root/chrome/test/android/javatests/src/org/chromium/chrome/test/util/ApplicationData.java

DEFINITIONS

1. clearAppData
2. getAppDirFromTargetContext
3. removeAppData
4. removeFile

// Copyright 2013 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.chrome.test.util;

import android.content.Context;

import static org.chromium.base.test.util.ScalableTimeout.scaleTimeout;

import org.chromium.content.browser.test.util.Criteria;
import org.chromium.content.browser.test.util.CriteriaHelper;

import java.io.File;
import java.util.concurrent.TimeUnit;

/**
 * A utility class to do operations on the application data directory, such as clearing the
 * application data.
 */
public final class ApplicationData {

    private static final long MAX_CLEAR_APP_DATA_TIMEOUT_MS =
        scaleTimeout(TimeUnit.SECONDS.toMillis(3));
    private static final long CLEAR_APP_DATA_POLL_INTERVAL_MS = MAX_CLEAR_APP_DATA_TIMEOUT_MS / 10;

    private ApplicationData() {}

    /**
     * Clear all files in target contexts application directory, except the directory 'lib'.
     * The timeout is specified in |MAX_CLEAR_APP_DATA_TIMEOUT_MS|.
     *
     * When deleting all files is complete, the 'cache' directory is recreated, to ensure that the
     * framework does not try to create it for sandbox processes and fail.
     *
     * When this is invoked from tests, the target context from the instrumentation must be used.
     *
     * @param targetContext the target Context.
     *
     * @return Whether clearing the application data was successful.
     */
    public static boolean clearAppData(Context targetContext) throws InterruptedException {
        final String appDir = getAppDirFromTargetContext(targetContext);
        return CriteriaHelper.pollForCriteria(
                new Criteria() {
                    private boolean mDataRemoved = false;

                    @Override
                    public boolean isSatisfied() {
                        if (!mDataRemoved && !removeAppData(appDir)) {
                            return false;
                        }
                        mDataRemoved = true;
                        // We have to make sure the cache directory still exists, as the framework
                        // will try to create it otherwise and will fail for sandbox processes with
                        // a NullPointerException.
                        File cacheDir = new File(appDir, "cache");
                        return cacheDir.exists() || cacheDir.mkdir();
                    }
                },
                MAX_CLEAR_APP_DATA_TIMEOUT_MS, CLEAR_APP_DATA_POLL_INTERVAL_MS);
    }

    /**
     * Find the absolute path of the application data directory for the given target context.
     *
     * When this is invoked from tests, the target context from the instrumentation must be used.
     *
     * @param targetContext the target Context.
     *
     * @return the absolute path of the application data directory.
     */
    public static String getAppDirFromTargetContext(Context targetContext) {
        String cacheDir = targetContext.getCacheDir().getAbsolutePath();
        return cacheDir.substring(0, cacheDir.lastIndexOf('/'));
    }

    /**
     * Remove all files and directories under the given application directory, except 'lib'.
     *
     * @param appDir the application directory to remove.
     *
     * @return whether removal succeeded.
     */
    private static boolean removeAppData(String appDir) {
        File[] files = new File(appDir).listFiles();
        if (files == null)
            return true;
        for (File file : files) {
            if (!file.getAbsolutePath().endsWith("/lib") && !removeFile(file))
                return false;
        }
        return true;
    }

    /**
     * Remove the given file or directory.
     *
     * @param file the file or directory to remove.
     *
     * @return whether removal succeeded.
     */
    private static boolean removeFile(File file) {
        if (file.isDirectory()) {
            File[] files = file.listFiles();
            if (files == null)
                return true;
            for (File sub_file : files) {
                if (!removeFile(sub_file))
                    return false;
            }
        }
        return file.delete();
    }
}