transient Node<K,V>[] table;
transient int size;

class Node<K,V> implements Map.Entry<K,V> {
 final int hash;
 final K key;
 V value;
 Node<K,V> next;
}

class TreeNode<K,V> extends LinkedHashMap.Entry<K,V> {
 TreeNode<K,V> parent; // red-black tree links
 TreeNode<K,V> left;
 TreeNode<K,V> right;
 TreeNode<K,V> prev; // needed to unlink next upon deletion
 boolean red;
 }

static final int TREEIFY_THRESHOLD = 8;
static final int UNTREEIFY_THRESHOLD = 6;
static final int MIN_TREEIFY_CAPACITY = 64;

public V put(K key, V value) {
 return putVal(hash(key), key, value, false, true);
}
final int hash(Object key) {
 int h;
 return (key == null) ? 0 : (h = key.hashCode()) ^ (h >>> 16);
}

V putVal(int hash, K key, V value, boolean onlyIfAbsent,
          boolean evict) {
    Node<K,V>[] tab; Node<K,V> p; int n, i;
    
    if ((tab = table) == null || (n = tab.length) == 0)
      n = (tab = resize()).length;

    //代碼段1
    if ((p = tab[i = (n - 1) & hash]) == null)
      tab[i] = newNode(hash, key, value, null);      
    else {
      Node<K,V> e; K k;
      //代碼段2
      if (p.hash == hash &&
        ((k = p.key) == key || (key != null && key.equals(k))))
        e = p;
      //代碼段3  
      else if (p instanceof TreeNode)
        e = ((TreeNode<K,V>)p).putTreeVal(this, tab, hash, key, value);
      else {
        //代碼段4
        for (int binCount = 0; ; ++binCount) {
          //代碼段4.1
          if ((e = p.next) == null) {
            p.next = newNode(hash, key, value, null);
            if (binCount >= TREEIFY_THRESHOLD - 1) // -1 for 1st
              treeifyBin(tab, hash);
            break;
          }
          //代碼段4.2
          if (e.hash == hash &&
            ((k = e.key) == key || (key != null && key.equals(k))))
            break;
          p = e;
        }
      }
      //代碼段5
      if (e != null) { // existing mapping for key
        V oldValue = e.value;
        if (!onlyIfAbsent || oldValue == null)
          e.value = value;
        afterNodeAccess(e);
        return oldValue;
      }
    }
    //代碼段6
    ++modCount;
    if (++size > threshold)
      resize();
    afterNodeInsertion(evict);
    return null;
  }

public V remove(Object key) {
  Node<K,V> e;
  return (e = removeNode(hash(key), key, null, false, true)) == null ?
    null : e.value;
}
  
Node<K,V> removeNode(int hash, Object key, Object value,
                boolean matchValue, boolean movable) {
  Node<K,V>[] tab; Node<K,V> p; int n, index;
  
  //代碼段1
  if ((tab = table) != null && (n = tab.length) > 0 &&
    (p = tab[index = (n - 1) & hash]) != null) {
    
    //代碼段2：
    Node<K,V> node = null, e; K k; V v;
    if (p.hash == hash &&
      ((k = p.key) == key || (key != null && key.equals(k))))
      node = p;
      
    //代碼段3:
    else if ((e = p.next) != null) {
      //代碼段3.1:
      if (p instanceof TreeNode)
        node = ((TreeNode<K,V>)p).getTreeNode(hash, key);
      else {
        //代碼段3.2:
        do {
          if (e.hash == hash &&
            ((k = e.key) == key ||
             (key != null && key.equals(k)))) {
            node = e;
            break;
          }
          p = e;
        } while ((e = e.next) != null);
      }
    }
    
    //代碼段4:
    if (node != null && (!matchValue || (v = node.value) == value ||
               (value != null && value.equals(v)))) {         
      //代碼段4.1:
      if (node instanceof TreeNode)
        ((TreeNode<K,V>)node).removeTreeNode(this, tab, movable);
      //代碼段4.2:
      else if (node == p)
        tab[index] = node.next;
      //代碼段4.3:
      else
        p.next = node.next;
      ++modCount;
      --size;
      afterNodeRemoval(node);
      return node;
    }
  }
  return null;
}

final float loadFactor;
int threshold;

static final int tableSizeFor(int cap) {
  int n = cap - 1;
  n |= n >>> 1;
  n |= n >>> 2;
  n |= n >>> 4;
  n |= n >>> 8;
  n |= n >>> 16;
  return (n < 0) ? 1 : (n >= MAXIMUM_CAPACITY) ? MAXIMUM_CAPACITY : n + 1;
}

Node<K,V>[] resize() {
  
   //此處省略了計(jì)算newCap的邏輯

  Node<K,V>[] newTab = (Node<K,V>[])new Node[newCap];
  table = newTab;
  if (oldTab != null) {
    for (int j = 0; j < oldCap; ++j) {
      Node<K,V> e;
      if ((e = oldTab[j]) != null) {
        oldTab[j] = null;
        
        //分支1
        if (e.next == null)
          newTab[e.hash & (newCap - 1)] = e;
        //分支2
        else if (e instanceof TreeNode)
          ((TreeNode<K,V>)e).split(this, newTab, j, oldCap);
        //分支3
        else { // preserve order
          //此處省略了鏈表拆分邏輯  
        }
    }
  }
  return newTab;
}

abstract class HashIterator {
  Node<K,V> next;    // next entry to return
  Node<K,V> current;   // current entry
  int expectedModCount; // for fast-fail
  int index;       // current slot

  final Node<K,V> nextNode() {
    Node<K,V>[] t;
    Node<K,V> e = next;
    if (modCount != expectedModCount)
      throw new ConcurrentModificationException();
    if (e == null)
      throw new NoSuchElementException();
    if ((next = (current = e).next) == null && (t = table) != null) {
      do {} while (index < t.length && (next = t[index++]) == null);
    }
    return e;
  }
}

final class KeyIterator extends HashIterator
  implements Iterator<K> {
  public final K next() { return nextNode().key; }
}

final class ValueIterator extends HashIterator
  implements Iterator<V> {
  public final V next() { return nextNode().value; }
}

final class EntryIterator extends HashIterator
  implements Iterator<Map.Entry<K,V>> {
  public final Map.Entry<K,V> next() { return nextNode(); }
}

final class KeySet extends AbstractSet<K> {
  public final int size()         { return size; }
  public final void clear()        { HashMap.this.clear(); }
  public final Iterator<K> iterator()   { return new KeyIterator(); }
  public final boolean contains(Object o) { return containsKey(o); }
  public final boolean remove(Object key) {
    return removeNode(hash(key), key, null, false, true) != null;
  }
}