From fd740350ca70b55a9372c9e146bdc5ee9364e972 Mon Sep 17 00:00:00 2001
From: Brendan Abolivier <contact@brendanabolivier.com>
Date: Wed, 26 Jul 2017 16:34:13 +0100
Subject: [PATCH] Add database functions to interact with aliases

---
 .../roomserver/storage/room_aliases_table.go  | 95 +++++++++++++++++++
 .../dendrite/roomserver/storage/sql.go        |  5 +
 .../dendrite/roomserver/storage/storage.go    | 20 ++++
 3 files changed, 120 insertions(+)
 create mode 100644 src/github.com/matrix-org/dendrite/roomserver/storage/room_aliases_table.go

diff --git a/src/github.com/matrix-org/dendrite/roomserver/storage/room_aliases_table.go b/src/github.com/matrix-org/dendrite/roomserver/storage/room_aliases_table.go
new file mode 100644
index 000000000..ed90fbd57
--- /dev/null
+++ b/src/github.com/matrix-org/dendrite/roomserver/storage/room_aliases_table.go
@@ -0,0 +1,95 @@
+// Copyright 2017 Vector Creations Ltd
+//
+// 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 storage
+
+import (
+	"database/sql"
+)
+
+const roomAliasesSchema = `
+-- Stores room aliases and room IDs they refer to
+CREATE TABLE IF NOT EXISTS room_aliases (
+    -- Alias of the room
+    alias TEXT NOT NULL PRIMARY KEY,
+    -- Room ID the alias refers to
+    room_id TEXT NOT NULL
+);
+`
+
+const insertRoomAliasSQL = "" +
+	"INSERT INTO room_aliases (alias, room_id) VALUES ($1, $2)"
+
+const selectRoomIDFromAliasSQL = "" +
+	"SELECT room_id FROM room_aliases WHERE alias = $1"
+
+const selectAliasesFromRoomIDSQL = "" +
+	"SELECT alias FROM room_aliases WHERE room_id = $1"
+
+const deleteRoomAliasSQL = "" +
+	"DELETE FROM room_aliases WHERE alias = $1"
+
+type roomAliasesStatements struct {
+	insertRoomAliasStmt         *sql.Stmt
+	selectRoomIDFromAliasStmt   *sql.Stmt
+	selectAliasesFromRoomIDStmt *sql.Stmt
+	deleteRoomAliasStmt         *sql.Stmt
+}
+
+func (s *roomAliasesStatements) prepare(db *sql.DB) (err error) {
+	_, err = db.Exec(roomAliasesSchema)
+	if err != nil {
+		return
+	}
+	return statementList{
+		{&s.insertRoomAliasStmt, insertRoomAliasSQL},
+		{&s.selectRoomIDFromAliasStmt, selectRoomIDFromAliasSQL},
+		{&s.selectAliasesFromRoomIDStmt, selectAliasesFromRoomIDSQL},
+		{&s.deleteRoomAliasStmt, deleteRoomAliasSQL},
+	}.prepare(db)
+}
+
+func (s *roomAliasesStatements) insertRoomAlias(alias string, roomID string) (err error) {
+	_, err = s.insertRoomAliasStmt.Exec(alias, roomID)
+	return
+}
+
+func (s *roomAliasesStatements) selectRoomIDFromAlias(alias string) (roomID string, err error) {
+	err = s.selectRoomIDFromAliasStmt.QueryRow(alias).Scan(&roomID)
+	return
+}
+
+func (s *roomAliasesStatements) selectAliasesFromRoomID(roomID string) (aliases []string, err error) {
+	aliases = []string{}
+	rows, err := s.selectRoomIDFromAliasStmt.Query(roomID)
+	if err != nil {
+		return
+	}
+
+	for rows.Next() {
+		var alias string
+		if err = rows.Scan(&alias); err != nil {
+			return
+		}
+
+		aliases = append(aliases, alias)
+	}
+
+	return
+}
+
+func (s *roomAliasesStatements) deleteRoomAlias(alias string) (err error) {
+	_, err = s.deleteRoomAliasStmt.Exec(alias)
+	return
+}
diff --git a/src/github.com/matrix-org/dendrite/roomserver/storage/sql.go b/src/github.com/matrix-org/dendrite/roomserver/storage/sql.go
index fcb414f02..1f247b554 100644
--- a/src/github.com/matrix-org/dendrite/roomserver/storage/sql.go
+++ b/src/github.com/matrix-org/dendrite/roomserver/storage/sql.go
@@ -27,6 +27,7 @@ type statements struct {
 	stateSnapshotStatements
 	stateBlockStatements
 	previousEventStatements
+	roomAliasesStatements
 }
 
 func (s *statements) prepare(db *sql.DB) error {
@@ -64,5 +65,9 @@ func (s *statements) prepare(db *sql.DB) error {
 		return err
 	}
 
+	if err = s.roomAliasesStatements.prepare(db); err != nil {
+		return err
+	}
+
 	return nil
 }
diff --git a/src/github.com/matrix-org/dendrite/roomserver/storage/storage.go b/src/github.com/matrix-org/dendrite/roomserver/storage/storage.go
index 50e2f44d6..37918ad5d 100644
--- a/src/github.com/matrix-org/dendrite/roomserver/storage/storage.go
+++ b/src/github.com/matrix-org/dendrite/roomserver/storage/storage.go
@@ -355,6 +355,26 @@ func (d *Database) LatestEventIDs(roomNID types.RoomNID) ([]gomatrixserverlib.Ev
 	return references, currentStateSnapshotNID, depth, nil
 }
 
+// SetRoomAlias implements query.RoomserverQueryAPIDB
+func (d *Database) SetRoomAlias(alias string, roomID string) error {
+	return d.statements.insertRoomAlias(alias, roomID)
+}
+
+// GetRoomIDFromAlias implements query.RoomserverQueryAPIDB
+func (d *Database) GetRoomIDFromAlias(alias string) (string, error) {
+	return d.statements.selectRoomIDFromAlias(alias)
+}
+
+// GetAliasesFromRoomID implements query.RoomserverQueryAPIDB
+func (d *Database) GetAliasesFromRoomID(roomID string) ([]string, error) {
+	return d.statements.selectAliasesFromRoomID(roomID)
+}
+
+// RemoveRoomAlias implements query.RoomserverQueryAPIDB
+func (d *Database) RemoveRoomAlias(alias string) error {
+	return d.statements.deleteRoomAlias(alias)
+}
+
 // StateEntriesForTuples implements state.RoomStateDatabase
 func (d *Database) StateEntriesForTuples(
 	stateBlockNIDs []types.StateBlockNID, stateKeyTuples []types.StateKeyTuple,