Use BackupManagerMonitor to handle K/V with no data changed

The fake package manager package is essential for the backup, but when its data doesn't change and we request a normal incremental backup, it doesn't get included, because our transport doesn't even get called for it. Only the BackupMonitor gets a hint that it had no (new?) data via LOG_EVENT_ID_NO_DATA_TO_SEND. This behavior started with Android 15 that fixed a bug that caused @pm@ to always backup. However, other K/V apps were probably affected before.
seedvault-app · Oct 7, 2024 · 1c3af13 · 1c3af13
1 parent f3f710c
commit 1c3af13
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diff --git a/app/src/main/java/com/stevesoltys/seedvault/BackupMonitor.kt b/app/src/main/java/com/stevesoltys/seedvault/BackupMonitor.kt
@@ -17,18 +17,26 @@ import android.util.Log.DEBUG
 
 private val TAG = BackupMonitor::class.java.name
 
-class BackupMonitor : IBackupManagerMonitor.Stub() {
+open class BackupMonitor : IBackupManagerMonitor.Stub() {
 
     override fun onEvent(bundle: Bundle) {
-        val id = bundle.getInt(EXTRA_LOG_EVENT_ID)
-        val packageName = bundle.getString(EXTRA_LOG_EVENT_PACKAGE_NAME, "?")
+        onEvent(
+            id = bundle.getInt(EXTRA_LOG_EVENT_ID),
+            category = bundle.getInt(EXTRA_LOG_EVENT_CATEGORY),
+            packageName = bundle.getString(EXTRA_LOG_EVENT_PACKAGE_NAME)
+                ?: error("no package name for $bundle"),
+            bundle = bundle,
+        )
+    }
+
+    open fun onEvent(id: Int, category: Int, packageName: String, bundle: Bundle) {
         if (id == LOG_EVENT_ID_ERROR_PREFLIGHT) {
             val preflightResult = bundle.getLong(EXTRA_LOG_PREFLIGHT_ERROR, -1)
             Log.w(TAG, "Pre-flight error from $packageName: $preflightResult")
         }
         if (!Log.isLoggable(TAG, DEBUG)) return
         Log.d(TAG, "ID: $id")
-        Log.d(TAG, "CATEGORY: " + bundle.getInt(EXTRA_LOG_EVENT_CATEGORY, -1))
+        Log.d(TAG, "CATEGORY: $category")
         Log.d(TAG, "PACKAGE: $packageName")
     }
 

diff --git a/app/src/main/java/com/stevesoltys/seedvault/metadata/Metadata.kt b/app/src/main/java/com/stevesoltys/seedvault/metadata/Metadata.kt
@@ -121,11 +121,7 @@ data class PackageMetadata(
     companion object {
         fun fromSnapshot(app: Snapshot.App) = PackageMetadata(
             time = app.time,
-            backupType = when (app.type) {
-                Snapshot.BackupType.FULL -> BackupType.FULL
-                Snapshot.BackupType.KV -> BackupType.KV
-                else -> null
-            },
+            backupType = app.type.toBackupType(),
             name = app.name,
             chunkIds = app.chunkIdsList.hexFromProto(),
             system = app.system,
@@ -153,6 +149,12 @@ data class PackageMetadata(
                 it.isNotEmpty()
             },
         )
+
+        fun Snapshot.BackupType.toBackupType() = when (this) {
+            Snapshot.BackupType.FULL -> BackupType.FULL
+            Snapshot.BackupType.KV -> BackupType.KV
+            else -> null
+        }
     }
 
     val isInternalSystem: Boolean = system && !isLaunchableSystemApp

diff --git a/app/src/main/java/com/stevesoltys/seedvault/metadata/MetadataManager.kt b/app/src/main/java/com/stevesoltys/seedvault/metadata/MetadataManager.kt
@@ -53,16 +53,13 @@ internal class MetadataManager(
     /**
      * Call this after a package has been backed up successfully.
      *
-     * It updates the packages' metadata
-     * and writes it encrypted to the given [OutputStream] as well as the internal cache.
-     *
-     * Closing the [OutputStream] is the responsibility of the caller.
+     * It updates the packages' metadata.
      */
     @Synchronized
     @Throws(IOException::class)
     fun onPackageBackedUp(
         packageInfo: PackageInfo,
-        type: BackupType,
+        type: BackupType?,
         size: Long?,
     ) {
         val packageName = packageInfo.packageName

diff --git a/app/src/main/java/com/stevesoltys/seedvault/repo/SnapshotCreator.kt b/app/src/main/java/com/stevesoltys/seedvault/repo/SnapshotCreator.kt
@@ -16,9 +16,11 @@ import android.provider.Settings
 import android.provider.Settings.Secure.ANDROID_ID
 import com.google.protobuf.ByteString
 import com.stevesoltys.seedvault.Clock
+import com.stevesoltys.seedvault.MAGIC_PACKAGE_MANAGER
 import com.stevesoltys.seedvault.header.VERSION
 import com.stevesoltys.seedvault.metadata.BackupType
 import com.stevesoltys.seedvault.metadata.MetadataManager
+import com.stevesoltys.seedvault.metadata.PackageMetadata.Companion.toBackupType
 import com.stevesoltys.seedvault.proto.Snapshot
 import com.stevesoltys.seedvault.proto.Snapshot.Apk
 import com.stevesoltys.seedvault.proto.Snapshot.App
@@ -28,6 +30,7 @@ import com.stevesoltys.seedvault.transport.backup.isSystemApp
 import io.github.oshai.kotlinlogging.KotlinLogging
 import org.calyxos.seedvault.core.backends.AppBackupFileType
 import org.calyxos.seedvault.core.toHexString
+import java.util.concurrent.ConcurrentHashMap
 
 /**
  * Assembles snapshot information over the course of a single backup run
@@ -43,8 +46,8 @@ internal class SnapshotCreator(
     private val log = KotlinLogging.logger { }
 
     private val snapshotBuilder = Snapshot.newBuilder()
-    private val appBuilderMap = mutableMapOf<String, App.Builder>()
-    private val blobsMap = mutableMapOf<String, Blob>()
+    private val appBuilderMap = ConcurrentHashMap<String, App.Builder>()
+    private val blobsMap = ConcurrentHashMap<String, Blob>()
 
     private val launchableSystemApps by lazy {
         // as we can't ask [PackageInfo] for this, we keep a set of packages around
@@ -103,6 +106,50 @@ internal class SnapshotCreator(
         metadataManager.onPackageBackedUp(packageInfo, backupType, backupData.size)
     }
 
+    /**
+     * Call this when the given [packageName] may not call our transport at all in this run,
+     * but we need to include data for the package in the current snapshot.
+     * This may happen for K/V apps like @pm@ that don't call us when their data didn't change.
+     *
+     * If we do *not* have data for the given [packageName],
+     * we try to extract data from the given [snapshot] (ideally we latest we have) and
+     * add it to the current snapshot under construction.
+     */
+    fun onNoDataInCurrentRun(snapshot: Snapshot, packageName: String) {
+        log.info { "onKvPackageNotChanged(${snapshot.token}, $packageName)" }
+
+        if (appBuilderMap.containsKey(packageName)) {
+            // the system backs up K/V apps repeatedly, e.g. @pm@
+            log.info { "  Already have data for $packageName in current snapshot, not touching it" }
+            return
+        }
+        val app = snapshot.appsMap[packageName]
+        if (app == null) {
+            log.error { "  No changed data for $packageName, but we had no data for it" }
+            return
+        }
+
+        // get chunkIds from last snapshot
+        val chunkIds = app.chunkIdsList.hexFromProto() +
+            app.apk.splitsList.flatMap { it.chunkIdsList }.hexFromProto()
+
+        // get blobs for chunkIds
+        val blobMap = mutableMapOf<String, Blob>()
+        chunkIds.forEach { chunkId ->
+            val blob = snapshot.blobsMap[chunkId]
+            if (blob == null) log.error { "  No blob for $packageName chunk $chunkId" }
+            else blobMap[chunkId] = blob
+        }
+
+        // add info to current snapshot
+        appBuilderMap[packageName] = app.toBuilder()
+        blobsMap.putAll(blobMap)
+
+        // record local metadata
+        val packageInfo = PackageInfo().apply { this.packageName = packageName }
+        metadataManager.onPackageBackedUp(packageInfo, app.type.toBackupType(), app.size)
+    }
+
     /**
      * Call this after all blobs for the app icons have been saved to the backend.
      */
@@ -134,6 +181,8 @@ internal class SnapshotCreator(
             putAllApps(appBuilderMap.mapValues { it.value.build() })
             putAllBlobs(this@SnapshotCreator.blobsMap)
         }.build()
+        // may as well fail the backup, if @pm@ isn't in it
+        check(MAGIC_PACKAGE_MANAGER in snapshot.appsMap) { "No metadata for @pm@" }
         appBuilderMap.clear()
         snapshotBuilder.clear()
         blobsMap.clear()

diff --git a/app/src/main/java/com/stevesoltys/seedvault/repo/SnapshotManager.kt b/app/src/main/java/com/stevesoltys/seedvault/repo/SnapshotManager.kt
@@ -39,6 +39,7 @@ internal class SnapshotManager(
      * The latest [Snapshot]. May be stale if [onSnapshotsLoaded] has not returned
      * or wasn't called since new snapshots have been created.
      */
+    @Volatile
     var latestSnapshot: Snapshot? = null
         private set
 

diff --git a/app/src/main/java/com/stevesoltys/seedvault/transport/backup/BackupModule.kt b/app/src/main/java/com/stevesoltys/seedvault/transport/backup/BackupModule.kt
@@ -9,6 +9,7 @@ import org.koin.android.ext.koin.androidContext
 import org.koin.dsl.module
 
 val backupModule = module {
+    factory { BackupTransportMonitor(get(), get()) }
     single { BackupInitializer(get()) }
     single { InputFactory() }
     single {

diff --git a/app/src/main/java/com/stevesoltys/seedvault/transport/backup/BackupTransportMonitor.kt b/app/src/main/java/com/stevesoltys/seedvault/transport/backup/BackupTransportMonitor.kt
@@ -0,0 +1,43 @@
+/*
+ * SPDX-FileCopyrightText: 2024 The Calyx Institute
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package com.stevesoltys.seedvault.transport.backup
+
+import android.app.backup.BackupManagerMonitor.LOG_EVENT_CATEGORY_BACKUP_MANAGER_POLICY
+import android.app.backup.BackupManagerMonitor.LOG_EVENT_ID_NO_DATA_TO_SEND
+import android.os.Bundle
+import com.stevesoltys.seedvault.BackupMonitor
+import com.stevesoltys.seedvault.repo.AppBackupManager
+import com.stevesoltys.seedvault.repo.SnapshotManager
+import io.github.oshai.kotlinlogging.KotlinLogging
+
+internal class BackupTransportMonitor(
+    private val appBackupManager: AppBackupManager,
+    private val snapshotManager: SnapshotManager,
+) : BackupMonitor() {
+
+    private val log = KotlinLogging.logger { }
+
+    override fun onEvent(id: Int, category: Int, packageName: String, bundle: Bundle) {
+        super.onEvent(id, category, packageName, bundle)
+        if (id == LOG_EVENT_ID_NO_DATA_TO_SEND &&
+            category == LOG_EVENT_CATEGORY_BACKUP_MANAGER_POLICY
+        ) {
+            sendNoDataChanged(packageName)
+        }
+    }
+
+    private fun sendNoDataChanged(packageName: String) {
+        log.info { "sendNoDataChanged($packageName)" }
+
+        val snapshot = snapshotManager.latestSnapshot
+        if (snapshot == null) {
+            log.error { "No latest snapshot!" }
+        } else {
+            val snapshotCreator = appBackupManager.snapshotCreator ?: error("No SnapshotCreator")
+            snapshotCreator.onNoDataInCurrentRun(snapshot, packageName)
+        }
+    }
+}
diff --git a/app/src/main/java/com/stevesoltys/seedvault/transport/backup/KVBackup.kt b/app/src/main/java/com/stevesoltys/seedvault/transport/backup/KVBackup.kt
@@ -14,6 +14,7 @@ import android.app.backup.BackupTransport.TRANSPORT_OK
 import android.content.pm.PackageInfo
 import android.os.ParcelFileDescriptor
 import android.util.Log
+import com.stevesoltys.seedvault.NO_DATA_END_SENTINEL
 import com.stevesoltys.seedvault.repo.BackupData
 import com.stevesoltys.seedvault.repo.BackupReceiver
 import java.io.IOException
@@ -52,6 +53,8 @@ internal class KVBackup(
             else -> Log.i(TAG, "Performing K/V backup for $packageName")
         }
         check(state == null) { "Have unexpected state for ${state?.packageInfo?.packageName}" }
+        // This fake package name just signals that we've seen all packages without new data
+        if (packageName == NO_DATA_END_SENTINEL) return TRANSPORT_OK
 
         // initialize state
         state = KVBackupState(packageInfo = packageInfo, db = dbManager.getDb(packageName))

diff --git a/app/src/main/java/com/stevesoltys/seedvault/transport/backup/PackageService.kt b/app/src/main/java/com/stevesoltys/seedvault/transport/backup/PackageService.kt
@@ -59,18 +59,17 @@ internal class PackageService(
                 logPackages(packages)
             }
 
-            val eligibleApps = packages.filter(::shouldIncludeAppInBackup).toTypedArray()
+            val eligibleApps = packages.filter(::shouldIncludeAppInBackup).toMutableList()
             // log eligible packages
             if (Log.isLoggable(TAG, INFO)) {
                 Log.i(TAG, "Filtering left ${eligibleApps.size} eligible packages:")
-                logPackages(eligibleApps.toList())
+                logPackages(eligibleApps)
             }
 
             // add magic @pm@ package (PACKAGE_MANAGER_SENTINEL) which holds package manager data
-            val packageArray = eligibleApps.toMutableList()
-            packageArray.add(MAGIC_PACKAGE_MANAGER)
+            eligibleApps.add(0, MAGIC_PACKAGE_MANAGER)
 
-            return packageArray
+            return eligibleApps
         }
 
     /**

diff --git a/app/src/main/java/com/stevesoltys/seedvault/worker/BackupRequester.kt b/app/src/main/java/com/stevesoltys/seedvault/worker/BackupRequester.kt
@@ -11,7 +11,7 @@ import android.content.Context
 import android.os.RemoteException
 import android.util.Log
 import androidx.annotation.WorkerThread
-import com.stevesoltys.seedvault.BackupMonitor
+import com.stevesoltys.seedvault.transport.backup.BackupTransportMonitor
 import com.stevesoltys.seedvault.transport.backup.PackageService
 import com.stevesoltys.seedvault.ui.notification.BackupNotificationManager
 import com.stevesoltys.seedvault.ui.notification.NotificationBackupObserver
@@ -32,6 +32,7 @@ internal const val NUM_PACKAGES_PER_TRANSACTION = 100
 internal class BackupRequester(
     context: Context,
     private val backupManager: IBackupManager,
+    private val monitor: BackupTransportMonitor,
     val packageService: PackageService,
 ) : KoinComponent {
 
@@ -43,7 +44,6 @@ internal class BackupRequester(
         backupRequester = this,
         requestedPackages = packages.size,
     )
-    private val monitor = BackupMonitor()
 
     /**
      * The current package index.

diff --git a/app/src/main/java/com/stevesoltys/seedvault/worker/WorkerModule.kt b/app/src/main/java/com/stevesoltys/seedvault/worker/WorkerModule.kt
@@ -13,6 +13,7 @@ val workerModule = module {
         BackupRequester(
             context = androidContext(),
             backupManager = get(),
+            monitor = get(),
             packageService = get(),
         )
     }