refactor(core): use Box<u8> for ModuleSource.code instead of a String (#14487)

Author: bartlomieju

cli/proc_state.rs

@@ -592,7 +592,7 @@ impl ProcState {
           }
         };
         Ok(ModuleSource {
-          code,
+          code: code.into_bytes().into_boxed_slice(),
           module_url_specified: specifier.to_string(),
           module_url_found: found.to_string(),
           module_type: match media_type {
@@ -646,7 +646,8 @@ impl SourceMapGetter for ProcState {
         let code = String::from_utf8(code).unwrap();
         source_map_from_code(code).or(maybe_map)
       } else if let Ok(source) = self.load(specifier, None, false) {
-        source_map_from_code(source.code)
+        let code = String::from_utf8(source.code.to_vec()).unwrap();
+        source_map_from_code(code)
       } else {
         None
       }

cli/standalone.rs

@@ -168,9 +168,9 @@ impl ModuleLoader for EmbeddedModuleLoader {
       .ok_or_else(|| type_error("Module not found"));
 
     async move {
-      if let Some((ref source, _)) = is_data_uri {
+      if let Some((source, _)) = is_data_uri {
         return Ok(deno_core::ModuleSource {
-          code: source.to_owned(),
+          code: source.into_bytes().into_boxed_slice(),
           module_type: deno_core::ModuleType::JavaScript,
           module_url_specified: module_specifier.to_string(),
           module_url_found: module_specifier.to_string(),
@@ -184,7 +184,7 @@ impl ModuleLoader for EmbeddedModuleLoader {
         .to_owned();
 
       Ok(deno_core::ModuleSource {
-        code,
+        code: code.into_bytes().into_boxed_slice(),
         module_type: match module.kind {
           eszip::ModuleKind::JavaScript => deno_core::ModuleType::JavaScript,
           eszip::ModuleKind::Json => deno_core::ModuleType::Json,

core/examples/ts_module_loader.rs

@@ -80,7 +80,7 @@ impl ModuleLoader for TypescriptModuleLoader {
         code
       };
       let module = ModuleSource {
-        code,
+        code: code.into_bytes().into_boxed_slice(),
         module_type,
         module_url_specified: module_specifier.to_string(),
         module_url_found: module_specifier.to_string(),

core/modules.rs

@@ -26,14 +26,14 @@ use std::task::Poll;
 pub type ModuleId = i32;
 pub(crate) type ModuleLoadId = i32;
 
-pub const BOM_CHAR: char = '\u{FEFF}';
+pub const BOM_CHAR: &[u8] = &[0xef, 0xbb, 0xbf];
 
 /// Strips the byte order mark from the provided text if it exists.
-fn strip_bom(text: &str) -> &str {
-  if text.starts_with(BOM_CHAR) {
-    &text[BOM_CHAR.len_utf8()..]
+fn strip_bom(source_code: &[u8]) -> &[u8] {
+  if source_code.starts_with(BOM_CHAR) {
+    &source_code[BOM_CHAR.len()..]
   } else {
-    text
+    source_code
   }
 }
 
@@ -190,7 +190,7 @@ impl std::fmt::Display for ModuleType {
 // intermediate redirects from file loader.
 #[derive(Debug, Clone, Eq, PartialEq)]
 pub struct ModuleSource {
-  pub code: String,
+  pub code: Box<[u8]>,
   pub module_type: ModuleType,
   pub module_url_specified: String,
   pub module_url_found: String,
@@ -315,9 +315,9 @@ impl ModuleLoader for FsModuleLoader {
         ModuleType::JavaScript
       };
 
-      let code = std::fs::read_to_string(path)?;
+      let code = std::fs::read(path)?;
       let module = ModuleSource {
-        code,
+        code: code.into_boxed_slice(),
         module_type,
         module_url_specified: module_specifier.to_string(),
         module_url_found: module_specifier.to_string(),
@@ -781,10 +781,15 @@ impl ModuleMap {
     &mut self,
     scope: &mut v8::HandleScope,
     name: &str,
-    source: &str,
+    source: &[u8],
   ) -> Result<ModuleId, ModuleError> {
     let name_str = v8::String::new(scope, name).unwrap();
-    let source_str = v8::String::new(scope, strip_bom(source)).unwrap();
+    let source_str = v8::String::new_from_utf8(
+      scope,
+      strip_bom(source),
+      v8::NewStringType::Normal,
+    )
+    .unwrap();
 
     let tc_scope = &mut v8::TryCatch::new(scope);
 
@@ -822,10 +827,12 @@ impl ModuleMap {
     scope: &mut v8::HandleScope,
     main: bool,
     name: &str,
-    source: &str,
+    source: &[u8],
   ) -> Result<ModuleId, ModuleError> {
     let name_str = v8::String::new(scope, name).unwrap();
-    let source_str = v8::String::new(scope, source).unwrap();
+    let source_str =
+      v8::String::new_from_utf8(scope, source, v8::NewStringType::Normal)
+        .unwrap();
 
     let origin = bindings::module_origin(scope, name_str);
     let source = v8::script_compiler::Source::new(source_str, Some(&origin));
@@ -1258,7 +1265,7 @@ import "/a.js";
       }
       match mock_source_code(&inner.url) {
         Some(src) => Poll::Ready(Ok(ModuleSource {
-          code: src.0.to_owned(),
+          code: src.0.as_bytes().to_vec().into_boxed_slice(),
           module_type: ModuleType::JavaScript,
           module_url_specified: inner.url.clone(),
           module_url_found: src.1.to_owned(),
@@ -1454,7 +1461,7 @@ import "/a.js";
           scope,
           true,
           &specifier_a,
-          r#"
+          br#"
           import { b } from './b.js'
           if (b() != 'b') throw Error();
           let control = 42;
@@ -1478,7 +1485,7 @@ import "/a.js";
           scope,
           false,
           "file:///b.js",
-          "export function b() { return 'b' }",
+          b"export function b() { return 'b' }",
         )
         .unwrap();
       let imports = module_map.get_requested_modules(mod_b).unwrap();
@@ -1561,7 +1568,7 @@ import "/a.js";
           scope,
           true,
           &specifier_a,
-          r#"
+          br#"
             import jsonData from './b.json' assert {type: "json"};
             assert(jsonData.a == "b");
             assert(jsonData.c.d == 10);
@@ -1582,7 +1589,7 @@ import "/a.js";
         .new_json_module(
           scope,
           "file:///b.json",
-          "{\"a\": \"b\", \"c\": {\"d\": 10}}",
+          b"{\"a\": \"b\", \"c\": {\"d\": 10}}",
         )
         .unwrap();
       let imports = module_map.get_requested_modules(mod_b).unwrap();
@@ -1692,7 +1699,9 @@ import "/a.js";
       let info = ModuleSource {
         module_url_specified: specifier.to_string(),
         module_url_found: specifier.to_string(),
-        code: "export function b() { return 'b' }".to_owned(),
+        code: b"export function b() { return 'b' }"
+          .to_vec()
+          .into_boxed_slice(),
         module_type: ModuleType::JavaScript,
       };
       async move { Ok(info) }.boxed()
@@ -1836,7 +1845,7 @@ import "/a.js";
         let info = ModuleSource {
           module_url_specified: specifier.to_string(),
           module_url_found: specifier.to_string(),
-          code: code.to_owned(),
+          code: code.as_bytes().to_vec().into_boxed_slice(),
           module_type: ModuleType::JavaScript,
         };
         async move { Ok(info) }.boxed()
@@ -2184,13 +2193,17 @@ if (import.meta.url != 'file:///main_with_code.js') throw Error();
           "file:///main_module.js" => Ok(ModuleSource {
             module_url_specified: "file:///main_module.js".to_string(),
             module_url_found: "file:///main_module.js".to_string(),
-            code: "if (!import.meta.main) throw Error();".to_owned(),
+            code: b"if (!import.meta.main) throw Error();"
+              .to_vec()
+              .into_boxed_slice(),
             module_type: ModuleType::JavaScript,
           }),
           "file:///side_module.js" => Ok(ModuleSource {
             module_url_specified: "file:///side_module.js".to_string(),
             module_url_found: "file:///side_module.js".to_string(),
-            code: "if (import.meta.main) throw Error();".to_owned(),
+            code: b"if (import.meta.main) throw Error();"
+              .to_vec()
+              .into_boxed_slice(),
             module_type: ModuleType::JavaScript,
           }),
           _ => unreachable!(),

core/runtime.rs

@@ -1554,7 +1554,7 @@ impl JsRuntime {
           // main module
           true,
           specifier.as_str(),
-          &code,
+          code.as_bytes(),
         )
         .map_err(|e| match e {
           ModuleError::Exception(exception) => {
@@ -1613,7 +1613,7 @@ impl JsRuntime {
           // not main module
           false,
           specifier.as_str(),
-          &code,
+          code.as_bytes(),
         )
         .map_err(|e| match e {
           ModuleError::Exception(exception) => {
@@ -3022,7 +3022,7 @@ assertEquals(1, notify_return_value);
       ) -> Pin<Box<ModuleSourceFuture>> {
         async move {
           Ok(ModuleSource {
-            code: "console.log('hello world');".to_string(),
+            code: b"console.log('hello world');".to_vec().into_boxed_slice(),
             module_url_specified: "file:///main.js".to_string(),
             module_url_found: "file:///main.js".to_string(),
             module_type: ModuleType::JavaScript,