a new java implementation of base64 for android-common

A new Base64 encoder/decoder class.  Some benchmarks comparing the
decoder it to those from android.os.Base64Utils (a decode-only native
implementation not accessible to apps) and
org.apache.commons.codec.binary.Base64, all with the JIT enabled:

  1k encoded data
  APACHE   avg:   811 us    min:   244 us    max: 13671 us
  COMMON   avg:   263 us    min:    30 us    max:  4730 us
  NATIVE   avg:   102 us    min:    61 us    max:  5493 us

  10k encoded data
  APACHE   avg:  3624 us    min:  2746 us    max: 23895 us
  COMMON   avg:   979 us    min:   518 us    max:  7751 us
  NATIVE   avg:   817 us    min:   762 us    max:  3143 us

  100k encoded data
  APACHE   avg: 33167 us    min: 31829 us    max: 140411 us
  COMMON   avg:  6047 us    min:  5493 us    max: 45227 us
  NATIVE   avg: 10109 us    min: 10009 us    max: 12451 us

Change-Id: Ic622e3a967a62d57d30bd25b80cbe4e0dd60e764

1 files changed, 208 insertions, 0 deletions

diff --git a/common/tests/src/com/android/common/Base64Test.java b/common/tests/src/com/android/common/Base64Test.java
new file mode 100644
index 0000000..39c4b20
--- /dev/null
+++ b/common/tests/src/com/android/common/Base64Test.java
@@ -0,0 +1,208 @@
+/*
+ * Copyright (C) 2010 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 com.android.common;
+
+import junit.framework.TestCase;
+
+public class Base64Test extends TestCase {
+    private static final String TAG = "B64Test";
+
+    /** Decodes a string, returning a string. */
+    private String decodeString(String in) throws Exception {
+        byte[] out = Base64.decode(in, 0);
+        return new String(out);
+    }
+
+    /**
+     * Encodes the string 'in' using 'flags'.  Asserts that decoding
+     * gives the same string.  Returns the encoded string.
+     */
+    private String encodeString(String in, int flags) throws Exception {
+        String b64 = Base64.encodeString(in.getBytes(), flags);
+        String dec = decodeString(b64);
+        assertEquals(in, dec);
+        return b64;
+    }
+
+    /** Assert that decoding 'in' throws IllegalArgumentException. */
+    private void assertBad(String in) throws Exception {
+        try {
+            byte[] out = Base64.decode(in, 0);
+            fail("should have failed to decode");
+        } catch (IllegalArgumentException e) {
+        }
+    }
+
+    /** Assert that actual equals the first len bytes of expected. */
+    private void assertEquals(byte[] expected, int len, byte[] actual) {
+        assertEquals(len, actual.length);
+        for (int i = 0; i < len; ++i) {
+            assertEquals(expected[i], actual[i]);
+        }
+    }
+
+    public void testDecodeExtraChars() throws Exception {
+        // padding 0
+        assertEquals("hello, world", decodeString("aGVsbG8sIHdvcmxk"));
+        assertBad("aGVsbG8sIHdvcmxk=");
+        assertBad("aGVsbG8sIHdvcmxk==");
+        assertBad("aGVsbG8sIHdvcmxk =");
+        assertBad("aGVsbG8sIHdvcmxk = = ");
+        assertEquals("hello, world", decodeString(" aGVs bG8s IHdv cmxk  "));
+        assertEquals("hello, world", decodeString(" aGV sbG8 sIHd vcmx k "));
+        assertEquals("hello, world", decodeString(" aG VsbG 8sIH dvcm xk "));
+        assertEquals("hello, world", decodeString(" a GVsb G8sI Hdvc mxk "));
+        assertEquals("hello, world", decodeString(" a G V s b G 8 s I H d v c m x k "));
+        assertEquals("hello, world", decodeString("_a*G_V*s_b*G_8*s_I*H_d*v_c*m_x*k_"));
+        assertEquals("hello, world", decodeString("aGVsbG8sIHdvcmxk"));
+
+        // padding 1
+        assertEquals("hello, world?!", decodeString("aGVsbG8sIHdvcmxkPyE="));
+        assertEquals("hello, world?!", decodeString("aGVsbG8sIHdvcmxkPyE"));
+        assertBad("aGVsbG8sIHdvcmxkPyE==");
+        assertBad("aGVsbG8sIHdvcmxkPyE ==");
+        assertBad("aGVsbG8sIHdvcmxkPyE = = ");
+        assertEquals("hello, world?!", decodeString("aGVsbG8sIHdvcmxkPy E="));
+        assertEquals("hello, world?!", decodeString("aGVsbG8sIHdvcmxkPy E"));
+        assertEquals("hello, world?!", decodeString("aGVsbG8sIHdvcmxkPy E ="));
+        assertEquals("hello, world?!", decodeString("aGVsbG8sIHdvcmxkPy E "));
+        assertEquals("hello, world?!", decodeString("aGVsbG8sIHdvcmxkPy E = "));
+        assertEquals("hello, world?!", decodeString("aGVsbG8sIHdvcmxkPy E   "));
+
+        // padding 2
+        assertEquals("hello, world.", decodeString("aGVsbG8sIHdvcmxkLg=="));
+        assertEquals("hello, world.", decodeString("aGVsbG8sIHdvcmxkLg"));
+        assertBad("aGVsbG8sIHdvcmxkLg=");
+        assertBad("aGVsbG8sIHdvcmxkLg =");
+        assertBad("aGVsbG8sIHdvcmxkLg = ");
+        assertEquals("hello, world.", decodeString("aGVsbG8sIHdvcmxkL g=="));
+        assertEquals("hello, world.", decodeString("aGVsbG8sIHdvcmxkL g"));
+        assertEquals("hello, world.", decodeString("aGVsbG8sIHdvcmxkL g =="));
+        assertEquals("hello, world.", decodeString("aGVsbG8sIHdvcmxkL g "));
+        assertEquals("hello, world.", decodeString("aGVsbG8sIHdvcmxkL g = = "));
+        assertEquals("hello, world.", decodeString("aGVsbG8sIHdvcmxkL g   "));
+    }
+
+    private static final byte[] BYTES = { (byte) 0xff, (byte) 0xee, (byte) 0xdd,
+                                          (byte) 0xcc, (byte) 0xbb, (byte) 0xaa,
+                                          (byte) 0x99, (byte) 0x88, (byte) 0x77 };
+
+    public void testBinaryDecode() throws Exception {
+        assertEquals(BYTES, 0, Base64.decode("", 0));
+        assertEquals(BYTES, 1, Base64.decode("/w==", 0));
+        assertEquals(BYTES, 2, Base64.decode("/+4=", 0));
+        assertEquals(BYTES, 3, Base64.decode("/+7d", 0));
+        assertEquals(BYTES, 4, Base64.decode("/+7dzA==", 0));
+        assertEquals(BYTES, 5, Base64.decode("/+7dzLs=", 0));
+        assertEquals(BYTES, 6, Base64.decode("/+7dzLuq", 0));
+        assertEquals(BYTES, 7, Base64.decode("/+7dzLuqmQ==", 0));
+        assertEquals(BYTES, 8, Base64.decode("/+7dzLuqmYg=", 0));
+    }
+
+    public void testWebSafe() throws Exception {
+        assertEquals(BYTES, 0, Base64.decode("", Base64.WEB_SAFE));
+        assertEquals(BYTES, 1, Base64.decode("_w==", Base64.WEB_SAFE));
+        assertEquals(BYTES, 2, Base64.decode("_-4=", Base64.WEB_SAFE));
+        assertEquals(BYTES, 3, Base64.decode("_-7d", Base64.WEB_SAFE));
+        assertEquals(BYTES, 4, Base64.decode("_-7dzA==", Base64.WEB_SAFE));
+        assertEquals(BYTES, 5, Base64.decode("_-7dzLs=", Base64.WEB_SAFE));
+        assertEquals(BYTES, 6, Base64.decode("_-7dzLuq", Base64.WEB_SAFE));
+        assertEquals(BYTES, 7, Base64.decode("_-7dzLuqmQ==", Base64.WEB_SAFE));
+        assertEquals(BYTES, 8, Base64.decode("_-7dzLuqmYg=", Base64.WEB_SAFE));
+
+        assertEquals("", Base64.encodeString(BYTES, 0, 0, Base64.WEB_SAFE));
+        assertEquals("_w==\n", Base64.encodeString(BYTES, 0, 1, Base64.WEB_SAFE));
+        assertEquals("_-4=\n", Base64.encodeString(BYTES, 0, 2, Base64.WEB_SAFE));
+        assertEquals("_-7d\n", Base64.encodeString(BYTES, 0, 3, Base64.WEB_SAFE));
+        assertEquals("_-7dzA==\n", Base64.encodeString(BYTES, 0, 4, Base64.WEB_SAFE));
+        assertEquals("_-7dzLs=\n", Base64.encodeString(BYTES, 0, 5, Base64.WEB_SAFE));
+        assertEquals("_-7dzLuq\n", Base64.encodeString(BYTES, 0, 6, Base64.WEB_SAFE));
+        assertEquals("_-7dzLuqmQ==\n", Base64.encodeString(BYTES, 0, 7, Base64.WEB_SAFE));
+        assertEquals("_-7dzLuqmYg=\n", Base64.encodeString(BYTES, 0, 8, Base64.WEB_SAFE));
+    }
+
+    public void testFlags() throws Exception {
+        assertEquals("YQ==\n",       encodeString("a", 0));
+        assertEquals("YQ==",         encodeString("a", Base64.NO_WRAP));
+        assertEquals("YQ\n",         encodeString("a", Base64.NO_PADDING));
+        assertEquals("YQ",           encodeString("a", Base64.NO_PADDING | Base64.NO_WRAP));
+        assertEquals("YQ==\r\n",     encodeString("a", Base64.CRLF));
+        assertEquals("YQ\r\n",       encodeString("a", Base64.CRLF | Base64.NO_PADDING));
+
+        assertEquals("YWI=\n",       encodeString("ab", 0));
+        assertEquals("YWI=",         encodeString("ab", Base64.NO_WRAP));
+        assertEquals("YWI\n",        encodeString("ab", Base64.NO_PADDING));
+        assertEquals("YWI",          encodeString("ab", Base64.NO_PADDING | Base64.NO_WRAP));
+        assertEquals("YWI=\r\n",     encodeString("ab", Base64.CRLF));
+        assertEquals("YWI\r\n",      encodeString("ab", Base64.CRLF | Base64.NO_PADDING));
+
+        assertEquals("YWJj\n",       encodeString("abc", 0));
+        assertEquals("YWJj",         encodeString("abc", Base64.NO_WRAP));
+        assertEquals("YWJj\n",       encodeString("abc", Base64.NO_PADDING));
+        assertEquals("YWJj",         encodeString("abc", Base64.NO_PADDING | Base64.NO_WRAP));
+        assertEquals("YWJj\r\n",     encodeString("abc", Base64.CRLF));
+        assertEquals("YWJj\r\n",     encodeString("abc", Base64.CRLF | Base64.NO_PADDING));
+
+        assertEquals("YWJjZA==\n",   encodeString("abcd", 0));
+        assertEquals("YWJjZA==",     encodeString("abcd", Base64.NO_WRAP));
+        assertEquals("YWJjZA\n",     encodeString("abcd", Base64.NO_PADDING));
+        assertEquals("YWJjZA",       encodeString("abcd", Base64.NO_PADDING | Base64.NO_WRAP));
+        assertEquals("YWJjZA==\r\n", encodeString("abcd", Base64.CRLF));
+        assertEquals("YWJjZA\r\n",   encodeString("abcd", Base64.CRLF | Base64.NO_PADDING));
+    }
+
+    public void testLineLength() throws Exception {
+        String in_56 = "abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcd";
+        String in_57 = in_56 + "e";
+        String in_58 = in_56 + "ef";
+        String in_59 = in_56 + "efg";
+        String in_60 = in_56 + "efgh";
+        String in_61 = in_56 + "efghi";
+
+        String prefix = "YWJjZGVmZ2hpamtsbW5vcHFyc3R1dnd4eXphYmNkZWZnaGlqa2xtbm9wcXJzdHV2d3h5emFi";
+        String out_56 = prefix + "Y2Q=\n";
+        String out_57 = prefix + "Y2Rl\n";
+        String out_58 = prefix + "Y2Rl\nZg==\n";
+        String out_59 = prefix + "Y2Rl\nZmc=\n";
+        String out_60 = prefix + "Y2Rl\nZmdo\n";
+        String out_61 = prefix + "Y2Rl\nZmdoaQ==\n";
+
+        // no newline for an empty input array.
+        assertEquals("", encodeString("", 0));
+
+        assertEquals(out_56, encodeString(in_56, 0));
+        assertEquals(out_57, encodeString(in_57, 0));
+        assertEquals(out_58, encodeString(in_58, 0));
+        assertEquals(out_59, encodeString(in_59, 0));
+        assertEquals(out_60, encodeString(in_60, 0));
+        assertEquals(out_61, encodeString(in_61, 0));
+
+        assertEquals(out_56.replaceAll("=", ""), encodeString(in_56, Base64.NO_PADDING));
+        assertEquals(out_57.replaceAll("=", ""), encodeString(in_57, Base64.NO_PADDING));
+        assertEquals(out_58.replaceAll("=", ""), encodeString(in_58, Base64.NO_PADDING));
+        assertEquals(out_59.replaceAll("=", ""), encodeString(in_59, Base64.NO_PADDING));
+        assertEquals(out_60.replaceAll("=", ""), encodeString(in_60, Base64.NO_PADDING));
+        assertEquals(out_61.replaceAll("=", ""), encodeString(in_61, Base64.NO_PADDING));
+
+        assertEquals(out_56.replaceAll("\n", ""), encodeString(in_56, Base64.NO_WRAP));
+        assertEquals(out_57.replaceAll("\n", ""), encodeString(in_57, Base64.NO_WRAP));
+        assertEquals(out_58.replaceAll("\n", ""), encodeString(in_58, Base64.NO_WRAP));
+        assertEquals(out_59.replaceAll("\n", ""), encodeString(in_59, Base64.NO_WRAP));
+        assertEquals(out_60.replaceAll("\n", ""), encodeString(in_60, Base64.NO_WRAP));
+        assertEquals(out_61.replaceAll("\n", ""), encodeString(in_61, Base64.NO_WRAP));
+    }
+}