[K/JS] Make interface subtyping faster and lighter.

2022-09-19 10:26:11 +00:00
parent 03f83ff339
commit a368fc37c7
22 changed files with 572 additions and 287 deletions
@@ -0,0 +1,72 @@
+/*
+ * Copyright 2010-2022 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package kotlin.js
+
+internal fun implement(vararg interfaces: dynamic): BitMask {
+    var maxSize = 1
+    val masks = js("[]")
+
+    for (i in interfaces) {
+        var currentSize = maxSize
+        val imask: BitMask? = i.prototype.`$imask$` ?: i.`$imask$`
+
+        if (imask != null) {
+            masks.push(imask)
+            currentSize = imask.intArray.size
+        }
+
+        val iid: Int? = i.`$metadata$`.iid
+        val iidImask: BitMask? = iid?.let { BitMask(arrayOf(it)) }
+
+        if (iidImask != null) {
+            masks.push(iidImask)
+            currentSize = JsMath.max(currentSize, iidImask.intArray.size)
+        }
+
+        if (currentSize > maxSize) {
+            maxSize = currentSize
+        }
+    }
+
+    val resultIntArray = IntArray(maxSize) { i ->
+        masks.reduce({ acc: Int, it: BitMask ->
+            if (i >= it.intArray.size)
+                acc
+            else
+                acc or it.intArray[i]
+        }, 0)
+    }
+
+    val result = BitMask(emptyArray())
+    result.intArray = resultIntArray
+    return result
+}
+
+internal class BitMask(activeBits: Array<Int>) {
+    var intArray: IntArray = run {
+        if (activeBits.size == 0) {
+            IntArray(0)
+        } else {
+            val max: Int = JsMath.asDynamic().max.apply(null, activeBits)
+            val intArray = IntArray((max shr 5) + 1)
+            for (activeBit in activeBits) {
+                val numberIndex = activeBit shr 5
+                val positionInNumber = activeBit and 31
+                val numberWithSettledBit = 1 shl positionInNumber
+                intArray[numberIndex] = intArray[numberIndex] or numberWithSettledBit
+            }
+            intArray
+        }
+    }
+
+    fun isBitSet(possibleActiveBit: Int): Boolean {
+        val numberIndex = possibleActiveBit shr 5
+        if (numberIndex > intArray.size) return false
+        val positionInNumber = possibleActiveBit and 31
+        val numberWithSettledBit = 1 shl positionInNumber
+        return intArray[numberIndex] and numberWithSettledBit != 0
+    }
+}