Building a Rust Program for Solana Reserve-Based Proof-of-Function (RBPF)

In this article, we’ll walk through the process of creating and deploying a Rust program that can be fed into Solana’s Reserve-Based Proof-of-Function (RBPF) to create a decentralized application.

Getting Started

To begin, install the necessary dependencies for Solana and Rust. Run the following command in your terminal:

cargo new solana_hello --lib

This will create a new Rust library project called solana_hello. You can then build and run it with:

cargo build --release
cargo run --release

Building a Hello World Program

The hello.rs file defines our program as a simple function that prints “Hello, World!” to the Solana blockchain. Let’s add some error handling and logging for fun.

use anchor_lang::prelude::*;
declare_id!("3bKgMxR7MwXLzGDfdsW8HsNYSSxRejf6uUF69Mmupfx7");
#[program]
mod pub hello {
use super::*;
pub fn hello() -> Result<(), AnchorError> {
let _ = ask!(get_state_query::state as Result, "account info"?);
OK(())
}
}

In this code, we have added a simple hello function that retrieves the current account information using the get_state_query function. We are also returning a result from this function to indicate whether the operation was successful.

Deploying to Solana

To deploy our program to Solana, we will use the Anchor CLI. Run the following command:

anchor node build --release --output path/to/deploy

This will create a deployment package in path/to/deploy. We can then upload this package to a Solana node using the anchor command.

Adding an Input to RBPF

To use our program in Solana’s RBPF, we need to add an input parameter. In this case, we will define a new input type called hello_input.

Add the following code to the hello.rs file:

use anchor_lang::prelude::*;
declare_id!("3bKgMxR7MwXLzGDfdsW8HsNYSSxRejf6uUF69Mmupfx7");
#[program]
mod pub hello {
use super::*;
pub fn hello(input: hello_input::HelloInput) -> Result<(), AnchorError> {
let _ = ask!(get_state_query::state as Result, "account info"?);
OK(())
}
}

The hello_input type represents a single input parameter. In this case, we are expecting a HelloInput structure with a single field called name.

Creating an RBPF contract

To create an RBPF contract that uses our program as the function to be called, we will define a new contract using Anchor’s contract macro.

use anchor_lang::prelude::*;
declare_id!("3bKgMxR7MwXLzGDfdsW8HsNYSSxRejf6uUF69Mmupfx7");
#[program]
mod pub hello {
use super::*;
pub fn hello(input: hello_input::HelloInput) -> Result<(), AnchorError> {
let _ = ask!(get_state_query::state as Result, "account info"?);
OK(())
}
}
contract MyRBPFContract {
use contract::prelude::*;
use hello::*;
async fn main() -> Result<()> {
let account_id = get_account().await?;
let input = hello_input::HelloInput {
name: b"World".to_vec(),
};
let output = MyRBPFContract::invoke(input, &[]);
OK(())
}
}

In this code, we define a new contract called MyRBPFContract. The main function creates an account and initializes the input parameter using our hello_input type.

Building and Running

To build and run the RBPF contract, run the following commands:

build cargo --release
build anchor node --release --output path/to/deploy

This will create a new deployment package at path/to/deploy. You can then upload this package to a Solana node using the anchor command.