add event dispatch

1 files changed, 70 insertions, 0 deletions

diff --git a/event/dispatch.go b/event/dispatch.go
new file mode 100644
index 0000000..e84da18
--- /dev/null
+++ b/event/dispatch.go
@@ -0,0 +1,70 @@
+package event
+
+import (
+	"strings"
+	"sync"
+)
+
+const Sep = "/"
+
+type Dispatch struct {
+	mu       sync.Mutex
+	handlers []func(event string)
+	trie     map[string]*Dispatch
+}
+
+func (d *Dispatch) Event(pattern string, handler func(event string)) {
+	if pattern == "" {
+		d.event(nil, handler)
+		return
+	}
+	d.event(strings.Split(pattern, Sep), handler)
+}
+
+func (d *Dispatch) Happen(event string) {
+	if event == "" {
+		d.happen(nil)
+		return
+	}
+	d.happen(strings.Split(event, Sep))
+}
+
+func (d *Dispatch) event(pattern []string, handler func(event string)) {
+	d.mu.Lock()
+	defer d.mu.Unlock()
+
+	if len(pattern) == 0 {
+		d.handlers = append(d.handlers, handler)
+		return
+	}
+
+	if d.trie == nil {
+		d.trie = make(map[string]*Dispatch)
+	}
+	if d.trie[pattern[0]] == nil {
+		d.trie[pattern[0]] = &Dispatch{}
+	}
+	d.trie[pattern[0]].event(pattern[1:], handler)
+}
+
+func (d *Dispatch) happen(event []string) {
+	d.mu.Lock()
+	handlers := d.handlers
+	d.mu.Unlock()
+
+	for _, handler := range handlers {
+		handler(strings.Join(event, Sep))
+	}
+
+	if len(event) == 0 {
+		return
+	}
+
+	d.mu.Lock()
+	next := d.trie[event[0]]
+	d.mu.Unlock()
+
+	if next != nil {
+		next.happen(event[1:])
+	}
+}