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dendrite/syncapi/storage/output_room_events_table.go
2019-07-12 16:43:01 +01:00

293 lines
9.8 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 storage
import (
"context"
"database/sql"
"sort"
"github.com/matrix-org/dendrite/roomserver/api"
"github.com/lib/pq"
"github.com/matrix-org/dendrite/common"
"github.com/matrix-org/gomatrixserverlib"
log "github.com/sirupsen/logrus"
)
const outputRoomEventsSchema = `
-- This sequence is shared between all the tables generated from kafka logs.
CREATE SEQUENCE IF NOT EXISTS syncapi_stream_id;
-- Stores output room events received from the roomserver.
CREATE TABLE IF NOT EXISTS syncapi_output_room_events (
-- An incrementing ID which denotes the position in the log that this event resides at.
-- NB: 'serial' makes no guarantees to increment by 1 every time, only that it increments.
-- This isn't a problem for us since we just want to order by this field.
id BIGINT PRIMARY KEY DEFAULT nextval('syncapi_stream_id'),
-- The event ID for the event
event_id TEXT NOT NULL,
-- The 'room_id' key for the event.
room_id TEXT NOT NULL,
-- The JSON for the event. Stored as TEXT because this should be valid UTF-8.
event_json TEXT NOT NULL,
-- A list of event IDs which represent a delta of added/removed room state. This can be NULL
-- if there is no delta.
add_state_ids TEXT[],
remove_state_ids TEXT[],
device_id TEXT, -- The local device that sent the event, if any
transaction_id TEXT -- The transaction id used to send the event, if any
);
-- for event selection
CREATE UNIQUE INDEX IF NOT EXISTS syncapi_event_id_idx ON syncapi_output_room_events(event_id);
`
const insertEventSQL = "" +
"INSERT INTO syncapi_output_room_events (" +
" room_id, event_id, event_json, add_state_ids, remove_state_ids, device_id, transaction_id" +
") VALUES ($1, $2, $3, $4, $5, $6, $7) RETURNING id"
const selectEventsSQL = "" +
"SELECT id, event_json FROM syncapi_output_room_events WHERE event_id = ANY($1)"
const selectRecentEventsSQL = "" +
"SELECT id, event_json, device_id, transaction_id FROM syncapi_output_room_events" +
" WHERE room_id = $1 AND id > $2 AND id <= $3" +
" ORDER BY id DESC LIMIT $4"
const selectMaxEventIDSQL = "" +
"SELECT MAX(id) FROM syncapi_output_room_events"
// In order for us to apply the state updates correctly, rows need to be ordered in the order they were received (id).
const selectStateInRangeSQL = "" +
"SELECT id, event_json, add_state_ids, remove_state_ids" +
" FROM syncapi_output_room_events" +
" WHERE (id > $1 AND id <= $2) AND (add_state_ids IS NOT NULL OR remove_state_ids IS NOT NULL)" +
" ORDER BY id ASC"
type outputRoomEventsStatements struct {
insertEventStmt *sql.Stmt
selectEventsStmt *sql.Stmt
selectMaxEventIDStmt *sql.Stmt
selectRecentEventsStmt *sql.Stmt
selectStateInRangeStmt *sql.Stmt
}
func (s *outputRoomEventsStatements) prepare(db *sql.DB) (err error) {
_, err = db.Exec(outputRoomEventsSchema)
if err != nil {
return
}
if s.insertEventStmt, err = db.Prepare(insertEventSQL); err != nil {
return
}
if s.selectEventsStmt, err = db.Prepare(selectEventsSQL); err != nil {
return
}
if s.selectMaxEventIDStmt, err = db.Prepare(selectMaxEventIDSQL); err != nil {
return
}
if s.selectRecentEventsStmt, err = db.Prepare(selectRecentEventsSQL); err != nil {
return
}
if s.selectStateInRangeStmt, err = db.Prepare(selectStateInRangeSQL); err != nil {
return
}
return
}
// selectStateInRange returns the state events between the two given PDU stream positions, exclusive of oldPos, inclusive of newPos.
// Results are bucketed based on the room ID. If the same state is overwritten multiple times between the
// two positions, only the most recent state is returned.
func (s *outputRoomEventsStatements) selectStateInRange(
ctx context.Context, txn *sql.Tx, oldPos, newPos int64,
) (map[string]map[string]bool, map[string]streamEvent, error) {
stmt := common.TxStmt(txn, s.selectStateInRangeStmt)
rows, err := stmt.QueryContext(ctx, oldPos, newPos)
if err != nil {
return nil, nil, err
}
// Fetch all the state change events for all rooms between the two positions then loop each event and:
// - Keep a cache of the event by ID (99% of state change events are for the event itself)
// - For each room ID, build up an array of event IDs which represents cumulative adds/removes
// For each room, map cumulative event IDs to events and return. This may need to a batch SELECT based on event ID
// if they aren't in the event ID cache. We don't handle state deletion yet.
eventIDToEvent := make(map[string]streamEvent)
// RoomID => A set (map[string]bool) of state event IDs which are between the two positions
stateNeeded := make(map[string]map[string]bool)
for rows.Next() {
var (
streamPos int64
eventBytes []byte
addIDs pq.StringArray
delIDs pq.StringArray
)
if err := rows.Scan(&streamPos, &eventBytes, &addIDs, &delIDs); err != nil {
return nil, nil, err
}
// Sanity check for deleted state and whine if we see it. We don't need to do anything
// since it'll just mark the event as not being needed.
if len(addIDs) < len(delIDs) {
log.WithFields(log.Fields{
"since": oldPos,
"current": newPos,
"adds": addIDs,
"dels": delIDs,
}).Warn("StateBetween: ignoring deleted state")
}
// TODO: Handle redacted events
ev, err := gomatrixserverlib.NewEventFromTrustedJSON(eventBytes, false)
if err != nil {
return nil, nil, err
}
needSet := stateNeeded[ev.RoomID()]
if needSet == nil { // make set if required
needSet = make(map[string]bool)
}
for _, id := range delIDs {
needSet[id] = false
}
for _, id := range addIDs {
needSet[id] = true
}
stateNeeded[ev.RoomID()] = needSet
eventIDToEvent[ev.EventID()] = streamEvent{
Event: ev,
streamPosition: streamPos,
}
}
return stateNeeded, eventIDToEvent, nil
}
// MaxID returns the ID of the last inserted event in this table. 'txn' is optional. If it is not supplied,
// then this function should only ever be used at startup, as it will race with inserting events if it is
// done afterwards. If there are no inserted events, 0 is returned.
func (s *outputRoomEventsStatements) selectMaxEventID(
ctx context.Context, txn *sql.Tx,
) (id int64, err error) {
var nullableID sql.NullInt64
stmt := common.TxStmt(txn, s.selectMaxEventIDStmt)
err = stmt.QueryRowContext(ctx).Scan(&nullableID)
if nullableID.Valid {
id = nullableID.Int64
}
return
}
// InsertEvent into the output_room_events table. addState and removeState are an optional list of state event IDs. Returns the position
// of the inserted event.
func (s *outputRoomEventsStatements) insertEvent(
ctx context.Context, txn *sql.Tx,
event *gomatrixserverlib.Event, addState, removeState []string,
transactionID *api.TransactionID,
) (streamPos int64, err error) {
var deviceID, txnID *string
if transactionID != nil {
deviceID = &transactionID.DeviceID
txnID = &transactionID.TransactionID
}
stmt := common.TxStmt(txn, s.insertEventStmt)
err = stmt.QueryRowContext(
ctx,
event.RoomID(),
event.EventID(),
event.JSON(),
pq.StringArray(addState),
pq.StringArray(removeState),
deviceID,
txnID,
).Scan(&streamPos)
return
}
// RecentEventsInRoom returns the most recent events in the given room, up to a maximum of 'limit'.
func (s *outputRoomEventsStatements) selectRecentEvents(
ctx context.Context, txn *sql.Tx,
roomID string, fromPos, toPos int64, limit int,
) ([]streamEvent, error) {
stmt := common.TxStmt(txn, s.selectRecentEventsStmt)
rows, err := stmt.QueryContext(ctx, roomID, fromPos, toPos, limit)
if err != nil {
return nil, err
}
defer rows.Close() // nolint: errcheck
events, err := rowsToStreamEvents(rows)
if err != nil {
return nil, err
}
// The events need to be returned from oldest to latest, which isn't
// necessarily the way the SQL query returns them, so a sort is necessary to
// ensure the events are in the right order in the slice.
sort.SliceStable(events, func(i int, j int) bool {
return events[i].streamPosition < events[j].streamPosition
})
return events, nil
}
// Events returns the events for the given event IDs. Returns an error if any one of the event IDs given are missing
// from the database.
func (s *outputRoomEventsStatements) selectEvents(
ctx context.Context, txn *sql.Tx, eventIDs []string,
) ([]streamEvent, error) {
stmt := common.TxStmt(txn, s.selectEventsStmt)
rows, err := stmt.QueryContext(ctx, pq.StringArray(eventIDs))
if err != nil {
return nil, err
}
defer rows.Close() // nolint: errcheck
return rowsToStreamEvents(rows)
}
func rowsToStreamEvents(rows *sql.Rows) ([]streamEvent, error) {
var result []streamEvent
for rows.Next() {
var (
streamPos int64
eventBytes []byte
deviceID *string
txnID *string
transactionID *api.TransactionID
)
if err := rows.Scan(&streamPos, &eventBytes, &deviceID, &txnID); err != nil {
return nil, err
}
// TODO: Handle redacted events
ev, err := gomatrixserverlib.NewEventFromTrustedJSON(eventBytes, false)
if err != nil {
return nil, err
}
if deviceID != nil && txnID != nil {
transactionID = &api.TransactionID{
DeviceID: *deviceID,
TransactionID: *txnID,
}
}
result = append(result, streamEvent{
Event: ev,
streamPosition: streamPos,
transactionID: transactionID,
})
}
return result, nil
}