The DBService class and its members
The class that abstracts the database itself and its operations is called DBService. The constructor requires a file system path, it opens the database (if it exists) or creates it on the spot (if it doesn't exist) at that moment.
To close the database, call the
DBService::close function. Aside from using the structures above, it also uses an internal pointer to a leveldb::DB object and a group of member functions that abstract the main CRUD operations for LevelDB:DBService::has- checks if a key exists in a given database prefix.DBService::get- gets a value from a key in a given database prefix, if it exists.DBService::put- inserts a key and value in a given database prefix. Due to the way LevelDB works, updating an entry is the same as inserting a different value in a key that already exists.DBService::del- deletes a key in a given database prefix.DBService::writeBatch- same as put + del but batched. The function requires aWriteBatchRequeststruct, therefore, all operations in it are done in one go.DBService::readBatch- same as get but returns all entries in a given database prefix. This function has two overloads - the first one returns all entries and requires only the prefix, and the second one returns only values from specific keys and requires both the prefix and a key list.DBService::removeKeyPrefix- helper function that removes the prefix from a given key (e.g. key"0003abc"with value"123", after going through this function it would return"abc").
Last modified 3mo ago