dendrite/syncapi/types/types.go

284 lines
10 KiB
Go

// 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
import (
"encoding/json"
"errors"
"fmt"
"strconv"
"strings"
"github.com/matrix-org/dendrite/roomserver/api"
"github.com/matrix-org/gomatrixserverlib"
"github.com/tidwall/gjson"
)
var (
// ErrInvalidPaginationTokenType is returned when an attempt at creating a
// new instance of PaginationToken with an invalid type (i.e. neither "s"
// nor "t").
ErrInvalidPaginationTokenType = fmt.Errorf("Pagination token has an unknown prefix (should be either s or t)")
// ErrInvalidPaginationTokenLen is returned when the pagination token is an
// invalid length
ErrInvalidPaginationTokenLen = fmt.Errorf("Pagination token has an invalid length")
)
// StreamPosition represents the offset in the sync stream a client is at.
type StreamPosition int64
// Same as gomatrixserverlib.Event but also has the PDU stream position for this event.
type StreamEvent struct {
gomatrixserverlib.HeaderedEvent
StreamPosition StreamPosition
TransactionID *api.TransactionID
ExcludeFromSync bool
}
// PaginationTokenType represents the type of a pagination token.
// It can be either "s" (representing a position in the whole stream of events)
// or "t" (representing a position in a room's topology/depth).
type PaginationTokenType string
const (
// PaginationTokenTypeStream represents a position in the server's whole
// stream of events
PaginationTokenTypeStream PaginationTokenType = "s"
// PaginationTokenTypeTopology represents a position in a room's topology.
PaginationTokenTypeTopology PaginationTokenType = "t"
)
// PaginationToken represents a pagination token, used for interactions with
// /sync or /messages, for example.
type PaginationToken struct {
//Position StreamPosition
Type PaginationTokenType
PDUPosition StreamPosition
EDUTypingPosition StreamPosition
}
// NewPaginationTokenFromString takes a string of the form "xyyyy..." where "x"
// represents the type of a pagination token and "yyyy..." the token itself, and
// parses it in order to create a new instance of PaginationToken. Returns an
// error if the token couldn't be parsed into an int64, or if the token type
// isn't a known type (returns ErrInvalidPaginationTokenType in the latter
// case).
func NewPaginationTokenFromString(s string) (token *PaginationToken, err error) {
if len(s) == 0 {
return nil, ErrInvalidPaginationTokenLen
}
token = new(PaginationToken)
var positions []string
switch t := PaginationTokenType(s[:1]); t {
case PaginationTokenTypeStream, PaginationTokenTypeTopology:
token.Type = t
positions = strings.Split(s[1:], "_")
default:
token.Type = PaginationTokenTypeStream
positions = strings.Split(s, "_")
}
// Try to get the PDU position.
if len(positions) >= 1 {
if pduPos, err := strconv.ParseInt(positions[0], 10, 64); err != nil {
return nil, err
} else if pduPos < 0 {
return nil, errors.New("negative PDU position not allowed")
} else {
token.PDUPosition = StreamPosition(pduPos)
}
}
// Try to get the typing position.
if len(positions) >= 2 {
if typPos, err := strconv.ParseInt(positions[1], 10, 64); err != nil {
return nil, err
} else if typPos < 0 {
return nil, errors.New("negative EDU typing position not allowed")
} else {
token.EDUTypingPosition = StreamPosition(typPos)
}
}
return
}
// NewPaginationTokenFromTypeAndPosition takes a PaginationTokenType and a
// StreamPosition and returns an instance of PaginationToken.
func NewPaginationTokenFromTypeAndPosition(
t PaginationTokenType, pdupos StreamPosition, typpos StreamPosition,
) (p *PaginationToken) {
return &PaginationToken{
Type: t,
PDUPosition: pdupos,
EDUTypingPosition: typpos,
}
}
// String translates a PaginationToken to a string of the "xyyyy..." (see
// NewPaginationToken to know what it represents).
func (p *PaginationToken) String() string {
return fmt.Sprintf("%s%d_%d", p.Type, p.PDUPosition, p.EDUTypingPosition)
}
// WithUpdates returns a copy of the PaginationToken with updates applied from another PaginationToken.
// If the latter PaginationToken contains a field that is not 0, it is considered an update,
// and its value will replace the corresponding value in the PaginationToken on which WithUpdates is called.
func (pt *PaginationToken) WithUpdates(other PaginationToken) PaginationToken {
ret := *pt
if other.PDUPosition != 0 {
ret.PDUPosition = other.PDUPosition
}
if other.EDUTypingPosition != 0 {
ret.EDUTypingPosition = other.EDUTypingPosition
}
return ret
}
// IsAfter returns whether one PaginationToken refers to states newer than another PaginationToken.
func (sp *PaginationToken) IsAfter(other PaginationToken) bool {
return sp.PDUPosition > other.PDUPosition ||
sp.EDUTypingPosition > other.EDUTypingPosition
}
// PrevEventRef represents a reference to a previous event in a state event upgrade
type PrevEventRef struct {
PrevContent json.RawMessage `json:"prev_content"`
ReplacesState string `json:"replaces_state"`
PrevSender string `json:"prev_sender"`
}
// Response represents a /sync API response. See https://matrix.org/docs/spec/client_server/r0.2.0.html#get-matrix-client-r0-sync
type Response struct {
NextBatch string `json:"next_batch"`
AccountData struct {
Events []gomatrixserverlib.ClientEvent `json:"events"`
} `json:"account_data"`
Presence struct {
Events []gomatrixserverlib.ClientEvent `json:"events"`
} `json:"presence"`
Rooms struct {
Join map[string]JoinResponse `json:"join"`
Invite map[string]InviteResponse `json:"invite"`
Leave map[string]LeaveResponse `json:"leave"`
} `json:"rooms"`
}
// NewResponse creates an empty response with initialised maps.
func NewResponse(token PaginationToken) *Response {
res := Response{
NextBatch: token.String(),
}
// Pre-initialise the maps. Synapse will return {} even if there are no rooms under a specific section,
// so let's do the same thing. Bonus: this means we can't get dreaded 'assignment to entry in nil map' errors.
res.Rooms.Join = make(map[string]JoinResponse)
res.Rooms.Invite = make(map[string]InviteResponse)
res.Rooms.Leave = make(map[string]LeaveResponse)
// Also pre-intialise empty slices or else we'll insert 'null' instead of '[]' for the value.
// TODO: We really shouldn't have to do all this to coerce encoding/json to Do The Right Thing. We should
// really be using our own Marshal/Unmarshal implementations otherwise this may prove to be a CPU bottleneck.
// This also applies to NewJoinResponse, NewInviteResponse and NewLeaveResponse.
res.AccountData.Events = make([]gomatrixserverlib.ClientEvent, 0)
res.Presence.Events = make([]gomatrixserverlib.ClientEvent, 0)
// Fill next_batch with a pagination token. Since this is a response to a sync request, we can assume
// we'll always return a stream token.
res.NextBatch = NewPaginationTokenFromTypeAndPosition(
PaginationTokenTypeStream,
StreamPosition(token.PDUPosition),
StreamPosition(token.EDUTypingPosition),
).String()
return &res
}
// IsEmpty returns true if the response is empty, i.e. used to decided whether
// to return the response immediately to the client or to wait for more data.
func (r *Response) IsEmpty() bool {
return len(r.Rooms.Join) == 0 &&
len(r.Rooms.Invite) == 0 &&
len(r.Rooms.Leave) == 0 &&
len(r.AccountData.Events) == 0 &&
len(r.Presence.Events) == 0
}
// JoinResponse represents a /sync response for a room which is under the 'join' key.
type JoinResponse struct {
State struct {
Events []gomatrixserverlib.ClientEvent `json:"events"`
} `json:"state"`
Timeline struct {
Events []gomatrixserverlib.ClientEvent `json:"events"`
Limited bool `json:"limited"`
PrevBatch string `json:"prev_batch"`
} `json:"timeline"`
Ephemeral struct {
Events []gomatrixserverlib.ClientEvent `json:"events"`
} `json:"ephemeral"`
AccountData struct {
Events []gomatrixserverlib.ClientEvent `json:"events"`
} `json:"account_data"`
}
// NewJoinResponse creates an empty response with initialised arrays.
func NewJoinResponse() *JoinResponse {
res := JoinResponse{}
res.State.Events = make([]gomatrixserverlib.ClientEvent, 0)
res.Timeline.Events = make([]gomatrixserverlib.ClientEvent, 0)
res.Ephemeral.Events = make([]gomatrixserverlib.ClientEvent, 0)
res.AccountData.Events = make([]gomatrixserverlib.ClientEvent, 0)
return &res
}
// InviteResponse represents a /sync response for a room which is under the 'invite' key.
type InviteResponse struct {
InviteState struct {
Events json.RawMessage `json:"events"`
} `json:"invite_state"`
}
// NewInviteResponse creates an empty response with initialised arrays.
func NewInviteResponse(event gomatrixserverlib.HeaderedEvent) *InviteResponse {
res := InviteResponse{}
res.InviteState.Events = json.RawMessage{'[', ']'}
if inviteRoomState := gjson.GetBytes(event.Unsigned(), "invite_room_state"); inviteRoomState.Exists() {
res.InviteState.Events = json.RawMessage(inviteRoomState.Raw)
}
return &res
}
// LeaveResponse represents a /sync response for a room which is under the 'leave' key.
type LeaveResponse struct {
State struct {
Events []gomatrixserverlib.ClientEvent `json:"events"`
} `json:"state"`
Timeline struct {
Events []gomatrixserverlib.ClientEvent `json:"events"`
Limited bool `json:"limited"`
PrevBatch string `json:"prev_batch"`
} `json:"timeline"`
}
// NewLeaveResponse creates an empty response with initialised arrays.
func NewLeaveResponse() *LeaveResponse {
res := LeaveResponse{}
res.State.Events = make([]gomatrixserverlib.ClientEvent, 0)
res.Timeline.Events = make([]gomatrixserverlib.ClientEvent, 0)
return &res
}