What is Polyglot Native?

Video overview of an ahead-of-time compiler for Java bytecode combined with a low-footprint VM
04 August 2017   11039


 Popular general-purpose programming language and computing platform

Execution of JVM-based programs uses bytecode loading and interpretation, just-in-time compilation, and monolithic heaps causes JVM-based programs to start-up slowly with a high memory footprint. In recent years, different projects were developed to address these issues:
ahead-of-time compilation for the JVM (JEP 295) improves on JVM startup time while Scala Native and Kotlin/Native provide language-specific solutions by compiling code with LLVM and providing language-specific runtimes.

Now Polyglot Native is presented an ahead-of-time compiler for Java bytecode combined with a low-footprint VM. With Polyglot Native, programs written in Kotlin, Scala, and other JVM-based languages have minimal startup time as they are compiled to native executables. Footprint of compiled programs is minimized by using a chunked heap and reducingnecessary program metadata.

In this talk, you will see:

  • the architecture of Polyglot Native and compare it to existing projects.
  • live-demo of a project that compiles code from Kotlin, Scala, Java, and C into a single binary executable.
  • intricacies of interoperability between Polyglot Native and C.

What is Web3j?

Small review of lightweight Java and Android library for integration with Ethereum clients
15 December 2017   985

What is webj3?

web3j is a lightweight, highly modular, reactive, type safe Java and Android library for working with Smart Contracts and integrating with clients (nodes) on the Ethereum network:

web3j architecture
Web3j Architecture

This allows you to work with the Ethereum blockchain, without the additional overhead of having to write your own integration code for the platform.

According to the developers, these are the features:

  • Complete implementation of Ethereum's JSON-RPC client API over HTTP and IPC
  • Ethereum wallet support
  • Auto-generation of Java smart contract wrappers to create, deploy, transact with and call smart contracts from native Java code (Solidity and Truffle definition formats supported)
  • Reactive-functional API for working with filters
  • Ethereum Name Service (ENS) support
  • Support for Parity's Personal, and Geth's Personal client APIs
  • Support for Infura, so you don't have to run an Ethereum client yourself
  • Comprehensive integration tests demonstrating a number of the above scenarios
  • Command line tools
  • Android compatible
  • Support for JP Morgan's Quorum via web3j-quorum

It has five runtime dependencies:

  • RxJava for its reactive-functional API
  • OKHttp for HTTP connections
  • Jackson Core for fast JSON serialisation/deserialisation
  • Bouncy Castle (Spongy Castle on Android) for crypto
  • Jnr-unixsocket for *nix IPC (not available on Android)

It also uses JavaPoet for generating smart contract wrappers.

Lear more at GitHub.