Mike Hearn mikehearn

## espresso-notes.md

      
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                mikehearn
                / espresso-notes.md
            
            
              Created
              January 20, 2021 13:56
            
              
                Espresso architecture notes
              
          
    Here are some rough notes on things observed in the codebase - not by the Espresso authors so may all be totally wrong.
Native components

Espresso is mostly written in Java but has some C components as well. These serve two purposes:

The espresso engine can be compiled with native-image down to a shared library so it no longer needs hotspot and runs AOT. This is called “libespresso”
Native code components from OpenJDK that use internal HotSpot APIs can be loaded. This allows a high degree of code re-use and means that unlike most JVM implementations, this one doesn’t need to implement the JDK class library, not even tricky parts in java.base or internal modules - in fact the classes you’d find in the java.base module in a regular OpenJDK should work as long as it’s of the right versions.

OpenJDK native code components include libjava, libjimage etc. These can be loaded as genuinely native components and also (it appears) via Sulong, which on GraalVM EE would give you sandboxing of these compon

  
## build-jfx-jdk.sh
#!/usr/bin/env bash

#
# To use, unpack a regular JDK somewhere and set JDK_HOME to point to it. The default here expects a JDK 15 early access
# in the same directory but you can set JDK_HOME to anything.
#

JDK_HOME=${JDK_HOME:-$PWD/jdk-15.jdk/Contents/Home}

#

## nodejvm1.java
import net.plan99.nodejs.NodeJS;

public class Demo {
    public static void main(String[] args) {
        int result = NodeJS.runJS(() ->
            NodeJS.eval("return 2 + 3 + 4").asInt()
        );
        System.out.println(result);
    }
}

## kotin-native-win32.kt
typealias WSTR = CPointer<ShortVar>

private fun WSTR.toKString(): String = memScoped {
    // Figure out how much memory we need after UTF-8 conversion.
    val sz = WideCharToMultiByte(CP_UTF8, WC_ERR_INVALID_CHARS, this@toKString, -1, null, 0, null, null)
    // Now convert to UTF-8 and from there, a String.
    val utf8 = allocArray<ByteVar>(sz)
    val r = WideCharToMultiByte(CP_UTF8, WC_ERR_INVALID_CHARS, this@toKString, -1, utf8, sz, null, null)
    if (r == 0) throw RuntimeException("Could not convert to UTF-8")
    utf8.toKString()

## di-helpers.kt
package net.corda.node.internal

import java.time.Clock
import java.time.Duration
import java.time.Instant
import java.time.ZoneId
import kotlin.properties.ReadWriteProperty
import kotlin.reflect.KProperty

/**

## hello.html
<html>
  <head>
    <title>Hello World!</title>
    <style>
      div.centered {
          padding: 1em;
          position: absolute;
          top: 50%;
          left: 50%;
          margin-right: -50%;

## hello.js
// Run like this:  jjs -fx hello.js
load("fx:base.js");
load("fx:controls.js");
load("fx:graphics.js");
// Set the title bar.
$STAGE.title = "Hello World!";
// Create a button and place it in a layout that will center it.
var button = new Button();
button.text = "Say 'Hello World'";
button.onAction = function() print("Hello World!");

## AmazonSearch.kt
enum SortBy {
  Featured,
  Relevance,
  PriceLowToHigh,
  PriceHighToLow,
  Reviews
}

@PermazenType
class AmazonSearch(

## jlink --list-plugins
/Library/Java/JavaVirtualMachines/jdk-9.jdk/Contents/Home/bin/jlink --list-plugins

List of available plugins:

Plugin Name: class-for-name
Option: --class-for-name
Description: Class optimization: convert Class.forName calls to constant loads.

Plugin Name: compress
Option: --compress=<0|1|2>[:filter=<pattern-list>]

## tinyram-opcodes.cpp
enum tinyram_opcode {
    tinyram_opcode_AND    = 0b00000,
    tinyram_opcode_OR     = 0b00001,
    tinyram_opcode_XOR    = 0b00010,
    tinyram_opcode_NOT    = 0b00011,
    tinyram_opcode_ADD    = 0b00100,
    tinyram_opcode_SUB    = 0b00101,

    // Multiplications
    tinyram_opcode_MULL   = 0b00110,
	#!/usr/bin/env bash

	#
	# To use, unpack a regular JDK somewhere and set JDK_HOME to point to it. The default here expects a JDK 15 early access
	# in the same directory but you can set JDK_HOME to anything.
	#

	JDK_HOME=${JDK_HOME:-$PWD/jdk-15.jdk/Contents/Home}

	#
	import net.plan99.nodejs.NodeJS;

	public class Demo {
	public static void main(String[] args) {
	int result = NodeJS.runJS(() ->
	NodeJS.eval("return 2 + 3 + 4").asInt()
	);
	System.out.println(result);
	}
	}
	typealias WSTR = CPointer<ShortVar>

	private fun WSTR.toKString(): String = memScoped {
	// Figure out how much memory we need after UTF-8 conversion.
	val sz = WideCharToMultiByte(CP_UTF8, WC_ERR_INVALID_CHARS, this@toKString, -1, null, 0, null, null)
	// Now convert to UTF-8 and from there, a String.
	val utf8 = allocArray<ByteVar>(sz)
	val r = WideCharToMultiByte(CP_UTF8, WC_ERR_INVALID_CHARS, this@toKString, -1, utf8, sz, null, null)
	if (r == 0) throw RuntimeException("Could not convert to UTF-8")
	utf8.toKString()
	package net.corda.node.internal

	import java.time.Clock
	import java.time.Duration
	import java.time.Instant
	import java.time.ZoneId
	import kotlin.properties.ReadWriteProperty
	import kotlin.reflect.KProperty

	/**
	<html>
	<head>
	<title>Hello World!</title>
	<style>
	div.centered {
	padding: 1em;
	position: absolute;
	top: 50%;
	left: 50%;
	margin-right: -50%;
	// Run like this: jjs -fx hello.js
	load("fx:base.js");
	load("fx:controls.js");
	load("fx:graphics.js");
	// Set the title bar.
	$STAGE.title = "Hello World!";
	// Create a button and place it in a layout that will center it.
	var button = new Button();
	button.text = "Say 'Hello World'";
	button.onAction = function() print("Hello World!");
	enum SortBy {
	Featured,
	Relevance,
	PriceLowToHigh,
	PriceHighToLow,
	Reviews
	}

	@PermazenType
	class AmazonSearch(
	/Library/Java/JavaVirtualMachines/jdk-9.jdk/Contents/Home/bin/jlink --list-plugins

	List of available plugins:

	Plugin Name: class-for-name
	Option: --class-for-name
	Description: Class optimization: convert Class.forName calls to constant loads.

	Plugin Name: compress
	Option: --compress=<0\|1\|2>[:filter=<pattern-list>]
	enum tinyram_opcode {
	tinyram_opcode_AND = 0b00000,
	tinyram_opcode_OR = 0b00001,
	tinyram_opcode_XOR = 0b00010,
	tinyram_opcode_NOT = 0b00011,
	tinyram_opcode_ADD = 0b00100,
	tinyram_opcode_SUB = 0b00101,

	// Multiplications
	tinyram_opcode_MULL = 0b00110,