services/core/java/com/android/server/compat/CompatChange.java - platform/frameworks/base - Git at Google

 /*
  * Copyright (C) 2019 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 com.android.server.compat;

 import android.annotation.Nullable;
 import android.compat.annotation.ChangeId;
 import android.compat.annotation.EnabledSince;
 import android.content.pm.ApplicationInfo;

 import com.android.internal.compat.CompatibilityChangeInfo;
 import com.android.server.compat.config.Change;

 import java.util.HashMap;
 import java.util.Map;

 /**
  * Represents the state of a single compatibility change.
  *
  * <p>A compatibility change has a default setting, determined by the {@code enableAfterTargetSdk}
  * and {@code disabled} constructor parameters. If a change is {@code disabled}, this overrides any
  * target SDK criteria set. These settings can be overridden for a specific package using
  * {@link #addPackageOverride(String, boolean)}.
  *
  * <p>Note, this class is not thread safe so callers must ensure thread safety.
  */
 public final class CompatChange extends CompatibilityChangeInfo {

     /**
      * A change ID to be used only in the CTS test for this SystemApi
      */
     @ChangeId
     @EnabledSince(targetSdkVersion = 1235) // Needs to be > test APK targetSdkVersion.
     static final long CTS_SYSTEM_API_CHANGEID = 149391281; // This is a bug id.

     /**
      * Callback listener for when compat changes are updated for a package.
      * See {@link #registerListener(ChangeListener)} for more details.
      */
     public interface ChangeListener {
         /**
          * Called upon an override change for packageName and the change this listener is
          * registered for. Called before the app is killed.
          */
         void onCompatChange(String packageName);
     }

     ChangeListener mListener = null;

     private Map<String, Boolean> mPackageOverrides;
     private Map<String, Boolean> mDeferredOverrides;

     public CompatChange(long changeId) {
         this(changeId, null, -1, -1, false, false, null, false);
     }

     /**
      * @param changeId Unique ID for the change. See {@link android.compat.Compatibility}.
      * @param name Short descriptive name.
      * @param enableAfterTargetSdk {@code targetSdkVersion} restriction. See {@link EnabledAfter};
      *                             -1 if the change is always enabled.
      * @param enableSinceTargetSdk {@code targetSdkVersion} restriction. See {@link EnabledSince};
      *                             -1 if the change is always enabled.
      * @param disabled If {@code true}, overrides any {@code enableAfterTargetSdk} set.
      */
     public CompatChange(long changeId, @Nullable String name, int enableAfterTargetSdk,
             int enableSinceTargetSdk, boolean disabled, boolean loggingOnly, String description,
             boolean overridable) {
         super(changeId, name, enableAfterTargetSdk, enableSinceTargetSdk, disabled, loggingOnly,
               description, overridable);
     }

     /**
      * @param change an object generated by services/core/xsd/platform-compat-config.xsd
      */
     public CompatChange(Change change) {
         super(change.getId(), change.getName(), change.getEnableAfterTargetSdk(),
                 change.getEnableSinceTargetSdk(), change.getDisabled(), change.getLoggingOnly(),
                 change.getDescription(), change.getOverridable());
     }

     void registerListener(ChangeListener listener) {
         if (mListener != null) {
             throw new IllegalStateException(
                     "Listener for change " + toString() + " already registered.");
         }
         mListener = listener;
     }


     /**
      * Force the enabled state of this change for a given package name. The change will only take
      * effect after that packages process is killed and restarted.
      *
      * <p>Note, this method is not thread safe so callers must ensure thread safety.
      *
      * @param pname Package name to enable the change for.
      * @param enabled Whether or not to enable the change.
      */
     void addPackageOverride(String pname, boolean enabled) {
         if (getLoggingOnly()) {
             throw new IllegalArgumentException(
                     "Can't add overrides for a logging only change " + toString());
         }
         if (mPackageOverrides == null) {
             mPackageOverrides = new HashMap<>();
         }
         mPackageOverrides.put(pname, enabled);
         notifyListener(pname);
     }

     /**
      * Tentatively set the state of this change for a given package name.
      * The override will only take effect after that package is installed, if applicable.
      *
      * <p>Note, this method is not thread safe so callers must ensure thread safety.
      *
      * @param packageName Package name to tentatively enable the change for.
      * @param enabled Whether or not to enable the change.
      */
     void addPackageDeferredOverride(String packageName, boolean enabled) {
         if (getLoggingOnly()) {
             throw new IllegalArgumentException(
                     "Can't add overrides for a logging only change " + toString());
         }
         if (mDeferredOverrides == null) {
             mDeferredOverrides = new HashMap<>();
         }
         mDeferredOverrides.put(packageName, enabled);
     }

     /**
      * Rechecks an existing (and possibly deferred) override.
      *
      * <p>For deferred overrides, check if they can be promoted to a regular override. For regular
      * overrides, check if they need to be demoted to deferred.</p>
      *
      * @param packageName Package name to apply deferred overrides for.
      * @param allowed Whether the override is allowed.
      *
      * @return {@code true} if the recheck yielded a result that requires invalidating caches
      *         (a deferred override was consolidated or a regular override was removed).
      */
     boolean recheckOverride(String packageName, boolean allowed) {
         // A deferred override now is allowed by the policy, so promote it to a regular override.
         if (hasDeferredOverride(packageName) && allowed) {
             boolean overrideValue = mDeferredOverrides.remove(packageName);
             addPackageOverride(packageName, overrideValue);
             return true;
         }
         // A previously set override is no longer allowed by the policy, so make it deferred.
         if (hasOverride(packageName) && !allowed) {
             boolean overrideValue = mPackageOverrides.remove(packageName);
             addPackageDeferredOverride(packageName, overrideValue);
             // Notify because the override was removed.
             notifyListener(packageName);
             return true;
         }
         return false;
     }

     /**
      * Remove any package override for the given package name, restoring the default behaviour.
      *
      * <p>Note, this method is not thread safe so callers must ensure thread safety.
      *
      * @param pname Package name to reset to defaults for.
      */
     void removePackageOverride(String pname) {
         if (mPackageOverrides != null) {
             if (mPackageOverrides.remove(pname) != null) {
                 notifyListener(pname);
             }
         }
         if (mDeferredOverrides != null) {
             mDeferredOverrides.remove(pname);
         }
     }

     /**
      * Find if this change is enabled for the given package, taking into account any overrides that
      * exist.
      *
      * @param app Info about the app in question
      * @return {@code true} if the change should be enabled for the package.
      */
     boolean isEnabled(ApplicationInfo app) {
         if (app == null) {
             return defaultValue();
         }
         if (mPackageOverrides != null && mPackageOverrides.containsKey(app.packageName)) {
             return mPackageOverrides.get(app.packageName);
         }
         if (getDisabled()) {
             return false;
         }
         if (getEnableSinceTargetSdk() != -1) {
             return app.targetSdkVersion >= getEnableSinceTargetSdk();
         }
         return true;
     }

     /**
      * Find if this change will be enabled for the given package after installation.
      *
      * @param packageName The package name in question
      * @return {@code true} if the change should be enabled for the package.
      */
     boolean willBeEnabled(String packageName) {
         if (hasDeferredOverride(packageName)) {
             return mDeferredOverrides.get(packageName);
         }
         return defaultValue();
     }

     /**
      * Returns the default value for the change id, assuming there are no overrides.
      *
      * @return {@code false} if it's a default disabled change, {@code true} otherwise.
      */
     boolean defaultValue() {
         return !getDisabled();
     }

     /**
      * Checks whether a change has an override for a package.
      * @param packageName name of the package
      * @return true if there is such override
      */
     boolean hasOverride(String packageName) {
         return mPackageOverrides != null && mPackageOverrides.containsKey(packageName);
     }

     /**
      * Checks whether a change has a deferred override for a package.
      * @param packageName name of the package
      * @return true if there is such a deferred override
      */
     boolean hasDeferredOverride(String packageName) {
         return mDeferredOverrides != null && mDeferredOverrides.containsKey(packageName);
     }

     @Override
     public String toString() {
         StringBuilder sb = new StringBuilder("ChangeId(")
                 .append(getId());
         if (getName() != null) {
             sb.append("; name=").append(getName());
         }
         if (getEnableSinceTargetSdk() != -1) {
             sb.append("; enableSinceTargetSdk=").append(getEnableSinceTargetSdk());
         }
         if (getDisabled()) {
             sb.append("; disabled");
         }
         if (getLoggingOnly()) {
             sb.append("; loggingOnly");
         }
         if (mPackageOverrides != null && mPackageOverrides.size() > 0) {
             sb.append("; packageOverrides=").append(mPackageOverrides);
         }
         if (mDeferredOverrides != null && mDeferredOverrides.size() > 0) {
             sb.append("; deferredOverrides=").append(mDeferredOverrides);
         }
         if (getOverridable()) {
             sb.append("; overridable");
         }
         return sb.append(")").toString();
     }

     private void notifyListener(String packageName) {
         if (mListener != null) {
             mListener.onCompatChange(packageName);
         }
     }
 }
	/*
	* Copyright (C) 2019 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 com.android.server.compat;

	import android.annotation.Nullable;
	import android.compat.annotation.ChangeId;
	import android.compat.annotation.EnabledSince;
	import android.content.pm.ApplicationInfo;

	import com.android.internal.compat.CompatibilityChangeInfo;
	import com.android.server.compat.config.Change;

	import java.util.HashMap;
	import java.util.Map;

	/**
	* Represents the state of a single compatibility change.
	*
	* <p>A compatibility change has a default setting, determined by the {@code enableAfterTargetSdk}
	* and {@code disabled} constructor parameters. If a change is {@code disabled}, this overrides any
	* target SDK criteria set. These settings can be overridden for a specific package using
	* {@link #addPackageOverride(String, boolean)}.
	*
	* <p>Note, this class is not thread safe so callers must ensure thread safety.
	*/
	public final class CompatChange extends CompatibilityChangeInfo {

	/**
	* A change ID to be used only in the CTS test for this SystemApi
	*/
	@ChangeId
	@EnabledSince(targetSdkVersion = 1235) // Needs to be > test APK targetSdkVersion.
	static final long CTS_SYSTEM_API_CHANGEID = 149391281; // This is a bug id.

	/**
	* Callback listener for when compat changes are updated for a package.
	* See {@link #registerListener(ChangeListener)} for more details.
	*/
	public interface ChangeListener {
	/**
	* Called upon an override change for packageName and the change this listener is
	* registered for. Called before the app is killed.
	*/
	void onCompatChange(String packageName);
	}

	ChangeListener mListener = null;

	private Map<String, Boolean> mPackageOverrides;
	private Map<String, Boolean> mDeferredOverrides;

	public CompatChange(long changeId) {
	this(changeId, null, -1, -1, false, false, null, false);
	}

	/**
	* @param changeId Unique ID for the change. See {@link android.compat.Compatibility}.
	* @param name Short descriptive name.
	* @param enableAfterTargetSdk {@code targetSdkVersion} restriction. See {@link EnabledAfter};
	* -1 if the change is always enabled.
	* @param enableSinceTargetSdk {@code targetSdkVersion} restriction. See {@link EnabledSince};
	* -1 if the change is always enabled.
	* @param disabled If {@code true}, overrides any {@code enableAfterTargetSdk} set.
	*/
	public CompatChange(long changeId, @Nullable String name, int enableAfterTargetSdk,
	int enableSinceTargetSdk, boolean disabled, boolean loggingOnly, String description,
	boolean overridable) {
	super(changeId, name, enableAfterTargetSdk, enableSinceTargetSdk, disabled, loggingOnly,
	description, overridable);
	}

	/**
	* @param change an object generated by services/core/xsd/platform-compat-config.xsd
	*/
	public CompatChange(Change change) {
	super(change.getId(), change.getName(), change.getEnableAfterTargetSdk(),
	change.getEnableSinceTargetSdk(), change.getDisabled(), change.getLoggingOnly(),
	change.getDescription(), change.getOverridable());
	}

	void registerListener(ChangeListener listener) {
	if (mListener != null) {
	throw new IllegalStateException(
	"Listener for change " + toString() + " already registered.");
	}
	mListener = listener;
	}


	/**
	* Force the enabled state of this change for a given package name. The change will only take
	* effect after that packages process is killed and restarted.
	*
	* <p>Note, this method is not thread safe so callers must ensure thread safety.
	*
	* @param pname Package name to enable the change for.
	* @param enabled Whether or not to enable the change.
	*/
	void addPackageOverride(String pname, boolean enabled) {
	if (getLoggingOnly()) {
	throw new IllegalArgumentException(
	"Can't add overrides for a logging only change " + toString());
	}
	if (mPackageOverrides == null) {
	mPackageOverrides = new HashMap<>();
	}
	mPackageOverrides.put(pname, enabled);
	notifyListener(pname);
	}

	/**
	* Tentatively set the state of this change for a given package name.
	* The override will only take effect after that package is installed, if applicable.
	*
	* <p>Note, this method is not thread safe so callers must ensure thread safety.
	*
	* @param packageName Package name to tentatively enable the change for.
	* @param enabled Whether or not to enable the change.
	*/
	void addPackageDeferredOverride(String packageName, boolean enabled) {
	if (getLoggingOnly()) {
	throw new IllegalArgumentException(
	"Can't add overrides for a logging only change " + toString());
	}
	if (mDeferredOverrides == null) {
	mDeferredOverrides = new HashMap<>();
	}
	mDeferredOverrides.put(packageName, enabled);
	}

	/**
	* Rechecks an existing (and possibly deferred) override.
	*
	* <p>For deferred overrides, check if they can be promoted to a regular override. For regular
	* overrides, check if they need to be demoted to deferred.</p>
	*
	* @param packageName Package name to apply deferred overrides for.
	* @param allowed Whether the override is allowed.
	*
	* @return {@code true} if the recheck yielded a result that requires invalidating caches
	* (a deferred override was consolidated or a regular override was removed).
	*/
	boolean recheckOverride(String packageName, boolean allowed) {
	// A deferred override now is allowed by the policy, so promote it to a regular override.
	if (hasDeferredOverride(packageName) && allowed) {
	boolean overrideValue = mDeferredOverrides.remove(packageName);
	addPackageOverride(packageName, overrideValue);
	return true;
	}
	// A previously set override is no longer allowed by the policy, so make it deferred.
	if (hasOverride(packageName) && !allowed) {
	boolean overrideValue = mPackageOverrides.remove(packageName);
	addPackageDeferredOverride(packageName, overrideValue);
	// Notify because the override was removed.
	notifyListener(packageName);
	return true;
	}
	return false;
	}

	/**
	* Remove any package override for the given package name, restoring the default behaviour.
	*
	* <p>Note, this method is not thread safe so callers must ensure thread safety.
	*
	* @param pname Package name to reset to defaults for.
	*/
	void removePackageOverride(String pname) {
	if (mPackageOverrides != null) {
	if (mPackageOverrides.remove(pname) != null) {
	notifyListener(pname);
	}
	}
	if (mDeferredOverrides != null) {
	mDeferredOverrides.remove(pname);
	}
	}

	/**
	* Find if this change is enabled for the given package, taking into account any overrides that
	* exist.
	*
	* @param app Info about the app in question
	* @return {@code true} if the change should be enabled for the package.
	*/
	boolean isEnabled(ApplicationInfo app) {
	if (app == null) {
	return defaultValue();
	}
	if (mPackageOverrides != null && mPackageOverrides.containsKey(app.packageName)) {
	return mPackageOverrides.get(app.packageName);
	}
	if (getDisabled()) {
	return false;
	}
	if (getEnableSinceTargetSdk() != -1) {
	return app.targetSdkVersion >= getEnableSinceTargetSdk();
	}
	return true;
	}

	/**
	* Find if this change will be enabled for the given package after installation.
	*
	* @param packageName The package name in question
	* @return {@code true} if the change should be enabled for the package.
	*/
	boolean willBeEnabled(String packageName) {
	if (hasDeferredOverride(packageName)) {
	return mDeferredOverrides.get(packageName);
	}
	return defaultValue();
	}

	/**
	* Returns the default value for the change id, assuming there are no overrides.
	*
	* @return {@code false} if it's a default disabled change, {@code true} otherwise.
	*/
	boolean defaultValue() {
	return !getDisabled();
	}

	/**
	* Checks whether a change has an override for a package.
	* @param packageName name of the package
	* @return true if there is such override
	*/
	boolean hasOverride(String packageName) {
	return mPackageOverrides != null && mPackageOverrides.containsKey(packageName);
	}

	/**
	* Checks whether a change has a deferred override for a package.
	* @param packageName name of the package
	* @return true if there is such a deferred override
	*/
	boolean hasDeferredOverride(String packageName) {
	return mDeferredOverrides != null && mDeferredOverrides.containsKey(packageName);
	}

	@Override
	public String toString() {
	StringBuilder sb = new StringBuilder("ChangeId(")
	.append(getId());
	if (getName() != null) {
	sb.append("; name=").append(getName());
	}
	if (getEnableSinceTargetSdk() != -1) {
	sb.append("; enableSinceTargetSdk=").append(getEnableSinceTargetSdk());
	}
	if (getDisabled()) {
	sb.append("; disabled");
	}
	if (getLoggingOnly()) {
	sb.append("; loggingOnly");
	}
	if (mPackageOverrides != null && mPackageOverrides.size() > 0) {
	sb.append("; packageOverrides=").append(mPackageOverrides);
	}
	if (mDeferredOverrides != null && mDeferredOverrides.size() > 0) {
	sb.append("; deferredOverrides=").append(mDeferredOverrides);
	}
	if (getOverridable()) {
	sb.append("; overridable");
	}
	return sb.append(")").toString();
	}

	private void notifyListener(String packageName) {
	if (mListener != null) {
	mListener.onCompatChange(packageName);
	}
	}
	}