Allow managing object observers

Switch player names to `std::string`

doc/lua_api.md

@@ -7583,6 +7583,20 @@ child will follow movement and rotation of that bone.
 * `get_bone_overrides()`: returns all bone overrides as table `{[bonename] = override, ...}`
 * `set_properties(object property table)`
 * `get_properties()`: returns a table of all object properties
+* `set_observers(observers)`: sets observers (players this object is sent to)
+    * If `observers` is `nil`, the object's observers are "unmanaged":
+      The object is sent to all players (in proximity). This is the default.
+    * `observers` is a "set" of player names: `{[player name] = true, [other player name] = true, ...}`
+        * A player is an observer if and only if the player's name is a key in the `observers` table.
+        * The values are irrelevant. To prevent the mistake of expecting `[player name] = false`
+          to "uninstall" a player as an observer, they must be truthy.
+    * If players are managed, they always need to have themselves as observers.
+    * Attachments:
+        * If an object's observers are managed, the observers of all children need to be managed too.
+        * The observers of children need to be a subset of the observers of parents.
+* `get_observers()`:
+    * returns `nil` if the observers are unmanaged
+    * returns a table with all observer names as keys and `true` values (a "set") otherwise
 * `is_player()`: returns true for players, false otherwise
 * `get_nametag_attributes()`
     * returns a table with the attributes of the nametag of an object

games/devtest/mods/testentities/init.lua

@@ -1,3 +1,4 @@
 dofile(minetest.get_modpath("testentities").."/visuals.lua")
+dofile(minetest.get_modpath("testentities").."/observers.lua")
 dofile(minetest.get_modpath("testentities").."/selectionbox.lua")
 dofile(minetest.get_modpath("testentities").."/armor.lua")

games/devtest/mods/testentities/observers.lua

@@ -0,0 +1,37 @@
+local function player_names_excluding(exclude_player_name)
+	local player_names = {}
+	for _, player in ipairs(minetest.get_connected_players()) do
+		player_names[player:get_player_name()] = true
+	end
+	player_names[exclude_player_name] = nil
+	return player_names
+end
+
+minetest.register_entity("testentities:observable", {
+	initial_properties = {
+		visual = "sprite",
+		textures = { "testentities_sprite.png" },
+		static_save = false,
+		infotext = "Punch to set observers to anyone but you"
+	},
+	on_activate = function(self)
+		self.object:set_armor_groups({punch_operable = 1})
+		assert(self.object:get_observers() == nil)
+		-- Using a value of `false` in the table should error.
+		assert(not pcall(self.object, self.object.set_observers, self.object, {test = false}))
+	end,
+	on_punch = function(self, puncher)
+		local puncher_name = puncher:get_player_name()
+		local observers = player_names_excluding(puncher_name)
+		self.object:set_observers(observers)
+		local got_observers = self.object:get_observers()
+		for name in pairs(observers) do
+			assert(got_observers[name])
+		end
+		for name in pairs(got_observers) do
+			assert(observers[name])
+		end
+		self.object:set_properties({infotext = "Excluding " .. puncher_name})
+		return true
+	end
+})

src/client/client.cpp

@@ -1579,7 +1579,7 @@ Inventory* Client::getInventory(const InventoryLocation &loc)
 	{
 		// Check if we are working with local player inventory
 		LocalPlayer *player = m_env.getLocalPlayer();
-		if (!player || strcmp(player->getName(), loc.name.c_str()) != 0)
+		if (!player || player->getName() != loc.name)
 			return NULL;
 		return &player->inventory;
 	}

src/client/content_cao.cpp

@@ -385,7 +385,7 @@ void GenericCAO::processInitData(const std::string &data)
 	if (m_is_player) {
 		// Check if it's the current player
 		LocalPlayer *player = m_env->getLocalPlayer();
-		if (player && strcmp(player->getName(), m_name.c_str()) == 0) {
+		if (player && player->getName() == m_name) {
 			m_is_local_player = true;
 			m_is_visible = false;
 			player->setCAO(this);

src/client/localplayer.cpp

@@ -19,6 +19,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 
 #include "localplayer.h"
 #include <cmath>
+#include <string>
 #include "mtevent.h"
 #include "collision.h"
 #include "nodedef.h"
@@ -32,7 +33,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 	LocalPlayer
 */
 
-LocalPlayer::LocalPlayer(Client *client, const char *name):
+LocalPlayer::LocalPlayer(Client *client, const std::string name):
 	Player(name, client->idef()),
 	m_client(client)
 {

src/client/localplayer.h

@@ -25,6 +25,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "settings.h"
 #include "lighting.h"
 #include <list>
+#include <string>
 
 class Client;
 class Environment;
@@ -45,7 +46,7 @@ enum class LocalPlayerAnimation
 class LocalPlayer : public Player
 {
 public:
-	LocalPlayer(Client *client, const char *name);
+	LocalPlayer(Client *client, const std::string name);
 	virtual ~LocalPlayer() = default;
 
 	// Initialize hp to 0, so that no hearts will be shown if server

src/database/database-files.cpp

@@ -47,8 +47,7 @@ void PlayerDatabaseFiles::deSerialize(RemotePlayer *p, std::istream &is,
 
 	p->m_dirty = true;
 	//args.getS32("version"); // Version field value not used
-	const std::string &name = args.get("name");
-	strlcpy(p->m_name, name.c_str(), PLAYERNAME_SIZE);
+	p->m_name = args.get("name");
 
 	if (sao) {
 		try {
@@ -95,7 +94,7 @@ void PlayerDatabaseFiles::deSerialize(RemotePlayer *p, std::istream &is,
 		p->inventory.deSerialize(is);
 	} catch (SerializationError &e) {
 		errorstream << "Failed to deserialize player inventory. player_name="
-			<< name << " " << e.what() << std::endl;
+			<< p->getName() << " " << e.what() << std::endl;
 	}
 
 	if (!p->inventory.getList("craftpreview") && p->inventory.getList("craftresult")) {
@@ -118,7 +117,7 @@ void PlayerDatabaseFiles::serialize(RemotePlayer *p, std::ostream &os)
 	// Utilize a Settings object for storing values
 	Settings args("PlayerArgsEnd");
 	args.setS32("version", 1);
-	args.set("name", p->m_name);
+	args.set("name", p->getName());
 
 	PlayerSAO *sao = p->getPlayerSAO();
 	// This should not happen
@@ -172,7 +171,7 @@ void PlayerDatabaseFiles::savePlayer(RemotePlayer *player)
 
 		deSerialize(&testplayer, is, path, NULL);
 		is.close();
-		if (strcmp(testplayer.getName(), player->getName()) == 0) {
+		if (testplayer.getName() == player->getName()) {
 			path_found = true;
 			continue;
 		}

src/database/database-postgresql.cpp

@@ -468,15 +468,15 @@ void PlayerDatabasePostgreSQL::savePlayer(RemotePlayer *player)
 	std::string hp = itos(sao->getHP());
 	std::string breath = itos(sao->getBreath());
 	const char *values[] = {
-		player->getName(),
+		player->getName().c_str(),
 		pitch.c_str(),
 		yaw.c_str(),
 		posx.c_str(), posy.c_str(), posz.c_str(),
 		hp.c_str(),
 		breath.c_str()
 	};
 
-	const char* rmvalues[] = { player->getName() };
+	const char* rmvalues[] = { player->getName().c_str() };
 	beginSave();
 
 	if (getPGVersion() < 90500) {
@@ -501,7 +501,7 @@ void PlayerDatabasePostgreSQL::savePlayer(RemotePlayer *player)
 			inv_id = itos(i), lsize = itos(list->getSize());
 
 		const char* inv_values[] = {
-			player->getName(),
+			player->getName().c_str(),
 			inv_id.c_str(),
 			width.c_str(),
 			name.c_str(),
@@ -516,7 +516,7 @@ void PlayerDatabasePostgreSQL::savePlayer(RemotePlayer *player)
 			std::string itemStr = oss.str(), slotId = itos(j);
 
 			const char* invitem_values[] = {
-				player->getName(),
+				player->getName().c_str(),
 				inv_id.c_str(),
 				slotId.c_str(),
 				itemStr.c_str()
@@ -529,7 +529,7 @@ void PlayerDatabasePostgreSQL::savePlayer(RemotePlayer *player)
 	const StringMap &attrs = sao->getMeta().getStrings();
 	for (const auto &attr : attrs) {
 		const char *meta_values[] = {
-			player->getName(),
+			player->getName().c_str(),
 			attr.first.c_str(),
 			attr.second.c_str()
 		};
@@ -545,7 +545,7 @@ bool PlayerDatabasePostgreSQL::loadPlayer(RemotePlayer *player, PlayerSAO *sao)
 	sanity_check(sao);
 	verifyDatabase();
 
-	const char *values[] = { player->getName() };
+	const char *values[] = { player->getName().c_str() };
 	PGresult *results = execPrepared("load_player", 1, values, false, false);
 
 	// Player not found, return not found
@@ -580,7 +580,7 @@ bool PlayerDatabasePostgreSQL::loadPlayer(RemotePlayer *player, PlayerSAO *sao)
 		std::string invIdStr = itos(invId);
 
 		const char* values2[] = {
-			player->getName(),
+			player->getName().c_str(),
 			invIdStr.c_str()
 		};
 		PGresult *results2 = execPrepared("load_player_inventory_items", 2,

src/database/database-sqlite3.h

@@ -49,11 +49,6 @@ class Database_SQLite3 : public Database
 		sqlite3_vrfy(sqlite3_bind_text(s, iCol, str.c_str(), str.size(), NULL));
 	}
 
-	inline void str_to_sqlite(sqlite3_stmt *s, int iCol, const char *str) const
-	{
-		sqlite3_vrfy(sqlite3_bind_text(s, iCol, str, strlen(str), NULL));
-	}
-
 	inline void int_to_sqlite(sqlite3_stmt *s, int iCol, int val) const
 	{
 		sqlite3_vrfy(sqlite3_bind_int(s, iCol, val));

src/network/serverpackethandler.cpp

@@ -612,7 +612,7 @@ void Server::handleCommand_InventoryAction(NetworkPacket* pkt)
 
 	// If something goes wrong, this player is to blame
 	RollbackScopeActor rollback_scope(m_rollback,
-			std::string("player:")+player->getName());
+			"player:" + player->getName());
 
 	/*
 		Note: Always set inventory not sent, to repair cases
@@ -1067,7 +1067,7 @@ void Server::handleCommand_Interact(NetworkPacket *pkt)
 		If something goes wrong, this player is to blame
 	*/
 	RollbackScopeActor rollback_scope(m_rollback,
-			std::string("player:")+player->getName());
+			"player:" + player->getName());
 
 	switch (action) {
 	// Start digging or punch object
@@ -1399,7 +1399,7 @@ void Server::handleCommand_NodeMetaFields(NetworkPacket* pkt)
 
 	// If something goes wrong, this player is to blame
 	RollbackScopeActor rollback_scope(m_rollback,
-			std::string("player:")+player->getName());
+			"player:" + player->getName());
 
 	// Check the target node for rollback data; leave others unnoticed
 	RollbackNode rn_old(&m_env->getMap(), p, this);

src/player.cpp

@@ -30,10 +30,10 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "porting.h"  // strlcpy
 
 
-Player::Player(const char *name, IItemDefManager *idef):
+Player::Player(const std::string name, IItemDefManager *idef):
 	inventory(idef)
 {
-	strlcpy(m_name, name, PLAYERNAME_SIZE);
+	m_name = name;
 
 	inventory.clear();
 	inventory.addList("main", PLAYER_INVENTORY_SIZE);

src/player.h

@@ -26,6 +26,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "util/basic_macros.h"
 #include <list>
 #include <mutex>
+#include <string>
 
 #define PLAYERNAME_SIZE 20
 
@@ -143,7 +144,7 @@ class Player
 {
 public:
 
-	Player(const char *name, IItemDefManager *idef);
+	Player(const std::string name, IItemDefManager *idef);
 	virtual ~Player() = 0;
 
 	DISABLE_CLASS_COPY(Player);
@@ -166,7 +167,7 @@ class Player
 		m_speed = speed;
 	}
 
-	const char *getName() const { return m_name; }
+	const std::string& getName() const { return m_name; }
 
 	u32 getFreeHudID()
 	{
@@ -233,7 +234,7 @@ class Player
 	s32 hud_hotbar_itemcount;
 
 protected:
-	char m_name[PLAYERNAME_SIZE];
+	std::string m_name;
 	v3f m_speed; // velocity; in BS-space
 	u16 m_wield_index = 0;
 	PlayerFovSpec m_fov_override_spec = { 0.0f, false, 0.0f };

src/remoteplayer.cpp

@@ -37,7 +37,7 @@ bool RemotePlayer::m_setting_cache_loaded = false;
 float RemotePlayer::m_setting_chat_message_limit_per_10sec = 0.0f;
 u16 RemotePlayer::m_setting_chat_message_limit_trigger_kick = 0;
 
-RemotePlayer::RemotePlayer(const char *name, IItemDefManager *idef):
+RemotePlayer::RemotePlayer(const std::string name, IItemDefManager *idef):
 	Player(name, idef)
 {
 	if (!RemotePlayer::m_setting_cache_loaded) {

src/remoteplayer.h

@@ -41,7 +41,7 @@ class RemotePlayer : public Player
 	friend class PlayerDatabaseFiles;
 
 public:
-	RemotePlayer(const char *name, IItemDefManager *idef);
+	RemotePlayer(const std::string name, IItemDefManager *idef);
 	virtual ~RemotePlayer() = default;
 
 	PlayerSAO *getPlayerSAO() { return m_sao; }

src/script/cpp_api/s_server.cpp

@@ -246,7 +246,7 @@ void ScriptApiServer::freeDynamicMediaCallback(u32 token)
 	lua_pop(L, 2);
 }
 
-void ScriptApiServer::on_dynamic_media_added(u32 token, const char *playername)
+void ScriptApiServer::on_dynamic_media_added(u32 token, const std::string &playername)
 {
 	SCRIPTAPI_PRECHECKHEADER
 
@@ -257,6 +257,6 @@ void ScriptApiServer::on_dynamic_media_added(u32 token, const char *playername)
 	lua_rawgeti(L, -1, token);
 	luaL_checktype(L, -1, LUA_TFUNCTION);
 
-	lua_pushstring(L, playername);
+	lua_pushstring(L, playername.c_str());
 	PCALL_RES(lua_pcall(L, 1, 0, error_handler));
 }

src/script/cpp_api/s_server.h

@@ -53,7 +53,7 @@ class ScriptApiServer
 	/* dynamic media handling */
 	static u32 allocateDynamicMediaCallback(lua_State *L, int f_idx);
 	void freeDynamicMediaCallback(u32 token);
-	void on_dynamic_media_added(u32 token, const char *playername);
+	void on_dynamic_media_added(u32 token, const std::string &playername);
 
 private:
 	void getAuthHandler();

src/script/lua_api/l_localplayer.cpp

@@ -72,7 +72,7 @@ int LuaLocalPlayer::l_get_name(lua_State *L)
 {
 	LocalPlayer *player = getobject(L, 1);
 
-	lua_pushstring(L, player->getName());
+	lua_pushstring(L, player->getName().c_str());
 	return 1;
 }