Changes

For these reasons, the extension runs in its own context. This is achieved by having a bootstrap loader that is a self-registering XPCOM component. This component uses the subscript loader to load application js files into its context. Only small amounts of "glue" code exist in the browser window context, and these pieces of glue essentially just call into the application context to do the heavy lifting.

Providing the data on the server for updates and lookups requires a fair amount of resources. To help maintain a high quality of service, it may be necessary for the update and lookup servers to ask the client to make less frequent requests. To handle this, the client watches for HTTP timeouts or errors from the server and if too many errors occur, it increases in the time between requests. If remote lookups start to fail, we fall back on using the tables provided during update requests.