| /* |
| * 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.ContentResolver; |
| import android.content.Context; |
| import android.content.res.AssetFileDescriptor; |
| import android.database.Cursor; |
| import android.net.Uri; |
| import android.text.TextUtils; |
| import android.util.Log; |
| |
| import java.io.BufferedInputStream; |
| import java.io.File; |
| import java.io.FileNotFoundException; |
| import java.io.FileOutputStream; |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.util.ArrayList; |
| import java.util.Arrays; |
| 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 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 = 1024; |
| // 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" }; |
| |
| public static final String QUERY_PARAMETER_MAY_PROMPT_USER = "mayPrompt"; |
| public static final String QUERY_PARAMETER_TRUE = "true"; |
| public static final String QUERY_PARAMETER_DELETE_RESULT = "result"; |
| public static final String QUERY_PARAMETER_SUCCESS = "success"; |
| public static final String QUERY_PARAMETER_FAILURE = "failure"; |
| |
| // 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); |
| } |
| |
| /** |
| * 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 ContentResolver resolver = context.getContentResolver(); |
| final Uri.Builder builder = getProviderUriBuilder(locale.toString()); |
| if (!hasDefaultWordList) { |
| builder.appendQueryParameter(QUERY_PARAMETER_MAY_PROMPT_USER, QUERY_PARAMETER_TRUE); |
| } |
| final Uri dictionaryPackUri = builder.build(); |
| |
| final Cursor c = resolver.query(dictionaryPackUri, DICTIONARY_PROJECTION, null, null, null); |
| if (null == c) return Collections.<WordListInfo>emptyList(); |
| if (c.getCount() <= 0 || !c.moveToFirst()) { |
| c.close(); |
| return Collections.<WordListInfo>emptyList(); |
| } |
| |
| try { |
| final List<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 (Exception e) { |
| // Just in case we hit a problem in communication with the dictionary pack. |
| // We don't want to die. |
| Log.e(TAG, "Exception communicating with the dictionary pack : " + e); |
| return Collections.<WordListInfo>emptyList(); |
| } |
| } |
| |
| |
| /** |
| * Helper method to encapsulate exception handling. |
| */ |
| private static AssetFileDescriptor openAssetFileDescriptor(final ContentResolver resolver, |
| final Uri uri) { |
| try { |
| return resolver.openAssetFileDescriptor(uri, "r"); |
| } catch (FileNotFoundException e) { |
| // I don't want to log the word list URI here for security concerns |
| Log.e(TAG, "Could not find a word list from the dictionary provider."); |
| 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 id, final String locale, |
| final ContentResolver resolver, 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 Uri.Builder wordListUriBuilder = getProviderUriBuilder(id); |
| final String finalFileName = BinaryDictionaryGetter.getCacheFileName(id, locale, context); |
| final String tempFileName = finalFileName + ".tmp"; |
| |
| for (int mode = MODE_MIN; mode <= MODE_MAX; ++mode) { |
| InputStream originalSourceStream = null; |
| InputStream inputStream = null; |
| File outputFile = null; |
| FileOutputStream outputStream = null; |
| AssetFileDescriptor afd = null; |
| final Uri wordListUri = wordListUriBuilder.build(); |
| try { |
| // Open input. |
| afd = openAssetFileDescriptor(resolver, 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(); |
| outputStream = new FileOutputStream(outputFile); |
| // Get the appropriate decryption method for this try |
| switch (mode) { |
| case COMPRESSED_CRYPTED_COMPRESSED: |
| inputStream = FileTransforms.getUncompressedStream( |
| FileTransforms.getDecryptedStream( |
| FileTransforms.getUncompressedStream( |
| originalSourceStream))); |
| break; |
| case CRYPTED_COMPRESSED: |
| inputStream = FileTransforms.getUncompressedStream( |
| FileTransforms.getDecryptedStream(originalSourceStream)); |
| break; |
| case COMPRESSED_CRYPTED: |
| inputStream = FileTransforms.getDecryptedStream( |
| FileTransforms.getUncompressedStream(originalSourceStream)); |
| break; |
| case COMPRESSED_ONLY: |
| inputStream = FileTransforms.getUncompressedStream(originalSourceStream); |
| break; |
| case CRYPTED_ONLY: |
| inputStream = FileTransforms.getDecryptedStream(originalSourceStream); |
| break; |
| case NONE: |
| inputStream = originalSourceStream; |
| break; |
| } |
| checkMagicAndCopyFileTo(new BufferedInputStream(inputStream), outputStream); |
| outputStream.flush(); |
| outputStream.close(); |
| final File finalFile = new File(finalFileName); |
| 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 >= resolver.delete(wordListUriBuilder.build(), null, null)) { |
| Log.e(TAG, "Could not have the dictionary pack delete a word list"); |
| } |
| BinaryDictionaryGetter.removeFilesWithIdExcept(context, id, 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(); |
| } catch (Exception e) { |
| Log.e(TAG, "Exception while closing a cross-process file descriptor : " + e); |
| } |
| try { |
| if (null != outputStream) outputStream.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); |
| if (0 >= resolver.delete(wordListUriBuilder.build(), null, null)) { |
| Log.e(TAG, "In addition, we were unable to delete it."); |
| } |
| 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 ContentResolver resolver = context.getContentResolver(); |
| final List<WordListInfo> idList = getWordListWordListInfos(locale, context, |
| hasDefaultWordList); |
| final List<AssetFileAddress> fileAddressList = CollectionUtils.newArrayList(); |
| for (WordListInfo id : idList) { |
| final AssetFileAddress afd = cacheWordList(id.mId, id.mLocale, resolver, context); |
| if (null != afd) { |
| fileAddressList.add(afd); |
| } |
| } |
| return fileAddressList; |
| } |
| |
| /** |
| * 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. |
| */ |
| private static void checkMagicAndCopyFileTo(final BufferedInputStream input, |
| final FileOutputStream 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(); |
| } |
| } |