From b772f9ee787bd53cb6e3d600035e5b1a22a6c7c7 Mon Sep 17 00:00:00 2001
From: PiotrKozimor <37144818+PiotrKozimor@users.noreply.github.com>
Date: Mon, 14 Nov 2022 08:56:52 +0100
Subject: [PATCH] Allow for only one pusher for given pushkey and app ID -
 remove pushers duplicates (#50)

---
 .../deltas/2022110311000000_unique_pushers.go | 37 +++++++++++++++++++
 userapi/storage/postgres/pusher_table.go      |  9 ++---
 userapi/storage/postgres/storage.go           |  4 ++
 3 files changed, 44 insertions(+), 6 deletions(-)
 create mode 100644 userapi/storage/postgres/deltas/2022110311000000_unique_pushers.go

diff --git a/userapi/storage/postgres/deltas/2022110311000000_unique_pushers.go b/userapi/storage/postgres/deltas/2022110311000000_unique_pushers.go
new file mode 100644
index 000000000..6f862a025
--- /dev/null
+++ b/userapi/storage/postgres/deltas/2022110311000000_unique_pushers.go
@@ -0,0 +1,37 @@
+package deltas
+
+import (
+	"context"
+	"database/sql"
+	"fmt"
+)
+
+func UpUniquePusher(ctx context.Context, tx *sql.Tx) error {
+	rows := tx.QueryRowContext(ctx, "SELECT EXISTS (select * from pg_tables where tablename = 'userapi_pushers')")
+	tableExists := false
+	err := rows.Scan(&tableExists)
+
+	if err != nil {
+		return fmt.Errorf("select table exists: %w", err)
+	}
+	if !tableExists {
+		return nil
+	}
+	_, err = tx.ExecContext(ctx, "DELETE FROM userapi_pushers p1 USING userapi_pushers p2 WHERE p1.pushkey_ts_ms < p2.pushkey_ts_ms AND p1.app_id = p2.app_id AND p1.pushkey = p2.pushkey")
+	if err != nil {
+		return fmt.Errorf("delete pusher duplicates: %w", err)
+	}
+	_, err = tx.ExecContext(ctx, "DROP INDEX IF EXISTS userapi_pusher_app_id_pushkey_localpart_idx")
+	if err != nil {
+		return fmt.Errorf("drop unique index: %w", err)
+	}
+	_, err = tx.ExecContext(ctx, "DROP INDEX IF EXISTS userapi_pusher_app_id_pushkey_idx")
+	if err != nil {
+		return fmt.Errorf("drop index: %w", err)
+	}
+	return nil
+}
+
+func DownUniquePusher(ctx context.Context, tx *sql.Tx) error {
+	return nil
+}
diff --git a/userapi/storage/postgres/pusher_table.go b/userapi/storage/postgres/pusher_table.go
index 6fb714fba..42618cf34 100644
--- a/userapi/storage/postgres/pusher_table.go
+++ b/userapi/storage/postgres/pusher_table.go
@@ -45,20 +45,17 @@ CREATE TABLE IF NOT EXISTS userapi_pushers (
 	data TEXT NOT NULL
 );
 
--- For faster deleting by app_id, pushkey pair.
-CREATE INDEX IF NOT EXISTS userapi_pusher_app_id_pushkey_idx ON userapi_pushers(app_id, pushkey);
-
 -- For faster retrieving by localpart.
 CREATE INDEX IF NOT EXISTS userapi_pusher_localpart_idx ON userapi_pushers(localpart);
 
--- Pushkey must be unique for a given user and app.
-CREATE UNIQUE INDEX IF NOT EXISTS userapi_pusher_app_id_pushkey_localpart_idx ON userapi_pushers(app_id, pushkey, localpart);
+-- Pushkey must be unique for a given app.
+CREATE UNIQUE INDEX IF NOT EXISTS userapi_pusher_app_id_pushkey_idx ON userapi_pushers(app_id, pushkey);
 `
 
 const insertPusherSQL = "" +
 	"INSERT INTO userapi_pushers (localpart, session_id, pushkey, pushkey_ts_ms, kind, app_id, app_display_name, device_display_name, profile_tag, lang, data)" +
 	"VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11)" +
-	"ON CONFLICT (app_id, pushkey, localpart) DO UPDATE SET session_id = $2, pushkey_ts_ms = $4, kind = $5, app_display_name = $7, device_display_name = $8, profile_tag = $9, lang = $10, data = $11"
+	"ON CONFLICT (app_id, pushkey) DO UPDATE SET localpart = $1, session_id = $2, pushkey_ts_ms = $4, kind = $5, app_display_name = $7, device_display_name = $8, profile_tag = $9, lang = $10, data = $11"
 
 const selectPushersSQL = "" +
 	"SELECT session_id, pushkey, pushkey_ts_ms, kind, app_id, app_display_name, device_display_name, profile_tag, lang, data FROM userapi_pushers WHERE localpart = $1"
diff --git a/userapi/storage/postgres/storage.go b/userapi/storage/postgres/storage.go
index c059e3e60..de97e60b1 100644
--- a/userapi/storage/postgres/storage.go
+++ b/userapi/storage/postgres/storage.go
@@ -42,6 +42,10 @@ func NewDatabase(base *base.BaseDendrite, dbProperties *config.DatabaseOptions,
 		Version: "userapi: rename tables",
 		Up:      deltas.UpRenameTables,
 		Down:    deltas.DownRenameTables,
+	}, sqlutil.Migration{
+		Version: "userapi: unique pushers",
+		Up:      deltas.UpUniquePusher,
+		Down:    deltas.DownUniquePusher,
 	})
 	if err = m.Up(base.Context()); err != nil {
 		return nil, err