From 4fca601e0cf74ce642e4e49ca7d4fe3e59915846 Mon Sep 17 00:00:00 2001
From: Wuzzy <wuzzy2@mail.ru>
Date: Tue, 5 Oct 2021 12:35:55 +0000
Subject: [PATCH] Add get_server_max_lag() (#11671)

---
 doc/lua_api.txt                 |  2 ++
 src/script/lua_api/l_server.cpp | 12 ++++++++++++
 src/script/lua_api/l_server.h   |  3 +++
 3 files changed, 17 insertions(+)

diff --git a/doc/lua_api.txt b/doc/lua_api.txt
index 9efe1afe7..e6cabb68e 100644
--- a/doc/lua_api.txt
+++ b/doc/lua_api.txt
@@ -5647,6 +5647,8 @@ Server
       a player joined.
     * This function may be overwritten by mods to customize the status message.
 * `minetest.get_server_uptime()`: returns the server uptime in seconds
+* `minetest.get_server_max_lag()`: returns the current maximum lag
+  of the server in seconds or nil if server is not fully loaded yet
 * `minetest.remove_player(name)`: remove player from database (if they are not
   connected).
     * As auth data is not removed, minetest.player_exists will continue to
diff --git a/src/script/lua_api/l_server.cpp b/src/script/lua_api/l_server.cpp
index 473faaa14..6438fa6fd 100644
--- a/src/script/lua_api/l_server.cpp
+++ b/src/script/lua_api/l_server.cpp
@@ -57,6 +57,17 @@ int ModApiServer::l_get_server_uptime(lua_State *L)
 	return 1;
 }
 
+// get_server_max_lag()
+int ModApiServer::l_get_server_max_lag(lua_State *L)
+{
+	NO_MAP_LOCK_REQUIRED;
+	ServerEnvironment *s_env = dynamic_cast<ServerEnvironment *>(getEnv(L));
+	if (!s_env)
+		lua_pushnil(L);
+	else
+		lua_pushnumber(L, s_env->getMaxLagEstimate());
+	return 1;
+}
 
 // print(text)
 int ModApiServer::l_print(lua_State *L)
@@ -512,6 +523,7 @@ void ModApiServer::Initialize(lua_State *L, int top)
 	API_FCT(request_shutdown);
 	API_FCT(get_server_status);
 	API_FCT(get_server_uptime);
+	API_FCT(get_server_max_lag);
 	API_FCT(get_worldpath);
 	API_FCT(is_singleplayer);
 
diff --git a/src/script/lua_api/l_server.h b/src/script/lua_api/l_server.h
index c688e494b..a6f709787 100644
--- a/src/script/lua_api/l_server.h
+++ b/src/script/lua_api/l_server.h
@@ -33,6 +33,9 @@ private:
 	// get_server_uptime()
 	static int l_get_server_uptime(lua_State *L);
 
+	// get_server_max_lag()
+	static int l_get_server_max_lag(lua_State *L);
+
 	// get_worldpath()
 	static int l_get_worldpath(lua_State *L);