| commit | d5938338e987cf717540bb95849f90acdfb4b512 | [log] [tgz] |
|---|---|---|
| author | Anton Hansson <hansson@google.com> | Tue May 04 09:28:09 2021 +0000 |
| committer | Anton Hansson <hansson@google.com> | Tue May 04 09:28:09 2021 +0000 |
| tree | 45b0ee4d421aa5361d4acbf6db1b0c342dae0bc8 | |
| parent | b5454aa2e549be5e6827c13c0afdd99e9daa4f4f [diff] |
Revert^2 "Change ALL_EXTENSIONS depending on API level" b5454aa2e549be5e6827c13c0afdd99e9daa4f4f Change-Id: Ibdacfe79526415f9a1bc644d901b0e39878352f6
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.binarypb 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.RollbackManagerServiceImpl#getExtensionVersions to account for the new extension version.