[JS IR] Copy paste native-wasm HashMap implementation

Copy from libraries/stdlib/native-wasm/src/kotlin/collections/HashMap.kt

^KT-59001
This commit is contained in:
Alexander Korepanov
2023-06-19 13:14:20 +02:00
committed by Space Team
parent 96b33007e5
commit e26c06f0e1
@@ -0,0 +1,735 @@
/*
* Copyright 2010-2023 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
* that can be found in the LICENSE file.
*/
package kotlin.collections
import kotlin.native.concurrent.isFrozen
import kotlin.native.FreezingIsDeprecated
@OptIn(FreezingIsDeprecated::class)
actual class HashMap<K, V> private constructor(
private var keysArray: Array<K>,
private var valuesArray: Array<V>?, // allocated only when actually used, always null in pure HashSet
private var presenceArray: IntArray,
private var hashArray: IntArray,
private var maxProbeDistance: Int,
private var length: Int
) : MutableMap<K, V> {
private var hashShift: Int = computeShift(hashSize)
private var _size: Int = 0
override actual val size: Int
get() = _size
private var keysView: HashMapKeys<K>? = null
private var valuesView: HashMapValues<V>? = null
private var entriesView: HashMapEntrySet<K, V>? = null
private var isReadOnly: Boolean = false
// ---------------------------- functions ----------------------------
/**
* Creates a new empty [HashMap].
*/
actual constructor() : this(INITIAL_CAPACITY)
/**
* Creates a new empty [HashMap] with the specified initial capacity.
*
* Capacity is the maximum number of entries the map is able to store in current internal data structure.
* When the map gets full by a certain default load factor, its capacity is expanded,
* which usually leads to rebuild of the internal data structure.
*
* @param initialCapacity the initial capacity of the created map.
* Note that the argument is just a hint for the implementation and can be ignored.
*
* @throws IllegalArgumentException if [initialCapacity] is negative.
*/
actual constructor(initialCapacity: Int) : this(
arrayOfUninitializedElements(initialCapacity),
null,
IntArray(initialCapacity),
IntArray(computeHashSize(initialCapacity)),
INITIAL_MAX_PROBE_DISTANCE,
0)
/**
* Creates a new [HashMap] filled with the contents of the specified [original] map.
*/
actual constructor(original: Map<out K, V>) : this(original.size) {
putAll(original)
}
/**
* Creates a new empty [HashMap] with the specified initial capacity and load factor.
*
* Capacity is the maximum number of entries the map is able to store in current internal data structure.
* Load factor is the measure of how full the map is allowed to get in relation to
* its capacity before the capacity is expanded, which usually leads to rebuild of the internal data structure.
*
* @param initialCapacity the initial capacity of the created map.
* Note that the argument is just a hint for the implementation and can be ignored.
* @param loadFactor the load factor of the created map.
* Note that the argument is just a hint for the implementation and can be ignored.
*
* @throws IllegalArgumentException if [initialCapacity] is negative or [loadFactor] is non-positive.
*/
actual constructor(initialCapacity: Int, loadFactor: Float) : this(initialCapacity) {
require(loadFactor > 0) { "Non-positive load factor: $loadFactor" }
}
@PublishedApi
internal fun build(): Map<K, V> {
checkIsMutable()
isReadOnly = true
return if (size > 0) this else EmptyHolder.value()
}
override actual fun isEmpty(): Boolean = _size == 0
override actual fun containsKey(key: K): Boolean = findKey(key) >= 0
override actual fun containsValue(value: V): Boolean = findValue(value) >= 0
override actual operator fun get(key: K): V? {
val index = findKey(key)
if (index < 0) return null
return valuesArray!![index]
}
override actual fun put(key: K, value: V): V? {
checkIsMutable()
val index = addKey(key)
val valuesArray = allocateValuesArray()
if (index < 0) {
val oldValue = valuesArray[-index - 1]
valuesArray[-index - 1] = value
return oldValue
} else {
valuesArray[index] = value
return null
}
}
override actual fun putAll(from: Map<out K, V>) {
checkIsMutable()
putAllEntries(from.entries)
}
override actual fun remove(key: K): V? {
val index = removeKey(key) // mutability gets checked here
if (index < 0) return null
val valuesArray = valuesArray!!
val oldValue = valuesArray[index]
valuesArray.resetAt(index)
return oldValue
}
override actual fun clear() {
checkIsMutable()
// O(length) implementation for hashArray cleanup
for (i in 0..length - 1) {
val hash = presenceArray[i]
if (hash >= 0) {
hashArray[hash] = 0
presenceArray[i] = TOMBSTONE
}
}
keysArray.resetRange(0, length)
valuesArray?.resetRange(0, length)
_size = 0
length = 0
}
override actual val keys: MutableSet<K> get() {
val cur = keysView
return if (cur == null) {
val new = HashMapKeys(this)
if (!isFrozen)
keysView = new
new
} else cur
}
override actual val values: MutableCollection<V> get() {
val cur = valuesView
return if (cur == null) {
val new = HashMapValues(this)
if (!isFrozen)
valuesView = new
new
} else cur
}
override actual val entries: MutableSet<MutableMap.MutableEntry<K, V>> get() {
val cur = entriesView
return if (cur == null) {
val new = HashMapEntrySet(this)
if (!isFrozen)
entriesView = new
new
} else cur
}
override fun equals(other: Any?): Boolean {
return other === this ||
(other is Map<*, *>) &&
contentEquals(other)
}
override fun hashCode(): Int {
var result = 0
val it = entriesIterator()
while (it.hasNext()) {
result += it.nextHashCode()
}
return result
}
override fun toString(): String {
val sb = StringBuilder(2 + _size * 3)
sb.append("{")
var i = 0
val it = entriesIterator()
while (it.hasNext()) {
if (i > 0) sb.append(", ")
it.nextAppendString(sb)
i++
}
sb.append("}")
return sb.toString()
}
// ---------------------------- private ----------------------------
private val capacity: Int get() = keysArray.size
private val hashSize: Int get() = hashArray.size
internal fun checkIsMutable() {
if (isReadOnly) throw UnsupportedOperationException()
}
private fun ensureExtraCapacity(n: Int) {
if (shouldCompact(extraCapacity = n)) {
rehash(hashSize)
} else {
ensureCapacity(length + n)
}
}
private fun shouldCompact(extraCapacity: Int): Boolean {
val spareCapacity = this.capacity - length
val gaps = length - size
return spareCapacity < extraCapacity // there is no room for extraCapacity entries
&& gaps + spareCapacity >= extraCapacity // removing gaps prevents capacity expansion
&& gaps >= this.capacity / 4 // at least 25% of current capacity is occupied by gaps
}
private fun ensureCapacity(minCapacity: Int) {
if (minCapacity < 0) throw OutOfMemoryError() // overflow
if (minCapacity > this.capacity) {
val newSize = AbstractList.newCapacity(this.capacity, minCapacity)
keysArray = keysArray.copyOfUninitializedElements(newSize)
valuesArray = valuesArray?.copyOfUninitializedElements(newSize)
presenceArray = presenceArray.copyOf(newSize)
val newHashSize = computeHashSize(newSize)
if (newHashSize > hashSize) rehash(newHashSize)
}
}
private fun allocateValuesArray(): Array<V> {
val curValuesArray = valuesArray
if (curValuesArray != null) return curValuesArray
val newValuesArray = arrayOfUninitializedElements<V>(capacity)
valuesArray = newValuesArray
return newValuesArray
}
// Null-check for escaping extra boxing for non-nullable keys.
private fun hash(key: K) = if (key == null) 0 else (key.hashCode() * MAGIC) ushr hashShift
private fun compact() {
var i = 0
var j = 0
val valuesArray = valuesArray
while (i < length) {
if (presenceArray[i] >= 0) {
keysArray[j] = keysArray[i]
if (valuesArray != null) valuesArray[j] = valuesArray[i]
j++
}
i++
}
keysArray.resetRange(j, length)
valuesArray?.resetRange(j, length)
length = j
//check(length == size) { "Internal invariant violated during compact: length=$length != size=$size" }
}
private fun rehash(newHashSize: Int) {
if (length > _size) compact()
if (newHashSize != hashSize) {
hashArray = IntArray(newHashSize)
hashShift = computeShift(newHashSize)
} else {
hashArray.fill(0, 0, hashSize)
}
var i = 0
while (i < length) {
if (!putRehash(i++)) {
throw IllegalStateException("This cannot happen with fixed magic multiplier and grow-only hash array. " +
"Have object hashCodes changed?")
}
}
}
private fun putRehash(i: Int): Boolean {
var hash = hash(keysArray[i])
var probesLeft = maxProbeDistance
while (true) {
val index = hashArray[hash]
if (index == 0) {
hashArray[hash] = i + 1
presenceArray[i] = hash
return true
}
if (--probesLeft < 0) return false
if (hash-- == 0) hash = hashSize - 1
}
}
private fun findKey(key: K): Int {
var hash = hash(key)
var probesLeft = maxProbeDistance
while (true) {
val index = hashArray[hash]
if (index == 0) return TOMBSTONE
if (index > 0 && keysArray[index - 1] == key) return index - 1
if (--probesLeft < 0) return TOMBSTONE
if (hash-- == 0) hash = hashSize - 1
}
}
private fun findValue(value: V): Int {
var i = length
while (--i >= 0) {
if (presenceArray[i] >= 0 && valuesArray!![i] == value)
return i
}
return TOMBSTONE
}
internal fun addKey(key: K): Int {
checkIsMutable()
retry@ while (true) {
var hash = hash(key)
// put is allowed to grow maxProbeDistance with some limits (resize hash on reaching limits)
val tentativeMaxProbeDistance = (maxProbeDistance * 2).coerceAtMost(hashSize / 2)
var probeDistance = 0
while (true) {
val index = hashArray[hash]
if (index <= 0) { // claim or reuse hash slot
if (length >= capacity) {
ensureExtraCapacity(1)
continue@retry
}
val putIndex = length++
keysArray[putIndex] = key
presenceArray[putIndex] = hash
hashArray[hash] = putIndex + 1
_size++
if (probeDistance > maxProbeDistance) maxProbeDistance = probeDistance
return putIndex
}
if (keysArray[index - 1] == key) {
return -index
}
if (++probeDistance > tentativeMaxProbeDistance) {
rehash(hashSize * 2) // cannot find room even with extra "tentativeMaxProbeDistance" -- grow hash
continue@retry
}
if (hash-- == 0) hash = hashSize - 1
}
}
}
internal fun removeKey(key: K): Int {
checkIsMutable()
val index = findKey(key)
if (index < 0) return TOMBSTONE
removeKeyAt(index)
return index
}
private fun removeKeyAt(index: Int) {
keysArray.resetAt(index)
removeHashAt(presenceArray[index])
presenceArray[index] = TOMBSTONE
_size--
}
private fun removeHashAt(removedHash: Int) {
var hash = removedHash
var hole = removedHash // will try to patch the hole in hash array
var probeDistance = 0
var patchAttemptsLeft = (maxProbeDistance * 2).coerceAtMost(hashSize / 2) // don't spend too much effort
while (true) {
if (hash-- == 0) hash = hashSize - 1
if (++probeDistance > maxProbeDistance) {
// too far away -- can release the hole, bad case will not happen
hashArray[hole] = 0
return
}
val index = hashArray[hash]
if (index == 0) {
// end of chain -- can release the hole, bad case will not happen
hashArray[hole] = 0
return
}
if (index < 0) {
// TOMBSTONE FOUND
// - <--- [ TS ] ------ [hole] ---> +
// \------------/
// probeDistance
// move tombstone into the hole
hashArray[hole] = TOMBSTONE
hole = hash
probeDistance = 0
} else {
val otherHash = hash(keysArray[index - 1])
// Bad case:
// - <--- [hash] ------ [hole] ------ [otherHash] ---> +
// \------------/
// probeDistance
if ((otherHash - hash) and (hashSize - 1) >= probeDistance) {
// move otherHash into the hole, move the hole
hashArray[hole] = index
presenceArray[index - 1] = hole
hole = hash
probeDistance = 0
}
}
// check how long we're patching holes
if (--patchAttemptsLeft < 0) {
// just place tombstone into the hole
hashArray[hole] = TOMBSTONE
return
}
}
}
internal fun containsEntry(entry: Map.Entry<K, V>): Boolean {
val index = findKey(entry.key)
if (index < 0) return false
return valuesArray!![index] == entry.value
}
internal fun getEntry(entry: Map.Entry<K, V>): MutableMap.MutableEntry<K, V>? {
val index = findKey(entry.key)
return if (index < 0 || valuesArray!![index] != entry.value) {
null
} else {
EntryRef(this, index)
}
}
internal fun getKey(key: K): K? {
val index = findKey(key)
return if (index >= 0) {
keysArray[index]!!
} else {
null
}
}
private fun contentEquals(other: Map<*, *>): Boolean = _size == other.size && containsAllEntries(other.entries)
internal fun containsAllEntries(m: Collection<*>): Boolean {
val it = m.iterator()
while (it.hasNext()) {
val entry = it.next()
try {
@Suppress("UNCHECKED_CAST") // todo: get rid of unchecked cast here somehow
if (entry == null || !containsEntry(entry as Map.Entry<K, V>))
return false
} catch (e: ClassCastException) {
return false
}
}
return true
}
private fun putEntry(entry: Map.Entry<K, V>): Boolean {
val index = addKey(entry.key)
val valuesArray = allocateValuesArray()
if (index >= 0) {
valuesArray[index] = entry.value
return true
}
val oldValue = valuesArray[-index - 1]
if (entry.value != oldValue) {
valuesArray[-index - 1] = entry.value
return true
}
return false
}
private fun putAllEntries(from: Collection<Map.Entry<K, V>>): Boolean {
if (from.isEmpty()) return false
ensureExtraCapacity(from.size)
val it = from.iterator()
var updated = false
while (it.hasNext()) {
if (putEntry(it.next()))
updated = true
}
return updated
}
internal fun removeEntry(entry: Map.Entry<K, V>): Boolean {
checkIsMutable()
val index = findKey(entry.key)
if (index < 0) return false
if (valuesArray!![index] != entry.value) return false
removeKeyAt(index)
return true
}
internal fun removeValue(element: V): Boolean {
checkIsMutable()
val index = findValue(element)
if (index < 0) return false
removeKeyAt(index)
return true
}
internal fun keysIterator() = KeysItr(this)
internal fun valuesIterator() = ValuesItr(this)
internal fun entriesIterator() = EntriesItr(this)
@kotlin.native.internal.CanBePrecreated
private companion object {
private const val MAGIC = -1640531527 // 2654435769L.toInt(), golden ratio
private const val INITIAL_CAPACITY = 8
private const val INITIAL_MAX_PROBE_DISTANCE = 2
private const val TOMBSTONE = -1
private fun computeHashSize(capacity: Int): Int = (capacity.coerceAtLeast(1) * 3).takeHighestOneBit()
private fun computeShift(hashSize: Int): Int = hashSize.countLeadingZeroBits() + 1
}
internal object EmptyHolder {
val value_ = HashMap<Nothing, Nothing>(0).also { it.isReadOnly = true }
fun <K, V> value(): HashMap<K, V> {
@Suppress("UNCHECKED_CAST")
return value_ as HashMap<K, V>
}
}
internal open class Itr<K, V>(
internal val map: HashMap<K, V>
) {
internal var index = 0
internal var lastIndex: Int = -1
init {
initNext()
}
internal fun initNext() {
while (index < map.length && map.presenceArray[index] < 0)
index++
}
fun hasNext(): Boolean = index < map.length
fun remove() {
map.checkIsMutable()
map.removeKeyAt(lastIndex)
lastIndex = -1
}
}
internal class KeysItr<K, V>(map: HashMap<K, V>) : Itr<K, V>(map), MutableIterator<K> {
override fun next(): K {
if (index >= map.length) throw NoSuchElementException()
lastIndex = index++
val result = map.keysArray[lastIndex]
initNext()
return result
}
}
internal class ValuesItr<K, V>(map: HashMap<K, V>) : Itr<K, V>(map), MutableIterator<V> {
override fun next(): V {
if (index >= map.length) throw NoSuchElementException()
lastIndex = index++
val result = map.valuesArray!![lastIndex]
initNext()
return result
}
}
internal class EntriesItr<K, V>(map: HashMap<K, V>) : Itr<K, V>(map),
MutableIterator<MutableMap.MutableEntry<K, V>> {
override fun next(): EntryRef<K, V> {
if (index >= map.length) throw NoSuchElementException()
lastIndex = index++
val result = EntryRef(map, lastIndex)
initNext()
return result
}
internal fun nextHashCode(): Int {
if (index >= map.length) throw NoSuchElementException()
lastIndex = index++
val result = map.keysArray[lastIndex].hashCode() xor map.valuesArray!![lastIndex].hashCode()
initNext()
return result
}
fun nextAppendString(sb: StringBuilder) {
if (index >= map.length) throw NoSuchElementException()
lastIndex = index++
val key = map.keysArray[lastIndex]
if (key == map) sb.append("(this Map)") else sb.append(key)
sb.append('=')
val value = map.valuesArray!![lastIndex]
if (value == map) sb.append("(this Map)") else sb.append(value)
initNext()
}
}
internal class EntryRef<K, V>(
private val map: HashMap<K, V>,
private val index: Int
) : MutableMap.MutableEntry<K, V> {
override val key: K
get() = map.keysArray[index]
override val value: V
get() = map.valuesArray!![index]
override fun setValue(newValue: V): V {
map.checkIsMutable()
val valuesArray = map.allocateValuesArray()
val oldValue = valuesArray[index]
valuesArray[index] = newValue
return oldValue
}
override fun equals(other: Any?): Boolean =
other is Map.Entry<*, *> &&
other.key == key &&
other.value == value
override fun hashCode(): Int = key.hashCode() xor value.hashCode()
override fun toString(): String = "$key=$value"
}
}
internal class HashMapKeys<E> internal constructor(
private val backing: HashMap<E, *>
) : MutableSet<E>, kotlin.native.internal.KonanSet<E>, AbstractMutableSet<E>() {
override val size: Int get() = backing.size
override fun isEmpty(): Boolean = backing.isEmpty()
override fun contains(element: E): Boolean = backing.containsKey(element)
override fun getElement(element: E): E? = backing.getKey(element)
override fun clear() = backing.clear()
override fun add(element: E): Boolean = throw UnsupportedOperationException()
override fun addAll(elements: Collection<E>): Boolean = throw UnsupportedOperationException()
override fun remove(element: E): Boolean = backing.removeKey(element) >= 0
override fun iterator(): MutableIterator<E> = backing.keysIterator()
override fun removeAll(elements: Collection<E>): Boolean {
backing.checkIsMutable()
return super.removeAll(elements)
}
override fun retainAll(elements: Collection<E>): Boolean {
backing.checkIsMutable()
return super.retainAll(elements)
}
}
internal class HashMapValues<V> internal constructor(
val backing: HashMap<*, V>
) : MutableCollection<V>, AbstractMutableCollection<V>() {
override val size: Int get() = backing.size
override fun isEmpty(): Boolean = backing.isEmpty()
override fun contains(element: V): Boolean = backing.containsValue(element)
override fun add(element: V): Boolean = throw UnsupportedOperationException()
override fun addAll(elements: Collection<V>): Boolean = throw UnsupportedOperationException()
override fun clear() = backing.clear()
override fun iterator(): MutableIterator<V> = backing.valuesIterator()
override fun remove(element: V): Boolean = backing.removeValue(element)
override fun removeAll(elements: Collection<V>): Boolean {
backing.checkIsMutable()
return super.removeAll(elements)
}
override fun retainAll(elements: Collection<V>): Boolean {
backing.checkIsMutable()
return super.retainAll(elements)
}
}
/**
* Note: intermediate class with [E] `: Map.Entry<K, V>` is required to support
* [contains] for values that are [Map.Entry] but not [MutableMap.MutableEntry],
* and probably same for other functions.
* This is important because an instance of this class can be used as a result of [Map.entries],
* which should support [contains] for [Map.Entry].
* For example, this happens when upcasting [MutableMap] to [Map].
*
* The compiler enables special type-safe barriers to methods like [contains], which has [UnsafeVariance].
* Changing type from [MutableMap.MutableEntry] to [E] makes the compiler generate barriers checking that
* argument `is` [E] (so technically `is` [Map.Entry]) instead of `is` [MutableMap.MutableEntry].
*
* See also [KT-42248](https://youtrack.jetbrains.com/issue/KT-42428).
*/
internal abstract class HashMapEntrySetBase<K, V, E : Map.Entry<K, V>> internal constructor(
val backing: HashMap<K, V>
) : MutableSet<E>, kotlin.native.internal.KonanSet<E>, AbstractMutableSet<E>() {
override val size: Int get() = backing.size
override fun isEmpty(): Boolean = backing.isEmpty()
override fun contains(element: E): Boolean = backing.containsEntry(element)
override fun getElement(element: E): E? = getEntry(element)
protected abstract fun getEntry(element: Map.Entry<K, V>): E?
override fun clear() = backing.clear()
override fun add(element: E): Boolean = throw UnsupportedOperationException()
override fun addAll(elements: Collection<E>): Boolean = throw UnsupportedOperationException()
override fun remove(element: E): Boolean = backing.removeEntry(element)
override fun containsAll(elements: Collection<E>): Boolean = backing.containsAllEntries(elements)
override fun removeAll(elements: Collection<E>): Boolean {
backing.checkIsMutable()
return super.removeAll(elements)
}
override fun retainAll(elements: Collection<E>): Boolean {
backing.checkIsMutable()
return super.retainAll(elements)
}
}
internal class HashMapEntrySet<K, V> internal constructor(
backing: HashMap<K, V>
) : HashMapEntrySetBase<K, V, MutableMap.MutableEntry<K, V>>(backing) {
override fun getEntry(element: Map.Entry<K, V>): MutableMap.MutableEntry<K, V>? = backing.getEntry(element)
override fun iterator(): MutableIterator<MutableMap.MutableEntry<K, V>> = backing.entriesIterator()
}
// This hash map keeps insertion order.
actual typealias LinkedHashMap<K, V> = HashMap<K, V>