1/* 2 * Copyright (C) 2013 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17package com.android.accessorydisplay.source; 18 19import com.android.accessorydisplay.common.Logger; 20import com.android.accessorydisplay.common.Transport; 21 22import android.hardware.usb.UsbAccessory; 23import android.os.ParcelFileDescriptor; 24 25import java.io.FileInputStream; 26import java.io.FileOutputStream; 27import java.io.IOException; 28 29/** 30 * Sends or receives messages over a file descriptor associated with a {@link UsbAccessory}. 31 */ 32public class UsbAccessoryStreamTransport extends Transport { 33 private ParcelFileDescriptor mFd; 34 private FileInputStream mInputStream; 35 private FileOutputStream mOutputStream; 36 37 public UsbAccessoryStreamTransport(Logger logger, ParcelFileDescriptor fd) { 38 super(logger, 16384); 39 mFd = fd; 40 mInputStream = new FileInputStream(fd.getFileDescriptor()); 41 mOutputStream = new FileOutputStream(fd.getFileDescriptor()); 42 } 43 44 @Override 45 protected void ioClose() { 46 try { 47 mFd.close(); 48 } catch (IOException ex) { 49 } 50 mFd = null; 51 mInputStream = null; 52 mOutputStream = null; 53 } 54 55 @Override 56 protected int ioRead(byte[] buffer, int offset, int count) throws IOException { 57 if (mInputStream == null) { 58 throw new IOException("Stream was closed."); 59 } 60 return mInputStream.read(buffer, offset, count); 61 } 62 63 @Override 64 protected void ioWrite(byte[] buffer, int offset, int count) throws IOException { 65 if (mOutputStream == null) { 66 throw new IOException("Stream was closed."); 67 } 68 mOutputStream.write(buffer, offset, count); 69 } 70} 71