dendrite/roomserver/storage/postgres/state_snapshot_table.go
kegsay 1647213fac
Implement new RoomVersionImpl API (#3062)
As outlined in https://github.com/matrix-org/gomatrixserverlib/pull/368

The main change Dendrite side is that `RoomVersion` no longer has any
methods on it. Instead, you need to bounce via `gmsl.GetRoomVersion`.

It's very interesting to see where exactly Dendrite cares about this.
For some places it's creating events (fine) but others are way more
specific. Those areas will need to migrate to GMSL at some point.
2023-04-21 17:06:29 +01:00

251 lines
9.9 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 postgres
import (
"context"
"database/sql"
"fmt"
"github.com/lib/pq"
"github.com/matrix-org/gomatrixserverlib"
"github.com/matrix-org/util"
"github.com/matrix-org/dendrite/internal/sqlutil"
"github.com/matrix-org/dendrite/roomserver/types"
)
const stateSnapshotSchema = `
-- The state of a room before an event.
-- Stored as a list of state_block entries stored in a separate table.
-- The actual state is constructed by combining all the state_block entries
-- referenced by state_block_nids together. If the same state key tuple appears
-- multiple times then the entry from the later state_block clobbers the earlier
-- entries.
-- This encoding format allows us to implement a delta encoding which is useful
-- because room state tends to accumulate small changes over time. Although if
-- the list of deltas becomes too long it becomes more efficient to encode
-- the full state under single state_block_nid.
CREATE SEQUENCE IF NOT EXISTS roomserver_state_snapshot_nid_seq;
CREATE TABLE IF NOT EXISTS roomserver_state_snapshots (
-- The state snapshot NID that identifies this snapshot.
state_snapshot_nid bigint PRIMARY KEY DEFAULT nextval('roomserver_state_snapshot_nid_seq'),
-- 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 BYTEA UNIQUE,
-- The room NID that the snapshot belongs to.
room_nid bigint NOT NULL,
-- The state blocks contained within this snapshot.
state_block_nids bigint[] NOT NULL
);
`
// 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" +
// Performing an update, above, ensures that the RETURNING statement
// below will always return a valid state snapshot ID
" 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 = ANY($1) ORDER BY state_snapshot_nid ASC"
// Looks up both the history visibility event and relevant membership events from
// a given domain name from a given state snapshot. This is used to optimise the
// helpers.CheckServerAllowedToSeeEvent function.
// TODO: There's a sequence scan here because of the hash join strategy, which is
// probably O(n) on state key entries, so there must be a way to avoid that somehow.
// Event type NIDs are:
// - 5: m.room.member as per https://github.com/matrix-org/dendrite/blob/c7f7aec4d07d59120d37d5b16a900f6d608a75c4/roomserver/storage/postgres/event_types_table.go#L40
// - 7: m.room.history_visibility as per https://github.com/matrix-org/dendrite/blob/c7f7aec4d07d59120d37d5b16a900f6d608a75c4/roomserver/storage/postgres/event_types_table.go#L42
const bulkSelectStateForHistoryVisibilitySQL = `
SELECT event_nid FROM (
SELECT event_nid, event_type_nid, event_state_key_nid FROM roomserver_events
WHERE (event_type_nid = 5 OR event_type_nid = 7)
AND event_nid = ANY(
SELECT UNNEST(event_nids) FROM roomserver_state_block
WHERE state_block_nid = ANY(
SELECT UNNEST(state_block_nids) FROM roomserver_state_snapshots
WHERE state_snapshot_nid = $1
)
)
ORDER BY depth ASC
) AS roomserver_events
INNER JOIN roomserver_event_state_keys
ON roomserver_events.event_state_key_nid = roomserver_event_state_keys.event_state_key_nid
AND (event_type_nid = 7 OR event_state_key LIKE '%:' || $2);
`
// bulkSelectMembershipForHistoryVisibilitySQL is an optimization to get membership events for a specific user for defined set of events.
// Returns the event_id of the event we want the membership event for, the event_id of the membership event and the membership event JSON.
const bulkSelectMembershipForHistoryVisibilitySQL = `
SELECT re.event_id, re2.event_id, rej.event_json
FROM roomserver_events re
LEFT JOIN roomserver_state_snapshots rss on re.state_snapshot_nid = rss.state_snapshot_nid
CROSS JOIN unnest(rss.state_block_nids) AS blocks(block_nid)
LEFT JOIN roomserver_state_block rsb ON rsb.state_block_nid = blocks.block_nid
CROSS JOIN unnest(rsb.event_nids) AS rsb2(event_nid)
JOIN roomserver_events re2 ON re2.room_nid = $3 AND re2.event_type_nid = 5 AND re2.event_nid = rsb2.event_nid AND re2.event_state_key_nid = $1
LEFT JOIN roomserver_event_json rej ON rej.event_nid = re2.event_nid
WHERE re.event_id = ANY($2)
`
type stateSnapshotStatements struct {
insertStateStmt *sql.Stmt
bulkSelectStateBlockNIDsStmt *sql.Stmt
bulkSelectStateForHistoryVisibilityStmt *sql.Stmt
bulktSelectMembershipForHistoryVisibilityStmt *sql.Stmt
}
func CreateStateSnapshotTable(db *sql.DB) error {
_, err := db.Exec(stateSnapshotSchema)
return err
}
func PrepareStateSnapshotTable(db *sql.DB) (*stateSnapshotStatements, error) {
s := &stateSnapshotStatements{}
return s, sqlutil.StatementList{
{&s.insertStateStmt, insertStateSQL},
{&s.bulkSelectStateBlockNIDsStmt, bulkSelectStateBlockNIDsSQL},
{&s.bulkSelectStateForHistoryVisibilityStmt, bulkSelectStateForHistoryVisibilitySQL},
{&s.bulktSelectMembershipForHistoryVisibilityStmt, bulkSelectMembershipForHistoryVisibilitySQL},
}.Prepare(db)
}
func (s *stateSnapshotStatements) InsertState(
ctx context.Context, txn *sql.Tx, roomNID types.RoomNID, nids types.StateBlockNIDs,
) (stateNID types.StateSnapshotNID, err error) {
nids = nids[:util.SortAndUnique(nids)]
err = sqlutil.TxStmt(txn, s.insertStateStmt).QueryRowContext(ctx, nids.Hash(), int64(roomNID), stateBlockNIDsAsArray(nids)).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([]int64, len(stateNIDs))
for i := range stateNIDs {
nids[i] = int64(stateNIDs[i])
}
stmt := sqlutil.TxStmt(txn, s.bulkSelectStateBlockNIDsStmt)
rows, err := stmt.QueryContext(ctx, pq.Int64Array(nids))
if err != nil {
return nil, err
}
defer rows.Close() // nolint: errcheck
results := make([]types.StateBlockNIDList, len(stateNIDs))
i := 0
var stateBlockNIDs pq.Int64Array
for ; rows.Next(); i++ {
result := &results[i]
if err = rows.Scan(&result.StateSnapshotNID, &stateBlockNIDs); err != nil {
return nil, err
}
result.StateBlockNIDs = make([]types.StateBlockNID, len(stateBlockNIDs))
for k := range stateBlockNIDs {
result.StateBlockNIDs[k] = types.StateBlockNID(stateBlockNIDs[k])
}
}
if err = rows.Err(); 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) {
stmt := sqlutil.TxStmt(txn, s.bulkSelectStateForHistoryVisibilityStmt)
rows, err := stmt.QueryContext(ctx, stateSnapshotNID, domain)
if err != nil {
return nil, err
}
defer rows.Close() // nolint: errcheck
results := make([]types.EventNID, 0, 16)
for rows.Next() {
var eventNID types.EventNID
if err = rows.Scan(&eventNID); err != nil {
return nil, err
}
results = append(results, eventNID)
}
return results, rows.Err()
}
func (s *stateSnapshotStatements) BulkSelectMembershipForHistoryVisibility(
ctx context.Context, txn *sql.Tx, userNID types.EventStateKeyNID, roomInfo *types.RoomInfo, eventIDs ...string,
) (map[string]*gomatrixserverlib.HeaderedEvent, error) {
stmt := sqlutil.TxStmt(txn, s.bulktSelectMembershipForHistoryVisibilityStmt)
rows, err := stmt.QueryContext(ctx, userNID, pq.Array(eventIDs), roomInfo.RoomNID)
if err != nil {
return nil, err
}
defer rows.Close() // nolint: errcheck
result := make(map[string]*gomatrixserverlib.HeaderedEvent, len(eventIDs))
var evJson []byte
var eventID string
var membershipEventID string
knownEvents := make(map[string]*gomatrixserverlib.HeaderedEvent, len(eventIDs))
verImpl, err := gomatrixserverlib.GetRoomVersion(roomInfo.RoomVersion)
if err != nil {
return nil, err
}
for rows.Next() {
if err = rows.Scan(&eventID, &membershipEventID, &evJson); err != nil {
return nil, err
}
if len(evJson) == 0 {
result[eventID] = &gomatrixserverlib.HeaderedEvent{}
continue
}
// If we already know this event, don't try to marshal the json again
if ev, ok := knownEvents[membershipEventID]; ok {
result[eventID] = ev
continue
}
event, err := verImpl.NewEventFromTrustedJSON(evJson, false)
if err != nil {
result[eventID] = &gomatrixserverlib.HeaderedEvent{}
// not fatal
continue
}
he := event.Headered(roomInfo.RoomVersion)
result[eventID] = he
knownEvents[membershipEventID] = he
}
return result, rows.Err()
}