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Simplify hook state and preallocate frame encoding

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This commit is contained in:
Michael Mikovsky
2026-04-25 22:42:45 -06:00
parent 80611a4d74
commit 090c2740f8
8 changed files with 163 additions and 141 deletions
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src/protocol/codec.rs
+42 -30
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@@ -1,6 +1,8 @@
//! Framed packet encoding and decoding.
use core::{fmt, mem};
use rkyv::{Serialize, access, api::high::to_bytes_in, deserialize, rancor::Error, util::AlignedVec};
use rkyv::{
Serialize, access, api::high::to_bytes_in, deserialize, rancor::Error, util::AlignedVec,
};
use super::types::{
ArchivedCallMessage, ArchivedDataMessage, ArchivedFaultMessage, ArchivedPacketHeader,
@@ -85,17 +87,19 @@ where
>,
{
let header_start = align_up(8usize, SECTION_ALIGN);
let mut frame = FrameBytes::new();
// Reserve enough space for the framing prefix plus a typical header/payload pair so the
// common encode path avoids early growth reallocations inside `to_bytes_in`.
let mut frame = FrameBytes::with_capacity(header_start + 256);
frame.resize(header_start, 0);
frame = to_bytes_in::<_, Error>(header, frame).map_err(FrameError::Serialize)?;
let header_len = u32::try_from(frame.len() - header_start)
.map_err(|_| FrameError::LengthOverflow)?;
let header_len =
u32::try_from(frame.len() - header_start).map_err(|_| FrameError::LengthOverflow)?;
let payload_start = align_up(frame.len(), SECTION_ALIGN);
frame.resize(payload_start, 0);
frame = to_bytes_in::<_, Error>(payload, frame).map_err(FrameError::Serialize)?;
let payload_len = u32::try_from(frame.len() - payload_start)
.map_err(|_| FrameError::LengthOverflow)?;
let payload_len =
u32::try_from(frame.len() - payload_start).map_err(|_| FrameError::LengthOverflow)?;
frame[0..4].copy_from_slice(&header_len.to_be_bytes());
frame[4..8].copy_from_slice(&payload_len.to_be_bytes());
@@ -104,36 +108,15 @@ where
/// Decodes one aligned two-section frame.
pub fn decode_frame(bytes: &[u8]) -> Result<ParsedFrame<'_>, FrameError> {
if bytes.len() < 8 {
return Err(FrameError::Truncated);
}
let header_len = read_u32(bytes, 0)? as usize;
let payload_len = read_u32(bytes, 4)? as usize;
let header_start = align_up(8usize, SECTION_ALIGN);
let header_end = header_start + header_len;
if header_end > bytes.len() {
return Err(FrameError::Truncated);
}
let payload_start = align_up(header_end, SECTION_ALIGN);
let payload_end = payload_start + payload_len;
if payload_end != bytes.len() {
return Err(FrameError::Truncated);
}
let (header_bytes, payload_bytes) = split_frame_sections(bytes)?;
let header = deserialize_section::<ArchivedPacketHeader, PacketHeader>(
bytes
.get(header_start..header_end)
.ok_or(FrameError::Truncated)?,
header_bytes,
FrameError::InvalidHeader,
)?;
Ok(ParsedFrame {
header,
payload_bytes: bytes
.get(payload_start..payload_end)
.ok_or(FrameError::Truncated)?,
payload_bytes,
})
}
@@ -159,6 +142,35 @@ fn read_u32(bytes: &[u8], start: usize) -> Result<u32, FrameError> {
))
}
fn split_frame_sections(bytes: &[u8]) -> Result<(&[u8], &[u8]), FrameError> {
if bytes.len() < 8 {
return Err(FrameError::Truncated);
}
let header_len = read_u32(bytes, 0)? as usize;
let payload_len = read_u32(bytes, 4)? as usize;
let header_start = align_up(8usize, SECTION_ALIGN);
let header_end = header_start + header_len;
if header_end > bytes.len() {
return Err(FrameError::Truncated);
}
let payload_start = align_up(header_end, SECTION_ALIGN);
let payload_end = payload_start + payload_len;
if payload_end != bytes.len() {
return Err(FrameError::Truncated);
}
Ok((
bytes
.get(header_start..header_end)
.ok_or(FrameError::Truncated)?,
bytes
.get(payload_start..payload_end)
.ok_or(FrameError::Truncated)?,
))
}
fn align_up(offset: usize, alignment: usize) -> usize {
let mask = alignment - 1;
(offset + mask) & !mask