Migrate shared memory to use content database source; add logic in DB::core to prevent double freeing [skip ci]

common/dbcore.cpp

@@ -42,11 +42,20 @@ DBcore::DBcore()
 	pCompress       = false;
 	pSSL            = false;
 	pStatus         = Closed;
-	connection_type = DATABASE_CONNECTION_DEFAULT;
 }
 
 DBcore::~DBcore()
 {
+	/**
+	 * This prevents us from doing a double free in multi-tenancy setups where we
+	 * are re-using the default database connection pointer when we dont have an
+	 * external configuration setup ex: (content_database)
+	 */
+	std::string mysql_connection_host = mysql.host;
+	if (GetOriginHost() != mysql_connection_host) {
+		return;
+	}
+
 	mysql_close(&mysql);
 	safe_delete_array(pHost);
 	safe_delete_array(pUser);
@@ -247,6 +256,10 @@ bool DBcore::Open(uint32 *errnum, char *errbuf)
 	}
 	if (mysql_real_connect(&mysql, pHost, pUser, pPassword, pDatabase, pPort, 0, flags)) {
 		pStatus = Connected;
+
+		std::string connected_origin_host = pHost;
+		SetOriginHost(connected_origin_host);
+
 		return true;
 	}
 	else {
@@ -266,18 +279,12 @@ void DBcore::SetMysql(MYSQL *mysql)
 	DBcore::mysql = *mysql;
 }
 
-int8 DBcore::GetConnectionType() const
+const std::string &DBcore::GetOriginHost() const
 {
-	return connection_type;
+	return origin_host;
 }
 
-void DBcore::SetConnectionType(int8 connection_type)
+void DBcore::SetOriginHost(const std::string &origin_host)
 {
-	DBcore::connection_type = connection_type;
+	DBcore::origin_host = origin_host;
 }
-
-
-
-
-
-

common/dbcore.h

@@ -13,9 +13,6 @@
 #include <mysql.h>
 #include <string.h>
 
-const int8 DATABASE_CONNECTION_DEFAULT = 0;
-const int8 DATABASE_CONNECTION_CONTENT = 1;
-
 class DBcore {
 public:
 	enum eStatus {
@@ -35,8 +32,8 @@ public:
 	MYSQL *getMySQL() { return &mysql; }
 	void SetMysql(MYSQL *mysql);
 
-	int8 GetConnectionType() const;
+	const std::string &GetOriginHost() const;
-	void SetConnectionType(int8 connection_type);
+	void SetOriginHost(const std::string &origin_host);
 
 protected:
 	bool Open(
@@ -54,11 +51,12 @@ protected:
 private:
 	bool Open(uint32 *errnum = nullptr, char *errbuf = nullptr);
 
-	int8    connection_type;
 	MYSQL   mysql;
 	Mutex   MDatabase;
 	eStatus pStatus;
 
+	std::string origin_host;
+
 	char   *pHost;
 	char   *pUser;
 	char   *pPassword;

shared_memory/main.cpp

@@ -87,6 +87,7 @@ int main(int argc, char **argv)
 	auto Config = EQEmuConfig::get();
 
 	SharedDatabase database;
+	SharedDatabase content_db;
 	LogInfo("Connecting to database");
 	if (!database.Connect(
 		Config->DatabaseHost.c_str(),
@@ -99,6 +100,24 @@ int main(int argc, char **argv)
 		return 1;
 	}
 
+	/**
+	 * Multi-tenancy: Content database
+	 */
+	if (!Config->ContentDbHost.empty()) {
+		if (!content_db.Connect(
+			Config->ContentDbHost.c_str() ,
+			Config->ContentDbUsername.c_str(),
+			Config->ContentDbPassword.c_str(),
+			Config->ContentDbName.c_str(),
+			Config->ContentDbPort
+		)) {
+			LogError("Cannot continue without a content database connection");
+			return 1;
+		}
+	} else {
+		content_db.SetMysql(database.getMySQL());
+	}
+
 	/* Register Log System and Settings */
 	database.LoadLogSettings(LogSys.log_settings);
 	LogSys.StartFileLogs();
@@ -194,7 +213,7 @@ int main(int argc, char **argv)
 	if (load_all || load_items) {
 		LogInfo("Loading items");
 		try {
-			LoadItems(&database, hotfix_name);
+			LoadItems(&content_db, hotfix_name);
 		} catch (std::exception &ex) {
 			LogError("{}", ex.what());
 			return 1;
@@ -204,7 +223,7 @@ int main(int argc, char **argv)
 	if (load_all || load_factions) {
 		LogInfo("Loading factions");
 		try {
-			LoadFactions(&database, hotfix_name);
+			LoadFactions(&content_db, hotfix_name);
 		} catch (std::exception &ex) {
 			LogError("{}", ex.what());
 			return 1;
@@ -214,7 +233,7 @@ int main(int argc, char **argv)
 	if (load_all || load_loot) {
 		LogInfo("Loading loot");
 		try {
-			LoadLoot(&database, hotfix_name);
+			LoadLoot(&content_db, hotfix_name);
 		} catch (std::exception &ex) {
 			LogError("{}", ex.what());
 			return 1;
@@ -224,7 +243,7 @@ int main(int argc, char **argv)
 	if (load_all || load_skill_caps) {
 		LogInfo("Loading skill caps");
 		try {
-			LoadSkillCaps(&database, hotfix_name);
+			LoadSkillCaps(&content_db, hotfix_name);
 		} catch (std::exception &ex) {
 			LogError("{}", ex.what());
 			return 1;
@@ -234,7 +253,7 @@ int main(int argc, char **argv)
 	if (load_all || load_spells) {
 		LogInfo("Loading spells");
 		try {
-			LoadSpells(&database, hotfix_name);
+			LoadSpells(&content_db, hotfix_name);
 		} catch (std::exception &ex) {
 			LogError("{}", ex.what());
 			return 1;
@@ -244,7 +263,7 @@ int main(int argc, char **argv)
 	if (load_all || load_bd) {
 		LogInfo("Loading base data");
 		try {
-			LoadBaseData(&database, hotfix_name);
+			LoadBaseData(&content_db, hotfix_name);
 		} catch (std::exception &ex) {
 			LogError("{}", ex.what());
 			return 1;