pinocchio

Create Solana programs with no dependencies attached.

I've got no dependencies
To hold me down
To make me fret
Or make me frown
I had dependencies
But now I'm free
There are no dependencies on me

Overview

Pinocchio is a zero-dependency library to create Solana programs in Rust. It takes advantage of the way SBF loaders serialize the program input parameters into a byte array that is then passed to the program's entrypoint to define zero-copy types to read the input. Since the communication between a program and SBF loader — either at the first time the program is called or when one program invokes the instructions of another program — is done via a byte array, a program can define its own types. This completely eliminates the dependency on the solana-program crate, which in turn mitigates dependency issues by having a crate specifically designed to create on-chain programs.

As a result, Pinocchio can be used as a replacement for solana-program to write on-chain programs, which are optimized in terms of both compute units consumption and binary size.

The library defines:

• program entrypoint
• core data types
• logging macros
• syscall functions
• access to system accounts (sysvars)
• cross-program invocation

Features

• Zero dependencies and no_std crate
• Efficient entrypoint! macro – no copies or allocations
• Improved CU consumption of cross-program invocations

Getting started

From your project folder:

cargo add pinocchio

This will add pinocchio as a dependency to your project.

Defining the program entrypoint

A Solana program needs to define an entrypoint, which will be called by the runtime to begin the program execution. The entrypoint! macro emits the common boilerplate to set up the program entrypoint. The macro will also set up global allocator and panic handler using the default_allocator! and default_panic_handler! macros.

The entrypoint! is a convenience macro that invokes three other macros to set all symbols required for a program execution:

• program_entrypoint!: declares the program entrypoint
• default_allocator!: declares the default (bump) global allocator
• default_panic_hanlder!: declares the default panic handler

To use the entrypoint! macro, use the following in your entrypoint definition:

use pinocchio::{
  account_info::AccountInfo,
  entrypoint,
  msg,
  ProgramResult,
  pubkey::Pubkey
};

entrypoint!(process_instruction);

pub fn process_instruction(
  program_id: &Pubkey,
  accounts: &[AccountInfo],
  instruction_data: &[u8],
) -> ProgramResult {
  msg!("Hello from my program!");
  Ok(())
}

The information from the input is parsed into their own entities:

• program_id: the ID of the program being called
• accounts: the accounts received
• instruction_data: data for the instruction

pinocchio also offers variations of the program entrypoint (lazy_program_allocator) and global allocator (no_allocator). In order to use these, the program needs to specify the program entrypoint, global allocator and panic handler individually. The entrypoint! macro is equivalent to writing:

program_entrypoint!(process_instruction);
default_allocator!();
default_panic_handler!();

Any of these macros can be replaced by other implementations and pinocchio offers a couple of variants for this.

📌 lazy_program_entrypoint!

The entrypoint! macro looks similar to the "standard" one found in solana-program. It parsers the whole input and provides the program_id, accounts and instruction_data separately. This consumes compute units before the program begins its execution. In some cases, it is beneficial for a program to have more control when the input parsing is happening, even whether the parsing is needed or not — this is the purpose of the lazy_program_entrypoint! macro. This macro only wraps the program input and provides methods to parse the input on demand.

The lazy_entrypoint is suitable for programs that have a single or very few instructions, since it requires the program to handle the parsing, which can become complex as the number of instructions increases. For larger programs, the program_entrypoint! will likely be easier and more efficient to use.

To use the lazy_program_entrypoint! macro, use the following in your entrypoint definition:

use pinocchio::{
  default_allocator,
  default_panic_handler,
  entrypoint::InstructionContext,
  lazy_program_entrypoint,
  msg,
  ProgramResult
};

lazy_program_entrypoint!(process_instruction);
default_allocator!();
default_panic_handler!();

pub fn process_instruction(
  mut context: InstructionContext
) -> ProgramResult {
    msg!("Hello from my lazy program!");
    Ok(())
}

The InstructionContext provides on-demand access to the information of the input:

• available(): number of available accounts
• next_account(): parsers the next available account (can be used as many times as accounts available)
• instruction_data(): parsers the intruction data
• program_id(): parsers the program id

⚠️ Note: The lazy_program_entrypoint! does not set up a global allocator nor a panic handler. A program should explicitly use one of the provided macros to set them up or include its own implementation.

📌 no_allocator!

When writing programs, it can be useful to make sure the program does not attempt to make any allocations. For this cases, pinocchio includes a no_allocator! macro that set a global allocator just panics at any attempt to allocate memory.

To use the no_allocator! macro, use the following in your entrypoint definition:

use pinocchio::{
  account_info::AccountInfo,
  default_panic_handler,
  msg,
  no_allocator,
  program_entrypoint,
  ProgramResult,
  pubkey::Pubkey
};

program_entrypoint!(process_instruction);
default_panic_handler!();
no_allocator!();

pub fn process_instruction(
  program_id: &Pubkey,
  accounts: &[AccountInfo],
  instruction_data: &[u8],
) -> ProgramResult {
  msg!("Hello from `no_std` program!");
  Ok(())
}

⚠️ Note: The no_allocator! macro can also be used in combination with the lazy_program_entrypoint!.

Crate feature: std

By default, pinocchio is a no_std crate. This means that it does not use any code from the standard (std) library. While this does not affect how pinocchio is used, there is a one particular apparent difference. In a no_std environment, the msg! macro does not provide any formatting options since the format! macro requires the std library. In order to use msg! with formatting, the std feature should be enable when adding pinocchio as a dependency:

pinocchio = { version = "0.7.0", features = ["std"] }

Instead of enabling the std feature to be able to format log messages with msg!, it is recommented to use the pinocchio-log crate. This crate provides a lightweight log! macro with better compute units consumption than the standard format! macro without requiring the std library.

Advance entrypoint configuration

The symbols emitted by the entrypoint macros — program entrypoint, global allocator and default panic handler — can only be defined once globally. If the program crate is also intended to be use as a library, it is common practice to define a Cargo feature in your program crate to conditionally enable the module that includes the entrypoint! macro invocation. The convention is to name the feature bpf-entrypoint.

#[cfg(feature = "bpf-entrypoint")]
mod entrypoint {
  use pinocchio::{
    account_info::AccountInfo,
    entrypoint,
    msg,
    ProgramResult,
    pubkey::Pubkey
  };

  entrypoint!(process_instruction);

  pub fn process_instruction(
    program_id: &Pubkey,
    accounts: &[AccountInfo],
    instruction_data: &[u8],
  ) -> ProgramResult {
    msg!("Hello from my program!");
    Ok(())
  }
}

When building the program binary, you must enable the bpf-entrypoint feature:

cargo build-sbf --features bpf-entrypoint

License

The code is licensed under the Apache License Version 2.0

The library in this repository is based/includes code from:

• nitrate
• solana-nostd-entrypoint
• solana-program