Documentation
¶
Index ¶
- Variables
- type BaseService
- func (bs *BaseService) IsRunning() bool
- func (bs *BaseService) OnReset() error
- func (bs *BaseService) OnStart() error
- func (bs *BaseService) OnStop()
- func (bs *BaseService) Quit() <-chan struct{}
- func (bs *BaseService) Reset() error
- func (bs *BaseService) SetLogger(l *slog.Logger)
- func (bs *BaseService) Start() error
- func (bs *BaseService) Stop() error
- func (bs *BaseService) String() string
- func (bs *BaseService) Wait()
- type Service
Constants ¶
This section is empty.
Variables ¶
var ( // ErrAlreadyStarted is returned when somebody tries to start an already // running service. ErrAlreadyStarted = errors.New("already started") // ErrAlreadyStopped is returned when somebody tries to stop an already // stopped service (without resetting it). ErrAlreadyStopped = errors.New("already stopped") // ErrNotStarted is returned when somebody tries to stop a not running // service. ErrNotStarted = errors.New("not started") )
Functions ¶
This section is empty.
Types ¶
type BaseService ¶
Classical-inheritance-style service declarations. Services can be started, then stopped, then optionally restarted.
Users can override the OnStart/OnStop methods. In the absence of errors, these methods are guaranteed to be called at most once. If OnStart returns an error, service won't be marked as started, so the user can call Start again.
A call to Reset will panic, unless OnReset is overwritten, allowing OnStart/OnStop to be called again.
The caller must ensure that Start and Stop are not called concurrently.
It is ok to call Stop without calling Start first.
Typical usage:
type FooService struct {
BaseService
// private fields
}
func NewFooService() *FooService {
fs := &FooService{
// init
}
fs.BaseService = *NewBaseService(log, "FooService", fs)
return fs
}
func (fs *FooService) OnStart() error {
fs.BaseService.OnStart() // Always call the overridden method.
// initialize private fields
// start subroutines, etc.
}
func (fs *FooService) OnStop() error {
fs.BaseService.OnStop() // Always call the overridden method.
// close/destroy private fields
// stop subroutines, etc.
}
func NewBaseService ¶
func NewBaseService(logger *slog.Logger, name string, impl Service) *BaseService
NewBaseService creates a new BaseService.
func (*BaseService) IsRunning ¶
func (bs *BaseService) IsRunning() bool
IsRunning implements Service by returning true or false depending on the service's state.
func (*BaseService) OnReset ¶
func (bs *BaseService) OnReset() error
OnReset implements Service by panicking.
func (*BaseService) OnStart ¶
func (bs *BaseService) OnStart() error
OnStart implements Service by doing nothing. NOTE: Do not put anything in here, that way users don't need to call BaseService.OnStart()
func (*BaseService) OnStop ¶
func (bs *BaseService) OnStop()
OnStop implements Service by doing nothing. NOTE: Do not put anything in here, that way users don't need to call BaseService.OnStop()
func (*BaseService) Quit ¶
func (bs *BaseService) Quit() <-chan struct{}
Quit Implements Service by returning a quit channel.
func (*BaseService) Reset ¶
func (bs *BaseService) Reset() error
Reset implements Service by calling OnReset callback (if defined). An error will be returned if the service is running.
func (*BaseService) SetLogger ¶
func (bs *BaseService) SetLogger(l *slog.Logger)
SetLogger implements Service by setting a logger.
func (*BaseService) Start ¶
func (bs *BaseService) Start() error
Start implements Service by calling OnStart (if defined). An error will be returned if the service is already running or stopped. Not to start the stopped service, you need to call Reset.
func (*BaseService) Stop ¶
func (bs *BaseService) Stop() error
Stop implements Service by calling OnStop (if defined) and closing quit channel. An error will be returned if the service is already stopped.
func (*BaseService) String ¶
func (bs *BaseService) String() string
String implements Service by returning a string representation of the service.
type Service ¶
type Service interface {
// Start the service.
// If it's already started or stopped, will return an error.
// If OnStart() returns an error, it's returned by Start()
Start() error
OnStart() error
// Stop the service.
// If it's already stopped, will return an error.
// OnStop must never error.
Stop() error
OnStop()
// Reset the service.
// Panics by default - must be overwritten to enable reset.
Reset() error
OnReset() error
// Return true if the service is running
IsRunning() bool
// Quit returns a channel, which is closed once service is stopped.
Quit() <-chan struct{}
// String representation of the service
String() string
// SetLogger sets a logger.
SetLogger(*slog.Logger)
}
Service defines a service that can be started, stopped, and reset.
Source Files