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 | |
| 19 | import android.os.Handler; |
| 20 | |
| 21 | import java.util.concurrent.Executor; |
| 22 | |
| 23 | /** |
| 24 | * Delivers responses and errors. |
| 25 | */ |
| 26 | public class ExecutorDelivery implements ResponseDelivery { |
| 27 | /** Used for posting responses, typically to the main thread. */ |
| 28 | private final Executor mResponsePoster; |
| 29 | |
| 30 | /** Requests with a sequence number below this one will have responses dropped. */ |
| 31 | private int mDiscardBefore = 0; |
| 32 | |
| 33 | /** |
| 34 | * Creates a new response delivery interface. |
| 35 | * @param handler {@link Handler} to post responses on |
| 36 | */ |
| 37 | public ExecutorDelivery(final Handler handler) { |
| 38 | // Make an Executor that just wraps the handler. |
| 39 | mResponsePoster = new Executor() { |
| 40 | @Override |
| 41 | public void execute(Runnable command) { |
| 42 | handler.post(command); |
| 43 | } |
| 44 | }; |
| 45 | } |
| 46 | |
| 47 | /** |
| 48 | * Creates a new response delivery interface, mockable version |
| 49 | * for testing. |
| 50 | * @param executor For running delivery tasks |
| 51 | */ |
| 52 | public ExecutorDelivery(Executor executor) { |
| 53 | mResponsePoster = executor; |
| 54 | } |
| 55 | |
| 56 | @Override |
| 57 | public void postResponse(Request<?> request, Response<?> response) { |
| 58 | postResponse(request, response, null); |
| 59 | } |
| 60 | |
| 61 | @Override |
| 62 | public void postResponse(Request<?> request, Response<?> response, Runnable runnable) { |
| 63 | request.markDelivered(); |
| 64 | request.addMarker("post-response"); |
| 65 | mResponsePoster.execute(new ResponseDeliveryRunnable(request, response, runnable)); |
| 66 | } |
| 67 | |
| 68 | @Override |
| 69 | public void postError(Request<?> request, VolleyError error) { |
| 70 | request.addMarker("post-error"); |
| 71 | Response<?> response = Response.error(error); |
| 72 | mResponsePoster.execute(new ResponseDeliveryRunnable(request, response, null)); |
| 73 | } |
| 74 | |
| 75 | @Override |
| 76 | public void discardBefore(int sequence) { |
| 77 | mDiscardBefore = sequence; |
| 78 | } |
| 79 | |
| 80 | /** |
| 81 | * A Runnable used for delivering network responses to a listener on the |
| 82 | * main thread. |
| 83 | */ |
| 84 | @SuppressWarnings("rawtypes") |
| 85 | private class ResponseDeliveryRunnable implements Runnable { |
| 86 | private final Request mRequest; |
| 87 | private final Response mResponse; |
| 88 | private final Runnable mRunnable; |
| 89 | |
| 90 | public ResponseDeliveryRunnable(Request request, Response response, Runnable runnable) { |
| 91 | mRequest = request; |
| 92 | mResponse = response; |
| 93 | mRunnable = runnable; |
| 94 | } |
| 95 | |
| 96 | @SuppressWarnings("unchecked") |
| 97 | @Override |
| 98 | public void run() { |
| 99 | // Don't deliver the response if this request was canceled during processing |
| 100 | // or if discardBefore() has been called with a sequence number greater than |
| 101 | // or equal to this request's sequence number. |
| 102 | boolean drained = mRequest.isDrainable() && |
| 103 | (mRequest.getSequence() < mDiscardBefore); |
| 104 | |
| 105 | // If this request has been drained or canceled, finish it and don't deliver. |
| 106 | if (drained || mRequest.isCanceled()) { |
| 107 | mRequest.finish("canceled-at-delivery"); |
| 108 | return; |
| 109 | } |
| 110 | |
| 111 | // Deliver a normal response or error, depending. |
| 112 | if (mResponse.isSuccess()) { |
| 113 | mRequest.deliverResponse(mResponse.result); |
| 114 | } else { |
| 115 | mRequest.deliverError(mResponse.error); |
| 116 | } |
| 117 | |
| 118 | // If this is an intermediate response, add a marker, otherwise we're done |
| 119 | // and the request can be finished. |
| 120 | if (mResponse.intermediate) { |
| 121 | mRequest.addMarker("intermediate-response"); |
| 122 | } else { |
| 123 | mRequest.finish("done"); |
| 124 | } |
| 125 | |
| 126 | // If we have been provided a post-delivery runnable, run it. |
| 127 | if (mRunnable != null) { |
| 128 | mRunnable.run(); |
| 129 | } |
| 130 | } |
| 131 | } |
| 132 | } |