Jean-Baptiste Queru | d56b88a | 2012-11-07 07:48:57 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2011 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 | |
| 17 | package com.android.volley; |
| 18 | |
Jean-Baptiste Queru | 6772bce | 2012-11-07 07:51:33 -0800 | [diff] [blame^] | 19 | import android.os.Process; |
| 20 | |
Jean-Baptiste Queru | d56b88a | 2012-11-07 07:48:57 -0800 | [diff] [blame] | 21 | import java.util.concurrent.BlockingQueue; |
| 22 | |
| 23 | /** |
| 24 | * Provides a thread for performing network dispatch from a queue of requests. |
| 25 | * |
| 26 | * Requests added to the specified queue are processed from the network via a |
| 27 | * specified {@link Network} interface. Responses are committed to cache, if |
| 28 | * eligible, using a specified {@link Cache} interface. Valid responses and |
| 29 | * errors are posted back to the caller via a {@link ResponseDelivery}. |
| 30 | */ |
| 31 | @SuppressWarnings("rawtypes") |
| 32 | public class NetworkDispatcher extends Thread { |
| 33 | /** The queue of requests to service. */ |
| 34 | private final BlockingQueue<Request> mQueue; |
| 35 | /** The network interface for processing requests. */ |
| 36 | private final Network mNetwork; |
| 37 | /** The cache to write to. */ |
| 38 | private final Cache mCache; |
| 39 | /** For posting responses and errors. */ |
| 40 | private final ResponseDelivery mDelivery; |
| 41 | /** Used for telling us to die. */ |
| 42 | private volatile boolean mQuit = false; |
| 43 | |
| 44 | /** |
| 45 | * Creates a new network dispatcher thread. You must call {@link #start()} |
| 46 | * in order to begin processing. |
| 47 | * |
| 48 | * @param queue Queue of incoming requests for triage |
| 49 | * @param network Network interface to use for performing requests |
| 50 | * @param cache Cache interface to use for writing responses to cache |
| 51 | * @param delivery Delivery interface to use for posting responses |
| 52 | */ |
| 53 | public NetworkDispatcher(BlockingQueue<Request> queue, |
| 54 | Network network, Cache cache, |
| 55 | ResponseDelivery delivery) { |
| 56 | mQueue = queue; |
| 57 | mNetwork = network; |
| 58 | mCache = cache; |
| 59 | mDelivery = delivery; |
| 60 | } |
| 61 | |
| 62 | /** |
| 63 | * Forces this dispatcher to quit immediately. If any requests are still in |
| 64 | * the queue, they are not guaranteed to be processed. |
| 65 | */ |
| 66 | public void quit() { |
| 67 | mQuit = true; |
| 68 | interrupt(); |
| 69 | } |
| 70 | |
| 71 | @Override |
| 72 | public void run() { |
Jean-Baptiste Queru | 6772bce | 2012-11-07 07:51:33 -0800 | [diff] [blame^] | 73 | Process.setThreadPriority(Process.THREAD_PRIORITY_BACKGROUND); |
Jean-Baptiste Queru | d56b88a | 2012-11-07 07:48:57 -0800 | [diff] [blame] | 74 | Request request; |
| 75 | while (true) { |
| 76 | try { |
| 77 | // Take a request from the queue. |
| 78 | request = mQueue.take(); |
| 79 | } catch (InterruptedException e) { |
| 80 | // We may have been interrupted because it was time to quit. |
| 81 | if (mQuit) { |
| 82 | return; |
| 83 | } |
| 84 | continue; |
| 85 | } |
| 86 | |
| 87 | try { |
| 88 | request.addMarker("network-queue-take"); |
| 89 | |
| 90 | // If the request was cancelled already, do not perform the |
| 91 | // network request. |
| 92 | if (request.isCanceled()) { |
| 93 | request.finish("network-discard-cancelled"); |
| 94 | continue; |
| 95 | } |
| 96 | |
| 97 | // Perform the network request. |
| 98 | NetworkResponse networkResponse = mNetwork.performRequest(request); |
| 99 | request.addMarker("network-http-complete"); |
| 100 | |
| 101 | // If the server returned 304 AND we delivered a response already, |
| 102 | // we're done -- don't deliver a second identical response. |
| 103 | if (networkResponse.notModified && request.hasHadResponseDelivered()) { |
| 104 | request.finish("not-modified"); |
| 105 | continue; |
| 106 | } |
| 107 | |
| 108 | // Parse the response here on the worker thread. |
| 109 | Response<?> response = request.parseNetworkResponse(networkResponse); |
| 110 | request.addMarker("network-parse-complete"); |
| 111 | |
| 112 | // Write to cache if applicable. |
| 113 | // TODO: Only update cache metadata instead of entire record for 304s. |
| 114 | if (request.shouldCache() && response.cacheEntry != null) { |
| 115 | mCache.put(request.getCacheKey(), response.cacheEntry); |
| 116 | request.addMarker("network-cache-written"); |
| 117 | } |
| 118 | |
| 119 | // Post the response back. |
| 120 | request.markDelivered(); |
| 121 | mDelivery.postResponse(request, response); |
| 122 | } catch (VolleyError volleyError) { |
| 123 | parseAndDeliverNetworkError(request, volleyError); |
| 124 | } catch (Exception e) { |
| 125 | VolleyLog.e("Unhandled exception %s", e.toString()); |
| 126 | mDelivery.postError(request, new VolleyError(e)); |
| 127 | } |
| 128 | } |
| 129 | } |
| 130 | |
| 131 | private void parseAndDeliverNetworkError(Request<?> request, VolleyError error) { |
| 132 | error = request.parseNetworkError(error); |
| 133 | mDelivery.postError(request, error); |
| 134 | } |
| 135 | } |