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 | /** |
| 20 | * Default retry policy for requests. |
| 21 | */ |
| 22 | public class DefaultRetryPolicy implements RetryPolicy { |
| 23 | /** The current timeout in milliseconds. */ |
| 24 | private int mCurrentTimeoutMs; |
| 25 | |
| 26 | /** The current retry count. */ |
| 27 | private int mCurrentRetryCount; |
| 28 | |
| 29 | /** The maximum number of attempts. */ |
| 30 | private final int mMaxNumRetries; |
| 31 | |
| 32 | /** The backoff multiplier for for the policy. */ |
| 33 | private final float mBackoffMultiplier; |
| 34 | |
| 35 | /** The default socket timeout in milliseconds */ |
| 36 | public static final int DEFAULT_TIMEOUT_MS = 2500; |
| 37 | |
| 38 | /** The default number of retries */ |
| 39 | public static final int DEFAULT_MAX_RETRIES = 1; |
| 40 | |
| 41 | /** The default backoff multiplier */ |
| 42 | public static final float DEFAULT_BACKOFF_MULT = 1f; |
| 43 | |
| 44 | /** |
| 45 | * Constructs a new retry policy using the default timeouts. |
| 46 | */ |
| 47 | public DefaultRetryPolicy() { |
| 48 | this(DEFAULT_TIMEOUT_MS, DEFAULT_MAX_RETRIES, DEFAULT_BACKOFF_MULT); |
| 49 | } |
| 50 | |
| 51 | /** |
| 52 | * Constructs a new retry policy. |
| 53 | * @param initialTimeoutMs The initial timeout for the policy. |
| 54 | * @param maxNumRetries The maximum number of retries. |
| 55 | * @param backoffMultiplier Backoff multiplier for the policy. |
| 56 | */ |
| 57 | public DefaultRetryPolicy(int initialTimeoutMs, int maxNumRetries, float backoffMultiplier) { |
| 58 | mCurrentTimeoutMs = initialTimeoutMs; |
| 59 | mMaxNumRetries = maxNumRetries; |
| 60 | mBackoffMultiplier = backoffMultiplier; |
| 61 | } |
| 62 | |
| 63 | /** |
| 64 | * Returns the current timeout. |
| 65 | */ |
| 66 | @Override |
| 67 | public int getCurrentTimeout() { |
| 68 | return mCurrentTimeoutMs; |
| 69 | } |
| 70 | |
| 71 | /** |
| 72 | * Returns the current retry count. |
| 73 | */ |
| 74 | @Override |
| 75 | public int getCurrentRetryCount() { |
| 76 | return mCurrentRetryCount; |
| 77 | } |
| 78 | |
| 79 | /** |
| 80 | * Prepares for the next retry by applying a backoff to the timeout. |
| 81 | * @param error The error code of the last attempt. |
| 82 | */ |
| 83 | @Override |
| 84 | public void retry(VolleyError error) throws VolleyError { |
| 85 | mCurrentRetryCount++; |
| 86 | mCurrentTimeoutMs += (mCurrentTimeoutMs * mBackoffMultiplier); |
| 87 | if (!hasAttemptRemaining()) { |
| 88 | throw error; |
| 89 | } |
| 90 | } |
| 91 | |
| 92 | /** |
| 93 | * Returns true if this policy has attempts remaining, false otherwise. |
| 94 | */ |
| 95 | protected boolean hasAttemptRemaining() { |
| 96 | return mCurrentRetryCount <= mMaxNumRetries; |
| 97 | } |
| 98 | } |