add SIEVE算法

hutool-core/src/main/java/cn/hutool/v7/core/cache/impl/SieveCache.java

@@ -33,6 +33,7 @@ import java.util.concurrent.locks.ReentrantLock;
  * 淘汰时，使用 {@code hand} 指针从尾部扫描，淘汰 {@code visited=false} 的节点。<br>
  * 新加入节点 {@code visited = false} 且置于头部，Hand 指针扫描时会优先淘汰它，提供抗扫描能力。<br>
  * </p>
+ * 来自：<a href="https://github.com/chinabugotech/hutool/pull/4157">pr#4157@Github</a>
  *
  * @param <K> 键类型
  * @param <V> 值类型
@@ -61,7 +62,7 @@ public class SieveCache<K, V> extends LockedCache<K, V> {
 	 *
 	 * @param capacity 容量
 	 */
-	public SieveCache(int capacity) {
+	public SieveCache(final int capacity) {
 		this(capacity, 0);
 	}
 
@@ -71,7 +72,7 @@ public class SieveCache<K, V> extends LockedCache<K, V> {
 	 * @param capacity 容量
 	 * @param timeout  默认超时时间，单位：毫秒
 	 */
-	public SieveCache(int capacity, long timeout) {
+	public SieveCache(int capacity, final long timeout) {
 		if (Integer.MAX_VALUE == capacity) {
 			capacity -= 1;
 		}
@@ -85,7 +86,7 @@ public class SieveCache<K, V> extends LockedCache<K, V> {
 	}
 
 	@Override
-	protected void putWithoutLock(K key, V object, long timeout) {
+	protected void putWithoutLock(final K key, final V object, final long timeout) {
 		final Mutable<K> keyObj = MutableObj.of(key);
 		SieveCacheObj<K, V> co = (SieveCacheObj<K, V>) cacheMap.get(keyObj);
 
@@ -116,7 +117,7 @@ public class SieveCache<K, V> extends LockedCache<K, V> {
 	 * @param oldNode 旧节点
 	 * @param newNode 新节点
 	 */
-	private void replaceNode(SieveCacheObj<K, V> oldNode, SieveCacheObj<K, V> newNode) {
+	private void replaceNode(final SieveCacheObj<K, V> oldNode, final SieveCacheObj<K, V> newNode) {
 		newNode.prev = oldNode.prev;
 		newNode.next = oldNode.next;
 
@@ -144,7 +145,7 @@ public class SieveCache<K, V> extends LockedCache<K, V> {
 	}
 
 	@Override
-	protected CacheObj<K, V> getOrRemoveExpiredWithoutLock(K key) {
+	protected CacheObj<K, V> getOrRemoveExpiredWithoutLock(final K key) {
 		final Mutable<K> keyObj = MutableObj.of(key);
 		final SieveCacheObj<K, V> co = (SieveCacheObj<K, V>) cacheMap.get(keyObj);
 
@@ -160,7 +161,7 @@ public class SieveCache<K, V> extends LockedCache<K, V> {
 	}
 
 	@Override
-	protected CacheObj<K, V> removeWithoutLock(K key) {
+	protected CacheObj<K, V> removeWithoutLock(final K key) {
 		final Mutable<K> keyObj = MutableObj.of(key);
 		final SieveCacheObj<K, V> co = (SieveCacheObj<K, V>) cacheMap.remove(keyObj);
 		if (co != null) {
@@ -223,7 +224,7 @@ public class SieveCache<K, V> extends LockedCache<K, V> {
 	 *
 	 * @param node 节点
 	 */
-	private void addToHead(SieveCacheObj<K, V> node) {
+	private void addToHead(final SieveCacheObj<K, V> node) {
 		node.next = head;
 		node.prev = null;
 		if (head != null) {
@@ -240,7 +241,7 @@ public class SieveCache<K, V> extends LockedCache<K, V> {
 	 *
 	 * @param node 节点
 	 */
-	private void removeNode(SieveCacheObj<K, V> node) {
+	private void removeNode(final SieveCacheObj<K, V> node) {
 		if (node == hand) {
 			hand = node.prev;
 		}

hutool-core/src/test/java/cn/hutool/v7/core/cache/SieveCacheTest.java

@@ -32,7 +32,7 @@ public class SieveCacheTest {
 
 	@Test
 	public void evictionLogicTest() {
-		SieveCache<String, String> cache = new SieveCache<>(3);
+		final SieveCache<String, String> cache = new SieveCache<>(3);
 
 		cache.put("A", "A");
 		cache.put("B", "B");
@@ -52,7 +52,7 @@ public class SieveCacheTest {
 
 	@Test
 	public void expiryTest() {
-		SieveCache<String, String> cache = new SieveCache<>(3);
+		final SieveCache<String, String> cache = new SieveCache<>(3);
 		cache.put("k1", "v1", 100);
 		cache.put("k2", "v2", 10000);
 
@@ -66,7 +66,7 @@ public class SieveCacheTest {
 	@Test
 	public void listenerTest() {
 		final AtomicInteger removeCount = new AtomicInteger();
-		SieveCache<Integer, Integer> cache = new SieveCache<>(2);
+		final SieveCache<Integer, Integer> cache = new SieveCache<>(2);
 
 		cache.setListener((key, value) -> {
 			removeCount.incrementAndGet();
@@ -81,9 +81,9 @@ public class SieveCacheTest {
 
 	@Test
 	public void concurrencyPressureTest() throws InterruptedException {
-		int threadCount = 20;
+		final int threadCount = 20;
-		int loopCount = 2000;
+		final int loopCount = 2000;
-		int capacity = 100;
+		final int capacity = 100;
 
 		final SieveCache<String, String> cache = new SieveCache<>(capacity);
 		final CountDownLatch latch = new CountDownLatch(threadCount);
@@ -93,14 +93,14 @@ public class SieveCacheTest {
 			new Thread(() -> {
 				try {
 					for (int j = 0; j < loopCount; j++) {
-						String key = String.valueOf(RandomUtil.randomInt(0, 1000));
+						final String key = String.valueOf(RandomUtil.randomInt(0, 1000));
 						if (RandomUtil.randomBoolean()) {
 							cache.put(key, "val-" + key);
 						} else {
 							cache.get(key);
 						}
 					}
-				} catch (Exception e) {
+				} catch (final Exception e) {
 					errorCount.incrementAndGet();
 				} finally {
 					latch.countDown();
@@ -114,7 +114,7 @@ public class SieveCacheTest {
 		Assertions.assertTrue(cache.size() <= capacity, "缓存大小不应超过容量");
 
 		int iteratorCount = 0;
-		for (String ignored : cache) {
+		for (final String ignored : cache) {
 			iteratorCount++;
 		}
 		Assertions.assertEquals(cache.size(), iteratorCount, "迭代器数量与 size() 应一致");
@@ -126,8 +126,8 @@ public class SieveCacheTest {
 	 */
 	@Test
 	public void scanResistanceTest() {
-		int capacity = 10;
+		final int capacity = 10;
-		SieveCache<Integer, Integer> cache = new SieveCache<>(capacity);
+		final SieveCache<Integer, Integer> cache = new SieveCache<>(capacity);
 
 		// 填满热点数据
 		for (int i = 0; i < capacity; i++) {