Add input API for adding invites to the roomserver. (#187)

* Add input API for adding invites to the roomserver.

This API handles invites received over federation that occur outside of a room.

* Add some docstring for withTransaction

* Use a nicer pattern for wrapping transactions

* Fix MembershipUpdater method to not commit the transaction before returning it

* Use the Transaction interface from common
main
Mark Haines 2017-08-21 16:37:11 +01:00 committed by GitHub
parent 5950293e79
commit 57b7097368
8 changed files with 166 additions and 53 deletions

View File

@ -18,6 +18,24 @@ import (
"database/sql"
)
// A Transaction is something that can be committed or rolledback.
type Transaction interface {
// Commit the transaction
Commit() error
// Rollback the transaction.
Rollback() error
}
// EndTransaction ends a transaction.
// If the transaction succeeded then it is committed, otherwise it is rolledback.
func EndTransaction(txn Transaction, succeeded *bool) {
if *succeeded {
txn.Commit()
} else {
txn.Rollback()
}
}
// WithTransaction runs a block of code passing in an SQL transaction
// If the code returns an error or panics then the transactions is rolledback
// Otherwise the transaction is committed.
@ -26,16 +44,14 @@ func WithTransaction(db *sql.DB, fn func(txn *sql.Tx) error) (err error) {
if err != nil {
return
}
defer func() {
if r := recover(); r != nil {
txn.Rollback()
panic(r)
} else if err != nil {
txn.Rollback()
} else {
err = txn.Commit()
}
}()
succeeded := false
defer EndTransaction(txn, &succeeded)
err = fn(txn)
if err != nil {
return
}
succeeded = true
return
}

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@ -68,9 +68,17 @@ type InputRoomEvent struct {
SendAsServer string `json:"send_as_server"`
}
// InputInviteEvent is a matrix invite event received over federation without
// the usual context a matrix room event would have. We usually do not have
// access to the events needed to check the event auth rules for the invite.
type InputInviteEvent struct {
Event gomatrixserverlib.Event `json:"event"`
}
// InputRoomEventsRequest is a request to InputRoomEvents
type InputRoomEventsRequest struct {
InputRoomEvents []InputRoomEvent `json:"input_room_events"`
InputRoomEvents []InputRoomEvent `json:"input_room_events"`
InputInviteEvents []InputInviteEvent `json:"input_invite_events"`
}
// InputRoomEventsResponse is a response to InputRoomEvents

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@ -15,6 +15,9 @@
package input
import (
"fmt"
"github.com/matrix-org/dendrite/common"
"github.com/matrix-org/dendrite/roomserver/api"
"github.com/matrix-org/dendrite/roomserver/state"
"github.com/matrix-org/dendrite/roomserver/types"
@ -39,6 +42,8 @@ type RoomEventDatabase interface {
GetLatestEventsForUpdate(roomNID types.RoomNID) (updater types.RoomRecentEventsUpdater, err error)
// Lookup the string event IDs for a list of numeric event IDs
EventIDs(eventNIDs []types.EventNID) (map[types.EventNID]string, error)
// Build a membership updater for the target user in a room.
MembershipUpdater(roomID, targerUserID string) (types.MembershipUpdater, error)
}
// OutputRoomEventWriter has the APIs needed to write an event to the output logs.
@ -103,13 +108,64 @@ func processRoomEvent(db RoomEventDatabase, ow OutputRoomEventWriter, input api.
return err
}
// TODO:
// * Caculate the new current state for the room if the forward extremities have changed.
// * Work out the delta between the new current state and the previous current state.
// * Work out the visibility of the event.
// * Write a message to the output logs containing:
// - The event itself
// - The visiblity of the event, i.e. who is allowed to see the event.
// - The changes to the current state of the room.
return nil
}
func processInviteEvent(db RoomEventDatabase, ow OutputRoomEventWriter, input api.InputInviteEvent) (err error) {
if input.Event.StateKey() == nil {
return fmt.Errorf("invite must be a state event")
}
roomID := input.Event.RoomID()
targetUserID := *input.Event.StateKey()
updater, err := db.MembershipUpdater(roomID, targetUserID)
if err != nil {
return err
}
succeeded := false
defer common.EndTransaction(updater, &succeeded)
if updater.IsJoin() {
// If the user is joined to the room then that takes precedence over this
// invite event. It makes little sense to move a user that is already
// joined to the room into the invite state.
// This could plausibly happen if an invite request raced with a join
// request for a user. For example if a user was invited to a public
// room and they joined the room at the same time as the invite was sent.
// The other way this could plausibly happen is if an invite raced with
// a kick. For example if a user was kicked from a room in error and in
// response someone else in the room re-invited them then it is possible
// for the invite request to race with the leave event so that the
// target receives invite before it learns that it has been kicked.
// There are a few ways this could be plausibly handled in the roomserver.
// 1) Store the invite, but mark it as retired. That will result in the
// permanent rejection of that invite event. So even if the target
// user leaves the room and the invite is retransmitted it will be
// ignored. However a new invite with a new event ID would still be
// accepted.
// 2) Silently discard the invite event. This means that if the event
// was retransmitted at a later date after the target user had left
// the room we would accept the invite. However since we hadn't told
// the sending server that the invite had been discarded it would
// have no reason to attempt to retry.
// 3) Signal the sending server that the user is already joined to the
// room.
// For now we will implement option 2. Since in the abesence of a retry
// mechanism it will be equivalent to option 1, and we don't have a
// signalling mechanism to implement option 3.
return nil
}
outputUpdates, err := updateToInviteMembership(updater, &input.Event, nil)
if err != nil {
return err
}
if err = ow.WriteOutputEvents(roomID, outputUpdates); err != nil {
return err
}
succeeded = true
return nil
}

View File

@ -61,6 +61,11 @@ func (r *RoomserverInputAPI) InputRoomEvents(
return err
}
}
for i := range request.InputInviteEvents {
if err := processInviteEvent(r.DB, r, request.InputInviteEvents[i]); err != nil {
return err
}
}
return nil
}

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@ -17,6 +17,7 @@ package input
import (
"bytes"
"github.com/matrix-org/dendrite/common"
"github.com/matrix-org/dendrite/roomserver/api"
"github.com/matrix-org/dendrite/roomserver/state"
"github.com/matrix-org/dendrite/roomserver/types"
@ -52,25 +53,19 @@ func updateLatestEvents(
if err != nil {
return
}
defer func() {
if err == nil {
// Commit if there wasn't an error.
// Set the returned err value if we encounter an error committing.
// This only works because err is a named return.
err = updater.Commit()
} else {
// Ignore any error we get rolling back since we don't want to
// clobber the current error
// TODO: log the error here.
updater.Rollback()
}
}()
succeeded := false
defer common.EndTransaction(updater, &succeeded)
u := latestEventsUpdater{
db: db, updater: updater, ow: ow, roomNID: roomNID,
stateAtEvent: stateAtEvent, event: event, sendAsServer: sendAsServer,
}
return u.doUpdateLatestEvents()
if err = u.doUpdateLatestEvents(); err != nil {
return err
}
succeeded = true
return
}
// latestEventsUpdater tracks the state used to update the latest events in the

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@ -80,15 +80,23 @@ func (s *roomStatements) prepare(db *sql.DB) (err error) {
}.prepare(db)
}
func (s *roomStatements) insertRoomNID(roomID string) (types.RoomNID, error) {
func (s *roomStatements) insertRoomNID(txn *sql.Tx, roomID string) (types.RoomNID, error) {
var roomNID int64
err := s.insertRoomNIDStmt.QueryRow(roomID).Scan(&roomNID)
stmt := s.insertRoomNIDStmt
if txn != nil {
stmt = txn.Stmt(stmt)
}
err := stmt.QueryRow(roomID).Scan(&roomNID)
return types.RoomNID(roomNID), err
}
func (s *roomStatements) selectRoomNID(roomID string) (types.RoomNID, error) {
func (s *roomStatements) selectRoomNID(txn *sql.Tx, roomID string) (types.RoomNID, error) {
var roomNID int64
err := s.selectRoomNIDStmt.QueryRow(roomID).Scan(&roomNID)
stmt := s.selectRoomNIDStmt
if txn != nil {
stmt = txn.Stmt(stmt)
}
err := stmt.QueryRow(roomID).Scan(&roomNID)
return types.RoomNID(roomNID), err
}

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@ -53,7 +53,7 @@ func (d *Database) StoreEvent(event gomatrixserverlib.Event, authEventNIDs []typ
err error
)
if roomNID, err = d.assignRoomNID(event.RoomID()); err != nil {
if roomNID, err = d.assignRoomNID(nil, event.RoomID()); err != nil {
return 0, types.StateAtEvent{}, err
}
@ -104,15 +104,15 @@ func (d *Database) StoreEvent(event gomatrixserverlib.Event, authEventNIDs []typ
}, nil
}
func (d *Database) assignRoomNID(roomID string) (types.RoomNID, error) {
func (d *Database) assignRoomNID(txn *sql.Tx, roomID string) (types.RoomNID, error) {
// Check if we already have a numeric ID in the database.
roomNID, err := d.statements.selectRoomNID(roomID)
roomNID, err := d.statements.selectRoomNID(txn, roomID)
if err == sql.ErrNoRows {
// We don't have a numeric ID so insert one into the database.
roomNID, err = d.statements.insertRoomNID(roomID)
roomNID, err = d.statements.insertRoomNID(txn, roomID)
if err == sql.ErrNoRows {
// We raced with another insert so run the select again.
roomNID, err = d.statements.selectRoomNID(roomID)
roomNID, err = d.statements.selectRoomNID(txn, roomID)
}
}
return roomNID, err
@ -329,7 +329,7 @@ func (u *roomRecentEventsUpdater) MembershipUpdater(targetUserNID types.EventSta
// RoomNID implements query.RoomserverQueryAPIDB
func (d *Database) RoomNID(roomID string) (types.RoomNID, error) {
roomNID, err := d.statements.selectRoomNID(roomID)
roomNID, err := d.statements.selectRoomNID(nil, roomID)
if err == sql.ErrNoRows {
return 0, nil
}
@ -380,6 +380,38 @@ func (d *Database) StateEntriesForTuples(
return d.statements.bulkSelectFilteredStateBlockEntries(stateBlockNIDs, stateKeyTuples)
}
// MembershipUpdater implements input.RoomEventDatabase
func (d *Database) MembershipUpdater(roomID, targetUserID string) (types.MembershipUpdater, error) {
txn, err := d.db.Begin()
if err != nil {
return nil, err
}
succeeded := false
defer func() {
if !succeeded {
txn.Rollback()
}
}()
roomNID, err := d.assignRoomNID(txn, roomID)
if err != nil {
return nil, err
}
targetUserNID, err := d.assignStateKeyNID(txn, targetUserID)
if err != nil {
return nil, err
}
updater, err := d.membershipUpdaterTxn(txn, roomNID, targetUserNID)
if err != nil {
return nil, err
}
succeeded = true
return updater, nil
}
type membershipUpdater struct {
transaction
d *Database

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@ -16,6 +16,7 @@
package types
import (
"github.com/matrix-org/dendrite/common"
"github.com/matrix-org/gomatrixserverlib"
)
@ -135,14 +136,6 @@ type StateEntryList struct {
StateEntries []StateEntry
}
// A Transaction is something that can be committed or rolledback.
type Transaction interface {
// Commit the transaction
Commit() error
// Rollback the transaction.
Rollback() error
}
// A RoomRecentEventsUpdater is used to update the recent events in a room.
// (On postgresql this wraps a database transaction that holds a "FOR UPDATE"
// lock on the row in the rooms table holding the latest events for the room.)
@ -175,7 +168,7 @@ type RoomRecentEventsUpdater interface {
// It will share the same transaction as this updater.
MembershipUpdater(targetUserNID EventStateKeyNID) (MembershipUpdater, error)
// Implements Transaction so it can be committed or rolledback
Transaction
common.Transaction
}
// A MembershipUpdater is used to update the membership of a user in a room.
@ -200,7 +193,7 @@ type MembershipUpdater interface {
// Returns a list of invite event IDs that this state change retired.
SetToLeave(senderUserID string, eventID string) (inviteEventIDs []string, err error)
// Implements Transaction so it can be committed or rolledback.
Transaction
common.Transaction
}
// A MissingEventError is an error that happened because the roomserver was