| commit | dbd774019fb1b07cf62a88111d0f79998fb26232 | [log] [tgz] |
|---|---|---|
| author | Treehugger Robot <treehugger-gerrit@google.com> | Thu May 13 09:49:34 2021 +0000 |
| committer | Gerrit Code Review <noreply-gerritcodereview@google.com> | Thu May 13 09:49:34 2021 +0000 |
| tree | 4811d53b8865a58d94ffc8c09e6422a5f968a85d | |
| parent | 3e180e3dbe38e583697562eec8e45c1dacb55558 [diff] | |
| parent | 90ed1e81d33e9425222016130636c97ca3645d4f [diff] |
Merge "Update todos in derive_classpath.cpp."
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.