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.sink;
18
19import com.android.accessorydisplay.common.Logger;
20import com.android.accessorydisplay.common.Transport;
21
22import android.hardware.usb.UsbDevice;
23import android.hardware.usb.UsbDeviceConnection;
24import android.hardware.usb.UsbEndpoint;
25
26import java.io.IOException;
27
28/**
29 * Sends or receives messages using bulk endpoints associated with a {@link UsbDevice}
30 * that represents a USB accessory.
31 */
32public class UsbAccessoryBulkTransport extends Transport {
33    private static final int TIMEOUT_MILLIS = 1000;
34
35    private UsbDeviceConnection mConnection;
36    private UsbEndpoint mBulkInEndpoint;
37    private UsbEndpoint mBulkOutEndpoint;
38
39    public UsbAccessoryBulkTransport(Logger logger, UsbDeviceConnection connection,
40            UsbEndpoint bulkInEndpoint, UsbEndpoint bulkOutEndpoint) {
41        super(logger, 16384);
42        mConnection = connection;
43        mBulkInEndpoint = bulkInEndpoint;
44        mBulkOutEndpoint = bulkOutEndpoint;
45    }
46
47    @Override
48    protected void ioClose() {
49        mConnection = null;
50        mBulkInEndpoint = null;
51        mBulkOutEndpoint = null;
52    }
53
54    @Override
55    protected int ioRead(byte[] buffer, int offset, int count) throws IOException {
56        if (mConnection == null) {
57            throw new IOException("Connection was closed.");
58        }
59        return mConnection.bulkTransfer(mBulkInEndpoint, buffer, offset, count, -1);
60    }
61
62    @Override
63    protected void ioWrite(byte[] buffer, int offset, int count) throws IOException {
64        if (mConnection == null) {
65            throw new IOException("Connection was closed.");
66        }
67        int result = mConnection.bulkTransfer(mBulkOutEndpoint,
68                buffer, offset, count, TIMEOUT_MILLIS);
69        if (result < 0) {
70            throw new IOException("Bulk transfer failed.");
71        }
72    }
73}
74