Fix binder exception when restoring a large number of applications
diff --git a/app/src/main/java/com/stevesoltys/seedvault/restore/RestoreViewModel.kt b/app/src/main/java/com/stevesoltys/seedvault/restore/RestoreViewModel.kt
index 03e6b70..1e7263f 100644
--- a/app/src/main/java/com/stevesoltys/seedvault/restore/RestoreViewModel.kt
+++ b/app/src/main/java/com/stevesoltys/seedvault/restore/RestoreViewModel.kt
@@ -1,6 +1,7 @@
package com.stevesoltys.seedvault.restore
import android.app.Application
+import android.app.backup.BackupTransport
import android.app.backup.IBackupManager
import android.app.backup.IRestoreObserver
import android.app.backup.IRestoreSession
@@ -64,11 +65,10 @@
import org.calyxos.backup.storage.restore.RestoreService.Companion.EXTRA_USER_ID
import org.calyxos.backup.storage.ui.restore.SnapshotViewModel
import java.util.LinkedList
-import kotlin.math.min
private val TAG = RestoreViewModel::class.java.simpleName
-internal const val PACKAGES_PER_CHUNK = 100
+internal const val PACKAGES_PER_CHUNK = 10
internal class RestoreViewModel(
app: Application,
@@ -140,6 +140,7 @@
Log.d(TAG, "Ignoring RestoreSet with no last backup time: $token.")
null
}
+
else -> RestorableBackup(metadata)
}
}
@@ -203,12 +204,13 @@
return
}
- // we need to retrieve the restore sets before starting the restore
- // otherwise restorePackages() won't work as they need the restore sets cached internally
- val packages = mChosenRestorableBackup.value?.packageMetadataMap?.keys?.toMutableList()
- ?: mutableListOf()
- // The chunked restoration is performed within the RestoreObserver.
+ // We need to retrieve the restore sets before starting the restore.
+ // Otherwise, restorePackages() won't work as they need the restore sets cached internally.
+ val packages = mChosenRestorableBackup.value?.packageMetadataMap?.keys?.toList()
+ ?: emptyList()
+
val observer = RestoreObserver(session, token, packages, monitor)
+
if (session.getAvailableRestoreSets(observer, monitor) != 0) {
Log.e(TAG, "getAvailableRestoreSets() returned non-zero value")
mRestoreBackupResult.postValue(
@@ -225,6 +227,7 @@
// check previous package first and change status
updateLatestPackage(list)
+
// add current package
list.addFirst(AppRestoreResult(packageName, getAppName(app, packageName), IN_PROGRESS))
mRestoreProgress.postValue(list)
@@ -293,11 +296,18 @@
private inner class RestoreObserver(
private val session: IRestoreSession,
private val token: Long,
- private val packages: MutableList<String>,
- private val monitor: BackupMonitor
+ private val packages: List<String>,
+ private val monitor: BackupMonitor,
) : IRestoreObserver.Stub() {
/**
+ * The current package index.
+ *
+ * Used for splitting the packages into chunks.
+ */
+ private var packageIndex: Int = 0
+
+ /**
* Supply a list of the restore datasets available from the current transport.
* This method is invoked as a callback following the application's use of the
* [IRestoreSession.getAvailableRestoreSets] method.
@@ -312,14 +322,20 @@
restoreNextPackages()
}
+ /**
+ * Restore the next chunk of packages.
+ *
+ * We need to restore in chunks, otherwise [BackupTransport.startRestore] in the
+ * framework's [PerformUnifiedRestoreTask] may fail due to an oversize Binder
+ * transaction, causing the entire restoration to fail.
+ */
private fun restoreNextPackages() {
- // Packages are restored in chunks, or else transport.startRestore() in the framework's
- // PerformUnifiedRestoreTask.java may fail due to an oversized Binder transaction,
- // causing the entire restoration to fail.
- val packagesChunk = packages.subList(0, min(packages.size, PACKAGES_PER_CHUNK))
- val result =
- session.restorePackages(token, this, packagesChunk.toTypedArray(), monitor)
- packagesChunk.clear()
+ val chunkSize = (packageIndex + PACKAGES_PER_CHUNK).coerceAtMost(packages.size)
+ val packageChunk = packages.subList(packageIndex, chunkSize).toTypedArray()
+ packageIndex += packageChunk.size
+
+ val result = session.restorePackages(token, this, packageChunk, monitor)
+
if (result != 0) {
Log.e(TAG, "restorePackages() returned non-zero value")
}
@@ -356,10 +372,13 @@
* as a whole failed.
*/
override fun restoreFinished(result: Int) {
- if (result == 0 && packages.size > 0) {
+
+ // Restore next chunk if successful and there are more packages to restore.
+ if (result == 0 && packageIndex < packages.size) {
restoreNextPackages()
return
}
+
val restoreResult = RestoreBackupResult(
if (result == 0) null
else app.getString(R.string.restore_finished_error)