perf(language_server): use simdutf8 when reading files from file system

crates/oxc_language_server/src/linter/isolated_lint_handler.rs

@@ -1,5 +1,4 @@
 use std::{
-    fs,
     path::{Path, PathBuf},
     sync::{Arc, OnceLock},
 };
@@ -14,7 +13,7 @@ use tower_lsp_server::{
 use oxc_allocator::Allocator;
 use oxc_linter::{
     LINTABLE_EXTENSIONS, LintService, LintServiceOptions, Linter, MessageWithPosition,
-    loader::Loader,
+    loader::Loader, read_to_string,
 };
 
 use super::error_with_position::{
@@ -103,7 +102,7 @@ impl IsolatedLintHandler {
             debug!("extension not supported yet.");
             return None;
         }
-        let source_text = source_text.or_else(|| fs::read_to_string(path).ok())?;
+        let source_text = source_text.or_else(|| read_to_string(path).ok())?;
 
         debug!("lint {path:?}");
 

crates/oxc_linter/src/lib.rs

@@ -44,6 +44,7 @@ pub use crate::{
     options::{AllowWarnDeny, InvalidFilterKind, LintFilter, LintFilterKind},
     rule::{RuleCategory, RuleFixMeta, RuleMeta, RuleWithSeverity},
     service::{LintService, LintServiceOptions},
+    utils::read_to_string,
 };
 use crate::{
     config::{LintConfig, OxlintEnv, OxlintGlobals, OxlintSettings, ResolvedLinterState},

crates/oxc_linter/src/utils/mod.rs

@@ -113,6 +113,11 @@ pub fn is_eslint_rule_adapted_to_typescript(rule_name: &str) -> bool {
     TYPESCRIPT_COMPATIBLE_ESLINT_RULES.binary_search(&rule_name).is_ok()
 }
 
+/// Reads the content of a path and returns it.
+/// This function is faster than native `fs:read_to_string`.
+///
+/// # Errors
+/// When the content of the path is not a valid UTF-8 bytes
 pub fn read_to_string(path: &Path) -> io::Result<String> {
     // `simdutf8` is faster than `std::str::from_utf8` which `fs::read_to_string` uses internally
     let bytes = std::fs::read(path)?;