Merge "Make default MTU size configurable" into rvc-dev

3 files changed, 23 insertions, 17 deletions

diff --git a/connected-device-lib/src/com/android/car/connecteddevice/ConnectedDeviceManager.java b/connected-device-lib/src/com/android/car/connecteddevice/ConnectedDeviceManager.java
index c673ac4d..b207ee01 100644
--- a/connected-device-lib/src/com/android/car/connecteddevice/ConnectedDeviceManager.java
+++ b/connected-device-lib/src/com/android/car/connecteddevice/ConnectedDeviceManager.java
@@ -155,7 +155,8 @@ public class ConnectedDeviceManager {
                 UUID.fromString(context.getString(R.string.car_reconnect_service_uuid)),
                 context.getString(R.string.car_bg_mask),
                 UUID.fromString(context.getString(R.string.car_secure_write_uuid)),
-                UUID.fromString(context.getString(R.string.car_secure_read_uuid)));
+                UUID.fromString(context.getString(R.string.car_secure_read_uuid)),
+                context.getResources().getInteger(R.integer.car_default_mtu_size));
     }
 
     private ConnectedDeviceManager(
@@ -168,13 +169,14 @@ public class ConnectedDeviceManager {
             @NonNull UUID reconnectServiceUuid,
             @NonNull String bgMask,
             @NonNull UUID writeCharacteristicUuid,
-            @NonNull UUID readCharacteristicUuid) {
+            @NonNull UUID readCharacteristicUuid,
+            int defaultMtuSize) {
         this(storage,
                 new CarBleCentralManager(context, bleCentralManager, storage, serviceUuid, bgMask,
                         writeCharacteristicUuid, readCharacteristicUuid),
                 new CarBlePeripheralManager(blePeripheralManager, storage, associationServiceUuid,
                         reconnectServiceUuid, writeCharacteristicUuid, readCharacteristicUuid,
-                        MAX_ADVERTISEMENT_DURATION));
+                        MAX_ADVERTISEMENT_DURATION, defaultMtuSize));
     }
 
     @VisibleForTesting
diff --git a/connected-device-lib/src/com/android/car/connecteddevice/ble/BleDeviceMessageStream.java b/connected-device-lib/src/com/android/car/connecteddevice/ble/BleDeviceMessageStream.java
index 9fc589e6..7ff39599 100644
--- a/connected-device-lib/src/com/android/car/connecteddevice/ble/BleDeviceMessageStream.java
+++ b/connected-device-lib/src/com/android/car/connecteddevice/ble/BleDeviceMessageStream.java
@@ -94,22 +94,20 @@ class BleDeviceMessageStream {
 
     private MessageReceivedErrorListener mMessageReceivedErrorListener;
 
-    /*
-     * This initial value is 20 because BLE has a default write of 23 bytes. However, 3 bytes are
-     * subtracted due to bytes being reserved for the command type and attribute ID.
-     */
-    private int mMaxWriteSize = 20;
+    private int mMaxWriteSize;
 
     BleDeviceMessageStream(@NonNull BlePeripheralManager blePeripheralManager,
             @NonNull BluetoothDevice device,
             @NonNull BluetoothGattCharacteristic writeCharacteristic,
-            @NonNull BluetoothGattCharacteristic readCharacteristic) {
+            @NonNull BluetoothGattCharacteristic readCharacteristic,
+            int defaultMaxWriteSize) {
         mBlePeripheralManager = blePeripheralManager;
         mDevice = device;
         mWriteCharacteristic = writeCharacteristic;
         mReadCharacteristic = readCharacteristic;
         mBlePeripheralManager.addOnCharacteristicWriteListener(this::onCharacteristicWrite);
         mBlePeripheralManager.addOnCharacteristicReadListener(this::onCharacteristicRead);
+        mMaxWriteSize = defaultMaxWriteSize;
     }
 
     /**
@@ -135,7 +133,8 @@ class BleDeviceMessageStream {
      * @param operationType The {@link OperationType} of this message.
      */
     void writeMessage(@NonNull DeviceMessage deviceMessage, OperationType operationType) {
-        logd(TAG, "Writing message to device: " + mDevice.getAddress() + ".");
+        logd(TAG, "Writing message with " + deviceMessage.getMessage().length + " bytes to device: "
+                + mDevice.getAddress() + ".");
         BleDeviceMessage.Builder builder = BleDeviceMessage.newBuilder()
                 .setOperation(operationType)
                 .setIsPayloadEncrypted(deviceMessage.isMessageEncrypted())
@@ -346,6 +345,9 @@ class BleDeviceMessageStream {
 
     /** The maximum amount of bytes that can be written over BLE. */
     void setMaxWriteSize(int maxWriteSize) {
+        if (maxWriteSize <= 0) {
+            return;
+        }
         mMaxWriteSize = maxWriteSize;
     }
 
diff --git a/connected-device-lib/src/com/android/car/connecteddevice/ble/CarBlePeripheralManager.java b/connected-device-lib/src/com/android/car/connecteddevice/ble/CarBlePeripheralManager.java
index fe36fb29..ebe05dcc 100644
--- a/connected-device-lib/src/com/android/car/connecteddevice/ble/CarBlePeripheralManager.java
+++ b/connected-device-lib/src/com/android/car/connecteddevice/ble/CarBlePeripheralManager.java
@@ -109,8 +109,7 @@ public class CarBlePeripheralManager extends CarBleManager {
 
     private final Duration mMaxReconnectAdvertisementDuration;
 
-    // BLE default is 23, minus 3 bytes for ATT_PROTOCOL.
-    private int mWriteSize = 20;
+    private final int mDefaultMtuSize;
 
     private String mOriginalBluetoothName;
 
@@ -137,6 +136,7 @@ public class CarBlePeripheralManager extends CarBleManager {
      * @param readCharacteristicUuid  {@link UUID} of characteristic the device will write to.
      * @param maxReconnectAdvertisementDuration Maximum duration to advertise for reconnect before
      *                                          restarting.
+     * @param defaultMtuSize          Default MTU size for new channels.
      */
     public CarBlePeripheralManager(@NonNull BlePeripheralManager blePeripheralManager,
             @NonNull ConnectedDeviceStorage connectedDeviceStorage,
@@ -144,7 +144,8 @@ public class CarBlePeripheralManager extends CarBleManager {
             @NonNull UUID reconnectServiceUuid,
             @NonNull UUID writeCharacteristicUuid,
             @NonNull UUID readCharacteristicUuid,
-            @NonNull Duration maxReconnectAdvertisementDuration) {
+            @NonNull Duration maxReconnectAdvertisementDuration,
+            int defaultMtuSize) {
         super(connectedDeviceStorage);
         mBlePeripheralManager = blePeripheralManager;
         mAssociationServiceUuid = associationServiceUuid;
@@ -160,6 +161,7 @@ public class CarBlePeripheralManager extends CarBleManager {
         mReadCharacteristic.addDescriptor(mDescriptor);
         mTimeoutHandler = new Handler(Looper.getMainLooper());
         mMaxReconnectAdvertisementDuration = maxReconnectAdvertisementDuration;
+        mDefaultMtuSize = defaultMtuSize;
     }
 
     @Override
@@ -545,12 +547,12 @@ public class CarBlePeripheralManager extends CarBleManager {
         }
 
         BleDeviceMessageStream secureStream = new BleDeviceMessageStream(mBlePeripheralManager,
-                device, mWriteCharacteristic, mReadCharacteristic);
+                device, mWriteCharacteristic, mReadCharacteristic,
+                mDefaultMtuSize - ATT_PROTOCOL_BYTES);
         secureStream.setMessageReceivedErrorListener(
                 exception -> {
                     disconnectWithError("Error occurred in stream: " + exception.getMessage());
                 });
-        secureStream.setMaxWriteSize(mWriteSize);
         SecureBleChannel secureChannel;
         // TODO(b/157492943): Define an out of band version of ReconnectSecureChannel
         if (isReconnect) {
@@ -574,12 +576,12 @@ public class CarBlePeripheralManager extends CarBleManager {
     }
 
     private void setMtuSize(int mtuSize) {
-        mWriteSize = mtuSize - ATT_PROTOCOL_BYTES;
         BleDevice connectedDevice = getConnectedDevice();
         if (connectedDevice != null
                 && connectedDevice.mSecureChannel != null
                 && connectedDevice.mSecureChannel.getStream() != null) {
-            connectedDevice.mSecureChannel.getStream().setMaxWriteSize(mWriteSize);
+            connectedDevice.mSecureChannel.getStream()
+                    .setMaxWriteSize(mtuSize - ATT_PROTOCOL_BYTES);
         }
     }