package netalloc

import (
	"sync"
)

type Store interface {
	sync.Locker
	Exists(key string) (bool, error)
	Add(key string) error
	Delete(key string) error
}

type MemStore struct {
	sync.Mutex
	m map[string]struct{}
}

func NewMemStore() Store {
	return &MemStore{m: make(map[string]struct{})}
}

func (m *MemStore) Exists(key string) (bool, error) {
	_, ok := m.m[key]
	return ok, nil
}

func (m *MemStore) Add(key string) error {
	m.m[key] = struct{}{}
	return nil
}

func (m *MemStore) Delete(key string) error {
	delete(m.m, key)
	return nil
}