1/*
2 * Copyright (C) 2016 The Android Open Source Project
3 * Copyright (C) 2016 Mopria Alliance, Inc.
4 *
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
8 *
9 *      http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17
18package com.android.bips.ipp;
19
20import android.net.Uri;
21import android.os.AsyncTask;
22import android.util.Log;
23
24import com.android.bips.jni.BackendConstants;
25import com.android.bips.jni.LocalPrinterCapabilities;
26
27import java.io.IOException;
28import java.net.InetAddress;
29import java.net.InetSocketAddress;
30import java.net.Socket;
31import java.net.UnknownHostException;
32import java.util.concurrent.locks.Lock;
33import java.util.concurrent.locks.ReentrantLock;
34
35/** A background task that queries a specific URI for its complete capabilities */
36class GetCapabilitiesTask extends AsyncTask<Void, Void, LocalPrinterCapabilities> {
37    private static final String TAG = GetCapabilitiesTask.class.getSimpleName();
38    private static final boolean DEBUG = false;
39
40    /** Lock to ensure we don't issue multiple simultaneous capability requests */
41    private static final Lock sJniLock = new ReentrantLock();
42
43    private final Backend mBackend;
44    private final Uri mUri;
45    private final long mTimeout;
46
47    GetCapabilitiesTask(Backend backend, Uri uri, long timeout) {
48        mUri = uri;
49        mBackend = backend;
50        mTimeout = timeout;
51    }
52
53    private boolean isDeviceOnline(Uri uri) {
54        try (Socket socket = new Socket()) {
55            InetSocketAddress a = new InetSocketAddress(uri.getHost(), uri.getPort());
56            socket.connect(a, (int) mTimeout);
57            return true;
58        } catch (IOException e) {
59            return false;
60        }
61    }
62
63    @Override
64    protected LocalPrinterCapabilities doInBackground(Void... dummy) {
65        long start = System.currentTimeMillis();
66
67        LocalPrinterCapabilities printerCaps = new LocalPrinterCapabilities();
68        try {
69            printerCaps.inetAddress = InetAddress.getByName(mUri.getHost());
70        } catch (UnknownHostException e) {
71            return null;
72        }
73
74        boolean online = isDeviceOnline(mUri);
75        if (DEBUG) {
76            Log.d(TAG, "isDeviceOnline uri=" + mUri + " online=" + online +
77                    " (" + (System.currentTimeMillis() - start) + "ms)");
78        }
79
80        if (!online || isCancelled()) return null;
81
82        // Do not permit more than a single call to this API or crashes may result
83        sJniLock.lock();
84        int status = -1;
85        start = System.currentTimeMillis();
86        try {
87            if (isCancelled()) return null;
88            status = mBackend.nativeGetCapabilities(Backend.getIp(mUri.getHost()),
89                    mUri.getPort(), mUri.getPath(), mUri.getScheme(), mTimeout, printerCaps);
90        } finally {
91            sJniLock.unlock();
92        }
93
94        if (DEBUG) {
95            Log.d(TAG, "callNativeGetCapabilities uri=" + mUri + " status=" + status +
96                    " (" + (System.currentTimeMillis() - start) + "ms)");
97        }
98
99        return status == BackendConstants.STATUS_OK ? printerCaps : null;
100    }
101}