use wasmer::{MemoryView, WasmPtr};
use crate::Result;
pub trait MemoryManipulation {
fn write_slice(&self, value_slice: &[u8], mem_offset: u32) -> Result<()>;
}
impl<'a> MemoryManipulation for MemoryView<'a> {
fn write_slice(&self, value_slice: &[u8], mem_offset: u32) -> Result<()> {
let ptr: WasmPtr<u8> = WasmPtr::new(mem_offset);
let slice = ptr.slice(self, value_slice.len() as u32)?;
Ok(slice.write_slice(value_slice)?)
}
}
#[cfg(test)]
mod tests {
use super::*;
use std::io::Cursor;
use darkfi_serial::Decodable;
use wasmer::{Memory, MemoryType, Store};
#[test]
fn test_memoryview_writeslice() {
let mut store = Store::default();
let m = Memory::new(&mut store, MemoryType::new(1, None, false)).unwrap();
let value: [u8; 3] = [3, 0, 1];
let view = m.view(&store);
let res = view.write_slice(&value, 0);
assert!(res.is_ok());
let ptr: WasmPtr<u8> = WasmPtr::new(0);
let slice = ptr.slice(&view, value.len() as u32);
let mut buf: [u8; 3] = [0; 3];
let _ = slice.expect("err").read_slice(&mut buf);
assert_eq!(buf, value);
}
#[test]
fn test_memoryview_allread() -> Result<()> {
let mut store = Store::default();
let m = Memory::new(&mut store, MemoryType::new(1, None, false)).unwrap();
let value: [u8; 3] = [3, 0, 1];
let view = m.view(&store);
let res = view.write_slice(&value, 0);
assert!(res.is_ok());
let ptr: WasmPtr<u8> = WasmPtr::new(0);
let slice = ptr.slice(&view, value.len() as u32)?;
let mut buf: [u8; 3] = [0; 3];
let _ = slice.read_slice(&mut buf);
let mut buf_reader = Cursor::new(buf);
let ret: [u8; 3] = Decodable::decode(&mut buf_reader)?;
assert!(buf.len() == (slice.len() as usize));
assert_eq!(ret, value);
assert!(buf_reader.position() == slice.len());
Ok(())
}
}