| /* |
| * Copyright (C) 2009 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 android.app.backup; |
| |
| import android.compat.annotation.UnsupportedAppUsage; |
| import android.os.ParcelFileDescriptor; |
| import android.util.Log; |
| |
| import java.io.FileDescriptor; |
| import java.io.IOException; |
| import java.util.Map; |
| import java.util.TreeMap; |
| |
| /** @hide */ |
| public class BackupHelperDispatcher { |
| private static final String TAG = "BackupHelperDispatcher"; |
| |
| private static class Header { |
| @UnsupportedAppUsage |
| int chunkSize; // not including the header |
| @UnsupportedAppUsage |
| String keyPrefix; |
| } |
| |
| TreeMap<String,BackupHelper> mHelpers = new TreeMap<String,BackupHelper>(); |
| |
| public BackupHelperDispatcher() { |
| } |
| |
| public void addHelper(String keyPrefix, BackupHelper helper) { |
| mHelpers.put(keyPrefix, helper); |
| } |
| |
| public void performBackup(ParcelFileDescriptor oldState, BackupDataOutput data, |
| ParcelFileDescriptor newState) throws IOException { |
| // First, do the helpers that we've already done, since they're already in the state |
| // file. |
| int err; |
| Header header = new Header(); |
| TreeMap<String,BackupHelper> helpers = (TreeMap<String,BackupHelper>)mHelpers.clone(); |
| FileDescriptor oldStateFD = null; |
| |
| if (oldState != null) { |
| oldStateFD = oldState.getFileDescriptor(); |
| while ((err = readHeader_native(header, oldStateFD)) >= 0) { |
| if (err == 0) { |
| BackupHelper helper = helpers.get(header.keyPrefix); |
| Log.d(TAG, "handling existing helper '" + header.keyPrefix + "' " + helper); |
| if (helper != null) { |
| doOneBackup(oldState, data, newState, header, helper); |
| helpers.remove(header.keyPrefix); |
| } else { |
| skipChunk_native(oldStateFD, header.chunkSize); |
| } |
| } |
| } |
| } |
| |
| // Then go through and do the rest that we haven't done. |
| for (Map.Entry<String,BackupHelper> entry: helpers.entrySet()) { |
| header.keyPrefix = entry.getKey(); |
| Log.d(TAG, "handling new helper '" + header.keyPrefix + "'"); |
| BackupHelper helper = entry.getValue(); |
| doOneBackup(oldState, data, newState, header, helper); |
| } |
| } |
| |
| private void doOneBackup(ParcelFileDescriptor oldState, BackupDataOutput data, |
| ParcelFileDescriptor newState, Header header, BackupHelper helper) |
| throws IOException { |
| int err; |
| FileDescriptor newStateFD = newState.getFileDescriptor(); |
| |
| // allocate space for the header in the file |
| int pos = allocateHeader_native(header, newStateFD); |
| if (pos < 0) { |
| throw new IOException("allocateHeader_native failed (error " + pos + ")"); |
| } |
| |
| data.setKeyPrefix(header.keyPrefix); |
| |
| // do the backup |
| helper.performBackup(oldState, data, newState); |
| |
| // fill in the header (seeking back to pos). The file pointer will be returned to |
| // where it was at the end of performBackup. Header.chunkSize will not be filled in. |
| err = writeHeader_native(header, newStateFD, pos); |
| if (err != 0) { |
| throw new IOException("writeHeader_native failed (error " + err + ")"); |
| } |
| } |
| |
| public void performRestore(BackupDataInput input, int appVersionCode, |
| ParcelFileDescriptor newState) |
| throws IOException { |
| boolean alreadyComplained = false; |
| |
| BackupDataInputStream stream = new BackupDataInputStream(input); |
| while (input.readNextHeader()) { |
| |
| String rawKey = input.getKey(); |
| int pos = rawKey.indexOf(':'); |
| if (pos > 0) { |
| String prefix = rawKey.substring(0, pos); |
| BackupHelper helper = mHelpers.get(prefix); |
| if (helper != null) { |
| stream.dataSize = input.getDataSize(); |
| stream.key = rawKey.substring(pos+1); |
| helper.restoreEntity(stream); |
| } else { |
| if (!alreadyComplained) { |
| Log.w(TAG, "Couldn't find helper for: '" + rawKey + "'"); |
| alreadyComplained = true; |
| } |
| } |
| } else { |
| if (!alreadyComplained) { |
| Log.w(TAG, "Entity with no prefix: '" + rawKey + "'"); |
| alreadyComplained = true; |
| } |
| } |
| input.skipEntityData(); // In case they didn't consume the data. |
| } |
| |
| // Write out the state files -- mHelpers is a TreeMap, so the order is well defined. |
| for (BackupHelper helper: mHelpers.values()) { |
| helper.writeNewStateDescription(newState); |
| } |
| } |
| |
| private static native int readHeader_native(Header h, FileDescriptor fd); |
| private static native int skipChunk_native(FileDescriptor fd, int bytesToSkip); |
| |
| private static native int allocateHeader_native(Header h, FileDescriptor fd); |
| private static native int writeHeader_native(Header h, FileDescriptor fd, int pos); |
| } |
| |