api

type Backend interface {
	// Get data at given path.
	// Returns ErrNotExist if path does not exist.
	Get(path string) ([]byte, error)
	// Put data at given path.
	// Returns ErrExist if path already exists.
	Put(path string, data []byte) error

	// ListAll enumerates all paths currently stored.
	// The paths are returned in lexicographical order.
	ListAll() ([]string, error)

	// Rename oldpath into newpath atomically.
	// Replaces newpath if it already exists.
	// Returns ErrNotExist if oldpath does not exist.
	Rename(oldpath, newpath string) error
	// Rename oldpath into newpath non-destructively.
	// Returns ErrExist if newpath already exists.
	// Returns ErrNotExist if oldpath does not exist.
	RenameNX(oldpath, newpath string) error

	// Lock acquires an exclusive lock on the store, suitable for writing.
	// This call blocks until the lock is acquired.
	// It can also deadlock if you already hold the lock.
	Lock() error
	// RLock acquires a shared lock on the store, suitable for reading.
	// This call blocks until the lock is acquired.
	RLock() error
	// Unlock releases the exclusive lock currently held by the process.
	// It is an error to call it without calling Lock() first.
	Unlock() error
	// RUnlock releases the shared lock currently held by the process.
	// It is an error to call it without calling RLock() first.
	RUnlock() error

	// Close this backend instance, freeing any associated resources.
	// This implicitly unlocks the store if any locks are held.
	Close() error
}