Merge both user API databases into one (#2186)

* Merge user API databases into one

* Remove DeviceDatabase from config

* Fix tests

* Try that again

* Clean up keyserver device keys when the devices no longer exist in the user API

* Tweak ordering

* Fix UserExists flag, device check

* Allow including empty entries so we can clean them up

* Remove logging

userapi/storage/postgres/logintoken_table.go

@@ -0,0 +1,96 @@
+// 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 postgres
+
+import (
+	"context"
+	"database/sql"
+	"time"
+
+	"github.com/matrix-org/dendrite/internal/sqlutil"
+	"github.com/matrix-org/dendrite/userapi/api"
+	"github.com/matrix-org/util"
+)
+
+type loginTokenStatements struct {
+	insertStmt        *sql.Stmt
+	deleteStmt        *sql.Stmt
+	selectByTokenStmt *sql.Stmt
+}
+
+// execSchema ensures tables and indices exist.
+func (s *loginTokenStatements) execSchema(db *sql.DB) error {
+	_, err := db.Exec(`
+CREATE TABLE IF NOT EXISTS login_tokens (
+	-- The random value of the token issued to a user
+	token TEXT NOT NULL PRIMARY KEY,
+	-- When the token expires
+	token_expires_at TIMESTAMP NOT NULL,
+
+    -- The mxid for this account
+	user_id TEXT NOT NULL
+);
+
+-- This index allows efficient garbage collection of expired tokens.
+CREATE INDEX IF NOT EXISTS login_tokens_expiration_idx ON login_tokens(token_expires_at);
+`)
+	return err
+}
+
+// prepare runs statement preparation.
+func (s *loginTokenStatements) prepare(db *sql.DB) error {
+	if err := s.execSchema(db); err != nil {
+		return err
+	}
+	return sqlutil.StatementList{
+		{&s.insertStmt, "INSERT INTO login_tokens(token, token_expires_at, user_id) VALUES ($1, $2, $3)"},
+		{&s.deleteStmt, "DELETE FROM login_tokens WHERE token = $1 OR token_expires_at <= $2"},
+		{&s.selectByTokenStmt, "SELECT user_id FROM login_tokens WHERE token = $1 AND token_expires_at > $2"},
+	}.Prepare(db)
+}
+
+// insert adds an already generated token to the database.
+func (s *loginTokenStatements) insert(ctx context.Context, txn *sql.Tx, metadata *api.LoginTokenMetadata, data *api.LoginTokenData) error {
+	stmt := sqlutil.TxStmt(txn, s.insertStmt)
+	_, err := stmt.ExecContext(ctx, metadata.Token, metadata.Expiration.UTC(), data.UserID)
+	return err
+}
+
+// deleteByToken removes the named token.
+//
+// As a simple way to garbage-collect stale tokens, we also remove all expired tokens.
+// The login_tokens_expiration_idx index should make that efficient.
+func (s *loginTokenStatements) deleteByToken(ctx context.Context, txn *sql.Tx, token string) error {
+	stmt := sqlutil.TxStmt(txn, s.deleteStmt)
+	res, err := stmt.ExecContext(ctx, token, time.Now().UTC())
+	if err != nil {
+		return err
+	}
+	if n, err := res.RowsAffected(); err == nil && n > 1 {
+		util.GetLogger(ctx).WithField("num_deleted", n).Infof("Deleted %d login tokens (%d likely additional expired token)", n, n-1)
+	}
+	return nil
+}
+
+// selectByToken returns the data associated with the given token. May return sql.ErrNoRows.
+func (s *loginTokenStatements) selectByToken(ctx context.Context, token string) (*api.LoginTokenData, error) {
+	var data api.LoginTokenData
+	err := s.selectByTokenStmt.QueryRowContext(ctx, token, time.Now().UTC()).Scan(&data.UserID)
+	if err != nil {
+		return nil, err
+	}
+
+	return &data, nil
+}