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

This is a prerequisite for having them live within APK splits.

Although pak files need to be renamed to be stored under res/raw,
ResourceExtractor restores their original name during extraction (so no
change to native code).

All sub-locales are stored and extracted together, just as before.

BUG=371610

Review URL: https://codereview.chromium.org/1158053005

Cr-Commit-Position: refs/heads/master@{#335350}

1 files changed, 92 insertions, 123 deletions

diff --git a/base/android/java/src/org/chromium/base/ResourceExtractor.java b/base/android/java/src/org/chromium/base/ResourceExtractor.java
index dd654ff..584dfae 100644
--- a/base/android/java/src/org/chromium/base/ResourceExtractor.java
+++ b/base/android/java/src/org/chromium/base/ResourceExtractor.java
@@ -6,16 +6,16 @@ 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;
@@ -26,9 +26,9 @@ 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
@@ -37,23 +37,24 @@ import java.util.regex.Pattern;
 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;
 
-    // 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);
+    /**
+     * 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;
     }
 
     private class ExtractTask extends AsyncTask<Void, Void, Void> {
@@ -61,12 +62,38 @@ public class ResourceExtractor {
 
         private final List<Runnable> mCompletionCallbacks = new ArrayList<Runnable>();
 
-        public ExtractTask() {
+        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();
+                    }
+                }
+            }
         }
 
         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;
@@ -83,97 +110,50 @@ public class ResourceExtractor {
                 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 {
-                // 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);
+                // Extract all files that don't already exist.
+                for (String fileName : sMandatoryPaks) {
+                    File output = new File(outputDir, fileName);
                     if (output.exists()) {
                         continue;
                     }
-
-                    InputStream is = null;
-                    OutputStream os = null;
                     beginTraceSection("ExtractResource");
+                    InputStream inputStream = assetManager.open(fileName);
                     try {
-                        is = manager.open(file);
-                        os = new FileOutputStream(output);
-                        Log.i(LOGTAG, "Extracting resource " + file);
-                        if (buffer == null) {
-                            buffer = new byte[BUFFER_SIZE];
-                        }
-
-                        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);
-                        }
+                        extractResourceHelper(inputStream, output, buffer);
                     } finally {
-                        try {
-                            if (is != null) {
-                                is.close();
+                        endTraceSection(); // ExtractResource
+                    }
+                }
+
+                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;
                             }
-                        } finally {
-                            if (os != null) {
-                                os.close();
+                            beginTraceSection("ExtractResource");
+                            InputStream inputStream = resources.openRawResource(resId);
+                            try {
+                                extractResourceHelper(inputStream, output, buffer);
+                            } finally {
+                                endTraceSection(); // ExtractResource
                             }
-                            endTraceSection(); // ExtractResource
                         }
+                    } finally {
+                        resIds.recycle();
                     }
                 }
             } catch (IOException e) {
@@ -303,32 +283,18 @@ public class ResourceExtractor {
     }
 
     /**
-     * Specifies the .pak files that should be extracted from the APK's asset resources directory
+     * Specifies the files that should be extracted from the APK.
      * and moved to {@link #getOutputDirFromContext(Context)}.
-     * @param mandatoryPaks The list of pak files to be loaded. If no pak files are
-     *     required, pass a single empty string.
+     * @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.
      */
-    public static void setMandatoryPaksToExtract(String... mandatoryPaks) {
+    public static void setMandatoryPaksToExtract(int localePaksResId, String... paths) {
         // 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";
-        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;
+        sLocalePaksResId = localePaksResId;
+        sMandatoryPaks = paths;
     }
 
     /**
@@ -347,7 +313,7 @@ public class ResourceExtractor {
         } catch (IOException e) {
             Log.w(LOGTAG, "Exception while accessing assets: " + e.getMessage(), e);
         }
-        setMandatoryPaksToExtract(pakAndSnapshotFileAssets.toArray(
+        setMandatoryPaksToExtract(0, pakAndSnapshotFileAssets.toArray(
                 new String[pakAndSnapshotFileAssets.size()]));
     }
 
@@ -420,6 +386,10 @@ public class ResourceExtractor {
             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;
         }
@@ -472,12 +442,11 @@ public class ResourceExtractor {
     }
 
     /**
-     * Pak extraction not necessarily required by the embedder; we allow them to skip
-     * this process if they call setMandatoryPaksToExtract with a single empty String.
+     * Pak extraction not necessarily required by the embedder.
      */
     private static boolean shouldSkipPakExtraction() {
-        // Must call setMandatoryPaksToExtract before beginning resource extraction.
-        assert sMandatoryPaks != null;
-        return sMandatoryPaks.length == 1 && "".equals(sMandatoryPaks[0]);
+        assert (sLocalePaksResId != -1 && sMandatoryPaks != null)
+            : "setMandatoryPaksToExtract() must be called before startExtractingResources()";
+        return sMandatoryPaks.length == 0 && sLocalePaksResId == 0;
     }
 }