Design And Implementation Of Web Resource Offline And Incremental Update Platform

With the rapid development of the Internet industry,high-speed iteration of software products has been focused to reduce the developing cost of software by more and more enterprises.In this context,the advantages of Web App,such as cross-platform and flexible update,attracted more and more attention of manufacturers.Users can access the latest version whenever they open,and manufacturers do not need to maintain multiple versions of the application,these advantages greatly reduced the cost of development,operation and maintenance.However,due to the high dependence of Web App on the network,the loading performance of Web App has always been a short board.In the process of Web App loading,multiple resource requests are generally required.Network delay and low bandwidth will extended the time of requesting resources,resulted in that many Web App cannot satisfy user needs under the conditions of weak networks.The platform focused the limits of Web app and a novel solution has been raised to solve them.The offline use of the resource file used by the user exists locally,and the resource can be directly read from the cache when the page is accessed,without re-entering the network request,which greatly reduces the number of network requests.Only the changed parts of the file will be downloaded using the incremental updating method during the update,which reduce the consumption of network without re-downloading the full amount of files.These core technologies reduced the dependence of network and pressure of application server which could greatly improve the concurrent performance of the application server.The cache will be controllable under the cache mode supported by the browser and the resource caching scheme provided here.The code-controlling strategy can achieve the same effects of Web app in different browsers compared with browser-caching strategy and the judgment of the validity of the cache will be more accurate.Users can cache the resources according to their needs without re-downloading,which can greatly improve the the loading performance of the page.At the same time,the cache check is added,and the reliability of the cache is improved to provide a basis for incremental update.The historical resources of the project can be systematically managed by constructing a resource management platform.Developers can manage their own Web resources through visual operation interfaces or command line tools,and can manage historical versions uniformly,making incremental updates possible.When the application is updating,the user only needs to send an incremental update request based on the historical version,the incremental updating server will calculate the upgrade to the latest version of the patch package.Update will be accomplished by only downloading the changing part of files.This method greatly reduces the network costs and dependence on the network,and improves the utilization of the cache.The system is simple and easy to use,the developer only needs a simple operation to complete the access,the intrusion of the business code is extremely low,and the access cost is greatly reduced.After the access,the loading performance and update speed of the web application can be greatly improved.In the project,I mainly completed the development of the command line tool,the background management system,the Local Storage module of the offline module,and the scheme design of the intelligent preheating module.In the end,the platform achieved the expected goals of the design,but there are still many areas where the platform needs to be optimized and improved,and it needs to be improved in the future work.