use std::alloc::{alloc, Layout};
use std::mem;
use super::memory_block_write::MemoryBlockWrite;
fn alloc_memory(size: usize) -> (*mut u8, Layout) {
let align = mem::align_of::<usize>();
if let Ok(layout) = Layout::from_size_align(size, align) {
unsafe {
if layout.size() > 0 {
let ptr = alloc(layout);
if !ptr.is_null() {
return (ptr, layout);
}
} else {
}
}
}
log::info!("Attempted allocation: {size}");
panic!("Allocation error");
}
#[derive(Debug)]
pub struct MemoryBlock {
ptr: *mut u8,
layout: Layout,
size: u32,
}
impl MemoryBlock {
pub fn new(size: u32) -> MemoryBlock {
let (ptr, layout) = alloc_memory(size as usize);
MemoryBlock {
ptr,
layout,
size,
}
}
pub fn from_slice(data: &[u8]) -> MemoryBlock {
let size = data.len() as u32;
let block = MemoryBlock::new(size);
let mut block = MemoryBlockWrite::new(block);
block.write(data);
block.get_block()
}
pub fn get_ptr_and_size(&self) -> (u32, u32) {
(self.ptr as u32, self.size)
}
pub fn get_ptr(&self) -> u32 {
self.ptr as u32
}
pub fn write(&self, offset: u32, data: &[u8]) {
let data_len = data.len() as u32;
if offset + data_len <= self.size {
let dest = unsafe { self.ptr.offset(offset as isize) };
unsafe {
std::ptr::copy(data.as_ptr(), dest, data_len as usize);
}
} else {
panic!("Buffer overflow size={} offset={offset} new_data={data_len}", self.size);
}
}
pub fn convert_to_vec(self) -> Vec<u8> {
let ptr = self.ptr;
let size = self.size as usize;
std::mem::forget(self);
unsafe {
Vec::<u8>::from_raw_parts(ptr, size, size)
}
}
}
impl Drop for MemoryBlock {
fn drop(&mut self) {
use std::alloc::{dealloc};
unsafe {
dealloc(self.ptr, self.layout);
}
}
}