| commit | 3fa6638b301ca54af6a21ad927a9fe57558934c2 | [log] [tgz] |
|---|---|---|
| author | Android Build Coastguard Worker <[email protected]> | Sat May 28 01:25:33 2022 +0000 |
| committer | Android Build Coastguard Worker <[email protected]> | Sat May 28 01:25:33 2022 +0000 |
| tree | ba3fa1adc90d93f024d7db5f8a53bf0f8a47d415 | |
| parent | 1b426e3ef4272964e0e3edba60236b454170e09e [diff] | |
| parent | 2446700fa5eb2e680b00535a2288ecc8b90a309d [diff] |
Snap for 8656341 from 2446700fa5eb2e680b00535a2288ecc8b90a309d to tm-d1-release Change-Id: Iee3f2b31ff07d813f50870efb4e0dfa04166f4d4
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.