checkpoint

Documentation

Overview

Package checkpoint persists event log state information so that event log consumer can resume from the last read event in the case of a restart or unexpected interruption.

Index

• Constants
• Variables
• type Checkpoint
• type Manager
• type State

Constants

const (
	SchemeKafka  = "kafka"
	SchemeBinlog = "myslave"
)

All valid State scheme.

Variables

var (
	ErrStateNotFound = errors.New("state info not found")
)

Types

type Checkpoint

type Checkpoint interface {

	// Shutdown stops the checkpoint and flush all inflight states to be persisted.
	Shutdown() error

	// Commit queues the given event state information to be persisted.
	Commit(state State) error

	// LastPersistedState returns the last committed and persisted state.
	LastPersistedState(state State) error
}

type Manager

type Manager interface {

	// AllStates dumps all event state information.
	AllStates() ([]State, error)
}

Manager is an interface that manages checkpoint.

type State

type State interface {

	// Marshal serialize the state data.
	Marshal() []byte

	// Unmarshal unserialize the state from byte array data.
	Unmarshal([]byte)

	// String returns the string form of the state position.
	String() string

	// DSN returns the data source of the state.
	DSN() string

	// Scheme returns the type of statte.
	Scheme() string

	// Name returns name of the state.
	Name() string

	// Delta returns difference of two state.
	Delta(that State) string
}

State is an interface for all event state information.