switchboard-on-demand 0.5.5

A Rust library to interact with the Switchboard Solana program.
Documentation 
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#[cfg(feature = "anchor")]
use anchor_lang::solana_program;
use solana_program::account_info::AccountInfo;
use anyhow::Error as AnyhowError;
use crate::sysvar::ed25519_sysvar::{Ed25519Sysvar, ParsedEd25519SignatureDataRef};

#[derive(Copy, Clone, Default, serde::Serialize, serde::Deserialize)]
pub struct Instructions;

#[cfg(feature = "anchor")]
impl anchor_lang::solana_program::sysvar::SysvarId for Instructions {
    fn id() -> solana_program::pubkey::Pubkey {
        solana_program::sysvar::instructions::id().to_bytes().into()
    }

    fn check_id(id: &solana_program::pubkey::Pubkey) -> bool {
        solana_program::sysvar::instructions::id() == id.to_bytes().into()
    }
}
#[cfg(feature = "anchor")]
impl anchor_lang::solana_program::sysvar::Sysvar for Instructions {
    // override
    fn size_of() -> usize {
        // hard-coded so that we don't have to construct an empty
        0 // golden, update if MAX_ENTRIES changes
    }
    fn from_account_info(
        _account_info: &anchor_lang::prelude::AccountInfo,
    ) -> Result<Self, solana_program::program_error::ProgramError> {
        Ok(Self {})
    }
}

impl Instructions {
    pub fn parse_ed25519_from_data(
        data: &[u8],
    ) -> Result<([ParsedEd25519SignatureDataRef<'_>; 8], u8, &[u8], u64, u8), AnyhowError> {
        Ed25519Sysvar::parse_instruction_zero_copy(data).map_err(|e| e)
    }

    #[inline(always)]
    #[allow(unexpected_cfgs)]
    pub fn write_instruction_0_data<'a>(ai: &AccountInfo<'a>, dst: &mut [u8]) -> u16 {
        unsafe {
            let base = (*ai.data.as_ptr()).as_ptr();
            let p = base.add((base.add(2) as *const u16).read_unaligned() as usize);
            let _ = 1u8 / (*p == 0) as u8; // trap if non-zero
            let len = min_branchless((p.add(34) as *const u16).read_unaligned(), dst.len() as u16);
            #[cfg(target_os = "solana")]
            solana_define_syscall::definitions::sol_memcpy_(dst.as_mut_ptr(), p.add(36), len as u64);
            len
        }
    }
}

#[inline(always)]
fn min_branchless(a: u16, b: u16) -> u16 {
    // mask = 0xFFFF if a < b, else 0x0000
    let mask = ((a < b) as u16).wrapping_neg();
    (a & mask) | (b & !mask)
}