ConcurrentHashMap源码解析（JDK1.8）
package java.util.concurrent;
import java.io.ObjectStreamField;
import java.io.Serializable;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.util.*;
import java.util.concurrent.atomic.AtomicReference;
import java.util.concurrent.locks.LockSupport;
import java.util.concurrent.locks.ReentrantLock;
import java.util.function.*;
import java.util.stream.Stream;
public class ConcurrentHashMap<K, V> extends AbstractMap<K, V>
implements ConcurrentMap<K, V>, Serializable {
private static final long serialVersionUID = 7249069246763182397L;
/* ---------------- Constants -------------- */
/**
* node数组最大容量
*/
private static final int MAXIMUM_CAPACITY = 1 << 30;
/**
* 默认初始值，必须是2的幂数
*/
private static final int DEFAULT_CAPACITY = 16;
/**
* 数组可能最大值，需要与toArray（）相关方法关联
*/
static final int MAX_ARRAY_SIZE = Integer.MAX_VALUE - 8;
/**
* 并发级别，遗留下来的，为兼容以前的版本
*/
private static final int DEFAULT_CONCURRENCY_LEVEL = 16;
/**
* 负载因子
*/
private static final float LOAD_FACTOR = 0.75f;
/**
* 链表转树的阀值，如果table[i]下面的链表长度大于8时就转化为数
*/
static final int TREEIFY_THRESHOLD = 8;
/**
* 树转链表的阀值，小于等于6是转为链表，仅在扩容tranfer时才可能树转链表
*/
static final int UNTREEIFY_THRESHOLD = 6;
/**
* 在转变成树之前，还会有一次判断，只有键值对数量大于 64 才会发生转换。
* 这是为了避免在哈希表建立初期，多个键值对恰好被放入了同一个链表中而导致不必要的转化。
*/
static final int MIN_TREEIFY_CAPACITY = 64;
/**
* Minimum number of rebinnings per transfer step. Ranges are
* subdivided to allow multiple resizer threads. This value
* serves as a lower bound to avoid resizers encountering
* excessive memory contention. The value should be at least
* DEFAULT_CAPACITY.
*/
private static final int MIN_TRANSFER_STRIDE = 16;
/**
* The number of bits used for generation stamp in sizeCtl.
* Must be at least 6 for 32bit arrays.
*/
private static int RESIZE_STAMP_BITS = 16;
/**
* 2^15-1，help resize的最大线程数
*/
private static final int MAX_RESIZERS = (1 << (32 - RESIZE_STAMP_BITS)) - 1;
/**
* 32-16=16，sizeCtl中记录size大小的偏移量
*/
private static final int RESIZE_STAMP_SHIFT = 32 - RESIZE_STAMP_BITS;
/*
* Encodings for Node hash fields. See above for explanation.
*/
static final int MOVED = -1; // hash for forwarding nodes （forwarding nodes的hash值）、标示位
static final int TREEBIN = -2; // hash值是-2 表示这是一个TreeBin节点
static final int RESERVED = -3; // hash for transient reservations
static final int HASH_BITS = 0x7fffffff; // usable bits of normal node hash （ReservationNode的hash值）
/**
* 可用处理器数量
*/
static final int NCPU = Runtime.getRuntime().availableProcessors();
/**
* For serialization compatibility.
*/
private static final ObjectStreamField[] serialPersistentFields = {
new ObjectStreamField("segments", Segment[].class),
new ObjectStreamField("segmentMask", Integer.TYPE),
new ObjectStreamField("segmentShift", Integer.TYPE)
};
/* ---------------- Nodes -------------- */
/**
* Node是最核心的内部类，它包装了key-value键值对，所有插入ConcurrentHashMap的数据都包装在这里面。
* 它与HashMap中的定义很相似，但是但是有一些差别，它对value和next属性设置了volatile同步锁，
* 它不允许调用setValue方法直接改变Node的value域，它增加了find方法辅助map.get()方法。
*/
static class Node<K, V> implements Map.Entry<K, V> {
final int hash;
final K key;
//val和next都会在扩容时发生变化，所以加上volatile来保持可见性和禁止重排序
volatile V val;
volatile Node<K, V> next;
Node(int hash, K key, V val, Node<K, V> next) {
this.hash = hash;
this.key = key;
this.val = val;
this.next = next;
}
public final K getKey() {
return key;
}
public final V getValue() {
return val;
}
/**
* HashMap中Node类的hashCode()方法中的代码为：Objects.hashCode(key) ^ Objects.hashCode(value)
* 而Objects.hashCode(key)最终也是调用了 key.hashCode()，但是效果一样
*/
public final int hashCode() {
return key.hashCode() ^ val.hashCode();
}
public final String toString() {
return key + "=" + val;
}
//不允许直接改变value的值
public final V setValue(V value) {
throw new UnsupportedOperationException();
}
/**
* HashMap使用if (o == this)，且嵌套if；ConcurrentHashMap使用&&
*/
public final boolean equals(Object o) {
Object k, v, u;
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 == (u = val) || v.equals(u)));
}
/**
* 增加find方法辅助get方法 ，HashMap中的Node类中没有此方法
*/
Node<K, V> find(int h, Object k) {
Node<K, V> e = this;
if (k != null) {
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 -------------- */
/**
* 对hashCode进行再散列，算法为(h ^ (h >>> 16)) & HASH_BITS
*/
static final int spread(int h) {
return (h ^ (h >>> 16)) & HASH_BITS;
}
/**
* 返回大于等于count的最小的2的幂次方
*/
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;
}
/**
* Returns x's Class if it is of the form "class C implements
* Comparable<C>", else null.
*/
static Class<?> comparableClassFor(Object x) {
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;
}
/**
* Returns k.compareTo(x) if x matches kc (k's screened comparable
* class), else 0.
*/
@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));
}
/* ---------------- Table element access -------------- */
/*
* Volatile access methods are used for table elements as well as
* elements of in-progress next table while resizing. All uses of
* the tab arguments must be null checked by callers. All callers
* also paranoically precheck that tab's length is not zero (or an
* equivalent check), thus ensuring that any index argument taking
* the form of a hash value anded with (length - 1) is a valid
* index. Note that, to be correct wrt arbitrary concurrency
* errors by users, these checks must operate on local variables,
* which accounts for some odd-looking inline assignments below.
* Note that calls to setTabAt always occur within locked regions,
* and so in principle require only release ordering, not
* full volatile semantics, but are currently coded as volatile
* writes to be conservative.
*/
/**
* 获得在i位置上的Node节点
*/
@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);
}
/**
* 利用CAS算法设置i位置上的Node节点（将c和table[i]比较，相同则插入v）。
*/
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);
}
/**
* 利用volatile方法设置第i个节点的值，这个操作一定是成功的。
*/
static final <K, V> void setTabAt(Node<K, V>[] tab, int i, Node<K, V> v) {
U.putObjectVolatile(tab, ((long) i << ASHIFT) + ABASE, v);
}
/* ---------------- Fields -------------- */
/**
* 存放node的数组,大小是2的幂次方
*/
transient volatile Node<K, V>[] table;
/**
* 扩容时用于存放数据的变量，扩容完成后会置为null。
*/
private transient volatile Node<K, V>[] nextTable;
/**
* 记录容器的容量大小，通过CAS更新
*/
private transient volatile long baseCount;
/**
* 负数代表正在进行初始化或扩容操作 ,其中-1代表正在初始化 ,-N 表示有N-1个线程正在进行扩容操作
* 正数或0代表hash表还没有被初始化，这个数值表示初始化或下一次进行扩容的大小，类似于扩容阈值。
* 它的值始终是当前ConcurrentHashMap容量的0.75倍，这与loadfactor是对应的。实际容量>=sizeCtl，则扩容。
*/
private transient volatile int sizeCtl;//控制标识符
/**
* The next table index (plus one) to split while resizing.
*/
private transient volatile int transferIndex;
/**
* 自旋锁 （锁定通过 CAS） 在调整大小和/或创建 CounterCells 时使用。
* 在CounterCell类更新value中会使用，功能类似显示锁和内置锁，性能更好
*/
private transient volatile int cellsBusy;
/**
* counter cell表，长度总为2的幂次
*/
private transient volatile CounterCell[] counterCells;
// views
private transient KeySetView<K, V> keySet;
private transient ValuesView<K, V> values;
private transient EntrySetView<K, V> entrySet;
/* ---------------- Public operations -------------- */
/**
* 默认的构造函数
*/
public ConcurrentHashMap() {
}
/**
* 指定容量的构造函数
*
* @param initialCapacity 初始化容量
* @throws IllegalArgumentException if the initial capacity of
* elements is negative
*/
public ConcurrentHashMap(int initialCapacity) {
if (initialCapacity < 0)
throw new IllegalArgumentException();
int cap = ((initialCapacity >= (MAXIMUM_CAPACITY >>> 1)) ?
MAXIMUM_CAPACITY :
tableSizeFor(initialCapacity + (initialCapacity >>> 1) + 1));
this.sizeCtl = cap;//初始化sizeCtl
}
/**
* 创建与给定map具有相同映射的新map
*
* @param m the map
*/
public ConcurrentHashMap(Map<? extends K, ? extends V> m) {
this.sizeCtl = DEFAULT_CAPACITY;
putAll(m);
}
/**
* Creates a new, empty map with an initial table size based on
* the given number of elements ({@code initialCapacity}) and
* initial table density ({@code loadFactor}).
*
* @param initialCapacity 初始容量
* @param loadFactor 负载因子,当容量达到initialCapacity*loadFactor时，执行扩容
* @throws IllegalArgumentException if the initial capacity of
* elements is negative or the load factor is nonpositive
* @since 1.6
*/
public ConcurrentHashMap(int initialCapacity, float loadFactor) {
this(initialCapacity, loadFactor, 1);
}
/**
* Creates a new, empty map with an initial table size based on
* the given number of elements ({@code initialCapacity}), table
* density ({@code loadFactor}), and number of concurrently
* updating threads ({@code concurrencyLevel}).
*
* @param initialCapacity 初始容量
* @param loadFactor 负载因子,当容量达到initialCapacity*loadFactor时，执行扩容
* @param concurrencyLevel 预估的并发更新线程数
* @throws IllegalArgumentException if the initial capacity is
* negative or the load factor or concurrencyLevel are
* nonpositive
*/
public ConcurrentHashMap(int initialCapacity,
float loadFactor, int concurrencyLevel) {
if (!(loadFactor > 0.0f) || initialCapacity < 0 || concurrencyLevel <= 0)
throw new IllegalArgumentException();
if (initialCapacity < concurrencyLevel) // Use at least as many bins
initialCapacity = concurrencyLevel; // as estimated threads
long size = (long) (1.0 + (long) initialCapacity / loadFactor);
int cap = (size >= (long) MAXIMUM_CAPACITY) ?
MAXIMUM_CAPACITY : tableSizeFor((int) size);
this.sizeCtl = cap;
}
// Original (since JDK1.2) Map methods
/**
* {@inheritDoc}
*/
public int size() {
long n = sumCount();
return ((n < 0L) ? 0 :
(n > (long) Integer.MAX_VALUE) ? Integer.MAX_VALUE :
(int) n);
}
/**
* {@inheritDoc}
*/
public boolean isEmpty() {
return sumCount() <= 0L; // ignore transient negative values
}
/**
* 根据key在Map中找出其对应的value，如果不存在key，则返回null，
* 其中key不允许为null，否则抛异常
* 对于节点可能在链表或树上的情况，需要分别去查找
*
* @throws NullPointerException if the specified key is null
*/
public V get(Object key) {
Node<K, V>[] tab;
Node<K, V> e, p;
int n, eh;
K ek;
int h = spread(key.hashCode());//两次hash计算出hash值
//根据hash值确定节点位置
if ((tab = table) != null && (n = tab.length) > 0 &&
(e = tabAt(tab, (n - 1) & h)) != null) {
// 搜索到的节点key与传入的key相同且不为null,直接返回这个节点
if ((eh = e.hash) == h) {
if ((ek = e.key) == key || (ek != null && key.equals(ek)))
return e.val;
} else if (eh < 0)//如果eh<0 说明这个节点在树上 直接寻找
return (p = e.find(h, key)) != null ? p.val : null;
//否则遍历链表 找到对应的值并返回
while ((e = e.next) != null) {
if (e.hash == h &&
((ek = e.key) == key || (ek != null && key.equals(ek))))
return e.val;
}
}
return null;
}
/**
* 检查table中是否含有key
*
* @param key possible key
* @return {@code true} if and only if the specified object
* is a key in this table, as determined by the
* {@code equals} method; {@code false} otherwise
* @throws NullPointerException if the specified key is null
*/
public boolean containsKey(Object key) {
//直接调用get(int key)方法即可，如果有返回值，则说明是包含key的
return get(key) != null;
}
/**
* 检查在所有映射(k,v)中只要出现一次及以上的v==value，返回true
* 这个方法可能需要完全遍历Map，因此比containsKey要慢的多
*
* @param value value whose presence in this map is to be tested
* @return {@code true} if this map maps one or more keys to the
* specified value
* @throws NullPointerException if the specified value is null
*/
public boolean containsValue(Object value) {
if (value == 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 v;
if ((v = p.val) == value || (v != null && value.equals(v)))
return true;
}
}
return false;
}
/**
* 直接调用putVal(key, value, false)方法
*
* @param key key with which the specified value is to be associated
* @param value value to be associated with the specified key
* @return the previous value associated with {@code key}, or
* {@code null} if there was no mapping for {@code key}
* @throws NullPointerException if the specified key or value is null
*/
public V put(K key, V value) {
return putVal(key, value, false);
}
/**
* putVal方法可以分为以下几步：
* 1、检查key/value是否为空，如果为空，则抛异常，否则进行2
* 2、进入for死循环，进行3
* 3、检查table是否初始化了，如果没有，则调用initTable()进行初始化然后进行 2，否则进行4
* 4、根据key的hash值计算出其应该在table中储存的位置i，取出table[i]的节点用f表示。
* 根据f的不同有如下三种情况：
* 1）如果table[i]==null(即该位置的节点为空，没有发生碰撞)，则利用CAS操作直接存储在该位置，如果CAS操作成功则退出死循环。
* 2）如果table[i]!=null(即该位置已经有其它节点，发生碰撞)，碰撞处理也有两种情况
* 2.1）检查table[i]的节点的hash是否等于MOVED，如果等于，则检测到正在扩容，则帮助其扩容
* 2.2）说明table[i]的节点的hash值不等于MOVED，如果table[i]为链表节点，则将此节点插入链表中即可
* 如果table[i]为树节点，则将此节点插入树中即可。插入成功后，进行 5
* 5、如果table[i]的节点是链表节点，则检查table的第i个位置的链表是否需要转化为数，如果需要则调用treeifyBin函数进行转化
*/
final V putVal(K key, V value, boolean onlyIfAbsent) {
if (key == null || value == null) throw new NullPointerException();// key和value不允许null
int hash = spread(key.hashCode());//两次hash，减少hash冲突，可以均匀分布
int binCount = 0;//i处结点标志，0: 未加入新结点, 2: TreeBin或链表结点数, 其它：链表结点数。主要用于每次加入结点后查看是否要由链表转为红黑树
for (Node<K, V>[] tab = table; ; ) {//CAS经典写法，不成功无限重试
Node<K, V> f;
int n, i, fh;
//检查是否初始化了，如果没有，则初始化
if (tab == null || (n = tab.length) == 0)
tab = initTable();
/**
* i=(n-1)&hash 等价于i=hash%n(前提是n为2的幂次方).即取出table中位置的节点用f表示。 有如下两种情况：
* 1、如果table[i]==null(即该位置的节点为空，没有发生碰撞)，则利用CAS操作直接存储在该位置， 如果CAS操作成功则退出死循环。
* 2、如果table[i]!=null(即该位置已经有其它节点，发生碰撞)
*/
else if ((f = tabAt(tab, i = (n - 1) & hash)) == null) {
if (casTabAt(tab, i, null,
new Node<K, V>(hash, key, value, null)))
break; // no lock when adding to empty bin
} else if ((fh = f.hash) == MOVED)//检查table[i]的节点的hash是否等于MOVED，如果等于，则检测到正在扩容，则帮助其扩容
tab = helpTransfer(tab, f);
else {//table[i]的节点的hash值不等于MOVED。
V oldVal = null;
// 针对首个节点进行加锁操作，而不是segment，进一步减少线程冲突
synchronized (f) {
if (tabAt(tab, i) == f) {
if (fh >= 0) {
binCount = 1;
for (Node<K, V> e = f; ; ++binCount) {
K ek;
// 如果在链表中找到值为key的节点e，直接设置e.val = value即可
if (e.hash == hash &&
((ek = e.key) == key ||
(ek != null && key.equals(ek)))) {
oldVal = e.val;
if (!onlyIfAbsent)
e.val = value;
break;
}
// 如果没有找到值为key的节点，直接新建Node并加入链表即可
Node<K, V> pred = e;
if ((e = e.next) == null) {//插入到链表末尾并跳出循环
pred.next = new Node<K, V>(hash, key,
value, null);
break;
}
}
} else if (f instanceof TreeBin) {// 如果首节点为TreeBin类型，说明为红黑树结构，执行putTreeVal操作
Node<K, V> p;
binCount = 2;
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>＝8，那么转换链表结构为红黑树结构
if (binCount >= TREEIFY_THRESHOLD)
treeifyBin(tab, i);//若length<64,直接tryPresize,两倍table.length;不转红黑树
if (oldVal != null)
return oldVal;
break;
}
}
}
// 计数增加1，有可能触发transfer操作(扩容)
addCount(1L, binCount);
return null;
}
/**
* Copies all of the mappings from the specified map to this one.
* These mappings replace any mappings that this map had for any of the
* keys currently in the specified map.
*
* @param m mappings to be stored in this map
*/
public void putAll(Map<? extends K, ? extends V> m) {
tryPresize(m.size());
for (Map.Entry<? extends K, ? extends V> e : m.entrySet())
putVal(e.getKey(), e.getValue(), false);
}
/**
* Removes the key (and its corresponding value) from this map.
* This method does nothing if the key is not in the map.
*
* @param key the key that needs to be removed
* @return the previous value associated with {@code key}, or
* {@code null} if there was no mapping for {@code key}
* @throws NullPointerException if the specified key is null
*/
public V remove(Object key) {
return replaceNode(key, null, null);
}
/**
* Implementation for the four public remove/replace methods:
* Replaces node value with v, conditional upon match of cv if
* non-null. If resulting value is null, delete.
*/
final V replaceNode(Object key, V value, Object cv) {
int hash = spread(key.hashCode());
for (Node<K, V>[] tab = table; ; ) {
Node<K, V> f;
int n, i, fh;
if (tab == null || (n = tab.length) == 0 ||
(f = tabAt(tab, i = (n - 1) & hash)) == null)
break;
else if ((fh = f.hash) == MOVED)
tab = helpTransfer(tab, f);
else {
V oldVal = null;
boolean validated = false;
synchronized (f) {
if (tabAt(tab, i) == f) {
if (fh >= 0) {
validated = true;
for (Node<K, V> e = f, pred = null; ; ) {
K ek;
if (e.hash == hash &&
((ek = e.key) == key ||
(ek != null && key.equals(ek)))) {
V ev = e.val;
if (cv == null || cv == ev ||
(ev != null && cv.equals(ev))) {
oldVal = ev;
if (value != null)
e.val = value;
else if (pred != null)
pred.next = e.next;
else
setTabAt(tab, i, e.next);
}
break;
}
pred = e;
if ((e = e.next) == null)
break;
}
} else if (f instanceof TreeBin) {
validated = true;
TreeBin<K, V> t = (TreeBin<K, V>) f;
TreeNode<K, V> r, p;
if ((r = t.root) != null &&
(p = r.findTreeNode(hash, key, null)) != null) {
V pv = p.val;
if (cv == null || cv == pv ||
(pv != null && cv.equals(pv))) {
oldVal = pv;
if (value != null)
p.val = value;
else if (t.removeTreeNode(p))
setTabAt(tab, i, untreeify(t.first));
}
}
}
}
}
if (validated) {
if (oldVal != null) {
if (value == null)
addCount(-1L, -1);
return oldVal;
}
break;
}
}
}
return null;
}
/**
* Removes all of the mappings from this map.
*/
public void clear() {
long delta = 0L; // negative number of deletions
int i = 0;
Node<K, V>[] tab = table;
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);
}
}
}
}
if (delta != 0L)
addCount(delta, -1);
}
/**
* Returns a {@link Set} view of the keys contained in this map.
* The set is backed by the map, so changes to the map are
* reflected in the set, and vice-versa. The set supports element
* removal, which removes the corresponding mapping from this map,
* via the {@code Iterator.remove}, {@code Set.remove},
* {@code removeAll}, {@code retainAll}, and {@code clear}
* operations. It does not support the {@code add} or
* {@code addAll} operations.
* <p>
* <p>The view's iterators and spliterators are
* <a href="package-summary.html#Weakly"><i>weakly consistent</i></a>.
* <p>
* <p>The view's {@code spliterator} reports {@link Spliterator#CONCURRENT},
* {@link Spliterator#DISTINCT}, and {@link Spliterator#NONNULL}.
*
* @return the set view
*/
public KeySetView<K, V> keySet() {
KeySetView<K, V> ks;
return (ks = keySet) != null ? ks : (keySet = new KeySetView<K, V>(this, null));
}
/**
* Returns a {@link Collection} view of the values contained in this map.
* The collection is backed by the map, so changes to the map are
* reflected in the collection, and vice-versa. The collection
* supports element removal, which removes the corresponding
* mapping from this map, via the {@code Iterator.remove},
* {@code Collection.remove}, {@code removeAll},
* {@code retainAll}, and {@code clear} operations. It does not
* support the {@code add} or {@code addAll} operations.
* <p>
* <p>The view's iterators and spliterators are
* <a href="package-summary.html#Weakly"><i>weakly consistent</i></a>.
* <p>
* <p>The view's {@code spliterator} reports {@link Spliterator#CONCURRENT}
* and {@link Spliterator#NONNULL}.
*
* @return the collection view
*/
public Collection<V> values() {
ValuesView<K, V> vs;
return (vs = values) != null ? vs : (values = new ValuesView<K, V>(this));
}
/**
* Returns a {@link Set} view of the mappings contained in this map.
* The set is backed by the map, so changes to the map are
* reflected in the set, and vice-versa. The set supports element
* removal, which removes the corresponding mapping from the map,
* via the {@code Iterator.remove}, {@code Set.remove},
* {@code removeAll}, {@code retainAll}, and {@code clear}
* operations.
* <p>
* <p>The view's iterators and spliterators are
* <a href="package-summary.html#Weakly"><i>weakly consistent</i></a>.
* <p>
* <p>The view's {@code spliterator} reports {@link Spliterator#CONCURRENT},
* {@link Spliterator#DISTINCT}, and {@link Spliterator#NONNULL}.
*
* @return the set view
*/
public Set<Map.Entry<K, V>> entrySet() {
EntrySetView<K, V> es;
return (es = entrySet) != null ? es : (entrySet = new EntrySetView<K, V>(this));
}
/**
* Returns the hash code value for this {@link Map}, i.e.,
* the sum of, for each key-value pair in the map,
* {@code key.hashCode() ^ value.hashCode()}.
*
* @return the hash code value for this map
*/
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;
}
/**
* Returns a string representation of this map. The string
* representation consists of a list of key-value mappings (in no
* particular order) enclosed in braces ("{@code {}}"). Adjacent
* mappings are separated by the characters {@code ", "} (comma
* and space). Each key-value mapping is rendered as the key
* followed by an equals sign ("{@code =}") followed by the
* associated value.
*
* @return a string representation of this map
*/
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();
}
/**
* Compares the specified object with this map for equality.
* Returns {@code true} if the given object is a map with the same
* mappings as this map. This operation may return misleading
* results if either map is concurrently modified during execution
* of this method.
*
* @param o object to be compared for equality with this map
* @return {@code true} if the specified object is equal to this map
*/
public boolean equals(Object o) {
if (o != this) {
if (!(o instanceof Map))
return false;
Map<?, ?> m = (Map<?, ?>) o;
Node<K, V>[] t;
int f = (t = table) == null ? 0 : t.length;
Traverser<K, V> it = new Traverser<K, V>(t, f, 0, f);
for (Node<K, V> p; (p = it.advance()) != null; ) {
V val = p.val;
Object v = m.get(p.key);
if (v == null || (v != val && !v.equals(val)))
return false;
}
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;
}
}
return true;
}
/**
* Stripped-down version of helper class used in previous version,
* declared for the sake of serialization compatibility
*/
static class Segment<K, V> extends ReentrantLock implements Serializable {
private static final long serialVersionUID = 2249069246763182397L;
final float loadFactor;
Segment(float lf) {
this.loadFactor = lf;
}
}
/**
* Saves the state of the {@code ConcurrentHashMap} instance to a
* stream (i.e., serializes it).
*
* @param s the stream
* @throws java.io.IOException if an I/O error occurs
* @serialData the key (Object) and value (Object)
* for each key-value mapping, followed by a null pair.
* The key-value mappings are emitted in no particular order.
*/
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
}
/**
* Reconstitutes the instance from a stream (that is, deserializes it).
*
* @param s the stream
* @throws ClassNotFoundException if the class of a serialized object
* could not be found
* @throws java.io.IOException if an I/O error occurs
*/
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;
}
}
// ConcurrentMap methods
/**
* {@inheritDoc}
*
* @return the previous value associated with the specified key,
* or {@code null} if there was no mapping for the key
* @throws NullPointerException if the specified key or value is null
*/
public V putIfAbsent(K key, V value) {
return putVal(key, value, true);
}
/**
* {@inheritDoc}
*
* @throws NullPointerException if the specified key is null
*/
public boolean remove(Object key, Object value) {
if (key == null)
throw new NullPointerException();
return value != null && replaceNode(key, null, value) != null;
}
/**
* {@inheritDoc}
*
* @throws NullPointerException if any of the arguments are null
*/
public boolean replace(K key, V oldValue, V newValue) {
if (key == null || oldValue == null || newValue == null)
throw new NullPointerException();
return replaceNode(key, newValue, oldValue) != null;
}
/**
* {@inheritDoc}
*
* @return the previous value associated with the specified key,
* or {@code null} if there was no mapping for the key
* @throws NullPointerException if the specified key or value is null
*/
public V replace(K key, V value) {
if (key == null || value == null)
throw new NullPointerException();
return replaceNode(key, value, null);
}
// Overrides of JDK8+ Map extension method defaults
/**
* Returns the value to which the specified key is mapped, or the
* given default value if this map contains no mapping for the
* key.
*
* @param key the key whose associated value is to be returned
* @param defaultValue the value to return if this map contains
* no mapping for the given key
* @return the mapping for the key, if present; else the default value
* @throws NullPointerException if the specified key is null
*/
public V getOrDefault(Object key, V defaultValue) {
V v;
return (v = get(key)) == null ? defaultValue : v;
}
public void forEach(BiConsumer<? super K, ? super V> action) {
if (action == 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; ) {
action.accept(p.key, p.val);
}
}
}
public void replaceAll(BiFunction<? super K, ? super V, ? extends V> function) {
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);
if (newValue == null)
throw new NullPointerException();
if (replaceNode(key, newValue, oldValue) != null ||
(oldValue = get(key)) == null)
break;
}
}
}
}
/**
* If the specified key is not already associated with a value,
* attempts to compute its value using the given mapping function
* and enters it into this map unless {@code null}. The entire
* method invocation is performed atomically, so the function is
* applied at most once per key. Some attempted update operations
* on this map by other threads may be blocked while computation
* is in progress, so the computation should be short and simple,
* and must not attempt to update any other mappings of this map.
*
* @param key key with which the specified value is to be associated
* @param mappingFunction the function to compute a value
* @return the current (existing or computed) value associated with
* the specified key, or null if the computed value is null
* @throws NullPointerException if the specified key or mappingFunction
* is null
* @throws IllegalStateException if the computation detectably
* attempts a recursive update to this map that would
* otherwise never complete
* @throws RuntimeException or Error if the mappingFunction does so,
* in which case the mapping is left unestablished
*/
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;
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>();
synchronized (r) {
if (casTabAt(tab, i, null, r)) {
binCount = 1;
Node<K, V> node = null;
try {
if ((val = mappingFunction.apply(key)) != null)
node = new Node<K, V>(h, key, val, null);
} finally {
setTabAt(tab, i, node);
}
}
}
if (binCount != 0)
break;
} else if ((fh = f.hash) == MOVED)
tab = helpTransfer(tab, f);
else {
boolean added = false;
synchronized (f) {
if (tabAt(tab, i) == f) {
if (fh >= 0) {
binCount = 1;
for (Node<K, V> e = f; ; ++binCount) {
K ek;
V ev;
if (e.hash == h &&
((ek = e.key) == key ||
(ek != null && key.equals(ek)))) {
val = e.val;
break;
}
Node<K, V> pred = e;
if ((e = e.next) == null) {
if ((val = mappingFunction.apply(key)) != null) {
added = true;
pred.next = new Node<K, V>(h, key, val, 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 = p.val;
else if ((val = mappingFunction.apply(key)) != null) {
added = true;
t.putTreeVal(h, key, val);
}
}
}
}
if (binCount != 0) {
if (binCount >= TREEIFY_THRESHOLD)
treeifyBin(tab, i);
if (!added)
return val;
break;
}
}
}
if (val != null)
addCount(1L, binCount);
return val;
}
/**
* If the value for the specified key is present, attempts to
* compute a new mapping given the key and its current mapped
* value. The entire method invocation is performed atomically.
* Some attempted update operations on this map by other threads
* may be blocked while computation is in progress, so the
* computation should be short and simple, and must not attempt to
* update any other mappings of this map.
*
* @param key key with which a value may be associated
* @param remappingFunction the function to compute a value
* @return the new value associated with the specified key, or null if none
* @throws NullPointerException if the specified key or remappingFunction
* is null
* @throws IllegalStateException if the computation detectably
* attempts a recursive update to this map that would
* otherwise never complete
* @throws RuntimeException or Error if the remappingFunction does so,
* in which case the mapping is unchanged
*/
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;
}
/**
* Attempts to compute a mapping for the specified key and its
* current mapped value (or {@code null} if there is no current
* mapping). The entire method invocation is performed atomically.
* Some attempted update operations on this map by other threads
* may be blocked while computation is in progress, so the
* computation should be short and simple, and must not attempt to
* update any other mappings of this Map.
*
* @param key key with which the specified value is to be associated
* @param remappingFunction the function to compute a value
* @return the new value associated with the specified key, or null if none
* @throws NullPointerException if the specified key or remappingFunction
* is null
* @throws IllegalStateException if the computation detectably
* attempts a recursive update to this map that would
* otherwise never complete
* @throws RuntimeException or Error if the remappingFunction does so,
* in which case the mapping is unchanged
*/
public V compute(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) {
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;
} 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;
}
}
}
if (delta != 0)
addCount((long) delta, binCount);
return val;
}
/**
* If the specified key is not already associated with a
* (non-null) value, associates it with the given value.
* Otherwise, replaces the value with the results of the given
* remapping function, or removes if {@code null}. The entire
* method invocation is performed atomically. Some attempted
* update operations on this map by other threads may be blocked
* while computation is in progress, so the computation should be
* short and simple, and must not attempt to update any other
* mappings of this Map.
*
* @param key key with which the specified value is to be associated
* @param value the value to use if absent
* @param remappingFunction the function to recompute a value if present
* @return the new value associated with the specified key, or null if none
* @throws NullPointerException if the specified key or the
* remappingFunction is null
* @throws RuntimeException or Error if the remappingFunction does so,
* in which case the mapping is unchanged
*/
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();
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) {
if (casTabAt(tab, i, null, new Node<K, V>(h, key, value, null))) {
delta = 1;
val = value;
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(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;
if ((e = e.next) == null) {
delta = 1;
val = value;
pred.next =
new Node<K, V>(h, key, val, null);
break;
}
}
} 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));
}
}
}
}
if (binCount != 0) {
if (binCount >= TREEIFY_THRESHOLD)
treeifyBin(tab, i);
break;
}
}
}
if (delta != 0)
addCount((long) delta, binCount);
return val;
}
// Hashtable legacy methods
/**
* Legacy method testing if some key maps into the specified value
* in this table. This method is identical in functionality to
* {@link #containsValue(Object)}, and exists solely to ensure
* full compatibility with class {@link java.util.Hashtable},
* which supported this method prior to introduction of the
* Java Collections framework.
*
* @param value a value to search for
* @return {@code true} if and only if some key maps to the
* {@code value} argument in this table as
* determined by the {@code equals} method;
* {@code false} otherwise
* @throws NullPointerException if the specified value is null
*/
public boolean contains(Object value) {
return containsValue(value);
}
/**
* Returns an enumeration of the keys in this table.
*
* @return an enumeration of the keys in this table
* @see #keySet()
*/
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);
}
/**
* Returns an enumeration of the values in this table.
*
* @return an enumeration of the values in this table
* @see #values()
*/
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);
}
// ConcurrentHashMap-only methods
/**
* Returns the number of mappings. This method should be used
* instead of {@link #size} because a ConcurrentHashMap may
* contain more mappings than can be represented as an int. The
* value returned is an estimate; the actual count may differ if
* there are concurrent insertions or removals.
*
* @return the number of mappings
* @since 1.8
*/
public long mappingCount() {
long n = sumCount();
return (n < 0L) ? 0L : n; // ignore transient negative values
}
/**
* Creates a new {@link Set} backed by a ConcurrentHashMap
* from the given type to {@code Boolean.TRUE}.
*
* @param <K> the element type of the returned set
* @return the new set
* @since 1.8
*/
public static <K> KeySetView<K, Boolean> newKeySet() {
return new KeySetView<K, Boolean>
(new ConcurrentHashMap<K, Boolean>(), Boolean.TRUE);
}
/**
* Creates a new {@link Set} backed by a ConcurrentHashMap
* from the given type to {@code Boolean.TRUE}.
*
* @param initialCapacity The implementation performs internal
* sizing to accommodate this many elements.
* @param <K> the element type of the returned set
* @return the new set
* @throws IllegalArgumentException if the initial capacity of
* elements is negative
* @since 1.8
*/
public static <K> KeySetView<K, Boolean> newKeySet(int initialCapacity) {
return new KeySetView<K, Boolean>
(new ConcurrentHashMap<K, Boolean>(initialCapacity), Boolean.TRUE);
}
/**
* Returns a {@link Set} view of the keys in this map, using the
* given common mapped value for any additions (i.e., {@link
* Collection#add} and {@link Collection#addAll(Collection)}).
* This is of course only appropriate if it is acceptable to use
* the same value for all additions from this view.
*
* @param mappedValue the mapped value to use for any additions
* @return the set view
* @throws NullPointerException if the mappedValue is null
*/
public KeySetView<K, V> keySet(V mappedValue) {
if (mappedValue == null)
throw new NullPointerException();
return new KeySetView<K, V>(this, mappedValue);
}
/* ---------------- Special Nodes -------------- */
/**
* A node inserted at head of bins during transfer operations.
*/
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;
}
Node<K, V> find(int h, Object k) {
// loop to avoid arbitrarily deep recursion on forwarding nodes
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;
}
}
}
}
/**
* A place-holder node used in computeIfAbsent and compute
*/
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 -------------- */
/**
* Returns the stamp bits for resizing a table of size n.
* Must be negative when shifted left by RESIZE_STAMP_SHIFT.
*/
static final int resizeStamp(int n) {
return Integer.numberOfLeadingZeros(n) | (1 << (RESIZE_STAMP_BITS - 1));
}
/**
* Initializes table, using the size recorded in sizeCtl.
*/
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;
}
/**
* Adds to count, and if table is too small and not already
* resizing, initiates transfer. If already resizing, helps
* perform transfer if work is available. Rechecks occupancy
* after a transfer to see if another resize is already needed
* because resizings are lagging additions.
*
* @param x the count to add
* @param check if <0, don't check resize, if <= 1 only check if uncontended
*/
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();
}
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();
}
}
}
/**
* Helps transfer if a resize is in progress.
*/
final Node<K, V>[] helpTransfer(Node<K, V>[] tab, Node<K, V> f) {
Node<K, V>[] nextTab;
int sc;
if (tab != null && (f instanceof ForwardingNode) &&
(nextTab = ((ForwardingNode<K, V>) f).nextTable) != null) {
int rs = resizeStamp(tab.length);
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;
}
/**
* Tries to presize table to accommodate the given number of elements.
*
* @param size number of elements (doesn't need to be perfectly accurate)
*/
private final void tryPresize(int size) {
int c = (size >= (MAXIMUM_CAPACITY >>> 1)) ? MAXIMUM_CAPACITY :
tableSizeFor(size + (size >>> 1) + 1);
int sc;
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;
}
}
} else if (c <= sc || n >= MAXIMUM_CAPACITY)
break;
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);
}
}
}
/**
* Moves and/or copies the nodes in each bin to new table. See
* above for explanation.
*/
private final void transfer(Node<K, V>[] tab, Node<K, V>[] nextTab) {
int n = tab.length, stride;
if ((stride = (NCPU > 1) ? (n >>> 3) / NCPU : n) < MIN_TRANSFER_STRIDE)
stride = MIN_TRANSFER_STRIDE; // subdivide range
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;
}
int nextn = nextTab.length;
ForwardingNode<K, V> fwd = new ForwardingNode<K, V>(nextTab);
boolean advance = true;
boolean finishing = false; // to ensure sweep before committing nextTab
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;
if (finishing) {
nextTable = null;
table = nextTab;
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;
}
}
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;
}
}
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;
}
}
}
}
}
}
/* ---------------- Counter support -------------- */
/**
* A padded cell for distributing counts. Adapted from LongAdder
* and Striped64. See their internal docs for explanation.
*/
@sun.misc.Contended
static final class CounterCell {
volatile long value;
CounterCell(long x) {
value = x;
}
}
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;
}
// See LongAdder version for explanation
private final void fullAddCount(long x, boolean wasUncontended) {
int h;
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) {
if (cellsBusy == 0) { // Try to attach new Cell
CounterCell r = new CounterCell(x); // Optimistic create
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;
} else if (!wasUncontended) // CAS already known to fail
wasUncontended = true; // Continue after rehash
else if (U.compareAndSwapLong(a, CELLVALUE, v = a.value, v + x))
break;
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;
} else if (U.compareAndSwapLong(this, BASECOUNT, v = baseCount, v + x))
break; // Fall back on using base
}
}
/* ---------------- Conversion from/to TreeBins -------------- */
/**
* Replaces all linked nodes in bin at given index unless table is
* too small, in which case resizes instead.
*/
private final void treeifyBin(Node<K, V>[] tab, int index) {
Node<K, V> b;
int n, sc;
if (tab != null) {
if ((n = tab.length) < MIN_TREEIFY_CAPACITY)
tryPresize(n << 1);
else if ((b = tabAt(tab, index)) != null && b.hash >= 0) {
synchronized (b) {
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;
}
setTabAt(tab, index, new TreeBin<K, V>(hd));
}
}
}
}
}
/**
* Returns a list on non-TreeNodes replacing those in given list.
*/
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 -------------- */
/**
* Nodes for use in TreeBins
*/
static final class TreeNode<K, V> extends Node<K, V> {
TreeNode<K, V> parent; // red-black tree links
TreeNode<K, V> left;
TreeNode<K, V> right;
TreeNode<K, V> prev; // needed to unlink next upon deletion
boolean red;
TreeNode(int hash, K key, V val, Node<K, V> next,
TreeNode<K, V> parent) {
super(hash, key, val, next);
this.parent = parent;
}
Node<K, V> find(int h, Object k) {
return findTreeNode(h, k, null);
}
/**
* Returns the TreeNode (or null if not found) for the given key
* starting at given root.
*/
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;
}
}
/* ---------------- TreeBins -------------- */
/**
* TreeNodes used at the heads of bins. TreeBins do not hold user
* keys or values, but instead point to list of TreeNodes and
* their root. They also maintain a parasitic read-write lock
* forcing writers (who hold bin lock) to wait for readers (who do
* not) to complete before tree restructuring operations.
*/
static final class TreeBin<K, V> extends Node<K, V> {
TreeNode<K, V> root;
volatile TreeNode<K, V> first;
volatile Thread waiter;
volatile int lockState;
// values for lockState
static final int WRITER = 1; // set while holding write lock
static final int WAITER = 2; // set when waiting for write lock
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;
}
/**
* Creates bin with initial set of nodes headed by b.
*/
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);
}
/**
* Acquires write lock for tree restructuring.
*/
private final void lockRoot() {
if (!U.compareAndSwapInt(this, LOCKSTATE, 0, WRITER))
contendedLock(); // offload to separate method
}
/**
* Releases write lock for tree restructuring.
*/
private final void unlockRoot() {
lockState = 0;
}
/**
* Possibly blocks awaiting root lock.
*/
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);
}
}
/**
* Returns matching node or null if none. Tries to search
* using tree comparisons from root, but continues linear
* search when lock not available.
*/
final Node<K, V> find(int h, Object k) {
if (k != null) {
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;
}
/**
* Finds or adds a node.
*
* @return null if added
*/
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;
}
/**
* Removes the given node, that must be present before this
* call. This is messier than typical red-black deletion code
* because we cannot swap the contents of an interior node
* with a leaf successor that is pinned by "next" pointers
* that are accessible independently of lock. So instead we
* swap the tree linkages.
*
* @return true if now too small, so should be untreeified
*/
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;
}
/* ------------------------------------------------------------ */
// Red-black tree methods, all adapted from CLR
static <K, V> TreeNode<K, V> rotateLeft(TreeNode<K, V> root,
TreeNode<K, V> p) {
TreeNode<K, V> r, pp, rl;
if (p != null && (r = p.right) != null) {
if ((rl = p.right = r.left) != null)
rl.parent = p;
if ((pp = r.parent = p.parent) == null)
(root = r).red = false;
else if (pp.left == p)
pp.left = r;
else
pp.right = r;
r.left = p;
p.parent = r;
}
return root;
}
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;
}
static <K, V> TreeNode<K, V> balanceInsertion(TreeNode<K, V> root,
TreeNode<K, V> x) {
x.red = true;
for (TreeNode<K, V> xp, xpp, xppl, xppr; ; ) {
if ((xp = x.parent) == null) {
x.red = false;
return x;
} else if (!xp.red || (xpp = xp.parent) == null)
return root;
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);
}
}
}
} 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);
}
}
}
}
}
}
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;
}
}
}
}
}
/**
* Recursive invariant check
*/
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;
}
private static final sun.misc.Unsafe U;
private static final long LOCKSTATE;
static {
try {
U = sun.misc.Unsafe.getUnsafe();
Class<?> k = TreeBin.class;
LOCKSTATE = U.objectFieldOffset
(k.getDeclaredField("lockState"));
} catch (Exception e) {
throw new Error(e);
}
}
}
/* ----------------Table Traversal -------------- */
/**
* Records the table, its length, and current traversal index for a
* traverser that must process a region of a forwarded table before
* proceeding with current table.
*/
static final class TableStack<K, V> {
int length;
int index;
Node<K, V>[] tab;
TableStack<K, V> next;
}
/**
* Encapsulates traversal for methods such as containsValue; also
* serves as a base class for other iterators and spliterators.
* <p>
* Method advance visits once each still-valid node that was
* reachable upon iterator construction. It might miss some that
* were added to a bin after the bin was visited, which is OK wrt
* consistency guarantees. Maintaining this property in the face
* of possible ongoing resizes requires a fair amount of
* bookkeeping state that is difficult to optimize away amidst
* volatile accesses. Even so, traversal maintains reasonable
* throughput.
* <p>
* Normally, iteration proceeds bin-by-bin traversing lists.
* However, if the table has been resized, then all future steps
* must traverse both the bin at the current index as well as at
* (index + baseSize); and so on for further resizings. To
* paranoically cope with potential sharing by users of iterators
* across threads, iteration terminates if a bounds checks fails
* for a table read.
*/
static class Traverser<K, V> {
Node<K, V>[] tab; // current table; updated if resized
Node<K, V> next; // the next entry to use
TableStack<K, V> stack, spare; // to save/restore on ForwardingNodes
int index; // index of bin to use next
int baseIndex; // current index of initial table
int baseLimit; // index bound for initial table
final int baseSize; // initial table size
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;
}
/**
* Advances if possible, returning next valid node, or null if none.
*/
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
}
}
/**
* Saves traversal state upon encountering a forwarding node.
*/
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;
}
/**
* Possibly pops traversal state.
*
* @param n length of current table
*/
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;
}
}
/**
* Base of key, value, and entry Iterators. Adds fields to
* Traverser to support iterator.remove.
*/
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();
}
public final boolean hasNext() {
return next != null;
}
public final boolean hasMoreElements() {
return next != null;
}
public final void remove() {
Node<K, V> p;
if ((p = lastReturned) == null)
throw new IllegalStateException();
lastReturned = null;
map.replaceNode(p.key, null, null);
}
}
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);
}
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();
}
}
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();
}
}
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);
}
}
/**
* Exported Entry for EntryIterator
*/
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;
}
}
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;
}
}
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;
}
}
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;
}
}
// Parallel bulk operations
/**
* Computes initial batch value for bulk tasks. The returned value
* is approximately exp2 of the number of times (minus one) to
* split task by two before executing leaf action. This value is
* faster to compute and more convenient to use as a guide to
* splitting than is the depth, since it is used while dividing by
* two anyway.
*/
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;
}
/**
* Performs the given action for each (key, value).
*
* @param parallelismThreshold the (estimated) number of elements
* needed for this operation to be executed in parallel
* @param action the action
* @since 1.8
*/
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();
}
/**
* Performs the given action for each non-null transformation
* of each (key, value).
*
* @param parallelismThreshold the (estimated) number of elements
* needed for this operation to be executed in parallel
* @param transformer a function returning the transformation
* for an element, or null if there is no transformation (in
* which case the action is not applied)
* @param action the action
* @param <U> the return type of the transformer
* @since 1.8
*/
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();
}
/**
* Returns a non-null result from applying the given search
* function on each (key, value), or null if none. Upon
* success, further element processing is suppressed and the
* results of any other parallel invocations of the search
* function are ignored.
*
* @param parallelismThreshold the (estimated) number of elements
* needed for this operation to be executed in parallel
* @param searchFunction a function returning a non-null
* result on success, else null
* @param <U> the return type of the search function
* @return a non-null result from applying the given search
* function on each (key, value), or null if none
* @since 1.8
*/
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();
}
/**
* Returns the result of accumulating the given transformation
* of all (key, value) pairs using the given reducer to
* combine values, or null if none.
*
* @param parallelismThreshold the (estimated) number of elements
* needed for this operation to be executed in parallel
* @param transformer a function returning the transformation
* for an element, or null if there is no transformation (in
* which case it is not combined)
* @param reducer a commutative associative combining function
* @param <U> the return type of the transformer
* @return the result of accumulating the given transformation
* of all (key, value) pairs
* @since 1.8
*/
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();
}
/**
* Returns the result of accumulating the given transformation
* of all (key, value) pairs using the given reducer to
* combine values, and the given basis as an identity value.
*
* @param parallelismThreshold the (estimated) number of elements
* needed for this operation to be executed in parallel
* @param transformer a function returning the transformation
* for an element
* @param basis the identity (initial default value) for the reduction
* @param reducer a commutative associative combining function
* @return the result of accumulating the given transformation
* of all (key, value) pairs
* @since 1.8
*/
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();
}
/**
* Returns the result of accumulating the given transformation
* of all (key, value) pairs using the given reducer to
* combine values, and the given basis as an identity value.
*
* @param parallelismThreshold the (estimated) number of elements
* needed for this operation to be executed in parallel
* @param transformer a function returning the transformation
* for an element
* @param basis the identity (initial default value) for the reduction
* @param reducer a commutative associative combining function
* @return the result of accumulating the given transformation
* of all (key, value) pairs
* @since 1.8
*/
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();
}
/**
* Returns the result of accumulating the given transformation
* of all (key, value) pairs using the given reducer to
* combine values, and the given basis as an identity value.
*
* @param parallelismThreshold the (estimated) number of elements
* needed for this operation to be executed in parallel
* @param transformer a function returning the transformation
* for an element
* @param basis the identity (initial default value) for the reduction
* @param reducer a commutative associative combining function
* @return the result of accumulating the given transformation
* of all (key, value) pairs
* @since 1.8
*/
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();
}
/**
* Performs the given action for each key.
*
* @param parallelismThreshold the (estimated) number of elements
* needed for this operation to be executed in parallel
* @param action the action
* @since 1.8
*/
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();
}
/**
* Performs the given action for each non-null transformation
* of each key.
*
* @param parallelismThreshold the (estimated) number of elements
* needed for this operation to be executed in parallel
* @param transformer a function returning the transformation
* for an element, or null if there is no transformation (in
* which case the action is not applied)
* @param action the action
* @param <U> the return type of the transformer
* @since 1.8
*/
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();
}
/**
* Returns a non-null result from applying the given search
* function on each key, or null if none. Upon success,
* further element processing is suppressed and the results of
* any other parallel invocations of the search function are
* ignored.
*
* @param parallelismThreshold the (estimated) number of elements
* needed for this operation to be executed in parallel
* @param searchFunction a function returning a non-null
* result on success, else null
* @param <U> the return type of the search function
* @return a non-null result from applying the given search
* function on each key, or null if none
* @since 1.8
*/
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();
}
/**
* Returns the result of accumulating all keys using the given
* reducer to combine values, or null if none.
*
* @param parallelismThreshold the (estimated) number of elements
* needed for this operation to be executed in parallel
* @param reducer a commutative associative combining function
* @return the result of accumulating all keys using the given
* reducer to combine values, or null if none
* @since 1.8
*/
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();
}
/**
* Returns the result of accumulating the given transformation
* of all keys using the given reducer to combine values, or
* null if none.
*
* @param parallelismThreshold the (estimated) number of elements
* needed for this operation to be executed in parallel
* @param transformer a function returning the transformation
* for an element, or null if there is no transformation (in
* which case it is not combined)
* @param reducer a commutative associative combining function
* @param <U> the return type of the transformer
* @return the result of accumulating the given transformation
* of all keys
* @since 1.8
*/
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();
}
/**
* Returns the result of accumulating the given transformation
* of all keys using the given reducer to combine values, and
* the given basis as an identity value.
*
* @param parallelismThreshold the (estimated) number of elements
* needed for this operation to be executed in parallel
* @param transformer a function returning the transformation
* for an element
* @param basis the identity (initial default value) for the reduction
* @param reducer a commutative associative combining function
* @return the result of accumulating the given transformation
* of all keys
* @since 1.8
*/
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();
}
/**
* Returns the result of accumulating the given transformation
* of all keys using the given reducer to combine values, and
* the given basis as an identity value.
*
* @param parallelismThreshold the (estimated) number of elements
* needed for this operation to be executed in parallel
* @param transformer a function returning the transformation
* for an element
* @param basis the identity (initial default value) for the reduction
* @param reducer a commutative associative combining function
* @return the result of accumulating the given transformation
* of all keys
* @since 1.8
*/
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();
}
/**
* Returns the result of accumulating the given transformation
* of all keys using the given reducer to combine values, and
* the given basis as an identity value.
*
* @param parallelismThreshold the (estimated) number of elements
* needed for this operation to be executed in parallel
* @param transformer a function returning the transformation
* for an element
* @param basis the identity (initial default value) for the reduction
* @param reducer a commutative associative combining function
* @return the result of accumulating the given transformation
* of all keys
* @since 1.8
*/
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();
}
/**
* Performs the given action for each value.
*
* @param parallelismThreshold the (estimated) number of elements
* needed for this operation to be executed in parallel
* @param action the action
* @since 1.8
*/
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();
}
/**
* Performs the given action for each non-null transformation
* of each value.
*
* @param parallelismThreshold the (estimated) number of elements
* needed for this operation to be executed in parallel
* @param transformer a function returning the transformation
* for an element, or null if there is no transformation (in
* which case the action is not applied)
* @param action the action
* @param <U> the return type of the transformer
* @since 1.8
*/
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();
}
/**
* Returns a non-null result from applying the given search
* function on each value, or null if none. Upon success,
* further element processing is suppressed and the results of
* any other parallel invocations of the search function are
* ignored.
*
* @param parallelismThreshold the (estimated) number of elements
* needed for this operation to be executed in parallel
* @param searchFunction a function returning a non-null
* result on success, else null
* @param <U> the return type of the search function
* @return a non-null result from applying the given search
* function on each value, or null if none
* @since 1.8
*/
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();
}
/**
* Returns the result of accumulating all values using the
* given reducer to combine values, or null if none.
*
* @param parallelismThreshold the (estimated) number of elements
* needed for this operation to be executed in parallel
* @param reducer a commutative associative combining function
* @return the result of accumulating all values
* @since 1.8
*/
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();
}
/**
* Returns the result of accumulating the given transformation
* of all values using the given reducer to combine values, or
* null if none.
*
* @param parallelismThreshold the (estimated) number of elements
* needed for this operation to be executed in parallel
* @param transformer a function returning the transformation
* for an element, or null if there is no transformation (in
* which case it is not combined)
* @param reducer a commutative associative combining function
* @param <U> the return type of the transformer
* @return the result of accumulating the given transformation
* of all values
* @since 1.8
*/
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();
}
/**
* Returns the result of accumulating the given transformation
* of all values using the given reducer to combine values,
* and the given basis as an identity value.
*
* @param parallelismThreshold the (estimated) number of elements
* needed for this operation to be executed in parallel
* @param transformer a function returning the transformation
* for an element
* @param basis the identity (initial default value) for the reduction
* @param reducer a commutative associative combining function
* @return the result of accumulating the given transformation
* of all values
* @since 1.8
*/
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();
}
/**
* Returns the result of accumulating the given transformation
* of all values using the given reducer to combine values,
* and the given basis as an identity value.
*
* @param parallelismThreshold the (estimated) number of elements
* needed for this operation to be executed in parallel
* @param transformer a function returning the transformation
* for an element
* @param basis the identity (initial default value) for the reduction
* @param reducer a commutative associative combining function
* @return the result of accumulating the given transformation
* of all values
* @since 1.8
*/
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();
}
/**
* Returns the result of accumulating the given transformation
* of all values using the given reducer to combine values,
* and the given basis as an identity value.
*
* @param parallelismThreshold the (estimated) number of elements
* needed for this operation to be executed in parallel
* @param transformer a function returning the transformation
* for an element
* @param basis the identity (initial default value) for the reduction
* @param reducer a commutative associative combining function
* @return the result of accumulating the given transformation
* of all values
* @since 1.8
*/
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();
}
/**
* Performs the given action for each entry.
*
* @param parallelismThreshold the (estimated) number of elements
* needed for this operation to be executed in parallel
* @param action the action
* @since 1.8
*/
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();
}
/**
* Performs the given action for each non-null transformation
* of each entry.
*
* @param parallelismThreshold the (estimated) number of elements
* needed for this operation to be executed in parallel
* @param transformer a function returning the transformation
* for an element, or null if there is no transformation (in
* which case the action is not applied)
* @param action the action
* @param <U> the return type of the transformer
* @since 1.8
*/
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();
}
/**
* Returns a non-null result from applying the given search
* function on each entry, or null if none. Upon success,
* further element processing is suppressed and the results of
* any other parallel invocations of the search function are
* ignored.
*
* @param parallelismThreshold the (estimated) number of elements
* needed for this operation to be executed in parallel
* @param searchFunction a function returning a non-null
* result on success, else null
* @param <U> the return type of the search function
* @return a non-null result from applying the given search
* function on each entry, or null if none
* @since 1.8
*/
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();
}
/**
* Returns the result of accumulating all entries using the
* given reducer to combine values, or null if none.
*
* @param parallelismThreshold the (estimated) number of elements
* needed for this operation to be executed in parallel
* @param reducer a commutative associative combining function
* @return the result of accumulating all entries
* @since 1.8
*/
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();
}
/**
* Returns the result of accumulating the given transformation
* of all entries using the given reducer to combine values,
* or null if none.
*
* @param parallelismThreshold the (estimated) number of elements
* needed for this operation to be executed in parallel
* @param transformer a function returning the transformation
* for an element, or null if there is no transformation (in
* which case it is not combined)
* @param reducer a commutative associative combining function
* @param <U> the return type of the transformer
* @return the result of accumulating the given transformation
* of all entries
* @since 1.8
*/
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();
}
/**
* Returns the result of accumulating the given transformation
* of all entries using the given reducer to combine values,
* and the given basis as an identity value.
*
* @param parallelismThreshold the (estimated) number of elements
* needed for this operation to be executed in parallel
* @param transformer a function returning the transformation
* for an element
* @param basis the identity (initial default value) for the reduction
* @param reducer a commutative associative combining function
* @return the result of accumulating the given transformation
* of all entries
* @since 1.8
*/
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();
}
/**
* Returns the result of accumulating the given transformation
* of all entries using the given reducer to combine values,
* and the given basis as an identity value.
*
* @param parallelismThreshold the (estimated) number of elements
* needed for this operation to be executed in parallel
* @param transformer a function returning the transformation
* for an element
* @param basis the identity (initial default value) for the reduction
* @param reducer a commutative associative combining function
* @return the result of accumulating the given transformation
* of all entries
* @since 1.8
*/
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();
}
/**
* Returns the result of accumulating the given transformation
* of all entries using the given reducer to combine values,
* and the given basis as an identity value.
*
* @param parallelismThreshold the (estimated) number of elements
* needed for this operation to be executed in parallel
* @param transformer a function returning the transformation
* for an element
* @param basis the identity (initial default value) for the reduction
* @param reducer a commutative associative combining function
* @return the result of accumulating the given transformation
* of all entries
* @since 1.8
*/
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();
}
/* ----------------Views -------------- */
/**
* Base class for views.
*/
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.
*/
public final void clear() {
map.clear();
}
public final int size() {
return map.size();
}
public final boolean isEmpty() {
return map.isEmpty();
}
// implementations below rely on concrete classes supplying these
// abstract methods
/**
* Returns an iterator over the elements in this collection.
* <p>
* <p>The returned iterator is
* <a href="package-summary.html#Weakly"><i>weakly consistent</i></a>.
*
* @return an iterator over the elements in this collection
*/
public abstract Iterator<E> iterator();
public abstract boolean contains(Object o);
public abstract boolean remove(Object o);
private static final String oomeMsg = "Required array size too large";
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);
}
/**
* Returns a string representation of this collection.
* The string representation consists of the string representations
* of the collection's elements in the order they are returned by
* its iterator, enclosed in square brackets ({@code "[]"}).
* Adjacent elements are separated by the characters {@code ", "}
* (comma and space). Elements are converted to strings as by
* {@link String#valueOf(Object)}.
*
* @return a string representation of this collection
*/
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();
}
public final boolean containsAll(Collection<?> c) {
if (c != this) {
for (Object e : c) {
if (e == null || !contains(e))
return false;
}
}
return true;
}
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;
}
}
/**
* A view of a ConcurrentHashMap as a {@link Set} of keys, in
* which additions may optionally be enabled by mapping to a
* common value. This class cannot be directly instantiated.
* See {@link #keySet() keySet()},
* {@link #keySet(Object) keySet(V)},
* {@link #newKeySet() newKeySet()},
* {@link #newKeySet(int) newKeySet(int)}.
*
* @since 1.8
*/
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));
}
}
}
// -------------------------------------------------------
/**
* Base class for bulk tasks. Repeats some fields and code from
* class Traverser, because we need to subclass CountedCompleter.
*/
@SuppressWarnings("serial")
abstract static class BulkTask<K, V, R> extends CountedCompleter<R> {
Node<K, V>[] tab; // same as Traverser
Node<K, V> next;
TableStack<K, V> stack, spare;
int index;
int baseIndex;
int baseLimit;
final int baseSize;
int batch; // split control
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;
}
}
/**
* Same as Traverser version
*/
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;
}
}
}
}
}
@SuppressWarnings("serial")
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 mechanics
private static final sun.misc.Unsafe U;
private static final long SIZECTL;
private static final long TRANSFERINDEX;
private static final long BASECOUNT;
private static final long CELLSBUSY;
private static final long CELLVALUE;
private static final long ABASE;
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);
}
}
}本文参与 腾讯云自媒体分享计划，分享自作者个人站点/博客。
原始发表：2018-03-22 ，如有侵权请联系 cloudcommunity@tencent.com 删除
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