62e3308879
The library has been built without SDK, and is used by an app GtsCastV2SignerApp that is built with SDK. Such this SDK -> non-SDK dependency has been causing link-type check warnings, which will turn into errors soon. This change fixes the warning by making a stub library com.android.mediadrm.signer.stubs from the runtime library and let the app to link against the stub library. Since the stubs library does not use any private APIs, it is built with SDK. Bug: 69899800 Test: m -j GtsCastV2SignerApp is successful and does not show any link-type check warning. Change-Id: I8a95cc3b14eb2fc4ca90b66aee002f77099187c4
38 lines
1.9 KiB
Plaintext
38 lines
1.9 KiB
Plaintext
There are two libraries defined in this directory:
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First, com.android.mediadrm.signer.jar is a shared java library
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containing classes required by unbundled apps running on devices that use
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the certficate provisioning and private key signing capabilities provided
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by the MediaDrm API.
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Second, com.android.mediadrm.signer.stubs.jar is a stub for the shared library
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which provides build-time APIs to the unbundled clients.
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At runtime, the shared library is added to the classloader of the app via the
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<uses-library> tag. And since Java always tries to load a class from the
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parent classloader, regardless of whether the stub library is linked to the
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app statically or dynamically, the real classes are loaded from the shared
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library.
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--- Rules of this library ---
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o The stub library is effectively a PUBLIC API for unbundled CAST receivers
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that may be distributed outside the system image. So it MUST BE API STABLE.
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You can add but not remove. The rules are the same as for the
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public platform SDK API.
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o This library can see and instantiate internal platform classes, but it must not
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expose them in any public method (or by extending them via inheritance). This would
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break clients of the library because they cannot see the internal platform classes.
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This library is distributed in the system image, and loaded as
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a shared library. So you can change the implementation, but not
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the interface. In this way it is like framework.jar.
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--- Why does this library exist? ---
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Unbundled apps cannot use internal platform classes.
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This library will eventually be replaced when the provisioned certificate-
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based signing infrastructure that is currently defined in the support library
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is reintegrated with the framework in a new API. That API isn't ready yet so
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this library is a compromise to make new capabilities available to the system
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without exposing the full surface area of the support library.
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