| Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
| TimedReloadContext |
|
| 2.0;2 |
| 1 | /* | |
| 2 | * Copyright (C) 1998-2001 Semiotek Inc. All Rights Reserved. | |
| 3 | * | |
| 4 | * Redistribution and use in source and binary forms, with or without | |
| 5 | * modification, are permitted under the terms of either of the following | |
| 6 | * Open Source licenses: | |
| 7 | * | |
| 8 | * The GNU General Public License, version 2, or any later version, as | |
| 9 | * published by the Free Software Foundation | |
| 10 | * (http://www.fsf.org/copyleft/gpl.html); | |
| 11 | * | |
| 12 | * or | |
| 13 | * | |
| 14 | * The Semiotek Public License (http://webmacro.org/LICENSE.) | |
| 15 | * | |
| 16 | * This software is provided "as is", with NO WARRANTY, not even the | |
| 17 | * implied warranties of fitness to purpose, or merchantability. You | |
| 18 | * assume all risks and liabilities associated with its use. | |
| 19 | * | |
| 20 | * See www.webmacro.org for more information on the WebMacro project. | |
| 21 | */ | |
| 22 | ||
| 23 | ||
| 24 | package org.webmacro.resource; | |
| 25 | ||
| 26 | import org.webmacro.util.Clock; | |
| 27 | ||
| 28 | /** | |
| 29 | * TimedReloadContext acts as an Decorator for Reload context to support | |
| 30 | * cache resources that are expensive to check for change. An example is a | |
| 31 | * resource fetch via the network, but could also be a file. | |
| 32 | * It is constructed with a reference to another CacheReloadContext and an interval. | |
| 33 | * Its shouldReload() method will pass calls to the referenced CacheReloadContext, but | |
| 34 | * will take sure, that this is done only once in the specified interval. In all other | |
| 35 | * cases it will return "false", to indicate, that the resource should not be reloaded. | |
| 36 | * @since 0.96 | |
| 37 | * @author skanthak@muehlheim.de | |
| 38 | **/ | |
| 39 | ||
| 40 | public class TimedReloadContext extends CacheReloadContext | |
| 41 | { | |
| 42 | ||
| 43 | private CacheReloadContext reloadContext; | |
| 44 | private long nextCheck; | |
| 45 | private long checkInterval; | |
| 46 | ||
| 47 | /** | |
| 48 | * Construct a new TimedReloadContext decorator. | |
| 49 | * This is just a wrapper object for another CacheReloadContext, ensuring | |
| 50 | * that the shouldReload() method of the refrenced reload context is only | |
| 51 | * called once per checkInterval milliseconds. | |
| 52 | * @param reloadContext reload context to wrap around | |
| 53 | * @param checkInterval interval to check for reload at most in milliseconds | |
| 54 | **/ | |
| 55 | public TimedReloadContext (CacheReloadContext reloadContext, long checkInterval) | |
| 56 | { | |
| 57 | 0 | super(); |
| 58 | 0 | this.reloadContext = reloadContext; |
| 59 | 0 | this.checkInterval = checkInterval; |
| 60 | 0 | this.nextCheck = Clock.TIME + checkInterval; |
| 61 | 0 | } |
| 62 | ||
| 63 | /** | |
| 64 | * Check, whether the underlying resource should be reloaded. | |
| 65 | * This method will simply call the shouldReload() method of the | |
| 66 | * referenced reload context, except when this method was called | |
| 67 | * again in the last checkInterval milliseconds. In this case, | |
| 68 | * this method will simply return false. | |
| 69 | * @return whether resource should be reloaded. | |
| 70 | **/ | |
| 71 | public boolean shouldReload () | |
| 72 | { | |
| 73 | //long time = System.currentTimeMillis(); | |
| 74 | 0 | if (Clock.TIME >= nextCheck) |
| 75 | { | |
| 76 | 0 | nextCheck = Clock.TIME + checkInterval; |
| 77 | 0 | return reloadContext.shouldReload(); |
| 78 | } | |
| 79 | else | |
| 80 | { | |
| 81 | 0 | return false; |
| 82 | } | |
| 83 | } | |
| 84 | } |