The Design And Implementation Of Embedded Browser Cache

It is worthwhile to note that, from the first half of2012, the number of mobilephone has exceeded that of personal computers in China, becoming the most popularinternet terminal. In terms of any terminals that connect to the Internet, the users sufferfrom offline visiting or response delay when use them. This situation could be evenworse on mobile phones. Thus, how to enusre the users get the same content and leavethem the same feelings when they browser Internet on the embeded system as they dothis on PC is the key point of designing a embedded browser. One of the most effectivesolutions is caching technique. By using the data from cache as much as possible,thistechnique can accelerate the response for each user request significantly and impoveuser experience consequently.xFace is a cross-platform supported developing and running environment ofwidgets, while as a crucial part of xFace project, this research mainly puts attentions oncaching system and the main goal is to improve response speed of mobile browser.Webkit is an open-source web browser engine and famous for high response speed, so,this thesis firstly analyses the architecture of Webkit engine, the function of eachmodule and the interaction among them in a systematic perspective. Then, it putsemphasis on one browser module that loads webpage and another module that managesthe cache resources. Finally, on this basis, considering the features of xFace andembedded running environment, the caching system is designed in reference to theresource managing strategy of Webkit. The cache system is composed by threecomponents: local cache, Http cache, and page cache.Local cache: it manages all resources, including resources that were uncompressedin the installing procedure and loaded from Internet. It works in cooperation with Httpcache, ensuring the resources are available when the system restarts, so that theutilization rate of resources could be improved. Moreover, SingleFile technique isdesigned and implemented in this module to improve the rate of file operations.Http cache: it implements the caching mechanism for all resources, deciding whatkinds of response can be cached, what data need to be cached and whether the resources are valid. Also, two replacement strategies are designed according to the exclusivefeatures of xFace, one is application oriented and another is resources oriented. Besides,considering the instability of cellular networks, the Http cache manages all theexceptional responses in a unified way and imports broken-pointcontinuingly-transferring mechanism to make full use of the data that has already beenreceived to avoid redundant data transferring.Page cache: it is used to cached the recent visited webpages, supporting back andforward commands.In the end of this thesis, introduced the test and certification of caching system.The caching system has improved resource loading rate and user’s experience throughtest and verification.