/
consumer.go
52 lines (44 loc) · 1.23 KB
/
consumer.go
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package sse
import (
"context"
"errors"
"fmt"
)
var ErrHandlerNotRegistered = errors.New("handler is not registered")
// HandlerFunc is the interface of function that should be implemented in each specific event handler.
type HandlerFunc func(context.Context, RawEvent) error
type Handler interface {
Handle(context.Context, RawEvent) error
}
// Consumer is a service that registers event handlers and assigns events from the stream to specific handlers.
type Consumer struct {
handlers map[EventType]HandlerFunc
}
func NewConsumer() *Consumer {
return &Consumer{
handlers: make(map[EventType]HandlerFunc),
}
}
func (c *Consumer) RegisterHandler(eventType EventType, handler HandlerFunc) {
c.handlers[eventType] = handler
}
func (c *Consumer) Run(ctx context.Context, events <-chan RawEvent, errCh chan<- error) error {
for {
select {
case <-ctx.Done():
return ctx.Err()
case rawEvent, ok := <-events:
if !ok {
return errors.New("events stream was closed")
}
handler, ok := c.handlers[rawEvent.EventType]
if !ok {
return fmt.Errorf("%s, type: %s", ErrHandlerNotRegistered, AllEventsNames[rawEvent.EventType])
}
if err := handler(ctx, rawEvent); err != nil {
errCh <- err
continue
}
}
}
}