commit | 9cba5699b077f26b603b0f7a6178fa83fb8737c3 | [log] [tgz] |
---|---|---|
author | Android Build Coastguard Worker <android-build-coastguard-worker@google.com> | Thu Apr 14 03:09:13 2022 +0000 |
committer | Android Build Coastguard Worker <android-build-coastguard-worker@google.com> | Thu Apr 14 03:09:13 2022 +0000 |
tree | 53a110fe621d0ab5ac2eb2cbccfcd4fc8d1b6c91 | |
parent | 7c0ed3038050e583fdebad8478700648c6350bb6 [diff] | |
parent | 795983b1d944e82e9c405b6c6a62ecbb293ec57f [diff] |
Snap for 8451773 from 795983b1d944e82e9c405b6c6a62ecbb293ec57f to tm-qpr1-release Change-Id: I841e4527a430a497be41a909e0a74af1d7a3f1bc
SdkExtensions module is responsible for:
The module is packaged in an apex, com.android.sdkext
, and has several components:
bin/derive_classpath
: a native binary that runs early in the device boot process. It reads individual classpath configs files from the system and other modules, merges them, and defines the definition of *CLASSPATH environ variables.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.pb
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)
.
derive_classpath
service reads and merges individual config files in the /system/etc/classpaths/
and /apex/*/etc/classpaths
. Each config stores protobuf message from classpaths.proto
in a proto binary format. Exact merging algorithm that determines the order of the classpath entries is described in derive_classpath.cpp
and may change over time.
An extension is a way to group a set of modules so that they are versioned together. We currently define a new extension for every Android SDK level that introduces new modules. Every module shipped in previous versions are also part of the new extension. For example, all the R modules are part of both the R extensions and the S extensions.
The steps to define a new extension are:
derive_sdk.cpp
by:GetSdkLevel
with the new enum setderive_sdk_test.cpp
verifying the new extensions workSdkExtensions.getExtensionVersion
API support the new extensions.