def create_request(self,
query=None,
variables=None,
mutations=None,
commit_now=None,
resp_format="JSON"):
if resp_format == "JSON":
resp_format = api.Request.RespFormat.JSON
elif resp_format == "RDF":
resp_format = api.Request.RespFormat.RDF
else:
raise errors.TransactionError(
'Response format should be either RDF or JSON')
"""Creates a request object"""
request = api.Request(start_ts=self._ctx.start_ts,
commit_now=commit_now,
read_only=self._read_only,
best_effort=self._best_effort,
resp_format=resp_format)
if variables is not None:
for key, value in variables.items():
if util.is_string(key) and util.is_string(value):
request.vars[key] = value
else:
raise errors.TransactionError(
'Values and keys in variable map must be strings')
if query:
request.query = query.encode('utf8')
if mutations:
request.mutations.extend(mutations)
return request
def _common_commit(self):
if self._read_only:
raise errors.TransactionError(
'Readonly transaction cannot run mutations or be committed')
if self._finished:
raise errors.TransactionError(
'Transaction has already been committed or discarded')
self._finished = True
return self._mutated
def do_request(self,
request,
timeout=None,
metadata=None,
credentials=None):
"""Executes a query/mutate operation on the server."""
if self._finished:
raise errors.TransactionError(
'Transaction has already been committed or discarded')
if len(request.mutations) > 0:
if self._read_only:
raise errors.TransactionError(
'Readonly transaction cannot run mutations')
self._mutated = True
request.hash = self._ctx.hash
new_metadata = self._dg.add_login_metadata(metadata)
query_error = None
try:
response = self._dc.query(request,
timeout=timeout,
metadata=new_metadata,
credentials=credentials)
except Exception as error:
if util.is_jwt_expired(error):
self._dg.retry_login()
new_metadata = self._dg.add_login_metadata(metadata)
try:
response = self._dc.query(request,
timeout=timeout,
metadata=new_metadata,
credentials=credentials)
except Exception as error:
query_error = error
else:
query_error = error
if query_error is not None:
try:
self.discard(timeout=timeout,
metadata=metadata,
credentials=credentials)
except:
# Ignore error - user should see the original error.
pass
self._common_except_mutate(query_error)
if request.commit_now:
self._finished = True
self.merge_context(response.txn)
return response
def merge_context(self, src=None):
"""Merges context from this instance with src."""
if src is None:
# This condition will be true only if the server doesn't return a
# txn context after a query or mutation.
return
if self._ctx.start_ts == 0:
self._ctx.start_ts = src.start_ts
elif self._ctx.start_ts != src.start_ts:
# This condition should never be true.
raise errors.TransactionError('StartTs mismatch')
self._ctx.hash = src.hash
self._ctx.keys.extend(src.keys)
self._ctx.preds.extend(src.preds)
def create_request(self,
query=None,
variables=None,
mutations=None,
commit_now=None):
"""Creates a request object"""
request = api.Request(start_ts=self._ctx.start_ts,
commit_now=commit_now,
read_only=self._read_only,
best_effort=self._best_effort)
if variables is not None:
for key, value in variables.items():
if util.is_string(key) and util.is_string(value):
request.vars[key] = value
else:
raise errors.TransactionError(
'Values and keys in variable map must be strings')
if query:
request.query = query.encode('utf8')
if mutations:
request.mutations.extend(mutations)
return request
