id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
214	use zsync to update offline routing data	Martin Kolman	Martin Kolman	"* use zsync to update routing data from the server
* like this, only changes would be transferred, making frequent routing data updates feasible
 * packs for large countries can take up multiple GBs

* zsync: http://zsync.moria.org.uk/


* how would an update look like:
 * before starting the update, mark the map package as dirt
  * .#dirty file ?
 * modRana downloads a file-list for the package, that contains also a link to a zsync control file for every file
 * iterate over the zsync files and update every local file
 * at the end, remove all files that are present in the local folder but not on the file-list (exclude the .#dirty file)
 * remove the .#dirty file

* drawbacks:
 * needs to store two copies of the routing data
  * one archive for direct download
  * one in uncompressed form + zsync control file for updates only
   * needs zsync files for all files
   * on the other hand as zsync won't overwrite the file until the download is finished, working on multiple smaller files helps
 "	enhancement	assigned	minor		gps