commit | a6caee837fb07a59121a9fe4ae5c72649daf9e42 | [log] [tgz] |
---|---|---|
author | Anton Hansson <hansson@google.com> | Wed Jul 15 12:34:13 2020 +0100 |
committer | Anton Hansson <hansson@google.com> | Wed Jul 15 12:55:22 2020 +0000 |
tree | 8d96ddabdbd548175e4733dc3b61fb1958d95d3d | |
parent | 5c3325b09f0ff4c4248437831adca57dda8b494c [diff] |
Document SdkExtensions module structure Bug: 161339866 Test: local markdown renderer Change-Id: I55b9292e8088911922ac998fb6ed1f3ea4d022bc
SdkExtensions is a module that decides the extension SDK level of the device, and provides APIs for applications to query the extension SDK level.
The module is packaged in an apex, com.android.sdkext
, and has two components:
bin/derive_sdk
: Native binary that runs early in the device boot process and reads metadata of other modules, to set system properties relating to the extension SDK (for instance build.version.extensions.r
).javalib/framework-sdkextension.jar
: This is a jar on the bootclasspath that exposes APIs to applications to query the extension SDK level.derive_sdk
is a program that reads metadata stored in other apex modules, in the form of binary protobuf files in subpath etc/sdkinfo.binarypb
inside each apex. The structure of this protobuf can be seen here. The exact steps for converting a set of metadata files to actual extension versions is likely to change over time, and should not be depended upon.
The module exposes a java class SdkExtensions
in the package android.os.ext
. The method getExtensionVersion(int)
can be used to read the version of a particular sdk extension, e.g. getExtensionVersion(Build.VERSION_CODES.R)
.