kvstore

Documentation

Index

• Variables
• type Backend
• type Config
• type KVPair
• type Store

Variables

var (
	// ErrBackendNotSupported is thrown when the backend k/v store is not supported by libkv
	ErrBackendNotSupported = errors.New("Backend storage not supported yet, please choose one of")
	// ErrKeyModified is thrown during an atomic operation if the index does not match the one in the store
	ErrKeyModified = errors.New("Unable to complete atomic operation, key modified")
	// ErrKeyNotFound is thrown when the key is not found in the store during a Get operation
	ErrKeyNotFound = errors.New("Key not found in store")
	// ErrPreviousNotSpecified is thrown when the previous value is not specified for an atomic operation
	ErrPreviousNotSpecified = errors.New("Previous K/V pair should be provided for the Atomic operation")
	// ErrKeyExists is thrown when the previous value exists in the case of an AtomicPut
	ErrKeyExists = errors.New("Previous K/V pair exists, cannot complete Atomic operation")
)

Types

type Backend

type Backend string

Backend represents a KV Store Backend

const BOLTDB Backend = "boltdb"

BOLTDB backend

type Config

type Config struct {
	ConnectionTimeout time.Duration
	Bucket            string
}

Config contains the options for a storage client

type KVPair

type KVPair struct {
	Key       string
	Value     []byte
	LastIndex uint64
}

KVPair represents {Key, Value, LastIndex} tuple

type Store

type Store interface {
	// Put a value at the specified key
	Put(key string, value []byte) error

	// Exists verifies if a Key exists in the store.
	Exists(key string) (bool, error)

	// List the content of a given prefix
	List(directory string) ([]*KVPair, error)

	// AtomicPut performs an atomic CAS operation on a single value.
	// Pass previous = nil to create a new key.
	AtomicPut(key string, value []byte, previous *KVPair) (*KVPair, error)

	// AtomicDelete performs an atomic delete of a single value.
	AtomicDelete(key string, previous *KVPair) error

	// Delete deletes a value at "key". Unlike AtomicDelete it doesn't check
	// whether the deleted key is at a specific version before deleting.
	Delete(key string) error

	// Close the store connection
	Close()
}

Store represents the backend K/V storage Each store should support every call listed here. Or it couldn't be implemented as a K/V backend for libkv