fidl_next_protocol/
wire.rs

1// Copyright 2024 The Fuchsia Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5use core::mem::MaybeUninit;
6
7use fidl_next_codec::{
8    Decode, DecodeError, Encodable, Encode, EncodeError, Slot, WireU32, WireU64, ZeroPadding,
9};
10
11use zerocopy::IntoBytes;
12
13/// A FIDL protocol message header
14#[derive(Clone, Copy, Debug, IntoBytes)]
15#[repr(C)]
16pub struct WireMessageHeader {
17    /// The transaction ID of the message header
18    pub txid: WireU32,
19    /// Flags
20    pub flags: [u8; 3],
21    /// Magic number
22    pub magic_number: u8,
23    /// The ordinal of the message following this header
24    pub ordinal: WireU64,
25}
26
27unsafe impl ZeroPadding for WireMessageHeader {
28    #[inline]
29    fn zero_padding(_: &mut MaybeUninit<Self>) {
30        // Wire message headers have no padding
31    }
32}
33
34/// The flag 0 bit indicating that the wire format is v2.
35pub const FLAG_0_WIRE_FORMAT_V2_BIT: u8 = 0b0000_0010;
36
37/// The magic number indicating FIDL protocol compatibility.
38pub const MAGIC_NUMBER: u8 = 0x01;
39
40impl Encodable for WireMessageHeader {
41    type Encoded = WireMessageHeader;
42}
43
44unsafe impl<E: ?Sized> Encode<E> for WireMessageHeader {
45    #[inline]
46    fn encode(
47        &mut self,
48        _: &mut E,
49        out: &mut MaybeUninit<Self::Encoded>,
50    ) -> Result<(), EncodeError> {
51        out.write(*self);
52        Ok(())
53    }
54}
55
56unsafe impl<D: ?Sized> Decode<D> for WireMessageHeader {
57    #[inline]
58    fn decode(_: Slot<'_, Self>, _: &mut D) -> Result<(), DecodeError> {
59        Ok(())
60    }
61}
fidl_next_protocol/wire.rs

fidl_next_protocol/
wire.rs
