refactor(h1): add spans for parse_headers and encode_headers (#2262)

src/proto/h1/conn.rs

@@ -474,7 +474,7 @@ where
  self.enforce_version(&mut head);
 
  let buf = self.io.headers_buf();
- match T::encode(
+ match super::role::encode_headers::<T>(
  Encode {
  head: &mut head,
  body,

src/proto/h1/io.rs

@@ -149,7 +149,7 @@ where
  S: Http1Transaction,
  {
  loop {
- match S::parse(
+ match super::role::parse_headers::<S>(
  &mut self.read_buf,
  ParseContext {
  cached_headers: parse_ctx.cached_headers,

src/proto/h1/role.rs

@@ -58,6 +58,35 @@ macro_rules! header_value {
  }};
 }
 
+pub(super) fn parse_headers<T>(
+ bytes: &mut BytesMut,
+ ctx: ParseContext<'_>,
+) -> ParseResult<T::Incoming>
+where
+ T: Http1Transaction,
+{
+ // If the buffer is empty, don't bother entering the span, it's just noise.
+ if bytes.is_empty() {
+ return Ok(None);
+ }
+
+ let span = trace_span!("parse_headers");
+ let _s = span.enter();
+ T::parse(bytes, ctx)
+}
+
+pub(super) fn encode_headers<T>(
+ enc: Encode<'_, T::Outgoing>,
+ dst: &mut Vec<u8>,
+) -> crate::Result<Encoder>
+where
+ T: Http1Transaction,
+{
+ let span = trace_span!("encode_headers");
+ let _s = span.enter();
+ T::encode(enc, dst)
+}
+
 // There are 2 main roles, Client and Server.
 
 pub(crate) enum Client {}
@@ -70,9 +99,7 @@ impl Http1Transaction for Server {
  const LOG: &'static str = "{role=server}";
 
  fn parse(buf: &mut BytesMut, ctx: ParseContext<'_>) -> ParseResult<RequestLine> {
- if buf.is_empty() {
- return Ok(None);
- }
+ debug_assert!(!buf.is_empty(), "parse called with empty buf");
 
  let mut keep_alive;
  let is_http_11;
@@ -614,11 +641,10 @@ impl Http1Transaction for Client {
  const LOG: &'static str = "{role=client}";
 
  fn parse(buf: &mut BytesMut, ctx: ParseContext<'_>) -> ParseResult<StatusCode> {
+ debug_assert!(!buf.is_empty(), "parse called with empty buf");
+
  // Loop to skip information status code headers (100 Continue, etc).
  loop {
- if buf.is_empty() {
- return Ok(None);
- }
  // Unsafe: see comment in Server Http1Transaction, above.
  let mut headers_indices: [HeaderIndices; MAX_HEADERS] = unsafe { mem::uninitialized() };
  let (len, status, version, headers_len) = {
@@ -688,6 +714,12 @@ impl Http1Transaction for Client {
  wants_upgrade: is_upgrade,
  }));
  }
+
+ // Parsing a 1xx response could have consumed the buffer, check if
+ // it is empty now...
+ if buf.is_empty() {
+ return Ok(None);
+ }
  }
  }