Pass the originating app's versionCode along with a restore set

This change amends the doRestore() / onRestore() interface to backup agents to
provide the integer android:versionCode of the app that stored the backup set.
This should help agents figure out how to handle whatever historical data set
they're handed at restore time.

core/java/android/app/BackupAgent.java

@@ -78,11 +78,16 @@ public abstract class BackupAgent extends ContextWrapper {
      *
      * @param data An open, read-only ParcelFileDescriptor pointing to a full snapshot
      *             of the application's data.
+     * @param appVersionCode The android:versionCode value of the application that backed
+     *        up this particular data set.  This makes it easier for an application's
+     *        agent to distinguish among several possible older data versions when
+     *        asked to perform the restore operation.
      * @param newState An open, read/write ParcelFileDescriptor pointing to an empty
      *                 file.  The application should record the final backup state
      *                 here after restoring its data from dataFd.
      */
-    public abstract void onRestore(BackupDataInput data, ParcelFileDescriptor newState)
+    public abstract void onRestore(BackupDataInput data, int appVersionCode,
+            ParcelFileDescriptor newState)
             throws IOException;
 
 
@@ -121,13 +126,13 @@ public abstract class BackupAgent extends ContextWrapper {
             }
         }
 
-        public void doRestore(ParcelFileDescriptor data,
+        public void doRestore(ParcelFileDescriptor data, int appVersionCode,
                 ParcelFileDescriptor newState) throws RemoteException {
             // !!! TODO - real implementation; for now just invoke the callbacks directly
             Log.v(TAG, "doRestore() invoked");
             BackupDataInput input = new BackupDataInput(data.getFileDescriptor());
             try {
-                BackupAgent.this.onRestore(input, newState);
+                BackupAgent.this.onRestore(input, appVersionCode, newState);
             } catch (IOException ex) {
                 Log.d(TAG, "onRestore (" + BackupAgent.this.getClass().getName() + ") threw", ex);
                 throw new RuntimeException(ex);

core/java/android/app/FullBackupAgent.java

@@ -53,6 +53,6 @@ public class FullBackupAgent extends BackupAgent {
     }
 
     @Override
-    public void onRestore(BackupDataInput data, ParcelFileDescriptor newState) {
+    public void onRestore(BackupDataInput data, int appVersionCode, ParcelFileDescriptor newState) {
     }
 }

core/java/android/app/IBackupAgent.aidl

@@ -51,9 +51,14 @@ interface IBackupAgent {
      *        app's backup.  This is to be a <i>replacement</i> of the app's
      *        current data, not to be merged into it.
      *
+     * @param appVersionCode The android:versionCode attribute of the application
+     *        that created this data set.  This can help the agent distinguish among
+     *        various historical backup content possibilities.
+     *
      * @param newState Read-write file, empty when onRestore() is called,
      *        that is to be written with the state description that holds after
      *        the restore has been completed.
      */
-    void doRestore(in ParcelFileDescriptor data, in ParcelFileDescriptor newState);
+    void doRestore(in ParcelFileDescriptor data, int appVersionCode,
+            in ParcelFileDescriptor newState);
 }

core/java/android/backup/BackupHelperAgent.java

@@ -39,9 +39,9 @@ public class BackupHelperAgent extends BackupAgent {
     }
 
     @Override
-    public void onRestore(BackupDataInput data, ParcelFileDescriptor newState)
+    public void onRestore(BackupDataInput data, int appVersionCode, ParcelFileDescriptor newState)
             throws IOException {
-        mDispatcher.performRestore(data, newState);
+        mDispatcher.performRestore(data, appVersionCode, newState);
     }
 
     public BackupHelperDispatcher getDispatcher() {

core/java/android/backup/BackupHelperDispatcher.java

@@ -46,7 +46,8 @@ public class BackupHelperDispatcher {
         }
     }
 
-    public void performRestore(BackupDataInput input, ParcelFileDescriptor newState)
+    public void performRestore(BackupDataInput input, int appVersionCode,
+            ParcelFileDescriptor newState)
             throws IOException {
         boolean alreadyComplained = false;
 

core/java/android/backup/IBackupManager.aidl

@@ -33,19 +33,19 @@ interface IBackupManager {
      * Tell the system service that the caller has made changes to its
      * data, and therefore needs to undergo an incremental backup pass.
      */
-    oneway void dataChanged(String packageName);
+    void dataChanged(String packageName);
 
     /**
      * Notifies the Backup Manager Service that an agent has become available.  This
      * method is only invoked by the Activity Manager.
      */
-    oneway void agentConnected(String packageName, IBinder agent);
+    void agentConnected(String packageName, IBinder agent);
 
     /**
      * Notify the Backup Manager Service that an agent has unexpectedly gone away.
      * This method is only invoked by the Activity Manager.
      */
-    oneway void agentDisconnected(String packageName);
+    void agentDisconnected(String packageName);
 
     /**
      * Schedule an immediate backup attempt for all pending updates.  This is
@@ -57,7 +57,7 @@ interface IBackupManager {
      *
      * <p>Callers must hold the android.permission.BACKUP permission to use this method.
      */
-    oneway void backupNow();
+    void backupNow();
 
     /**
      * Identify the currently selected transport.  Callers must hold the