perf(compile): pass module source data from binary directly to v8 (#26494)

This changes denort to pass a static reference of the moude source bytes found in the binary to v8 instead of copying it.

1 files changed, 15 insertions, 0 deletions

diff --git a/cli/util/text_encoding.rs b/cli/util/text_encoding.rs
index 0b7601cb9..df72cc2be 100644
--- a/cli/util/text_encoding.rs
+++ b/cli/util/text_encoding.rs
@@ -103,6 +103,21 @@ pub fn arc_str_to_bytes(arc_str: Arc<str>) -> Arc<[u8]> {
   unsafe { Arc::from_raw(raw as *const [u8]) }
 }
 
+/// Converts an `Arc<u8>` to an `Arc<str>` if able.
+#[allow(dead_code)]
+pub fn arc_u8_to_arc_str(
+  arc_u8: Arc<[u8]>,
+) -> Result<Arc<str>, std::str::Utf8Error> {
+  // Check that the string is valid UTF-8.
+  std::str::from_utf8(&arc_u8)?;
+  // SAFETY: the string is valid UTF-8, and the layout Arc<[u8]> is the same as
+  // Arc<str>. This is proven by the From<Arc<str>> impl for Arc<[u8]> from the
+  // standard library.
+  Ok(unsafe {
+    std::mem::transmute::<std::sync::Arc<[u8]>, std::sync::Arc<str>>(arc_u8)
+  })
+}
+
 #[cfg(test)]
 mod tests {
   use std::sync::Arc;