hhru/tornado-protobuf-utils

Tornado protocol buffers utilities

Usage Example: copy and paste in any RequestHandler

Asynchronous

from protoctor.client import construct_async_protobuf_service
from protoctor.controller import RpcController

rpc_controller = RpcController()

def _search_service_cb(resume_search_result):
   if resume_search_result is not None:
       logging.debug('Search without error')
       logging.debug('\n' + str(resume_search_result))
   else:
       logging.debug('Search error: ' + controller.ErrorText())

fetcher = AsyncHTTPClient().fetch

search_service = construct_async_protobuf_service(ResumeSearch_Stub,
    self.config.protoSearchHost,
    fetcher,
    logger = logging, method = 'POST', data = {'requestId' : self.requestId}
)
search_service.ResumeSearch(rpc_controller, resume_pb2.ResumeCriteria(), _search_service_cb)

fetcher can be:

• tornado.httpclient.AsyncHTTPClient().fetch async http client built in Tornado
• frontik.handler.PageHandler().fetch_request async http client wrapper in Frontik-based applications
• any other http client that accepts tornado.httpclient.HTTPRequest in their fetch function.

construct_async_protobuf_service almost accepts any number of kw arguments that will be proxied to HTTPRequest constructor, except:

• data argument, that should be dict of any additional params that should be passed into request url (for example, passing data = {'requestId' : 1} would provide request url as the following: http://proto.host:port/SearchService/ResumeSearch?requestId=1)
• logger to log messages about client-server interaction inside rpc channel

If your request method differs from POST, PATCH, PUT (which require http request body), GET for e.g., your protobuf request would be base64-encoded and will be applied to request argument. For example:

http://proto.host:port/SearchService/ResumeSearch?request=IAAoADAyQhYKEtC90LDRh9Cw0LvRjNC90LjQuhgASgYIARCF7QfaAcABCLr%2FIQin7YYHCJ%2Fx5gYI5L5kCMHkjgEI%2B%2B6bAwjI77gGCIf7jwcI9Ir%2BAwiCoZoFCJPG8QYI%2BrK%2BAwi07P4FCMWPLQjBhtgGCMCt9QYI5MC7BgiU8osHCPCbvgQIm8vEBgjsi6wGCNiZjwcI%2Bbi7Bgi6kqsCCP%2FWpgQIqe%2FlAwjX5%2B8GCJqn6wYIttqLBwjcyLIECKryrgYI5cSLBwj6pIcHCMC5mgYIspz5BAiJsIwHCMG63QQI6vOWBgjP34cH&requestId=11

Synchronous

Everything is similar to async way, but:

fetcher should be:

• tornado.httpclient.HTTPClient.fetch blocking http client built in Tornado

Function for creating protobuf service is construct_sync_protobuf_service

Protobuf service url convention

By default, protobuf service url compiles by the following way:

url = self.host.rstrip('/') + '/{0}/{1}'.format(method_descriptor.containing_service.name, method_descriptor.name)

where method_descriptor is the first argument in CallMethod of RpcChannel class.