Add google-endpoints to third_party/.

third_party/google-endpoints/apitools/base/py/batch.py

+#!/usr/bin/env python
+#
+# Copyright 2015 Google Inc.
+#
+# 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.
+
+"""Library for handling batch HTTP requests for apitools."""
+
+import collections
+import email.generator as generator
+import email.mime.multipart as mime_multipart
+import email.mime.nonmultipart as mime_nonmultipart
+import email.parser as email_parser
+import itertools
+import time
+import uuid
+
+import six
+from six.moves import http_client
+from six.moves import urllib_parse
+
+from apitools.base.py import exceptions
+from apitools.base.py import http_wrapper
+
+__all__ = [
+    'BatchApiRequest',
+]
+
+
+class RequestResponseAndHandler(collections.namedtuple(
+        'RequestResponseAndHandler', ['request', 'response', 'handler'])):
+
+    """Container for data related to completing an HTTP request.
+
+    This contains an HTTP request, its response, and a callback for handling
+    the response from the server.
+
+    Attributes:
+      request: An http_wrapper.Request object representing the HTTP request.
+      response: The http_wrapper.Response object returned from the server.
+      handler: A callback function accepting two arguments, response
+        and exception. Response is an http_wrapper.Response object, and
+        exception is an apiclient.errors.HttpError object if an error
+        occurred, or otherwise None.
+    """
+
+
+class BatchApiRequest(object):
+
+    class ApiCall(object):
+
+        """Holds request and response information for each request.
+
+        ApiCalls are ultimately exposed to the client once the HTTP
+        batch request has been completed.
+
+        Attributes:
+          http_request: A client-supplied http_wrapper.Request to be
+              submitted to the server.
+          response: A http_wrapper.Response object given by the server as a
+              response to the user request, or None if an error occurred.
+          exception: An apiclient.errors.HttpError object if an error
+              occurred, or None.
+
+        """
+
+        def __init__(self, request, retryable_codes, service, method_config):
+            """Initialize an individual API request.
+
+            Args:
+              request: An http_wrapper.Request object.
+              retryable_codes: A list of integer HTTP codes that can
+                  be retried.
+              service: A service inheriting from base_api.BaseApiService.
+              method_config: Method config for the desired API request.
+
+            """
+            self.__retryable_codes = list(
+                set(retryable_codes + [http_client.UNAUTHORIZED]))
+            self.__http_response = None
+            self.__service = service
+            self.__method_config = method_config
+
+            self.http_request = request
+            # TODO(user): Add some validation to these fields.
+            self.__response = None
+            self.__exception = None
+
+        @property
+        def is_error(self):
+            return self.exception is not None
+
+        @property
+        def response(self):
+            return self.__response
+
+        @property
+        def exception(self):
+            return self.__exception
+
+        @property
+        def authorization_failed(self):
+            return (self.__http_response and (
+                self.__http_response.status_code == http_client.UNAUTHORIZED))
+
+        @property
+        def terminal_state(self):
+            if self.__http_response is None:
+                return False
+            response_code = self.__http_response.status_code
+            return response_code not in self.__retryable_codes
+
+        def HandleResponse(self, http_response, exception):
+            """Handles an incoming http response to the request in http_request.
+
+            This is intended to be used as a callback function for
+            BatchHttpRequest.Add.
+
+            Args:
+              http_response: Deserialized http_wrapper.Response object.
+              exception: apiclient.errors.HttpError object if an error
+                  occurred.
+
+            """
+            self.__http_response = http_response
+            self.__exception = exception
+            if self.terminal_state and not self.__exception:
+                self.__response = self.__service.ProcessHttpResponse(
+                    self.__method_config, self.__http_response)
+
+    def __init__(self, batch_url=None, retryable_codes=None):
+        """Initialize a batch API request object.
+
+        Args:
+          batch_url: Base URL for batch API calls.
+          retryable_codes: A list of integer HTTP codes that can be retried.
+        """
+        self.api_requests = []
+        self.retryable_codes = retryable_codes or []
+        self.batch_url = batch_url or 'https://www.googleapis.com/batch'
+
+    def Add(self, service, method, request, global_params=None):
+        """Add a request to the batch.
+
+        Args:
+          service: A class inheriting base_api.BaseApiService.
+          method: A string indicated desired method from the service. See
+              the example in the class docstring.
+          request: An input message appropriate for the specified
+              service.method.
+          global_params: Optional additional parameters to pass into
+              method.PrepareHttpRequest.
+
+        Returns:
+          None
+
+        """
+        # Retrieve the configs for the desired method and service.
+        method_config = service.GetMethodConfig(method)
+        upload_config = service.GetUploadConfig(method)
+
+        # Prepare the HTTP Request.
+        http_request = service.PrepareHttpRequest(
+            method_config, request, global_params=global_params,
+            upload_config=upload_config)
+
+        # Create the request and add it to our master list.
+        api_request = self.ApiCall(
+            http_request, self.retryable_codes, service, method_config)
+        self.api_requests.append(api_request)
+
+    def Execute(self, http, sleep_between_polls=5, max_retries=5):
+        """Execute all of the requests in the batch.
+
+        Args:
+          http: httplib2.Http object for use in the request.
+          sleep_between_polls: Integer number of seconds to sleep between
+              polls.
+          max_retries: Max retries. Any requests that have not succeeded by
+              this number of retries simply report the last response or
+              exception, whatever it happened to be.
+
+        Returns:
+          List of ApiCalls.
+        """
+        requests = [request for request in self.api_requests
+                    if not request.terminal_state]
+
+        for attempt in range(max_retries):
+            if attempt:
+                time.sleep(sleep_between_polls)
+
+            # Create a batch_http_request object and populate it with
+            # incomplete requests.
+            batch_http_request = BatchHttpRequest(batch_url=self.batch_url)
+            for request in requests:
+                batch_http_request.Add(
+                    request.http_request, request.HandleResponse)
+            batch_http_request.Execute(http)
+
+            # Collect retryable requests.
+            requests = [request for request in self.api_requests if not
+                        request.terminal_state]
+
+            if hasattr(http.request, 'credentials'):
+                if any(request.authorization_failed for request in requests):
+                    http.request.credentials.refresh(http)
+
+            if not requests:
+                break
+
+        return self.api_requests
+
+
+class BatchHttpRequest(object):
+
+    """Batches multiple http_wrapper.Request objects into a single request."""
+
+    def __init__(self, batch_url, callback=None):
+        """Constructor for a BatchHttpRequest.
+
+        Args:
+          batch_url: URL to send batch requests to.
+          callback: A callback to be called for each response, of the
+              form callback(response, exception). The first parameter is
+              the deserialized Response object. The second is an
+              apiclient.errors.HttpError exception object if an HTTP error
+              occurred while processing the request, or None if no error
+              occurred.
+        """
+        # Endpoint to which these requests are sent.
+        self.__batch_url = batch_url
+
+        # Global callback to be called for each individual response in the
+        # batch.
+        self.__callback = callback
+
+        # List of requests, responses and handlers.
+        self.__request_response_handlers = {}
+
+        # The last auto generated id.
+        self.__last_auto_id = itertools.count()
+
+        # Unique ID on which to base the Content-ID headers.
+        self.__base_id = uuid.uuid4()
+
+    def _ConvertIdToHeader(self, request_id):
+        """Convert an id to a Content-ID header value.
+
+        Args:
+          request_id: String identifier for a individual request.
+
+        Returns:
+          A Content-ID header with the id_ encoded into it. A UUID is
+          prepended to the value because Content-ID headers are
+          supposed to be universally unique.
+
+        """
+        return '<%s+%s>' % (self.__base_id, urllib_parse.quote(request_id))
+
+    @staticmethod
+    def _ConvertHeaderToId(header):
+        """Convert a Content-ID header value to an id.
+
+        Presumes the Content-ID header conforms to the format that
+        _ConvertIdToHeader() returns.
+
+        Args:
+          header: A string indicating the Content-ID header value.
+
+        Returns:
+          The extracted id value.
+
+        Raises:
+          BatchError if the header is not in the expected format.
+        """
+        if not (header.startswith('<') or header.endswith('>')):
+            raise exceptions.BatchError(
+                'Invalid value for Content-ID: %s' % header)
+        if '+' not in header:
+            raise exceptions.BatchError(
+                'Invalid value for Content-ID: %s' % header)
+        _, request_id = header[1:-1].rsplit('+', 1)
+
+        return urllib_parse.unquote(request_id)
+
+    def _SerializeRequest(self, request):
+        """Convert a http_wrapper.Request object into a string.
+
+        Args:
+          request: A http_wrapper.Request to serialize.
+
+        Returns:
+          The request as a string in application/http format.
+        """
+        # Construct status line
+        parsed = urllib_parse.urlsplit(request.url)
+        request_line = urllib_parse.urlunsplit(
+            (None, None, parsed.path, parsed.query, None))
+        status_line = u' '.join((
+            request.http_method,
+            request_line.decode('utf-8'),
+            u'HTTP/1.1\n'
+        ))
+        major, minor = request.headers.get(
+            'content-type', 'application/json').split('/')
+        msg = mime_nonmultipart.MIMENonMultipart(major, minor)
+
+        # MIMENonMultipart adds its own Content-Type header.
+        # Keep all of the other headers in `request.headers`.
+        for key, value in request.headers.items():
+            if key == 'content-type':
+                continue
+            msg[key] = value
+
+        msg['Host'] = parsed.netloc
+        msg.set_unixfrom(None)
+
+        if request.body is not None:
+            msg.set_payload(request.body)
+
+        # Serialize the mime message.
+        str_io = six.StringIO()
+        # maxheaderlen=0 means don't line wrap headers.
+        gen = generator.Generator(str_io, maxheaderlen=0)
+        gen.flatten(msg, unixfrom=False)
+        body = str_io.getvalue()
+
+        return status_line + body
+
+    def _DeserializeResponse(self, payload):
+        """Convert string into Response and content.
+
+        Args:
+          payload: Header and body string to be deserialized.
+
+        Returns:
+          A Response object
+        """
+        # Strip off the status line.
+        status_line, payload = payload.split('\n', 1)
+        _, status, _ = status_line.split(' ', 2)
+
+        # Parse the rest of the response.
+        parser = email_parser.Parser()
+        msg = parser.parsestr(payload)
+
+        # Get the headers.
+        info = dict(msg)
+        info['status'] = status
+
+        # Create Response from the parsed headers.
+        content = msg.get_payload()
+
+        return http_wrapper.Response(info, content, self.__batch_url)
+
+    def _NewId(self):
+        """Create a new id.
+
+        Auto incrementing number that avoids conflicts with ids already used.
+
+        Returns:
+           A new unique id string.
+        """
+        return str(next(self.__last_auto_id))
+
+    def Add(self, request, callback=None):
+        """Add a new request.
+
+        Args:
+          request: A http_wrapper.Request to add to the batch.
+          callback: A callback to be called for this response, of the
+              form callback(response, exception). The first parameter is the
+              deserialized response object. The second is an
+              apiclient.errors.HttpError exception object if an HTTP error
+              occurred while processing the request, or None if no errors
+              occurred.
+
+        Returns:
+          None
+        """
+        handler = RequestResponseAndHandler(request, None, callback)
+        self.__request_response_handlers[self._NewId()] = handler
+
+    def _Execute(self, http):
+        """Serialize batch request, send to server, process response.
+
+        Args:
+          http: A httplib2.Http object to be used to make the request with.
+
+        Raises:
+          httplib2.HttpLib2Error if a transport error has occured.
+          apiclient.errors.BatchError if the response is the wrong format.
+        """
+        message = mime_multipart.MIMEMultipart('mixed')
+        # Message should not write out its own headers.
+        setattr(message, '_write_headers', lambda self: None)
+
+        # Add all the individual requests.
+        for key in self.__request_response_handlers:
+            msg = mime_nonmultipart.MIMENonMultipart('application', 'http')
+            msg['Content-Transfer-Encoding'] = 'binary'
+            msg['Content-ID'] = self._ConvertIdToHeader(key)
+
+            body = self._SerializeRequest(
+                self.__request_response_handlers[key].request)
+            msg.set_payload(body)
+            message.attach(msg)
+
+        request = http_wrapper.Request(self.__batch_url, 'POST')
+        request.body = message.as_string()
+        request.headers['content-type'] = (
+            'multipart/mixed; boundary="%s"') % message.get_boundary()
+
+        response = http_wrapper.MakeRequest(http, request)
+
+        if response.status_code >= 300:
+            raise exceptions.HttpError.FromResponse(response)
+
+        # Prepend with a content-type header so Parser can handle it.
+        header = 'content-type: %s\r\n\r\n' % response.info['content-type']
+
+        parser = email_parser.Parser()
+        mime_response = parser.parsestr(header + response.content)
+
+        if not mime_response.is_multipart():
+            raise exceptions.BatchError(
+                'Response not in multipart/mixed format.')
+
+        for part in mime_response.get_payload():
+            request_id = self._ConvertHeaderToId(part['Content-ID'])
+            response = self._DeserializeResponse(part.get_payload())
+
+            # Disable protected access because namedtuple._replace(...)
+            # is not actually meant to be protected.
+            # pylint: disable=protected-access
+            self.__request_response_handlers[request_id] = (
+                self.__request_response_handlers[request_id]._replace(
+                    response=response))
+
+    def Execute(self, http):
+        """Execute all the requests as a single batched HTTP request.
+
+        Args:
+          http: A httplib2.Http object to be used with the request.
+
+        Returns:
+          None
+
+        Raises:
+          BatchError if the response is the wrong format.
+        """
+
+        self._Execute(http)
+
+        for key in self.__request_response_handlers:
+            response = self.__request_response_handlers[key].response
+            callback = self.__request_response_handlers[key].handler
+
+            exception = None
+
+            if response.status_code >= 300:
+                exception = exceptions.HttpError.FromResponse(response)
+
+            if callback is not None:
+                callback(response, exception)
+            if self.__callback is not None:
+                self.__callback(response, exception)