poller

Documentation

Overview

Package poller implments a simple poller for the weather service. It consists of a Pulse worker that periodically calls the weather service to retrieve the weather forecast for given US cities.

Index

• type Service
  • func New(ctx context.Context, nominatimc nominatim.Client, weatherc weathergov.Client, ...) (*Service, error)
  • func (svc *Service) AddLocation(ctx context.Context, p *genpoller.CityAndState) error
  • func (svc *Service) AddWorker(ctx context.Context) (*genpoller.Worker, error)
  • func (svc *Service) RemoveWorker(ctx context.Context) error
  • func (svc *Service) Status(ctx context.Context) (*genpoller.PollerStatus, error)
  • func (svc *Service) Stop(ctx context.Context) error
  • func (svc *Service) Subscribe(ctx context.Context, location *genpoller.CityAndState, ...) error
• type Worker
  • func NewWorker(ctx context.Context, updateStream *streaming.Stream, ...) *Worker
  • func (worker *Worker) Start(job *pool.Job) error
  • func (worker *Worker) Stop(key string) error

Types

type Service

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

Service is the poller service implementation.

func New

func New(ctx context.Context, nominatimc nominatim.Client, weatherc weathergov.Client, rdb *redis.Client) (*Service, error)

New instantiates a new poller service.

func (*Service) AddLocation

func (svc *Service) AddLocation(ctx context.Context, p *genpoller.CityAndState) error

AddJob adds a new job to the poller worker pool.

func (*Service) AddWorker

func (svc *Service) AddWorker(ctx context.Context) (*genpoller.Worker, error)

AddWorker adds a new worker to the poller worker pool.

func (*Service) RemoveWorker

func (svc *Service) RemoveWorker(ctx context.Context) error

RemoveWorker removes a worker from the poller worker pool.

func (*Service) Status

func (svc *Service) Status(ctx context.Context) (*genpoller.PollerStatus, error)

Status returns the status and statistics of the poller service.

func (*Service) Stop

func (svc *Service) Stop(ctx context.Context) error

Stop stops the poller service gracefully.

func (*Service) Subscribe

func (svc *Service) Subscribe(ctx context.Context, location *genpoller.CityAndState, sub genpoller.SubscribeServerStream) error

Subscribe subscribes to forecasts for the given location.

type Worker

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

Worker is the type that implements the Pulse worker interface.

func NewWorker

func NewWorker(ctx context.Context, updateStream *streaming.Stream, nominatimc nominatim.Client, weatherc weathergov.Client) *Worker

New returns a new poller.

func (*Worker) Start

func (worker *Worker) Start(job *pool.Job) error

Start starts polling the weather service for the city and state encoded in the Pulse job payload and associates the poller with the given key.

func (*Worker) Stop

func (worker *Worker) Stop(key string) error

Stop stops the poller associated with the given key.