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use crate::{
ser::{serializers::BufferScratch, ScratchSpace, Serializer, SharedSerializeRegistry},
AlignedBytes, AlignedVec, Archive, ArchiveUnsized, Fallible, RelPtr,
};
#[cfg(not(feature = "std"))]
use ::alloc::{alloc, boxed::Box, vec::Vec};
#[cfg(feature = "std")]
use ::std::alloc;
use core::{
alloc::Layout,
borrow::{Borrow, BorrowMut},
convert::Infallible,
fmt, mem,
ptr::NonNull,
};
#[cfg(not(feature = "std"))]
use hashbrown::hash_map;
#[cfg(feature = "std")]
use std::collections::hash_map;
#[derive(Debug)]
pub struct AlignedSerializer<A> {
inner: A,
}
impl<A: Borrow<AlignedVec>> AlignedSerializer<A> {
#[inline]
pub fn new(inner: A) -> Self {
Self { inner }
}
#[inline]
pub fn into_inner(self) -> A {
self.inner
}
}
impl<A: Default> Default for AlignedSerializer<A> {
#[inline]
fn default() -> Self {
Self {
inner: A::default(),
}
}
}
impl<A> Fallible for AlignedSerializer<A> {
type Error = Infallible;
}
impl<A: Borrow<AlignedVec> + BorrowMut<AlignedVec>> Serializer for AlignedSerializer<A> {
#[inline]
fn pos(&self) -> usize {
self.inner.borrow().len()
}
#[inline]
fn write(&mut self, bytes: &[u8]) -> Result<(), Self::Error> {
self.inner.borrow_mut().extend_from_slice(bytes);
Ok(())
}
#[inline]
unsafe fn resolve_aligned<T: Archive + ?Sized>(
&mut self,
value: &T,
resolver: T::Resolver,
) -> Result<usize, Self::Error> {
let pos = self.pos();
debug_assert_eq!(pos & (mem::align_of::<T::Archived>() - 1), 0);
let vec = self.inner.borrow_mut();
let additional = mem::size_of::<T::Archived>();
vec.reserve(additional);
vec.set_len(vec.len() + additional);
let ptr = vec.as_mut_ptr().add(pos).cast::<T::Archived>();
ptr.write_bytes(0, 1);
value.resolve(pos, resolver, ptr);
Ok(pos)
}
#[inline]
unsafe fn resolve_unsized_aligned<T: ArchiveUnsized + ?Sized>(
&mut self,
value: &T,
to: usize,
metadata_resolver: T::MetadataResolver,
) -> Result<usize, Self::Error> {
let from = self.pos();
debug_assert_eq!(from & (mem::align_of::<RelPtr<T::Archived>>() - 1), 0);
let vec = self.inner.borrow_mut();
let additional = mem::size_of::<RelPtr<T::Archived>>();
vec.reserve(additional);
vec.set_len(vec.len() + additional);
let ptr = vec.as_mut_ptr().add(from).cast::<RelPtr<T::Archived>>();
ptr.write_bytes(0, 1);
value.resolve_unsized(from, to, metadata_resolver, ptr);
Ok(from)
}
}
#[derive(Debug)]
pub struct HeapScratch<const N: usize> {
inner: BufferScratch<Box<AlignedBytes<N>>>,
}
impl<const N: usize> HeapScratch<N> {
pub fn new() -> Self {
if N != 0 {
unsafe {
let layout = Layout::new::<AlignedBytes<N>>();
let ptr = alloc::alloc(layout).cast();
let buf = Box::from_raw(ptr);
Self {
inner: BufferScratch::new(buf),
}
}
} else {
Self {
inner: BufferScratch::new(Box::new(AlignedBytes::default())),
}
}
}
pub fn layout() -> Layout {
unsafe { Layout::from_size_align_unchecked(N, 1) }
}
}
impl<const N: usize> Default for HeapScratch<N> {
fn default() -> Self {
Self::new()
}
}
impl<const N: usize> Fallible for HeapScratch<N> {
type Error = <BufferScratch<Box<[u8]>> as Fallible>::Error;
}
impl<const N: usize> ScratchSpace for HeapScratch<N> {
#[inline]
unsafe fn push_scratch(&mut self, layout: Layout) -> Result<NonNull<[u8]>, Self::Error> {
self.inner.push_scratch(layout)
}
#[inline]
unsafe fn pop_scratch(&mut self, ptr: NonNull<u8>, layout: Layout) -> Result<(), Self::Error> {
self.inner.pop_scratch(ptr, layout)
}
}
#[derive(Debug)]
pub enum AllocScratchError {
ExceededLimit {
requested: usize,
remaining: usize,
},
NotPoppedInReverseOrder {
expected: *mut u8,
expected_layout: Layout,
actual: *mut u8,
actual_layout: Layout,
},
NoAllocationsToPop,
}
unsafe impl Send for AllocScratchError {}
unsafe impl Sync for AllocScratchError {}
impl fmt::Display for AllocScratchError {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
match self {
Self::ExceededLimit { requested, remaining } => write!(
f,
"exceeded the maxmium limit of scratch space: requested {}, remaining {}",
requested, remaining
),
Self::NotPoppedInReverseOrder {
expected,
expected_layout,
actual,
actual_layout,
} => write!(
f,
"scratch space was not popped in reverse order: expected {:p} with size {} and align {}, found {:p} with size {} and align {}",
expected, expected_layout.size(), expected_layout.align(), actual, actual_layout.size(), actual_layout.align()
),
Self::NoAllocationsToPop => write!(
f, "attempted to pop scratch space but there were no allocations to pop"
),
}
}
}
#[cfg(feature = "std")]
const _: () = {
use std::error::Error;
impl Error for AllocScratchError {}
};
#[derive(Debug)]
pub struct AllocScratch {
remaining: Option<usize>,
allocations: Vec<(*mut u8, Layout)>,
}
unsafe impl Send for AllocScratch {}
unsafe impl Sync for AllocScratch {}
impl AllocScratch {
pub fn new() -> Self {
Self {
remaining: None,
allocations: Vec::new(),
}
}
pub fn with_limit(limit: usize) -> Self {
Self {
remaining: Some(limit),
allocations: Vec::new(),
}
}
}
impl Drop for AllocScratch {
fn drop(&mut self) {
for (ptr, layout) in self.allocations.drain(..).rev() {
unsafe {
alloc::dealloc(ptr, layout);
}
}
}
}
impl Default for AllocScratch {
fn default() -> Self {
Self::new()
}
}
impl Fallible for AllocScratch {
type Error = AllocScratchError;
}
impl ScratchSpace for AllocScratch {
#[inline]
unsafe fn push_scratch(&mut self, layout: Layout) -> Result<NonNull<[u8]>, Self::Error> {
if let Some(remaining) = self.remaining {
if remaining < layout.size() {
return Err(AllocScratchError::ExceededLimit {
requested: layout.size(),
remaining,
});
}
}
let result_ptr = alloc::alloc(layout);
self.allocations.push((result_ptr, layout));
let result_slice = ptr_meta::from_raw_parts_mut(result_ptr.cast(), layout.size());
let result = NonNull::new_unchecked(result_slice);
Ok(result)
}
#[inline]
unsafe fn pop_scratch(&mut self, ptr: NonNull<u8>, layout: Layout) -> Result<(), Self::Error> {
if let Some(&(last_ptr, last_layout)) = self.allocations.last() {
if ptr.as_ptr() == last_ptr && layout == last_layout {
alloc::dealloc(ptr.as_ptr(), layout);
self.allocations.pop();
Ok(())
} else {
Err(AllocScratchError::NotPoppedInReverseOrder {
expected: last_ptr,
expected_layout: last_layout,
actual: ptr.as_ptr(),
actual_layout: layout,
})
}
} else {
Err(AllocScratchError::NoAllocationsToPop)
}
}
}
#[derive(Debug)]
pub enum SharedSerializeMapError {
DuplicateSharedPointer(*const u8),
}
unsafe impl Send for SharedSerializeMapError {}
unsafe impl Sync for SharedSerializeMapError {}
impl fmt::Display for SharedSerializeMapError {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
match self {
Self::DuplicateSharedPointer(p) => write!(f, "duplicate shared pointer: {:p}", p),
}
}
}
#[cfg(feature = "std")]
const _: () = {
use std::error::Error;
impl Error for SharedSerializeMapError {}
};
#[derive(Debug)]
pub struct SharedSerializeMap {
shared_resolvers: hash_map::HashMap<*const u8, usize>,
}
unsafe impl Send for SharedSerializeMap {}
unsafe impl Sync for SharedSerializeMap {}
impl SharedSerializeMap {
#[inline]
pub fn new() -> Self {
Self {
shared_resolvers: hash_map::HashMap::new(),
}
}
}
impl Default for SharedSerializeMap {
#[inline]
fn default() -> Self {
Self::new()
}
}
impl Fallible for SharedSerializeMap {
type Error = SharedSerializeMapError;
}
impl SharedSerializeRegistry for SharedSerializeMap {
fn get_shared_ptr(&self, value: *const u8) -> Option<usize> {
self.shared_resolvers.get(&value).copied()
}
fn add_shared_ptr(&mut self, value: *const u8, pos: usize) -> Result<(), Self::Error> {
match self.shared_resolvers.entry(value) {
hash_map::Entry::Occupied(_) => {
Err(SharedSerializeMapError::DuplicateSharedPointer(value))
}
hash_map::Entry::Vacant(e) => {
e.insert(pos);
Ok(())
}
}
}
}