Merge branch 'develop' of github.com:matrix-org/synapse into erikj-perf

1 files changed, 563 insertions, 0 deletions

diff --git a/synapse/federation/federation_client.py b/synapse/federation/federation_client.py
new file mode 100644
index 0000000000..f131941f45
--- /dev/null
+++ b/synapse/federation/federation_client.py
@@ -0,0 +1,563 @@
+# -*- coding: utf-8 -*-
+# Copyright 2015 OpenMarket Ltd
+#
+# 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.
+
+
+from twisted.internet import defer
+
+from .federation_base import FederationBase
+from .units import Edu
+
+from synapse.api.errors import (
+    CodeMessageException, HttpResponseException, SynapseError,
+)
+from synapse.util.expiringcache import ExpiringCache
+from synapse.util.logutils import log_function
+from synapse.events import FrozenEvent
+
+from synapse.util.retryutils import get_retry_limiter, NotRetryingDestination
+
+import itertools
+import logging
+import random
+
+
+logger = logging.getLogger(__name__)
+
+
+class FederationClient(FederationBase):
+    def __init__(self):
+        self._get_pdu_cache = None
+
+    def start_get_pdu_cache(self):
+        self._get_pdu_cache = ExpiringCache(
+            cache_name="get_pdu_cache",
+            clock=self._clock,
+            max_len=1000,
+            expiry_ms=120*1000,
+            reset_expiry_on_get=False,
+        )
+
+        self._get_pdu_cache.start()
+
+    @log_function
+    def send_pdu(self, pdu, destinations):
+        """Informs the replication layer about a new PDU generated within the
+        home server that should be transmitted to others.
+
+        TODO: Figure out when we should actually resolve the deferred.
+
+        Args:
+            pdu (Pdu): The new Pdu.
+
+        Returns:
+            Deferred: Completes when we have successfully processed the PDU
+            and replicated it to any interested remote home servers.
+        """
+        order = self._order
+        self._order += 1
+
+        logger.debug("[%s] transaction_layer.enqueue_pdu... ", pdu.event_id)
+
+        # TODO, add errback, etc.
+        self._transaction_queue.enqueue_pdu(pdu, destinations, order)
+
+        logger.debug(
+            "[%s] transaction_layer.enqueue_pdu... done",
+            pdu.event_id
+        )
+
+    @log_function
+    def send_edu(self, destination, edu_type, content):
+        edu = Edu(
+            origin=self.server_name,
+            destination=destination,
+            edu_type=edu_type,
+            content=content,
+        )
+
+        # TODO, add errback, etc.
+        self._transaction_queue.enqueue_edu(edu)
+        return defer.succeed(None)
+
+    @log_function
+    def send_failure(self, failure, destination):
+        self._transaction_queue.enqueue_failure(failure, destination)
+        return defer.succeed(None)
+
+    @log_function
+    def make_query(self, destination, query_type, args,
+                   retry_on_dns_fail=True):
+        """Sends a federation Query to a remote homeserver of the given type
+        and arguments.
+
+        Args:
+            destination (str): Domain name of the remote homeserver
+            query_type (str): Category of the query type; should match the
+                handler name used in register_query_handler().
+            args (dict): Mapping of strings to strings containing the details
+                of the query request.
+
+        Returns:
+            a Deferred which will eventually yield a JSON object from the
+            response
+        """
+        return self.transport_layer.make_query(
+            destination, query_type, args, retry_on_dns_fail=retry_on_dns_fail
+        )
+
+    @defer.inlineCallbacks
+    @log_function
+    def backfill(self, dest, context, limit, extremities):
+        """Requests some more historic PDUs for the given context from the
+        given destination server.
+
+        Args:
+            dest (str): The remote home server to ask.
+            context (str): The context to backfill.
+            limit (int): The maximum number of PDUs to return.
+            extremities (list): List of PDU id and origins of the first pdus
+                we have seen from the context
+
+        Returns:
+            Deferred: Results in the received PDUs.
+        """
+        logger.debug("backfill extrem=%s", extremities)
+
+        # If there are no extremeties then we've (probably) reached the start.
+        if not extremities:
+            return
+
+        transaction_data = yield self.transport_layer.backfill(
+            dest, context, extremities, limit)
+
+        logger.debug("backfill transaction_data=%s", repr(transaction_data))
+
+        pdus = [
+            self.event_from_pdu_json(p, outlier=False)
+            for p in transaction_data["pdus"]
+        ]
+
+        for i, pdu in enumerate(pdus):
+            pdus[i] = yield self._check_sigs_and_hash(pdu)
+
+            # FIXME: We should handle signature failures more gracefully.
+
+        defer.returnValue(pdus)
+
+    @defer.inlineCallbacks
+    @log_function
+    def get_pdu(self, destinations, event_id, outlier=False):
+        """Requests the PDU with given origin and ID from the remote home
+        servers.
+
+        Will attempt to get the PDU from each destination in the list until
+        one succeeds.
+
+        This will persist the PDU locally upon receipt.
+
+        Args:
+            destinations (list): Which home servers to query
+            pdu_origin (str): The home server that originally sent the pdu.
+            event_id (str)
+            outlier (bool): Indicates whether the PDU is an `outlier`, i.e. if
+                it's from an arbitary point in the context as opposed to part
+                of the current block of PDUs. Defaults to `False`
+
+        Returns:
+            Deferred: Results in the requested PDU.
+        """
+
+        # TODO: Rate limit the number of times we try and get the same event.
+
+        if self._get_pdu_cache:
+            e = self._get_pdu_cache.get(event_id)
+            if e:
+                defer.returnValue(e)
+
+        pdu = None
+        for destination in destinations:
+            try:
+                limiter = yield get_retry_limiter(
+                    destination,
+                    self._clock,
+                    self.store,
+                )
+
+                with limiter:
+                    transaction_data = yield self.transport_layer.get_event(
+                        destination, event_id
+                    )
+
+                    logger.debug("transaction_data %r", transaction_data)
+
+                    pdu_list = [
+                        self.event_from_pdu_json(p, outlier=outlier)
+                        for p in transaction_data["pdus"]
+                    ]
+
+                    if pdu_list:
+                        pdu = pdu_list[0]
+
+                        # Check signatures are correct.
+                        pdu = yield self._check_sigs_and_hash(pdu)
+
+                        break
+
+            except SynapseError:
+                logger.info(
+                    "Failed to get PDU %s from %s because %s",
+                    event_id, destination, e,
+                )
+                continue
+            except CodeMessageException as e:
+                if 400 <= e.code < 500:
+                    raise
+
+                logger.info(
+                    "Failed to get PDU %s from %s because %s",
+                    event_id, destination, e,
+                )
+                continue
+            except NotRetryingDestination as e:
+                logger.info(e.message)
+                continue
+            except Exception as e:
+                logger.info(
+                    "Failed to get PDU %s from %s because %s",
+                    event_id, destination, e,
+                )
+                continue
+
+        if self._get_pdu_cache is not None:
+            self._get_pdu_cache[event_id] = pdu
+
+        defer.returnValue(pdu)
+
+    @defer.inlineCallbacks
+    @log_function
+    def get_state_for_room(self, destination, room_id, event_id):
+        """Requests all of the `current` state PDUs for a given room from
+        a remote home server.
+
+        Args:
+            destination (str): The remote homeserver to query for the state.
+            room_id (str): The id of the room we're interested in.
+            event_id (str): The id of the event we want the state at.
+
+        Returns:
+            Deferred: Results in a list of PDUs.
+        """
+
+        result = yield self.transport_layer.get_room_state(
+            destination, room_id, event_id=event_id,
+        )
+
+        pdus = [
+            self.event_from_pdu_json(p, outlier=True) for p in result["pdus"]
+        ]
+
+        auth_chain = [
+            self.event_from_pdu_json(p, outlier=True)
+            for p in result.get("auth_chain", [])
+        ]
+
+        signed_pdus = yield self._check_sigs_and_hash_and_fetch(
+            destination, pdus, outlier=True
+        )
+
+        signed_auth = yield self._check_sigs_and_hash_and_fetch(
+            destination, auth_chain, outlier=True
+        )
+
+        signed_auth.sort(key=lambda e: e.depth)
+
+        defer.returnValue((signed_pdus, signed_auth))
+
+    @defer.inlineCallbacks
+    @log_function
+    def get_event_auth(self, destination, room_id, event_id):
+        res = yield self.transport_layer.get_event_auth(
+            destination, room_id, event_id,
+        )
+
+        auth_chain = [
+            self.event_from_pdu_json(p, outlier=True)
+            for p in res["auth_chain"]
+        ]
+
+        signed_auth = yield self._check_sigs_and_hash_and_fetch(
+            destination, auth_chain, outlier=True
+        )
+
+        signed_auth.sort(key=lambda e: e.depth)
+
+        defer.returnValue(signed_auth)
+
+    @defer.inlineCallbacks
+    def make_join(self, destinations, room_id, user_id):
+        for destination in destinations:
+            try:
+                ret = yield self.transport_layer.make_join(
+                    destination, room_id, user_id
+                )
+
+                pdu_dict = ret["event"]
+
+                logger.debug("Got response to make_join: %s", pdu_dict)
+
+                defer.returnValue(
+                    (destination, self.event_from_pdu_json(pdu_dict))
+                )
+                break
+            except CodeMessageException:
+                raise
+            except Exception as e:
+                logger.warn(
+                    "Failed to make_join via %s: %s",
+                    destination, e.message
+                )
+
+        raise RuntimeError("Failed to send to any server.")
+
+    @defer.inlineCallbacks
+    def send_join(self, destinations, pdu):
+        for destination in destinations:
+            try:
+                time_now = self._clock.time_msec()
+                _, content = yield self.transport_layer.send_join(
+                    destination=destination,
+                    room_id=pdu.room_id,
+                    event_id=pdu.event_id,
+                    content=pdu.get_pdu_json(time_now),
+                )
+
+                logger.debug("Got content: %s", content)
+
+                state = [
+                    self.event_from_pdu_json(p, outlier=True)
+                    for p in content.get("state", [])
+                ]
+
+                auth_chain = [
+                    self.event_from_pdu_json(p, outlier=True)
+                    for p in content.get("auth_chain", [])
+                ]
+
+                signed_state = yield self._check_sigs_and_hash_and_fetch(
+                    destination, state, outlier=True
+                )
+
+                signed_auth = yield self._check_sigs_and_hash_and_fetch(
+                    destination, auth_chain, outlier=True
+                )
+
+                auth_chain.sort(key=lambda e: e.depth)
+
+                defer.returnValue({
+                    "state": signed_state,
+                    "auth_chain": signed_auth,
+                    "origin": destination,
+                })
+            except CodeMessageException:
+                raise
+            except Exception as e:
+                logger.warn(
+                    "Failed to send_join via %s: %s",
+                    destination, e.message
+                )
+
+        raise RuntimeError("Failed to send to any server.")
+
+    @defer.inlineCallbacks
+    def send_invite(self, destination, room_id, event_id, pdu):
+        time_now = self._clock.time_msec()
+        code, content = yield self.transport_layer.send_invite(
+            destination=destination,
+            room_id=room_id,
+            event_id=event_id,
+            content=pdu.get_pdu_json(time_now),
+        )
+
+        pdu_dict = content["event"]
+
+        logger.debug("Got response to send_invite: %s", pdu_dict)
+
+        pdu = self.event_from_pdu_json(pdu_dict)
+
+        # Check signatures are correct.
+        pdu = yield self._check_sigs_and_hash(pdu)
+
+        # FIXME: We should handle signature failures more gracefully.
+
+        defer.returnValue(pdu)
+
+    @defer.inlineCallbacks
+    def query_auth(self, destination, room_id, event_id, local_auth):
+        """
+        Params:
+            destination (str)
+            event_it (str)
+            local_auth (list)
+        """
+        time_now = self._clock.time_msec()
+
+        send_content = {
+            "auth_chain": [e.get_pdu_json(time_now) for e in local_auth],
+        }
+
+        code, content = yield self.transport_layer.send_query_auth(
+            destination=destination,
+            room_id=room_id,
+            event_id=event_id,
+            content=send_content,
+        )
+
+        auth_chain = [
+            self.event_from_pdu_json(e)
+            for e in content["auth_chain"]
+        ]
+
+        signed_auth = yield self._check_sigs_and_hash_and_fetch(
+            destination, auth_chain, outlier=True
+        )
+
+        signed_auth.sort(key=lambda e: e.depth)
+
+        ret = {
+            "auth_chain": signed_auth,
+            "rejects": content.get("rejects", []),
+            "missing": content.get("missing", []),
+        }
+
+        defer.returnValue(ret)
+
+    @defer.inlineCallbacks
+    def get_missing_events(self, destination, room_id, earliest_events_ids,
+                           latest_events, limit, min_depth):
+        """Tries to fetch events we are missing. This is called when we receive
+        an event without having received all of its ancestors.
+
+        Args:
+            destination (str)
+            room_id (str)
+            earliest_events_ids (list): List of event ids. Effectively the
+                events we expected to receive, but haven't. `get_missing_events`
+                should only return events that didn't happen before these.
+            latest_events (list): List of events we have received that we don't
+                have all previous events for.
+            limit (int): Maximum number of events to return.
+            min_depth (int): Minimum depth of events tor return.
+        """
+        try:
+            content = yield self.transport_layer.get_missing_events(
+                destination=destination,
+                room_id=room_id,
+                earliest_events=earliest_events_ids,
+                latest_events=[e.event_id for e in latest_events],
+                limit=limit,
+                min_depth=min_depth,
+            )
+
+            events = [
+                self.event_from_pdu_json(e)
+                for e in content.get("events", [])
+            ]
+
+            signed_events = yield self._check_sigs_and_hash_and_fetch(
+                destination, events, outlier=True
+            )
+
+            have_gotten_all_from_destination = True
+        except HttpResponseException as e:
+            if not e.code == 400:
+                raise
+
+            # We are probably hitting an old server that doesn't support
+            # get_missing_events
+            signed_events = []
+            have_gotten_all_from_destination = False
+
+        if len(signed_events) >= limit:
+            defer.returnValue(signed_events)
+
+        servers = yield self.store.get_joined_hosts_for_room(room_id)
+
+        servers = set(servers)
+        servers.discard(self.server_name)
+
+        failed_to_fetch = set()
+
+        while len(signed_events) < limit:
+            # Are we missing any?
+
+            seen_events = set(earliest_events_ids)
+            seen_events.update(e.event_id for e in signed_events)
+
+            missing_events = {}
+            for e in itertools.chain(latest_events, signed_events):
+                if e.depth > min_depth:
+                    missing_events.update({
+                        e_id: e.depth for e_id, _ in e.prev_events
+                        if e_id not in seen_events
+                        and e_id not in failed_to_fetch
+                    })
+
+            if not missing_events:
+                break
+
+            have_seen = yield self.store.have_events(missing_events)
+
+            for k in have_seen:
+                missing_events.pop(k, None)
+
+            if not missing_events:
+                break
+
+            # Okay, we haven't gotten everything yet. Lets get them.
+            ordered_missing = sorted(missing_events.items(), key=lambda x: x[0])
+
+            if have_gotten_all_from_destination:
+                servers.discard(destination)
+
+            def random_server_list():
+                srvs = list(servers)
+                random.shuffle(srvs)
+                return srvs
+
+            deferreds = [
+                self.get_pdu(
+                    destinations=random_server_list(),
+                    event_id=e_id,
+                )
+                for e_id, depth in ordered_missing[:limit - len(signed_events)]
+            ]
+
+            res = yield defer.DeferredList(deferreds, consumeErrors=True)
+            for (result, val), (e_id, _) in zip(res, ordered_missing):
+                if result:
+                    signed_events.append(val)
+                else:
+                    failed_to_fetch.add(e_id)
+
+        defer.returnValue(signed_events)
+
+    def event_from_pdu_json(self, pdu_json, outlier=False):
+        event = FrozenEvent(
+            pdu_json
+        )
+
+        event.internal_metadata.outlier = outlier
+
+        return event