[feat] improve speed of server startup

To avoid corrupting data, Soledad Server checks all user databases
during startup to make sure all of them use the correct schema version.
This was done synchronously, so when there are many databases startup
would take a long time. This commit makes that verification
asynchronous, thus speeding up server startup.

2 files changed, 43 insertions, 11 deletions

diff --git a/tests/couch/test_command.py b/tests/couch/test_command.py
index 9fb2c153..52719065 100644
--- a/tests/couch/test_command.py
+++ b/tests/couch/test_command.py
@@ -10,7 +10,7 @@ class CommandBasedDBCreationTest(unittest.TestCase):
 
     def test_ensure_db_using_custom_command(self):
         state = couch_state.CouchServerState(
-            "url", create_cmd="/bin/echo", check_schema_versions=False)
+            "url", create_cmd="/bin/echo")
         mock_db = Mock()
         mock_db.replica_uid = 'replica_uid'
         state.open_database = Mock(return_value=mock_db)
@@ -20,12 +20,11 @@ class CommandBasedDBCreationTest(unittest.TestCase):
 
     def test_raises_unauthorized_on_failure(self):
         state = couch_state.CouchServerState(
-            "url", create_cmd="inexistent", check_schema_versions=False)
+            "url", create_cmd="inexistent")
         self.assertRaises(u1db_errors.Unauthorized,
                           state.ensure_database, "user-1337")
 
     def test_raises_unauthorized_by_default(self):
-        state = couch_state.CouchServerState("url",
-                                             check_schema_versions=False)
+        state = couch_state.CouchServerState("url")
         self.assertRaises(u1db_errors.Unauthorized,
                           state.ensure_database, "user-1337")
diff --git a/tests/couch/test_state.py b/tests/couch/test_state.py
index e5ac3704..673d9c41 100644
--- a/tests/couch/test_state.py
+++ b/tests/couch/test_state.py
@@ -1,14 +1,21 @@
+import mock
 import pytest
+
 from leap.soledad.common.couch import CONFIG_DOC_ID
 from leap.soledad.common.couch import SCHEMA_VERSION
 from leap.soledad.common.couch import SCHEMA_VERSION_KEY
-from leap.soledad.common.couch.state import CouchServerState
+from leap.soledad.common.couch.state import _check_db_schema_version
+from leap.soledad.common.couch.state import check_schema_versions
 from uuid import uuid4
 
 from leap.soledad.common.errors import WrongCouchSchemaVersionError
 from leap.soledad.common.errors import MissingCouchConfigDocumentError
 from test_soledad.util import CouchDBTestCase
 
+from twisted.internet import defer
+from twisted.internet import reactor
+from twisted.web.client import HTTPConnectionPool, Agent
+
 
 class CouchDesignDocsTests(CouchDBTestCase):
 
@@ -16,17 +23,43 @@ class CouchDesignDocsTests(CouchDBTestCase):
         CouchDBTestCase.setUp(self)
         self.db = self.couch_server.create('user-' + uuid4().hex)
         self.addCleanup(self.delete_db, self.db.name)
+        self.pool = HTTPConnectionPool(reactor, persistent=False)
+        self.agent = Agent(reactor, pool=self.pool)
+
+    @defer.inlineCallbacks
+    def tearDown(self):
+        yield self.pool.closeCachedConnections()
 
-    def test_wrong_couch_version_raises(self):
+    @defer.inlineCallbacks
+    def test__check_db_schema_version_wrong_schema_version_raises(self):
         wrong_schema_version = SCHEMA_VERSION + 1
         self.db.create(
             {'_id': CONFIG_DOC_ID, SCHEMA_VERSION_KEY: wrong_schema_version})
         with pytest.raises(WrongCouchSchemaVersionError):
-            CouchServerState(self.couch_url, create_cmd='/bin/echo',
-                             check_schema_versions=True)
+            yield _check_db_schema_version(
+                self.couch_url, self.db.name, None, agent=self.agent)
 
-    def test_missing_config_doc_raises(self):
+    @defer.inlineCallbacks
+    def test_check_schema_versions_wrong_schema_version_stops_reactor(self):
+        wrong_schema_version = SCHEMA_VERSION + 1
+        self.db.create(
+            {'_id': CONFIG_DOC_ID, SCHEMA_VERSION_KEY: wrong_schema_version})
+        mocked_reactor = mock.Mock()
+        yield check_schema_versions(
+            self.couch_url, agent=self.agent, reactor=mocked_reactor)
+        self.assertTrue(mocked_reactor.stop.call_count == 1)
+
+    @defer.inlineCallbacks
+    def test__check_db_schema_version_missing_config_doc_raises(self):
         self.db.create({})
         with pytest.raises(MissingCouchConfigDocumentError):
-            CouchServerState(self.couch_url, create_cmd='/bin/echo',
-                             check_schema_versions=True)
+            yield _check_db_schema_version(
+                self.couch_url, self.db.name, None, agent=self.agent)
+
+    @defer.inlineCallbacks
+    def test_check_schema_versions_missing_config_doc_stops_reactor(self):
+        self.db.create({})
+        mocked_reactor = mock.Mock()
+        yield check_schema_versions(
+            self.couch_url, agent=self.agent, reactor=mocked_reactor)
+        self.assertTrue(mocked_reactor.stop.call_count == 1)