| commit | 3d8587f304f249fb7e6f7ab35739cac67dbd186a | [log] [tgz] |
|---|---|---|
| author | Android Build Coastguard Worker <[email protected]> | Thu Jun 08 17:31:36 2023 +0000 |
| committer | Android Build Coastguard Worker <[email protected]> | Thu Jun 08 17:31:36 2023 +0000 |
| tree | cbc2c6edd44f6cea7f1e05e2f25365a6644b436f | |
| parent | 9ce8c93e9d15471e5df466769e8c72c81f39dc19 [diff] | |
| parent | 8730d1c6f988f4e9a8aed3eb31a8b0389efae27e [diff] |
Snap for 10276566 from 8730d1c6f988f4e9a8aed3eb31a8b0389efae27e to tm-platform-release Change-Id: If4c0bf7f1fa73ddf2dc26cab65a9215e39310ff1
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.