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.

1 files changed, 8 insertions, 5 deletions

diff --git a/runtime/web_worker.rs b/runtime/web_worker.rs
index 8bd5cf21e..4be40c9b0 100644
--- a/runtime/web_worker.rs
+++ b/runtime/web_worker.rs
@@ -9,6 +9,7 @@ use crate::BootstrapOptions;
 use deno_broadcast_channel::InMemoryBroadcastChannel;
 use deno_cache::CreateCache;
 use deno_cache::SqliteBackedCache;
+use deno_core::ascii_str;
 use deno_core::error::AnyError;
 use deno_core::error::JsError;
 use deno_core::futures::channel::mpsc;
@@ -572,11 +573,13 @@ impl WebWorker {
     // TODO(bartlomieju): this could be done using V8 API, without calling `execute_script`.
     // Save a reference to function that will start polling for messages
     // from a worker host; it will be called after the user code is loaded.
-    let script = r#"
+    let script = ascii_str!(
+      r#"
     const pollForMessages = globalThis.pollForMessages;
     delete globalThis.pollForMessages;
     pollForMessages
-    "#;
+    "#
+    );
     let poll_for_messages_fn = self
       .js_runtime
       .execute_script(located_script_name!(), script)
@@ -585,10 +588,10 @@ impl WebWorker {
   }
 
   /// See [JsRuntime::execute_script](deno_core::JsRuntime::execute_script)
-  pub fn execute_script<S: Into<ModuleCode>>(
+  pub fn execute_script(
     &mut self,
     name: &'static str,
-    source_code: S,
+    source_code: ModuleCode,
   ) -> Result<(), AnyError> {
     self.js_runtime.execute_script(name, source_code)?;
     Ok(())
@@ -777,7 +780,7 @@ pub fn run_web_worker(
 
     // Execute provided source code immediately
     let result = if let Some(source_code) = maybe_source_code.take() {
-      let r = worker.execute_script(located_script_name!(), source_code);
+      let r = worker.execute_script(located_script_name!(), source_code.into());
       worker.start_polling_for_messages();
       r
     } else {