Implement new state resolution algorithm

1 files changed, 357 insertions, 71 deletions

diff --git a/tests/test_state.py b/tests/test_state.py
index 98ad9e54cd..019e794aa2 100644
--- a/tests/test_state.py
+++ b/tests/test_state.py
@@ -16,11 +16,120 @@
 from tests import unittest
 from twisted.internet import defer
 
+from synapse.events import FrozenEvent
+from synapse.api.auth import Auth
+from synapse.api.constants import EventTypes, Membership
 from synapse.state import StateHandler
 
 from mock import Mock
 
 
+_next_event_id = 1000
+
+
+def create_event(name=None, type=None, state_key=None, depth=2, event_id=None,
+                 prev_events=[], **kwargs):
+    global _next_event_id
+
+    if not event_id:
+        _next_event_id += 1
+        event_id = str(_next_event_id)
+
+    if not name:
+        if state_key is not None:
+            name = "<%s-%s, %s>" % (type, state_key, event_id,)
+        else:
+            name = "<%s, %s>" % (type, event_id,)
+
+    d = {
+        "event_id": event_id,
+        "type": type,
+        "sender": "@user_id:example.com",
+        "room_id": "!room_id:example.com",
+        "depth": depth,
+        "prev_events": prev_events,
+    }
+
+    if state_key is not None:
+        d["state_key"] = state_key
+
+    d.update(kwargs)
+
+    event = FrozenEvent(d)
+
+    return event
+
+
+class StateGroupStore(object):
+    def __init__(self):
+        self._event_to_state_group = {}
+        self._group_to_state = {}
+
+        self._next_group = 1
+
+    def get_state_groups(self, event_ids):
+        groups = {}
+        for event_id in event_ids:
+            group = self._event_to_state_group.get(event_id)
+            if group:
+                groups[group] = self._group_to_state[group]
+
+        return defer.succeed(groups)
+
+    def store_state_groups(self, event, context):
+        if context.current_state is None:
+            return
+
+        state_events = context.current_state
+
+        if event.is_state():
+            state_events[(event.type, event.state_key)] = event
+
+        state_group = context.state_group
+        if not state_group:
+            state_group = self._next_group
+            self._next_group += 1
+
+            self._group_to_state[state_group] = state_events.values()
+
+        self._event_to_state_group[event.event_id] = state_group
+
+
+class DictObj(dict):
+    def __init__(self, **kwargs):
+        super(DictObj, self).__init__(kwargs)
+        self.__dict__ = self
+
+
+class Graph(object):
+    def __init__(self, nodes, edges):
+        events = {}
+        clobbered = set(events.keys())
+
+        for event_id, fields in nodes.items():
+            refs = edges.get(event_id)
+            if refs:
+                clobbered.difference_update(refs)
+                prev_events = [(r, {}) for r in refs]
+            else:
+                prev_events = []
+
+            events[event_id] = create_event(
+                event_id=event_id,
+                prev_events=prev_events,
+                **fields
+            )
+
+        self._leaves = clobbered
+        self._events = sorted(events.values(), key=lambda e: e.depth)
+
+    def walk(self):
+        return iter(self._events)
+
+    def get_leaves(self):
+        return (self._events[i] for i in self._leaves)
+
+
 class StateTestCase(unittest.TestCase):
     def setUp(self):
         self.store = Mock(
@@ -29,20 +138,188 @@ class StateTestCase(unittest.TestCase):
                 "add_event_hashes",
             ]
         )
-        hs = Mock(spec=["get_datastore"])
+        hs = Mock(spec=["get_datastore", "get_auth", "get_state_handler"])
         hs.get_datastore.return_value = self.store
+        hs.get_state_handler.return_value = None
+        hs.get_auth.return_value = Auth(hs)
 
         self.state = StateHandler(hs)
         self.event_id = 0
 
     @defer.inlineCallbacks
+    def test_branch_no_conflict(self):
+        graph = Graph(
+            nodes={
+                "START": DictObj(
+                    type=EventTypes.Create,
+                    state_key="",
+                    depth=1,
+                ),
+                "A": DictObj(
+                    type=EventTypes.Message,
+                    depth=2,
+                ),
+                "B": DictObj(
+                    type=EventTypes.Message,
+                    depth=3,
+                ),
+                "C": DictObj(
+                    type=EventTypes.Name,
+                    state_key="",
+                    depth=3,
+                ),
+                "D": DictObj(
+                    type=EventTypes.Message,
+                    depth=4,
+                ),
+            },
+            edges={
+                "A": ["START"],
+                "B": ["A"],
+                "C": ["A"],
+                "D": ["B", "C"]
+            }
+        )
+
+        store = StateGroupStore()
+        self.store.get_state_groups.side_effect = store.get_state_groups
+
+        context_store = {}
+
+        for event in graph.walk():
+            context = yield self.state.compute_event_context(event)
+            store.store_state_groups(event, context)
+            context_store[event.event_id] = context
+
+        self.assertEqual(2, len(context_store["D"].current_state))
+
+    @defer.inlineCallbacks
+    def test_branch_basic_conflict(self):
+        graph = Graph(
+            nodes={
+                "START": DictObj(
+                    type=EventTypes.Create,
+                    state_key="creator",
+                    content={"membership": "@user_id:example.com"},
+                    depth=1,
+                ),
+                "A": DictObj(
+                    type=EventTypes.Member,
+                    state_key="@user_id:example.com",
+                    content={"membership": Membership.JOIN},
+                    membership=Membership.JOIN,
+                    depth=2,
+                ),
+                "B": DictObj(
+                    type=EventTypes.Name,
+                    state_key="",
+                    depth=3,
+                ),
+                "C": DictObj(
+                    type=EventTypes.Name,
+                    state_key="",
+                    depth=4,
+                ),
+                "D": DictObj(
+                    type=EventTypes.Message,
+                    depth=5,
+                ),
+            },
+            edges={
+                "A": ["START"],
+                "B": ["A"],
+                "C": ["A"],
+                "D": ["B", "C"]
+            }
+        )
+
+        store = StateGroupStore()
+        self.store.get_state_groups.side_effect = store.get_state_groups
+
+        context_store = {}
+
+        for event in graph.walk():
+            context = yield self.state.compute_event_context(event)
+            store.store_state_groups(event, context)
+            context_store[event.event_id] = context
+
+        self.assertSetEqual(
+            {"START", "A", "C"},
+            {e.event_id for e in context_store["D"].current_state.values()}
+        )
+
+    @defer.inlineCallbacks
+    def test_branch_have_banned_conflict(self):
+        graph = Graph(
+            nodes={
+                "START": DictObj(
+                    type=EventTypes.Create,
+                    state_key="creator",
+                    content={"membership": "@user_id:example.com"},
+                    depth=1,
+                ),
+                "A": DictObj(
+                    type=EventTypes.Member,
+                    state_key="@user_id:example.com",
+                    content={"membership": Membership.JOIN},
+                    membership=Membership.JOIN,
+                    depth=2,
+                ),
+                "B": DictObj(
+                    type=EventTypes.Name,
+                    state_key="",
+                    depth=3,
+                ),
+                "C": DictObj(
+                    type=EventTypes.Member,
+                    state_key="@user_id_2:example.com",
+                    content={"membership": Membership.BAN},
+                    membership=Membership.BAN,
+                    depth=4,
+                ),
+                "D": DictObj(
+                    type=EventTypes.Name,
+                    state_key="",
+                    depth=4,
+                    sender="@user_id_2:example.com",
+                ),
+                "E": DictObj(
+                    type=EventTypes.Message,
+                    depth=5,
+                ),
+            },
+            edges={
+                "A": ["START"],
+                "B": ["A"],
+                "C": ["B"],
+                "D": ["B"],
+                "E": ["C", "D"]
+            }
+        )
+
+        store = StateGroupStore()
+        self.store.get_state_groups.side_effect = store.get_state_groups
+
+        context_store = {}
+
+        for event in graph.walk():
+            context = yield self.state.compute_event_context(event)
+            store.store_state_groups(event, context)
+            context_store[event.event_id] = context
+
+        self.assertSetEqual(
+            {"START", "A", "B", "C"},
+            {e.event_id for e in context_store["E"].current_state.values()}
+        )
+
+    @defer.inlineCallbacks
     def test_annotate_with_old_message(self):
-        event = self.create_event(type="test_message", name="event")
+        event = create_event(type="test_message", name="event")
 
         old_state = [
-            self.create_event(type="test1", state_key="1"),
-            self.create_event(type="test1", state_key="2"),
-            self.create_event(type="test2", state_key=""),
+            create_event(type="test1", state_key="1"),
+            create_event(type="test1", state_key="2"),
+            create_event(type="test2", state_key=""),
         ]
 
         context = yield self.state.compute_event_context(
@@ -62,12 +339,12 @@ class StateTestCase(unittest.TestCase):
 
     @defer.inlineCallbacks
     def test_annotate_with_old_state(self):
-        event = self.create_event(type="state", state_key="", name="event")
+        event = create_event(type="state", state_key="", name="event")
 
         old_state = [
-            self.create_event(type="test1", state_key="1"),
-            self.create_event(type="test1", state_key="2"),
-            self.create_event(type="test2", state_key=""),
+            create_event(type="test1", state_key="1"),
+            create_event(type="test1", state_key="2"),
+            create_event(type="test2", state_key=""),
         ]
 
         context = yield self.state.compute_event_context(
@@ -88,13 +365,12 @@ class StateTestCase(unittest.TestCase):
 
     @defer.inlineCallbacks
     def test_trivial_annotate_message(self):
-        event = self.create_event(type="test_message", name="event")
-        event.prev_events = []
+        event = create_event(type="test_message", name="event")
 
         old_state = [
-            self.create_event(type="test1", state_key="1"),
-            self.create_event(type="test1", state_key="2"),
-            self.create_event(type="test2", state_key=""),
+            create_event(type="test1", state_key="1"),
+            create_event(type="test1", state_key="2"),
+            create_event(type="test2", state_key=""),
         ]
 
         group_name = "group_name_1"
@@ -119,13 +395,12 @@ class StateTestCase(unittest.TestCase):
 
     @defer.inlineCallbacks
     def test_trivial_annotate_state(self):
-        event = self.create_event(type="state", state_key="", name="event")
-        event.prev_events = []
+        event = create_event(type="state", state_key="", name="event")
 
         old_state = [
-            self.create_event(type="test1", state_key="1"),
-            self.create_event(type="test1", state_key="2"),
-            self.create_event(type="test2", state_key=""),
+            create_event(type="test1", state_key="1"),
+            create_event(type="test1", state_key="2"),
+            create_event(type="test2", state_key=""),
         ]
 
         group_name = "group_name_1"
@@ -150,30 +425,21 @@ class StateTestCase(unittest.TestCase):
 
     @defer.inlineCallbacks
     def test_resolve_message_conflict(self):
-        event = self.create_event(type="test_message", name="event")
-        event.prev_events = []
+        event = create_event(type="test_message", name="event")
 
         old_state_1 = [
-            self.create_event(type="test1", state_key="1"),
-            self.create_event(type="test1", state_key="2"),
-            self.create_event(type="test2", state_key=""),
+            create_event(type="test1", state_key="1"),
+            create_event(type="test1", state_key="2"),
+            create_event(type="test2", state_key=""),
         ]
 
         old_state_2 = [
-            self.create_event(type="test1", state_key="1"),
-            self.create_event(type="test3", state_key="2"),
-            self.create_event(type="test4", state_key=""),
+            create_event(type="test1", state_key="1"),
+            create_event(type="test3", state_key="2"),
+            create_event(type="test4", state_key=""),
         ]
 
-        group_name_1 = "group_name_1"
-        group_name_2 = "group_name_2"
-
-        self.store.get_state_groups.return_value = {
-            group_name_1: old_state_1,
-            group_name_2: old_state_2,
-        }
-
-        context = yield self.state.compute_event_context(event)
+        context = yield self._get_context(event, old_state_1, old_state_2)
 
         self.assertEqual(len(context.current_state), 5)
 
@@ -181,56 +447,76 @@ class StateTestCase(unittest.TestCase):
 
     @defer.inlineCallbacks
     def test_resolve_state_conflict(self):
-        event = self.create_event(type="test4", state_key="", name="event")
-        event.prev_events = []
+        event = create_event(type="test4", state_key="", name="event")
 
         old_state_1 = [
-            self.create_event(type="test1", state_key="1"),
-            self.create_event(type="test1", state_key="2"),
-            self.create_event(type="test2", state_key=""),
+            create_event(type="test1", state_key="1"),
+            create_event(type="test1", state_key="2"),
+            create_event(type="test2", state_key=""),
         ]
 
         old_state_2 = [
-            self.create_event(type="test1", state_key="1"),
-            self.create_event(type="test3", state_key="2"),
-            self.create_event(type="test4", state_key=""),
+            create_event(type="test1", state_key="1"),
+            create_event(type="test3", state_key="2"),
+            create_event(type="test4", state_key=""),
         ]
 
-        group_name_1 = "group_name_1"
-        group_name_2 = "group_name_2"
-
-        self.store.get_state_groups.return_value = {
-            group_name_1: old_state_1,
-            group_name_2: old_state_2,
-        }
-
-        context = yield self.state.compute_event_context(event)
+        context = yield self._get_context(event, old_state_1, old_state_2)
 
         self.assertEqual(len(context.current_state), 5)
 
         self.assertIsNone(context.state_group)
 
-    def create_event(self, name=None, type=None, state_key=None):
-        self.event_id += 1
-        event_id = str(self.event_id)
+    @defer.inlineCallbacks
+    def test_standard_depth_conflict(self):
+        event = create_event(type="test4", name="event")
+
+        member_event = create_event(
+            type=EventTypes.Member,
+            state_key="@user_id:example.com",
+            content={
+                "membership": Membership.JOIN,
+            }
+        )
 
-        if not name:
-            if state_key is not None:
-                name = "<%s-%s>" % (type, state_key)
-            else:
-                name = "<%s>" % (type, )
+        old_state_1 = [
+            member_event,
+            create_event(type="test1", state_key="1", depth=1),
+        ]
+
+        old_state_2 = [
+            member_event,
+            create_event(type="test1", state_key="1", depth=2),
+        ]
 
-        event = Mock(name=name, spec=[])
-        event.type = type
+        context = yield self._get_context(event, old_state_1, old_state_2)
 
-        if state_key is not None:
-            event.state_key = state_key
-        event.event_id = event_id
+        self.assertEqual(old_state_2[1], context.current_state[("test1", "1")])
+
+        # Reverse the depth to make sure we are actually using the depths
+        # during state resolution.
+
+        old_state_1 = [
+            member_event,
+            create_event(type="test1", state_key="1", depth=2),
+        ]
+
+        old_state_2 = [
+            member_event,
+            create_event(type="test1", state_key="1", depth=1),
+        ]
+
+        context = yield self._get_context(event, old_state_1, old_state_2)
+
+        self.assertEqual(old_state_1[1], context.current_state[("test1", "1")])
 
-        event.is_state = lambda: (state_key is not None)
-        event.unsigned = {}
+    def _get_context(self, event, old_state_1, old_state_2):
+        group_name_1 = "group_name_1"
+        group_name_2 = "group_name_2"
 
-        event.user_id = "@user_id:example.com"
-        event.room_id = "!room_id:example.com"
+        self.store.get_state_groups.return_value = {
+            group_name_1: old_state_1,
+            group_name_2: old_state_2,
+        }
 
-        return event
+        return self.state.compute_event_context(event)