{"id":201457,"date":"2025-05-10T09:31:09","date_gmt":"2025-05-10T01:31:09","guid":{"rendered":"https:\/\/server.hk\/cnblog\/201457\/"},"modified":"2025-05-10T09:31:09","modified_gmt":"2025-05-10T01:31:09","slug":"redis%ef%bc%9a%e5%86%85%e5%ad%98%e8%a2%ab%e6%88%91%e7%94%a8%e5%ae%8c%e4%ba%86%ef%bc%81%e8%af%a5%e6%80%8e%e4%b9%88%e5%8a%9e%ef%bc%9f","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/201457\/","title":{"rendered":"Redis\uff1a\u5185\u5b58\u88ab\u6211\u7528\u5b8c\u4e86\uff01\u8be5\u600e\u4e48\u529e\uff1f"},"content":{"rendered":"

<\/b> <\/p>\n

Redis\uff1a\u5185\u5b58\u88ab\u6211\u7528\u5b8c\u4e86\uff01\u8be5\u600e\u4e48\u529e\uff1f<\/h1>\n

<\/i>\u6536\u85cf<\/span> <\/p>\n

\u5728\u6570\u636e\u5e93\u5b9e\u6218\u5f00\u53d1\u7684\u8fc7\u7a0b\u4e2d\uff0c\u6211\u4eec\u7ecf\u5e38\u4f1a\u9047\u5230\u4e00\u4e9b\u8fd9\u6837\u90a3\u6837\u7684\u95ee\u9898\uff0c\u7136\u540e\u8981\u5361\u597d\u534a\u5929\uff0c\u7b49\u95ee\u9898\u89e3\u51b3\u4e86\u624d\u53d1\u73b0\u539f\u6765\u4e00\u4e9b\u7ec6\u8282\u77e5\u8bc6\u70b9\u8fd8\u662f\u6ca1\u6709\u638c\u63e1\u597d\u3002\u4eca\u5929golang\u5b66\u4e60\u7f51\u5c31\u6574\u7406\u5206\u4eab\u300aRedis\uff1a\u5185\u5b58\u88ab\u6211\u7528\u5b8c\u4e86\uff01\u8be5\u600e\u4e48\u529e\uff1f\u300b\uff0c\u804a\u804a\u5185\u5b58\u3001Redis\u3001\u6570\u636e\u5e93\uff0c\u5e0c\u671b\u53ef\u4ee5\u5e2e\u52a9\u5230\u6b63\u5728\u52aa\u529b\u8d5a\u94b1\u7684\u4f60\u3002<\/p>\n<\/p>\n

\u4ecb\u7ecd<\/strong><\/p>\n<\/p>\n

Redis\u662f\u4e00\u4e2a\u5185\u5b58\u6570\u636e\u5e93\uff0c\u5f53Redis\u4f7f\u7528\u7684\u5185\u5b58\u8d85\u8fc7\u7269\u7406\u5185\u5b58\u7684\u9650\u5236\u540e\uff0c\u5185\u5b58\u6570\u636e\u4f1a\u548c\u78c1\u76d8\u4ea7\u751f\u9891\u7e41\u7684\u4ea4\u6362\uff0c\u4ea4\u6362\u4f1a\u5bfc\u81f4Redis\u6027\u80fd\u6025\u5267\u4e0b\u964d\u3002\u6240\u4ee5\u5728\u751f\u4ea7\u73af\u5883\u4e2d\u6211\u4eec\u901a\u8fc7\u914d\u7f6e\u53c2\u6570maxmemoey\u6765\u9650\u5236\u4f7f\u7528\u7684\u5185\u5b58\u5927\u5c0f\u3002<\/p>\n

\u5f53\u5b9e\u9645\u4f7f\u7528\u7684\u5185\u5b58\u8d85\u8fc7maxmemoey\u540e\uff0cRedis\u63d0\u4f9b\u4e86\u5982\u4e0b\u51e0\u79cd\u53ef\u9009\u7b56\u7565\u3002<\/p>\n

noeviction\uff1a\u5199\u8bf7\u6c42\u8fd4\u56de\u9519\u8bef<\/p>\n

volatile-lru\uff1a\u4f7f\u7528lru\u7b97\u6cd5\u5220\u9664\u8bbe\u7f6e\u4e86\u8fc7\u671f\u65f6\u95f4\u7684\u952e\u503c\u5bf9 volatile-lfu\uff1a\u4f7f\u7528lfu\u7b97\u6cd5\u5220\u9664\u8bbe\u7f6e\u4e86\u8fc7\u671f\u65f6\u95f4\u7684\u952e\u503c\u5bf9 volatile-random\uff1a\u5728\u8bbe\u7f6e\u4e86\u8fc7\u671f\u65f6\u95f4\u7684\u952e\u503c\u5bf9\u4e2d\u968f\u673a\u8fdb\u884c\u5220\u9664 volatile-ttl\uff1a\u6839\u636e\u8fc7\u671f\u65f6\u95f4\u7684\u5148\u540e\u8fdb\u884c\u5220\u9664\uff0c\u8d8a\u65e9\u8fc7\u671f\u7684\u8d8a\u5148\u88ab\u5220\u9664<\/p>\n

allkeys-lru\uff1a\u5728\u6240\u6709\u952e\u503c\u5bf9\u4e2d\uff0c\u4f7f\u7528lru\u7b97\u6cd5\u8fdb\u884c\u5220\u9664 allkeys-lfu\uff1a\u5728\u6240\u6709\u952e\u503c\u5bf9\u4e2d\uff0c\u4f7f\u7528lfu\u7b97\u6cd5\u8fdb\u884c\u5220\u9664 allkeys-random\uff1a\u6240\u6709\u952e\u503c\u5bf9\u4e2d\u968f\u673a\u5220\u9664<\/p>\n

\u6211\u4eec\u6765\u8be6\u7ec6\u4e86\u89e3\u4e00\u4e0blru\u548clfu\u7b97\u6cd5\uff0c\u8fd9\u662f2\u4e2a\u5e38\u89c1\u7684\u7f13\u5b58\u6dd8\u6c70\u7b97\u6cd5\u3002\u300c\u56e0\u4e3a\u8ba1\u7b97\u673a\u7f13\u5b58\u7684\u5bb9\u91cf\u662f\u6709\u9650\u7684\uff0c\u6240\u4ee5\u6211\u4eec\u8981\u5220\u9664\u90a3\u4e9b\u6ca1\u7528\u7684\u6570\u636e\uff0c\u800c\u8fd9\u4e24\u79cd\u7b97\u6cd5\u7684\u533a\u522b\u5c31\u662f\u5224\u5b9a\u6ca1\u7528\u7684\u7eac\u5ea6\u4e0d\u4e00\u6837\u3002\u300d<\/p>\n

LRU\u7b97\u6cd5<\/strong><\/p>\n

\u300clru(Least recently used\uff0c\u6700\u8fd1\u6700\u5c11\u4f7f\u7528)\u7b97\u6cd5\uff0c\u5373\u6700\u8fd1\u8bbf\u95ee\u7684\u6570\u636e\uff0c\u540e\u7eed\u5f88\u5927\u6982\u7387\u8fd8\u4f1a\u88ab\u8bbf\u95ee\u5230\uff0c\u5373\u662f\u6709\u7528\u7684\u3002\u800c\u957f\u65f6\u95f4\u672a\u88ab\u8bbf\u95ee\u7684\u6570\u636e\uff0c\u5e94\u8be5\u88ab\u6dd8\u6c70\u300d<\/p>\n

lru\u7b97\u6cd5\u4e2d\u6570\u636e\u4f1a\u88ab\u653e\u5230\u4e00\u4e2a\u94fe\u8868\u4e2d\uff0c\u94fe\u8868\u7684\u5934\u8282\u70b9\u4e3a\u6700\u8fd1\u88ab\u8bbf\u95ee\u7684\u6570\u636e\uff0c\u94fe\u8868\u7684\u5c3e\u8282\u70b9\u4e3a\u957f\u65f6\u95f4\u6ca1\u6709\u88ab\u8bbf\u95ee\u7684\u6570\u636e<\/p>\n<\/p>\n

\u300clru\u7b97\u6cd5\u7684\u6838\u5fc3\u5b9e\u73b0\u5c31\u662f\u54c8\u5e0c\u8868\u52a0\u53cc\u5411\u94fe\u8868\u300d\u3002\u94fe\u8868\u53ef\u4ee5\u7528\u6765\u7ef4\u62a4\u8bbf\u95ee\u5143\u7d20\u7684\u987a\u5e8f\uff0c\u800chash\u8868\u53ef\u4ee5\u5e2e\u6211\u4eec\u5728O(1)\u65f6\u95f4\u590d\u6742\u5ea6\u4e0b\u8bbf\u95ee\u5230\u5143\u7d20\u3002<\/p>\n

\u300c\u81f3\u4e8e\u4e3a\u4ec0\u4e48\u662f\u53cc\u5411\u94fe\u8868\u5462\u300d?\u4e3b\u8981\u662f\u8981\u5220\u9664\u5143\u7d20\uff0c\u6240\u4ee5\u8981\u83b7\u53d6\u524d\u7ee7\u8282\u70b9\u3002\u6570\u636e\u7ed3\u6784\u56fe\u793a\u5982\u4e0b<\/p>\n<\/p>\n

\u4f7f\u7528\u53cc\u5411\u94fe\u8868+HashMap<\/strong><\/p>\n

\u53cc\u5411\u94fe\u8868\u8282\u70b9\u5b9a\u4e49\u5982\u4e0b<\/p>\n<\/p>\n

public class ListNode\n   \n     { \r\n    K key; \r\n    V value; \r\n    ListNode pre; \r\n    ListNode next; \r\n    public ListNode() {} \r\n    public ListNode(K key, V value) { \r\n        this.key = key; \r\n        this.value = value; \r\n\n   <\/pre>\n
\u5c01\u88c5\u53cc\u5411\u94fe\u8868\u7684\u5e38\u7528\u64cd\u4f5c<\/p>\n<\/p>\n
public class DoubleList { \r\n    private ListNode head; \r\n    private ListNode tail; \r\n    public DoubleList() { \r\n        head = new ListNode(); \r\n        tail = new ListNode(); \r\n        head.next = tail; \r\n        tail.pre = head; \r\n    public void remove(ListNode node) { \r\n        node.pre.next = node.next; \r\n        node.next.pre = node.pre; \r\n    public void addLast(ListNode node) { \r\n        node.pre = tail.pre; \r\n        tail.pre = node; \r\n        node.pre.next = node; \r\n        node.next = tail; \r\n    public ListNode removeFirst() { \r\n        if (head.next == tail) { \r\n            return null; \r\n        ListNode first = head.next; \r\n        remove(first); \r\n        return first; \r\n<\/pre>\n
\u5c01\u88c5\u4e00\u4e2a\u7f13\u5b58\u7c7b\uff0c\u63d0\u4f9b\u6700\u57fa\u672c\u7684get\u548cput\u65b9\u6cd5\u3002\u300c\u9700\u8981\u6ce8\u610f\uff0c\u8fd9\u4e24\u79cd\u57fa\u672c\u7684\u65b9\u6cd5\u90fd\u6d89\u53ca\u5230\u5bf9\u4e24\u79cd\u6570\u636e\u7ed3\u6784\u7684\u4fee\u6539\u300d\u3002<\/p>\n<\/p>\n
public class MyLruCache\n   \n     { \r\n    private int capacity; \r\n    private DoubleList doubleList; \r\n    private Map\n    \n      map;      public MyLruCache(int capacity) {          this.capacity = capacity;          map = new HashMap();          doubleList = new DoubleList();      public V get(Object key) {          ListNode\n     \n       node = map.get(key);          if (node == null) {              return null;          doubleList.remove(node);          doubleList.addLast(node);          return node.value;      public void put(K key, V value) {          \/\/ \u76f4\u63a5\u8c03\u7528\u8fd9\u8fb9\u7684get\u65b9\u6cd5\uff0c\u5982\u679c\u5b58\u5728\uff0c\u5b83\u4f1a\u5728get\u5185\u90e8\u88ab\u79fb\u52a8\u5230\u5c3e\u5df4\uff0c\u4e0d\u7528\u518d\u79fb\u52a8\u4e00\u904d,\u76f4\u63a5\u4fee\u6539\u503c\u5373\u53ef          if ((get(key)) != null) {              map.get(key).value = value;              return;          if (map.size() == capacity) {              ListNode listNode = doubleList.removeFirst();              map.remove(listNode.key);          \/\/ \u82e5\u4e0d\u5b58\u5728\uff0cnew\u4e00\u4e2a\u51fa\u6765          ListNode node = new ListNode(key, value);          map.put(key, node);          doubleList.addLast(node);  \n     \n    \n   <\/pre>\n
\u8fd9\u91cc\u6211\u4eec\u7684\u5b9e\u73b0\u4e3a\u6700\u8fd1\u8bbf\u95ee\u7684\u653e\u5728\u94fe\u8868\u7684\u5c3e\u8282\u70b9\uff0c\u4e0d\u7ecf\u5e38\u8bbf\u95ee\u7684\u653e\u5728\u94fe\u8868\u7684\u5934\u8282\u70b9<\/p>\n
\u6d4b\u8bd5\u4e00\u6ce2\uff0c\u8f93\u51fa\u4e3a\u94fe\u8868\u7684\u6b63\u5e8f\u8f93\u51fa(\u4ee3\u7801\u4e3a\u4e86\u7b80\u6d01\u6ca1\u6709\u8d34toString\u65b9\u6cd5)<\/p>\n<\/p>\n
MyLruCache\n   \n     myLruCache = new MyLruCache(3); \r\n\/\/ {5 : 5} \r\nmyLruCache.put(\"5\", \"5\"); \r\n\/\/ {5 : 5}{3 : 3} \r\nmyLruCache.put(\"3\", \"3\"); \r\n\/\/ {5 : 5}{3 : 3}{4 : 4} \r\nmyLruCache.put(\"4\", \"4\"); \r\n\/\/ {3 : 3}{4 : 4}{2 : 2} \r\nmyLruCache.put(\"2\", \"2\"); \r\n\/\/ {4 : 4}{2 : 2}{3 : 3} \r\nmyLruCache.get(\"3\"); \r\n\n   <\/pre>\n
\u300c\u56e0\u4e3aLinkedHashMap\u7684\u5e95\u5c42\u5b9e\u73b0\u5c31\u662f\u54c8\u5e0c\u8868\u52a0\u53cc\u5411\u94fe\u8868\uff0c\u6240\u4ee5\u4f60\u53ef\u4ee5\u7528LinkedHashMap\u66ff\u6362HashMap\u548cDoubleList\u6765\u6539\u5199\u4e00\u4e0b\u4e0a\u9762\u7684\u7c7b\u300d\u3002<\/p>\n
\u6211\u6765\u6f14\u793a\u4e00\u4e0b\u66f4\u9a9a\u7684\u64cd\u4f5c\uff0c\u53ea\u9700\u8981\u91cd\u5199\u4e00\u4e2a\u6784\u9020\u51fd\u6570\u548cremoveEldestEntry\u65b9\u6cd5\u5373\u53ef\u3002<\/p>\n
\u4f7f\u7528LinkedHashMap\u5b9e\u73b0LRU<\/strong><\/p>\n<\/p>\n
public class LruCache\n   \n     extends LinkedHashMap\n    \n      {      private int cacheSize;      public LruCache(int cacheSize) {           * initialCapacity: \u521d\u59cb\u5bb9\u91cf\u5927\u5c0f           * loadFactor: \u8d1f\u8f7d\u56e0\u5b50           * accessOrder: false\u57fa\u4e8e\u63d2\u5165\u6392\u5e8f\uff08\u9ed8\u8ba4\uff09\uff0ctrue\u57fa\u4e8e\u8bbf\u95ee\u6392\u5e8f          super(cacheSize, 0.75f, true);          this.cacheSize = cacheSize;       * \u5f53\u8c03\u7528put\u6216\u8005putAll\u65b9\u6cd5\u65f6\u4f1a\u8c03\u7528\u5982\u4e0b\u65b9\u6cd5\uff0c\u662f\u5426\u5220\u9664\u6700\u8001\u7684\u6570\u636e\uff0c\u9ed8\u8ba4\u4e3afalse      @Override      protected boolean removeEldestEntry(Map.Entry\n     \n       eldest) {          return size() > cacheSize;  \n     \n    \n   <\/pre>\n
\u6ce8\u610f\u8fd9\u4e2a\u7f13\u5b58\u5e76\u4e0d\u662f\u7ebf\u7a0b\u5b89\u5168\u7684\uff0c\u53ef\u4ee5\u8c03\u7528Collections.synchronizedMap\u65b9\u6cd5\u8fd4\u56de\u7ebf\u7a0b\u5b89\u5168\u7684map<\/p>\n<\/p>\n
LruCache\n   \n     lruCache = new LruCache(3); \r\nMap\n    \n      safeMap = Collections.synchronizedMap(lruCache);  \n    \n   <\/pre>\n
Collections.synchronizedMap\u5b9e\u73b0\u7ebf\u7a0b\u5b89\u5168\u7684\u65b9\u5f0f\u5f88\u7b80\u5355\uff0c\u53ea\u662f\u8fd4\u56de\u4e00\u4e2a\u4ee3\u7406\u7c7b\u3002\u4ee3\u7406\u7c7b\u5bf9Map\u63a5\u53e3\u7684\u6240\u6709\u65b9\u6cd5\u52a0\u9501<\/p>\n<\/p>\n
public static \n   \n     Map\n    \n      synchronizedMap(Map\n     \n       m) {      return new SynchronizedMap(m);  \n     \n    \n   <\/pre>\n
LFU\u7b97\u6cd5<\/strong><\/p>\n
\u300cLRU\u7b97\u6cd5\u6709\u4e00\u4e2a\u95ee\u9898\uff0c\u5f53\u4e00\u4e2a\u957f\u65f6\u95f4\u4e0d\u88ab\u8bbf\u95ee\u7684key\uff0c\u5076\u5c14\u88ab\u8bbf\u95ee\u4e00\u4e0b\u540e\uff0c\u53ef\u80fd\u4f1a\u9020\u6210\u4e00\u4e2a\u6bd4\u8fd9\u4e2akey\u8bbf\u95ee\u66f4\u9891\u7e41\u7684key\u88ab\u6dd8\u6c70\u3002\u300d<\/p>\n
\u5373LRU\u7b97\u6cd5\u5bf9key\u7684\u51b7\u70ed\u7a0b\u5ea6\u7684\u5224\u65ad\u53ef\u80fd\u4e0d\u51c6\u786e\u3002\u800cLFU\u7b97\u6cd5(Least Frequently Used\uff0c\u6700\u4e0d\u7ecf\u5e38\u4f7f\u7528)\u5219\u662f\u6309\u7167\u8bbf\u95ee\u9891\u7387\u6765\u5224\u65adkey\u7684\u51b7\u70ed\u7a0b\u5ea6\u7684\uff0c\u6bcf\u6b21\u5220\u9664\u7684\u662f\u4e00\u6bb5\u65f6\u95f4\u5185\u8bbf\u95ee\u9891\u7387\u8f83\u4f4e\u7684\u6570\u636e\uff0c\u6bd4LRU\u7b97\u6cd5\u66f4\u51c6\u786e\u3002<\/p>\n
\u4f7f\u75283\u4e2ahash\u8868\u5b9e\u73b0lfu\u7b97\u6cd5<\/strong><\/p>\n
\u90a3\u4e48\u6211\u4eec\u5e94\u8be5\u5982\u4f55\u7ec4\u7ec7\u6570\u636e\u5462?<\/p>\n
\u4e3a\u4e86\u5b9e\u73b0\u952e\u503c\u7684\u5bf9\u5feb\u901f\u8bbf\u95ee\uff0c\u7528\u4e00\u4e2amap\u6765\u4fdd\u5b58\u952e\u503c\u5bf9<\/p>\n<\/p>\n
private HashMap\n   \n     keyToFreq; \r\n\n   <\/pre>\n
\u8fd8\u9700\u8981\u7528\u4e00\u4e2amap\u6765\u4fdd\u5b58\u952e\u7684\u8bbf\u95ee\u9891\u7387<\/p>\n<\/p>\n
private HashMap\n   \n     keyToFreq; \r\n\n   <\/pre>\n
\u300c\u5f53\u7136\u4f60\u4e5f\u53ef\u4ee5\u628a\u503c\u548c\u8bbf\u95ee\u9891\u7387\u5c01\u88c5\u5230\u4e00\u4e2a\u7c7b\u4e2d\uff0c\u7528\u4e00\u4e2amap\u6765\u66ff\u4ee3\u4e0a\u8ff0\u76842\u4e2amap\u300d<\/p>\n
\u63a5\u4e0b\u6765\u5c31\u662f\u6700\u6838\u5fc3\u7684\u90e8\u5206\uff0c\u5220\u9664\u8bbf\u95ee\u9891\u7387\u6700\u4f4e\u7684\u6570\u636e\u3002<\/p>\n
    \n
  • \u4e3a\u4e86\u80fd\u5728O(1)\u65f6\u95f4\u590d\u6742\u5ea6\u5185\u627e\u5230\u8bbf\u95ee\u9891\u7387\u6700\u4f4e\u7684\u6570\u636e\uff0c\u6211\u4eec\u9700\u8981\u4e00\u4e2a\u53d8\u91cfminFreq\u8bb0\u5f55\u8bbf\u95ee\u6700\u4f4e\u7684\u9891\u7387<\/li>\n
  • \u6bcf\u4e2a\u8bbf\u95ee\u9891\u7387\u6709\u53ef\u80fd\u5bf9\u5e94\u591a\u4e2a\u952e\u3002\u5f53\u7a7a\u95f4\u4e0d\u591f\u7528\u65f6\uff0c\u6211\u4eec\u8981\u5220\u9664\u6700\u65e9\u88ab\u8bbf\u95ee\u7684\u6570\u636e\uff0c\u6240\u4ee5\u9700\u8981\u5982\u4e0b\u6570\u636e\u7ed3\u6784\uff0cMap\u3002\u6bcf\u6b21\u5185\u5b58\u4e0d\u591f\u7528\u65f6\uff0c\u5220\u9664\u6709\u5e8f\u96c6\u5408\u7684\u7b2c\u4e00\u4e2a\u5143\u7d20\u5373\u53ef\u3002\u5e76\u4e14\u8fd9\u4e2a\u6709\u5e8f\u96c6\u5408\u8981\u80fd\u5feb\u901f\u5220\u9664\u67d0\u4e2akey\uff0c\u56e0\u4e3a\u67d0\u4e2akey\u88ab\u8bbf\u95ee\u540e\uff0c\u9700\u8981\u4ece\u8fd9\u4e2a\u96c6\u5408\u4e2d\u5220\u9664\uff0c\u52a0\u5165freq+1\u5bf9\u5e94\u7684\u96c6\u5408\u4e2d<\/li>\n
  • \u6709\u5e8f\u96c6\u5408\u5f88\u591a\uff0c\u4f46\u662f\u80fd\u6ee1\u8db3\u5feb\u901f\u5220\u9664\u67d0\u4e2akey\u7684\u53ea\u6709set\uff0c\u4f46\u662fset\u63d2\u5165\u6570\u636e\u662f\u65e0\u5e8f\u7684\u3002\u300c\u5e78\u4e8fJava\u6709LinkedHashSet\u8fd9\u4e2a\u7c7b\uff0c\u94fe\u8868\u548c\u96c6\u5408\u7684\u7ed3\u5408\u4f53\uff0c\u94fe\u8868\u4e0d\u80fd\u5feb\u901f\u5220\u9664\u5143\u7d20\uff0c\u4f46\u662f\u80fd\u4fdd\u8bc1\u63d2\u5165\u987a\u5e8f\u3002\u96c6\u5408\u5185\u90e8\u5143\u7d20\u65e0\u5e8f\uff0c\u4f46\u662f\u80fd\u5feb\u901f\u5220\u9664\u5143\u7d20\uff0c\u5b8c\u7f8e\u300d<\/li>\n<\/ul>\n
    \u4e0b\u9762\u5c31\u662f\u5177\u4f53\u7684\u5b9e\u73b0\u3002<\/p>\n<\/p>\n
    public class LfuCache\n   \n     { \r\n    private HashMap\n    \n      keyToVal;      private HashMap\n     \n       keyToFreq;      private HashMap\n      \n       > freqTokeys;      private int minFreq;      private int capacity;      public LfuCache(int capacity) {          keyToVal = new HashMap();          keyToFreq = new HashMap();          freqTokeys = new HashMap();          this.capacity = capacity;          this.minFreq = 0;      public V get(K key) {          V v = keyToVal.get(key);          if (v == null) {              return null;          increaseFrey(key);          return v;      public void put(K key, V value) {          \/\/ get\u65b9\u6cd5\u91cc\u9762\u4f1a\u589e\u52a0\u9891\u6b21          if (get(key) != null) {              keyToVal.put(key, value);              return;          \/\/ \u8d85\u51fa\u5bb9\u91cf\uff0c\u5220\u9664\u9891\u7387\u6700\u4f4e\u7684key          if (keyToVal.size() >= capacity) {              removeMinFreqKey();          keyToVal.put(key, value);          keyToFreq.put(key, 1);          \/\/ key\u5bf9\u5e94\u7684value\u5b58\u5728\uff0c\u8fd4\u56de\u5b58\u5728\u7684key          \/\/ key\u5bf9\u5e94\u7684value\u4e0d\u5b58\u5728\uff0c\u6dfb\u52a0key\u548cvalue          freqTokeys.putIfAbsent(1, new LinkedHashSet());          freqTokeys.get(1).add(key);          this.minFreq = 1;      \/\/ \u5220\u9664\u51fa\u73b0\u9891\u7387\u6700\u4f4e\u7684key      private void removeMinFreqKey() {          LinkedHashSet\n       \n         keyList = freqTokeys.get(minFreq);          K deleteKey = keyList.iterator().next();          keyList.remove(deleteKey);          if (keyList.isEmpty()) {              \/\/ \u8fd9\u91cc\u5220\u9664\u5143\u7d20\u540e\u4e0d\u9700\u8981\u91cd\u65b0\u8bbe\u7f6eminFreq              \/\/ \u56e0\u4e3aput\u65b9\u6cd5\u6267\u884c\u5b8c\u4f1a\u5c06minFreq\u8bbe\u7f6e\u4e3a1              freqTokeys.remove(keyList);          keyToVal.remove(deleteKey);          keyToFreq.remove(deleteKey);      private void increaseFrey(K key) {          int freq = keyToFreq.get(key);          keyToFreq.put(key, freq + 1);          freqTokeys.get(freq).remove(key);          freqTokeys.putIfAbsent(freq + 1, new LinkedHashSet());          freqTokeys.get(freq + 1).add(key);          if (freqTokeys.get(freq).isEmpty()) {              freqTokeys.remove(freq);              \/\/ \u6700\u5c0f\u9891\u7387\u7684set\u4e3a\u7a7a\uff0ckey\u88ab\u79fb\u52a8\u5230minFreq+1\u5bf9\u5e94\u7684set\u4e86              \/\/ \u6240\u4ee5minFreq\u4e5f\u8981\u52a01              if (freq == this.minFreq) {                  this.minFreq++;  \n       \n      \n     \n    \n   <\/pre>\n
    \u6d4b\u8bd5\u4e00\u4e0b<\/p>\n<\/p>\n
    LfuCache\n   \n     lfuCache = new LfuCache(2); \r\nlfuCache.put(\"1\", \"1\"); \r\nlfuCache.put(\"2\", \"2\"); \r\n\/\/ 1 \r\nSystem.out.println(lfuCache.get(\"1\")); \r\nlfuCache.put(\"3\", \"3\"); \r\n\/\/ 1\u7684\u9891\u7387\u4e3a2\uff0c2\u548c3\u7684\u9891\u7387\u4e3a1\uff0c\u4f462\u66f4\u65e9\u4e4b\u524d\u88ab\u8bbf\u95ee\uff0c\u6240\u4ee5\u88ab\u6e05\u9664 \r\n\/\/ \u7ed3\u679c\u4e3anull \r\nSystem.out.println(lfuCache.get(\"2\")); \r\n\n   <\/pre>\n
     <\/p>\n","protected":false},"excerpt":{"rendered":"
    Redis\uff1a\u5185\u5b58\u88ab\u6211\u7528\u5b8c\u4e86\uff01\u8be5\u600e...<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[101],"tags":[],"class_list":["post-201457","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/201457","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=201457"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/201457\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=201457"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=201457"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=201457"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}