commit | 6075f1ddc17813bd3cb1a8d88cfdca1019044058 | [log] [tgz] |
---|---|---|
author | Remi NGUYEN VAN <reminv@google.com> | Mon Feb 28 17:22:13 2022 +0900 |
committer | Remi NGUYEN VAN <reminv@google.com> | Mon Feb 28 17:22:13 2022 +0900 |
tree | b4bdd6215ba881d8a2ebda6152e3dbe3ea26891c | |
parent | 30e7c30da3f2ff3433093a24df3b6f0e2ba1b5e4 [diff] |
Use C strings in unbounded_sdk_level This allows unbounded_sdk_level.h to not require libc++, so smaller users of the library can stay small. Bug: 220819740 Test: m Change-Id: I7b7c8167a39e2815cbe0e7b5de3dc406bbd64a8a
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.
For every new Android SDK level a new extension version should be defined. These are the steps necessary to do that:
derive_sdk.cpp
by:GetSdkLevel
with the new enum setderive_sdk_test.cpp
verifying the new extensions worksSdkExtensions.getExtensionVersion
API support the new extensions.