| /* |
| * Copyright (C) 2016 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package com.android.printservice.recommendation.plugin.samsung; |
| |
| import android.net.nsd.NsdManager; |
| import android.net.nsd.NsdServiceInfo; |
| import android.util.Pair; |
| import com.android.printservice.recommendation.util.NsdResolveQueue; |
| |
| import java.util.LinkedList; |
| |
| final class ServiceResolveQueue { |
| |
| private final NsdManager mNsdManager; |
| private final LinkedList<Pair<NsdServiceInfo, ResolveCallback>> mQueue = new LinkedList<>(); |
| private final Object mLock = new Object(); |
| |
| private static Object sLock = new Object(); |
| private static ServiceResolveQueue sInstance = null; |
| private final NsdResolveQueue mNsdResolveQueue; |
| private Pair<NsdServiceInfo, ResolveCallback> mCurrentRequest = null; |
| |
| public static void createInstance(NsdManager nsdManager) { |
| if (sInstance == null) sInstance = new ServiceResolveQueue(nsdManager); |
| } |
| |
| public static ServiceResolveQueue getInstance(NsdManager nsdManager) { |
| synchronized (sLock) { |
| createInstance(nsdManager); |
| return sInstance; |
| } |
| } |
| |
| public static void destroyInstance() { |
| sInstance = null; |
| } |
| |
| public interface ResolveCallback { |
| void serviceResolved(NsdServiceInfo nsdServiceInfo); |
| } |
| |
| public ServiceResolveQueue(NsdManager nsdManager) { |
| mNsdManager = nsdManager; |
| mNsdResolveQueue = NsdResolveQueue.getInstance(); |
| } |
| |
| public void queueRequest(NsdServiceInfo serviceInfo, ResolveCallback callback) { |
| synchronized (mLock) { |
| Pair<NsdServiceInfo, ResolveCallback> newRequest = Pair.create(serviceInfo, callback); |
| if (mQueue.contains(newRequest)) return; |
| mQueue.add(newRequest); |
| makeNextRequest(); |
| } |
| } |
| |
| public void removeRequest(NsdServiceInfo serviceInfo, ResolveCallback callback) { |
| synchronized (mLock) { |
| Pair<NsdServiceInfo, ResolveCallback> newRequest = Pair.create(serviceInfo, callback); |
| mQueue.remove(newRequest); |
| if ((mCurrentRequest != null) && newRequest.equals(mCurrentRequest)) mCurrentRequest = null; |
| } |
| } |
| |
| private void makeNextRequest() { |
| synchronized (mLock) { |
| if (mCurrentRequest != null) return; |
| if (mQueue.isEmpty()) return; |
| mCurrentRequest = mQueue.removeFirst(); |
| mNsdResolveQueue.resolve(mNsdManager, mCurrentRequest.first, |
| new NsdManager.ResolveListener() { |
| @Override |
| public void onResolveFailed(NsdServiceInfo nsdServiceInfo, int i) { |
| synchronized (mLock) { |
| if (mCurrentRequest != null) mQueue.add(mCurrentRequest); |
| makeNextRequest(); |
| } |
| } |
| |
| @Override |
| public void onServiceResolved(NsdServiceInfo nsdServiceInfo) { |
| synchronized (mLock) { |
| if (mCurrentRequest != null) { |
| mCurrentRequest.second.serviceResolved(nsdServiceInfo); |
| mCurrentRequest = null; |
| } |
| makeNextRequest(); |
| } |
| } |
| }); |
| |
| } |
| } |
| |
| |
| } |