db

Documentation

Index

• Constants
• func IsValidInstanceID(instanceID string) bool
• type Action
• type ActionType
• type Event
• type EventCodec
• type InstanceID
  • func NewInstanceID() InstanceID
  • func (e InstanceID) String() string
• type ReduceAction

Constants

const (
	// EmptyInstanceID represents an empty InstanceID.
	EmptyInstanceID = InstanceID("")
)

Functions

func IsValidInstanceID

func IsValidInstanceID(instanceID string) bool

Types

type Action

type Action struct {
	// Type of the action.
	Type ActionType
	// InstanceID of the instance in action.
	InstanceID InstanceID
	// CollectionName of the instance in action.
	CollectionName string
	// Previous is the instance before the action.
	Previous []byte
	// Current is the instance after the action was done.
	Current []byte
}

Action is a operation done in the collection.

type ActionType

type ActionType int

ActionType is the type used by actions done in a txn.

const (
	// Create indicates the creation of an instance in a txn.
	Create ActionType = iota
	// Save indicates the mutation of an instance in a txn.
	Save
	// Delete indicates the deletion of an instance by ID in a txn.
	Delete
)

type Event

type Event interface {
	Time() []byte
	InstanceID() InstanceID
	Collection() string
}

Event is a local or remote event generated in collection and dispatcher by Dispatcher.

type EventCodec

type EventCodec interface {
	// Reduce applies generated events into state.
	Reduce(
		events []Event,
		datastore ds.TxnDatastore,
		baseKey ds.Key,
		indexFunc func(collection string, key ds.Key, oldData, newData []byte, txn ds.Txn) error,
	) ([]ReduceAction, error)
	// Create corresponding events to be dispatched.
	Create(ops []Action) ([]Event, format.Node, error)
	// EventsFromBytes deserializes a format.Node bytes payload into
	// Events.
	EventsFromBytes(data []byte) ([]Event, error)
}

EventCodec transforms actions generated in collections to events dispatched to thread logs, and viceversa.

type InstanceID

type InstanceID string

InstanceID is the type used in instance identities.

func NewInstanceID

func NewInstanceID() InstanceID

NewInstanceID generates a new identity for an instance.

func (InstanceID) String

func (e InstanceID) String() string

type ReduceAction

type ReduceAction struct {
	// Type of the reduced action.
	Type ActionType
	// Collection in which action was made.
	Collection string
	// InstanceID of the instance in reduced action.
	InstanceID InstanceID
}