULL
exc_type = exceptions.OperationalError
code = pgmsg = None
# If no custom message is passed then get the message from postgres.
# If pgres is available then we first try to get the message for the
# last command, and then the error message for the connection
if pgres:
pgmsg = libpq.PQresultErrorMessage(pgres)
pgmsg = bytes_to_ascii(ffi.string(pgmsg)) if pgmsg else None
# Get the correct exception class based on the error code
code = libpq.PQresultErrorField(pgres, libpq.PG_DIAG_SQLSTATE)
if code != ffi.NULL:
code = bytes_to_ascii(ffi.string(code))
exc_type = util.get_exception_for_sqlstate(code)
else:
code = None
exc_type = exceptions.DatabaseError
if not pgmsg:
pgmsg = libpq.PQerrorMessage(self._pgconn)
pgmsg = bytes_to_ascii(ffi.string(pgmsg)) if pgmsg else None
if msg is None and pgmsg:
msg = pgmsg
for prefix in ("ERROR: ", "FATAL: ", "PANIC: "):
if msg.startswith(prefix):
msg = msg[len(prefix):]
break
# Clear the connection if the status is CONNECTION_BAD (fatal error)
if self._pgconn and libpq.PQstatus(
self._pgconn) == libpq.CONNECTION_BAD:
self._closed = 2
exc = exc_type(msg)
exc.pgcode = code
exc.pgerror = pgmsg
exc.cursor = cursor
exc._pgres = pgres
return exc
def _get_field(self, field):
if self._exc and self._exc._pgres:
b = libpq.PQresultErrorField(self._exc._pgres, field)
if b:
return ffi.string(b)