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use crate::sys::exports::{ExportError, Exportable};
use crate::sys::externals::Extern;
use crate::sys::store::{AsStoreMut, AsStoreRef};
use crate::sys::MemoryType;
use crate::MemoryAccessError;
use std::convert::TryInto;
use std::marker::PhantomData;
use std::mem;
use std::mem::MaybeUninit;
use std::slice;
#[cfg(feature = "tracing")]
use tracing::warn;
use wasmer_types::Pages;
use wasmer_vm::{InternalStoreHandle, LinearMemory, MemoryError, StoreHandle, VMExtern, VMMemory};
use super::MemoryView;
#[derive(Debug, Clone)]
pub struct Memory {
pub(crate) handle: StoreHandle<VMMemory>,
}
impl Memory {
#[cfg(feature = "compiler")]
pub fn new(store: &mut impl AsStoreMut, ty: MemoryType) -> Result<Self, MemoryError> {
let mut store = store.as_store_mut();
let tunables = store.tunables();
let style = tunables.memory_style(&ty);
let memory = tunables.create_host_memory(&ty, &style)?;
Ok(Self {
handle: StoreHandle::new(store.objects_mut(), memory),
})
}
pub fn new_from_existing(new_store: &mut impl AsStoreMut, memory: VMMemory) -> Self {
let handle = StoreHandle::new(new_store.objects_mut(), memory);
Self::from_vm_extern(new_store, handle.internal_handle())
}
pub fn ty(&self, store: &impl AsStoreRef) -> MemoryType {
self.handle.get(store.as_store_ref().objects()).ty()
}
pub fn view<'a>(&'a self, store: &impl AsStoreRef) -> MemoryView<'a> {
MemoryView::new(self, store)
}
pub fn grow<IntoPages>(
&self,
store: &mut impl AsStoreMut,
delta: IntoPages,
) -> Result<Pages, MemoryError>
where
IntoPages: Into<Pages>,
{
self.handle.get_mut(store.objects_mut()).grow(delta.into())
}
pub(crate) fn from_vm_extern(
store: &impl AsStoreRef,
internal: InternalStoreHandle<VMMemory>,
) -> Self {
Self {
handle: unsafe {
StoreHandle::from_internal(store.as_store_ref().objects().id(), internal)
},
}
}
pub fn is_from_store(&self, store: &impl AsStoreRef) -> bool {
self.handle.store_id() == store.as_store_ref().objects().id()
}
pub fn try_clone(&self, store: &impl AsStoreRef) -> Option<VMMemory> {
let mem = self.handle.get(store.as_store_ref().objects());
mem.try_clone().map(|mem| mem.into())
}
pub(crate) fn to_vm_extern(&self) -> VMExtern {
VMExtern::Memory(self.handle.internal_handle())
}
}
impl std::cmp::PartialEq for Memory {
fn eq(&self, other: &Self) -> bool {
self.handle == other.handle
}
}
impl std::cmp::Eq for Memory {}
impl<'a> Exportable<'a> for Memory {
fn get_self_from_extern(_extern: &'a Extern) -> Result<&'a Self, ExportError> {
match _extern {
Extern::Memory(memory) => Ok(memory),
_ => Err(ExportError::IncompatibleType),
}
}
}
#[derive(Debug, Copy, Clone)]
pub(crate) struct MemoryBuffer<'a> {
pub(crate) base: *mut u8,
pub(crate) len: usize,
pub(crate) marker: PhantomData<&'a MemoryView<'a>>,
}
impl<'a> MemoryBuffer<'a> {
pub(crate) fn read(&self, offset: u64, buf: &mut [u8]) -> Result<(), MemoryAccessError> {
let end = offset
.checked_add(buf.len() as u64)
.ok_or(MemoryAccessError::Overflow)?;
if end > self.len.try_into().unwrap() {
#[cfg(feature = "tracing")]
warn!(
"attempted to read ({} bytes) beyond the bounds of the memory view ({} > {})",
buf.len(),
end,
self.len
);
return Err(MemoryAccessError::HeapOutOfBounds);
}
unsafe {
volatile_memcpy_read(self.base.add(offset as usize), buf.as_mut_ptr(), buf.len());
}
Ok(())
}
pub(crate) fn read_uninit<'b>(
&self,
offset: u64,
buf: &'b mut [MaybeUninit<u8>],
) -> Result<&'b mut [u8], MemoryAccessError> {
let end = offset
.checked_add(buf.len() as u64)
.ok_or(MemoryAccessError::Overflow)?;
if end > self.len.try_into().unwrap() {
#[cfg(feature = "tracing")]
warn!(
"attempted to read ({} bytes) beyond the bounds of the memory view ({} > {})",
buf.len(),
end,
self.len
);
return Err(MemoryAccessError::HeapOutOfBounds);
}
let buf_ptr = buf.as_mut_ptr() as *mut u8;
unsafe {
volatile_memcpy_read(self.base.add(offset as usize), buf_ptr, buf.len());
}
Ok(unsafe { slice::from_raw_parts_mut(buf_ptr, buf.len()) })
}
pub(crate) fn write(&self, offset: u64, data: &[u8]) -> Result<(), MemoryAccessError> {
let end = offset
.checked_add(data.len() as u64)
.ok_or(MemoryAccessError::Overflow)?;
if end > self.len.try_into().unwrap() {
#[cfg(feature = "tracing")]
warn!(
"attempted to write ({} bytes) beyond the bounds of the memory view ({} > {})",
data.len(),
end,
self.len
);
return Err(MemoryAccessError::HeapOutOfBounds);
}
unsafe {
volatile_memcpy_write(data.as_ptr(), self.base.add(offset as usize), data.len());
}
Ok(())
}
}
#[inline]
unsafe fn volatile_memcpy_read(mut src: *const u8, mut dst: *mut u8, mut len: usize) {
#[inline]
unsafe fn copy_one<T>(src: &mut *const u8, dst: &mut *mut u8, len: &mut usize) {
#[repr(packed)]
struct Unaligned<T>(T);
let val = (*src as *const Unaligned<T>).read_volatile();
(*dst as *mut Unaligned<T>).write(val);
*src = src.add(mem::size_of::<T>());
*dst = dst.add(mem::size_of::<T>());
*len -= mem::size_of::<T>();
}
while len >= 8 {
copy_one::<u64>(&mut src, &mut dst, &mut len);
}
if len >= 4 {
copy_one::<u32>(&mut src, &mut dst, &mut len);
}
if len >= 2 {
copy_one::<u16>(&mut src, &mut dst, &mut len);
}
if len >= 1 {
copy_one::<u8>(&mut src, &mut dst, &mut len);
}
}
#[inline]
unsafe fn volatile_memcpy_write(mut src: *const u8, mut dst: *mut u8, mut len: usize) {
#[inline]
unsafe fn copy_one<T>(src: &mut *const u8, dst: &mut *mut u8, len: &mut usize) {
#[repr(packed)]
struct Unaligned<T>(T);
let val = (*src as *const Unaligned<T>).read();
(*dst as *mut Unaligned<T>).write_volatile(val);
*src = src.add(mem::size_of::<T>());
*dst = dst.add(mem::size_of::<T>());
*len -= mem::size_of::<T>();
}
while len >= 8 {
copy_one::<u64>(&mut src, &mut dst, &mut len);
}
if len >= 4 {
copy_one::<u32>(&mut src, &mut dst, &mut len);
}
if len >= 2 {
copy_one::<u16>(&mut src, &mut dst, &mut len);
}
if len >= 1 {
copy_one::<u8>(&mut src, &mut dst, &mut len);
}
}