dendrite/roomserver/types/types.go

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// Copyright 2017 Vector Creations 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.
// Package types provides the types that are used internally within the roomserver.
package types
import (
"encoding/json"
"sort"
"strings"
"github.com/matrix-org/gomatrixserverlib"
"golang.org/x/crypto/blake2b"
)
// EventTypeNID is a numeric ID for an event type.
type EventTypeNID int64
// EventStateKeyNID is a numeric ID for an event state_key.
type EventStateKeyNID int64
// EventNID is a numeric ID for an event.
type EventNID int64
// RoomNID is a numeric ID for a room.
type RoomNID int64
// StateSnapshotNID is a numeric ID for the state at an event.
type StateSnapshotNID int64
// StateBlockNID is a numeric ID for a block of state data.
// These blocks of state data are combined to form the actual state.
type StateBlockNID int64
// EventNIDs is used to sort and dedupe event NIDs.
type EventNIDs []EventNID
func (a EventNIDs) Len() int { return len(a) }
func (a EventNIDs) Swap(i, j int) { a[i], a[j] = a[j], a[i] }
func (a EventNIDs) Less(i, j int) bool { return a[i] < a[j] }
func (a EventNIDs) Hash() []byte {
j, err := json.Marshal(a)
if err != nil {
return nil
}
h := blake2b.Sum256(j)
return h[:]
}
// StateBlockNIDs is used to sort and dedupe state block NIDs.
type StateBlockNIDs []StateBlockNID
func (a StateBlockNIDs) Len() int { return len(a) }
func (a StateBlockNIDs) Swap(i, j int) { a[i], a[j] = a[j], a[i] }
func (a StateBlockNIDs) Less(i, j int) bool { return a[i] < a[j] }
func (a StateBlockNIDs) Hash() []byte {
j, err := json.Marshal(a)
if err != nil {
return nil
}
h := blake2b.Sum256(j)
return h[:]
}
// A StateKeyTuple is a pair of a numeric event type and a numeric state key.
// It is used to lookup state entries.
type StateKeyTuple struct {
// The numeric ID for the event type.
EventTypeNID EventTypeNID
// The numeric ID for the state key.
EventStateKeyNID EventStateKeyNID
}
func (a StateKeyTuple) IsCreate() bool {
return a.EventTypeNID == MRoomCreateNID && a.EventStateKeyNID == EmptyStateKeyNID
}
// LessThan returns true if this state key is less than the other state key.
// The ordering is arbitrary and is used to implement binary search and to efficiently deduplicate entries.
func (a StateKeyTuple) LessThan(b StateKeyTuple) bool {
if a.EventTypeNID != b.EventTypeNID {
return a.EventTypeNID < b.EventTypeNID
}
return a.EventStateKeyNID < b.EventStateKeyNID
}
// A StateEntry is an entry in the room state of a matrix room.
type StateEntry struct {
StateKeyTuple
// The numeric ID for the event.
EventNID EventNID
}
type StateEntries []StateEntry
func (a StateEntries) Len() int { return len(a) }
func (a StateEntries) Swap(i, j int) { a[i], a[j] = a[j], a[i] }
func (a StateEntries) Less(i, j int) bool { return a[i].EventNID < a[j].EventNID }
// LessThan returns true if this state entry is less than the other state entry.
// The ordering is arbitrary and is used to implement binary search and to efficiently deduplicate entries.
func (a StateEntry) LessThan(b StateEntry) bool {
if a.StateKeyTuple != b.StateKeyTuple {
return a.StateKeyTuple.LessThan(b.StateKeyTuple)
}
return a.EventNID < b.EventNID
}
// Deduplicate takes a set of state entries and ensures that there are no
// duplicate (event type, state key) tuples. If there are then we dedupe
// them, making sure that the latest/highest NIDs are always chosen.
func DeduplicateStateEntries(a []StateEntry) []StateEntry {
if len(a) < 2 {
return a
}
sort.SliceStable(a, func(i, j int) bool {
return a[i].LessThan(a[j])
})
for i := 0; i < len(a)-1; i++ {
if a[i].StateKeyTuple == a[i+1].StateKeyTuple {
a = append(a[:i], a[i+1:]...)
i--
}
}
return a
}
// StateAtEvent is the state before and after a matrix event.
type StateAtEvent struct {
// Should this state overwrite the latest events and memberships of the room?
// This might be necessary when rejoining a federated room after a period of
// absence, as our state and latest events will be out of date.
Overwrite bool
// The state before the event.
BeforeStateSnapshotNID StateSnapshotNID
// True if this StateEntry is rejected. State resolution should then treat this
// StateEntry as being a message event (not a state event).
IsRejected bool
// The state entry for the event itself, allows us to calculate the state after the event.
StateEntry
}
// IsStateEvent returns whether the event the state is at is a state event.
func (s StateAtEvent) IsStateEvent() bool {
return s.EventStateKeyNID != 0
}
// StateAtEventAndReference is StateAtEvent and gomatrixserverlib.EventReference glued together.
// It is used when looking up the latest events in a room in the database.
// The gomatrixserverlib.EventReference is used to check whether a new event references the event.
// The StateAtEvent is used to construct the current state of the room from the latest events.
type StateAtEventAndReference struct {
StateAtEvent
gomatrixserverlib.EventReference
}
type StateAtEventAndReferences []StateAtEventAndReference
func (s StateAtEventAndReferences) Less(a, b int) bool {
return strings.Compare(s[a].EventID, s[b].EventID) < 0
}
func (s StateAtEventAndReferences) Len() int {
return len(s)
}
func (s StateAtEventAndReferences) Swap(a, b int) {
s[a], s[b] = s[b], s[a]
}
// An Event is a gomatrixserverlib.Event with the numeric event ID attached.
// It is when performing bulk event lookup in the database.
type Event struct {
EventNID EventNID
*gomatrixserverlib.Event
}
const (
// MRoomCreateNID is the numeric ID for the "m.room.create" event type.
MRoomCreateNID = 1
// MRoomPowerLevelsNID is the numeric ID for the "m.room.power_levels" event type.
MRoomPowerLevelsNID = 2
// MRoomJoinRulesNID is the numeric ID for the "m.room.join_rules" event type.
MRoomJoinRulesNID = 3
// MRoomThirdPartyInviteNID is the numeric ID for the "m.room.third_party_invite" event type.
MRoomThirdPartyInviteNID = 4
// MRoomMemberNID is the numeric ID for the "m.room.member" event type.
MRoomMemberNID = 5
// MRoomRedactionNID is the numeric ID for the "m.room.redaction" event type.
MRoomRedactionNID = 6
// MRoomHistoryVisibilityNID is the numeric ID for the "m.room.history_visibility" event type.
MRoomHistoryVisibilityNID = 7
)
const (
// EmptyStateKeyNID is the numeric ID for the empty state key.
EmptyStateKeyNID = 1
)
// StateBlockNIDList is used to return the result of bulk StateBlockNID lookups from the database.
type StateBlockNIDList struct {
StateSnapshotNID StateSnapshotNID
StateBlockNIDs []StateBlockNID
}
// StateEntryList is used to return the result of bulk state entry lookups from the database.
type StateEntryList struct {
StateBlockNID StateBlockNID
StateEntries []StateEntry
}
// A MissingEventError is an error that happened because the roomserver was
// missing requested events from its database.
type MissingEventError string
func (e MissingEventError) Error() string { return string(e) }
// A MissingStateError is an error that happened because the roomserver was
// missing requested state snapshots from its databases.
type MissingStateError string
func (e MissingStateError) Error() string { return string(e) }
// A RejectedError is returned when an event is stored as rejected. The error
// contains the reason why.
type RejectedError string
func (e RejectedError) Error() string { return string(e) }
// RoomInfo contains metadata about a room
type RoomInfo struct {
RoomNID RoomNID
RoomVersion gomatrixserverlib.RoomVersion
StateSnapshotNID StateSnapshotNID
IsStub bool
}