commit | b14688f37323cd7ab7759b4a48f33a637f4988d6 | [log] [tgz] |
---|---|---|
author | Anton Hansson <hansson@google.com> | Wed Jul 15 12:34:13 2020 +0100 |
committer | Anton Hansson <hansson@google.com> | Wed Oct 28 13:34:59 2020 +0000 |
tree | d2fb949b90a67086b09a2938c2de89211c87884d | |
parent | 1602c0a9bc5d71db85ad95cb675c5a687ebe097d [diff] |
Document SdkExtensions module structure Bug: 161339866 Test: local markdown renderer Change-Id: I55b9292e8088911922ac998fb6ed1f3ea4d022bc Merged-In: I55b9292e8088911922ac998fb6ed1f3ea4d022bc (cherry picked from commit a6caee837fb07a59121a9fe4ae5c72649daf9e42)
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)
.