LatinIME/java/src/com/android/inputmethod/latin/BinaryDictionaryFileDumper.java
Jean Chalard d4cbc4fd07 Implement getting data files with protocol v2
This also does it for deleting them
Bug: 8167342
Bug: 6789534
Change-Id: I1823f98508881f109a667146d3608003f87aa4cb
2013-02-15 11:09:16 -08:00

453 lines
22 KiB
Java

/*
* Copyright (C) 2011 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.inputmethod.latin;
import android.content.ContentProviderClient;
import android.content.ContentResolver;
import android.content.ContentValues;
import android.content.Context;
import android.content.res.AssetFileDescriptor;
import android.database.Cursor;
import android.net.Uri;
import android.os.RemoteException;
import android.text.TextUtils;
import android.util.Log;
import com.android.inputmethod.latin.DictionaryInfoUtils.DictionaryInfo;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.Arrays;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Locale;
/**
* Group class for static methods to help with creation and getting of the binary dictionary
* file from the dictionary provider
*/
public final class BinaryDictionaryFileDumper {
private static final String TAG = BinaryDictionaryFileDumper.class.getSimpleName();
private static final boolean DEBUG = false;
/**
* The size of the temporary buffer to copy files.
*/
private static final int FILE_READ_BUFFER_SIZE = 8192;
// TODO: make the following data common with the native code
private static final byte[] MAGIC_NUMBER_VERSION_1 =
new byte[] { (byte)0x78, (byte)0xB1, (byte)0x00, (byte)0x00 };
private static final byte[] MAGIC_NUMBER_VERSION_2 =
new byte[] { (byte)0x9B, (byte)0xC1, (byte)0x3A, (byte)0xFE };
private static final String DICTIONARY_PROJECTION[] = { "id" };
private static final String QUERY_PARAMETER_MAY_PROMPT_USER = "mayPrompt";
private static final String QUERY_PARAMETER_TRUE = "true";
private static final String QUERY_PARAMETER_DELETE_RESULT = "result";
private static final String QUERY_PARAMETER_SUCCESS = "success";
private static final String QUERY_PARAMETER_FAILURE = "failure";
// Using protocol version 2 to communicate with the dictionary pack
private static final String QUERY_PARAMETER_PROTOCOL = "protocol";
private static final String QUERY_PARAMETER_PROTOCOL_VALUE = "2";
// The path fragment to append after the client ID for dictionary info requests.
private static final String QUERY_PATH_DICT_INFO = "dict";
// The path fragment to append after the client ID for dictionary datafile requests.
private static final String QUERY_PATH_DATAFILE = "datafile";
// The path fragment to append after the client ID for updating the metadata URI.
private static final String QUERY_PATH_METADATA = "metadata";
private static final String INSERT_METADATA_CLIENT_ID_COLUMN = "clientid";
private static final String INSERT_METADATA_METADATA_URI_COLUMN = "uri";
// Prevents this class to be accidentally instantiated.
private BinaryDictionaryFileDumper() {
}
/**
* Returns a URI builder pointing to the dictionary pack.
*
* This creates a URI builder able to build a URI pointing to the dictionary
* pack content provider for a specific dictionary id.
*/
private static Uri.Builder getProviderUriBuilder(final String path) {
return new Uri.Builder().scheme(ContentResolver.SCHEME_CONTENT)
.authority(BinaryDictionary.DICTIONARY_PACK_AUTHORITY).appendPath(
path);
}
/**
* Gets the content URI builder for a specified type.
*
* Supported types include QUERY_PATH_DICT_INFO, which takes the locale as
* the extraPath argument, and QUERY_PATH_DATAFILE, which needs a wordlist ID
* as the extraPath argument.
*
* @param clientId the clientId to use
* @param contentProviderClient the instance of content provider client
* @param queryPathType the path element encoding the type
* @param extraPath optional extra argument for this type (typically word list id)
* @return a builder that can build the URI for the best supported protocol version
* @throws RemoteException if the client can't be contacted
*/
private static Uri.Builder getContentUriBuilderForType(final String clientId,
final ContentProviderClient contentProviderClient, final String queryPathType,
final String extraPath) throws RemoteException {
// Check whether protocol v2 is supported by building a v2 URI and calling getType()
// on it. If this returns null, v2 is not supported.
final Uri.Builder uriV2Builder = getProviderUriBuilder(clientId);
uriV2Builder.appendPath(queryPathType);
uriV2Builder.appendPath(extraPath);
uriV2Builder.appendQueryParameter(QUERY_PARAMETER_PROTOCOL,
QUERY_PARAMETER_PROTOCOL_VALUE);
if (null != contentProviderClient.getType(uriV2Builder.build())) return uriV2Builder;
// Protocol v2 is not supported, so create and return the protocol v1 uri.
return getProviderUriBuilder(extraPath);
}
/**
* Queries a content provider for the list of word lists for a specific locale
* available to copy into Latin IME.
*/
private static List<WordListInfo> getWordListWordListInfos(final Locale locale,
final Context context, final boolean hasDefaultWordList) {
final String clientId = context.getString(R.string.dictionary_pack_client_id);
final ContentProviderClient client = context.getContentResolver().
acquireContentProviderClient(getProviderUriBuilder("").build());
if (null == client) return Collections.<WordListInfo>emptyList();
try {
final Uri.Builder builder = getContentUriBuilderForType(clientId, client,
QUERY_PATH_DICT_INFO, locale.toString());
if (!hasDefaultWordList) {
builder.appendQueryParameter(QUERY_PARAMETER_MAY_PROMPT_USER,
QUERY_PARAMETER_TRUE);
}
final Uri queryUri = builder.build();
final boolean isProtocolV2 = (QUERY_PARAMETER_PROTOCOL_VALUE.equals(
queryUri.getQueryParameter(QUERY_PARAMETER_PROTOCOL)));
Cursor c = client.query(queryUri, DICTIONARY_PROJECTION, null, null, null);
if (isProtocolV2 && null == c) {
reinitializeClientRecordInDictionaryContentProvider(context, client, clientId);
c = client.query(queryUri, DICTIONARY_PROJECTION, null, null, null);
}
if (null == c) return Collections.<WordListInfo>emptyList();
if (c.getCount() <= 0 || !c.moveToFirst()) {
c.close();
return Collections.<WordListInfo>emptyList();
}
final ArrayList<WordListInfo> list = CollectionUtils.newArrayList();
do {
final String wordListId = c.getString(0);
final String wordListLocale = c.getString(1);
if (TextUtils.isEmpty(wordListId)) continue;
list.add(new WordListInfo(wordListId, wordListLocale));
} while (c.moveToNext());
c.close();
return list;
} catch (RemoteException e) {
// The documentation is unclear as to in which cases this may happen, but it probably
// happens when the content provider got suddenly killed because it crashed or because
// the user disabled it through Settings.
Log.e(TAG, "RemoteException: communication with the dictionary pack cut", e);
return Collections.<WordListInfo>emptyList();
} catch (Exception e) {
// A crash here is dangerous because crashing here would brick any encrypted device -
// we need the keyboard to be up and working to enter the password, so we don't want
// to die no matter what. So let's be as safe as possible.
Log.e(TAG, "Unexpected exception communicating with the dictionary pack", e);
return Collections.<WordListInfo>emptyList();
} finally {
client.release();
}
}
/**
* Helper method to encapsulate exception handling.
*/
private static AssetFileDescriptor openAssetFileDescriptor(
final ContentProviderClient providerClient, final Uri uri) {
try {
return providerClient.openAssetFile(uri, "r");
} catch (FileNotFoundException e) {
// I don't want to log the word list URI here for security concerns. The exception
// contains the name of the file, so let's not pass it to Log.e here.
Log.e(TAG, "Could not find a word list from the dictionary provider."
/* intentionally don't pass the exception (see comment above) */);
return null;
} catch (RemoteException e) {
Log.e(TAG, "Can't communicate with the dictionary pack", e);
return null;
}
}
/**
* Caches a word list the id of which is passed as an argument. This will write the file
* to the cache file name designated by its id and locale, overwriting it if already present
* and creating it (and its containing directory) if necessary.
*/
private static AssetFileAddress cacheWordList(final String wordlistId, final String locale,
final ContentProviderClient providerClient, final Context context) {
final int COMPRESSED_CRYPTED_COMPRESSED = 0;
final int CRYPTED_COMPRESSED = 1;
final int COMPRESSED_CRYPTED = 2;
final int COMPRESSED_ONLY = 3;
final int CRYPTED_ONLY = 4;
final int NONE = 5;
final int MODE_MIN = COMPRESSED_CRYPTED_COMPRESSED;
final int MODE_MAX = NONE;
final String clientId = context.getString(R.string.dictionary_pack_client_id);
final Uri.Builder wordListUriBuilder;
try {
wordListUriBuilder = getContentUriBuilderForType(clientId,
providerClient, QUERY_PATH_DATAFILE, wordlistId /* extraPath */);
} catch (RemoteException e) {
Log.e(TAG, "Can't communicate with the dictionary pack", e);
return null;
}
final String finalFileName =
DictionaryInfoUtils.getCacheFileName(wordlistId, locale, context);
String tempFileName;
try {
tempFileName = BinaryDictionaryGetter.getTempFileName(wordlistId, context);
} catch (IOException e) {
Log.e(TAG, "Can't open the temporary file", e);
return null;
}
for (int mode = MODE_MIN; mode <= MODE_MAX; ++mode) {
InputStream originalSourceStream = null;
InputStream inputStream = null;
InputStream uncompressedStream = null;
InputStream decryptedStream = null;
BufferedInputStream bufferedInputStream = null;
File outputFile = null;
BufferedOutputStream bufferedOutputStream = null;
AssetFileDescriptor afd = null;
final Uri wordListUri = wordListUriBuilder.build();
try {
// Open input.
afd = openAssetFileDescriptor(providerClient, wordListUri);
// If we can't open it at all, don't even try a number of times.
if (null == afd) return null;
originalSourceStream = afd.createInputStream();
// Open output.
outputFile = new File(tempFileName);
// Just to be sure, delete the file. This may fail silently, and return false: this
// is the right thing to do, as we just want to continue anyway.
outputFile.delete();
// Get the appropriate decryption method for this try
switch (mode) {
case COMPRESSED_CRYPTED_COMPRESSED:
uncompressedStream =
FileTransforms.getUncompressedStream(originalSourceStream);
decryptedStream = FileTransforms.getDecryptedStream(uncompressedStream);
inputStream = FileTransforms.getUncompressedStream(decryptedStream);
break;
case CRYPTED_COMPRESSED:
decryptedStream = FileTransforms.getDecryptedStream(originalSourceStream);
inputStream = FileTransforms.getUncompressedStream(decryptedStream);
break;
case COMPRESSED_CRYPTED:
uncompressedStream =
FileTransforms.getUncompressedStream(originalSourceStream);
inputStream = FileTransforms.getDecryptedStream(uncompressedStream);
break;
case COMPRESSED_ONLY:
inputStream = FileTransforms.getUncompressedStream(originalSourceStream);
break;
case CRYPTED_ONLY:
inputStream = FileTransforms.getDecryptedStream(originalSourceStream);
break;
case NONE:
inputStream = originalSourceStream;
break;
}
bufferedInputStream = new BufferedInputStream(inputStream);
bufferedOutputStream = new BufferedOutputStream(new FileOutputStream(outputFile));
checkMagicAndCopyFileTo(bufferedInputStream, bufferedOutputStream);
bufferedOutputStream.flush();
bufferedOutputStream.close();
final File finalFile = new File(finalFileName);
finalFile.delete();
if (!outputFile.renameTo(finalFile)) {
throw new IOException("Can't move the file to its final name");
}
wordListUriBuilder.appendQueryParameter(QUERY_PARAMETER_DELETE_RESULT,
QUERY_PARAMETER_SUCCESS);
if (0 >= providerClient.delete(wordListUriBuilder.build(), null, null)) {
Log.e(TAG, "Could not have the dictionary pack delete a word list");
}
BinaryDictionaryGetter.removeFilesWithIdExcept(context, wordlistId, finalFile);
// Success! Close files (through the finally{} clause) and return.
return AssetFileAddress.makeFromFileName(finalFileName);
} catch (Exception e) {
if (DEBUG) {
Log.i(TAG, "Can't open word list in mode " + mode, e);
}
if (null != outputFile) {
// This may or may not fail. The file may not have been created if the
// exception was thrown before it could be. Hence, both failure and
// success are expected outcomes, so we don't check the return value.
outputFile.delete();
}
// Try the next method.
} finally {
// Ignore exceptions while closing files.
try {
// inputStream.close() will close afd, we should not call afd.close().
if (null != inputStream) inputStream.close();
if (null != uncompressedStream) uncompressedStream.close();
if (null != decryptedStream) decryptedStream.close();
if (null != bufferedInputStream) bufferedInputStream.close();
} catch (Exception e) {
Log.e(TAG, "Exception while closing a file descriptor", e);
}
try {
if (null != bufferedOutputStream) bufferedOutputStream.close();
} catch (Exception e) {
Log.e(TAG, "Exception while closing a file", e);
}
}
}
// We could not copy the file at all. This is very unexpected.
// I'd rather not print the word list ID to the log out of security concerns
Log.e(TAG, "Could not copy a word list. Will not be able to use it.");
// If we can't copy it we should warn the dictionary provider so that it can mark it
// as invalid.
wordListUriBuilder.appendQueryParameter(QUERY_PARAMETER_DELETE_RESULT,
QUERY_PARAMETER_FAILURE);
try {
if (0 >= providerClient.delete(wordListUriBuilder.build(), null, null)) {
Log.e(TAG, "In addition, we were unable to delete it.");
}
} catch (RemoteException e) {
Log.e(TAG, "In addition, communication with the dictionary provider was cut", e);
}
return null;
}
/**
* Queries a content provider for word list data for some locale and cache the returned files
*
* This will query a content provider for word list data for a given locale, and copy the
* files locally so that they can be mmap'ed. This may overwrite previously cached word lists
* with newer versions if a newer version is made available by the content provider.
* @returns the addresses of the word list files, or null if no data could be obtained.
* @throw FileNotFoundException if the provider returns non-existent data.
* @throw IOException if the provider-returned data could not be read.
*/
public static List<AssetFileAddress> cacheWordListsFromContentProvider(final Locale locale,
final Context context, final boolean hasDefaultWordList) {
final ContentProviderClient providerClient = context.getContentResolver().
acquireContentProviderClient(getProviderUriBuilder("").build());
if (null == providerClient) {
Log.e(TAG, "Can't establish communication with the dictionary provider");
return CollectionUtils.newArrayList();
}
try {
final List<WordListInfo> idList = getWordListWordListInfos(locale, context,
hasDefaultWordList);
final ArrayList<AssetFileAddress> fileAddressList = CollectionUtils.newArrayList();
for (WordListInfo id : idList) {
final AssetFileAddress afd =
cacheWordList(id.mId, id.mLocale, providerClient, context);
if (null != afd) {
fileAddressList.add(afd);
}
}
return fileAddressList;
} finally {
providerClient.release();
}
}
/**
* Copies the data in an input stream to a target file if the magic number matches.
*
* If the magic number does not match the expected value, this method throws an
* IOException. Other usual conditions for IOException or FileNotFoundException
* also apply.
*
* @param input the stream to be copied.
* @param output an output stream to copy the data to.
*/
public static void checkMagicAndCopyFileTo(final BufferedInputStream input,
final BufferedOutputStream output) throws FileNotFoundException, IOException {
// Check the magic number
final int length = MAGIC_NUMBER_VERSION_2.length;
final byte[] magicNumberBuffer = new byte[length];
final int readMagicNumberSize = input.read(magicNumberBuffer, 0, length);
if (readMagicNumberSize < length) {
throw new IOException("Less bytes to read than the magic number length");
}
if (!Arrays.equals(MAGIC_NUMBER_VERSION_2, magicNumberBuffer)) {
if (!Arrays.equals(MAGIC_NUMBER_VERSION_1, magicNumberBuffer)) {
throw new IOException("Wrong magic number for downloaded file");
}
}
output.write(magicNumberBuffer);
// Actually copy the file
final byte[] buffer = new byte[FILE_READ_BUFFER_SIZE];
for (int readBytes = input.read(buffer); readBytes >= 0; readBytes = input.read(buffer))
output.write(buffer, 0, readBytes);
input.close();
}
private static void reinitializeClientRecordInDictionaryContentProvider(final Context context,
final ContentProviderClient client, final String clientId) throws RemoteException {
final String metadataFileUri = context.getString(R.string.dictionary_pack_metadata_uri);
if (TextUtils.isEmpty(metadataFileUri)) return;
// Tell the content provider to reset all information about this client id
final Uri metadataContentUri = getProviderUriBuilder(clientId)
.appendPath(QUERY_PATH_METADATA)
.appendQueryParameter(QUERY_PARAMETER_PROTOCOL, QUERY_PARAMETER_PROTOCOL_VALUE)
.build();
client.delete(metadataContentUri, null, null);
// Update the metadata URI
final ContentValues metadataValues = new ContentValues();
metadataValues.put(INSERT_METADATA_CLIENT_ID_COLUMN, clientId);
metadataValues.put(INSERT_METADATA_METADATA_URI_COLUMN, metadataFileUri);
client.insert(metadataContentUri, metadataValues);
// Update the dictionary list.
final Uri dictionaryContentUriBase = getProviderUriBuilder(clientId)
.appendPath(QUERY_PATH_DICT_INFO)
.appendQueryParameter(QUERY_PARAMETER_PROTOCOL, QUERY_PARAMETER_PROTOCOL_VALUE)
.build();
final ArrayList<DictionaryInfo> dictionaryList =
DictionaryInfoUtils.getCurrentDictionaryFileNameAndVersionInfo(context);
final int length = dictionaryList.size();
for (int i = 0; i < length; ++i) {
final DictionaryInfo info = dictionaryList.get(i);
client.insert(Uri.withAppendedPath(dictionaryContentUriBase, info.mId),
info.toContentValues());
}
}
}