Refactoring: cut out a method for caching a word list

This is preparation to have the decrypting/unzipping code
moved over to LatinIME.

Bug: 5095140
Change-Id: Ic3fdcc3de673b46cef2eb9ebe6a52cbdd614e50a

java/src/com/android/inputmethod/latin/BinaryDictionaryFileDumper.java

@@ -63,10 +63,10 @@ public class BinaryDictionaryFileDumper {
     }
 
     /**
-     * Queries a content provider for the list of dictionaries for a specific locale
+     * Queries a content provider for the list of word lists for a specific locale
      * available to copy into Latin IME.
      */
-    private static List<String> getDictIdList(final Locale locale, final Context context) {
+    private static List<String> getWordListIds(final Locale locale, final Context context) {
         final ContentResolver resolver = context.getContentResolver();
         final Uri dictionaryPackUri = getProviderUri(locale.toString());
 
@@ -88,30 +88,14 @@ public class BinaryDictionaryFileDumper {
     }
 
     /**
-     * Queries a content provider for dictionary data for some locale and cache the returned files
+     * Caches a word list the id of which is passed as an argument.
-     *
-     * This will query a content provider for dictionary data for a given locale, and copy the
-     * files locally so that they can be mmap'ed. This may overwrite previously cached dictionaries
-     * with newer versions if a newer version is made available by the content provider.
-     * @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> cacheDictionariesFromContentProvider(final Locale locale,
+    private static AssetFileAddress cacheWordList(final String id, final Locale locale,
-            final Context context) {
+            final ContentResolver resolver, final Context context) {
-        final ContentResolver resolver = context.getContentResolver();
-        final List<String> idList = getDictIdList(locale, context);
-        final List<AssetFileAddress> fileAddressList = new ArrayList<AssetFileAddress>();
-        for (String id : idList) {
         final Uri wordListUri = getProviderUri(id);
-            AssetFileDescriptor afd = null;
-            try {
-                afd = resolver.openAssetFileDescriptor(wordListUri, "r");
-            } catch (FileNotFoundException e) {
-                // leave null inside afd and continue
-            }
-            if (null == afd) continue;
         try {
+            final AssetFileDescriptor afd = resolver.openAssetFileDescriptor(wordListUri, "r");
+            if (null == afd) return null;
             final String fileName = copyFileTo(afd.createInputStream(),
                     BinaryDictionaryGetter.getCacheFileName(id, locale, context));
             afd.close();
@@ -119,11 +103,37 @@ public class BinaryDictionaryFileDumper {
                 // I'd rather not print the word list ID to the log out of security concerns
                 Log.e(TAG, "Could not have the dictionary pack delete a word list");
             }
-                fileAddressList.add(AssetFileAddress.makeFromFileName(fileName));
+            return AssetFileAddress.makeFromFileName(fileName);
+        } catch (FileNotFoundException e) {
+            // This may only come from openAssetFileDescriptor
+            return null;
         } catch (IOException e) {
-                // Can't read the file for some reason. Continue onto the next file.
+            // Can't read the file for some reason.
             Log.e(TAG, "Cannot read a word list from the dictionary pack : " + 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 ContentResolver resolver = context.getContentResolver();
+        final List<String> idList = getWordListIds(locale, context);
+        final List<AssetFileAddress> fileAddressList = new ArrayList<AssetFileAddress>();
+        for (String id : idList) {
+            final AssetFileAddress afd = cacheWordList(id, locale, resolver, context);
+            if (null != afd) {
+                fileAddressList.add(afd);
+            }
         }
         return fileAddressList;
     }

java/src/com/android/inputmethod/latin/BinaryDictionaryGetter.java

@@ -205,7 +205,7 @@ class BinaryDictionaryGetter {
      * @param context the context on which to open the files upon.
      * @return an array of binary dictionary files, which may be empty but may not be null.
      */
-    private static File[] getCachedDictionaryList(final Locale locale,
+    private static File[] getCachedWordLists(final Locale locale,
             final Context context) {
         final String directoryName = getCacheDirectoryForLocale(locale, context);
         final File[] cacheFiles = new File(directoryName).listFiles();
@@ -235,11 +235,11 @@ class BinaryDictionaryGetter {
     public static List<AssetFileAddress> getDictionaryFiles(final Locale locale,
             final Context context, final int fallbackResId) {
 
-        // cacheDictionariesFromContentProvider returns the list of files it copied to local
+        // cacheWordListsFromContentProvider returns the list of files it copied to local
         // storage, but we don't really care about what was copied NOW: what we want is the
         // list of everything we ever cached, so we ignore the return value.
-        BinaryDictionaryFileDumper.cacheDictionariesFromContentProvider(locale, context);
+        BinaryDictionaryFileDumper.cacheWordListsFromContentProvider(locale, context);
-        final File[] cachedDictionaryList = getCachedDictionaryList(locale, context);
+        final File[] cachedWordLists = getCachedWordLists(locale, context);
 
         final String mainDictId = getMainDictId(locale);
 
@@ -247,8 +247,8 @@ class BinaryDictionaryGetter {
 
         boolean foundMainDict = false;
         final ArrayList<AssetFileAddress> fileList = new ArrayList<AssetFileAddress>();
-        // cachedDictionaryList may not be null, see doc for getCachedDictionaryList
+        // cachedWordLists may not be null, see doc for getCachedDictionaryList
-        for (final File f : cachedDictionaryList) {
+        for (final File f : cachedWordLists) {
             final String wordListId = getWordListIdFromFileName(f.getName());
             if (wordListId.equals(mainDictId)) {
                 foundMainDict = true;