auto commit

notes/缓存.md

@@ -58,6 +58,7 @@ public class LRU<K, V> implements Iterable<K> {
         }
     }
 
+
     public LRU(int maxSize) {
 
         this.maxSize = maxSize;
@@ -70,6 +71,7 @@ public class LRU<K, V> implements Iterable<K> {
         tail.pre = head;
     }
 
+
     public V get(K key) {
 
         if (!map.containsKey(key)) {
@@ -83,6 +85,7 @@ public class LRU<K, V> implements Iterable<K> {
         return node.v;
     }
 
+
     public void put(K key, V value) {
 
         if (map.containsKey(key)) {
@@ -100,30 +103,34 @@ public class LRU<K, V> implements Iterable<K> {
         }
     }
 
+
     private void unlink(Node node) {
         Node pre = node.pre;
-        node.pre = node.next;
-        node.next = pre;
+        Node next = node.next;
+        pre.next = next;
+        next.pre = pre;
     }
 
+
     private void appendHead(Node node) {
         node.next = head.next;
+        node.pre = head;
         head.next = node;
     }
 
+
     private Node removeTail() {
         Node node = tail.pre;
-        node.pre = tail;
+        tail.pre = node.pre;
         return node;
     }
 
+
     @Override
     public Iterator<K> iterator() {
 
         return new Iterator<K>() {
-
             private Node cur = head.next;
-
             @Override
             public boolean hasNext() {
                 return cur != tail;