Revert of Android: Store language .pak files in res/raw rather than assets

base/android/java/src/org/chromium/base/ResourceExtractor.java

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package org.chromium.base;
 
 import android.annotation.TargetApi;
 import android.content.Context;
+import android.content.SharedPreferences;
 import android.content.pm.PackageInfo;
 import android.content.pm.PackageManager;
 import android.content.res.AssetManager;
-import android.content.res.Resources;
-import android.content.res.TypedArray;
 import android.os.AsyncTask;
 import android.os.Build;
 import android.os.Handler;
 import android.os.Looper;
 import android.os.Trace;
+import android.preference.PreferenceManager;
 import android.util.Log;
 
 import java.io.File;
 import java.io.FileOutputStream;
 import java.io.FilenameFilter;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.util.ArrayList;
 import java.util.List;
-import java.util.Locale;
 import java.util.concurrent.CancellationException;
 import java.util.concurrent.ExecutionException;
+import java.util.regex.Pattern;
 
 /**
  * Handles extracting the necessary resources bundled in an APK and moving them to a location on
  * the file system accessible from the native code.
  */
 public class ResourceExtractor {
 
     private static final String LOGTAG = "ResourceExtractor";
+    private static final String LAST_LANGUAGE = "Last language";
+    private static final String PAK_FILENAMES_LEGACY_NOREUSE = "Pak filenames";
     private static final String ICU_DATA_FILENAME = "icudtl.dat";
     private static final String V8_NATIVES_DATA_FILENAME = "natives_blob.bin";
     private static final String V8_SNAPSHOT_DATA_FILENAME = "snapshot_blob.bin";
 
     private static String[] sMandatoryPaks = null;
-    private static int sLocalePaksResId = -1;
 
-    /**
-     * Applies the reverse mapping done by locale_pak_resources.py.
-     */
-    private static String toChromeLocaleName(String srcFileName) {
-        String[] parts = srcFileName.split("_");
-        if (parts.length > 1) {
-            int dotIdx = parts[1].indexOf('.');
-            return parts[0] + "-" + parts[1].substring(0, dotIdx).toUpperCase(Locale.ENGLISH)
-                    + parts[1].substring(dotIdx);
-        }
-        return srcFileName;
+    // By default, we attempt to extract a pak file for the users
+    // current device locale. Use setExtractImplicitLocale() to
+    // change this behavior.
+    private static boolean sExtractImplicitLocalePak = true;
+
+    private static boolean isAppDataFile(String file) {
+        return ICU_DATA_FILENAME.equals(file)
+                || V8_NATIVES_DATA_FILENAME.equals(file)
+                || V8_SNAPSHOT_DATA_FILENAME.equals(file);
     }
 
     private class ExtractTask extends AsyncTask<Void, Void, Void> {
         private static final int BUFFER_SIZE = 16 * 1024;
 
         private final List<Runnable> mCompletionCallbacks = new ArrayList<Runnable>();
 
-        private void extractResourceHelper(InputStream is, File outFile, byte[] buffer)
-                throws IOException {
-            OutputStream os = null;
-            try {
-                os = new FileOutputStream(outFile);
-                Log.i(LOGTAG, "Extracting resource " + outFile);
-
-                int count = 0;
-                while ((count = is.read(buffer, 0, BUFFER_SIZE)) != -1) {
-                    os.write(buffer, 0, count);
-                }
-                os.flush();
-
-                // Ensure something reasonable was written.
-                if (outFile.length() == 0) {
-                    throw new IOException(outFile + " extracted with 0 length!");
-                }
-            } finally {
-                try {
-                    if (is != null) {
-                        is.close();
-                    }
-                } finally {
-                    if (os != null) {
-                        os.close();
-                    }
-                }
-            }
+        public ExtractTask() {
         }
 
         private void doInBackgroundImpl() {
             final File outputDir = getOutputDir();
+            final File appDataDir = getAppDataDir();
             if (!outputDir.exists() && !outputDir.mkdirs()) {
                 Log.e(LOGTAG, "Unable to create pak resources directory!");
                 return;
             }
 
             String timestampFile = null;
             beginTraceSection("checkPakTimeStamp");
             try {
                 timestampFile = checkPakTimestamp(outputDir);
             } finally {
                 endTraceSection();
             }
             if (timestampFile != null) {
                 deleteFiles();
             }
 
+            SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(mContext);
+            String currentLocale = LocaleUtils.getDefaultLocale();
+            String currentLanguage = currentLocale.split("-", 2)[0];
+            // If everything we need is already there (and the locale hasn't
+            // changed), quick exit.
+            if (prefs.getString(LAST_LANGUAGE, "").equals(currentLanguage)) {
+                boolean filesPresent = true;
+                for (String file : sMandatoryPaks) {
+                    File directory = isAppDataFile(file) ? appDataDir : outputDir;
+                    if (!new File(directory, file).exists()) {
+                        filesPresent = false;
+                        break;
+                    }
+                }
+                if (filesPresent) return;
+            } else {
+                prefs.edit().putString(LAST_LANGUAGE, currentLanguage).apply();
+            }
+
+            StringBuilder p = new StringBuilder();
+            for (String mandatoryPak : sMandatoryPaks) {
+                if (p.length() > 0) p.append('|');
+                p.append("\\Q" + mandatoryPak + "\\E");
+            }
+
+            if (sExtractImplicitLocalePak) {
+                if (p.length() > 0) p.append('|');
+                // As well as the minimum required set of .paks above, we'll
+                // also add all .paks that we have for the user's currently
+                // selected language.
+                p.append(currentLanguage);
+                p.append("(-\\w+)?\\.pak");
+            }
+
+            Pattern paksToInstall = Pattern.compile(p.toString());
+
+            AssetManager manager = mContext.getResources().getAssets();
             beginTraceSection("WalkAssets");
-            AssetManager assetManager = mContext.getAssets();
-            byte[] buffer = new byte[BUFFER_SIZE];
             try {
-                // Extract all files that don't already exist.
-                for (String fileName : sMandatoryPaks) {
-                    File output = new File(outputDir, fileName);
+                // Loop through every asset file that we have in the APK, and look for the
+                // ones that we need to extract by trying to match the Patterns that we
+                // created above.
+                byte[] buffer = null;
+                String[] files = manager.list("");
+                for (String file : files) {
+                    if (!paksToInstall.matcher(file).matches()) {
+                        continue;
+                    }
+                    File output = new File(isAppDataFile(file) ? appDataDir : outputDir, file);
                     if (output.exists()) {
                         continue;
                     }
+
+                    InputStream is = null;
+                    OutputStream os = null;
                     beginTraceSection("ExtractResource");
-                    InputStream inputStream = assetManager.open(fileName);
                     try {
-                        extractResourceHelper(inputStream, output, buffer);
-                    } finally {
-                        endTraceSection(); // ExtractResource
-                    }
-                }
+                        is = manager.open(file);
+                        os = new FileOutputStream(output);
+                        Log.i(LOGTAG, "Extracting resource " + file);
+                        if (buffer == null) {
+                            buffer = new byte[BUFFER_SIZE];
+                        }
 
-                if (sLocalePaksResId != 0) {
-                    // locale_paks yields the current language's pak file paths.
-                    Resources resources = mContext.getResources();
-                    TypedArray resIds = resources.obtainTypedArray(sLocalePaksResId);
-                    try {
-                        int len = resIds.length();
-                        for (int i = 0; i < len; ++i) {
-                            int resId = resIds.getResourceId(i, 0);
-                            String resPath = resources.getString(resId);
-                            String srcBaseName = new File(resPath).getName();
-                            String dstBaseName = toChromeLocaleName(srcBaseName);
-                            File output = new File(outputDir, dstBaseName);
-                            if (output.exists()) {
-                                continue;
-                            }
-                            beginTraceSection("ExtractResource");
-                            InputStream inputStream = resources.openRawResource(resId);
-                            try {
-                                extractResourceHelper(inputStream, output, buffer);
-                            } finally {
-                                endTraceSection(); // ExtractResource
-                            }
+                        int count = 0;
+                        while ((count = is.read(buffer, 0, BUFFER_SIZE)) != -1) {
+                            os.write(buffer, 0, count);
+                        }
+                        os.flush();
+
+                        // Ensure something reasonable was written.
+                        if (output.length() == 0) {
+                            throw new IOException(file + " extracted with 0 length!");
+                        }
+
+                        if (isAppDataFile(file)) {
+                            // icu and V8 data need to be accessed by a renderer
+                            // process.
+                            output.setReadable(true, false);
                         }
                     } finally {
-                        resIds.recycle();
+                        try {
+                            if (is != null) {
+                                is.close();
+                            }
+                        } finally {
+                            if (os != null) {
+                                os.close();
+                            }
+                            endTraceSection(); // ExtractResource
+                        }
                     }
                 }
             } catch (IOException e) {
                 // TODO(benm): See crbug/152413.
                 // Try to recover here, can we try again after deleting files instead of
                 // returning null? It might be useful to gather UMA here too to track if
                 // this happens with regularity.
                 Log.w(LOGTAG, "Exception unpacking required pak resources: " + e.getMessage());
                 deleteFiles();
                 return;
@@ skipping 109 matching lines @@
     private static ResourceExtractor sInstance;
 
     public static ResourceExtractor get(Context context) {
         if (sInstance == null) {
             sInstance = new ResourceExtractor(context);
         }
         return sInstance;
     }
 
     /**
-     * Specifies the files that should be extracted from the APK.
+     * Specifies the .pak files that should be extracted from the APK's asset resources directory
      * and moved to {@link #getOutputDirFromContext(Context)}.
-     * @param localePaksResId Resource ID for the locale_paks string array. Pass
-     *     in 0 to disable locale pak extraction.
-     * @param paths The list of paths to be extracted.
+     * @param mandatoryPaks The list of pak files to be loaded. If no pak files are
+     *     required, pass a single empty string.
      */
-    public static void setMandatoryPaksToExtract(int localePaksResId, String... paths) {
+    public static void setMandatoryPaksToExtract(String... mandatoryPaks) {
         // TODO(agrieve): Remove the need to call this once all files are loaded from the apk.
         assert (sInstance == null || sInstance.mExtractTask == null)
                 : "Must be called before startExtractingResources is called";
-        sLocalePaksResId = localePaksResId;
-        sMandatoryPaks = paths;
+        sMandatoryPaks = mandatoryPaks;
+
     }
 
     /**
+     * By default the ResourceExtractor will attempt to extract a pak resource for the users
+     * currently specified locale. This behavior can be changed with this function and is
+     * only needed by tests.
+     * @param extract False if we should not attempt to extract a pak file for
+     *         the users currently selected locale and try to extract only the
+     *         pak files specified in sMandatoryPaks.
+     */
+    @VisibleForTesting
+    public static void setExtractImplicitLocaleForTesting(boolean extract) {
+        assert (sInstance == null || sInstance.mExtractTask == null)
+                : "Must be called before startExtractingResources is called";
+        sExtractImplicitLocalePak = extract;
+    }
+
+    /**
      * Marks all the 'pak' resources, packaged as assets, for extraction during
      * running the tests.
      */
     @VisibleForTesting
     public void setExtractAllPaksAndV8SnapshotForTesting() {
         List<String> pakAndSnapshotFileAssets = new ArrayList<String>();
         AssetManager manager = mContext.getResources().getAssets();
         try {
             String[] files = manager.list("");
             for (String file : files) {
                 if (file.endsWith(".pak")) pakAndSnapshotFileAssets.add(file);
             }
         } catch (IOException e) {
             Log.w(LOGTAG, "Exception while accessing assets: " + e.getMessage(), e);
         }
-        setMandatoryPaksToExtract(0, pakAndSnapshotFileAssets.toArray(
+        setMandatoryPaksToExtract(pakAndSnapshotFileAssets.toArray(
                 new String[pakAndSnapshotFileAssets.size()]));
     }
 
     private ResourceExtractor(Context context) {
         mContext = context.getApplicationContext();
     }
 
     /**
      * Synchronously wait for the resource extraction to be completed.
      * <p>
@@ skipping 52 matching lines @@
     /**
      * This will extract the application pak resources in an
      * AsyncTask. Call waitForCompletion() at the point resources
      * are needed to block until the task completes.
      */
     public void startExtractingResources() {
         if (mExtractTask != null) {
             return;
         }
 
-        // If a previous release extracted resources, and the current release does not,
-        // deleteFiles() will not run and some files will be left. This currently
-        // can happen for ContentShell, but not for Chrome proper, since we always extract
-        // locale pak files.
         if (shouldSkipPakExtraction()) {
             return;
         }
 
         mExtractTask = new ExtractTask();
         mExtractTask.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
     }
 
     private File getAppDataDir() {
         return new File(PathUtils.getDataDirectory(mContext));
@@ skipping 32 matching lines @@
             File[] files = dir.listFiles();
             for (File file : files) {
                 if (!file.delete()) {
                     Log.e(LOGTAG, "Unable to remove existing resource " + file.getName());
                 }
             }
         }
     }
 
     /**
-     * Pak extraction not necessarily required by the embedder.
+     * Pak extraction not necessarily required by the embedder; we allow them to skip
+     * this process if they call setMandatoryPaksToExtract with a single empty String.
      */
     private static boolean shouldSkipPakExtraction() {
-        assert (sLocalePaksResId != -1 && sMandatoryPaks != null)
-            : "setMandatoryPaksToExtract() must be called before startExtractingResources()";
-        return sMandatoryPaks.length == 0 && sLocalePaksResId == 0;
+        // Must call setMandatoryPaksToExtract before beginning resource extraction.
+        assert sMandatoryPaks != null;
+        return sMandatoryPaks.length == 1 && "".equals(sMandatoryPaks[0]);
     }
 }