bus

package
v0.30.1 Latest Latest
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 Go to latest Published: Aug 18, 2023 License: MIT Imports: 13 Imported by: 63

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Constants

This section is empty.

Variables

View Source 
var (
	// ErrDirectiveDisposed is returned when the directive was unexpectedly disposed.
	ErrDirectiveDisposed = errors.New("directive disposed unexpectedly")
)

Functions

func ExecCollectValues 

func ExecCollectValues[T directive.Value](
	ctx context.Context,
	bus Bus,
	dir directive.Directive,
	waitOne bool,
	valDisposeCb func(),
) ([]T, directive.Instance, directive.Reference, error)

ExecCollectValues collects one or more values while ctx is active and directive is not idle.

Returns vals, ref, nil if the directive is idle. Returns err if any resolver returns an error. valDisposeCb is called if any of the values are no longer valid. valDisposeCb might be called multiple times. If err != nil, ref == nil. If waitOne=true, waits for at least one value before returning.

func ExecOneOff 

func ExecOneOff(
	ctx context.Context,
	bus Bus,
	dir directive.Directive,
	idleCb ExecIdleCallback,
	valDisposeCallback func(),
) (directive.AttachedValue, directive.Instance, directive.Reference, error)

ExecOneOff executes a one-off directive.

idleCb is called when idle with the list of resolver errors. idleCb should return (wait, error): if wait=true, continues to wait. if idleCb is nil: continues to wait when the directive becomes idle errs is the list of errors from the resolvers (if any)

If any resolvers return an error, returns that error. valDisposeCb is called if the value is no longer valid. valDisposeCb might be called multiple times. If err != nil, ref == nil.

func ExecOneOffWatchCh added in v0.8.7 

func ExecOneOffWatchCh(
	b Bus,
	dir directive.Directive,
) (<-chan directive.AttachedValue, directive.Instance, directive.Reference, error)

ExecOneOffWatchCh executes a one-off directive and watches for changes. Returns a channel with size 1 which will hold the latest value. Continues to watch for changes until the directive is released.

func ExecOneOffWatchCtr added in v0.28.0 

func ExecOneOffWatchCtr(
	ctr *ccontainer.CContainer[*directive.AttachedValue],
	b Bus,
	dir directive.Directive,
) (
	directive.Instance,
	directive.Reference,
	error,
)

ExecOneOffWatchCtr executes a one-off directive and watches for changes. Stores the latest value into the ccontainer. Continues to watch for changes until the directive is released.

func ExecOneOffWatchRoutine added in v0.22.4 

func ExecOneOffWatchRoutine[T directive.Value](
	routineCtr *routine.RoutineContainer,
	b Bus,
	dir directive.Directive,
	cb func(ctx context.Context, value T) error,
) (directive.Instance, directive.Reference, error)

ExecOneOffWatchRoutine executes a one-off directive and watches for changes.

Calls SetRoutine on the routine container. The routine will be restarted when the value changes. The routine will not start until SetContext is called on the routine container. If the routine returns nil or any error, the function returns that value. If the routine context is canceled, return context.Canceled. If the directive is disposed, the routine will return ErrDirectiveDisposed.

func ExecOneOffWithFilter added in v0.20.8 

func ExecOneOffWithFilter(
	ctx context.Context,
	bus Bus,
	dir directive.Directive,
	idleCb ExecIdleCallback,
	valDisposeCallback func(),
	filterCb func(val directive.AttachedValue) (bool, error),
) (directive.AttachedValue, directive.Instance, directive.Reference, error)

ExecOneOffWithFilter executes a one-off directive with a filter cb.

Waits until the callback returns true before returning a value. valDisposeCb is called if the value is no longer valid. valDisposeCb might be called multiple times.

idleCb is called when idle with the list of resolver errors. idleCb should return (wait, error): if wait=true, continues to wait. if idleCb is nil: continues to wait when the directive becomes idle errs is the list of errors from the resolvers (if any)

If err != nil, ref == nil.

func ExecWaitValue added in v0.15.0 

func ExecWaitValue[T directive.Value](
	ctx context.Context,
	b Bus,
	dir directive.Directive,
	idleCb func(errs []error) (bool, error),
	valDisposeCallback func(),
	checkCb func(val T) (bool, error),
) (T, directive.Instance, directive.Reference, error)

ExecWaitValue executes a directive and waits for a value matching the cb.

valDisposeCallback can be nil, will be called if the value is disposed. If cb returns true, nil, returns the value. If checkCb is nil, returns first value.

idleCb is called when idle with the list of resolver errors. idleCb should return (wait, error): if wait=true, continues to wait. if idleCb is nil: continues to wait when the directive becomes idle errs is the list of errors from the resolvers (if any)

func NewCallbackHandler 

func NewCallbackHandler(
	valCb func(directive.AttachedValue),
	removedCb func(directive.AttachedValue),
	disposeCb func(),
) directive.ReferenceHandler

NewCallbackHandler wraps callback functions into a handler object.

func NewPassThruHandler 

func NewPassThruHandler(
	passthru directive.ResolverHandler,
	disposeCb func(),
) directive.ReferenceHandler

NewPassThruHandler builds a new pass-through handler.

func NewTransformHandler added in v0.29.2 

func NewTransformHandler(
	passthru directive.ResolverHandler,
	xfrm func(val directive.AttachedValue) (directive.Value, bool),
	disposeCb func(),
) directive.ReferenceHandler

NewTransformHandler builds a new pass-through handler.

Types

type Bus 

type Bus interface {
	// Controller is the directive controller.
	directive.Controller

	// GetControllers returns a list of all currently active controllers.
	GetControllers() []controller.Controller

	// AddController adds a controller to the bus and calls Execute().
	// The controller will exit if ctx is canceled.
	// Returns a release function for the controller reference.
	// The controller will receive directive callbacks until removed.
	// Any fatal error in the controller is written to cb.
	// If the controller is released, cb will be called with nil.
	// cb can be nil
	AddController(ctx context.Context, ctrl controller.Controller, cb func(exitErr error)) (func(), error)

	// ExecuteController adds a controller to the bus and calls Execute().
	// The controller will exit if ctx is canceled.
	// Any fatal error in the controller is returned.
	// The controller will receive directive callbacks.
	// If this function returns nil, call RemoveController to remove the controller.
	ExecuteController(context.Context, controller.Controller) error

	// RemoveController removes the controller from the bus.
	// The controller will no longer receive callbacks.
	// Note: this might not cancel the Execute() context automatically.
	RemoveController(controller.Controller)
}

Bus manages running controllers. It has an attached directive controller, which is used to build declarative state requests between controllers.

type BusController added in v0.15.1 

type BusController[T config.Config] struct {
	// contains filtered or unexported fields
}

BusController implements a base Controller with an attached Bus for directives. It has stubs for the functions implementing all required interfaces. Usually you should extend this type, overriding functions as needed.

func NewBusController added in v0.15.1 

func NewBusController[T config.Config](
	le *logrus.Entry,
	b Bus,
	conf T,
	controllerID string,
	controllerVersion semver.Version,
	controllerDescrip string,
) *BusController[T]

NewBusController constructs a new Controller with details.

func (*BusController[T]) Close added in v0.15.1 

func (c *BusController[T]) Close() error

Close releases any resources used by the controller.

func (*BusController[T]) Execute added in v0.15.1 

func (c *BusController[T]) Execute(ctx context.Context) error

Execute executes the given controller.

func (*BusController[T]) GetBus added in v0.15.1 

func (c *BusController[T]) GetBus() Bus

GetBus returns the bus.

func (*BusController[T]) GetConfig added in v0.15.1 

func (c *BusController[T]) GetConfig() T

GetConfig returns the config. Note: don't modify this object!

func (*BusController[T]) GetControllerInfo added in v0.15.1 

func (c *BusController[T]) GetControllerInfo() *controller.Info

GetControllerInfo returns information about the controller.

func (*BusController[T]) GetLogger added in v0.15.1 

func (c *BusController[T]) GetLogger() *logrus.Entry

GetLogger returns the root logger.

func (*BusController[T]) HandleDirective added in v0.15.1 

func (c *BusController[T]) HandleDirective(ctx context.Context, di directive.Instance) ([]directive.Resolver, error)

HandleDirective asks if the handler can resolve the directive.

type BusFactory added in v0.15.0 

type BusFactory[T config.Config, C controller.Controller] struct {
	// contains filtered or unexported fields
}

BusFactory implements Factory with an attached Bus for directives.

func NewBusControllerFactory added in v0.15.1 

func NewBusControllerFactory[T config.Config, C controller.Controller](
	b Bus,
	configID string,
	controllerID string,
	version semver.Version,
	controllerDescription string,
	newConfig func() T,
	newController func(base *BusController[T]) (C, error),
) *BusFactory[T, C]

NewBusControllerFactory builds a Factory for a type wrapping BusController.

func NewBusFactory added in v0.23.2 

func NewBusFactory[T config.Config, C controller.Controller](
	b Bus,
	configID string,
	version semver.Version,
	newConfig func() T,
	newController func(le *logrus.Entry, b Bus, conf T) (C, error),
) *BusFactory[T, C]

NewBusFactory constructs a new Factory with details.

func (*BusFactory[T, C]) Construct added in v0.15.0 

func (f *BusFactory[T, C]) Construct(cc config.Config, opts controller.ConstructOpts) (controller.Controller, error)

Construct constructs the associated controller given configuration.

func (*BusFactory[T, C]) ConstructConfig added in v0.15.0 

func (f *BusFactory[T, C]) ConstructConfig() config.Config

ConstructConfig constructs an instance of the controller configuration.

func (*BusFactory[T, C]) GetConfigID added in v0.15.0 

func (f *BusFactory[T, C]) GetConfigID() string

GetConfigID returns the unique config ID for the controller.

func (*BusFactory[T, C]) GetVersion added in v0.15.0 

func (f *BusFactory[T, C]) GetVersion() semver.Version

GetVersion returns the version of this controller.

type CallbackHandler 

type CallbackHandler = directive.CallbackHandler

CallbackHandler is a reference handler that uses function callbacks.

type ExecIdleCallback added in v0.27.0 

type ExecIdleCallback func(errs []error) (bool, error)

ExecIdleCallback is an idle callback for ExecOneOffWithFilter.

idleCb is called when idle with the list of resolver errors. idleCb should return (wait, error): if wait=true, continues to wait. if idleCb is nil: continues to wait when the directive becomes idle errs is the list of errors from the resolvers (if any)

func ReturnIfIdle added in v0.27.1 

func ReturnIfIdle(returnIfIdle bool) ExecIdleCallback

ReturnIfIdle returns an ExecIdleCallback that returns when the directive becomes idle if true.

func ReturnWhenIdle added in v0.27.0 

func ReturnWhenIdle() ExecIdleCallback

ReturnWhenIdle returns an ExecIdleCallback that returns when the directive becomes idle.

func WaitWhenIdle added in v0.27.0 

func WaitWhenIdle(ignoreErrors bool) ExecIdleCallback

WaitWhenIdle returns an ExecIdleCallback that waits when the directive becomes idle.

if ignoreErrors is false, returns any non-nil resolver error that occurs.

type PassThruHandler 

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

PassThruHandler is a reference handler that passes through to a resolver handler.

func (*PassThruHandler) HandleInstanceDisposed 

func (h *PassThruHandler) HandleInstanceDisposed(di directive.Instance)

HandleInstanceDisposed is called when a directive instance is disposed. This will occur if Close() is called on the directive instance.

func (*PassThruHandler) HandleValueAdded 

func (h *PassThruHandler) HandleValueAdded(
	_ directive.Instance,
	v directive.AttachedValue,
)

HandleValueAdded is called when a value is added to the directive.

func (*PassThruHandler) HandleValueRemoved 

func (h *PassThruHandler) HandleValueRemoved(
	_ directive.Instance,
	v directive.AttachedValue,
)

HandleValueRemoved is called when a value is removed from the directive.

type TransformHandler added in v0.29.2 

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

TransformHandler is a reference handler that transforms values to a resolver handler. xfrm is the transformation callback called with each AttachedValue. xfrm should return the Value to add to the ResolverHandler. if xfrm returns nil, false, the value is ignored. if xfrm is nil, acts identically to PassThruHandler.

func (*TransformHandler) HandleInstanceDisposed added in v0.29.2 

func (h *TransformHandler) HandleInstanceDisposed(di directive.Instance)

HandleInstanceDisposed is called when a directive instance is disposed. This will occur if Close() is called on the directive instance.

func (*TransformHandler) HandleValueAdded added in v0.29.2 

func (h *TransformHandler) HandleValueAdded(
	_ directive.Instance,
	v directive.AttachedValue,
)

HandleValueAdded is called when a value is added to the directive.

func (*TransformHandler) HandleValueRemoved added in v0.29.2 

func (h *TransformHandler) HandleValueRemoved(
	_ directive.Instance,
	v directive.AttachedValue,
)

HandleValueRemoved is called when a value is removed from the directive.

Source Files

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Directories

Path Synopsis
api
controller

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