Function OpenPrefixQueue

prefix_queue.go:43–71

OpenPrefixQueue opens a prefix queue if one exists at the given directory. If one does not already exist, a new prefix queue is created.

(dataDir string)

// OpenPrefixQueue opens a prefix queue if one exists at the given directory.
// If one does not already exist, a new prefix queue is created.
func OpenPrefixQueue(dataDir string) (*PrefixQueue, error) {
	var err error

	// Create a new Queue.
	pq := &PrefixQueue{
		DataDir: dataDir,
		db:      &leveldb.DB{},
		isOpen:  false,
	}

	// Open database for the prefix queue.
	pq.db, err = leveldb.OpenFile(dataDir, nil)
	if err != nil {
		return nil, err
	}

	// Check if this Goque type can open the requested data directory.
	ok, err := checkGoqueType(dataDir, goquePrefixQueue)
	if err != nil {
		return nil, err
	}
	if !ok {
		return nil, ErrIncompatibleType
	}

	// Set isOpen and return.
	pq.isOpen = true
	return pq, pq.init()
}

// Enqueue adds an item to the queue.
func (pq *PrefixQueue) Enqueue(prefix, value []byte) (*Item, error) {