Module envelope_codec 

Length-prefixed envelope framing for stream transports.

The wire record is:

  [ u32 BE length ][ buffa-encoded ObsEnvelope ]

No per-record CRC — stream transports (vsock, unix socket, TCP) are reliable byte-streams; buffa decode catches truncation. Any transport that needs integrity beyond TCP-level checksums can wrap the framed stream in its own MAC layer.

Boundary-review § 3.5 (moved upstream from tok-initd::obs::ObsEnvelopeCodec).

Usage

Reuse a single buffa::SizeCache across every envelope in one flush window — encode_into_with_cache calls clear() before each encode so the backing storage is amortised without leaking stale state between envelopes.

use obs_core::wire::envelope_codec;
use obs_proto::obs::v1::ObsEnvelope;

let env = ObsEnvelope::default();
let mut buf = Vec::with_capacity(4096);
let mut cache = buffa::SizeCache::new();
envelope_codec::encode_into_with_cache(&env, &mut buf, &mut cache);

// On the other side:
if let Some((decoded, consumed)) =
    envelope_codec::decode_frame(&buf, 1 << 20).expect("framing ok")
{
    assert_eq!(consumed, buf.len());
    let _ = decoded;
}

Functions

decode_frame

Decode one length-prefixed envelope from buf.

encode_into

Encode env into out, length-prefixed. Reuses out’s capacity so caller can amortise allocations across envelopes within one flush window.

encode_into_with_cache

Encode env into out reusing a caller-owned SizeCache.