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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
代码语言：javascript复制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
代码语言：javascript复制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 -> Cache
private final ConcurrentHashMap<String, ConcurrentHashMap<String, Cache>> caches = new ConcurrentHashMap<>();
private final ConcurrentHashMap<String, BroadcastManager> broadcastManagers = new ConcurrentHashMap();
private CacheBuilderTemplate cacheBuilderTemplate;
public SimpleCacheManager() {
}
@PreDestroy
@Override
public 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<>());
}
@Override
public Cache getCache(String area, String cacheName) {
ConcurrentHashMap<String, Cache> areaMap = getCachesByArea(area);
return areaMap.get(cacheName);
}
@Override
public void putCache(String area, String cacheName, Cache cache) {
ConcurrentHashMap<String, Cache> areaMap = getCachesByArea(area);
areaMap.put(cacheName, cache);
}
@Override
public BroadcastManager getBroadcastManager(String area) {
return broadcastManagers.get(area);
}
@Override
public void putBroadcastManager(String area, BroadcastManager broadcastManager) {
broadcastManagers.put(area, broadcastManager);
}
public CacheBuilderTemplate getCacheBuilderTemplate() {
return cacheBuilderTemplate;
}
public void setCacheBuilderTemplate(CacheBuilderTemplate cacheBuilderTemplate) {
this.cacheBuilderTemplate = cacheBuilderTemplate;
}
@Override
public <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
代码语言：javascript复制 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
代码语言：javascript复制 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。
