commit | 5e8d97d53db91ff629fbe3da6226d8d2fa333b55 | [log] [tgz] |
---|---|---|
author | Xin Li <delphij@google.com> | Tue Apr 19 04:21:30 2022 +0000 |
committer | Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com> | Tue Apr 19 04:21:30 2022 +0000 |
tree | e50c12e8b3534b7b518c8f4abdc1c8588eacfd03 | |
parent | c407a86b3ccabc12e05788c2601096cd5bc8c970 [diff] | |
parent | e4463aff5ddd991cd4d5b77af18feba3e1b6293c [diff] |
[automerger skipped] Empty merge of sc-v2-dev-plus-aosp-without-vendor@8433047 am: e4463aff5d -s ours am skip reason: Merged-In I11f450eeae532c9a2140195ad129200c095015ea with SHA-1 9f6dd556bc is already in history Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/modules/SdkExtensions/+/17805279 Change-Id: If5b159ed6806b9c791b08f1736d6c271eb77ef02 Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>
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.