48 lines
1.4 KiB
Go
48 lines
1.4 KiB
Go
// Package events contains interfaces for managing events within distributed systems
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package events
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import (
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"context"
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"encoding/json"
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"errors"
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"time"
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)
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var (
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// ErrMissingTopic is returned if a blank topic was provided to publish
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ErrMissingTopic = errors.New("Missing topic")
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// ErrEncodingMessage is returned from publish if there was an error encoding the message option
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ErrEncodingMessage = errors.New("Error encoding message")
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)
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// Stream of events
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type Stream interface {
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Publish(ctx context.Context, topic string, msg interface{}, opts ...PublishOption) error
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Subscribe(ctx context.Context, topic string, opts ...SubscribeOption) (<-chan Event, error)
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}
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// Store of events
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type Store interface {
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Read(ctx context.Context, opts ...ReadOption) ([]*Event, error)
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Write(ctx context.Context, event *Event, opts ...WriteOption) error
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}
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// Event is the object returned by the broker when you subscribe to a topic
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type Event struct {
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// ID to uniquely identify the event
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ID string
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// Topic of event, e.g. "registry.service.created"
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Topic string
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// Timestamp of the event
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Timestamp time.Time
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// Metadata contains the encoded event was indexed by
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Metadata map[string]string
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// Payload contains the encoded message
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Payload []byte
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}
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// Unmarshal the events message into an object
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func (e *Event) Unmarshal(v interface{}) error {
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return json.Unmarshal(e.Payload, v)
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}
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