dendrite/roomserver/storage/sqlite3/state_snapshot_table.go
Till eb29a31550
Optimize /sync and history visibility (#2961)
Should fix the following issues or make a lot less worse when using
Postgres:

The main issue behind #2911: The client gives up after a certain time,
causing a cascade of context errors, because the response couldn't be
built up fast enough. This mostly happens on accounts with many rooms,
due to the inefficient way we're getting recent events and current state

For #2777: The queries for getting the membership events for history
visibility were being executed for each room (I think 185?), resulting
in a whooping 2k queries for membership events. (Getting the
statesnapshot -> block nids -> actual wanted membership event)

Both should now be better by:
- Using a LATERAL join to get all recent events for all joined rooms in
one go (TODO: maybe do the same for room summary and current state etc)
- If we're lazy loading on initial syncs, we're now not getting the
whole current state, just to drop the majority of it because we're lazy
loading members - we add a filter to exclude membership events on the
first call to `CurrentState`.
- Using an optimized query to get the membership events needed to
calculate history visibility

---------

Co-authored-by: kegsay <kegan@matrix.org>
2023-02-07 14:31:23 +01:00

185 lines
6.4 KiB
Go

// Copyright 2017-2018 New Vector Ltd
// Copyright 2019-2020 The Matrix.org Foundation C.I.C.
//
// 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 sqlite3
import (
"context"
"database/sql"
"encoding/json"
"fmt"
"strings"
"github.com/matrix-org/dendrite/internal"
"github.com/matrix-org/dendrite/internal/sqlutil"
"github.com/matrix-org/dendrite/roomserver/storage/tables"
"github.com/matrix-org/dendrite/roomserver/types"
"github.com/matrix-org/gomatrixserverlib"
"github.com/matrix-org/util"
)
const stateSnapshotSchema = `
CREATE TABLE IF NOT EXISTS roomserver_state_snapshots (
-- The state snapshot NID that identifies this snapshot.
state_snapshot_nid INTEGER PRIMARY KEY AUTOINCREMENT,
-- The hash of the state snapshot, which is used to enforce uniqueness. The hash is
-- generated in Dendrite and passed through to the database, as a btree index over
-- this column is cheap and fits within the maximum index size.
state_snapshot_hash BLOB UNIQUE,
-- The room NID that the snapshot belongs to.
room_nid INTEGER NOT NULL,
-- The state blocks contained within this snapshot, encoded as JSON.
state_block_nids TEXT NOT NULL DEFAULT '[]'
);
`
// Insert a new state snapshot. If we conflict on the hash column then
// we must perform an update so that the RETURNING statement returns the
// ID of the row that we conflicted with, so that we can then refer to
// the original snapshot.
const insertStateSQL = `
INSERT INTO roomserver_state_snapshots (state_snapshot_hash, room_nid, state_block_nids)
VALUES ($1, $2, $3)
ON CONFLICT (state_snapshot_hash) DO UPDATE SET room_nid=$2
RETURNING state_snapshot_nid
`
// Bulk state data NID lookup.
// Sorting by state_snapshot_nid means we can use binary search over the result
// to lookup the state data NIDs for a state snapshot NID.
const bulkSelectStateBlockNIDsSQL = "" +
"SELECT state_snapshot_nid, state_block_nids FROM roomserver_state_snapshots" +
" WHERE state_snapshot_nid IN ($1) ORDER BY state_snapshot_nid ASC"
const selectStateBlockNIDsForRoomNID = "" +
"SELECT state_block_nids FROM roomserver_state_snapshots WHERE room_nid = $1"
type stateSnapshotStatements struct {
db *sql.DB
insertStateStmt *sql.Stmt
bulkSelectStateBlockNIDsStmt *sql.Stmt
selectStateBlockNIDsStmt *sql.Stmt
}
func CreateStateSnapshotTable(db *sql.DB) error {
_, err := db.Exec(stateSnapshotSchema)
return err
}
func PrepareStateSnapshotTable(db *sql.DB) (*stateSnapshotStatements, error) {
s := &stateSnapshotStatements{
db: db,
}
return s, sqlutil.StatementList{
{&s.insertStateStmt, insertStateSQL},
{&s.bulkSelectStateBlockNIDsStmt, bulkSelectStateBlockNIDsSQL},
{&s.selectStateBlockNIDsStmt, selectStateBlockNIDsForRoomNID},
}.Prepare(db)
}
func (s *stateSnapshotStatements) InsertState(
ctx context.Context, txn *sql.Tx, roomNID types.RoomNID, stateBlockNIDs types.StateBlockNIDs,
) (stateNID types.StateSnapshotNID, err error) {
if stateBlockNIDs == nil {
stateBlockNIDs = []types.StateBlockNID{} // zero slice to not store 'null' in the DB
}
stateBlockNIDs = stateBlockNIDs[:util.SortAndUnique(stateBlockNIDs)]
stateBlockNIDsJSON, err := json.Marshal(stateBlockNIDs)
if err != nil {
return
}
insertStmt := sqlutil.TxStmt(txn, s.insertStateStmt)
err = insertStmt.QueryRowContext(ctx, stateBlockNIDs.Hash(), int64(roomNID), string(stateBlockNIDsJSON)).Scan(&stateNID)
if err != nil {
return 0, err
}
return
}
func (s *stateSnapshotStatements) BulkSelectStateBlockNIDs(
ctx context.Context, txn *sql.Tx, stateNIDs []types.StateSnapshotNID,
) ([]types.StateBlockNIDList, error) {
nids := make([]interface{}, len(stateNIDs))
for k, v := range stateNIDs {
nids[k] = v
}
selectOrig := strings.Replace(bulkSelectStateBlockNIDsSQL, "($1)", sqlutil.QueryVariadic(len(nids)), 1)
selectPrep, err := s.db.Prepare(selectOrig)
if err != nil {
return nil, err
}
defer selectPrep.Close() // nolint:errcheck
selectStmt := sqlutil.TxStmt(txn, selectPrep)
rows, err := selectStmt.QueryContext(ctx, nids...)
if err != nil {
return nil, err
}
defer internal.CloseAndLogIfError(ctx, rows, "bulkSelectStateBlockNIDs: rows.close() failed")
results := make([]types.StateBlockNIDList, len(stateNIDs))
i := 0
var stateBlockNIDsJSON string
for ; rows.Next(); i++ {
result := &results[i]
if err := rows.Scan(&result.StateSnapshotNID, &stateBlockNIDsJSON); err != nil {
return nil, err
}
if err := json.Unmarshal([]byte(stateBlockNIDsJSON), &result.StateBlockNIDs); err != nil {
return nil, err
}
}
if i != len(stateNIDs) {
return nil, types.MissingStateError(fmt.Sprintf("storage: state NIDs missing from the database (%d != %d)", i, len(stateNIDs)))
}
return results, nil
}
func (s *stateSnapshotStatements) BulkSelectStateForHistoryVisibility(
ctx context.Context, txn *sql.Tx, stateSnapshotNID types.StateSnapshotNID, domain string,
) ([]types.EventNID, error) {
return nil, tables.OptimisationNotSupportedError
}
func (s *stateSnapshotStatements) BulkSelectMembershipForHistoryVisibility(ctx context.Context, txn *sql.Tx, userNID types.EventStateKeyNID, roomInfo *types.RoomInfo, eventIDs ...string) (map[string]*gomatrixserverlib.HeaderedEvent, error) {
return nil, tables.OptimisationNotSupportedError
}
func (s *stateSnapshotStatements) selectStateBlockNIDsForRoomNID(
ctx context.Context, txn *sql.Tx, roomNID types.RoomNID,
) ([]types.StateBlockNID, error) {
var res []types.StateBlockNID
rows, err := sqlutil.TxStmt(txn, s.selectStateBlockNIDsStmt).QueryContext(ctx, roomNID)
if err != nil {
return res, nil
}
defer internal.CloseAndLogIfError(ctx, rows, "selectStateBlockNIDsForRoomNID: rows.close() failed")
var stateBlockNIDs []types.StateBlockNID
var stateBlockNIDsJSON string
for rows.Next() {
if err = rows.Scan(&stateBlockNIDsJSON); err != nil {
return nil, err
}
if err = json.Unmarshal([]byte(stateBlockNIDsJSON), &stateBlockNIDs); err != nil {
return nil, err
}
res = append(res, stateBlockNIDs...)
}
return res, rows.Err()
}