Use copy on write when available.

google · Oct 13, 2023 · b266901 · b266901
1 parent 83ae668
commit b266901
Showing 1 changed file with 9 additions and 1 deletion.
diff --git a/src/util/copy.ts b/src/util/copy.ts
@@ -79,7 +79,15 @@ export const copyEntries = async (
  */
 const copyFileGracefully = async (src: string, dest: string): Promise<void> => {
   try {
-    await fs.copyFile(src, dest, fs.constants.COPYFILE_EXCL);
+    await fs.copyFile(
+      src,
+      dest,
+      // COPYFILE_FICLONE: Copy the file using copy-on-write semantics, so that
+      //   the copy takes constant time and space. This is a noop currently
+      //   on some platforms, but it's a nice optimization to have.
+      //   See https://github.com/libuv/libuv/issues/2936 for macos support.
+      fs.constants.COPYFILE_EXCL | fs.constants.COPYFILE_FICLONE,
+    );
   } catch (error) {
     const {code} = error as {code: string};
     if (code === /* does not exist */ 'ENOENT') {