Add holder.

hold/hold.go

@@ -0,0 +1,68 @@
+package hold
+
+import "github.com/nu7hatch/gouuid"
+
+type holdchan chan interface{}
+type gethold struct {
+	id    *uuid.UUID
+	reply chan holdchan
+}
+type delhold struct {
+	id *uuid.UUID
+}
+
+type Holder struct {
+	data    map[uuid.UUID]holdchan
+	getchan chan gethold
+	delchan chan delhold
+}
+
+var Hold Holder
+
+func (self *Holder) DelChan(id *uuid.UUID) {
+	req := delhold{id}
+	self.delchan <- req
+}
+
+func (self *Holder) GetChan(id *uuid.UUID) holdchan {
+	reply := make(chan holdchan)
+	req := gethold{id, reply}
+	self.getchan <- req
+	return <-reply
+}
+
+func (self *Holder) Get(id *uuid.UUID) interface{} {
+	ch := self.GetChan(id)
+	return <-ch
+}
+
+func (self *Holder) Set(id *uuid.UUID, value interface{}) {
+	ch := self.GetChan(id)
+	go func() {
+		ch <- value
+		self.DelChan(id)
+	}()
+}
+
+func (self *Holder) run() {
+	var greq gethold
+	var dreq delhold
+	for {
+		select {
+		case greq = <-self.getchan:
+			item, ok := self.data[*greq.id]
+			if !ok {
+				item = make(holdchan)
+				self.data[*greq.id] = item
+			}
+			greq.reply <- item
+		case dreq = <-self.delchan:
+			delete(self.data, *dreq.id)
+		}
+	}
+}
+
+func init() {
+	Hold = Holder{make(map[uuid.UUID]holdchan), make(chan gethold), make(chan delhold)}
+	go Hold.run()
+}

hold/hold_test.go

@@ -0,0 +1,27 @@
+package hold
+
+import (
+	"testing"
+	"time"
+
+	"github.com/nu7hatch/gouuid"
+	. "github.com/smartystreets/goconvey/convey"
+)
+
+func TestHoldChan(t *testing.T) {
+	Convey("set then get", t, func() {
+		id, _ := uuid.NewV4()
+		Hold.Set(id, "derp")
+		derp := Hold.Get(id)
+		So(derp, ShouldEqual, "derp")
+	})
+	Convey("get then set", t, func() {
+		id, _ := uuid.NewV4()
+		go func() {
+			time.Sleep(time.Second / 10)
+			Hold.Set(id, "derpsy")
+		}()
+		derp := Hold.Get(id)
+		So(derp, ShouldEqual, "derpsy")
+	})
+}