# Functions
New create URLStorage base on given config.
NewDatabaseStorage create database storage and run migrations.
NewFileStorage create file storage with file at given path.
NewInMemoryStorage create in memory storage.
# Variables
PgUniqueIndexErrorCode is code of postgresql error.
# Structs
DatabaseStorage is storage that store all information in database.
FileStorage is storage that store all information in file on disk.
InMemoryStorage is storage that store all information in memory.
# Interfaces
URLStorage is common interface for all storages.