Change the way pagination works to support out of order events.

This commit is contained in:
Erik Johnston 2014-08-19 14:19:48 +01:00
parent 1422a22970
commit 598a1d8ff9
8 changed files with 226 additions and 81 deletions

View File

@ -20,23 +20,23 @@ class PaginationConfig(object):
"""A configuration object which stores pagination parameters."""
def __init__(self, from_tok=None, to_tok=None, limit=0):
def __init__(self, from_tok=None, to_tok=None, direction='f', limit=0):
self.from_tok = from_tok
self.to_tok = to_tok
self.direction = direction
self.limit = limit
@classmethod
def from_request(cls, request, raise_invalid_params=True):
params = {
"from_tok": PaginationStream.TOK_START,
"to_tok": PaginationStream.TOK_END,
"limit": 0
"direction": 'f',
}
query_param_mappings = [ # 3-tuple of qp_key, attribute, rules
("from", "from_tok", lambda x: type(x) == str),
("to", "to_tok", lambda x: type(x) == str),
("limit", "limit", lambda x: x.isdigit())
("limit", "limit", lambda x: x.isdigit()),
("dir", "direction", lambda x: x == 'f' or x == 'b'),
]
for qp, attr, is_valid in query_param_mappings:
@ -48,12 +48,17 @@ class PaginationConfig(object):
return PaginationConfig(**params)
def __str__(self):
return (
"<PaginationConfig from_tok=%s, to_tok=%s, "
"direction=%s, limit=%s>"
) % (self.from_tok, self.to_tok, self.direction, self.limit)
class PaginationStream(object):
""" An interface for streaming data as chunks. """
TOK_START = "START"
TOK_END = "END"
def get_chunk(self, config=None):
@ -76,7 +81,7 @@ class StreamData(object):
self.hs = hs
self.store = hs.get_datastore()
def get_rows(self, user_id, from_pkey, to_pkey, limit):
def get_rows(self, user_id, from_pkey, to_pkey, limit, direction):
""" Get event stream data between the specified pkeys.
Args:

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@ -38,8 +38,8 @@ class EventsStreamData(StreamData):
self.with_feedback = feedback
@defer.inlineCallbacks
def get_rows(self, user_id, from_key, to_key, limit):
data, latest_ver = yield self.store.get_room_events_stream(
def get_rows(self, user_id, from_key, to_key, limit, direction):
data, latest_ver = yield self.store.get_room_events(
user_id=user_id,
from_key=from_key,
to_key=to_key,
@ -70,6 +70,15 @@ class EventStream(PaginationStream):
pagination_config.from_tok)
pagination_config.to_tok = yield self.fix_token(
pagination_config.to_tok)
if (
not pagination_config.to_tok
and pagination_config.direction == 'f'
):
pagination_config.to_tok = yield self.get_current_max_token()
logger.debug("pagination_config: %s", pagination_config)
defer.returnValue(pagination_config)
@defer.inlineCallbacks
@ -81,39 +90,42 @@ class EventStream(PaginationStream):
Returns:
The fixed-up token, which may == token.
"""
# replace TOK_START and TOK_END with 0_0_0 or -1_-1_-1 depending.
replacements = [
(PaginationStream.TOK_START, "0"),
(PaginationStream.TOK_END, "-1")
]
for magic_token, key in replacements:
if magic_token == token:
token = EventStream.SEPARATOR.join(
[key] * len(self.stream_data)
)
if token == PaginationStream.TOK_END:
new_token = yield self.get_current_max_token()
# replace -1 values with an actual pkey
token_segments = self._split_token(token)
for i, tok in enumerate(token_segments):
if tok == -1:
# add 1 to the max token because results are EXCLUSIVE from the
# latest version.
token_segments[i] = 1 + (yield self.stream_data[i].max_token())
defer.returnValue(EventStream.SEPARATOR.join(
str(x) for x in token_segments
))
logger.debug("fix_token: From %s to %s", token, new_token)
token = new_token
defer.returnValue(token)
@defer.inlineCallbacks
def get_chunk(self, config=None):
def get_current_max_token(self):
new_token_parts = []
for s in self.stream_data:
mx = yield s.max_token()
new_token_parts.append(str(mx))
new_token = EventStream.SEPARATOR.join(new_token_parts)
logger.debug("get_current_max_token: %s", new_token)
defer.returnValue(new_token)
@defer.inlineCallbacks
def get_chunk(self, config):
# no support for limit on >1 streams, makes no sense.
if config.limit and len(self.stream_data) > 1:
raise EventStreamError(
400, "Limit not supported on multiplexed streams."
)
(chunk_data, next_tok) = yield self._get_chunk_data(config.from_tok,
chunk_data, next_tok = yield self._get_chunk_data(
config.from_tok,
config.to_tok,
config.limit)
config.limit,
config.direction,
)
defer.returnValue({
"chunk": chunk_data,
@ -122,7 +134,7 @@ class EventStream(PaginationStream):
})
@defer.inlineCallbacks
def _get_chunk_data(self, from_tok, to_tok, limit):
def _get_chunk_data(self, from_tok, to_tok, limit, direction):
""" Get event data between the two tokens.
Tokens are SEPARATOR separated values representing pkey values of
@ -140,6 +152,7 @@ class EventStream(PaginationStream):
EventStreamError if something went wrong.
"""
# sanity check
if to_tok is not None:
if (from_tok.count(EventStream.SEPARATOR) !=
to_tok.count(EventStream.SEPARATOR) or
(from_tok.count(EventStream.SEPARATOR) + 1) !=
@ -158,7 +171,7 @@ class EventStream(PaginationStream):
continue
(event_chunk, max_pkey) = yield self.stream_data[i].get_rows(
self.user_id, from_pkey, to_pkey, limit
self.user_id, from_pkey, to_pkey, limit, direction,
)
chunk.extend([
@ -177,9 +190,8 @@ class EventStream(PaginationStream):
Returns:
A list of ints.
"""
if token:
segments = token.split(EventStream.SEPARATOR)
try:
int_segments = [int(x) for x in segments]
except ValueError:
raise EventStreamError(400, "Bad token: %s" % token)
return int_segments
else:
segments = [None] * len(self.stream_data)
return segments

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@ -684,7 +684,7 @@ class PresenceStreamData(StreamData):
super(PresenceStreamData, self).__init__(hs)
self.presence = hs.get_handlers().presence_handler
def get_rows(self, user_id, from_key, to_key, limit):
def get_rows(self, user_id, from_key, to_key, limit, direction):
cachemap = self.presence._user_cachemap
# TODO(paul): limit, and filter by visibility

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@ -466,7 +466,7 @@ class RoomMemberHandler(BaseHandler):
for entry in member_list
]
chunk_data = {
"start": "START",
"start": "START", # FIXME (erikj): START is no longer a valid value
"end": "END",
"chunk": event_list
}
@ -811,4 +811,5 @@ class RoomListHandler(BaseHandler):
@defer.inlineCallbacks
def get_public_room_list(self):
chunk = yield self.store.get_rooms(is_public=True)
# FIXME (erikj): START is no longer a valid value
defer.returnValue({"start": "START", "end": "END", "chunk": chunk})

View File

@ -14,7 +14,7 @@
*/
CREATE TABLE IF NOT EXISTS events(
token_ordering INTEGER PRIMARY KEY AUTOINCREMENT,
stream_ordering INTEGER PRIMARY KEY AUTOINCREMENT,
topological_ordering INTEGER NOT NULL,
event_id TEXT NOT NULL,
type TEXT NOT NULL,

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@ -16,8 +16,9 @@
from twisted.internet import defer
from ._base import SQLBaseStore
from synapse.api.errors import SynapseError
from synapse.api.constants import Membership
from synapse.util.logutils import log_function
import json
import logging
@ -29,9 +30,96 @@ logger = logging.getLogger(__name__)
MAX_STREAM_SIZE = 1000
_STREAM_TOKEN = "stream"
_TOPOLOGICAL_TOKEN = "topological"
def _parse_stream_token(string):
try:
if string[0] != 's':
raise
return int(string[1:])
except:
logger.debug("Not stream token: %s", string)
raise SynapseError(400, "Invalid token")
def _parse_topological_token(string):
try:
if string[0] != 't':
raise
parts = string[1:].split('-', 1)
return (int(parts[0]), int(parts[1]))
except:
logger.debug("Not topological token: %s", string)
raise SynapseError(400, "Invalid token")
def is_stream_token(string):
try:
_parse_stream_token(string)
return True
except:
return False
def is_topological_token(string):
try:
_parse_topological_token(string)
return True
except:
return False
def _get_token_bound(token, comparison):
try:
s = _parse_stream_token(token)
return "%s %s %d" % ("stream_ordering", comparison, s)
except:
pass
try:
top, stream = _parse_topological_token(token)
return "%s %s %d AND %s %s %d" % (
"topological_ordering", comparison, top,
"stream_ordering", comparison, stream,
)
except:
pass
raise SynapseError(400, "Invalid token")
class StreamStore(SQLBaseStore):
@log_function
def get_room_events(self, user_id, from_key, to_key, room_id, limit=0,
direction='f', with_feedback=False):
is_events = (
direction == 'f'
and is_stream_token(from_key)
and to_key and is_stream_token(to_key)
)
if is_events:
return self.get_room_events_stream(
user_id=user_id,
from_key=from_key,
to_key=to_key,
room_id=room_id,
limit=limit,
with_feedback=with_feedback,
)
else:
return self.paginate_room_events(
from_key=from_key,
to_key=to_key,
room_id=room_id,
limit=limit,
with_feedback=with_feedback,
)
@defer.inlineCallbacks
@log_function
def get_room_events_stream(self, user_id, from_key, to_key, room_id,
limit=0, with_feedback=False):
# TODO (erikj): Handle compressed feedback
@ -54,8 +142,8 @@ class StreamStore(SQLBaseStore):
limit = MAX_STREAM_SIZE
# From and to keys should be integers from ordering.
from_key = int(from_key)
to_key = int(to_key)
from_id = _parse_stream_token(from_key)
to_id = _parse_stream_token(to_key)
if from_key == to_key:
defer.returnValue(([], to_key))
@ -65,41 +153,78 @@ class StreamStore(SQLBaseStore):
"SELECT * FROM events as e WHERE "
"((room_id IN (%(current)s)) OR "
"(event_id IN (%(invites)s))) "
"AND e.stream_ordering > ? AND e.stream_ordering < ? "
"ORDER BY stream_ordering ASC LIMIT %(limit)d "
) % {
"current": current_room_membership_sql,
"invites": invites_sql,
"limit": limit
}
# Constraints and ordering depend on direction.
if from_key < to_key:
sql += (
"AND e.token_ordering > ? AND e.token_ordering < ? "
"ORDER BY token_ordering ASC LIMIT %(limit)d "
) % {"limit": limit}
else:
sql += (
"AND e.token_ordering < ? "
"AND e.token_ordering > ? "
"ORDER BY e.token_ordering DESC LIMIT %(limit)d "
) % {"limit": int(limit)}
rows = yield self._execute_and_decode(
sql,
user_id, user_id, Membership.INVITE, from_key, to_key
user_id, user_id, Membership.INVITE, from_id, to_id
)
ret = [self._parse_event_from_row(r) for r in rows]
if rows:
if from_key < to_key:
key = max([r["token_ordering"] for r in rows])
else:
key = min([r["token_ordering"] for r in rows])
key = "s%d" % max([r["stream_ordering"] for r in rows])
else:
# Assume we didn't get anything because there was nothing to get.
key = to_key
defer.returnValue((ret, key))
@defer.inlineCallbacks
@log_function
def paginate_room_events(self, room_id, from_key, to_key=None,
direction='b', limit=-1,
with_feedback=False):
# TODO (erikj): Handle compressed feedback
from_comp = '<' if direction =='b' else '>'
to_comp = '>' if direction =='b' else '<'
order = "DESC" if direction == 'b' else "ASC"
args = [room_id]
bounds = _get_token_bound(from_key, from_comp)
if to_key:
bounds = "%s AND %s" % (bounds, _get_token_bound(to_key, to_comp))
if int(limit) > 0:
args.append(int(limit))
limit_str = " LIMIT ?"
else:
limit_str = ""
sql = (
"SELECT * FROM events "
"WHERE room_id = ? AND %(bounds)s "
"ORDER BY topological_ordering %(order)s, stream_ordering %(order)s %(limit)s "
) % {"bounds": bounds, "order": order, "limit": limit_str}
rows = yield self._execute_and_decode(
sql,
*args
)
if rows:
topo = rows[-1]["topological_ordering"]
toke = rows[-1]["stream_ordering"]
next_token = "t%s-%s" % (topo, toke)
else:
# TODO (erikj): We should work out what to do here instead.
next_token = to_key if to_key else from_key
defer.returnValue(
(
[self._parse_event_from_row(r) for r in rows],
next_token
)
)
@defer.inlineCallbacks
def get_recent_events_for_room(self, room_id, limit, with_feedback=False):
# TODO (erikj): Handle compressed feedback
@ -108,8 +233,8 @@ class StreamStore(SQLBaseStore):
sql = (
"SELECT * FROM events "
"WHERE room_id = ? AND token_ordering <= ? "
"ORDER BY topological_ordering, token_ordering DESC LIMIT ? "
"WHERE room_id = ? AND stream_ordering <= ? "
"ORDER BY topological_ordering, stream_ordering DESC LIMIT ? "
)
rows = yield self._execute_and_decode(
@ -121,12 +246,12 @@ class StreamStore(SQLBaseStore):
if rows:
topo = rows[0]["topological_ordering"]
toke = rows[0]["token_ordering"]
toke = rows[0]["stream_ordering"]
start_token = "p%s-%s" % (topo, toke)
token = (start_token, end_token)
else:
token = ("START", end_token)
token = (end_token, end_token)
defer.returnValue(
(
@ -138,11 +263,14 @@ class StreamStore(SQLBaseStore):
@defer.inlineCallbacks
def get_room_events_max_id(self):
res = yield self._execute_and_decode(
"SELECT MAX(token_ordering) as m FROM events"
"SELECT MAX(stream_ordering) as m FROM events"
)
if not res:
defer.returnValue(0)
logger.debug("get_room_events_max_id: %s", res)
if not res or not res[0] or not res[0]["m"]:
defer.returnValue("s1")
return
defer.returnValue(res[0]["m"])
key = res[0]["m"] + 1
defer.returnValue("s%d" % (key,))

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@ -25,7 +25,6 @@ the eventHandlerService.
angular.module('eventStreamService', [])
.factory('eventStreamService', ['$q', '$timeout', 'matrixService', 'eventHandlerService', function($q, $timeout, matrixService, eventHandlerService) {
var END = "END";
var START = "START";
var TIMEOUT_MS = 30000;
var ERR_TIMEOUT_MS = 5000;

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@ -230,8 +230,8 @@ angular.module('matrixService', [])
path = path.replace("$room_id", room_id);
var params = {
from: from_token,
to: "START",
limit: limit
limit: limit,
dir: 'b'
};
return doRequest("GET", path, params);
},