perf(dpi): drop redundant lines().collect::<Vec<&str>>() in HTTP + SSH parsers#339
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obchain wants to merge 1 commit into
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perf(dpi): drop redundant lines().collect::<Vec<&str>>() in HTTP + SSH parsers#339obchain wants to merge 1 commit into
lines().collect::<Vec<&str>>() in HTTP + SSH parsers#339obchain wants to merge 1 commit into
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…SSH parsers
Both `analyze_http` and `analyze_ssh` were materializing the full line
iterator into a `Vec<&str>` and then walking it sequentially:
let lines: Vec<&str> = text.lines().collect();
if lines.is_empty() { return None; }
// …then index `lines[0]` and iterate `lines.iter().skip(1)`,
// or just `for line in lines { … }`.
Neither path needs random access. Drive the `Lines` iterator directly:
- `http.rs` pulls the request/status line via `next()?` (which also
subsumes the old `is_empty()` guard) and iterates the remainder for
headers.
- `ssh.rs` iterates `text.lines()` straight into the banner loop; the
`is_empty()` guard is dead because `is_likely_ssh` already requires
`payload.len() >= 4` plus a banner / packet-structure check upstream.
Per-packet on the DPI hot path, this saves one heap allocation per
parse (one `Vec<&str>` plus the slice it points into). An HTTP request
with N headers used to allocate a Vec of N+1 entries; now it allocates
zero. SSH banner parsing was a smaller win but the same shape of fix.
No behavior change — verified by the existing HTTP and SSH unit tests
(5 + 17, all passing) plus the full lib sweep (371 passed).
Closes domcyrus#338
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Summary
analyze_httpandanalyze_sshboth collectedtext.lines()into aVec<&str>and then walked it sequentially. Neither path needed random access —http.rsonly indexed[0]andskip(1)'d the rest, andssh.rsjust iterated.Drive the
Linesiterator directly instead:src/network/dpi/http.rs—lines.next()?for the request/status line (which also subsumes the oldis_empty()guard); the remaining iterator drives the header loop.src/network/dpi/ssh.rs— iteratetext.lines()straight into the banner loop. Theis_empty()guard was dead:is_likely_sshalready requirespayload.len() >= 4plus a banner/packet-structure check upstream.Per-packet on the DPI hot path, this drops one heap allocation per parse. An HTTP request with N headers used to allocate a Vec of N+1 entries; now zero. SSH banner parsing is a smaller win but identical shape.
Closes #338.
Behavior
No change. The first-line
next()?returns identically to indexing[0]after the oldis_empty()guard, and the header/banner iterators yield the same&stritems in the same order. Verified by the existing tests:Test plan
cargo test --libcargo fmt --checkcargo clippy --all-targets -- -D warnings