refactor(app): zero-alloc process-name diff for lsof debug log#329
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refactor(app): zero-alloc process-name diff for lsof debug log#329Pablosinyores wants to merge 1 commit into
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`enrich_with_lsof` walks every connection that already has a
`process_name` set and, when lsof returns a new candidate name, compares
the two to log a debug-level mismatch:
```rust
let existing_normalized = existing_name
.split_whitespace()
.collect::<Vec<&str>>()
.join(" ");
let new_normalized =
name.split_whitespace().collect::<Vec<&str>>().join(" ");
if existing_normalized != new_normalized {
debug!(...);
}
```
That's a `Vec<&str>` + a heap `String` for each side, both dropped on
the next statement, every connection, every enrichment pass — even when
debug logging is off.
Use `Iterator::ne` on the `split_whitespace` token iterators directly:
```rust
if existing_name
.split_whitespace()
.ne(name.split_whitespace())
{
debug!(...);
}
```
Iterator::ne walks both iterators in lockstep and short-circuits on the
first divergence, so the whitespace-collapsed comparison is equivalent
to the old join-then-compare but allocates nothing.
cargo fmt clean, cargo clippy --all-targets -- -D warnings clean,
cargo test --lib 365/365.
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Summary
`enrich_with_lsof` (`src/app.rs:1177`) walks every connection that already has a `process_name` set and, when lsof returns a new candidate name, compares the two to log a debug-level mismatch:
```rust
let existing_normalized = existing_name
.split_whitespace()
.collect::<Vec<&str>>()
.join(" ");
let new_normalized =
name.split_whitespace().collect::<Vec<&str>>().join(" ");
if existing_normalized != new_normalized {
debug!("...");
}
```
That's a `Vec<&str>` + a heap `String` per side, both dropped on the next statement, every connection, every enrichment pass — even when debug logging is off.
Patch
Use `Iterator::ne` on the `split_whitespace` token iterators directly:
```rust
if existing_name
.split_whitespace()
.ne(name.split_whitespace())
{
debug!("...");
}
```
`Iterator::ne` walks both iterators in lockstep and short-circuits on the first divergence, so the whitespace-collapsed comparison is equivalent to the old join-then-compare but allocates nothing.
Test plan
No behavior change (debug-log gating is unchanged, branch condition is observationally equivalent).