| // Protocol Buffers - Google's data interchange format |
| // Copyright 2023 Google LLC. All rights reserved. |
| // https://developers.google.com/protocol-buffers/ |
| // |
| // Redistribution and use in source and binary forms, with or without |
| // modification, are permitted provided that the following conditions are |
| // met: |
| // |
| // * Redistributions of source code must retain the above copyright |
| // notice, this list of conditions and the following disclaimer. |
| // * Redistributions in binary form must reproduce the above |
| // copyright notice, this list of conditions and the following disclaimer |
| // in the documentation and/or other materials provided with the |
| // distribution. |
| // * Neither the name of Google LLC. nor the names of its |
| // contributors may be used to endorse or promote products derived from |
| // this software without specific prior written permission. |
| // |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| |
| // Rust Protobuf runtime using the C++ kernel. |
| |
| use std::alloc; |
| use std::alloc::Layout; |
| use std::cell::UnsafeCell; |
| use std::fmt; |
| use std::marker::PhantomData; |
| use std::mem::MaybeUninit; |
| use std::ops::Deref; |
| use std::ptr::NonNull; |
| use std::slice; |
| |
| /// A wrapper over a `proto2::Arena`. |
| /// |
| /// This is not a safe wrapper per se, because the allocation functions still |
| /// have sharp edges (see their safety docs for more info). |
| /// |
| /// This is an owning type and will automatically free the arena when |
| /// dropped. |
| /// |
| /// Note that this type is neither `Sync` nor `Send`. |
| pub struct Arena { |
| #[allow(dead_code)] |
| ptr: NonNull<u8>, |
| _not_sync: PhantomData<UnsafeCell<()>>, |
| } |
| |
| impl Arena { |
| /// Allocates a fresh arena. |
| #[inline] |
| pub fn new() -> Self { |
| Self { ptr: NonNull::dangling(), _not_sync: PhantomData } |
| } |
| |
| /// Returns the raw, C++-managed pointer to the arena. |
| #[inline] |
| pub fn raw(&self) -> ! { |
| unimplemented!() |
| } |
| |
| /// Allocates some memory on the arena. |
| /// |
| /// # Safety |
| /// |
| /// `layout`'s alignment must be less than `UPB_MALLOC_ALIGN`. |
| #[inline] |
| pub unsafe fn alloc(&self, _layout: Layout) -> &mut [MaybeUninit<u8>] { |
| unimplemented!() |
| } |
| |
| /// Resizes some memory on the arena. |
| /// |
| /// # Safety |
| /// |
| /// After calling this function, `ptr` is essentially zapped. `old` must |
| /// be the layout `ptr` was allocated with via [`Arena::alloc()`]. `new`'s |
| /// alignment must be less than `UPB_MALLOC_ALIGN`. |
| #[inline] |
| pub unsafe fn resize(&self, _ptr: *mut u8, _old: Layout, _new: Layout) -> &[MaybeUninit<u8>] { |
| unimplemented!() |
| } |
| } |
| |
| impl Drop for Arena { |
| #[inline] |
| fn drop(&mut self) { |
| // unimplemented |
| } |
| } |
| |
| /// 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 { |
| pub unsafe fn from_raw_parts(data: NonNull<u8>, len: usize) -> Self { |
| Self { data, len } |
| } |
| } |
| |
| impl Deref for SerializedData { |
| type Target = [u8]; |
| fn deref(&self) -> &Self::Target { |
| unsafe { slice::from_raw_parts(self.data.as_ptr(), self.len) } |
| } |
| } |
| |
| impl Drop for SerializedData { |
| fn drop(&mut self) { |
| unsafe { |
| alloc::dealloc(self.data.as_ptr(), Layout::array::<u8>(self.len).unwrap()); |
| }; |
| } |
| } |
| |
| impl fmt::Debug for SerializedData { |
| fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
| fmt::Debug::fmt(self.deref(), f) |
| } |
| } |
| |
| #[cfg(test)] |
| mod tests { |
| use super::*; |
| use std::boxed::Box; |
| |
| // 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: len }; |
| assert_eq!(&*serialized_data, b"Hello world"); |
| } |
| } |