1 files changed, 95 insertions, 0 deletions
diff --git a/client/object/object.go b/client/object/object.go
new file mode 100644
index 0000000..f42eaf8
--- /dev/null
+++ b/client/object/object.go
@@ -0,0 +1,95 @@
+package object
+
+import (
+	"citrons.xyz/talk/proto"
+)
+
+type ObjCache struct {
+	stream ObjStream
+	objects map[string]cacheEntry
+}
+
+type cacheEntry struct {
+	o proto.Object
+	refCount int
+	cached bool
+}
+
+type ObjStream interface {
+	Sub(id string)
+	GetInfo(id string, callback func(proto.Command))
+	Unsub(id string)
+}
+
+func NewCache(stream ObjStream) ObjCache {
+	return ObjCache {stream, make(map[string]cacheEntry)}
+}
+
+func (oc *ObjCache) Get(id string) *proto.Object {
+	entry := oc.objects[id]
+	if !entry.cached {
+		return nil
+	}
+	return &entry.o
+}
+
+func (oc *ObjCache) Fetch(id string, callback func(*proto.Object)) {
+	entry := oc.objects[id]
+	if !entry.cached {
+		oc.stream.GetInfo(id, func(cmd proto.Command) {
+			if cmd.Kind == "i" && len(cmd.Args) > 0 {
+				callback(&cmd.Args[0])
+			} else {
+				callback(nil)
+			}
+		})
+	}
+	callback(&entry.o)
+}
+
+func (oc *ObjCache) Watch(id string) {
+	entry, ok := oc.objects[id]
+	if !ok {
+		oc.stream.Sub(id)
+	}
+	oc.objects[id] = entry
+}
+
+func (oc *ObjCache) Unwatch(id string) {
+	entry, ok := oc.objects[id]
+	if ok {
+		entry.refCount--
+		if entry.refCount <= 0 {
+			oc.stream.Unsub(id)
+			delete(oc.objects, id)
+		} else {
+			oc.objects[id] = entry
+		}
+	}
+}
+
+func (oc *ObjCache) Update(id string, new proto.Object) {
+	entry := oc.objects[id]
+	if entry.cached && new.Kind == entry.o.Kind {
+		for k, v := range new.Fields {
+			entry.o.Fields[k] = v
+		}
+	} else {
+		entry.o = new
+	}
+	entry.cached = true
+	oc.objects[id] = entry
+}
+
+func (oc *ObjCache) Gone(id string) {
+	entry := oc.objects[id]
+	if entry.cached {
+		obj := entry.o
+		obj.Fields["kind"] = obj.Kind
+		obj.Kind = "gone"
+		entry.o = obj
+		oc.objects[id] = entry
+	}
+}
+
+