File System Support for Low-Bandwidth Thumbnails
Jonathan Ledlie · 2008
Users are frustrated by the current experience of browsing, downloading, and exchanging files in low-bandwidth networks, such as ad hoc wireless networks. One improvement to this experience is to let users first locally interact with file thumbnails — graphical summaries of file contents — and fetch complete files only if necessary. These thumbnails can be sent quickly over the network and augment traditional metadata, such as file names and ownership. To reduce bandwidth consumption, thumbnails must be generated remotely. In prior work, server-side application programs generate thumbnails in response to users’ requests. In contrast, we propose extending underlying file system functionality to support direct generation and storage of thumbnails. Through inode changes or, more simply, through extended file attributes, we envision embedding thumbnails within the file system itself, just as human-readable names and ownership are today. Making thumbnails a first-class object directly linked to their uncompressed counterpart ensures consistency through modify-onwrite regeneration and guarantees equal thumbnail and file data access control. Through directly embedding thumbnails within the file system, we can provide assurances and efficiencies beyond what is possible with application-level techniques.