Upstream: DexOptimizer and DexLoader classes

chrome/android/webapk/shell_apk/javatests/dex_optimizer/src/org/chromium/webapk/shell_apk/test/dex_optimizer/DexOptimizerServiceImpl.java

+// Copyright 2016 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.webapk.shell_apk.test.dex_optimizer;
+
+import android.app.Service;
+import android.content.Context;
+import android.content.Intent;
+import android.os.IBinder;
+
+import org.chromium.base.FileUtils;
+import org.chromium.webapk.lib.client.DexOptimizer;
+
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+
+public class DexOptimizerServiceImpl extends Service {
+    private static int sCounter = 0;
+
+    public IBinder onBind(Intent intent) {
+        return new IDexOptimizerService.Stub() {
+            private static final String DEX_ASSET_NAME = "canary.dex";
+            private static final String DEX_DIR = "dex";
+
+            @Override
+            public boolean deleteDexDirectory() {
+                File dir = getDir(DEX_DIR, Context.MODE_PRIVATE);
+                FileUtils.recursivelyDeleteFile(dir);
+                return !dir.exists();
+            }
+
+            @Override
+            public String extractAndOptimizeDex() {
+                // DexClassLoader does not generate an optimized dex if a DexClassLoader was
+                // previously constructed for the exact same dex path (presumably due to
+                // cached state in Android). This restriction does not seem to hold if
+                // DexOptimizerService is restarted. Hack around this restriction by extracting the
+                // dex from the APK to a different file every time. The hack is okay because
+                // deleting a dex file and immediately recreating an identical one is only done in
+                // tests.
+                String dexName = "canary" + sCounter + ".dex";
+                ++sCounter;
+
+                File dexFile = new File(getDir(DEX_DIR, Context.MODE_PRIVATE), dexName);
+                if (!extractAsset(DEX_ASSET_NAME, dexFile)) {
+                    return null;
+                }
+
+                // Make dex file world readable.
+                try {
+                    dexFile.setReadable(true, false);
+                } catch (Exception e) {
+                    return null;
+                }
+
+                if (!DexOptimizer.optimize(dexFile)) {
+                    return null;
+                }
+                return dexFile.getPath();
+            }
+
+
+            /**
+             * Extracts an asset from the app's APK to a file.
+             * @param assetName Name of the asset to extract.
+             * @param dest File to extract the asset to.
+             * @return true on success.
+             */
+            public boolean extractAsset(String assetName, File dest) {
+                try (InputStream inputStream = getAssets().open(assetName);
+                    OutputStream outputStream = new FileOutputStream(dest)) {
+                    byte[] buffer = new byte[16 * 1024];
+                    int c;
+                    while ((c = inputStream.read(buffer, 0, buffer.length)) != -1) {
+                        outputStream.write(buffer, 0, c);
+                    }
+                } catch (IOException e) {
+                    return false;
+                }
+                return true;
+            }
+        };
+    }
+}