/* * Copyright (C) 2011 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.derson.pumelo.network.volley; import android.annotation.TargetApi; import android.net.TrafficStats; import android.os.Build; import android.os.Process; import android.os.SystemClock; import java.util.concurrent.BlockingQueue; /** * Provides a thread for performing network dispatch from a queue of requests. * * Requests added to the specified queue are processed from the network via a * specified {@link Network} interface. Responses are committed to cache, if * eligible, using a specified {@link Cache} interface. Valid responses and * errors are posted back to the caller via a {@link ResponseDelivery}. */ public class NetworkDispatcher extends Thread { /** The queue of requests to service. */ private final BlockingQueue<Request<?>> mQueue; /** The network interface for processing requests. */ private final Network mNetwork; /** The cache to write to. */ private final Cache mCache; /** For posting responses and errors. */ private final ResponseDelivery mDelivery; /** Used for telling us to die. */ private volatile boolean mQuit = false; /** * Creates a new network dispatcher thread. You must call {@link #start()} * in order to begin processing. * * @param queue Queue of incoming requests for triage * @param network Network interface to use for performing requests * @param cache Cache interface to use for writing responses to cache * @param delivery Delivery interface to use for posting responses */ public NetworkDispatcher(BlockingQueue<Request<?>> queue, Network network, Cache cache, ResponseDelivery delivery) { mQueue = queue; mNetwork = network; mCache = cache; mDelivery = delivery; } /** * Forces this dispatcher to quit immediately. If any requests are still in * the queue, they are not guaranteed to be processed. */ public void quit() { mQuit = true; interrupt(); } @TargetApi(Build.VERSION_CODES.ICE_CREAM_SANDWICH) private void addTrafficStatsTag(Request<?> request) { // Tag the request (if API >= 14) if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.ICE_CREAM_SANDWICH) { TrafficStats.setThreadStatsTag(request.getTrafficStatsTag()); } } @Override public void run() { Process.setThreadPriority(Process.THREAD_PRIORITY_BACKGROUND); while (true) { long startTimeMs = SystemClock.elapsedRealtime(); Request<?> request; try { // Take a request from the queue. request = mQueue.take(); } catch (InterruptedException e) { // We may have been interrupted because it was time to quit. if (mQuit) { return; } continue; } try { request.addMarker("network-queue-take"); // If the request was cancelled already, do not perform the // network request. if (request.isCanceled()) { request.finish("network-discard-cancelled"); continue; } addTrafficStatsTag(request); // Perform the network request. NetworkResponse networkResponse = mNetwork.performRequest(request); request.addMarker("network-http-complete"); // If the server returned 304 AND we delivered a response already, // we're done -- don't deliver a second identical response. if (networkResponse.notModified && request.hasHadResponseDelivered()) { request.finish("not-modified"); continue; } // Parse the response here on the worker thread. Response<?> response = request.parseNetworkResponse(networkResponse); request.addMarker("network-parse-complete"); // Write to cache if applicable. // TODO: Only update cache metadata instead of entire record for 304s. if (request.shouldCache() && response.cacheEntry != null) { mCache.put(request.getCacheKey(), response.cacheEntry); request.addMarker("network-cache-written"); } // Post the response back. request.markDelivered(); mDelivery.postResponse(request, response); } catch (VolleyError volleyError) { volleyError.setNetworkTimeMs(SystemClock.elapsedRealtime() - startTimeMs); parseAndDeliverNetworkError(request, volleyError); } catch (Exception e) { VolleyLog.e(e, "Unhandled exception %s", e.toString()); VolleyError volleyError = new VolleyError(e); volleyError.setNetworkTimeMs(SystemClock.elapsedRealtime() - startTimeMs); mDelivery.postError(request, volleyError); } } } private void parseAndDeliverNetworkError(Request<?> request, VolleyError error) { error = request.parseNetworkError(error); mDelivery.postError(request, error); } }