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本文主要研究一下jetcache的CacheManager

CacheManager

jetcache-core/src/main/java/com/alicp/jetcache/CacheManager.java

public interface CacheManager {<K, V> Cache<K, V> getCache(String area, String cacheName);void putCache(String area, String cacheName, Cache cache);BroadcastManager getBroadcastManager(String area);void putBroadcastManager(String area, BroadcastManager broadcastManager);default <K, V> Cache<K, V> getCache(String cacheName) {return getCache(CacheConsts.DEFAULT_AREA, cacheName);}default void putCache(String cacheName, Cache cache){putCache(CacheConsts.DEFAULT_AREA, cacheName, cache);}/*** create or get Cache instance.* @see QuickConfig#newBuilder(String)*/<K, V> Cache<K, V> getOrCreateCache(QuickConfig config);default void putBroadcastManager(BroadcastManager broadcastManager){putBroadcastManager(CacheConsts.DEFAULT_AREA, broadcastManager);}}

CacheManager定义了getCache、putCache、getBroadcastManager、putBroadcastManager、getOrCreateCache方法，并提供了aera为default的默认getCache、putCache、putBroadcastManager方法

SimpleCacheManager

jetcache-core/src/main/java/com/alicp/jetcache/SimpleCacheManager.java

public class SimpleCacheManager implements CacheManager, AutoCloseable {private static final boolean DEFAULT_CACHE_NULL_VALUE = false;private static final Logger logger = LoggerFactory.getLogger(SimpleCacheManager.class);// area -> cacheName -> Cacheprivate final ConcurrentHashMap<String, ConcurrentHashMap<String, Cache>> caches = new ConcurrentHashMap<>();private final ConcurrentHashMap<String, BroadcastManager> broadcastManagers = new ConcurrentHashMap();private CacheBuilderTemplate cacheBuilderTemplate;public SimpleCacheManager() {}@PreDestroy@Overridepublic void close() {broadcastManagers.forEach((area, bm) -> {try {bm.close();} catch (Exception e) {logger.error("error during close broadcast manager", e);}});broadcastManagers.clear();caches.forEach((area, areaMap) -> {areaMap.forEach((cacheName, cache) -> {try {cache.close();} catch (Exception e) {logger.error("error during close Cache", e);}});});caches.clear();}private ConcurrentHashMap<String, Cache> getCachesByArea(String area) {return caches.computeIfAbsent(area, (key) -> new ConcurrentHashMap<>());}@Overridepublic Cache getCache(String area, String cacheName) {ConcurrentHashMap<String, Cache> areaMap = getCachesByArea(area);return areaMap.get(cacheName);}@Overridepublic void putCache(String area, String cacheName, Cache cache) {ConcurrentHashMap<String, Cache> areaMap = getCachesByArea(area);areaMap.put(cacheName, cache);}@Overridepublic BroadcastManager getBroadcastManager(String area) {return broadcastManagers.get(area);}@Overridepublic void putBroadcastManager(String area, BroadcastManager broadcastManager) {broadcastManagers.put(area, broadcastManager);}public CacheBuilderTemplate getCacheBuilderTemplate() {return cacheBuilderTemplate;}public void setCacheBuilderTemplate(CacheBuilderTemplate cacheBuilderTemplate) {this.cacheBuilderTemplate = cacheBuilderTemplate;}@Overridepublic <K, V> Cache<K, V> getOrCreateCache(QuickConfig config) {if (cacheBuilderTemplate == null) {throw new IllegalStateException("cacheBuilderTemplate not set");}Objects.requireNonNull(config.getArea());Objects.requireNonNull(config.getName());ConcurrentHashMap<String, Cache> m = getCachesByArea(config.getArea());Cache c = m.get(config.getName());if (c != null) {return c;}return m.computeIfAbsent(config.getName(), n -> create(config));}//......
}    

SimpleCacheManager实现了CacheManager及AutoCloseable接口，其close方法先遍历broadcastManagers、caches执行其close方法然后进行clear；它在内存中维护了caches及broadcastManagers的ConcurrentHashMap，其getOrCreateCache主要根据QuickConfig来创建Cache，支持buildRemote、buildLocal以及multiLevelCache，并支持包装为RefreshCache或者LoadingCache，另外也支持设置cachePenetrationProtect以及CacheMonitor

buildLocal

    private Cache buildLocal(QuickConfig config) {EmbeddedCacheBuilder cacheBuilder = (EmbeddedCacheBuilder) cacheBuilderTemplate.getCacheBuilder(0, config.getArea());if (cacheBuilder == null) {throw new CacheConfigException("no local cache builder: " + config.getArea());}if (config.getLocalLimit() != null && config.getLocalLimit() > 0) {cacheBuilder.setLimit(config.getLocalLimit());}if (config.getCacheType() == CacheType.BOTH &&config.getLocalExpire() != null && config.getLocalExpire().toMillis() > 0) {cacheBuilder.expireAfterWrite(config.getLocalExpire().toMillis(), TimeUnit.MILLISECONDS);} else if (config.getExpire() != null && config.getExpire().toMillis() > 0) {cacheBuilder.expireAfterWrite(config.getExpire().toMillis(), TimeUnit.MILLISECONDS);}if (config.getKeyConvertor() != null) {cacheBuilder.getConfig().setKeyConvertor(config.getKeyConvertor());}cacheBuilder.setCacheNullValue(config.getCacheNullValue() != null ?config.getCacheNullValue() : DEFAULT_CACHE_NULL_VALUE);return cacheBuilder.buildCache();}

buildLocal通过cacheBuilderTemplate.getCacheBuilder获取EmbeddedCacheBuilder，然后支持设置limit、expireAfterWrite、keyConvertor、cacheNullValue

buildRemote

    private Cache buildRemote(QuickConfig config) {ExternalCacheBuilder cacheBuilder = (ExternalCacheBuilder) cacheBuilderTemplate.getCacheBuilder(1, config.getArea());if (cacheBuilder == null) {throw new CacheConfigException("no remote cache builder: " + config.getArea());}if (config.getExpire() != null && config.getExpire().toMillis() > 0) {cacheBuilder.expireAfterWrite(config.getExpire().toMillis(), TimeUnit.MILLISECONDS);}String prefix;if (config.getUseAreaInPrefix() != null && config.getUseAreaInPrefix()) {prefix = config.getArea() + "_" + config.getName();} else {prefix = config.getName();}if (cacheBuilder.getConfig().getKeyPrefixSupplier() != null) {Supplier<String> supplier = cacheBuilder.getConfig().getKeyPrefixSupplier();cacheBuilder.setKeyPrefixSupplier(() -> supplier.get() + prefix);} else {cacheBuilder.setKeyPrefix(prefix);}if (config.getKeyConvertor() != null) {cacheBuilder.getConfig().setKeyConvertor(config.getKeyConvertor());}if (config.getValueEncoder() != null) {cacheBuilder.getConfig().setValueEncoder(config.getValueEncoder());}if (config.getValueDecoder() != null) {cacheBuilder.getConfig().setValueDecoder(config.getValueDecoder());}cacheBuilder.setCacheNullValue(config.getCacheNullValue() != null ?config.getCacheNullValue() : DEFAULT_CACHE_NULL_VALUE);return cacheBuilder.buildCache();}

buildRemote方法通过cacheBuilderTemplate.getCacheBuilder获取ExternalCacheBuilder，然后支持设置expireAfterWrite、keyPrefix、keyConvertor、valueEncoder、valueDecoder、cacheNullValue

小结

CacheManager定义了getCache、putCache、getBroadcastManager、putBroadcastManager、getOrCreateCache方法，并提供了aera为default的默认getCache、putCache、putBroadcastManager方法；SimpleCacheManager实现了CacheManager及AutoCloseable接口，其close方法先遍历broadcastManagers、caches执行其close方法然后进行clear；它在内存中维护了caches及broadcastManagers的ConcurrentHashMap，其getOrCreateCache主要根据QuickConfig来创建Cache，支持buildRemote、buildLocal以及multiLevelCache，并支持包装为RefreshCache或者LoadingCache，另外也支持设置cachePenetrationProtect以及CacheMonitor。