Implement storage interfaces (#841)

* Implement interfaces for federationsender storage

* Implement interfaces for mediaapi storage

* Implement interfaces for publicroomsapi storage

* Implement interfaces for roomserver storage

* Implement interfaces for syncapi storage

* Implement interfaces for keydb storage

* common.PartitionStorer in publicroomsapi interface

* Update copyright notices

roomserver/storage/postgres/rooms_table.go

@@ -0,0 +1,156 @@
+// 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"
+
+	"github.com/lib/pq"
+	"github.com/matrix-org/dendrite/common"
+	"github.com/matrix-org/dendrite/roomserver/types"
+)
+
+const roomsSchema = `
+CREATE SEQUENCE IF NOT EXISTS roomserver_room_nid_seq;
+CREATE TABLE IF NOT EXISTS roomserver_rooms (
+    -- Local numeric ID for the room.
+    room_nid BIGINT PRIMARY KEY DEFAULT nextval('roomserver_room_nid_seq'),
+    -- Textual ID for the room.
+    room_id TEXT NOT NULL CONSTRAINT roomserver_room_id_unique UNIQUE,
+    -- The most recent events in the room that aren't referenced by another event.
+    -- This list may empty if the server hasn't joined the room yet.
+    -- (The server will be in that state while it stores the events for the initial state of the room)
+    latest_event_nids BIGINT[] NOT NULL DEFAULT '{}'::BIGINT[],
+    -- The last event written to the output log for this room.
+    last_event_sent_nid BIGINT NOT NULL DEFAULT 0,
+    -- The state of the room after the current set of latest events.
+    -- This will be 0 if there are no latest events in the room.
+    state_snapshot_nid BIGINT NOT NULL DEFAULT 0
+);
+`
+
+// Same as insertEventTypeNIDSQL
+const insertRoomNIDSQL = "" +
+	"INSERT INTO roomserver_rooms (room_id) VALUES ($1)" +
+	" ON CONFLICT ON CONSTRAINT roomserver_room_id_unique" +
+	" DO NOTHING RETURNING (room_nid)"
+
+const selectRoomNIDSQL = "" +
+	"SELECT room_nid FROM roomserver_rooms WHERE room_id = $1"
+
+const selectLatestEventNIDsSQL = "" +
+	"SELECT latest_event_nids, state_snapshot_nid FROM roomserver_rooms WHERE room_nid = $1"
+
+const selectLatestEventNIDsForUpdateSQL = "" +
+	"SELECT latest_event_nids, last_event_sent_nid, state_snapshot_nid FROM roomserver_rooms WHERE room_nid = $1 FOR UPDATE"
+
+const updateLatestEventNIDsSQL = "" +
+	"UPDATE roomserver_rooms SET latest_event_nids = $2, last_event_sent_nid = $3, state_snapshot_nid = $4 WHERE room_nid = $1"
+
+type roomStatements struct {
+	insertRoomNIDStmt                  *sql.Stmt
+	selectRoomNIDStmt                  *sql.Stmt
+	selectLatestEventNIDsStmt          *sql.Stmt
+	selectLatestEventNIDsForUpdateStmt *sql.Stmt
+	updateLatestEventNIDsStmt          *sql.Stmt
+}
+
+func (s *roomStatements) prepare(db *sql.DB) (err error) {
+	_, err = db.Exec(roomsSchema)
+	if err != nil {
+		return
+	}
+	return statementList{
+		{&s.insertRoomNIDStmt, insertRoomNIDSQL},
+		{&s.selectRoomNIDStmt, selectRoomNIDSQL},
+		{&s.selectLatestEventNIDsStmt, selectLatestEventNIDsSQL},
+		{&s.selectLatestEventNIDsForUpdateStmt, selectLatestEventNIDsForUpdateSQL},
+		{&s.updateLatestEventNIDsStmt, updateLatestEventNIDsSQL},
+	}.prepare(db)
+}
+
+func (s *roomStatements) insertRoomNID(
+	ctx context.Context, txn *sql.Tx, roomID string,
+) (types.RoomNID, error) {
+	var roomNID int64
+	stmt := common.TxStmt(txn, s.insertRoomNIDStmt)
+	err := stmt.QueryRowContext(ctx, roomID).Scan(&roomNID)
+	return types.RoomNID(roomNID), err
+}
+
+func (s *roomStatements) selectRoomNID(
+	ctx context.Context, txn *sql.Tx, roomID string,
+) (types.RoomNID, error) {
+	var roomNID int64
+	stmt := common.TxStmt(txn, s.selectRoomNIDStmt)
+	err := stmt.QueryRowContext(ctx, roomID).Scan(&roomNID)
+	return types.RoomNID(roomNID), err
+}
+
+func (s *roomStatements) selectLatestEventNIDs(
+	ctx context.Context, roomNID types.RoomNID,
+) ([]types.EventNID, types.StateSnapshotNID, error) {
+	var nids pq.Int64Array
+	var stateSnapshotNID int64
+	stmt := s.selectLatestEventNIDsStmt
+	err := stmt.QueryRowContext(ctx, int64(roomNID)).Scan(&nids, &stateSnapshotNID)
+	if err != nil {
+		return nil, 0, err
+	}
+	eventNIDs := make([]types.EventNID, len(nids))
+	for i := range nids {
+		eventNIDs[i] = types.EventNID(nids[i])
+	}
+	return eventNIDs, types.StateSnapshotNID(stateSnapshotNID), nil
+}
+
+func (s *roomStatements) selectLatestEventsNIDsForUpdate(
+	ctx context.Context, txn *sql.Tx, roomNID types.RoomNID,
+) ([]types.EventNID, types.EventNID, types.StateSnapshotNID, error) {
+	var nids pq.Int64Array
+	var lastEventSentNID int64
+	var stateSnapshotNID int64
+	stmt := common.TxStmt(txn, s.selectLatestEventNIDsForUpdateStmt)
+	err := stmt.QueryRowContext(ctx, int64(roomNID)).Scan(&nids, &lastEventSentNID, &stateSnapshotNID)
+	if err != nil {
+		return nil, 0, 0, err
+	}
+	eventNIDs := make([]types.EventNID, len(nids))
+	for i := range nids {
+		eventNIDs[i] = types.EventNID(nids[i])
+	}
+	return eventNIDs, types.EventNID(lastEventSentNID), types.StateSnapshotNID(stateSnapshotNID), nil
+}
+
+func (s *roomStatements) updateLatestEventNIDs(
+	ctx context.Context,
+	txn *sql.Tx,
+	roomNID types.RoomNID,
+	eventNIDs []types.EventNID,
+	lastEventSentNID types.EventNID,
+	stateSnapshotNID types.StateSnapshotNID,
+) error {
+	stmt := common.TxStmt(txn, s.updateLatestEventNIDsStmt)
+	_, err := stmt.ExecContext(
+		ctx,
+		roomNID,
+		eventNIDsAsArray(eventNIDs),
+		int64(lastEventSentNID),
+		int64(stateSnapshotNID),
+	)
+	return err
+}