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/*
* Scala (https://www.scala-lang.org)
*
* Copyright EPFL and Lightbend, Inc.
*
* Licensed under Apache License 2.0
* (http://www.apache.org/licenses/LICENSE-2.0).
*
* See the NOTICE file distributed with this work for
* additional information regarding copyright ownership.
*/
package scala.jdk
import java.io.{ObjectInputStream, ObjectOutputStream}
import java.util.Spliterator
import java.util.function.{Consumer, LongConsumer}
import java.{lang => jl}
import scala.collection.Stepper.EfficientSplit
import scala.collection.{AnyStepper, Factory, LongStepper, SeqFactory, Stepper, StepperShape, mutable}
import scala.language.implicitConversions
/** A specialized Accumulator that holds `Long`s without boxing, see [[Accumulator]]. */
final class LongAccumulator
extends Accumulator[Long, AnyAccumulator, LongAccumulator]
with mutable.SeqOps[Long, AnyAccumulator, LongAccumulator]
with Serializable {
private[jdk] var current: Array[Long] = LongAccumulator.emptyLongArray
private[jdk] var history: Array[Array[Long]] = LongAccumulator.emptyLongArrayArray
private[jdk] def cumulative(i: Int) = { val x = history(i); x(x.length-1) }
override protected[this] def className: String = "LongAccumulator"
def efficientStepper[S <: Stepper[_]](implicit shape: StepperShape[Long, S]): S with EfficientSplit = {
val st = new LongAccumulatorStepper(this)
val r =
if (shape.shape == StepperShape.LongShape) st
else {
assert(shape.shape == StepperShape.ReferenceShape, s"unexpected StepperShape: $shape")
AnyStepper.ofParLongStepper(st)
}
r.asInstanceOf[S with EfficientSplit]
}
private def expand(): Unit = {
if (index > 0) {
current(current.length-1) = (if (hIndex > 0) { val x = history(hIndex-1); x(x.length-1) } else 0) + index
if (hIndex >= history.length) hExpand()
history(hIndex) = current
hIndex += 1
}
current = new Array[Long](nextBlockSize+1)
index = 0
}
private def hExpand(): Unit = {
if (hIndex == 0) history = new Array[Array[Long]](4)
else history = java.util.Arrays.copyOf(history, history.length << 1)
}
/** Appends an element to this `LongAccumulator`. */
def addOne(a: Long): this.type = {
totalSize += 1
if (index+1 >= current.length) expand()
current(index) = a
index += 1
this
}
/** Result collection consisting of all elements appended so far. */
override def result(): LongAccumulator = this
/** Removes all elements from `that` and appends them to this `LongAccumulator`. */
def drain(that: LongAccumulator): Unit = {
var h = 0
var prev = 0L
var more = true
while (more && h < that.hIndex) {
val cuml = that.cumulative(h)
val n = (cuml - prev).toInt
if (current.length - index - 1 >= n) {
System.arraycopy(that.history(h), 0, current, index, n)
prev = cuml
index += n
h += 1
}
else more = false
}
if (h >= that.hIndex && current.length - index - 1>= that.index) {
if (that.index > 0) System.arraycopy(that.current, 0, current, index, that.index)
index += that.index
}
else {
val slots = (if (index > 0) 1 else 0) + that.hIndex - h
if (hIndex + slots > history.length) {
val n = math.max(4, 1 << (32 - jl.Integer.numberOfLeadingZeros(1 + hIndex + slots)))
history = java.util.Arrays.copyOf(history, n)
}
var pv = if (hIndex > 0) cumulative(hIndex-1) else 0L
if (index > 0) {
val x =
if (index < (current.length >>> 3) && current.length - 1 > 32) {
val ans = java.util.Arrays.copyOf(current, index + 1)
ans(ans.length - 1) = current(current.length - 1)
ans
}
else current
pv = pv + index
x(x.length - 1) = pv
history(hIndex) = x
hIndex += 1
}
while (h < that.hIndex) {
val cuml = that.cumulative(h)
pv = pv + cuml - prev
prev = cuml
val x = that.history(h)
x(x.length - 1) = pv
history(hIndex) = x
h += 1
hIndex += 1
}
index = that.index
current = that.current
}
totalSize += that.totalSize
that.clear()
}
override def clear(): Unit = {
super.clear()
current = LongAccumulator.emptyLongArray
history = LongAccumulator.emptyLongArrayArray
}
/** Retrieves the `ix`th element. */
def apply(ix: Long): Long = {
if (totalSize - ix <= index || hIndex == 0) current((ix - (totalSize - index)).toInt)
else {
val w = seekSlot(ix)
history((w >>> 32).toInt)((w & 0xFFFFFFFFL).toInt)
}
}
/** Retrieves the `ix`th element, using an `Int` index. */
def apply(i: Int): Long = apply(i.toLong)
def update(idx: Long, elem: Long): Unit = {
if (totalSize - idx <= index || hIndex == 0) current((idx - (totalSize - index)).toInt) = elem
else {
val w = seekSlot(idx)
history((w >>> 32).toInt)((w & 0xFFFFFFFFL).toInt) = elem
}
}
def update(idx: Int, elem: Long): Unit = update(idx.toLong, elem)
/** Returns an `Iterator` over the contents of this `LongAccumulator`. The `Iterator` is not specialized. */
def iterator: Iterator[Long] = stepper.iterator
override def foreach[U](f: Long => U): Unit = {
val s = stepper
while (s.hasStep) f(s.nextStep())
}
def map(f: Long => Long): LongAccumulator = {
val b = newSpecificBuilder
val s = stepper
while (s.hasStep)
b.addOne(f(s.nextStep()))
b.result()
}
def flatMap(f: Long => IterableOnce[Long]): LongAccumulator = {
val b = newSpecificBuilder
val s = stepper
while (s.hasStep)
b.addAll(f(s.nextStep()))
b.result()
}
def collect(pf: PartialFunction[Long, Long]): LongAccumulator = {
val b = newSpecificBuilder
val s = stepper
while (s.hasStep) {
val n = s.nextStep()
pf.runWith(b.addOne)(n)
}
b.result()
}
private def filterAccImpl(pred: Long => Boolean, not: Boolean): LongAccumulator = {
val b = newSpecificBuilder
val s = stepper
while (s.hasStep) {
val n = s.nextStep()
if (pred(n) != not) b.addOne(n)
}
b.result()
}
override def filter(pred: Long => Boolean): LongAccumulator = filterAccImpl(pred, not = false)
override def filterNot(pred: Long => Boolean): LongAccumulator = filterAccImpl(pred, not = true)
override def forall(p: Long => Boolean): Boolean = {
val s = stepper
while (s.hasStep)
if (!p(s.nextStep())) return false
true
}
override def exists(p: Long => Boolean): Boolean = {
val s = stepper
while (s.hasStep)
if (p(s.nextStep())) return true
false
}
override def count(p: Long => Boolean): Int = {
var r = 0
val s = stepper
while (s.hasStep)
if (p(s.nextStep())) r += 1
r
}
def countLong(p: Long => Boolean): Long = {
var r = 0L
val s = stepper
while (s.hasStep)
if (p(s.nextStep())) r += 1
r
}
/** Copies the elements in this `LongAccumulator` into an `Array[Long]` */
def toArray: Array[Long] = {
if (totalSize > Int.MaxValue) throw new IllegalArgumentException("Too many elements accumulated for an array: "+totalSize.toString)
val a = new Array[Long](totalSize.toInt)
var j = 0
var h = 0
var pv = 0L
while (h < hIndex) {
val x = history(h)
val cuml = x(x.length-1)
val n = (cuml - pv).toInt
pv = cuml
System.arraycopy(x, 0, a, j, n)
j += n
h += 1
}
System.arraycopy(current, 0, a, j, index)
j += index
a
}
/** Copies the elements in this `LongAccumulator` to a `List` */
override def toList: List[Long] = {
var ans: List[Long] = Nil
var i = index - 1
while (i >= 0) {
ans = current(i) :: ans
i -= 1
}
var h = hIndex - 1
while (h >= 0) {
val a = history(h)
i = (cumulative(h) - (if (h == 0) 0L else cumulative(h-1))).toInt - 1
while (i >= 0) {
ans = a(i) :: ans
i -= 1
}
h -= 1
}
ans
}
/**
* Copy the elements in this `LongAccumulator` to a specified collection.
* Note that the target collection is not specialized.
* Usage example: `acc.to(Vector)`
*/
override def to[C1](factory: Factory[Long, C1]): C1 = {
if (totalSize > Int.MaxValue) throw new IllegalArgumentException("Too many elements accumulated for a Scala collection: "+totalSize.toString)
factory.fromSpecific(iterator)
}
override protected def fromSpecific(coll: IterableOnce[Long]): LongAccumulator = LongAccumulator.fromSpecific(coll)
override protected def newSpecificBuilder: LongAccumulator = LongAccumulator.newBuilder
override def iterableFactory: SeqFactory[AnyAccumulator] = AnyAccumulator
override def empty: LongAccumulator = LongAccumulator.empty
private def writeReplace(): AnyRef = new LongAccumulator.SerializationProxy(this)
}
object LongAccumulator extends collection.SpecificIterableFactory[Long, LongAccumulator] {
private val emptyLongArray = new Array[Long](0)
private val emptyLongArrayArray = new Array[Array[Long]](0)
implicit def toJavaLongAccumulator(ia: LongAccumulator.type): collection.SpecificIterableFactory[jl.Long, LongAccumulator] = LongAccumulator.asInstanceOf[collection.SpecificIterableFactory[jl.Long, LongAccumulator]]
import java.util.{function => jf}
/** A `Supplier` of `LongAccumulator`s, suitable for use with `java.util.stream.LongStream`'s `collect` method. Suitable for `Stream[Long]` also. */
def supplier: jf.Supplier[LongAccumulator] = () => new LongAccumulator
/** A `BiConsumer` that adds an element to an `LongAccumulator`, suitable for use with `java.util.stream.LongStream`'s `collect` method. */
def adder: jf.ObjLongConsumer[LongAccumulator] = (ac: LongAccumulator, a: Long) => ac addOne a
/** A `BiConsumer` that adds a boxed `Long` to an `LongAccumulator`, suitable for use with `java.util.stream.Stream`'s `collect` method. */
def boxedAdder: jf.BiConsumer[LongAccumulator, Long] = (ac: LongAccumulator, a: Long) => ac addOne a
/** A `BiConsumer` that merges `LongAccumulator`s, suitable for use with `java.util.stream.LongStream`'s `collect` method. Suitable for `Stream[Long]` also. */
def merger: jf.BiConsumer[LongAccumulator, LongAccumulator] = (a1: LongAccumulator, a2: LongAccumulator) => a1 drain a2
private def fromArray(a: Array[Long]): LongAccumulator = {
val r = new LongAccumulator
var i = 0
while (i < a.length) { r addOne a(i); i += 1 }
r
}
override def fromSpecific(it: IterableOnce[Long]): LongAccumulator = it match {
case acc: LongAccumulator => acc
case as: collection.immutable.ArraySeq.ofLong => fromArray(as.unsafeArray)
case as: collection.mutable.ArraySeq.ofLong => fromArray(as.array) // this case ensures Array(1).to(Accumulator) doesn't box
case _ => (new LongAccumulator).addAll(it)
}
override def empty: LongAccumulator = new LongAccumulator
override def newBuilder: LongAccumulator = new LongAccumulator
class SerializationProxy[A](@transient private val acc: LongAccumulator) extends Serializable {
@transient private var result: LongAccumulator = _
private def writeObject(out: ObjectOutputStream): Unit = {
out.defaultWriteObject()
val size = acc.sizeLong
out.writeLong(size)
val st = acc.stepper
while (st.hasStep)
out.writeLong(st.nextStep())
}
private def readObject(in: ObjectInputStream): Unit = {
in.defaultReadObject()
val res = new LongAccumulator()
var elems = in.readLong()
while (elems > 0) {
res += in.readLong()
elems -= 1L
}
result = res
}
private def readResolve(): AnyRef = result
}
}
private[jdk] class LongAccumulatorStepper(private val acc: LongAccumulator) extends LongStepper with EfficientSplit {
import java.util.Spliterator._
private var h: Int = 0
private var i: Int = 0
private var a: Array[Long] = if (acc.hIndex > 0) acc.history(0) else acc.current
private var n: Long = if (acc.hIndex > 0) acc.cumulative(0) else acc.index
private var N: Long = acc.totalSize
private def duplicateSelf(limit: Long): LongAccumulatorStepper = {
val ans = new LongAccumulatorStepper(acc)
ans.h = h
ans.i = i
ans.a = a
ans.n = n
ans.N = limit
ans
}
private def loadMore(): Unit = {
h += 1
if (h < acc.hIndex) { a = acc.history(h); n = acc.cumulative(h) - acc.cumulative(h-1) }
else { a = acc.current; n = acc.index }
i = 0
}
def characteristics: Int = ORDERED | SIZED | SUBSIZED | NONNULL
def estimateSize: Long = N
def hasStep: Boolean = N > 0
def nextStep(): Long =
if (n <= 0) throw new NoSuchElementException("next on empty Stepper")
else {
if (i >= n) loadMore()
val ans = a(i)
i += 1
N -= 1
ans
}
def trySplit(): LongStepper =
if (N <= 1) null
else {
val half = N >> 1
val M = (if (h <= 0) 0L else acc.cumulative(h-1)) + i
val R = M + half
val ans = duplicateSelf(half)
if (h < acc.hIndex) {
val w = acc.seekSlot(R)
h = (w >>> 32).toInt
if (h < acc.hIndex) {
a = acc.history(h)
n = acc.cumulative(h) - (if (h > 0) acc.cumulative(h-1) else 0)
}
else {
a = acc.current
n = acc.index
}
i = (w & 0xFFFFFFFFL).toInt
}
else i += half.toInt
N -= half
ans
}
override def spliterator[B >: Long]: Spliterator.OfLong = new LongStepper.LongStepperSpliterator(this) {
// Overridden for efficiency
override def tryAdvance(c: LongConsumer): Boolean =
if (N <= 0) false
else {
if (i >= n) loadMore()
c.accept(a(i))
i += 1
N -= 1
true
}
// Overridden for efficiency
override def tryAdvance(c: Consumer[_ >: jl.Long]): Boolean = (c: AnyRef) match {
case ic: LongConsumer => tryAdvance(ic)
case _ =>
if (N <= 0) false
else {
if (i >= n) loadMore()
c.accept(a(i))
i += 1
N -= 1
true
}
}
// Overridden for efficiency
override def forEachRemaining(c: LongConsumer): Unit =
while (N > 0) {
if (i >= n) loadMore()
val i0 = i
if ((n-i) > N) n = i + N.toInt
while (i < n) {
c.accept(a(i))
i += 1
}
N -= (n - i0)
}
// Overridden for efficiency
override def forEachRemaining(c: Consumer[_ >: jl.Long]): Unit = (c: AnyRef) match {
case ic: LongConsumer => forEachRemaining(ic)
case _ =>
while (N > 0) {
if (i >= n) loadMore()
val i0 = i
if ((n-i) > N) n = i + N.toInt
while (i < n) {
c.accept(a(i))
i += 1
}
N -= (n - i0)
}
}
}
}