Merge "Fast follow-on unit tests for HashedStringCache" into qt-dev (884e901c) · Commits · e / os / android_frameworks_base

core/java/android/util/HashedStringCache.java

+10 −5

Original line number	Diff line number	Diff line
		@@ -22,6 +22,8 @@ import android.os.Environment;
		import android.os.storage.StorageManager;
		import android.text.TextUtils;

		import com.android.internal.annotations.VisibleForTesting;

		import java.io.File;
		import java.nio.charset.Charset;
		import java.security.MessageDigest;
		@@ -32,7 +34,6 @@ import java.security.SecureRandom;
		* HashedStringCache provides hashing functionality with an underlying LRUCache and expiring salt.
		* Salt and expiration time are being stored under the tag passed in by the calling package --
		* intended usage is the calling package name.
		* TODO: Add unit tests b/129870147
		* @hide
		*/
		public class HashedStringCache {
		@@ -40,9 +41,12 @@ public class HashedStringCache {
		private static final Charset UTF_8 = Charset.forName("UTF-8");
		private static final int HASH_CACHE_SIZE = 100;
		private static final int HASH_LENGTH = 8;
		private static final String HASH_SALT = "_hash_salt";
		private static final String HASH_SALT_DATE = "_hash_salt_date";
		private static final String HASH_SALT_GEN = "_hash_salt_gen";
		@VisibleForTesting
		static final String HASH_SALT = "_hash_salt";
		@VisibleForTesting
		static final String HASH_SALT_DATE = "_hash_salt_date";
		@VisibleForTesting
		static final String HASH_SALT_GEN = "_hash_salt_gen";
		// For privacy we need to rotate the salt regularly
		private static final long DAYS_TO_MILLIS = 1000 * 60 * 60 * 24;
		private static final int MAX_SALT_DAYS = 100;
		@@ -94,7 +98,8 @@ public class HashedStringCache {
		*/
		public HashResult hashString(Context context, String tag, String clearText,
		int saltExpirationDays) {
		if (TextUtils.isEmpty(clearText) \|\| saltExpirationDays == -1) {
		if (saltExpirationDays == -1 \|\| context == null
		\|\| TextUtils.isEmpty(clearText) \|\| TextUtils.isEmpty(tag)) {
		return null;
		}

core/tests/coretests/src/android/util/HashedStringCacheTest.java

0 → 100644

+189 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2019 The Android Open Source Project
		*
		* Licensed under the Apache License, Version 2.0 (the "License");
		* you may not use this file except in compliance with the License.
		* You may obtain a copy of the License at
		*
		* http://www.apache.org/licenses/LICENSE-2.0
		*
		* Unless required by applicable law or agreed to in writing, software
		* distributed under the License is distributed on an "AS IS" BASIS,
		* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
		* See the License for the specific language governing permissions and
		* limitations under the License.
		*/

		package android.util;

		import static org.hamcrest.CoreMatchers.is;
		import static org.hamcrest.CoreMatchers.not;
		import static org.hamcrest.CoreMatchers.notNullValue;
		import static org.hamcrest.CoreMatchers.nullValue;
		import static org.hamcrest.MatcherAssert.assertThat;

		import android.content.Context;
		import android.content.SharedPreferences;
		import android.os.Environment;
		import android.os.storage.StorageManager;

		import androidx.test.InstrumentationRegistry;

		import org.junit.Before;
		import org.junit.Test;

		import java.io.File;


		/**
		* Unit tests for {@link HashedStringCache}.
		*/
		public class HashedStringCacheTest {
		private static final String TAG = "HashedStringCacheTest";
		private Context mContext;
		private static final String TEST_STRING = "test_string";

		@Before
		public void setup() {
		mContext = null;
		mContext = InstrumentationRegistry.getContext();
		clearSharedPreferences();
		}

		@Test
		public void testInstanceNotNull() {
		HashedStringCache cache = HashedStringCache.getInstance();
		assertThat(cache, is(notNullValue()));
		}

		@Test
		public void testInstanceMatchesOnSecondCall() {
		HashedStringCache cache = HashedStringCache.getInstance();
		assertThat(HashedStringCache.getInstance(), is(cache));
		}

		@Test
		public void testHashedStringNotOriginalString() {
		HashedStringCache cache = HashedStringCache.getInstance();
		HashedStringCache.HashResult cachedResult =
		cache.hashString(mContext, TAG, TEST_STRING, 7);
		assertThat(cachedResult.hashedString, is(not(TEST_STRING)));
		}

		@Test
		public void testThatMultipleCallsResultInSameHash() {
		HashedStringCache cache = HashedStringCache.getInstance();
		HashedStringCache.HashResult cachedResult =
		cache.hashString(mContext, TAG, TEST_STRING, 7);
		HashedStringCache.HashResult cachedResult2 =
		cache.hashString(mContext, TAG, TEST_STRING, 7);
		assertThat(cachedResult2.hashedString, is(cachedResult.hashedString));
		}

		@Test
		public void testThatZeroDaysResultsInNewHash() {
		HashedStringCache cache = HashedStringCache.getInstance();
		HashedStringCache.HashResult cachedResult =
		cache.hashString(mContext, TAG, TEST_STRING, 7);
		HashedStringCache.HashResult cachedResult2 =
		cache.hashString(mContext, TAG, TEST_STRING, 0);
		assertThat(cachedResult2.hashedString, is(not(cachedResult.hashedString)));
		}

		@Test
		public void testThatNegativeDaysResultsInNewHash() {
		HashedStringCache cache = HashedStringCache.getInstance();
		HashedStringCache.HashResult cachedResult =
		cache.hashString(mContext, TAG, TEST_STRING, 7);
		HashedStringCache.HashResult cachedResult2 =
		cache.hashString(mContext, TAG, TEST_STRING, -10);
		assertThat(cachedResult2.hashedString, is(not(cachedResult.hashedString)));
		}

		@Test
		public void testThatDaysGreater365ResultsInSameResult() {
		HashedStringCache cache = HashedStringCache.getInstance();
		HashedStringCache.HashResult cachedResult =
		cache.hashString(mContext, TAG, TEST_STRING, 7);
		HashedStringCache.HashResult cachedResult2 =
		cache.hashString(mContext, TAG, TEST_STRING, 400);
		assertThat(cachedResult2.hashedString, is(cachedResult.hashedString));
		}

		/**
		* -1 is treated as a special input to short-circuit out of doing the hashing to give us
		* the option to turn this feature off if need be while incurring as little computational cost
		* as possible.
		*/
		@Test
		public void testMinusOneResultsInNull() {
		HashedStringCache cache = HashedStringCache.getInstance();
		HashedStringCache.HashResult cachedResult =
		cache.hashString(mContext, TAG, TEST_STRING, -1);
		assertThat(cachedResult, is(nullValue()));
		}

		@Test
		public void testEmptyStringInput() {
		HashedStringCache cache = HashedStringCache.getInstance();
		HashedStringCache.HashResult cachedResult =
		cache.hashString(mContext, TAG, "", -1);
		assertThat(cachedResult, is(nullValue()));
		}

		@Test
		public void testNullInput() {
		HashedStringCache cache = HashedStringCache.getInstance();
		HashedStringCache.HashResult cachedResult =
		cache.hashString(mContext, TAG, null, -1);
		assertThat(cachedResult, is(nullValue()));
		}

		@Test
		public void testEmptyStringTag() {
		HashedStringCache cache = HashedStringCache.getInstance();
		HashedStringCache.HashResult cachedResult =
		cache.hashString(mContext, "", TEST_STRING, -1);
		assertThat(cachedResult, is(nullValue()));
		}

		@Test
		public void testNullTag() {
		HashedStringCache cache = HashedStringCache.getInstance();
		HashedStringCache.HashResult cachedResult =
		cache.hashString(mContext, null, TEST_STRING, -1);
		assertThat(cachedResult, is(nullValue()));
		}

		@Test
		public void testNullContext() {
		HashedStringCache cache = HashedStringCache.getInstance();
		HashedStringCache.HashResult cachedResult =
		cache.hashString(null, TAG, TEST_STRING, -1);
		assertThat(cachedResult, is(nullValue()));
		}

		private void clearSharedPreferences() {
		SharedPreferences preferences = getTestSharedPreferences(mContext);
		preferences.edit()
		.remove(TAG + HashedStringCache.HASH_SALT)
		.remove(TAG + HashedStringCache.HASH_SALT_DATE)
		.remove(TAG + HashedStringCache.HASH_SALT_GEN).apply();
		}

		/**
		* Android:ui doesn't have persistent preferences, so need to fall back on this hack originally
		* from ChooserActivity.java
		* @param context
		* @return
		*/
		private SharedPreferences getTestSharedPreferences(Context context) {
		final File prefsFile = new File(new File(
		Environment.getDataUserCePackageDirectory(
		StorageManager.UUID_PRIVATE_INTERNAL,
		context.getUserId(), context.getPackageName()),
		"shared_prefs"),
		"hashed_cache_test.xml");
		return context.getSharedPreferences(prefsFile, Context.MODE_PRIVATE);
		}
		}