logos-execution-zone/lee/state_machine/src/program/mod.rs

use std::borrow::Cow;

use borsh::{BorshDeserialize, BorshSerialize};
use lee_core::{
    account::AccountWithMetadata,
    from_frame,
    program::{InstructionData, ProgramId, ProgramInput, ProgramOutput},
    to_frame,
};
use risc0_zkvm::{ExecutorEnv, ExecutorEnvBuilder, default_executor};

use crate::error::LeeError;

/// Maximum number of cycles for a public execution.
/// TODO: Make this variable when fees are implemented.
const MAX_NUM_CYCLES_PUBLIC_EXECUTION: u64 = 1024 * 1024 * 32; // 32M cycles

#[derive(Clone, Debug, PartialEq, Eq, BorshSerialize, BorshDeserialize)]
pub struct Program {
    id: ProgramId,
    elf: Cow<'static, [u8]>,
}

impl Program {
    pub fn new(elf: Cow<'static, [u8]>) -> Result<Self, LeeError> {
        let binary = risc0_binfmt::ProgramBinary::decode(elf.as_ref())
            .map_err(LeeError::InvalidProgramBytecode)?;
        let id = binary
            .compute_image_id()
            .map_err(LeeError::InvalidProgramBytecode)?
            .into();
        Ok(Self { id, elf })
    }

    #[must_use]
    pub const fn new_unchecked(id: ProgramId, elf: Cow<'static, [u8]>) -> Self {
        Self { id, elf }
    }

    #[must_use]
    pub const fn id(&self) -> ProgramId {
        self.id
    }

    #[must_use]
    pub fn elf(&self) -> &[u8] {
        &self.elf
    }

    pub fn serialize_instruction<T: BorshSerialize>(
        instruction: T,
    ) -> Result<InstructionData, LeeError> {
        borsh::to_vec(&instruction)
            .map_err(|e| LeeError::InstructionSerializationError(e.to_string()))
    }

    pub(crate) fn execute(
        &self,
        caller_program_id: Option<ProgramId>,
        pre_states: &[AccountWithMetadata],
        instruction_data: &InstructionData,
    ) -> Result<ProgramOutput, LeeError> {
        // Write inputs to the program
        let mut env_builder = ExecutorEnv::builder();
        env_builder.session_limit(Some(MAX_NUM_CYCLES_PUBLIC_EXECUTION));
        self.write_inputs(
            caller_program_id,
            pre_states,
            instruction_data,
            &mut env_builder,
        )?;
        let env = env_builder.build().unwrap();

        // Execute the program (without proving)
        let executor = default_executor();
        let session_info = executor
            .execute(env, self.elf())
            .map_err(|e| LeeError::ProgramExecutionFailed(e.to_string()))?;

        // Get outputs
        let framed = from_frame(&session_info.journal.bytes).ok_or_else(|| {
            LeeError::ProgramExecutionFailed("malformed program journal frame".to_owned())
        })?;
        let program_output = borsh::from_slice(framed)
            .map_err(|e| LeeError::ProgramExecutionFailed(e.to_string()))?;

        Ok(program_output)
    }

    /// Writes inputs to `env_builder` in the order expected by the programs.
    pub fn write_inputs(
        &self,
        caller_program_id: Option<ProgramId>,
        pre_states: &[AccountWithMetadata],
        instruction_data: &[u8],
        env_builder: &mut ExecutorEnvBuilder,
    ) -> Result<(), LeeError> {
        let input = ProgramInput {
            self_program_id: self.id,
            caller_program_id,
            pre_states: pre_states.to_vec(),
            instruction: instruction_data.to_vec(),
        };
        let payload =
            borsh::to_vec(&input).map_err(|e| LeeError::ProgramWriteInputFailed(e.to_string()))?;
        env_builder.write_slice(&to_frame(&payload));
        Ok(())
    }
}

#[cfg(test)]
mod tests;