Rust Developer Guide

Prerequisites

Before getting started, ensure you have the following dependencies installed on your system:

• Wabt: Install the latest version of WebAssembly Binary Toolkit. Instructions can be found on the GitHub repository.

• Clang and CMake: Install these if they are not already on your system.

• For macOS users, LLVM can be installed via Homebrew:

  brew install llvm

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Install Fluent Scaffold CLI tool

To install the Fluent scaffold CLI tool, run the following command in your terminal:

cargo install gblend

To create a project, run the following in your terminal:

gblend

After installing the Fluent build tool, you can initialize a new project and choose the Rust option to bootstrap the starter project.

Project Structure

.
├── Cargo.toml
├── Makefile
├── deployer
│   ├── deployer.js
│   └── package.json
├── src
│   ├── lib.rs
└── 

Getting Started

For this guide, we will be working with the lib.rs file located in the src folder.

src/lib.rs

#![cfg_attr(target_arch = "wasm32", no_std)]
extern crate fluentbase_sdk;

use fluentbase_sdk::{basic_entrypoint, SharedAPI};

#[derive(Default)]
struct GREETING;

impl GREETING {
    fn deploy<SDK: SharedAPI>(&self) {
        // any custom deployment logic here
    }
    fn main<SDK: SharedAPI>(&self) {
        // b"Hello, world": "b" here tells the compiler that the string should be treated as a byte sequence. 
        // This is called a byte string literal.
        const HELLO: &[u8] = b"Hello, world";
        SDK::write(HELLO.as_ptr(), HELLO.len() as u32);
    }
}
basic_entrypoint!(GREETING);

In this snippet, we can see how easy it is to interact with the Fluent VM. We only need to call the SDK, initialize the string, and transform it into bytes, which is the format supported by rWasm.

Compiling the Rust Smart Contract

Understanding the deployment process starts with comprehending the role of the Makefile. This file compiles Rust code into Wasm & rWasm and generates the necessary binaries that will be embedded in a tx for deployment.

make

Executing this command compiles the code and produces two files: greeting.wasm and greeting.rwasm which is utilized for deployment purposes.

Deploying the Contract

To initiate deployment, navigate to the deployer directory using the following command:

cd deployer

Once there, execute the following command to install any dependencies:

npm install

Subsequently, run this command to deploy the contract:

node deploy-contract.js --dev ../bin/greeting.wasm

Upon successful deployment, the receipt of your deployment transaction will be displayed, confirming the smart contract deployment on Fluent using the Fluent SDK.

To view your deployed Fluent contract, navigate to the Fluent Devnet Explorer. From there, you can input your token address to explore your deployed contract.