GF
Go Foundation API
dispatcher API

dispatcher

package

API reference for the dispatcher package.

Imports

(4)
STD context STD testing STD fmt STD sync
F
function

TestDispatcher_RegisterAndDispatch

Parameters

t
*testing.T
pkg/dispatcher/dispatcher_test.go:8-27 
func TestDispatcher_RegisterAndDispatch(t *testing.T)

{
	d := New()
	d.Register("greet", func(ctx context.Context, payload ...any) (any, error) {
		name := "world"
		if len(payload) > 0 {
			if s, ok := payload[0].(string); ok {
				name = s
			}
		}
		return "hello " + name, nil
	})

	result, err := d.Dispatch(context.Background(), "greet", "alice")
	if err != nil {
		t.Fatalf("Dispatch: %v", err)
	}
	if result != "hello alice" {
		t.Errorf("result = %v, want hello alice", result)
	}
}
F
function

TestDispatcher_NotFound

Parameters

t
*testing.T
pkg/dispatcher/dispatcher_test.go:29-35 
func TestDispatcher_NotFound(t *testing.T)

{
	d := New()
	_, err := d.Dispatch(context.Background(), "missing")
	if err == nil {
		t.Fatal("expected error for missing handler")
	}
}
F
function

TestDispatcher_Has

Parameters

t
*testing.T
pkg/dispatcher/dispatcher_test.go:37-48 
func TestDispatcher_Has(t *testing.T)

{
	d := New()
	if d.Has("action") {
		t.Error("Has should be false before register")
	}
	d.Register("action", func(ctx context.Context, payload ...any) (any, error) {
		return nil, nil
	})
	if !d.Has("action") {
		t.Error("Has should be true after register")
	}
}
F
function

TestDispatcher_Names

Parameters

t
*testing.T
pkg/dispatcher/dispatcher_test.go:50-59 
func TestDispatcher_Names(t *testing.T)

{
	d := New()
	d.Register("a", func(ctx context.Context, payload ...any) (any, error) { return nil, nil })
	d.Register("b", func(ctx context.Context, payload ...any) (any, error) { return nil, nil })

	names := d.Names()
	if len(names) != 2 {
		t.Errorf("Names length = %d, want 2", len(names))
	}
}
F
function

TestDispatcher_DuplicatePanic

Parameters

t
*testing.T
pkg/dispatcher/dispatcher_test.go:61-70 
func TestDispatcher_DuplicatePanic(t *testing.T)

{
	defer func() {
		if r := recover(); r == nil {
			t.Error("expected panic on duplicate register")
		}
	}()
	d := New()
	d.Register("dup", func(ctx context.Context, payload ...any) (any, error) { return nil, nil })
	d.Register("dup", func(ctx context.Context, payload ...any) (any, error) { return nil, nil })
}
T
type

HandlerFunc

HandlerFunc is a named dispatch handler.

pkg/dispatcher/dispatcher.go:10-10 
type HandlerFunc func(ctx context.Context, payload ...any) (any, error)
S
struct

Dispatcher

Dispatcher provides synchronous named dispatch of handlers.

pkg/dispatcher/dispatcher.go:13-16 
type Dispatcher struct

Methods

Register
Method

Register registers a handler by name. Panics if name is already registered.

Parameters

name string
handler HandlerFunc 
func (*Dispatcher) Register(name string, handler HandlerFunc)
{
	d.mu.Lock()
	defer d.mu.Unlock()
	if _, ok := d.handlers[name]; ok {
		panic(fmt.Sprintf("dispatcher: handler %q already registered", name))
	}
	d.handlers[name] = handler
}
Dispatch
Method

Dispatch calls the handler registered under name, passing the payload. Returns an error if no handler is found.

Parameters

ctx context.Context
name string
payload ...any

Returns

any
error 
func (*Dispatcher) Dispatch(ctx context.Context, name string, payload ...any) (any, error)
{
	d.mu.RLock()
	handler, ok := d.handlers[name]
	d.mu.RUnlock()
	if !ok {
		return nil, fmt.Errorf("dispatcher: no handler for %q", name)
	}
	return handler(ctx, payload...)
}
Has
Method

Has returns true if a handler is registered under name.

Parameters

name string

Returns

bool 
func (*Dispatcher) Has(name string) bool
{
	d.mu.RLock()
	defer d.mu.RUnlock()
	_, ok := d.handlers[name]
	return ok
}
Names
Method

Names returns all registered handler names.

Returns

[]string 
func (*Dispatcher) Names() []string
{
	d.mu.RLock()
	defer d.mu.RUnlock()
	names := make([]string, 0, len(d.handlers))
	for name := range d.handlers {
		names = append(names, name)
	}
	return names
}

Fields

Name Type Description
mu sync.RWMutex
handlers map[string]HandlerFunc
F
function

New

New creates a new Dispatcher.

Returns

*Dispatcher
pkg/dispatcher/dispatcher.go:19-21 
func New() *Dispatcher

{
	return &Dispatcher{handlers: make(map[string]HandlerFunc)}
}