From a1764f7690cfdc3e42724fcad29ef954b7e576a4 Mon Sep 17 00:00:00 2001
From: Matt Mastracci <matthew@mastracci.com>
Date: Tue, 4 Apr 2023 06:46:31 -0600
Subject: refactor(core): Improve ergonomics of managing ASCII strings (#18498)

This is a follow-on to the earlier work in reducing string copies,
mainly focused on ensuring that ASCII strings are easy to provide to the
JS runtime.

While we are replacing a 16-byte reference in a number of places with a
24-byte structure (measured via `std::mem::size_of`), the reduction in
copies wins out over the additional size of the arguments passed into
functions.

Benchmarking shows approximately the same if not slightly less wallclock
time/instructions retired, but I believe this continues to open up
further refactoring opportunities.
---
 cli/tsc/mod.rs | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

(limited to 'cli/tsc')

diff --git a/cli/tsc/mod.rs b/cli/tsc/mod.rs
index a9dc5b7f3..3bd8efefa 100644
--- a/cli/tsc/mod.rs
+++ b/cli/tsc/mod.rs
@@ -13,6 +13,7 @@ use crate::util::path::mapped_specifier_for_tsc;
 use deno_ast::MediaType;
 use deno_core::anyhow::anyhow;
 use deno_core::anyhow::Context;
+use deno_core::ascii_str;
 use deno_core::error::AnyError;
 use deno_core::located_script_name;
 use deno_core::op;
@@ -131,8 +132,8 @@ fn get_asset_texts_from_new_runtime() -> Result<Vec<AssetText>, AnyError> {
     extensions: vec![deno_cli_tsc::init_ops()],
     ..Default::default()
   });
-  let global =
-    runtime.execute_script("get_assets.js", "globalThis.getAssets()")?;
+  let global = runtime
+    .execute_script("get_assets.js", ascii_str!("globalThis.getAssets()"))?;
   let scope = &mut runtime.handle_scope();
   let local = deno_core::v8::Local::new(scope, global);
   Ok(serde_v8::from_v8::<Vec<AssetText>>(scope, local)?)
@@ -792,15 +793,14 @@ pub fn exec(request: Request) -> Result<Response, AnyError> {
     },
   );
 
-  let startup_source = "globalThis.startup({ legacyFlag: false })";
+  let startup_source = ascii_str!("globalThis.startup({ legacyFlag: false })");
   let request_value = json!({
     "config": request.config,
     "debug": request.debug,
     "rootNames": root_names,
     "localOnly": request.check_mode == TypeCheckMode::Local,
   });
-  let request_str = request_value.to_string();
-  let exec_source = format!("globalThis.exec({request_str})");
+  let exec_source = format!("globalThis.exec({request_value})").into();
 
   let mut runtime = JsRuntime::new(RuntimeOptions {
     startup_snapshot: Some(compiler_snapshot()),
@@ -974,7 +974,7 @@ mod tests {
       ..Default::default()
     });
     js_runtime
-      .execute_script(
+      .execute_script_static(
         "<anon>",
         r#"
       if (!(startup)) {
-- 
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