command

type Command ¶

type Command interface {
	Execute(storage *btree.BTree) (string, error)
	Type() Type
	Key() []byte
}

Command interface describes how a command affects the low level storage. Each command should implement 3 methods: Execute(), Type() and Key()

- Execute should represent how certain Command will affect the storage, Read commands should return value of specified key and Write commands should return it's own value as result. Any error returned will be considered as fatal (for now). Interaction with storage is done via btree.Btree

- Type should return CommandType for a certain Command. If a Command is not writing any data - it is considered as read, otherwise - as write

- Key should return single string which represents what Command is querying. Embed pair struct to automatically embed Key() method

func Get(key string) Command

func Set(key, value string) Command

type Type ¶

type Type int

Type represents which mutex behavior will be used for a command.

- Read = 0 - command only reads from storage without altering it. Locks read mutex

- Write = 1 - command can alter the storage. Locks read and write mutex

const (
	Read Type = iota
	Write
)