Move util classes to the latin/utils directory

Change-Id: I1c5b27c8edf231680edb8d96f63b9d04cfc6a6fa

1 files changed, 366 insertions, 0 deletions

diff --git a/java/src/com/android/inputmethod/latin/utils/DictionaryInfoUtils.java b/java/src/com/android/inputmethod/latin/utils/DictionaryInfoUtils.java
new file mode 100644
index 000000000..b3d37d78c
--- /dev/null
+++ b/java/src/com/android/inputmethod/latin/utils/DictionaryInfoUtils.java
@@ -0,0 +1,366 @@
+/*
+ * Copyright (C) 2013 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.utils;
+
+import android.content.ContentValues;
+import android.content.Context;
+import android.content.res.AssetManager;
+import android.content.res.Resources;
+import android.text.format.DateUtils;
+import android.util.Log;
+
+import com.android.inputmethod.latin.AssetFileAddress;
+import com.android.inputmethod.latin.BinaryDictionaryGetter;
+import com.android.inputmethod.latin.R;
+import com.android.inputmethod.latin.makedict.BinaryDictIOUtils;
+import com.android.inputmethod.latin.makedict.FormatSpec.FileHeader;
+import com.android.inputmethod.latin.makedict.UnsupportedFormatException;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.Locale;
+
+/**
+ * This class encapsulates the logic for the Latin-IME side of dictionary information management.
+ */
+public class DictionaryInfoUtils {
+    private static final String TAG = DictionaryInfoUtils.class.getSimpleName();
+    private static final String RESOURCE_PACKAGE_NAME = R.class.getPackage().getName();
+    private static final String DEFAULT_MAIN_DICT = "main";
+    private static final String MAIN_DICT_PREFIX = "main_";
+    // 6 digits - unicode is limited to 21 bits
+    private static final int MAX_HEX_DIGITS_FOR_CODEPOINT = 6;
+
+    public static class DictionaryInfo {
+        private static final String LOCALE_COLUMN = "locale";
+        private static final String WORDLISTID_COLUMN = "id";
+        private static final String LOCAL_FILENAME_COLUMN = "filename";
+        private static final String DESCRIPTION_COLUMN = "description";
+        private static final String DATE_COLUMN = "date";
+        private static final String FILESIZE_COLUMN = "filesize";
+        private static final String VERSION_COLUMN = "version";
+        public final String mId;
+        public final Locale mLocale;
+        public final String mDescription;
+        public final AssetFileAddress mFileAddress;
+        public final int mVersion;
+        public DictionaryInfo(final String id, final Locale locale, final String description,
+                final AssetFileAddress fileAddress, final int version) {
+            mId = id;
+            mLocale = locale;
+            mDescription = description;
+            mFileAddress = fileAddress;
+            mVersion = version;
+        }
+        public ContentValues toContentValues() {
+            final ContentValues values = new ContentValues();
+            values.put(WORDLISTID_COLUMN, mId);
+            values.put(LOCALE_COLUMN, mLocale.toString());
+            values.put(DESCRIPTION_COLUMN, mDescription);
+            values.put(LOCAL_FILENAME_COLUMN, mFileAddress.mFilename);
+            values.put(DATE_COLUMN,
+                    new File(mFileAddress.mFilename).lastModified() / DateUtils.SECOND_IN_MILLIS);
+            values.put(FILESIZE_COLUMN, mFileAddress.mLength);
+            values.put(VERSION_COLUMN, mVersion);
+            return values;
+        }
+    }
+
+    private DictionaryInfoUtils() {
+        // Private constructor to forbid instantation of this helper class.
+    }
+
+    /**
+     * Returns whether we may want to use this character as part of a file name.
+     *
+     * This basically only accepts ascii letters and numbers, and rejects everything else.
+     */
+    private static boolean isFileNameCharacter(int codePoint) {
+        if (codePoint >= 0x30 && codePoint <= 0x39) return true; // Digit
+        if (codePoint >= 0x41 && codePoint <= 0x5A) return true; // Uppercase
+        if (codePoint >= 0x61 && codePoint <= 0x7A) return true; // Lowercase
+        return codePoint == '_'; // Underscore
+    }
+
+    /**
+     * Escapes a string for any characters that may be suspicious for a file or directory name.
+     *
+     * Concretely this does a sort of URL-encoding except it will encode everything that's not
+     * alphanumeric or underscore. (true URL-encoding leaves alone characters like '*', which
+     * we cannot allow here)
+     */
+    // TODO: create a unit test for this method
+    public static String replaceFileNameDangerousCharacters(final String name) {
+        // This assumes '%' is fully available as a non-separator, normal
+        // character in a file name. This is probably true for all file systems.
+        final StringBuilder sb = new StringBuilder();
+        final int nameLength = name.length();
+        for (int i = 0; i < nameLength; i = name.offsetByCodePoints(i, 1)) {
+            final int codePoint = name.codePointAt(i);
+            if (DictionaryInfoUtils.isFileNameCharacter(codePoint)) {
+                sb.appendCodePoint(codePoint);
+            } else {
+                sb.append(String.format((Locale)null, "%%%1$0" + MAX_HEX_DIGITS_FOR_CODEPOINT + "x",
+                        codePoint));
+            }
+        }
+        return sb.toString();
+    }
+
+    /**
+     * Helper method to get the top level cache directory.
+     */
+    private static String getWordListCacheDirectory(final Context context) {
+        return context.getFilesDir() + File.separator + "dicts";
+    }
+
+    /**
+     * Helper method to get the top level temp directory.
+     */
+    public static String getWordListTempDirectory(final Context context) {
+        return context.getFilesDir() + File.separator + "tmp";
+    }
+
+    /**
+     * Reverse escaping done by replaceFileNameDangerousCharacters.
+     */
+    public static String getWordListIdFromFileName(final String fname) {
+        final StringBuilder sb = new StringBuilder();
+        final int fnameLength = fname.length();
+        for (int i = 0; i < fnameLength; i = fname.offsetByCodePoints(i, 1)) {
+            final int codePoint = fname.codePointAt(i);
+            if ('%' != codePoint) {
+                sb.appendCodePoint(codePoint);
+            } else {
+                // + 1 to pass the % sign
+                final int encodedCodePoint = Integer.parseInt(
+                        fname.substring(i + 1, i + 1 + MAX_HEX_DIGITS_FOR_CODEPOINT), 16);
+                i += MAX_HEX_DIGITS_FOR_CODEPOINT;
+                sb.appendCodePoint(encodedCodePoint);
+            }
+        }
+        return sb.toString();
+    }
+
+    /**
+     * Helper method to the list of cache directories, one for each distinct locale.
+     */
+    public static File[] getCachedDirectoryList(final Context context) {
+        return new File(DictionaryInfoUtils.getWordListCacheDirectory(context)).listFiles();
+    }
+
+    /**
+     * Returns the category for a given file name.
+     *
+     * This parses the file name, extracts the category, and returns it. See
+     * {@link #getMainDictId(Locale)} and {@link #isMainWordListId(String)}.
+     * @return The category as a string or null if it can't be found in the file name.
+     */
+    public static String getCategoryFromFileName(final String fileName) {
+        final String id = getWordListIdFromFileName(fileName);
+        final String[] idArray = id.split(BinaryDictionaryGetter.ID_CATEGORY_SEPARATOR);
+        // An id is supposed to be in format category:locale, so splitting on the separator
+        // should yield a 2-elements array
+        if (2 != idArray.length) return null;
+        return idArray[0];
+    }
+
+    /**
+     * Find out the cache directory associated with a specific locale.
+     */
+    private static String getCacheDirectoryForLocale(final String locale, final Context context) {
+        final String relativeDirectoryName = replaceFileNameDangerousCharacters(locale);
+        final String absoluteDirectoryName = getWordListCacheDirectory(context) + File.separator
+                + relativeDirectoryName;
+        final File directory = new File(absoluteDirectoryName);
+        if (!directory.exists()) {
+            if (!directory.mkdirs()) {
+                Log.e(TAG, "Could not create the directory for locale" + locale);
+            }
+        }
+        return absoluteDirectoryName;
+    }
+
+    /**
+     * Generates a file name for the id and locale passed as an argument.
+     *
+     * In the current implementation the file name returned will always be unique for
+     * any id/locale pair, but please do not expect that the id can be the same for
+     * different dictionaries with different locales. An id should be unique for any
+     * dictionary.
+     * The file name is pretty much an URL-encoded version of the id inside a directory
+     * named like the locale, except it will also escape characters that look dangerous
+     * to some file systems.
+     * @param id the id of the dictionary for which to get a file name
+     * @param locale the locale for which to get the file name as a string
+     * @param context the context to use for getting the directory
+     * @return the name of the file to be created
+     */
+    public static String getCacheFileName(String id, String locale, Context context) {
+        final String fileName = replaceFileNameDangerousCharacters(id);
+        return getCacheDirectoryForLocale(locale, context) + File.separator + fileName;
+    }
+
+    public static boolean isMainWordListId(final String id) {
+        final String[] idArray = id.split(BinaryDictionaryGetter.ID_CATEGORY_SEPARATOR);
+        // An id is supposed to be in format category:locale, so splitting on the separator
+        // should yield a 2-elements array
+        if (2 != idArray.length) return false;
+        return BinaryDictionaryGetter.MAIN_DICTIONARY_CATEGORY.equals(idArray[0]);
+    }
+
+    /**
+     * Helper method to return a dictionary res id for a locale, or 0 if none.
+     * @param locale dictionary locale
+     * @return main dictionary resource id
+     */
+    public static int getMainDictionaryResourceIdIfAvailableForLocale(final Resources res,
+            final Locale locale) {
+        int resId;
+        // Try to find main_language_country dictionary.
+        if (!locale.getCountry().isEmpty()) {
+            final String dictLanguageCountry =
+                    MAIN_DICT_PREFIX + locale.toString().toLowerCase(Locale.ROOT);
+            if ((resId = res.getIdentifier(
+                    dictLanguageCountry, "raw", RESOURCE_PACKAGE_NAME)) != 0) {
+                return resId;
+            }
+        }
+
+        // Try to find main_language dictionary.
+        final String dictLanguage = MAIN_DICT_PREFIX + locale.getLanguage();
+        if ((resId = res.getIdentifier(dictLanguage, "raw", RESOURCE_PACKAGE_NAME)) != 0) {
+            return resId;
+        }
+
+        // Not found, return 0
+        return 0;
+    }
+
+    /**
+     * Returns a main dictionary resource id
+     * @param locale dictionary locale
+     * @return main dictionary resource id
+     */
+    public static int getMainDictionaryResourceId(final Resources res, final Locale locale) {
+        int resourceId = getMainDictionaryResourceIdIfAvailableForLocale(res, locale);
+        if (0 != resourceId) return resourceId;
+        return res.getIdentifier(DEFAULT_MAIN_DICT, "raw", RESOURCE_PACKAGE_NAME);
+    }
+
+    /**
+     * Returns the id associated with the main word list for a specified locale.
+     *
+     * Word lists stored in Android Keyboard's resources are referred to as the "main"
+     * word lists. Since they can be updated like any other list, we need to assign a
+     * unique ID to them. This ID is just the name of the language (locale-wise) they
+     * are for, and this method returns this ID.
+     */
+    public static String getMainDictId(final Locale locale) {
+        // This works because we don't include by default different dictionaries for
+        // different countries. This actually needs to return the id that we would
+        // like to use for word lists included in resources, and the following is okay.
+        return BinaryDictionaryGetter.MAIN_DICTIONARY_CATEGORY +
+                BinaryDictionaryGetter.ID_CATEGORY_SEPARATOR + locale.getLanguage().toString();
+    }
+
+    public static FileHeader getDictionaryFileHeaderOrNull(final File file) {
+        try {
+            return BinaryDictIOUtils.getDictionaryFileHeader(file, 0, file.length());
+        } catch (UnsupportedFormatException e) {
+            return null;
+        } catch (IOException e) {
+            return null;
+        }
+    }
+
+    private static DictionaryInfo createDictionaryInfoFromFileAddress(
+            final AssetFileAddress fileAddress) {
+        final FileHeader header = BinaryDictIOUtils.getDictionaryFileHeaderOrNull(
+                new File(fileAddress.mFilename), fileAddress.mOffset, fileAddress.mLength);
+        final String id = header.getId();
+        final Locale locale = LocaleUtils.constructLocaleFromString(header.getLocaleString());
+        final String description = header.getDescription();
+        final String version = header.getVersion();
+        return new DictionaryInfo(id, locale, description, fileAddress, Integer.parseInt(version));
+    }
+
+    private static void addOrUpdateDictInfo(final ArrayList<DictionaryInfo> dictList,
+            final DictionaryInfo newElement) {
+        final Iterator<DictionaryInfo> iter = dictList.iterator();
+        while (iter.hasNext()) {
+            final DictionaryInfo thisDictInfo = iter.next();
+            if (thisDictInfo.mLocale.equals(newElement.mLocale)) {
+                if (newElement.mVersion <= thisDictInfo.mVersion) {
+                    return;
+                }
+                iter.remove();
+            }
+        }
+        dictList.add(newElement);
+    }
+
+    public static ArrayList<DictionaryInfo> getCurrentDictionaryFileNameAndVersionInfo(
+            final Context context) {
+        final ArrayList<DictionaryInfo> dictList = CollectionUtils.newArrayList();
+
+        // Retrieve downloaded dictionaries
+        final File[] directoryList = getCachedDirectoryList(context);
+        if (null != directoryList) {
+            for (final File directory : directoryList) {
+                final String localeString = getWordListIdFromFileName(directory.getName());
+                File[] dicts = BinaryDictionaryGetter.getCachedWordLists(localeString, context);
+                for (final File dict : dicts) {
+                    final String wordListId = getWordListIdFromFileName(dict.getName());
+                    if (!DictionaryInfoUtils.isMainWordListId(wordListId)) continue;
+                    final Locale locale = LocaleUtils.constructLocaleFromString(localeString);
+                    final AssetFileAddress fileAddress = AssetFileAddress.makeFromFile(dict);
+                    final DictionaryInfo dictionaryInfo =
+                            createDictionaryInfoFromFileAddress(fileAddress);
+                    // Protect against cases of a less-specific dictionary being found, like an
+                    // en dictionary being used for an en_US locale. In this case, the en dictionary
+                    // should be used for en_US but discounted for listing purposes.
+                    if (!dictionaryInfo.mLocale.equals(locale)) continue;
+                    addOrUpdateDictInfo(dictList, dictionaryInfo);
+                }
+            }
+        }
+
+        // Retrieve files from assets
+        final Resources resources = context.getResources();
+        final AssetManager assets = resources.getAssets();
+        for (final String localeString : assets.getLocales()) {
+            final Locale locale = LocaleUtils.constructLocaleFromString(localeString);
+            final int resourceId =
+                    DictionaryInfoUtils.getMainDictionaryResourceIdIfAvailableForLocale(
+                            context.getResources(), locale);
+            if (0 == resourceId) continue;
+            final AssetFileAddress fileAddress =
+                    BinaryDictionaryGetter.loadFallbackResource(context, resourceId);
+            final DictionaryInfo dictionaryInfo = createDictionaryInfoFromFileAddress(fileAddress);
+            // Protect against cases of a less-specific dictionary being found, like an
+            // en dictionary being used for an en_US locale. In this case, the en dictionary
+            // should be used for en_US but discounted for listing purposes.
+            if (!dictionaryInfo.mLocale.equals(locale)) continue;
+            addOrUpdateDictInfo(dictList, dictionaryInfo);
+        }
+
+        return dictList;
+    }
+}