http-protocol: Add a method to invalidate the VCSServer cache.

This method allows to invalidate the cached repository objects in the VCSServer.
It generates a new UUID which is used by the VCSServer as cache key.

rhodecode/lib/vcs/client_http.py

@@ -1,235 +1,250 b''
 # -*- coding: utf-8 -*-
 
 # Copyright (C) 2016-2016  RhodeCode GmbH
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU Affero General Public License, version 3
 # (only), as published by the Free Software Foundation.
 #
 # This program is distributed in the hope that it will be useful,
 # but WITHOUT ANY WARRANTY; without even the implied warranty of
 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 # GNU General Public License for more details.
 #
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #
 # This program is dual-licensed. If you wish to learn more about the
 # RhodeCode Enterprise Edition, including its added features, Support services,
 # and proprietary license terms, please see https://rhodecode.com/licenses/
 
 """
 Client for the VCSServer implemented based on HTTP.
 
 
 Status
 ------
 
 This client implementation shall eventually replace the Pyro4 based
 implementation.
 """
 
 import copy
 import logging
 import threading
 import urllib2
 import urlparse
 import uuid
 
 import msgpack
 import requests
 
 from . import exceptions, CurlSession
 
 
 log = logging.getLogger(__name__)
 
 
 # TODO: mikhail: Keep it in sync with vcsserver's
 # HTTPApplication.ALLOWED_EXCEPTIONS
 EXCEPTIONS_MAP = {
     'KeyError': KeyError,
     'URLError': urllib2.URLError,
 }
 
 
 class RepoMaker(object):
 
     def __init__(self, server_and_port, backend_endpoint, session_factory):
         self.url = urlparse.urljoin(
             'http://%s' % server_and_port, backend_endpoint)
         self._session_factory = session_factory
 
     def __call__(self, path, config, with_wire=None):
         log.debug('RepoMaker call on %s', path)
         return RemoteRepo(
             path, config, self.url, self._session_factory(),
             with_wire=with_wire)
 
     def __getattr__(self, name):
         def f(*args, **kwargs):
             return self._call(name, *args, **kwargs)
         return f
 
     @exceptions.map_vcs_exceptions
     def _call(self, name, *args, **kwargs):
         payload = {
             'id': str(uuid.uuid4()),
             'method': name,
             'params': {'args': args, 'kwargs': kwargs}
         }
         return _remote_call(
             self.url, payload, EXCEPTIONS_MAP, self._session_factory())
 
 
 class RemoteRepo(object):
 
     def __init__(self, path, config, url, session, with_wire=None):
         self.url = url
         self._session = session
         self._wire = {
             "path": path,
             "config": config,
-            "context": str(uuid.uuid4()),
+            "context": self._create_vcs_cache_context(),
         }
         if with_wire:
             self._wire.update(with_wire)
 
         # johbo: Trading complexity for performance. Avoiding the call to
         # log.debug brings a few percent gain even if is is not active.
         if log.isEnabledFor(logging.DEBUG):
             self._call = self._call_with_logging
 
     def __getattr__(self, name):
         def f(*args, **kwargs):
             return self._call(name, *args, **kwargs)
         return f
 
     @exceptions.map_vcs_exceptions
     def _call(self, name, *args, **kwargs):
         # TODO: oliver: This is currently necessary pre-call since the
         # config object is being changed for hooking scenarios
         wire = copy.deepcopy(self._wire)
         wire["config"] = wire["config"].serialize()
         payload = {
             'id': str(uuid.uuid4()),
             'method': name,
             'params': {'wire': wire, 'args': args, 'kwargs': kwargs}
         }
         return _remote_call(self.url, payload, EXCEPTIONS_MAP, self._session)
 
     def _call_with_logging(self, name, *args, **kwargs):
         log.debug('Calling %s@%s', self.url, name)
         return RemoteRepo._call(self, name, *args, **kwargs)
 
     def __getitem__(self, key):
         return self.revision(key)
 
+    def _create_vcs_cache_context(self):
+        """
+        Creates a unique string which is passed to the VCSServer on every
+        remote call. It is used as cache key in the VCSServer.
+        """
+        return str(uuid.uuid4())
+
+    def invalidate_vcs_cache(self):
+        """
+        This invalidates the context which is sent to the VCSServer on every
+        call to a remote method. It forces the VCSServer to create a fresh
+        repository instance on the next call to a remote method.
+        """
+        self._wire['context'] = self._create_vcs_cache_context()
+
 
 class RemoteObject(object):
 
     def __init__(self, url, session):
         self._url = url
         self._session = session
 
         # johbo: Trading complexity for performance. Avoiding the call to
         # log.debug brings a few percent gain even if is is not active.
         if log.isEnabledFor(logging.DEBUG):
             self._call = self._call_with_logging
 
     def __getattr__(self, name):
         def f(*args, **kwargs):
             return self._call(name, *args, **kwargs)
         return f
 
     @exceptions.map_vcs_exceptions
     def _call(self, name, *args, **kwargs):
         payload = {
             'id': str(uuid.uuid4()),
             'method': name,
             'params': {'args': args, 'kwargs': kwargs}
         }
         return _remote_call(self._url, payload, EXCEPTIONS_MAP, self._session)
 
     def _call_with_logging(self, name, *args, **kwargs):
         log.debug('Calling %s@%s', self._url, name)
         return RemoteObject._call(self, name, *args, **kwargs)
 
 
 def _remote_call(url, payload, exceptions_map, session):
     response = session.post(url, data=msgpack.packb(payload))
     response = msgpack.unpackb(response.content)
     error = response.get('error')
     if error:
         type_ = error.get('type', 'Exception')
         exc = exceptions_map.get(type_, Exception)
         exc = exc(error.get('message'))
         try:
             exc._vcs_kind = error['_vcs_kind']
         except KeyError:
             pass
         raise exc
     return response.get('result')
 
 
 class VcsHttpProxy(object):
 
     CHUNK_SIZE = 16384
 
     def __init__(self, server_and_port, backend_endpoint):
         adapter = requests.adapters.HTTPAdapter(max_retries=5)
         self.base_url = urlparse.urljoin(
             'http://%s' % server_and_port, backend_endpoint)
         self.session = requests.Session()
         self.session.mount('http://', adapter)
 
     def handle(self, environment, input_data, *args, **kwargs):
         data = {
             'environment': environment,
             'input_data': input_data,
             'args': args,
             'kwargs': kwargs
         }
         result = self.session.post(
             self.base_url, msgpack.packb(data), stream=True)
         return self._get_result(result)
 
     def _deserialize_and_raise(self, error):
         exception = Exception(error['message'])
         try:
             exception._vcs_kind = error['_vcs_kind']
         except KeyError:
             pass
         raise exception
 
     def _iterate(self, result):
         unpacker = msgpack.Unpacker()
         for line in result.iter_content(chunk_size=self.CHUNK_SIZE):
             unpacker.feed(line)
             for chunk in unpacker:
                 yield chunk
 
     def _get_result(self, result):
         iterator = self._iterate(result)
         error = iterator.next()
         if error:
             self._deserialize_and_raise(error)
 
         status = iterator.next()
         headers = iterator.next()
 
         return iterator, status, headers
 
 
 class ThreadlocalSessionFactory(object):
     """
     Creates one CurlSession per thread on demand.
     """
 
     def __init__(self):
         self._thread_local = threading.local()
 
     def __call__(self):
         if not hasattr(self._thread_local, 'curl_session'):
             self._thread_local.curl_session = CurlSession()
         return self._thread_local.curl_session