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/*
* 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 com.android.browser;
import android.app.backup.BackupAgent;
import android.app.backup.BackupDataInput;
import android.app.backup.BackupDataOutput;
import android.content.ContentValues;
import android.database.Cursor;
import android.os.ParcelFileDescriptor;
import android.provider.BrowserContract;
import android.provider.BrowserContract.Bookmarks;
import android.util.Log;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.EOFException;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.zip.CRC32;
/**
* Settings backup agent for the Android browser. Currently the only thing
* stored is the set of bookmarks. It's okay if I/O exceptions are thrown
* out of the agent; the calling code handles it and the backup operation
* simply fails.
*
* @hide
*/
public class BrowserBackupAgent extends BackupAgent {
static final String TAG = "BrowserBackupAgent";
static final boolean DEBUG = false;
static final String BOOKMARK_KEY = "_bookmarks_";
/** this version num MUST be incremented if the flattened-file schema ever changes */
static final int BACKUP_AGENT_VERSION = 0;
/**
* This simply preserves the existing state as we now prefer Chrome Sync
* to handle bookmark backup.
*/
@Override
public void onBackup(ParcelFileDescriptor oldState, BackupDataOutput data,
ParcelFileDescriptor newState) throws IOException {
long savedFileSize = -1;
long savedCrc = -1;
int savedVersion = -1;
// Extract the previous bookmark file size & CRC from the saved state
DataInputStream in = new DataInputStream(
new FileInputStream(oldState.getFileDescriptor()));
try {
savedFileSize = in.readLong();
savedCrc = in.readLong();
savedVersion = in.readInt();
} catch (EOFException e) {
// It means we had no previous state; that's fine
return;
} finally {
if (in != null) {
in.close();
}
}
// Write the existing state
writeBackupState(savedFileSize, savedCrc, newState);
}
/**
* Restore from backup -- reads in the flattened bookmark file as supplied from
* the backup service, parses that out, and rebuilds the bookmarks table in the
* browser database from it.
*/
@Override
public void onRestore(BackupDataInput data, int appVersionCode,
ParcelFileDescriptor newState) throws IOException {
long crc = -1;
File tmpfile = File.createTempFile("rst", null, getFilesDir());
try {
while (data.readNextHeader()) {
if (BOOKMARK_KEY.equals(data.getKey())) {
// Read the flattened bookmark data into a temp file
crc = copyBackupToFile(data, tmpfile, data.getDataSize());
FileInputStream infstream = new FileInputStream(tmpfile);
DataInputStream in = new DataInputStream(infstream);
try {
int count = in.readInt();
ArrayList<Bookmark> bookmarks = new ArrayList<Bookmark>(count);
// Read all the bookmarks, then process later -- if we can't read
// all the data successfully, we don't touch the bookmarks table
for (int i = 0; i < count; i++) {
Bookmark mark = new Bookmark();
mark.url = in.readUTF();
mark.visits = in.readInt();
mark.date = in.readLong();
mark.created = in.readLong();
mark.title = in.readUTF();
bookmarks.add(mark);
}
// Okay, we have all the bookmarks -- now see if we need to add
// them to the browser's database
int N = bookmarks.size();
int nUnique = 0;
if (DEBUG) Log.v(TAG, "Restoring " + N + " bookmarks");
String[] urlCol = new String[] { Bookmarks.URL };
for (int i = 0; i < N; i++) {
Bookmark mark = bookmarks.get(i);
// Does this URL exist in the bookmark table?
Cursor cursor = getContentResolver().query(
Bookmarks.CONTENT_URI, urlCol,
Bookmarks.URL + " == ?",
new String[] { mark.url }, null);
// if not, insert it
if (cursor.getCount() <= 0) {
if (DEBUG) Log.v(TAG, "Did not see url: " + mark.url);
addBookmark(mark);
nUnique++;
} else {
if (DEBUG) Log.v(TAG, "Skipping extant url: " + mark.url);
}
cursor.close();
}
Log.i(TAG, "Restored " + nUnique + " of " + N + " bookmarks");
} catch (IOException ioe) {
Log.w(TAG, "Bad backup data; not restoring");
crc = -1;
} finally {
if (in != null) {
in.close();
}
}
}
// Last, write the state we just restored from so we can discern
// changes whenever we get invoked for backup in the future
writeBackupState(tmpfile.length(), crc, newState);
}
} finally {
// Whatever happens, delete the temp file
tmpfile.delete();
}
}
void addBookmark(Bookmark mark) {
ContentValues values = new ContentValues();
values.put(Bookmarks.TITLE, mark.title);
values.put(Bookmarks.URL, mark.url);
values.put(Bookmarks.IS_FOLDER, 0);
values.put(Bookmarks.DATE_CREATED, mark.created);
values.put(Bookmarks.DATE_MODIFIED, mark.date);
getContentResolver().insert(Bookmarks.CONTENT_URI, values);
}
static class Bookmark {
public String url;
public int visits;
public long date;
public long created;
public String title;
}
/*
* Utility functions
*/
// Read the given file from backup to a file, calculating a CRC32 along the way
private long copyBackupToFile(BackupDataInput data, File file, int toRead)
throws IOException {
final int CHUNK = 8192;
byte[] buf = new byte[CHUNK];
CRC32 crc = new CRC32();
FileOutputStream out = new FileOutputStream(file);
try {
while (toRead > 0) {
int numRead = data.readEntityData(buf, 0, CHUNK);
crc.update(buf, 0, numRead);
out.write(buf, 0, numRead);
toRead -= numRead;
}
} finally {
if (out != null) {
out.close();
}
}
return crc.getValue();
}
// Write the given metrics to the new state file
private void writeBackupState(long fileSize, long crc, ParcelFileDescriptor stateFile)
throws IOException {
DataOutputStream out = new DataOutputStream(
new FileOutputStream(stateFile.getFileDescriptor()));
try {
out.writeLong(fileSize);
out.writeLong(crc);
out.writeInt(BACKUP_AGENT_VERSION);
} finally {
if (out != null) {
out.close();
}
}
}
}
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