KeyValueStorage

A key is the identifier for a specific value stored in the key-value storage. The key is unique.

A value can contain arbitrary data and is identified by a key.

Store a value in the key-value storage for a given key.

Example

storage.store(key: "name", value: Data("John Doe".utf8)) {
    optionalError in

    if let error = optionalError {
        // TODO Handle error
    }
}

Retrieve a value from the key-value storage for a given key.

Example

storage.retrieve(for: "name") {
    optionalValue, optionalError in

    precondition((optionalValue != nil) == (optionalError != nil))

    guard let value = optionalValue else {
        let error = optionalError!
        // TODO Handle error
        return
    }

    // Success, do something with `value`
}

Remove the value from the key-value storage for a given key.

Example

storage.remove(key: "name") {
    optionalError in

    if let error = optionalError {
        // TODO Handle error
    }
}