Memory on JVM and JS

benchmarks/build.gradle

@@ -16,6 +16,7 @@ dependencies {
     implementation project(":kmath-commons")
     implementation project(":kmath-koma")
     implementation group: "com.kyonifer", name:"koma-core-ejml", version: "0.12"
+    implementation "org.jetbrains.kotlinx:kotlinx-io-jvm:0.1.5"
     //compile "org.jetbrains.kotlin:kotlin-stdlib-jdk8"
     //jmh project(':kmath-core')
 }

benchmarks/src/jmh/kotlin/scientifik/kmath/structures/NDFieldBenchmark.kt

@@ -61,7 +61,7 @@ open class NDFieldBenchmark {
         val dim = 1000
         val n = 100
 
-        val bufferedField = NDField.auto(intArrayOf(dim, dim), RealField)
+        val bufferedField = NDField.auto(RealField, intArrayOf(dim, dim))
         val specializedField = NDField.real(intArrayOf(dim, dim))
         val genericField = NDField.buffered(intArrayOf(dim, dim), RealField)
         val lazyNDField = NDField.lazy(intArrayOf(dim, dim), RealField)

benchmarks/src/main/kotlin/scientifik/kmath/structures/ComplexNDBenchmark.kt

@@ -1,15 +1,13 @@
 package scientifik.kmath.structures
 
-import scientifik.kmath.operations.Complex
-import scientifik.kmath.operations.toComplex
 import kotlin.system.measureTimeMillis
 
 fun main() {
     val dim = 1000
     val n = 1000
 
-    val realField = NDField.real(intArrayOf(dim, dim))
+    val realField = NDField.real(dim, dim)
-    val complexField = NDField.complex(intArrayOf(dim, dim))
+    val complexField = NDField.complex(dim, dim)
 
 
     val realTime = measureTimeMillis {

benchmarks/src/main/kotlin/scientifik/kmath/structures/NDFieldBenchmark.kt

@@ -9,9 +9,9 @@ fun main(args: Array<String>) {
     val n = 1000
 
     // automatically build context most suited for given type.
-    val autoField = NDField.auto(intArrayOf(dim, dim), RealField)
+    val autoField = NDField.auto(RealField, dim, dim)
     // specialized nd-field for Double. It works as generic Double field as well
-    val specializedField = NDField.real(intArrayOf(dim, dim))
+    val specializedField = NDField.real(dim, dim)
     //A generic boxing field. It should be used for objects, not primitives.
     val genericField = NDField.buffered(intArrayOf(dim, dim), RealField)
 

build.gradle.kts

@@ -2,7 +2,7 @@ import org.jetbrains.kotlin.gradle.dsl.KotlinMultiplatformExtension
 
 buildscript {
     val kotlinVersion: String by rootProject.extra("1.3.21")
-    val ioVersion: String by rootProject.extra("0.1.4")
+    val ioVersion: String by rootProject.extra("0.1.5")
     val coroutinesVersion: String by rootProject.extra("1.1.1")
     val atomicfuVersion: String by rootProject.extra("0.12.1")
 

kmath-core/build.gradle.kts

@@ -12,6 +12,7 @@ kotlin {
     sourceSets {
         val commonMain by getting {
             dependencies {
+                api(project(":kmath-memory"))
                 api(kotlin("stdlib"))
             }
         }

kmath-core/src/commonMain/kotlin/scientifik/kmath/operations/Complex.kt

@@ -1,5 +1,11 @@
 package scientifik.kmath.operations
 
+import scientifik.kmath.structures.Buffer
+import scientifik.kmath.structures.MutableBuffer
+import scientifik.kmath.structures.ObjectBuffer
+import scientifik.memory.MemoryReader
+import scientifik.memory.MemorySpec
+import scientifik.memory.MemoryWriter
 import kotlin.math.*
 
 /**
@@ -67,7 +73,25 @@ data class Complex(val re: Double, val im: Double) : FieldElement<Complex, Compl
 
     val theta: Double get() = atan(im / re)
 
-    companion object
+    companion object : MemorySpec<Complex> {
+        override val objectSize: Int = 16
+
+        override fun MemoryReader.read(offset: Int): Complex =
+            Complex(readDouble(offset), readDouble(offset + 8))
+
+        override fun MemoryWriter.write(offset: Int, value: Complex) {
+            writeDouble(offset, value.re)
+            writeDouble(offset + 8, value.im)
+        }
+    }
 }
 
-fun Double.toComplex() = Complex(this, 0.0)
+fun Double.toComplex() = Complex(this, 0.0)
+
+fun Buffer.Companion.complex(size: Int, init: (Int) -> Complex): Buffer<Complex> {
+    return ObjectBuffer.create(Complex, size, init)
+}
+
+fun MutableBuffer.Companion.complex(size: Int, init: (Int) -> Complex): Buffer<Complex> {
+    return ObjectBuffer.create(Complex, size, init)
+}

kmath-core/src/commonMain/kotlin/scientifik/kmath/structures/ComplexNDField.kt

@@ -3,6 +3,7 @@ package scientifik.kmath.structures
 import scientifik.kmath.operations.Complex
 import scientifik.kmath.operations.ComplexField
 import scientifik.kmath.operations.FieldElement
+import scientifik.kmath.operations.complex
 
 typealias ComplexNDElement = BufferedNDFieldElement<Complex, ComplexField>
 
@@ -128,4 +129,6 @@ operator fun ComplexNDElement.plus(arg: Double) =
     map { it + arg }
 
 operator fun ComplexNDElement.minus(arg: Double) =
-    map { it - arg }
+    map { it - arg }
+
+fun NDField.Companion.complex(vararg shape: Int) = ComplexNDField(shape)

kmath-core/src/commonMain/kotlin/scientifik/kmath/structures/NDAlgebra.kt

@@ -3,6 +3,7 @@ package scientifik.kmath.structures
 import scientifik.kmath.operations.Field
 import scientifik.kmath.operations.Ring
 import scientifik.kmath.operations.Space
+import kotlin.jvm.JvmName
 
 
 /**
@@ -118,7 +119,7 @@ interface NDField<T, F : Field<T>, N : NDStructure<T>> : Field<N>, NDRing<T, F,
         /**
          * Create a nd-field for [Double] values or pull it from cache if it was created previously
          */
-        fun real(shape: IntArray) = realNDFieldCache.getOrPut(shape){RealNDField(shape)}
+        fun real(vararg shape: Int) = realNDFieldCache.getOrPut(shape) { RealNDField(shape) }
 
         /**
          * Create a nd-field with boxing generic buffer
@@ -134,9 +135,9 @@ interface NDField<T, F : Field<T>, N : NDStructure<T>> : Field<N>, NDRing<T, F,
          * Create a most suitable implementation for nd-field using reified class.
          */
         @Suppress("UNCHECKED_CAST")
-        inline fun <reified T : Any, F : Field<T>> auto(shape: IntArray, field: F): BufferedNDField<T, F> =
+        inline fun <reified T : Any, F : Field<T>> auto(field: F, vararg shape: Int): BufferedNDField<T, F> =
             when {
-                T::class == Double::class -> real(shape) as BufferedNDField<T, F>
+                T::class == Double::class -> real(*shape) as BufferedNDField<T, F>
                 else -> BoxingNDField(shape, field, Buffer.Companion::auto)
             }
     }

kmath-core/src/commonMain/kotlin/scientifik/kmath/structures/NDElement.kt

@@ -24,7 +24,7 @@ interface NDElement<T, C, N : NDStructure<T>> : NDStructure<T> {
          * Create a optimized NDArray of doubles
          */
         fun real(shape: IntArray, initializer: RealField.(IntArray) -> Double = { 0.0 }) =
-            NDField.real(shape).produce(initializer)
+            NDField.real(*shape).produce(initializer)
 
 
         fun real1D(dim: Int, initializer: (Int) -> Double = { _ -> 0.0 }) =
@@ -55,7 +55,7 @@ interface NDElement<T, C, N : NDStructure<T>> : NDStructure<T> {
             field: F,
             noinline initializer: F.(IntArray) -> T
         ): BufferedNDFieldElement<T, F> {
-            val ndField = NDField.auto(shape, field)
+            val ndField = NDField.auto(field, *shape)
             return BufferedNDFieldElement(ndField, ndField.produce(initializer).buffer)
         }
     }

kmath-core/src/commonMain/kotlin/scientifik/kmath/structures/ObjectBuffer.kt

@@ -0,0 +1,48 @@
+package scientifik.kmath.structures
+
+import scientifik.memory.*
+
+/**
+ * A non-boxing buffer based on [ByteBuffer] storage
+ */
+open class ObjectBuffer<T : Any>(protected val memory: Memory, protected val spec: MemorySpec<T>) : Buffer<T> {
+
+    override val size: Int get() = memory.size / spec.objectSize
+
+    private val reader = memory.reader()
+
+    override fun get(index: Int): T = reader.read(spec, spec.objectSize * index)
+
+    override fun iterator(): Iterator<T> = (0 until size).asSequence().map { get(it) }.iterator()
+
+
+    companion object {
+        fun <T : Any> create(spec: MemorySpec<T>, size: Int) =
+            ObjectBuffer(Memory.allocate(size * spec.objectSize), spec)
+
+        inline fun <T : Any> create(
+            spec: MemorySpec<T>,
+            size: Int,
+            crossinline initializer: (Int) -> T
+        ): ObjectBuffer<T> =
+            MutableObjectBuffer(Memory.allocate(size * spec.objectSize), spec).also { buffer ->
+                (0 until size).forEach {
+                    buffer[it] = initializer(it)
+                }
+            }
+    }
+}
+
+class MutableObjectBuffer<T : Any>(memory: Memory, spec: MemorySpec<T>) : ObjectBuffer<T>(memory, spec),
+    MutableBuffer<T> {
+
+    private val writer = memory.writer()
+
+    override fun set(index: Int, value: T) = writer.write(spec, spec.objectSize * index, value)
+
+    override fun copy(): MutableBuffer<T> = MutableObjectBuffer(memory.copy(), spec)
+
+    companion object {
+
+    }
+}

kmath-core/src/commonTest/kotlin/scientifik/kmath/structures/ComplexBufferSpecTest.kt

@@ -1,13 +1,14 @@
 package scientifik.kmath.structures
 
-import org.junit.Test
 import scientifik.kmath.operations.Complex
+import scientifik.kmath.operations.complex
+import kotlin.test.Test
 import kotlin.test.assertEquals
 
 class ComplexBufferSpecTest {
     @Test
     fun testComplexBuffer() {
-        val buffer = MutableBuffer.complex(20){Complex(it.toDouble(), -it.toDouble())}
+        val buffer = Buffer.complex(20) { Complex(it.toDouble(), -it.toDouble()) }
         assertEquals(Complex(5.0, -5.0), buffer[5])
     }
 }

kmath-core/src/commonTest/kotlin/scientifik/kmath/structures/NumberNDFieldTest.kt

@@ -63,7 +63,7 @@ class NumberNDFieldTest {
 
     @Test
     fun testInternalContext() {
-        NDField.real(array1.shape).run {
+        NDField.real(*array1.shape).run {
             with(L2Norm) {
                 1 + norm(array1) + exp(array2)
             }

kmath-core/src/jvmMain/kotlin/scientifik/kmath/structures/BufferSpec.kt

@@ -1,44 +0,0 @@
-package scientifik.kmath.structures
-
-import java.nio.ByteBuffer
-
-
-/**
- * A specification for serialization and deserialization objects to buffer (at current buffer position)
- */
-interface BufferSpec<T : Any> {
-    /**
-     * Read an object from buffer in current position
-     */
-    fun ByteBuffer.readObject(): T
-
-    /**
-     * Write object to [ByteBuffer] in current buffer position
-     */
-    fun ByteBuffer.writeObject(value: T)
-}
-
-/**
- * A [BufferSpec] with fixed unit size. Allows storage of any object without boxing.
- */
-interface FixedSizeBufferSpec<T : Any> : BufferSpec<T> {
-    val unitSize: Int
-
-
-    /**
-     * Read an object from buffer in given index (not buffer position
-     */
-    fun ByteBuffer.readObject(index: Int): T {
-        position(index * unitSize)
-        return readObject()
-    }
-
-
-    /**
-     * Put an object in given index
-     */
-    fun ByteBuffer.writeObject(index: Int, obj: T) {
-        position(index * unitSize)
-        writeObject(obj)
-    }
-}

kmath-core/src/jvmMain/kotlin/scientifik/kmath/structures/ComplexBufferSpec.kt

@@ -1,46 +0,0 @@
-package scientifik.kmath.structures
-
-import scientifik.kmath.operations.Complex
-import scientifik.kmath.operations.ComplexField
-import java.nio.ByteBuffer
-
-/**
- * A serialization specification for complex numbers
- */
-object ComplexBufferSpec : FixedSizeBufferSpec<Complex> {
-
-    override val unitSize: Int = 16
-
-    override fun ByteBuffer.readObject(): Complex {
-        val re = double
-        val im = double
-        return Complex(re, im)
-    }
-
-    override fun ByteBuffer.writeObject(value: Complex) {
-        putDouble(value.re)
-        putDouble(value.im)
-    }
-}
-
-/**
- * Create a read-only/mutable buffer which ignores boxing
- */
-fun Buffer.Companion.complex(size: Int): Buffer<Complex> =
-    ObjectBuffer.create(ComplexBufferSpec, size)
-
-inline fun Buffer.Companion.complex(size: Int, crossinline initializer: (Int) -> Complex): Buffer<Complex> =
-    ObjectBuffer.create(ComplexBufferSpec, size, initializer)
-
-fun MutableBuffer.Companion.complex(size: Int) =
-    ObjectBuffer.create(ComplexBufferSpec, size)
-
-inline fun MutableBuffer.Companion.complex(size: Int, crossinline initializer: (Int) -> Complex) =
-    ObjectBuffer.create(ComplexBufferSpec, size, initializer)
-
-fun NDField.Companion.complex(shape: IntArray) = ComplexNDField(shape)
-
-fun NDElement.Companion.complex(shape: IntArray, initializer: ComplexField.(IntArray) -> Complex) =
-    NDField.complex(shape).produce(initializer)
-
-

kmath-core/src/jvmMain/kotlin/scientifik/kmath/structures/ObjectBuffer.kt

@@ -1,39 +0,0 @@
-package scientifik.kmath.structures
-
-import java.nio.ByteBuffer
-
-/**
- * A non-boxing buffer based on [ByteBuffer] storage
- */
-class ObjectBuffer<T : Any>(private val buffer: ByteBuffer, private val spec: FixedSizeBufferSpec<T>) :
-    MutableBuffer<T> {
-    override val size: Int
-        get() = buffer.limit() / spec.unitSize
-
-    override fun get(index: Int): T = with(spec) { buffer.readObject(index) }
-
-    override fun iterator(): Iterator<T> = (0 until size).asSequence().map { get(it) }.iterator()
-
-    override fun set(index: Int, value: T) = with(spec) { buffer.writeObject(index, value) }
-
-    override fun copy(): MutableBuffer<T> {
-        val dup = buffer.duplicate()
-        val copy = ByteBuffer.allocate(dup.capacity())
-        dup.rewind()
-        copy.put(dup)
-        copy.flip()
-        return ObjectBuffer(copy, spec)
-    }
-
-    companion object {
-        fun <T : Any> create(spec: FixedSizeBufferSpec<T>, size: Int) =
-            ObjectBuffer(ByteBuffer.allocate(size * spec.unitSize), spec)
-
-        inline fun <T : Any> create(spec: FixedSizeBufferSpec<T>, size: Int, crossinline initializer: (Int) -> T) =
-            ObjectBuffer(ByteBuffer.allocate(size * spec.unitSize), spec).also { buffer ->
-                (0 until size).forEach {
-                    buffer[it] = initializer(it)
-                }
-            }
-    }
-}

kmath-core/src/jvmMain/kotlin/scientifik/kmath/structures/RealBufferSpec.kt

@@ -1,28 +0,0 @@
-package scientifik.kmath.structures
-
-import scientifik.kmath.operations.Real
-import java.nio.ByteBuffer
-
-object RealBufferSpec : FixedSizeBufferSpec<Real> {
-    override val unitSize: Int = 8
-
-    override fun ByteBuffer.readObject(): Real = Real(double)
-
-    override fun ByteBuffer.writeObject(value: Real) {
-        putDouble(value.value)
-    }
-}
-
-object DoubleBufferSpec : FixedSizeBufferSpec<Double> {
-    override val unitSize: Int = 8
-
-    override fun ByteBuffer.readObject() = double
-
-    override fun ByteBuffer.writeObject(value: Double) {
-        putDouble(value)
-    }
-
-}
-
-fun Double.Companion.createBuffer(size: Int) = ObjectBuffer.create(DoubleBufferSpec, size)
-fun Real.Companion.createBuffer(size: Int) = ObjectBuffer.create(RealBufferSpec, size)

kmath-memory/build.gradle.kts

@@ -0,0 +1,50 @@
+plugins {
+    kotlin("multiplatform")
+}
+
+val ioVersion: String by rootProject.extra
+
+
+kotlin {
+    jvm()
+    js()
+
+    sourceSets {
+        val commonMain by getting {
+            dependencies {
+                api(kotlin("stdlib"))
+            }
+        }
+        val commonTest by getting {
+            dependencies {
+                implementation(kotlin("test-common"))
+                implementation(kotlin("test-annotations-common"))
+            }
+        }
+        val jvmMain by getting {
+            dependencies {
+                api(kotlin("stdlib-jdk8"))
+            }
+        }
+        val jvmTest by getting {
+            dependencies {
+                implementation(kotlin("test"))
+                implementation(kotlin("test-junit"))
+            }
+        }
+        val jsMain by getting {
+            dependencies {
+                api(kotlin("stdlib-js"))
+            }
+        }
+        val jsTest by getting {
+            dependencies {
+                implementation(kotlin("test-js"))
+            }
+        }
+//        mingwMain {
+//        }
+//        mingwTest {
+//        }
+    }
+}

kmath-memory/src/commonMain/kotlin/scientifik/memory/Memory.kt

@@ -0,0 +1,71 @@
+package scientifik.memory
+
+interface Memory {
+    val size: Int
+
+    /**
+     * Get a projection of this memory (it reflects the changes in the parent memory block)
+     */
+    fun view(offset: Int, length: Int): Memory
+
+    /**
+     * Create a copy of this memory, which does not know anything about this memory
+     */
+    fun copy(): Memory
+
+    /**
+     * Create and possibly register a new reader
+     */
+    fun reader(): MemoryReader
+
+    fun writer(): MemoryWriter
+
+    companion object {
+
+    }
+}
+
+interface MemoryReader {
+    val memory: Memory
+
+    fun readDouble(offset: Int): Double
+    fun readFloat(offset: Int): Float
+    fun readByte(offset: Int): Byte
+    fun readShort(offset: Int): Short
+    fun readInt(offset: Int): Int
+    fun readLong(offset: Int): Long
+
+    fun release()
+}
+
+/**
+ * Use the memory for read then release the reader
+ */
+inline fun Memory.read(block: MemoryReader.() -> Unit) {
+    reader().apply(block).apply { release() }
+}
+
+interface MemoryWriter {
+    val memory: Memory
+
+    fun writeDouble(offset: Int, value: Double)
+    fun writeFloat(offset: Int, value: Float)
+    fun writeByte(offset: Int, value: Byte)
+    fun writeShort(offset: Int, value: Short)
+    fun writeInt(offset: Int, value: Int)
+    fun writeLong(offset: Int, value: Long)
+
+    fun release()
+}
+
+/**
+ * Use the memory for write then release the writer
+ */
+inline fun Memory.write(block: MemoryWriter.() -> Unit) {
+    writer().apply(block).apply { release() }
+}
+
+/**
+ * Allocate the most effective platform-specific memory
+ */
+expect fun Memory.Companion.allocate(length: Int): Memory

kmath-memory/src/commonMain/kotlin/scientifik/memory/MemorySpec.kt

@@ -0,0 +1,34 @@
+package scientifik.memory
+
+/**
+ * A specification to read or write custom objects with fixed size in bytes
+ */
+interface MemorySpec<T : Any> {
+    /**
+     * Size of [T] in bytes after serialization
+     */
+    val objectSize: Int
+
+    fun MemoryReader.read(offset: Int): T
+    fun MemoryWriter.write(offset: Int, value: T)
+}
+
+fun <T : Any> MemoryReader.read(spec: MemorySpec<T>, offset: Int): T = spec.run { read(offset) }
+fun <T : Any> MemoryWriter.write(spec: MemorySpec<T>, offset: Int, value: T) = spec.run { write(offset, value) }
+
+inline fun <reified T : Any> MemoryReader.readArray(spec: MemorySpec<T>, offset: Int, size: Int) =
+    Array(size) { i ->
+        spec.run {
+            read(offset + i * objectSize)
+        }
+    }
+
+fun <T : Any> MemoryWriter.writeArray(spec: MemorySpec<T>, offset: Int, array: Array<T>) {
+    spec.run {
+        for (i in 0 until array.size) {
+            write(offset + i * objectSize, array[i])
+        }
+    }
+}
+
+//TODO It is possible to add elastic MemorySpec with unknown object size

kmath-memory/src/jsMain/kotlin/scientifik/memory/DataViewMemory.kt

@@ -0,0 +1,91 @@
+package scientifik.memory
+
+import org.khronos.webgl.ArrayBuffer
+import org.khronos.webgl.DataView
+
+/**
+ * Allocate the most effective platform-specific memory
+ */
+actual fun Memory.Companion.allocate(length: Int): Memory {
+    val buffer = ArrayBuffer(length)
+    return DataViewMemory(DataView(buffer, 0, length))
+}
+
+class DataViewMemory(val view: DataView) : Memory {
+
+    override val size: Int get() = view.byteLength
+
+    override fun view(offset: Int, length: Int): Memory {
+        require(offset >= 0) { "offset shouldn't be negative: $offset" }
+        require(length >= 0) { "length shouldn't be negative: $length" }
+        if (offset + length > size) {
+            throw IndexOutOfBoundsException("offset + length > size: $offset + $length > $size")
+        }
+        return DataViewMemory(DataView(view.buffer, view.byteOffset + offset, length))
+    }
+
+
+    override fun copy(): Memory {
+        TODO("not implemented") //To change body of created functions use File | Settings | File Templates.
+    }
+
+    private val reader = object : MemoryReader {
+        override val memory: Memory get() = this@DataViewMemory
+
+        override fun readDouble(offset: Int): Double = view.getFloat64(offset, false)
+
+        override fun readFloat(offset: Int): Float = view.getFloat32(offset, false)
+
+        override fun readByte(offset: Int): Byte = view.getInt8(offset)
+
+        override fun readShort(offset: Int): Short = view.getInt16(offset, false)
+
+        override fun readInt(offset: Int): Int = view.getInt32(offset, false)
+
+        override fun readLong(offset: Int): Long = (view.getInt32(offset, false).toLong() shl 32) or
+                view.getInt32(offset + 4, false).toLong()
+
+        override fun release() {
+            // does nothing on JS because of GC
+        }
+    }
+
+    override fun reader(): MemoryReader = reader
+
+    private val writer = object : MemoryWriter {
+        override val memory: Memory get() = this@DataViewMemory
+
+        override fun writeDouble(offset: Int, value: Double) {
+            view.setFloat64(offset, value, false)
+        }
+
+        override fun writeFloat(offset: Int, value: Float) {
+            view.setFloat32(offset, value, false)
+        }
+
+        override fun writeByte(offset: Int, value: Byte) {
+            view.setInt8(offset, value)
+        }
+
+        override fun writeShort(offset: Int, value: Short) {
+            view.setUint16(offset, value, false)
+        }
+
+        override fun writeInt(offset: Int, value: Int) {
+            view.setInt32(offset, value, false)
+        }
+
+        override fun writeLong(offset: Int, value: Long) {
+            view.setInt32(offset, (value shr 32).toInt(), littleEndian = false)
+            view.setInt32(offset + 4, (value and 0xffffffffL).toInt(), littleEndian = false)
+        }
+
+        override fun release() {
+            //does nothing on JS
+        }
+
+    }
+
+    override fun writer(): MemoryWriter = writer
+
+}

kmath-memory/src/jvmMain/kotlin/scientifik/memory/ByteBufferMemory.kt

@@ -0,0 +1,93 @@
+package scientifik.memory
+
+import java.nio.ByteBuffer
+
+
+/**
+ * Allocate the most effective platform-specific memory
+ */
+actual fun Memory.Companion.allocate(length: Int): Memory {
+    val buffer = ByteBuffer.allocate(length)
+    return ByteBufferMemory(buffer)
+}
+
+class ByteBufferMemory(
+    val buffer: ByteBuffer,
+    val startOffset: Int = 0,
+    override val size: Int = buffer.limit()
+) : Memory {
+
+
+    @Suppress("NOTHING_TO_INLINE")
+    private inline fun position(o: Int): Int = startOffset + o
+
+    override fun view(offset: Int, length: Int): Memory {
+        if (offset + length > size) error("Selecting a Memory view outside of memory range")
+        return ByteBufferMemory(buffer, position(offset), length)
+    }
+
+    override fun copy(): Memory {
+        val copy = ByteBuffer.allocate(buffer.capacity())
+        buffer.rewind()
+        copy.put(buffer)
+        copy.flip()
+        return ByteBufferMemory(copy)
+
+    }
+
+    private val reader = object : MemoryReader {
+        override val memory: Memory get() = this@ByteBufferMemory
+
+        override fun readDouble(offset: Int) = buffer.getDouble(position(offset))
+
+        override fun readFloat(offset: Int) = buffer.getFloat(position(offset))
+
+        override fun readByte(offset: Int) = buffer.get(position(offset))
+
+        override fun readShort(offset: Int) = buffer.getShort(position(offset))
+
+        override fun readInt(offset: Int) = buffer.getInt(position(offset))
+
+        override fun readLong(offset: Int) = buffer.getLong(position(offset))
+
+        override fun release() {
+            //does nothing on JVM
+        }
+    }
+
+    override fun reader(): MemoryReader = reader
+
+    private val writer = object : MemoryWriter {
+        override val memory: Memory get() = this@ByteBufferMemory
+
+        override fun writeDouble(offset: Int, value: Double) {
+            buffer.putDouble(position(offset), value)
+        }
+
+        override fun writeFloat(offset: Int, value: Float) {
+            buffer.putFloat(position(offset), value)
+        }
+
+        override fun writeByte(offset: Int, value: Byte) {
+            buffer.put(position(offset), value)
+        }
+
+        override fun writeShort(offset: Int, value: Short) {
+            buffer.putShort(position(offset), value)
+        }
+
+        override fun writeInt(offset: Int, value: Int) {
+            buffer.putInt(position(offset), value)
+        }
+
+        override fun writeLong(offset: Int, value: Long) {
+            buffer.putLong(position(offset), value)
+        }
+
+        override fun release() {
+            //does nothing on JVM
+        }
+    }
+
+    override fun writer(): MemoryWriter = writer
+}

kmath-sequential/src/commonMain/kotlin/scientifik/kmath/sequential/BufferStreaming.kt

@@ -1,6 +1,7 @@
 package scientifik.kmath.sequential
 
 import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.channels.Channel
 import kotlinx.coroutines.channels.produce
 import kotlinx.coroutines.isActive
@@ -12,6 +13,7 @@ import scientifik.kmath.structures.BufferFactory
 /**
  * A processor that collects incoming elements into fixed size buffers
  */
+@ExperimentalCoroutinesApi
 class JoinProcessor<T>(
     scope: CoroutineScope,
     bufferSize: Int,
@@ -68,9 +70,11 @@ class SplitProcessor<T>(scope: CoroutineScope) : AbstractProcessor<Buffer<T>, T>
     }
 }
 
+@ExperimentalCoroutinesApi
 fun <T> Producer<T>.chunked(chunkSize: Int, bufferFactory: BufferFactory<T>) =
     JoinProcessor<T>(this, chunkSize, bufferFactory).also { connect(it) }
 
+@ExperimentalCoroutinesApi
 inline fun <reified T : Any> Producer<T>.chunked(chunkSize: Int) =
     JoinProcessor<T>(this, chunkSize, Buffer.Companion::auto).also { connect(it) }
 

settings.gradle.kts

@@ -15,10 +15,11 @@ pluginManagement {
     }
 }
 
-//enableFeaturePreview("GRADLE_METADATA")
+enableFeaturePreview("GRADLE_METADATA")
 
 rootProject.name = "kmath"
 include(
+    ":kmath-memory",
     ":kmath-core",
 //    ":kmath-io",
     ":kmath-coroutines",