dendrite/syncapi/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
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import (
"encoding/json"
"errors"
"fmt"
"strconv"
"strings"
"github.com/matrix-org/dendrite/roomserver/api"
"github.com/matrix-org/gomatrixserverlib"
"github.com/tidwall/gjson"
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)
var (
// ErrInvalidSyncTokenType is returned when an attempt at creating a
// new instance of SyncToken with an invalid type (i.e. neither "s"
// nor "t").
ErrInvalidSyncTokenType = fmt.Errorf("Sync token has an unknown prefix (should be either s or t)")
// ErrInvalidSyncTokenLen is returned when the pagination token is an
// invalid length
ErrInvalidSyncTokenLen = fmt.Errorf("Sync token has an invalid length")
)
// StreamPosition represents the offset in the sync stream a client is at.
type StreamPosition int64
// StreamEvent is the 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
}
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// Range represents a range between two stream positions.
type Range struct {
// From is the position the client has already received.
From StreamPosition
// To is the position the client is going towards.
To StreamPosition
// True if the client is going backwards
Backwards bool
}
// Low returns the low number of the range.
// This represents the position the client already has and hence is exclusive.
func (r *Range) Low() StreamPosition {
if !r.Backwards {
return r.From
}
return r.To
}
// High returns the high number of the range
// This represents the position the client is going towards and hence is inclusive.
func (r *Range) High() StreamPosition {
if !r.Backwards {
return r.To
}
return r.From
}
// SyncTokenType represents the type of a sync 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 SyncTokenType string
const (
// SyncTokenTypeStream represents a position in the server's whole
// stream of events
SyncTokenTypeStream SyncTokenType = "s"
// SyncTokenTypeTopology represents a position in a room's topology.
SyncTokenTypeTopology SyncTokenType = "t"
)
type StreamingToken struct {
syncToken
}
func (t *StreamingToken) PDUPosition() StreamPosition {
return t.Positions[0]
}
func (t *StreamingToken) EDUPosition() StreamPosition {
return t.Positions[1]
}
// IsAfter returns true if ANY position in this token is greater than `other`.
func (t *StreamingToken) IsAfter(other StreamingToken) bool {
for i := range other.Positions {
if t.Positions[i] > other.Positions[i] {
return true
}
}
return false
}
// WithUpdates returns a copy of the StreamingToken with updates applied from another StreamingToken.
// If the latter StreamingToken contains a field that is not 0, it is considered an update,
// and its value will replace the corresponding value in the StreamingToken on which WithUpdates is called.
func (t *StreamingToken) WithUpdates(other StreamingToken) (ret StreamingToken) {
ret.Type = t.Type
ret.Positions = make([]StreamPosition, len(t.Positions))
for i := range t.Positions {
ret.Positions[i] = t.Positions[i]
if other.Positions[i] == 0 {
continue
}
ret.Positions[i] = other.Positions[i]
}
return ret
}
type TopologyToken struct {
syncToken
}
func (t *TopologyToken) Depth() StreamPosition {
return t.Positions[0]
}
func (t *TopologyToken) PDUPosition() StreamPosition {
return t.Positions[1]
}
func (t *TopologyToken) StreamToken() StreamingToken {
return NewStreamToken(t.PDUPosition(), 0)
}
func (t *TopologyToken) String() string {
return t.syncToken.String()
}
// Decrement the topology token to one event earlier.
func (t *TopologyToken) Decrement() {
depth := t.Positions[0]
pduPos := t.Positions[1]
if depth-1 <= 0 {
// nothing can be lower than this
depth = 1
} else {
// this assumes that we will never have 1000 events all with the same
// depth. TODO: work out what the right PDU position is to use, probably needs a db hit.
depth--
pduPos += 1000
}
// The lowest token value is 1, therefore we need to manually set it to that
// value if we're below it.
if depth < 1 {
depth = 1
}
t.Positions = []StreamPosition{
depth, pduPos,
}
}
// NewSyncTokenFromString 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 SyncToken. Returns an
// error if the token couldn't be parsed into an int64, or if the token type
// isn't a known type (returns ErrInvalidSyncTokenType in the latter
// case).
func newSyncTokenFromString(s string) (token *syncToken, err error) {
if len(s) == 0 {
return nil, ErrInvalidSyncTokenLen
}
token = new(syncToken)
var positions []string
switch t := SyncTokenType(s[:1]); t {
case SyncTokenTypeStream, SyncTokenTypeTopology:
token.Type = t
positions = strings.Split(s[1:], "_")
default:
return nil, ErrInvalidSyncTokenType
}
for _, pos := range positions {
if posInt, err := strconv.ParseInt(pos, 10, 64); err != nil {
return nil, err
} else if posInt < 0 {
return nil, errors.New("negative position not allowed")
} else {
token.Positions = append(token.Positions, StreamPosition(posInt))
}
}
return
}
// NewTopologyToken creates a new sync token for /messages
func NewTopologyToken(depth, streamPos StreamPosition) TopologyToken {
if depth < 0 {
depth = 1
}
return TopologyToken{
syncToken: syncToken{
Type: SyncTokenTypeTopology,
Positions: []StreamPosition{depth, streamPos},
},
}
}
func NewTopologyTokenFromString(tok string) (token TopologyToken, err error) {
t, err := newSyncTokenFromString(tok)
if err != nil {
return
}
if t.Type != SyncTokenTypeTopology {
err = fmt.Errorf("token %s is not a topology token", tok)
return
}
if len(t.Positions) != 2 {
err = fmt.Errorf("token %s wrong number of values, got %d want 2", tok, len(t.Positions))
return
}
return TopologyToken{
syncToken: *t,
}, nil
}
// NewStreamToken creates a new sync token for /sync
func NewStreamToken(pduPos, eduPos StreamPosition) StreamingToken {
return StreamingToken{
syncToken: syncToken{
Type: SyncTokenTypeStream,
Positions: []StreamPosition{pduPos, eduPos},
},
}
}
func NewStreamTokenFromString(tok string) (token StreamingToken, err error) {
t, err := newSyncTokenFromString(tok)
if err != nil {
return
}
if t.Type != SyncTokenTypeStream {
err = fmt.Errorf("token %s is not a streaming token", tok)
return
}
if len(t.Positions) != 2 {
err = fmt.Errorf("token %s wrong number of values, got %d want 2", tok, len(t.Positions))
return
}
return StreamingToken{
syncToken: *t,
}, nil
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}
// syncToken represents a syncapi token, used for interactions with
// /sync or /messages, for example.
type syncToken struct {
Type SyncTokenType
// A list of stream positions, their meanings vary depending on the token type.
Positions []StreamPosition
}
// String translates a SyncToken to a string of the "xyyyy..." (see
// NewSyncToken to know what it represents).
func (p *syncToken) String() string {
posStr := make([]string, len(p.Positions))
for i := range p.Positions {
posStr[i] = strconv.FormatInt(int64(p.Positions[i]), 10)
}
return fmt.Sprintf("%s%s", p.Type, strings.Join(posStr, "_"))
}
// 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"`
}
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// 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"`
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} `json:"account_data"`
Presence struct {
Events []gomatrixserverlib.ClientEvent `json:"events"`
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} `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 StreamingToken) *Response {
res := Response{
NextBatch: token.String(),
}
// Pre-initialise the maps. Synapse will return {} even if there are no rooms under a specific section,
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// 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)
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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
}
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// JoinResponse represents a /sync response for a room which is under the 'join' key.
type JoinResponse struct {
State struct {
Events []gomatrixserverlib.ClientEvent `json:"events"`
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} `json:"state"`
Timeline struct {
Events []gomatrixserverlib.ClientEvent `json:"events"`
Limited bool `json:"limited"`
PrevBatch string `json:"prev_batch"`
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} `json:"timeline"`
Ephemeral struct {
Events []gomatrixserverlib.ClientEvent `json:"events"`
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} `json:"ephemeral"`
AccountData struct {
Events []gomatrixserverlib.ClientEvent `json:"events"`
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} `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)
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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"`
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} `json:"invite_state"`
}
// NewInviteResponse creates an empty response with initialised arrays.
func NewInviteResponse(event gomatrixserverlib.HeaderedEvent) *InviteResponse {
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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)
}
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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"`
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} `json:"state"`
Timeline struct {
Events []gomatrixserverlib.ClientEvent `json:"events"`
Limited bool `json:"limited"`
PrevBatch string `json:"prev_batch"`
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} `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)
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return &res
}