/* * 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.dictionarypack.DictionaryPackConstants; import com.android.inputmethod.latin.utils.CollectionUtils; import com.android.inputmethod.latin.utils.DictionaryInfoUtils; import com.android.inputmethod.latin.utils.DictionaryInfoUtils.DictionaryInfo; import com.android.inputmethod.latin.utils.MetadataFileUriGetter; import java.io.BufferedInputStream; import java.io.BufferedOutputStream; import java.io.Closeable; 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"; private static final String INSERT_METADATA_METADATA_ADDITIONAL_ID_COLUMN = "additionalid"; // 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(DictionaryPackConstants.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 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.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.emptyList(); if (c.getCount() <= 0 || !c.moveToFirst()) { c.close(); return Collections.emptyList(); } final ArrayList 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.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.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 void 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; } 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; } for (int mode = MODE_MIN; mode <= MODE_MAX; ++mode) { final InputStream originalSourceStream; 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; 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; } 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. closeAssetFileDescriptorAndReportAnyException(afd); closeCloseableAndReportAnyException(inputStream); closeCloseableAndReportAnyException(uncompressedStream); closeCloseableAndReportAnyException(decryptedStream); closeCloseableAndReportAnyException(bufferedInputStream); closeCloseableAndReportAnyException(bufferedOutputStream); } } // 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); } } // Ideally the two following methods should be merged, but AssetFileDescriptor does not // implement Closeable although it does implement #close(), and Java does not have // structural typing. private static void closeAssetFileDescriptorAndReportAnyException( final AssetFileDescriptor file) { try { if (null != file) file.close(); } catch (Exception e) { Log.e(TAG, "Exception while closing a file", e); } } private static void closeCloseableAndReportAnyException(final Closeable file) { try { if (null != file) file.close(); } catch (Exception e) { Log.e(TAG, "Exception while closing a file", e); } } /** * 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. * @throw FileNotFoundException if the provider returns non-existent data. * @throw IOException if the provider-returned data could not be read. */ public static void cacheWordListsFromContentProvider(final Locale locale, final Context context, final boolean hasDefaultWordList) { final ContentProviderClient providerClient; try { providerClient = context.getContentResolver(). acquireContentProviderClient(getProviderUriBuilder("").build()); } catch (final SecurityException e) { Log.e(TAG, "No permission to communicate with the dictionary provider", e); return; } if (null == providerClient) { Log.e(TAG, "Can't establish communication with the dictionary provider"); return; } try { final List idList = getWordListWordListInfos(locale, context, hasDefaultWordList); for (WordListInfo id : idList) { cacheWordList(id.mId, id.mLocale, providerClient, context); } } 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 = MetadataFileUriGetter.getMetadataUri(context); final String metadataAdditionalId = MetadataFileUriGetter.getMetadataAdditionalId(context); // 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); metadataValues.put(INSERT_METADATA_METADATA_ADDITIONAL_ID_COLUMN, metadataAdditionalId); 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 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()); } } /** * Initialize a client record with the dictionary content provider. * * This merely acquires the content provider and calls * #reinitializeClientRecordInDictionaryContentProvider. * * @param context the context for resources and providers. * @param clientId the client ID to use. */ public static void initializeClientRecordHelper(final Context context, final String clientId) { try { final ContentProviderClient client = context.getContentResolver(). acquireContentProviderClient(getProviderUriBuilder("").build()); if (null == client) return; reinitializeClientRecordInDictionaryContentProvider(context, client, clientId); } catch (RemoteException e) { Log.e(TAG, "Cannot contact the dictionary content provider", e); } } }