• dbstl will free/delete any memory allocated by dbstl itself.

Type specific notes

DbEnv/Db

When you open a or Db object using dbstl::open_env() or dbstl::open_db(), you do not need to delete that object. However, if you new’d that object and then opened it without using the dbstl::open_env() or dbstl::open_db() methods, you are responsible for deleting the object.

You can call dbstl_exit() before the process exits, to release any memory allocated by dbstl that has to live during the entire process lifetime. Releasing the memory explicitly will not make much difference, because the process is about to exit and so all memory allocated on the heap is going to be returned to the operating system anyway. The only real difference is that your memory leak checker will not report false memory leaks.

dbstl_exit() releases any memory allocated by dbstl on the heap. It also performs other required shutdown operations, such as closing any databases and environments registered to dbstl and shared across the process.

If you are calling the dbstl_exit() function, and your DbEnv or objects are new’d by your code, the dbstl_exit() function should be called before deleting the DbEnv or Db objects, because they need to be closed before being deleted. Alternatively, you can call the dbstl::close_env() or dbstl::close_db() functions before deleting the DbEnv or Db objects in order to explicitly close the databases or environments. If you do this, can then delete these objects, and then call dbstl_exit().

DbstlDbt

Only when you are storing raw bytes (such as a bitmap) do you have to store and retrieve data by using the helper class. Although you also can do so simply by using the Berkeley DB Dbt class, the DbstlDbt class offers more convenient memory management behavior.

When you are storing DbstlDbt objects (such as db_vector<DbstlDbt>), you must allocate heap memory explicitly using the malloc() function for the DbstlDbt object to reference, but you do not need to free the memory – it is automatically freed by the DbstlDbt object that owns it by calling the standard C library free() function.

However, because dbstl supports storing any type of object or primitive data, it is rare that you would have to store data using DbstlDbt objects while using dbstl. Examples of storing DbstlDbt objects can be found in the StlAdvancedFeaturesExample::arbitrary_object_storage() and StlAdvancedFeaturesExample::char_star_string_storage() methods.