objdb

README

objdb

Object store client and API

Documentation

Index

• Constants
• func RegisterPlugin(name string, plugin Plugin) error
• type API
  • func InitClient(storeName string, storeURLs []string) (API, error)
  • func NewClient(dbURL string) (API, error)
• type ConsulClient
  • func (cp *ConsulClient) DelObj(key string) error
  • func (cp *ConsulClient) DeregisterService(serviceInfo ServiceInfo) error
  • func (cp *ConsulClient) GetObj(key string, retVal interface{}) error
  • func (cp *ConsulClient) GetService(srvName string) ([]ServiceInfo, error)
  • func (cp *ConsulClient) ListDir(key string) ([]string, error)
  • func (cp *ConsulClient) NewLock(name string, myID string, ttl uint64) (LockInterface, error)
  • func (cp *ConsulClient) RegisterService(serviceInfo ServiceInfo) error
  • func (cp *ConsulClient) SetObj(key string, value interface{}) error
  • func (cp *ConsulClient) WatchService(srvName string, eventCh chan WatchServiceEvent, stopCh chan bool) error
• type EtcdClient
  • func (ep *EtcdClient) DelObj(key string) error
  • func (ep *EtcdClient) DeregisterService(serviceInfo ServiceInfo) error
  • func (ep *EtcdClient) GetObj(key string, retVal interface{}) error
  • func (ep *EtcdClient) GetService(name string) ([]ServiceInfo, error)
  • func (ep *EtcdClient) ListDir(key string) ([]string, error)
  • func (ep *EtcdClient) NewLock(name string, myID string, ttl uint64) (LockInterface, error)
  • func (ep *EtcdClient) RegisterService(serviceInfo ServiceInfo) error
  • func (ep *EtcdClient) SetObj(key string, value interface{}) error
  • func (ep *EtcdClient) WatchService(name string, eventCh chan WatchServiceEvent, stopCh chan bool) error
• type LockEvent
• type LockInterface
• type Plugin
  • func GetPlugin(name string) Plugin
• type ServiceInfo
• type WatchServiceEvent

Constants

const (
	LockAcquired       = iota // Successfully acquired
	LockReleased              // explicitly released
	LockAcquireTimeout        // Timeout trying to acquire lock
	LockAcquireError          // Error while acquiring
	LockRefreshError          // Error during ttl refresh
	LockLost                  // We lost the lock
)

Lock event types

const (
	WatchServiceEventAdd   = iota // New Service endpoint added
	WatchServiceEventDel          // A service endpoint was deleted
	WatchServiceEventError        // Error occurred while watching for service
)

Watch events

Functions

func RegisterPlugin

func RegisterPlugin(name string, plugin Plugin) error

RegisterPlugin Register a plugin

Types

type API

type API interface {
	// Get a Key from conf store
	GetObj(key string, retValue interface{}) error

	// Set a key in conf store
	SetObj(key string, value interface{}) error

	// Remove an object
	DelObj(key string) error

	// List all objects in a directory
	ListDir(key string) ([]string, error)

	// Create a new lock
	NewLock(name string, holderID string, ttl uint64) (LockInterface, error)

	// Register a service
	// Service is registered with a ttl for 60sec and a goroutine is created
	// to refresh the ttl.
	RegisterService(serviceInfo ServiceInfo) error

	// List all end points for a service
	GetService(name string) ([]ServiceInfo, error)

	// Watch for addition/deletion of service end points
	WatchService(name string, eventCh chan WatchServiceEvent, stopCh chan bool) error

	// Deregister a service
	// This removes the service from the registry and stops the refresh groutine
	DeregisterService(serviceInfo ServiceInfo) error
}

API Plugin API

func InitClient

func InitClient(storeName string, storeURLs []string) (API, error)

InitClient aims to support multi endpoints

func NewClient

func NewClient(dbURL string) (API, error)

NewClient Create a new conf store

type ConsulClient

type ConsulClient struct {
	// contains filtered or unexported fields
}

ConsulClient has consul client state

func (*ConsulClient) DelObj

func (cp *ConsulClient) DelObj(key string) error

DelObj deletes an object

func (*ConsulClient) DeregisterService

func (cp *ConsulClient) DeregisterService(serviceInfo ServiceInfo) error

DeregisterService deregisters a service instance

func (*ConsulClient) GetObj

func (cp *ConsulClient) GetObj(key string, retVal interface{}) error

GetObj reads the object

func (*ConsulClient) GetService

func (cp *ConsulClient) GetService(srvName string) ([]ServiceInfo, error)

GetService gets all instances of a service

func (*ConsulClient) ListDir

func (cp *ConsulClient) ListDir(key string) ([]string, error)

ListDir returns a list of keys in a directory

func (*ConsulClient) NewLock

func (cp *ConsulClient) NewLock(name string, myID string, ttl uint64) (LockInterface, error)

NewLock returns a new lock instance

func (*ConsulClient) RegisterService

func (cp *ConsulClient) RegisterService(serviceInfo ServiceInfo) error

RegisterService registers a service

func (*ConsulClient) SetObj

func (cp *ConsulClient) SetObj(key string, value interface{}) error

SetObj writes an object

func (*ConsulClient) WatchService

func (cp *ConsulClient) WatchService(srvName string, eventCh chan WatchServiceEvent, stopCh chan bool) error

WatchService watches for service instance changes

type EtcdClient

type EtcdClient struct {
	// contains filtered or unexported fields
}

EtcdClient has etcd client state

func (*EtcdClient) DelObj

func (ep *EtcdClient) DelObj(key string) error

DelObj Remove an object

func (*EtcdClient) DeregisterService

func (ep *EtcdClient) DeregisterService(serviceInfo ServiceInfo) error

DeregisterService Deregister a service This removes the service from the registry and stops the refresh groutine

func (*EtcdClient) GetObj

func (ep *EtcdClient) GetObj(key string, retVal interface{}) error

GetObj Get an object

func (*EtcdClient) GetService

func (ep *EtcdClient) GetService(name string) ([]ServiceInfo, error)

GetService lists all end points for a service

func (*EtcdClient) ListDir

func (ep *EtcdClient) ListDir(key string) ([]string, error)

ListDir Get a list of objects in a directory

func (*EtcdClient) NewLock

func (ep *EtcdClient) NewLock(name string, myID string, ttl uint64) (LockInterface, error)

NewLock Create a new lock

func (*EtcdClient) RegisterService

func (ep *EtcdClient) RegisterService(serviceInfo ServiceInfo) error

RegisterService Register a service Service is registered with a ttl for 60sec and a goroutine is created to refresh the ttl.

func (*EtcdClient) SetObj

func (ep *EtcdClient) SetObj(key string, value interface{}) error

SetObj Save an object, create if it doesnt exist

func (*EtcdClient) WatchService

func (ep *EtcdClient) WatchService(name string, eventCh chan WatchServiceEvent, stopCh chan bool) error

WatchService Watch for a service

type LockEvent

type LockEvent struct {
	EventType uint // Type of event
}

LockEvent Lock Event notifications

type LockInterface

type LockInterface interface {
	// Acquire a lock.
	// Give up acquiring lock after timeout seconds. if timeout is 0, wait forever
	Acquire(timeout uint64) error

	// Release the lock. This explicitly releases the lock and cleans up all state
	// If we were still waiting to acquire lock, it stops it and cleans up
	Release() error

	// For debug purposes only.
	// Just stops refreshing the lock
	Kill() error

	// Get the event channel
	EventChan() <-chan LockEvent

	// Is the lock acquired
	IsAcquired() bool

	// Get current holder of the lock
	GetHolder() string
}

LockInterface Lock interface

type Plugin

type Plugin interface {
	// Initialize the plugin, only called once
	NewClient(endpoints []string) (API, error)
}

Plugin interface

func GetPlugin

func GetPlugin(name string) Plugin

GetPlugin returns the plugin by name

type ServiceInfo

type ServiceInfo struct {
	ServiceName string // Name of the service
	Role        string // Role of the service. (leader, follower etc)
	Version     string // Version string for the service
	TTL         int    // TTL for this service
	HostAddr    string // Host name or IP address where its running
	Port        int    // Port number where its listening
	Hostname    string // Host name where its running
}

ServiceInfo hash Information about a service Notes:

There could be multiple instances of a service. hostname:port uniquely
identify an instance of a service

type WatchServiceEvent

type WatchServiceEvent struct {
	EventType   uint        // event type
	ServiceInfo ServiceInfo // Information about the service
}

WatchServiceEvent : watch event on services