基本适应win7,win10,win server 08,win server 12,win server 16的截图

grdp/emission/emitter.go

@@ -0,0 +1,273 @@
+// Package emission provides an event emitter.
+// copy form https://raw.githubusercontent.com/chuckpreslar/emission/master/emitter.go
+// fix issue with nest once
+
+package emission
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"reflect"
+	"sync"
+)
+
+// Default number of maximum listeners for an event.
+const DefaultMaxListeners = 10
+
+// Error presented when an invalid argument is provided as a listener function
+var ErrNoneFunction = errors.New("Kind of Value for listener is not Func.")
+
+// RecoveryListener ...
+type RecoveryListener func(interface{}, interface{}, error)
+
+// Emitter ...
+type Emitter struct {
+	// Mutex to prevent race conditions within the Emitter.
+	*sync.Mutex
+	// Map of event to a slice of listener function's reflect Values.
+	events map[interface{}][]reflect.Value
+	// Optional RecoveryListener to call when a panic occurs.
+	recoverer RecoveryListener
+	// Maximum listeners for debugging potential memory leaks.
+	maxListeners int
+
+	// Map of event to a slice of listener function's reflect Values.
+	onces map[interface{}][]reflect.Value
+}
+
+// AddListener appends the listener argument to the event arguments slice
+// in the Emitter's events map. If the number of listeners for an event
+// is greater than the Emitter's maximum listeners then a warning is printed.
+// If the relect Value of the listener does not have a Kind of Func then
+// AddListener panics. If a RecoveryListener has been set then it is called
+// recovering from the panic.
+func (emitter *Emitter) AddListener(event, listener interface{}) *Emitter {
+	emitter.Lock()
+	defer emitter.Unlock()
+
+	fn := reflect.ValueOf(listener)
+
+	if reflect.Func != fn.Kind() {
+		if nil == emitter.recoverer {
+			panic(ErrNoneFunction)
+		} else {
+			emitter.recoverer(event, listener, ErrNoneFunction)
+		}
+	}
+
+	if emitter.maxListeners != -1 && emitter.maxListeners < len(emitter.events[event])+1 {
+		fmt.Fprintf(os.Stdout, "Warning: event `%v` has exceeded the maximum "+
+			"number of listeners of %d.\n", event, emitter.maxListeners)
+	}
+
+	emitter.events[event] = append(emitter.events[event], fn)
+
+	return emitter
+}
+
+// On is an alias for AddListener.
+func (emitter *Emitter) On(event, listener interface{}) *Emitter {
+	return emitter.AddListener(event, listener)
+}
+
+// RemoveListener removes the listener argument from the event arguments slice
+// in the Emitter's events map.  If the reflect Value of the listener does not
+// have a Kind of Func then RemoveListener panics. If a RecoveryListener has
+// been set then it is called after recovering from the panic.
+func (emitter *Emitter) RemoveListener(event, listener interface{}) *Emitter {
+	emitter.Lock()
+	defer emitter.Unlock()
+
+	fn := reflect.ValueOf(listener)
+
+	if reflect.Func != fn.Kind() {
+		if nil == emitter.recoverer {
+			panic(ErrNoneFunction)
+		} else {
+			emitter.recoverer(event, listener, ErrNoneFunction)
+		}
+	}
+
+	if events, ok := emitter.events[event]; ok {
+		newEvents := []reflect.Value{}
+
+		for _, listener := range events {
+			if fn.Pointer() != listener.Pointer() {
+				newEvents = append(newEvents, listener)
+			}
+		}
+
+		emitter.events[event] = newEvents
+	}
+
+	if events, ok := emitter.onces[event]; ok {
+		newEvents := []reflect.Value{}
+
+		for _, listener := range events {
+			if fn.Pointer() != listener.Pointer() {
+				newEvents = append(newEvents, listener)
+			}
+		}
+
+		emitter.onces[event] = newEvents
+	}
+
+	return emitter
+}
+
+// Off is an alias for RemoveListener.
+func (emitter *Emitter) Off(event, listener interface{}) *Emitter {
+	return emitter.RemoveListener(event, listener)
+}
+
+// Once generates a new function which invokes the supplied listener
+// only once before removing itself from the event's listener slice
+// in the Emitter's events map. If the reflect Value of the listener
+// does not have a Kind of Func then Once panics. If a RecoveryListener
+// has been set then it is called after recovering from the panic.
+func (emitter *Emitter) Once(event, listener interface{}) *Emitter {
+	emitter.Lock()
+	defer emitter.Unlock()
+
+	fn := reflect.ValueOf(listener)
+
+	if reflect.Func != fn.Kind() {
+		if nil == emitter.recoverer {
+			panic(ErrNoneFunction)
+		} else {
+			emitter.recoverer(event, listener, ErrNoneFunction)
+		}
+	}
+
+	if emitter.maxListeners != -1 && emitter.maxListeners < len(emitter.onces[event])+1 {
+		fmt.Fprintf(os.Stdout, "Warning: event `%v` has exceeded the maximum "+
+			"number of listeners of %d.\n", event, emitter.maxListeners)
+	}
+
+	emitter.onces[event] = append(emitter.onces[event], fn)
+	return emitter
+}
+
+// Emit attempts to use the reflect package to Call each listener stored
+// in the Emitter's events map with the supplied arguments. Each listener
+// is called within its own go routine. The reflect package will panic if
+// the agruments supplied do not align the parameters of a listener function.
+// If a RecoveryListener has been set then it is called after recovering from
+// the panic.
+func (emitter *Emitter) Emit(event interface{}, arguments ...interface{}) *Emitter {
+	var (
+		listeners []reflect.Value
+		ok        bool
+	)
+
+	// Lock the mutex when reading from the Emitter's
+	// events map.
+	emitter.Lock()
+
+	if listeners, ok = emitter.events[event]; !ok {
+		// If the Emitter does not include the event in its
+		// event map, it has no listeners to Call yet.
+		emitter.Unlock()
+		goto ONCES
+	}
+
+	// Unlock the mutex immediately following the read
+	// instead of deferring so that listeners registered
+	// with Once can aquire the mutex for removal.
+	emitter.Unlock()
+	emitter.callListeners(listeners, event, arguments...)
+
+ONCES:
+	// execute onces
+	emitter.Lock()
+	if listeners, ok = emitter.onces[event]; !ok {
+		emitter.Unlock()
+		return emitter
+	}
+	emitter.Unlock()
+	emitter.callListeners(listeners, event, arguments...)
+	// clear executed listeners
+	emitter.onces[event] = emitter.onces[event][len(listeners):]
+	return emitter
+}
+
+func (emitter *Emitter) callListeners(listeners []reflect.Value, event interface{}, arguments ...interface{}) {
+	var wg sync.WaitGroup
+
+	wg.Add(len(listeners))
+
+	for _, fn := range listeners {
+		go func(fn reflect.Value) {
+			defer wg.Done()
+
+			// Recover from potential panics, supplying them to a
+			// RecoveryListener if one has been set, else allowing
+			// the panic to occur.
+			if nil != emitter.recoverer {
+				defer func() {
+					if r := recover(); nil != r {
+						err := fmt.Errorf("%v", r)
+						emitter.recoverer(event, fn.Interface(), err)
+					}
+				}()
+			}
+
+			var values []reflect.Value
+
+			for i := 0; i < len(arguments); i++ {
+				if arguments[i] == nil {
+					values = append(values, reflect.New(fn.Type().In(i)).Elem())
+				} else {
+					values = append(values, reflect.ValueOf(arguments[i]))
+				}
+			}
+
+			fn.Call(values)
+		}(fn)
+	}
+
+	wg.Wait()
+}
+
+// RecoverWith sets the listener to call when a panic occurs, recovering from
+// panics and attempting to keep the application from crashing.
+func (emitter *Emitter) RecoverWith(listener RecoveryListener) *Emitter {
+	emitter.recoverer = listener
+	return emitter
+}
+
+// SetMaxListeners sets the maximum number of listeners per
+// event for the Emitter. If -1 is passed as the maximum,
+// all events may have unlimited listeners. By default, each
+// event can have a maximum number of 10 listeners which is
+// useful for finding memory leaks.
+func (emitter *Emitter) SetMaxListeners(max int) *Emitter {
+	emitter.Lock()
+	defer emitter.Unlock()
+
+	emitter.maxListeners = max
+	return emitter
+}
+
+// GetListenerCount gets count of listeners for a given event.
+func (emitter *Emitter) GetListenerCount(event interface{}) (count int) {
+	emitter.Lock()
+	if listeners, ok := emitter.events[event]; ok {
+		count = len(listeners)
+	}
+	emitter.Unlock()
+	return
+}
+
+// NewEmitter returns a new Emitter object, defaulting the
+// number of maximum listeners per event to the DefaultMaxListeners
+// constant and initializing its events map.
+func NewEmitter() (emitter *Emitter) {
+	emitter = new(Emitter)
+	emitter.Mutex = new(sync.Mutex)
+	emitter.events = make(map[interface{}][]reflect.Value)
+	emitter.maxListeners = DefaultMaxListeners
+	emitter.onces = make(map[interface{}][]reflect.Value)
+	return
+}