use crate::detectors::base::Detector;
use crate::models::{deterministic_finding_id, Finding, Severity};
use anyhow::Result;
use std::path::PathBuf;
use tracing::info;
use super::{clone_call, hot_path_indicator};
pub struct CloneInHotPathDetector {
repository_path: PathBuf,
max_findings: usize,
}
impl CloneInHotPathDetector {
pub fn new(repository_path: impl Into<PathBuf>) -> Self {
Self {
repository_path: repository_path.into(),
max_findings: 25,
}
}
fn is_hot_path_context(content: &str, line_idx: usize, current_line: &str) -> bool {
if hot_path_indicator().is_match(current_line) {
return true;
}
let lines: Vec<&str> = content.lines().collect();
let start = line_idx.saturating_sub(10);
let mut brace_depth = 0;
for i in (start..line_idx).rev() {
if let Some(line) = lines.get(i) {
brace_depth += line.matches('}').count();
brace_depth = brace_depth.saturating_sub(line.matches('{').count());
if brace_depth == 0 && hot_path_indicator().is_match(line) {
return true;
}
}
}
false
}
}
impl Detector for CloneInHotPathDetector {
fn name(&self) -> &'static str { "rust-clone-in-hot-path" }
fn description(&self) -> &'static str { "Detects .clone() in loops and iterators" }
fn detect(&self, _graph: &dyn crate::graph::GraphQuery) -> Result<Vec<Finding>> {
let mut findings = vec![];
let walker = ignore::WalkBuilder::new(&self.repository_path)
.hidden(false).git_ignore(true).build();
for entry in walker.filter_map(|e| e.ok()) {
if findings.len() >= self.max_findings { break; }
let path = entry.path();
if !path.is_file() { continue; }
if path.extension().and_then(|e| e.to_str()) != Some("rs") { continue; }
let Some(content) = crate::cache::global_cache().get_content(path) else { continue };
for (i, line) in content.lines().enumerate() {
let trimmed = line.trim();
if trimmed.starts_with("//") { continue; }
if clone_call().is_match(line) && Self::is_hot_path_context(&content, i, line) {
let file_str = path.to_string_lossy();
let line_num = (i + 1) as u32;
findings.push(Finding {
id: deterministic_finding_id("CloneInHotPathDetector", &file_str, line_num, "clone in hot path"),
detector: "CloneInHotPathDetector".to_string(),
severity: Severity::Low,
title: ".clone() in loop/iterator (performance)".to_string(),
description: "Cloning in a hot path can cause performance issues. Consider references, Cow, or Arc.".to_string(),
affected_files: vec![path.to_path_buf()],
line_start: Some(line_num),
line_end: Some(line_num),
suggested_fix: Some("Use references, Cow<str>, or Arc instead of clone.".to_string()),
estimated_effort: Some("20 minutes".to_string()),
category: Some("performance".to_string()),
why_it_matters: Some("Cloning inside loops multiplies allocation overhead.".to_string()),
..Default::default()
});
}
}
}
info!("CloneInHotPathDetector found {} findings", findings.len());
Ok(findings)
}
}