javalib/src/android/system/virtualmachine/VirtualMachineDescriptor.java

/*
 * Copyright 2022 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package android.system.virtualmachine;

import static java.util.Objects.requireNonNull;

import android.annotation.NonNull;
import android.os.Parcel;
import android.os.ParcelFileDescriptor;
import android.os.Parcelable;

import com.android.internal.annotations.VisibleForTesting;

/**
 * A VM descriptor that captures the state of a Virtual Machine.
 *
 * <p>You can capture the current state of VM by creating an instance of this class with {@link
 * VirtualMachine#toDescriptor()}, optionally pass it to another App, and then build an identical VM
 * with the descriptor received.
 *
 * @hide
 */
public final class VirtualMachineDescriptor implements Parcelable {
    private final @NonNull ParcelFileDescriptor mConfigFd;
    private final @NonNull ParcelFileDescriptor mInstanceImgFd;
    // TODO(b/243129654): Add trusted storage fd once it is available.

    @Override
    public int describeContents() {
        return CONTENTS_FILE_DESCRIPTOR;
    }

    @Override
    public void writeToParcel(Parcel out, int flags) {
        mConfigFd.writeToParcel(out, flags);
        mInstanceImgFd.writeToParcel(out, flags);
    }

    public static final Parcelable.Creator<VirtualMachineDescriptor> CREATOR =
            new Parcelable.Creator<VirtualMachineDescriptor>() {
                public VirtualMachineDescriptor createFromParcel(Parcel in) {
                    return new VirtualMachineDescriptor(in);
                }

                public VirtualMachineDescriptor[] newArray(int size) {
                    return new VirtualMachineDescriptor[size];
                }
            };

    /**
     * @return File descriptor of the VM configuration file config.xml.
     * @hide
     */
    @VisibleForTesting
    public @NonNull ParcelFileDescriptor getConfigFd() {
        return mConfigFd;
    }

    /**
     * @return File descriptor of the instance.img of the VM.
     * @hide
     */
    @VisibleForTesting
    public @NonNull ParcelFileDescriptor getInstanceImgFd() {
        return mInstanceImgFd;
    }

    VirtualMachineDescriptor(
            @NonNull ParcelFileDescriptor configFd, @NonNull ParcelFileDescriptor instanceImgFd) {
        mConfigFd = configFd;
        mInstanceImgFd = instanceImgFd;
    }

    private VirtualMachineDescriptor(Parcel in) {
        mConfigFd = requireNonNull(in.readFileDescriptor());
        mInstanceImgFd = requireNonNull(in.readFileDescriptor());
    }
}