I've been trying to reproduce and minimize an auto-complete and semantic highlighting slowdown in our closed-source codebase. It's a rather large async method spanning over 500 lines of code. I've figured that the number of expressions (including the 20x tracing::debug!() lines) and it being async might be the reason why.
This Python script produces the repro code:
python3 - <<'EOF'
n = 1600
body = "".join(f" let s{i} = String::new();\n let l{i} = s{i}.len();\n"
for i in range(n))
open("repro.rs", "w").write(
f"pub fn sync_body() {{\n{body}}}\n"
f"pub async fn async_body() {{\n{body}}}\n")
EOFThis produces a file that looks like:
pub fn sync_body() {
let s0 = String::new();
let l0 = s0.len();
let s1 = String::new();
let l1 = s1.len();
// ...
// s0.<|>
// s0<|>
}
pub async fn async_body() {
let s0 = String::new();
let l0 = s0.len();
let s1 = String::new();
let l1 = s1.len();
// ...
// s0.<|>
// s0<|>
} Auto-complete in sync_body completes in roughly 1–2s. The async variant completes in roughly 5–6s.
Using rust-analyzer: d2e55da
I've been trying to reproduce and minimize an auto-complete and semantic highlighting slowdown in our closed-source codebase. It's a rather large async method spanning over 500 lines of code. I've figured that the number of expressions (including the 20x tracing::debug!() lines) and it being async might be the reason why.
This Python script produces the repro code:
This produces a file that looks like:
Auto-complete in sync_body completes in roughly 1–2s. The async variant completes in roughly 5–6s.
Using rust-analyzer: d2e55da