| # Licensed to the Apache Software Foundation (ASF) under one |
| # or more contributor license agreements. See the NOTICE file |
| # distributed with this work for additional information |
| # regarding copyright ownership. The ASF licenses this file |
| # to you under the Apache License, Version 2.0 (the |
| # "License"); you may not use this file except in compliance |
| # with the License. You may obtain a copy of the License at |
| # |
| # http://www.apache.org/licenses/LICENSE-2.0 |
| # |
| # Unless required by applicable law or agreed to in writing, |
| # software distributed under the License is distributed on an |
| # "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| # KIND, either express or implied. See the License for the |
| # specific language governing permissions and limitations |
| # under the License. |
| import queue |
| from concurrent.futures import Future |
| |
| from gremlin_python.driver import resultset, useragent |
| from gremlin_python.driver.aiohttp.transport import AiohttpHTTPTransport |
| from gremlin_python.driver.http_request import HttpRequest |
| |
| __author__ = 'David M. Brown (davebshow@gmail.com)' |
| |
| |
| class GremlinServerError(Exception): |
| def __init__(self, status): |
| super(GremlinServerError, self).__init__('{0}: {1}'.format(status['code'], status['message'])) |
| self.status_code = status['code'] |
| self.status_message = status['message'] |
| self.status_exception = status['exception'] |
| |
| |
| class Connection: |
| |
| def __init__(self, url, traversal_source, |
| executor, pool, |
| response_serializer=None, auth=None, interceptors=None, |
| headers=None, enable_user_agent_on_connect=True, |
| bulk_results=False, **transport_kwargs): |
| if callable(interceptors): |
| interceptors = [interceptors] |
| elif isinstance(interceptors, tuple): |
| interceptors = list(interceptors) |
| elif not (isinstance(interceptors, list) or interceptors is None): |
| raise TypeError("interceptors must be a callable, tuple, list or None") |
| |
| # Auth is just an interceptor. As a convenience (and for discoverability), the auth |
| # interceptor is appended to the end of the interceptor list so it runs last, after |
| # any user interceptors have modified the request. |
| if auth is not None: |
| interceptors = (interceptors or []) + [auth] |
| |
| self._url = url |
| self._headers = headers |
| self._traversal_source = traversal_source |
| self._transport_kwargs = transport_kwargs |
| self._executor = executor |
| self._transport = None |
| self._pool = pool |
| self._result_set = None |
| self._inited = False |
| self._response_serializer = response_serializer |
| self._interceptors = interceptors |
| self._enable_user_agent_on_connect = enable_user_agent_on_connect |
| if self._enable_user_agent_on_connect: |
| self.__add_header(useragent.userAgentHeader, useragent.userAgent) |
| self._bulk_results = bulk_results |
| if self._bulk_results: |
| self.__add_header("bulkResults", "true") |
| |
| def connect(self): |
| if self._transport: |
| self._transport.close() |
| self._transport = AiohttpHTTPTransport(**self._transport_kwargs) |
| self._transport.connect(self._url, self._headers) |
| self._inited = True |
| |
| def close(self): |
| if self._inited: |
| self._transport.close() |
| |
| def _write_request(self, request_message): |
| accept = str(self._response_serializer.version, encoding='utf-8') |
| |
| headers = {'accept': accept} |
| |
| # Promote transactionId to HTTP header before interceptors run. |
| # The field remains in the serialized body as well (dual transmission |
| # per the HTTP transaction protocol specification). |
| if hasattr(request_message, 'fields') and 'transactionId' in request_message.fields: |
| headers['X-Transaction-Id'] = request_message.fields['transactionId'] |
| |
| http_request = HttpRequest( |
| method="POST", |
| url=self._url, |
| headers=headers, |
| body=request_message |
| ) |
| |
| for interceptor in self._interceptors or []: |
| interceptor(http_request) |
| |
| # Auto-serialize if no interceptor already did so |
| http_request.serialize_body() |
| |
| # Build the transport message in the format the transport expects |
| message = { |
| 'headers': http_request.headers, |
| 'payload': http_request.body |
| } |
| self._transport.write(message) |
| |
| def write(self, request_message): |
| if not self._inited: |
| self.connect() |
| self._result_set = resultset.ResultSet(queue.Queue()) |
| # Create write task |
| future = Future() |
| future_write = self._executor.submit( |
| self._write_request, request_message) |
| |
| def cb(f): |
| try: |
| f.result() |
| except Exception as e: |
| future.set_exception(e) |
| self._pool.put_nowait(self) |
| else: |
| # Start receive task |
| done = self._executor.submit(self._receive) |
| self._result_set.done = done |
| future.set_result(self._result_set) |
| |
| future_write.add_done_callback(cb) |
| return future |
| |
| def _receive(self): |
| try: |
| # Surface error responses whose Content-Type doesn't match the |
| # configured response serializer (e.g. plain-text 5xx). |
| status = getattr(self._transport, 'status_code', None) |
| response_content_type = str(self._response_serializer.version, encoding='utf-8') |
| if status is not None and status >= 400: |
| content_type = getattr(self._transport, 'content_type', '') |
| if response_content_type not in content_type: |
| body = self._transport.read_body().decode('utf-8', errors='replace') |
| raise GremlinServerError({ |
| 'code': status, |
| 'message': body, |
| 'exception': '' |
| }) |
| |
| # 204 No Content |
| if status == 204: |
| return |
| |
| # Stream items through the configured response serializer; it |
| # raises GremlinServerError if the response ends with a non-success status. |
| stream = self._transport.get_stream() |
| for obj in self._response_serializer.deserialize_response_stream(stream): |
| self._result_set.stream.put_nowait(obj) |
| finally: |
| self._pool.put_nowait(self) |
| |
| def __add_header(self, key, value): |
| if self._headers is None: |
| self._headers = dict() |
| # Headers may be a list of pairs |
| if isinstance(self._headers, list): |
| for pair in self._headers: |
| if pair[0] == key: |
| self._headers.remove(pair) |
| self._headers.append((key, value)) |
| else: |
| self._headers[key] = value |
