commit | b0a7bf909896c43a02a2b58c93e23e232c56b2d7 | [log] [tgz] |
---|---|---|
author | satayev <satayev@google.com> | Tue Oct 19 18:44:27 2021 +0000 |
committer | satayev <satayev@google.com> | Wed Oct 20 16:01:04 2021 +0000 |
tree | 7255d617a7dc5a3a9f90f06c006fcd040109347f | |
parent | c7884214319621e9ce38fcb6ce73608cf2cd3b00 [diff] |
Add default visibility to javatests/. Bug: 203542767 Test: presubmit Change-Id: I520a64c5758462d0329da305148e8c4a95782813
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.
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.