Arriba: jdk-HashMap (1.8) aprendizaje del código fuente
Introducción a concurrentHashMap
concurrentHashMap es un HashMap seguro para subprocesos y de alto rendimiento. La estructura de datos subyacente se implementa principalmente mediante matriz + lista vinculada + árbol rojo-negro, que es coherente con la estructura de HashMap.
¿La diferencia entre concurrentHashMap1.7 y 1.8?
comparar nombres |
1.7 |
1.8 |
Observación |
seguridad del hilo |
Sí |
Sí |
|
estructura de datos |
matriz + lista enlazada |
Matriz + lista enlazada/árbol rojo-negro |
|
implementación concurrente |
ReentrantLock+Segment+HashEntry |
Spin + cas + bloqueo de segmento sincronizado + CAS + HashEntry + árbol rojo-negro |
|
implementación de bloqueo |
Bloqueo de segmento, la simultaneidad predeterminada es 16, el tamaño de la matriz de segmento se fija después de la inicialización y no se puede expandir |
CAS+sincronizado garantiza seguridad concurrente |
|
liberar bloqueo |
Necesito llamar a unlock() |
No se requiere desbloqueo de pantalla |
¿Por qué necesita concurrentHashMap cuando tiene hashTable?
La aparición de concurrentHashMap se usa principalmente para reemplazar el HashTable muy disgustado.La razón es que aunque HashTable es seguro para subprocesos, utiliza un bloqueo de clase sincronizado, lo que hace que toda la clase se bloquee cada vez que se bloquea.Rendimiento en alto -Escenarios de concurrencia es muy baja, y en algunos escenarios de producción, hay accidentes en línea importantes debido al uso de este. Por lo tanto, se puede decir que la aparición de concurrentHashMap está diseñada para resolver escenarios de alta concurrencia, alta eficiencia y seguridad para subprocesos.
Uso básico de concurrentHashMap
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());
}
}resultado
{a=1, b=2, c=3}
1
null
{a=1, b=2, c=3, d=5}Para otras API más, busque automáticamente
Aprendizaje del código fuente
ConcurrentHashMap implementa las interfaces ConcurrentMap y Serializable, y hereda AbstractMap
Nombre del Atributo |
efecto |
Observación |
MAXIMA CAPACIDAD |
La capacidad máxima de la matriz de tablas hash |
para juicio |
CAPACIDAD_DEFAULT |
La capacidad predeterminada de la tabla hash (es una potencia de 2) |
inicializado a 16 |
MAX_ARRAY_SIZE |
Tamaño máximo de matriz (no una potencia de 2) requerido por toArray y métodos relacionados. |
Inicializado a Integer.MAX_VALUE - 8 |
FACTOR DE CARGA |
factor de carga |
El valor predeterminado es 0,75 |
TREEIFY_UMBRAL |
Umbral de árbol (más de 8 en árbol rojo-negro) |
Convertir lista enlazada a árbol rojo-negro |
UNTREEIFY_UMBRAL |
Umbral para conversión a lista enlazada |
Menos de 6 en una lista enlazada |
MIN_TRANSFER_STRIDE |
Convertido a una capacidad mínima en forma de árbol |
|
MIN_TRANSFER_STRIDE |
umbral de migración |
El valor predeterminado es 16 |
RESIZE_STAMP_BITS |
Base de expansión |
Fijo 16 es para expansión |
MAX_RESIZADORES |
Umbral máximo para subprocesos de expansión simultáneos |
|
RESIZE_STAMP_SHIFT |
Valor de cálculo de la expansión |
Juicio y valor de cálculo para expansión de capacidad |
Implementación detallada del código fuente:
//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);
}
}
}por fin
La estructura de datos de concurrentHashMap es similar a la de hashmap, y la gran diferencia se ha comparado anteriormente. La razón principal es usar este HashMap concurrente para resolver operaciones de mapas en escenarios concurrentes, de lo contrario puede causar accidentes. Por supuesto, 1.7 también es resistente. Puedes aprender más sobre esto tú mismo.
Referencias
https://www.bilibili.com/video/BV1x741117jq/?vd_source=7d0e42b081e08cb3cefaea55cc1fa8b7
http://static.kancloud.cn/alex_wsc/java_source_interview/187499