LavCahce

Introduction: LavCache是一款可以支持现有大多数业务场景的缓存框架，支持自定义存储媒介、项目初始化加载、过期重试、访问统计等多种特性， 并且支持yml文件配置。技术水平有限，欢迎各位大佬批评指正(lonelyangel.jcw@gmail.com)

Poject Address：https://github.com/L-Angel/lavcache

一. 相关概念

1. 特定名词

   • Piece: 对于执行缓存的Method的称呼，缓存执行的单位
   • Sector: 管理一组Piece，同一个Sector下面的Piece使用同一个Cache实例，突破了类文件的隔离
   • Container: 管理Sector
   • CachePool: 管理Cache，内部CacheName与Sector Name一致，通过两个Name进行匹配

2. LavCache中缓存的管理和Sectors的管理是独立的，通过CacheName与SectorName匹配来进行组合， 在Preload的场景下可能会出现先加载缓存然后BuildCache，然后缓存使用默认的ConcurrentCache的情况，开发需要保证调用顺序

3. 特性

   • 缓存行为事件扩展
   • 缓存自动过期
   • 缓存预加载
   • 自定义缓存媒介，支持是否设置过期时间（ms）
   • 动态生成缓存KEY
   • 支持yml文件配置
   • 缓存启动Launcher扩展

二. 配置文件

• resouces/lavcache.yml

 cache   :
   - name   : "DemoCustomizeCache" # same as sector name
     expire : 60000   # ms
     record : false # cache visited log
     autoreload : true # switch which used to auto reload cache
     impl   : com.langel.lavcache.mock.DemoCustomizeCache # class name with implement Cache interface.
 
 preload :
   - com.langel.lavcache.mock.MySector # sector class name with need preload
   - com.langel.lavcache.mock.DemoSector
 
 sectors :
   #- com.langel.lavcache.DemoSector
 
 redis   : # Beta，is not a release feature
   ip : 127.0.0.1
   host : 6379

三. 缓存过期

每1min触发一次Job进行对缓存的expire(ms)进行处理,此处的清理时类似于懒加载，当sector中expire字段的值<=0, needReload将被置为true，当下次访问到这个sector中的缓存时将被重新加载

缓存在执行getRaw方法的时候会事先进行过期时间的校验，如果当前时间大于等于expireAt时间，就会将Sector下面 所有的Piece中needreload字段置为True，执行懒刷新。所谓的懒刷新指的是在在获取缓存里面的数据的时候，会事先 对Method对应下的Piece中needReload字段进行判断，如果为True则进行异步的加载。

四. 缓存预加载

Notice:由于预加载并不知晓函数执行时的参数，因此对于有预加载需求的Piece不要指定参数

   PieceLoader loader = SectorInjector.getInstance(PieceLoader.class);
   boolean val = loader.preload();

五. Action,缓存事件

LavCache一大亮点就是在Piece初始化缓存之后，会出发一系列自定的Action事件，来进行缓存返回数据的重构，

/**
 *PreloadAction 即为自己定义的Action行为，该Action必须实现，com.langel.lavcache.action.Action接口 
 */
@Piece(prefix = "piece", preload = true, after = {PreloadPieceAction.class})
public String preloadPiece() {
   System.out.println("With no hit cache");
   return "PreLoadTest";
}

/**
 * @author L-Angel,Rick(lonelyangel.jcw@gamil.com)
 * @date 2018/9/29 3:42 PM
 **/
public class PreloadPieceAction implements Action {

    @Override
    public void call(MethodHolder holder, String key, Object val) {
        ActionDataCache.DATA = val;
        System.out.println("PreloadPiece action");
        System.out.println(key);
        System.out.println(val);
    }
}

六. 相关说明

1. 缓存key生成规则（大写），无参Piece=PREFIX，有参Piece=PREFIX://FIELD1=VAL1;FIELD2=VAL2; 其中FIELD1，FIELD2 为 com.langel.lavcache.annotation.PieceKey 中field字段

2. 线程

   Cache运行过程中会启动两组线程(已删除该线程)

   • lavcache-single-schedule-thread （threadSize:1）

   调度线程，1分钟运行1次，用于对expire的处理

   • lavcache-pool-x-thread-x（coreSize:0,maxSize:30,keepAlive:33mins,queueSize:1000）

     用于异步重载缓存等

七. 使用

Demo

 @Test
 public void injectTest() {
     MySector sector = SectorInjector.getInstance(MySector.class);
     System.out.println(sector.piece("UserId 111"));
     System.out.println(sector.piece("UserId 111"));
     System.out.println(sector.piece("UserId 111"));
     System.out.println(sector.piece("UserId 111"));
     sector.erase("UserId 111");
     System.out.println(sector.piece("UserId 111"));
     System.out.println(sector.piece("UserId 111"));
     System.out.println(sector.piece("UserId 111"));
     System.out.println(sector.pieceMultiParam("UserId 111","key2"));

     System.out.println(sector.pieceMultiParam("UserId 111","key2"));
     System.out.println(sector.eraseMultiParam("UserId 111","key2"));
     System.out.println(sector.pieceMultiParam("UserId 111","key2"));
     System.out.println(sector.pieceMultiParam("UserId 111","key3"));
     System.out.println(sector.pieceMultiParam("UserId 111","key3"));

     System.out.println(sector.piece("UserId 111"));

     Assert.assertNotNull(sector.piece("test2"));

 }
 
 /**
  * @author L-Angel,Rick(lonelyangel.jcw@gamil.com)
  * @date 2018/9/20
  **/
 @Sector("MyTestSector")
 public class MySector {
 
     @Piece(prefix = "piece", preload = true, after = {PreloadPieceAction.class})
     public String preloadPiece() {
         System.out.println("With no hit cache");
         return "PreLoadTest";
     }
 
     @Piece(prefix = "testkey#userId")
     public String piece(@PieceKey(field = "userId") String userId) {
         System.out.println("With no hit cache");
         return "MyTestPiece";
     }
 
     @Erase(prefix = "testkey#userId")
     public String erase(@PieceKey(field = "userId") String userId) {
         return "";
     }
 
     @Piece(prefix = "testkey2")
     public String pieceMultiParam(@PieceKey(field = "userId") String userId,
                                   @PieceKey(field = "key2") String keys) {
         System.out.println("With no hit cache");
         return "MyTestPiece";
     }
 
     @Erase(prefix = "testkey2")
     public String eraseMultiParam(@PieceKey(field = "userId") String userId,
                                   @PieceKey(field = "key2") String keys) {
         System.out.println("With no hit cache");
         return "MyTestPiece";
     }
 }

如果要使用autoreload，过期控制，preload，自定义Cache等功能，需要 首先使用Luancher进行初始化

     LavCacheLauncher launcher=new LavCacheLauncher();
     launcher.load();

八. In the future

In the future,lavcache will support invoke by SpringFramework style.Bring the document to completion.
And I wish more and more developer who interested in this tools and like open source activities join us.
You can contract me with open a issue in github or send a mail to me,Rick,L-Angel(lonelyangel.jcw@gmail.com)