Google has announced that it is developing a new system, File-by-File technique which will result in a reduction of the update size of any apps and games on Google Play. The Android smartphone users download the apps and games from Google Play for over tens of billions times. The developers also frequently update their apps to offer improved security, latest content and enhancing the user experience.
The Android Smartphone users have to complain about the annoying app updates from a long time and hence the company has brought a new technique. The new technique will reduce the weight of an app to 65 percent of their original app size, whereas in some cases the size is more than 90 percent smaller.
To simplify the technique, Google has shown the comparison of the uncompressed version of both old and new version of the files and realized the changes which are required with the bsdiff algorithm. After this, the system decompresses the old file and patches the new file to the uncompressed content. Hereafter re compresses the new file.
Here are examples of app updates already using File-by-File Patching:
| Application | Original Size | Previous (BSDiff) Patch Size (% vs original) | File-by-File Patch Size (% vs original) |
| Farm Heroes Super Saga | 71.1 MB | 13.4 MB (-81%) | 8.0 MB (-89%) |
| Google Maps | 32.7 MB | 17.5 MB (-46%) | 9.6 MB (-71%) |
| Gmail | 17.8 MB | 7.6 MB (-57%) | 7.3 MB (-59%) |
| Google TTS | 18.9 MB | 17.2 MB (-9%) | 13.1 MB (-31%) |
| Kindle | 52.4 MB | 19.1 MB (-64%) | 8.4 MB (-84%) |
| Netflix | 16.2 MB | 7.7 MB (-52%) | 1.2 MB (-92%) |
(Source: Android Developers Blog)
The new approach is called as File-by-File patching which saves up to 6 petabytes of user data per day when compared with the previous approach. To facilitate the new version of the app, the Google Play sends a patch file to your device which describes the difference between the old and the new version of the app.
This process resembles with book publishing. If the author wishes to change a single sentence in a book before publishing, he just tells the editor to change the exact sentence which is to be changed and not the entire book. Similarly, the app update patches are much smaller and easier to download than the entire new APK.
While doing so, Google requires confirming that the APK on your device is a perfect match, byte for byte to the existing APK on the Play Store. The company has previously developed the bsdiff algorithm with Colin Percival.
The File-by-File patching is a good addition to the Play Store. Many people are having limited data plans, even on their home internet connection. Hence, the saving in megabytes is good for them.