[DataStore] Support backup data with compression
Bug: 325144964
Test: Manual tests
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:4303555ef342eea5dc3d50eb8f5bfe68639f9c91)
Merged-In: Ida5d71f2b39aeb271f4ad10e200f28dbfe5ed9c8
Change-Id: Ida5d71f2b39aeb271f4ad10e200f28dbfe5ed9c8
diff --git a/packages/SettingsLib/DataStore/Android.bp b/packages/SettingsLib/DataStore/Android.bp
index 1806544..9fafcab 100644
--- a/packages/SettingsLib/DataStore/Android.bp
+++ b/packages/SettingsLib/DataStore/Android.bp
@@ -14,4 +14,5 @@
"androidx.core_core-ktx",
"guava",
],
+ kotlincflags: ["-Xjvm-default=all"],
}
diff --git a/packages/SettingsLib/DataStore/src/com/android/settingslib/datastore/BackupCodec.kt b/packages/SettingsLib/DataStore/src/com/android/settingslib/datastore/BackupCodec.kt
new file mode 100644
index 0000000..550645f
--- /dev/null
+++ b/packages/SettingsLib/DataStore/src/com/android/settingslib/datastore/BackupCodec.kt
@@ -0,0 +1,98 @@
+/*
+ * Copyright (C) 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.settingslib.datastore
+
+import androidx.annotation.IntDef
+import java.io.InputStream
+import java.io.OutputStream
+import java.util.zip.Deflater
+import java.util.zip.DeflaterOutputStream
+import java.util.zip.InflaterInputStream
+
+/** Unique id of the codec. */
+@Target(AnnotationTarget.TYPE)
+@IntDef(
+ BackupCodecId.NO_OP.toInt(),
+ BackupCodecId.ZIP.toInt(),
+)
+@Retention(AnnotationRetention.SOURCE)
+annotation class BackupCodecId {
+ companion object {
+ /** Unknown reason of the change. */
+ const val NO_OP: Byte = 0
+ /** Data is updated. */
+ const val ZIP: Byte = 1
+ }
+}
+
+/** How to encode/decode the backup data. */
+interface BackupCodec {
+ /** Unique id of the codec. */
+ val id: @BackupCodecId Byte
+
+ /** Name of the codec. */
+ val name: String
+
+ /** Encodes the backup data. */
+ fun encode(outputStream: OutputStream): OutputStream
+
+ /** Decodes the backup data. */
+ fun decode(inputStream: InputStream): InputStream
+
+ companion object {
+ @JvmStatic
+ fun fromId(id: @BackupCodecId Byte): BackupCodec =
+ when (id) {
+ BackupCodecId.NO_OP -> BackupNoOpCodec()
+ BackupCodecId.ZIP -> BackupZipCodec.BEST_COMPRESSION
+ else -> throw IllegalArgumentException("Unknown codec id $id")
+ }
+ }
+}
+
+/** Codec without any additional encoding/decoding. */
+class BackupNoOpCodec : BackupCodec {
+ override val id
+ get() = BackupCodecId.NO_OP
+
+ override val name
+ get() = "N/A"
+
+ override fun encode(outputStream: OutputStream) = outputStream
+
+ override fun decode(inputStream: InputStream) = inputStream
+}
+
+/** Codec with ZIP compression. */
+class BackupZipCodec(
+ private val compressionLevel: Int,
+ override val name: String,
+) : BackupCodec {
+ override val id
+ get() = BackupCodecId.ZIP
+
+ override fun encode(outputStream: OutputStream) =
+ DeflaterOutputStream(outputStream, Deflater(compressionLevel))
+
+ override fun decode(inputStream: InputStream) = InflaterInputStream(inputStream)
+
+ companion object {
+ val DEFAULT_COMPRESSION = BackupZipCodec(Deflater.DEFAULT_COMPRESSION, "ZipDefault")
+ val BEST_COMPRESSION = BackupZipCodec(Deflater.BEST_COMPRESSION, "ZipBestCompression")
+ val BEST_SPEED = BackupZipCodec(Deflater.BEST_SPEED, "ZipBestSpeed")
+ }
+}
diff --git a/packages/SettingsLib/DataStore/src/com/android/settingslib/datastore/BackupRestoreEntity.kt b/packages/SettingsLib/DataStore/src/com/android/settingslib/datastore/BackupRestoreEntity.kt
index 6a7ef5a..817ee4c 100644
--- a/packages/SettingsLib/DataStore/src/com/android/settingslib/datastore/BackupRestoreEntity.kt
+++ b/packages/SettingsLib/DataStore/src/com/android/settingslib/datastore/BackupRestoreEntity.kt
@@ -36,6 +36,13 @@
val key: String
/**
+ * Codec used to encode/decode the backup data.
+ *
+ * When it is null, the [BackupRestoreStorage.defaultCodec] will be used.
+ */
+ fun codec(): BackupCodec? = null
+
+ /**
* Backs up the entity.
*
* @param backupContext context for backup
diff --git a/packages/SettingsLib/DataStore/src/com/android/settingslib/datastore/BackupRestoreFileArchiver.kt b/packages/SettingsLib/DataStore/src/com/android/settingslib/datastore/BackupRestoreFileArchiver.kt
index a447ace..3db46509 100644
--- a/packages/SettingsLib/DataStore/src/com/android/settingslib/datastore/BackupRestoreFileArchiver.kt
+++ b/packages/SettingsLib/DataStore/src/com/android/settingslib/datastore/BackupRestoreFileArchiver.kt
@@ -41,6 +41,11 @@
override fun createBackupRestoreEntities(): List<BackupRestoreEntity> =
fileStorages.map { it.toBackupRestoreEntity() }
+ override fun wrapBackupOutputStream(codec: BackupCodec, outputStream: OutputStream) =
+ outputStream
+
+ override fun wrapRestoreInputStream(codec: BackupCodec, inputStream: InputStream) = inputStream
+
override fun restoreEntity(data: BackupDataInputStream) {
val key = data.key
val fileStorage = fileStorages.firstOrNull { it.storageFilePath == key }
@@ -56,11 +61,19 @@
File(context.dataDirCompat, key)
}
Log.i(LOG_TAG, "[$name] Restore ${data.size()} bytes for $key to $file")
+ val inputStream = LimitedNoCloseInputStream(data)
try {
+ val codec = BackupCodec.fromId(inputStream.read().toByte())
+ if (fileStorage != null && fileStorage.defaultCodec().id != codec.id) {
+ Log.i(
+ LOG_TAG,
+ "[$name] $key different codec: ${codec.id}, ${fileStorage.defaultCodec().id}"
+ )
+ }
file.parentFile?.mkdirs() // ensure parent folders are created
- val wrappedInputStream = wrapRestoreInputStream(data)
- file.outputStream().use { wrappedInputStream.copyTo(it) }
- Log.i(LOG_TAG, "[$name] $key restored")
+ val wrappedInputStream = codec.decode(inputStream)
+ val bytesCopied = file.outputStream().use { wrappedInputStream.copyTo(it) }
+ Log.i(LOG_TAG, "[$name] $key restore $bytesCopied bytes with ${codec.name}")
fileStorage?.onRestoreFinished(file)
} catch (e: Exception) {
Log.e(LOG_TAG, "[$name] Fail to restore $key", e)
@@ -90,8 +103,12 @@
Log.i(LOG_TAG, "[$name] $key not exist")
return EntityBackupResult.DELETE
}
- val wrappedOutputStream = wrapBackupOutputStream(outputStream)
- file.inputStream().use { it.copyTo(wrappedOutputStream) }
+ val codec = codec() ?: defaultCodec()
+ // MUST close to flush the data
+ wrapBackupOutputStream(codec, outputStream).use { stream ->
+ val bytesCopied = file.inputStream().use { it.copyTo(stream) }
+ Log.i(LOG_TAG, "[$name] $key backup $bytesCopied bytes with ${codec.name}")
+ }
onBackupFinished(file)
return EntityBackupResult.UPDATE
}
diff --git a/packages/SettingsLib/DataStore/src/com/android/settingslib/datastore/BackupRestoreStorage.kt b/packages/SettingsLib/DataStore/src/com/android/settingslib/datastore/BackupRestoreStorage.kt
index 88d9dd6..8ff4bc8 100644
--- a/packages/SettingsLib/DataStore/src/com/android/settingslib/datastore/BackupRestoreStorage.kt
+++ b/packages/SettingsLib/DataStore/src/com/android/settingslib/datastore/BackupRestoreStorage.kt
@@ -50,6 +50,9 @@
/** Entities to back up and restore. */
abstract fun createBackupRestoreEntities(): List<BackupRestoreEntity>
+ /** Default codec used to encode/decode the entity data. */
+ open fun defaultCodec(): BackupCodec = BackupZipCodec.BEST_COMPRESSION
+
override fun performBackup(
oldState: ParcelFileDescriptor?,
data: BackupDataOutput,
@@ -64,9 +67,10 @@
for (entity in entities) {
val key = entity.key
val outputStream = ByteArrayOutputStream()
+ val codec = entity.codec() ?: defaultCodec()
val result =
try {
- entity.backup(backupContext, wrapBackupOutputStream(outputStream))
+ entity.backup(backupContext, wrapBackupOutputStream(codec, outputStream))
} catch (exception: Exception) {
Log.e(LOG_TAG, "[$name] Fail to backup entity $key", exception)
continue
@@ -94,8 +98,10 @@
/** Returns if backup is enabled. */
open fun enableBackup(backupContext: BackupContext): Boolean = true
- fun wrapBackupOutputStream(outputStream: OutputStream): OutputStream {
- return outputStream
+ open fun wrapBackupOutputStream(codec: BackupCodec, outputStream: OutputStream): OutputStream {
+ // write a codec id header for safe restore
+ outputStream.write(codec.id.toInt())
+ return codec.encode(outputStream)
}
override fun restoreEntity(data: BackupDataInputStream) {
@@ -111,8 +117,12 @@
}
Log.i(LOG_TAG, "[$name] Restore $key: ${data.size()} bytes")
val restoreContext = RestoreContext(key)
+ val codec = entity.codec() ?: defaultCodec()
try {
- entity.restore(restoreContext, wrapRestoreInputStream(data))
+ entity.restore(
+ restoreContext,
+ wrapRestoreInputStream(codec, LimitedNoCloseInputStream(data))
+ )
} catch (exception: Exception) {
Log.e(LOG_TAG, "[$name] Fail to restore entity $key", exception)
}
@@ -121,8 +131,16 @@
/** Returns if restore is enabled. */
open fun enableRestore(): Boolean = true
- fun wrapRestoreInputStream(inputStream: BackupDataInputStream): InputStream {
- return LimitedNoCloseInputStream(inputStream)
+ open fun wrapRestoreInputStream(
+ codec: BackupCodec,
+ inputStream: InputStream,
+ ): InputStream {
+ // read the codec id first to check if it is expected codec
+ val id = inputStream.read()
+ val expectedId = codec.id.toInt()
+ if (id == expectedId) return codec.decode(inputStream)
+ Log.i(LOG_TAG, "Expect codec id $expectedId but got $id")
+ return BackupCodec.fromId(id.toByte()).decode(inputStream)
}
override fun writeNewStateDescription(newState: ParcelFileDescriptor) {}