FileDocCategorySizeDatePackage
SettingsBackupAgent.javaAPI DocAndroid 5.1 API42265Thu Mar 12 22:22:42 GMT 2015com.android.providers.settings

SettingsBackupAgent

public class SettingsBackupAgent extends android.app.backup.BackupAgentHelper
Performs backup and restore of the System and Secure settings. List of settings that are backed up are stored in the Settings.java file

Fields Summary
private static final boolean
DEBUG
private static final boolean
DEBUG_BACKUP
private static final String
KEY_SYSTEM
private static final String
KEY_SECURE
private static final String
KEY_GLOBAL
private static final String
KEY_LOCALE
private static final int
STATE_VERSION
private static final int
STATE_SYSTEM
private static final int
STATE_SECURE
private static final int
STATE_LOCALE
private static final int
STATE_WIFI_SUPPLICANT
private static final int
STATE_WIFI_CONFIG
private static final int
STATE_GLOBAL
private static final int
STATE_SIZE
private static final int[]
STATE_SIZES
private static final int
FULL_BACKUP_VERSION
private static final int
FULL_BACKUP_ADDED_GLOBAL
private static final int
INTEGER_BYTE_COUNT
private static final byte[]
EMPTY_DATA
private static final String
TAG
private static final int
COLUMN_NAME
private static final int
COLUMN_VALUE
private static final String[]
PROJECTION
private static final String
FILE_WIFI_SUPPLICANT
private static final String
FILE_WIFI_SUPPLICANT_TEMPLATE
private static final String
KEY_WIFI_SUPPLICANT
private static final String
KEY_WIFI_CONFIG
private static final String
STAGE_FILE
private static final long
WIFI_BOUNCE_DELAY_MILLIS
private SettingsHelper
mSettingsHelper
private android.net.wifi.WifiManager
mWfm
private static String
mWifiConfigFile
WifiRestoreRunnable
mWifiRestore
Constructors Summary
Methods Summary
private voidcopyWifiSupplicantTemplate(java.io.BufferedWriter bw)

        try {
            BufferedReader br = new BufferedReader(new FileReader(FILE_WIFI_SUPPLICANT_TEMPLATE));
            char[] temp = new char[1024];
            int size;
            while ((size = br.read(temp)) > 0) {
                bw.write(temp, 0, size);
            }
            br.close();
        } catch (IOException ioe) {
            Log.w(TAG, "Couldn't copy wpa_supplicant file");
        }
private intenableWifi(boolean enable)

        if (mWfm == null) {
            mWfm = (WifiManager) getSystemService(Context.WIFI_SERVICE);
        }
        if (mWfm != null) {
            int state = mWfm.getWifiState();
            mWfm.setWifiEnabled(enable);
            return state;
        } else {
            Log.e(TAG, "Failed to fetch WifiManager instance");
        }
        return WifiManager.WIFI_STATE_UNKNOWN;
private byte[]extractRelevantValues(android.database.Cursor cursor, java.lang.String[] settings)
Given a cursor and a set of keys, extract the required keys and values and write them to a byte array.

param
cursor A cursor with settings data.
param
settings The settings to extract.
return
The byte array of extracted values.

        final int settingsCount = settings.length;
        byte[][] values = new byte[settingsCount * 2][]; // keys and values
        if (!cursor.moveToFirst()) {
            Log.e(TAG, "Couldn't read from the cursor");
            return new byte[0];
        }

        // Obtain the relevant data in a temporary array.
        int totalSize = 0;
        int backedUpSettingIndex = 0;
        Map<String, String> cachedEntries = new HashMap<String, String>();
        for (int i = 0; i < settingsCount; i++) {
            String key = settings[i];
            String value = cachedEntries.remove(key);

            // If the value not cached, let us look it up.
            if (value == null) {
                while (!cursor.isAfterLast()) {
                    String cursorKey = cursor.getString(COLUMN_NAME);
                    String cursorValue = cursor.getString(COLUMN_VALUE);
                    cursor.moveToNext();
                    if (key.equals(cursorKey)) {
                        value = cursorValue;
                        break;
                    }
                    cachedEntries.put(cursorKey, cursorValue);
                }
            }

            // Intercept the keys and see if they need special handling
            value = mSettingsHelper.onBackupValue(key, value);

            if (value == null) {
                continue;
            }
            // Write the key and value in the intermediary array.
            byte[] keyBytes = key.getBytes();
            totalSize += INTEGER_BYTE_COUNT + keyBytes.length;
            values[backedUpSettingIndex * 2] = keyBytes;

            byte[] valueBytes = value.getBytes();
            totalSize += INTEGER_BYTE_COUNT + valueBytes.length;
            values[backedUpSettingIndex * 2 + 1] = valueBytes;

            backedUpSettingIndex++;

            if (DEBUG) {
                Log.d(TAG, "Backed up setting: " + key + "=" + value);
            }
        }

        // Aggregate the result.
        byte[] result = new byte[totalSize];
        int pos = 0;
        final int keyValuePairCount = backedUpSettingIndex * 2;
        for (int i = 0; i < keyValuePairCount; i++) {
            pos = writeInt(result, pos, values[i].length);
            pos = writeBytes(result, pos, values[i]);
        }
        return result;
private byte[]getFileData(java.lang.String filename)

        InputStream is = null;
        try {
            File file = new File(filename);
            is = new FileInputStream(file);

            //Will truncate read on a very long file,
            //should not happen for a config file
            byte[] bytes = new byte[(int)file.length()];

            int offset = 0;
            int numRead = 0;
            while (offset < bytes.length
                    && (numRead=is.read(bytes, offset, bytes.length-offset)) >= 0) {
                offset += numRead;
            }

            //read failure
            if (offset < bytes.length) {
                Log.w(TAG, "Couldn't backup " + filename);
                return EMPTY_DATA;
            }
            return bytes;
        } catch (IOException ioe) {
            Log.w(TAG, "Couldn't backup " + filename);
            return EMPTY_DATA;
        } finally {
            if (is != null) {
                try {
                    is.close();
                } catch (IOException e) {
                }
            }
        }
private byte[]getGlobalSettings()

        Cursor cursor = getContentResolver().query(Settings.Global.CONTENT_URI, PROJECTION, null,
                null, null);
        try {
            return extractRelevantValues(cursor, Settings.Global.SETTINGS_TO_BACKUP);
        } finally {
            cursor.close();
        }
private byte[]getSecureSettings()

        Cursor cursor = getContentResolver().query(Settings.Secure.CONTENT_URI, PROJECTION, null,
                null, null);
        try {
            return extractRelevantValues(cursor, Settings.Secure.SETTINGS_TO_BACKUP);
        } finally {
            cursor.close();
        }
private byte[]getSystemSettings()

        Cursor cursor = getContentResolver().query(Settings.System.CONTENT_URI, PROJECTION, null,
                null, null);
        try {
            return extractRelevantValues(cursor, Settings.System.SETTINGS_TO_BACKUP);
        } finally {
            cursor.close();
        }
private byte[]getWifiSupplicant(java.lang.String filename)

        BufferedReader br = null;
        try {
            File file = new File(filename);
            if (!file.exists()) {
                return EMPTY_DATA;
            }

            WifiManager wifi = (WifiManager) getSystemService(WIFI_SERVICE);
            List<WifiConfiguration> configs = wifi.getConfiguredNetworks();

            WifiNetworkSettings fromFile = new WifiNetworkSettings();
            br = new BufferedReader(new FileReader(file));
            fromFile.readNetworks(br, configs);

            // Write the parsed networks into a packed byte array
            if (fromFile.mKnownNetworks.size() > 0) {
                ByteArrayOutputStream bos = new ByteArrayOutputStream();
                OutputStreamWriter out = new OutputStreamWriter(bos);
                fromFile.write(out);
                out.flush();
                return bos.toByteArray();
            } else {
                return EMPTY_DATA;
            }
        } catch (IOException ioe) {
            Log.w(TAG, "Couldn't backup " + filename);
            return EMPTY_DATA;
        } finally {
            IoUtils.closeQuietly(br);
        }
voidinitWifiRestoreIfNecessary()

        if (mWifiRestore == null) {
            mWifiRestore = new WifiRestoreRunnable();
        }
booleannetworkInWhitelist(com.android.providers.settings.SettingsBackupAgent$Network net, java.util.List whitelist)

        final String netConfigKey = net.configKey();
        final int N = whitelist.size();
        for (int i = 0; i < N; i++) {
            if (Objects.equals(netConfigKey, whitelist.get(i).configKey(true))) {
                return true;
            }
        }
        return false;
public voidonBackup(android.os.ParcelFileDescriptor oldState, android.app.backup.BackupDataOutput data, android.os.ParcelFileDescriptor newState)


        byte[] systemSettingsData = getSystemSettings();
        byte[] secureSettingsData = getSecureSettings();
        byte[] globalSettingsData = getGlobalSettings();
        byte[] locale = mSettingsHelper.getLocaleData();
        byte[] wifiSupplicantData = getWifiSupplicant(FILE_WIFI_SUPPLICANT);
        byte[] wifiConfigData = getFileData(mWifiConfigFile);

        long[] stateChecksums = readOldChecksums(oldState);

        stateChecksums[STATE_SYSTEM] =
            writeIfChanged(stateChecksums[STATE_SYSTEM], KEY_SYSTEM, systemSettingsData, data);
        stateChecksums[STATE_SECURE] =
            writeIfChanged(stateChecksums[STATE_SECURE], KEY_SECURE, secureSettingsData, data);
        stateChecksums[STATE_GLOBAL] =
            writeIfChanged(stateChecksums[STATE_GLOBAL], KEY_GLOBAL, globalSettingsData, data);
        stateChecksums[STATE_LOCALE] =
            writeIfChanged(stateChecksums[STATE_LOCALE], KEY_LOCALE, locale, data);
        stateChecksums[STATE_WIFI_SUPPLICANT] =
            writeIfChanged(stateChecksums[STATE_WIFI_SUPPLICANT], KEY_WIFI_SUPPLICANT,
                    wifiSupplicantData, data);
        stateChecksums[STATE_WIFI_CONFIG] =
            writeIfChanged(stateChecksums[STATE_WIFI_CONFIG], KEY_WIFI_CONFIG, wifiConfigData,
                    data);

        writeNewChecksums(stateChecksums, newState);
public voidonCreate()

        if (DEBUG_BACKUP) Log.d(TAG, "onCreate() invoked");

        mSettingsHelper = new SettingsHelper(this);
        super.onCreate();

        WifiManager mWfm = (WifiManager) getSystemService(Context.WIFI_SERVICE);
        if (mWfm != null) mWifiConfigFile = mWfm.getConfigFile();
public voidonFullBackup(android.app.backup.FullBackupDataOutput data)

        byte[] systemSettingsData = getSystemSettings();
        byte[] secureSettingsData = getSecureSettings();
        byte[] globalSettingsData = getGlobalSettings();
        byte[] locale = mSettingsHelper.getLocaleData();
        byte[] wifiSupplicantData = getWifiSupplicant(FILE_WIFI_SUPPLICANT);
        byte[] wifiConfigData = getFileData(mWifiConfigFile);

        // Write the data to the staging file, then emit that as our tarfile
        // representation of the backed-up settings.
        String root = getFilesDir().getAbsolutePath();
        File stage = new File(root, STAGE_FILE);
        try {
            FileOutputStream filestream = new FileOutputStream(stage);
            BufferedOutputStream bufstream = new BufferedOutputStream(filestream);
            DataOutputStream out = new DataOutputStream(bufstream);

            if (DEBUG_BACKUP) Log.d(TAG, "Writing flattened data version " + FULL_BACKUP_VERSION);
            out.writeInt(FULL_BACKUP_VERSION);

            if (DEBUG_BACKUP) Log.d(TAG, systemSettingsData.length + " bytes of settings data");
            out.writeInt(systemSettingsData.length);
            out.write(systemSettingsData);
            if (DEBUG_BACKUP) Log.d(TAG, secureSettingsData.length + " bytes of secure settings data");
            out.writeInt(secureSettingsData.length);
            out.write(secureSettingsData);
            if (DEBUG_BACKUP) Log.d(TAG, globalSettingsData.length + " bytes of global settings data");
            out.writeInt(globalSettingsData.length);
            out.write(globalSettingsData);
            if (DEBUG_BACKUP) Log.d(TAG, locale.length + " bytes of locale data");
            out.writeInt(locale.length);
            out.write(locale);
            if (DEBUG_BACKUP) Log.d(TAG, wifiSupplicantData.length + " bytes of wifi supplicant data");
            out.writeInt(wifiSupplicantData.length);
            out.write(wifiSupplicantData);
            if (DEBUG_BACKUP) Log.d(TAG, wifiConfigData.length + " bytes of wifi config data");
            out.writeInt(wifiConfigData.length);
            out.write(wifiConfigData);

            out.flush();    // also flushes downstream

            // now we're set to emit the tar stream
            fullBackupFile(stage, data);
        } finally {
            stage.delete();
        }
public voidonRestore(android.app.backup.BackupDataInput data, int appVersionCode, android.os.ParcelFileDescriptor newState)


        HashSet<String> movedToGlobal = new HashSet<String>();
        Settings.System.getMovedKeys(movedToGlobal);
        Settings.Secure.getMovedKeys(movedToGlobal);

        while (data.readNextHeader()) {
            final String key = data.getKey();
            final int size = data.getDataSize();
            if (KEY_SYSTEM.equals(key)) {
                restoreSettings(data, Settings.System.CONTENT_URI, movedToGlobal);
                mSettingsHelper.applyAudioSettings();
            } else if (KEY_SECURE.equals(key)) {
                restoreSettings(data, Settings.Secure.CONTENT_URI, movedToGlobal);
            } else if (KEY_GLOBAL.equals(key)) {
                restoreSettings(data, Settings.Global.CONTENT_URI, null);
            } else if (KEY_WIFI_SUPPLICANT.equals(key)) {
                initWifiRestoreIfNecessary();
                mWifiRestore.incorporateWifiSupplicant(data);
            } else if (KEY_LOCALE.equals(key)) {
                byte[] localeData = new byte[size];
                data.readEntityData(localeData, 0, size);
                mSettingsHelper.setLocaleData(localeData, size);
            } else if (KEY_WIFI_CONFIG.equals(key)) {
                initWifiRestoreIfNecessary();
                mWifiRestore.incorporateWifiConfigFile(data);
             } else {
                data.skipEntityData();
            }
        }

        // If we have wifi data to restore, post a runnable to perform the
        // bounce-and-update operation a little ways in the future.
        if (mWifiRestore != null) {
            long wifiBounceDelayMillis = Settings.Global.getLong(
                    getContentResolver(),
                    Settings.Global.WIFI_BOUNCE_DELAY_OVERRIDE_MS,
                    WIFI_BOUNCE_DELAY_MILLIS);
            new Handler(getMainLooper()).postDelayed(mWifiRestore, wifiBounceDelayMillis);
        }
public voidonRestoreFile(android.os.ParcelFileDescriptor data, long size, int type, java.lang.String domain, java.lang.String relpath, long mode, long mtime)

        if (DEBUG_BACKUP) Log.d(TAG, "onRestoreFile() invoked");
        // Our data is actually a blob of flattened settings data identical to that
        // produced during incremental backups.  Just unpack and apply it all in
        // turn.
        FileInputStream instream = new FileInputStream(data.getFileDescriptor());
        DataInputStream in = new DataInputStream(instream);

        int version = in.readInt();
        if (DEBUG_BACKUP) Log.d(TAG, "Flattened data version " + version);
        if (version <= FULL_BACKUP_VERSION) {
            // Generate the moved-to-global lookup table
            HashSet<String> movedToGlobal = new HashSet<String>();
            Settings.System.getMovedKeys(movedToGlobal);
            Settings.Secure.getMovedKeys(movedToGlobal);

            // system settings data first
            int nBytes = in.readInt();
            if (DEBUG_BACKUP) Log.d(TAG, nBytes + " bytes of settings data");
            byte[] buffer = new byte[nBytes];
            in.readFully(buffer, 0, nBytes);
            restoreSettings(buffer, nBytes, Settings.System.CONTENT_URI, movedToGlobal);

            // secure settings
            nBytes = in.readInt();
            if (DEBUG_BACKUP) Log.d(TAG, nBytes + " bytes of secure settings data");
            if (nBytes > buffer.length) buffer = new byte[nBytes];
            in.readFully(buffer, 0, nBytes);
            restoreSettings(buffer, nBytes, Settings.Secure.CONTENT_URI, movedToGlobal);

            // Global only if sufficiently new
            if (version >= FULL_BACKUP_ADDED_GLOBAL) {
                nBytes = in.readInt();
                if (DEBUG_BACKUP) Log.d(TAG, nBytes + " bytes of global settings data");
                if (nBytes > buffer.length) buffer = new byte[nBytes];
                in.readFully(buffer, 0, nBytes);
                movedToGlobal.clear();  // no redirection; this *is* the global namespace
                restoreSettings(buffer, nBytes, Settings.Global.CONTENT_URI, movedToGlobal);
            }

            // locale
            nBytes = in.readInt();
            if (DEBUG_BACKUP) Log.d(TAG, nBytes + " bytes of locale data");
            if (nBytes > buffer.length) buffer = new byte[nBytes];
            in.readFully(buffer, 0, nBytes);
            mSettingsHelper.setLocaleData(buffer, nBytes);

            // wifi supplicant
            nBytes = in.readInt();
            if (DEBUG_BACKUP) Log.d(TAG, nBytes + " bytes of wifi supplicant data");
            if (nBytes > buffer.length) buffer = new byte[nBytes];
            in.readFully(buffer, 0, nBytes);
            int retainedWifiState = enableWifi(false);
            restoreWifiSupplicant(FILE_WIFI_SUPPLICANT, buffer, nBytes);
            FileUtils.setPermissions(FILE_WIFI_SUPPLICANT,
                    FileUtils.S_IRUSR | FileUtils.S_IWUSR |
                    FileUtils.S_IRGRP | FileUtils.S_IWGRP,
                    Process.myUid(), Process.WIFI_UID);
            // retain the previous WIFI state.
            enableWifi(retainedWifiState == WifiManager.WIFI_STATE_ENABLED ||
                    retainedWifiState == WifiManager.WIFI_STATE_ENABLING);

            // wifi config
            nBytes = in.readInt();
            if (DEBUG_BACKUP) Log.d(TAG, nBytes + " bytes of wifi config data");
            if (nBytes > buffer.length) buffer = new byte[nBytes];
            in.readFully(buffer, 0, nBytes);
            restoreFileData(mWifiConfigFile, buffer, nBytes);

            if (DEBUG_BACKUP) Log.d(TAG, "Full restore complete.");
        } else {
            data.close();
            throw new IOException("Invalid file schema");
        }
private intreadInt(byte[] in, int pos)

        int result =
                ((in[pos    ] & 0xFF) << 24) |
                ((in[pos + 1] & 0xFF) << 16) |
                ((in[pos + 2] & 0xFF) <<  8) |
                ((in[pos + 3] & 0xFF) <<  0);
        return result;
private long[]readOldChecksums(android.os.ParcelFileDescriptor oldState)

        long[] stateChecksums = new long[STATE_SIZE];

        DataInputStream dataInput = new DataInputStream(
                new FileInputStream(oldState.getFileDescriptor()));

        try {
            int stateVersion = dataInput.readInt();
            for (int i = 0; i < STATE_SIZES[stateVersion]; i++) {
                stateChecksums[i] = dataInput.readLong();
            }
        } catch (EOFException eof) {
            // With the default 0 checksum we'll wind up forcing a backup of
            // any unhandled data sets, which is appropriate.
        }
        dataInput.close();
        return stateChecksums;
private voidrestoreFileData(java.lang.String filename, byte[] bytes, int size)

        try {
            File file = new File(filename);
            if (file.exists()) file.delete();

            OutputStream os = new BufferedOutputStream(new FileOutputStream(filename, true));
            os.write(bytes, 0, size);
            os.close();
        } catch (IOException ioe) {
            Log.w(TAG, "Couldn't restore " + filename);
        }
private voidrestoreSettings(android.app.backup.BackupDataInput data, android.net.Uri contentUri, java.util.HashSet movedToGlobal)

        byte[] settings = new byte[data.getDataSize()];
        try {
            data.readEntityData(settings, 0, settings.length);
        } catch (IOException ioe) {
            Log.e(TAG, "Couldn't read entity data");
            return;
        }
        restoreSettings(settings, settings.length, contentUri, movedToGlobal);
private voidrestoreSettings(byte[] settings, int bytes, android.net.Uri contentUri, java.util.HashSet movedToGlobal)

        if (DEBUG) {
            Log.i(TAG, "restoreSettings: " + contentUri);
        }

        // Figure out the white list and redirects to the global table.
        String[] whitelist = null;
        if (contentUri.equals(Settings.Secure.CONTENT_URI)) {
            whitelist = Settings.Secure.SETTINGS_TO_BACKUP;
        } else if (contentUri.equals(Settings.System.CONTENT_URI)) {
            whitelist = Settings.System.SETTINGS_TO_BACKUP;
        } else if (contentUri.equals(Settings.Global.CONTENT_URI)) {
            whitelist = Settings.Global.SETTINGS_TO_BACKUP;
        } else {
            throw new IllegalArgumentException("Unknown URI: " + contentUri);
        }

        // Restore only the white list data.
        int pos = 0;
        Map<String, String> cachedEntries = new HashMap<String, String>();
        ContentValues contentValues = new ContentValues(2);
        SettingsHelper settingsHelper = mSettingsHelper;

        final int whiteListSize = whitelist.length;
        for (int i = 0; i < whiteListSize; i++) {
            String key = whitelist[i];
            String value = cachedEntries.remove(key);

            // If the value not cached, let us look it up.
            if (value == null) {
                while (pos < bytes) {
                    int length = readInt(settings, pos);
                    pos += INTEGER_BYTE_COUNT;
                    String dataKey = length > 0 ? new String(settings, pos, length) : null;
                    pos += length;
                    length = readInt(settings, pos);
                    pos += INTEGER_BYTE_COUNT;
                    String dataValue = length > 0 ? new String(settings, pos, length) : null;
                    pos += length;
                    if (key.equals(dataKey)) {
                        value = dataValue;
                        break;
                    }
                    cachedEntries.put(dataKey, dataValue);
                }
            }

            if (value == null) {
                continue;
            }

            final Uri destination = (movedToGlobal != null && movedToGlobal.contains(key))
                    ? Settings.Global.CONTENT_URI
                    : contentUri;

            // The helper doesn't care what namespace the keys are in
            if (settingsHelper.restoreValue(key, value)) {
                contentValues.clear();
                contentValues.put(Settings.NameValueTable.NAME, key);
                contentValues.put(Settings.NameValueTable.VALUE, value);
                getContentResolver().insert(destination, contentValues);
            }

            if (DEBUG) {
                Log.d(TAG, "Restored setting: " + destination + " : "+ key + "=" + value);
            }
        }
private voidrestoreWifiSupplicant(java.lang.String filename, byte[] bytes, int size)

        try {
            WifiNetworkSettings supplicantImage = new WifiNetworkSettings();

            File supplicantFile = new File(FILE_WIFI_SUPPLICANT);
            if (supplicantFile.exists()) {
                // Retain the existing APs; we'll append the restored ones to them
                BufferedReader in = new BufferedReader(new FileReader(FILE_WIFI_SUPPLICANT));
                supplicantImage.readNetworks(in, null);
                in.close();

                supplicantFile.delete();
            }

            // Incorporate the restore AP information
            if (size > 0) {
                char[] restoredAsBytes = new char[size];
                for (int i = 0; i < size; i++) restoredAsBytes[i] = (char) bytes[i];
                BufferedReader in = new BufferedReader(new CharArrayReader(restoredAsBytes));
                supplicantImage.readNetworks(in, null);

                if (DEBUG_BACKUP) {
                    Log.v(TAG, "Final AP list:");
                    supplicantImage.dump();
                }
            }

            // Install the correct default template
            BufferedWriter bw = new BufferedWriter(new FileWriter(FILE_WIFI_SUPPLICANT));
            copyWifiSupplicantTemplate(bw);

            // Write the restored supplicant config and we're done
            supplicantImage.write(bw);
            bw.close();
        } catch (IOException ioe) {
            Log.w(TAG, "Couldn't restore " + filename);
        }
private intwriteBytes(byte[] out, int pos, byte[] value)

        System.arraycopy(value, 0, out, pos, value.length);
        return pos + value.length;
private longwriteIfChanged(long oldChecksum, java.lang.String key, byte[] data, android.app.backup.BackupDataOutput output)

        CRC32 checkSummer = new CRC32();
        checkSummer.update(data);
        long newChecksum = checkSummer.getValue();
        if (oldChecksum == newChecksum) {
            return oldChecksum;
        }
        try {
            output.writeEntityHeader(key, data.length);
            output.writeEntityData(data, data.length);
        } catch (IOException ioe) {
            // Bail
        }
        return newChecksum;
private intwriteInt(byte[] out, int pos, int value)
Write an int in BigEndian into the byte array.

param
out byte array
param
pos current pos in array
param
value integer to write
return
the index after adding the size of an int (4) in bytes.

        out[pos + 0] = (byte) ((value >> 24) & 0xFF);
        out[pos + 1] = (byte) ((value >> 16) & 0xFF);
        out[pos + 2] = (byte) ((value >>  8) & 0xFF);
        out[pos + 3] = (byte) ((value >>  0) & 0xFF);
        return pos + INTEGER_BYTE_COUNT;
private voidwriteNewChecksums(long[] checksums, android.os.ParcelFileDescriptor newState)

        DataOutputStream dataOutput = new DataOutputStream(
                new FileOutputStream(newState.getFileDescriptor()));

        dataOutput.writeInt(STATE_VERSION);
        for (int i = 0; i < STATE_SIZE; i++) {
            dataOutput.writeLong(checksums[i]);
        }
        dataOutput.close();