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cleanup(serde_v8): streamline magic types (#14076)

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Formalize magic types and how they're "transerialized", also makes U16String deserializable
This commit is contained in:
Aaron O'Mullan 2022-03-23 21:15:01 +01:00 committed by GitHub
parent b82ded84d3
commit f580134b1e
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GPG Key ID: 4AEE18F83AFDEB23
12 changed files with 388 additions and 623 deletions
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6
.github/workflows/ci.yml vendored
View File

@ -236,7 +236,7 @@ jobs:
~/.cargo/registry/index
~/.cargo/registry/cache
~/.cargo/git/db
key: 2-cargo-home-${{ matrix.os }}-${{ hashFiles('Cargo.lock') }}
key: 3-cargo-home-${{ matrix.os }}-${{ hashFiles('Cargo.lock') }}
# In main branch, always creates fresh cache
- name: Cache build output (main)
@ -252,7 +252,7 @@ jobs:
!./target/*/*.zip
!./target/*/*.tar.gz
key: |
2-cargo-target-${{ matrix.os }}-${{ matrix.profile }}-${{ github.sha }}
3-cargo-target-${{ matrix.os }}-${{ matrix.profile }}-${{ github.sha }}
# Restore cache from the latest 'main' branch build.
- name: Cache build output (PR)
@ -268,7 +268,7 @@ jobs:
!./target/*/*.tar.gz
key: never_saved
restore-keys: |
2-cargo-target-${{ matrix.os }}-${{ matrix.profile }}-
3-cargo-target-${{ matrix.os }}-${{ matrix.profile }}-
# Don't save cache after building PRs or branches other than 'main'.
- name: Skip save cache (PR)

106
serde_v8/src/de.rs
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@ -4,9 +4,10 @@ use serde::Deserialize;
use crate::error::{Error, Result};
use crate::keys::{v8_struct_key, KeyCache};
use crate::magic::transl8::FromV8;
use crate::magic::transl8::{visit_magic, MagicType};
use crate::payload::ValueType;
use crate::magic;
use crate::{magic, Buffer, ByteString, U16String};
pub struct Deserializer<'a, 'b, 's> {
input: v8::Local<'a, v8::Value>,
@ -131,23 +132,8 @@ impl<'de, 'a, 'b, 's, 'x> de::Deserializer<'de>
ValueType::Object => self.deserialize_map(visitor),
// Map to Vec<u8> when deserialized via deserialize_any
// e.g: for untagged enums or StringOrBuffer
ValueType::ArrayBufferView => {
v8::Local::<v8::ArrayBufferView>::try_from(self.input)
.and_then(|view| {
magic::zero_copy_buf::ZeroCopyBuf::try_from((
&mut *self.scope,
view,
))
})
.map_err(|_| Error::ExpectedBuffer)
.and_then(|zb| visitor.visit_byte_buf(Vec::from(&*zb)))
}
ValueType::ArrayBuffer => {
v8::Local::<v8::ArrayBuffer>::try_from(self.input)
.and_then(|buffer| {
magic::zero_copy_buf::ZeroCopyBuf::try_from(buffer)
})
.map_err(|_| Error::ExpectedBuffer)
ValueType::ArrayBufferView | ValueType::ArrayBuffer => {
magic::zero_copy_buf::ZeroCopyBuf::from_v8(&mut *self.scope, self.input)
.and_then(|zb| visitor.visit_byte_buf(Vec::from(&*zb)))
}
}
@ -338,71 +324,31 @@ impl<'de, 'a, 'b, 's, 'x> de::Deserializer<'de>
where
V: Visitor<'de>,
{
// Magic for serde_v8::magic::Value, to passthrough v8::Value
// TODO: ensure this is cross-platform and there's no alternative
if name == magic::NAME {
let mv = magic::Value {
v8_value: self.input,
};
let hack: u64 = unsafe { std::mem::transmute(mv) };
return visitor.visit_u64(hack);
}
// Magic Buffer
if name == magic::buffer::BUF_NAME {
let zero_copy_buf = match self.input.is_array_buffer() {
// ArrayBuffer
true => v8::Local::<v8::ArrayBuffer>::try_from(self.input)
.and_then(magic::zero_copy_buf::ZeroCopyBuf::try_from),
// maybe ArrayBufferView
false => v8::Local::<v8::ArrayBufferView>::try_from(self.input)
.and_then(|view| {
magic::zero_copy_buf::ZeroCopyBuf::try_from((
&mut *self.scope,
view,
))
}),
match name {
Buffer::MAGIC_NAME => {
visit_magic(visitor, Buffer::from_v8(self.scope, self.input)?)
}
.map_err(|_| Error::ExpectedBuffer)?;
let data: [u8; 32] = unsafe { std::mem::transmute(zero_copy_buf) };
return visitor.visit_bytes(&data);
}
// Magic ByteString
if name == magic::bytestring::NAME {
let v8str = v8::Local::<v8::String>::try_from(self.input)
.map_err(|_| Error::ExpectedString)?;
if !v8str.contains_only_onebyte() {
return Err(Error::ExpectedLatin1);
ByteString::MAGIC_NAME => {
visit_magic(visitor, ByteString::from_v8(self.scope, self.input)?)
}
let len = v8str.length();
let mut buffer = Vec::with_capacity(len);
#[allow(clippy::uninit_vec)]
unsafe {
buffer.set_len(len);
U16String::MAGIC_NAME => {
visit_magic(visitor, U16String::from_v8(self.scope, self.input)?)
}
magic::Value::MAGIC_NAME => {
visit_magic(visitor, magic::Value::from_v8(self.scope, self.input)?)
}
_ => {
// Regular struct
let obj = self.input.try_into().or(Err(Error::ExpectedObject))?;
visitor.visit_seq(StructAccess {
fields,
obj,
pos: 0,
scope: self.scope,
_cache: None,
})
}
let written = v8str.write_one_byte(
self.scope,
&mut buffer,
0,
v8::WriteOptions::NO_NULL_TERMINATION,
);
assert!(written == len);
return visitor.visit_byte_buf(buffer);
}
// Regular struct
let obj = v8::Local::<v8::Object>::try_from(self.input)
.map_err(|_| Error::ExpectedObject)?;
let struct_access = StructAccess {
fields,
obj,
pos: 0,
scope: self.scope,
_cache: None,
};
visitor.visit_seq(struct_access)
}
/// To be compatible with `serde-json`, we expect enums to be:

107
serde_v8/src/magic/buffer.rs
View File

@ -1,12 +1,13 @@
// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.
use std::convert::TryFrom;
use std::fmt;
use std::ops::Deref;
use std::ops::DerefMut;
use std::sync::Mutex;
use super::transl8::FromV8;
use super::transl8::ToV8;
use super::zero_copy_buf::ZeroCopyBuf;
use crate::magic::transl8::impl_magic;
// An asymmetric wrapper around ZeroCopyBuf,
// allowing us to use a single type for familiarity
@ -14,6 +15,7 @@ pub enum MagicBuffer {
FromV8(ZeroCopyBuf),
ToV8(Mutex<Option<Box<[u8]>>>),
}
impl_magic!(MagicBuffer);
impl MagicBuffer {
pub fn empty() -> Self {
@ -21,27 +23,6 @@ impl MagicBuffer {
}
}
impl<'s> TryFrom<v8::Local<'s, v8::ArrayBuffer>> for MagicBuffer {
type Error = v8::DataError;
fn try_from(buffer: v8::Local<v8::ArrayBuffer>) -> Result<Self, Self::Error> {
Ok(Self::FromV8(ZeroCopyBuf::try_from(buffer)?))
}
}
// TODO(@AaronO): consider streamlining this as "ScopedValue" ?
type ScopedView<'a, 'b, 's> = (
&'s mut v8::HandleScope<'a>,
v8::Local<'b, v8::ArrayBufferView>,
);
impl<'a, 'b, 's> TryFrom<ScopedView<'a, 'b, 's>> for MagicBuffer {
type Error = v8::DataError;
fn try_from(
scoped_view: ScopedView<'a, 'b, 's>,
) -> Result<Self, Self::Error> {
Ok(Self::FromV8(ZeroCopyBuf::try_from(scoped_view)?))
}
}
impl Clone for MagicBuffer {
fn clone(&self) -> Self {
match self {
@ -94,61 +75,45 @@ impl From<Vec<u8>> for MagicBuffer {
}
}
pub const BUF_NAME: &str = "$__v8_magic_Buffer";
pub const BUF_FIELD_1: &str = "$__v8_magic_buffer_1";
pub const BUF_FIELD_2: &str = "$__v8_magic_buffer_2";
impl serde::Serialize for MagicBuffer {
fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
where
S: serde::Serializer,
{
use serde::ser::SerializeStruct;
let mut s = serializer.serialize_struct(BUF_NAME, 1)?;
let boxed: Box<[u8]> = match self {
impl ToV8 for MagicBuffer {
fn to_v8<'a>(
&self,
scope: &mut v8::HandleScope<'a>,
) -> Result<v8::Local<'a, v8::Value>, crate::Error> {
let buf: Box<[u8]> = match self {
Self::FromV8(buf) => {
let value: &[u8] = buf;
value.into()
}
Self::ToV8(x) => x.lock().unwrap().take().expect("MagicBuffer was empty"),
};
let hack: [usize; 2] = unsafe { std::mem::transmute(boxed) };
let f1: u64 = hack[0] as u64;
let f2: u64 = hack[1] as u64;
s.serialize_field(BUF_FIELD_1, &f1)?;
s.serialize_field(BUF_FIELD_2, &f2)?;
s.end()
}
}
impl<'de, 's> serde::Deserialize<'de> for MagicBuffer {
fn deserialize<D>(deserializer: D) -> Result<MagicBuffer, D::Error>
where
D: serde::Deserializer<'de>,
{
struct ValueVisitor {}
impl<'de> serde::de::Visitor<'de> for ValueVisitor {
type Value = MagicBuffer;
fn expecting(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
formatter.write_str("a serde_v8::MagicBuffer")
}
fn visit_bytes<E>(self, v: &[u8]) -> Result<Self::Value, E>
where
E: serde::de::Error,
{
let p1: &[usize] = unsafe { &*(v as *const [u8] as *const [usize]) };
let p2: [usize; 4] = [p1[0], p1[1], p1[2], p1[3]];
let zero_copy: ZeroCopyBuf = unsafe { std::mem::transmute(p2) };
Ok(MagicBuffer::FromV8(zero_copy))
}
if buf.is_empty() {
let ab = v8::ArrayBuffer::new(scope, 0);
return Ok(
v8::Uint8Array::new(scope, ab, 0, 0)
.expect("Failed to create Uint8Array")
.into(),
);
}
static FIELDS: [&str; 0] = [];
let visitor = ValueVisitor {};
deserializer.deserialize_struct(BUF_NAME, &FIELDS, visitor)
let buf_len = buf.len();
let backing_store =
v8::ArrayBuffer::new_backing_store_from_boxed_slice(buf);
let backing_store_shared = backing_store.make_shared();
let ab = v8::ArrayBuffer::with_backing_store(scope, &backing_store_shared);
Ok(
v8::Uint8Array::new(scope, ab, 0, buf_len)
.expect("Failed to create Uint8Array")
.into(),
)
}
}
impl FromV8 for MagicBuffer {
fn from_v8(
scope: &mut v8::HandleScope,
value: v8::Local<v8::Value>,
) -> Result<Self, crate::Error> {
Ok(Self::FromV8(ZeroCopyBuf::from_v8(scope, value)?))
}
}

79
serde_v8/src/magic/bytestring.rs
View File

@ -2,14 +2,13 @@
use std::ops::{Deref, DerefMut};
use serde::{de::Visitor, Deserialize, Deserializer, Serialize, Serializer};
pub const NAME: &str = "$__v8_magic_bytestring";
pub const FIELD_PTR: &str = "$__v8_magic_bytestring_ptr";
pub const FIELD_LEN: &str = "$__v8_magic_bytestring_len";
use super::transl8::{FromV8, ToV8};
use crate::magic::transl8::impl_magic;
use crate::Error;
#[derive(PartialEq, Eq, Clone, Debug)]
pub struct ByteString(pub Vec<u8>);
impl_magic!(ByteString);
impl ByteString {
pub fn new() -> ByteString {
@ -81,45 +80,43 @@ impl AsMut<[u8]> for ByteString {
}
}
impl Serialize for ByteString {
fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
where
S: Serializer,
{
use serde::ser::SerializeStruct;
let mut s = serializer.serialize_struct(NAME, 1)?;
s.serialize_field(FIELD_PTR, &(self.0.as_ptr() as usize))?;
s.serialize_field(FIELD_LEN, &self.0.len())?;
s.end()
impl ToV8 for ByteString {
fn to_v8<'a>(
&self,
scope: &mut v8::HandleScope<'a>,
) -> Result<v8::Local<'a, v8::Value>, crate::Error> {
let v =
v8::String::new_from_one_byte(scope, self, v8::NewStringType::Normal)
.unwrap();
Ok(v.into())
}
}
impl<'de> Deserialize<'de> for ByteString {
fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
where
D: Deserializer<'de>,
{
struct ValueVisitor {}
impl<'de> Visitor<'de> for ValueVisitor {
type Value = ByteString;
fn expecting(
&self,
formatter: &mut std::fmt::Formatter,
) -> std::fmt::Result {
formatter.write_str("a serde_v8::ByteString")
}
fn visit_byte_buf<E>(self, v: Vec<u8>) -> Result<Self::Value, E>
where
E: serde::de::Error,
{
Ok(ByteString(v))
}
impl FromV8 for ByteString {
fn from_v8(
scope: &mut v8::HandleScope,
value: v8::Local<v8::Value>,
) -> Result<Self, crate::Error> {
let v8str = v8::Local::<v8::String>::try_from(value)
.map_err(|_| Error::ExpectedString)?;
if !v8str.contains_only_onebyte() {
return Err(Error::ExpectedLatin1);
}
deserializer.deserialize_struct(NAME, &[], ValueVisitor {})
let len = v8str.length();
let mut buffer = Vec::with_capacity(len);
// SAFETY: we set length == capacity (see previous line),
// before immediately writing into that buffer and sanity check with an assert
#[allow(clippy::uninit_vec)]
unsafe {
buffer.set_len(len);
let written = v8str.write_one_byte(
scope,
&mut buffer,
0,
v8::WriteOptions::NO_NULL_TERMINATION,
);
assert!(written == len);
}
Ok(ByteString(buffer))
}
}

144
serde_v8/src/magic/field.rs
View File

@ -1,144 +0,0 @@
// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.
use crate::error::{Error, Result};
use serde::ser::{Impossible, Serialize, Serializer};
/// All serde_v8 "magic" values are reduced to structs with 1 or 2 u64 fields
/// assuming usize==u64, most types are simply a pointer or pointer+len (e.g: Box<T>)
pub type TransmutedField = u64;
pub type FieldResult = Result<TransmutedField>;
macro_rules! not_reachable {
($($name:ident($ty:ty);)*) => {
$(fn $name(self, _v: $ty) -> FieldResult {
unreachable!();
})*
};
}
/// FieldSerializer is a simple serde::Serializer that only returns u64s
/// it allows the "magic" struct serializers to obtain the transmuted field values
pub struct FieldSerializer {}
impl Serializer for FieldSerializer {
type Ok = TransmutedField;
type Error = Error;
type SerializeSeq = Impossible<TransmutedField, Error>;
type SerializeTuple = Impossible<TransmutedField, Error>;
type SerializeTupleStruct = Impossible<TransmutedField, Error>;
type SerializeTupleVariant = Impossible<TransmutedField, Error>;
type SerializeMap = Impossible<TransmutedField, Error>;
type SerializeStruct = Impossible<TransmutedField, Error>;
type SerializeStructVariant = Impossible<TransmutedField, Error>;
fn serialize_u64(self, transmuted_field: u64) -> FieldResult {
Ok(transmuted_field)
}
not_reachable! {
serialize_i8(i8);
serialize_i16(i16);
serialize_i32(i32);
serialize_i64(i64);
serialize_u8(u8);
serialize_u16(u16);
serialize_u32(u32);
// serialize_u64(TransmutedField); the chosen one
serialize_f32(f32);
serialize_f64(f64);
serialize_bool(bool);
serialize_char(char);
serialize_str(&str);
serialize_bytes(&[u8]);
}
fn serialize_none(self) -> FieldResult {
unreachable!();
}
fn serialize_some<T: ?Sized + Serialize>(self, _value: &T) -> FieldResult {
unreachable!();
}
fn serialize_unit(self) -> FieldResult {
unreachable!();
}
fn serialize_unit_struct(self, _name: &'static str) -> FieldResult {
unreachable!();
}
fn serialize_unit_variant(
self,
_name: &'static str,
_variant_index: u32,
_variant: &'static str,
) -> FieldResult {
unreachable!();
}
fn serialize_newtype_struct<T: ?Sized + Serialize>(
self,
_name: &'static str,
_value: &T,
) -> FieldResult {
unreachable!();
}
fn serialize_newtype_variant<T: ?Sized + Serialize>(
self,
_name: &'static str,
_variant_index: u32,
_variant: &'static str,
_value: &T,
) -> FieldResult {
unreachable!();
}
fn serialize_seq(self, _len: Option<usize>) -> Result<Self::SerializeSeq> {
unreachable!();
}
fn serialize_tuple(self, _len: usize) -> Result<Self::SerializeTuple> {
unreachable!();
}
fn serialize_tuple_struct(
self,
_name: &'static str,
_len: usize,
) -> Result<Self::SerializeTupleStruct> {
unreachable!();
}
fn serialize_tuple_variant(
self,
_name: &'static str,
_variant_index: u32,
_variant: &'static str,
_len: usize,
) -> Result<Self::SerializeTupleVariant> {
unreachable!();
}
fn serialize_map(self, _len: Option<usize>) -> Result<Self::SerializeMap> {
unreachable!();
}
fn serialize_struct(
self,
_name: &'static str,
_len: usize,
) -> Result<Self::SerializeStruct> {
unreachable!();
}
fn serialize_struct_variant(
self,
_name: &'static str,
_variant_index: u32,
_variant: &'static str,
_len: usize,
) -> Result<Self::SerializeStructVariant> {
unreachable!();
}
}

6
serde_v8/src/magic/mod.rs
View File

@ -1,11 +1,9 @@
// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.
pub mod buffer;
pub mod bytestring;
mod field;
pub mod string_or_buffer;
pub mod transl8;
pub mod u16string;
mod value;
pub mod zero_copy_buf;
pub use field::FieldSerializer;
pub use value::{Value, FIELD, NAME};
pub use value::Value;

143
serde_v8/src/magic/transl8.rs Normal file
View File

@ -0,0 +1,143 @@
// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.
//! Transerialization extends the set of serde-compatible types (for given de/serializers).
//! By "hackishly" transmuting references across serde boundaries as u64s.
//! Type-safety is enforced using special struct names for each "magic type".
//! Memory-safety relies on transerialized values being "pinned" during de/serialization.
pub(crate) const MAGIC_FIELD: &str = "$__v8_magic_field";
pub(crate) trait MagicType {
const NAME: &'static str;
const MAGIC_NAME: &'static str;
}
pub(crate) trait ToV8 {
fn to_v8<'a>(
&self,
scope: &mut v8::HandleScope<'a>,
) -> Result<v8::Local<'a, v8::Value>, crate::Error>;
}
pub(crate) trait FromV8: Sized {
fn from_v8(
scope: &mut v8::HandleScope,
value: v8::Local<v8::Value>,
) -> Result<Self, crate::Error>;
}
pub(crate) fn magic_serialize<T, S>(
serializer: S,
x: &T,
) -> Result<S::Ok, S::Error>
where
S: serde::Serializer,
T: MagicType,
{
use serde::ser::SerializeStruct;
let mut s = serializer.serialize_struct(T::MAGIC_NAME, 1)?;
let ptr = opaque_send(x);
s.serialize_field(MAGIC_FIELD, &ptr)?;
s.end()
}
pub(crate) fn magic_deserialize<'de, T, D>(
deserializer: D,
) -> Result<T, D::Error>
where
D: serde::Deserializer<'de>,
T: MagicType,
{
struct ValueVisitor<T> {
p1: std::marker::PhantomData<T>,
}
impl<'de, T: MagicType> serde::de::Visitor<'de> for ValueVisitor<T> {
type Value = T;
fn expecting(
&self,
formatter: &mut std::fmt::Formatter,
) -> std::fmt::Result {
formatter.write_str("a ")?;
formatter.write_str(T::NAME)
}
fn visit_u64<E>(self, ptr: u64) -> Result<Self::Value, E>
where
E: serde::de::Error,
{
// SAFETY: opaque ptr originates from visit_magic, which forgets ownership so we can take it
Ok(unsafe { opaque_take(ptr) })
}
}
deserializer.deserialize_struct(
T::MAGIC_NAME,
&[MAGIC_FIELD],
ValueVisitor::<T> {
p1: std::marker::PhantomData,
},
)
}
pub(crate) fn visit_magic<'de, T, V, E>(visitor: V, x: T) -> Result<V::Value, E>
where
V: serde::de::Visitor<'de>,
E: serde::de::Error,
{
let y = visitor.visit_u64::<E>(opaque_send(&x));
std::mem::forget(x);
y
}
/// Constructs an "opaque" ptr from a reference to transerialize
pub(crate) fn opaque_send<T: Sized>(x: &T) -> u64 {
(x as *const T) as u64
}
/// Copies an "opaque" ptr from a reference to an opaque ptr (transerialized)
/// NOTE: ptr-to-ptr, extra indirection
pub(crate) unsafe fn opaque_recv<T: ?Sized>(ptr: &T) -> u64 {
*(ptr as *const T as *const u64)
}
/// Transmutes an "opaque" ptr back into a reference
pub(crate) unsafe fn opaque_deref<'a, T>(ptr: u64) -> &'a T {
std::mem::transmute(ptr)
}
/// Transmutes & copies the value from the "opaque" ptr
/// NOTE: takes ownership & requires other end to forget its ownership
pub(crate) unsafe fn opaque_take<T>(ptr: u64) -> T {
std::mem::transmute_copy::<T, T>(std::mem::transmute(ptr))
}
macro_rules! impl_magic {
($t:ty) => {
impl crate::magic::transl8::MagicType for $t {
const NAME: &'static str = stringify!($t);
const MAGIC_NAME: &'static str = concat!("$__v8_magic_", stringify!($t));
}
impl serde::Serialize for $t {
fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
where
S: serde::Serializer,
{
crate::magic::transl8::magic_serialize(serializer, self)
}
}
impl<'de> serde::Deserialize<'de> for $t {
fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
where
D: serde::Deserializer<'de>,
{
crate::magic::transl8::magic_deserialize(deserializer)
}
}
};
}
pub(crate) use impl_magic;

57
serde_v8/src/magic/u16string.rs
View File

@ -1,13 +1,12 @@
use crate::magic::transl8::impl_magic;
use crate::Error;
use std::ops::{Deref, DerefMut};
use serde::Serialize;
use super::transl8::{FromV8, ToV8};
pub const NAME: &str = "$__v8_magic_u16string";
pub const FIELD_PTR: &str = "$__v8_magic_u16string_ptr";
pub const FIELD_LEN: &str = "$__v8_magic_u16string_len";
#[derive(Default, PartialEq, Eq)]
#[derive(Default, PartialEq, Eq, Debug)]
pub struct U16String(pub Vec<u16>);
impl_magic!(U16String);
impl U16String {
pub fn with_zeroes(length: usize) -> U16String {
@ -45,18 +44,40 @@ impl AsMut<[u16]> for U16String {
}
}
impl Serialize for U16String {
fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
where
S: serde::Serializer,
{
use serde::ser::SerializeStruct;
let mut s = serializer.serialize_struct(NAME, 3)?;
s.serialize_field(FIELD_PTR, &(self.0.as_ptr() as usize))?;
s.serialize_field(FIELD_LEN, &self.0.len())?;
s.end()
impl ToV8 for U16String {
fn to_v8<'a>(
&self,
scope: &mut v8::HandleScope<'a>,
) -> Result<v8::Local<'a, v8::Value>, crate::Error> {
let v =
v8::String::new_from_two_byte(scope, self, v8::NewStringType::Normal)
.unwrap();
Ok(v.into())
}
}
// TODO: Deserialize
impl FromV8 for U16String {
fn from_v8(
scope: &mut v8::HandleScope,
value: v8::Local<v8::Value>,
) -> Result<Self, crate::Error> {
let v8str = v8::Local::<v8::String>::try_from(value)
.map_err(|_| Error::ExpectedString)?;
let len = v8str.length();
let mut buffer = Vec::with_capacity(len);
// SAFETY: we set length == capacity (see previous line),
// before immediately writing into that buffer and sanity check with an assert
#[allow(clippy::uninit_vec)]
unsafe {
buffer.set_len(len);
let written = v8str.write(
scope,
&mut buffer,
0,
v8::WriteOptions::NO_NULL_TERMINATION,
);
assert!(written == len);
}
Ok(U16String(buffer))
}
}

76
serde_v8/src/magic/value.rs
View File

@ -1,21 +1,19 @@
// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.
use std::fmt;
use std::marker::PhantomData;
pub const FIELD: &str = "$__v8_magic_value";
pub const NAME: &str = "$__v8_magic_Value";
use crate::magic::transl8::impl_magic;
use crate::magic::transl8::FromV8;
use crate::magic::transl8::ToV8;
use std::mem::transmute;
/// serde_v8::Value allows passing through `v8::Value`s untouched
/// when encoding/decoding and allows mixing rust & v8 values in
/// structs, tuples...
/// The implementation mainly breaks down to:
/// 1. Transmuting between u64 <> serde_v8::Value
/// 2. Using special struct/field names to detect these values
/// 3. Then serde "boilerplate"
/// when de/serializing & allows mixing rust & v8 values in structs, tuples...
//
// SAFETY: caveat emptor, the rust-compiler can no longer link lifetimes to their
// original scope, you must take special care in ensuring your handles don't outlive their scope
pub struct Value<'s> {
pub v8_value: v8::Local<'s, v8::Value>,
}
impl_magic!(Value<'_>);
impl<'s> From<v8::Local<'s, v8::Value>> for Value<'s> {
fn from(v8_value: v8::Local<'s, v8::Value>) -> Self {
@ -29,50 +27,22 @@ impl<'s> From<Value<'s>> for v8::Local<'s, v8::Value> {
}
}
impl serde::Serialize for Value<'_> {
fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
where
S: serde::Serializer,
{
use serde::ser::SerializeStruct;
let mut s = serializer.serialize_struct(NAME, 1)?;
let mv = Value {
v8_value: self.v8_value,
};
let hack: u64 = unsafe { std::mem::transmute(mv) };
s.serialize_field(FIELD, &hack)?;
s.end()
impl ToV8 for Value<'_> {
fn to_v8<'a>(
&self,
_scope: &mut v8::HandleScope<'a>,
) -> Result<v8::Local<'a, v8::Value>, crate::Error> {
// SAFETY: not fully safe, since lifetimes are detached from original scope
Ok(unsafe { transmute(self.v8_value) })
}
}
impl<'de, 's> serde::Deserialize<'de> for Value<'s> {
fn deserialize<D>(deserializer: D) -> Result<Value<'s>, D::Error>
where
D: serde::Deserializer<'de>,
{
struct ValueVisitor<'s> {
p1: PhantomData<&'s ()>,
}
impl<'de, 's> serde::de::Visitor<'de> for ValueVisitor<'s> {
type Value = Value<'s>;
fn expecting(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
formatter.write_str("a v8::Value")
}
fn visit_u64<E>(self, v: u64) -> Result<Self::Value, E>
where
E: serde::de::Error,
{
let mv: Value<'s> = unsafe { std::mem::transmute(v) };
Ok(mv)
}
}
static FIELDS: [&str; 1] = [FIELD];
let visitor = ValueVisitor { p1: PhantomData };
deserializer.deserialize_struct(NAME, &FIELDS, visitor)
impl FromV8 for Value<'_> {
fn from_v8(
_scope: &mut v8::HandleScope,
value: v8::Local<v8::Value>,
) -> Result<Self, crate::Error> {
// SAFETY: not fully safe, since lifetimes are detached from original scope
Ok(unsafe { transmute::<Value, Value>(value.into()) })
}
}

43
serde_v8/src/magic/zero_copy_buf.rs
View File

@ -4,6 +4,8 @@ use std::cell::Cell;
use std::ops::Deref;
use std::ops::DerefMut;
use super::transl8::FromV8;
/// A ZeroCopyBuf encapsulates a slice that's been borrowed from a JavaScript
/// ArrayBuffer object. JavaScript objects can normally be garbage collected,
/// but the existence of a ZeroCopyBuf inhibits this until it is dropped. It
@ -43,28 +45,33 @@ impl ZeroCopyBuf {
}),
}
}
}
impl<'s> TryFrom<v8::Local<'s, v8::ArrayBuffer>> for ZeroCopyBuf {
type Error = v8::DataError;
fn try_from(buffer: v8::Local<v8::ArrayBuffer>) -> Result<Self, Self::Error> {
Self::from_buffer(buffer, 0, buffer.byte_length())
pub fn from_view(
scope: &mut v8::HandleScope,
view: v8::Local<v8::ArrayBufferView>,
) -> Result<Self, v8::DataError> {
let buffer = view.buffer(scope).ok_or(v8::DataError::NoData {
expected: "view to have a buffer",
})?;
Self::from_buffer(buffer, view.byte_offset(), view.byte_length())
}
}
// TODO(@AaronO): consider streamlining this as "ScopedValue" ?
type ScopedView<'a, 'b, 's> = (
&'s mut v8::HandleScope<'a>,
v8::Local<'b, v8::ArrayBufferView>,
);
impl<'a, 'b, 's> TryFrom<ScopedView<'a, 'b, 's>> for ZeroCopyBuf {
type Error = v8::DataError;
fn try_from(
scoped_view: ScopedView<'a, 'b, 's>,
) -> Result<Self, Self::Error> {
let (scope, view) = scoped_view;
let buffer = view.buffer(scope).unwrap();
Self::from_buffer(buffer, view.byte_offset(), view.byte_length())
impl FromV8 for ZeroCopyBuf {
fn from_v8(
scope: &mut v8::HandleScope,
value: v8::Local<v8::Value>,
) -> Result<Self, crate::Error> {
if value.is_array_buffer() {
value
.try_into()
.and_then(|b| Self::from_buffer(b, 0, b.byte_length()))
} else {
value
.try_into()
.and_then(|view| Self::from_view(scope, view))
}
.map_err(|_| crate::Error::ExpectedBuffer)
}
}

229
serde_v8/src/ser.rs
View File

@ -6,7 +6,9 @@ use std::cell::RefCell;
use crate::error::{Error, Result};
use crate::keys::v8_struct_key;
use crate::magic;
use crate::magic::transl8::MAGIC_FIELD;
use crate::magic::transl8::{opaque_deref, opaque_recv, MagicType, ToV8};
use crate::{magic, Buffer, ByteString, U16String};
type JsValue<'s> = v8::Local<'s, v8::Value>;
type JsResult<'s> = Result<JsValue<'s>>;
@ -212,191 +214,55 @@ impl<'a, 'b, 'c> ser::SerializeStruct for ObjectSerializer<'a, 'b, 'c> {
}
}
pub struct MagicSerializer<'a> {
v8_value: Option<v8::Local<'a, v8::Value>>,
}
impl<'a> ser::SerializeStruct for MagicSerializer<'a> {
type Ok = JsValue<'a>;
type Error = Error;
fn serialize_field<T: ?Sized + Serialize>(
&mut self,
key: &'static str,
value: &T,
) -> Result<()> {
if key != magic::FIELD {
unreachable!();
}
let transmuted: u64 = value.serialize(magic::FieldSerializer {})?;
let mv: magic::Value<'a> = unsafe { std::mem::transmute(transmuted) };
self.v8_value = Some(mv.v8_value);
Ok(())
}
fn end(self) -> JsResult<'a> {
Ok(self.v8_value.unwrap())
}
}
// TODO(@AaronO): refactor this and streamline how we transmute values
pub struct MagicBufferSerializer<'a, 'b, 'c> {
pub struct MagicalSerializer<'a, 'b, 'c, T> {
scope: ScopePtr<'a, 'b, 'c>,
f1: u64,
f2: u64,
opaque: u64,
p1: std::marker::PhantomData<T>,
}
impl<'a, 'b, 'c> MagicBufferSerializer<'a, 'b, 'c> {
pub fn new(scope: ScopePtr<'a, 'b, 'c>) -> Self {
impl<'a, 'b, 'c, T> MagicalSerializer<'a, 'b, 'c, T> {
pub fn new(scope: ScopePtr<'a, 'b, 'c>) -> MagicalSerializer<'a, 'b, 'c, T> {
Self {
scope,
f1: 0,
f2: 0,
opaque: 0,
p1: std::marker::PhantomData::<T> {},
}
}
}
impl<'a, 'b, 'c> ser::SerializeStruct for MagicBufferSerializer<'a, 'b, 'c> {
type Ok = JsValue<'a>;
type Error = Error;
fn serialize_field<T: ?Sized + Serialize>(
&mut self,
key: &'static str,
value: &T,
) -> Result<()> {
// Get u64 chunk
let transmuted: u64 = value.serialize(magic::FieldSerializer {})?;
match key {
magic::buffer::BUF_FIELD_1 => self.f1 = transmuted,
magic::buffer::BUF_FIELD_2 => self.f2 = transmuted,
_ => unreachable!(),
}
Ok(())
}
fn end(self) -> JsResult<'a> {
let x: [usize; 2] = [self.f1 as usize, self.f2 as usize];
let buf: Box<[u8]> = unsafe { std::mem::transmute(x) };
let scope = &mut *self.scope.borrow_mut();
let v8_value = boxed_slice_to_uint8array(scope, buf);
Ok(v8_value.into())
}
}
pub struct MagicByteStringSerializer<'a, 'b, 'c> {
scope: ScopePtr<'a, 'b, 'c>,
ptr: Option<std::ptr::NonNull<u8>>,
len: Option<usize>,
}
impl<'a, 'b, 'c> MagicByteStringSerializer<'a, 'b, 'c> {
pub fn new(scope: ScopePtr<'a, 'b, 'c>) -> Self {
Self {
scope,
ptr: None,
len: None,
}
}
}
impl<'a, 'b, 'c> ser::SerializeStruct
for MagicByteStringSerializer<'a, 'b, 'c>
impl<'a, 'b, 'c, T: MagicType + ToV8> ser::SerializeStruct
for MagicalSerializer<'a, 'b, 'c, T>
{
type Ok = JsValue<'a>;
type Error = Error;
fn serialize_field<T: ?Sized + Serialize>(
fn serialize_field<U: ?Sized + Serialize>(
&mut self,
key: &'static str,
value: &T,
value: &U,
) -> Result<()> {
// Get u64 chunk
let transmuted: u64 = value.serialize(magic::FieldSerializer {})?;
match key {
magic::bytestring::FIELD_PTR => {
self.ptr = std::ptr::NonNull::new(transmuted as *mut u8);
}
magic::bytestring::FIELD_LEN => {
self.len = Some(transmuted as usize);
}
_ => unreachable!(),
}
assert_eq!(key, MAGIC_FIELD);
let ptr: &U = value;
// SAFETY: MagicalSerializer only ever receives single field u64s,
// type-safety is ensured by MAGIC_NAME checks in `serialize_struct()`
self.opaque = unsafe { opaque_recv(ptr) };
Ok(())
}
fn end(self) -> JsResult<'a> {
// SAFETY: This function is only called from ByteString::serialize(), which
// guarantees the Vec is still alive.
let bytes = unsafe {
std::slice::from_raw_parts(self.ptr.unwrap().as_ptr(), self.len.unwrap())
};
// SAFETY: transerialization assumptions imply `T` is still alive.
let x: &T = unsafe { opaque_deref(self.opaque) };
let scope = &mut *self.scope.borrow_mut();
let v8_value =
v8::String::new_from_one_byte(scope, bytes, v8::NewStringType::Normal)
.unwrap();
Ok(v8_value.into())
}
}
pub struct MagicU16StringSerializer<'a, 'b, 'c> {
scope: ScopePtr<'a, 'b, 'c>,
ptr: Option<std::ptr::NonNull<u16>>,
len: Option<usize>,
}
impl<'a, 'b, 'c> MagicU16StringSerializer<'a, 'b, 'c> {
pub fn new(scope: ScopePtr<'a, 'b, 'c>) -> Self {
Self {
scope,
ptr: None,
len: None,
}
}
}
impl<'a, 'b, 'c> ser::SerializeStruct for MagicU16StringSerializer<'a, 'b, 'c> {
type Ok = JsValue<'a>;
type Error = Error;
fn serialize_field<T: ?Sized + Serialize>(
&mut self,
key: &'static str,
value: &T,
) -> Result<()> {
// Get u64 chunk
let transmuted = value.serialize(magic::FieldSerializer {})?;
match key {
magic::u16string::FIELD_PTR => {
self.ptr = std::ptr::NonNull::new(transmuted as *mut u16)
}
magic::u16string::FIELD_LEN => self.len = Some(transmuted as usize),
_ => unreachable!(),
}
Ok(())
}
fn end(self) -> JsResult<'a> {
// SAFETY: This function is only called from U16String::serialize(), which
// guarantees the Vec is still alive.
let slice = unsafe {
std::slice::from_raw_parts(self.ptr.unwrap().as_ptr(), self.len.unwrap())
};
let scope = &mut *self.scope.borrow_mut();
let v8_value =
v8::String::new_from_two_byte(scope, slice, v8::NewStringType::Normal)
.unwrap();
Ok(v8_value.into())
x.to_v8(scope)
}
}
// Dispatches between magic and regular struct serializers
pub enum StructSerializers<'a, 'b, 'c> {
Magic(MagicSerializer<'a>),
MagicBuffer(MagicBufferSerializer<'a, 'b, 'c>),
MagicByteString(MagicByteStringSerializer<'a, 'b, 'c>),
MagicU16String(MagicU16StringSerializer<'a, 'b, 'c>),
Magic(MagicalSerializer<'a, 'b, 'c, magic::Value<'a>>),
MagicBuffer(MagicalSerializer<'a, 'b, 'c, Buffer>),
MagicByteString(MagicalSerializer<'a, 'b, 'c, ByteString>),
MagicU16String(MagicalSerializer<'a, 'b, 'c, U16String>),
Regular(ObjectSerializer<'a, 'b, 'c>),
}
@ -650,23 +516,24 @@ impl<'a, 'b, 'c> ser::Serializer for Serializer<'a, 'b, 'c> {
len: usize,
) -> Result<Self::SerializeStruct> {
match name {
magic::NAME => {
let m: MagicSerializer<'a> = MagicSerializer { v8_value: None };
Ok(StructSerializers::Magic(m))
}
magic::buffer::BUF_NAME => {
let m = MagicBufferSerializer::new(self.scope);
Ok(StructSerializers::MagicBuffer(m))
}
magic::bytestring::NAME => {
let m = MagicByteStringSerializer::new(self.scope);
ByteString::MAGIC_NAME => {
let m = MagicalSerializer::<ByteString>::new(self.scope);
Ok(StructSerializers::MagicByteString(m))
}
magic::u16string::NAME => {
let m = MagicU16StringSerializer::new(self.scope);
U16String::MAGIC_NAME => {
let m = MagicalSerializer::<U16String>::new(self.scope);
Ok(StructSerializers::MagicU16String(m))
}
Buffer::MAGIC_NAME => {
let m = MagicalSerializer::<Buffer>::new(self.scope);
Ok(StructSerializers::MagicBuffer(m))
}
magic::Value::MAGIC_NAME => {
let m = MagicalSerializer::<magic::Value<'a>>::new(self.scope);
Ok(StructSerializers::Magic(m))
}
_ => {
// Regular structs
let o = ObjectSerializer::new(self.scope, len);
Ok(StructSerializers::Regular(o))
}
@ -685,21 +552,3 @@ impl<'a, 'b, 'c> ser::Serializer for Serializer<'a, 'b, 'c> {
Ok(VariantSerializer::new(scope, variant, x))
}
}
// Used to map MagicBuffers to v8
pub fn boxed_slice_to_uint8array<'a>(
scope: &mut v8::HandleScope<'a>,
buf: Box<[u8]>,
) -> v8::Local<'a, v8::Uint8Array> {
if buf.is_empty() {
let ab = v8::ArrayBuffer::new(scope, 0);
return v8::Uint8Array::new(scope, ab, 0, 0)
.expect("Failed to create UintArray8");
}
let buf_len = buf.len();
let backing_store = v8::ArrayBuffer::new_backing_store_from_boxed_slice(buf);
let backing_store_shared = backing_store.make_shared();
let ab = v8::ArrayBuffer::with_backing_store(scope, &backing_store_shared);
v8::Uint8Array::new(scope, ab, 0, buf_len)
.expect("Failed to create UintArray8")
}

15
serde_v8/tests/de.rs
View File

@ -2,9 +2,9 @@
use serde::Deserialize;
use serde_v8::utils::{js_exec, v8_do};
use serde_v8::Buffer;
use serde_v8::ByteString;
use serde_v8::Error;
use serde_v8::{Buffer, U16String};
#[derive(Debug, Deserialize, PartialEq)]
struct MathOp {
@ -316,3 +316,16 @@ detest!(
detest!(de_bstr, ByteString, "'hello'", ByteString("hello".into()));
defail!(defail_bstr, ByteString, "'👋bye'", |e| e
== Err(Error::ExpectedLatin1));
detest!(
de_u16str,
U16String,
"'hello'",
U16String("hello".encode_utf16().collect())
);
detest!(
de_u16str_non_latin1,
U16String,
"'👋bye'",
U16String("👋bye".encode_utf16().collect())
);