changepub

Documentation

Overview

Package changepub publishes write-change events on the IPC PUB socket after every successful DB write on the primary instance, allowing secondaries to invalidate caches and refresh views without polling.

Index

• func MethodToTopic(method string) string
• type BusPublisher
  • func NewBusPublisher(publishFn PublishFunc, instanceID, path string) *BusPublisher
  • func (p *BusPublisher) Publish(_ context.Context, topic string, payload any) error
• type NoopPublisher
  • func (NoopPublisher) Publish(_ context.Context, _ string, _ any) error
• type PublishFunc
• type Publisher
• type WriteChange

Functions

func MethodToTopic

func MethodToTopic(method string) string

MethodToTopic maps a db.write method name to the corresponding PUB topic. Returns an empty string for methods that do not warrant a change event (e.g. read-only helpers or internal bookkeeping that secondaries need not see).

Types

type BusPublisher

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

BusPublisher publishes write-change events through an ipc.Bus.

func NewBusPublisher

func NewBusPublisher(publishFn PublishFunc, instanceID, path string) *BusPublisher

NewBusPublisher creates a BusPublisher that wraps the given bus publish function.

func (*BusPublisher) Publish

func (p *BusPublisher) Publish(_ context.Context, topic string, payload any) error

Publish wraps payload in a WriteChange envelope and sends it on the bus. The context parameter is reserved for future cancellation support.

type NoopPublisher

type NoopPublisher struct{}

NoopPublisher discards all events — used when no bus is available.

func (NoopPublisher) Publish

func (NoopPublisher) Publish(_ context.Context, _ string, _ any) error

Publish is a no-op that always succeeds.

type PublishFunc

type PublishFunc func(topic string, payload any) error

PublishFunc is the signature of the bus publish function.

type Publisher

type Publisher interface {
	Publish(ctx context.Context, topic string, payload any) error
}

Publisher sends write-change events on the IPC bus after every DB write.

type WriteChange

type WriteChange struct {
	InstanceID string          `json:"instance_id"`
	Path       string          `json:"path"`
	Topic      string          `json:"topic"`
	Payload    json.RawMessage `json:"payload"`
	Timestamp  string          `json:"timestamp"` // RFC3339
}

WriteChange is the standard envelope for write-change events.