Add an 'init everything' operation to the first backup pass
IBackupTransport.performBackup() now takes a flag "wipeAllFirst", which if set
will result in the entire restore set for the current device/account being wiped
clean prior to the storage of the provided package. This ensures that a device
on which backup has just been enabled will not confront potentially-stale
information, nor will the restore set potentially contain mismatched data from
orphaned packages.
The Backup Manager has also been revised to pass this flag when first backing up
its master metadata block (and never pass it thereafter unless something has
caused the backup state tracking to be erased, e.g. the user has opted out of
backup and then later re-enabled it).
diff --git a/core/java/com/android/internal/backup/IBackupTransport.aidl b/core/java/com/android/internal/backup/IBackupTransport.aidl
index af06965..250bc91 100644
--- a/core/java/com/android/internal/backup/IBackupTransport.aidl
+++ b/core/java/com/android/internal/backup/IBackupTransport.aidl
@@ -77,10 +77,15 @@
* @param data The data stream that resulted from invoking the application's
* BackupService.doBackup() method. This may be a pipe rather than a file on
* persistent media, so it may not be seekable.
+ * @param wipeAllFirst When true, <i>all</i> backed-up data for the current device/account
+ * will be erased prior to the storage of the data provided here. The purpose of this
+ * is to provide a guarantee that no stale data exists in the restore set when the
+ * device begins providing backups.
* @return false if errors occurred (the backup should be aborted and rescheduled),
* true if everything is OK so far (but {@link #finishBackup} must be called).
*/
- boolean performBackup(in PackageInfo packageInfo, in ParcelFileDescriptor inFd);
+ boolean performBackup(in PackageInfo packageInfo, in ParcelFileDescriptor inFd,
+ boolean wipeAllFirst);
/**
* Erase the give application's data from the backup destination. This clears
diff --git a/core/java/com/android/internal/backup/LocalTransport.java b/core/java/com/android/internal/backup/LocalTransport.java
index 2facce2..981ea82 100644
--- a/core/java/com/android/internal/backup/LocalTransport.java
+++ b/core/java/com/android/internal/backup/LocalTransport.java
@@ -56,12 +56,16 @@
return 0;
}
- public boolean performBackup(PackageInfo packageInfo, ParcelFileDescriptor data)
- throws RemoteException {
+ public boolean performBackup(PackageInfo packageInfo, ParcelFileDescriptor data,
+ boolean wipeAllFirst) throws RemoteException {
if (DEBUG) Log.v(TAG, "performBackup() pkg=" + packageInfo.packageName);
File packageDir = new File(mDataDir, packageInfo.packageName);
packageDir.mkdirs();
+ if (wipeAllFirst) {
+ if (DEBUG) Log.v(TAG, "wiping all data first");
+ deleteContents(mDataDir);
+ }
// Each 'record' in the restore set is kept in its own file, named by
// the record key. Wind through the data file, extracting individual
@@ -111,6 +115,21 @@
}
}
+ // Deletes the contents but not the given directory
+ private void deleteContents(File dirname) {
+ File[] contents = dirname.listFiles();
+ if (contents != null) {
+ for (File f : contents) {
+ if (f.isDirectory()) {
+ // delete the directory's contents then fall through
+ // and delete the directory itself.
+ deleteContents(f);
+ }
+ f.delete();
+ }
+ }
+ }
+
public boolean clearBackupData(PackageInfo packageInfo) {
if (DEBUG) Log.v(TAG, "clearBackupData() pkg=" + packageInfo.packageName);