Add parse method to parse UUID from bytes for 16 bit, 32 bit and 128 bit

Bluetooth UUIDs. Added unit tests.

Change-Id: I4ecf0ede02561a5e9815acf8a5a1309d5756b887

core/java/android/bluetooth/BluetoothUuid.java

@@ -18,6 +18,8 @@ package android.bluetooth;
 
 import android.os.ParcelUuid;
 
+import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
 import java.util.Arrays;
 import java.util.HashSet;
 import java.util.UUID;
@@ -76,6 +78,12 @@ public final class BluetoothUuid {
     public static final ParcelUuid BASE_UUID =
             ParcelUuid.fromString("00000000-0000-1000-8000-00805F9B34FB");
 
+    /** Length of bytes for 16 bit UUID */
+    public static final int UUID_BYTES_16_BIT = 2;
+    /** Length of bytes for 32 bit UUID */
+    public static final int UUID_BYTES_32_BIT = 4;
+    /** Length of bytes for 128 bit UUID */
+    public static final int UUID_BYTES_128_BIT = 16;
 
     public static final ParcelUuid[] RESERVED_UUIDS = {
         AudioSink, AudioSource, AdvAudioDist, HSP, Handsfree, AvrcpController, AvrcpTarget,
@@ -215,16 +223,61 @@ public final class BluetoothUuid {
         return (int)value;
     }
 
+    /**
+     * Parse UUID from bytes. The {@code uuidBytes} can represent a 16-bit, 32-bit or 128-bit UUID,
+     * but the returned UUID is always in 128-bit format.
+     * Note UUID is little endian in Bluetooth.
+     *
+     * @param uuidBytes Byte representation of uuid.
+     * @return {@link ParcelUuid} parsed from bytes.
+     * @throws IllegalArgumentException If the {@code uuidBytes} cannot be parsed.
+     */
+    public static ParcelUuid parseUuidFrom(byte[] uuidBytes) {
+        if (uuidBytes == null) {
+            throw new IllegalArgumentException("uuidBytes cannot be null");
+        }
+        int length = uuidBytes.length;
+        if (length != UUID_BYTES_16_BIT && length != UUID_BYTES_32_BIT &&
+                length != UUID_BYTES_128_BIT) {
+            throw new IllegalArgumentException("uuidBytes length invalid - " + length);
+        }
+
+        // Construct a 128 bit UUID.
+        if (length == UUID_BYTES_128_BIT) {
+            ByteBuffer buf = ByteBuffer.wrap(uuidBytes).order(ByteOrder.LITTLE_ENDIAN);
+            long msb = buf.getLong(8);
+            long lsb = buf.getLong(0);
+            return new ParcelUuid(new UUID(msb, lsb));
+        }
+
+        // For 16 bit and 32 bit UUID we need to convert them to 128 bit value.
+        // 128_bit_value = uuid * 2^96 + BASE_UUID
+        long shortUuid;
+        if (length == UUID_BYTES_16_BIT) {
+            shortUuid = uuidBytes[0] & 0xFF;
+            shortUuid += (uuidBytes[1] & 0xFF) << 8;
+        } else {
+            shortUuid = uuidBytes[0] & 0xFF ;
+            shortUuid += (uuidBytes[1] & 0xFF) << 8;
+            shortUuid += (uuidBytes[2] & 0xFF) << 16;
+            shortUuid += (uuidBytes[3] & 0xFF) << 24;
+        }
+        long msb = BASE_UUID.getUuid().getMostSignificantBits() + (shortUuid << 32);
+        long lsb = BASE_UUID.getUuid().getLeastSignificantBits();
+        return new ParcelUuid(new UUID(msb, lsb));
+    }
+
     /**
      * Check whether the given parcelUuid can be converted to 16 bit bluetooth uuid.
+     *
      * @param parcelUuid
      * @return true if the parcelUuid can be converted to 16 bit uuid, false otherwise.
      */
     public static boolean isShortUuid(ParcelUuid parcelUuid) {
-      UUID uuid = parcelUuid.getUuid();
-      if (uuid.getLeastSignificantBits() != BASE_UUID.getUuid().getLeastSignificantBits()) {
-        return false;
-      }
-      return ((uuid.getMostSignificantBits() & 0xFFFF0000FFFFFFFFL) == 0x1000L);
+        UUID uuid = parcelUuid.getUuid();
+        if (uuid.getLeastSignificantBits() != BASE_UUID.getUuid().getLeastSignificantBits()) {
+            return false;
+        }
+        return ((uuid.getMostSignificantBits() & 0xFFFF0000FFFFFFFFL) == 0x1000L);
     }
 }

core/tests/bluetoothtests/src/android/bluetooth/BluetoothUuidTest.java

@@ -0,0 +1,50 @@
+/*
+ * Copyright (C) 2014 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.bluetooth;
+
+import android.os.ParcelUuid;
+import android.test.suitebuilder.annotation.SmallTest;
+
+import junit.framework.TestCase;
+
+/**
+ * Unit test cases for {@link BluetoothUuid}.
+ * <p>
+ * To run this test, use adb shell am instrument -e class 'android.bluetooth.BluetoothUuidTest' -w
+ * 'com.android.bluetooth.tests/android.bluetooth.BluetoothTestRunner'
+ */
+public class BluetoothUuidTest extends TestCase {
+
+    @SmallTest
+    public void testUuidParser() {
+        byte[] uuid16 = new byte[] {
+                0x0B, 0x11 };
+        assertEquals(ParcelUuid.fromString("0000110B-0000-1000-8000-00805F9B34FB"),
+                BluetoothUuid.parseUuidFrom(uuid16));
+
+        byte[] uuid32 = new byte[] {
+                0x0B, 0x11, 0x33, (byte) 0xFE };
+        assertEquals(ParcelUuid.fromString("FE33110B-0000-1000-8000-00805F9B34FB"),
+                BluetoothUuid.parseUuidFrom(uuid32));
+
+        byte[] uuid128 = new byte[] {
+                0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08,
+                0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, (byte) 0xFF };
+        assertEquals(ParcelUuid.fromString("FF0F0E0D-0C0B-0A09-0807-0060504030201"),
+                BluetoothUuid.parseUuidFrom(uuid128));
+    }
+}