codegen: local counter per repeated field on decode
Replaces `list[#list + 1] = val` with `_n_<fname> = _n_<fname> + 1;
list[_n_<fname>] = val` in every generated M.X_decode repeated-field
append site. One counter local per repeated non-map field, declared at
function entry. Counters survive across loop iterations so out-of-order
wire entries for the same field continue past the existing length
without re-scanning.
Profile attributed 6.2% of hello.Person 1KB decode to the `#list + 1`
re-traversal (26-email Person paid 26 list scans per decode).
Bench (Person full decode, msgs/s, median-of-3 vs post-4kj):
1KB +5.0%, 10KB +5.0%, 100KB +7.1%. Encode flat. Tests 745/745.
JIT 37/37, 0 bridges.
beads-tarantool-protobuf-cch
codegen: inline 1-byte tag fast path at decode call sites
Hoists wire.decode_tag's 1-byte fast path into every generated
M.X_decode while-loop, falling back to the helper for multi-byte
tags (field ids > 15). The 1-byte case covers every protobuf field
with id 1..15 and is the dominant decode dispatch in real payloads.
Header now localizes string.byte, bit.band, and bit.rshift so the
inlined ops compile to straight local calls.
Bench (Person full decode, msgs/s, median-of-3 vs proper post-h8v
3-run baseline): 10B +14.7%, 100B +8.9%, 1KB +7.5%, 10KB +7.0%,
100KB +8.5%. Full encode is flat to small (-0.1% to -2.6%) at large
sizes, plausibly from header-upvalue layout. JIT trace gate: 37/37,
all bridges still 0. Tests: 745/745.
Also documented in bench/PERF_LOG.md, including the methodology
note that h8v's earlier numbers used single-run baselines and are
therefore ~3-5% optimistic; medians-of-3 are the standard now.
beads-tarantool-protobuf-4kj
codegen: inline 1-byte varint length prefix at every LEN emit site
Eliminates the wire.encode_varint(#body) call + dispatch for every
length-delimited field in mode=full codegen. Profile flagged the
out[n] = wire.encode_varint(#_b) line as ~33% of hello.Person 1KB
encode time, with another ~17% in encode_varint dispatch — together
~50% of encode time. Lifting the 1-byte fast path (the dominant case
for proto strings and small message bodies) to the call site removes
the function frame entirely for lengths < 128.
Applied at every LEN emit site: singular/repeated message body,
singular/repeated string|bytes, packed scalar bundle, packed enum
bundle, map entry. Map value pieces (emitMapPiece message branch)
left as-is — they sit inside a single slot assignment that would
require a deeper restructure, and maps are not on the current hot
benchmark.
Results (hello.Person full encode, msgs/s): 10B +6.9%, 100B +7.9%,
1KB +25.7%, 10KB +48.1%, 100KB +31.9%. Decode flat (unchanged path).
Runtime mode flat (descriptor dispatch still calls encode_varint).
JIT trace gate: 37/37. Test suite: 745/745.
Bench history saved to bench/PERF_LOG.md with full numbers and the
workflow this iteration follows.
beads-tarantool-protobuf-h8v
bench,codec: pin proto2 paths, kill pairs() on extension hot path
JIT trace gate gains 12 proto2-specific checks (required encode/decode,
groups singular + repeated, extension encode/decode). The extension-encode
check fired NYI on bytecode 72 (ISNEXT) — pairs() over the new
extensions_by_full_name hash is the same trace-abort that gates map
encode. Fix: register_extension now also appends to extensions_list,
an array view. codec.encode_message, text.emit_message and
json.encode_message all switch to ipairs over the list. Hash tables
stay around for O(1) lookups in decode (extensions_by_id) and bracket-
name resolution (extensions_by_full_name).
Inline (full-mode) codegen learns to walk extensions too: before this
commit the inline encoder skipped t._extensions entirely (only the
runtime codec walked it), so a generated _encode silently dropped any
extension data set on the message. Add the array-walk after the field
loop and a decode_extension dispatch in the unknown-tag branch — the
inline path now matches runtime byte-for-byte.
bench/bench.lua parameterizes over a FIXTURES list so the baseline can
cover both hello.Person and a new proto2_basic.BenchPayload fixture
(required + group + extension + repeated). baseline.json restructured
under "schemas": [{schema, results}, …]; compare walks both. Fresh
numbers committed.
740/740 luatest cases pass; JIT gate 37/37; conformance 2806 binary+JSON
and 434 text-format, both 0 failures.
text,codec: proto2 group text syntax + closed-enum semantics
Text decoder now resolves a group field reference by the group's
capitalized submessage name (e.g. \`Data\`, \`MultiWordGroupField\`)
and by the ASCII-lowercase fold (\`data\`, \`multiwordgroupfield\`),
in addition to the existing lowercase field-name lookup. The \`:\`
between field and \`{\` is optional for groups (matches the
message/map rule).
Proto2 enums are closed: parse_enum_value now rejects an integer
literal that doesn't map to any declared value. The plugin emits
\`closed = true\` on every proto2 enum descriptor (driven by
protoreflect's IsClosed()); proto3 enums stay open to preserve
forward-compatibility on the wire.
Conformance text-format suite: 16 unexpected failures → 3, all in
the remaining extension-bracketed-group cases.
codec: proto2 groups (SGROUP/EGROUP wire format)
Plugin: detect protoreflect.GroupKind, emit kind='group' in the
field descriptor and a SGROUP opening tag in inline codegen. The
group body bypasses the LEN-prefix path entirely — encoder emits
start-tag, body bytes, end-tag in three slots; decoder calls
pb.codec.decode_group(desc, buf, pos, field_id) which reads inner
tags until the matching EGROUP id.
Wire layer already understood SGROUP/EGROUP for skip_field; the new
decode_group reuses the per-tag dispatch from decode_message but
stops on EGROUP instead of end-of-buffer. Repeated groups bracket
each element with its own SGROUP/EGROUP pair.
Runtime parser now desugars `optional|required|repeated group Name
= id { body }` into (a) a nested message named Name and (b) a
synthetic field of kind=group whose lowercased name is `name` — so
source-parsed proto2 schemas behave the same as build-time codegen.
Text format renders groups under the submessage's capitalized name
(`SingleGroup { ... }`) rather than the lowercase field name,
matching mainline protoc's convention.
Adds a vendored, MessageSet-stripped test_messages_proto2.proto in
test/conformance/proto/ (header comment documents the patch).
10 new luatest cases (group_*) cover singular + repeated + text +
descriptor kind, across both codegen modes. 739 tests pass.
codegen: proto2 baseline — required, optional, custom defaults
Lifts the proto3-only syntax gate in the plugin and threads three
new field-descriptor attributes through codegen and the codec:
* required=true — fields declared with the proto2 `required` keyword.
Inline codegen and the runtime codec both error when
a required field is missing on encode (vs the silent
elide that proto3 implicit-presence fields get).
* optional=true — already wired for proto3 explicit `optional`; in
proto2 every singular field carries it via the
existing HasOptionalKeyword() check, giving presence
semantics without a separate emission path.
* default_value=… — proto2 [default = X] from the field descriptor,
rendered as a Lua literal (cdata for 64-bit ints,
symbolic name for enums) so consumers can surface
it; the codec itself does not auto-materialize
defaults on decode, matching how proto3 absent
fields stay nil.
Packed-by-default already flips correctly because we ask
protoreflect's `IsPacked()`, which is syntax-aware.
Adds test/proto/proto2_basic.proto with 33 luatest cases covering
required validation, optional presence, custom defaults, the proto2
unpacked-by-default repeated rule, nested-required messages, and
full-vs-runtime mode parity. `just gen-proto2-tests` regenerates the
fixture into examples/expected/{full,runtime}/.
Out of scope: extensions, extend, group; conformance harness still
skips TestAllTypesProto2.