Saving Data : Reducing the Size of the App Updates by 65%

Google has announced a new method of updating your apps on the Play Store. A previous change had reduced the size of updates by 47% on average, but this new one can reduce the size by a further 65%.

The new method is called File-by-File patching. Since APKs are zipped up and compressed, one can’t just replace a single file without changing the entire file’s compressed output. Therefore this new method will decompress both the old and the new APK, apply the patch from the new APK, and compress the APK on your device. While this takes less data, it takes more time and processing power.

Because these patches can take longer, Google has opted to only use file-by-file patching for background auto-updates right now. So, your Play Store client may end up using a lot fewer data. It won't necessarily be faster at updating, though.

Because of these drawbacks, Google is limiting this new update method to automatic updates that it can do in the background. Manually updating apps won’t utilize this new technique in saving data.

Techniques used in File-by-File patching

Android apps are packaged as APKs, which are ZIP files with special conventions. Most of the content within the ZIP files (and APKs) is compressed using a technology called Deflate. Deflate is really good at compressing data but it has a drawback: it makes identifying changes in the original (uncompressed) content really hard. Even a tiny change to the original content (like changing one word in a book) can make the compressed output of deflating look completely different. Describing the differences between the original content is easy, but describing the differences between the compressed content is so hard that it leads to inefficient patches. File-by-File, therefore, is based on detecting changes in the uncompressed data.

To generate a patch, First decompress both old and new files before computing the delta. Then to apply the patch, decompress the old file, apply the delta to the uncompressed content and then recompress the new file. In doing so, make sure that the APK on your device is a perfect match, byte for byte, to the one on the Play Store

Thankfully, developers won’t have to change anything to utilize this new update system. It’s all on Google’s end. If you want to learn more about File-by-File patching, hit the source link!

Source:  Android Developers Blog

Google Play service to drop support for Android Gingerbread, Honeycomb in early 2017

In an Android Developers blog - post-Google announced that Google play services and firebase for Android will support API level 14 at a minimum. Version 10.0.0 of the Google Play services client libraries, as well as the Firebase client libraries for Android, will be the last version of these libraries that support Android API level 9 (Android 2.3, Gingerbread). The next scheduled release of these libraries, version 10.2.0, will increase the minimum supported API level from 9 to 14 (Android 4.0.1, Ice Cream Sandwich) and will be released by early 2017. In other words, for the new version play services to work, smartphones will require a minimum of Android 4.0 Ice Cream Sandwich and above. As a result, the lower version Android 2.3 Gingerbread and Android 3.0/3.1/3.2 Honeycomb will be dropped by next year.

The Gingerbread platform is almost 6 years old. Introduced first in 2012, Google Play services are Google’s background service and API package for Android. It’s the company’s way of delivering updates and improvements for its services and apps to Android users without actually upgrading the whole operating system. Google explains that one of the reasons for discontinuing support for Gingerbread is that many Android developers have already discontinued support for Gingerbread in their apps. This helps developers build better apps by making use of newer capabilities of the Android platform. And it works similarly for Google as well. By making this change, Google will be able to provide a more robust collection of tools for Android developers with greater speed.

As for the users who are still on the older version, you may use version 10.0.0 of Google Play services and Firebase as you are currently. Developers are being asked to use a minimum of API level 14, and those opting to follow these guidelines will no longer be able to deliver updates to older devices. However, users will still be able to download the most recently published version of the app that does target their device.

Looking how the Android distribution stands right now, a very little percentage of users are still working with these versions of Android OS. According to the Android distribution numbers for the first week of November, Gingerbread (2.3.3 and 2.3.7 combined) has reduced its presence from 1.5 percent to 1.3 percent. Ice Cream Sandwich (4.0.3 and 4.0.4 combined) joins Gingerbread with 1.3 percent, a decrease from the previous 1.4 percent. This is in comparison to the new version, where Marshmallow runs on 24 percent devices, while Lollipop (5.0 and 5.1 combined) leads the charts with 34.1 percent market share, followed by KitKat with 25.2 percent. Jelly Bean (4.1.x and 4.2.x combined) comes third with 13.7 percent.

To be clear, developers can continue to use version 10.0.0 of Google Play services and Firebase with Gingerbread and Honeycomb devices. Once you upgrade to version 10.2.0 or above, however, you will have to either target API level 14 as the minimum supported version or build multiple APKs to support devices with an API level less than 14. Given that Gingerbread and Honeycomb will continue to be slowly but surely phased out, the former is your best option.