update

lib/asyncTaskMgr.js

@@ -0,0 +1,51 @@
+function asyncTaskMgr(){
+    var self = this;
+
+    self.callbackList = {
+        sampleName:{
+            status:0, /* 0,stopped,will not callback  /  1,loading / 2,loaded */
+            result:null,
+            callbackList:[]
+        }
+    }
+
+    self.addTask = function(name,cb,action){
+        if(self.callbackList[name]){
+            var task = self.callbackList[name];
+
+            if(task.status == 2){ //done
+                cb && cb.apply(null,task.result);
+
+            }else if(task.status == 1){ //pending
+                task.callbackList.push(cb);
+            
+            }else if(task.status == 0){ //stopped
+                return; //do nothing
+            }
+        }else{
+            var task;
+            task = self.callbackList[name] = {
+                status : 1,
+                result : null,
+                callbackList : [cb]
+            };
+
+            action && action.call(null,function(){  //action应该带一个回调
+                if(arguments && arguments[0] === -1){  //返回第一个参数为-1，为停止任务
+                    task.status = 0;
+                    task.callbackList = [];
+                }else{
+                    task.result = arguments;
+                    task.status = 2;
+                    var tmpCb;
+                    while(tmpCb = task.callbackList.shift()){
+                        tmpCb && tmpCb.apply(null,task.result);
+                    }
+                    
+                }
+            });
+        }
+    }
+};
+
+module.exports = asyncTaskMgr;