112 lines
3.2 KiB
Python
112 lines
3.2 KiB
Python
# -*- coding: utf-8 -*-
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# Copyright 2019 New Vector Ltd
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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import logging
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import attr
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from synapse.api.errors import SynapseError
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logger = logging.getLogger(__name__)
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@attr.s(slots=True)
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class PaginationChunk:
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"""Returned by relation pagination APIs.
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Attributes:
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chunk (list): The rows returned by pagination
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next_batch (Any|None): Token to fetch next set of results with, if
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None then there are no more results.
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prev_batch (Any|None): Token to fetch previous set of results with, if
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None then there are no previous results.
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"""
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chunk = attr.ib()
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next_batch = attr.ib(default=None)
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prev_batch = attr.ib(default=None)
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def to_dict(self):
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d = {"chunk": self.chunk}
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if self.next_batch:
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d["next_batch"] = self.next_batch.to_string()
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if self.prev_batch:
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d["prev_batch"] = self.prev_batch.to_string()
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return d
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@attr.s(frozen=True, slots=True)
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class RelationPaginationToken:
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"""Pagination token for relation pagination API.
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As the results are in topological order, we can use the
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`topological_ordering` and `stream_ordering` fields of the events at the
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boundaries of the chunk as pagination tokens.
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Attributes:
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topological (int): The topological ordering of the boundary event
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stream (int): The stream ordering of the boundary event.
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"""
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topological = attr.ib()
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stream = attr.ib()
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@staticmethod
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def from_string(string):
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try:
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t, s = string.split("-")
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return RelationPaginationToken(int(t), int(s))
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except ValueError:
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raise SynapseError(400, "Invalid token")
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def to_string(self):
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return "%d-%d" % (self.topological, self.stream)
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def as_tuple(self):
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return attr.astuple(self)
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@attr.s(frozen=True, slots=True)
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class AggregationPaginationToken:
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"""Pagination token for relation aggregation pagination API.
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As the results are order by count and then MAX(stream_ordering) of the
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aggregation groups, we can just use them as our pagination token.
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Attributes:
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count (int): The count of relations in the boundar group.
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stream (int): The MAX stream ordering in the boundary group.
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"""
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count = attr.ib()
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stream = attr.ib()
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@staticmethod
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def from_string(string):
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try:
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c, s = string.split("-")
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return AggregationPaginationToken(int(c), int(s))
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except ValueError:
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raise SynapseError(400, "Invalid token")
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def to_string(self):
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return "%d-%d" % (self.count, self.stream)
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def as_tuple(self):
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return attr.astuple(self)
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