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- # Copyright 2019 New Vector 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.
- import logging
- from typing import Any, Dict, List, Optional, Tuple
- import attr
- from synapse.api.errors import SynapseError
- from synapse.types import JsonDict
- logger = logging.getLogger(__name__)
- @attr.s(slots=True)
- class PaginationChunk:
- """Returned by relation pagination APIs.
- Attributes:
- chunk: The rows returned by pagination
- next_batch: Token to fetch next set of results with, if
- None then there are no more results.
- prev_batch: Token to fetch previous set of results with, if
- None then there are no previous results.
- """
- chunk = attr.ib(type=List[JsonDict])
- next_batch = attr.ib(type=Optional[Any], default=None)
- prev_batch = attr.ib(type=Optional[Any], default=None)
- def to_dict(self) -> Dict[str, Any]:
- d = {"chunk": self.chunk}
- if self.next_batch:
- d["next_batch"] = self.next_batch.to_string()
- if self.prev_batch:
- d["prev_batch"] = self.prev_batch.to_string()
- return d
- @attr.s(frozen=True, slots=True)
- class RelationPaginationToken:
- """Pagination token for relation pagination API.
- As the results are in topological order, we can use the
- `topological_ordering` and `stream_ordering` fields of the events at the
- boundaries of the chunk as pagination tokens.
- Attributes:
- topological: The topological ordering of the boundary event
- stream: The stream ordering of the boundary event.
- """
- topological = attr.ib(type=int)
- stream = attr.ib(type=int)
- @staticmethod
- def from_string(string: str) -> "RelationPaginationToken":
- try:
- t, s = string.split("-")
- return RelationPaginationToken(int(t), int(s))
- except ValueError:
- raise SynapseError(400, "Invalid relation pagination token")
- def to_string(self) -> str:
- return "%d-%d" % (self.topological, self.stream)
- def as_tuple(self) -> Tuple[Any, ...]:
- return attr.astuple(self)
- @attr.s(frozen=True, slots=True)
- class AggregationPaginationToken:
- """Pagination token for relation aggregation pagination API.
- As the results are order by count and then MAX(stream_ordering) of the
- aggregation groups, we can just use them as our pagination token.
- Attributes:
- count: The count of relations in the boundary group.
- stream: The MAX stream ordering in the boundary group.
- """
- count = attr.ib(type=int)
- stream = attr.ib(type=int)
- @staticmethod
- def from_string(string: str) -> "AggregationPaginationToken":
- try:
- c, s = string.split("-")
- return AggregationPaginationToken(int(c), int(s))
- except ValueError:
- raise SynapseError(400, "Invalid aggregation pagination token")
- def to_string(self) -> str:
- return "%d-%d" % (self.count, self.stream)
- def as_tuple(self) -> Tuple[Any, ...]:
- return attr.astuple(self)
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