Method Keys

ch04/sharding.go:90–115

Keys returns a list of all keys in the sharded map.

()

// Keys returns a list of all keys in the sharded map.
func (m ShardedMap[K, V]) Keys() []K {
	var keys []K         // Declare an empty keys slice
	var mutex sync.Mutex // Mutex for write safety to keys

	var wg sync.WaitGroup // Create a wait group and add a
	wg.Add(len(m))        // wait value for each slice

	for _, shard := range m { // Run a goroutine for each slice in m
		go func(s *Shard[K, V]) {
			s.RLock() // Establish a read lock on s

			defer wg.Done()   // Release of the read lock
			defer s.RUnlock() // Tell the WaitGroup it's done

			for key, _ := range s.items { // Get the slice's keys
				mutex.Lock()
				keys = append(keys, key)
				mutex.Unlock()
			}
		}(shard)
	}

	wg.Wait() // Block until all goroutines are done

	return keys // Return combined keys slice
}