#![deny(missing_docs)]
extern crate solana_program;
use arrayref::{array_refs, mut_array_refs};
use solana_program::{
declare_id, entrypoint::MAX_PERMITTED_DATA_INCREASE, entrypoint::SUCCESS,
program_error::ProgramError, pubkey::Pubkey,
};
use std::{
mem::{align_of, size_of},
ptr::read,
slice::{from_raw_parts, from_raw_parts_mut},
};
declare_id!("shmem4EWT2sPdVGvTZCzXXRAURL9G5vpPxNwSeKhHUL");
fn fast_copy(mut src: &[u8], mut dst: &mut [u8]) {
while src.len() >= 8 {
#[allow(clippy::ptr_offset_with_cast)]
let (src_word, src_rem) = array_refs![src, 8; ..;];
#[allow(clippy::ptr_offset_with_cast)]
let (dst_word, dst_rem) = mut_array_refs![dst, 8; ..;];
*dst_word = *src_word;
src = src_rem;
dst = dst_rem;
}
unsafe {
std::ptr::copy_nonoverlapping(src.as_ptr(), dst.as_mut_ptr(), src.len());
}
}
unsafe fn deserialize_input_parameters<'a>(
input: *mut u8,
) -> Result<(&'a mut [u8], &'a [u8]), u64> {
let num_accounts = read(input as *const u64);
if num_accounts == 0 {
return Err(ProgramError::NotEnoughAccountKeys.into());
} else if num_accounts > 1 {
return Err(ProgramError::InvalidArgument.into());
}
let data_len_offset = size_of::<u64>()
+ size_of::<u8>()
+ size_of::<u8>()
+ size_of::<u8>()
+ size_of::<u8>()
+ size_of::<u32>()
+ size_of::<Pubkey>()
+ size_of::<Pubkey>()
+ size_of::<u64>();
let account_data_len = read(input.add(data_len_offset) as *const usize);
let data_ptr = input.add(data_len_offset + size_of::<u64>());
let account_data = from_raw_parts_mut(data_ptr, account_data_len);
let instruction_len_offset = account_data_len
+ MAX_PERMITTED_DATA_INCREASE
+ (account_data_len as *const u8).align_offset(align_of::<u128>())
+ size_of::<u64>();
let instruction_data_len = read(data_ptr.add(instruction_len_offset) as *const usize);
let instruction_data = from_raw_parts(
data_ptr.add(instruction_len_offset + size_of::<u64>()),
instruction_data_len,
);
Ok((account_data, instruction_data))
}
#[no_mangle]
pub unsafe extern "C" fn entrypoint(input: *mut u8) -> u64 {
match deserialize_input_parameters(input) {
Ok((account_data, instruction_data)) => {
if instruction_data.len() < 8 {
return ProgramError::AccountDataTooSmall.into();
}
#[allow(clippy::ptr_offset_with_cast)]
let (offset, content) = array_refs![instruction_data, 8; ..;];
let offset = usize::from_le_bytes(*offset);
if account_data.len() < offset + content.len() {
return ProgramError::AccountDataTooSmall.into();
}
let data_ptr = account_data.as_mut_ptr() as usize;
let data = from_raw_parts_mut((data_ptr + offset) as *mut u8, content.len());
fast_copy(content, data);
}
Err(err) => return err,
}
SUCCESS
}