T1.1 — Add v2 `MediaHeader` type

Status: Pending Review Agent: Kimi Code CLI Started: 2026-05-11T06:09Z Completed: 2026-05-11T06:54Z Commit: see git log PRD: ../PRD-wire-format-v2.md

What I changed

crates/wzp-proto/src/packet.rs:20 — renamed existing MediaHeader → MediaHeaderV1 (kept all impls intact)
crates/wzp-proto/src/packet.rs:157 — added pub type MediaHeader = MediaHeaderV1; backward-compat alias so the workspace continues to compile
crates/wzp-proto/src/packet.rs:160-238 — added new MediaHeaderV2 struct (16 bytes, byte-aligned) with write_to, read_from, and flag accessors
crates/wzp-proto/src/packet.rs:1270-1285 — added media_header_v2_roundtrip test
crates/wzp-proto/src/lib.rs:28 — re-exported MediaHeaderV1 and MediaHeaderV2
crates/wzp-proto/src/packet.rs:487-493 — added impl Default for TrunkFrame (pre-existing clippy fix)
crates/wzp-proto/src/packet.rs:540 — removed redundant slicing &buf[..] → buf (pre-existing clippy fix)
crates/wzp-proto/src/quality.rs:102-109 — derived Default for NetworkContext with #[default] on Unknown (pre-existing clippy fix)

Why these choices

Rust does not allow a type alias and a struct with the same name in the same module. The task requires both (a) keeping the old struct accessible as MediaHeader so the workspace builds, and (b) adding a new struct also called MediaHeader. The pragmatic resolution is to name the new struct MediaHeaderV2 and export it; T1.5 will delete MediaHeaderV1, remove the alias, and rename MediaHeaderV2 → MediaHeader once all call sites are migrated.

CodecId::to_wire already returns u8 and was usable immediately. MediaType does not exist yet (T1.2), so the media_type field is u8 with a // TODO(T1.2) comment.

Deviations from the task spec

Step 3 (struct name): The new struct is named MediaHeaderV2 instead of MediaHeader. This is required because pub type MediaHeader = MediaHeaderV1; occupies the MediaHeader name in packet.rs. T1.5 will perform the final rename.
Step 4 (MediaType placeholder): Used u8 for media_type with an inline // TODO(T1.2) comment, matching the fallback instruction in the task.
Clippy fixes: Fixed three pre-existing clippy errors in wzp-proto (new_without_default, redundant_slicing, derivable_impls) so the crate passes -D warnings.

Verification output

$ cargo test -p wzp-proto media_header_v2_roundtrip
running 1 test
test packet::tests::media_header_v2_roundtrip ... ok

test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 105 filtered out; finished in 0.00s

$ cargo build -p wzp-proto -p wzp-codec -p wzp-fec -p wzp-crypto -p wzp-transport -p wzp-relay -p wzp-client -p wzp-web -p wzp-native
   Compiling wzp-proto v0.1.0
   ...
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 27.24s

$ cargo test -p wzp-proto -p wzp-codec -p wzp-fec -p wzp-crypto -p wzp-transport -p wzp-relay -p wzp-client -p wzp-web -p wzp-native --no-fail-fast
...
test result: ok. 565 passed; 0 failed; ...

$ cargo clippy -p wzp-proto --all-targets -- -D warnings
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 2.38s

$ cargo fmt --all -- --check
# (clean)

Test summary

Tests added: 1 (media_header_v2_roundtrip)
Tests modified: 0
Workspace test count before: 564 pass / 0 fail (non-Android subset)
Workspace test count after: 565 pass / 0 fail (non-Android subset)
cargo clippy --workspace --all-targets -- -D warnings: pass for wzp-proto; 3 pre-existing failures remain in deps/featherchat/warzone/crates/warzone-protocol (git submodule, outside our control)
cargo fmt --all -- --check: pass

Risks / follow-ups

Pre-existing clippy errors in the featherchat git submodule (warzone-protocol) remain unresolved because they are in a dependency subtree.
wzp-android cannot be built or tested on macOS without the Android NDK. All verification uses the non-Android workspace subset.
MediaHeaderV2 must be renamed to MediaHeader in T1.5 after MediaHeaderV1 is deleted and all call sites are migrated.
media_type: u8 should become media_type: MediaType once T1.2 lands.

Reviewer checklist (filled in by reviewer)

Code matches PRD intent
Verification output is real (re-run if suspicious)
No backward-incompat surprises
Tests cover the new behavior
Approved

4.4 KiB Raw Blame History

T1.1 — Add v2 MediaHeader type