FastIO : Eliminating the Deserialization Overhead in Launching Web Applications

Web applications are launched by Webkit engine. Dominant fraction of launch latency is spe nt on serializing the resource file. Webkit engine loads the HTML format based resources from the storage de vice, and converts them to memory representation creating DOM (Document Object Model) tree and render tree. The overhead of this deserialization is excessive and the modern web applications suffers from tens of a second in application launch latency. We develop a new software layer FastIO. FastIO maps a file system region to memory and us es this memory region to persistently store the tree representatio n, e.g., DOM tree and render tree, of the resources dir ctly to the storage device. The FastIO layer eliminates the ove rhead of serializing and deserializing the HTML bas ed resources; parsing the documents, and creating DOM tree and re er tree. We implement FastIO layer in commodity P C and adopted FastIO on the Webkit engine. With FastIO, t he speed of launching an application increases by 4 4.8x, 7.9x, and 2.9x when the resource files reside in ramdisk, SSD, and eMMC, respectively.