concurrentHashMap介绍
concurrentHashMap是一个高性能、线程安全的HashMap，底层数据结构主要还是以数组+链表+红黑树实现与HashMap的结构是一致的。
concurrentHashMap1.7和1.8的区别？
对比名称 |
1.7 |
1.8 |
备注 |
线程安全 |
是 |
是 |
|
数据结构 |
数组+链表 |
数组+链表/红黑树 |
|
并发实现 |
ReentrantLock+Segment+HashEntry |
自旋+cas+分段锁 synchronized+CAS+HashEntry+红黑树 |
|
锁实现 |
分段锁，默认并发是16，初始化后Segment数组大小就固定，无法扩容 |
CAS+synchronized 保证并发安全 |
|
释放锁 |
需要调用unlock() |
不需要显示解锁 |
为什么有hashTable还需要concurrentHashMap？
concurrentHashMap的出现主要是用来替换饱受嫌弃的HashTable，原因是HashTable虽然线程安全的但是使用的是synchronized的类锁，导致每次加锁都是把整个类锁了，在高并发的场景下性能非常低下，在有些生产的场景因为使用这个出现线上重大事故。所以可以说concurrentHashMap的出现用于解决高并发、高效率及线程安全的场景而设计的。
concurrentHashMap的基础使用
public class ConcurrentHashMapStudy {
public static void main(String[] args) {
ConcurrentHashMap map = new ConcurrentHashMap(32);
map.put("a",1);
map.put("b",2);
map.put("c",3);
System.out.println(map.toString());
//添加不成功，返回旧值，原因是原来的key已存在
Object a = map.putIfAbsent("a", 2);
System.out.println(a);
//添加成功 返回Null
Object d = map.putIfAbsent("d", 5);
System.out.println(d);
System.out.println(map.toString());
}
}结果
{a=1, b=2, c=3}
1
null
{a=1, b=2, c=3, d=5}其它更多api请自动search
源码学习
ConcurrentHashMap实现ConcurrentMap和Serializable 接口，继承 AbstractMap
属性名称 |
作用 |
备注 |
MAXIMUM_CAPACITY |
散列表数组最大容量 |
用于判断 |
DEFAULT_CAPACITY |
散列表默认容量（是2的幂次方） |
初始化为16 |
MAX_ARRAY_SIZE |
最大的数组大小（不是2的幂次方）toArray和相关方法所需。 |
实始化为Integer.MAX_VALUE - 8 |
LOAD_FACTOR |
负载因子 |
默认为0.75 |
TREEIFY_THRESHOLD |
树化阈值（超过8转成红黑树） |
将链表转为红黑树 |
UNTREEIFY_THRESHOLD |
转为链表的阈值 |
小于6转为链表 |
MIN_TRANSFER_STRIDE |
转为树型化的小最容量 |
|
MIN_TRANSFER_STRIDE |
迁移阈值 |
默认为16 |
RESIZE_STAMP_BITS |
扩容基数 |
固定16是为了扩容的时候使用 |
MAX_RESIZERS |
并发扩容线程最大阈值 |
|
RESIZE_STAMP_SHIFT |
扩容计算值 |
用于扩容的判断和计算值 |
详细源码实现：
//线程安全map实现 默认继承AbstractMap（与hashMap一致）
public class ConcurrentHashMap<K,V> extends AbstractMap<K,V>
implements ConcurrentMap<K,V>, Serializable {
private static final long serialVersionUID = 7249069246763182397L;
/* ---------------- Constants -------------- */
//散列表数组最大容量
private static final int MAXIMUM_CAPACITY = 1 << 30;
//散列表默认容量（是2的幂次方）
private static final int DEFAULT_CAPACITY = 16;
//最大的数组大小（不是2的幂次方）toArray和相关方法所需。
static final int MAX_ARRAY_SIZE = Integer.MAX_VALUE - 8;
//默认的并发级别，目前未被使用，用于旧版本的兼容（jdk1.7遗留）
private static final int DEFAULT_CONCURRENCY_LEVEL = 16;
//负载因子
private static final float LOAD_FACTOR = 0.75f;
//树化阈值（超过8转成红黑树）：将链表转为红黑树
static final int TREEIFY_THRESHOLD = 8;
//转为链表的阈值：将红黑树转为树
static final int UNTREEIFY_THRESHOLD = 6;
//转为树型化的小最容量：需要某个桶容量达到8才会转为红黑树
static final int MIN_TREEIFY_CAPACITY = 64;
//迁移阈值：控制线程迁移的最小阈值
private static final int MIN_TRANSFER_STRIDE = 16;
//扩容基数：固定16是为了扩容的时候使用
private static int RESIZE_STAMP_BITS = 16;
//并发扩容线程最大阈值 （1<<(32-16)）-1
private static final int MAX_RESIZERS = (1 << (32 - RESIZE_STAMP_BITS)) - 1;
//扩容计算值：用于扩容的判断和计算值
private static final int RESIZE_STAMP_SHIFT = 32 - RESIZE_STAMP_BITS;
static final int MOVED = -1; // 正在转移状态
static final int TREEBIN = -2; // 表示已转换成树状态
static final int RESERVED = -3; // 临时保留节点状态
static final int HASH_BITS = 0x7fffffff; // 值大于0就是链表
//CPU的数量
static final int NCPU = Runtime.getRuntime().availableProcessors();
//序列化兼容性
private static final ObjectStreamField[] serialPersistentFields = {
new ObjectStreamField("segments", Segment[].class),
new ObjectStreamField("segmentMask", Integer.TYPE),
new ObjectStreamField("segmentShift", Integer.TYPE)
};
/* ---------------- Nodes -------------- */
//node节点
static class Node<K,V> implements Map.Entry<K,V> {
//hash值（不可变 ）
final int hash;
//key值（不可变）
final K key;
//值 内存可见
volatile V val;
//下一个节点
volatile Node<K,V> next;
//带参构造方法
Node(int hash, K key, V val, Node<K,V> next) {
this.hash = hash;
this.key = key;
this.val = val;
this.next = next;
}
//获取当前key方法
public final K getKey() { return key; }
//获取当前key的值
public final V getValue() { return val; }
//藜取这个对应的哈希值
public final int hashCode() { return key.hashCode() ^ val.hashCode(); }
//转成字符串方法
public final String toString(){ return key + "=" + val; }
//设置当前节点的值（会直接抛出异常）
public final V setValue(V value) {
throw new UnsupportedOperationException();
}
/对比是否一致方法
public final boolean equals(Object o) {
Object k, v, u; Map.Entry<?,?> e;
//主要判断key和内容一样才为一致的对象
return ((o instanceof Map.Entry) &&
(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
(v = e.getValue()) != null &&
(k == key || k.equals(key)) &&
(v == (u = val) || v.equals(u)));
}
//查询对象 h为传进来的哈希值
Node<K,V> find(int h, Object k) {
//获取当前对象
Node<K,V> e = this;
//传进来的k如果为空直接返回空
if (k != null) {
//do循环去查找的，主要是从头到尾
do {
K ek;
if (e.hash == h &&
((ek = e.key) == k || (ek != null && k.equals(ek))))
return e;
} while ((e = e.next) != null);
}
return null;
}
}
/* ---------------- Static utilities -------------- */
//获取hash值
static final int spread(int h) {
return (h ^ (h >>> 16)) & HASH_BITS;
}
//扩容的时候使用到，判断当前的值是否达到扩容条件，如果是进行扩容计算，然后返回扩容空量大小。
private static final int tableSizeFor(int c) {
int n = c - 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;
}
//获取指定的对象，如果存在返回class否则返回空
static Class<?> comparableClassFor(Object x) {
//判断为Comparable类型
if (x instanceof Comparable) {
Class<?> c; Type[] ts, as; Type t; ParameterizedType p;
if ((c = x.getClass()) == String.class) // bypass checks
return c;
if ((ts = c.getGenericInterfaces()) != null) {
for (int i = 0; i < ts.length; ++i) {
if (((t = ts[i]) instanceof ParameterizedType) &&
((p = (ParameterizedType)t).getRawType() ==
Comparable.class) &&
(as = p.getActualTypeArguments()) != null &&
as.length == 1 && as[0] == c) // type arg is c
return c;
}
}
}
return null;
}
//对比对象是否一致
@SuppressWarnings({"rawtypes","unchecked"}) // for cast to Comparable
static int compareComparables(Class<?> kc, Object k, Object x) {
return (x == null || x.getClass() != kc ? 0 :
((Comparable)k).compareTo(x));
}
//从Unsafe获取对象
@SuppressWarnings("unchecked")
static final <K,V> Node<K,V> tabAt(Node<K,V>[] tab, int i) {
return (Node<K,V>)U.getObjectVolatile(tab, ((long)i << ASHIFT) + ABASE);
}
//同上类型
static final <K,V> boolean casTabAt(Node<K,V>[] tab, int i,
Node<K,V> c, Node<K,V> v) {
return U.compareAndSwapObject(tab, ((long)i << ASHIFT) + ABASE, c, v);
}
//设置内容到指定下标位置
static final <K,V> void setTabAt(Node<K,V>[] tab, int i, Node<K,V> v) {
U.putObjectVolatile(tab, ((long)i << ASHIFT) + ABASE, v);
}
//存储数据的数组
transient volatile Node<K,V>[] table;
//临时表列，扩展的时候
private transient volatile Node<K,V>[] nextTable;
//用于计算的基础统计值
private transient volatile long baseCount;
//-1的时候代表正在node数组正在初始化 初始化之后赋值为扩容的阈值
private transient volatile int sizeCtl;
/**
* 调整大小时下一个表的索引+1
*/
private transient volatile int transferIndex;
/**
* 自旋锁标记（用于计算size的加锁标记）
*/
private transient volatile int cellsBusy;
//计算size的默认长度
private transient volatile CounterCell[] counterCells;
//当前节点的keySet
private transient KeySetView<K,V> keySet;
//当前节点的内容
private transient ValuesView<K,V> values;
//当前节点的entrySet
private transient EntrySetView<K,V> entrySet;
//空构造方法
public ConcurrentHashMap() {
}
//指定容量的构造方法
public ConcurrentHashMap(int initialCapacity) {
//小于0抛出异常
if (initialCapacity < 0)
throw new IllegalArgumentException();
int cap = ((initialCapacity >= (MAXIMUM_CAPACITY >>> 1)) ?
MAXIMUM_CAPACITY :
tableSizeFor(initialCapacity + (initialCapacity >>> 1) + 1));
this.sizeCtl = cap;
}
//构造方法 带初始化参数
public ConcurrentHashMap(Map<? extends K, ? extends V> m) {
this.sizeCtl = DEFAULT_CAPACITY;
putAll(m);
}
//构造方法
//initialCapacity 初始容量
//loadFactor 负载因子
public ConcurrentHashMap(int initialCapacity, float loadFactor) {
this(initialCapacity, loadFactor, 1);
}
//构造方法
//initialCapacity 初始容量
//loadFactor 负载因子
//concurrencyLevel 并发级别
public ConcurrentHashMap(int initialCapacity,
float loadFactor, int concurrencyLevel) {
//如果loadFactor小于0 或 initialCapacity 小于0 或 concurrencyLevel 小于等于0 直接抛出异常
if (!(loadFactor > 0.0f) || initialCapacity < 0 || concurrencyLevel <= 0)
throw new IllegalArgumentException();
//初始容易小于等级 则 初始容易等于等级
if (initialCapacity < concurrencyLevel) // Use at least as many bins
initialCapacity = concurrencyLevel; // as estimated threads
//计算大小为 初如容量/赋载因子
long size = (long)(1.0 + (long)initialCapacity / loadFactor);
//容量为 size大于最大值取最大容易否则 计算这个size
int cap = (size >= (long)MAXIMUM_CAPACITY) ?
MAXIMUM_CAPACITY : tableSizeFor((int)size);
//最后将这个 计算出来赋值给sizeCtl
this.sizeCtl = cap;
}
//获取当前数组长度（超过最大值取默认最大值）
public int size() {
long n = sumCount();
return ((n < 0L) ? 0 :
(n > (long)Integer.MAX_VALUE) ? Integer.MAX_VALUE :
(int)n);
}
//判断是否数组为空方法
public boolean isEmpty() {
return sumCount() <= 0L; // ignore transient negative values
}
//通过key获取内容
public V get(Object key) {
Node<K,V>[] tab; Node<K,V> e, p; int n, eh; K ek;
//获取key
int h = spread(key.hashCode());
//判断不为空且长度大于0且获取的下标不为空
if ((tab = table) != null && (n = tab.length) > 0 &&
(e = tabAt(tab, (n - 1) & h)) != null) {
//如果获取的哈希等于计算出来的哈希
if ((eh = e.hash) == h) {
//key一致则返回内容
if ((ek = e.key) == key || (ek != null && key.equals(ek)))
return e.val;
}
//如果小于0(有可能正在扩容)
else if (eh < 0)
//返回 通过find方法获取的这个对象不为空返回内容否则直接返回空
return (p = e.find(h, key)) != null ? p.val : null;
//最后循环判断是否key一致，如果是返回内容
while ((e = e.next) != null) {
if (e.hash == h &&
((ek = e.key) == key || (ek != null && key.equals(ek))))
return e.val;
}
}
//如果什么都不匹配则返回Null
return null;
}
//判断当前数组是否包含key
public boolean containsKey(Object key) {
return get(key) != null;
}
//包含内容方法
public boolean containsValue(Object value) {
//如果内容为空则抛出异常
if (value == null)
throw new NullPointerException();
//存放链表数据
Node<K,V>[] t;
//如果不为空
if ((t = table) != null) {
//转换为Traverser 格式
Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
//迭代判断内容如果一致则返回true
for (Node<K,V> p; (p = it.advance()) != null; ) {
V v;
if ((v = p.val) == value || (v != null && value.equals(v)))
return true;
}
}
//找不到则返回false
return false;
}
//添加元素方法
public V put(K key, V value) {
return putVal(key, value, false);
}
//真实添加元素方法
final V putVal(K key, V value, boolean onlyIfAbsent) {
//key为空 或 value为空直接抛出异常
if (key == null || value == null) throw new NullPointerException();
//计算哈希值
int hash = spread(key.hashCode());
//
int binCount = 0;
for (Node<K,V>[] tab = table;;) {
Node<K,V> f; int n, i, fh;
//如果为空 或长度等于0 则进行初始化
if (tab == null || (n = tab.length) == 0)
tab = initTable();
//判断指定位置如果为空
else if ((f = tabAt(tab, i = (n - 1) & hash)) == null) {
//通过cas进行新节点添加
if (casTabAt(tab, i, null,
new Node<K,V>(hash, key, value, null)))
break; // no lock when adding to empty bin
}
//如果节点已被移动，表示正在扩容，过去协助扩容
else if ((fh = f.hash) == MOVED)
//协作转移或扩容 并返回最新表
tab = helpTransfer(tab, f);
else {
//初始化oldVal为空
V oldVal = null;
//使用同步锁
synchronized (f) {
//再次获取元素与之前元素进行比较
if (tabAt(tab, i) == f) {
//如果哈希大于等于，证明还不是红黑树，（红黑树为-2）
if (fh >= 0) {
binCount = 1;
//循环判断哈希是否一致，如果一致进行赋值
for (Node<K,V> e = f;; ++binCount) {
K ek;
if (e.hash == hash &&
((ek = e.key) == key ||
(ek != null && key.equals(ek)))) {
oldVal = e.val;
if (!onlyIfAbsent)
e.val = value;
break;
}
Node<K,V> pred = e;
if ((e = e.next) == null) {
pred.next = new Node<K,V>(hash, key,
value, null);
break;
}
}
}
//如果为红黑树
else if (f instanceof TreeBin) {
Node<K,V> p;
binCount = 2;
//添加到红黑树中
if ((p = ((TreeBin<K,V>)f).putTreeVal(hash, key,
value)) != null) {
oldVal = p.val;
if (!onlyIfAbsent)
p.val = value;
}
}
}
}
if (binCount != 0) {
//如果节点数超过或等于8则进行转换为树
if (binCount >= TREEIFY_THRESHOLD)
treeifyBin(tab, i);
if (oldVal != null)
return oldVal;
break;
}
}
}
//增加统计数
addCount(1L, binCount);
//返回空
return null;
}
//添加多个map到列表的方法
public void putAll(Map<? extends K, ? extends V> m) {
//尝试调整大小
tryPresize(m.size());
//循环增加
for (Map.Entry<? extends K, ? extends V> e : m.entrySet())
putVal(e.getKey(), e.getValue(), false);
}
//从队列中移除元素
public V remove(Object key) {
return replaceNode(key, null, null);
}
//替换节点信息 被remove引用和需要替换场景使用
final V replaceNode(Object key, V value, Object cv) {
//计算哈希值
int hash = spread(key.hashCode());
//循环查找节点
for (Node<K,V>[] tab = table;;) {
Node<K,V> f; int n, i, fh;
//列表为空直接退出
if (tab == null || (n = tab.length) == 0 ||
(f = tabAt(tab, i = (n - 1) & hash)) == null)
break;
//如果当前正在扩容 或位置已经改变
else if ((fh = f.hash) == MOVED)
//协作转移或扩容 并返回最新表
tab = helpTransfer(tab, f);
else {
//初始化值
V oldVal = null;
//初始化处理过的标记
boolean validated = false;
//同步锁(对象锁)
synchronized (f) {
//重新获取内容判断是否一致（有可能转移后或被替换后不一样了）
if (tabAt(tab, i) == f) {
//大于等于0 证明非黑树
if (fh >= 0) {
//标记为是
validated = true;
//循环判断
for (Node<K,V> e = f, pred = null;;) {
K ek;
//如果哈希且key一致 替换内容
if (e.hash == hash &&
((ek = e.key) == key ||
(ek != null && key.equals(ek)))) {
//获取e的值
V ev = e.val;
//如果cv为空 或cv等于ev 或 ev不为空 且cv与ev相等
if (cv == null || cv == ev ||
(ev != null && cv.equals(ev))) {
//内容为ev
oldVal = ev;
if (value != null)
//e.val重新赋值
e.val = value;
else if (pred != null)
//获取下一节点
pred.next = e.next;
else
//设置下一节点
setTabAt(tab, i, e.next);
}
//退出
break;
}
//下一节点赋值
pred = e;
//为空退出
if ((e = e.next) == null)
break;
}
}
//如果节点为红黑树
else if (f instanceof TreeBin) {
//标识为是
validated = true;
//转换类型
TreeBin<K,V> t = (TreeBin<K,V>)f;
TreeNode<K,V> r, p;
//r赋值为根节点不为空 且 查出来的节点信息不为空
if ((r = t.root) != null &&
(p = r.findTreeNode(hash, key, null)) != null) {
//获取p的内容
V pv = p.val;
//cv不为空 或 cv等于pv 或pv不为空 并且 cv等于pv
if (cv == null || cv == pv ||
(pv != null && cv.equals(pv))) {
//赋值
oldVal = pv;
//不为空进行赋值
if (value != null)
p.val = value;
//为空进行删除节点
else if (t.removeTreeNode(p))
//重新将数赋值
setTabAt(tab, i, untreeify(t.first));
}
}
}
}
}
//如果标识是直
if (validated) {
//并且有值
if (oldVal != null) {
//如果传进来的value为空 则长度-1
if (value == null)
addCount(-1L, -1);
//返回旧值
return oldVal;
}
//退出
break;
}
}
}
//返回空
return null;
}
//清空所有数据
public void clear() {
long delta = 0L; // negative number of deletions
int i = 0;
//获取当前列表
Node<K,V>[] tab = table;
//循环清空
while (tab != null && i < tab.length) {
int fh;
Node<K,V> f = tabAt(tab, i);
if (f == null)
++i;
else if ((fh = f.hash) == MOVED) {
tab = helpTransfer(tab, f);
i = 0; // restart
}
else {
synchronized (f) {
if (tabAt(tab, i) == f) {
Node<K,V> p = (fh >= 0 ? f :
(f instanceof TreeBin) ?
((TreeBin<K,V>)f).first : null);
while (p != null) {
--delta;
p = p.next;
}
setTabAt(tab, i++, null);
}
}
}
}
//清除所有统计
if (delta != 0L)
addCount(delta, -1);
}
//获取keySet
public KeySetView<K,V> keySet() {
KeySetView<K,V> ks;
return (ks = keySet) != null ? ks : (keySet = new KeySetView<K,V>(this, null));
}
//获取列表的 值列表
public Collection<V> values() {
ValuesView<K,V> vs;
return (vs = values) != null ? vs : (values = new ValuesView<K,V>(this));
}
//获取set列表
public Set<Map.Entry<K,V>> entrySet() {
EntrySetView<K,V> es;
return (es = entrySet) != null ? es : (entrySet = new EntrySetView<K,V>(this));
}
//获取哈希code
public int hashCode() {
int h = 0;
Node<K,V>[] t;
if ((t = table) != null) {
Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
for (Node<K,V> p; (p = it.advance()) != null; )
h += p.key.hashCode() ^ p.val.hashCode();
}
return h;
}
//转成string的方法
public String toString() {
Node<K,V>[] t;
int f = (t = table) == null ? 0 : t.length;
Traverser<K,V> it = new Traverser<K,V>(t, f, 0, f);
StringBuilder sb = new StringBuilder();
sb.append('{');
Node<K,V> p;
if ((p = it.advance()) != null) {
for (;;) {
K k = p.key;
V v = p.val;
sb.append(k == this ? "(this Map)" : k);
sb.append('=');
sb.append(v == this ? "(this Map)" : v);
if ((p = it.advance()) == null)
break;
sb.append(',').append(' ');
}
}
return sb.append('}').toString();
}
//判断对象是否一致
public boolean equals(Object o) {
//o不等于当前对象
if (o != this) {
//o为map 直接返回false
if (!(o instanceof Map))
return false;
//map
Map<?,?> m = (Map<?,?>) o;
Node<K,V>[] t;
//获取长度
int f = (t = table) == null ? 0 : t.length;
//创建迭代器
Traverser<K,V> it = new Traverser<K,V>(t, f, 0, f);
//遍历
for (Node<K,V> p; (p = it.advance()) != null; ) {
V val = p.val;
Object v = m.get(p.key);
//如果v为空 或v不等于val那就返回false
if (v == null || (v != val && !v.equals(val)))
return false;
}
//通过map方式判断 主要比较key
for (Map.Entry<?,?> e : m.entrySet()) {
Object mk, mv, v;
if ((mk = e.getKey()) == null ||
(mv = e.getValue()) == null ||
(v = get(mk)) == null ||
(mv != v && !mv.equals(v)))
return false;
}
}
//如果没有不一致就是存在
return true;
}
//兼容老板本
static class Segment<K,V> extends ReentrantLock implements Serializable {
private static final long serialVersionUID = 2249069246763182397L;
final float loadFactor;
Segment(float lf) { this.loadFactor = lf; }
}
//序列化实现，如果发现异常则抛出
private void writeObject(java.io.ObjectOutputStream s)
throws java.io.IOException {
// For serialization compatibility
// Emulate segment calculation from previous version of this class
int sshift = 0;
int ssize = 1;
while (ssize < DEFAULT_CONCURRENCY_LEVEL) {
++sshift;
ssize <<= 1;
}
int segmentShift = 32 - sshift;
int segmentMask = ssize - 1;
@SuppressWarnings("unchecked")
Segment<K,V>[] segments = (Segment<K,V>[])
new Segment<?,?>[DEFAULT_CONCURRENCY_LEVEL];
for (int i = 0; i < segments.length; ++i)
segments[i] = new Segment<K,V>(LOAD_FACTOR);
s.putFields().put("segments", segments);
s.putFields().put("segmentShift", segmentShift);
s.putFields().put("segmentMask", segmentMask);
s.writeFields();
Node<K,V>[] t;
if ((t = table) != null) {
Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
for (Node<K,V> p; (p = it.advance()) != null; ) {
s.writeObject(p.key);
s.writeObject(p.val);
}
}
s.writeObject(null);
s.writeObject(null);
segments = null; // throw away
}
//返序列化实现（实例化） 如果发生异常则抛出
private void readObject(java.io.ObjectInputStream s)
throws java.io.IOException, ClassNotFoundException {
/*
* To improve performance in typical cases, we create nodes
* while reading, then place in table once size is known.
* However, we must also validate uniqueness and deal with
* overpopulated bins while doing so, which requires
* specialized versions of putVal mechanics.
*/
sizeCtl = -1; // force exclusion for table construction
s.defaultReadObject();
long size = 0L;
Node<K,V> p = null;
for (;;) {
@SuppressWarnings("unchecked")
K k = (K) s.readObject();
@SuppressWarnings("unchecked")
V v = (V) s.readObject();
if (k != null && v != null) {
p = new Node<K,V>(spread(k.hashCode()), k, v, p);
++size;
}
else
break;
}
if (size == 0L)
sizeCtl = 0;
else {
int n;
if (size >= (long)(MAXIMUM_CAPACITY >>> 1))
n = MAXIMUM_CAPACITY;
else {
int sz = (int)size;
n = tableSizeFor(sz + (sz >>> 1) + 1);
}
@SuppressWarnings("unchecked")
Node<K,V>[] tab = (Node<K,V>[])new Node<?,?>[n];
int mask = n - 1;
long added = 0L;
while (p != null) {
boolean insertAtFront;
Node<K,V> next = p.next, first;
int h = p.hash, j = h & mask;
if ((first = tabAt(tab, j)) == null)
insertAtFront = true;
else {
K k = p.key;
if (first.hash < 0) {
TreeBin<K,V> t = (TreeBin<K,V>)first;
if (t.putTreeVal(h, k, p.val) == null)
++added;
insertAtFront = false;
}
else {
int binCount = 0;
insertAtFront = true;
Node<K,V> q; K qk;
for (q = first; q != null; q = q.next) {
if (q.hash == h &&
((qk = q.key) == k ||
(qk != null && k.equals(qk)))) {
insertAtFront = false;
break;
}
++binCount;
}
if (insertAtFront && binCount >= TREEIFY_THRESHOLD) {
insertAtFront = false;
++added;
p.next = first;
TreeNode<K,V> hd = null, tl = null;
for (q = p; q != null; q = q.next) {
TreeNode<K,V> t = new TreeNode<K,V>
(q.hash, q.key, q.val, null, null);
if ((t.prev = tl) == null)
hd = t;
else
tl.next = t;
tl = t;
}
setTabAt(tab, j, new TreeBin<K,V>(hd));
}
}
}
if (insertAtFront) {
++added;
p.next = first;
setTabAt(tab, j, p);
}
p = next;
}
table = tab;
sizeCtl = n - (n >>> 2);
baseCount = added;
}
}
//添加成功返回Null 如果已存在抛出异常
public V putIfAbsent(K key, V value) {
return putVal(key, value, true);
}
//删除指定的key 如果key为空抛出NullPointerException
public boolean remove(Object key, Object value) {
if (key == null)
throw new NullPointerException();
return value != null && replaceNode(key, null, value) != null;
}
//替换指定key内容方法
public boolean replace(K key, V oldValue, V newValue) {
//key为空或新旧内容为空则抛出空指针异常
if (key == null || oldValue == null || newValue == null)
throw new NullPointerException();
return replaceNode(key, newValue, oldValue) != null;
}
//替换key内容方法
public V replace(K key, V value) {
//key或内容为空则抛出异常
if (key == null || value == null)
throw new NullPointerException();
return replaceNode(key, value, null);
}
//获取指定key的值，如果没有则返回默认值(这个默认值是自已传进来的)
public V getOrDefault(Object key, V defaultValue) {
V v;
return (v = get(key)) == null ? defaultValue : v;
}
//循环遍历方法
public void forEach(BiConsumer<? super K, ? super V> action) {
//如果对象为空则抛出NullPointerException
if (action == null) throw new NullPointerException();
Node<K,V>[] t;
if ((t = table) != null) {
//通过迭代器实现
Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
for (Node<K,V> p; (p = it.advance()) != null; ) {
action.accept(p.key, p.val);
}
}
}
//替换所有Key相同的节点
public void replaceAll(BiFunction<? super K, ? super V, ? extends V> function) {
//为空抛出异常
if (function == null) throw new NullPointerException();
Node<K,V>[] t;
if ((t = table) != null) {
Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
for (Node<K,V> p; (p = it.advance()) != null; ) {
V oldValue = p.val;
for (K key = p.key;;) {
V newValue = function.apply(key, oldValue);
//新值为空抛出NullPointerException
if (newValue == null)
throw new NullPointerException();
//替换节点信息
if (replaceNode(key, newValue, oldValue) != null ||
(oldValue = get(key)) == null)
break;
}
}
}
}
//添加方法，如果key不存在mappingFunction的结果作为value的值
public V computeIfAbsent(K key, Function<? super K, ? extends V> mappingFunction) {
if (key == null || mappingFunction == null)
throw new NullPointerException();
int h = spread(key.hashCode());
V val = null;
int binCount = 0;
for (Node<K,V>[] tab = table;;) {
Node<K,V> f; int n, i, fh;
//初始化
if (tab == null || (n = tab.length) == 0)
tab = initTable();
else if ((f = tabAt(tab, i = (n - 1) & h)) == null) {
Node<K,V> r = new ReservationNode<K,V>();
//同步锁实现
synchronized (r) {
//cas获取锁
if (casTabAt(tab, i, null, r)) {
binCount = 1;
Node<K,V> node = null;
try {
//提交函数后不为空，则但也建新节点
if ((val = mappingFunction.apply(key)) != null)
node = new Node<K,V>(h, key, val, null);
} finally {
//最后将结果存放到指定位置
setTabAt(tab, i, node);
}
}
}
if (binCount != 0)
break;
}
//正在迁移 去辅助转移
else if ((fh = f.hash) == MOVED)
tab = helpTransfer(tab, f);
else {
boolean added = false;
//同步锁
synchronized (f) {
//获取元素一致
if (tabAt(tab, i) == f) {
if (fh >= 0) {
binCount = 1;
for (Node<K,V> e = f;; ++binCount) {
K ek; V ev;
//判断为同一个对象，则跳出
if (e.hash == h &&
((ek = e.key) == key ||
(ek != null && key.equals(ek)))) {
val = e.val;
break;
}
Node<K,V> pred = e;
//如果没有下一个节点则跳出
if ((e = e.next) == null) {
//将mappingFunction的结果作为value
if ((val = mappingFunction.apply(key)) != null) {
added = true;
pred.next = new Node<K,V>(h, key, val, null);
}
break;
}
}
}
//如果为红黑树
else if (f instanceof TreeBin) {
binCount = 2;
TreeBin<K,V> t = (TreeBin<K,V>)f;
TreeNode<K,V> r, p;
if ((r = t.root) != null &&
(p = r.findTreeNode(h, key, null)) != null)
val = p.val;
else if ((val = mappingFunction.apply(key)) != null) {
added = true;
//添加到红墨树中
t.putTreeVal(h, key, val);
}
}
}
}
//判断是否需要扩容
if (binCount != 0) {
if (binCount >= TREEIFY_THRESHOLD)
treeifyBin(tab, i);
if (!added)
return val;
break;
}
}
}
//不为空有值，自增+1
if (val != null)
addCount(1L, binCount);
return val;
}
//同上类似
public V computeIfPresent(K key, BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
if (key == null || remappingFunction == null)
throw new NullPointerException();
int h = spread(key.hashCode());
V val = null;
int delta = 0;
int binCount = 0;
for (Node<K,V>[] tab = table;;) {
Node<K,V> f; int n, i, fh;
if (tab == null || (n = tab.length) == 0)
tab = initTable();
else if ((f = tabAt(tab, i = (n - 1) & h)) == null)
break;
else if ((fh = f.hash) == MOVED)
tab = helpTransfer(tab, f);
else {
synchronized (f) {
if (tabAt(tab, i) == f) {
if (fh >= 0) {
binCount = 1;
for (Node<K,V> e = f, pred = null;; ++binCount) {
K ek;
if (e.hash == h &&
((ek = e.key) == key ||
(ek != null && key.equals(ek)))) {
val = remappingFunction.apply(key, e.val);
if (val != null)
e.val = val;
else {
delta = -1;
Node<K,V> en = e.next;
if (pred != null)
pred.next = en;
else
setTabAt(tab, i, en);
}
break;
}
pred = e;
if ((e = e.next) == null)
break;
}
}
else if (f instanceof TreeBin) {
binCount = 2;
TreeBin<K,V> t = (TreeBin<K,V>)f;
TreeNode<K,V> r, p;
if ((r = t.root) != null &&
(p = r.findTreeNode(h, key, null)) != null) {
val = remappingFunction.apply(key, p.val);
if (val != null)
p.val = val;
else {
delta = -1;
if (t.removeTreeNode(p))
setTabAt(tab, i, untreeify(t.first));
}
}
}
}
}
if (binCount != 0)
break;
}
}
if (delta != 0)
addCount((long)delta, binCount);
return val;
}
//同上类似
public V compute(K key,
BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
if (key == null || remappingFunction == null)
throw new NullPointerException();
//获取hash值
int h = spread(key.hashCode());
V val = null;
int delta = 0;
int binCount = 0;
//遍历
for (Node<K,V>[] tab = table;;) {
Node<K,V> f; int n, i, fh;
//实始化
if (tab == null || (n = tab.length) == 0)
tab = initTable();
//获取位置
else if ((f = tabAt(tab, i = (n - 1) & h)) == null) {
Node<K,V> r = new ReservationNode<K,V>();
synchronized (r) {
if (casTabAt(tab, i, null, r)) {
binCount = 1;
Node<K,V> node = null;
try {
if ((val = remappingFunction.apply(key, null)) != null) {
delta = 1;
node = new Node<K,V>(h, key, val, null);
}
} finally {
setTabAt(tab, i, node);
}
}
}
if (binCount != 0)
break;
}
//正在转移
else if ((fh = f.hash) == MOVED)
tab = helpTransfer(tab, f);
else {
synchronized (f) {
if (tabAt(tab, i) == f) {
if (fh >= 0) {
binCount = 1;
for (Node<K,V> e = f, pred = null;; ++binCount) {
K ek;
if (e.hash == h &&
((ek = e.key) == key ||
(ek != null && key.equals(ek)))) {
val = remappingFunction.apply(key, e.val);
if (val != null)
e.val = val;
else {
delta = -1;
Node<K,V> en = e.next;
if (pred != null)
pred.next = en;
else
setTabAt(tab, i, en);
}
break;
}
pred = e;
if ((e = e.next) == null) {
val = remappingFunction.apply(key, null);
if (val != null) {
delta = 1;
pred.next =
new Node<K,V>(h, key, val, null);
}
break;
}
}
}
else if (f instanceof TreeBin) {
binCount = 1;
TreeBin<K,V> t = (TreeBin<K,V>)f;
TreeNode<K,V> r, p;
if ((r = t.root) != null)
p = r.findTreeNode(h, key, null);
else
p = null;
V pv = (p == null) ? null : p.val;
val = remappingFunction.apply(key, pv);
if (val != null) {
if (p != null)
p.val = val;
else {
delta = 1;
t.putTreeVal(h, key, val);
}
}
else if (p != null) {
delta = -1;
if (t.removeTreeNode(p))
setTabAt(tab, i, untreeify(t.first));
}
}
}
}
if (binCount != 0) {
if (binCount >= TREEIFY_THRESHOLD)
treeifyBin(tab, i);
break;
}
}
}
//自增1
if (delta != 0)
addCount((long)delta, binCount);
return val;
}
//合并方法
public V merge(K key, V value, BiFunction<? super V, ? super V, ? extends V> remappingFunction) {
if (key == null || value == null || remappingFunction == null)
throw new NullPointerException();
//计算哈希
int h = spread(key.hashCode());
V val = null;
int delta = 0;
int binCount = 0;
//循环添加
for (Node<K,V>[] tab = table;;) {
Node<K,V> f; int n, i, fh;
//初始化
if (tab == null || (n = tab.length) == 0)
tab = initTable();
//通过cas获取位置并赋值
else if ((f = tabAt(tab, i = (n - 1) & h)) == null) {
if (casTabAt(tab, i, null, new Node<K,V>(h, key, value, null))) {
delta = 1;
val = value;
break;
}
}
//辅助扩容
else if ((fh = f.hash) == MOVED)
tab = helpTransfer(tab, f);
else {
//同步锁增加
synchronized (f) {
if (tabAt(tab, i) == f) {
if (fh >= 0) {
binCount = 1;
for (Node<K,V> e = f, pred = null;; ++binCount) {
K ek;
if (e.hash == h &&
((ek = e.key) == key ||
(ek != null && key.equals(ek)))) {
//获取计算后的值
val = remappingFunction.apply(e.val, value);
if (val != null)
e.val = val;
else {
delta = -1;
Node<K,V> en = e.next;
if (pred != null)
pred.next = en;
else
setTabAt(tab, i, en);
}
break;
}
pred = e;
//如果下一个节点为空进行创建新对象并赋值
if ((e = e.next) == null) {
delta = 1;
val = value;
pred.next =
new Node<K,V>(h, key, val, null);
break;
}
}
}
//如果为红黑树类型进行增加逻辑
else if (f instanceof TreeBin) {
binCount = 2;
TreeBin<K,V> t = (TreeBin<K,V>)f;
TreeNode<K,V> r = t.root;
TreeNode<K,V> p = (r == null) ? null :
r.findTreeNode(h, key, null);
val = (p == null) ? value :
remappingFunction.apply(p.val, value);
if (val != null) {
if (p != null)
p.val = val;
else {
delta = 1;
t.putTreeVal(h, key, val);
}
}
else if (p != null) {
delta = -1;
if (t.removeTreeNode(p))
setTabAt(tab, i, untreeify(t.first));
}
}
}
}
//扩容逻辑
if (binCount != 0) {
if (binCount >= TREEIFY_THRESHOLD)
treeifyBin(tab, i);
break;
}
}
}
//自动指定数量
if (delta != 0)
addCount((long)delta, binCount);
return val;
}
// Hashtable legacy methods
//判断是否包含这个值
public boolean contains(Object value) {
return containsValue(value);
}
//获取所有的key
public Enumeration<K> keys() {
Node<K,V>[] t;
int f = (t = table) == null ? 0 : t.length;
return new KeyIterator<K,V>(t, f, 0, f, this);
}
//获取所有的元素
public Enumeration<V> elements() {
Node<K,V>[] t;
int f = (t = table) == null ? 0 : t.length;
return new ValueIterator<K,V>(t, f, 0, f, this);
}
//返回映射的数量
public long mappingCount() {
long n = sumCount();
return (n < 0L) ? 0L : n; // ignore transient negative values
}
//创建新的set
public static <K> KeySetView<K,Boolean> newKeySet() {
return new KeySetView<K,Boolean>
(new ConcurrentHashMap<K,Boolean>(), Boolean.TRUE);
}
//带初始容易的set
public static <K> KeySetView<K,Boolean> newKeySet(int initialCapacity) {
return new KeySetView<K,Boolean>
(new ConcurrentHashMap<K,Boolean>(initialCapacity), Boolean.TRUE);
}
//初始化keySet方法
public KeySetView<K,V> keySet(V mappedValue) {
if (mappedValue == null)
throw new NullPointerException();
return new KeySetView<K,V>(this, mappedValue);
}
/* ---------------- Special Nodes -------------- */
//在转移操作时插入在箱头的节点。
static final class ForwardingNode<K,V> extends Node<K,V> {
final Node<K,V>[] nextTable;
ForwardingNode(Node<K,V>[] tab) {
super(MOVED, null, null, null);
this.nextTable = tab;
}
//查到方法
Node<K,V> find(int h, Object k) {
// 循环以避免转发节点上的任意深度递归
outer: for (Node<K,V>[] tab = nextTable;;) {
Node<K,V> e; int n;
if (k == null || tab == null || (n = tab.length) == 0 ||
(e = tabAt(tab, (n - 1) & h)) == null)
return null;
for (;;) {
int eh; K ek;
if ((eh = e.hash) == h &&
((ek = e.key) == k || (ek != null && k.equals(ek))))
return e;
if (eh < 0) {
if (e instanceof ForwardingNode) {
tab = ((ForwardingNode<K,V>)e).nextTable;
continue outer;
}
else
return e.find(h, k);
}
if ((e = e.next) == null)
return null;
}
}
}
}
//ReservationNode 类
static final class ReservationNode<K,V> extends Node<K,V> {
ReservationNode() {
super(RESERVED, null, null, null);
}
Node<K,V> find(int h, Object k) {
return null;
}
}
/* ---------------- Table Initialization and Resizing -------------- */
//获取初始化大小计算
static final int resizeStamp(int n) {
return Integer.numberOfLeadingZeros(n) | (1 << (RESIZE_STAMP_BITS - 1));
}
//初始化表方法
private final Node<K,V>[] initTable() {
Node<K,V>[] tab; int sc;
while ((tab = table) == null || tab.length == 0) {
if ((sc = sizeCtl) < 0)
Thread.yield(); // lost initialization race; just spin
else if (U.compareAndSwapInt(this, SIZECTL, sc, -1)) {
try {
if ((tab = table) == null || tab.length == 0) {
int n = (sc > 0) ? sc : DEFAULT_CAPACITY;
@SuppressWarnings("unchecked")
Node<K,V>[] nt = (Node<K,V>[])new Node<?,?>[n];
table = tab = nt;
sc = n - (n >>> 2);
}
} finally {
sizeCtl = sc;
}
break;
}
}
return tab;
}
//自增数量的实现
private final void addCount(long x, int check) {
CounterCell[] as; long b, s;
if ((as = counterCells) != null ||
!U.compareAndSwapLong(this, BASECOUNT, b = baseCount, s = b + x)) {
CounterCell a; long v; int m;
boolean uncontended = true;
if (as == null || (m = as.length - 1) < 0 ||
(a = as[ThreadLocalRandom.getProbe() & m]) == null ||
!(uncontended =
U.compareAndSwapLong(a, CELLVALUE, v = a.value, v + x))) {
fullAddCount(x, uncontended);
return;
}
if (check <= 1)
return;
s = sumCount();
}
//大于等于0才进来
if (check >= 0) {
Node<K,V>[] tab, nt; int n, sc;
while (s >= (long)(sc = sizeCtl) && (tab = table) != null &&
(n = tab.length) < MAXIMUM_CAPACITY) {
int rs = resizeStamp(n);
if (sc < 0) {
if ((sc >>> RESIZE_STAMP_SHIFT) != rs || sc == rs + 1 ||
sc == rs + MAX_RESIZERS || (nt = nextTable) == null ||
transferIndex <= 0)
break;
if (U.compareAndSwapInt(this, SIZECTL, sc, sc + 1))
transfer(tab, nt);
}
else if (U.compareAndSwapInt(this, SIZECTL, sc,
(rs << RESIZE_STAMP_SHIFT) + 2))
transfer(tab, null);
s = sumCount();
}
}
}
//如果正在调整大小，则帮助转移方法
final Node<K,V>[] helpTransfer(Node<K,V>[] tab, Node<K,V> f) {
Node<K,V>[] nextTab; int sc;
//如果传进来的tab不为空 且 f的类型为ForwardingNode 且 获取f的nextTable不为空
if (tab != null && (f instanceof ForwardingNode) &&
(nextTab = ((ForwardingNode<K,V>)f).nextTable) != null) {
//计算新的长度
int rs = resizeStamp(tab.length);
//循环复制表
while (nextTab == nextTable && table == tab &&
(sc = sizeCtl) < 0) {
if ((sc >>> RESIZE_STAMP_SHIFT) != rs || sc == rs + 1 ||
sc == rs + MAX_RESIZERS || transferIndex <= 0)
break;
if (U.compareAndSwapInt(this, SIZECTL, sc, sc + 1)) {
transfer(tab, nextTab);
break;
}
}
return nextTab;
}
return table;
}
//尝试调整大小(带初始大小)
private final void tryPresize(int size) {
int c = (size >= (MAXIMUM_CAPACITY >>> 1)) ? MAXIMUM_CAPACITY :
tableSizeFor(size + (size >>> 1) + 1);
int sc;
//sc 如果为0则待初始化，大于0则为下一个需要初始化大小的计数值
while ((sc = sizeCtl) >= 0) {
Node<K,V>[] tab = table; int n;
if (tab == null || (n = tab.length) == 0) {
n = (sc > c) ? sc : c;
if (U.compareAndSwapInt(this, SIZECTL, sc, -1)) {
try {
if (table == tab) {
@SuppressWarnings("unchecked")
Node<K,V>[] nt = (Node<K,V>[])new Node<?,?>[n];
table = nt;
sc = n - (n >>> 2);
}
} finally {
sizeCtl = sc;
}
}
}
//如果初始化的值小于原来的值或大于最大值则直接跳出
else if (c <= sc || n >= MAXIMUM_CAPACITY)
break;
//赋值表 然后进行复制到新表
else if (tab == table) {
int rs = resizeStamp(n);
if (sc < 0) {
Node<K,V>[] nt;
if ((sc >>> RESIZE_STAMP_SHIFT) != rs || sc == rs + 1 ||
sc == rs + MAX_RESIZERS || (nt = nextTable) == null ||
transferIndex <= 0)
break;
if (U.compareAndSwapInt(this, SIZECTL, sc, sc + 1))
transfer(tab, nt);
}
else if (U.compareAndSwapInt(this, SIZECTL, sc,
(rs << RESIZE_STAMP_SHIFT) + 2))
transfer(tab, null);
}
}
}
//移动或复制每个bin中的节点到新表方法
private final void transfer(Node<K,V>[] tab, Node<K,V>[] nextTab) {
//获取列表长度
int n = tab.length, stride;
//判断cpu数量是否大于1
如果是再判断计算出来的结果是否小于初始容量
if ((stride = (NCPU > 1) ? (n >>> 3) / NCPU : n) < MIN_TRANSFER_STRIDE)
//初始化最小容易
stride = MIN_TRANSFER_STRIDE; // subdivide range
//如下没有下一个nextTab则进行初始化(2倍初始化)
if (nextTab == null) { // initiating
try {
@SuppressWarnings("unchecked")
Node<K,V>[] nt = (Node<K,V>[])new Node<?,?>[n << 1];
nextTab = nt;
} catch (Throwable ex) { // try to cope with OOME
sizeCtl = Integer.MAX_VALUE;
return;
}
nextTable = nextTab;
transferIndex = n;
}
//获取nextTab长度
int nextn = nextTab.length;
//fwd用于并发控制
ForwardingNode<K,V> fwd = new ForwardingNode<K,V>(nextTab);
//是否继续向前查找标志位
boolean advance = true;
//完成清理标记
boolean finishing = false; // to ensure sweep before committing nextTab
//下面是移动或复制到新表逻辑
for (int i = 0, bound = 0;;) {
Node<K,V> f; int fh;
while (advance) {
int nextIndex, nextBound;
if (--i >= bound || finishing)
advance = false;
else if ((nextIndex = transferIndex) <= 0) {
i = -1;
advance = false;
}
else if (U.compareAndSwapInt
(this, TRANSFERINDEX, nextIndex,
nextBound = (nextIndex > stride ?
nextIndex - stride : 0))) {
bound = nextBound;
i = nextIndex - 1;
advance = false;
}
}
if (i < 0 || i >= n || i + n >= nextn) {
int sc;
//表示已完成转移
if (finishing) {
nextTable = null;
table = nextTab;
//计算扩容后的0.75
sizeCtl = (n << 1) - (n >>> 1);
return;
}
if (U.compareAndSwapInt(this, SIZECTL, sc = sizeCtl, sc - 1)) {
if ((sc - 2) != resizeStamp(n) << RESIZE_STAMP_SHIFT)
return;
finishing = advance = true;
i = n; // recheck before commit
}
}
else if ((f = tabAt(tab, i)) == null)
advance = casTabAt(tab, i, null, fwd);
else if ((fh = f.hash) == MOVED)
advance = true; // already processed
else {
synchronized (f) {
if (tabAt(tab, i) == f) {
Node<K,V> ln, hn;
if (fh >= 0) {
int runBit = fh & n;
Node<K,V> lastRun = f;
for (Node<K,V> p = f.next; p != null; p = p.next) {
int b = p.hash & n;
if (b != runBit) {
runBit = b;
lastRun = p;
}
}
//下面的逻辑同上面的类似
if (runBit == 0) {
ln = lastRun;
hn = null;
}
else {
hn = lastRun;
ln = null;
}
for (Node<K,V> p = f; p != lastRun; p = p.next) {
int ph = p.hash; K pk = p.key; V pv = p.val;
if ((ph & n) == 0)
ln = new Node<K,V>(ph, pk, pv, ln);
else
hn = new Node<K,V>(ph, pk, pv, hn);
}
setTabAt(nextTab, i, ln);
setTabAt(nextTab, i + n, hn);
setTabAt(tab, i, fwd);
advance = true;
}
else if (f instanceof TreeBin) {
TreeBin<K,V> t = (TreeBin<K,V>)f;
TreeNode<K,V> lo = null, loTail = null;
TreeNode<K,V> hi = null, hiTail = null;
int lc = 0, hc = 0;
for (Node<K,V> e = t.first; e != null; e = e.next) {
int h = e.hash;
TreeNode<K,V> p = new TreeNode<K,V>
(h, e.key, e.val, null, null);
if ((h & n) == 0) {
if ((p.prev = loTail) == null)
lo = p;
else
loTail.next = p;
loTail = p;
++lc;
}
else {
if ((p.prev = hiTail) == null)
hi = p;
else
hiTail.next = p;
hiTail = p;
++hc;
}
}
//小于等于6为链表不是红黑树
ln = (lc <= UNTREEIFY_THRESHOLD) ? untreeify(lo) :
(hc != 0) ? new TreeBin<K,V>(lo) : t;
hn = (hc <= UNTREEIFY_THRESHOLD) ? untreeify(hi) :
(lc != 0) ? new TreeBin<K,V>(hi) : t;
setTabAt(nextTab, i, ln);
setTabAt(nextTab, i + n, hn);
setTabAt(tab, i, fwd);
advance = true;
}
}
}
}
}
}
//获取分配计算器
@sun.misc.Contended static final class CounterCell {
volatile long value;
CounterCell(long x) { value = x; }
}
//计算数量方法
final long sumCount() {
CounterCell[] as = counterCells; CounterCell a;
long sum = baseCount;
if (as != null) {
for (int i = 0; i < as.length; ++i) {
if ((a = as[i]) != null)
sum += a.value;
}
}
return sum;
}
//
private final void fullAddCount(long x, boolean wasUncontended) {
int h;
//获取随机数 如果为0进行初始化
if ((h = ThreadLocalRandom.getProbe()) == 0) {
ThreadLocalRandom.localInit(); // force initialization
h = ThreadLocalRandom.getProbe();
wasUncontended = true;
}
boolean collide = false; // True if last slot nonempty
//
for (;;) {
CounterCell[] as; CounterCell a; int n; long v;
if ((as = counterCells) != null && (n = as.length) > 0) {
if ((a = as[(n - 1) & h]) == null) {
//尝试连接新的单元格
if (cellsBusy == 0) { // Try to attach new Cell
//进行初始化
CounterCell r = new CounterCell(x); // Optimistic create
//进行cas加锁操作
if (cellsBusy == 0 &&
U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
boolean created = false;
try { // Recheck under lock
CounterCell[] rs; int m, j;
if ((rs = counterCells) != null &&
(m = rs.length) > 0 &&
rs[j = (m - 1) & h] == null) {
rs[j] = r;
created = true;
}
} finally {
cellsBusy = 0;
}
if (created)
break;
continue; // Slot is now non-empty
}
}
collide = false;
}
//如果cas已上锁，那么标记会失败
else if (!wasUncontended) // CAS already known to fail
//进行标记
wasUncontended = true; // Continue after rehash
//cas计算count 计算成功直接跳出循环
else if (U.compareAndSwapLong(a, CELLVALUE, v = a.value, v + x))
break;
//超过cpu数量
else if (counterCells != as || n >= NCPU)
collide = false; // At max size or stale
else if (!collide)
collide = true;
else if (cellsBusy == 0 &&
U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
try {
if (counterCells == as) {// Expand table unless stale
CounterCell[] rs = new CounterCell[n << 1];
for (int i = 0; i < n; ++i)
rs[i] = as[i];
counterCells = rs;
}
} finally {
cellsBusy = 0;
}
collide = false;
continue; // Retry with expanded table
}
h = ThreadLocalRandom.advanceProbe(h);
}
else if (cellsBusy == 0 && counterCells == as &&
U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) {
boolean init = false;
try { // Initialize table
if (counterCells == as) {
CounterCell[] rs = new CounterCell[2];
rs[h & 1] = new CounterCell(x);
counterCells = rs;
init = true;
}
} finally {
cellsBusy = 0;
}
if (init)
break;
}
//如果最后还是没有算出来，跳出循环
else if (U.compareAndSwapLong(this, BASECOUNT, v = baseCount, v + x))
break; // Fall back on using base
}
}
/* ---------------- Conversion from/to TreeBins -------------- */
//替换表中的索引（带扩容）
private final void treeifyBin(Node<K,V>[] tab, int index) {
Node<K,V> b; int n, sc;
if (tab != null) {
//如果数组小于64那么进行扩容
if ((n = tab.length) < MIN_TREEIFY_CAPACITY)
tryPresize(n << 1);
//如果tabAt位值不为空 值b.hash有值
else if ((b = tabAt(tab, index)) != null && b.hash >= 0) {
//同步锁
synchronized (b) {
//将链表转化为红黑树
if (tabAt(tab, index) == b) {
TreeNode<K,V> hd = null, tl = null;
for (Node<K,V> e = b; e != null; e = e.next) {
TreeNode<K,V> p =
new TreeNode<K,V>(e.hash, e.key, e.val,
null, null);
if ((p.prev = tl) == null)
hd = p;
else
tl.next = p;
tl = p;
}
//将数组下标的值设置转化完的红黑树使用
setTabAt(tab, index, new TreeBin<K,V>(hd));
}
}
}
}
}
/**
* 返回一个给定列表的非树列表
*/
static <K,V> Node<K,V> untreeify(Node<K,V> b) {
Node<K,V> hd = null, tl = null;
for (Node<K,V> q = b; q != null; q = q.next) {
Node<K,V> p = new Node<K,V>(q.hash, q.key, q.val, null);
if (tl == null)
hd = p;
else
tl.next = p;
tl = p;
}
return hd;
}
/* ---------------- TreeNodes -------------- */
//树节点的实现
static final class TreeNode<K,V> extends Node<K,V> {
TreeNode<K,V> parent; // 父节点
TreeNode<K,V> left; // 左子节点
TreeNode<K,V> right; //右节点
TreeNode<K,V> prev; // 前一节点(前区节点)
boolean red;
//构造方法
TreeNode(int hash, K key, V val, Node<K,V> next,
TreeNode<K,V> parent) {
super(hash, key, val, next);
this.parent = parent;
}
//查询节点方法
Node<K,V> find(int h, Object k) {
return findTreeNode(h, k, null);
}
//查询节点的实现 没有返回Null
final TreeNode<K,V> findTreeNode(int h, Object k, Class<?> kc) {
if (k != null) {
TreeNode<K,V> p = this;
do {
int ph, dir; K pk; TreeNode<K,V> q;
TreeNode<K,V> pl = p.left, pr = p.right;
if ((ph = p.hash) > h)
p = pl;
else if (ph < h)
p = pr;
else if ((pk = p.key) == k || (pk != null && k.equals(pk)))
return p;
else if (pl == null)
p = pr;
else if (pr == null)
p = pl;
else if ((kc != null ||
(kc = comparableClassFor(k)) != null) &&
(dir = compareComparables(kc, k, pk)) != 0)
p = (dir < 0) ? pl : pr;
else if ((q = pr.findTreeNode(h, k, kc)) != null)
return q;
else
p = pl;
} while (p != null);
}
return null;
}
}
//陈树黑类实现
static final class TreeBin<K,V> extends Node<K,V> {
//根节点
TreeNode<K,V> root;
//首节点
volatile TreeNode<K,V> first;
//等待线程
volatile Thread waiter;
//锁状态 写锁为独占状态
volatile int lockState;
// values for lockState
//写锁状态
static final int WRITER = 1; // set while holding write lock
//等待获取锁状态
static final int WAITER = 2; // set when waiting for write lock
//读锁状态
static final int READER = 4; // increment value for setting read lock
/**
* Tie-breaking utility for ordering insertions when equal
* hashCodes and non-comparable. We don't require a total
* order, just a consistent insertion rule to maintain
* equivalence across rebalancings. Tie-breaking further than
* necessary simplifies testing a bit.
*/
static int tieBreakOrder(Object a, Object b) {
int d;
if (a == null || b == null ||
(d = a.getClass().getName().
compareTo(b.getClass().getName())) == 0)
d = (System.identityHashCode(a) <= System.identityHashCode(b) ?
-1 : 1);
return d;
}
//红黑树初始化
TreeBin(TreeNode<K,V> b) {
super(TREEBIN, null, null, null);
this.first = b;
TreeNode<K,V> r = null;
for (TreeNode<K,V> x = b, next; x != null; x = next) {
next = (TreeNode<K,V>)x.next;
x.left = x.right = null;
if (r == null) {
x.parent = null;
x.red = false;
r = x;
}
else {
K k = x.key;
int h = x.hash;
Class<?> kc = null;
for (TreeNode<K,V> p = r;;) {
int dir, ph;
K pk = p.key;
if ((ph = p.hash) > h)
dir = -1;
else if (ph < h)
dir = 1;
else if ((kc == null &&
(kc = comparableClassFor(k)) == null) ||
(dir = compareComparables(kc, k, pk)) == 0)
dir = tieBreakOrder(k, pk);
TreeNode<K,V> xp = p;
if ((p = (dir <= 0) ? p.left : p.right) == null) {
x.parent = xp;
if (dir <= 0)
xp.left = x;
else
xp.right = x;
r = balanceInsertion(r, x);
break;
}
}
}
}
this.root = r;
assert checkInvariants(root);
}
//获取树的写锁
private final void lockRoot() {
if (!U.compareAndSwapInt(this, LOCKSTATE, 0, WRITER))
contendedLock(); // offload to separate method
}
//释放锁
private final void unlockRoot() {
lockState = 0;
}
//等待锁
private final void contendedLock() {
boolean waiting = false;
for (int s;;) {
if (((s = lockState) & ~WAITER) == 0) {
if (U.compareAndSwapInt(this, LOCKSTATE, s, WRITER)) {
if (waiting)
waiter = null;
return;
}
}
else if ((s & WAITER) == 0) {
if (U.compareAndSwapInt(this, LOCKSTATE, s, s | WAITER)) {
waiting = true;
waiter = Thread.currentThread();
}
}
else if (waiting)
LockSupport.park(this);
}
}
//获取匹配的方法
final Node<K,V> find(int h, Object k) {
if (k != null) {
//循环判断
for (Node<K,V> e = first; e != null; ) {
int s; K ek;
if (((s = lockState) & (WAITER|WRITER)) != 0) {
if (e.hash == h &&
((ek = e.key) == k || (ek != null && k.equals(ek))))
return e;
e = e.next;
}
else if (U.compareAndSwapInt(this, LOCKSTATE, s,
s + READER)) {
TreeNode<K,V> r, p;
try {
p = ((r = root) == null ? null :
r.findTreeNode(h, k, null));
} finally {
Thread w;
if (U.getAndAddInt(this, LOCKSTATE, -READER) ==
(READER|WAITER) && (w = waiter) != null)
LockSupport.unpark(w);
}
return p;
}
}
}
return null;
}
//添加树节点
final TreeNode<K,V> putTreeVal(int h, K k, V v) {
Class<?> kc = null;
boolean searched = false;
for (TreeNode<K,V> p = root;;) {
int dir, ph; K pk;
if (p == null) {
first = root = new TreeNode<K,V>(h, k, v, null, null);
break;
}
else if ((ph = p.hash) > h)
dir = -1;
else if (ph < h)
dir = 1;
else if ((pk = p.key) == k || (pk != null && k.equals(pk)))
return p;
else if ((kc == null &&
(kc = comparableClassFor(k)) == null) ||
(dir = compareComparables(kc, k, pk)) == 0) {
if (!searched) {
TreeNode<K,V> q, ch;
searched = true;
if (((ch = p.left) != null &&
(q = ch.findTreeNode(h, k, kc)) != null) ||
((ch = p.right) != null &&
(q = ch.findTreeNode(h, k, kc)) != null))
return q;
}
dir = tieBreakOrder(k, pk);
}
TreeNode<K,V> xp = p;
if ((p = (dir <= 0) ? p.left : p.right) == null) {
TreeNode<K,V> x, f = first;
first = x = new TreeNode<K,V>(h, k, v, f, xp);
if (f != null)
f.prev = x;
if (dir <= 0)
xp.left = x;
else
xp.right = x;
if (!xp.red)
x.red = true;
else {
lockRoot();
try {
root = balanceInsertion(root, x);
} finally {
unlockRoot();
}
}
break;
}
}
assert checkInvariants(root);
return null;
}
//删除树节点
final boolean removeTreeNode(TreeNode<K,V> p) {
TreeNode<K,V> next = (TreeNode<K,V>)p.next;
TreeNode<K,V> pred = p.prev; // unlink traversal pointers
TreeNode<K,V> r, rl;
if (pred == null)
first = next;
else
pred.next = next;
if (next != null)
next.prev = pred;
if (first == null) {
root = null;
return true;
}
if ((r = root) == null || r.right == null || // too small
(rl = r.left) == null || rl.left == null)
return true;
lockRoot();
try {
TreeNode<K,V> replacement;
TreeNode<K,V> pl = p.left;
TreeNode<K,V> pr = p.right;
if (pl != null && pr != null) {
TreeNode<K,V> s = pr, sl;
while ((sl = s.left) != null) // find successor
s = sl;
boolean c = s.red; s.red = p.red; p.red = c; // swap colors
TreeNode<K,V> sr = s.right;
TreeNode<K,V> pp = p.parent;
if (s == pr) { // p was s's direct parent
p.parent = s;
s.right = p;
}
else {
TreeNode<K,V> sp = s.parent;
if ((p.parent = sp) != null) {
if (s == sp.left)
sp.left = p;
else
sp.right = p;
}
if ((s.right = pr) != null)
pr.parent = s;
}
p.left = null;
if ((p.right = sr) != null)
sr.parent = p;
if ((s.left = pl) != null)
pl.parent = s;
if ((s.parent = pp) == null)
r = s;
else if (p == pp.left)
pp.left = s;
else
pp.right = s;
if (sr != null)
replacement = sr;
else
replacement = p;
}
else if (pl != null)
replacement = pl;
else if (pr != null)
replacement = pr;
else
replacement = p;
if (replacement != p) {
TreeNode<K,V> pp = replacement.parent = p.parent;
if (pp == null)
r = replacement;
else if (p == pp.left)
pp.left = replacement;
else
pp.right = replacement;
p.left = p.right = p.parent = null;
}
root = (p.red) ? r : balanceDeletion(r, replacement);
if (p == replacement) { // detach pointers
TreeNode<K,V> pp;
if ((pp = p.parent) != null) {
if (p == pp.left)
pp.left = null;
else if (p == pp.right)
pp.right = null;
p.parent = null;
}
}
} finally {
unlockRoot();
}
assert checkInvariants(root);
return false;
}
//左黑树左旋
static <K,V> TreeNode<K,V> rotateLeft(TreeNode<K,V> root,
TreeNode<K,V> p) {
TreeNode<K,V> r, pp, rl;
//p不为Null 且 p右边节点不为空
if (p != null && (r = p.right) != null) {
//左边赋值给右边且不为空 那么rl的父节点为p （向上挪）
if ((rl = p.right = r.left) != null)
rl.parent = p;
//r的父节点来自p的父节点赋值并且为空
if ((pp = r.parent = p.parent) == null)
//红黑树标识为false
(root = r).red = false;
//p等于pp的左边
else if (pp.left == p)
//r赋给pp左边
pp.left = r;
else
//r赋给pp右边
pp.right = r;
//p赋给r的左边
r.left = p;
//r赋给p的父索引
p.parent = r;
}
return root;
}
//右旋节点（同上类型）
static <K,V> TreeNode<K,V> rotateRight(TreeNode<K,V> root,
TreeNode<K,V> p) {
TreeNode<K,V> l, pp, lr;
if (p != null && (l = p.left) != null) {
if ((lr = p.left = l.right) != null)
lr.parent = p;
if ((pp = l.parent = p.parent) == null)
(root = l).red = false;
else if (pp.right == p)
pp.right = l;
else
pp.left = l;
l.right = p;
p.parent = l;
}
return root;
}
//平衡红黑树（在节点插入之后会调用）
static <K,V> TreeNode<K,V> balanceInsertion(TreeNode<K,V> root,
TreeNode<K,V> x) {
//红黑树标记
x.red = true;
//循环标记那些parent为空的不是红黑树并返回
for (TreeNode<K,V> xp, xpp, xppl, xppr;;) {
if ((xp = x.parent) == null) {
x.red = false;
return x;
}
//如果不是红黑树标记或父过引为空直接返回根节点
else if (!xp.red || (xpp = xp.parent) == null)
return root;
//如果父节点为红色的那么需要调整（再平衡）
if (xp == (xppl = xpp.left)) {
if ((xppr = xpp.right) != null && xppr.red) {
xppr.red = false;
xp.red = false;
xpp.red = true;
x = xpp;
}
else {
if (x == xp.right) {
root = rotateLeft(root, x = xp);
xpp = (xp = x.parent) == null ? null : xp.parent;
}
if (xp != null) {
xp.red = false;
if (xpp != null) {
xpp.red = true;
root = rotateRight(root, xpp);
}
}
}
}
//其他的需要再平衡的节点 比如上级的上级
else {
if (xppl != null && xppl.red) {
xppl.red = false;
xp.red = false;
xpp.red = true;
x = xpp;
}
else {
if (x == xp.left) {
root = rotateRight(root, x = xp);
xpp = (xp = x.parent) == null ? null : xp.parent;
}
if (xp != null) {
xp.red = false;
if (xpp != null) {
xpp.red = true;
root = rotateLeft(root, xpp);
}
}
}
}
}
}
//平衡红黑树方法（同上类似）
static <K,V> TreeNode<K,V> balanceDeletion(TreeNode<K,V> root,
TreeNode<K,V> x) {
for (TreeNode<K,V> xp, xpl, xpr;;) {
if (x == null || x == root)
return root;
else if ((xp = x.parent) == null) {
x.red = false;
return x;
}
else if (x.red) {
x.red = false;
return root;
}
else if ((xpl = xp.left) == x) {
if ((xpr = xp.right) != null && xpr.red) {
xpr.red = false;
xp.red = true;
root = rotateLeft(root, xp);
xpr = (xp = x.parent) == null ? null : xp.right;
}
if (xpr == null)
x = xp;
else {
TreeNode<K,V> sl = xpr.left, sr = xpr.right;
if ((sr == null || !sr.red) &&
(sl == null || !sl.red)) {
xpr.red = true;
x = xp;
}
else {
if (sr == null || !sr.red) {
if (sl != null)
sl.red = false;
xpr.red = true;
root = rotateRight(root, xpr);
xpr = (xp = x.parent) == null ?
null : xp.right;
}
if (xpr != null) {
xpr.red = (xp == null) ? false : xp.red;
if ((sr = xpr.right) != null)
sr.red = false;
}
if (xp != null) {
xp.red = false;
root = rotateLeft(root, xp);
}
x = root;
}
}
}
else { // symmetric
if (xpl != null && xpl.red) {
xpl.red = false;
xp.red = true;
root = rotateRight(root, xp);
xpl = (xp = x.parent) == null ? null : xp.left;
}
if (xpl == null)
x = xp;
else {
TreeNode<K,V> sl = xpl.left, sr = xpl.right;
if ((sl == null || !sl.red) &&
(sr == null || !sr.red)) {
xpl.red = true;
x = xp;
}
else {
if (sl == null || !sl.red) {
if (sr != null)
sr.red = false;
xpl.red = true;
root = rotateLeft(root, xpl);
xpl = (xp = x.parent) == null ?
null : xp.left;
}
if (xpl != null) {
xpl.red = (xp == null) ? false : xp.red;
if ((sl = xpl.left) != null)
sl.red = false;
}
if (xp != null) {
xp.red = false;
root = rotateRight(root, xp);
}
x = root;
}
}
}
}
}
//递归检查
static <K,V> boolean checkInvariants(TreeNode<K,V> t) {
TreeNode<K,V> tp = t.parent, tl = t.left, tr = t.right,
tb = t.prev, tn = (TreeNode<K,V>)t.next;
if (tb != null && tb.next != t)
return false;
if (tn != null && tn.prev != t)
return false;
if (tp != null && t != tp.left && t != tp.right)
return false;
if (tl != null && (tl.parent != t || tl.hash > t.hash))
return false;
if (tr != null && (tr.parent != t || tr.hash < t.hash))
return false;
if (t.red && tl != null && tl.red && tr != null && tr.red)
return false;
if (tl != null && !checkInvariants(tl))
return false;
if (tr != null && !checkInvariants(tr))
return false;
return true;
}
//cas锁
private static final sun.misc.Unsafe U;
//状态
private static final long LOCKSTATE;
//初始化
static {
try {
U = sun.misc.Unsafe.getUnsafe();
Class<?> k = TreeBin.class;
LOCKSTATE = U.objectFieldOffset
(k.getDeclaredField("lockState"));
} catch (Exception e) {
throw new Error(e);
}
}
}
//遍历器记录表
static final class TableStack<K,V> {
int length;
int index;
Node<K,V>[] tab;
TableStack<K,V> next;
}
//保存当前便利数组以及索引的信息的类信息
static class Traverser<K,V> {
//当前数组
Node<K,V>[] tab; // current table; updated if resized
//下一个元素的指针
Node<K,V> next; // the next entry to use
//栈顶结点
TableStack<K,V> stack, spare; // to save/restore on ForwardingNodes
//下一个读取的索引下标
int index; // index of bin to use next
//开始下标
int baseIndex; // current index of initial table
//终止下标
int baseLimit; // index bound for initial table
//数组的总长度
final int baseSize; // initial table size
//构造方法
Traverser(Node<K,V>[] tab, int size, int index, int limit) {
this.tab = tab;
this.baseSize = size;
this.baseIndex = this.index = index;
this.baseLimit = limit;
this.next = null;
}
//返回有效节点(就是下一个节点)
final Node<K,V> advance() {
Node<K,V> e;
if ((e = next) != null)
e = e.next;
for (;;) {
Node<K,V>[] t; int i, n; // must use locals in checks
if (e != null)
return next = e;
if (baseIndex >= baseLimit || (t = tab) == null ||
(n = t.length) <= (i = index) || i < 0)
return next = null;
if ((e = tabAt(t, i)) != null && e.hash < 0) {
if (e instanceof ForwardingNode) {
tab = ((ForwardingNode<K,V>)e).nextTable;
e = null;
pushState(t, i, n);
continue;
}
else if (e instanceof TreeBin)
e = ((TreeBin<K,V>)e).first;
else
e = null;
}
if (stack != null)
recoverState(n);
else if ((index = i + baseSize) >= n)
index = ++baseIndex; // visit upper slots if present
}
}
//保存状态（遍历时使用）
private void pushState(Node<K,V>[] t, int i, int n) {
TableStack<K,V> s = spare; // reuse if possible
if (s != null)
spare = s.next;
else
s = new TableStack<K,V>();
s.tab = t;
s.length = n;
s.index = i;
s.next = stack;
stack = s;
}
//移除方法
private void recoverState(int n) {
TableStack<K,V> s; int len;
while ((s = stack) != null && (index += (len = s.length)) >= n) {
n = len;
index = s.index;
tab = s.tab;
s.tab = null;
TableStack<K,V> next = s.next;
s.next = spare; // save for reuse
stack = next;
spare = s;
}
if (s == null && (index += baseSize) >= n)
index = ++baseIndex;
}
}
//基础迭代器
static class BaseIterator<K,V> extends Traverser<K,V> {
final ConcurrentHashMap<K,V> map;
Node<K,V> lastReturned;
BaseIterator(Node<K,V>[] tab, int size, int index, int limit,
ConcurrentHashMap<K,V> map) {
super(tab, size, index, limit);
this.map = map;
advance();
}
//判断是否有下一个节点
public final boolean hasNext() { return next != null; }
//判断是否有更多元素方法（同上）
public final boolean hasMoreElements() { return next != null; }
//移除方法
public final void remove() {
Node<K,V> p;
if ((p = lastReturned) == null)
throw new IllegalStateException();
lastReturned = null;
map.replaceNode(p.key, null, null);
}
}
//迭代key
static final class KeyIterator<K,V> extends BaseIterator<K,V>
implements Iterator<K>, Enumeration<K> {
KeyIterator(Node<K,V>[] tab, int index, int size, int limit,
ConcurrentHashMap<K,V> map) {
super(tab, index, size, limit, map);
}
//获取下一个节点
public final K next() {
Node<K,V> p;
if ((p = next) == null)
throw new NoSuchElementException();
K k = p.key;
lastReturned = p;
advance();
return k;
}
public final K nextElement() { return next(); }
}
//获取所有值的列表
static final class ValueIterator<K,V> extends BaseIterator<K,V>
implements Iterator<V>, Enumeration<V> {
ValueIterator(Node<K,V>[] tab, int index, int size, int limit,
ConcurrentHashMap<K,V> map) {
super(tab, index, size, limit, map);
}
public final V next() {
Node<K,V> p;
if ((p = next) == null)
throw new NoSuchElementException();
V v = p.val;
lastReturned = p;
advance();
return v;
}
public final V nextElement() { return next(); }
}
//迭代器
static final class EntryIterator<K,V> extends BaseIterator<K,V>
implements Iterator<Map.Entry<K,V>> {
EntryIterator(Node<K,V>[] tab, int index, int size, int limit,
ConcurrentHashMap<K,V> map) {
super(tab, index, size, limit, map);
}
public final Map.Entry<K,V> next() {
Node<K,V> p;
if ((p = next) == null)
throw new NoSuchElementException();
K k = p.key;
V v = p.val;
lastReturned = p;
advance();
return new MapEntry<K,V>(k, v, map);
}
}
//导出map格式的列表
static final class MapEntry<K,V> implements Map.Entry<K,V> {
final K key; // non-null
V val; // non-null
final ConcurrentHashMap<K,V> map;
MapEntry(K key, V val, ConcurrentHashMap<K,V> map) {
this.key = key;
this.val = val;
this.map = map;
}
public K getKey() { return key; }
public V getValue() { return val; }
public int hashCode() { return key.hashCode() ^ val.hashCode(); }
public String toString() { return key + "=" + val; }
public boolean equals(Object o) {
Object k, v; Map.Entry<?,?> e;
return ((o instanceof Map.Entry) &&
(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
(v = e.getValue()) != null &&
(k == key || k.equals(key)) &&
(v == val || v.equals(val)));
}
/**
* Sets our entry's value and writes through to the map. The
* value to return is somewhat arbitrary here. Since we do not
* necessarily track asynchronous changes, the most recent
* "previous" value could be different from what we return (or
* could even have been removed, in which case the put will
* re-establish). We do not and cannot guarantee more.
*/
public V setValue(V value) {
if (value == null) throw new NullPointerException();
V v = val;
val = value;
map.put(key, value);
return v;
}
}
//获取key的分割器实现
static final class KeySpliterator<K,V> extends Traverser<K,V>
implements Spliterator<K> {
long est; // size estimate
KeySpliterator(Node<K,V>[] tab, int size, int index, int limit,
long est) {
super(tab, size, index, limit);
this.est = est;
}
public Spliterator<K> trySplit() {
int i, f, h;
return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
new KeySpliterator<K,V>(tab, baseSize, baseLimit = h,
f, est >>>= 1);
}
public void forEachRemaining(Consumer<? super K> action) {
if (action == null) throw new NullPointerException();
for (Node<K,V> p; (p = advance()) != null;)
action.accept(p.key);
}
public boolean tryAdvance(Consumer<? super K> action) {
if (action == null) throw new NullPointerException();
Node<K,V> p;
if ((p = advance()) == null)
return false;
action.accept(p.key);
return true;
}
public long estimateSize() { return est; }
public int characteristics() {
return Spliterator.DISTINCT | Spliterator.CONCURRENT |
Spliterator.NONNULL;
}
}
//值的分割器实现
static final class ValueSpliterator<K,V> extends Traverser<K,V>
implements Spliterator<V> {
long est; // size estimate
ValueSpliterator(Node<K,V>[] tab, int size, int index, int limit,
long est) {
super(tab, size, index, limit);
this.est = est;
}
public Spliterator<V> trySplit() {
int i, f, h;
return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
new ValueSpliterator<K,V>(tab, baseSize, baseLimit = h,
f, est >>>= 1);
}
public void forEachRemaining(Consumer<? super V> action) {
if (action == null) throw new NullPointerException();
for (Node<K,V> p; (p = advance()) != null;)
action.accept(p.val);
}
public boolean tryAdvance(Consumer<? super V> action) {
if (action == null) throw new NullPointerException();
Node<K,V> p;
if ((p = advance()) == null)
return false;
action.accept(p.val);
return true;
}
public long estimateSize() { return est; }
public int characteristics() {
return Spliterator.CONCURRENT | Spliterator.NONNULL;
}
}
//节点的分割器
static final class EntrySpliterator<K,V> extends Traverser<K,V>
implements Spliterator<Map.Entry<K,V>> {
final ConcurrentHashMap<K,V> map; // To export MapEntry
long est; // size estimate
EntrySpliterator(Node<K,V>[] tab, int size, int index, int limit,
long est, ConcurrentHashMap<K,V> map) {
super(tab, size, index, limit);
this.map = map;
this.est = est;
}
public Spliterator<Map.Entry<K,V>> trySplit() {
int i, f, h;
return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null :
new EntrySpliterator<K,V>(tab, baseSize, baseLimit = h,
f, est >>>= 1, map);
}
public void forEachRemaining(Consumer<? super Map.Entry<K,V>> action) {
if (action == null) throw new NullPointerException();
for (Node<K,V> p; (p = advance()) != null; )
action.accept(new MapEntry<K,V>(p.key, p.val, map));
}
public boolean tryAdvance(Consumer<? super Map.Entry<K,V>> action) {
if (action == null) throw new NullPointerException();
Node<K,V> p;
if ((p = advance()) == null)
return false;
action.accept(new MapEntry<K,V>(p.key, p.val, map));
return true;
}
public long estimateSize() { return est; }
public int characteristics() {
return Spliterator.DISTINCT | Spliterator.CONCURRENT |
Spliterator.NONNULL;
}
}
//计算批量任务的初始批处理值
final int batchFor(long b) {
long n;
if (b == Long.MAX_VALUE || (n = sumCount()) <= 1L || n < b)
return 0;
int sp = ForkJoinPool.getCommonPoolParallelism() << 2; // slack of 4
return (b <= 0L || (n /= b) >= sp) ? sp : (int)n;
}
//循环处理
public void forEach(long parallelismThreshold,
BiConsumer<? super K,? super V> action) {
if (action == null) throw new NullPointerException();
new ForEachMappingTask<K,V>
(null, batchFor(parallelismThreshold), 0, 0, table,
action).invoke();
}
//同上类似
public <U> void forEach(long parallelismThreshold,
BiFunction<? super K, ? super V, ? extends U> transformer,
Consumer<? super U> action) {
if (transformer == null || action == null)
throw new NullPointerException();
new ForEachTransformedMappingTask<K,V,U>
(null, batchFor(parallelismThreshold), 0, 0, table,
transformer, action).invoke();
}
//查询方法
public <U> U search(long parallelismThreshold,
BiFunction<? super K, ? super V, ? extends U> searchFunction) {
if (searchFunction == null) throw new NullPointerException();
return new SearchMappingsTask<K,V,U>
(null, batchFor(parallelismThreshold), 0, 0, table,
searchFunction, new AtomicReference<U>()).invoke();
}
//返回累加结果
public <U> U reduce(long parallelismThreshold,
BiFunction<? super K, ? super V, ? extends U> transformer,
BiFunction<? super U, ? super U, ? extends U> reducer) {
if (transformer == null || reducer == null)
throw new NullPointerException();
return new MapReduceMappingsTask<K,V,U>
(null, batchFor(parallelismThreshold), 0, 0, table,
null, transformer, reducer).invoke();
}
//同上类似
public double reduceToDouble(long parallelismThreshold,
ToDoubleBiFunction<? super K, ? super V> transformer,
double basis,
DoubleBinaryOperator reducer) {
if (transformer == null || reducer == null)
throw new NullPointerException();
return new MapReduceMappingsToDoubleTask<K,V>
(null, batchFor(parallelismThreshold), 0, 0, table,
null, transformer, basis, reducer).invoke();
}
//类似同上
public long reduceToLong(long parallelismThreshold,
ToLongBiFunction<? super K, ? super V> transformer,
long basis,
LongBinaryOperator reducer) {
if (transformer == null || reducer == null)
throw new NullPointerException();
return new MapReduceMappingsToLongTask<K,V>
(null, batchFor(parallelismThreshold), 0, 0, table,
null, transformer, basis, reducer).invoke();
}
public int reduceToInt(long parallelismThreshold,
ToIntBiFunction<? super K, ? super V> transformer,
int basis,
IntBinaryOperator reducer) {
if (transformer == null || reducer == null)
throw new NullPointerException();
return new MapReduceMappingsToIntTask<K,V>
(null, batchFor(parallelismThreshold), 0, 0, table,
null, transformer, basis, reducer).invoke();
}
//循环key
public void forEachKey(long parallelismThreshold,
Consumer<? super K> action) {
if (action == null) throw new NullPointerException();
new ForEachKeyTask<K,V>
(null, batchFor(parallelismThreshold), 0, 0, table,
action).invoke();
}
//同上类似
public <U> void forEachKey(long parallelismThreshold,
Function<? super K, ? extends U> transformer,
Consumer<? super U> action) {
if (transformer == null || action == null)
throw new NullPointerException();
new ForEachTransformedKeyTask<K,V,U>
(null, batchFor(parallelismThreshold), 0, 0, table,
transformer, action).invoke();
}
//查询指定的key并返回方法
public <U> U searchKeys(long parallelismThreshold,
Function<? super K, ? extends U> searchFunction) {
if (searchFunction == null) throw new NullPointerException();
return new SearchKeysTask<K,V,U>
(null, batchFor(parallelismThreshold), 0, 0, table,
searchFunction, new AtomicReference<U>()).invoke();
}
//累加结果返回
public K reduceKeys(long parallelismThreshold,
BiFunction<? super K, ? super K, ? extends K> reducer) {
if (reducer == null) throw new NullPointerException();
return new ReduceKeysTask<K,V>
(null, batchFor(parallelismThreshold), 0, 0, table,
null, reducer).invoke();
}
//同上学业有成似
public <U> U reduceKeys(long parallelismThreshold,
Function<? super K, ? extends U> transformer,
BiFunction<? super U, ? super U, ? extends U> reducer) {
if (transformer == null || reducer == null)
throw new NullPointerException();
return new MapReduceKeysTask<K,V,U>
(null, batchFor(parallelismThreshold), 0, 0, table,
null, transformer, reducer).invoke();
}
public double reduceKeysToDouble(long parallelismThreshold,
ToDoubleFunction<? super K> transformer,
double basis,
DoubleBinaryOperator reducer) {
if (transformer == null || reducer == null)
throw new NullPointerException();
return new MapReduceKeysToDoubleTask<K,V>
(null, batchFor(parallelismThreshold), 0, 0, table,
null, transformer, basis, reducer).invoke();
}
public long reduceKeysToLong(long parallelismThreshold,
ToLongFunction<? super K> transformer,
long basis,
LongBinaryOperator reducer) {
if (transformer == null || reducer == null)
throw new NullPointerException();
return new MapReduceKeysToLongTask<K,V>
(null, batchFor(parallelismThreshold), 0, 0, table,
null, transformer, basis, reducer).invoke();
}
public int reduceKeysToInt(long parallelismThreshold,
ToIntFunction<? super K> transformer,
int basis,
IntBinaryOperator reducer) {
if (transformer == null || reducer == null)
throw new NullPointerException();
return new MapReduceKeysToIntTask<K,V>
(null, batchFor(parallelismThreshold), 0, 0, table,
null, transformer, basis, reducer).invoke();
}
//为每个值执行给定的操作
public void forEachValue(long parallelismThreshold,
Consumer<? super V> action) {
if (action == null)
throw new NullPointerException();
new ForEachValueTask<K,V>
(null, batchFor(parallelismThreshold), 0, 0, table,
action).invoke();
}
//同上类似
public <U> void forEachValue(long parallelismThreshold,
Function<? super V, ? extends U> transformer,
Consumer<? super U> action) {
if (transformer == null || action == null)
throw new NullPointerException();
new ForEachTransformedValueTask<K,V,U>
(null, batchFor(parallelismThreshold), 0, 0, table,
transformer, action).invoke();
}
//为每个值搜索返回一个非空结果
public <U> U searchValues(long parallelismThreshold,
Function<? super V, ? extends U> searchFunction) {
if (searchFunction == null) throw new NullPointerException();
return new SearchValuesTask<K,V,U>
(null, batchFor(parallelismThreshold), 0, 0, table,
searchFunction, new AtomicReference<U>()).invoke();
}
//为每个值进行累计
public V reduceValues(long parallelismThreshold,
BiFunction<? super V, ? super V, ? extends V> reducer) {
if (reducer == null) throw new NullPointerException();
return new ReduceValuesTask<K,V>
(null, batchFor(parallelismThreshold), 0, 0, table,
null, reducer).invoke();
}
public <U> U reduceValues(long parallelismThreshold,
Function<? super V, ? extends U> transformer,
BiFunction<? super U, ? super U, ? extends U> reducer) {
if (transformer == null || reducer == null)
throw new NullPointerException();
return new MapReduceValuesTask<K,V,U>
(null, batchFor(parallelismThreshold), 0, 0, table,
null, transformer, reducer).invoke();
}
public double reduceValuesToDouble(long parallelismThreshold,
ToDoubleFunction<? super V> transformer,
double basis,
DoubleBinaryOperator reducer) {
if (transformer == null || reducer == null)
throw new NullPointerException();
return new MapReduceValuesToDoubleTask<K,V>
(null, batchFor(parallelismThreshold), 0, 0, table,
null, transformer, basis, reducer).invoke();
}
public long reduceValuesToLong(long parallelismThreshold,
ToLongFunction<? super V> transformer,
long basis,
LongBinaryOperator reducer) {
if (transformer == null || reducer == null)
throw new NullPointerException();
return new MapReduceValuesToLongTask<K,V>
(null, batchFor(parallelismThreshold), 0, 0, table,
null, transformer, basis, reducer).invoke();
}
public int reduceValuesToInt(long parallelismThreshold,
ToIntFunction<? super V> transformer,
int basis,
IntBinaryOperator reducer) {
if (transformer == null || reducer == null)
throw new NullPointerException();
return new MapReduceValuesToIntTask<K,V>
(null, batchFor(parallelismThreshold), 0, 0, table,
null, transformer, basis, reducer).invoke();
}
//为每个元素给定执行操作
public void forEachEntry(long parallelismThreshold,
Consumer<? super Map.Entry<K,V>> action) {
if (action == null) throw new NullPointerException();
new ForEachEntryTask<K,V>(null, batchFor(parallelismThreshold), 0, 0, table,
action).invoke();
}
public <U> void forEachEntry(long parallelismThreshold,
Function<Map.Entry<K,V>, ? extends U> transformer,
Consumer<? super U> action) {
if (transformer == null || action == null)
throw new NullPointerException();
new ForEachTransformedEntryTask<K,V,U>
(null, batchFor(parallelismThreshold), 0, 0, table,
transformer, action).invoke();
}
public <U> U searchEntries(long parallelismThreshold,
Function<Map.Entry<K,V>, ? extends U> searchFunction) {
if (searchFunction == null) throw new NullPointerException();
return new SearchEntriesTask<K,V,U>
(null, batchFor(parallelismThreshold), 0, 0, table,
searchFunction, new AtomicReference<U>()).invoke();
}
public Map.Entry<K,V> reduceEntries(long parallelismThreshold,
BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
if (reducer == null) throw new NullPointerException();
return new ReduceEntriesTask<K,V>
(null, batchFor(parallelismThreshold), 0, 0, table,
null, reducer).invoke();
}
public <U> U reduceEntries(long parallelismThreshold,
Function<Map.Entry<K,V>, ? extends U> transformer,
BiFunction<? super U, ? super U, ? extends U> reducer) {
if (transformer == null || reducer == null)
throw new NullPointerException();
return new MapReduceEntriesTask<K,V,U>
(null, batchFor(parallelismThreshold), 0, 0, table,
null, transformer, reducer).invoke();
}
public double reduceEntriesToDouble(long parallelismThreshold,
ToDoubleFunction<Map.Entry<K,V>> transformer,
double basis,
DoubleBinaryOperator reducer) {
if (transformer == null || reducer == null)
throw new NullPointerException();
return new MapReduceEntriesToDoubleTask<K,V>
(null, batchFor(parallelismThreshold), 0, 0, table,
null, transformer, basis, reducer).invoke();
}
public long reduceEntriesToLong(long parallelismThreshold,
ToLongFunction<Map.Entry<K,V>> transformer,
long basis,
LongBinaryOperator reducer) {
if (transformer == null || reducer == null)
throw new NullPointerException();
return new MapReduceEntriesToLongTask<K,V>
(null, batchFor(parallelismThreshold), 0, 0, table,
null, transformer, basis, reducer).invoke();
}
public int reduceEntriesToInt(long parallelismThreshold,
ToIntFunction<Map.Entry<K,V>> transformer,
int basis,
IntBinaryOperator reducer) {
if (transformer == null || reducer == null)
throw new NullPointerException();
return new MapReduceEntriesToIntTask<K,V>
(null, batchFor(parallelismThreshold), 0, 0, table,
null, transformer, basis, reducer).invoke();
}
//视图的基类实现
abstract static class CollectionView<K,V,E>
implements Collection<E>, java.io.Serializable {
private static final long serialVersionUID = 7249069246763182397L;
final ConcurrentHashMap<K,V> map;
CollectionView(ConcurrentHashMap<K,V> map) { this.map = map; }
/**
* Returns the map backing this view.
*
* @return the map backing this view
*/
public ConcurrentHashMap<K,V> getMap() { return map; }
/**
* Removes all of the elements from this view, by removing all
* the mappings from the map backing this view.
*/
//清空方法
public final void clear() { map.clear(); }
//长度
public final int size() { return map.size(); }
//是否为空
public final boolean isEmpty() { return map.isEmpty(); }
//迭代器方法
public abstract Iterator<E> iterator();
//判断是否包含方法
public abstract boolean contains(Object o);
//删除方法
public abstract boolean remove(Object o);
private static final String oomeMsg = "Required array size too large";
//转成数组方法
public final Object[] toArray() {
long sz = map.mappingCount();
if (sz > MAX_ARRAY_SIZE)
throw new OutOfMemoryError(oomeMsg);
int n = (int)sz;
Object[] r = new Object[n];
int i = 0;
for (E e : this) {
if (i == n) {
if (n >= MAX_ARRAY_SIZE)
throw new OutOfMemoryError(oomeMsg);
if (n >= MAX_ARRAY_SIZE - (MAX_ARRAY_SIZE >>> 1) - 1)
n = MAX_ARRAY_SIZE;
else
n += (n >>> 1) + 1;
r = Arrays.copyOf(r, n);
}
r[i++] = e;
}
return (i == n) ? r : Arrays.copyOf(r, i);
}
@SuppressWarnings("unchecked")
public final <T> T[] toArray(T[] a) {
long sz = map.mappingCount();
if (sz > MAX_ARRAY_SIZE)
throw new OutOfMemoryError(oomeMsg);
int m = (int)sz;
T[] r = (a.length >= m) ? a :
(T[])java.lang.reflect.Array
.newInstance(a.getClass().getComponentType(), m);
int n = r.length;
int i = 0;
for (E e : this) {
if (i == n) {
if (n >= MAX_ARRAY_SIZE)
throw new OutOfMemoryError(oomeMsg);
if (n >= MAX_ARRAY_SIZE - (MAX_ARRAY_SIZE >>> 1) - 1)
n = MAX_ARRAY_SIZE;
else
n += (n >>> 1) + 1;
r = Arrays.copyOf(r, n);
}
r[i++] = (T)e;
}
if (a == r && i < n) {
r[i] = null; // null-terminate
return r;
}
return (i == n) ? r : Arrays.copyOf(r, i);
}
//转成string方法
public final String toString() {
StringBuilder sb = new StringBuilder();
sb.append('[');
Iterator<E> it = iterator();
if (it.hasNext()) {
for (;;) {
Object e = it.next();
sb.append(e == this ? "(this Collection)" : e);
if (!it.hasNext())
break;
sb.append(',').append(' ');
}
}
return sb.append(']').toString();
}
//判断是否包含全部方法
public final boolean containsAll(Collection<?> c) {
if (c != this) {
for (Object e : c) {
if (e == null || !contains(e))
return false;
}
}
return true;
}
//删除指定元素的方法
public final boolean removeAll(Collection<?> c) {
if (c == null) throw new NullPointerException();
boolean modified = false;
for (Iterator<E> it = iterator(); it.hasNext();) {
if (c.contains(it.next())) {
it.remove();
modified = true;
}
}
return modified;
}
public final boolean retainAll(Collection<?> c) {
if (c == null) throw new NullPointerException();
boolean modified = false;
for (Iterator<E> it = iterator(); it.hasNext();) {
if (!c.contains(it.next())) {
it.remove();
modified = true;
}
}
return modified;
}
}
//key视图类实现
public static class KeySetView<K,V> extends CollectionView<K,V,K>
implements Set<K>, java.io.Serializable {
private static final long serialVersionUID = 7249069246763182397L;
private final V value;
KeySetView(ConcurrentHashMap<K,V> map, V value) { // non-public
super(map);
this.value = value;
}
/**
* Returns the default mapped value for additions,
* or {@code null} if additions are not supported.
*
* @return the default mapped value for additions, or {@code null}
* if not supported
*/
public V getMappedValue() { return value; }
/**
* {@inheritDoc}
* @throws NullPointerException if the specified key is null
*/
public boolean contains(Object o) { return map.containsKey(o); }
/**
* Removes the key from this map view, by removing the key (and its
* corresponding value) from the backing map. This method does
* nothing if the key is not in the map.
*
* @param o the key to be removed from the backing map
* @return {@code true} if the backing map contained the specified key
* @throws NullPointerException if the specified key is null
*/
public boolean remove(Object o) { return map.remove(o) != null; }
/**
* @return an iterator over the keys of the backing map
*/
public Iterator<K> iterator() {
Node<K,V>[] t;
ConcurrentHashMap<K,V> m = map;
int f = (t = m.table) == null ? 0 : t.length;
return new KeyIterator<K,V>(t, f, 0, f, m);
}
/**
* Adds the specified key to this set view by mapping the key to
* the default mapped value in the backing map, if defined.
*
* @param e key to be added
* @return {@code true} if this set changed as a result of the call
* @throws NullPointerException if the specified key is null
* @throws UnsupportedOperationException if no default mapped value
* for additions was provided
*/
public boolean add(K e) {
V v;
if ((v = value) == null)
throw new UnsupportedOperationException();
return map.putVal(e, v, true) == null;
}
/**
* Adds all of the elements in the specified collection to this set,
* as if by calling {@link #add} on each one.
*
* @param c the elements to be inserted into this set
* @return {@code true} if this set changed as a result of the call
* @throws NullPointerException if the collection or any of its
* elements are {@code null}
* @throws UnsupportedOperationException if no default mapped value
* for additions was provided
*/
public boolean addAll(Collection<? extends K> c) {
boolean added = false;
V v;
if ((v = value) == null)
throw new UnsupportedOperationException();
for (K e : c) {
if (map.putVal(e, v, true) == null)
added = true;
}
return added;
}
public int hashCode() {
int h = 0;
for (K e : this)
h += e.hashCode();
return h;
}
public boolean equals(Object o) {
Set<?> c;
return ((o instanceof Set) &&
((c = (Set<?>)o) == this ||
(containsAll(c) && c.containsAll(this))));
}
public Spliterator<K> spliterator() {
Node<K,V>[] t;
ConcurrentHashMap<K,V> m = map;
long n = m.sumCount();
int f = (t = m.table) == null ? 0 : t.length;
return new KeySpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n);
}
public void forEach(Consumer<? super K> action) {
if (action == null) throw new NullPointerException();
Node<K,V>[] t;
if ((t = map.table) != null) {
Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
for (Node<K,V> p; (p = it.advance()) != null; )
action.accept(p.key);
}
}
}
/**
* A view of a ConcurrentHashMap as a {@link Collection} of
* values, in which additions are disabled. This class cannot be
* directly instantiated. See {@link #values()}.
*/
static final class ValuesView<K,V> extends CollectionView<K,V,V>
implements Collection<V>, java.io.Serializable {
private static final long serialVersionUID = 2249069246763182397L;
ValuesView(ConcurrentHashMap<K,V> map) { super(map); }
public final boolean contains(Object o) {
return map.containsValue(o);
}
public final boolean remove(Object o) {
if (o != null) {
for (Iterator<V> it = iterator(); it.hasNext();) {
if (o.equals(it.next())) {
it.remove();
return true;
}
}
}
return false;
}
public final Iterator<V> iterator() {
ConcurrentHashMap<K,V> m = map;
Node<K,V>[] t;
int f = (t = m.table) == null ? 0 : t.length;
return new ValueIterator<K,V>(t, f, 0, f, m);
}
public final boolean add(V e) {
throw new UnsupportedOperationException();
}
public final boolean addAll(Collection<? extends V> c) {
throw new UnsupportedOperationException();
}
public Spliterator<V> spliterator() {
Node<K,V>[] t;
ConcurrentHashMap<K,V> m = map;
long n = m.sumCount();
int f = (t = m.table) == null ? 0 : t.length;
return new ValueSpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n);
}
public void forEach(Consumer<? super V> action) {
if (action == null) throw new NullPointerException();
Node<K,V>[] t;
if ((t = map.table) != null) {
Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
for (Node<K,V> p; (p = it.advance()) != null; )
action.accept(p.val);
}
}
}
/**
* A view of a ConcurrentHashMap as a {@link Set} of (key, value)
* entries. This class cannot be directly instantiated. See
* {@link #entrySet()}.
*/
static final class EntrySetView<K,V> extends CollectionView<K,V,Map.Entry<K,V>>
implements Set<Map.Entry<K,V>>, java.io.Serializable {
private static final long serialVersionUID = 2249069246763182397L;
EntrySetView(ConcurrentHashMap<K,V> map) { super(map); }
public boolean contains(Object o) {
Object k, v, r; Map.Entry<?,?> e;
return ((o instanceof Map.Entry) &&
(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
(r = map.get(k)) != null &&
(v = e.getValue()) != null &&
(v == r || v.equals(r)));
}
public boolean remove(Object o) {
Object k, v; Map.Entry<?,?> e;
return ((o instanceof Map.Entry) &&
(k = (e = (Map.Entry<?,?>)o).getKey()) != null &&
(v = e.getValue()) != null &&
map.remove(k, v));
}
/**
* @return an iterator over the entries of the backing map
*/
public Iterator<Map.Entry<K,V>> iterator() {
ConcurrentHashMap<K,V> m = map;
Node<K,V>[] t;
int f = (t = m.table) == null ? 0 : t.length;
return new EntryIterator<K,V>(t, f, 0, f, m);
}
public boolean add(Entry<K,V> e) {
return map.putVal(e.getKey(), e.getValue(), false) == null;
}
public boolean addAll(Collection<? extends Entry<K,V>> c) {
boolean added = false;
for (Entry<K,V> e : c) {
if (add(e))
added = true;
}
return added;
}
public final int hashCode() {
int h = 0;
Node<K,V>[] t;
if ((t = map.table) != null) {
Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
for (Node<K,V> p; (p = it.advance()) != null; ) {
h += p.hashCode();
}
}
return h;
}
public final boolean equals(Object o) {
Set<?> c;
return ((o instanceof Set) &&
((c = (Set<?>)o) == this ||
(containsAll(c) && c.containsAll(this))));
}
public Spliterator<Map.Entry<K,V>> spliterator() {
Node<K,V>[] t;
ConcurrentHashMap<K,V> m = map;
long n = m.sumCount();
int f = (t = m.table) == null ? 0 : t.length;
return new EntrySpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n, m);
}
public void forEach(Consumer<? super Map.Entry<K,V>> action) {
if (action == null) throw new NullPointerException();
Node<K,V>[] t;
if ((t = map.table) != null) {
Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
for (Node<K,V> p; (p = it.advance()) != null; )
action.accept(new MapEntry<K,V>(p.key, p.val, map));
}
}
}
//批量任务的基类。
@SuppressWarnings("serial")
abstract static class BulkTask<K,V,R> extends CountedCompleter<R> {
//数组
Node<K,V>[] tab; // same as Traverser
//下一个节点
Node<K,V> next;
//当前节眯
TableStack<K,V> stack, spare;
//下标
int index;
//开始索引
int baseIndex;
//结束索引
int baseLimit;
//总数量
final int baseSize;
//批量控制器
int batch; // split control
//构造方法
BulkTask(BulkTask<K,V,?> par, int b, int i, int f, Node<K,V>[] t) {
super(par);
this.batch = b;
this.index = this.baseIndex = i;
if ((this.tab = t) == null)
this.baseSize = this.baseLimit = 0;
else if (par == null)
this.baseSize = this.baseLimit = t.length;
else {
this.baseLimit = f;
this.baseSize = par.baseSize;
}
}
//与遍历版本相同
final Node<K,V> advance() {
Node<K,V> e;
if ((e = next) != null)
e = e.next;
for (;;) {
Node<K,V>[] t; int i, n;
if (e != null)
return next = e;
if (baseIndex >= baseLimit || (t = tab) == null ||
(n = t.length) <= (i = index) || i < 0)
return next = null;
if ((e = tabAt(t, i)) != null && e.hash < 0) {
if (e instanceof ForwardingNode) {
tab = ((ForwardingNode<K,V>)e).nextTable;
e = null;
pushState(t, i, n);
continue;
}
else if (e instanceof TreeBin)
e = ((TreeBin<K,V>)e).first;
else
e = null;
}
if (stack != null)
recoverState(n);
else if ((index = i + baseSize) >= n)
index = ++baseIndex;
}
}
private void pushState(Node<K,V>[] t, int i, int n) {
TableStack<K,V> s = spare;
if (s != null)
spare = s.next;
else
s = new TableStack<K,V>();
s.tab = t;
s.length = n;
s.index = i;
s.next = stack;
stack = s;
}
private void recoverState(int n) {
TableStack<K,V> s; int len;
while ((s = stack) != null && (index += (len = s.length)) >= n) {
n = len;
index = s.index;
tab = s.tab;
s.tab = null;
TableStack<K,V> next = s.next;
s.next = spare; // save for reuse
stack = next;
spare = s;
}
if (s == null && (index += baseSize) >= n)
index = ++baseIndex;
}
}
/*
* Task classes. Coded in a regular but ugly format/style to
* simplify checks that each variant differs in the right way from
* others. The null screenings exist because compilers cannot tell
* that we've already null-checked task arguments, so we force
* simplest hoisted bypass to help avoid convoluted traps.
*/
@SuppressWarnings("serial")
static final class ForEachKeyTask<K,V>
extends BulkTask<K,V,Void> {
final Consumer<? super K> action;
ForEachKeyTask
(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
Consumer<? super K> action) {
super(p, b, i, f, t);
this.action = action;
}
public final void compute() {
final Consumer<? super K> action;
if ((action = this.action) != null) {
for (int i = baseIndex, f, h; batch > 0 &&
(h = ((f = baseLimit) + i) >>> 1) > i;) {
addToPendingCount(1);
new ForEachKeyTask<K,V>
(this, batch >>>= 1, baseLimit = h, f, tab,
action).fork();
}
for (Node<K,V> p; (p = advance()) != null;)
action.accept(p.key);
propagateCompletion();
}
}
}
@SuppressWarnings("serial")
static final class ForEachValueTask<K,V>
extends BulkTask<K,V,Void> {
final Consumer<? super V> action;
ForEachValueTask
(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
Consumer<? super V> action) {
super(p, b, i, f, t);
this.action = action;
}
public final void compute() {
final Consumer<? super V> action;
if ((action = this.action) != null) {
for (int i = baseIndex, f, h; batch > 0 &&
(h = ((f = baseLimit) + i) >>> 1) > i;) {
addToPendingCount(1);
new ForEachValueTask<K,V>
(this, batch >>>= 1, baseLimit = h, f, tab,
action).fork();
}
for (Node<K,V> p; (p = advance()) != null;)
action.accept(p.val);
propagateCompletion();
}
}
}
@SuppressWarnings("serial")
static final class ForEachEntryTask<K,V>
extends BulkTask<K,V,Void> {
final Consumer<? super Entry<K,V>> action;
ForEachEntryTask
(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
Consumer<? super Entry<K,V>> action) {
super(p, b, i, f, t);
this.action = action;
}
public final void compute() {
final Consumer<? super Entry<K,V>> action;
if ((action = this.action) != null) {
for (int i = baseIndex, f, h; batch > 0 &&
(h = ((f = baseLimit) + i) >>> 1) > i;) {
addToPendingCount(1);
new ForEachEntryTask<K,V>
(this, batch >>>= 1, baseLimit = h, f, tab,
action).fork();
}
for (Node<K,V> p; (p = advance()) != null; )
action.accept(p);
propagateCompletion();
}
}
}
@SuppressWarnings("serial")
static final class ForEachMappingTask<K,V>
extends BulkTask<K,V,Void> {
final BiConsumer<? super K, ? super V> action;
ForEachMappingTask
(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
BiConsumer<? super K,? super V> action) {
super(p, b, i, f, t);
this.action = action;
}
public final void compute() {
final BiConsumer<? super K, ? super V> action;
if ((action = this.action) != null) {
for (int i = baseIndex, f, h; batch > 0 &&
(h = ((f = baseLimit) + i) >>> 1) > i;) {
addToPendingCount(1);
new ForEachMappingTask<K,V>
(this, batch >>>= 1, baseLimit = h, f, tab,
action).fork();
}
for (Node<K,V> p; (p = advance()) != null; )
action.accept(p.key, p.val);
propagateCompletion();
}
}
}
@SuppressWarnings("serial")
static final class ForEachTransformedKeyTask<K,V,U>
extends BulkTask<K,V,Void> {
final Function<? super K, ? extends U> transformer;
final Consumer<? super U> action;
ForEachTransformedKeyTask
(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
Function<? super K, ? extends U> transformer, Consumer<? super U> action) {
super(p, b, i, f, t);
this.transformer = transformer; this.action = action;
}
public final void compute() {
final Function<? super K, ? extends U> transformer;
final Consumer<? super U> action;
if ((transformer = this.transformer) != null &&
(action = this.action) != null) {
for (int i = baseIndex, f, h; batch > 0 &&
(h = ((f = baseLimit) + i) >>> 1) > i;) {
addToPendingCount(1);
new ForEachTransformedKeyTask<K,V,U>
(this, batch >>>= 1, baseLimit = h, f, tab,
transformer, action).fork();
}
for (Node<K,V> p; (p = advance()) != null; ) {
U u;
if ((u = transformer.apply(p.key)) != null)
action.accept(u);
}
propagateCompletion();
}
}
}
@SuppressWarnings("serial")
static final class ForEachTransformedValueTask<K,V,U>
extends BulkTask<K,V,Void> {
final Function<? super V, ? extends U> transformer;
final Consumer<? super U> action;
ForEachTransformedValueTask
(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
Function<? super V, ? extends U> transformer, Consumer<? super U> action) {
super(p, b, i, f, t);
this.transformer = transformer; this.action = action;
}
public final void compute() {
final Function<? super V, ? extends U> transformer;
final Consumer<? super U> action;
if ((transformer = this.transformer) != null &&
(action = this.action) != null) {
for (int i = baseIndex, f, h; batch > 0 &&
(h = ((f = baseLimit) + i) >>> 1) > i;) {
addToPendingCount(1);
new ForEachTransformedValueTask<K,V,U>
(this, batch >>>= 1, baseLimit = h, f, tab,
transformer, action).fork();
}
for (Node<K,V> p; (p = advance()) != null; ) {
U u;
if ((u = transformer.apply(p.val)) != null)
action.accept(u);
}
propagateCompletion();
}
}
}
@SuppressWarnings("serial")
static final class ForEachTransformedEntryTask<K,V,U>
extends BulkTask<K,V,Void> {
final Function<Map.Entry<K,V>, ? extends U> transformer;
final Consumer<? super U> action;
ForEachTransformedEntryTask
(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
Function<Map.Entry<K,V>, ? extends U> transformer, Consumer<? super U> action) {
super(p, b, i, f, t);
this.transformer = transformer; this.action = action;
}
public final void compute() {
final Function<Map.Entry<K,V>, ? extends U> transformer;
final Consumer<? super U> action;
if ((transformer = this.transformer) != null &&
(action = this.action) != null) {
for (int i = baseIndex, f, h; batch > 0 &&
(h = ((f = baseLimit) + i) >>> 1) > i;) {
addToPendingCount(1);
new ForEachTransformedEntryTask<K,V,U>
(this, batch >>>= 1, baseLimit = h, f, tab,
transformer, action).fork();
}
for (Node<K,V> p; (p = advance()) != null; ) {
U u;
if ((u = transformer.apply(p)) != null)
action.accept(u);
}
propagateCompletion();
}
}
}
@SuppressWarnings("serial")
static final class ForEachTransformedMappingTask<K,V,U>
extends BulkTask<K,V,Void> {
final BiFunction<? super K, ? super V, ? extends U> transformer;
final Consumer<? super U> action;
ForEachTransformedMappingTask
(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
BiFunction<? super K, ? super V, ? extends U> transformer,
Consumer<? super U> action) {
super(p, b, i, f, t);
this.transformer = transformer; this.action = action;
}
public final void compute() {
final BiFunction<? super K, ? super V, ? extends U> transformer;
final Consumer<? super U> action;
if ((transformer = this.transformer) != null &&
(action = this.action) != null) {
for (int i = baseIndex, f, h; batch > 0 &&
(h = ((f = baseLimit) + i) >>> 1) > i;) {
addToPendingCount(1);
new ForEachTransformedMappingTask<K,V,U>
(this, batch >>>= 1, baseLimit = h, f, tab,
transformer, action).fork();
}
for (Node<K,V> p; (p = advance()) != null; ) {
U u;
if ((u = transformer.apply(p.key, p.val)) != null)
action.accept(u);
}
propagateCompletion();
}
}
}
@SuppressWarnings("serial")
static final class SearchKeysTask<K,V,U>
extends BulkTask<K,V,U> {
final Function<? super K, ? extends U> searchFunction;
final AtomicReference<U> result;
SearchKeysTask
(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
Function<? super K, ? extends U> searchFunction,
AtomicReference<U> result) {
super(p, b, i, f, t);
this.searchFunction = searchFunction; this.result = result;
}
public final U getRawResult() { return result.get(); }
public final void compute() {
final Function<? super K, ? extends U> searchFunction;
final AtomicReference<U> result;
if ((searchFunction = this.searchFunction) != null &&
(result = this.result) != null) {
for (int i = baseIndex, f, h; batch > 0 &&
(h = ((f = baseLimit) + i) >>> 1) > i;) {
if (result.get() != null)
return;
addToPendingCount(1);
new SearchKeysTask<K,V,U>
(this, batch >>>= 1, baseLimit = h, f, tab,
searchFunction, result).fork();
}
while (result.get() == null) {
U u;
Node<K,V> p;
if ((p = advance()) == null) {
propagateCompletion();
break;
}
if ((u = searchFunction.apply(p.key)) != null) {
if (result.compareAndSet(null, u))
quietlyCompleteRoot();
break;
}
}
}
}
}
@SuppressWarnings("serial")
static final class SearchValuesTask<K,V,U>
extends BulkTask<K,V,U> {
final Function<? super V, ? extends U> searchFunction;
final AtomicReference<U> result;
SearchValuesTask
(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
Function<? super V, ? extends U> searchFunction,
AtomicReference<U> result) {
super(p, b, i, f, t);
this.searchFunction = searchFunction; this.result = result;
}
public final U getRawResult() { return result.get(); }
public final void compute() {
final Function<? super V, ? extends U> searchFunction;
final AtomicReference<U> result;
if ((searchFunction = this.searchFunction) != null &&
(result = this.result) != null) {
for (int i = baseIndex, f, h; batch > 0 &&
(h = ((f = baseLimit) + i) >>> 1) > i;) {
if (result.get() != null)
return;
addToPendingCount(1);
new SearchValuesTask<K,V,U>
(this, batch >>>= 1, baseLimit = h, f, tab,
searchFunction, result).fork();
}
while (result.get() == null) {
U u;
Node<K,V> p;
if ((p = advance()) == null) {
propagateCompletion();
break;
}
if ((u = searchFunction.apply(p.val)) != null) {
if (result.compareAndSet(null, u))
quietlyCompleteRoot();
break;
}
}
}
}
}
@SuppressWarnings("serial")
static final class SearchEntriesTask<K,V,U>
extends BulkTask<K,V,U> {
final Function<Entry<K,V>, ? extends U> searchFunction;
final AtomicReference<U> result;
SearchEntriesTask
(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
Function<Entry<K,V>, ? extends U> searchFunction,
AtomicReference<U> result) {
super(p, b, i, f, t);
this.searchFunction = searchFunction; this.result = result;
}
public final U getRawResult() { return result.get(); }
public final void compute() {
final Function<Entry<K,V>, ? extends U> searchFunction;
final AtomicReference<U> result;
if ((searchFunction = this.searchFunction) != null &&
(result = this.result) != null) {
for (int i = baseIndex, f, h; batch > 0 &&
(h = ((f = baseLimit) + i) >>> 1) > i;) {
if (result.get() != null)
return;
addToPendingCount(1);
new SearchEntriesTask<K,V,U>
(this, batch >>>= 1, baseLimit = h, f, tab,
searchFunction, result).fork();
}
while (result.get() == null) {
U u;
Node<K,V> p;
if ((p = advance()) == null) {
propagateCompletion();
break;
}
if ((u = searchFunction.apply(p)) != null) {
if (result.compareAndSet(null, u))
quietlyCompleteRoot();
return;
}
}
}
}
}
@SuppressWarnings("serial")
static final class SearchMappingsTask<K,V,U>
extends BulkTask<K,V,U> {
final BiFunction<? super K, ? super V, ? extends U> searchFunction;
final AtomicReference<U> result;
SearchMappingsTask
(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
BiFunction<? super K, ? super V, ? extends U> searchFunction,
AtomicReference<U> result) {
super(p, b, i, f, t);
this.searchFunction = searchFunction; this.result = result;
}
public final U getRawResult() { return result.get(); }
public final void compute() {
final BiFunction<? super K, ? super V, ? extends U> searchFunction;
final AtomicReference<U> result;
if ((searchFunction = this.searchFunction) != null &&
(result = this.result) != null) {
for (int i = baseIndex, f, h; batch > 0 &&
(h = ((f = baseLimit) + i) >>> 1) > i;) {
if (result.get() != null)
return;
addToPendingCount(1);
new SearchMappingsTask<K,V,U>
(this, batch >>>= 1, baseLimit = h, f, tab,
searchFunction, result).fork();
}
while (result.get() == null) {
U u;
Node<K,V> p;
if ((p = advance()) == null) {
propagateCompletion();
break;
}
if ((u = searchFunction.apply(p.key, p.val)) != null) {
if (result.compareAndSet(null, u))
quietlyCompleteRoot();
break;
}
}
}
}
}
@SuppressWarnings("serial")
static final class ReduceKeysTask<K,V>
extends BulkTask<K,V,K> {
final BiFunction<? super K, ? super K, ? extends K> reducer;
K result;
ReduceKeysTask<K,V> rights, nextRight;
ReduceKeysTask
(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
ReduceKeysTask<K,V> nextRight,
BiFunction<? super K, ? super K, ? extends K> reducer) {
super(p, b, i, f, t); this.nextRight = nextRight;
this.reducer = reducer;
}
public final K getRawResult() { return result; }
public final void compute() {
final BiFunction<? super K, ? super K, ? extends K> reducer;
if ((reducer = this.reducer) != null) {
for (int i = baseIndex, f, h; batch > 0 &&
(h = ((f = baseLimit) + i) >>> 1) > i;) {
addToPendingCount(1);
(rights = new ReduceKeysTask<K,V>
(this, batch >>>= 1, baseLimit = h, f, tab,
rights, reducer)).fork();
}
K r = null;
for (Node<K,V> p; (p = advance()) != null; ) {
K u = p.key;
r = (r == null) ? u : u == null ? r : reducer.apply(r, u);
}
result = r;
CountedCompleter<?> c;
for (c = firstComplete(); c != null; c = c.nextComplete()) {
@SuppressWarnings("unchecked")
ReduceKeysTask<K,V>
t = (ReduceKeysTask<K,V>)c,
s = t.rights;
while (s != null) {
K tr, sr;
if ((sr = s.result) != null)
t.result = (((tr = t.result) == null) ? sr :
reducer.apply(tr, sr));
s = t.rights = s.nextRight;
}
}
}
}
}
@SuppressWarnings("serial")
static final class ReduceValuesTask<K,V>
extends BulkTask<K,V,V> {
final BiFunction<? super V, ? super V, ? extends V> reducer;
V result;
ReduceValuesTask<K,V> rights, nextRight;
ReduceValuesTask
(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
ReduceValuesTask<K,V> nextRight,
BiFunction<? super V, ? super V, ? extends V> reducer) {
super(p, b, i, f, t); this.nextRight = nextRight;
this.reducer = reducer;
}
public final V getRawResult() { return result; }
public final void compute() {
final BiFunction<? super V, ? super V, ? extends V> reducer;
if ((reducer = this.reducer) != null) {
for (int i = baseIndex, f, h; batch > 0 &&
(h = ((f = baseLimit) + i) >>> 1) > i;) {
addToPendingCount(1);
(rights = new ReduceValuesTask<K,V>
(this, batch >>>= 1, baseLimit = h, f, tab,
rights, reducer)).fork();
}
V r = null;
for (Node<K,V> p; (p = advance()) != null; ) {
V v = p.val;
r = (r == null) ? v : reducer.apply(r, v);
}
result = r;
CountedCompleter<?> c;
for (c = firstComplete(); c != null; c = c.nextComplete()) {
@SuppressWarnings("unchecked")
ReduceValuesTask<K,V>
t = (ReduceValuesTask<K,V>)c,
s = t.rights;
while (s != null) {
V tr, sr;
if ((sr = s.result) != null)
t.result = (((tr = t.result) == null) ? sr :
reducer.apply(tr, sr));
s = t.rights = s.nextRight;
}
}
}
}
}
//计数类实现
static final class ReduceEntriesTask<K,V>
extends BulkTask<K,V,Map.Entry<K,V>> {
final BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer;
Map.Entry<K,V> result;
ReduceEntriesTask<K,V> rights, nextRight;
ReduceEntriesTask
(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
ReduceEntriesTask<K,V> nextRight,
BiFunction<Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer) {
super(p, b, i, f, t); this.nextRight = nextRight;
this.reducer = reducer;
}
public final Map.Entry<K,V> getRawResult() { return result; }
public final void compute() {
final BiFunction<Map.Entry<K,V>, Map.Entry<K,V>, ? extends Map.Entry<K,V>> reducer;
if ((reducer = this.reducer) != null) {
for (int i = baseIndex, f, h; batch > 0 &&
(h = ((f = baseLimit) + i) >>> 1) > i;) {
addToPendingCount(1);
(rights = new ReduceEntriesTask<K,V>
(this, batch >>>= 1, baseLimit = h, f, tab,
rights, reducer)).fork();
}
Map.Entry<K,V> r = null;
for (Node<K,V> p; (p = advance()) != null; )
r = (r == null) ? p : reducer.apply(r, p);
result = r;
CountedCompleter<?> c;
for (c = firstComplete(); c != null; c = c.nextComplete()) {
@SuppressWarnings("unchecked")
ReduceEntriesTask<K,V>
t = (ReduceEntriesTask<K,V>)c,
s = t.rights;
while (s != null) {
Map.Entry<K,V> tr, sr;
if ((sr = s.result) != null)
t.result = (((tr = t.result) == null) ? sr :
reducer.apply(tr, sr));
s = t.rights = s.nextRight;
}
}
}
}
}
@SuppressWarnings("serial")
static final class MapReduceKeysTask<K,V,U>
extends BulkTask<K,V,U> {
final Function<? super K, ? extends U> transformer;
final BiFunction<? super U, ? super U, ? extends U> reducer;
U result;
MapReduceKeysTask<K,V,U> rights, nextRight;
MapReduceKeysTask
(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
MapReduceKeysTask<K,V,U> nextRight,
Function<? super K, ? extends U> transformer,
BiFunction<? super U, ? super U, ? extends U> reducer) {
super(p, b, i, f, t); this.nextRight = nextRight;
this.transformer = transformer;
this.reducer = reducer;
}
public final U getRawResult() { return result; }
public final void compute() {
final Function<? super K, ? extends U> transformer;
final BiFunction<? super U, ? super U, ? extends U> reducer;
if ((transformer = this.transformer) != null &&
(reducer = this.reducer) != null) {
for (int i = baseIndex, f, h; batch > 0 &&
(h = ((f = baseLimit) + i) >>> 1) > i;) {
addToPendingCount(1);
(rights = new MapReduceKeysTask<K,V,U>
(this, batch >>>= 1, baseLimit = h, f, tab,
rights, transformer, reducer)).fork();
}
U r = null;
for (Node<K,V> p; (p = advance()) != null; ) {
U u;
if ((u = transformer.apply(p.key)) != null)
r = (r == null) ? u : reducer.apply(r, u);
}
result = r;
CountedCompleter<?> c;
for (c = firstComplete(); c != null; c = c.nextComplete()) {
@SuppressWarnings("unchecked")
MapReduceKeysTask<K,V,U>
t = (MapReduceKeysTask<K,V,U>)c,
s = t.rights;
while (s != null) {
U tr, sr;
if ((sr = s.result) != null)
t.result = (((tr = t.result) == null) ? sr :
reducer.apply(tr, sr));
s = t.rights = s.nextRight;
}
}
}
}
}
@SuppressWarnings("serial")
static final class MapReduceValuesTask<K,V,U>
extends BulkTask<K,V,U> {
final Function<? super V, ? extends U> transformer;
final BiFunction<? super U, ? super U, ? extends U> reducer;
U result;
MapReduceValuesTask<K,V,U> rights, nextRight;
MapReduceValuesTask
(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
MapReduceValuesTask<K,V,U> nextRight,
Function<? super V, ? extends U> transformer,
BiFunction<? super U, ? super U, ? extends U> reducer) {
super(p, b, i, f, t); this.nextRight = nextRight;
this.transformer = transformer;
this.reducer = reducer;
}
public final U getRawResult() { return result; }
public final void compute() {
final Function<? super V, ? extends U> transformer;
final BiFunction<? super U, ? super U, ? extends U> reducer;
if ((transformer = this.transformer) != null &&
(reducer = this.reducer) != null) {
for (int i = baseIndex, f, h; batch > 0 &&
(h = ((f = baseLimit) + i) >>> 1) > i;) {
addToPendingCount(1);
(rights = new MapReduceValuesTask<K,V,U>
(this, batch >>>= 1, baseLimit = h, f, tab,
rights, transformer, reducer)).fork();
}
U r = null;
for (Node<K,V> p; (p = advance()) != null; ) {
U u;
if ((u = transformer.apply(p.val)) != null)
r = (r == null) ? u : reducer.apply(r, u);
}
result = r;
CountedCompleter<?> c;
for (c = firstComplete(); c != null; c = c.nextComplete()) {
@SuppressWarnings("unchecked")
MapReduceValuesTask<K,V,U>
t = (MapReduceValuesTask<K,V,U>)c,
s = t.rights;
while (s != null) {
U tr, sr;
if ((sr = s.result) != null)
t.result = (((tr = t.result) == null) ? sr :
reducer.apply(tr, sr));
s = t.rights = s.nextRight;
}
}
}
}
}
@SuppressWarnings("serial")
static final class MapReduceEntriesTask<K,V,U>
extends BulkTask<K,V,U> {
final Function<Map.Entry<K,V>, ? extends U> transformer;
final BiFunction<? super U, ? super U, ? extends U> reducer;
U result;
MapReduceEntriesTask<K,V,U> rights, nextRight;
MapReduceEntriesTask
(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
MapReduceEntriesTask<K,V,U> nextRight,
Function<Map.Entry<K,V>, ? extends U> transformer,
BiFunction<? super U, ? super U, ? extends U> reducer) {
super(p, b, i, f, t); this.nextRight = nextRight;
this.transformer = transformer;
this.reducer = reducer;
}
public final U getRawResult() { return result; }
public final void compute() {
final Function<Map.Entry<K,V>, ? extends U> transformer;
final BiFunction<? super U, ? super U, ? extends U> reducer;
if ((transformer = this.transformer) != null &&
(reducer = this.reducer) != null) {
for (int i = baseIndex, f, h; batch > 0 &&
(h = ((f = baseLimit) + i) >>> 1) > i;) {
addToPendingCount(1);
(rights = new MapReduceEntriesTask<K,V,U>
(this, batch >>>= 1, baseLimit = h, f, tab,
rights, transformer, reducer)).fork();
}
U r = null;
for (Node<K,V> p; (p = advance()) != null; ) {
U u;
if ((u = transformer.apply(p)) != null)
r = (r == null) ? u : reducer.apply(r, u);
}
result = r;
CountedCompleter<?> c;
for (c = firstComplete(); c != null; c = c.nextComplete()) {
@SuppressWarnings("unchecked")
MapReduceEntriesTask<K,V,U>
t = (MapReduceEntriesTask<K,V,U>)c,
s = t.rights;
while (s != null) {
U tr, sr;
if ((sr = s.result) != null)
t.result = (((tr = t.result) == null) ? sr :
reducer.apply(tr, sr));
s = t.rights = s.nextRight;
}
}
}
}
}
@SuppressWarnings("serial")
static final class MapReduceMappingsTask<K,V,U>
extends BulkTask<K,V,U> {
final BiFunction<? super K, ? super V, ? extends U> transformer;
final BiFunction<? super U, ? super U, ? extends U> reducer;
U result;
MapReduceMappingsTask<K,V,U> rights, nextRight;
MapReduceMappingsTask
(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
MapReduceMappingsTask<K,V,U> nextRight,
BiFunction<? super K, ? super V, ? extends U> transformer,
BiFunction<? super U, ? super U, ? extends U> reducer) {
super(p, b, i, f, t); this.nextRight = nextRight;
this.transformer = transformer;
this.reducer = reducer;
}
public final U getRawResult() { return result; }
public final void compute() {
final BiFunction<? super K, ? super V, ? extends U> transformer;
final BiFunction<? super U, ? super U, ? extends U> reducer;
if ((transformer = this.transformer) != null &&
(reducer = this.reducer) != null) {
for (int i = baseIndex, f, h; batch > 0 &&
(h = ((f = baseLimit) + i) >>> 1) > i;) {
addToPendingCount(1);
(rights = new MapReduceMappingsTask<K,V,U>
(this, batch >>>= 1, baseLimit = h, f, tab,
rights, transformer, reducer)).fork();
}
U r = null;
for (Node<K,V> p; (p = advance()) != null; ) {
U u;
if ((u = transformer.apply(p.key, p.val)) != null)
r = (r == null) ? u : reducer.apply(r, u);
}
result = r;
CountedCompleter<?> c;
for (c = firstComplete(); c != null; c = c.nextComplete()) {
@SuppressWarnings("unchecked")
MapReduceMappingsTask<K,V,U>
t = (MapReduceMappingsTask<K,V,U>)c,
s = t.rights;
while (s != null) {
U tr, sr;
if ((sr = s.result) != null)
t.result = (((tr = t.result) == null) ? sr :
reducer.apply(tr, sr));
s = t.rights = s.nextRight;
}
}
}
}
}
@SuppressWarnings("serial")
static final class MapReduceKeysToDoubleTask<K,V>
extends BulkTask<K,V,Double> {
final ToDoubleFunction<? super K> transformer;
final DoubleBinaryOperator reducer;
final double basis;
double result;
MapReduceKeysToDoubleTask<K,V> rights, nextRight;
MapReduceKeysToDoubleTask
(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
MapReduceKeysToDoubleTask<K,V> nextRight,
ToDoubleFunction<? super K> transformer,
double basis,
DoubleBinaryOperator reducer) {
super(p, b, i, f, t); this.nextRight = nextRight;
this.transformer = transformer;
this.basis = basis; this.reducer = reducer;
}
public final Double getRawResult() { return result; }
public final void compute() {
final ToDoubleFunction<? super K> transformer;
final DoubleBinaryOperator reducer;
if ((transformer = this.transformer) != null &&
(reducer = this.reducer) != null) {
double r = this.basis;
for (int i = baseIndex, f, h; batch > 0 &&
(h = ((f = baseLimit) + i) >>> 1) > i;) {
addToPendingCount(1);
(rights = new MapReduceKeysToDoubleTask<K,V>
(this, batch >>>= 1, baseLimit = h, f, tab,
rights, transformer, r, reducer)).fork();
}
for (Node<K,V> p; (p = advance()) != null; )
r = reducer.applyAsDouble(r, transformer.applyAsDouble(p.key));
result = r;
CountedCompleter<?> c;
for (c = firstComplete(); c != null; c = c.nextComplete()) {
@SuppressWarnings("unchecked")
MapReduceKeysToDoubleTask<K,V>
t = (MapReduceKeysToDoubleTask<K,V>)c,
s = t.rights;
while (s != null) {
t.result = reducer.applyAsDouble(t.result, s.result);
s = t.rights = s.nextRight;
}
}
}
}
}
@SuppressWarnings("serial")
static final class MapReduceValuesToDoubleTask<K,V>
extends BulkTask<K,V,Double> {
final ToDoubleFunction<? super V> transformer;
final DoubleBinaryOperator reducer;
final double basis;
double result;
MapReduceValuesToDoubleTask<K,V> rights, nextRight;
MapReduceValuesToDoubleTask
(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
MapReduceValuesToDoubleTask<K,V> nextRight,
ToDoubleFunction<? super V> transformer,
double basis,
DoubleBinaryOperator reducer) {
super(p, b, i, f, t); this.nextRight = nextRight;
this.transformer = transformer;
this.basis = basis; this.reducer = reducer;
}
public final Double getRawResult() { return result; }
public final void compute() {
final ToDoubleFunction<? super V> transformer;
final DoubleBinaryOperator reducer;
if ((transformer = this.transformer) != null &&
(reducer = this.reducer) != null) {
double r = this.basis;
for (int i = baseIndex, f, h; batch > 0 &&
(h = ((f = baseLimit) + i) >>> 1) > i;) {
addToPendingCount(1);
(rights = new MapReduceValuesToDoubleTask<K,V>
(this, batch >>>= 1, baseLimit = h, f, tab,
rights, transformer, r, reducer)).fork();
}
for (Node<K,V> p; (p = advance()) != null; )
r = reducer.applyAsDouble(r, transformer.applyAsDouble(p.val));
result = r;
CountedCompleter<?> c;
for (c = firstComplete(); c != null; c = c.nextComplete()) {
@SuppressWarnings("unchecked")
MapReduceValuesToDoubleTask<K,V>
t = (MapReduceValuesToDoubleTask<K,V>)c,
s = t.rights;
while (s != null) {
t.result = reducer.applyAsDouble(t.result, s.result);
s = t.rights = s.nextRight;
}
}
}
}
}
@SuppressWarnings("serial")
static final class MapReduceEntriesToDoubleTask<K,V>
extends BulkTask<K,V,Double> {
final ToDoubleFunction<Map.Entry<K,V>> transformer;
final DoubleBinaryOperator reducer;
final double basis;
double result;
MapReduceEntriesToDoubleTask<K,V> rights, nextRight;
MapReduceEntriesToDoubleTask
(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
MapReduceEntriesToDoubleTask<K,V> nextRight,
ToDoubleFunction<Map.Entry<K,V>> transformer,
double basis,
DoubleBinaryOperator reducer) {
super(p, b, i, f, t); this.nextRight = nextRight;
this.transformer = transformer;
this.basis = basis; this.reducer = reducer;
}
public final Double getRawResult() { return result; }
public final void compute() {
final ToDoubleFunction<Map.Entry<K,V>> transformer;
final DoubleBinaryOperator reducer;
if ((transformer = this.transformer) != null &&
(reducer = this.reducer) != null) {
double r = this.basis;
for (int i = baseIndex, f, h; batch > 0 &&
(h = ((f = baseLimit) + i) >>> 1) > i;) {
addToPendingCount(1);
(rights = new MapReduceEntriesToDoubleTask<K,V>
(this, batch >>>= 1, baseLimit = h, f, tab,
rights, transformer, r, reducer)).fork();
}
for (Node<K,V> p; (p = advance()) != null; )
r = reducer.applyAsDouble(r, transformer.applyAsDouble(p));
result = r;
CountedCompleter<?> c;
for (c = firstComplete(); c != null; c = c.nextComplete()) {
@SuppressWarnings("unchecked")
MapReduceEntriesToDoubleTask<K,V>
t = (MapReduceEntriesToDoubleTask<K,V>)c,
s = t.rights;
while (s != null) {
t.result = reducer.applyAsDouble(t.result, s.result);
s = t.rights = s.nextRight;
}
}
}
}
}
@SuppressWarnings("serial")
static final class MapReduceMappingsToDoubleTask<K,V>
extends BulkTask<K,V,Double> {
final ToDoubleBiFunction<? super K, ? super V> transformer;
final DoubleBinaryOperator reducer;
final double basis;
double result;
MapReduceMappingsToDoubleTask<K,V> rights, nextRight;
MapReduceMappingsToDoubleTask
(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
MapReduceMappingsToDoubleTask<K,V> nextRight,
ToDoubleBiFunction<? super K, ? super V> transformer,
double basis,
DoubleBinaryOperator reducer) {
super(p, b, i, f, t); this.nextRight = nextRight;
this.transformer = transformer;
this.basis = basis; this.reducer = reducer;
}
public final Double getRawResult() { return result; }
public final void compute() {
final ToDoubleBiFunction<? super K, ? super V> transformer;
final DoubleBinaryOperator reducer;
if ((transformer = this.transformer) != null &&
(reducer = this.reducer) != null) {
double r = this.basis;
for (int i = baseIndex, f, h; batch > 0 &&
(h = ((f = baseLimit) + i) >>> 1) > i;) {
addToPendingCount(1);
(rights = new MapReduceMappingsToDoubleTask<K,V>
(this, batch >>>= 1, baseLimit = h, f, tab,
rights, transformer, r, reducer)).fork();
}
for (Node<K,V> p; (p = advance()) != null; )
r = reducer.applyAsDouble(r, transformer.applyAsDouble(p.key, p.val));
result = r;
CountedCompleter<?> c;
for (c = firstComplete(); c != null; c = c.nextComplete()) {
@SuppressWarnings("unchecked")
MapReduceMappingsToDoubleTask<K,V>
t = (MapReduceMappingsToDoubleTask<K,V>)c,
s = t.rights;
while (s != null) {
t.result = reducer.applyAsDouble(t.result, s.result);
s = t.rights = s.nextRight;
}
}
}
}
}
@SuppressWarnings("serial")
static final class MapReduceKeysToLongTask<K,V>
extends BulkTask<K,V,Long> {
final ToLongFunction<? super K> transformer;
final LongBinaryOperator reducer;
final long basis;
long result;
MapReduceKeysToLongTask<K,V> rights, nextRight;
MapReduceKeysToLongTask
(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
MapReduceKeysToLongTask<K,V> nextRight,
ToLongFunction<? super K> transformer,
long basis,
LongBinaryOperator reducer) {
super(p, b, i, f, t); this.nextRight = nextRight;
this.transformer = transformer;
this.basis = basis; this.reducer = reducer;
}
public final Long getRawResult() { return result; }
public final void compute() {
final ToLongFunction<? super K> transformer;
final LongBinaryOperator reducer;
if ((transformer = this.transformer) != null &&
(reducer = this.reducer) != null) {
long r = this.basis;
for (int i = baseIndex, f, h; batch > 0 &&
(h = ((f = baseLimit) + i) >>> 1) > i;) {
addToPendingCount(1);
(rights = new MapReduceKeysToLongTask<K,V>
(this, batch >>>= 1, baseLimit = h, f, tab,
rights, transformer, r, reducer)).fork();
}
for (Node<K,V> p; (p = advance()) != null; )
r = reducer.applyAsLong(r, transformer.applyAsLong(p.key));
result = r;
CountedCompleter<?> c;
for (c = firstComplete(); c != null; c = c.nextComplete()) {
@SuppressWarnings("unchecked")
MapReduceKeysToLongTask<K,V>
t = (MapReduceKeysToLongTask<K,V>)c,
s = t.rights;
while (s != null) {
t.result = reducer.applyAsLong(t.result, s.result);
s = t.rights = s.nextRight;
}
}
}
}
}
@SuppressWarnings("serial")
static final class MapReduceValuesToLongTask<K,V>
extends BulkTask<K,V,Long> {
final ToLongFunction<? super V> transformer;
final LongBinaryOperator reducer;
final long basis;
long result;
MapReduceValuesToLongTask<K,V> rights, nextRight;
MapReduceValuesToLongTask
(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
MapReduceValuesToLongTask<K,V> nextRight,
ToLongFunction<? super V> transformer,
long basis,
LongBinaryOperator reducer) {
super(p, b, i, f, t); this.nextRight = nextRight;
this.transformer = transformer;
this.basis = basis; this.reducer = reducer;
}
public final Long getRawResult() { return result; }
public final void compute() {
final ToLongFunction<? super V> transformer;
final LongBinaryOperator reducer;
if ((transformer = this.transformer) != null &&
(reducer = this.reducer) != null) {
long r = this.basis;
for (int i = baseIndex, f, h; batch > 0 &&
(h = ((f = baseLimit) + i) >>> 1) > i;) {
addToPendingCount(1);
(rights = new MapReduceValuesToLongTask<K,V>
(this, batch >>>= 1, baseLimit = h, f, tab,
rights, transformer, r, reducer)).fork();
}
for (Node<K,V> p; (p = advance()) != null; )
r = reducer.applyAsLong(r, transformer.applyAsLong(p.val));
result = r;
CountedCompleter<?> c;
for (c = firstComplete(); c != null; c = c.nextComplete()) {
@SuppressWarnings("unchecked")
MapReduceValuesToLongTask<K,V>
t = (MapReduceValuesToLongTask<K,V>)c,
s = t.rights;
while (s != null) {
t.result = reducer.applyAsLong(t.result, s.result);
s = t.rights = s.nextRight;
}
}
}
}
}
@SuppressWarnings("serial")
static final class MapReduceEntriesToLongTask<K,V>
extends BulkTask<K,V,Long> {
final ToLongFunction<Map.Entry<K,V>> transformer;
final LongBinaryOperator reducer;
final long basis;
long result;
MapReduceEntriesToLongTask<K,V> rights, nextRight;
MapReduceEntriesToLongTask
(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
MapReduceEntriesToLongTask<K,V> nextRight,
ToLongFunction<Map.Entry<K,V>> transformer,
long basis,
LongBinaryOperator reducer) {
super(p, b, i, f, t); this.nextRight = nextRight;
this.transformer = transformer;
this.basis = basis; this.reducer = reducer;
}
public final Long getRawResult() { return result; }
public final void compute() {
final ToLongFunction<Map.Entry<K,V>> transformer;
final LongBinaryOperator reducer;
if ((transformer = this.transformer) != null &&
(reducer = this.reducer) != null) {
long r = this.basis;
for (int i = baseIndex, f, h; batch > 0 &&
(h = ((f = baseLimit) + i) >>> 1) > i;) {
addToPendingCount(1);
(rights = new MapReduceEntriesToLongTask<K,V>
(this, batch >>>= 1, baseLimit = h, f, tab,
rights, transformer, r, reducer)).fork();
}
for (Node<K,V> p; (p = advance()) != null; )
r = reducer.applyAsLong(r, transformer.applyAsLong(p));
result = r;
CountedCompleter<?> c;
for (c = firstComplete(); c != null; c = c.nextComplete()) {
@SuppressWarnings("unchecked")
MapReduceEntriesToLongTask<K,V>
t = (MapReduceEntriesToLongTask<K,V>)c,
s = t.rights;
while (s != null) {
t.result = reducer.applyAsLong(t.result, s.result);
s = t.rights = s.nextRight;
}
}
}
}
}
@SuppressWarnings("serial")
static final class MapReduceMappingsToLongTask<K,V>
extends BulkTask<K,V,Long> {
final ToLongBiFunction<? super K, ? super V> transformer;
final LongBinaryOperator reducer;
final long basis;
long result;
MapReduceMappingsToLongTask<K,V> rights, nextRight;
MapReduceMappingsToLongTask
(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
MapReduceMappingsToLongTask<K,V> nextRight,
ToLongBiFunction<? super K, ? super V> transformer,
long basis,
LongBinaryOperator reducer) {
super(p, b, i, f, t); this.nextRight = nextRight;
this.transformer = transformer;
this.basis = basis; this.reducer = reducer;
}
public final Long getRawResult() { return result; }
public final void compute() {
final ToLongBiFunction<? super K, ? super V> transformer;
final LongBinaryOperator reducer;
if ((transformer = this.transformer) != null &&
(reducer = this.reducer) != null) {
long r = this.basis;
for (int i = baseIndex, f, h; batch > 0 &&
(h = ((f = baseLimit) + i) >>> 1) > i;) {
addToPendingCount(1);
(rights = new MapReduceMappingsToLongTask<K,V>
(this, batch >>>= 1, baseLimit = h, f, tab,
rights, transformer, r, reducer)).fork();
}
for (Node<K,V> p; (p = advance()) != null; )
r = reducer.applyAsLong(r, transformer.applyAsLong(p.key, p.val));
result = r;
CountedCompleter<?> c;
for (c = firstComplete(); c != null; c = c.nextComplete()) {
@SuppressWarnings("unchecked")
MapReduceMappingsToLongTask<K,V>
t = (MapReduceMappingsToLongTask<K,V>)c,
s = t.rights;
while (s != null) {
t.result = reducer.applyAsLong(t.result, s.result);
s = t.rights = s.nextRight;
}
}
}
}
}
@SuppressWarnings("serial")
static final class MapReduceKeysToIntTask<K,V>
extends BulkTask<K,V,Integer> {
final ToIntFunction<? super K> transformer;
final IntBinaryOperator reducer;
final int basis;
int result;
MapReduceKeysToIntTask<K,V> rights, nextRight;
MapReduceKeysToIntTask
(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
MapReduceKeysToIntTask<K,V> nextRight,
ToIntFunction<? super K> transformer,
int basis,
IntBinaryOperator reducer) {
super(p, b, i, f, t); this.nextRight = nextRight;
this.transformer = transformer;
this.basis = basis; this.reducer = reducer;
}
public final Integer getRawResult() { return result; }
public final void compute() {
final ToIntFunction<? super K> transformer;
final IntBinaryOperator reducer;
if ((transformer = this.transformer) != null &&
(reducer = this.reducer) != null) {
int r = this.basis;
for (int i = baseIndex, f, h; batch > 0 &&
(h = ((f = baseLimit) + i) >>> 1) > i;) {
addToPendingCount(1);
(rights = new MapReduceKeysToIntTask<K,V>
(this, batch >>>= 1, baseLimit = h, f, tab,
rights, transformer, r, reducer)).fork();
}
for (Node<K,V> p; (p = advance()) != null; )
r = reducer.applyAsInt(r, transformer.applyAsInt(p.key));
result = r;
CountedCompleter<?> c;
for (c = firstComplete(); c != null; c = c.nextComplete()) {
@SuppressWarnings("unchecked")
MapReduceKeysToIntTask<K,V>
t = (MapReduceKeysToIntTask<K,V>)c,
s = t.rights;
while (s != null) {
t.result = reducer.applyAsInt(t.result, s.result);
s = t.rights = s.nextRight;
}
}
}
}
}
@SuppressWarnings("serial")
static final class MapReduceValuesToIntTask<K,V>
extends BulkTask<K,V,Integer> {
final ToIntFunction<? super V> transformer;
final IntBinaryOperator reducer;
final int basis;
int result;
MapReduceValuesToIntTask<K,V> rights, nextRight;
MapReduceValuesToIntTask
(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
MapReduceValuesToIntTask<K,V> nextRight,
ToIntFunction<? super V> transformer,
int basis,
IntBinaryOperator reducer) {
super(p, b, i, f, t); this.nextRight = nextRight;
this.transformer = transformer;
this.basis = basis; this.reducer = reducer;
}
public final Integer getRawResult() { return result; }
public final void compute() {
final ToIntFunction<? super V> transformer;
final IntBinaryOperator reducer;
if ((transformer = this.transformer) != null &&
(reducer = this.reducer) != null) {
int r = this.basis;
for (int i = baseIndex, f, h; batch > 0 &&
(h = ((f = baseLimit) + i) >>> 1) > i;) {
addToPendingCount(1);
(rights = new MapReduceValuesToIntTask<K,V>
(this, batch >>>= 1, baseLimit = h, f, tab,
rights, transformer, r, reducer)).fork();
}
for (Node<K,V> p; (p = advance()) != null; )
r = reducer.applyAsInt(r, transformer.applyAsInt(p.val));
result = r;
CountedCompleter<?> c;
for (c = firstComplete(); c != null; c = c.nextComplete()) {
@SuppressWarnings("unchecked")
MapReduceValuesToIntTask<K,V>
t = (MapReduceValuesToIntTask<K,V>)c,
s = t.rights;
while (s != null) {
t.result = reducer.applyAsInt(t.result, s.result);
s = t.rights = s.nextRight;
}
}
}
}
}
@SuppressWarnings("serial")
static final class MapReduceEntriesToIntTask<K,V>
extends BulkTask<K,V,Integer> {
final ToIntFunction<Map.Entry<K,V>> transformer;
final IntBinaryOperator reducer;
final int basis;
int result;
MapReduceEntriesToIntTask<K,V> rights, nextRight;
MapReduceEntriesToIntTask
(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
MapReduceEntriesToIntTask<K,V> nextRight,
ToIntFunction<Map.Entry<K,V>> transformer,
int basis,
IntBinaryOperator reducer) {
super(p, b, i, f, t); this.nextRight = nextRight;
this.transformer = transformer;
this.basis = basis; this.reducer = reducer;
}
public final Integer getRawResult() { return result; }
public final void compute() {
final ToIntFunction<Map.Entry<K,V>> transformer;
final IntBinaryOperator reducer;
if ((transformer = this.transformer) != null &&
(reducer = this.reducer) != null) {
int r = this.basis;
for (int i = baseIndex, f, h; batch > 0 &&
(h = ((f = baseLimit) + i) >>> 1) > i;) {
addToPendingCount(1);
(rights = new MapReduceEntriesToIntTask<K,V>
(this, batch >>>= 1, baseLimit = h, f, tab,
rights, transformer, r, reducer)).fork();
}
for (Node<K,V> p; (p = advance()) != null; )
r = reducer.applyAsInt(r, transformer.applyAsInt(p));
result = r;
CountedCompleter<?> c;
for (c = firstComplete(); c != null; c = c.nextComplete()) {
@SuppressWarnings("unchecked")
MapReduceEntriesToIntTask<K,V>
t = (MapReduceEntriesToIntTask<K,V>)c,
s = t.rights;
while (s != null) {
t.result = reducer.applyAsInt(t.result, s.result);
s = t.rights = s.nextRight;
}
}
}
}
}
@SuppressWarnings("serial")
static final class MapReduceMappingsToIntTask<K,V>
extends BulkTask<K,V,Integer> {
final ToIntBiFunction<? super K, ? super V> transformer;
final IntBinaryOperator reducer;
final int basis;
int result;
MapReduceMappingsToIntTask<K,V> rights, nextRight;
MapReduceMappingsToIntTask
(BulkTask<K,V,?> p, int b, int i, int f, Node<K,V>[] t,
MapReduceMappingsToIntTask<K,V> nextRight,
ToIntBiFunction<? super K, ? super V> transformer,
int basis,
IntBinaryOperator reducer) {
super(p, b, i, f, t); this.nextRight = nextRight;
this.transformer = transformer;
this.basis = basis; this.reducer = reducer;
}
public final Integer getRawResult() { return result; }
public final void compute() {
final ToIntBiFunction<? super K, ? super V> transformer;
final IntBinaryOperator reducer;
if ((transformer = this.transformer) != null &&
(reducer = this.reducer) != null) {
int r = this.basis;
for (int i = baseIndex, f, h; batch > 0 &&
(h = ((f = baseLimit) + i) >>> 1) > i;) {
addToPendingCount(1);
(rights = new MapReduceMappingsToIntTask<K,V>
(this, batch >>>= 1, baseLimit = h, f, tab,
rights, transformer, r, reducer)).fork();
}
for (Node<K,V> p; (p = advance()) != null; )
r = reducer.applyAsInt(r, transformer.applyAsInt(p.key, p.val));
result = r;
CountedCompleter<?> c;
for (c = firstComplete(); c != null; c = c.nextComplete()) {
@SuppressWarnings("unchecked")
MapReduceMappingsToIntTask<K,V>
t = (MapReduceMappingsToIntTask<K,V>)c,
s = t.rights;
while (s != null) {
t.result = reducer.applyAsInt(t.result, s.result);
s = t.rights = s.nextRight;
}
}
}
}
}
// Unsafe 锁
private static final sun.misc.Unsafe U;
//比特数
private static final long SIZECTL;
//调整大小时拆分的下一个表索引(+ 1)。
private static final long TRANSFERINDEX;
//基础计数器
private static final long BASECOUNT;
//自旋锁
private static final long CELLSBUSY;
//ConcurrentHashMap中内存的偏移地址
private static final long CELLVALUE;
//表示数组第一个元素的偏移地址
private static final long ABASE;
//数组寻址
private static final int ASHIFT;
static {
try {
U = sun.misc.Unsafe.getUnsafe();
Class<?> k = ConcurrentHashMap.class;
SIZECTL = U.objectFieldOffset
(k.getDeclaredField("sizeCtl"));
TRANSFERINDEX = U.objectFieldOffset
(k.getDeclaredField("transferIndex"));
BASECOUNT = U.objectFieldOffset
(k.getDeclaredField("baseCount"));
CELLSBUSY = U.objectFieldOffset
(k.getDeclaredField("cellsBusy"));
Class<?> ck = CounterCell.class;
CELLVALUE = U.objectFieldOffset
(ck.getDeclaredField("value"));
Class<?> ak = Node[].class;
ABASE = U.arrayBaseOffset(ak);
int scale = U.arrayIndexScale(ak);
if ((scale & (scale - 1)) != 0)
throw new Error("data type scale not a power of two");
ASHIFT = 31 - Integer.numberOfLeadingZeros(scale);
} catch (Exception e) {
throw new Error(e);
}
}
}最后
concurrentHashMap的数据结构类似与hashmap一致，大的区别在上面已作比较。主要是在并发场景要用这个concurrentHashMap来解决map的操作，否则很可能引发事估，当然1.7也是有抗的具体可以自行再了解了解。
参考资料
https://www.bilibili.com/video/BV1x741117jq/?vd_source=7d0e42b081e08cb3cefaea55cc1fa8b7
http://static.kancloud.cn/alex_wsc/java_source_interview/187499