Define new and simpler BackupPlugin API

leaving the old one in place still

app/src/main/java/com/stevesoltys/seedvault/plugins/saf/DocumentsProviderBackupPlugin.kt

@@ -3,12 +3,19 @@ package com.stevesoltys.seedvault.plugins.saf
 import android.content.Context
 import android.content.pm.PackageInfo
 import android.content.pm.PackageManager
+import android.net.Uri
+import android.util.Log
+import androidx.documentfile.provider.DocumentFile
 import com.stevesoltys.seedvault.transport.backup.BackupPlugin
+import com.stevesoltys.seedvault.transport.backup.EncryptedMetadata
 import com.stevesoltys.seedvault.transport.backup.FullBackupPlugin
 import com.stevesoltys.seedvault.transport.backup.KVBackupPlugin
+import java.io.FileNotFoundException
 import java.io.IOException
+import java.io.InputStream
 import java.io.OutputStream
 
+private val TAG = DocumentsProviderBackupPlugin::class.java.simpleName
 private const val MIME_TYPE_APK = "application/vnd.android.package-archive"
 
 @Suppress("BlockingMethodInNonBlockingContext")
@@ -45,12 +52,60 @@ internal class DocumentsProviderBackupPlugin(
     }
 
     @Throws(IOException::class)
-    override suspend fun getMetadataOutputStream(): OutputStream {
+    override suspend fun hasData(token: Long, name: String): Boolean {
-        val setDir = storage.getSetDir() ?: throw IOException()
+        val setDir = storage.getSetDir(token) ?: return false
+        return setDir.findFileBlocking(context, name) != null
+    }
+
+    @Throws(IOException::class)
+    override suspend fun getOutputStream(token: Long, name: String): OutputStream {
+        val setDir = storage.getSetDir(token) ?: throw IOException()
+        val file = setDir.createOrGetFile(context, name)
+        return storage.getOutputStream(file)
+    }
+
+    @Throws(IOException::class)
+    override suspend fun getInputStream(token: Long, name: String): InputStream {
+        val setDir = storage.getSetDir(token) ?: throw IOException()
+        val file = setDir.findFileBlocking(context, name) ?: throw FileNotFoundException()
+        return storage.getInputStream(file)
+    }
+
+    @Throws(IOException::class)
+    override suspend fun removeData(token: Long, name: String) {
+        val setDir = storage.getSetDir(token) ?: throw IOException()
+        val file = setDir.findFileBlocking(context, name) ?: return
+        if (!file.delete()) throw IOException("Failed to delete $name")
+    }
+
+    @Throws(IOException::class)
+    override suspend fun getMetadataOutputStream(token: Long): OutputStream {
+        val setDir = storage.getSetDir(token) ?: throw IOException()
         val metadataFile = setDir.createOrGetFile(context, FILE_BACKUP_METADATA)
         return storage.getOutputStream(metadataFile)
     }
 
+    @Throws(IOException::class)
+    override suspend fun hasBackup(uri: Uri): Boolean {
+        val parent = DocumentFile.fromTreeUri(context, uri) ?: throw AssertionError()
+        val rootDir = parent.findFileBlocking(context, DIRECTORY_ROOT) ?: return false
+        val backupSets = getBackups(context, rootDir)
+        return backupSets.isNotEmpty()
+    }
+
+    override suspend fun getAvailableBackups(): Sequence<EncryptedMetadata>? {
+        val rootDir = storage.rootBackupDir ?: return null
+        val backupSets = getBackups(context, rootDir)
+        val iterator = backupSets.iterator()
+        return generateSequence {
+            if (!iterator.hasNext()) return@generateSequence null // end sequence
+            val backupSet = iterator.next()
+            EncryptedMetadata(backupSet.token) {
+                storage.getInputStream(backupSet.metadataFile)
+            }
+        }
+    }
+
     @Throws(IOException::class)
     override suspend fun getApkOutputStream(
         packageInfo: PackageInfo,
@@ -69,3 +124,64 @@ internal class DocumentsProviderBackupPlugin(
     }
 
 }
+
+class BackupSet(val token: Long, val metadataFile: DocumentFile)
+
+@Suppress("BlockingMethodInNonBlockingContext")
+internal suspend fun getBackups(context: Context, rootDir: DocumentFile): List<BackupSet> {
+    val backupSets = ArrayList<BackupSet>()
+    val files = try {
+        // block until the DocumentsProvider has results
+        rootDir.listFilesBlocking(context)
+    } catch (e: IOException) {
+        Log.e(TAG, "Error loading backups from storage", e)
+        return backupSets
+    }
+    for (set in files) {
+        // retrieve name only once as this causes a DB query
+        val name = set.name
+
+        // get current token from set or continue to next file/set
+        val token = set.getTokenOrNull(name) ?: continue
+
+        // block until children of set are available
+        val metadata = try {
+            set.findFileBlocking(context, FILE_BACKUP_METADATA)
+        } catch (e: IOException) {
+            Log.e(TAG, "Error reading metadata file in backup set folder: $name", e)
+            null
+        }
+        if (metadata == null) {
+            Log.w(TAG, "Missing metadata file in backup set folder: $name")
+        } else {
+            backupSets.add(BackupSet(token, metadata))
+        }
+    }
+    return backupSets
+}
+
+private val tokenRegex = Regex("([0-9]{13})") // good until the year 2286
+private val chunkFolderRegex = Regex("[a-f0-9]{2}")
+
+private fun DocumentFile.getTokenOrNull(name: String?): Long? {
+    val looksLikeToken = name != null && tokenRegex.matches(name)
+    // check for isDirectory only if we already have a valid token (causes DB query)
+    if (!looksLikeToken || !isDirectory) {
+        // only log unexpected output
+        if (name != null && isUnexpectedFile(name)) {
+            Log.w(TAG, "Found invalid backup set folder: $name")
+        }
+        return null
+    }
+    return try {
+        name?.toLong()
+    } catch (e: NumberFormatException) {
+        throw AssertionError(e)
+    }
+}
+
+private fun isUnexpectedFile(name: String): Boolean {
+    return name != FILE_NO_MEDIA &&
+        !chunkFolderRegex.matches(name) &&
+        !name.endsWith(".SeedSnap")
+}

app/src/main/java/com/stevesoltys/seedvault/plugins/saf/DocumentsProviderRestorePlugin.kt

@@ -24,9 +24,6 @@ internal class DocumentsProviderRestorePlugin(
     override val fullRestorePlugin: FullRestorePlugin
 ) : RestorePlugin {
 
-    private val tokenRegex = Regex("([0-9]{13})") // good until the year 2286
-    private val chunkFolderRegex = Regex("[a-f0-9]{2}")
-
     @Throws(IOException::class)
     override suspend fun hasBackup(uri: Uri): Boolean {
         val parent = DocumentFile.fromTreeUri(context, uri) ?: throw AssertionError()
@@ -52,61 +49,6 @@ internal class DocumentsProviderRestorePlugin(
         }
     }
 
-    private suspend fun getBackups(context: Context, rootDir: DocumentFile): List<BackupSet> {
-        val backupSets = ArrayList<BackupSet>()
-        val files = try {
-            // block until the DocumentsProvider has results
-            rootDir.listFilesBlocking(context)
-        } catch (e: IOException) {
-            Log.e(TAG, "Error loading backups from storage", e)
-            return backupSets
-        }
-        for (set in files) {
-            // retrieve name only once as this causes a DB query
-            val name = set.name
-
-            // get current token from set or continue to next file/set
-            val token = set.getTokenOrNull(name) ?: continue
-
-            // block until children of set are available
-            val metadata = try {
-                set.findFileBlocking(context, FILE_BACKUP_METADATA)
-            } catch (e: IOException) {
-                Log.e(TAG, "Error reading metadata file in backup set folder: $name", e)
-                null
-            }
-            if (metadata == null) {
-                Log.w(TAG, "Missing metadata file in backup set folder: $name")
-            } else {
-                backupSets.add(BackupSet(token, metadata))
-            }
-        }
-        return backupSets
-    }
-
-    private fun DocumentFile.getTokenOrNull(name: String?): Long? {
-        val looksLikeToken = name != null && tokenRegex.matches(name)
-        // check for isDirectory only if we already have a valid token (causes DB query)
-        if (!looksLikeToken || !isDirectory) {
-            // only log unexpected output
-            if (name != null && isUnexpectedFile(name)) {
-                Log.w(TAG, "Found invalid backup set folder: $name")
-            }
-            return null
-        }
-        return try {
-            name?.toLong()
-        } catch (e: NumberFormatException) {
-            throw AssertionError(e)
-        }
-    }
-
-    private fun isUnexpectedFile(name: String): Boolean {
-        return name != FILE_NO_MEDIA &&
-            !chunkFolderRegex.matches(name) &&
-            !name.endsWith(".SeedSnap")
-    }
-
     @Throws(IOException::class)
     override suspend fun getApkInputStream(
         token: Long,
@@ -120,5 +62,3 @@ internal class DocumentsProviderRestorePlugin(
     }
 
 }
-
-class BackupSet(val token: Long, val metadataFile: DocumentFile)

app/src/main/java/com/stevesoltys/seedvault/transport/backup/BackupCoordinator.kt

@@ -28,9 +28,11 @@ import com.stevesoltys.seedvault.metadata.PackageState.NO_DATA
 import com.stevesoltys.seedvault.metadata.PackageState.QUOTA_EXCEEDED
 import com.stevesoltys.seedvault.metadata.PackageState.UNKNOWN_ERROR
 import com.stevesoltys.seedvault.metadata.PackageState.WAS_STOPPED
+import com.stevesoltys.seedvault.plugins.saf.FILE_BACKUP_METADATA
 import com.stevesoltys.seedvault.settings.SettingsManager
 import com.stevesoltys.seedvault.ui.notification.BackupNotificationManager
 import java.io.IOException
+import java.io.OutputStream
 import java.util.concurrent.TimeUnit.DAYS
 import java.util.concurrent.TimeUnit.HOURS
 
@@ -492,4 +494,9 @@ internal class BackupCoordinator(
         }
     }
 
+    private suspend fun BackupPlugin.getMetadataOutputStream(): OutputStream {
+        val token = settingsManager.getToken() ?: throw IOException("no current token")
+        return getOutputStream(token, FILE_BACKUP_METADATA)
+    }
+
 }

app/src/main/java/com/stevesoltys/seedvault/transport/backup/BackupPlugin.kt

@@ -2,13 +2,18 @@ package com.stevesoltys.seedvault.transport.backup
 
 import android.app.backup.RestoreSet
 import android.content.pm.PackageInfo
+import android.net.Uri
+import androidx.annotation.WorkerThread
 import java.io.IOException
+import java.io.InputStream
 import java.io.OutputStream
 
 interface BackupPlugin {
 
+    @Deprecated("Use methods in this interface instead")
     val kvBackupPlugin: KVBackupPlugin
 
+    @Deprecated("Use methods in this interface instead")
     val fullBackupPlugin: FullBackupPlugin
 
     /**
@@ -25,16 +30,60 @@ interface BackupPlugin {
     @Throws(IOException::class)
     suspend fun initializeDevice()
 
+    /**
+     * Return true if there is data stored for the given name.
+     */
+    @Throws(IOException::class)
+    suspend fun hasData(token: Long, name: String): Boolean
+
+    /**
+     * Return a raw byte stream for writing data for the given name.
+     */
+    @Throws(IOException::class)
+    suspend fun getOutputStream(token: Long, name: String): OutputStream
+
+    /**
+     * Return a raw byte stream with data for the given name.
+     */
+    @Throws(IOException::class)
+    suspend fun getInputStream(token: Long, name: String): InputStream
+
+    /**
+     * Remove all data associated with the given name.
+     */
+    @Throws(IOException::class)
+    suspend fun removeData(token: Long, name: String)
+
     /**
      * Returns an [OutputStream] for writing backup metadata.
      */
     @Throws(IOException::class)
-    suspend fun getMetadataOutputStream(): OutputStream
+    @Deprecated("use getOutputStream() instead")
+    suspend fun getMetadataOutputStream(token: Long): OutputStream
+
+    /**
+     * Searches if there's really a backup available in the given location.
+     * Returns true if at least one was found and false otherwise.
+     *
+     * FIXME: Passing a Uri is too plugin-specific and should be handled differently
+     */
+    @WorkerThread
+    @Throws(IOException::class)
+    suspend fun hasBackup(uri: Uri): Boolean
+
+    /**
+     * Get the set of all backups currently available for restore.
+     *
+     * @return metadata for the set of restore images available,
+     * or null if an error occurred (the attempt should be rescheduled).
+     **/
+    suspend fun getAvailableBackups(): Sequence<EncryptedMetadata>?
 
     /**
      * Returns an [OutputStream] for writing an APK to be backed up.
      */
     @Throws(IOException::class)
+    @Deprecated("Use getOutputStream() instead")
     suspend fun getApkOutputStream(packageInfo: PackageInfo, suffix: String): OutputStream
 
     /**
@@ -48,3 +97,5 @@ interface BackupPlugin {
     val providerPackageName: String?
 
 }
+
+class EncryptedMetadata(val token: Long, val inputStreamRetriever: () -> InputStream)

app/src/main/java/com/stevesoltys/seedvault/transport/backup/FullBackupPlugin.kt

@@ -4,6 +4,7 @@ import android.content.pm.PackageInfo
 import java.io.IOException
 import java.io.OutputStream
 
+@Deprecated("Use BackupPlugin instead")
 interface FullBackupPlugin {
 
     fun getQuota(): Long

app/src/main/java/com/stevesoltys/seedvault/transport/backup/KVBackupPlugin.kt

@@ -4,6 +4,7 @@ import android.content.pm.PackageInfo
 import java.io.IOException
 import java.io.OutputStream
 
+@Deprecated("Use BackupPlugin instead")
 interface KVBackupPlugin {
 
     /**

app/src/test/java/com/stevesoltys/seedvault/transport/CoordinatorIntegrationTest.kt

@@ -16,6 +16,7 @@ import com.stevesoltys.seedvault.header.MAX_SEGMENT_CLEARTEXT_LENGTH
 import com.stevesoltys.seedvault.metadata.MetadataReaderImpl
 import com.stevesoltys.seedvault.metadata.PackageMetadata
 import com.stevesoltys.seedvault.metadata.PackageState.UNKNOWN_ERROR
+import com.stevesoltys.seedvault.plugins.saf.FILE_BACKUP_METADATA
 import com.stevesoltys.seedvault.transport.backup.ApkBackup
 import com.stevesoltys.seedvault.transport.backup.BackupCoordinator
 import com.stevesoltys.seedvault.transport.backup.BackupPlugin
@@ -166,7 +167,10 @@ internal class CoordinatorIntegrationTest : TransportTest() {
                 any()
             )
         } returns packageMetadata
-        coEvery { backupPlugin.getMetadataOutputStream() } returns metadataOutputStream
+        every { settingsManager.getToken() } returns token
+        coEvery {
+            backupPlugin.getOutputStream(token, FILE_BACKUP_METADATA)
+        } returns metadataOutputStream
         every {
             metadataManager.onApkBackedUp(
                 packageInfo,
@@ -244,7 +248,10 @@ internal class CoordinatorIntegrationTest : TransportTest() {
         } returns bOutputStream
         every { kvBackupPlugin.packageFinished(packageInfo) } just Runs
         coEvery { apkBackup.backupApkIfNecessary(packageInfo, UNKNOWN_ERROR, any()) } returns null
-        coEvery { backupPlugin.getMetadataOutputStream() } returns metadataOutputStream
+        every { settingsManager.getToken() } returns token
+        coEvery {
+            backupPlugin.getOutputStream(token, FILE_BACKUP_METADATA)
+        } returns metadataOutputStream
         every { metadataManager.onPackageBackedUp(packageInfo, metadataOutputStream) } just Runs
 
         // start and finish K/V backup
@@ -296,7 +303,10 @@ internal class CoordinatorIntegrationTest : TransportTest() {
                 any()
             )
         } returns packageMetadata
-        coEvery { backupPlugin.getMetadataOutputStream() } returns metadataOutputStream
+        every { settingsManager.getToken() } returns token
+        coEvery {
+            backupPlugin.getOutputStream(token, FILE_BACKUP_METADATA)
+        } returns metadataOutputStream
         every {
             metadataManager.onApkBackedUp(
                 packageInfo,

app/src/test/java/com/stevesoltys/seedvault/transport/backup/BackupCoordinatorTest.kt

@@ -21,6 +21,7 @@ import com.stevesoltys.seedvault.metadata.PackageState.NO_DATA
 import com.stevesoltys.seedvault.metadata.PackageState.QUOTA_EXCEEDED
 import com.stevesoltys.seedvault.metadata.PackageState.UNKNOWN_ERROR
 import com.stevesoltys.seedvault.metadata.PackageState.WAS_STOPPED
+import com.stevesoltys.seedvault.plugins.saf.FILE_BACKUP_METADATA
 import com.stevesoltys.seedvault.settings.Storage
 import com.stevesoltys.seedvault.ui.notification.BackupNotificationManager
 import io.mockk.Runs
@@ -85,7 +86,7 @@ internal class BackupCoordinatorTest : BackupTest() {
     fun `device initialization succeeds and delegates to plugin`() = runBlocking {
         every { settingsManager.getToken() } returns token
         coEvery { plugin.initializeDevice() } just Runs
-        coEvery { plugin.getMetadataOutputStream() } returns metadataOutputStream
+        coEvery { plugin.getOutputStream(token, FILE_BACKUP_METADATA) } returns metadataOutputStream
         every { metadataManager.onDeviceInitialization(token, metadataOutputStream) } just Runs
         every { kv.hasState() } returns false
         every { full.hasState() } returns false
@@ -251,7 +252,8 @@ internal class BackupCoordinatorTest : BackupTest() {
         every { kv.hasState() } returns true
         every { full.hasState() } returns false
         every { kv.getCurrentPackage() } returns packageInfo
-        coEvery { plugin.getMetadataOutputStream() } returns metadataOutputStream
+        every { settingsManager.getToken() } returns token
+        coEvery { plugin.getOutputStream(token, FILE_BACKUP_METADATA) } returns metadataOutputStream
         every { metadataManager.onPackageBackedUp(packageInfo, metadataOutputStream) } just Runs
         every { kv.finishBackup() } returns result
         every { metadataOutputStream.close() } just Runs
@@ -268,7 +270,8 @@ internal class BackupCoordinatorTest : BackupTest() {
         every { kv.hasState() } returns false
         every { full.hasState() } returns true
         every { full.getCurrentPackage() } returns packageInfo
-        coEvery { plugin.getMetadataOutputStream() } returns metadataOutputStream
+        every { settingsManager.getToken() } returns token
+        coEvery { plugin.getOutputStream(token, FILE_BACKUP_METADATA) } returns metadataOutputStream
         every { metadataManager.onPackageBackedUp(packageInfo, metadataOutputStream) } just Runs
         every { full.finishBackup() } returns result
         every { metadataOutputStream.close() } just Runs
@@ -412,7 +415,8 @@ internal class BackupCoordinatorTest : BackupTest() {
         coEvery {
             apkBackup.backupApkIfNecessary(notAllowedPackages[1], WAS_STOPPED, any())
         } returns packageMetadata
-        coEvery { plugin.getMetadataOutputStream() } returns metadataOutputStream
+        every { settingsManager.getToken() } returns token
+        coEvery { plugin.getOutputStream(token, FILE_BACKUP_METADATA) } returns metadataOutputStream
         every {
             metadataManager.onApkBackedUp(
                 notAllowedPackages[1],
@@ -445,7 +449,8 @@ internal class BackupCoordinatorTest : BackupTest() {
         } returns oldPackageMetadata
         // state differs now, was stopped before
         every { oldPackageMetadata.state } returns WAS_STOPPED
-        coEvery { plugin.getMetadataOutputStream() } returns metadataOutputStream
+        every { settingsManager.getToken() } returns token
+        coEvery { plugin.getOutputStream(token, FILE_BACKUP_METADATA) } returns metadataOutputStream
         every {
             metadataManager.onPackageBackupError(
                 packageInfo,
@@ -473,7 +478,8 @@ internal class BackupCoordinatorTest : BackupTest() {
         every {
             metadataManager.getPackageMetadata(packageInfo.packageName)
         } returns null
-        coEvery { plugin.getMetadataOutputStream() } returns metadataOutputStream
+        every { settingsManager.getToken() } returns token
+        coEvery { plugin.getOutputStream(token, FILE_BACKUP_METADATA) } returns metadataOutputStream
         every {
             metadataManager.onPackageBackupError(
                 packageInfo,
@@ -499,7 +505,8 @@ internal class BackupCoordinatorTest : BackupTest() {
                 any()
             )
         } returns packageMetadata
-        coEvery { plugin.getMetadataOutputStream() } returns metadataOutputStream
+        every { settingsManager.getToken() } returns token
+        coEvery { plugin.getOutputStream(token, FILE_BACKUP_METADATA) } returns metadataOutputStream
         every {
             metadataManager.onApkBackedUp(
                 any(),