Mobile web platforms are facing new demands for emerging applications, such as machine learning or augmented reality, which require significant computing powers beyond that of current mobile hardware. Computation offloading can accelerate these apps by offloading the computation-intensive parts of an app from a client to a powerful server. Unfortunately, previous studies of offloading in the field of web apps have a limitation for the offloading target code or require complex user annotations, hindering the widespread use of offloading in web apps. This article proposes a novel offloading system for web apps, which can simplify the offloading process by sending and receiving the execution state of a running web app in the form of another web app called the snapshot . Since running the snapshot restores the whole app state and continues the execution from the point where it was saved, we can offload regular web app computations that affect the DOM state as well as the JavaScript state, and we do not have to pre-install the app binary at the server. Moreover, the snapshot does not require any annotations to be captured, making computation offloading more transparent to app developers. We qualitatively compared the proposed system with previous approaches in terms of programming difficulty and the scope of offloadable codes. In addition, we implemented the proposed system based on a WebKit browser and evaluated the offloading performance with five computation-intensive web apps. Our system achieved significant speedup (from 1.7 to approximately 9.0) in all of the apps, compared to local execution, which proves the feasibility of the proposed approach.

中文翻译：

---

使用快照动态卸载 Web 应用程序执行

移动 Web 平台正面临对新兴应用程序的新需求，例如机器学习或增强现实，这些应用程序需要强大的计算能力，超出当前移动硬件的计算能力。计算卸载可以通过将应用程序的计算密集型部分从客户端卸载到强大的服务器来加速这些应用程序。不幸的是，之前在 Web 应用领域的卸载研究对卸载目标代码存在限制或需要复杂的用户注释，阻碍了卸载在 Web 应用中的广泛使用。本文提出了一种新颖的 Web 应用卸载系统，它可以通过以另一个名为快照. 由于运行快照会恢复所有的应用程序状态并从保存点继续执行，我们可以卸载影响 DOM 状态以及 JavaScript 状态的常规 Web 应用程序计算，并且我们不必在服务器上预先安装应用程序二进制文件。此外，快照不需要捕获任何注释，从而使计算卸载对应用程序开发人员更加透明。我们在编程难度和可卸载代码的范围方面定性地比较了所提出的系统与以前的方法。此外，我们基于 WebKit 浏览器实现了所提出的系统，并评估了五个计算密集型 Web 应用程序的卸载性能。与本地执行相比，我们的系统在所有应用程序中实现了显着的加速（从 1.7 到大约 9.0），这证明了所提出方法的可行性。