| Clover coverage report - |
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| Source file | Conditionals | Statements | Methods | TOTAL | |||||||||||||||
| FIFOCache.java | 75% | 77,8% | 83,3% | 78,6% |
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| 1 | /* | |
| 2 | * Copyright (c) 2002-2003 by OpenSymphony | |
| 3 | * All rights reserved. | |
| 4 | */ | |
| 5 | package com.opensymphony.oscache.base.algorithm; | |
| 6 | ||
| 7 | import java.util.*; | |
| 8 | ||
| 9 | /** | |
| 10 | * FIFO (First In First Out) based queue algorithm for the cache. | |
| 11 | * | |
| 12 | * No synchronization is required in this class since the | |
| 13 | * <code>AbstractConcurrentReadCache</code> already takes care of any | |
| 14 | * synchronization requirements. | |
| 15 | * | |
| 16 | * @version $Revision: 1.1 $ | |
| 17 | * @author <a href="mailto:mike@atlassian.com">Mike Cannon-Brookes</a> | |
| 18 | * @author <a href="mailto:abergevin@pyxis-tech.com">Alain Bergevin</a> | |
| 19 | * @author <a href="mailto:chris@swebtec.com">Chris Miller</a> | |
| 20 | */ | |
| 21 | public class FIFOCache extends AbstractConcurrentReadCache { | |
| 22 | /** | |
| 23 | * A queue containing all cache keys | |
| 24 | */ | |
| 25 | private Collection list; | |
| 26 | ||
| 27 | /** | |
| 28 | * A flag indicating whether we are using a List or a Set for the key collection | |
| 29 | */ | |
| 30 | private boolean isSet = false; | |
| 31 | ||
| 32 | /** | |
| 33 | * Constructs a FIFO Cache. | |
| 34 | */ | |
| 35 | 8 | public FIFOCache() { |
| 36 | 8 | super(); |
| 37 | ||
| 38 | // Check if we're running under JRE 1.4+. If so we can use a LinkedHashSet | |
| 39 | // instead of a LinkedList for a big performance boost when removing elements. | |
| 40 | 8 | try { |
| 41 | 8 | Class.forName("java.util.LinkedHashSet"); |
| 42 | 8 | list = new LinkedHashSet(); |
| 43 | 8 | isSet = true; |
| 44 | } catch (ClassNotFoundException e) { | |
| 45 | 0 | list = new LinkedList(); |
| 46 | } | |
| 47 | } | |
| 48 | ||
| 49 | /** | |
| 50 | * Constructs a FIFO Cache of the specified capacity. | |
| 51 | * | |
| 52 | * @param capacity The maximum cache capacity. | |
| 53 | */ | |
| 54 | 0 | public FIFOCache(int capacity) { |
| 55 | 0 | this(); |
| 56 | 0 | maxEntries = capacity; |
| 57 | } | |
| 58 | ||
| 59 | /** | |
| 60 | * An object was retrieved from the cache. This implementation | |
| 61 | * does noting since this event has no impact on the FIFO algorithm. | |
| 62 | * | |
| 63 | * @param key The cache key of the item that was retrieved. | |
| 64 | */ | |
| 65 | 16 | protected void itemRetrieved(Object key) { |
| 66 | } | |
| 67 | ||
| 68 | /** | |
| 69 | * An object was put in the cache. This implementation just adds | |
| 70 | * the key to the end of the list if it doesn't exist in the list | |
| 71 | * already. | |
| 72 | * | |
| 73 | * @param key The cache key of the item that was put. | |
| 74 | */ | |
| 75 | 120 | protected void itemPut(Object key) { |
| 76 | 120 | if (!list.contains(key)) { |
| 77 | 112 | list.add(key); |
| 78 | } | |
| 79 | } | |
| 80 | ||
| 81 | /** | |
| 82 | * An item needs to be removed from the cache. The FIFO implementation | |
| 83 | * removes the first element in the list (ie, the item that has been in | |
| 84 | * the cache for the longest time). | |
| 85 | * | |
| 86 | * @return The key of whichever item was removed. | |
| 87 | */ | |
| 88 | 28 | protected Object removeItem() { |
| 89 | 28 | Object toRemove; |
| 90 | ||
| 91 | 28 | if (isSet) { |
| 92 | 28 | Iterator it = list.iterator(); |
| 93 | 28 | toRemove = it.next(); |
| 94 | 28 | it.remove(); |
| 95 | } else { | |
| 96 | 0 | toRemove = ((List) list).remove(0); |
| 97 | } | |
| 98 | ||
| 99 | 28 | return toRemove; |
| 100 | } | |
| 101 | ||
| 102 | /** | |
| 103 | * Remove specified key since that object has been removed from the cache. | |
| 104 | * | |
| 105 | * @param key The cache key of the item that was removed. | |
| 106 | */ | |
| 107 | 84 | protected void itemRemoved(Object key) { |
| 108 | 84 | list.remove(key); |
| 109 | } | |
| 110 | } |
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