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.

8 files changed, 46 insertions, 42 deletions

diff --git a/cli/js.rs b/cli/js.rs
index fac771fd5..e3a5b94be 100644
--- a/cli/js.rs
+++ b/cli/js.rs
@@ -22,7 +22,7 @@ mod tests {
       ..Default::default()
     });
     js_runtime
-      .execute_script(
+      .execute_script_static(
         "<anon>",
         r#"
       if (!(bootstrap.mainRuntime && bootstrap.workerRuntime)) {
diff --git a/cli/lsp/tsc.rs b/cli/lsp/tsc.rs
index ef5d0e645..e236eee0a 100644
--- a/cli/lsp/tsc.rs
+++ b/cli/lsp/tsc.rs
@@ -2899,7 +2899,7 @@ fn start(runtime: &mut JsRuntime, debug: bool) -> Result<(), AnyError> {
   let init_config = json!({ "debug": debug });
   let init_src = format!("globalThis.serverInit({init_config});");
 
-  runtime.execute_script(located_script_name!(), init_src)?;
+  runtime.execute_script(located_script_name!(), init_src.into())?;
   Ok(())
 }
 
@@ -3493,7 +3493,7 @@ pub fn request(
   };
   let mark = performance.mark("request", Some(request_params.clone()));
   let request_src = format!("globalThis.serverRequest({request_params});");
-  runtime.execute_script(located_script_name!(), request_src)?;
+  runtime.execute_script(located_script_name!(), request_src.into())?;
 
   let op_state = runtime.op_state();
   let mut op_state = op_state.borrow_mut();
diff --git a/cli/module_loader.rs b/cli/module_loader.rs
index 7f6101d80..b7df15e31 100644
--- a/cli/module_loader.rs
+++ b/cli/module_loader.rs
@@ -78,7 +78,7 @@ impl CliModuleLoader {
   fn load_prepared_module(
     &self,
     specifier: &ModuleSpecifier,
-    maybe_referrer: Option<ModuleSpecifier>,
+    maybe_referrer: Option<&ModuleSpecifier>,
   ) -> Result<ModuleCodeSource, AnyError> {
     if specifier.scheme() == "node" {
       unreachable!(); // Node built-in modules should be handled internally.
@@ -92,7 +92,7 @@ impl CliModuleLoader {
         specifier,
         ..
       })) => Ok(ModuleCodeSource {
-        code: source.into(),
+        code: source.clone().into(),
         found_url: specifier.clone(),
         media_type: *media_type,
       }),
@@ -107,7 +107,7 @@ impl CliModuleLoader {
           | MediaType::Unknown
           | MediaType::Cjs
           | MediaType::Mjs
-          | MediaType::Json => source.into(),
+          | MediaType::Json => source.clone().into(),
           MediaType::Dts | MediaType::Dcts | MediaType::Dmts => {
             Default::default()
           }
@@ -154,7 +154,7 @@ impl CliModuleLoader {
   fn load_sync(
     &self,
     specifier: &ModuleSpecifier,
-    maybe_referrer: Option<ModuleSpecifier>,
+    maybe_referrer: Option<&ModuleSpecifier>,
     is_dynamic: bool,
   ) -> Result<ModuleSource, AnyError> {
     let code_source = if self.ps.npm_resolver.in_npm_package(specifier) {
@@ -210,15 +210,15 @@ impl CliModuleLoader {
       // because we don't need it
       code_without_source_map(code_source.code)
     };
-    Ok(ModuleSource {
-      code,
-      module_url_specified: specifier.to_string(),
-      module_url_found: code_source.found_url.to_string(),
-      module_type: match code_source.media_type {
+    Ok(ModuleSource::new_with_redirect(
+      match code_source.media_type {
         MediaType::Json => ModuleType::Json,
         _ => ModuleType::JavaScript,
       },
-    })
+      code,
+      specifier,
+      &code_source.found_url,
+    ))
   }
 }
 
@@ -240,7 +240,7 @@ impl ModuleLoader for CliModuleLoader {
   fn load(
     &self,
     specifier: &ModuleSpecifier,
-    maybe_referrer: Option<ModuleSpecifier>,
+    maybe_referrer: Option<&ModuleSpecifier>,
     is_dynamic: bool,
   ) -> Pin<Box<deno_core::ModuleSourceFuture>> {
     // NOTE: this block is async only because of `deno_core` interface
diff --git a/cli/standalone.rs b/cli/standalone.rs
index 527e8d975..08caacda6 100644
--- a/cli/standalone.rs
+++ b/cli/standalone.rs
@@ -25,6 +25,7 @@ use deno_core::url::Url;
 use deno_core::v8_set_flags;
 use deno_core::ModuleLoader;
 use deno_core::ModuleSpecifier;
+use deno_core::ModuleType;
 use deno_core::ResolutionKind;
 use deno_graph::source::Resolver;
 use deno_runtime::fmt_errors::format_js_error;
@@ -165,7 +166,7 @@ impl ModuleLoader for EmbeddedModuleLoader {
   fn load(
     &self,
     module_specifier: &ModuleSpecifier,
-    _maybe_referrer: Option<ModuleSpecifier>,
+    _maybe_referrer: Option<&ModuleSpecifier>,
     _is_dynamic: bool,
   ) -> Pin<Box<deno_core::ModuleSourceFuture>> {
     let is_data_uri = get_source_from_data_url(module_specifier).ok();
@@ -173,33 +174,33 @@ impl ModuleLoader for EmbeddedModuleLoader {
       .eszip
       .get_module(module_specifier.as_str())
       .ok_or_else(|| type_error("Module not found"));
-
+    // TODO(mmastrac): This clone can probably be removed in the future if ModuleSpecifier is no longer a full-fledged URL
     let module_specifier = module_specifier.clone();
+
     async move {
       if let Some((source, _)) = is_data_uri {
-        return Ok(deno_core::ModuleSource {
-          code: source.into(),
-          module_type: deno_core::ModuleType::JavaScript,
-          module_url_specified: module_specifier.to_string(),
-          module_url_found: module_specifier.to_string(),
-        });
+        return Ok(deno_core::ModuleSource::new(
+          deno_core::ModuleType::JavaScript,
+          source.into(),
+          &module_specifier,
+        ));
       }
 
       let module = module?;
       let code = module.source().await;
       let code = std::str::from_utf8(&code)
         .map_err(|_| type_error("Module source is not utf-8"))?
-        .to_owned();
+        .to_owned()
+        .into();
 
-      Ok(deno_core::ModuleSource {
-        code: code.into(),
-        module_type: match module.kind {
-          eszip::ModuleKind::JavaScript => deno_core::ModuleType::JavaScript,
-          eszip::ModuleKind::Json => deno_core::ModuleType::Json,
+      Ok(deno_core::ModuleSource::new(
+        match module.kind {
+          eszip::ModuleKind::JavaScript => ModuleType::JavaScript,
+          eszip::ModuleKind::Json => ModuleType::Json,
         },
-        module_url_specified: module_specifier.to_string(),
-        module_url_found: module_specifier.to_string(),
-      })
+        code,
+        &module_specifier,
+      ))
     }
     .boxed_local()
   }
diff --git a/cli/tools/coverage/mod.rs b/cli/tools/coverage/mod.rs
index 2346b3614..7f2598811 100644
--- a/cli/tools/coverage/mod.rs
+++ b/cli/tools/coverage/mod.rs
@@ -691,7 +691,7 @@ pub async fn cover_files(
       | MediaType::Unknown
       | MediaType::Cjs
       | MediaType::Mjs
-      | MediaType::Json => file.source.into(),
+      | MediaType::Json => file.source.clone().into(),
       MediaType::Dts | MediaType::Dmts | MediaType::Dcts => Default::default(),
       MediaType::TypeScript
       | MediaType::Jsx
@@ -718,7 +718,7 @@ pub async fn cover_files(
     let source_map = source_map_from_code(&transpiled_code);
     let coverage_report = generate_coverage_report(
       &script_coverage,
-      transpiled_code.take_as_string(),
+      transpiled_code.as_str().to_owned(),
       &source_map,
       &out_mode,
     );
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)) {
diff --git a/cli/util/text_encoding.rs b/cli/util/text_encoding.rs
index 0111ec82f..29a8d4069 100644
--- a/cli/util/text_encoding.rs
+++ b/cli/util/text_encoding.rs
@@ -160,7 +160,9 @@ mod tests {
 
     fn run_test(input: &'static str, output: &'static str) {
       assert_eq!(
-        code_without_source_map(input.into()).take_as_string(),
+        code_without_source_map(ModuleCode::from_static(input))
+          .as_str()
+          .to_owned(),
         output
       );
     }
diff --git a/cli/worker.rs b/cli/worker.rs
index 5beef84ff..edd604519 100644
--- a/cli/worker.rs
+++ b/cli/worker.rs
@@ -5,6 +5,7 @@ use std::rc::Rc;
 use std::sync::Arc;
 
 use deno_ast::ModuleSpecifier;
+use deno_core::ascii_str;
 use deno_core::error::AnyError;
 use deno_core::futures::task::LocalFutureObj;
 use deno_core::futures::FutureExt;
@@ -184,7 +185,7 @@ impl CliMainWorker {
     // Enable op call tracing in core to enable better debugging of op sanitizer
     // failures.
     if self.ps.options.trace_ops() {
-      self.worker.js_runtime.execute_script(
+      self.worker.js_runtime.execute_script_static(
         located_script_name!(),
         "Deno[Deno.internal].core.enableOpCallTracing();",
       )?;
@@ -231,7 +232,7 @@ impl CliMainWorker {
 
     self.worker.execute_script(
       located_script_name!(),
-      "Deno[Deno.internal].core.enableOpCallTracing();",
+      ascii_str!("Deno[Deno.internal].core.enableOpCallTracing();"),
     )?;
 
     if mode != TestMode::Documentation {