Not everyone has supremely fast mobile data when on the go. And even those with many bars of LTE reception shouldn’t have to waste their bandwidth downloading overly sized ROM updates. But let’s face it: We all want the absolute bleeding edge ROM and featureset at all times.
So what do we do when we’re on the go and happen to see that our favorite developer issued a new version? We download a huge, often 100 MB or larger complete update.zip via mobile data and flash it on the go. This is a given, as we wouldn’t be very good ORDers otherwise. Unfortunately, stuff happens, and not every download goes as expected. When a download arrives corrupted, that becomes bandwidth and time that is wasted—frustrating all around.
Well, thanks to work by XDA Senior Recognized Developer Chainfire, this is no longer an issue—at least not for those running OmniROM. Thanks to Chainfire’s work, OmniROM now uses Chainfire’s OpenDelta OTA technology. As its name suggests, this uses deltas, when possible, to reduce download sizes. Differences are determined using existing VCDIFF technology, and the delta files are then pushed out to the OmniROM public download server.
Then, a local Android client checks in with the update server and retrieves the latest .delta file. And one neat trick is that if you forget to update for a few rounds, OpenDelta can chain multiple .delta files to install many incremental updates at once. Finally, the Android app also allows you to automatically check for and download updates when connected to specified network types.
End users should be pretty excited about OpenDelta, as it means smaller and more streamlined update downloads. Developers should be as well. OpenDelta, as well as the whole OmniROM project is open source. Of note, however, users must be running TWRP recovery to use these incremental update deltas.
What are your thoughts on OmniROM’s new update system? Personally, I think it’s about time that a large-scale custom ROM incorporates an open source delta OTA system.
[Source: Official OmniROM Blog]_________