Layouts और Structs

import java.lang.foreign.ValueLayout;

public class Main {
    public static void main(String[] args) {
        System.out.println("int size: " + ValueLayout.JAVA_INT.byteSize());
        System.out.println("double size: " + ValueLayout.JAVA_DOUBLE.byteSize());
    }
}

import java.lang.foreign.*;

public class Main {
    public static void main(String[] args) {
        StructLayout point = MemoryLayout.structLayout(
            ValueLayout.JAVA_INT.withName("x"),
            ValueLayout.JAVA_INT.withName("y"));
        System.out.println("Point size: " + point.byteSize());
    }
}

import java.lang.foreign.*;
import java.lang.invoke.VarHandle;

public class Main {
    public static void main(String[] args) {
        StructLayout point = MemoryLayout.structLayout(
            ValueLayout.JAVA_INT.withName("x"),
            ValueLayout.JAVA_INT.withName("y"));
        VarHandle xHandle = point.varHandle(
            MemoryLayout.PathElement.groupElement("x"));
        System.out.println("Built VarHandle for x: " + xHandle);
    }
}

import java.lang.foreign.*;
import java.lang.invoke.VarHandle;

public class Main {
    public static void main(String[] args) {
        StructLayout point = MemoryLayout.structLayout(
            ValueLayout.JAVA_INT.withName("x"),
            ValueLayout.JAVA_INT.withName("y"));
        VarHandle xh = point.varHandle(MemoryLayout.PathElement.groupElement("x"));
        VarHandle yh = point.varHandle(MemoryLayout.PathElement.groupElement("y"));
        try (Arena arena = Arena.ofConfined()) {
            MemorySegment p = arena.allocate(point);
            xh.set(p, 0L, 3);
            yh.set(p, 0L, 4);
            System.out.println("Point = (" + xh.get(p, 0L) + ", " + yh.get(p, 0L) + ")");
        }
    }
}

import java.lang.foreign.*;

public class Main {
    public static void main(String[] args) {
        StructLayout s = MemoryLayout.structLayout(
            ValueLayout.JAVA_BYTE.withName("c"),
            MemoryLayout.paddingLayout(3),
            ValueLayout.JAVA_INT.withName("n"));
        System.out.println("Aligned struct size: " + s.byteSize());
    }
}

import java.lang.foreign.*;

public class Main {
    public static void main(String[] args) {
        SequenceLayout arr = MemoryLayout.sequenceLayout(10, ValueLayout.JAVA_DOUBLE);
        System.out.println("Array bytes: " + arr.byteSize());
    }
}