| commit | 1de7c7199a28d63211d440327f220e43f2791b58 | [log] [tgz] |
|---|---|---|
| author | Android Build Coastguard Worker <[email protected]> | Sat May 21 12:38:01 2022 +0000 |
| committer | Android Build Coastguard Worker <[email protected]> | Sat May 21 12:38:01 2022 +0000 |
| tree | d71a8ac81af99a88fa0a1448b968ffc382107a55 | |
| parent | da7bfa3561c2c654df12639f00e1338ff4b90b6d [diff] | |
| parent | 70ac4587787796565bcba2012c8efcf3cc6ce794 [diff] |
Snap for 8626064 from 70ac4587787796565bcba2012c8efcf3cc6ce794 to mainline-go-adservices-release Change-Id: Ib64feb17be403d538ad3cb6609b61e0226ab4171
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.