Merge branch 'dups' into add-support-for-async-rest-streaming

google/api_core/_rest_streaming_base.py

@@ -0,0 +1,132 @@
+# Copyright 2021 Google LLC
+#
+# Licensed 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.
+
+"""Helpers for server-side streaming in REST."""
+
+from collections import deque
+import string
+from typing import Deque, Union
+
+import proto
+import requests
+import google.protobuf.message
+from google.protobuf.json_format import Parse
+
+
+class ResponseIterator:
+ """Iterator over REST API responses.
+
+ Args:
+ response (requests.Response): An API response object.
+ response_message_cls (Union[proto.Message, google.protobuf.message.Message]): A response
+ class expected to be returned from an API.
+
+ Raises:
+ ValueError: If `response_message_cls` is not a subclass of `proto.Message` or `google.protobuf.message.Message`.
+ """
+
+ def __init__(
+ self,
+ response: requests.Response,
+ response_message_cls: Union[proto.Message, google.protobuf.message.Message],
+ ):
+ self._response = response
+ self._response_message_cls = response_message_cls
+ # Inner iterator over HTTP response's content.
+ self._response_itr = self._response.iter_content(decode_unicode=True)
+ # Contains a list of JSON responses ready to be sent to user.
+ self._ready_objs: Deque[str] = deque()
+ # Current JSON response being built.
+ self._obj = ""
+ # Keeps track of the nesting level within a JSON object.
+ self._level = 0
+ # Keeps track whether HTTP response is currently sending values
+ # inside of a string value.
+ self._in_string = False
+ # Whether an escape symbol "\" was encountered.
+ self._escape_next = False
+
+ def cancel(self):
+ """Cancel existing streaming operation."""
+ self._response.close()
+
+ def _process_chunk(self, chunk: str):
+ if self._level == 0:
+ if chunk[0] != "[":
+ raise ValueError(
+ "Can only parse array of JSON objects, instead got %s" % chunk
+ )
+ for char in chunk:
+ if char == "{":
+ if self._level == 1:
+ # Level 1 corresponds to the outermost JSON object
+ # (i.e. the one we care about).
+ self._obj = ""
+ if not self._in_string:
+ self._level += 1
+ self._obj += char
+ elif char == "}":
+ self._obj += char
+ if not self._in_string:
+ self._level -= 1
+ if not self._in_string and self._level == 1:
+ self._ready_objs.append(self._obj)
+ elif char == '"':
+ # Helps to deal with an escaped quotes inside of a string.
+ if not self._escape_next:
+ self._in_string = not self._in_string
+ self._obj += char
+ elif char in string.whitespace:
+ if self._in_string:
+ self._obj += char
+ elif char == "[":
+ if self._level == 0:
+ self._level += 1
+ else:
+ self._obj += char
+ elif char == "]":
+ if self._level == 1:
+ self._level -= 1
+ else:
+ self._obj += char
+ else:
+ self._obj += char
+ self._escape_next = not self._escape_next if char == "\\" else False
+
+ def __next__(self):
+ while not self._ready_objs:
+ try:
+ chunk = next(self._response_itr)
+ self._process_chunk(chunk)
+ except StopIteration as e:
+ if self._level > 0:
+ raise ValueError("Unfinished stream: %s" % self._obj)
+ raise e
+ return self._grab()
+
+ def _grab(self):
+ # Add extra quotes to make json.loads happy.
+ if issubclass(self._response_message_cls, proto.Message):
+ return self._response_message_cls.from_json(
+ self._ready_objs.popleft(), ignore_unknown_fields=True
+ )
+ elif issubclass(self._response_message_cls, google.protobuf.message.Message):
+ return Parse(self._ready_objs.popleft(), self._response_message_cls())
+ else:
+ raise ValueError(
+ "Response message class must be a subclass of proto.Message or google.protobuf.message.Message."
+ )
+
+ def __iter__(self):
+ return self

google/api_core/rest_streaming_async.py

@@ -0,0 +1,132 @@
+# Copyright 2021 Google LLC
+#
+# Licensed 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.
+
+"""Helpers for server-side streaming in REST."""
+
+from collections import deque
+import string
+from typing import Deque, Union
+
+import proto
+import requests
+import google.protobuf.message
+from google.protobuf.json_format import Parse
+
+
+class ResponseIterator:
+ """Iterator over REST API responses.
+
+ Args:
+ response (requests.Response): An API response object.
+ response_message_cls (Union[proto.Message, google.protobuf.message.Message]): A response
+ class expected to be returned from an API.
+
+ Raises:
+ ValueError: If `response_message_cls` is not a subclass of `proto.Message` or `google.protobuf.message.Message`.
+ """
+
+ def __init__(
+ self,
+ response: requests.Response,
+ response_message_cls: Union[proto.Message, google.protobuf.message.Message],
+ ):
+ self._response = response
+ self._response_message_cls = response_message_cls
+ # Inner iterator over HTTP response's content.
+ self._response_itr = self._response.iter_content(decode_unicode=True)
+ # Contains a list of JSON responses ready to be sent to user.
+ self._ready_objs: Deque[str] = deque()
+ # Current JSON response being built.
+ self._obj = ""
+ # Keeps track of the nesting level within a JSON object.
+ self._level = 0
+ # Keeps track whether HTTP response is currently sending values
+ # inside of a string value.
+ self._in_string = False
+ # Whether an escape symbol "\" was encountered.
+ self._escape_next = False
+
+ def cancel(self):
+ """Cancel existing streaming operation."""
+ self._response.close()
+
+ def _process_chunk(self, chunk: str):
+ if self._level == 0:
+ if chunk[0] != "[":
+ raise ValueError(
+ "Can only parse array of JSON objects, instead got %s" % chunk
+ )
+ for char in chunk:
+ if char == "{":
+ if self._level == 1:
+ # Level 1 corresponds to the outermost JSON object
+ # (i.e. the one we care about).
+ self._obj = ""
+ if not self._in_string:
+ self._level += 1
+ self._obj += char
+ elif char == "}":
+ self._obj += char
+ if not self._in_string:
+ self._level -= 1
+ if not self._in_string and self._level == 1:
+ self._ready_objs.append(self._obj)
+ elif char == '"':
+ # Helps to deal with an escaped quotes inside of a string.
+ if not self._escape_next:
+ self._in_string = not self._in_string
+ self._obj += char
+ elif char in string.whitespace:
+ if self._in_string:
+ self._obj += char
+ elif char == "[":
+ if self._level == 0:
+ self._level += 1
+ else:
+ self._obj += char
+ elif char == "]":
+ if self._level == 1:
+ self._level -= 1
+ else:
+ self._obj += char
+ else:
+ self._obj += char
+ self._escape_next = not self._escape_next if char == "\\" else False
+
+ def __next__(self):
+ while not self._ready_objs:
+ try:
+ chunk = next(self._response_itr)
+ self._process_chunk(chunk)
+ except StopIteration as e:
+ if self._level > 0:
+ raise ValueError("Unfinished stream: %s" % self._obj)
+ raise e
+ return self._grab()
+
+ def _grab(self):
+ # Add extra quotes to make json.loads happy.
+ if issubclass(self._response_message_cls, proto.Message):
+ return self._response_message_cls.from_json(
+ self._ready_objs.popleft(), ignore_unknown_fields=True
+ )
+ elif issubclass(self._response_message_cls, google.protobuf.message.Message):
+ return Parse(self._ready_objs.popleft(), self._response_message_cls())
+ else:
+ raise ValueError(
+ "Response message class must be a subclass of proto.Message or google.protobuf.message.Message."
+ )
+
+ def __iter__(self):
+ return self