fedsender: add cache tables for notary keys (#1923)

* Add notary server tables for postgres

* Add sqlite tables

* fedsender: GetServerKeys -> QueryServerKeys

As it now checks a cache and can return multiple responses

federationsender/storage/sqlite3/notary_server_keys_json_table.go

@@ -0,0 +1,63 @@
+// Copyright 2021 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"
+
+	"github.com/matrix-org/dendrite/federationsender/storage/tables"
+	"github.com/matrix-org/gomatrixserverlib"
+)
+
+const notaryServerKeysJSONSchema = `
+CREATE TABLE IF NOT EXISTS federationsender_notary_server_keys_json (
+    notary_id INTEGER PRIMARY KEY AUTOINCREMENT,
+	response_json TEXT NOT NULL,
+	server_name TEXT NOT NULL,
+	valid_until BIGINT NOT NULL
+);
+`
+
+const insertServerKeysJSONSQL = "" +
+	"INSERT INTO federationsender_notary_server_keys_json (response_json, server_name, valid_until) VALUES ($1, $2, $3)" +
+	" RETURNING notary_id"
+
+type notaryServerKeysStatements struct {
+	db                       *sql.DB
+	insertServerKeysJSONStmt *sql.Stmt
+}
+
+func NewSQLiteNotaryServerKeysTable(db *sql.DB) (s *notaryServerKeysStatements, err error) {
+	s = &notaryServerKeysStatements{
+		db: db,
+	}
+	_, err = db.Exec(notaryServerKeysJSONSchema)
+	if err != nil {
+		return
+	}
+
+	if s.insertServerKeysJSONStmt, err = db.Prepare(insertServerKeysJSONSQL); err != nil {
+		return
+	}
+	return
+}
+
+func (s *notaryServerKeysStatements) InsertJSONResponse(
+	ctx context.Context, txn *sql.Tx, keyQueryResponseJSON gomatrixserverlib.ServerKeys, serverName gomatrixserverlib.ServerName, validUntil gomatrixserverlib.Timestamp,
+) (tables.NotaryID, error) {
+	var notaryID tables.NotaryID
+	return notaryID, txn.Stmt(s.insertServerKeysJSONStmt).QueryRowContext(ctx, string(keyQueryResponseJSON.Raw), serverName, validUntil).Scan(&notaryID)
+}