Add LevelDB player database (#9982)

doc/minetest.6

@@ -105,12 +105,12 @@ Migrate from current map backend to another. Possible values are sqlite3,
 leveldb, redis, postgresql, and dummy.
 .TP
 .B \-\-migrate-auth <value>
-Migrate from current auth backend to another. Possible values are sqlite3 and
-files.
+Migrate from current auth backend to another. Possible values are sqlite3,
+leveldb, and files.
 .TP
 .B \-\-migrate-players <value>
 Migrate from current players backend to another. Possible values are sqlite3,
-postgresql, dummy, and files.
+leveldb, postgresql, dummy, and files.
 .TP
 .B \-\-terminal
 Display an interactive terminal over ncurses during execution.

src/database/database-leveldb.cpp

@@ -26,6 +26,8 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "log.h"
 #include "filesys.h"
 #include "exceptions.h"
+#include "remoteplayer.h"
+#include "server/player_sao.h"
 #include "util/serialize.h"
 #include "util/string.h"
 
@@ -98,6 +100,116 @@ void Database_LevelDB::listAllLoadableBlocks(std::vector<v3s16> &dst)
 	delete it;
 }
 
+PlayerDatabaseLevelDB::PlayerDatabaseLevelDB(const std::string &savedir)
+{
+	leveldb::Options options;
+	options.create_if_missing = true;
+	leveldb::Status status = leveldb::DB::Open(options,
+		savedir + DIR_DELIM + "players.db", &m_database);
+	ENSURE_STATUS_OK(status);
+}
+
+PlayerDatabaseLevelDB::~PlayerDatabaseLevelDB()
+{
+	delete m_database;
+}
+
+void PlayerDatabaseLevelDB::savePlayer(RemotePlayer *player)
+{
+	/*
+	u8 version = 1
+	u16 hp
+	v3f position
+	f32 pitch
+	f32 yaw
+	u16 breath
+	u32 attribute_count
+	for each attribute {
+		std::string name
+		std::string (long) value
+	}
+	std::string (long) serialized_inventory
+	*/
+
+	std::ostringstream os;
+	writeU8(os, 1);
+
+	PlayerSAO *sao = player->getPlayerSAO();
+	sanity_check(sao);
+	writeU16(os, sao->getHP());
+	writeV3F32(os, sao->getBasePosition());
+	writeF32(os, sao->getLookPitch());
+	writeF32(os, sao->getRotation().Y);
+	writeU16(os, sao->getBreath());
+
+	StringMap stringvars = sao->getMeta().getStrings();
+	writeU32(os, stringvars.size());
+	for (const auto &it : stringvars) {
+		os << serializeString(it.first);
+		os << serializeLongString(it.second);
+	}
+
+	player->inventory.serialize(os);
+
+	leveldb::Status status = m_database->Put(leveldb::WriteOptions(),
+		player->getName(), os.str());
+	ENSURE_STATUS_OK(status);
+	player->onSuccessfulSave();
+}
+
+bool PlayerDatabaseLevelDB::removePlayer(const std::string &name)
+{
+	leveldb::Status s = m_database->Delete(leveldb::WriteOptions(), name);
+	return s.ok();
+}
+
+bool PlayerDatabaseLevelDB::loadPlayer(RemotePlayer *player, PlayerSAO *sao)
+{
+	std::string raw;
+	leveldb::Status s = m_database->Get(leveldb::ReadOptions(),
+		player->getName(), &raw);
+	if (!s.ok())
+		return false;
+	std::istringstream is(raw);
+
+	if (readU8(is) > 1)
+		return false;
+
+	sao->setHPRaw(readU16(is));
+	sao->setBasePosition(readV3F32(is));
+	sao->setLookPitch(readF32(is));
+	sao->setPlayerYaw(readF32(is));
+	sao->setBreath(readU16(is), false);
+
+	u32 attribute_count = readU32(is);
+	for (u32 i = 0; i < attribute_count; i++) {
+		std::string name = deSerializeString(is);
+		std::string value = deSerializeLongString(is);
+		sao->getMeta().setString(name, value);
+	}
+	sao->getMeta().setModified(false);
+
+	// This should always be last.
+	try {
+		player->inventory.deSerialize(is);
+	} catch (SerializationError &e) {
+		errorstream << "Failed to deserialize player inventory. player_name="
+			<< player->getName() << " " << e.what() << std::endl;
+	}
+
+	return true;
+}
+
+void PlayerDatabaseLevelDB::listPlayers(std::vector<std::string> &res)
+{
+	leveldb::Iterator* it = m_database->NewIterator(leveldb::ReadOptions());
+	res.clear();
+	for (it->SeekToFirst(); it->Valid(); it->Next()) {
+		res.push_back(it->key().ToString());
+	}
+	delete it;
+}
+
 AuthDatabaseLevelDB::AuthDatabaseLevelDB(const std::string &savedir)
 {
 	leveldb::Options options;

src/database/database-leveldb.h

@@ -45,6 +45,21 @@ private:
 	leveldb::DB *m_database;
 };
 
+class PlayerDatabaseLevelDB : public PlayerDatabase
+{
+public:
+	PlayerDatabaseLevelDB(const std::string &savedir);
+	~PlayerDatabaseLevelDB();
+
+	void savePlayer(RemotePlayer *player);
+	bool loadPlayer(RemotePlayer *player, PlayerSAO *sao);
+	bool removePlayer(const std::string &name);
+	void listPlayers(std::vector<std::string> &res);
+
+private:
+	leveldb::DB *m_database;
+};
+
 class AuthDatabaseLevelDB : public AuthDatabase
 {
 public:

src/serverenvironment.cpp

@@ -2089,6 +2089,7 @@ PlayerDatabase *ServerEnvironment::openPlayerDatabase(const std::string &name,
 
 	if (name == "dummy")
 		return new Database_Dummy();
+
 #if USE_POSTGRESQL
 	if (name == "postgresql") {
 		std::string connect_string;
@@ -2096,6 +2097,12 @@ PlayerDatabase *ServerEnvironment::openPlayerDatabase(const std::string &name,
 		return new PlayerDatabasePostgreSQL(connect_string);
 	}
 #endif
+
+#if USE_LEVELDB
+	if (name == "leveldb")
+		return new PlayerDatabaseLevelDB(savedir);
+#endif
+
 	if (name == "files")
 		return new PlayerDatabaseFiles(savedir + DIR_DELIM + "players");
 
@@ -2116,7 +2123,7 @@ bool ServerEnvironment::migratePlayersDatabase(const GameParams &game_params,
 	if (!world_mt.exists("player_backend")) {
 		errorstream << "Please specify your current backend in world.mt:"
 			<< std::endl
-			<< "	player_backend = {files|sqlite3|postgresql}"
+			<< "	player_backend = {files|sqlite3|leveldb|postgresql}"
 			<< std::endl;
 		return false;
 	}