diff options
Diffstat (limited to 'java/src/com/android/inputmethod/latin/BinaryDictionaryFileDumper.java')
-rw-r--r-- | java/src/com/android/inputmethod/latin/BinaryDictionaryFileDumper.java | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/java/src/com/android/inputmethod/latin/BinaryDictionaryFileDumper.java b/java/src/com/android/inputmethod/latin/BinaryDictionaryFileDumper.java new file mode 100644 index 000000000..76a230f82 --- /dev/null +++ b/java/src/com/android/inputmethod/latin/BinaryDictionaryFileDumper.java @@ -0,0 +1,151 @@ +/* + * 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.net.Uri; +import android.text.TextUtils; + +import java.io.File; +import java.io.FileInputStream; +import java.io.FileNotFoundException; +import java.io.FileOutputStream; +import java.io.IOException; +import java.io.InputStream; +import java.util.Arrays; +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 { + /** + * The size of the temporary buffer to copy files. + */ + static final int FILE_READ_BUFFER_SIZE = 1024; + + // Prevents this class to be accidentally instantiated. + private BinaryDictionaryFileDumper() { + } + + /** + * Generates a file name that matches the locale passed as an argument. + * The file name is basically the result of the .toString() method, except we replace + * any @File.separator with an underscore to avoid generating a file name that may not + * be created. + * @param locale the locale for which to get the file name + * @param context the context to use for getting the directory + * @return the name of the file to be created + */ + private static String getCacheFileNameForLocale(Locale locale, Context context) { + // The following assumes two things : + // 1. That File.separator is not the same character as "_" + // I don't think any android system will ever use "_" as a path separator + // 2. That no two locales differ by only a File.separator versus a "_" + // Since "_" can't be part of locale components this should be safe. + // Examples: + // en -> en + // en_US_POSIX -> en_US_POSIX + // en__foo/bar -> en__foo_bar + final String[] separator = { File.separator }; + final String[] empty = { "_" }; + final CharSequence basename = TextUtils.replace(locale.toString(), separator, empty); + return context.getFilesDir() + File.separator + basename; + } + + /** + * Return for a given locale the provider URI to query to get the dictionary. + */ + public static Uri getProviderUri(Locale locale) { + return new Uri.Builder().scheme(ContentResolver.SCHEME_CONTENT) + .authority(BinaryDictionary.DICTIONARY_PACK_AUTHORITY).appendPath( + locale.toString()).build(); + } + + /** + * Queries a content provider for dictionary data for some locale and returns the file addresses + * + * This will query a content provider for dictionary data for a given locale, and return + * the addresses of a file set the members of which are suitable to be mmap'ed. It will copy + * them to local storage if needed. + * It should also check the dictionary versions to avoid unnecessary copies but this is + * still in TODO state. + * This will make the data from the content provider the cached dictionary for this locale, + * overwriting any previous cached data. + * @returns the addresses of the 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> getDictSetFromContentProvider(Locale locale, + Context context) throws FileNotFoundException, IOException { + // TODO: check whether the dictionary is the same or not and if it is, return the cached + // file. + // TODO: This should be able to read a number of files from the dictionary pack, copy + // them all and return them. + final ContentResolver resolver = context.getContentResolver(); + final Uri dictionaryPackUri = getProviderUri(locale); + final AssetFileDescriptor afd = resolver.openAssetFileDescriptor(dictionaryPackUri, "r"); + if (null == afd) return null; + final String fileName = + copyFileTo(afd.createInputStream(), getCacheFileNameForLocale(locale, context)); + return Arrays.asList(AssetFileAddress.makeFromFileName(fileName)); + } + + /** + * Accepts a file as dictionary data for some locale and returns the name of a file. + * + * This will make the data in the input file the cached dictionary for this locale, overwriting + * any previous cached data. + */ + public static String getDictionaryFileFromFile(String fileName, Locale locale, + Context context) throws FileNotFoundException, IOException { + return copyFileTo(new FileInputStream(fileName), getCacheFileNameForLocale(locale, + context)); + } + + /** + * Accepts a resource number as dictionary data for some locale and returns the name of a file. + * + * This will make the resource the cached dictionary for this locale, overwriting any previous + * cached data. + */ + public static String getDictionaryFileFromResource(int resource, Locale locale, + Context context) throws FileNotFoundException, IOException { + return copyFileTo(context.getResources().openRawResource(resource), + getCacheFileNameForLocale(locale, context)); + } + + /** + * Copies the data in an input stream to a target file, creating the file if necessary and + * overwriting it if it already exists. + * @param input the stream to be copied. + * @param outputFileName the name of a file to copy the data to. It is created if necessary. + */ + private static String copyFileTo(final InputStream input, final String outputFileName) + throws FileNotFoundException, IOException { + final byte[] buffer = new byte[FILE_READ_BUFFER_SIZE]; + final FileOutputStream output = new FileOutputStream(outputFileName); + for (int readBytes = input.read(buffer); readBytes >= 0; readBytes = input.read(buffer)) + output.write(buffer, 0, readBytes); + input.close(); + return outputFileName; + } +} |