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cpp.rs
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cpp.rs
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// Protocol Buffers - Google's data interchange format
// Copyright 2023 Google LLC. All rights reserved.
//
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file or at
// https://developers.google.com/open-source/licenses/bsd
// Rust Protobuf runtime using the C++ kernel.
use crate::__internal::{Enum, Private};
use crate::{
Map, MapIter, Mut, ProtoStr, Proxied, ProxiedInMapValue, ProxiedInRepeated, Repeated,
RepeatedMut, RepeatedView, SettableValue, View,
};
use core::fmt::Debug;
use paste::paste;
use std::convert::identity;
use std::ffi::{c_int, c_void};
use std::fmt;
use std::marker::PhantomData;
use std::mem::MaybeUninit;
use std::ops::Deref;
use std::ptr::{self, NonNull};
use std::slice;
/// Defines a set of opaque, unique, non-accessible pointees.
///
/// The [Rustonomicon][nomicon] currently recommends a zero-sized struct,
/// though this should use [`extern type`] when that is stabilized.
/// [nomicon]: https://doc.rust-lang.org/nomicon/ffi.html#representing-opaque-structs
/// [`extern type`]: https://github.com/rust-lang/rust/issues/43467
mod _opaque_pointees {
/// Opaque pointee for [`RawMessage`]
///
/// This type is not meant to be dereferenced in Rust code.
/// It is only meant to provide type safety for raw pointers
/// which are manipulated behind FFI.
///
/// [`RawMessage`]: super::RawMessage
#[repr(C)]
pub struct RawMessageData {
_data: [u8; 0],
_marker: std::marker::PhantomData<(*mut u8, ::std::marker::PhantomPinned)>,
}
/// Opaque pointee for [`RawRepeatedField`]
///
/// This type is not meant to be dereferenced in Rust code.
/// It is only meant to provide type safety for raw pointers
/// which are manipulated behind FFI.
#[repr(C)]
pub struct RawRepeatedFieldData {
_data: [u8; 0],
_marker: std::marker::PhantomData<(*mut u8, ::std::marker::PhantomPinned)>,
}
/// Opaque pointee for [`RawMap`]
///
/// This type is not meant to be dereferenced in Rust code.
/// It is only meant to provide type safety for raw pointers
/// which are manipulated behind FFI.
#[repr(C)]
pub struct RawMapData {
_data: [u8; 0],
_marker: std::marker::PhantomData<(*mut u8, ::std::marker::PhantomPinned)>,
}
}
/// A raw pointer to the underlying message for this runtime.
pub type RawMessage = NonNull<_opaque_pointees::RawMessageData>;
/// A raw pointer to the underlying repeated field container for this runtime.
pub type RawRepeatedField = NonNull<_opaque_pointees::RawRepeatedFieldData>;
/// A raw pointer to the underlying arena for this runtime.
pub type RawMap = NonNull<_opaque_pointees::RawMapData>;
/// Represents an ABI-stable version of `NonNull<[u8]>`/`string_view` (a
/// borrowed slice of bytes) for FFI use only.
///
/// Has semantics similar to `std::string_view` in C++ and `&[u8]` in Rust,
/// but is not ABI-compatible with either.
///
/// If `len` is 0, then `ptr` can be null or dangling. C++ considers a dangling
/// 0-len `std::string_view` to be invalid, and Rust considers a `&[u8]` with a
/// null data pointer to be invalid.
#[repr(C)]
#[derive(Copy, Clone)]
pub struct PtrAndLen {
/// Pointer to the first byte.
/// Borrows the memory.
pub ptr: *const u8,
/// Length of the `[u8]` pointed to by `ptr`.
pub len: usize,
}
impl PtrAndLen {
/// Unsafely dereference this slice.
///
/// # Safety
/// - `self.ptr` must be dereferencable and immutable for `self.len` bytes
/// for the lifetime `'a`. It can be null or dangling if `self.len == 0`.
pub unsafe fn as_ref<'a>(self) -> &'a [u8] {
if self.ptr.is_null() {
assert_eq!(self.len, 0, "Non-empty slice with null data pointer");
&[]
} else {
// SAFETY:
// - `ptr` is non-null
// - `ptr` is valid for `len` bytes as promised by the caller.
unsafe { slice::from_raw_parts(self.ptr, self.len) }
}
}
}
impl From<&[u8]> for PtrAndLen {
fn from(slice: &[u8]) -> Self {
Self { ptr: slice.as_ptr(), len: slice.len() }
}
}
impl From<&ProtoStr> for PtrAndLen {
fn from(s: &ProtoStr) -> Self {
let bytes = s.as_bytes();
Self { ptr: bytes.as_ptr(), len: bytes.len() }
}
}
/// Serialized Protobuf wire format data. It's typically produced by
/// `<Message>.serialize()`.
///
/// This struct is ABI-compatible with the equivalent struct on the C++ side. It
/// owns (and drops) its data.
#[repr(C)]
pub struct SerializedData {
/// Owns the memory.
data: NonNull<u8>,
len: usize,
}
impl SerializedData {
/// Constructs owned serialized data from raw components.
///
/// # Safety
/// - `data` must be readable for `len` bytes.
/// - `data` must be an owned pointer and valid until deallocated.
/// - `data` must have been allocated by the Rust global allocator with a
/// size of `len` and align of 1.
pub unsafe fn from_raw_parts(data: NonNull<u8>, len: usize) -> Self {
Self { data, len }
}
/// Gets a raw slice pointer.
pub fn as_ptr(&self) -> *const [u8] {
ptr::slice_from_raw_parts(self.data.as_ptr(), self.len)
}
/// Gets a mutable raw slice pointer.
fn as_mut_ptr(&mut self) -> *mut [u8] {
ptr::slice_from_raw_parts_mut(self.data.as_ptr(), self.len)
}
}
impl Deref for SerializedData {
type Target = [u8];
fn deref(&self) -> &Self::Target {
// SAFETY: `data` is valid for `len` bytes until deallocated as promised by
// `from_raw_parts`.
unsafe { &*self.as_ptr() }
}
}
// TODO: remove after IntoProxied has been implemented for bytes.
impl AsRef<[u8]> for SerializedData {
fn as_ref(&self) -> &[u8] {
self
}
}
impl Drop for SerializedData {
fn drop(&mut self) {
// SAFETY: `data` was allocated by the Rust global allocator with a
// size of `len` and align of 1 as promised by `from_raw_parts`.
unsafe { drop(Box::from_raw(self.as_mut_ptr())) }
}
}
impl fmt::Debug for SerializedData {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
fmt::Debug::fmt(self.deref(), f)
}
}
/// A type to transfer an owned Rust string across the FFI boundary:
/// * This struct is ABI-compatible with the equivalent C struct.
/// * It owns its data but does not drop it. Immediately turn it into a
/// `String` by calling `.into()` on it.
/// * `.data` points to a valid UTF-8 string that has been allocated with the
/// Rust allocator and is 1-byte aligned.
/// * `.data` contains exactly `.len` bytes.
/// * The empty string is represented as `.data.is_null() == true`.
#[repr(C)]
pub struct RustStringRawParts {
data: *const u8,
len: usize,
}
impl From<RustStringRawParts> for String {
fn from(value: RustStringRawParts) -> Self {
if value.data.is_null() {
// Handle the case where the string is empty.
return String::new();
}
// SAFETY:
// - `value.data` contains valid UTF-8 bytes as promised by
// `RustStringRawParts`.
// - `value.data` has been allocated with the Rust allocator and is 1-byte
// aligned as promised by `RustStringRawParts`.
// - `value.data` contains and is allocated for exactly `value.len` bytes.
unsafe { String::from_raw_parts(value.data as *mut u8, value.len, value.len) }
}
}
extern "C" {
fn utf8_debug_string(msg: RawMessage) -> RustStringRawParts;
}
pub fn debug_string(_private: Private, msg: RawMessage, f: &mut fmt::Formatter<'_>) -> fmt::Result {
// SAFETY:
// - `msg` is a valid protobuf message.
let dbg_str: String = unsafe { utf8_debug_string(msg) }.into();
write!(f, "{dbg_str}")
}
pub type MessagePresentMutData<'msg, T> = crate::vtable::RawVTableOptionalMutatorData<'msg, T>;
pub type MessageAbsentMutData<'msg, T> = crate::vtable::RawVTableOptionalMutatorData<'msg, T>;
pub type BytesPresentMutData<'msg> = crate::vtable::RawVTableOptionalMutatorData<'msg, [u8]>;
pub type BytesAbsentMutData<'msg> = crate::vtable::RawVTableOptionalMutatorData<'msg, [u8]>;
pub type InnerBytesMut<'msg> = crate::vtable::RawVTableMutator<'msg, [u8]>;
pub type InnerPrimitiveMut<'msg, T> = crate::vtable::RawVTableMutator<'msg, T>;
pub type RawMapIter = UntypedMapIterator;
#[derive(Debug)]
pub struct MessageVTable {
pub getter: unsafe extern "C" fn(msg: RawMessage) -> RawMessage,
pub mut_getter: unsafe extern "C" fn(msg: RawMessage) -> RawMessage,
pub clearer: unsafe extern "C" fn(msg: RawMessage),
}
impl MessageVTable {
pub const fn new(
_private: Private,
getter: unsafe extern "C" fn(msg: RawMessage) -> RawMessage,
mut_getter: unsafe extern "C" fn(msg: RawMessage) -> RawMessage,
clearer: unsafe extern "C" fn(msg: RawMessage),
) -> Self {
MessageVTable { getter, mut_getter, clearer }
}
}
/// The raw contents of every generated message.
#[derive(Debug)]
pub struct MessageInner {
pub msg: RawMessage,
}
/// Mutators that point to their original message use this to do so.
///
/// Since C++ messages manage their own memory, this can just copy the
/// `RawMessage` instead of referencing an arena like UPB must.
///
/// Note: even though this type is `Copy`, it should only be copied by
/// protobuf internals that can maintain mutation invariants:
///
/// - No concurrent mutation for any two fields in a message: this means
/// mutators cannot be `Send` but are `Sync`.
/// - If there are multiple accessible `Mut` to a single message at a time, they
/// must be different fields, and not be in the same oneof. As such, a `Mut`
/// cannot be `Clone` but *can* reborrow itself with `.as_mut()`, which
/// converts `&'b mut Mut<'a, T>` to `Mut<'b, T>`.
#[derive(Clone, Copy, Debug)]
pub struct MutatorMessageRef<'msg> {
msg: RawMessage,
_phantom: PhantomData<&'msg mut ()>,
}
impl<'msg> MutatorMessageRef<'msg> {
#[allow(clippy::needless_pass_by_ref_mut)] // Sound construction requires mutable access.
pub fn new(_private: Private, msg: &'msg mut MessageInner) -> Self {
MutatorMessageRef { msg: msg.msg, _phantom: PhantomData }
}
pub fn from_parent(
_private: Private,
_parent_msg: MutatorMessageRef<'msg>,
message_field_ptr: RawMessage,
) -> Self {
Self { msg: message_field_ptr, _phantom: PhantomData }
}
pub fn msg(&self) -> RawMessage {
self.msg
}
pub fn from_raw_msg(_private: Private, msg: &RawMessage) -> Self {
Self { msg: *msg, _phantom: PhantomData }
}
}
pub fn copy_bytes_in_arena_if_needed_by_runtime<'msg>(
_msg_ref: MutatorMessageRef<'msg>,
val: &'msg [u8],
) -> &'msg [u8] {
// Nothing to do, the message manages its own string memory for C++.
val
}
/// The raw type-erased version of an owned `Repeated`.
#[derive(Debug)]
pub struct InnerRepeated {
raw: RawRepeatedField,
}
impl InnerRepeated {
pub fn as_mut(&mut self) -> InnerRepeatedMut<'_> {
InnerRepeatedMut::new(Private, self.raw)
}
}
/// The raw type-erased pointer version of `RepeatedMut`.
///
/// Contains a `proto2::RepeatedField*` or `proto2::RepeatedPtrField*`.
#[derive(Clone, Copy, Debug)]
pub struct InnerRepeatedMut<'msg> {
pub(crate) raw: RawRepeatedField,
_phantom: PhantomData<&'msg ()>,
}
impl<'msg> InnerRepeatedMut<'msg> {
#[doc(hidden)]
pub fn new(_private: Private, raw: RawRepeatedField) -> Self {
InnerRepeatedMut { raw, _phantom: PhantomData }
}
}
trait CppTypeConversions: Proxied {
type ElemType;
fn elem_to_view<'msg>(v: Self::ElemType) -> View<'msg, Self>;
}
macro_rules! impl_cpp_type_conversions_for_scalars {
($($t:ty),* $(,)?) => {
$(
impl CppTypeConversions for $t {
type ElemType = Self;
fn elem_to_view<'msg>(v: Self) -> View<'msg, Self> {
v
}
}
)*
}
}
impl_cpp_type_conversions_for_scalars!(i32, u32, i64, u64, f32, f64, bool);
impl CppTypeConversions for ProtoStr {
type ElemType = PtrAndLen;
fn elem_to_view<'msg>(v: PtrAndLen) -> View<'msg, ProtoStr> {
ptrlen_to_str(v)
}
}
impl CppTypeConversions for [u8] {
type ElemType = PtrAndLen;
fn elem_to_view<'msg>(v: Self::ElemType) -> View<'msg, Self> {
ptrlen_to_bytes(v)
}
}
// This type alias is used so macros can generate valid extern "C" symbol names
// for functions working with [u8] types.
type Bytes = [u8];
macro_rules! impl_repeated_primitives {
(@impl $($t:ty => [
$new_thunk:ident,
$free_thunk:ident,
$add_thunk:ident,
$size_thunk:ident,
$get_thunk:ident,
$set_thunk:ident,
$clear_thunk:ident,
$copy_from_thunk:ident $(,)?
]),* $(,)?) => {
$(
extern "C" {
fn $new_thunk() -> RawRepeatedField;
fn $free_thunk(f: RawRepeatedField);
fn $add_thunk(f: RawRepeatedField, v: <$t as CppTypeConversions>::ElemType);
fn $size_thunk(f: RawRepeatedField) -> usize;
fn $get_thunk(
f: RawRepeatedField,
i: usize) -> <$t as CppTypeConversions>::ElemType;
fn $set_thunk(
f: RawRepeatedField,
i: usize,
v: <$t as CppTypeConversions>::ElemType);
fn $clear_thunk(f: RawRepeatedField);
fn $copy_from_thunk(src: RawRepeatedField, dst: RawRepeatedField);
}
unsafe impl ProxiedInRepeated for $t {
#[allow(dead_code)]
fn repeated_new(_: Private) -> Repeated<$t> {
Repeated::from_inner(InnerRepeated {
raw: unsafe { $new_thunk() }
})
}
#[allow(dead_code)]
unsafe fn repeated_free(_: Private, f: &mut Repeated<$t>) {
unsafe { $free_thunk(f.as_mut().as_raw(Private)) }
}
fn repeated_len(f: View<Repeated<$t>>) -> usize {
unsafe { $size_thunk(f.as_raw(Private)) }
}
fn repeated_push(mut f: Mut<Repeated<$t>>, v: View<$t>) {
unsafe { $add_thunk(f.as_raw(Private), v.into()) }
}
fn repeated_clear(mut f: Mut<Repeated<$t>>) {
unsafe { $clear_thunk(f.as_raw(Private)) }
}
unsafe fn repeated_get_unchecked(f: View<Repeated<$t>>, i: usize) -> View<$t> {
<$t as CppTypeConversions>::elem_to_view(
unsafe { $get_thunk(f.as_raw(Private), i) })
}
unsafe fn repeated_set_unchecked(mut f: Mut<Repeated<$t>>, i: usize, v: View<$t>) {
unsafe { $set_thunk(f.as_raw(Private), i, v.into()) }
}
fn repeated_copy_from(src: View<Repeated<$t>>, mut dest: Mut<Repeated<$t>>) {
unsafe { $copy_from_thunk(src.as_raw(Private), dest.as_raw(Private)) }
}
}
)*
};
($($t:ty),* $(,)?) => {
paste!{
impl_repeated_primitives!(@impl $(
$t => [
[< __pb_rust_RepeatedField_ $t _new >],
[< __pb_rust_RepeatedField_ $t _free >],
[< __pb_rust_RepeatedField_ $t _add >],
[< __pb_rust_RepeatedField_ $t _size >],
[< __pb_rust_RepeatedField_ $t _get >],
[< __pb_rust_RepeatedField_ $t _set >],
[< __pb_rust_RepeatedField_ $t _clear >],
[< __pb_rust_RepeatedField_ $t _copy_from >],
],
)*);
}
};
}
impl_repeated_primitives!(i32, u32, i64, u64, f32, f64, bool, ProtoStr, Bytes);
/// Cast a `RepeatedView<SomeEnum>` to `RepeatedView<c_int>`.
pub fn cast_enum_repeated_view<E: Enum + ProxiedInRepeated>(
private: Private,
repeated: RepeatedView<E>,
) -> RepeatedView<c_int> {
// SAFETY: the implementer of `Enum` has promised that this
// raw repeated is a type-erased `proto2::RepeatedField<int>*`.
unsafe { RepeatedView::from_raw(private, repeated.as_raw(Private)) }
}
/// Cast a `RepeatedMut<SomeEnum>` to `RepeatedMut<c_int>`.
///
/// Writing an unknown value is sound because all enums
/// are representationally open.
pub fn cast_enum_repeated_mut<E: Enum + ProxiedInRepeated>(
private: Private,
mut repeated: RepeatedMut<E>,
) -> RepeatedMut<c_int> {
// SAFETY: the implementer of `Enum` has promised that this
// raw repeated is a type-erased `proto2::RepeatedField<int>*`.
unsafe {
RepeatedMut::from_inner(
private,
InnerRepeatedMut { raw: repeated.as_raw(Private), _phantom: PhantomData },
)
}
}
#[derive(Debug)]
pub struct InnerMap {
pub(crate) raw: RawMap,
}
impl InnerMap {
pub fn new(_private: Private, raw: RawMap) -> Self {
Self { raw }
}
pub fn as_mut(&mut self) -> InnerMapMut<'_> {
InnerMapMut { raw: self.raw, _phantom: PhantomData }
}
}
#[derive(Clone, Copy, Debug)]
pub struct InnerMapMut<'msg> {
pub(crate) raw: RawMap,
_phantom: PhantomData<&'msg ()>,
}
#[doc(hidden)]
impl<'msg> InnerMapMut<'msg> {
pub fn new(_private: Private, raw: RawMap) -> Self {
InnerMapMut { raw, _phantom: PhantomData }
}
#[doc(hidden)]
pub fn as_raw(&self, _private: Private) -> RawMap {
self.raw
}
}
/// An untyped iterator in a map, produced via `.cbegin()` on a typed map.
///
/// This struct is ABI-compatible with `proto2::internal::UntypedMapIterator`.
/// It is trivially constructible and destructible.
#[repr(C)]
pub struct UntypedMapIterator {
node: *mut c_void,
map: *const c_void,
bucket_index: u32,
}
impl UntypedMapIterator {
/// Returns `true` if this iterator is at the end of the map.
fn at_end(&self) -> bool {
// This behavior is verified via test `IteratorNodeFieldIsNullPtrAtEnd`.
self.node.is_null()
}
/// Assumes that the map iterator is for the input types, gets the current
/// entry, and moves the iterator forward to the next entry.
///
/// Conversion to and from FFI types is provided by the user.
/// This is a helper function for implementing
/// `ProxiedInMapValue::iter_next`.
///
/// # Safety
/// - The backing map must be valid and not be mutated for `'a`.
/// - The thunk must be safe to call if the iterator is not at the end of
/// the map.
/// - The thunk must always write to the `key` and `value` fields, but not
/// read from them.
/// - The get thunk must not move the iterator forward or backward.
#[inline(always)]
pub unsafe fn next_unchecked<'a, K, V, FfiKey, FfiValue>(
&mut self,
_private: Private,
iter_get_thunk: unsafe extern "C" fn(
iter: &mut UntypedMapIterator,
key: *mut FfiKey,
value: *mut FfiValue,
),
from_ffi_key: impl FnOnce(FfiKey) -> View<'a, K>,
from_ffi_value: impl FnOnce(FfiValue) -> View<'a, V>,
) -> Option<(View<'a, K>, View<'a, V>)>
where
K: Proxied + ?Sized + 'a,
V: ProxiedInMapValue<K> + ?Sized + 'a,
{
if self.at_end() {
return None;
}
let mut ffi_key = MaybeUninit::uninit();
let mut ffi_value = MaybeUninit::uninit();
// SAFETY:
// - The backing map outlives `'a`.
// - The iterator is not at the end (node is non-null).
// - `ffi_key` and `ffi_value` are not read (as uninit) as promised by the
// caller.
unsafe { (iter_get_thunk)(self, ffi_key.as_mut_ptr(), ffi_value.as_mut_ptr()) }
// SAFETY:
// - The backing map is alive as promised by the caller.
// - `self.at_end()` is false and the `get` does not change that.
// - `UntypedMapIterator` has the same ABI as
// `proto2::internal::UntypedMapIterator`. It is statically checked to be:
// - Trivially copyable.
// - Trivially destructible.
// - Standard layout.
// - The size and alignment of the Rust type above.
// - With the `node_` field first.
unsafe { __rust_proto_thunk__UntypedMapIterator_increment(self) }
// SAFETY:
// - The `get` function always writes valid values to `ffi_key` and `ffi_value`
// as promised by the caller.
unsafe {
Some((from_ffi_key(ffi_key.assume_init()), from_ffi_value(ffi_value.assume_init())))
}
}
}
extern "C" {
fn __rust_proto_thunk__UntypedMapIterator_increment(iter: &mut UntypedMapIterator);
}
macro_rules! impl_ProxiedInMapValue_for_non_generated_value_types {
($key_t:ty, $ffi_key_t:ty, $to_ffi_key:expr, $from_ffi_key:expr, for $($t:ty, $ffi_t:ty, $to_ffi_value:expr, $from_ffi_value:expr;)*) => {
paste! { $(
extern "C" {
fn [< __rust_proto_thunk__Map_ $key_t _ $t _new >]() -> RawMap;
fn [< __rust_proto_thunk__Map_ $key_t _ $t _free >](m: RawMap);
fn [< __rust_proto_thunk__Map_ $key_t _ $t _clear >](m: RawMap);
fn [< __rust_proto_thunk__Map_ $key_t _ $t _size >](m: RawMap) -> usize;
fn [< __rust_proto_thunk__Map_ $key_t _ $t _insert >](m: RawMap, key: $ffi_key_t, value: $ffi_t) -> bool;
fn [< __rust_proto_thunk__Map_ $key_t _ $t _get >](m: RawMap, key: $ffi_key_t, value: *mut $ffi_t) -> bool;
fn [< __rust_proto_thunk__Map_ $key_t _ $t _iter >](m: RawMap) -> UntypedMapIterator;
fn [< __rust_proto_thunk__Map_ $key_t _ $t _iter_get >](iter: &mut UntypedMapIterator, key: *mut $ffi_key_t, value: *mut $ffi_t);
fn [< __rust_proto_thunk__Map_ $key_t _ $t _remove >](m: RawMap, key: $ffi_key_t, value: *mut $ffi_t) -> bool;
}
impl ProxiedInMapValue<$key_t> for $t {
fn map_new(_private: Private) -> Map<$key_t, Self> {
unsafe {
Map::from_inner(
Private,
InnerMap {
raw: [< __rust_proto_thunk__Map_ $key_t _ $t _new >](),
}
)
}
}
unsafe fn map_free(_private: Private, map: &mut Map<$key_t, Self>) {
// SAFETY:
// - `map.inner.raw` is a live `RawMap`
// - This function is only called once for `map` in `Drop`.
unsafe { [< __rust_proto_thunk__Map_ $key_t _ $t _free >](map.as_mut().as_raw(Private)); }
}
fn map_clear(mut map: Mut<'_, Map<$key_t, Self>>) {
unsafe { [< __rust_proto_thunk__Map_ $key_t _ $t _clear >](map.as_raw(Private)); }
}
fn map_len(map: View<'_, Map<$key_t, Self>>) -> usize {
unsafe { [< __rust_proto_thunk__Map_ $key_t _ $t _size >](map.as_raw(Private)) }
}
fn map_insert(mut map: Mut<'_, Map<$key_t, Self>>, key: View<'_, $key_t>, value: View<'_, Self>) -> bool {
let ffi_key = $to_ffi_key(key);
let ffi_value = $to_ffi_value(value);
unsafe { [< __rust_proto_thunk__Map_ $key_t _ $t _insert >](map.as_raw(Private), ffi_key, ffi_value) }
}
fn map_get<'a>(map: View<'a, Map<$key_t, Self>>, key: View<'_, $key_t>) -> Option<View<'a, Self>> {
let ffi_key = $to_ffi_key(key);
let mut ffi_value = MaybeUninit::uninit();
let found = unsafe { [< __rust_proto_thunk__Map_ $key_t _ $t _get >](map.as_raw(Private), ffi_key, ffi_value.as_mut_ptr()) };
if !found {
return None;
}
// SAFETY: if `found` is true, then the `ffi_value` was written to by `get`.
Some($from_ffi_value(unsafe { ffi_value.assume_init() }))
}
fn map_remove(mut map: Mut<'_, Map<$key_t, Self>>, key: View<'_, $key_t>) -> bool {
let ffi_key = $to_ffi_key(key);
let mut ffi_value = MaybeUninit::uninit();
unsafe { [< __rust_proto_thunk__Map_ $key_t _ $t _remove >](map.as_raw(Private), ffi_key, ffi_value.as_mut_ptr()) }
}
fn map_iter(map: View<'_, Map<$key_t, Self>>) -> MapIter<'_, $key_t, Self> {
// SAFETY:
// - The backing map for `map.as_raw` is valid for at least '_.
// - A View that is live for '_ guarantees the backing map is unmodified for '_.
// - The `iter` function produces an iterator that is valid for the key
// and value types, and live for at least '_.
unsafe {
MapIter::from_raw(
Private,
[< __rust_proto_thunk__Map_ $key_t _ $t _iter >](map.as_raw(Private))
)
}
}
fn map_iter_next<'a>(iter: &mut MapIter<'a, $key_t, Self>) -> Option<(View<'a, $key_t>, View<'a, Self>)> {
// SAFETY:
// - The `MapIter` API forbids the backing map from being mutated for 'a,
// and guarantees that it's the correct key and value types.
// - The thunk is safe to call as long as the iterator isn't at the end.
// - The thunk always writes to key and value fields and does not read.
// - The thunk does not increment the iterator.
unsafe {
iter.as_raw_mut(Private).next_unchecked::<$key_t, Self, _, _>(
Private,
[< __rust_proto_thunk__Map_ $key_t _ $t _iter_get >],
$from_ffi_key,
$from_ffi_value,
)
}
}
}
)* }
}
}
fn str_to_ptrlen<'msg>(val: impl Into<&'msg ProtoStr>) -> PtrAndLen {
val.into().as_bytes().into()
}
// Warning: this function is unsound on its own! `val.as_ref()` must be safe to
// call.
fn ptrlen_to_str<'msg>(val: PtrAndLen) -> &'msg ProtoStr {
unsafe { ProtoStr::from_utf8_unchecked(val.as_ref()) }
}
fn bytes_to_ptrlen(val: &[u8]) -> PtrAndLen {
val.into()
}
// Warning: this function is unsound on its own! `val.as_ref()` must be safe to
// call.
fn ptrlen_to_bytes<'msg>(val: PtrAndLen) -> &'msg [u8] {
unsafe { val.as_ref() }
}
macro_rules! impl_ProxiedInMapValue_for_key_types {
($($t:ty, $ffi_t:ty, $to_ffi_key:expr, $from_ffi_key:expr;)*) => {
paste! {
$(
impl_ProxiedInMapValue_for_non_generated_value_types!(
$t, $ffi_t, $to_ffi_key, $from_ffi_key, for
f32, f32, identity, identity;
f64, f64, identity, identity;
i32, i32, identity, identity;
u32, u32, identity, identity;
i64, i64, identity, identity;
u64, u64, identity, identity;
bool, bool, identity, identity;
ProtoStr, PtrAndLen, str_to_ptrlen, ptrlen_to_str;
Bytes, PtrAndLen, bytes_to_ptrlen, ptrlen_to_bytes;
);
)*
}
}
}
impl_ProxiedInMapValue_for_key_types!(
i32, i32, identity, identity;
u32, u32, identity, identity;
i64, i64, identity, identity;
u64, u64, identity, identity;
bool, bool, identity, identity;
ProtoStr, PtrAndLen, str_to_ptrlen, ptrlen_to_str;
);
#[cfg(test)]
mod tests {
use super::*;
use googletest::prelude::*;
// We need to allocate the byte array so SerializedData can own it and
// deallocate it in its drop. This function makes it easier to do so for our
// tests.
fn allocate_byte_array(content: &'static [u8]) -> (*mut u8, usize) {
let content: &mut [u8] = Box::leak(content.into());
(content.as_mut_ptr(), content.len())
}
#[test]
fn test_serialized_data_roundtrip() {
let (ptr, len) = allocate_byte_array(b"Hello world");
let serialized_data = SerializedData { data: NonNull::new(ptr).unwrap(), len };
assert_that!(&*serialized_data, eq(b"Hello world"));
}
#[test]
fn test_empty_string() {
let empty_str: String = RustStringRawParts { data: std::ptr::null(), len: 0 }.into();
assert_that!(empty_str, eq(""));
}
}