# Functions
NewPostgresqlDB creates a new PostgresqlDB instance, initializes the database connection and create database schema, tables and indexes.
NewStorage creates a new Storage instance with the provided file name and logger.
SetStorage is a constructor function for data storage object.
# Variables
ErrDeletedURL indicates that requested url was deleted.
ErrReadOriginalURL indicates that the provided URL can not be read.
ErrShortURLAlreadyExist indicates that a corresponding short URL already exists.
# Structs
PostgresqlDB represents a structure for working with a PostgreSQL database.
Storage represents a storage structure for managing file storage, mappings between original and short URLs, synchronization with a mutex, and logging functionality.
# Interfaces
Database is a set of method signatures for data storage.