ban

type Ban struct {
	ID
	net.IP
}

type Banner interface {
	// Closer allows closing the Banner instance.
	//
	// The interface does not define persistence considerations on a closed instance:
	// some implementations may persist (e.g. SQL), while others will not (e.g. Memory).
	io.Closer

	// Ban adds an IP to the ban list.
	//
	// Although it is idempotent at the storage level, repeated calls for the
	// same IP will return ErrAlreadyBanned, and should be seen as a logic error.
	Ban(ctx context.Context, ip net.IP) (ID, error)

	// FindAll may return large slices, and is very inefficient in the general case:
	// because of the concurrent access property, it only represents a crawl through
	// the ban storage, which may not represent an actual snapshot of that storage at any time.
	//
	// As such, it is considered an unstable function, mostly be seen as a debugging tool,
	// which could be used for admin UIs on sites with smaller ban lists.
	FindAll(ctx context.Context) ([]Ban, error)

	// FindByID is an administrative operation, which should not be used in the
	// hot path, as it may be highly inefficient (O(n) by number of IPs).
	//
	// For most situations, access the storage using IsBanned instead.
	FindByID(ctx context.Context, id ID) (net.IP, error)

	// IsBanned is the only operation meant for the hot path, and is expected to
	// the most used one, by far.
	IsBanned(ctx context.Context, ip net.IP) (bool, error)

	// UnBan removes an IP from the ban list.
	//
	// Although it is idempotent at the storage level, repeated calls for the
	// same IP will return ErrNonExistentBan, and should be seen as a logic error.
	UnBan(ctx context.Context, ip net.IP) error
}

type ID uint64

type Memory struct {
	// Map is used here because each entry is expected to be written only once,
	// when banning (and deleted one when unbanning) but read ofte to check access.
	// Keys are IPs in string format (because net.IP cannot he hashed), values are IDs.
	sync.Map
	// contains filtered or unexported fields
}

type SQL struct {
	*sql.DB

	TableName string
	// contains filtered or unexported fields
}