Enable sparse file support on macOS

src/builder.rs

@@ -1062,19 +1062,34 @@ fn find_sparse_entries(
     file: &mut fs::File,
     stat: &fs::Metadata,
 ) -> io::Result<Option<SparseEntries>> {
-    #[cfg(not(any(target_os = "android", target_os = "freebsd", target_os = "linux")))]
+    #[cfg(not(any(
+        target_os = "android",
+        target_os = "freebsd",
+        target_os = "linux",
+        target_os = "macos"
+    )))]
     {
         let _ = file;
         let _ = stat;
         Ok(None)
     }
 
-    #[cfg(any(target_os = "android", target_os = "freebsd", target_os = "linux"))]
+    #[cfg(any(
+        target_os = "android",
+        target_os = "freebsd",
+        target_os = "linux",
+        target_os = "macos"
+    ))]
     find_sparse_entries_seek(file, stat)
 }
 
 /// Implementation of `find_sparse_entries` using `SEEK_HOLE` and `SEEK_DATA`.
-#[cfg(any(target_os = "android", target_os = "freebsd", target_os = "linux"))]
+#[cfg(any(
+    target_os = "android",
+    target_os = "freebsd",
+    target_os = "linux",
+    target_os = "macos"
+))]
 fn find_sparse_entries_seek(
     file: &mut fs::File,
     stat: &fs::Metadata,

tests/all.rs

@@ -1489,6 +1489,8 @@ fn writing_sparse() {
     assert!(data.len() <= 37 * 1024); // ext4 (defaults to 4k block size)
     #[cfg(target_os = "freebsd")]
     assert!(data.len() <= 273 * 1024); // UFS (defaults to 32k block size, last block isn't a hole)
+    #[cfg(target_os = "macos")]
+    assert!(data.len() <= 37 * 1024); // APFS (4k block size)
 
     let mut ar = Archive::new(&data[..]);
     let mut entries = ar.entries().unwrap();