content: /* Copyright 2013 Google Inc.
   *
   * This library is free software; you can redistribute it and/or
   * modify it under the terms of the GNU Lesser General Public
   * License as published by the Free Software Foundation; either
   * version 2.1 of the License, or (at your option) any later version.
   *
   * This library is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   * Lesser General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
   * USA.
   *
   * Project home page: http://code.google.com/p/usb-serial-for-android/
   */
  
  package com.hoho.android.usbserial.driver;
  
  import android.hardware.usb.UsbDevice;
  import android.hardware.usb.UsbDeviceConnection;
  
  import java.io.IOException;
  
  /**
   * A base class shared by several driver implementations.
   *
   * @author mike wakerly (opensource@hoho.com)
   */
  abstract class CommonUsbSerialDriver implements UsbSerialDriver {
  
      public static final int DEFAULT_READ_BUFFER_SIZE = 16 * 1024;
      public static final int DEFAULT_WRITE_BUFFER_SIZE = 16 * 1024;
  
      protected final UsbDevice mDevice;
      protected final UsbDeviceConnection mConnection;
  
      protected final Object mReadBufferLock = new Object();
      protected final Object mWriteBufferLock = new Object();
  
      /** Internal read buffer.  Guarded by {@link #mReadBufferLock}. */
      protected byte[] mReadBuffer;
  
      /** Internal write buffer.  Guarded by {@link #mWriteBufferLock}. */
      protected byte[] mWriteBuffer;
  
      public CommonUsbSerialDriver(UsbDevice device, UsbDeviceConnection connection) {
          mDevice = device;
          mConnection = connection;
  
          mReadBuffer = new byte[DEFAULT_READ_BUFFER_SIZE];
          mWriteBuffer = new byte[DEFAULT_WRITE_BUFFER_SIZE];
      }
  
      /**
       * Returns the currently-bound USB device.
       *
       * @return the device
       */
      public final UsbDevice getDevice() {
          return mDevice;
      }
  
      /**
       * Sets the size of the internal buffer used to exchange data with the USB
       * stack for read operations.  Most users should not need to change this.
       *
       * @param bufferSize the size in bytes
       */
      public final void setReadBufferSize(int bufferSize) {
          synchronized (mReadBufferLock) {
              if (bufferSize == mReadBuffer.length) {
                  return;
              }
              mReadBuffer = new byte[bufferSize];
          }
      }
  
      /**
       * Sets the size of the internal buffer used to exchange data with the USB
       * stack for write operations.  Most users should not need to change this.
       *
       * @param bufferSize the size in bytes
       */
      public final void setWriteBufferSize(int bufferSize) {
          synchronized (mWriteBufferLock) {
              if (bufferSize == mWriteBuffer.length) {
                  return;
              }
              mWriteBuffer = new byte[bufferSize];
          }
      }
  
      @Override
      public abstract void open() throws IOException;
  
      @Override
      public abstract void close() throws IOException;
  
      @Override
      public abstract int read(final byte[] dest, final int timeoutMillis) throws IOException;
  
      @Override
      public abstract int write(final byte[] src, final int timeoutMillis) throws IOException;
  
      @Override
      @Deprecated
      public abstract int setBaudRate(final int baudRate) throws IOException;
  
      @Override
      public abstract void setParameters(
              int baudRate, int dataBits, int stopBits, int parity) throws IOException;
  
      @Override
      public abstract boolean getCD() throws IOException;
  
      @Override
      public abstract boolean getCTS() throws IOException;
  
      @Override
      public abstract boolean getDSR() throws IOException;
  
      @Override
      public abstract boolean getDTR() throws IOException;
  
      @Override
      public abstract void setDTR(boolean value) throws IOException;
  
      @Override
      public abstract boolean getRI() throws IOException;
  
      @Override
      public abstract boolean getRTS() throws IOException;
  
      @Override
      public abstract void setRTS(boolean value) throws IOException;
  
  }
  