def begin(self):
"""
Begins this transaction.
"""
if hasattr(self._locals,
'transaction_exists') and self._locals.transaction_exists:
raise TransactionError("Nested transactions are not allowed.")
if self.state != _STATE_NOT_STARTED:
raise TransactionError("Transaction has already been started.")
self._locals.transaction_exists = True
self.start_time = time.time()
self.thread_id = thread_id()
try:
request = transaction_create_codec.encode_request(
timeout=int(self.timeout * 1000),
durability=self.durability,
transaction_type=self.transaction_type,
thread_id=self.thread_id)
invocation = Invocation(request,
connection=self.connection,
response_handler=lambda m: m)
invocation_service = self._context.invocation_service
invocation_service.invoke(invocation)
response = invocation.future.result()
self.id = transaction_create_codec.decode_response(response)
self.state = _STATE_ACTIVE
except:
self._locals.transaction_exists = False
raise
def _get_or_create_object(self, name, proxy_type):
if self.state != _STATE_ACTIVE:
raise TransactionError("Transaction is not in active state.")
self._check_thread()
key = (proxy_type, name)
try:
return self._objects[key]
except KeyError:
proxy = proxy_type(name, self, self._context)
self._objects[key] = proxy
return make_blocking(proxy)
def rollback(self):
"""Rollback of this current transaction."""
self._check_thread()
if self.state not in (_STATE_ACTIVE, _STATE_PARTIAL_COMMIT):
raise TransactionError("Transaction is not active.")
try:
if self.state != _STATE_PARTIAL_COMMIT:
request = transaction_rollback_codec.encode_request(
self.id, self.thread_id)
invocation = Invocation(request, connection=self.connection)
invocation_service = self._context.invocation_service
invocation_service.invoke(invocation)
invocation.future.result()
self.state = _STATE_ROLLED_BACK
finally:
self._locals.transaction_exists = False
def commit(self):
"""Commits this transaction."""
self._check_thread()
if self.state != _STATE_ACTIVE:
raise TransactionError("Transaction is not active.")
try:
self._check_timeout()
request = transaction_commit_codec.encode_request(
self.id, self.thread_id)
invocation = Invocation(request, connection=self.connection)
invocation_service = self._context.invocation_service
invocation_service.invoke(invocation)
invocation.future.result()
self.state = _STATE_COMMITTED
except:
self.state = _STATE_PARTIAL_COMMIT
raise
finally:
self._locals.transaction_exists = False
def _check_timeout(self):
if time.time() > self.timeout + self.start_time:
raise TransactionError("Transaction has timed out.")
def _check_thread(self):
if not thread_id() == self.thread_id:
raise TransactionError("Transaction cannot span multiple threads.")