Interface Storage

storage.go:62–105

Storage is a type that implements a key-value store with basic file system (folder path) semantics. Keys use the forward slash '/' to separate path components and have no leading or trailing slashes. A "prefix" of a key is defined on a component basis, e.g. "a" is a prefix of "a/b" but not "ab/c".

// For simplicity, this is not a streaming API and is not
// suitable for very large files.
type Storage interface {
	// Locker enables the storage backend to synchronize
	// operational units of work.
	//
	// The use of Locker is NOT employed around every
	// Storage method call (Store, Load, etc), as these
	// should already be thread-safe. Locker is used for
	// high-level jobs or transactions that need
	// synchronization across a cluster; it's a simple
	// distributed lock. For example, CertMagic uses the
	// Locker interface to coordinate the obtaining of
	// certificates.
	Locker

	// Store puts value at key. It creates the key if it does
	// not exist and overwrites any existing value at this key.
	Store(ctx context.Context, key string, value []byte) error

	// Load retrieves the value at key.
	Load(ctx context.Context, key string) ([]byte, error)

	// Delete deletes the named key. If the name is a
	// directory (i.e. prefix of other keys), all keys
	// prefixed by this key should be deleted. An error
	// should be returned only if the key still exists
	// when the method returns.
	Delete(ctx context.Context, key string) error

	// Exists returns true if the key exists either as
	// a directory (prefix to other keys) or a file,
	// and there was no error checking.
	Exists(ctx context.Context, key string) bool

	// List returns all keys in the given path.
	//
	// If recursive is true, non-terminal keys
	// will be enumerated (i.e. "directories"
	// should be walked); otherwise, only keys
	// prefixed exactly by prefix will be listed.
	List(ctx context.Context, path string, recursive bool) ([]string, error)

	// Stat returns information about key.
	Stat(ctx context.Context, key string) (KeyInfo, error)
}

// Locker facilitates synchronization across machines and networks.
// It essentially provides a distributed named-mutex service so