// file : mod/database-module.hxx -*- C++ -*- // license : MIT; see accompanying LICENSE file #ifndef MOD_DATABASE_MODULE_HXX #define MOD_DATABASE_MODULE_HXX #include <odb/forward.hxx> // odb::core::database, odb::core::connection_ptr #include <libbrep/types.hxx> #include <libbrep/utility.hxx> #include <mod/module.hxx> #include <mod/module-options.hxx> namespace brep { struct tenant_service; // A handler that utilises the database. Specifically, it will retry the // request in the face of recoverable database failures (deadlock, loss of // connection, etc) up to a certain number of times. // class database_module: public handler { protected: database_module () = default; // Create a shallow copy (handling instance) if initialized and a deep // copy (context exemplar) otherwise. // explicit database_module (const database_module&); // Required to avoid getting warning from clang that // database_module::init() hides handler::init() virtual functions. This // way all functions get to the same scope and become overloaded set. // using handler::init; // Initialize the package database instance. Throw odb::exception on // failure. // void init (const options::package_db&, size_t retry); // Initialize the build database instance. Throw odb::exception on // database failure. // void init (const options::build_db&, size_t retry); virtual bool handle (request&, response&) = 0; // Helpers. // // Update the tenant-associated service state if the specified // notification callback-returned function (expected to be not NULL) // returns the new state data. Return the service state data, if updated, // and nullopt otherwise. // // Specifically, start the database transaction, query the service state, // and call the callback-returned function on this state. If this call // returns the data string (rather than nullopt), then update the service // state with this data and persist the change. Repeat all the above steps // on the recoverable database failures (deadlocks, etc). // optional<string> update_tenant_service_state ( const odb::core::connection_ptr&, const string& tid, const function<optional<string> (const tenant_service&)>&); protected: size_t retry_ = 0; // Max of all retries. shared_ptr<odb::core::database> package_db_; shared_ptr<odb::core::database> build_db_; // NULL if not building. private: virtual bool handle (request&, response&, log&); }; } #endif // MOD_DATABASE_MODULE_HXX