commit | 518b446ae165730ec8022af24f268991eeb6fb93 | [log] [tgz] |
---|---|---|
author | Treehugger Robot <treehugger-gerrit@google.com> | Thu May 13 10:24:16 2021 +0000 |
committer | Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com> | Thu May 13 10:24:16 2021 +0000 |
tree | e249afc86e6e3b66101f089f1d28236d3c7ca64e | |
parent | 75bfa6b337aeaf73d4f9de8c7983bdeb1b676970 [diff] | |
parent | 78767716ecc6c206c58a67b0dafb43d64ab0a96a [diff] |
Merge "Update todos in derive_classpath.cpp." am: dbd774019f am: 78767716ec Original change: https://android-review.googlesource.com/c/platform/packages/modules/SdkExtensions/+/1705825 Change-Id: Ifdfc9f88b7fbf15cf66153e65f65bbac5cc1afe6
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.